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Wärtsilä 34SG Power Plant Product Guide

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Issue I: 17.01.2008

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Wärtsilä 34SG Power Plant Product Guide TABLE OF CONTENTS

Wärtsilä Finland Oy Power PlantsPage 1

Subject to change without notice. Please read disclaimer inside front cover.

TABLE OF CONTENTSPREFACE ........................................................... 4

1. GENERAL ................................................. 51.1 Introduction .................................................... 51.2 Applications.................................................... 61.3 Plant performance .......................................... 61.3.1 Plant output ...................................................... 61.3.2 Engine de-rating ............................................... 71.3.3 Start and stop performance............................... 81.3.4 Loading performance ........................................ 91.4 Environmental impacts................................... 91.4.1 Exhaust gas emissions...................................... 91.4.2 Noise emissions.............................................. 101.4.3 Water consumption and site effluents .............. 121.4.4 Miscellaneous................................................. 121.5 Operation and maintenance......................... 121.5.1 Plant operation ............................................... 121.5.2 Output control................................................. 131.5.3 Routine maintenance ...................................... 141.5.4 Overhaul intervals........................................... 151.5.5 Tools and spare parts ..................................... 151.5.6 Safety aspects................................................ 15

2. ENGINE GENERATOR SET.................... 162.1 Engine generator set .................................... 162.1.1 Overview ........................................................ 162.1.2 Flexible coupling............................................. 162.1.3 Common base frame....................................... 162.1.4 Flexible mounting............................................ 162.2 Engine........................................................... 172.2.1 General .......................................................... 172.2.2 Main components ........................................... 172.2.3 Gas injection and ignition ................................ 182.2.4 Engine mounted equipment............................. 192.2.5 Internal and engine mounted auxiliary systems 192.2.6 Engine control system..................................... 212.3 Generator ...................................................... 232.3.1 General .......................................................... 232.3.2 Generator type and size.................................. 232.3.3 Excitation system............................................ 232.3.4 Main terminal box ........................................... 242.3.5 Instrumentation............................................... 242.3.6 Protection....................................................... 24

3. ENGINE AUXILIARY SYSTEMS.............. 253.1 Overview....................................................... 253.2 Standard modules......................................... 263.2.1 Engine auxiliary module (EAM)........................ 263.2.2 Exhaust gas module ....................................... 273.3 Fuel gas system............................................ 283.3.1 System description.......................................... 283.3.2 Gas regulating unit (GRU)............................... 293.3.3 Main shut-off valve(s)...................................... 303.3.4 Vent valve ...................................................... 313.3.5 Pressure reduction station............................... 313.3.6 Gas filtration unit............................................. 313.3.7 Flow metering unit........................................... 323.4 Lube oil system............................................. 323.4.1 System description.......................................... 323.4.2 Lube oil storage tanks..................................... 33

3.4.3 Lube oil pump units .........................................343.5 Compressed air systems ..............................343.5.1 System description..........................................343.5.2 Starting air unit................................................363.5.3 Control and instrument air unit .........................363.5.4 Compressed air tanks......................................363.6 Cooling water system ...................................373.6.1 System description..........................................373.6.2 Radiators ........................................................383.6.3 Central coolers................................................393.6.4 Maintenance water tank...................................403.7 Intake air system...........................................403.7.1 System description..........................................403.7.2 Intake air filters................................................423.8 Exhaust gas system......................................433.8.1 System description..........................................433.8.2 Exhaust gas silencers......................................443.8.3 Rupture disks..................................................443.9 Emission control systems............................453.9.1 General...........................................................453.9.2 Oxidation catalyst............................................453.9.3 Selective catalytic reduction (SCR) ..................453.9.4 Integration in exhaust gas system....................473.9.5 Emission testing..............................................47

4. HEAT RECOVERY SYSTEM ...................494.1 General ..........................................................494.2 Heat recovery from exhaust gases ...............494.2.1 System description..........................................494.2.2 Heat recovery boiler ........................................504.2.3 Arrangements to decrease boiler fouling ..........504.2.4 Safety arrangements .......................................504.3 Heat recovery from cooling water and lube oil

.......................................................................504.3.1 General...........................................................504.3.2 Standard modules for hot water production ......51

5. PIPING SYSTEMS...................................535.1 Design principles ..........................................535.1.1 General principles ...........................................535.1.2 Pressure and temperature ratings....................535.1.3 Pipe materials .................................................535.1.4 Pipe dimensions..............................................555.1.5 Flexible pipes and pipe supports.....................555.1.6 Trace heating..................................................555.1.7 Insulation ........................................................565.1.8 Pipe instrumentation........................................565.1.9 Fuel gas pipes.................................................565.1.10 Lube oil pipes..................................................575.1.11 Compressed air pipes......................................585.1.12 Cooling water pipes.........................................585.1.13 Intake air ducts................................................595.1.14 Exhaust gas ducts...........................................595.1.15 Miscellaneous .................................................60

6. ELECTRICAL SYSTEM...........................616.1 General ..........................................................616.1.1 System overview.............................................616.1.2 Basic system design........................................626.1.3 Protection relays .............................................62




6.1.4 Protection classes of electrical equipment........ 636.1.5 Internal power consumption ............................ 636.2 Generator system ......................................... 646.2.1 Measurement and protection........................... 646.2.2 Neutral grounding ........................................... 646.3 Medium voltage switchgear.......................... 646.3.1 General .......................................................... 646.3.2 General design principles................................ 646.3.3 Medium voltage busbars ................................. 656.3.4 Incoming feeder cubicles................................. 656.3.5 Main outgoing feeder cubicles ......................... 656.3.6 Station transformer feeder cubicles................. 666.3.7 Busbar voltage measurement.......................... 666.4 Transformers ................................................ 666.4.1 General .......................................................... 666.4.2 Power (step-up) transformer............................ 666.4.3 Station transformer ......................................... 666.5 Low voltage switchgear................................ 676.5.1 Overview ........................................................ 676.5.2 Design principles ............................................ 676.5.3 Busbars and conductors.................................. 686.5.4 Incoming feeders ............................................ 686.5.5 Outgoing feeders ............................................ 686.5.6 Busbar voltage measurement.......................... 686.5.7 Emergency generator...................................... 686.5.8 Emergency busbar.......................................... 696.6 DC system..................................................... 696.6.1 DC power consumers...................................... 696.6.2 DC system design........................................... 696.7 Grounding..................................................... 706.7.1 General .......................................................... 706.7.2 Grounding grid................................................ 716.7.3 Main grounding bar ......................................... 726.7.4 Neutral point grounding................................... 726.7.5 Lightning protection......................................... 726.8 Cabling.......................................................... 726.8.1 General .......................................................... 726.8.2 Medium voltage cables.................................... 736.8.3 Low voltage cables ......................................... 736.8.4 DC cables....................................................... 736.8.5 Grounding conductors..................................... 73

7. PLANT CONTROL SYSTEM ................... 747.1 Overview....................................................... 747.2 Generator set control cabinet....................... 757.2.1 Overview ........................................................ 757.2.2 Generator set PLC.......................................... 767.2.3 Manual control unit.......................................... 767.2.4 Automatic voltage regulator (AVR)................... 767.2.5 Protection relays............................................. 767.3 Common control cabinet ............................. 777.3.1 Overview ........................................................ 777.3.2 Common PLC................................................. 777.3.3 Synchronization units ...................................... 787.4 Workstations................................................. 787.4.1 General .......................................................... 787.4.2 Operator station WOIS.................................... 787.4.3 Reporting station WISE................................... 807.4.4 Remote monitoring.......................................... 807.4.5 Data sharing with external systems.................. 817.4.6 Condition based maintenance ......................... 817.5 Signal and data communication................... 817.5.1 General .......................................................... 817.5.2 Signal types.................................................... 81

7.5.3 Communication buses .....................................817.5.4 Hard-wired signals...........................................827.5.5 Control cables.................................................827.6 Functional description ..................................837.6.1 Start and stop processes .................................837.6.2 Output control .................................................837.6.3 Control of auxiliary systems .............................847.6.4 Safety functions ..............................................84

8. PLANT LAYOUT......................................868.1 Site layout .....................................................868.1.1 Site Layout principles ......................................868.1.2 Site layout notes..............................................868.1.3 Site layout examples .......................................878.2 Engine hall layout..........................................908.2.1 Engine bays....................................................908.2.2 Other space requirements ...............................908.2.3 Layout notes ...................................................908.2.4 Layout example...............................................908.3 Service rooms or buildings..........................928.3.1 General...........................................................928.3.2 Electrical rooms ..............................................928.4 Tank yard and unloading station .................938.4.1 Tank yard........................................................938.4.2 Unloading pump station...................................938.5 Pipes and cables...........................................938.5.1 Pipe layout......................................................938.5.2 Cabling ...........................................................938.6 Hazardous areas ...........................................938.6.1 General...........................................................938.6.2 Classification of hazardous areas....................948.6.3 Protection methods in hazardous areas ...........95

9. SITE, CIVIL WORKS AND STRUCTURES.969.1 Site considerations .......................................969.1.1 Site selection criteria .......................................969.1.2 Geotechnical investigation...............................969.2 Earthworks and site works............................979.2.1 General...........................................................979.2.2 Site drainage...................................................979.2.3 Underground utilities .......................................979.3 Engine hall foundation..................................979.3.1 General...........................................................979.3.2 Engine generator set foundation ......................979.3.3 Material and strength.......................................999.3.4 Floor tolerances ..............................................999.3.5 Floor drains...................................................1009.3.6 Surface treatment..........................................1009.4 Other foundations .......................................1009.4.1 Tank yard and pump station ..........................1009.4.2 Stacks, radiators and transformers.................1009.5 Frames, outer walls and roofs ....................1019.5.1 General.........................................................1019.5.2 Engine hall....................................................1019.5.3 Auxiliary structures........................................1029.6 Interior structures .......................................1029.6.1 Inner walls, floors, and ceilings ......................1029.6.2 Lifting and transportation arrangements .........1029.6.3 Support structures.........................................1029.7 Heating, ventilation and air conditioning....1039.7.1 Process ventilation ........................................1039.7.2 Comfort ventilation and air conditioning.........1049.7.3 Air filtering and silencers................................1049.8 Fire protection.............................................105




9.8.1 General ........................................................ 1059.8.2 Fire areas..................................................... 1059.8.3 Fire alarm system ......................................... 1059.8.4 Gas detection system.................................... 1059.8.5 Fire extinguishing systems ............................ 1069.9 Water supply system .................................. 1079.9.1 General ........................................................ 1079.9.2 Water consumption....................................... 1079.9.3 Water treatment unit ..................................... 1089.9.4 Water booster unit......................................... 1089.9.5 Water storage tanks...................................... 1089.10 Waste water systems.................................. 1089.10.1 Sewage system ............................................ 1089.10.2 Oily water system ......................................... 1089.11 Lighting....................................................... 109

10. INSTALLATION AND COMMISSIONING11110.1 Delivery and storage................................... 11110.1.1 Engine generator set..................................... 11110.1.2 Engine auxiliary equipment and pipes............ 11110.1.3 Electrical and control system equipment ........ 11110.2 Installation .................................................. 11210.2.1 General ........................................................ 11210.2.2 Installation of engine generator set ................ 11210.2.3 Installation of auxiliary equipment .................. 11210.2.4 Installation of piping systems......................... 11310.2.5 Installation of electrical and control systems... 11310.3 Commissioning........................................... 11410.3.1 General ........................................................ 11410.3.2 Pre-commissioning ....................................... 11410.3.3 Running in and fine tuning............................. 11510.3.4 Performance tests......................................... 115

11. TECHNICAL DATA ............................... 11611.1 Engine generator set .................................. 11611.2 Engine Technical data ................................ 11711.3 Engine heat balances.................................. 11811.4 Generator data (typical) .............................. 121

12. FLUID REQUIREMENTS....................... 12212.1 Fuel gas requirements................................ 12212.2 Lubricating oils........................................... 12312.2.1 General requirements ................................... 12312.2.2 Additives....................................................... 12312.2.3 Approved lubricating oils ............................... 12312.3 Water quality requirements ........................ 124

13. DIMENSIONS AND WEIGHTS .............. 12513.1 Engine generator set .................................. 12513.2 Standard auxiliary equipment..................... 12613.2.1 Gas regulating unit........................................ 12613.2.2 Engine auxiliary module (EAM)...................... 12713.2.3 Exhaust gas module ..................................... 12713.2.4 Standard auxiliary units................................. 128

APP A. STANDARDS AND CODES................ 131

APP B. UNIT CONVERSIONS......................... 133

Wärtsilä 34SG Product Guide PREFACE



PREFACE

This product guide provides general guidelines andtechnical information for planning land-based powerplants using the Wärtsilä 34SG lean-burn gas engines.The guide is directed to customers and customer rep-resentatives, designers and sales personnel with theaim to serve as a plant design overview and supportduring the early project phase.

This guide does not provide detailed engineering in-formation.

The content of this document is based on the mostcurrent information available at the time of publica-tion and is subject to change without notice.

Data given in this guide – in texts, tables,graphs, and figures – are to be regarded as typi-cal values or sample values and must not be usedas design data. Actual values may deviate signifi-cantly from the typical values.

All power plant design must be in accordance withlocally applicable rules and regulations. Should anyadvice, recommendation or requirement given in thisguide differ from the ones given in local, national orinternational regulations, the strictest requirementsare valid.

Wärtsilä assumes no responsibility for customer orcontractor designed plants, even in cases where theyare designed in accordance with this guide.

Wärtsilä 34SG Product Guide 1. GENERAL



1. GENERAL

1.1 Introduction

A Wärtsilä 34SG power plant typically comprises oneor several engine generator sets. The main compo-nents of the plant are the gas fired reciprocating en-gines, the medium voltage generators, the engine aux-iliary systems, the electrical system and the controlsystem.

The engine generator sets are delivered as factoryassembled and tested units. The generators have beensized to match the actual engine power output at siteconditions. Before delivery, the engines can be opti-mized for the available fuel gas quality and the emis-sion requirements at site.

The engine auxiliary systems include fuel gas, lubri-cating oil, compressed air, cooling water, intake air,and exhaust gas systems. Heat recovery and emissioncontrol systems can be installed depending on theproject specific requirements. To a large extent, theauxiliary systems are implemented as prefabricatedand tested, skid mounted standard modules and units,which minimizes the space requirement and simpli-fies the installation at site.

Each engine generator set has its own fuel gas supply,lubrication system, cooling circuits, intake air andexhaust gas systems, and control system. It can there-fore be started, stopped and operated independentlyof the other generator sets in the plant. This modularstructure is also an advantage at a possible future ex-tension of the plant.

Normally, the buildings are newly built and specifi-cally designed for power plant operation. In specialcases, existing buildings can be used. A low buildingheight gives the plant the appearance of a light indus-trial facility.

Wärtsilä delivers well over 100 power plants a year, allaround the world, based on a standard product de-sign developed from long experience. If needed, theplants can be adapted to local codes and standards.Also customer-specific requirements can be included.

Figure 1. Cross section of a typical Wärtsilä 20V34SG power plant

Wärtsilä 34SG Power Plant Product Guide 1. GENERAL



1.2 Applications

A Wärtsilä 34SG power plant is suitable for baseload, intermediate load, and peak-load power genera-tion. The plant can be used for feeding a large grid(parallel operation) or a limited grid, for instance amanufacturing plant (island operation). It is also pos-sible to switch between island and parallel operation.

The plant can be specified for either 50 or 60 Hz.The generator voltage is typically 6 to 15kV (50Hz) or4.16 to 13.8kV (60 Hz). Frequency and generatorvoltage can be selected to best suit the project re-quirement.

High efficiency at full and part load, fast start-up timeand quick load response makes the Wärtsilä 34SGpower plants suitable for base load, load followingand reserve capacity applications.

In a multi-engine plant the engine generator sets canbe started, stopped and controlled individually, partof the plant can be running at the required load point,while part of it is kept as reserve capacity.

The power generation can be controlled from theplant’s own control room, and – with proper configu-ration – from an external control system, for instance,an ISO dispatch centre. As options, the control sys-tem supports power management functions, such asautomatic load sharing, load shedding, automatic startand stop, and load following.

Wärtsilä 34SG power plants are also suited for com-bined heat and power generation (cogeneration).Heat can be recovered from the exhaust gases, enginecooling water, and lubricating oil. Heat recoveredfrom the cooling water and lubricating oil is suitablefor hot water distribution systems. Heat from theexhaust gases – delivered as steam or hot water – canbe used in applications demanding higher tempera-ture heat, such as industrial processes.

The Wärtsilä 34SG engine performs well at high alti-tudes and in hot ambient conditions. Due to low ex-haust gas emissions, which can be further reducedwith emission control systems, they can be located inareas with strict emission limits.

1.3 Plant performance

1.3.1 Plant output

General

The plant output and efficiency depends on the siteconditions, fuel gas quality, generator efficiency, andpower factor. It also depends on the plant design andthe level of the internal power consumption. Maxi-mum total plant efficiency is obtained in plants utiliz-ing the waste heat.

On request, Wärtsilä can provide calculated plant-specific performance data.

Engine efficiency and optimization

Although the Wärtsilä 34SG engines have their opti-mal efficiency at full load, they also have a high part-load efficiency, which can be seen in the engine heatbalances found in chapter Technical Data.

Thanks to the totally electronic engine control-system, and that several compression ratios are avail-able, the engine can be tuned for optimal perform-ance at different ambient conditions, with differentfuel gas qualities and different emission requirements.

Reference conditions

Rated power, specific fuel consumption, and emis-sions stated in this document are based on the stan-dard reference conditions according to ISO 3046-1;except for charge air coolant temperature which is 35C (see the table below). For other conditions, reduc-

tion of the engine output may be necessary. See sec-tion Engine De-rating

Condition Value

Total barometric pressure 100 kPaAir temperature 25°CRelative humidity 30%Charge air coolant tem-perature 25°C

Table 1. Standard reference conditions accordingto ISO 3046-1

Generator power

The generator power is determined by the generatorefficiency and the power factor according to the for-mula:




S = P /cos

where:

S = generator power in kVA (apparent power)P = engine shaft power in kW

= generator efficiencycosø = cosine (power factor)

Internal power consumption

The plant’s internal power consumption depends onthe size and configuration of the plant, the ambientconditions, and the condition of the equipment.Typically, the internal power consumption is below3% of the generator power.

1.3.2 Engine de-rating

General

De-rating means a temporary or permanent reductionof maximum power output to protect the enginefrom overloading. De-rating may be necessary due toenvironmental or operational conditions.

Temperature definitions

The figure explains the temperatures given in thederating descriptions below.

Table 2. Explanation of temperatures1 = Suction air temperature (temperatureat turbo charger inlet)2 = Receiver air temperature (tempera-ture in charge air receiver)3 = Charge air cooling water tempera-ture

The receiver air temperature is defined as the tem-perature in the air receiver after the charge air cool-ers. The following formulas can be used for estimat-ing the receiver air temperature, Treceiver, based on thecharge air coolant temperature to the engine, TLT:

Treceiver[oC] TLT [oC] + 5 oC

De-rating factors

Engine de-rating is determined by the following de-rating factors:

KTC

De-rating due to high altitude and/or high suc-tion air temperature, see Figure 2. This de-ratingfactor is a function of suction air temperature (thetemperature at the turbocharger suction flange) andthe required compression ratio of the turbochargercompressor. The compression ratio, in turn, is a func-tion of the altitude, the NOx setting and the com-pression ratio of the engine. Higher suction air tem-perature and higher altitude mean increased de-rating.Low NOx optimized engines (with higher receivertemperature) require more de-rating, while engineswith higher compression ratio require less de-rating.

KGAS

De-rating due to low fuel gas feed pressureand/or low LHV, see Figure 3. Required fuel gasflow to the engine depends on the fuel gas feed pres-sure before the engine (the pressure at the gas pipeflange on the engine, after the gas regulating unit(GRU)), the lower heating value (LHV) of the fuelgas, and the air pressure in the air receiver. The mainfuel gas valve on the engine is designed to handle aspecific fuel gas quality. The engine has to be de-ratedif the fuel gas flow does not correspond to the enginedemand. Lower LHV or lower fuel gas pressure im-plies more de-rating. Low NOx optimized engines(with higher receiver pressure) require more de-rating.

KKNOCK

De-rating due to low fuel gas methane number(MN) and/or high combustion air temperaturein air receiver, see Figure 4. Knocking (self igni-tion) in the cylinder occurs if the fuel-air mixture issubject to temperatures and pressures that are aboveits self ignition point. The tendency for knocking isaffected by the MN value of the fuel gas, the receiverair temperature, and the compression ratio of theengine. A lower MN value of the fuel gas or a higherreceiver air temperature implies increased de-rating.Lower compression ratio of the engine, on the otherhand, means less de-rating.

The graphs below show the values of the de-ratingfactors. Value 1 means no de-rating.




Note! The de-rating diagrams are made forhigh Methane number optimised engine andNOx setting of 500 mg/Nm³ at 5% O2. Theyshall be used guidance purposes only. Projectspecific de-rating must be verified by Wärtsilä.

Figure 2. De-rating factor KTC

Figure 3. De-rating factor KGAS

Figure 4. De-rating factor KKNOCK

Other factors affecting engine de-rating:

Relative humidity. High relative humidity requiresraised LT cooling water temperature (and withthat raised receiver air temperature) to avoid con-densation in the charge air cooler. This may leadto de-rating.

The glycol content in the cooling water may leadto engine de-rating.

Calculating service power

The actual service power can be calculated as:

Px = Pr x Kmin

where Px is the brake power under the ambient con-ditions at site, Pr is rated power, and Kmin is the low-est de-rating factor:

Kmin = MIN(KTC, KGAS, KKNOCK)

Other performance corrections

The engine brake efficiency has to be adjusted forambient air pressure even in cases when the serviceoutput is rated output. The rule is that the brake effi-ciency drops 0.5% per 10 kPa lower ambient pres-sure, starting from 85 kPa a (or 0.5% per 1000 mhigher altitude starting from 1500 m).

No adjustment of engine efficiency is needed for en-gine output de-rated for KKNOCK and KGAS.

1.3.3 Start and stop performanceThe following graphs indicate the start and stop per-formances. The stated time intervals are guidancevalues only. The time required for starting a cold en-gine depends on the actual cooling water tempera-ture. Engines are normally kept preheated.

Figure 5. Engine start-up time (preheated engine)




Figure 6. Engine stop time

1.3.4 Loading performanceThe following graph indicates the loading time afterstarting a preheated engine. Immediately after syn-chronization, a 25% load is applied. The stated timeintervals are guidance values only.

Figure 7. Loading time after starting a preheatedengine

The maximum ramp up rate for an engine which hasachieved normal operating conditions is 25 % perminute. The ramp down rate is 25 % per minute.

The following graph shows maximum instant loadincrease when running in isolated mode. Maximumfirst load step is 31%. Optimal loading is 0 – 31 – 57– 77 – 92 – 100%. To keep the frequency band 5%,there must be a 15 seconds delay between subsequentload steps.

Figure 8. Maximum instant load increase at dif-ferent actual loads when running in iso-lated mode (island mode)

1.4 Environmental impacts

1.4.1 Exhaust gas emissions

General

Due to the low peak combustion temperature in theWärtsilä 34SG engines, the emission of nitrogen ox-ides (NOx) is low. Running on clean natural gas, theengines have inherently low emissions of particulatematter (PM) and sulphur dioxide (SO2).

Natural gas fired Wärtsilä 34SG engines typically gen-erate lower carbon dioxide (CO2) emissions com-pared to oil and coal plants due lower carbon contentper fuel energy input and high efficiency of the en-gine. By using co-generation the total efficiency canbe improved and hence relative CO2 emissions perproduced energy unit further reduced.

Wärtsilä 34SG engines can be tuned for reducedNOx emission levels, which may have a minor impacton plant efficiency. The plant can also be equippedwith secondary emission control systems.

On project specific basis, the engines can be opti-mized to achieve best economical and environmentalperformance.

Emission levels

The following table shows typical emission values forthe Wärtsilä 34SG engines at stable operating condi-tions. The table shows the emissions from an effi-ciency optimized engine and an engine optimized forlow NOx emission.




VOC (Volatile Organic Compounds) is herein de-fined as total hydrocarbon excluding methane andethane. The organic compounds consist of unburnedfuel gas and components generated in the combus-tion process, such as formaldehyde. The VOC emis-sions depend significantly on the composition of thefuel gas.

Efficiencyoptimizedengine

Low NOxoptimizedengine

ppm vol,dry, 15% O2

90 45NOx(nitrogen oxides)Typical setpoint

g/kWh 1.3 0.6

ppm vol,dry, 15% O2

265 455CO(carbon monox-ide)

g/kWh 2.2 3.9

CH2O(formaldehyde)

ppm vol,dry, 15% O2

24 42

Typical O2concentration

vol %, dry 11.5 12.1

ppm vol,dry, 15% O2

80 - 170 140 - 300VOC as CH4(volatile organiccompounds)

g/kWh 0.4 - 0.8 0.7 - 1.5PM (dry) mg/m3, 15

% O2, dry,(0°C & 1 atm)

< 10 < 10

Table 3 Emission levels at steady 100% load,constant speed 720RPM or 750RPM, CR= 12, VOC based on fuel gas with C3and higher representing less than 3mole-% of the total hydrocarbons.

Notes:

During start, stop and transient load variations,the exhaust gas emissions may temporarily devi-ate from the steady state conditions.

Due to performance and emission optimizationthe project-specific values might differ from theones given above.

Secondary emission control systems

The following methods are available for reducing theemissions in the exhaust gas system:

Catalytic oxidization for reducing CO, CH2O, andvolatile organic compounds

Selective Catalytic Reduction (SCR) for reducingthe NOx emission.

1.4.2 Noise emissions

Suitable solutions for different environments

Power plants should be designed to meet set mini-mum criteria. The requirements set for noise varydepending on the location of the plant. The noiselimit in or near a residential area, for instance, aremuch stricter than in an industrial area.

Designing power plants to be located on industrialareas to the acoustical standards required in residen-tial areas is not feasible. The background noise level isoften relatively high and thus the noise generated bythe plant would not have significant impact on theambient noise level. This applies also for plants con-structed in areas that do not contain sites detrimen-tally affected by noise.

Varied design criteria

Primary design target is to meet local legislation andregulations on environmental noise. In absence oflocal norms, international criteria on environmentalnoise such as World Bank Environmental, Healthand Safety (EHS) guidelines can be applied.

The responsibility for environmental noise impactdepends on the scope of the delivery.. The noise im-mission of a power plant can be specified at a certaindistance from the site or at specified receptor posi-tions. Alternatively, the sound power level (noiseemission) of plant equipment can be specified.

In a limited equipment delivery project, only thenoise emission of the delivered equipment can beguaranteed. The immission levels at receptor posi-tions depend on the auxiliary equipment and plantstructures.

Power plant acoustics integrated in the per-mitting process

Power plant noise impact is estimated during the en-vironmental impact assessment process. Startingpoint is the evaluation of background noise on thearea surrounding the power plant. The potential dis-turbance to facilities in the plant proximity such asresidences, schools and hospitals can be assessed byenvironmental noise modelling. The purpose of thisacoustical modelling, including structural investiga-tions, is to optimize the methods used to reduce theplant noise impact. The modelling process is iterativeby nature:

the estimated plant noise impact is con-trasted with the ambient or target noise level




component selection, process design optimi-sation and structural modifications are ap-plied if needed to reach the set target

the effect of modifications is simulated andcross-checked with the ambient or targetnoise level until the set target is reached.

The following aspects are addressed in the acousticaldesign of power plant:

Optimising the plant layout, selection and lo-cation of noise-critical components.

Attenuation of the charge air intake and ex-haust outlet

Engine cooling system: type and location ofthe radiator or other cooling equipment

Plant ventilation system: ventilation air in-take, fan-generated noise, outlet noise emis-sion

Power plant building design: optimal wallstructures

It is apparent that the plant noise emission is as muchdue to auxiliary components as the actual generatingset. One important aspect of power plant acoustics isthe design of better and silent auxiliary components.

W34SG engine sound power levels

Engine sound power levels have been measured ac-cording to ISO9614-2 as applicable. Measurementuncertainty is ±2dB

Engine Sound Power Level

0

20

40

60

80

100

120

140

63 125 250 500 1000 2000 4000 8000 Lw tot

Frequency [Hz]

Lw [d

B(A)

]

W9L34SGW12V34SGW20V34SG

Figure 9 Engine sound power levels

W34SG exhaust gas sound power levels

In Figure 10 can be seen free field sound power spec-trum after turbo charger. Measurement in exhaustduct, actual engine operating conditions. Measure-ment uncertainty is ±3dB.

Exhaust Gas Sound Power Level

0

20

40

60

80

100

120

140

31,5 63 125 250 500 1000 2000 4000 Lw tot

Frequency [Hz]

Lw [d

B(A

)] W9L34SGW12V34SGW20V34SG

Figure 10 Engine exhaust gas sound power levels

Typically 35 dB(A) exhaust gas silencers are used inpower plants. Figure 11 shows typical transmissionloss spectrum for a silencer

Exhaust Gas Silencer Attenuation

0

5

10

15

20

25

30

35

40

45

50

31,5 63 125 250 500 1000 2000 4000 8000

Frequency [Hz]

TL [d

B] W9L34SG

W12V34SGW20V34SG

Figure 11 Exhaust gas silencer typical transmissionloss

W34SG charge air sound power levels

In Figure 12 can be seen free field sound power spec-trum after turbo charger. Measurement uncertainty is±3dB.

Charge Air Sound Power Level

0

20

40

60

80

100

120

140

31,5 63 125 250 500 1000 2000 4000 8000 Lw tot

Frequency [Hz]

Lw [d

B(A)

]

W34SG

Figure 12 Charge air sound power levels




Typically 35 dB(A) charge air silencers are used inpower plants. Figure 13 shows typical transmissionloss spectrum for a silencer

Charge Air Silencer Attenuation

0

10

20

30

40

50

60

31,5 63 125 250 500 1000 2000 4000 8000

Frequency [Hz]

TL [d

B] W9L34SGW12V34SGW20V34SG

Figure 13 Charge air silencer typical transmission loss

Sound power is a measure of acoustical energy radi-ated by the sound source. Perceived sound pressuredepends on the sound power rating, the distancefrom the source, and the environmental conditions.

Figure 14 indicates typical noise levels at differentdistances from a plant with ten Wärtsilä 20V34 en-gine generator sets and standard attenuation equip-ment.

Radiators

Engine hall

Exhaust gas pipes and stacks

0 ft 100 ft

Figure 14. Typical noise levels at different dis-tances from a plant with ten engines

1.4.3 Water consumption and siteeffluents

With radiator cooling, which is the most commoncooling method, the cooling water is circulated in aclosed circuit. No waste water results from the proc-ess. Any contaminated water, for instance, water usedfor cleaning the equipment, is collected in a tank.

The process water consumption when using radiatorcooling is negligible (less than 4 litres per producedMWhe). No de-mineralized water is needed.

Water consumption for heat recovery systems shouldbe investigated case-by-case.

1.4.4 MiscellaneousAt low exhaust gas temperatures, mainly during start-up, the exhaust gases may form visible smoke.

Oil mist emerging with the crankcase ventilationgases is reduced with an oil mist separator and is neg-ligible.

The flexible mounting of the engine generator setsalong with elastic material between the floor slabsdampen the vibrations from the engines so that prac-tically no vibration is transmitted to the environment.

The power generating process produces negligibleamounts of solid waste.

1.5 Operation andmaintenance

1.5.1 Plant operation

General

The operator supervises and controls the plant mainlyfrom one or more PC workstations, the WOIS work-stations, in the plant control room. Most actionsneeded for normal operation, such as start and stopof the engines, synchronization, circuit breaker con-trol, and change of set points can be done at theworkstations.

Also manual controls and a mimic diagram are pro-vided.




Figure 15. Typical control room

Normally, the plant is operated in automatic mode,where the control system takes care of the start andstop processes, synchronization and output control.In manual mode, the operator controls the outputwith switches.

With remote monitoring services, the plant’s person-nel can monitor the plant from a remote location viaa secure internet connection. Provided that the datasecurity requirements are fulfilled, remote control canbe implemented.

Start and stop

The operator starts and stops the engines from theWOIS workstations. The auxiliary units are generallykept in an automatic mode, where they are startedand stopped automatically.

For emergency stop, engine-specific emergency stopbuttons and buttons for stopping the entire plant arelocated in the control room. In the engine hall, eachengine has an emergency stop button, and plantemergency stop buttons can be installed

Supervision and control

Most temperature and pressure measurements can bemonitored in the control room. The control systemalso records and stores the readings in the WISEworkstation (WISE = Wärtsilä Information SystemEnvironment).

Abnormal conditions requiring prompt operator ef-forts are noted by alarms, which are indicated bysound and light signals in the control room. Enginealarms may also be indicated by status and alarm an-nunciator lights in the engine hall. Alarms and eventsare recorded by the control system.

The operator should also make regular tours aroundthe plant to check local meters, drain points, vibra-tions, etc.

Personnel requirements

When the plant is in operation, personnel should bepresent at site, or, if the plant is remotely controlled,personnel on duty should be stationed close enoughto reach the plant at short notice when needed.

1.5.2 Output control

General

When feeding a small isolated grid (island operation),the power generation follows the system load. Thecontrol system controls the frequency (engine speed)by regulating the fuel supply to the engine and thevoltage by regulating the excitation current of thegenerator. When connected to a strong grid (paralleloperation), the grid determines the frequency andvoltage. The control system controls the active powerby regulating the fuel supply, and the reactive powerby regulating the excitation current.

Engine speed and load control

The following engine control modes are available:

kW control. In this mode, which can only be usedin parallel operation, the control system keeps theengine load (active power) constant at a set value.The operator can change the set point manually ifneeded, based on changes in the demand. Powermanagement functions, which change the set va-lue automatically, are available as options.

Speed droop control. In this mode, the engine iscontrolled against a speed set point. At an in-creased load, the speed drops, the maximumspeed reduction (droop) generally being 4% fromzero to full load. The load is shared equally be-tween parallel engines with the same set point.Automatic fine tuning to keep the speed constantis available as an option. Speed droop is the typi-cal engine control mode in island operation, andwhen providing spinning reserve Ancillary Ser-vices. It can also be used as a manual back-upcontrol method in parallel operation.




Isochronous control. In this mode a generatorset will operate at the same frequency regardlessof the load it is supplying, up to the full load ca-pability of the generator. This mode can be usedon one generator set running alone in an isolatedsystem. The isochronous mode can also be usedfor multiple generator sets running in parallel andsupplying an isolated system (island operation) forthis application load sharing lines (CAN bus) arerequired between the speed controllers, the activeload is shared equally between the parallel unitsand the frequency is kept at 100%

Generator output control

The following control modes are available:

Power factor control. In this mode, which isavailable only in parallel operation, the controlsystem strives to keep the power factor (relationbetween active and reactive power, cosine phi)constant at a set value.

Voltage droop control. In this mode, the voltageis controlled against a set point. At an increasedreactive load, the voltage drops, the maximumvoltage drop being 1 – 10% (adjustable) from zeroto full load. A function that adjusts the voltage setpoint automatically to keep the voltage constant isavailable as an option. Voltage droop is the typicalcontrol mode for small grids and island operation.It can also be used as a manual back-up controlmethod in parallel operation.

Voltage droop compensation. In this mode,which is available only in island operation and re-quires data communication between parallel units,the reactive load is shared equally between theparallel units and the voltage is kept at 100%.

Synchronization

Before connecting a generator set to a live busbar, itmust be synchronized. Synchronization is automaticwith manual backup.

Loading and unloading

In automatic mode, the load is gradually increasedafter connecting a generator set to the grid, andgradually decreased before disconnecting it.

1.5.3 Routine maintenance

General

Most routine maintenance can be done by the ordi-nary operating personnel while the engine is in opera-tion. Extended maintenance measures may requirethat the gas is shut-off and the system vented.

Maintenance schedule

The following schedule gives an indication of re-quired routine maintenance and typical time intervals.

Time in-terval

Maintenance measure

Check cooling water level, pressuredrops over filters, level in the oil sump.

50 runninghours

Clean the compressor side of the turbo-charger.Clean the centrifugal lube oil filters.Take lube oil samples for analyzing.

500 - 1000runninghours

Check the water quality.Clean the turbocharger air filter.1000 run-

ning hours Change spark plugs.Change the lube oil in the turning device.Inspect safety equipment.Inspect and clean starting air vessels.Clean cooling water circuits.Clean the pre-chamber.Replace the main gas valve filter insert.

2000 run-ning hours

Clean the lube oil cooler.Inspect the lube oil automatic filter.Clean or replace gas filters.Overhaul the compressed air systems.

Yearly

Inspect tanks, clean if needed.Replace the filter candles in the auto-matic lube oil filter.

Every sec-ond year

Check the cooling water pumps.

Table 4. Maintenance schedule (example)

The oil change interval depends on the lube oil qual-ity, operating conditions and engine condition.

The need for cooler and filter cleaning is evaluated bymeasuring the pressure drop over the devices.




Maintenance of stand-by plants

Stand-by plants which are to be kept ready for start-up at short notice must be regularly operated. Theengines should be test run once a week.

1.5.4 Overhaul intervalsThe following table lists engine overhaul intervals andaverage lifetimes for engines. The figures are to beregarded as guiding values only. The actual serviceconditions will have an impact on the overhaul inter-vals and component lifetimes.

Part Time betweenoverhauls (h)

Average life-time (h)

Piston 16 000 – 24 000 60 000 – 100 000Piston rings 16 000 – 24 000 16 000 – 24 000Cylinder liner 16 000 – 24 000 60 000 – 100 000Cylinder head 16 000 – 24 000 60 000 – 100 000Inlet valve 16 000 – 24 000 32 000Exhaust valve 16 000 – 24 000 16 000 – 24 000Main bearing 16 000 32 000Big end bearing 16 000 – 24 000 16 000 – 24 000Main gas ad-mission valve

8 000 16 000

Prechambercontrol valve

4 000 16 000

Prechamber 16 000 – 24 000 32 000 – 48 000Prechambernon-returnvalve

1 000 8 000 – 12 000

Ignition coil onplug

16 000 – 24 000 16 000 – 24 000

Spark plug 1 000 1 000

Table 5. Time between overhauls and expectedlifetime of components

1.5.5 Tools and spare partsNormal maintenance and repair can be done usingconventional tools and tools supplied with the en-gine. If required, special tools are available from theWärtsilä service stations. Spare parts are availablefrom Wärtsilä.

1.5.6 Safety aspectsThe safety risks in a Wärtsilä 34SG power plant areposed by heavy machines with rotating parts, hightemperatures and pressures, high voltages, and poten-tially explosive fuel gas mixtures.

A gas explosion may occur if an ignition source arises(spark or hot surface) in a space with a gas - air mix-ture of an ignitable ratio. In a power plant, the mostserious danger situations are caused by gas leakinginto the engine hall or unburned gas escaping into theexhaust gas system.

In a Wärtsilä 34SG power plant, all reasonable safetymeasures should be employed, for instance:

The plant should be equipped with gas detectionand alarm systems.

The exhaust gas system should be designed so asto avoid gas pockets, and ventilated after each en-gine stop. Rupture disks should be installed tominimize the pressure build up in case of a defla-gration.

During engine start-up, a number of automaticsafety checks and actions take place. The gas sup-ply is kept shut off during the first engine revolu-tions to purge any gas in the engine cylinders andexhaust gas pipes.

Running time in unloaded condition, where com-bustion efficiency is low, is limited.

In an emergency situation, the gas supply is shutoff and the combustion is disabled immediately.

It is not recommended to stay in the engine room orin a possible exhaust gas boiler room or silencerroom during engine start and no-load operation.

All personnel with access to the plant should be givensafety training.

Wärtsilä 34SG Power Plant Product Guide 2. ENGINE GENERATOR SET



2. ENGINE GENERATOR SET

2.1 Engine generator set

2.1.1 OverviewThe engine and the generator are factory assembledand aligned, and rigidly fastened to a common baseframe of welded steel. At installation, the baseframe is flexibly mounted to the concrete founda-tion.

Figure 16. Engine generator set

The engine crankshaft is connected to the generatorshaft via a flexible coupling, protected by a flywheelcover.

2.1.2 Flexible couplingThe engine torque is transmitted to the generatorwith the flexible coupling located between the en-gine flywheel and the generator shaft. The couplingreduces vibration and provides torque dampingcharacteristics.

Possible torque due to an inadvertent out-of-phasecoupling or a 3-phase short circuit would deform orbreak the elastic elements, which can be easily re-placed, but the machine structural parts would notbe damaged.

Since the coupling is flexible, it prevents engine fir-ing irregularities from being transmitted to the gen-erator.

2.1.3 Common base frameThe base frame is a welded structural steel assemblyengineered and reinforced to provide the engineand generator with a stable and torsion resistantplatform. A clearance between the generator feetand the frame resting pads allows for accurate shaftline alignment by shimming.

Lifting eyes are provided on the frame for lifting thewhole generator set. Lateral handling plates allowfor jacking.

2.1.4 Flexible mountingTo prevent structural born noise and vibration, thegenerator set is mounted on steel springs, which arenormally resting directly on the foundation. Thesteel springs are mounted under the base frame dur-ing installation.


Wärtsilä Finland Oy Power Plants Page 17


2.2 Engine

2.2.1 General The Wärtsilä 34SG engine is a reciprocating four-stroke spark ignited gas engine, which works ac-cording to the Otto process and the lean burn prin-ciple. The engine is turbocharged and intercooled. It is started with compressed air.

Cylinder headcovers

Turbochargers

Wastegate

Cooling water pumps

Lube oil pump

Charge air coolers

Gas manifold

Figure 17. Wärtsilä 20V34SG engine

The Wärtsilä 34SG engine has the following main characteristics:

Cylinder configuration In-line and V-form Number of cylinders 9L, 16V and 20V Cylinder bore 340 mm Stroke 400 mm Number of valves per cylinder

2 inlet valves 2 exhaust valves

Rotational direction Clockwise Rated speed 720/750 rpm Mean piston speed 9.6/10 m/s Mechanical efficiency 0.9 Compression ratio 11:1 or 12:1 (dependent

on engine optimization)

Table 6. Engine main characteristics

The following picture illustrates the engine termi-nology.

Drivin

gend

Free

end

A bank

Rear side

Operating side

B bank

Counter-c

lockwise

Clockwise

Figure 18. Engine terminology

2.2.2 Main components

Engine block

The engine block is made of nodular cast iron and cast in one piece. It incorporates the jacket water manifold, the camshaft bearing housings, and the charge air receiver. The crankshaft is mounted in the engine block in an under slung way. The oil sump, a light welded design, is mounted to the en-gine block from below.

The engine block has large crankcase doors allowing easy maintenance.

Crankshaft

The crankshaft is forged in one piece and counter-balanced by weights on all crank webs.

Main bearings and big end bearings

The main bearings and the big end bearings are of trimetal design with steel back, lead-bronze lining, and a soft running layer.

Connecting rods

The connecting rods are of forged alloy steel and fully machined with a round cross section. The connecting rod is a three-piece design, which gives a minimum dismantling height and enables the piston be dismounted without opening the big end bear-ing.




Pistons and piston rings

The pistons are of composite type with steel crown and aluminium skirt. The piston tops are oil cooled by means of “shaker effect”. The piston ring grooves are hardened.

The piston ring set consists of two chrome-plated compression rings and one spring-loaded oil scraper ring with chrome-plated edges

Air receiver

Fuel gas system

Cylinder head

Camshaft

Crankshaft

Spark plug

Prechamber

Cylinder liner

Hot box

Exhaust gas manifold

Oil sump

Piston

Connecting rod

Figure 19. Engine cross section

Cylinder liners

The cylinder liners are centrifugally cast of a special alloyed cast iron. The top collar is provided with bore cooling for efficient control of the liner tem-perature. The liner is provided with an anti polish-ing ring.

Cylinder heads

Each cylinder head contains a centrally located pre-chamber with a fuel gas valve. A multi-duct casting fitted to the cylinder head contains a charge air inlet from the air receiver, an exhaust gas outlet, cooling water outlet to return pipe, and a gas inlet from gas manifold. Exhaust gas and inlet valves are equipped with valve rotators.

The cylinder heads are made of vermicular cast iron (CGI – compacted graphite iron). The valve seat rings are made of specially alloyed cast iron with good wear resistance. The inlet valves as well as exhaust valves have stellite-plated seat faces and chromium-plated stems.

Camshafts

The camshafts are made up of one-cylinder pieces with integrated cams. The camshafts are driven by the crankshaft through a gear train.

Figure 20. Camshaft driving gears

2.2.3 Gas injection and ignition In a lean burn gas engine, the air-fuel mixture in the cylinders contains more air than necessary for com-bustion. The ignition is initiated by spark plugs in the pre-chamber, where a richer fuel mixture is used. The gas flame from the pre-chamber ignites the gas blend in the cylinder. The ignition system consists of two ignition coil drivers, one for each bank, and ignition coils located on top of the cylin-der head covers.

EXIN

Figure 21. Ignition

Gas is mixed with combustion air only in the intake channels in the cylinder head, thus ensuring that only air is present in the intake air manifold.




2.2.4 Engine mounted equipment

Flywheel

The flywheel is fastened to the crankshaft with fit-ted bolts. The generator is connected to the fly-wheel with a flexible coupling fastened to the fly-wheel.

Turbochargers

The 16V and 20V engines have two turbochargers,one per bank, the 9L engine has one turbochargerlocated at the free end of the engine. The turbo-chargers utilize the energy of the engine exhaustgases to feed air to the engine, thus, raising the effi-ciency of the combustion. The turbochargers are ofaxial turbine type, each with an exhaust gas driventurbine and a centrifugal compressor mounted onthe same shaft.

The turbochargers are equipped with a water wash-ing device which can be used during operation.Regular cleaning delays the formation of deposits.

Exhaust gas waste-gate

The waste-gate valve in the exhaust gas system actsas a regulator that limits the charge air pressure athigh loads. When opened, the valve lets part of theexhaust gases by-pass the turbocharger, thus reduc-ing the turbocharger speed and the intake air pres-sure in the receiver.

Anti-surge device

An anti-surge device can be installed for applica-tions where rapid load reductions may occur. Thefunction of the anti-surge device is to keep suffi-cient air flow through the turbochargers at suddenload reductions.

Turning device

The engine is fitted with an electrically driven turn-ing device to allow slow turning of the engine. Forfine adjustment of the crankshaft position there is ahand wheel. Engine start-up is prohibited while theturning device is being used.

2.2.5 Internal and engine mountedauxiliary systems

Fuel Gas system

The fuel gas system consists of a main gas line thatprovides gas to the cylinders and a pre-chamber linethat provides gas to the pre-chambers. The maingas valves are opened and closed by the engine con-trol system. The pre-chamber gas injection valvesare mechanically operated by the camshaft.

Figure 22. Gas admission system

Gas is supplied to the engine through the gas regu-lating unit with separate outlets for main gas andpre-chamber gas. A gas filter mounted on the en-gine performs a final filtration of the main chambergas.

The main gas line on the engine has a vent valvecontrolled by the engine control system.

Lubricating oil system

The lubricating oil system lubricates the bearingsand cylinder liners in the engine. Besides lubricatingthe engine, the lubricating oil has a cooling func-tion.

Lubricating oil is circulated by an engine driven gearpump. Besides the pump, the lube oil system com-prises an automatic oil filter and a centrifugal filterfor cleaning the back-flush oil from the automaticfilter, a lubricating oil cooler with a thermostaticvalve, and an electrically driven pre-lubricatingpump.

From the oil sump at the bottom of the engine, oilis pumped at a pressure of 4 - 5 bar via the coolerand the filter, through the hydraulic jacks (fitted formaintenance purposes) to the main bearings,through the connecting rods, to the gudgeon pins,and partly to the piston skirts. Finally, it is sprayedon the piston crown cooling surfaces.




Figure 23. Internal and built on lube oil system

Lube oil is also conducted to other lubricatingpoints, like camshaft bearings, rocker arm bearings,valve mechanism gear wheel bearings, and the tur-bocharger.

The electrically driven pre-lubricating pump is usedfor filling the engine lube oil system before start,and for continuous lubrication of stand-by engines.

The engine is equipped with a wet oil sump. Thesump is equipped with high and low level switches,an oil dipstick indicating maximum and minimumoil levels and remote level indication

Compressed air starting system

The engine is started by direct injection of com-pressed air into the cylinders. Starting air is admittedto the cylinders through pneumatically controlledstarting air valves in the cylinder heads (see Figure24).

Control air to the starting air valves is fed through acamshaft driven distributor. Control air feed isblocked when the turning gear is engaged, thus pre-venting start.

The main starting valve that admits air to the start-ing system is activated by the engine control system.

Figure 24. Starting air system

Cooling system

The main function of the engine cooling water sys-tem is to remove the heat generated by the engine.The cooling water is cooled in an external coolingsystem.

The cooling water system is divided into a hightemperature (HT) circuit and a low temperature(LT) circuit. The HT circuit comprises the engineblock (cylinder jacket and cylinder heads) and thefirst stage charge air cooler. The LT circuit com-prises the lube oil cooler and the second stagecharge air cooler.

Two engine driven centrifugal pumps circulate thecooling water through the engine and the externalcooling system. The water temperatures in the twocircuits are controlled by two temperature controlvalves.

Intake air system

The intake air system comprises the compressor onthe turbocharger and a two-stage intake air coolerof tube type located after the turbocharger. Whencompressed in the turbocharger, the air is heated. Inthe charge air cooler, it is cooled with cooling waterto optimal level before entering the charge air re-ceiver in the engine block.




Exhaust gas system

The exhaust gases are led from the cylinders,through multiducts to common exhaust pipes, oneper bank, leading the exhaust gases to the turbo-chargers. The exhaust pipes are designed to providean equal flow of gases to the turbochargers withoutdisturbing gas pulses to the cylinders.

The exhaust pipes are cast of special alloy nodularcast iron, with separate sections for each cylinder.Metal bellows of multiple type absorb the heat ex-pansion. The complete exhaust system is enclosedby an insulation box of steel sheets.

Figure 25. Exhaust manifold

Exhaust gas temperature sensors are mounted aftereach exhaust valve, and before and after the turbo-chargers.

2.2.6 Engine control system

General

Monitoring and control of the engine is handled bythe engine mounted UNIC (UNIfied Controls) en-gine control system. The main functions of the sys-tem are:

Start and stop management


Speed measuring and over-speed protection

Gas pressure control and air-fuel ratio control

Cylinder control: gas injection, ignition andknock control

Safety functions: start blocking, alarm activation,load reduction, and shutdown.

The Wärtsilä UNIC control system is a distributedand redundant control system composed of severalhardware modules which communicate through tworedundant communication buses using the CANprotocol. The main modules are mounted in thecontrol cabinet at the driving end of the engine. TheI/O modules and the cylinder control modules aremounted along the engine side close to the sensorsand actuators they are monitoring and controlling.The main control module is responsible for all con-trol functions. It communicates with the plant con-trol system through the plant network.

Figure 26. UNIC main system components

The system is specifically designed for the demand-ing environment on engines. Special attention hasbeen paid to temperature and vibration endurance.The rugged design allows the system to be directlymounted on the engine, and the engine can be fullytested at factory before delivery.

UNIC collects signals from the engine sensors,processes them and compares them with given con-trol parameters. All data collected by UNIC can betransferred to the plant control system.

The local control panel on the engine mounted con-trol cabinet contains two graphical displays, onestatic display showing the most important engineparameters, and one interactive, menu based displaywhere all engine data as well as the control systemstatus can be viewed.




Local display unit

Push buttonsEmergency stop button

Local display unit

Local control panel

Main controlmodule (MCM)

Power distributionmodule (PDM)

Engine safetymodule (ESM)

Opto-couplers

Terminals

Figure 27. Engine mounted control cabinet


The engine control system has two engine control modes: speed control and load control. The active mode is selected with the plant control system.

A PID type controller controls the fuel injection based on the difference between measured speed or load, depending on the active control mode, and the respective set point. In speed control mode, a fixed speed based on the engine rated speed is used as set point. The internal engine speed reference is de-creased linearly at increased load (speed droop). In load control mode, the load reference is set by the plant control system.

Engine speed measuring and over-speed protection

The engine speed and phase are measured with two speed and phase sensors located on the flywheel. The speed and phase signals are used to determine the timing and duration of the gas injection and ignition. Using the speed signals, UNIC calculates measured engine speed, which is used as feedback for the internal speed controller and for over-speed protection. UNIC calculates the speed in several different units, and the results are cross-checked.

In case of an engine over-speed, UNIC initiates an instant emergency stop. A safety module in UNIC provides an independent second over-speed protec-tion based on two back-up speed sensors.

Gas pressure and fuel-air ratio control

Gas pressure is monitored and controlled to ensure proper gas supply and air - fuel ratio. Taking into account the engine load and the air receiver pres-sure, UNIC calculates and sends a pressure refer-ence signal to the Gas Regulating unit.

The actual gas pressure is measured on the engine and compared to the reference pressure. If the gas pressure is too low or high related to the charge air pressure, the engine is shut down. If the pressure is too high, the control system will open safety valves on the engine and the gas regulating unit to evacu-ate excess gas pressure.

The air pressure in the air receiver is controlled with the waste-gate valve.

Cylinder control

Each engine has several cylinder control modules which control the gas injection and timing of the main gas valve, and the ignition timing. They also monitor the exhaust gas temperature, cylinder knocking, cylinder liner and main bearing tempera-tures.

UNIC controls the duration and timing of the gas injection to each cylinder main combustion cham-ber and the timing of the spark. The timing can be set individually for each cylinder.

Knocking is due to the auto-ignition of gas before or after the spark ignition. This is harmful to the engine. Knock sensors are mounted on each cylin-der head, and if knocking is detected, UNIC takes appropriate actions – adjustments, load reduction or shutdown – depending on the knock intensity.

During operation, the system monitors the exhaust gas temperature of each cylinder and the average temperature. Deviations may lead to load reduction or shutdown.

Safety functions

The safety functions include start blocking, alarm activation, load reduction, shut-down and emer-gency stop.

Before the plant control system activates a start re-quest, it checks with UNIC that the engine is ready for start. UNIC will not allow start if, for instance, the lubricating oil pressure is too low, the HT cool-ing water temperature is too low, the exhaust gas ventilation has not been performed, or the engine turning device is engaged.

UNIC generates a number of alarms, all of which are transmitted to the plant control system, for in-stance:

• Sensor failure or wire break

• Gas pressure deviation




High exhaust gas temperature after a cylinder

Failed start attempt

High charge air temperature

High crankcase pressure

De-rating caused by knocking

Engine overload.

Some alarms, for instance, heavy knocking, gaspressure deviation, and high exhaust gas tempera-ture will initiate a load reduction. More serious inci-dents, like CAN bus failure, high crankcase pres-sure, high exhaust gas temperature after cylinder,high cylinder liner temperature, and high main bear-ing temperature will activate an immediate engineshut-down.

At an emergency stop, the engine will be shut downimmediately. An automatic emergency stop will beexecuted, for instance, at engine overload, engineover-speed, or if both speed sensors have failed.

2.3 Generator

2.3.1 GeneralThe generator converts the mechanical power ofthe engine into electrical power.

The standard generators used with Wärtsilä 34SGengines are medium voltage synchronous AC gen-erators with a brushless excitation system, horizon-tally mounted, and provided with two sleeve bear-ings. The generators are connected to the engineflywheels by means of flexible couplings. The statorframes rest on machined feet.

The generators are air-cooled with a shaft-mountedfan which takes cooling air from the engine hall. Anelectrical anti-condensation heater prevents watercondensation in a stand-by generator.

The generators follow the design criteria describedby IEC (International Electrical Commission).

2.3.2 Generator type and sizeGenerators are typically operated at nominal speed.The output frequency is determined by the numberof pole pairs and the engine speed.

Frequency 50 Hz 60 HzEngine speed, rpm 750 rpm 720 rpmNumber of poles 8 (4 pairs) 10 (5 pairs)

Table 7. Number of poles in 50 Hz and 60 Hzapplications

The rotor construction is salient pole. A fully inter-connected damper winding stabilizes the rotor dur-ing load changes. This makes the generator suitablefor operation in parallel with other generating sets.

The generator is sized for the engine power at thesite where the engine generator set will be installed.

2.3.3 Excitation systemWhile the active power output from the generatordepends on the engine power and the generatorefficiency, the voltage and reactive power is regu-lated by the excitation system.

The brushless excitation and voltage regulation sys-tem consists of an automatic voltage regulator(AVR), an exciter and a rotating diode bridge. Exci-tation power is taken from voltage transformers orauxiliary windings mounted on the generator. Dueto a permanent magnet pole in the exciter, no ex-ternal power source is required for the initial excita-tion at start-up.

Figure 28. Principle scheme of the excitation sys-tem

At full load, the power plant has an operating rangefrom a power factor of 0.95 leading (under-excited)to a power factor of 0.8 lagging (over-excited).

The automatic voltage regulator is contained in thegenerator set control cabinet.

Stator windings




2.3.4 Main terminal boxAll stator winding ends and the neutral point cableare brought into the main terminal box, which ismounted on the generator side or on top of thegenerator.

2.3.5 InstrumentationThe generator has current and voltage measurementtransformers which provide measured data for con-trol and protection functions. In addition, the statorwindings and the bearings are equipped with tem-perature sensors. All signals from the sensors areconnected to a connection box on the generator.

2.3.6 ProtectionThe generator is protected by the protection relaysin the generator set control cabinet.

If the generator circuit breaker in the MV switch-gear is of vacuum breaker type, the generator mustbe equipped with surge protection (surge arrestersand surge capacitors).

Wärtsilä 34SG Power Plant Product Guide 3. ENGINE AUXILIARY SYSTEMS



3. ENGINE AUXILIARY SYSTEMS

3.1 Overview

Figure 29 shows an overview of the engine auxiliary system equipment.

Figure 29. Overview of 20V34SG engine auxiliary system equipment




Each engine has its own gas regulating unit (GRU), engine auxiliary module, exhaust gas module, intake air filter, exhaust gas silencer and radiator(s). The maintenance water tank(s), compressed air units, storage tanks, and lube oil pump units are common to several engines or the whole plant.

3.2 Standard modules

3.2.1 Engine auxiliary module (EAM)

General

The Wärtsilä 34SG Engine Auxiliary Module (EAM) (Figure 30) is a prefabricated module composed of pipes, pumps, heaters, valves, instrumentation and control for handling the flows of cooling water, lubri-cating oil and compressed air to and from the engine.

The EAM module is available in four models for 16V and 20V34SG engines according to Table 8.

A separate jacket water cooler is required with one-circuit models in arctic conditions where high glycol content in the LT-circuit calls for separate LT and HT-circuits.

The EAM module is built within a rigid steel frame and is equipped with an auxiliary platform.

HT preheating unit

Instrument air panelControl panel

Hose reel, air gun

Temperature control valves

Expansion water pump (option)

LT preheating unit(option)

Header pipes

Figure 30. Engine auxiliary module viewed from the engine side




Model Description Ambient temp. range

EAM 1C MC One common external cooling water circuit. -8oC - +44oCEAM 1C JC One cooling water circuit, but separate cooling of

the jacket water.-35oC - +44oC

EAM 2C Two cooling water circuits. The model supportsHT water heat recovery.

-35oC - +44oC

EAM CHP Two cooling water circuits with connections to theCHP module (page 51).

-35oC - +44oC

Table 8. The EAM models for 16V and 20V34SG engines

Lube oil system equipment

The EAM module comprises pipes for transportinglube oil to the engine, and connections for pumpinglube oil from the engine.

Compressed air system equipment

Starting air pipes within the EAM convey starting airto the engine, and control air pipes convey control air(instrument air) to the consumers. Control air is dis-tributed through one or more pressure reductionunits, containing an air pressure regulating valve, afilter and a water separator. The EAM module is alsoequipped with a service air outlet.

To protect the most sensitive engine components at amalfunction of a compressor filter or drier, there is asafety filter (micro filter) in the EAM module close tothe engine. Immediately before the engine, there are anon-return valve and a blow-off valve.

Cooling water system equipment

The EAM module contains an HT pre-heating unitfor heating the high temperature (HT) cooling waterbefore engine start-up. The unit consists of a cen-trifugal pump and an electrical heat exchanger de-signed to heat the cooling water to about 70oC and tokeep it at this temperature when the engine isstopped.

For cold climates, the module may also contain asimilar LT pre-heating unit for pre-heating the lowtemperature (LT) water, which preheats the intake airin the intake air cooler.

The module contains two temperature controlvalves, one for the LT and one for the HT circuit.

An expansion water pressure increasing pumpwith variable speed control can be included in caseswhere the HT expansion vessel (in two-circuit sys-tems and systems with a separate jacket cooler) can-not be placed high enough, that is, at least 7 metersabove the engine HT cooling water pump.

Instrumentation and control

The control cabinet of the EAM module containspump motor starters, relays, switches, timers andlogical circuits. It also contains a remote I/O whichcommunicates with the generator set PLC in the con-trol room.

The sensors, switches and actuating devices in theEAM module are all connected to the remote I/O. Inaddition, the sensors and actuators in the exhaust gasmodule (see below) and the intake air filter are con-nected to the remote I/O.

In automatic mode, the pumps and heaters in themodule are started and stopped automatically basedon the engine running signal, level switches or ther-mostats.

3.2.2 Exhaust gas module

General

The exhaust gas module contains an optimized ex-haust gas branch pipe, intake air silencers, one or twoexpansion vessel(s), an exhaust gas ventilation fan,and an oil mist separator unit . In plants with an SCRtype emission control system, the module may in-clude a platform for the reagent dosing unit.

Intake air silencers

The charge air silencers, which are of absorptiontype, are available in two sizes. The smaller charge airsilencers are designed to give about 35 dB(A) attenua-tion in the high frequency band, which is enough inmost cases. The larger silencers give about 45 dB(A)attenuation.




Figure 31. Exhaust gas module

Cooling water expansion vessel(s)

The expansion vessel(s) compensate for volumechanges in the cooling water system due to tempera-ture changes. They also provide continuous air vent-ing of the engine cooling water circuit(s) and staticpressure at the inlet of the engine mounted coolingwater pumps.

In two-circuit installations and one-circuit installa-tions with separate jacket cooler, there are two vesselsof 300 litres each, one for HT water and one for LTwater. In one circuit installations with mixed HT andLT water, there is one expansion vessel of 600 litres.The expansion vessels are equipped with low levelswitches for activating low level alarm, and local levelindicators.

Exhaust gas vent fan

The exhaust gas vent fan purges the exhaust gas sys-tem from any accumulated unburned gas. The fan isof radial type and is driven by an electrical motor. Itis started automatically by the plant control systemafter the engine has stopped. A flow switch ensuresthat the fan is running.

Oil mist separator unit

The oil mist separator unit removes the oil particlesfrom the crankcase vent gases utilizing the centrifugalforce principle. The separated oil flows back to theoil sump via the crankcase ventilation pipe.

3.3 Fuel gas system

3.3.1 System description

System overview

The purpose of the fuel gas system is to supply theengine with a constant gas feed of suitable pressure,temperature and cleanness. It should also shut off thegas supply if any problem arises, and provide ventila-tion of trapped gas.

Fuel gas is supplied to the engine from the gas distri-bution system through an engine-specific gas regu-lating unit (GRU), or “gas train”, which includes aparticle filter, pressure control valves, safety shut-offvalves and vent valves. The gas regulating unit is al-ways supplied by Wärtsilä along with the engine.

Gas is supplied to the power plant through a com-mon gas pipe which splits into engine-specific gaspipes in a header pipe. To enable gas shut off, theremust be one or more main shut off valves outsidethe engine hall. Generally, the valves are located inthe common gas pipe. Alternatively, there may bemain shut-off valves in each of the engine-specificgas pipes.

Gas flow metering unit can be installed in thecommon gas pipe for measuring the gas consumptionof the plant. Engine-specific flow meters may also beincluded in the gas regulating unit.

The common fuel gas system can also include thefollowing equipment:

A pressure reduction station if the pressuresupplied by the gas company is higher than maxi-mum allowed pressure to the GRU

A gas compressor if the fuel gas pressure sup-plied by the gas company is too low

A filtration unit if the gas may contain impurities,oil, water or condensed hydrocarbons

A heating unit if the gas temperature may dropbelow the dew point

A venting valve to depressurize the fuel gas pipesinside the engine hall

The filtration and heating units may be included inthe pressure reduction station as shown in the figurebelow.




Figure 32. Diagram of a fuel gas system with common gas shut off and flow metering, and a pressure reductionstation with filtration and heating

Fuel gas pressure requirements

The required fuel gas pressure to the engine dependson the engine configuration and the heating value ofthe gas. The exact minimum pressure must thereforebe determined case by case.

Normally, the inlet pressure to the GRU is 4.5-6.0bar(g). The maximum pressure to the GRU is about10 bar(g) in ANSI/ASME design and 6 or 16 bar(g)in DIN design. Typical pressure drop over the GRUis 50 kPa.

The required fuel gas pressure to the plant is theminimum GRU pressure, plus the pressure drop overthe upstream units, plus a safety margin.

Temperatures

The fuel gas temperature before the engine must behigh enough to avoid condensation and icing. Therecommended minimum temperature is +5oC, and aminimum of +15oC over the hydrocarbon and waterdew points.

Gas filtration

The mechanical components in the engine fuel gassystem are sensitive to particles. Particles must there-fore be removed before the engine. The followingtable gives typical filtration properties for the gas fil-ters in different locations of the system.

Particlesize

Filtrationefficiency

Location

m %Plant filter unit 5 95Flow metering unit 2 95Gas regulating unit 2 95Engine gas pipe inlet(main pipe)

0.5 98.5

Metal net at engine maingas valve inlet on theengine (safety filtration)

90 NA

Table 9. Particle filtration efficiency

3.3.2 Gas regulating unit (GRU)

General

The skid mounted gas regulating unit (GRU), whichis always supplied by Wärtsilä, provides correct fuelsupply to the engine by regulating the gas feed pres-sure according to the engine load.




Figure 33. Gas regulating unit

The GRU has two pipe connections to the engine: alarger line to the main combustion chambers, and asmaller one to the pre-combustion chambers. Thelines may have different pressures.

The main components of the GRU are:

A manual ball valve for closing the gas inlet line

An inert gas line for purging the unit when re-quired for maintenance purposes

A particulate filter

Two pressure regulating valves, one per line

Two main shut-off valves (blocking valves) perline, and three vent valves per line

A safety relief valve per line (in ANSI design)

Optionally, a flow meter with a flow computer

Instrumentation such as pressure and temperaturegauges and transmitters.

The pressure regulating valves are controlled by theengine control system. The plant control system con-trols the shut-off and ventilation valves and monitorsthe unit.

The electrical components are EX-classified to besuited for installation in zone 2 (class I division 2).

Particulate filter unit

Typically, the particle filters have a separation effi-ciency of over 95 % of particles down to 2 µm.

Pressure regulating valves

The pilot operated pressure regulating valves are ofdiaphragm type. They are operated with control airsupplied through an I/P converter controlled by theengine control system. If the inlet pressure is in therange 6 - 16 barg (DIN design), the regulating valvesare supplied with safety shut-off valves.

Shut-off valve and vent valves

The GRU is equipped with four shut-off valves, twoin the main gas line and two in the pre-chamber gasline. The valves, which are doubled for safety reasons,are mounted in series. The shut-off valves are openedpneumatically, and closed by a spring.

Gas trapped in the pipes at shut off is vented to theatmosphere through solenoid operated vent valves –three for the main gas line and three for the pre-chamber gas line. During operation the shut-offvalves are open and all the vent valves are closed.When the engine is stopped (normal stop or engineshut-down), the shut-off valves are closed, and thevent valves are opened and closed according to a de-fined sequence to prevent air from replacing gas inthe pipes. At an emergency stop, all the valves will goto their fail-safe positions.

The vent pipes must be pulled as two separate linesup to the roof, grouped according to Figure 32.

Instrumentation and control

The measurements and control signals from and tothe unit are collected in electrical cabinets or switchboxes mounted on the unit.

3.3.3 Main shut-off valve(s)To enable fuel gas shut off, there must be one ormore main shut off valves outside the engine hall. Inthe event of a gas leak, fire or gas explosion inside thebuilding, the gas flow must be shut off automatically.It must also be possible to shut off the gas flowmanually outside the building. It is therefore recom-mended to have two valves in series, one manuallyand one automatically operated. The automatic valvemust be of fail-safe type with a limit switch for re-mote indication.

Minimum performance requirements for large valves>DN200 :

Shut off: < 4 secondsOpen: ~30 seconds




For smaller valves, shorter closing time is recom-mended.

Generally, the main shut off valves are located in thecommon gas pipe before the header pipe. Alterna-tively, there may be main shut-off valves in each ofthe engine-specific gas pipes. The latter design maybe preferable in cold climates as it allows engine ven-tilation to be shut off during standby.

In plants with a common main shut-off valve, theautomatic valve is closed by the control system at aplant emergency stop. In plants with engine specificvalves, the valve is closed at stop, shut-down, oremergency stop of the respective engine. All valvesare closed in case of a plant emergency stop.

3.3.4 Vent valveA vent valve may be installed outside the engine hallbetween the main shut-off valve and the wall. Thevalve is opened in case of a plant emergency shutdown to let pressurized fuel gas out of the fuel gaspipes. The valve should be of fail-safe type andclosed by a spring in loss of power or control air.

3.3.5 Pressure reduction station

General

The design of a pressure reduction station can vary.In addition to the pressure regulator, the station mayinclude a filter, a gas flow meter, a heater, and a gaschromatograph for measuring the gas quality.

Pressure regulating valves

To secure the availability, the pressure regulatingvalves should be doubled, one valve being in opera-tion and one in stand-by. The valves can be con-nected in parallel or in series. If the valves are parallel,both lines are designed for 100 % capacity andequipped with safety shut-off valves. An automaticduty/slave control switches to the slave line if theduty line fails. With two valves in series, the setpoints are adjusted so that if one regulator fails, theother one takes over.

Heating

When the pressure is reduced, the fuel gas tempera-ture will drop. The size of the drop depends on thegas composition. A rule of thumb is 0.5oC/bar. Thetemperature drop may cause condensation, icing andhydrate formation. If a risk for malfunction arises,heating is required. Electrical heaters are recom-mended. The components must be EX-classified.

Safety devices

Depending on the inlet and outlet pressures, one ormore safety devices are required. The minimum re-quirement is a monitoring regulator or safety shut offvalve. When activated (closed), the safety shut-offvalve must remain closed until it is opened manually.

3.3.6 Gas filtration unit

General

A gas filtration unit is needed if the gas contains ormay contain high concentrations of impurities in theform of particles – rust, debris, sand, etc. – oil, ormoisture and hydrocarbon condensate. If there is agas compressor, it may leave traces of lubrication oilin the gas stream. Liquid removal and also gas heatingmay be required depending on the inlet temperatureand pressure, and the hydrocarbon and water dewpoints of the gas. The filter type may be, for instance,a particle, coalescing, vane, or demister filters. Allelectrical devices must be EX-classified.

Liquid separation

Natural gas containing traces of C4 - C7 hydrocar-bons and a slight amount of water vapour normallyneeds no liquid separation. However, if the gas con-tains higher hydrocarbons, C12 or higher, liquid sepa-ration will be necessary as these compounds maycause condensation problems even in small concen-trations (e.g. 0.5 ppm).

Liquids can be separated, for instance, with gravityseparators, centrifugal separators, vane separators,mist eliminator pads and coalescing filters. Generally,the liquid present in the gas stream is a very fine fumewith a droplet diameter < 1 m. For removing suchsmall droplets, a coalescing filter is normally required.




Design principles

The filtration unit should have full stand-by capacityand be designed for maximum flow (the flow at theminimum operating pressure and maximum tempera-ture). The filter must be equipped with differentialpressure measurement and filter switch over. Thereshould also be manual venting and isolation valves orthree way valves. If liquid is removed, a manual orautomatic drain and possibly a collector will beneeded. If the filter is installed indoors, normal car-bon steel can be used.

3.3.7 Flow metering unit

General

The gas flow is metered for determining the fuel con-sumption. The gas flow meter can be an industrialmeter or a custody transfer meter approved for bill-ing purposes. The flow meter must be equipped witha flow corrector or a computer to change the actualflow to standard conditions. For more exact flowdetermination, the compressibility of the gas shouldbe taken into account.

Design

The plant specific flow meter includes:

A flow meter, normally a turbine meter, with aflow corrector or computer

High accuracy pressure and temperature sensors

A particulate filter

A by-pass line, a vent connection, isolation valves,and straight pipe sections before and after the me-ter

The meter shall be the same size as the gas pipe. Re-stricting or enlarging cones are not recommended.The valves must be designed for gas applications.

3.4 Lube oil system

3.4.1 System descriptionThe lubrication oil system includes tanks for storingnew and used lube oil, pumps for emptying and fill-ing lube oil, and loading/unloading pump units in thetank yard. The pump for filling lube oil can be com-mon for the entire plant. A common mobile pumpcan be used for emptying the system.

Figure 34. A typical lube oil system

The new lube oil tank stores fresh lubricating oil foroil changes and for compensating oil consumption(topping up). The used lube oil tank contains usedlube oil stored for disposal. There may also be a ser-vice tank for storing lube oil temporarily for reuse.

The required size for the fresh lube oil tank dependson the lube oil delivery interval. Generally, the tank issized for 28 days consumption or as a minimum, thetank should contain a sufficient quantity of lubricat-ing oil for an oil change in one engine.




The lube oil tank for used lube oil and the servicetank must be able to store oil from at least one en-gine, plus a 15 % safety margin.

When sizing the pumps, the lube oil quality and vis-cosity should be considered. To avoid emulsificationof water, the lube oil pumps should be of screwpump type.

The reciprocating movements of the engine pistonsand the slight pressure leakage past the piston ringsgive rise to crankcase gases, which may contain lubeoil. The crankcase gases are led to the oil mist separa-tor, where the lube oil traces are minimized. Thecondensate is drained back to the engine oil sump.

3.4.2 Lube oil storage tanksAccording to tank standards, vertical cylindrical tanksare typically used for volumes >35m3. Smaller tanksare normally horizontal. Large storage tanks are usu-ally built on site while smaller ones can be prefabri-cated elsewhere.

The standard tanks delivered by Wärtsilä are made ofsteel. Each tank has inlet and outlet connections, adrain pipe, a vent pipe, an overflow pipe and a man-hole.

Vertical tanks have slightly sloping bottoms with wa-ter collecting pockets from where the drain tubing isconducted. The filling pipe inlet is turned to the tankwall to give a smooth flow. The tanks are equippedwith level switches.

°C

Figure 35. Temperature – viscosity diagram for SAE 30 and SAE 40




Figure 36. An example of a vertical tank

If needed, the tanks are equipped with heating coils.Note that if a tank contains an electrical heating coil,the level in the tank must always cover the coil toprotect it from overheating.

3.4.3 Lube oil pump unitsThe standard transfer pump unit consists of a suctionfilter, one or two electrically driven screw pumps,valves, and a control panel. To protect the pumpsfrom over pressure, they are equipped with built onoverflow valves.

Figure 37. Lube oil pump unit (single pump)

3.5 Compressed air systems


General

Compressed air is used to start the engines (startingair), and as actuating energy in pneumatic safety andcontrol devices (instrument and control air). Instru-ment and control air can also be used as “workingair” in diaphragm pumps and in pneumatic tools. Thenominal starting air pressure is 30 bar and minimumpressure is 15 bar. The instrument air pressure is 7bar. While starting air is required only during start-up,instrument air is required for operating the engineand the gas regulating unit.

Compressed air is produced in compressor units,generally with automatic pressure control. The air isstored in compressed air tanks, which serve as buff-ers. The starting and instrument air units can also beinterconnected, enabling the starting air unit to beused as back-up for the instrument air unit.

To ensure the functionality of the components in thecompressed air system, the air has to be dry, cleanand free from solid particles and oil.

Starting air quality requirements

Starting air should be cleaned with an oil and waterseparator. Normally there is no need for a dryer.

Instrument air quality requirements

The instrument air is to meet the requirements in“Contaminants and quality” Class 343 as specified inthe ISO:8573-1 standard. With this, it also meets“Quality standard for Instrument air” by ANSI MC11.1-1975, considering an ambient temperature ofmin. 11°C (52°F).

Maximum particle size: 3 micronMaximum particle concentration: 5 mg/m3

Maximum pressure dew point: + 3°C (37°F)Maximum oil content: 1 mg/m3

Table 10. Instrument air quality requirements

The strict requirements imposed on instrument airmake an air filter and drier necessary. In addition,water separators should be installed before instru-ments that are sensitive to water.




Starting air system sizing principles

The required capacity of the starting air units, and thenumber and size of the starting air tanks depend onthe required start-up time of the plant. The standardprinciple is to size the tanks for three start attemptsper engine in small plants, and two starts per enginein larger plants.

If the requirement is three start attempts per engine,the minimum starting air tank volume is 4.4 m3 perengine. The starting air compressor is typically di-mensioned to fill the tanks from minimum pressure(15 bar) to nominal pressure (30 bar) in one hour.With this principle, required compressor capacity for4.4 m3 tank volume would be 4.4 x 15 = 66 Nm3/h at30 bar.

Instrument air system sizing principles

The control and instrument air unit(s) should havesufficient capacity to supply the peak consumption ofthe plant, even in case of a leakage. The required ca-pacity depends on the size of the plant and the typeof installed equipment. Instrument air is consumed atleast by the engines, the gas regulating units, the fuelgas shut-off valve(s), and the exhaust gas system ven-tilation valve. Minimum capacity is typically 1.1Nm3/min for a one engine plant and 2 x 2.7Nm3/min for a plant with ten engines.

In plants with one to three engines, an air receiver of200 litres and a design pressure of 10 bar is recom-mended. In larger plants, and in plants with irregularair consumption, more receivers may be needed. Bigconsumers, for example soot blowers, may need theirown local air receivers.

Figure 38. Compressed air system diagram




3.5.2 Starting air unit

General

Wärtsilä’s standard starting air unit consists of thefollowing main components mounted on a commonsteel frame:

one or two compressors with a control panel

an oil and water separator

a pressure reducer for connection to the controland instrument air system.

Vibration dampers are mounted between the com-pressor unit and the floor.

Figure 39. Starting air unit with two compressors

If there are two compressors, one compressor isworking while the other one is stand-by. Both com-pressors may be electrically driven, or one of themmay be a diesel driven emergency unit. The air outletsare connected in parallel. For fast production, bothcompressors may be used simultaneously.

The compressor is of two-stage type with intermedi-ary air cooling. It is designed for 40 bar maximumoperating pressure and includes a pressure releasevalve. The compressor is started and stopped auto-matically by the signals from a pressure switch. It isstarted at about 23 bar and stopped at 30 bar. A lowpressure alarm signal is activated at 18 bar.

Oil and water separator

An oil and water separator and a non-return valve arelocated in the feed pipe between the compressor andthe starting air receiver..

3.5.3 Control and instrument airunit

General

The standard control and instrument air unit deliv-ered by Wärtsilä contains the following equipmentbuilt on a common steel frame:

an electrically driven compressor with a controlpanel

a compressed air receiver

an air cooled refrigeration dryer

a filter for removal of oil, water and particles

Compressor

Wärtsilä’s standard control and instrument air com-pressor is a single-stage air-cooled screw compressordesigned for a working pressure of 7 bar and maxi-mum pressure of 10 bar. The compressor is equippedwith a suction filter and a suction silencer.

The pressure is controlled automatically by openingand closing the air intake valve while the compressoris continuously running. The compressor is stoppedautomatically after some time of inactivity.

Air dryer

The air dryer removes water from the compressed airbefore it leaves the unit. In most cases, a refrigerationdryer gives sufficiently high air quality and is the pre-ferred type of dryer.

3.5.4 Compressed air tanksThe air receivers are to be equipped with at least onemanual valve for condensate drainage. Horizontallymounted air receivers must be inclined 3-5° towardsthe drain valve. Being pressure vessels, they must betested and stamped for the design pressure accordingto locally valid regulations.




3.6 Cooling water system


General

Heat removed from the engine must be dissipatedthrough an external cooling system, either radiatorsor central coolers. Radiators provide a closed systemand require no secondary cooling. With central cool-ing, a secondary cooling circuit is required with anexternal source of cooling such as cooling tower orraw water. The choice of cooling method depends onthe ambient conditions, water availability, and envi-ronmental requirements.

Cooling water quality requirements

For the required cooling water quality, refer to sec-tion 12.3. Note that neither sea water nor rain watermust be used. Sea-water would cause severe corro-sion and deposits. Rain water is unsuitable due to itshigh oxygen and carbon dioxide content.

To prevent corrosion, corrosion inhibitors are alwaysmandatory. Water additives may also be required toprevent freezing, deposit formation, or cavitation.

LT and HT circuits

The engine cooling water system is divided into a lowtemperature (LT) circuit and a high temperature (HT)circuit. The LT circuit includes the lube oil cooler andthe second stage, low temperature charge air cooler(LTCAC). The HT circuit includes the first stage,high temperature charge air cooler (HTCAC) and theengine jacket. The water is circulated by two engine-driven pumps, and the temperatures are regulated bytwo three-way temperature control valves.

One and two circuit systems

Outside the engine, the cooling system may be ar-ranged as a one-circuit system, where the LT and HTcircuits are joined to one flow through the radiators,or as a two-circuit system, which has two separateflows through the radiators. One-circuit systems aresuitable in most cases, but two-circuit systems areusually preferred in heat recovery applications.

Figure 40. Cooling water system (one-circuit system with mixed cooling).




If the ambient temperature may drop below 0oC, ananti-freeze agent, generally ethylene glycol must beadded to the outdoor circuits. The required amountdepends on the minimum ambient temperature.Maximum allowed glycol content in the water thatcools the engine jacket is 20% without de-rating. Ifthis is not enough to prevent freezing, a two-circuitsystem or a separate jacket water cooler must be used,or the engine must be de-rated. The de-rating limitfor the LT water is 50% glycol.

Cooling water temperature control

The performance of the engine relies on a stable andcorrectly set charge air receiver temperature, which,in turn, depends on the cooling water temperatures.

The temperatures in the HT and LT cooling watercircuits are controlled by two three-way valves. Thevalves control the flow through the external coolingequipment.

The LT temperature control loop controls the cool-ing water temperature at the inlet to the LT charge aircooler according to a load-dependent set-point curveprovided by the engine control system. The defaultset point range is 36 - 43°C.

The HT temperature control loop controls the HTwater temperature at the outlet from the engine. Thedefault set point is 85°C in one-circuit systems and91°C in two-circuit systems.

Pre-heating

For pre-heating the engine block before start, there isa preheating unit in the EAM module. The unit heatsthe HT water to the required temperature before en-gine start. In cold climates, there may also be a LT-water preheating unit.

Expansion vessel(s)

Volume changes due to changes in water temperatureare compensated by one or two expansion vessels –two vessels in two-circuit systems and one-circuitsystems with jacket cooler. The expansion vesselsalso serve as continuous air venting points.

In two-circuit systems and one-circuit systems withjacket cooler, a pressure increasing pump is requiredif a static pressure of 0.7 bar cannot be obtained be-fore the HT cooling water pump by an elevated loca-tion of the HT expansion vessel. The required staticpressure for the LT pump is 0.3 bar.

Maintenance water tank(s)

One or more maintenance water tanks are recom-mended for emptying and filling the cooling watercircuits during maintenance. In systems where glycolis added only to the LT water, two tanks are needed,one for water and one for glycol mixed water.

3.6.2 Radiators

General

In radiators, fans draw air through a tube bundlewhere the cooling water flows in one or two closedcircuits.

Radiators must be installed outdoors with a suffi-ciently large space around. The primary design pa-rameters are the heat load and the ambient condi-tions. In addition, possible noise emission limitations,corrosive environment, high site altitude or glycolcontent of the cooling water can have a significantimpact on the radiator size and design.

Radiator design

The recommended radiator type is the horizontaltype with induced draft and direct-driven fans.

The standard radiators delivered by Wärtsilä are ofone or two circuit type. The two circuit radiators haveone LT and one HT circuit in the same body but withindependent and separated heat transfer areas. Theradiators have copper tubes equipped with aluminiumfins. In maritime climates with salt-laden air, and inacid polluted areas, corrosion protection of the fins isrequired.

Figure 41. Air flow through a radiator (horizontalinduced draft, 2 circuit type)




Sizing radiator systems

The size of the radiators and the number of radiatorsper engine depend on the ambient conditions andrequired heat transfer.

The radiators are sized for a certain approach tem-perature (temperature difference) between ambientair and water. The ambient air temperature to be usedfor the LT circuit is the maximum ambient tempera-ture, but no higher than the temperature at which de-rating starts. The temperature to be used for sizingHT radiator sections in two-circuit systems is themaximum ambient temperature.

The heat transfer area must be increased if glycol isused in the cooling water.

Radiator arrangements

If multiple radiators are installed, it is recommendedto group them tightly in order to minimize recircula-tion of hot air between the radiators. The radiatorsshould be installed at such a height that the verticalair inlet area equals or exceeds the radiator footprintarea, but, in any case, no lower than 2 m aboveground. They can also be installed on the roof of thepower house.

Noise emission considerations

The noise from the radiator field depends on theamount of radiators and radiator type. Emissions canbe lowered by selecting a lower rotation speed, andpossibly a smaller fan diameter. Both measures willhave a negative effect on the air flow through the fan,which must be compensated with larger heat transferarea and/or more fans.

Standard radiators:

The sound power levels presented in Table 11 belowcorrespond to A-weighted sound pressure levels of61 dB per radiator at 40 meters distance.

Engine Qty / Eng. Fans / Rad. Lw,A [dB] / radiator9L34SG 1 7 10516V34SG 2 5 10320V34SG 2 6 104

Table 11 Typical sound power level per standardradiator

Low noise radiators:

The sound power levels presented in Table 12 belowcorrespond to A-weighted sound pressure levels of56 dB per radiator at 40 meters distance

Engine Qty / Eng. Fans / Rad. Lw,A [dB] / radiator9L34SG 2 4 9716V34SG 2 6 9920V34SG 3 5 98

Table 12 Typical sound power level per low-noiseradiator

The values are indicative. Actual design will be ad-justed to suit project specific conditions.

Using frequency converters

By controlling the fan operation using variable fre-quency converters, a considerable reduction of aver-age noise level and power consumption can be ob-tained when the ambient temperature and coolingrequirements so allow. The frequency converters aresized for the current required by the load, and re-quired spare capacity (about 5 – 10%).

3.6.3 Central coolers

General

In a central cooler, the engine cooling water is cooledby a secondary cooling circuit, which may be raw wa-ter or water cooled in cooling towers. Cooling towersare needed if raw water of suitable quality is not avail-able, or if it is not permissible to discharge heatedwater. Cooling towers are not recommended if theambient temperature may fall below 5oC.

Central cooler design

A central cooler is a plate type heat exchanger, whichcan be installed either inside the power house or out-doors. In one-circuit systems, only the LT circuit iscooled in the central cooler. In two-circuit systems,the HT and LT circuits can either have separate cool-ers, or they can be joined in the cooler and divided totwo circuits after the cooler.

If raw water is used in the secondary cooling circuit,the cooler will be exposed to fouling. Fouling can beavoided by keeping the water temperature low and byusing softened or treated water. If fouling cannot beavoided, heat exchangers which can be cleanedshould be used.




Cooling towers

The cooling effect of a cooling tower is based 95% on the evaporation of water. The heated water from the secondary circuit of a central cooler is lead to the top of the cooling tower and injected by nozzles. The water is cooled by the upward air flow, and then pumped back to the central cooler.

The water losses in a cooling tower are mainly caused by evaporation and bleed off. Bleed off is necessary to prevent the build up of impurities and high salt concentration. When designing cooling towers, care should be taken to allow for replenishment of fresh water.

Cooling towers must be installed outdoors with a sufficiently large space around.

Raw water systems

If raw water from sea, river or lake of suitable quality is available close enough to the power plant, it can be used in the secondary circuit of the central cooler. The water has to be filtered and cleaned before use.

Raw water intake and discharge systems should be designed to avoid blockage during all operating con-ditions, reduce biological growth in the cooling sys-tem and in accordance with local rules and regula-tions for water usage and discharge.

3.6.4 Maintenance water tank

General

The maintenance water tank is used for retrieving and storing the cooling system water while the engine is emptied for maintenance work. Clean water and chemicals can be added in the tank and mixed by cir-culating the tank content. A pump is needed for emp-tying and filling the cooling water circuits.

Pump

Hose for chemical dosing

Figure 42. Maintenance water tank

Tank design

The standard maintenance water tank unit delivered by Wärtsilä is a tank with an electric pump. The tank has connections for filling fresh water, emptying and filling the cooling water system, a drain valve, and a vent/overflow pipe.

Sizing maintenance water tanks

The maintenance water tank must be sized to store at least the entire water volume in the HT and LT cool-ing water systems of one engine, including the engine itself, the external piping systems, the pre-heater, the expansion vessels, and the radiators. If the tank will be equipped with a secondary containment for leak-age collection, the containment should be sized to hold the total volume of the tank.

The recommended number of tanks is one tank for 1 to 3 engines, and two tanks for 4 to 10 engines.

3.7 Intake air system


General

The design of the intake air system depends on the ambient temperature, altitude, particle content in the ambient air, and noise level allowed outside the plant. Possible extreme conditions, such as sand storms, snow storms, and heavy rain must also be considered.




Combustion air to the engine is generally taken fromoutdoors through an intake air filter. Air filtration isrequired to protect the turbochargers and to removeparticles in the air that may cause deposit formationsor damage the engine.

When measuring the concentration of dust andchemicals in the air, the worst scenario should betaken into account. A detailed investigation of the airfiltration must be done in areas where the air includescaustic, corrosive or toxic components.

Air filtration requirements

The highest permissible dust concentration at theturbocharger inlet after filtration is 3 mg/m3, and thefilter should be able to separate 70% of particlesabove 5 m.

Other air quality requirements

Component Maximum value

Sulphur Dioxide (SO2) 0.43 vol-ppmHydrogen Sulphide (H2S) 0.25 vol-ppmChlorides (Cl-) 1.16 mass-ppmAmmonia (NH3) 0.125 vol-ppm

Table 13. Maximum content of chemicals

Temperature requirements

While too high an inlet air temperature will cause anexcessive thermal load on the engine and requires theengine to be de-rated, cold suction air with a highdensity will cause high firing pressures.

The following graph illustrates minimum continuousintake air temperature as a function of the load.Temporary operation below the minimum tempera-ture is possible.

Figure 43. Minimum continuous air temperaturebefore the turbocharger at differentloads

By preheating the LT water, the engine can be startedat combustion air temperatures below 5oC. An LTpre-heater can be included in the EAM module.

Other solutions for starting as well as operating theengine at low ambient air temperatures are:

Taking the intake air from the engine hall

Heating the intake air, for instance, with electricalcoils or by using heat recovered from the enginecooling circuits.

Air humidity

At high ambient air humidity, the high pressure in thecharge air system (about 3.5 bar(a) at 100 % load)can cause the airborne humidity to condensate atnormal charge air temperatures. In these cases, thecharge air temperature should be raised in order toavoid corrosion of the charge air cooler and intakevalves. See the dew point temperature curve in Figure44. De-rating of the engine may be necessary due tothe increased temperature.

Figure 44. Dew point temperature curve at 3.5bar(a)

Pressures and flows

Maximum allowed pressure drop in the intake air sys-tem up to the turbochargers, including pipes, filtersand silencers, is 2000 Pa. The system should prefera-bly be designed to not exceed half the limit at fullload. The air flow depends on the air temperature andthe altitude.




Noise

The charge air sound pressure level at the turbo-charger inlet is typically 120 dB(A) and very high fre-quency distributed. To dampen the noise, charge airsilencers should be installed.

Figure 45. Typical combustion air system

3.7.2 Intake air filters

Filter types

The following filter types are most commonly used:

Dry type filters. These filters are static filters withfilter elements which must be regularly replaced.

Oil wetted filters. The oil wetted filters have amoving screen which is washed in an oil bath atthe bottom of the filter.

Jet pulse filter.

Figure 46. Dry type charge air filter

Figure 47. Cutaway of an oil wetted filter

In most cases, dry type filters (EN 779 filter class G4)are suitable. Oil wetted filters are suitable in areaswith high dust load and coarse particles. In thesecases, the oil wetted filter (EN 779 class G2/G3) is tobe combined with a secondary dry filter (EN 779class F5).

In desert conditions, jet pulse filters or sand separatorpre-filters are recommended.




Lovers and hoods

The air intakes must be protected from heavy rain,snow, insects, etc. The standard intake air filters usedby Wärtsilä include a vertical weather louver (Figure46) which removes most water droplets. In heavy rainareas, a rain hood must be used.

Figure 48. Rain hood for intake air filters (example)

Ice prevention

Ice on the intake air filter can result in a very highpressure drop in the charge air system and trip theengine. Ice may be formed if the air temperaturedrops below the dew point and the surface tempera-ture is at or below the freezing point. The criticaltemperature range is -5ºC to +3ºC. Ice formation canbe avoided with heating arrangements.

Instrumentation

The intake air filter should be equipped with a differ-ential pressure alarm.

3.8 Exhaust gas system


General

The main function of the exhaust gas system is tolead exhaust gases safely out from the power plant.Each engine must have its own exhaust gas system.The main components besides the ducts are an ex-haust gas silencer, an exhaust gas stack, and safetyequipment, such as an exhaust gas ventilation fan andrupture disks.

Design pressures

Allowed maximum back pressure at the outlet of theturbochargers is 5000 Pa (0.05 bar). However, thesystem components shall be capable of toleratinghigher pressure due to the risk for exhaust gas defla-grations. Thus, the design pressure for the exhaustgas system is minimum 0.1 bar(g), and the systemmust be able to sustain 0.5 bar(g) peak pressure for atleast one second.

Due to gas velocities created by a possible gas defla-gration, under-pressure (partial vacuum) may occur.Therefore, the stack must be sized to sustain an un-der pressure of 0.3 bar without collapse.

Safety arrangements

In case of a malfunction or incomplete combustion,the exhaust gas may contain unburned components,which may ignite upon contact with hot surfaces. Theresulting deflagration may cause damage to the ex-haust gas system. Unburned gas in the exhaust gasesmay also damage a catalytic converter, if installed.

The following protection methods are required:

Minimizing the risk of gas build-up by designingthe pipe system with only upward slopes

Ventilating the exhaust gas system to dischargeany unburned gas after the engine has stopped

Relieving the pressure at a possible deflagrationwith rupture disks.

The exhaust gas ventilation system consists of a cen-trifugal fan, a flow switch and a butterfly valve. Thevalve is opened and the fan started after each enginestop. The flow switch monitors the fan operation andactivates an alarm in case of a malfunction. The fan isdesigned to change the volume in the exhaust gassystem at least three times during a ventilation run.




Figure 49. Typical exhaust gas system

3.8.2 Exhaust gas silencersThe exhaust gas silencers must be effectively purgedduring the exhaust gas system ventilation. Silencers ofabsorption, reactive or combination type can be used.The required attenuation of the silencers is deter-mined by the environmental noise requirements.

The standard exhaust gas silencers delivered by Wärt-silä are of combination type, giving a noise attenua-tion of 35 dBA or 45 dBA. The silencers are providedwith a water drain. A soot collector and a spark arres-tor are optional.

The exhaust gas silencers can be mounted eitherhorizontally or vertically, inside or outside the build-ing. Generally, they are installed in the stack.

3.8.3 Rupture disks

Design

Rupture disks are the only approved pressure reliefdevices. The rupture disks shall be designed to openat an excess pressure of 0.5 0.05 bar at the operat-ing temperature. Spring loaded devices are not al-lowed to be used.

The diameter of the rupture disks should be at leastthe same as the exhaust gas pipe diameter. The disksmust be installed directly in the main duct.

Location of rupture disks

On a straight pipe, the rupture disks shall be installedat a distance of maximum ten pipe diameters apart.The first rupture disk is to be placed within ten pipediameters after the turbocharger and so arranged thatmaterial from the rupture disk will not fall into theturbocharger. The rupture disks must not be exposedto dynamic pressure pulses.

The inlet and outlet of the silencer shall be equippedwith rupture disks, but the rupture disk in the inletmay be omitted if the distance from the previous diskis less than 5 times the pipe diameter. If the silencer isthe last component in the piping before the stack, theoutlet needs not be protected with a rupture disk.

A possible exhaust gas boiler can be equipped withintegrated rupture disks, or the rupture disks can belocated in the exhaust gas duct close to the inlet andoutlet pipes of the boiler. Catalytic converters in-stalled in the exhaust gas system, should be fittedwith rupture disks in a similar way.

Outlet ducts

The outlets of the rupture disks are to be ducted out-doors with pipes of the same size as the rupturedisks. The length of the duct should be minimizedand not longer than six meters. The duct is to becovered with a lightweight noise insulation materialand to be weather protected. The outlets should beplaced where no personnel are present during plantoperation. A 5 m wide and 10 m long zone continuedin the direction of the outlet duct must be marked asa hazardous, possibly lethal zone.




3.9 Emission controlsystems

3.9.1 GeneralIf required by local environmental regulations secon-dary emission control equipment can be installed.SCR is rarely used today for gas engine applications;only in bigger plants or/and if ambient air is de-graded, the SCR unit is typically demanded.

Emissions of Carbon Monoxide (CO), Formaldehyde(CH2O) and Volatile Organic Compounds (VOC) aretypically controlled using an oxidation catalyst. Therecommended secondary method for reducing theNOX emissions of a lean burn gas engine is SelectiveCatalytic Reduction (SCR).

3.9.2 Oxidation catalyst

Functional description

Using the oxidation catalyst, carbon monoxide (CO),formaldehyde (CH2O), and volatile organic com-pounds (VOC) are oxidized to carbon dioxide andwater according to the following simplified formulas:

CO + O2 CO2

CmHn + O2 CO2 + H2OCmHnO + O2 CO2 + H2O

The reactions take place at the surface of the catalyst,the function of which is to reduce the activation en-ergy required for the oxidization reaction. No re-agents are needed, that is, no consumables are re-quired, and no by-products are formed.

The catalyst is optimized by choosing the correct ac-tive material, substrate and wash coat. The activecatalyst is typically a noble metal such as platinum(Pt), or palladium (Pd), or a combination of them.

Performance

The performance of the catalyst depends on the sizeand composition of the catalyst. The performancedemand is set by the project-specific requirements.

Compound Unit Standard ULECO ppm-v, 15

% O2, dry90 15

CH2O (for-maldehyde)

ppm-v, 15% O2, dry

14 1 … 5

VOC (vola-tile organiccompo-nents)

ppm-v, 15% O2, dry,as CH4

Low reduc-tion

20 … 40Dependsstrongly onnatural gascomposi-tion

Table 14. Typical emission levels achieved for gasengines with oxidation catalyst

3.9.3 Selective catalytic reduction(SCR)

Functional description

In the selective catalytic reduction (SCR) method,NOx reacts with ammonia (NH3) forming water andatmospheric nitrogen according to the following sim-plified formula:

NOx + NH3 N2 + H2O

The reaction takes place on the surface of a catalyst inthe presence of a reducing agent, which is injectedinto the flue gas before the catalyst. For the reducingagent, aqueous ammonia, aqueous urea or urea granu-lates can be used. When urea is used, it decomposesto ammonia (NH3) in the flue gas.

Due to the hazardous and explosive nature of am-monia, urea solution often is preferred.

Performance

A SCR system is often designed for 90 % NOX emis-sion reduction, i.e. the level of less than 10 ppm, dry,15 % O2 is reachable in stable running conditions.

Main components

The catalysts are installed in a reactor designed ac-cording to the project requirements. The SCR catalysttypically consists of honeycomb blocks of ceramicmaterial arranged in layers. If the emission controlsystem includes oxidation catalysts, the oxidationcatalyst elements are typically located in the SCR re-actor, downstream of the SCR elements.

The reagent solution is sprayed into the flue gas witha dosing unit using compressed air to achieve agood atomization.




A mixing duct ensures that the reducing agent iscompletely vaporized and mixed with the exhaust gas.In the first section of the duct, the reducing agent willvaporize, and if urea is used it will decompose to

ammonia (NH3). The second section is equipped withstatic mixers to ensure a homogeneous distribution ofNH3.

Figure 50. Typical SCR emission control system setup for gas engine applications

Consumables

The consumption of the reducing agentdepends on the NOX emission level fromthe engine and the target level. Operatingconditions and the choice of catalyst mate-rial may also influence the consumption ofthe reducing agent. When using SCR, it isgenerally more economic to tune the enginefor optimal heat rate instead of low NOX

emission.

An indicative value for reducing agent con-sumption for one 20V34SG engine is 15 -25 kg/h (25 % ammonia water or 40 % ureawater). The ammonia or urea must be of atleast technical grade.

Typically, the useful lifetime of the SCRcatalyst elements is several years. The possi-bility to replace individual catalyst layersenables the development of an optimal cata-lyst exchange strategy.

Storage of reducing agents

For gas engine applications ammonia orurea is typically brought to site as a readymade water solution. The tank material forurea solutions is often stainless steel tankswhile black steel tanks (DIN – ST37-2 orbetter) can be used for aqueous ammoniasolutions. If there is a risk for freezing orprecipitation of urea solution (depends onthe concentration and the temperature), thetanks must be insulated and either heated orequipped with a circulation system. Atten-tion must be paid to the safety issues relatedto the handling of ammonia.




The storage space is typically sized for twoweeks’ consumption. In addition, the size ofone truck load must be taken into account.

Control and instrumentation

There may be one control unit per engine,or a unit can control the emissions fromseveral engines. The local control panels canbe located e.g. in the engine hall or in thecontrol room. The control unit calculatesthe set point to the reducing agent dosingunit based on the engine load and the NOX

measurements, if analyzer(s) are provided inthe system.

3.9.4 Integration in exhaustgas system

Placement

The SCR and the oxidation catalyst shouldbe located before a possible heat recoverysystem and before any exhaust gas silencercontaining wool. The oxidation catalystmust not be placed between the reducingagent injection point and the SCR reactor.

Space requirements

The required space depends on the emissionreduction requirements and the design ofthe emission control system. The compactoxidation catalysts for low emission reduc-tion demands can be integrated in the ex-haust gas duct with negligible impact on theplant layout while the big combined SCRoxidation catalyst reactors might have alength up to 6 meters or even more.

Special attention should be put on havingsufficient space for the mixing duct in case aSCR system is required. In systems wherethe oxidation catalyst is integrated into theSCR, the catalyst elements are placed as anadditional layer in the reactor.

Temperatures and pressures

The SCR and oxidation catalyst have a tem-perature window for optimal operation. Thenormal operating temperature of the 34SGengine fits well with the typical operatingwindows. The efficiency of the oxidationcatalyst increases with higher exhaust gastemperature.

The design pressure for the catalysts isminimum 0.1 bar(g), but they shall be capa-ble of tolerating 0.5 bar(g) peak pressure.

Typically, the emission control system cre-ates a back pressure of maximum 2000 to3000 Pa.

3.9.5 Emission testingEmission tests and measurements are anintegral part of the performance testing andthe environmental management of thepower plant. Emission tests for commis-sioning and reporting purposes are typicallyperformed by impartial emission testingconsultants. The source testing should beperformed using methods that are provenfor gas engine applications. The commonparameters for the emission tests of gasfired units are NOX, CO and O2. In somecases hydrocarbons are to be tested accord-ing to the national requirements.

Sampling ports and access to the samplinglocation must be part of the of the exhaustgas system design.

If specifically required by authorities, a con-tinuous emission monitoring system(CEMS) can be installed. For gas engineplants, the monitored parameters are typi-cally NOX, CO and O2. Other componentsare either not present in relevant concentra-tions in the exhaust gas, or they cannot bemonitored due to the lack of proven moni-toring methods.




Typical legislative requirements

In Table 15 typical requirements (statusJanuary 2008) are depicted as examples forgas fired engines in different countries andby International Finance Corporation (IFC,a part of the World Bank Group). The IFCGuidelines are more and more commonlyapplied for power generation projects, inwhich international financing or exportcredits is given.

Note that the limits below are given on thefederal level. Local requirements, ambientair quality or other project-specific issuesmight call for more stringent requirements.Note also that the values are converted tothe same units and reference oxygen condi-tions for comparison purposes.

No secondary controlNo secondary controlOxidation catalystOxidation catalystOxidation catalystWärtsilä solution

-

14

-

-

169

Japan, 1991

a) Efficiency correction based on the reference efficiency of 30 % Limit = efficiency % / 30 x 1050b) Efficiency correction based on the reference efficiency of 37 % (no cogeneration) or 63 % (with

cogeneration) Limit = efficiency % / reference efficiency % x base limitc) Normalized to 0 °C and 101.3 kPad) International Finance Institute, General EHS Guidelines, plants 3 – 50 MWth

Notes

-8 (b--SO2 emissions, ppm

-49 (b--PM emissions, mg/m3 (c

--1050 as THC (as C1) (a17 for formaldehydeHC emissions, ppm

-195 (b15090CO emissions, ppm

9791 (b10091NOX emissions, ppm

IFC, 2007 (dTurkey, 2004Denmark, 1998Germany,TA-Luft 2002

No secondary controlNo secondary controlOxidation catalystOxidation catalystOxidation catalystWärtsilä solution

-

14

-

-

169

Japan, 1991

a) Efficiency correction based on the reference efficiency of 30 % Limit = efficiency % / 30 x 1050b) Efficiency correction based on the reference efficiency of 37 % (no cogeneration) or 63 % (with

cogeneration) Limit = efficiency % / reference efficiency % x base limitc) Normalized to 0 °C and 101.3 kPad) International Finance Institute, General EHS Guidelines, plants 3 – 50 MWth

Notes

-8 (b--SO2 emissions, ppm

-49 (b--PM emissions, mg/m3 (c

--1050 as THC (as C1) (a17 for formaldehydeHC emissions, ppm

-195 (b15090CO emissions, ppm

9791 (b10091NOX emissions, ppm

IFC, 2007 (dTurkey, 2004Denmark, 1998Germany,TA-Luft 2002

Table 15 Emission limits for spark-ignited lean-burn gas engines (dry @ 15 % O2)

Wärtsilä 34SG Power Plant Product Guide 4. HEAT RECOVERY SYSTEM



4. HEAT RECOVERY SYSTEM

4.1 General

Heat recovery systems utilize the heat generated bythe engine which would otherwise be wasted. Heatcan be recovered from the exhaust gases and fromthe engine cooling system (charge air, lubricating oil,and jacket cooling). The following table gives a roughindication of the temperatures of the engine circuitsand the available energy amounts.

Energy source Temperature(approx.)

Portion offuel energy(approx.)

Exhaust gas ~ 400 °C 32 -33 %Jacket water ~ 85 °C 5.8 %HT charge air ~ 90 °C 9.0 %Lubricating oil ~ 60 °C 4.7 %LT charge air ~ 40 °C 1.8 %Generator cooling ~ 35 °C 1.4 %

Table 16. Different energy sources

The heat is normally used to produce hot water,steam or thermal oil. The amount of recovered heatdepends on the ambient temperature and the tem-perature of the heated media. The following tableshows typical values for steam and hot water whenutilizing heat from exhaust gases, lubricating oil andcooling water 20V34SG engine.

Heated media Generatorpower

Recoverableheat

Planteffi-ciency

Steam 8 bar(a) 8730 kW 3000 kW 59 %Hot water 75 –105 °C

8730 kW 6400 kW 76 %

Hot water 45 -75 °C

8730 kW 7800 kW 83 %

Hot water 45 -75 °C(no heat recov-ery from ex-haust gases)

8730 kW 3700 kW 63 %

Table 17. Typical values for different types of heatcarrying media. Except for the last rowthe values apply when heat is recoveredfrom both exhaust gases and coolingwater.

4.2 Heat recovery from ex-haust gases

4.2.1 System descriptionA typical exhaust gas heat recovery system for steamproduction consists of an exhaust gas boiler, a steamdrum, one or more pumps and one or more watertanks. On the consumption side, there is a steamheader and one or more heat exchangers.

The exhaust gas steam boiler contains evaporatorpipes, where the feed water is heated to its saturationpoint. The mixture of saturated water and steam islead to the steam drum, where steam is separatedfrom water. The steam drum is typically integrated inthe boiler. The boilers should be equipped with a by-pass line to avoid boiler overheating on the waterside.

The steam can be further heated in a super-heater, orconducted to the consumers. The condensate fromthe consumers is circulated back to the boiler via acondensate water tank.

The feed water tank, the feed water pumps, and thecondensate return tank are usually common for thewhole plant. The steam boilers are engine specific.

Figure 51. A simplified example of steam produc-tion in an exhaust gas boiler

In order to intensify the heat transfer and improvethe efficiency, the boiler can be equipped with aneconomiser for pre-heating the water.




If the steam drum is located higher than the boiler,no circulation pump is needed (natural circulationboiler). Otherwise, there must be a circulation pump(forced circulation boiler).

To avoid corrosion in the pipes, steam systems mustbe equipped with deaeration, and the feed water tem-perature should be at least 105oC.

In district heating and warm water applications, thereis only a hot water boiler with a by-pass line and amain water pump. Alternatively, water can be heatedin a condenser.

The design pressure on the exhaust gas side is mini-mum 0.1 bar(g), but the system must be capable oftolerating a peak pressure of 0.5 bar(g).


4.2.2 Heat recovery boilerHeat recovery boilers are heat exchangers, where theexhaust gas transfers some of its thermal energy tothe heat transfer media, most commonly water. Typi-cally full capacity boilers are used to maximize theheat recovery from the exhaust gases.

The boilers can be divided into two groups:

Smoke tube boilers, where the exhaust gas flowsthrough pipes surrounded by water

Water tube boilers, where the exhaust gas flowsthrough finned pipes in which water circulates.

The choice of boiler type depends on many factors,e.g. the heat recovery application that is being used.

The energy recovered depends directly on theamount of exhaust gas and the temperature dropacross the boiler. In steam production, the tempera-ture is limited by the steam saturation temperature.The pinch point (minimum temperature differencebetween heating and heated media) is the differencebetween the saturation temperature and the exhaustgas temperature at the outlet of the evaporation sec-tion.

4.2.3 Arrangements to decreaseboiler fouling

A common phenomenon with exhaust gas boilers isboiler fouling. It is caused by soot, unburned hydro-carbons, lubrication oil residues, etc. which comeswith the exhaust gases and forms layers on the heatexchanger surfaces. This results in reduced and in-efficient heat transfer. The fouling rate depends onthe temperature. The most critical area is on heattransfer surfaces, where the water side temperature is50 - 80°C.

Methods to decrease the fouling rate and keep theboiler clean involve:

Avoiding water temperatures between 50 and 80°C

Using soot blowing equipment (for instance, wa-ter spray, pressurized air or steam blowers)

Using Oxi-Catalyst (HC)

Off-line cleaning is needed periodically, typically twoto four times a year.

4.2.4 Safety arrangementsThe heat recovery boiler should be protected withrupture disks installed in the exhaust gas duct beforeand after the boiler. In some cases, there might beadditional explosion vents in the boiler casing.

The heat recovery boiler should be designed accord-ing to applicable rules and regulations.

4.3 Heat recovery fromcooling water and lubeoil

4.3.1 GeneralHeat for hot water production can be recovered fromthe HT cooling water and from the lube oil.




For hot water applications with heat recovery fromboth lube oil and HT water, a pre-designed, pre-tested, and skid mounted heat recovery module isavailable, the CHP module (CHP = combined heatand power). The CHP module is designed for 16 barhot water heating systems. It is used along with theEAM module designed for CHP applications.

When heat recovery systems are used for cooling theHT water, there could be a back-up HT cooler forcooling the engine in cases when it is impossible tolead the heat into the heat recovery system. A back-up HT cooler can be included in the CHP module.

4.3.2 Standard modules for hot wa-ter production

The EAM and CHP modules (Figure 53) for hot wa-ter production contain the following equipment:

Two heat exchangers for heat recovery from HTwater and lube oil.

An optional HT back-up cooler cooled with LTcooling water from the engine.

Two parallel hot water circulating pumps withfrequency converter control, one working, onestand-by for internal circulation

Six 3-way temperature control valves (four inEAM, two in CHP)

Flow meter (optional)

Figure 52. Typical arrangement of combined lube oil, cooling water and exhaust gas heat recovery using theCHP module




Figure 53. EAM and CHP modules for hot water applications

Wärtsilä 34SG Power Plant Product Guide 5. PIPING SYSTEMS



5. PIPING SYSTEMS

5.1 Design principles

5.1.1 General principlesThe following general principles should be consid-ered in the piping system design:

The pipes must be designed for the maximum andminimum pressures and temperatures they willexperience during operation or upset conditions.

The risk for pump cavitation – the formation ofbubbles at the suction side of the pump, whichreduces pump efficiency and harms the pump –must be minimized. The suction pipes to pumpsshould be as short as possible and have suffi-ciently large diameters.

The pipes must be fitted without tension. Flexiblepipe connections must be used between pipes andunits where vibrations or thermal expansion mayoccur.

Each pipe must have sufficient pipe supports.Weak supports may cause operational problems ordamages.

All pipes must have provisions for drainage andventing.

Pockets should be avoided, or, if they cannot beavoided, be equipped with drain plugs or air vents.

Drain pipes must be continuously sloping, andvent pipes continuously rising.

All pipe work must follow local rules and regula-tions.

5.1.2 Pressure and temperature rat-ings

Design pressures

For estimating the design pressure, the following ruleof thumb can be used:

design pressure = 1.1 x max. working pressure

The maximum working pressure in a circuit is equalto the setting of the safety valves in the system.

Nominal pressures

The nominal pressure of a pipe should be equal to orhigher than the design pressure of the pipe.

According to European standards, the pressure rat-ings of piping systems are given as PN numbers(Pressure Nominale), for instance, PN6, PN10,PN16, where the number indicates the nominal pres-sure in bar up to a given maximum temperature.

The nominal pressures of the pipe connections onthe engine and the standard modules are found in thesection below. The nominal pressure of a connectionmay be higher than the nominal pressure required forthe pipe.

Test pressures

Typical test pressure according to the applicable ENstandards is 1.43 times the design pressure The testpressure to be used at actual operating conditionsmust always be checked with the respective stan-dards.

5.1.3 Pipe materialsFor guidance, Table 19 lists the pipe material nor-mally used in different systems in Wärtsilä designedplants.




Nominal pressureSystem Max work-ing pres-sure (g)

Designpressure

(g)

Testpressure

(g) 1)

Max work-ing temp.

Designtemp.

DIN/EN

Fuel gas systembefore gas regulat-ing unit

6/16 bar 8/20 bar Case bycase Ambient 50 C

PN16

Fuel gas systemafter gas regulat-ing unit

4 bar 6 bar 10 bar Ambient 50 CPN16

Starting air system 30 bar 33 bar 48 bar 75 C 75 CPN40

Instrument air sys-tem 7 bar 10 bar 15 bar Ambient 75 C

PN16

Lube oil system 6 bar 10 bar 12 bar 90 C 120 CPN16

Sludge and oilywater systems 6 bar 8 bar 12 bar 90 C 120 C

PN16

Cooling water sys-tem (LT and HT) 5 bar 5.5 bar 8 bar 98 C 120 C

PN16

Intake air system 0 1 bar No Ambient 75 CPN2,5

Exhaust gas sys-tem 0.07 bar 0.5 bar No 450 C 480 C PN2,5

Water supply sys-tem 5 bar 6 bar 9 bar Ambient 40 C

PN16

Fire water system 9 bar 10 bar 15 bar Ambient - PN16

Emission treat-ment systems 0.07 bar 0.5 bar No 450 C 480 C

PN2,5

Table 18. Pressures and temperatures which can be used as guidelines in the piping system design1) = Typical test pressure according to EN 13840-5 1

System Flow media Piping material

Fuel gas system Natural gas or similar AISI 304LLube oil system Lubricating oil St 37.0 (St 35.8)Cooling water system Cooling water St 37.0 (St 35.8)Water supply system Fresh water

Treated waterSt 37.0 (St 35.8), St 37.0 Zn, Cu

AISI 304LStarting air system Compressed air St 37.0Heat recovery system Steam

Fresh waterTreated water

St 35.8

District heating system Fresh water St 37.0Exhaust gas system Exhaust gas St 37.0/ CortenCharge air system Air St 37.0

Table 19. Standard pipe material used by Wärtsilä




5.1.4 Pipe dimensions

General

The pipes used in the Wärtsilä designed engines,standard modules and standard units follow applica-ble parts of the DIN/EN standards. To ensure com-patibility, the Wärtsilä engines, standard modules andunits are delivered with companion flanges, whichcan be welded to the mating pipes during installation.

The nominal pipe diameter is given as DN (DiametreNominale). The nominal values do not generally co-incide with the actual pipe diameters in mm. See theconversion table in appendix B.

Pipe diameters

When sizing pipes, the required flow, the velocity,and the length of the pipe must be considered. Thehigher the velocity in a pipe, the higher is the pres-sure drop per unit length.

Wall thickness

When deciding the wall thickness, the pipe material,the type of media in the pipe, the pressure and tem-perature of the transported media, and the outsidetemperature must be considered.

5.1.5 Flexible pipes andpipe supports

Flexible pipe connections

To compensate for movements due to thermal ex-pansion, and to prevent the engine vibrations frombeing transferred to the pipe system, pipes must beconnected with the engine by means of flexible bel-lows – rubber or steel bellows – or hoses.

Figure 54. Flexible bellow

Bellows and hoses may also be required at other loca-tions.

Pipe supports

The recommended distances between pipe supportsdepend on the size of the pipe, and the weight of thesubstance, liquid or gas, transported in the pipe.

Figure 55. Pipe supports

If the temperature of the pipes may vary, the supportmust allow for thermal movement. If needed, heatexpansion must be enabled with bends, bellows,flexible hoses, or loops.

Figure 56. Pipe loop for enabling heat expansion

5.1.6 Trace heatingTo avoid freezing and ensure pumpability in coldclimates, the following pipes may need to beequipped with trace heating:

Oily water pipes

Urea solution pipes (if urea solution is used)

Lubricating oil pipes.

Most commonly, electrical heating is used, but alsosteam, thermal oil or hot water can be used providedthat it is continuously available.

The trace heating system is sized based on the esti-mated heat losses in the pipes. To minimize heatlosses, trace heated pipes should be insulated. Theheating must be so arranged that it can be shut off.

Electrical trace heating cables can be of self-regulating type or thermostat regulated.




Figure 57. Trace heated and insulated pipe

5.1.7 InsulationGenerally, the following pipes should be insulated:

All trace heated pipes

All pipes included in heat recovery system

The indoor portions of the exhaust gas pipes (andoutdoors up to SCR if SCR used).

In addition, the risks of fire and personnel injury dueto hot surfaces must be considered. All pipes with asurface temperature over 60 °C should be insulated ifthey are in the reach of the operating personnel.

Suitable insulation material is mineral wool. To pro-tect the insulation, it should be covered with alumin-ium sheets. The sheets should be at least 1 mm thick.

5.1.8 Pipe instrumentationThermometers should be installed wherever needed,for instance, before and after heat exchangers. Byusing thermo wells (metal housings), replacement ofdefect thermometers is possible without draining thesystem.

Pressure gauges can, for instance, be installed on thesuction and/or discharge sides of pumps.

Local indication is sufficient if the instrument is ac-cessible for reading and no central supervision isneeded.

System specific notes

5.1.9 Fuel gas pipes

General

The fuel gas system includes the following pipes:

The common gas supply pipe from the gas grid tothe gas manifold

The engine specific gas lines from the gas mani-fold to the gas regulating units

The pipes from the gas regulating units to the en-gines

Vent pipes, at least two pipes from each gas regu-lating unit and one from each engine.

Design notes

In fuel gas pipes, the amount of welded joints shouldbe minimized. Bent pipes and tee connections shouldbe used when possible. Flanged connections shouldbe avoided.

Fuel gas supply pipes

The main fuel gas supply pipe should be sized for agas velocity of about 20 m/s. The required pipe sizedepends on the pressure and flow requirements.

The gas flow in the engine-specific supply pipes de-pends on the engine output, the LHV (lower heatingvalue) of the gas and the heat rate of the engine.

Table 20 shows data for determining the pipe size inrelation to gas flow and pressure.

Gas vent pipes

For safety reasons, and to prevent any back pressurerelease, the gas vent pipes must be individually routedout into open air. The pipes must be of the same sizeas the vent pipe connections. The outlets must beprotected from becoming blocked.




Pipe size DN80 DN100 DN125 DN150 DN200 DN250 DN300Pressure Flow rate

Bar(g) Nm3/h Nm3/h Nm3/h Nm3/h Nm3/h Nm3/h Nm3/h3.5 1600 2690 4060 5940 9980 15870 22450

4.0 1770 2990 4510 6600 11090 17640 24940

4.5 1950 3290 4970 7260 12200 19400 27440

5.0 2130 3580 5420 7920 13310 21160 29930

5.5 2310 3880 5870 8580 14420 22920 32420

6.0 2480 4180 6320 9240 15530 24690 34920

6.5 2660 4480 6770 9900 16640 26450 37410

7.0 2840 4780 7220 10560 17740 28210 39910

7.5 3010 5080 7670 11220 18850 29980 42400

8.0 3190 5370 8120 11880 19960 31740 44890

8.5 3370 5670 8570 12540 21070 33500 47390

9.0 3540 5970 9020 13200 22180 35270 49880

9.5 3720 6270 9480 13860 23290 37030 52380

10.0 3900 6570 9930 14520 24400 38790 54870

10.5 4080 6860 10380 15180 25510 40560 57360

11.0 4250 7160 10830 15840 26610 42320 59860

11.5 4430 7460 11280 16500 27720 44080 62350

12.0 4610 7760 11730 17160 28830 45840 64840

12.5 4780 8060 12180 17820 29940 47610 67340

13.0 4960 8360 12630 18480 31050 49370 69830

13.5 5140 8650 13080 19140 32160 51130 72330

14.0 5310 8950 13530 19800 33270 52900 74820

14.5 5490 9250 13990 20460 34380 54660 77310

15.0 5670 9550 14440 21120 35480 56420 79810

15.5 5840 9850 14890 21780 36590 58190 82300

16.0 6020 10150 15340 22440 37700 59950 84800

Table 20. Pipe sizes for gas at varying gas flows and pressures. Maximum velocity: 20 m/s.

5.1.10 Lube oil pipesThe piping must be built so that it can be dismantledin suitable parts to make cleaning and pickling possi-ble. Flanged connections and tee connections shouldbe used. All branches should be equipped with flangeconnections.

To keep the pressure drop in the pipes within accept-able limits, the following velocities are recommended:

Suction DeliveryPipe dimen-sion, DN m/s m/s

25 0.3-0.5 0.7-0.932 0.4-0.6 0.8-1.040 0.5-0.7 1.0-1.250 0.6-0.8 1.2-1.465 0.6-0.8 1.3-1.580 0.7-0.9 1.4-1.6

100 0.8-1.0 1.5-1.7125 0.8-1.0 1.5-1.7150 0.8-1.0 1.5-1.7200 0.8-1.0 1.5-1.7250 0.9-1.0 1.5-1.7300 1.0-1.1 1.5-1.7

Table 21. Recommended velocities in lube oilpipes




For determining pipe diameter, the following diagramcan be used:

Figure 58. Diagram for determining lube oil pipedimensions

5.1.11 Compressed air pipesCompressed air pipes include:

Starting air pipes

Instrument air pipes

To prevent possible water condensate from enteringthe engines or collecting onto pockets, the com-pressed air pipes should have a continuous slope ofmin. 1/100 to manual or automatic drain outlets lo-cated at the lowest points. Swan necks (see Figure 59)must be used on all branches to the distributionpipes.

Figure 59. Compressed air pipes

If the instrument air system contains an air dryer, nocondensate will normally form in the piping system.However, for the event of the air dryer being out oforder, the same arrangements with sloping pipes andswan necks should be employed in the instrument airsystem.

If flexible hoses are used in the compressed air sys-tem, there must be a closing valve in front of eachhose to allow shutting off the air flow.

5.1.12 Cooling water pipesThe following table shows recommended velocities,and the figure shows the flow for different pipe sizes.

HT and LT circuits Raw waterPipe di-mension,DN m/s m/s

25 1.5-1.732 1.7-1.940 1.9-2.150 2.1-2.365 2.3-2.580 2.5-2.7

100 2.7-2.9 2.2-2.4125 2.9-3.1 2.3-2.5150 3.0-3.2 2.5-2.7200 3.0-3.2 2.7-2.9250 3.1-3.3 2.9-3.0300 3.2-3.4 3.0-3.1

Table 22. Recommended velocities in cooling wa-ter pipes




Figure 60. Water flow/velocity diagram

The cooling water vent pipes from the engine and theexpansion pipes from the engine auxiliary modulemust be run separately to the expansion vessel(s) andbe continuously rising with a slope of min. 1/100.

Welded connections should be used, but flangedconnections can also be used if the installation, main-tenance, cleaning or pipe material so demand.

5.1.13 Intake air ductsEach engine must have its own intake air ducting.

The permissible pressure drop in the entire intake airsystem, including the intake air filter and the silencers,is max 2000 Pa. The maximum permissible total pres-sure drop in the intake air and the exhaust gas sys-tems together is 7000 Pa.

Design velocities: 20 -30 m/s.

The intake air ducts should be as short and straight aspossible. Any bends shall be made with the largestpossible bending ratio R/D, or at least 1.5.

Figure 61. Bending ratio

Flanged connections should be used.

When using the exhaust gas module, the steel supportfor the intake air ducts is the same as for the exhaustgas system. The intake air ducts in the exhaust gasmodule are connected to the turbochargers withflexible connection pieces.

5.1.14 Exhaust gas ducts

General

To prevent exhaust gases from entering an enginethat is out of service, each engine must have its ownexhaust gas duct system all the way from the engineinto open air via the stack. In the exhaust gas module,the branch pipes from the two turbochargers of theengine are joined to a common exhaust gas pipe.

Any bends shall be made with the largest possiblebending ratio R/D, or at least 1.5.

The design velocity in the common pipe is 20 – 30m/s.

Maximum back pressure

The entire exhaust gas line must be designed as shortand straight as possible to minimize flow restrictions.The limit of the total pressure drop for the exhaustgas system, the maximum back pressure, is 5000 Pa.The maximum permissible total pressure drop in theintake air and the exhaust gas systems together is7000 Pa.

Bellows and pipe supports

Besides the engine being connected to the branchpipes with flexible bellows, bellows may also beneeded before and after the silencer.




The pipes have to be properly supported with fixedsupports and sliding supports that allow the duct tomove in axial direction. The exhaust gas module in-cludes one fixed and one sliding support. Other sup-port locations must be determined case by case.

Figure 62. Examples of fixed and sliding supportsfor exhaust gas ducts

Insulation

The indoor exhaust pipes must be insulated all theway from the turbocharger, and the insulation mustbe protected by metal cladding or similar. At the partclosest to the turbocharger, the insulation and clad-ding should be made as a removable piece to facilitatemaintenance.

There must be no risk for the insulation materialbeing drawn into the turbocharger during opera-tion.

If the plant contains SCR, also the outdoor pipes upto the SCR should be insulated.

Water drainage

To prevent water from entering the engine, the ex-haust gas pipes shall be provided with water drains atthe lowest points. Normally, the system is drainedfrom the silencers.

Exhaust gas stack

Each engine must have its own exhaust gas stack, butin installations with two or more engines, several ex-haust gas ducts may be conducted to a commonmulti-pass chimney or cluster chimney, which gener-ally gives better lift of the emissions.

The stack should be sized for a velocity of about 20 -30 m/s at the end. Higher exhaust gas velocity maycause noise emissions.


In case the inner surface temperature of the stack isbelow 50oC, there is a risk for condensation in thepipes. Insulation may therefore be needed in plantswhere heat is recovered from the exhaust gases.

5.1.15 Miscellaneous

Crankcase vent pipes

The crankcase vent pipe from the engine is con-ducted to the oil mist separator. The pipe must beconnected to the engine with a flexible connection.

The crankcase gases from the oil mist separator mustbe led out to open air. The outlet should be equippedwith a condensate trap (oil trap) so arranged that anyresidual oil flows back to the oil mist separator.

Wärtsilä 34SG Power Plant Product Guide 6. ELECTRICAL SYSTEM



6. ELECTRICAL SYSTEM

6.1 General

6.1.1 System overviewBelow is an overview of the electrical system in atypical Wärtsilä 34SG power plant.

The main components are:

The engine driven medium voltage generators

The medium voltage switchgear for connectingthe generators and the outgoing feeders

Possibly one or more step-up transformers in theswitchyard for raising the generated voltage

A station transformer (step-down transformer) forthe internal power consumption

Low voltage power distribution system compris-ing the main LV switchgear, motor control cen-tres (MCC), distribution boards and panels (in thisguide all called LV switchgear)

DC power supply system

Grounding system

Cables.

Figure 63. Typical electrical system overview




Each engine generator set delivers power through acircuit breaker in the medium voltage switchgear,which distributes the generated power to a nationalgrid, a local grid, and/or directly to local consumers(factory or utility), possibly via a step-up transformer.

The station transformer lowers the generated me-dium voltage power to the voltage level used in thepower plant. The low voltage switchgear distributeselectricity to the plant power consumers. There maybe separate MCC (motor control centre) cabinets orthe motor control may be included in the plant LVswitchgear and in local control cabinets.

Figure 64. Principle diagram of a medium voltagepower plant

6.1.2 Basic system designThe design of the electrical system depends on size ofthe system, the number of connected generators andnumber of transformers.

It may be built up as shown in Figure 64. The me-dium voltage generators are connected to mediumvoltage switchgear. In a big plant with many genera-tors it may be necessary to divide the generators inseveral groups and connect each group to electricallyisolated bus bars in the switchgear. The system set upis dependant on the specific circumstances at theplant and is a design issue to be agreed between sellerand plant owner, taking into account the load flow,full load current and level of fault current. Thepower is evacuated trough one or several feeders ei-ther on the same voltage level or the voltage is raisedto a higher level by means of one or several trans-formers.

The main low voltage 400V switchgear is fed troughone or several station service transformers. Theswitchgears may be divided in several bus bars de-pending on size and logical structure of the system.The latest electrical IEC standards are followed.

Selection of main components and sizing of differentcurrent currying part like bus bars and cables arebased on ambient conditions and system calculations.

6.1.3 Protection relaysThe protection relays used are selected to give a fullcoverage and include all necessary features in the me-dium voltage distribution protection systems. Addi-tionally the relays may include a number of other in-novative and unique features, such as comprehensiveand versatile setting and programming possibilities,programmable blocking and output matrix, distur-bance recorder, evaluation software and continuousself-supervision.

Several communication protocols are available in therelays. Maximum demand measurement quantitiesand disturbance recorder are available for load profil-ing and fault evaluation.

Thanks to optional integrated transducers, any meas-ured and calculated values can freely be connected tothe mA outputs.

The numerical generator protection relay includes allthe essential functions needed for protection of smallor medium-sized power generators in modern fullyautomatic power plants. Further the relay includesseveral programmable protection functions, trip cir-cuit supervision, circuit breaker protection and com-munication protocols for various protection andcommunication situations.




6.1.4 Protection classes of electricalequipment

Enclosure protection class

The electrical equipment used in dry, indoor condi-tions should be of class IP20 or IP2X according tothe Ingress protection codes defined in the IEC 529standard. The minimum requirement for equipmentinstalled outdoors is IP23, but normally equipmentintended for outdoor installations should be of classIP34 or IP54.

Table 23 shows typical applications for various IPcodes

IECclassification

Name Typical application

IP20 Ordinary Indoors, dry ambient

IP22 Drip proof Humid ambientIP23 Rain proof OutdoorsIP34 Splash proof Wet or humid ambientIP54 Dust proof Dusty ambientIP55 Jet proof Wet ambientIP67 Water tight Dusty ambientIP68 - Under water

Table 23. Typical ingress protection applications

Hazardous area classification

The electrical equipment in a hazardous area must bedesigned for the classification of the area.

Minimum seismic design

The equipment is designed in order to resist the ef-fects of seismic ground motions acc. to UBC 97

6.1.5 Internal power consumptionThe following table lists the main power consumersalong with rough estimations of the power consump-tion in a plant with seven 20V34SG engines. The val-ues used in the table are maximum values based onthe nominal power of the motors. In practice, how-ever, the motors will never be running at 100% si-multaneously.

Note! The power consumption dependslargely on the plant configuration and the ambi-ent conditions. The values in the table must notbe used as design data.

Consumer Power Type of useEngine-specific consumersEngine auxiliary module 7 x 90 kW Stand-by engine

(mainly pre-heating and pre-lubrication)Radiator fans 7 x 100 kW ContinuousVentilation 7 x 20 kW ContinuousCommon auxiliary systemsStarting air compressor 50 kW IntermittentInstrument air compressor 20 kW IntermittentMaintenance water pump 2 kW IntermittentLubricating oil transfer pump 2 kW IntermittentTrace heating, heating of tanks 30 kW SeasonalCommon electrical systemsHeaters, battery chargers, etc. 20 kW IntermittentCommon civil systemsVentilation (switchgear rooms, control room,workshop, etc)

200 kW Continuous

Lighting 50 kW ContinuousMiscellaneous (cranes, workshop, etc.) 150 kW Intermittent

Table 24. Main power consumers and estimated consumption in a plant with seven 20V34SG engines




6.2 Generator system

6.2.1 Measurement and protectionThe generator is equipped with measuring transform-ers for differential protection and generator protec-tion. The differential protection relay and generatorprotection relay are located in the generator set con-trol cabinet.

6.2.2 Neutral groundingNeutral grounding cubicles, one per generator, areused for grounding the generator neutral points. Theneutral points are normally high resistance grounded.The neutral grounding cubicles delivered by Wärtsiläare equipped with current measuring transformers forearth fault protection and differential earth fault pro-tection. Earth fault current is typically limited to 5A.

An earthing transformer serving several generatorscan also be employed.

6.3 Medium voltage switch-gear

6.3.1 GeneralThe medium voltage switchgear consists of a rowcubicles installed side by side with a common mainbusbar running horizontally along the row.

Figure 65. Medium voltage switchgear

The main busbar runs through the main busbar com-partments of the cubicles.

Figure 66. Cross section of a medium voltageswitchgear cubicle (example)

The medium voltage main circuit and equipment in acubicle is supported by a secondary circuit housed ina low voltage compartment. The secondary apparatuscomprise control equipment, meters, switches, actua-tors, protection equipment, and terminal blocks forremote connections.

Generally, the medium voltage switchgear has thefollowing cubicles:

Incoming feeders from the generators (one pergenerator set)

Outgoing feeders to power transmission systems(possibly via a step-up transformer) or local con-sumers

Outgoing feeder to the low voltage station servicesystem (station transformer)

Possibly a busbar measurement transformer.(Busbar measurement may also be included in astation transformer feeder cubicle.)

Possibly one or more bus tie cubicles if the busbaris composed of two or more sections.

6.3.2 General design principles

Basic requirements

The medium voltage switchgear and all componentsare designed, manufactured, assembled and tested inaccordance with the latest applicable IEC standards.




The required withstand capability and interruptingratings of the busbars, circuit breakers and otherequipment shall be based on the system studies.

All cubicles must be equipped with earthing switches.

Circuit breakers

The circuit breakers are of three pole truck type (thatcan be withdrawn) to support interchange and main-tenance of the breakers. For economical and practicalreasons, circuit breakers of equal rating should beinterchangeable.

Enclosure

The medium voltage switchgear is designed to belocated indoors. It is typically metal-enclosed and air-insulated. Typically, control and auxiliary power ca-bles are connected from the top and power cablesfrom the bottom.

Power supply

Generally, 110 VDC is required for breaker controlmotors, protection relays, etc. Low voltage powerneeded for lighting and heating (230 VAC) can betaken from the low voltage power system.

Heating and cooling

To prevent condensation, anti-condensation heaterscontrolled by thermostats are installed to ensure thatthe inner parts of the cubicles are kept above the am-bient temperature.

The switchgears should be placed in rooms with airconditioning. Forced air cooling within the switch-gear is normally not needed.

6.3.3 Medium voltage busbarsThe main busbars are located in a separate compart-ment isolated from the other compartments by metalwalls. The compartment contains copper or alumi-num busbars, which are supported by cast resin insu-lators to withstand dynamic forces caused by shortcircuit currents. Busbars are rated for nominal- andshort circuit currents.

6.3.4 Incoming feeder cubicles

Generator circuit breaker

Wärtsilä recommends using SF6 circuit breakers (cir-cuit breakers isolated with SF6 gas). If vacuum circuitbreakers are used, the generators should be equippedwith surge arresters and surge capacitors.

The generator circuit breakers are operated by astored energy spring, charged by an electrical motor.For emergency cases, there must also be a manualhandle to manually charge the spring

Other main circuit apparatus

The generator feeder cubicles contain current andvoltage measuring transformers for the protectionfunctions and the power monitoring unit. Besides forprotection, the voltage measurements are also usedfor synchronization.

Secondary apparatus

The breakers have coils for breaker remote controls,generator breakers are also provided with an undervoltage coil which will trip the breaker if the controlvoltage is lost, at a breaker trip an alarm signal is tobe sent to the plant control system.

The breakers have position indicators for remote su-pervision. They also have interlocks that prevent maloperation of the breaker

The generator circuit breaker protection relay, differ-ential protection relay, and power monitoring unit areincluded in the generator set control cabinet.

6.3.5 Main outgoing feeder cubiclesThe grid feeder circuit breaker is of the same type asthe generator breakers. Loss of control voltageshould generate an alarm signal. SF6 type breakers arerecommended.

The grid feeder cubicle is be equipped with currentand voltage measuring transformers, Minimum pro-tection requirements for the grid feeder circuit are:

Protection Symbol ANSI No.Over current (I >)(I>>) 50Earth fault (Io >) 50N

Table 25. Minimum protection requirements forthe grid feeder circuit




6.3.6 Station transformerfeeder cubicles

The station transformer feeder circuit breaker is ofthe same type as the grid feeder circuit breaker, andhas the same protection.

6.3.7 Busbar voltage measurementThe main busbar is equipped with voltage transform-ers for synchronization of the generators and for sys-tem voltage- and frequency protection relays.

Minimum protection requirements are:

Protection Symbol ANSI No.Over/under frequency(typically alarm only)

f>, f< 81H, 81L

Over/under voltage(typically alarm only)

U>, U< 27, 59

Residual voltage(earth fault)

U0> 59N

Table 26. Minimum protection for busbar voltagemeasurement transformers

6.4 Transformers

6.4.1 GeneralA transformer consists of a three-legged magneticcore in a transformer tank with primary and secon-dary windings around the core, bushings, and an tapchanger. The function of the transformer is to supplythe load to another voltage level.

The primary- and secondary windings have no gal-vanic connection and thus form two different electri-cal systems.

6.4.2 Power (step-up) transformerThe step-up transformer(s) is to be sized for the ratedpower of the generators connected to the trans-former.

The power transformers used by Wärtsilä are oil im-mersed, conservator transformers with Oil NaturalAir Forced (ONAF) cooling.

The transformer is equipped with surge arresters toprotect the transformer against atmospheric overvoltage.

The transformer is equipped with a tap changer.

6.4.3 Station transformerThe required capacity of the station transformer (aux-iliary transformer) depends on the power consump-tion of the equipment connected to the system.

The main design alternatives for station transformersare:

dry type transformers (cast resin transformers)

oil immersed transformers, either hermeticallysealed or conservator type

The transformers delivered by Wärtsilä are either drytype transformers or oil insulated, hermetically sealedtransformers with mineral oil as insulation and cool-ing medium.

Table 27. Hermetically sealed transformer (exam-ple)

Dry type transformers are placed indoors, preferablyclose to the plant LV switchgear. The oil insulated,hermetically sealed transformers can be placed out-doors.

The transformers are cooled by natural circulation.When located in a switchgear room, or in a separatearea, it is important to provide the transformer withsufficient cooling air.




6.5 Low voltage switchgear

6.5.1 OverviewThe low voltage power distribution system in theplant provides the power supply to the engine auxil-iary equipment, such as pumps, fans, heaters andcompressors, the ventilation system and the buildingelectricity system. The system includes:

A main low voltage switchgear (main distributionswitchboard), which distributes power to possiblemotor control centres, control panels, and sub-distribution boards.

Possibly one or more motor control centres(MCCs), which supply motors

Radiator switchgear

Control panels and sub-distribution boards, whichsupply motors and other electrical consumers inthe plant.

Table 28. Low voltage switchgear (example)

Generally a low voltage switchgear, motor controlcentre, sub-distribution board or panel contains thefollowing equipment and apparatus:

A common busbar

One or more incoming feeders. The main LVswitchgear is fed from the MV switchgear via thestation transformer, possibly also from an emer-gency generator or other alternative feed lines.Other switchgears are fed from the main LVswitchgear.

Outgoing feeders to motor control centres, con-trol panels, sub-distribution switchboards, motorsand other consumers

Possibly a busbar voltage metering transformer

Secondary equipment for measurements and pro-tection.

All motor control centres and auxiliary control panelsare supplied by three phase low voltage.

6.5.2 Design principles

Enclosure

The switchgears are designed for indoor use, exceptthe radiator switchgear which is designed for outdooruse.

The low voltage standard switchgears delivered byWärtsilä are metal enclosed with natural ventilation.The compartmentalization is usually FORM4A (metalclad), and the assembly is type tested according toEN60439-1.

Power supply

Generally, 110 VDC is required for breaker controlmotors, protection relays, etc. Power needed forlighting and heating can be taken from the low volt-age power system.

Secondary wiring

The switchgear includes necessary numbers of termi-nal blocks for signal wiring to the plant control sys-tem.

Heating and cooling

To prevent condensation, anti-condensation heaterscontrolled by thermostats are installed to keep theinner parts of the cubicles above the ambient tem-perature.

If the switchgear is placed in rooms with air condi-tioning, forced air cooling is normally not needed.

Standards

The LV switchgear, switchboards, and motor controlcentres shall be designed, manufactured, assembledand tested in accordance with the latest applicableIEC standards.




6.5.3 Busbars and conductorsEach switchgear, switchboard and MCC contains acommon busbar or terminal. The ratings of the bus-bar is selected to match the connected load.

The switchgear is provided with separate busbars forneutral and protective earth.

6.5.4 Incoming feeders

General

Typically, there is one incoming feeder per switchgearor switchboard. The feeders shall be sized for themaximum power load. The main low voltage feeder,which is supplied from the station transformer, mustbe rated to match the rating of the station trans-former.

Circuit breakers

The feeder circuit breakers are fixed mountedmoulded case circuit breakers or air circuit breakers.

Measurements and protection

Voltage measurement is required if synchronizationwill be needed. Possible synchronization is handledby the plant control system.

Circuit breaker protection is generally incorporated inthe breaker.

6.5.5 Outgoing feeders

Feeder types

The most common feeder types are direct feeders,heater feeders and motor starters.

Direct feeders

Feeders to control cabinets and lighting are directfeeders equipped with switch fuses, or alternatively,MCCB:s or MCB:s.

Motor starters

Motor starters are typically of direct on-line type. Amotor starter contains at least:

A contactor that switches the power on and off

A circuit breaker, either a miniature circuit breaker(MCB) or moulded case circuit breaker (MCCB)for breaking the circuit at over-current

A thermal overload relay

A control switch

Running and fault signal lamps

Terminal blocks for remote supervision and con-trol.

Each motor starter is equipped with auxiliary contactsto indicate the contactor closed/open status, andcontacts to indicate the tripped status.

Other feeder types

Heater feeders have protection and control.

Protection

Outgoing feeders shall be equipped with protectionsuitable for the load. The basic protections whichmust be included for outgoing feeders are:

Protection Symbol ANSI No.Over current (I >) 50Short-circuit (I >>) 51

6.5.6 Busbar voltage measurementBusbar voltage measurement is needed if two busbarsor a busbar and an incoming feeder will be synchro-nized. This is the case, for instance, if there is a black-start unit.

6.5.7 Emergency generatorAn emergency generator (black start unit) is used tosupply power in case of a black-out situation. Thegenerator should be sized to supply at least the powerneeded for starting one main engine generator set.See the table below. The required power is muchhigher if the emergency generator is to also supplythe ventilation systems and emergency lighting.




Consumer PowerEngine specific auxiliary systemsPre-lubrication pump 30 kWPreheating unit(s) 50 kW

(+50 kW)Common auxiliary systems (seven engines)Starting air compressor 50 kWInstrument air compressor 20 kWCommon electrical systems (seven engines)Battery charging 20 kW

Table 29. Estimated power requirements for start-ing one engine generator set

6.5.8 Emergency busbarThe main LV switchgear can be equipped with anemergency busbar fed from an emergency generator(black start unit). Besides for the emergency start-upof engine generator sets, the emergency busbar mayfeed highly critical consumers, such as emergencylighting. The emergency busbar is connected to theLV busbar with a bus tie breaker.

Figure 67. Emergency busbar and black start gen-erator set (BS)

6.6 DC system

6.6.1 DC power consumersDC (direct current) power is used by the control andautomation systems, the protection relays, and theswitchgears. Using DC power for the control systemand generator breaker control ensures that vital func-tions will work in case of failure in the auxiliary ACvoltage supply. Two voltage levels are used:

24 VDC is used by the engine control system(nominal current: 2x40 A + 1x40 A stand-by), theplant control system, and the gas regulating units

110 VDC is used in the switchgears for control-ling circuit breakers (nominal current: 2x15 A +1x15 A stand-by) and for the instrumentation.

The 24 VDC consumption can be estimated as fol-lows:

Consumer Estimatedconsumption

Common control panel 300 WGenerator set control panels 100 – 200 W / panelEAM control panels 100 W / panelEngine control system(main and backup supply)

2 x 500 W /engine

Gas regulating units 100 W / unitFire detection system 100 W

Table 30. Estimated 24 VDC consumption

For switchgears, the DC power consumption de-pends on how frequently the circuit breakers are op-erated. Generally, the consumption under normaloperating conditions can be estimated to 20 VA percubicle, plus the power consumed by protection re-lays, transducers, etc.

6.6.2 DC system design

General

A DC system consists of batteries, battery charger(s)(rectifiers), and a DC distribution system. The systemcan be built as one compact DC unit.

Figure 68. An example of a DC unit




Normally, the rectifiers supply the load. The batterybank supplies the load for a limited time if the mainssupply is interrupted.

Batteries

Lead acid batteries are the preferred battery type.Nickel-cadmium batteries can also be used.

The required operating time with batteries is normally5 - 10 hours.

Battery chargers (rectifiers)

The charger capacity is selected so that the charger iscapable of feeding the total plant load while simulta-neously charging the batteries. The charger is alsocapable of supplying load if the battery is discon-nected.

The DC system is normally provided with redundantchargers

DC distribution system

The DC-distribution system consists of miniaturecircuit breakers (MCB:s) for the batteries, batterychargers and outgoing feeders.

6.7 Grounding

6.7.1 GeneralThe general purpose of the grounding system is toprotect life and property in the event of short-circuits, earth faults, or transient occurrences (forinstance, caused by lightning or switching opera-tions). The protection is arranged by preventing adangerous potential difference between the referenceearth and the accessible conductive (metallic) equip-ment and structures.

There are the following three types of groundingconnections in a plant:

Neutral point grounding for establishing a com-mon ground reference within a connected grid

Safety grounding of system parts that are normallynot energized but may become energized underabnormal or fault situations

Equipment grounding for ensuring a low imped-ance path for the ground current, and a fast trip ofthe faulty circuit in case of an earth fault.

Figure 69. Grounding types (TN-S system)

The main components of the grounding system are:

The grounding grid

The main grounding bar

Grounding cables

Lightning protection electrodes




Figure 70. A simplified grounding diagram for a power plant (example)

The grounding system is designed according to theIEEE 80 standard.

6.7.2 Grounding gridThe grounding grid is a copper grid installed underthe foundation of the engine hall and possibly thesurrounding site area. The design of the groundingand the required area of the grid depend on the soilqualities, maximum earth fault current and time, thenetwork configuration, and the number of incominglines and grounding wires.

The impedance of the grounding grid must be suchthat it ensures safe step and touch voltages. The mostsuitable impedance value depends on the soil proper-ties.

Figure 71. An example of a grounding grid

The recommendation is to ground at sufficient depthto ensure moisture during dry seasons and to avoidfreezing in winter. If needed, vertical grounding elec-trodes can be installed under the grid to improve theearth contact.

Inadequate soil around the power plant may make itnecessary to install the grounding grid at a distancefrom the plant.




6.7.3 Main grounding barThe main grounding bar is a copper bar which is di-rectly connected to the grounding grid. All majorequipment, and possible other grounding bars, shouldbe connected to the main grounding bar.

The main grounding bar must be sized according tonational standards.

6.7.4 Neutral point groundingThe main alternatives for neutral point grounding areillustrated below. The type of grounding to be useddepends on the grid, the power feed, possible trans-formers, etc.

Figure 72. Neutral grounding, main alternatives

The generator neutral point is typically high resistancegrounded. Other types are used when required.

Station service systems equipped with neutral con-ductor are always solidly grounded. The recom-mended grounding method is TN-S (separate neutraland protective earthing conductors). 110 VDC sys-tems are floating provided with earth fault monitor-ing, 24VDC systems directly grounded.

Neutral grounding systems shall ensure the efficientprotection of equipment and personnel.

6.7.5 Lightning protectionFor lightning protection, lightning rods with lightningdown conductors of copper from the rods down intothe earth must be installed in all high structures.

The underground lightning conductors should beconnected to the plant grounding system in order toprevent the build up of potential differences, whichcould damage sensitive components, or cause per-sonal injury or loss of life.

6.8 Cabling

6.8.1 GeneralThe plant comprises medium voltage cables, lowvoltage cables, DC cables and grounding conductors.

The required amount of cables depends on the extentof the plant and the plant layout. The required cablesize (diameter) for a connection depends on the volt-age, current, temperature, mounting method, numberof cables within the same conduit, type of cable, typeof fed equipment, and cable length.

Power cables must fulfil the following basic require-ments:

The cable dimension must be selected so that ca-ble losses are acceptable.

The cable insulation level must withstand existingsystem voltages.

The cable must withstand existing short-circuitcurrents in the system.

The voltage drop in the cable must not exceedacceptable limits. For maximum allowed voltagedrops in cables for various applications and loads,refer to applicable standards.

The cable temperature in all operating conditionsmust remain under acceptable limits.

The cable must fulfil requirements regarding firewithstand capability.

The cables must withstand existing mechanicalloads and vibrations.

Cabling routes and cable qualities must be selected insuch a way that they do not cause disturbances toother systems.

To determine the technically and commercially mostsuitable cables for each case, Wärtsilä performs a ca-ble optimization study. The calculations are based onstandards such as IEC 60364 guidelines.




6.8.2 Medium voltage cablesSingle core medium voltage cables are pulled fromeach generator set to the respective generator breakercubicle in the medium voltage switchgear, from themedium voltage switchgear to the station trans-former, and from the medium voltage switchgear tothe step-up transformer in the switchyard. Neutralpoint ground cables are pulled from each generator tothe neutral grounding cubicle or possible groundingtransformer.

6.8.3 Low voltage cables3-phase low voltage cables are pulled from the mainlow voltage switchgear to all motor control centres,switchgears and control panels containing motor con-trols, and to the building switchboard.

1-phase low voltage cables are pulled from the mainlow voltage switchgear to the one phase consumers.

6.8.4 DC cablesDC cables are pulled from the DC cabinet(s) to themedium voltage switchgear, to the main low voltageswitchgear, to the UNIC main units on the engines,and to the control cabinets in the control room.

6.8.5 Grounding conductorsGrounding conductors are pulled between thegrounding bar and the grounded equipments, for in-stance, switchgears, control panels, engine generatorsets, and auxiliary units.

The material and cross-section area of the groundingconductors depend on the earth resistance and powersystem arrangements and must be decided from caseto case.

Wärtsilä 34SG Power Plant Product Guide 7. PLANT CONTROL SYSTEM



7. PLANT CONTROL SYSTEM

7.1 Overview

Figure 73 shows a simplified picture of the system architecture of a standard plant control system. The generatorset control cabinets, the common control cabinet and the workstations are typically located in a control room.

Figure 73. Plant control system architecture (simplified)




Each engine generator set has a generator set con-trol cabinet. It handles the following functions:

Engine start and stop

Engine speed and load control via UNIC

Generator set voltage and reactive power controlthrough the automatic voltage regulator

Supervision and control of engine auxiliaryequipment via the EAM module

Alarm activation and indication

Safety functions, such as start blocks, shutdowns,control of gas shut-off and vent valves in the gasregulating units, and control of possible engine-specific main shut-off valves

Control of engine-specific ventilation units androof monitors if they are remotely controlled.

The common control cabinet, generally one perplant, has the following main functions:

Synchronization and control of outgoing feederbreakers

Monitoring of common auxiliaries (lube oil tanksand pumps, compressed air systems, etc.)

Control of a common main gas shut-off valve (ifinstalled)

Power management functions, such as load shar-ing, load shedding, automatic start/stop, and loadfollowing (options)

Monitoring of the transformers, the plant LVswitchgear, and the DC system

Control of a possible black start unit

Gas supply measuring (option)

Supervision of fire and gas detection systems

Supervision of environmental parameters.

At the WOIS and WISE workstations, the operatorcan start and stop the engine generator sets, changeset values, and supervise the plant through processdisplays, alarm and event lists, graphical trends andreports.

The control system is always delivered by Wärtsilä,but the customer can use existing user interfaces as acomplement to the Wärtsilä workstations. Third partyconnections are supported over Ethernet OPCthrough a firewall.

7.2 Generator set controlcabinet

7.2.1 OverviewFigure 74 shows the front of the standard generatorset control cabinet. The cabinet is typically located inthe control room.

Figure 74. Generator set control cabinet

The front panel contains frequency, current, voltage,power factor and active power meters, an emergencystop button, and a manual control unit with start andstop buttons and control switches. It also containsthe front panels of the power monitoring unit, thegenerator protection relay, and the differential protec-tion relay located in the cabinet. Inside the cabinet,are the generator set PLC and the automatic voltageregulator (AVR).




Figure 75. Devices and communication inside thegenerator set control cabinet

7.2.2 Generator set PLCThe PLC (programmable logical controller) is thecore of the generator set control system. The PLCincludes a CPU (central processing unit), which con-tains the control functions, and I/O cards of varioustypes for collecting and transmitting process signals.The PLC collects data from all I/O:s connected tothe IO cards, executes controls, and generates output.

7.2.3 Manual control unitThe manual control unit contains selector switchesfor choosing the control mode, start and stop but-tons, manual output control switches, button andindication lamp for closing and opening the generatorbreaker, and alarm lamps.

Figure 76. Manual control unit

7.2.4 Automatic voltage regulator(AVR)

The automatic voltage regulator (AVR) controls theoutput voltage from the generator by controlling theDC field current in the rotor of the excitation system.The AVR detects changes in the terminal voltage(caused, for example, by a sudden load change) andvaries the field excitation as required to restore theterminal voltage of the generator. The excitation isautomatically switched on and off at a specified en-gine speed.

Under steady loading conditions, the regulator main-tains a constant and stable generator voltage within+/-1% of the set value. The operating range of thegenerator voltage is +/-5% of the nominal voltage.The adjustment rage for AVR is +/- 10%

The AVR has two main control modes: voltagedroop control mode and power factor control mode.In addition, voltage droop compensation is available.

Power System Stabilizer (PSS) is available as an op-tion.

7.2.5 Protection relays

Generator protection relay

When a fault is detected the generator protection re-lay opens the generator breaker in the main switch-gear. Wärtsilä typically uses a multi function relaycontaining the following functions:




Protection Symbol ANSI NoOver voltage, twostages

U>, U>> 59

Under voltage U< 27Reverse power, twostages

P >, P >> 32R

Under, and over fre-quency

f<, f> 81H, 81L

Under excitation, twostages

X<, X<< 40

Voltage dependentover-current

Iv> 51V

Residual voltage, twostages

Uo>, Uo>> 59N

Unbalanced load I2/I> 46Stator overload > 49Over current, twostages

3I> , 3I>> 50, 51

Earth fault Io>, Io>> 50N, 51N

Table 31. Generator protection relay functions

The generator protection relay also provides transientrecording by 12 channels with a cycle of 20 ms. Re-cords from eight seconds before to eight secondsafter a breaker trip are stored.

Differential relay

The differential relay provides differential protectionof the generator, based on measurements in the MVswitchgear and in the generator.

Power monitoring unit

The power monitoring unit measures the phase cur-rents and voltages, the frequency and running hours,and calculates the active, reactive and apparentpower, the power factor, and the active and reactiveenergy. The active power is shown on the indicatoron the front panel of the generator set cabinet.

7.3 Common controlcabinet

7.3.1 Overview

Main components

The common control panel contains:

a PLC unit for centralized supervision and controlof the common plant systems

an auto synchronizer for automatic synchroniza-tion

a manual synchronization unit containing a syn-chronoscope, and double frequency and voltagemeters (source and target)

Figure 77. Common control cabinet, front panel(example)

In addition to the manual synchronization equip-ment, the front panel contains a mimic diagram ofthe plant power distribution system, and plant emer-gency stop and reset buttons. The plant emergencystop will affect all engine generator sets in the plant.

If the plant contains an emergency engine generatorset (black start unit), the common control cabinetcould also contain the starting logic for the unit.

7.3.2 Common PLCThe common PLC is similar to the generator setPLCs but handles functions and units that are com-mon to the entire plant. The common PLC commu-nicates with the generator set PLCs and the operatorstations via the plant network.




7.3.3 Synchronization units

Auto synchronizer

The auto synchronizer compares the generator fre-quency and voltage to the frequency and voltage ofthe busbar, and adjusts the engine speed and genera-tor excitation to equalize them. When the deviationsare within preset limits and the phase difference isalso within preset limits, the auto synchronizer issuesa breaker close signal. To compensate for the breakerclosing time and the operation time of the outputrelay, it calculates required advance phase angle.

Manual synchronization set

The synchroscope measures the phase differencebetween the generator and the busbar and indicateswith LEDs when the breaker can be closed. It alsoindicates when the generator frequency needs to beraised or lowered, and if the voltage difference iswithin set limits. The operator controls the voltageand frequency manually with switches and by super-vising the double voltage and frequency meters onthe common panel.

A sync check relay prevents breaker closing if nosynchronization has been done, or if the synchroniza-tion has failed.

7.4 Workstations

7.4.1 GeneralA workstation is a PC computer with a monitor, key-board and mouse, and HMI (Human Machine Inter-face) type software. There are two types of worksta-tions:

The Wärtsilä Operator Interface Station (WOIS),which is a graphical user interface for supervisingand controlling the plant.

The Wärtsilä Information System Environment(WISE), which handles the long term data storageand report functions of the power plant.

The control system may comprise one or moreWOIS workstations, a WISE workstation, and one ormore printers for hardcopy and report printing. Theworkstations must always be kept running and cannotbe used for other purposes.

The workstations enable remote monitoring and datasharing with external systems.

7.4.2 Operator station WOIS

General

At the WOIS workstation, the operator can monitorthe plant and take actions, such as starting and stop-ping the engine generator sets, and changing the setvalues used in the engine and generator control. Theoperator can supervise plant key data, such as varioustemperatures and pressures, as well as measurementsof electrical variables, for instance, generator output,voltage and frequency.

WOIS provides process displays, alarm and eventhandling, process trends, instant reports, and controlsystem supervision. The user selects displays by click-ing on buttons in dynamic menus at the top and bot-tom of the screen, or by clicking in the process dis-plays. The most important displays are always acces-sible at the top of the screen.

Process displays

In the process displays, the process components areillustrated by graphical objects, such as images ofpumps and valves, with dynamic status indicationimplemented as change of symbol or colour. By se-lecting an object, the operator can access more de-tailed data on the object, for instance, trend data ofmeasured values. A plant overview display provides aclear and concise view of the entire plant.




Figure 78. A plant overview display, a generator settemperature display, and an object datawindow

Alarm and event handling

An alarm banner, which is always visible in the up-permost part of all displays, informs about the latestalarm that has occurred. The operator sees a compre-hensive view of the alarm situation from the activealarm list, which contains all active or unacknow-ledged alarms. The alarms can also be acknowledgedfrom this list.

A further evaluation of historical alarms can be donein the event list. In addition to the alarms, the eventlist contains all normal changes of operational state,for instance, engine start and stop and change ofbreaker status. WOIS events, such as change ofpower setpoint, can also be seen in the event list.

Figure 79. Event list

Process trends

The graphical trends show measured values such aspressures, temperatures, speed, engine generator setload, etc., on a time axis. To get a comprehensiveview of the process, the operator can combine thevalues of up to six features in one graph. The trendsare stored for up to 180 days.

Figure 80. A process trend

System security

The WOIS workstation security system prevents un-authorized use by requesting a password at user login. Each user is associated with a certain authoriza-tion level, which determines the allowed operations.There are three different authorization levels: Opera-tor, Manager and Administrator.




7.4.3 Reporting station WISE Using WISE, the operator can view and print out daily, monthly and yearly reports produced by the reporting program. WISE keeps the engine and pro-duction reports available for later study and archiving. WISE gets the information from WOIS.

WISE provides the following functionality:

• Production reports of generated active and reac-tive energy along with the hourly fuel consump-tion. Daily production reports are stored for one year. Monthly production reports (on daily level) are stored for 5 years and yearly production re-ports for 10 years. The production reports include minimum, maximum, average and total sum calcu-lations for the period.

• Daily engine and plant reports of measured values, such as bearing temperature and lubrication oil temperature. Daily minimum, maximum and aver-age values are generated and stored for one year. The measurements can be viewed as trend dis-plays, which enables long term follow-up of the plant performance.

• Electronic log book with search possibilities for recording of operation and maintenance activities. The logbook automatically inserts events like en-gine starts and stops into the logbook, along with timestamps. The operator can also enter events into the log book.

• Support for storage and viewing electronic plant documentation (manuals, layouts and drawings).

Figure 81. A typical daily operation data report

Figure 82. A production report

Figure 83. Log book

7.4.4 Remote monitoring Provisions for Remote Monitoring services are in-cluded in the WOIS and WISE applications. Depend-ing on the communication lines and infrastructure at the plant, these services can be offered based on a separate Support Agreement.

The Remote Monitoring system allows the plant per-sonnel to access the power plant’s control network from a PC via Internet. The system only allows “read only” access, that is, any control actions are prohib-ited. The service includes:

• Real-time access to all the process information in WOIS

• Access to all historical trends stored in WOIS and WISE

• Access to active and historical alarm information

• Access to the log book, including present and his-torical log book events




Remote monitoring uses standard Internet relatedprotocols and widely used services for secure andreliable communication. Supported techniques for thephysical connection to the system are DSL or leasedline communication.

7.4.5 Data sharing with external sys-tems

Plant control system signals available in WOIS andWISE can be transferred to external systems, for in-stance, an existing control system or an ISO dispatchcentre, using Ethernet TCP/IP communication witha firewall between the Wärtsilä control system andthe external system. For transferring WOIS real-timedata, the OPC protocol is used on top of Ethernet,with WOIS acting as an OPC Server. For reading theWISE reporting database, ODBC-SQL requests areused.

The connection point for the external system is thefirewall, which is to be located in the Wärtsilä controlroom. The firewall is supplied and configured byWärtsilä, while cabling and communication onwardsfrom the firewall is the customer’s responsibility.

Alternatively, data can be transferred through cus-tomer-supplied RTUs.

7.4.6 Condition based maintenanceThe WOIS and WISE applications contain provisionsfor Condition Based Maintenance (CBM) servicesoffered by Wärtsilä. The extent of the services de-pends on the communication lines and infrastructureavailable at the plant. If applicable communicationlines and transfer methods are available, the meas-urement data of the plant is automatically sent toWärtsilä on regular basis. Alternatively, the data canbe sent manually. A separate CBM agreement shouldbe made for this service. The CBM agreement canalso cover on-line monitoring with trouble-shootingsupport.

7.5 Signal and data com-munication

7.5.1 GeneralIn a typical power plant, the control system handlesabout 150 … 200 process signals per engine andabout 100 … 1000 common signals, depending onthe size of the plant.

The majority of the signals communicated betweenthe engine control system (UNIC), PLCs and remoteI/Os are transferred via communication buses. How-ever, all primary control signals such as AVR, speed,synchronization and breaker trip signals are hard-wired. Likewise, the safety related signals, such asemergency stop signals and critical alarm signals arehardwired.

7.5.2 Signal typesThe signals handled by the plant control system areof the following types:

Analogue input signals (AI), for instance, pressureand temperature measurements. The control sys-tem recognizes AI signals scaled to 4 … 20 mA,and PT100 and thermocouple temperature meas-urements.

Analog output signals (AO), for instance, setpoints to thermostatic valves. AO signals arescaled to 4 … 20 mA.

Digital input signals (DI), for instance levelswitches. The digital input signals must be ar-ranged as potential-free contacts.

Digital output signals (DO), for instancestart/stop signals. The digital output signals arearranged as potential-free contacts.

7.5.3 Communication busesThe communication between the control room PLCsand the engine control systems go through the plantnetwork. The plant network is a standard local areanetwork using Ethernet TCP/IP and twisted paircables, or fibre optics if the distances are longer than100 meters. The Ethernet switches are located in thecontrol cabinets.




Most data and signals from UNIC to the generatorset PLC, for instance, engine measurements, andstatus and alarm signals, go through the Ethernetplant network. Likewise, the set values from the PLCto UNIC go through the Ethernet plant network.

Also, the protection relays delivered by Wärtsiläcommunicate with the PLCs via the Ethernet plantnetwork.

The communication between the engine generator setPLC and the remote I/O in the EAM module goesthrough a communication bus using a high levelstandard protocol.

7.5.4 Hard-wired signals

Engine-specific signals

The following figure illustrates the engine-specifichard-wired signals.

Figure 84. Overview of engine-specific hard-wiredsignals (example)

The hard-wired signals between the instrumentationwithin the EAM module and the EAM cabinet arefactory installed and not shown in Figure 84.

Common signals

The following figure illustrates the amount of hard-wired signals that are common to the plant.

Figure 85. Overview of common hard-wired signals(example)

7.5.5 Control cablesThe cables should be PVC insulated copper cables.They must not absorb static or magnetic noise signalsfrom the surroundings.

Signals of the same type can be contained in the samecable. Signals of different voltages require separatecables.




7.6 Functional description

7.6.1 Start and stop processes

Start

At an engine start command, the generator set PLCchecks that the generator, engine and auxiliary sys-tems are ready for start, for instance, that the genera-tor breaker is open, starting air and control air isavailable, lube oil inlet pressure is high enough, HT-water outlet temperature is high enough, and theturning gear is not engaged. Provided that all startconditions are fulfilled, the PLC activates gas systemtightness check, and sends a start command to theengine control system (UNIC).

Normal stop

At a normal stop request, the generator set PLCunloads the engine according to a specified ramp andopens the generator breaker. Then it shuts off the gassupply from the gas regulating unit to the engine, andsends a shut-down command to UNIC. When theengine has stopped, the PLC starts the exhaust gasvent fan, and ensures that the ventilation is done. Theengine cannot be restarted until the exhaust gas venti-lation fan has been operated.

Synchronization

In AUTO mode, the PLC initiates synchronizationwhen it detects that the engine is running and a ter-minal voltage exists. The auto-synchronizer matchesbusbar and generator voltages, frequencies and phas-ing and issues a generator breaker close command asdescribed earlier.

Synchronization and breaker control can also bemanually initiated from the mimic diagram.

7.6.2 Output control


The PLC controls the engine speed and load by send-ing set values to UNIC according to the active con-trol mode: kW control mode or speed droop.

In speed droop control mode, the speed - load rela-tionship will follow a linear speed droop curve de-fined in UNIC. Generally, the speed droop setting is4%.

Figure 86. Speed droop graph (speed droop 4%,speed set point 51 Hz)

The operator can change the setpoint at a work-station or with a switch at the control panel. Auto-matic fine tuning of the frequency is available as anoption in the generator set PLC.

In the kW mode, UNIC maintains the engine powerconstant. The set value can be changed from an op-erator station or the control panel.

In isochronous load sharing control, the genera-tors sets will operate at a constant frequency regard-less of the load they are supplying, up to the full loadcapability of the generators. Load sharing lines(CAN-bus) are required between the speed control-lers (UNIC) in order to share the load between theparalleled units.

Speed droop control is enabled in island operation,and in the MANUAL mode, also in parallel opera-tion. The kW control mode is enabled in parallel op-eration only. The isochronous mode is only enabledin island operation. The operator selects a controlmode on the control panel. The control system willalso automatically switch control mode when the gridbreaker is opened or closed.

Generator output control

The generator voltage and reactive power (powerfactor) are controlled by the automatic voltage regula-tor (AVR) according to the chosen mode – voltagedroop, voltage droop compensation, or power factorcontrol mode – and set values from the generator setPLC.




In the voltage droop control mode, the relationshipvoltage - reactive load follows a linear droop curve.The droop setting, that is, the voltage drop when thereactive load is increased from 0 to 100%, is adjust-able and is normally in the range 1 ... 10 %. To main-tain the voltage at an increased load, the operator canchange the voltage reference (set value) in WOIS orwith a control switch. The optional Master VoltageControl function changes the voltage referenceautomatically.

Voltage droop compensation is used to share thereactive power equally between parallel engine gen-erator sets in the island mode. The AVR compensatesfor the voltage droop to keep the voltage at 100%.Voltage droop compensation requires an RS-485 busconnection between the AVRs.

Power factor control means that the AVR will adjustthe generator excitation current in such a way that thePower factor (cosine phi) of the generator outputremains constant at a set value.

The power factor control mode can be used only dur-ing parallel operation. Voltage droop can be used inboth parallel and island operation modes, but is nor-mally used only during island operation. Voltagedroop compensation is only available in the islandmode. The operator selects a control mode from thecontrol panel. The control system will also automati-cally switch the control mode based on the gridbreaker position.

Power management functions

With the power management functions, the operatorcan order a plant output power at a workstation. Thecontrol system shares the ordered power equally be-tween the running generator sets, and sets the engine-specific load references accordingly.

If the ordered load exceeds the capacity of the run-ning generator sets, there will be an alarm requestingthe operator to start up more generator sets. As anoption, automatic start and stop of generator setsmay be included.

Another power management option is the load fol-lowing system. Load following helps the operatorsplan the generation load pattern according to thepower need, the imported energy, and other factorssuch as system losses. The system is implemented inWISE, WOIS and the common PLC.

Load shedding

The plant can be provided with a load sheddingscheme, which will be activated when the consump-tion tends to increase over the capacity of the plant.Load shedding is applicable during island operationonly.

7.6.3 Control of auxiliary systems

Engine specific auxiliary systems

The engine specific auxiliary equipment, except forthe radiators, are supervised and controlled via thecontrol panel in the engine auxiliary module (EAM).The panel controls start and stop of pumps and heat-ers. The thermostatic valves in the cooling water sys-tem are controlled centrally from the engine genera-tor set PLC. The PLC receives cooling water tem-peratures from the EAM module and sends set pointsto the three way valves.

The radiators are controlled directly from the genera-tor set PLC. The PLC sends set points to the fre-quency converters in the radiator control panelsbased on measured temperature in the return line.

Common auxiliaries

Common auxiliaries are controlled by local panels.Running signals and alarm signals are sent to thecommon plant control panel.

7.6.4 Safety functions

General

The automatic safety functions work in the same wayin manual and automatic mode.

Alarm sources and alarm indication

Alarms can be initiated in the control room panels, inUNIC, in the EAM panel, and in the local panels ofthe common auxiliary equipment. All alarms are indi-cated in the control room, either as individual alarmsor group alarms (common alarm), and local alarmsare also indicated at the local panels. Engine alarmsare also indicated by light signals in the engine hall.




Engine load reduction and derating

Bad operating conditions that do not require an en-gine stop will activate a load reduction alarm uponwhich the operator should reduce load. Automaticload reduction (derating) takes place when derating isrequired due to ambient conditions. The PLC willlower the load setpoint sent to UNIC. UNIC can alsoactivate a load reduction in risky situations.

Automatic shutdown

Highly critical or urgent occurrences will activate animmediate shut-down of the engine without unload-ing. A shutdown may be initiated by UNIC or by thegenerator set control system. In case of an engineinitiated shutdown, the PLC shuts off the gas supplyto the engine immediately. The main consequences ofa shut-down are:

Generator breaker opens.

Stop command is sent to UNIC.

Gas regulating unit is closed.

The shut down cause will be noted in the WOISalarm list.

Emergency stop

An emergency stop activates an immediate shut-down of the engine. An emergency stop of an enginecan be activated with a push button on the generatorset panel. An emergency stop is automatically acti-vated when an emergency mode has been activated inUNIC, for instance at over-speed. An automaticemergency stop is also activated if a wire break is de-tected in an emergency stop cable.

A plant emergency stop can be activated from thecommon control panel and will affect all engines.

Depending on local rules and regulations, the controlsystem can be programmed for an automatic plantemergency stop in the following situations:

a gas detector senses 20 % of LEL (lower explo-sion limit)

a fire detector is activated

Alternatively, the activation of a detector only causesan alarm and the operator takes the necessary actions.

Wärtsilä 34SG Power Plant Product Guide 8. PLANT LAYOUT



8. PLANT LAYOUT

8.1 Site layout

8.1.1 Site Layout principlesThe following primary facts should be consideredwhen arranging the site layout:

The size, shape and topography of the site

The location of the power transmission lines

Soil conditions

The location of the gas supply pipe.

The location of the power transmission lines may bedecisive when determining the placement of theswitchyard, and it may affect the orientation of theentire plant. Generally, the switchyard is located onthe generator side of the engine hall and the radiatorson the engine side of the engine hall.

Space should be reserved for:

The power house including the engine hall andpossibly service rooms, administration rooms andelectrical rooms

Any separate service buildings, like administrationbuilding, electrical room, workshops, and storage

Exhaust gas pipes and stacks, including possibleheat recovery and emission control equipment

The radiator field with switchgears and frequencyconverters, or possible cooling tower

The switchyard and possible outdoor transformers

Tank yard and unloading pump station

Oily water sumps

Gas pipes above ground, main valves and a possi-ble pressure reduction station

Fire equipment house, and possibly a fire fightingwater tank and pumps

Fire protection spaces

A possible black start unit with fuel storage tank

Stormy water pond if needed

Possible water treatment unit and water tank

Possible sewage water treatment

Roads and parking lots, access roads, and turningplaces for transport vehicles

Reservations for possible future expansions.

8.1.2 Site layout notes

Radiator field

The performance of the cooling radiators, and thusthe performance of the plant, is greatly affected bythe airflow to the radiator field.

To ensure the air flow to the radiators, they should beinstalled at such a height that the vertical radiator airinlet face area equals or exceeds the horizontal radia-tor inlet face area (=radiator footprint). However, theminimum height above ground should be 2m.

In case of possible noise walls around the radiatorfield, they have to be placed at a distance of 3 timesthe radiator installation height.

The distance between radiator field and adjacent size-able objects (like the powerhouse) should be as longas possible. For plants with less than 5 gensets, theminimum recommended length = 2,5 times the build-ing height. For larger plants the following formula isrecommended, which yields a longer distance

7tanhpd , dmin = 2.5 x p

where

d = distance between power house and radiator field[m]

p = power house height [m]

h = radiator field free height above the ground [m]




7°

h

d (= min 2.5 x p)l

w

!

p 7°

h

d (= min 2.5 x p)l

w

!

p

The possible re-circulation of hot air will reduce thecapacity of the cooling radiators and must thereforebe avoided. A reduced air flow will also increase therisk of re-circulation and combined, these issueswould affect the cooling capacity considerably.

In order to minimise the risk for hot air recirculation,the radiators should be grouped together tightly toform a uniform field. If gaps between the radiatorscan not be avoided, they should be covered withhorizontal metal sheets or similar.

Other factors that affect both the air flow and possi-ble re-circulation are

Wind speed and direction

Site topography

Buildings, vegetation, tanks etc

Tank yard and unloading station

The tank yard and unloading pump station should belocated in an area where the risk of fire is small. Itmust also be ensured that it will impose no hindrancefor the operation of the fire protection system in caseof a fire accident. Fire fighting regulations as well aslocal regulations must be followed.

Other factors to consider are the location of otherbuildings nearby, and access from road, railway orwaterway for filling the tanks.

The unloading station must be located in the open airnext to the tank yard.

Administration buildings

If the control room is placed in a separate building,maximum control cable length must be considered.

8.1.3 Site layout examplesFigure 87 and Figure 88 show typical site layouts forpower plants with 6 x Wärtsilä 20V34SG and 20 x20V34SG respectively. Smaller plants usually haveone common building including engine hall, controlroom, electrical room, and a possible workshop. Big-ger plants usually have separate administration build-ing with control room, electrical room and workshop.




Figure 87 Typical site layout example for a plant with six engines and integrated service rooms, control room andswitchgear rooms




Figure 88 Typical site layout for a plant with 20 engines in two separate engine halls and separate service building




8.2 Engine hall layout

8.2.1 Engine baysThe following figure shows the space required for theengine generator sets. The recommended distancebetween adjacent engine generator sets, from centreto centre, is 5400 mm.

Figure 89. 20V34SG Engine bays with serviceplatforms

The standard modules are designed to be intercon-nected with service platforms in between – the engineauxiliary modules on floor level and the exhaust gasmodules above. About five EAM modules can beconnected in parallel and use common header pipes.

The gas regulating units must be placed close to theengines

8.2.2 Other space requirementsSpace must also be reserved for:

Common auxiliaries, as compressor units andcompressor air tanks, maintenance water tank(s),lube oil pump unit(s), etc.

Pipes, cables, pipe and cable supports, fire fightinghoses, sprinklers, electrical fittings, etc.

Maintenance areas and transportation routes.

8.2.3 Layout notes

Air intakes

Air intakes should be in a dust free location andtherefore as high as possible, still accessible for main-tenance. The intake should be placed away from heatsources such as exhaust gas pipes, ventilation outlets,etc.

Expansion vessels

The expansion vessels must be located above thehighest part of the cooling water system. If needed,they must be moved from the exhaust gas modules toa higher location.

Air compressors and tanks

Air compressors must be installed in a well ventilated,dust free, freezing free and water free area. The com-pressed air tanks should be located close to the con-sumers to avoid large pressure drops in the pipes.

Lube oil pump unit

The lube oil pump unit should be situated as close aspossible to the lube oil storage tank.

Maintenance water tank

The maintenance water tank should be placed as lowas possible to allow drainage of the water.

Transportation and maintenance space

The engine hall should have space for transportingmain components to and from the engine.

The possibility should be maintained to make anopening in the wall on the generator side of the en-gine hall for replacing a generator or entire enginegenerator set. There should be no fixed structures,such as pipes or cable ladders mounted on this wall.

8.2.4 Layout exampleFigure 90 shows a layout example of an engine halland the exhaust gas systems. The engine generatorsets along with their gas regulating units, engine auxil-iary modules, and exhaust gas modules are groupedthree and three, each group having common headerpipes in the EAM modules. The space between thegroups is utilized for maintenance water tanks and airbottles, and as maintenance and lay down area.




Figure 90 Typical Engine hall layout




8.3 Service rooms orbuildings

8.3.1 GeneralThe requirements for other spaces in the power plantbuilding – switchgear rooms, control room, offices,workshop, social rooms, etc. – depend on the owner'srequirements and the operating profile of the plant.

The service rooms can be incorporated in the powerhouse building, or they can be located in separatebuildings.

Figure 91 shows an example of service rooms incor-porated in the power house.

8.3.2 Electrical roomsThe medium voltage switchgear, the main LV switch-gear, distribution boards, possible motor control cen-tres and the DC system must all be situated indoorsin electrical rooms with air conditioning. To permitshortest possible wiring between the generators andthe medium voltage switchgear, it is recommended tolocate the switchgear at the generator side of the en-gine hall.

Depending on the type, the station transformer canbe placed indoors or outdoors.

Figure 91. Service rooms (example)




8.4 Tank yard andunloading station

8.4.1 Tank yardThe tank yard contains the lubricating oil tanks, theoily water tanks, and possible reagent tanks for SCR.The water tanks may be located in the tank yard.

The distance between the tanks, as well as the dis-tance between storage tanks and the toe of the stor-age tank area dike wall must obey the applicable stan-dards and local regulations.

There should be separate containment areas for tankscontaining oil and water solutions (SCR reagents) asthey should not be mixed in case of a leakage.

Figure 92. Tank yard example

8.4.2 Unloading pump stationThe unloading pump station contains unloadingpumps with control panels for lube oil and sludge,possibly also Urea or ammonia in plants with SCR.

8.5 Pipes and cables

8.5.1 Pipe layoutTo minimize the pressure drop in the pipes, pipe runsshould be as simple and direct as possible. To sim-plify supporting and improve appearance, the pipesare generally arranged parallel to building steel work.

Factors to consider when reserving space for pipesare the pipe diameter, possible insulation, minimumdistance between pipes, and minimum distance be-tween pipes and walls or bars. Also the need formaintenance space and access to equipment shouldbe regarded.

8.5.2 CablingCabling routes must be selected in such a way thatthe cables will not cause disturbances to other sys-tems. It is recommended to run the cables betweenthe generators and the main switchgear in cable con-duits under the floor

Low voltage cables and control system cables are car-ried by cable ladders, separate ladders for control sys-tem cables and power feeder cables. Where applica-ble, the pipe supports can be used as supports for thecable ladders.

Figure 93. Cable ladders

8.6 Hazardous areas

8.6.1 GeneralA hazardous area is a location where the atmospherecontains or may contain a combustible material, suchas fuel gas, in sufficient concentration to form anexplosive or ignitable mixture.




In hazardous areas, it is important to avoid all poten-tial ignition sources, including electrical and mechani-cal equipment which could form sparks and hot sur-faces. The primary recommendation is not to installor use any electrical equipment in these areas. Whenthis is not practicable, certified equipment must beused.

The hazardous areas are classified to determine thelevel of safety required for the electrical and me-chanical equipment installed or used in the areas. Theclassification and the required or recommended pro-tection methods are based on standards and direc-tives. In Appendix A are listed the most commonlyused standards for the classification of hazardousareas and for the requirements placed on electricalapparatus installed or used in classified areas. In addi-tion, local requirements must always be met.

8.6.2 Classification of hazardousareas

The classification of hazardous areas is based on thelikelihood of an ignitable gas mixture being present.Table 32 lists the principles for defining hazardousareas according to European and American stan-dards, IEC and NFPA 70 (NEC) respectively. “ClassI” in the NEC designations refers to gas (class II isdust and class III fibres).

IEC NEC 505 NEC 500 ExplanationZone 0 Class I,

zone 0An ignitable mixtureis present continu-ously

Zone 1 Class I,zone 1

Class I,division 1

An ignitable mixtureis present intermit-tently

Zone 2 Class I,zone 2

Class I,division 2

An ignitable mixtureis not normally pre-sent, but may bepresent under ab-normal conditions

Table 32. Classification according to the IEC andNFPA70 (NEC) standards

Figure 94 shows a typical example of the hazardousarea classification of an engine hall with lean burn gasengines. The indicated hazardous areas are spheresaround the potential release points.

Figure 94. Classification of hazardous areas during operation in a gas engine power plant according to the IECand NFPA standards (example)




In a gas fuelled power plant, all flange joints andvalves in the fuel gas system should be consideredpotential sources of release. Generally, in a Wärtsilädesigned power plant, the only units inside the enginehall containing these components are the gas regulat-ing units (GRUs). The hazardous area around aflange joint is a sphere with a radius of typically 1meter (3.3 feet), provided that the ventilation is ade-quate. The radius should be determined for each in-stallation individually, if needed, in consultation withlocal authorities.

Outside the engine hall, the spaces around the gassystem vent pipe outlets are hazardous areas.

In a gas plant, the tank yard is not a hazardous area.

During maintenance and repair work, additional areasmay need to be classified as hazardous.

If the plant contains other sources of release not re-lated to the Wärtsilä engines, they must be analyzedand considered as well.

8.6.3 Protection methods in hazard-ous areas

Within hazardous areas, it is mandatory to use onlysuitable, certified devices. The requirements are de-termined by the properties of the gas. The normalgaseous fuel, natural gas, is classified as a group IIA(IEC / NEC 505) or group D (NEC 500) flammablegas. The auto-ignition temperature for natural gas isoften considered to be the same as for the base com-ponent, methane, which is 537°C (999°F). The actualauto-ignition temperature for most natural gases ishigher due to inert constituents.

There are different explosion-protection techniquesfor electrical equipment. Unless local rules imposestricter requirements, Wärtsilä follows either the IECor NFPA standards. Table 33 shows some typicalprotection methods for equipment installed or usedin hazardous areas in a gas power plant.

Device Typical protection methodInstruments andcontrol devices

Ex i Intrinsic safety

Electrical motors Ex d FlameproofElectrical heaters Ex d FlameproofJunction boxes Ex d

Ex eFlameproof andIncreased safety

Table 33. Typical protection in hazardous areas

Wärtsilä 34SG Power Plant Product Guide 9. SITE, CIVIL WORKS AND STRUCTURES



9. SITE, CIVIL WORKS AND STRUCTURES

9.1 Site considerations

9.1.1 Site selection criteriaThe following factors, which may have an impact onthe construction costs, plant performance, and pro-duction economy, should be considered when evalu-ating the appropriateness of a site:

Size requirements

The size requirements are determined by the site lay-out. On the other hand, the site layout can be ad-justed to suit the available site.

Also to be considered is the need for a laydown areaand space for site offices in the immediate vicinity ofthe plant during the construction phase.

Proximity to power and heat consumers

For economical reasons, the plant should be locatedas close as possible to the load centres, electricaltransmission lines, and potential users of waste heat(if heat recovery is included).

Environmental issues and building permits

The type of neighbourhood – industrial area or hous-ing area, for instance – has a considerable impact onallowed noise, air emission levels, rain water issues,aesthetic values, acceptable levels of pollutants duringthe construction phase, etc.

Available connections

The nearness to fuel gas pipes is of vital importance.Important, although less crucial, is the existence ofutility connections, such as clean water and sewagewater pipes, and telephone communication.

Seismic conditions

Risk for seismic activity will have a considerable im-pact on all plant design and installations. All build-ings, structures and installations must be designedaccording to applicable regulations for the seismicconditions.

Soil conditions

The soil conditions should appear from the geotech-nical investigation, see below. Local soil improvementor piling may be needed.

Ambient conditions

Possible risks for hurricanes, flooding and sandstorms must be regarded in the design of the plant.Also, in coastal areas with salt laden air, additionalcorrosion protection of outdoor structures may beneeded.

Access by road, railroad, or waterway

When evaluating road connections, the largest trans-portation weights and sizes, required road width, pos-sible sharp curves, and the bearing capacity must betaken into account. The roads must fulfil local trans-portation regulations regarding design width andminimum radius of road curves.

9.1.2 Geotechnical investigationA detailed geotechnical investigation, including in-formation on topography, terrain, seismic conditionsand soil conditions is necessary for evaluating the siteand deciding on required earth work.

The topography is of importance for the site layout,grading and drainage. The risk for earthquakes in anarea is indicated by the seismic zone, zone 0 repre-senting the lowest risk level and zone 4 the highest.

The soil investigation should determine the followingsoil conditions:

Density and bearing capacity

Dynamical properties

Hydrocollapse potential and liquefaction

Potential to corrode steel, or to adversely reactwith concrete

Soil resistivity (suitability for electrical earthing)

Presence of groundwater, percolation.

Minimum allowable soil bearing pressure must bedetermined from case to case.




9.2 Earthworks and siteworks

9.2.1 GeneralThe required earth works is based on the geotechni-cal investigation and locally valid regulations. Earthworks generally comprise excavating and compactingsoil, and grading. Depending on the soil quality, itmay also involve soil replacement, blending and pil-ing, as well as the use of a geomembrane betweenlayers of different soil types. If the soil quality so al-lows, the foundations can be laid on well drained andcompacted structural fill.

Regarding roads and pavements, they must fulfil lo-cally valid rules and transportation regulations.

9.2.2 Site drainageThe objective of the drainage is a controlled removalof rainwater from the site. Local regulations may re-quire the rainwater be collected to a retention pond.The drainage system, and the rain water pond (if re-quired), should be sized for the design rain in the re-gion according to local regulations.

The site should be sloped to carry all surface wateroff the site or to the retention pond. In case of a flatsite, the powerhouse must be raised above the exist-ing ground level according to local regulations. If thesite is located in a flood area, all structures must beraised above the maximum flood height.

9.2.3 Underground utilitiesUnderground utilities include:

Gas pipes

Pure water, fire water and sewage pipes

Oily water pipes for conducting oily water to theoily water sumps

Underground conduits for electrical cables, withsupport structures if valid regulations so require

Grounding grid.

Local regulations must be followed.

9.3 Engine hall foundation

9.3.1 GeneralAs standard, Wärtsilä uses a shallow foundation withreinforced ground floor slabs strengthened withbeams along the column lines of the building. Thissolution is suitable at sites where the bearing capacityis at least 150 kN/m2 at 0-level and there is no set-tlement risk.

Figure 95. Engine generator set foundations andbeam strips

The static loads on the foundation are the weight ofthe equipment and the support reactions from thebuildings and structures.

Note! The planned route for hauling in theengine generator sets during installation must bestrengthened to carry the engine generator sets.

9.3.2 Engine generator set founda-tion

With steel springs under the engine generator sets,the dynamic forces and vibrations acting on thefoundation are close to zero.

The foundation of the engine generator set must bein accordance with Wärtsilä’s design or approved byWärtsilä.

The engine generator set foundation is a block, whichis cast in a single continuous pour. It is separatedfrom the surrounding floor slab with an elastic joint.A drain channel connected to an oily waste collectionsump runs around the block. See Figure 97.

For dimensions and details, see Figure 98. The figureapplies at sites where no piling is needed. A deeperblock is required at sites where piling is necessary.




Figure 96. Typical engine hall foundation

Figure 97. Cross section of the engine hall foundation




Figure 98. Engine generator set foundation drawing

9.3.3 Material and strengthUnless local exposure conditions or local regulationsset stricter requirements, the foundations shall bemade of grade C20/25 concrete reinforced with highyield deformed reinforcing bars with minimum yieldstrength fy = 414 N/mm2.

The required load bearing capacity of the floor slabsoutside the engine generator set foundations is 10kN/m2 for spread loads and 40 kN/m2 for pointloads.

For quality requirements, refer to applicable buildingcodes.

9.3.4 Floor tolerancesThe following figure shows the tolerance require-ments for the zones under the engine generator setfeet.

For the foundation under the auxiliary module, thetolerance is 10 mm.




Figure 99. Floor tolerance for the engine generatorset (helical springs = hatched area)

9.3.5 Floor drainsFor drain collection, there are the following alterna-tives:

A long drain channel running under the row ofEAM modules with one or several collection pits

A short channel with a collection pit per engine.

The floor should slope slightly towards the floordrains.

Typical dimensions of the drain channels:

width = about 300 mm

depth = about 200 mm with a slope of 1:100 tothe collection pit.

9.3.6 Surface treatmentThe upper surface should be coated with an Epoxypaint (or hydrocarbon resistant paint) to prevent con-tamination of the concrete.

9.4 Other foundations

9.4.1 Tank yard and pump stationThe tank foundations are normally ring beams filledwith fine sand or similar material. They are made ofconcrete and about 200 - 500 mm (8 - 20 inch) thick,depending on whether anchorage is needed or not.The need for anchorage is determined by local regula-tions and depends on the height of the tank, windconditions and seismic conditions, etc.

Generally, according to applicable standards andbuilding regulations, the tanks must be located insidea concrete basin type containment area sized to holdthe volume of the biggest tank plus a safety margin.

There should be two different collecting systems, onefor drained water and possible oil leakages, and onefor rain water. The operator decides whether toempty the containment area to the rain water drainsystem or the oily water sump.

Figure 100. Tank yard oily water and rain water col-lecting systems

The platform of the pump station must be designedwith drain grooves and drain pit according to localstandards and regulations.

9.4.2 Stacks, radiators and trans-formers

The stack, radiator field and transformer foundations,are sized in accordance with the soil study results andthe weight of the equipment.

The foundations of oil filled transformers are typi-cally built as a containment area. Depending on localregulations, a containment area may also be requiredunder the radiator field if glycol mixed water is used.




9.5 Frames, outer walls androofs

9.5.1 GeneralLocal building regulations determine the loadings thatthe building must be designed to withstand. Factorsto be considered include local weather conditions,risks for earthquake and hurricanes, as well as otherdead loads, live loads and design loads.

The fire resistance of the building must fulfil nationalor local regulations.

9.5.2 Engine hallThe Wärtsilä standard engine hall building is normallya steel structure with a moment resisting frame whereboth ends of the columns are rigidly connected intransversal direction, and a braced frame is used inlongitudinal direction. Two rows of columns in thecentre of the hall.

Alternatively, a frame is used instead of columns(Figure 102), and the ends are fastened with joints(“Free standing building”).

The standard wall panel used by Wärtsilä is an insu-lated, lightweight, sandwich type construction wherethe surface metal sheets are bonded to the rock wool.The exterior surface is made of galvanized, substratecoated, mouldable steel sheet with polyvinylchloridecoating. The wall is fire resistant and non-combustible.

Figure 101. Standard wall panel

The standard roof consists of load bearing steelsheets, noise and heat insulation and water proofingcorrugated steel sheet.

Figure 102. Steel structures for free standing building




9.5.3 Auxiliary structures

Stacks

The main function of the stack is to conduct the ex-haust gases to such a height that the emissions meas-ured for a specific area are according to the localregulations. Required stack height depends on thedispersion of the stack emission, which depends onthe stack design, topography, wind conditions, andnumber of engines in the plant.

Stacks can be arranged as a clustered stack with sev-eral exhaust gas pipes grouped together or individualstacks for each engine.

Exhaust gas pipe support structures

The exhaust gas pipes must be supported as requiredby the load of the pipes considering the static forcesfrom the weight of the pipes, the vibrations from theengine, and thermal and pulsating forces.

9.6 Interior structures

9.6.1 Inner walls, floors, and ceilingsWärtsilä typically designs switchgear floors withraised floor with at least 1600 mm space underneathto pull cables, etc.

9.6.2 Lifting and transportation ar-rangements

For maintenance purposes, it is recommended thatthe engine hall is equipped with a suspended travel-ling overhead crane that reaches all engines, with acapacity of minimum 2 tons.

Figure 103. Travelling overhead crane

9.6.3 Support structures

Exhaust gas module supports

Supports for the exhaust gas are constructed as be-low.

Figure 104. The exhaust gas module supports

Stairs, catwalks and landings

As standard, stairs catwalks and landings are con-structed of galvanized steel gratings built on frames.Applicable labour codes and standards must be fol-lowed.

Gratings and ladders must not be fixed to the enginegenerator set.




9.7 Heating, ventilation and air conditioning

9.7.1 Process ventilation

General

The ventilation of the engine hall can be classified as process ventilation. The basic design principles are:

• to remove the heat produced by the engines, gen-erators, auxiliary equipment and electrical equip-ment

• to change air according to applicable standards

• to prohibit environmental dust from entering by keeping the hall slightly pressurized.

Air intakes and outlets

The engine hall in a Wärtsilä designed plant has two ventilation units per engine generator set, one at the engine side and one at the generator side of the build-ing and one air outlet per engine, generally located on the roof. The ventilation outlets can be continuously open, manually opened and closed, or opened and closed with locally or remotely controlled motors, dependent on the climate.

Ventilation units Figure 105. Ventilation of engine hall

If the outlets cannot be placed on the roof, exhaust air fans are needed. In these cases, the inlet and outlet fans must be interlocked to ensure that the exhaust air flow follows the intake air flow. Maximum over pressure in the engine hall is 60 Pa.

The air intake louvers should be designed to prevent rain water and dust from entering the system. If the environment is heavily polluted, a high performing filtering system is needed. In arctic climate, a heater element can be placed in the inlet chamber to preheat the ventilation air to about +5 °C.

Air change rate

The prerequisite for the engine hall being unclassified area regarding explosion safety is that the ventilation shall be adequate at all times according to valid regu-lations. According to API500, the minimum demand is 6 air changes/hour and 18m3/h per m2 building area. To meet the heat evacuation demand, described in the following section, the ventilation in a Wärtsilä designed plant normally achieve up to 50 room vol-umes air changes per hour.

The minimum ventilation must be on at all times as long as the equipment in the enclosed classified area contains gas. However, if the gas supply to the engine is closed outside the engine hall, no ventilation is re-quired of an engine in stand by mode.

Heat evacuation

The Wärtsilä design target is to restrict the tempera-ture increase in the occupied zones of the engine hall to 10°C above the maximum ambient temperature in hot climates. Due to stratification, 10°C temperature increase in the occupied zone means that the total temperature increase in the hall from inlet to outlet is in the range 14 - 17°C.

Figure 106. Computerized modelling of engine hall

temperatures related to the intake air temperature

The ventilation air should be equally distributed in the engine hall considering air flows from points of delivery towards the outlets.




For estimating the total heat to be evacuated, all heatsources should be considered. The heat losses fromthe engine generator set depend largely on the load.For an estimation of the heat radiation, see the tech-nical data tables in chapter 11. The heat emissionfrom the engine auxiliary module can be estimated tobe 10 kW.

Process ventilation units

In plants built by Wärtsilä, the engine hall ventilationunits are equipped with axial fans, which are compactand easy to maintain. The inlet fans can either bestarted manually, or each fan can be started automati-cally at start-up of the respective engine. The engineventilation fans can be equipped with frequency con-verter control, which gives enhanced flexibility, re-duced electricity consumption and increased comfort.

9.7.2 Comfort ventilation andair conditioning

General

The comfort ventilation covers the control room,possible offices and restrooms, and the electricalrooms. The main task of the comfort ventilation is torestrict the temperature and maintain air-changes.The basic design principles are:

to change air according to the rate prescribed inlocally applicable laws or regulations (for instance,American Society of Heating, Refrigerating andAir-Conditioning Engineers, ASHRAE)

to remove the heat dissipated by the electricalequipment and heat loads caused by sun radiationand people

to keep the air-conditioned rooms slightly pressur-ized to prohibit moisture from condensing in theconstructions.

Ventilation of electrical rooms

The electrical rooms must be equipped with air con-ditioning systems if the temperature cannot otherwisebe kept below 30°C. These rooms are not consideredas continuously occupied. The air conditioning sys-tem is generally handled by roof top units with back-up arrangements, usually two independently operat-ing units. The AC system is to be sized according tothe heat dissipation from the electrical equipment.

Ventilation of DC room

During the charging process, hydrogen gases will bereleased from the DC batteries. If the batteries aremetal enclosed, the gases must be conducted to wellventilated surroundings. Due to the explosion risks,the ventilation air from the DC enclosures or DCroom should have separate outlet ducts.

The medium voltage switchgear may require arc gasexhaust ducts depending on local standards and themanufacturer’s recommendations.

Ventilation of control rooms and offices

Control rooms and offices are considered as normaloffices, and the comfort ventilation is handled ac-cording to the requirements in valid regulations (forinstance, ASHRAE 55 and 62). The air conditioningis handled either by a roof top unit arrangement or bya separate, modular, unit. Generally, the design prin-ciple is to maintain a temperature of 20 - 25°C.

9.7.3 Air filtering and silencers

Air filtering

Air filtering is needed to prevent dust particles fromentering the building. Filtering panels are designedfor particles of a given size and should be sized toallow acceptable ventilation even when the filter me-dia is clogged. The air filters should be equipped withlocal differential pressure meters, optionally with re-mote supervision in the plant control system.

The filters used by Wärtsilä are changeable bag filterswith filter media made of fibre. Standard filtrationclass is Eurovent 779 G4 or ASHRAE 52.2 MERV 8for the process ventilation and F5 or MERV 10 forthe comfort ventilation. On locations with high con-centrations of dust in the outside air, various types ofpre-filtration systems are used.

Silencers

Project specific noise calculations give the allowablenoise emission to the surroundings from the ventila-tion system. As a rough assumption, total allowedsound level for all ventilation units can be regarded tobe 65 dB(A) at 100 m distance.




9.8 Fire protection

9.8.1 GeneralFire protection is a combination of passive and activemethods. Passive fire protection comprises safetydistances and fire barriers to ensure structural integ-rity and limit the spread of fire. Active fire protectionincludes detection and alarm systems as well as fireextinguishing systems.

Wärtsilä defines two standard levels of fire protec-tion, base level and extended level, which differmainly in the extent and capacity of the fire extin-guishing system. In a gas plant, the extended level isrecommended. The fire protection system design isbased on a fire risk evaluation and the NFPA stan-dards which are used as guidelines.

Each country has its own fire protection legislationand practices. Fire protection design must, therefore,always be reviewed with local authorities. In addition,the insurance companies may require a certain fireprotection level, or may offer reduced fees for plantswith a high protection level.

9.8.2 Fire areasIn order to limit the spread of fire, protect personneland limit the consequential damages in case of a fire,the power plant should be subdivided into separatefire areas. Different fire areas should be separatedwith fire barriers, spatial separation or other approvedmeans.

Fire barriers are typically used to separate the controlroom, oil filled transformers, electrical rooms and thebattery room. Spatial separation is used between en-gine halls, maintenance shops, tank areas, fire pumps,warehouses, and offices. Typical minimum space is9.1 meters.

9.8.3 Fire alarm system

General

The purpose of the fire alarm system is to give peoplein the building enough time to escape in case of afire, and to start the fire extinction as early as possi-ble. Fire detectors and alarm devices must be installedthroughout the plant. In hazardous areas, explosionproof equipment must be used.

The plant control system can be programmed to initi-ate a plant shut down on a specific fire alarm.

Fire alarm centre

The fire alarm centre should be centrally located,preferably in the control room. The alarm centremust be equipped with a DC system as reserve powersupply.

Fire detectors and manual call points

The engine hall should be provided with opticalsmoke detectors, differential heat detectors or flamedetectors. In other rooms, heat detectors or ionisa-tion smoke detectors can be used. The number ofdetectors depends on their coverage area or allowedspacing, the size, shape and height of the rooms, theventilation, and the air change rate. To avoid falsealarms, the intended use of the room must be consid-ered when designing the fire detection system.

Manual call points should be provided at criticalpoints and exit points.

Fire alarm signalling devices

Alarm devices should be so placed that they can beseen or heard in all locations where people stay morethan temporarily. Alarm lights are obligatory insidethe engine hall where the sound level is high. Outsidethe buildings, sound alarm can be used.

Fire alarm cables

The system supplier’s recommendations should befollowed. In addition, locally valid standards, rulesand regulations must be followed. Local fire regula-tions may, for instance, require the use of fire resis-tant cables. Unless EMT conduits are required, Wärt-silä uses aluminium tubes around indoor cables notrunning on cable ladders.

9.8.4 Gas detection systemGas detectors are required in the engine hall to detectany gas leak. The detectors, at least two per engine,should be located where gas most likely will be pre-sent in case of a leakage, that is, normally above thegas regulating units and at the ventilation air outlets atroof level.




Figure 107. Gas detectors

The gas detection system should be connected to theplant control system, which activates an alarm when agas detector is sensing 10 % of the lower explosionlimit (LEL). When a gas detector is sensing 20 % ofLEL or more, the gas supply is shut off. If the gasdetectors have only one alarm level, 20 % of LEL isused for initiating shut-off of the gas supply.

9.8.5 Fire extinguishing systems

General

Water-based, gas-based, or dry chemical fire extin-guishing systems can be used. Chemical systems aremainly used locally and in small spaces. Gas-basedsystems are used in small enclosed spaces. Water-based systems can also be used in an optional sprin-kler system in the engine hall.

A water-based fire fighting system consists of:

A water supply source, possibly a fire water tankand pumps

A fire water piping system, fire hydrants, loose firehose equipment, permanently connected fire hosereels, and mobile foam units

Possibly an automatic sprinkler system

Portable extinguishers.

Primarily, a burning gas flame should be extinguishedby shutting off the gas flow. Otherwise, remainingunburned gas may explode on contact with hot sur-faces. A sprinkler system cools the hot surfaces andso reduces the risk for re-ignition.

Fire fighting water supply requirements

The fire fighting water source should supply the firehydrants, hoses and sprinklers with adequate amountof water. Unless local regulations impose stricter re-quirements, the system should be sized for two hoursof operation for both hydrant and sprinkler systemsin accordance with NFPA 850-4-2.1.

Required flow in hoses according to NFPA 850 is1900 l/min. The flow required for the sprinkler sys-tem calculated according to NFPA 13 Area/densitymethod and Extra Hazard Group I, is about 3000l/minute (for one engine generator set). As bothshould be able to operate simultaneously, requiredminimum flow is about 5000 l/minute.

At the rated flow, the pressure must be at least 8 bar,but not exceeding the design pressure of the pipesystem at zero flow, max. 12 bar.

If fire brigade services are available, there should beat least one fire department connection to allow foradditional water supply.

Fire water tank and pumps

A fire water tank and fire fighting pumps are requiredif the regular water supply system cannot be reliedupon to supply water for the required flow and pres-sure.

According to the Wärtsilä base level system design,the water capacity of the fire water tank is at least 240m3 and according to the extended level systems, atleast 600 m3. For filling the tank, raw water must beavailable, and possibly one or more pumps. Accord-ing to NFPA22, the tank must be filled within eighthours.

There should be two fire fighting pumps of adequatecapacity, one electric and one diesel engine driven,either one able to deliver the required amount of wa-ter. The pumps should be located near the fire watertank and so that they are not exposed to fire in thesurrounding areas.

Wärtsilä can provide a standard fire fighting pumpcontainer including a control system. The containerhas two fire fighting pumps, one diesel driven andone electrically driven, and a jockey pump that main-tains the system pressure in the pipes. The fire fight-ing pumps are started automatically when the pres-sure drops below a certain limit.




Fire water pipes, hydrant posts, hoses andmobile foam units

The fire service piping conducting water to the hy-drants, hoses and foaming units is a closed loop sys-tem consisting of pipes, valves, elbows, branches,reducers and shut-off valves. To ensure adequatepressure at the outlet points, the pressure drop in thesystem must be calculated and checked.

Generally, Wärtsilä uses standpipes of class II in ac-cordance with NFPA 14. The main pipe from the firewater source is built with NFPA24 as guideline (pri-vate fire service main).

Hydrant posts and hose reels shall be located in ac-cordance with locally valid laws and regulations. Ac-cording to NFPA 14, maximum distance betweenhydrant posts is 40 m.

Mobile foam units are used to suppress possible oilfires.

Automatic sprinkler system

Wärtsilä’s extended level fire fighting system includesa wet type sprinkler system. The system is heat acti-vated – sprinklers in the fire area are activated by theheat – and equipped with a flow activated alarm. Toavoid accidental release, temperature class high (bluebulb) is used.

When designing a sprinkler system, note that the pipesupport structures must be substantial enough tocarry the piping system filled with water.

The sprinkler system must be supplied directly fromthe fire service main pipe.

Portable extinguishers

Carbon dioxide extinguishers are used in electricalspaces, the control room, and accommodationspaces. Powder extinguishers are used in the enginehall, auxiliary hall and workshop.

9.9 Water supply system

9.9.1 GeneralThe water used in the plant can be taken from a mu-nicipal water supply system or ground water well ifreliable supply of sufficient quality, amount and pres-sure is available. In areas where this is not the case, awater tank and possibly a water treatment unit will beneeded. The need for water treatment depends on theraw water quality, which must be investigated by araw water analysis.

The water should fulfil the highest requirements forany process in the plant. Possible seasonal changes inthe raw water quality must be considered.

The following scheme gives an overview of the watersupply system in a plant with water treatment.

Figure 108. Water treatment and storage

Even though no water treatment is needed, a purewater tank and booster pumps may be needed forpeak consumption.

The plant is designed for a water pressure of at least 4bar. Water boosters are needed if this water pressureis not otherwise obtained.

9.9.2 Water consumptionProcess water is consumed by the following proc-esses:

Make up water in the primary cooling water sys-tem, and make up water in the secondary coolingwater system if central cooler is used

Heat recovery system (if included)




In addition, water is needed for the fire fighting sys-tem, washing, and for sanitary water in toilets andpersonnel rooms. In a gas plant with radiator cooling,the largest water consumer is the sanitary system.

In a plant without heat recovery, the water supplysystem should be sized for a consumption of 4 li-tres/MWhe. Heat recovery requires min. 10 % of thesteam production when there is full condensate re-turn (boiler feed water quality).

If water treatment is employed, the continuous aver-age raw water consumption will be higher due to wa-ter rejected from the treatment process. Typically,there should be raw water available 1.7 times the purewater consumption as continuous average.

9.9.3 Water treatment unitWater can be treated in several different stages de-pending on the purpose of the water. Rough particlesare separated by screening. Metals and organic matterare removed by sedimentation and/or flotation. If ahigher level of cleanness is required, e.g. softening,evaporation, reverse osmosis and disinfection can beutilised.

Wärtsilä offers a standard water treatment plantcomprising filtration, softening, and Reverse Osmosis(demineralisation). The plant is available in four sizes:1, 2, 4 and 6 m3/h. A treatment plant with a capacitylarger than the calculated demand should be chosen,including a safety margin of at least 20%.

For big power plants two smaller water treatmentplants can be considered instead of one big system.Using two plants provides redundancy and ensureswater supply for critical process equipment.

For quality requirements, see section 12.3.

9.9.4 Water booster unitIn a power plant there are several small water con-sumptions that require water only for short periods.On the other hand, the pipe connections can be rela-tively long and tortuous. This exposes pumps to ex-cessive wearing and pressure strokes. In order to pro-tect the pump from ageing too fast, pressure balanc-ing water tanks can be installed close to the consump-tion points. A pressure balancing tank is basically asmall tank, about 100 … 120 l (26 … 32 gallons) witha certain water level that is divided by a diaphragm.Compressed air is fed into the tank in order toachieve the start pressure level of the pump.

9.9.5 Water storage tanksThe pure water tank should be sized to allow for 8hours’ stop in the water supply. Likewise, in a plantwith water treatment, the recommended volume ofthe raw water tank is 8 hours’ raw water demand orminimum 5 m3.

The water tanks can be fibreglass, plastic or stainlesssteel tanks, or carbon steel tanks with immersionproof epoxy paint inside.

9.10 Waste water systems

9.10.1 Sewage systemThe sewage water comprises water from toilets,washing basins, and washing water from drainage.The amount of sewage water can be estimated to bethe same as the sanitary water consumption.

If local laws and regulations so require, the sewagewater must be treated before discharged to the mu-nicipal water treatment plant or nature. The sewagewater treatment should be chosen based on the localoutlet water requirements.

For treating sewage water, Wärtsilä can deliver astandard unit including a septic tank and sewage wa-ter pumps.

9.10.2 Oily water system

General

Oil contaminated water from the floor drains in theengine hall, workshop, tank yard and unloading pumpstation should be collected by gravity to oily watercollecting sumps, generally concrete tanks situatedbelow ground. See Figure 100. From the collectingsumps oily water is pumped to the oily water tank,where it is stored until transportation for disposal ortreatment.

Local regulations may require double containment oftanks and pipes.

Oily water sumps

Oily water sumps are available in three standard sizes:2.5 m3 , 5 m3 and 10m3.




Figure 109. Oily water sump

The sumps are equipped with upper and lower levelswitches for automatic control of the transfer pumps.

The needed number of sumps depends on the plantsize and layout.

Oily water transfer pump unit

The standard oily water pump unit for transferringsludge from the sludge sumps to the oily water tank isan air-driven diaphragm pump mounted on a frame.The typical pump unit has a capacity of 6 m3/h.

The transfer pump unit can be configured for manualor automatic operation. In automatic operation it isequipped with a control panel.

Figure 110. Membrane pump

Oily water unloading pump unit

The oily water unloading pump unit for pumping oilywater from the oily water tank to a truck is similar tothe oily water transfer pump unit described above.The pump is started and stopped manually.

Oily water tank

The standard oily water tank delivered by Wärtsilä is avertical cylindrical tank made of carbon steel, which isplaced above ground. To prevent freezing in coldclimates, the oily water tank should be equipped witha heating coil.

When sizing the oily water tank, the factors to con-sider are the amount of oily water produced per dayand the appropriate emptying interval. Note that, inorder to protect a possible heating coil from over-heating, the tank should not be emptied completely.

The available standard tank sizes are 35, 55 and 80m3.

9.11 Lighting

General

The requirements set by local laws and regulationsmust be followed. If needed, all equipment on thesite, indoors and outdoors, should be illuminated.

Figure 111. Site lighting example

Lighting levels

As standard Wärtsilä uses the following lighting lev-els:

Engine hall: 300 luxControl rooms: 500 luxElectrical rooms: 200 luxOther rooms: 100 luxOutdoors: 20 lux

Table 34. Lighting levels

Emergency lighting

Emergency lights should be installed at all exit doors.In hazardous areas, emergency lighting shall be ex-classified.




Aviation obstruction lighting

If local regulations so require, the stacks must beequipped with obstruction lights.

Wärtsilä 34SG Power Plant Product Guide 10. INSTALLATION AND COMMISSIONING



10. INSTALLATION AND COMMISSIONING

10.1 Delivery and storage

10.1.1 Engine generator set

Transportation

The engine generator set is usually delivered andtransported as one unit covered by a tarpaulin.

Storage

It is recommended to store the generator sets in-doors. If stored outdoors, the original covering of theengine generator sets must be kept unbroken.

Lifting the engine generator set

If needed, the engine generator set can be lifted witha crane.

Figure 112. Lifting the engine generator set with acrane

The engine generator set can be lifted on and off thetrailers using hydraulic jacks placed in the four jackingpoints, two on each side of the engine generator set.

Figure 113. Lifting engine generator set by jacking

10.1.2 Engine auxiliary equipmentand pipes

The auxiliary modules and units are delivered in con-tainers or boxes. It is recommended to store themindoors. If stored outdoors, they should be kept un-packed or covered with a tarpaulin. Pipes must bestored indoors in dry and warm conditions.

10.1.3 Electrical and control systemequipment

The electrical equipment should be stored indoors indry and warm conditions according to the manufac-turer’s instructions. In cold climates, also the cablesneed to be stored in a warm location for 24 hoursbefore installation.

The equipment must be lifted in accordance with themanufacturer’s instructions.




10.2 Installation

10.2.1 GeneralThe installation of the engine generator sets and theauxiliary equipment must be done in accordance withthe drawings and installation instructions providedfor the specific project in the installation file. Beforestarting the installation work, all necessary documentsare given to the client and to the subcontractors atsite.

The site manager and his supervisors follow up thatthe quality instructions, installation instructions andcontract requirements are followed at site.

The mechanical installation involves the followingmain work phases (not necessarily in this order):

Installation of the engine generator sets

Installation of the standard modules and otherauxiliary units

Pipe installation and flushing

Installation of maintenance platforms

The installation of the electrical systems and controlsystems involves lifting and placing switchgear, con-trol cabinets, transformers, etc., cable pulling, andconnecting the cables.

To enable the installation of the engine generatorsets, a sufficient large opening should be left in thewall at the generator side. Alternatively, the entirewall may be left open until the engine generator setshave been installed.

If there is restricted space in the auxiliary area, it maybe most practical, or even necessary, to place the en-gine auxiliary modules and exhaust gas modules intheir approximate positions before installing the en-gine generator sets. However, the modules cannot bealigned and mounted until the engine generator set isplaced in its final position.

10.2.2 Installation of engine genera-tor set

Moving the engine generator set to its posi-tion

The engine generator set can be brought into the en-gine hall and positioned on the foundation using rails.

Positioning and aligning generator set

The engine generator set must be installed exactly inaccordance with the installation drawings.

The vibration mounts must be fixed to the commonbase frame in exact positions in accordance with thedrawings. For aligning the generator set horizontallyshim plates are to be used.

Figure 114. Spring elements

Anchorage to foundation

The engine generator sets are mounted on anti-vibration mounts and do not need an anchorage ontothe foundation, except in earthquake sensitive areas.In earthquake sensitive areas, the anchorage for per-manent equipment shall be designed to resist the lat-eral seismic forces prescribed in national standards.The lateral anchorage to the concrete foundationmust be arranged with chemical anchor bolts.

10.2.3 Installation of auxiliaryequipment

Engine auxiliary modules

The engine auxiliary module must be exactly alignedwith the engine and is therefore installed after theengine, although it may be necessary to place itroughly in its position before the engine is installed.The module is mounted to the floor with bolts, andthe feet are welded to the module frame after themodule is finally aligned in its position.




Exhaust gas module

Like the engine auxiliary modules, the exhaust gasmodules should be lifted on their stands before theengine generator sets are brought to their places. Theexhaust gas modules are lifted on to the stands with acrane or fork-lift truck.

Other auxiliary units

Generally, standard auxiliary units are skid mountedfor easy installation.

10.2.4 Installation of piping systems

Installation procedure

The following aspects shall be taken into considera-tion when planning the installation:

Install all units and major equipment before start-ing to install the pipes.

Install larger pipes prior to smaller ones and mainlines before branches.

Technically more difficult systems should be builtbefore simpler systems.

Cleaning procedures

All pipes must be inspected and ensured to be cleanfrom debris before installation and joining. Espe-cially, all fuel gas and lubricating oil pipes must bewell cleaned to ensure that no sand, rust, slag, etc. willenter the engine.

The following cleaning methods should be used:

Pipe A B C D FFuel gas pipes x x x x xLube oil pipes x x x x xStarting air pipes x x xCooling water pipes x x xExhaust gas pipes x x xCharge air pipes x x x

where:

A = Degreasing by washing with alkaline solution inhot water at 80 oC (if the pipe has been greased)

B = Removal of rust and scale with steel brush (notrequired for seamless precision tubes)

C = Purging with compressed airD = PicklingF = Flushing with lube oil

The pipes included in the standard modules arecleaned and plugged in the shop. If a pipe inspectionat site shows that no dirt or rust has been formed inthe pipes during transportation and storage, a finalflushing of the lube oil pipes is enough.

Installation of flexible pipe connections

Great care must be taken to ensure the proper instal-lation of flexible pipe connections between resilientlymounted engines and fixed piping. The flexible bel-lows and hoses included in the engine delivery mustbe used.

Note, for instance, the following:

Flexible pipes must not be twisted.

The installation length must be correct.

Minimum bending radius must be respected.

Piping must be concentrically aligned.

Mating flanges shall be clean from rust, burrs andanticorrosion coatings.

Flexible elements must not be painted.

The piping must be rigidly supported close to theflexible piping connections.

10.2.5 Installation of electrical andcontrol systems

General

The installation of the electrical and control systemsmust be done by authorized electricians.

The installation of boards, panels and cabinets can bestarted when the installation site is dry, painted andfinished. The cabling can be done when the equip-ment has been installed and the conduits and cableladders are in place. Cable racks are generally installedafter the process piping and ventilation ducts to en-sure future accessibility.




The electrical contractor should supervise the con-struction of elevated floors, cable trenches, and open-ings to ensure trouble free installation of the electricalequipment, and to ensure that trays and racks arelifted in before the routes are blocked.

Installation of equipment

Electrical equipment, such as switchgear, transform-ers, control cabinets, neutral point cubicles, and DCcabinets are assembled, mounted and fixed in accor-dance with the manufacturer’s instructions, the elec-trical drawings and the layout drawings.

Before installing the switchgear, the positions anddimensions of the foundations and cable openingsmust be verified. During the installation, the arc dis-charge channels must be regarded.

Installation of electrical cables

When installing the cables, cooperation with the me-chanical installation personnel is required in order toavoid encounters with piping or other structures.Borings for small penetrations through the walls arecarried out by the installer. Larger openings are re-served in the construction drawings.

Cable pulling must be done in controlled circum-stances, and not in too low ambient temperatures,according to the manufacturer’s instructions. To re-duce friction, the cables should be lubricated withappropriate grease.

All cables connected to the engine generator set mustbe cut, laid and fastened with slack so as to allow themovements of the engine generator set without caus-ing stress on cables and terminals.

Marking of cables

The cables must be marked in both ends with theidentification number in accordance with the cablelists. Each cable core is marked with the codes of theterminals to which it is connected.

10.3 Commissioning

10.3.1 GeneralThe term “commissioning” means the activities nec-essary to bring the power plant into operation afterthe installation. It can be divided into the followingphases:

Pre-commissioning before first start-up of theengine generator sets

First start-up, running in and fine tuning

Performance tests.

Part of the activities can be performed simultane-ously; part of them must be performed sequentially.

10.3.2 Pre-commissioningPre-commissioning covers all the mechanical andelectrical inspections and tests required to prepare theplant before the plant is energized.

Pre-commissioning involves, for instance:

Pressure tests and cleaning procedures

Functional tests of protection relays

Tests of main and control circuits

Voltage tests of generators and power cables.

The tests must be done in accordance with applicablestandards.

Pre-commissioning involves also the inspections andtests related to civil works, such as buildings,grounds, heating, ventilation, etc. These activitiesstart already during the construction phase and con-tinue through the installation phase.

When the plant electrical systems are energized forthe first time, the power is usually supplied by an ex-ternal source, normally back-fed from the grid. Whenenergizing equipment, the correct voltage and phaserotation must be checked and verified.




10.3.3 Running in and fine tuning

Engine generator sets

First start-up and running in of a new engine must beperformed according to the program provided for theengine. Functional tests must be done and recorded.

Required adjustments of the engine generator setsand gas regulating units should be done by qualifiedpersonnel from Wärtsilä.

Auxiliary systems

Before starting the auxiliary systems, they must befilled. During first start-up, they are verified for cor-rect function. The commissioning staff should finetune and record the process values. Fine tuning re-quired on the auxiliary systems at site involves cool-ing system flow adjustments.

10.3.4 Performance tests

General

Performance tests are conducted to demonstrate andverify compliance with the performance guarantees inthe contract. The test parameters, guaranteed per-formance values, and the performance tests proce-dures are project-specific and specified in the con-tract.

The tests may include the following performance pa-rameters:

Power output, from individual engine generatorsets and/or from entire plant

Heat rate

Lube oil consumption

Power consumption of plant auxiliaries

Voltage and frequency variations

Noise emissions

Stack emissions.

The tests are documented in a commissioning file anda handing over certificate. Any open items will belisted in a punch list, and a schedule for correctiveactions is made.

Performance tests can be done when the installationis completed, and all pipe systems, auxiliary units,electrical systems, and control equipment are adjustedand calibrated for correct operation.

Wärtsilä 34SG Power Plant Product Guide 11. TECHNICAL DATA



11. TECHNICAL DATA


The following data is based on 100% load (power factor = 0.8), standard reference conditions according to ISO30461 and defined at generator terminals.

Table 35 Electrical Output and -heat rate for 50 Hz

Engine type Wärtsilä 9L34SG Wärtsilä 16V34SG Wärtsilä 20V34SGNOX setting mg/Nm³ 250 500 250 500 250 500Compression ratio 11:1 12:1 11:1 12:1 11:1 12:1 11:1 12:1 11:1 12:1 11:1 12:1Electrical Power kW 3888 3888 3888 3888 6970 6970 6970 6970 8730 8730 8730 8730Electrical heat rate kJ/kWh 8254 8065 7986 7817 8186 7999 7920 7753 8169 7982 7904 7737Electrical efficiency % 43,6 44,6 45,1 46,1 44,0 45,0 45,5 46,4 44,1 45,1 45,5 46,5

Table 36 Electrical Output and -heat rate for 60 Hz

Engine type Wärtsilä 9L34SG Wärtsilä 16V34SG Wärtsilä 20V34SGNOX setting mg/Nm³ 250 500 250 500 250 500Compression ratio 11:1 12:1 11:1 12:1 11:1 12:1 11:1 12:1 11:1 12:1 11:1 12:1Electrical Power kW 3758 3758 3758 3758 6737 6737 6737 6737 8439 8439 8439 8439Electrical heat rate kJ/kWh 8254 8065 7986 7817 8186 7999 7920 7753 8169 7982 7904 7737Electrical efficiency % 43,6 44,6 45,1 46,1 44,0 45,0 45,5 46,4 44,1 45,1 45,5 46,5

Including engine driven pumps, heat rate and efficiency includes 5% tolerance according to ISO 3046-1

1 Except for charge air coolant temperature, which is 35 °C




11.2 Engine Technical data

Engine type Wärtsilä 9L34SG

Wärtsilä 16V34SG

Wärtsilä 20V34SG

Engine speed rpm 750 720 750 720 750 720 Fuel gas system Pressure before engine, typical kPa (bar) 450 (4,5) Gas inlet temperature °C 0 - 60 Lubricating oil system Specific consumption, max g/kWh 0,4 Pressure before engine, nominal kpa (bar) 450 (4,5) Pressure before engine, alarm kpa (bar) 300 (3,0) Pressure before engine, stop kpa (bar) 200 (2,0) Oil volume, wet sump (nom) m³ 2,7 4,4 5,2 Pump capacity, main m³/h 110 105 158 152 180 173 Pump capacity, priming m³/h 19,5 23,5 52 63 52 63 Starting air system

Pressure before engine, nominal maximum Mpa (bar) 3 (30)

Pressure before engine, minimum for succesful start Mpa (bar) 1,5 (15)

Air consumption per start attempt, average at 20°C Nm³/h 8 11 13 Engine Control air system Consumption at high load Nm³ 8,3 ± 2 Cooling water system

Pump capacities (LT & HT), nominal flow m³/h 90 90 135 135 150 150

Pump differential pressure (LT & HT) kPa 283 251 255 226 265 235 LT water volume in engine m³ 0,18 0,27 0,31 HT water volume in engine m³ 0,56 0,84 0,94

HT temp after engine, nom. 1-C system / 2-C system °C 85 / 92

Static pressure before HT-pump, min. (g) °C 70 - 150 (0,7-1,5)

Static pressure before LT-pump, min. (g) kPa (bar) 70 - 150 (0,7-1,5) Pressure drop over engine, LT kPa (bar) 150 (1,5) 150 (1,5) 180 (1,8) Pressure drop over engine, HT kPa (bar) 150 (1,5) 150 (1,5) 150 (1,5)

Table 37 Technical data




11.3 Engine heat balances

The heat balances are based on standard reference conditions as defined in ISO3046-1, except for charge aircoolant temperature which is 35°C. Output, BSEC and efficiency are declared at the flywheel.

The following tolerances will apply: BSEC and efficiency 5% (ISO 3046-1), flows ± 5%, Exhaust gas tempera-ture ± 10°C, Charge air temperature after compressor ± 5°C, Heat loads ± 10%, Radiation ± 20%.

Table 38 9L34SG, 50 Hz, NOX = 500 mg/Nm³, CR=12:1

Load % 100 90 75 50 30Rated output kW 4050Brake mean effectivepressure, BMEP bar 19,83 17,84 14,87 9,91 5,95Brake specific energyconsumption, BSEC kJ/kWh 7505 7581 7771 8381 8893Efficiency % 48,0 47,5 46,3 43,0 40,5Engine output kW 4050 3645 3037,5 2025 1215Lube oil kW 430 420 390 340 280Jacket water kW 570 530 480 420 360Air temp. after comp. °C 183 169 149 115 74Charge air HT kW 540 400 270 110 -30Charge air LT kW 330 300 230 140 100Charge air total kW 870 700 500 250 70Charge air flow kg/s 6,4 6,0 5,3 4,0 3,1Radiation kW 130 120 120 120 110Exhaust gas flow after TC kg/s 6,46 5,8 4,9 3,7 2,6 xh. gas temp after TC °C 400 415 435 440 440




Table 39 9L34SG, 60 Hz, NOX = 500 mg/Nm³, CR=12:1

Load % 100 90 75 50 30 Rated output kW 3915Brake mean effectivepressure, BMEP kPa 19,96 17,97 14,97 9,98 5,99Brake specific energyconsumption, BSEC kJ/kWh 7505 7581 7771 8381 8893Efficiency % 48,0 47,5 46,3 43,0 40,5 Engine output kW 3915 3523,5 2936,25 1957,5 1174,5 Lube oil kW 420 410 380 330 270 Jacket water kW 550 510 470 400 350Air temp. after comp. °C 184 169 150 116 74,7

Charge air HT kW 520 390 260 110 -20 Charge air LT kW 320 290 220 140 100 Charge air total kW 840 680 480 250 80 Charge air flow kg/s 6,2 5,8 5,1 3,9 3,0 Radiation kW 120 120 120 110 110 Exhaust gas flow after TC kg/s 6,2 5,6 4,7 3,5 2,5 Exh. gas temp after TC °C 400 415 435 440 440

Table 40 16V34SG, 50 Hz, NOX = 500 mg/Nm³, CR=12:1

Load % 100 90 75 50 30 Rated output kW 7200Brake mean effectivepressure, BMEP bar 19,83 17,84 14,87 9,91 5,95Brake specific energyconsumption, BSEC kJ/kWh 7505 7581 7771 8381 8893Efficiency % 48,0 47,5 46,3 43,0 40,5 Engine output kW 7200 6480 5400 3600 2160 Lube oil kW 770 750 700 610 500 Jacket water kW 1020 950 860 740 640Air temp. after comp. °C 183 169 149 115 74






Load % 100 90 75 50 30 Rated output kW 6960Brake mean effectivepressure, BMEP kPa 19,96 17,97 14,97 9,98 5,99Brake specific energyconsumption, BSEC kJ/kWh 7505 7581 7771 8381 8893Efficiency % 48,0 47,5 46,3 43,0 40,5 Engine output kW 6960 6264 5220 3480 2088 Lube oil kW 750 720 680 590 480 Jacket water kW 980 910 830 720 620Air temp. after comp. °C 184 169 150 116 74,7

Charge air HT kW 930 700 470 190 -40 Charge air LT kW 570 510 390 240 170 Charge air total kW 1500 1210 860 430 130 Charge air flow kg/s 11,1 10,3 9,1 6,9 5,2 Radiation kW 220 210 210 200 190 Exhaust gas flow after TC kg/s 11,1 10 8,4 6,3 4,4 Exh. gas temp after TC °C 400 415 435 440 440


Load % 100 90 75 50 30 Rated output kW 9000Brake mean effectivepressure, BMEP bar 19,83 17,84 14,87 9,91 5,95Brake specific energyconsumption, BSEC kJ/kWh 7505 7581 7771 8381 8893Efficiency % 48,0 47,5 46,3 43,0 40,5 Engine output kW 9000 8100 6750 4500 2700 Lube oil kW 970 930 870 760 620 Jacket water kW 1270 1180 1070 930 800Air temp. after comp. °C 183 169 149 115 74

Charge air HT kW 1190 900 600 240 -60 Charge air LT kW 740 660 500 320 220 Charge air total kW 1930 1560 1100 560 160 Charge air flow kg/s 14,3 13,4 11,7 9,0 6,8 Radiation kW 290 280 270 260 250 Exhaust gas flow after TC kg/s 14,36 13 10,9 8,1 5,7 Exh. gas temp after TC °C 400 415 435 440 440





Load % 100 90 75 50 30 Rated output kW 8700Brake mean effectivepressure, BMEP kPa 19,96 17,97 14,97 9,98 5,99Brake specific energyconsumption, BSEC kJ/kWh 7505 7581 7771 8381 8893Efficiency % 48,0 47,5 46,3 43,0 40,5 Engine output kW 8700 7830 6525 4350 2610 Lube oil kW 930 900 850 730 600 Jacket water kW 1230 1140 1040 900 770Air temp. after comp. °C 184 169 150 116 74,7


11.4 Generator data (typical)

Engine Wärtsilä 9L34SG Wärtsilä 16V34SG Wärtsilä 20V34SGFrequency 50Hz 60Hz 50Hz 60Hz 50Hz 60HzRated output KVA 5428 5211 8712 8422 10913 10549Power factor cos phi 0,8 0,8 0,8 0,8 0,8 0,8Rated voltage V 11000 13800 11000 13800 11000 13800Rated current A 285 218 457 352 573 441Insul.class/Temp.rise F/F F/F F/F F/F F/F F/Fr.p.m. 750 720 750 720 750 720Enclosure IP23 IP23 IP23 IP23 IP23 IP23Standard IEC60034Ambient C° 50 50 50 50 50 50Altitude m 1000 1000 1000 1000 1000 1000Table 44 Technical data for medium voltage generators

Wärtsilä 34SG Power Plant Product Guide 12. FLUID REQUIREMENTS



12. FLUID REQUIREMENTS

12.1 Fuel gas requirements

The Wärtsilä 34SG engine is designed to operate without derating on natural gas qualities according to the fol-lowing specification.

In addition, to ensure the long term performance of the emission control system (if included), the concentrationsof sulphur components and catalyst poisons must be within the limits specified by the catalyst supplier.

Quality Limit values Notes

Lower Heating Value (LHV) 28 MJ/Nm3 Lower Heating Value corresponds to the energy content ofthe gas. If the LHV is too low, the engine output has to bereduced, or the gas pressure to the engine must be raised.

Methane number (MN) 55 - 80 Dependent on engine optimisation and ambient conditions.Methane content, CH4 70 vol. %Hydrogen sulphide, H2S 500 ppm Hydrogen sulphide H2S may cause corrosion on the gas

handling equipment.Hydrogen, H2 3 vol. % Any higher hydrogen contents must be agreed upon case

by case.Water and hydrocarbon conden-sates before the engine

Not allowed The dew point of natural gas is below the minimum operat-ing temperature and pressure.

Ammonia, NH3 25 mg/Nm3

Chlorines + Fluorines 50 mg/Nm3

Particles or solids, content 50 mg/Nm3

Particles or solids, size 5 mAt the engine inlet.Particles can be the reason for improper sealing and func-tion of the gas handling equipment.

Gas inlet temperature 0 – 60 °C

Table 45. Fuel gas quality requirements

The Methane Number provides a scale for evaluating the knock resistance of the fuel gas. Methane number(MN) indicates the percentage by volume of methane in blend with hydrogen that exactly matches the knockintensity of the gas mixture in question under specified operating conditions in a knock testing engine. A highermethane number means better knock resistance. If the components of the fuel gas are known, the methanenumber can be calculated. Heavier hydrocarbons as ethane, propane and butane will lower the methane number.Carbon dioxide and nitrogen will increase the methane number.




12.2 Lubricating oils

12.2.1 General requirementsThe lubricating oil should fill the following generalrequirements:

Viscosity class SAE 40Viscosity index (VI) Minimum 95Alkalinity (BN) 4 - 7 mg KOH/gSulphated ash level Maximum 0.6 weight %

Too high ash content can causepre-ignition, knocking and sparkplug fouling, while too low ashcontent can lead to increasedvalve wear.

Foaming character-istics according tothe ASTMD 892-92test method (freshlube oil)

Sequence I (24oC): 100/0 ml,Sequence II (93.5oC): 100/0 ml,Sequence III (24oC): 100/0 ml

Table 46. Lube oil requirements

For the speed governor, both turbine and normalsystem oil can be used. Turbine oil must not be usedin the engine.

Recycled or re-refined base oils are not allowed.

12.2.2 AdditivesThe oils should contain additives that give good oxi-dation stability, corrosion protection, load carryingcapacity, neutralization of acid combustion and oxi-dation residues, and should prevent deposit forma-tion on internal engine parts (piston cooling gallery,piston ring zone and bearing surfaces in particular).

12.2.3 Approved lubricating oilsLubricating oils approved by Wärtsilä should be used.See Table 47. The use of approved lubricating oils ismandatory during the warranty period and is alsostrongly recommended after the warranty period hasexpired.

Supplier Brand name Viscosity BN Sulphated ash(w-%)

BP Energas NGL SAE 40 4.5 0.45Castrol Duratec L SAE 40 4.5 0.45ChevronTexaco Geotex LA

Low Ash Gas EngineOil SAE 40

SAE 40SAE 40

5.24.2

0.450.50

ExxonMobil Pegasus 705Pegasus 805Pegasus 905Pegasus 1

SAE 40SAE 40SAE 40SAE 40

5.36.26.26.5

0.490.500.490.49

Idemitsu Kosan Co.Ltd.

Apolloil GHP 40L SAE 40 4.7 0.45

Petro-Canada Sentron 445 SAE 40 4.7 0.40Shell Mysella LA 40

Mysella XL 40SAE 40SAE 40

5.24.5

0.450.50

Total Nateria X 405 SAE 40 5.2 0.45

Table 47. Approved lubricating oils




12.3 Water quality requirements

Parameter UnitEnginecoolingwater

Turbinewashing

Coolingtower(circula-tion)

Boilermake-up

Boilerfeed

Boilerwater(p<15bar)

Oily watertreatment

General appearance Visually clear and colourless. No smell.pH at 25 °C > 6,5 7 to 8 9 to 9.5 9,5 to 11 6 to 8Conductivityat 25 °C

mS/m < 100 < 75 < 20 < 500

TDS mg/l < 500 < 130 < 2600Total Hard-ness TH

°dH < 10 < 10 4.5 - 28 (1) < 0.4 < 0.1

AlkalinityHCO3

mg/l < 300 < 100 < 25 < 500

TH + Alkalinityas CaCO3

mg/l < 650

p - alkalinity mg/l 5 - 15Oxygen O2 mg/l < 0,005Iron Fe andCopper Cu

mg/l < 0,1 < 0,2 < 0,1 < 0,5

Silicate SiO2 mg/l < 50 < 50 < 150 < 20 < 5 < 100 (2)

Organics(KMnO4value)

mg/l (< 30) (< 15) < 300 (3) < 15

Oil mg/l < 5 ND < 1 < 1Chlorides Cl mg/l < 80 < 80 < 450 (4) < 40 < 10 < 200 < 100Phosphates mg/l (5) 20 – 40SulphatesSO4

mg/l < 150 < 1200

Sodium + Po-tassium Na+K

mg/l < 160 < 40 < 800

Suspendedsolids

mg/l < 10 < 10 < 80 < 5 < 2 < 10

Table 48. Water quality requirements

(1) Maximum hardness in the cooling tower circuit water without chemical scaling inhibitors. Minimumhardness requirement to prevent corrosion.

(2) Maximum silicate content in the boiler is pressure dependent. The limit is lower for steam turbine instal-lations.

(3) Organic matter in the boiler water may lead to water bursting with steam resulting bad condensate qual-ity

(4) The maximum allowed chloride content in the cooling tower circuit can vary from 100 to 600 mg/l oreven higher depending on construction. Note that the maximum recommended chloride content in forthe stainless steel plate heat exchanger is only 300 mg/l.

(5) Phosphates are added to the boiler feed water for binding hardness of the water. It will also raise pHslightly. The final adjustment of pH is done by sodium hydroxide to maintain p- value. The activated so-dium sulphite or other oxygen binding chemical is also dosed to boiler feed water.

Wärtsilä 34SG Power Plant Product Guide 13. DIMENSIONS AND WEIGHTS



13. DIMENSIONS AND WEIGHTS


Figure 115 9L34SG Generating set

Figure 116 16V34SG Generating set

Figure 117 20V34SG Generating set




13.2 Standard auxiliary equipment

13.2.1 Gas regulating unit

Dimension / Pipe DIN design ANSI design NotesLength 2850 mm 117”Width 600 mm 26.5“Height 1430 mm 50”Weight (gross) 730 kgFuel gas inlet DN80 3”Fuel gas outlet, main DN100 3” or 4” Depends on the manufacturer and componentsFuel gas outlet, pre-chamber

DN25 1”

Venting 1 EO 12 1”Venting 2 DN25 2”Control air ¼” NPT ¾“ NPTInert gas EO 12 1”

Table 49. Typical GRU dimensions




13.2.2 Engine auxiliary module (EAM)

Figure 118 Wärtsilä 16V and 2034SG EAM module dimensions

13.2.3 Exhaust gas module

Figure 119 Wärtsilä 16V and 20V34SG Exhaust gas module dimensions




13.2.4 Standard auxiliary units

Maintenance water tanks

Tankvolume

Pump flow50 / 60 Hz

A B C D E

2.5 m3 5.4 / 6.5 m3/h 1206 mm 1500 mm 1209 mm 2000 mm 2527 mm4 m3 5.4 / 6.5 m3/h 1206 mm 1800 mm 1509 mm 2500 mm 3027 mm6 m3 9 / 10.8 m3/h 1636 mm 1800 mm 1509 mm 2500 mm 3027 mm10 m3 9 / 10.8 m3/h 2036 mm 1800 mm 1509 mm 3400 mm 3927 mm

Figure 120. Dimensions of standard maintenance water tanks

Exhaust gas silencers

Engine Type Attenuation [dB (A)] L [mm] D [mm] a [mm] b [mm] c [mm] d [mm] Weight[kg]

9L34SG 35 5 770 1700 2120 550 1020 1730 2860 9L34SG 45 7 520 1900 2320 550 1120 1930 417016V34SG 35 7 020 2000 2440 780 1140 2030 497016V34SG 45 10 020 2100 2540 780 1140 2130 705020V34SG 35 8 280 2300 2740 900 1320 2330 717020V34SG 45 9 270 2450 2890 900 1395 2480 8840

Figure 121. Typical dimensions of exhaust gas silencers




Intake air filter (example)

Figure 122. Intake air filter dimensions 20V34SG (example)




Radiators (example)

Figure 123 Radiator field

EngineType

Fans / Radiator[Qty]

Radiators / Engine[Qty]

Radiator field / engineL x W [m]

L1[mm]

L[mm]

W1[mm]

W[mm]

9L34SG 7 1 12.0 x 2.5 1650 11950 2520 252016V34SG 5 2 10.4 x 5.4 2000 10400 2520 504020V34SG 6 2 12.4 x 5.4 2000 12400 2520 5040

Table 50 Typical dimensions of Standard radiator field

EngineType

Fans / Radiator[Qty]

Radiators / Engine[Qty]

Radiator field / engineL x W [m]

L1[mm]

L[mm]

W1[mm]

W[mm]

9L34SG 4 2 8.4 x 5.1 2000 8400 2520 504016V34SG 6 2 12.4 x 5.1 2000 12400 2520 504020V34SG 5 3 11.4 x 7.6 2200 11400 2520 7560

Table 51 Typical dimensions of low-noise radiator field

Wärtsilä 34SG APP A. STANDARDS AND CODESProduct Guide



APP A. STANDARDS AND CODES

General

This appendix lists the most significant standardsand codes that Wärtsilä follows, where applicable, inthe manufacturing, design and engineering of Wärt-silä 20W34 power plants.

Explanation of abbreviations:

API American Petroleum Institute

ASHRAE American Society of Heating, Refriger-ating and Air-Conditioning Engineers

EN European standard

IEC International Electrotechnical Commis-sion

ISO International Organization for Stan-dardization

NFPA National Fire Protection Association

OSHA Occupational Safety & Health Admini-stration

Engine generator setIEC 34-1(EN 60034-1)

Rotating electrical machines

ISO 3046, 1 - 6 Specification for reciprocating in-ternal combustion engines

ISO 8178 Reciprocating internal combustionengines. Exhaust gas emissionmeasurement.

ISO 8528 Reciprocating internal combustionengine driven alternating currentgenerating sets

EN 1834-1 Resiprocating internal combustionengines. Safety requirements fordesign and construction of enginesfor use in potentially explosiveatmospheres.

EN 60204-1 Safety of machinery. Electricalequipment of machines. Generalrequirements.

NFPA 37 Standard for the installation anduse of stationary combustion en-gines and gas turbines

Fuel gas systemNFPA 54 Fuel gas code

Standard auxiliary modules and unitsEN 292 Safety of machinery. Basic con-

cept, general principles for design.

Piping systemsEN 13480-3 Metallic industrial piping. Design

and calculationEN 1591-1 Flanges and Their Joints - Design

Rules for Gasketed CircularFlange Connections

Electrical and control systemsIEC 298 A.C. Metal Enclosed Switchgear

and Controlgear for Rated Volt-ages Above 1 kV and Up to andIncluding 52 kV

IEC 56IEC502EN 60439-1 Specification for low-voltage

switchgear and controlgear as-semblies. Type-tested and partiallytested assemblies.

Fire protectionNFPA 10 Standard for portable fire extin-

guishersNFPA 13 Installation of sprinkler systemNFPA 14 Standard for the installation of

standpipe and hose systemNFPA 15 Water spray fixed systems for fire

protectionNFPA 22 Standard for Water tanks for Pri-

vate FM ProtectionNFPA 24 Standard for the Installation of

Private Fire Service Mains andTheir Appurtenances

NFPA 30 Flammable and combustible liq-uids Code

NFPA 37 Standard for the Installation andUse of Stationary CombustionEngines and Gas Turbines

NFPA 101 Life Safety CodeNFPA 850 Recommended practice for fire

protection for electric generatingplants and high voltage direct cur-rent converted stations

CEA 4001 Sprinkler System Planning andInstallation

Wärtsilä 34SG APP A. STANDARDS AND CODESProduct Guide



API 650 Tank Design Standard

Classification of hazardous areas

American codes

API 500 Recommended Practice for Classifica-tion of Locations for Electrical Installa-tions at Petroleum Facilities Classifiedas Class I, Division 1 and Division 2.

API 505 Recommended Practice for Classifica-tion of Locations for Electrical Installa-tions at Petroleum Facilities Classifiedas Class I, Zone 0, Zone 1, and Zone 2

NFPA 30 Flammable and Combustible LiquidsCode

European Codes

EN-60079-10

Electrical apparatus for explosive gasatmospheres; part 10 Classification ofhazardous areas

EN-1834-1 Reciprocating internal combustion en-gines – Safety requirements for designand construction of engines for use inpotentially explosive atmospheres –Part II engines for use in flammablegas and vapour atmospheres.

Platforms and staircasesISO 14122 Safety of machinery – permanent

means of access to machinery,part 1 - 4

OSHA 1910 Occupational safety and healthstandard, sub part D – Walking-working surfaces

OSHA 1926 Safety and health regulations forconstruction, subpart X - Stair-ways

Ventilation and air conditioningASHRAE 55 Thermal environmental conditions

for human occupancyASHRAE 55 Compliant Ventilation System.

:

Wärtsilä 34SG APP B. UNIT CONVERSIONSProduct Guide



APP B. UNIT CONVERSIONS

Length unitsLength m in ftm 1 39.370 3.2808in 0.0254 1 0.083333ft 0.3048 12 1mile 1609.3 63360 5280

Table 52. Conversion table for length units

Length m In ftm 1 1/0.0254 1/(12*0.0254)in 0.0254 1 1/12ft 0.0254*12 12 1mile 0.0254*63360 63360 5280

Table 53. Formulas for converting length units

Volume unitsVolume cubic m l (liter) cubic foot Imperial

gallonUS gallon

cubic m 1 1000 35.315 219.97 264.17l (liter) 0.001 1 0.35315 0.21997 0.26417cubic foot 0.028317 28.317 1 6.2288 7.4805Imperial gallon 0.0045461 4.5461 0.16054 1 1.2009US gallon 0.0037854 3.7854 0.13368 0.83267 1

Table 54. Conversion table for volume units

Volume cubic m l (liter) cubic foot Imperial gallon US galloncubic m 1 1000 1 / (12 * 0.0254)3 1/0.00454609 1/(231 * 0.02543)l (liter) 0.001 1 1 / (12 * 0.254)3 1/4.54609 1 / (231 * 0.2543)cubic foot (12 * 0.0254)3 (12 * 0.254)3 1 (12 * 0.254)3 /

4.54609123 / 231

Imperial gallon 0.00454609 4.54609 4.54609 /(12*0.0254)3

1 4.54609 /(231*0.2543)

US gallon 231 * 0.02543 231 * 0.2543 231 / 123 231* 0.2543 /4.54609

1

Table 55. Formulas for converting volume units




Normal cubic meter (Nm3) – Standard cubic foot (SCF)

336,37

(a)psi14.7F,60SCFkPa(a)325.101,0

Nm

336,37*kPa(a)325.101,0Nm

(a)psi14.7F,60SCF

3

3

F

CF

CFF

Mass unitsMass kg lb ozkg 1 2.2046 35.274lb 0.45359 1 16oz 0.028350 0.0625 1

Table 56. Conversion table for mass units

Density unitsDensity kg / cubic m lb / US gallon lb / imperial gallon lb / cubic ftkg / cubic m 1 0.0083454 0.010022 0.062428lb / US gallon 119.83 1 0.83267 0.13368lb / imperial gallon 99.776 1.2009 1 0.16054lb / cubic ft 16.018 7.4805 6.2288 1

Table 57. Conversion table for density units

Energy unitsEnergy J BTU cal lbf ftJ 1 9.4781e-04 0.23885 0.73756BTU 1055.06 1 252.00 778.17cal 4.1868 3.9683e-03 1 0.32383lbf ft 1.35582 1.2851e-03 3.0880 1

Table 58. Conversion table for energy units

Power unitsPower W hp US hpW 1 0.0013596 0.0013410hp 735.499 1 1.0136US hp 745.7 0.98659 1

Table 59. Conversion table for power units




Pressure unitsPressure Pa bar mmWG psiPa 1 0.00001 0.10197 0.00014504bar 100000 1 10197 14.504mmWG 9.80665 9.80665e-05 1 0.0014223psi 6894.76 0.0689476 703.07 1

Table 60. Conversion table for pressure units

Mass flow unitsMass flow kg/s lb/skg/s 1 2.2046lb/s 0.45359 1

Table 61. Conversion table for mass flow units

Volume flow unitsVolumeflow

cubic m/s l / min cubic m/h cubic ft/s cubic ft/h USG / s USG / h

cubic m / s 1 60000 3600 35.315 127133 264.17 951019l / min 1.6667e-05 1 0.06 1699.0 0.47195 227.12 0.063090cubic m / h 0.00027778 16.667 1 101.94 0.028317 13.627 0.0037854cubic ft / s 0.028317 0.00058858 0.0098096 1 0.00027778 0.13368 3.7133e-05cubic ft / h 7.8658e-06 2.1189 35.315 3600 1 481.25 0.13368USG / s 0.0037854 0.0044029 0.073381 7.4805 0.0020779 1 0.00027778USG / h 1.0515e-06 15.850 264.17 26930 7.4805 3600 1

Table 62. Conversion table for volume flow units

Temperature unitsTemperature K oC oFK 1 value[°C] + 273.15 5 / 9 * (value[F] - 32) + 273.15oC value[K] - 273.15 1 5 / 9 * (value[F] - 32)oF 9 / 5 * (value[K] - 273.15) + 32 9 / 5 * value[°C] + 32 1

Table 63. Temperature conversion formulas

Prefixes

T = Tera = 1 000 000 000 000 times

G = Giga = 1 000 000 000 times

M = Mega = 1 000 000 times

k = kilo = 1 000 times

m = milli = divided by 1 000

µ = micro = divided by 1 000 000

n = nano = divided by 1 000 000 000




Pipe dimensions metric - imperialEurope USADN OD/mm NPS OD/Inch OD/mmDN 15 21.3 ½” 0.840 21.3DN 20 26.9 ¾” 1.050 26.7DN 25 33.7 1” 1.315 33.4DN 32 42.4 1 ¼” 1.660 42.2DN 40 48.3 1 ½” 1.900 48.3DN 50 60.3 2” 2.375 60.3DN 65 76.1 2 ½” 2.875 73.0DN 80 88.9 3” 3.500 88.9DN 100 114.3 4” 4.500 114.3DN 125 139.7 5” 5.563 141.3DN 150 168.3 6” 6.625 168.3DN 200 219.1 8” 8.625 219.1DN 250 273.0 10” 10.750 273.0DN 300 323.9 12” 12.750 323.8DN 350 355.6 14” 14.000 355.6DN 400 406.4 16” 16.000 406.4DN 450 457.2 18” 18.000 457.0DN 500 508.0 20” 20.000 508.0DN 600 609.6 24” 24.000 610.0DN 900 914.4 36” 36.000 914.0DN1000 1016.8 40” 40.000 1016DN1100 1118.0 44” 44.000 1118DN1200 1219.0 48” 48.000 1219DN1300 1320.0 52” 52.000 1321DN1400 1420.0 56” 56.000 1422

Table 64. Pipe dimensions according to European and American standards and outer pipe diameters (O