Boiler_Operation Personnel Training

P-3218 VantaaSystems training steam boiler

Operating personnel trainingEdition 04.06.2013

2Name of Presentation

Introduction

The purpose of this training is to familiarise operating staff with the plant equipment and how to use it. It is a good idea for staff to visit the plant while the equipment is being fitted, in order to be able to see where the equipment is located on the plant, especially the connecting pipelines. Once the insulation has been installed the plant will look quite different.

Training will cover the following basic topics:

Theoretical classroom training

Practical training at the boiler plant


Table of Contents

Process

Configuration Vantaa

I&CO functions

Plant operation

Safety at work

Fault rectification

Maintenance

Table of contents

Process


I&CO functions

Plant operation

Safety at work

Fault rectification

Maintenance


Process

Fundamental of waste incineration steam generators

The following slides are not related to a specific plant.

For simplification, the expression „boiler“ is used for „steam generator“

Main Components of Boiler

Principle of Natural Circulation in Evaporators

saturated steam to superheaters

water from eco(below boiling temperature)

downcomer(not heated)

risers = evaporators(heat exchanger tubes)

heat input

saturated steam

boiling water

steam drum

Circulation caused by difference in density in risers and downcomers

Steam content in risers: at inlet: 0 % (water at boiling temperature) at outlet: ca. 5 mass -% (> 50 volume-%)

circ

ulat

ion

Main Control Loops

Life steam flow → waste input, combustion air flow (control within Combustion Control System (CCS)

Life steam pressure → turbine inlet valve (control turbine, no control within boiler)

Drum water level → feed water input (control of constant level)

Steam temperature → throughput water injection attemperators (control constant steam temperature)

Arrangement of Heating Surfaces (Heat Exchangers)Example: 2-Pass Horizontal Boiler

superheated steam

feed water

steam

water

SH 1SH 3 SH 2 Eco

saturated steam

Ev

ap

ora

tor

Evaporator(membrane walls)

Note:• Each heat exchanger may consist of several bundles (banks) e.g.: Eco = Eco 1.1 + Eco 1.2 + Eco 1.3 + Eco 1.4 + Eco 1.5 + Eco 2

+ Eco 3 , SH 1 = SH 1.1 + SH 1.2

• Additional heat exchangers may be installed, e.g.: evaporator between SH and Eco

Control of Flue Gas Temperatureat Boiler Outlet with preheater (External economiser)


Minimum flue gas temperature maybe required by flue gas cleaning system.

Note: max. flue gas temperature can not be controlled (results from boiler fouling).

Control of Flue Gas Temperatureat Boiler Outlet with preheater (External economiser)

Control of Flue Gas Temperatureat Boiler Outlet with Eco-Bypass (1)

3-way valve

eco

no

mis

er

flue gas

T FG out

steam drum

bypass

Minimum flue gas temperature maybe required by flue gas cleaning system.

Note: max. flue gas temperature can not be controlled (results from boiler fouling).

Continuous Boiler Blow Down

Steam generation =„distillation“

→ impurities are accumulated in boiler water (evaporators)

Continuous blow down from drumis adjusted in order to maintain boiler water qualitiy within acceptable limits.

Typical continuous blow down:0.5 % of life steam flow

steamconductivity < 0.2 μS/cm

feed water from ecoconductivity 0.2 < μS/cm << 50(downstream chemical dosing)

circulating boiler water (evaporators)conductivity < 50 μS/cm

blow down valve

expansion vessel

steam vent

drain

steam drum

Effect of Boiler Fouling on Flue Gas Temperature

Flue Gas Temperature in Clean and Fouled Boiler

100

200

300

400

500

600

700

800

900

1000

1100

1200

flue gas path (-)

flu

e g

as

te

mp

era

ture

(°C

)

economiserssuperheaters

radiationpasses

190

163

fouled

clean

inlet boiler exit boiler

• Fouling increases with boiler operation time

• Fouling = „insulation“ of boiler tubes

• Assuming same flue gas and water/steam temperatures in heat exchanger:

heat flux can be reduced by up to ca. 50 % due to fouling

• Due to higher flue gas temperature in case of fouled boiler: heat flux in whole boiler is reduced only by few % and results in an increase of flue gas temperature at boiler exit of ca. 30 °C within 8000 h

Minimizing Corrosion: Final Superheater (SH 4) with Co-Flow

• Steam temperature and therefore tube surface temperature is highest in final superheater• Highest risk of corrosion in final superheater (SH3 = SH3.1 + SH3.2)• Co-flow: reduction of corrosion rate, but

reduction of heat flux compared to counter-flow

Final Superheater with Co-Flow

300

350

400

450

500

550

600

650

700

Ste

am

- a

nd

Flu

e G

as

Tem

per

atu

re (

°C)

flue gas flow diection

steam flow direction

steam temperature

flue gas temperatureavoid combinationof high flue gas and high steam temperature

inlet outlet

Table of contents

Process


I&CO functions

Plant operation

Safety at work

Fault rectification

Maintenance


Natural circulation boiler

Most common type of boiler (used in industry, combined heat and power stations)

Uneconomical for larger plants (> 500 t/h steam)

Simple evaporator design

Part loads and changes in load are easily possible

Changes in load: require control through injection, variation of live steam temperature

Sensitive to rapid pressure drops (profuse steam generation)

Reduced output of feed water pumps required

Lower feed water quality required (due to blow-down)


Boiler operating principle

The feed water pump (6) conveys the feed water through the economiser (1) into the boiler drum (2). The difference in density between the water/steam mixture in the heated riser pipes (3) and the water in the non-heated downpipes (5) causes a natural circulation to occur. The saturated steam, which is ultimately superheated in the superheater (4), accumulates in the top part of the boiler drum (2).

No. Description

1 Economiser(pre-heater)

2 Boiler drum

3 Evaporators (heated risers)

4 Superheaters

5 Non-heated downpipes

6 Feed water pump


Boiler plant assembly method

Description of the boiler assembly process:

Pipes with 21.3 to 219.1 mm diameter are welded together

The diaphragm walls are made with longitudinal welding of pipes and steel strips

Method of transporting the parts from the workshop to the site and final assembly.

When the boiler is assembled, further procedures are to be carried out, such as:

Rinsing the boiler

Cleaning the water side of the boiler chemically

Drying the refractory lining

Steam cleaning of superheating surfaces.


Steam boiler

Description Data

Nominal rating (saturated steam) 83 t/h

Live steam nominal pressure 91 bar (a)

Live steam nominal temperature 400 °C

Feed water temperature 132 °C

• Technical specifications


Steam boiler

• Size of heating surfacesDescription Data KKS-No.

External economiser 1.1 451 m2 J1HAC05 AC011





Economiser 2L/2R 1438 m2 J1HAC10 AC021J1HAC10 AC022

Economiser 3L/3R 1438 m2 J1HAC10 AC031J1HAC10 AC032

Evaporator walls 2063 m2 J1HAD10 AC001

Evaporator 1 214 m2 J1HAD10 AC002

Superheater 1.1L/1.1R 902 m2 J1HAH10 AC111 J1HAH10 AC112


Superheater 2L/2R 867 m2 J1HAH20 AC201 J1HAH20 AC202



Total 7190 m2 -


• Volume of the boiler pressure system

Steam boiler

Description Data KKS-No.

Boiler drum 22,908 m³ J1HAD10 BB001

Evaporator 1 2,193 m³ J1HAD10 AC002

Superheater 1.1L/1.1R8,528 m³

J1HAH10 AC111 J1HAH10 AC112



Superheater 2L/2R7,118 m³






External economiser 1.1 2,435 m³J1HAC05 AC011





Economiser 2L/2R13,204 m³

J1HAC10 AC021J1HAC10 AC022

Economiser 3L/3R13,204 m³

J1HAC10 AC031J1HAC10 AC032

Membran walls - vertical part 35,816 m³ J1HAD10 AC001

Membran walls-horizontal part 16,547 m³ J1HAD10 AC001

Connecting pipings 18,969 m³ -

Total 168,73 m³ -


Structure of the boiler





The steam is generated with a 5-pass horizontal boiler. This consists of the vertical 1st to 3rd pass the horizontal 4th pass, and vertical 5th pass

The lower part of the 1st pass forms the furnace. In the grate area, the side walls are fitted with refractory lining.

The side walls of passes 1 to 4 are designed as evaporator pipes with a gas-tight diaphragm construction and are connected to the natural circulation system.

The economiser, the evaporator and the superheater are arranged in the horizontal 4th pass. The boiler drum is arranged diagonally at the top, on the boiler.

External vertical convection 5th pass with economiser heating surfaces and

sheet metal casing


Boiler layout and internal circulation of all fluids

Passes (vertical and horizontal) including associated heating surfaces

are to be indicated as follows:

Superheating surfaces SH 1.1, SH 1.2, SH2, SH3.1, SH 3.2 with internal attemperators for outlet temperature control

Evaporating surfaces ECO1.1 – ECO1.5, ECO2, ECO3

Internal connecting pipelines; feed-water heater – drum – steam

Superheater 1.1. – steam superheaters 1.2 - Attemperator 1 – steam superheaters 2 - Attemperator 2 – steam superheaters 3.1 - steam superheaters and main steam line.

Location of draining and venting points

– evaporators

Feed-water heaters -

Directions of flue gas flow through the boiler are also to be indicated. Flue gases from domestic waste incineration boilers contain a high amount of ash that should be removed from heating surfaces by means of mechanical rapping devices.


Superheater: final superheater co-flow 2 desuperheatersEconomiserEvaporator protection evaporator upstream SH

Inlet economiser:≥ 132 °C

Outlet economiser:≥ 15 °C belowboiling

Live steam:Typically402 °C, 41.5 bar


Evaporator - Vantaa


Economiser - Vantaa


Superheater – Vantaa

External economiser - Vantaa



Associated components: refractory lining

Reference to the following training of J + G


Safety equipment and control circuits overview

Installed safety equipment includes:

Safety transmitter of minimum and maximum level in the drum J1 HAD10 CP001, J1 HAD10 CP002, J1 HAD10 CP003.

Safety valve J1 LBA10 AA510 with control unit J1 HAD10 CG501

Thermometer J1 LBA10 CT002 – protection of maximum temperature of superheated steam

Transmitter J1 LBA10 CP002 – maximum steam pressure protection

The purpose of the installed safety equipment is to protect the plantagainst deviations from default values.


Safety equipment and control circuits overview

Control circuits are:

Control of drum level consisting of feed-water control level transmitters, including water and steam flow meters

Control circuit to protect feed-water from dropping below minimum temperature

Control circuit of steam attemperation

Control circuit to protect against high drum level.

Other operating (auxiliary) systems are:

Chemicals dosing system in order to maintain pH values of steam and water within default values

System for collecting water from blow-down

Boiler warming system, i.e. maintaining standby condition.


Presentation and description of operation of fitted equipment:

Safety valves

Cooling valves including associated attemperators

Valves for continuous water blow-down from the boiler drum

Water and steam quantity measurement – measuring orifices

Three-way control valve J1 HAC05 AA020 for protecting feed water against dropping below minimum temperature,

Water and steam sampling system

System for mechanical cleaning of heating surfaces

Wet cleaning.

Each part of the equipment should be provided

with the relevant suppliers’ brochure.

Fitted equipment overview


Safety valve

Safety valve on main steam line

Flow area – 2827 mm2

Normal pressure – 91 bar (g)

Set pressure in main steam line 1 96 bar(g)

Set pressure in main steam line 2 97 bar(g)

Set pressure in drum 107,0 bar(g)

Pneumatic contol unit

M1 – 96 barg – main steam line

M1 – 96 barg – main steam line

M3 – 108 barg – boiler drum


Instruments

Thermometer J1 LBA10 CT003 – protection of maximum temperature of superheated steam

Transmitter J1 LBA10 CP001 – maximum steam pressure protection

The purpose of the installed safety equipment is to protect the plant against deviations from default values.


Control circuits are

Control of drum level consisting of feed-water control valve, level transmitters including water and

steam flow meters.

The function of the transparent water level indicator J1 HAD10 CL502 is checked as follows:

No.

Description KKS-No.

1 Boiler Drum J1HAD10 BB001

2 Shut-off valve boiler drum measurement connection J1HAD10 AA654


4 Level measurement boiler drum J1HAD10 CL502



7 Shut-off valve measuring instrument drain boiler J1LCL90 AA830


Drum level measuring

Bicolour level gauge


Blow-down expansion tank level measuring

Blow-down expansion tank


Cooling valves including associated attemperators


AUMA actuator


Water and steam quantity measuring

Orifice plate


Pneumatic rapping device

The rapping system is an automatically working cleaning device that cleans off the bundle of pipes of a heating boiler through strikes against especially developed rapping points of the bundle of pipes. For this a rapping carriage moves between two travelling way supports on the outer wall of the heating boiler. The rapping carriage is moved via a rubber wheel on the travelling way by a geared motor. The rapping carriage is guided by curved rollers on ball bearings. Rams are built into the boiler wall at regular intervals and are situated at the rapping points of the bundles of pipes. If the rapping carriage reaches a ram an initiator is occupied by a positioning lug on the ram structural component. The rapping carriage stops in this position. The occupation of the initiator is a fundamental precondition for the rapping procedure. A further precondition is that compressed air is pending. These are arranged on both side walls.The dirty heating surfaces are caused to vibrate so that the resulting caking falls off.


Pneumatic rapping device

Rapping device KKS-No.

Rapping device 1 1 HCE40 AW001

Rapping device 2 1 HCE40 AW002

Helical Soot Blowers


Long retractable blower The long retractable blowers consist of a blow pipe and a nozzle head on theend of the blow pipe. They move in an axial direction past the heating surfacesto be cleaned. Live steam/MP steam is used as a blowing medium. The restposition of the lance-type screw blowers is outside of the combustion gas flow.

Scoot blower KKS-No.

Helical Soot Blowers 1 J1HCB05 AN001







Area of application: Cleaning of heating surface banks.The blowing tube is installed in the flue gas pass and it and is helically moved forward and backwards. The helical movement of the blowing tube / lance tube is effected by chain drive at the soot blower carriage which is driven by a geared motor. The blowing tube is on its entire length equipped with Venturi nozzles. A full cleaning effect over the whole blowing distance is ensured due to the conical expansion of the blowing jets and due to the arrangement of the nozzles.



Soot Blowes - parts


Three-way control valve J1 HAC05 AA020


P&I diagrams

All P&I diagrams and their functions are to be included:

P&I diagram of boiler drum eco

P&I diagram of boiler superheaters

P&I diagram of boiler blow-down

P&I diagram of boiler drains vents

P&I diagram of boiler FG-side 2

P&I diagram of primary air preheater

P&I diagram of external eco & soot blowers


P&I diagram of boiler drum eco


P&I diagram of boiler superheaters


P&I diagram of boiler drains vents


P&I diagram of boiler blow-down


P&I diagram of boiler FG-side 2

P&I diagram of primary air preheater


P&I diagram of external eco & soot blowers


Table of contents

Process

Structure

I&CO functions

Plant operation

Safety at work

Fault rectification

Maintenance


Description and preparation of plant start-up

This section contains a brief description of the plant preparation and start-up, its operation and shutdown.

Presentation of the preparation for starting up the plant:

Procedures for plant start-up preparations

Initial drum water level

Top up from the start-up pipeline and valve

Warming up the superheated steam pipeline from the main steam valve to the steam

Turbine by using the bypass valve for warming up

Description of work during regular boiler plant operation

Controlled shutdown procedure.

The "Operating instructions manual for boiler plant" should be used to describe the above-mentioned procedures, i.e. the most common plant operation scenarios.


Associated components: scrubbing systems

The problem!


Example: Shower Cleaning SystemOn-load boiler water cleaning

Spray nozzle


Associated components: sampling station

Table of contents

Process

Structure

I&CO functions

Plant operation

Safety at work

Fault rectification

Maintenance

Safety

You have probably gone through hundreds of site

inductions and will probably go through hundreds more

The induction is important as all sites are different andhave a wide range of hazards which will

change as the site develops

This site induction is specific to this site and provides you with information on the current hazards of

the site and tells you about the site rules

Signs on Site

Always comply with safety signage

Read the labels on containers before using any substances

Use any safety precautions required

Personal Protective Equipment

Look after your P.P.E. and always wear it when required

Table of contents

Process

Structure

I&CO functions

Plant operation

Safety at work

Fault rectification

Maintenance

Table of contents

Process

Structure

I&CO functions

Plant operation

Safety at work

Fault rectification

Maintenance

Most important aspects of maintenance

InputB3.10 Chap.1.2 Maintenance work planB3.10 Chap.1.3 Lubrication schedule and products

Thank you very muchfor your attention

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Boiler_Operation Personnel Training