Energy Audit Guidebook

2

Imprint

Publishedbythe

DeutscheGesellschaftfur

InternationaleZusammenarbeit(GIZ)GmbH

Registeredof�ices

BonnandEschborn,Germany

MOIT/GIZEnergySupportProgramme

Unit042A,4thFloor,CocoBuilding,

14ThuyKhue,TayHoDistrict,

Hanoi,Vietnam

T+842439412605

F+842439412606

of�ice.energy@giz.de

www.giz.de/viet-nam

Asat

August2017

Text

EnergyConservationResearchandDevelopmentCenter

GIZisresponsibleforthecontentofthispublication.

Onbehalfofthe

GermanFederalMinistryforEconomicCooperationand

Development(BMZ)

3

TABLE OF CONTENT GENERAL 13

Objectives 13

Audiences 13

AssessmentofCurrentEnergyAuditing 13

CategoryorLevelofanEnergyAudit 14

REQUIREDCONTENTSFORENERGYAUDIT 16

1.AUDITPLANANDRESOURCE

1.1.Auditplan

1.2.Resources

161616

1.2.1.Humanresource 161.2.2.Technicalresource 17

2. AUDITMETHODOLYANDAPPROACH 182.1. Approach 18

2.1.1.Energybenchmarking 182.1.2.Energybalance 182.1.3.Proposeenergyconsumptionreductionsolutions 19

2.2. Auditmethodology 192.2.1.Auditpreparation 192.2.2.Datacollection 22

2.2.3.Dataanalysis 24

3. STANDARDAUDITREPORTTEMPLATE 33

3.1. Summary 333.2. Introduction 333.3. GeneralInformationoftheauditorganization 343.4. Descriptionofoperationprocess 343.5. Energydemand,supplyandconsumption 353.6. Economicandtechnicalconstraints 363.7. Energysavingmeasure 363.8. Conclusionandfutureplan 373.9. Annexes 37

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PARTII.RECOMMENDATIONFORENERGYAUDITPRACTICES 39

39

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1. MEASUREMENTDEVICES

1.1. Electricitymeasurement

1.2. Thermalmeasurementequipment

1.3. Pressure,velocityand�lowratemeasurementequipment 42

2. OVERALLENERGYCONSUMPTIONANDENERGYMANAGEMENTASSESSMENT 44

2.1. Generalinformation 442.2. Materialconsumptionandproductvolume 442.3. Powerandwaterconsumptiondata 442.4. Energyperformanceindicatorandbenchmarkingreferences 462.5. Energymanagementassessment 49

2.5.1.Objectives

2.5.2.Evaluationmethod

4949

3. COMMONENERGYCONSUMPTIONSYSTEMANALYSIS 543.1. Electricitysupplysystem

3.1.1.Introduction

3.1.2.Loadgraphandelectricalloadmanagement

3.1.3.Harmoniceffects

3.1.4.Datacollectionforelectricitysystem

Lightingsystem

3.2.1.Introduction

3.2.2.Energy�lowdiagramoflightingsystems

3.2.3.Energysavingsmeasureforlighting

3.2.4.Datacollection

Motor

3.3.1.Introduction

3.3.2.Energy�lowformotor

3.3.3.Theenergysavingmeasures

3.3.4.Datacollection

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3.2.

system

3.3.

65 66 71

3.4. Fans 723.4.1.Introduction 723.4.2.Energy�lowforfan 763.4.3.Energyef�iciencyforfan 773.4.4.Collectiontoolsforfansystem 78

3.5. Pump 803.5.1.Introduction

3.5.2.Energy�lowforpump

3.5.3.Energysavingsmeasures

3.5.4.Datacollection

Aircompressor

80 84

85 86

3.6. 883.6.1.Introduction 883.6.2.Energy�lowdiagram 923.6.3.Energysavingsmeasures 933.6.4.Datacollection 97

3.7. Airconditioningsystem 1023.7.1.Introduction 1023.7.2.Assessmentofairconditioning 1053.7.3.Energysavingsmeasures 1063.7.4.Datacollection 107

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3.8. Industryrefrigerationsystem 1083.8.1.Introduction

3.8.2.Energy�low

3.8.3.Energysavingsmeasures

3.8.4.Datacollection

108 111 111 116

3.9. Boiler 1183.9.1.Introduction

3.9.2.Energy�low

3.9.3.Energysavingmeasures

3.9.4.Datacollection

118 125 125 135

3.10. Furnace 1363.10.1.Introduction

3.10.2.Heatlossesaffectingfurnaceperformance

3.10.3.Energysavingsmeasures

3.10.4.Datacollection

136140141144

4. SAFETYREQUIREMENTANDEQUIPMENT 1454.1. Electricalsafety 1454.2. Chemicalsafety 1464.3. Pressureequipmentsafety 1474.4. SafetyforworkingatHeights 148

APPENDIXES 149

REFERENCE 155

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ABBREVIATIONS

ACB

ATS

BEE

BEP

CO2

COP

DB

AirCircuitBreaker

AutomaticTransferSwitch

BureauofEnergyEf�iciency,MinistryofPower,India

BestEf�iciencyPoint

CarbonDioxide

Coef�icientofPerformance

DistributionBoard

DepartmentofIndustryandTrade

Lawon

DoIT

EE&C EnergyEf�iciencyandConservation

EnMS EnergyManagementSystem

EnergyServiceProvider

ElectricityofVietnam

Fibre

ESP

EVN

FRP -reinforcedPlastic

GDE GeneralDirectorateofEnergy

GDP GrossDomesticProduct

GreenHouseGas

DeutscheGesellschaftfurInternationaleZusammenarbeit(GIZ)GmbH

GHG

GIZ

GCV GrossCaloricValue

HVAC Heating,VentilationandAirConditioning

IGA InvestmentGradeAudit

IndividualQuickFreezer

ModeledCaseCircuitBreaker

MinistryofIndustryandTrade

MainDistributionBoard

Speci�icEnergyConsumption

IQF

MCCB

MOIT

MSB

SEC

TOE TonofOilEquivalent

VFD VariableFrequencyDrive

VNEEP VietnamNationalEnergyEf�iciencyProgram

VSD VariableSpeedDrive

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Listoftables

Table1.Energyauditlevels

Table2.Summaryofenergysavingpotentialandestimationofinvestmentcost

Table3.Thelistofdedicatedequipmentusedintheenergyaudit

Table4.Rawmaterialandmainproducts

Table5.Operatinghourperayearofenergyconsumptionareas/workshop

Table6.Electricitytariff(appliedfrom…)

Table7.Electricityconsumptionandelectricitycostsinmonthly(…)

Table8.Fuelconsumptionandcostsinmonthy(...)

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Table9.Waterconsumptioninmonthly(…)

Table10.Energyconstrainsandstandards

Table11.Powerfactor

Table12.Energyconsumptionrateuntil2020s.

Table13.Energyconsumptionratefrom2021s–to2025s

Table14.Energyconsumptionrateforsteelindustryuntil2020s

Table15.Energyconsumptionrateforsteelindustryfrom2021sto2025s.

Table16.Energyconsumpationrateinchemistryindustry

Table17.Amatrixofenergymanagementevaluation

Table18.Assessmentresultsandimprovementact ions

Table19.Classi�icationoftransformers

Table20. Strategytomanagepeakload

Table21.Applicationsofcolorrenderinggroups

Table22.Luminousperformancecharacteristicsofcommonlyusedluminaries

Table23.EnergysavingbyusingLED

Table24.Energysavingcalculationtable

Table25.Ratedpower,numberandcurrentstatus

Table26.Lightingtransformer,ratedpowerandnumbers

Table27.Thebasicmotorloadtypes

Table28.Operatingcostestimationofselectedmotors

Table29.Standardef�iciencymotorvs.premiumef�iciencymotor

Table30.Motor

investmentcomparison

Table31.Correlationbetweentherotationspeed,�low,andpowercapacity

Table32.Motordatacollection

Table33.Ef�iciencyoftypesoffan

Table34. Fanspeedvs.�low

Table35.Fanspeedvs.powercapacity

Table36.Percentageofpowerconsumprionby�lowpercentage

Table37.Datacollectiontemplateforfan

Table38.Datacollectiontoolforpump

Table39.Relationshipbetweenpressureandpowerconsumption

Table40.Pressuredropfordifferentpipesize

Table41.Inletairtemperaturevs.Powersaving

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Table42.Basedatabasetocompressorsystem

Table43.Currentcompressors

Table44.Componentsofcompressor

Table45.Tanksandreliefvalve

Table46.Mastercontrollersandairmaincharging

Table47.Distributionsystem,pipe,connections,anddistributionairline

Table48.Compressorroom

Table49.Airconditionatcompressorroom

Table50.Airrequirements(Operatingtime,pressuredemands)

Table51.Tableofeffectivemaintenanceforpowerconsumptionofthecompressor

Table52.Effectofvariationinevaporatortemperatureonthecompressorpowerconsumption

Table53.Effectofvariationincondensatetemperatureonthecompressorpowerconsumption

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measurements,openingsetc.

Table54.Propertiesofsaturatedwaterandsteam

Table55.AdvantageanddisadvantageofFiretubeboiler

Table56.Advantageanddisadvantageofwatertubeboiler

Table57.Advantageanddisadvantage ofwatertubeboilerwithsteamdrum

Table58.Boileref�iciencycalculation

Table59.Heatlossduetouninsulation

Table60.Heatlosscalculationduetouninsulation

Table61.Advantagesanddisadvantagesofsteamtrap –free�loat

Table62.Advantagesanddisadvantag esofsteamtrap–Invertedbucket

Table63.Advantagesanddisadvantagesofthermodynamicsteamtrap

Table64.AdvantagesandDisadvantagesofthermostaticsteamtrap –balancedpressure

Table65.Steamtrapselection

Table66.Classi�icationoffurnaces

Table67.Heatbalance

Table68.Measuringinstruments

Table69.Datacollectiontemplateforfurnaceperformance

Table70.Spreadsheetforenergysavingcalculation

Table71.Theelectricitypricesforenterprisesinrecentyears

Table72.TheconversionintoTOE, MGandemissionfactorsofsomeenergytypes

Table73.Theemissionfactorofsomecommonenergytypes

Table74.Metrologicalcontrolmeasuresandinstrumentinspectionintervals

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Listof�igures

Figure1.Approachtoenergyaudits

Figure2.Energybalancetoindentifytheloss

Figure3.Exampleofregressionanalysisforelectricityconsumptionandproduction

Figure4.EPIforglassmelting

Figure5.Comparisonbetweenthemill

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andthebenchmarkandestimatedenergysavings

Figure6.Flowchartofadyingprocesswithenergyandmaterial�low

Figure7.Sankeydiagramfortheenergylossinsteamsystem

Figure8.Shareoftheenergyusers

Figure9.Energymanagementassessmentchart

Figure10.Thetransformerinpowersystem

Figure11.Maindistributionswitchboard

Figure12.Distributionboard

Figure13.Exampleofsinglelinediagramofelectricalsupply

Figure14.Adailyloadcurve

Figure15.Waveformsofharmonics

Figure16.Sankeydiagramoflightingsystem

Figure17.Daylightingwithpolycarbonatedsheet

Figure18.AtriumwithFRPdome

Figure19.LEDphaseandaroundlighting

Figure20.Squirrelcagerotormotor

Figure21.Woundrotormotor

Figure22.Costdistributionofmotor

Figure23.Ef�iciencyandfullloadpercent

Figure24.Ef�iciencyandrotatingspeedofsquirrelcagerotor

Figure25.Standardef�iciencymotorvs.premiumef�iciencymotor

Figure26.Performancecurveofpumpwith�lowcontrolvalve

Figure27.Loaddiagramofairconditioning

Figure28.Fanpowercalculation

Figure29.Calculationoffancapaciy

Figure30.Costdistributionoffan

Figure31.Sankeydiagramoffan

Figure32.Reducemotorspeedbydecreasingthepulleysize

Figure33.Calculatepumppower

Figure34.ParametersofPumpsystem

Figure35.PumpPerformanceCurve

Figure36.ParallelPumps&pumpscurve

Figure37.Pumpcontrolmethods

Figure38.ON-OFFcontrolforpump

Figure39.PerformancecurveofpumpwithVSD

Figure40.PowerRequirementsforvariouspumpingcontroloptions

Figure41.Costdistributionofpump

10

Figure42.SanSankeydiagramofpump 84

Figure43.Aircompressionsystemillustration 88

Figure44.Typeofaircompressors 88

Figure45.Effectofinlettemperatureandpowerconsumption 92

Figure46.Costdistributionofaircompressor 92

Figure47.Sankeydiagramforcompressedairsystem 93

Figure48.Energysavingspotentialforaircompressedsystem 93

Figure49.Effectofrelativehumidityandpowerconsumption 94

Figure50.Effectofsuctionpressureandpowerconsumption 94

Figure51.Heatrecovery 96

Figure52.Airconditionsystemtypes 102

Figure53.Air-cooledchiller 103

Figure54.Water-cooledchiller 103

Figure55.OperatingPrinciplesofairconditioner 104

Figure56.CalculationmethodofCOP 105

Figure57.HVACsystemdatacollection 105

Figure58.Glassproperties 106

Figure59.DetectheatsourcesinsideHVACspace 106

Figure60.Therefrigerationcycle 108

Figure61.Basictypesofcompressors 108

Figure62.Typicalheattransferloopinrefrigerationsystem 111

Figure63.DiagramofHeatRecoveryfromdischargeoutletfromcompressor 112

Figure64.Comparisonofpowerconsumptionbydifferentregulationmethods(screwcompressor)112

Figure65.Relationshipofthecondensationtemperatureandtheperformanceoftherefrigeration 113

temperature 114

Figure67.Steamphasediagram 119

Figure68.SimplediagramofTubeboiler 119

Figure69.Firetubeboiler 120

Figure70.Watertubeboiler 120

Figure71.Watertubeboilerwithsteamdrum 121

Figure72.Typicallossesfromcoal�iredboiler 123

Figure73.Sankeydiagramofboiler 125

Figure74.Heatrecovery�lowdiagram 127

Figure75.Waterpre-heaterandairdryer 128

Figure76.Typicalsteamtraps 129

Figure77.Functionsofsteamtraps 129

Figure78.Classi�icationofsteamtraps 129

Figure79.Mechanicalsteamtrap–Free�loat(source:TLV) 130

Figure80.Operatingprinciplesofmechanicalsteamtrap–Free�loat 130

Figure81.Mechanicalsteamtrap–invertedbucket(source:TLV) 131

Figure82.OperatingPrinciplesofmechanicalsteamtrap–Invertedbucket 131

Figure83.Thermodynamicsteamtrap(source:TLV) 132

Figure84.Operatingprinciplesofthermodynamicsteamtrap 132

Figure85.Thermostaticsteamtrap–Balancedpressure(source:TLV) 133

Figure66.Principleschematicoftworefrigerationsystemswiththedifferentofthecevaporator

11

Figure86.Operatingprinciplesofthermostaticsteamtrap-balancedpressure

Figure87Steamtrapoperation

Figure88.Ultrasonictesting

Figure89.Spira -tecmeasurement

Figure91.Typesoffurnaces

Figure92.Radiation factorforheat

Figure93.Blackbodyradiationatdifferenttemperature

Figure94.Heatlossfromtheceiling,sidewallandhearthoffurnace

Figure95.Heatlossedinafurnace

Figure96.GHSPictograms

Figure97.Exampleofpressureequipment (boiler)

Figure98.Workingatheight

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General

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13

GENERAL

Objectives

Theguidebookisdevelopedtoinstructenergyauditorsandotherstakeholderstoassessandconduct

well-structured and effective energy audits in industrial facilities aswell as in commercial building.

Followingtopicsareconsidered:

· Frameworkoftheauditwhichwilldescribescopes,tasks,qualityrequirements,budget,timeframe,

kickoffmeeting,energyauditteametc.

· Asummaryoftheregulatoryrequirements,includingVietnameseStandardsonenergyef�iciencyof

industrialprocesssystem

· Collectingrequireddataandreviewing

· Conductingsiteinspectionandmeasurement

· Analyzingdata,interpretingand�indings

· Energyauditreportincludingpotentialenergysavingmeasures

Audiences

TargetedaudiencesoftheGuidebookare:

· EnergyAuditors

· Energyandfacilitymanagers

· EnergyManagementDepartmentofProvincial/CitylevelofDepartmentofIndustryandTrade(DOIT)

· MinistryofIndustryandTrade

· Lecturers

Energyauditors are assumed tohaveadequateknowledgeof energyandenergy systems.Thus, this

guidebookisdesignedtoprovideasystematicapproachinconductingauditinindustrial/commercial

facilities,which includesmethodologyandapproachesof anaudit and supporting toolsof checklist,

questionnaireanddataanalysisetc.

AssessmentofCurrentEnergyAuditing

EnergyAuditingcanbeseenasadiagnosticofthecurrentconditionsofafacilityregardingitsenergy

performanceandconsumption.Energyauditingde�inesviablemeasures toward the improvementof

energyef�iciencyorlowercostenergysourcealternatives.Overallobjectiveistosupporttheaudited

facilityinoutlineactionplantoimproveeitherhigherenergyef�iciencyorlowerenergycostandinsome

casesbothofthem.

InVietnam,energyauditingisneededtocompensatefortherisingenergyprices(especiallyelectricity),

reducemanufacturingcost,reducepollutantemission,andconservationofenergyresources.

TheLawNo.50/2010/QH12onEnergyEf�iciencyandConservation(EE&C)approvedon17June,2010is

akeymilestoneinthedevelopmentprocessofEE&Clegislationinthecountry.Accordinglyenergyauditis

mandatorytostate-ownedagenciesandintensiveenergyconsumingenterprises,whichannualenergy

consumptionisfrom1,000TOE–Industrialandfrom500TOE–Commercial.Theseenterprisesand

14

Table1.Energyauditlevels

Level1– PreliminaryAudit Level2– DetailedAudit

Objectives: Different energy systems (pump, fan,compressedair,steam,processheating,etc.)areassessedindetail

Provide energy saving measures withcostanalysisandprioritytobeinvested

Pros: Lowestcost

Overallassessment

Shorttime

Highcon�idence

Give a more accurate picture of theenergy performance and more speci�icrecommendationforimprovements

Cons: Lowcon�idence Highcost

Level 2 – EnergyAudit is preferred by the Law of EE&C, Degree 21/2011/ND-CP and the Circular

09/2012/BCTduetoitslevelofdetails.Thisguidebookonlyfocusesonlevel2energyaudit.

organizationshave todevelopaplan to conduct their energyaudits in accordancewith theexisting

regulationsandprocedurestoidentifyenergysavingopportunities.

Currently,therearemorethanthousandsofenergyauditswhichhasbeentakenplaceinVietnamin

variousindustrialsub-sectors.However,thequalityoftheseactivitiesseemsinadequate. Inaddition,

thereisnotechnicalguidebookindetailforenergyauditstostandardizeandensurethecomplianceofthe

auditactivitiestotheregulatedprocedure.

CategoryorLevelofanEnergyAudit

An Energy Audit is typically categorized based on the level of detail for investigation. Two level

categorizationisnormallyusedregardingthementionedaspects:

Quickassessmentofenergyconsumptionandenergyperformance

Provide action plan and focus points toLevel2–DetailedEnergyAudit

Can be used as guide toward detailedenergyaudit

15

01 Required Contents For Energy Audit

16

PARTI.

REQUIREDCONTENTSFORENERGYAUDIT

1. AUDITPLANANDRESOURCE

Planningforauditandde�iningthenecessaryresourcesareimportantstepsthatshouldbeperformed

beforetheaudits.This�irstchapteroftheguidebookwillhelptheaudiencetounderstandtheimportance

ofplanningandwhataretheresourcesneededpriortoaudit.

1.1. Auditplan

Anauditplanoutlinesthestrategyandprocedureoftheaudit.Auditobjectiveshouldbede�inedclearly

beforetheauditplanning.

Theauditplanshouldprovidethefollowinginformation:

· Preparationstepsfortheaudit

· Auditprocedure,inwhichtimeoftheauditandthetimetableforeachstepshouldbede�inedclearly.

Theaudittimedependsontheorganization'sconditionsandstatus.Audittimecanbeshortenedifthe

auditplanningiswellestablished

· Responsibilitiesandtasksofeachauditteammembershouldbeclari�ied.

Audit resources consist of human resources, �inance resources, time resources, and available

measurementdevices.Safetyprocedureandequipmentshouldbewellprepared.Anauditplanisalsoa

vitalcommunicationstoolforensuringthattheauditwillbeconsistent,completeandeffectiveinitsuseof

resources.

Keystepsneedtobeplannedintheauditprocedureincluding:

· Preparepre-auditquestionnaire

· Preliminaryauditplan

· Audit check list preparation: Detailed daily work plan with timetable for on-site survey: work

description,area,supportrequiredfromauditedfacility(e.g.technician,technicalmanageretc.)

· Dataanalysisandreportwithtimetable.

Anauditplanmustbe�lexibleenoughtoaccommodateadjustmentstoallowforunexpectedinformation

and/orchangedconditions.Methodologytoimplementeachofthestepswillbedescribedinthepart2.

1.2. Resources

The necessary resources to implement energy auditare human and technical resources. These two

resoucesshouldbepreparedwelltoensurethequalityoftheaudit.

1.2.1. Humanresource

Energy audit is carried out by a certi�ied auditor including an energymanager in the company or

outsourcedtoexternalspecialists.

1.2.1.1. Auditors

Quali�ication

Theauditormustbeacompetentandprofessionalone,whoisfamiliarwithenergyauditingprocessand

techniques. Energy auditors can be accredited separately for electrical and thermal energy audits,

accordingtotheirquali�ications.Energyauditorsmustbeeitherelectrical,thermalorenergyrelated

engineerswithabove3yearsexperienceinenergy.

TherearecertainrequirementstobeanEnergyAuditors:

· Technical/Engineeringbackgroundispreferrede.g.bachelorofengineering

· Participateinatleasttwoenergyaudits

· Participateandpassthetrainingcourseofenergyauditor,hostedbyDirectorateofEnergy,Ministryof

IndustryandTrade.

Itemof#1and#2arenotregulatedinthecurrentlegaldocuments,however,thesearescreeningcriteria

tocandidateswhowanttoregisterintheitem#3.Certi�icateofenergyauditorisproofthatanenergy

auditorhasparticipatedinthetrainingcourseandpassedtheexam.

Certi�icate

Energyauditormustbecerti�iedbyMinistryofIndustryandTrade,byaninternationalorganizationwith

mutualrecognitionagreementsaccordingtotheCircular39/2011/TT-BCT.AccordingtocircularNo.

39/2011/TT-BCT,onlytheMinistryofIndustry&Tradeisauthorizedtoofferexamsandissueof�icial

certi�icationsforenergyauditorsandenergymanagers.Thesecerti�icationsaresignedbytheMinister

andareconsideredtobetheof�icialprofessionallicensesissuedbytheState.

Theenergyauditorsmustbetrainedonworksafetyandelectricalsafety.

Experience

Energyauditorshouldunderstandwelltheproductionprocessandhaveexperienceonthesame�ield

whichtheyareassignedtoperformtheaudit.

1.2.1.2. Energyauditteamleader

Energyauditteamleaderwillassignthetaskforteammembers.Heshouldhavethefollowingskills:

· Strongcommunicationandorganizationalskill

· Abilitytothinkcriticallyandattendtodetail

· Abilitytointeracteffectivelyandpositivelywithprospectivecustomers

· Apositiveattitudeandabilitytoworkwellinateamsetting

· Timemanagementskills

· Problemsolvingskills.

1.2.2. Technicalresource

Technicalresourcesincludeinstrumentationrequiredfordatacollection.Thetechnicalavailabilityfor

themeasurementshouldbeconsideredandthefeasibilityofdatacollectionshouldbeestimated.

Instrumentation could be available at the audited factories, or rented from other professional

organization.

17

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Figure1.Approachtoenergyaudits

Energy

benchmarking

Energy

balance

Energy

consump�on reduc�on

2. AUDITMETHODOLOGYANDAPPROACH

2.1. Approach

Thenecessaryoutput informationorexpectation �indingsof theaudit shouldbeunderstoodclearly

beforetheaudit.Approachandmethodologyofenergyauditaredescribedbrie�lyinthischapter.

Approachis,inasystematicallyway,toproposeasuitableenergymanagementsolutionsapplyingin

energyconsumersandequipment.

The pathway solution is presented in the Figure 1, including three stages (1) benchmark energy

consumptionwithinthesectors,(2)establishandstudyenergybalanceand(3)�indoutsolutionsfor

energyconsumptionreductioninenergymanagementstrategy

2.1.1. Energybenchmarking

Energybenchmarkingisamethodtoevaluatetheenergyperformanceoftheauditplantbycomparing

withsomethingsimilar. “Somethingsimilar”mightbeinternal,likeperformanceatthesametimelast

year.Oritmightbeexternal,likeperformancecomparedtosimilarfacilitieselsewhere.

Energyperformanceindicatorisusedforcomparingthespeci�icenergyconsumptionoftheorganization

toenergybenchmarkinginthesameproductionlineorproducttypeinanindustry.

Through benchmarking, the key metrics for assessing performance are identi�ied, baselines are

established,andgoalsareset.Thisprocesshelpstoidentifythekeydriversofenergyuseandprovidesan

importantdiagnosticstoolforimprovingperformance.

Itisakeystepinidentifyingopportunitiestoincreasepro�itabilitybyloweringenergyandoperating

costs.

2.1.2. Energybalance

Energybalanceisananalyticalmethodtoprovideinformationofplant'senergyperformanceandthe

causeofloss.Oneoftheimplicationsoftheenergybalanceprincipleisthatwecanquantifyallenergy

inputs andbalance themagainst all energyoutputs. Lossof energy is identi�iedby energybalance

analysis.

Maintasksofenergyauditaretoinspect,surveyandanalysisofenergy�lows,balancingtheenergyinput

andoutputoftheoperation,de�ininglossinthe�low,andproposesolutionstoreducetheamountof

energyinputintothesystem.

Basedon theenergybalanceanalysis results,opportunities toreduceenergyconsumptionwouldbe

identi�ied.Methodologytostudyenergybalanceisexplainedinpart2.2.3.5.

2.1.3. Proposeenergyconsumptionreductionsolutions

Energyef�iciencyde�inedasthegoaltoreducetheamountofenergyrequiredtoproduceproductsand

services.Inotherwords,energyef�iciencyisdoingthesameamountofworkwhileusinglessenergy,

withoutcompromisingonthecomfortorqualitylevels.Forconvenienceofinterpretation,electricaland

thermalenergyhasbeenseparatelymentioned.

The electricity consumption investigation and thermal energy consumption investigation are good

startingpointsinthesearchofenergysavingopportunities.

Bybenchmarkinganalysisandenergybalancestudy,energylossesareidenti�ied,andthemeasuresfor

energyconsumptionreductionwillberecognizedbyminimizingthelosses.

2.2. Auditmethodology

Astep-by-stepmethodology,referredtoCircular09(AnnexIV)willbedescribedinChapter3.Anaudit

procedureusuallyconsistsofthreesteps:(1)preparation;(2)datacollection,(3)datainterpretationand

�indings,andwritingareport.

2.2.1. Auditpreparation

Thekeytoasuccessfulauditisproperauditpreparation.Inadequatepreparationmaycausedelaysin

reportsubmission,excessiveauditfees,penalties,non-compliancewithregulationsordebtcovenantsand

ultimately,embarrassment.

2.2.1.1. De�ineauditobjectiveandexpectationoutput

Theauditobjectivemayvaryfromoneorganizationtoanother.Anenergyauditisusuallyconductedto

· Understandhowenergyisusedwithintheorganization

· Findopportunitiesforimprovementandenergysaving

· Faiseenergyusingawarenessforemployees

· Provideabenchmark(referencepoint)formanagingenergyintheorganization

· Evaluatetheeffectivenessofanenergyef�iciencyprojectorprogram.

Figure2.Energybalancetoindentifytheloss

Energy

?Losses

UsefulEnergy

19

Theauditcanbecarriedouttomeettheneedtoreduceenergycosts,toparticipateinanenergyprogram

orberegulatedbythegovernment.

AccordingtotheDecree09/2012/TT-BCT,thekeyenergyusedorganizationsareresponsibletoestablish,

registerandreporttheirenegyconsumptionannually.Theyareregulatedtoconducttheenergyaudit

everythreeyears(Clause33,Ef�icientEnergyConsumptionandSavingsLaw).

Otherorganizationsaremotivatedtoperformtheenergyauditsandreporttheirenergyconsumption

regularly(Clause25,Decree21/2011/NĐ-CP).

2.2.1.2.Scopeofauditandfocus

Theauditteamshould:

· Identi�iesthesystemboundary

· Speci�iesthephysicalextentoftheauditbysettingthetermsoftheboundaryaroundtheaudited

energyconsumingsystem

· Identi�iesenergyinputsthatcrosstheboundarytobeaudited.

The audit scope depends on the audit objective, audit program, the available resources and the

organization'sdemand.

Basedon(1)Functionandtypeofindustry,(2)Depthtowhich�inalauditisneeded,and(3)Potentialand

magnitudeofcostreductiondesired,ascopeofauditcanbe:

· Theentireplant

· Thedepartment,productionline,orprocessstep,suchasthekilnorthepackagingplant

· Speci�ic(energy)equipmentsorresources,suchassteam,compressedair,motors,orfans.

Thefocusareaischosenbasedon:

· Sizeoftheplant

· Management'sareasofinterestorconcern

· Highenergy/resourceconsumptionorcosts

· Highpotentialenergysavingsarea

· Areasforwhichenergyef�iciencyauditsorprojecthavenotyetbeencarriedout

· Plansforconstructionorupgrading.

2.2.1.3.Setuptheauditteam

Number of required auditorswith speci�ic tasks should be determined. The factory's engineers and

technician could be invited to participate in energy audits for their knowledge and experience on

equipment,O&M,etc.

Auditorscouldbeinternalstaff(s)orexternalspecialists.

Auditteamleaderwithrequiredskillsshouldbeappointed,andshe/hewillorganizeandassignthetask

forteammemberswhenestablishingtheauditplan.

Ameetingfortheteammembersshouldbeorganizedbeforetheauditstartstohavebetterinteractionfor

theef�icientteamwork.

2.2.1.4.Timeandcostestimation

Thetimeandcostofenergyauditsishighlyvariabledependingon:

20

· Thesector

· Thesizeofthefacility

· Thequali�icationsoftheenergyauditorand/orauditing�irm

· Thetypeofaudit(buildings,processesortransportoracombination)

· Theaccuracyandcompletenessofinformationprovidedbytheclient;andthedetailprovidedbythe

expert.

Theenergycostincluding:

· Laborcostforauditorsandexternalprofessionalswhenneeded

· Rentalfeeformeasurementdevicesandotherfacilitiesifnotavailableatthefactory.

2.2.1.5.Preliminaryaudit

Thepreliminaryanalysishelpsprovidingageneralpictureoftheplantenergyuse,operation,andenergy

losses.

Theinitialwalk-throughvisitisfortheenergyauditteamtobecomefamiliarwiththefacilitytobeaudited.

Theauditteamcanobservetheexistingmeasurementinstrumentationontheequipmentandthedata

recorded,sothattheycandeterminewhatextrameasurementanddatacollectionarerequiredduringthe

audit.

Informationshouldbede�inedduringpreliminaryaudit:

· Layoutoftheorganizationtoplanwithtimeframe

· Operational status of the audited plant, operating characteristics of equipment, database of

productionandenergyconsumption.

· Loadinventoryandkeyenergyconsumingareatobesurveyedduringtheaudit

· Energy�low(input/output)ofthecommonload

· Measurementpoints,existinginstrumentationandadditionalmeteringrequired

· Whetheranymeterswillhavetobeinstalledpriortotheaudite.g.,powermeter,steam,oilorgas

meter.

Abriefmeeting–kickoffmeetingwithalldivisionheadsandpersonalconcernedcouldbeorganizedto

develop orientation awareness creation and build up the cooperation. The auditors can inquire for

commentsfromthefacilitystaffandcancollectreadily-availabledataduringthewalk-throughvisit.

Inthepreliminaryanalysis,a�lowchartcanbeconstructedthatshowstheenergy�lowsofthesystem

beingaudited.Anoverviewofunitoperations,importantprocesssteps,areasofmaterialandenergyuse,

andsourcesofwastegenerationshouldbepresentedinthis�lowchart.

The auditor should identify the various inputs and outputs at each process step. The preliminary

�lowchartisasimplebutdetailedinformationanddataabouttheinputandoutputstreamscanbeadded

laterafterthedetailedenergyaudit.

2.2.1.6.AuditChecklistPreparation

Audit checklist is designed to stimulate questions about energypractices. Audit checklist should be

preparedbeforeonsiteauditingforeachsections/utilities.Thechecklisthelpsgatheringtherightdata,

withtheappropriateamountofdetail,whichisakeycomponenttorealizethemaximumsavingsfroman

energyaudit.

21

Thechecklistshouldbearrangedaccordingtotheitineraryoftheaudit.Itineraryofdatacollectionisset

upbasedonthelayoutoftheorganizationwhichshouldbeobtainedduringthepreliminaryaudit.

Processfordatacollectioniscurrentlynon-standardized,andcrucialdatacanbeoverlookedorthelevelof

detailisinsuf�icientfortherequiredenergyand�inancialanalyses.Toaddresstheseissues,templatedata

collectionformshavebeencreated.Thepurposeofthesesampleformsistoassistenergyauditorscollect

datarequiredtocompletecomprehensiveenergyand�inancialanalysesofproposedmodi�icationstothe

organization.

In the following part, standardized templates of audit checklists of common load system will be

introduced.However,theactualchecklistortemplateshouldbemodi�iedafterthepreliminaryaudits

becauseactual load inventories,dataavailability, andoperation conditionsarevaried fromplants to

plants.

2.2.1.7. Measurementequipmentpreparation

Dependingonenergytypetobeaudited,alistofinstrumentationswillbede�inedandprepared.The

numberofmeasurementpointsaredeterminedbasedontheneedsandpracticalability.Amoredetailed

breakdownwillrequiremoremeasurements,measurementequipmentandexpertise.

The operating instruction for all Measurement equipment must be understood and staff should

familiarizethemselveswiththeinstrumentsandtheiroperationpriortoactualaudituse.

TheMeasurementequipmentshouldbecalibratedregularly.Listofcommonmeasurementequipmentis

describedinpart.II.

2.2.1.8. WorkSafetyPreparation

Auditorshavetoconductsurveysinlotofareasinfactoriesandbuildings,suchastransformerstations,

coldstorage,boilerarea,thewastewatertreatment,etc.Eachplaceispotentiallyharmfultoauditors.

Therefore,auditorsneedtotalktotheorganization'ssafetyof�icerstotakemeasurestosecuresuitable

work.

Auditorsshouldbetrainedorunderstandwellonworkplacesafetyandfullyequippedwithsafetybefore

enteringtheauditedsites.

Worksafetytrainingforauditorsshouldinclude:

· ElectricalSafety

· ChemicalSafety

· Boilerandpressurevesselsafety.

· Safetyatheight

WorksafetyrequirementandpracticesaredescribedmoredetailsinthepartII.

2.2.2. Datacollection

Datacollectionisanimportantstepinauditprocess.TheDatacollectionshouldbeenoughandaccurate

fortheanalysis,thereforethequantityandqualityofthedataisalwaysachallengetoauditors.Auditors

shouldknowwhichdatatheyneedtocollectandhowtoobtaintheaccuracyofthedata.

Somedataareavailableatthefacilityandcanbeprovidedthroughquestionnaireandinterviewsurvey.

Datawhicharenotavailablewillbeobtainedthroughmeasurementandcalculation.

2.2.2.1. Availabledatacollection

Energybillsalongwithothercurrentandhistoricalenergy-andproduction-relateddataandinformation

shouldbecollectedatthebeginningoftheauditprocess.

22

Thedatathatcanbecollectedatthebeginningofanenergyauditincludethefollowings:

· Generalinformationabouttheplant(yearofconstruction,ownershipstatus,renovations,typesof

products,operationschedule,operatinghours,scheduledshutdowns,etc.)

· Energybillsandinvoices(electricityandfuels)forthelast3years

· Monthlyproductiondataforthelast3years

· Possiblearchivedrecordswithmeasurementsfromexistingrecorders

· Architecturalandengineeringstructureoftheplantanditsequipment

· Statusofenergymanagementandalreadyimplementedenergy-savingmeasures

· Thetechnicalspeci�icationsoftheequipmentandproductionlinestobeaudited(inwhichcaseit

shouldbenotedthebuilding�loorarea,structure,directionandnumberofdevices)

· Operatingparameter(temperature,pressure,capacity,etc.)

· Operatingproceduresandequipmentrepairguidelines.

Acomprehensivequestionnairetemplateshouldbepreparedandsendtotheauditedplanttocollectthe

generalinformation.Otherinformationwouldbesurveyedduringthepreliminaryaudit,briefmeeting,

plant'sstaffinterviewandmoreinsuf�icientdetailsarecollectedduringtheaudit.

Achecklistshouldbepreparedinadvancetoensuredatasuf�iciencytobecollected.

2.2.2.2.Measurement

Energy audits require identi�ication and quanti�ication of energy necessitates measurements with

equipment.Auditorsshouldselecttheparameterstomeasureandpointstomeasureintheenergy�low.

Measurementequipmentshouldbeportable,durable,easytooperateandrelativelyinexpensive.

Theauditteamshouldde�inewhichinformationcouldbecollectedbyavailabledataandinformationthat

needed tobe collectedbymeasurement afterpreliminary audit.Additional equipment,which isnot

availableattheauditfacilityshouldbede�inedandpreparedbeforeaudit.

Basicmeasurementduringenergyauditmayincludethefollowing:

· Basicelectricalparametersinalternativeanddirectcurrentsystems-Voltage(V),Current(I),Power

factor,activepower(kW),reactivepower(kVAR)

· Energyconsumption(kWh),Frequency(Hz)

· Temperature

· Heat�low

· Airandgas�low,airvelocity

· Liquid�low

· Moisturecontent

· Relativehumidity

· Fluegasanalysis-CO ,O ,CO,SO ,NO2 2 x x

· Combustionef�iciency.

23

2.2.2.3.Instrumentinspectionrequirements

Inorder toperformdata collectioneffectively andaccurately, the instrument shall be inspectedand

calibrated.AccordingtotheCircularNo.23/2013/TT-BKHCNdatedSeptember26,2013oftheMinistryof

ScienceandTechnologyongroup2measuringinstruments,therearethreetypesofinspection:

· Initialinspectionisperformedbeforetheinstrumentisputintooperation

· Theperiodicinspectionmeansinspectionofthemeasuringinstrumentswhichareinoperation

· Theinspectionafterrepairmeansinspectionofthemeasuringinstrumentinoneofthefollowing

cases:

-Therepairedmeasuringinstrumentfailstosatisfytechnicalmetrologicalrequirements;

-Inspectioncerti�ications(inspectionseals,stamps,certi�icates)ofthemeasuringinstrumentislost

ordamaged,butitsstructureandmetrologicalcharacteristicsarenotchangedcomparedtothe

approvedtype;

-Theinspectionisnecessaryaccordingtotheconclusionofthecompetentauthorityorperson;

- Users of themeasuring instrument suspects that themeasuring instrument does not satisfy

technicalmetrologicalrequirementsandrequestsare-inspection.

Measuringinstruments,metrologicalcontrolmeasures,andmeasuringinstrumentinspectionintervals

arespeci�iedintheTable74.

2.2.3. Dataanalysis

Theinitialworkofenergyauditistoassessthecurrentoperationalstatusoftheequipment,establish

performanceindicatorsofrespondents.

Informationthatneededtobestudiedaftertheauditare:

· Energyconsumption

· Energycost

· Energydemand/supply(energy�low)

· Energydistributionandloss.

Afterdatacollectionandmeasurement,auditorsscreenandsynthesisthedataintoanalysisfactorsand

identifythevalue.Data�luctuationshouldbeanalyzed.

Energyperformanceofthewholeorganizationwouldbeanalyzedafterde�iningtheenergyconsumption

indicators,andbenchmarkinganalysis.To�indoutthelossandpotentialsavings,studyonenergy�low

shouldbeconductedonkeyenergyconsumptionareas.

Energysavingspotentialswillbeproposedafterdataanalysisandauditorshavetoproposetheproven

amountofsavingsorsavingpercentageforeachenergysavingssolutions.

ToolsfordataanalysisofcommonenergyconsumerwillbeintroducedinpartII.

2.2.3.1. Energybillanalysis

Energyauditorsshouldunderstandwelltheenergypricesystemandallenergycost,whichisimportantto

calculatetheamountofsavings.

Energybillsre�lecttheenergyconsumptionofthefactory.Byanalyzingmonthlyandannuallyenergybills,

auditorscanassesstheenergyconsumptionstatusofthefacility,trendofincreasingordecreasingin

energyconsumptionthroughoutthetime.

24

25

Figure3.Exampleofregressionanalysis forelectricityconsumptionandproduction

Energyperformanceindicator(EPI)=Energyconsumption(convertedtoMJ,KWhorTOE)

Productionvolume(mostlyintons)

Tabulating historical energy consumption records provides a summary of annual consumption at a

glance.

Utility and fuel supplier invoices also contain valuable information about consumption that can be

tabulated.Templatesfortabulating,graphingandanalyzinghistoricalenergyconsumptionandpurchase

datacouldbegeneratedwhennecessary.

Atheoreticalassessmentofspeci�icprocessesyieldsalinearrelationshipwhenplottingenergyagainst

production,producingastraightlineofthegeneralform

Y=mx+c

Linearregression,i.e.by�indingthebest�itofastraightlineusingtheleastsquaresmethodtotheplotof

energyconsumptionvs.production,couldhelptode�inethecaseofconsistentperformance,installed

improveorbreakdown.ExampleisillustratedinFigure3.

Thebaselineandthetargetoftheperformancecanbesetinconsistentperformancethatisunaffectedby

improvementsorbreakdowns.

2.2.3.2. Energyperformanceindicator

Energy Performance Indicators (EPI) are used to explain the status and effect of the management

externally.Themostpracticalandfrequentlyusedenergyperformanceindicatorisenergyintensityor

speci�icenergyconsumption(SEC),whichreferstoenergynecessaryforacertainproductionunit(ton,

piece,set,etc.)asshowninthefollowingformula.

Benchmarkingtheenergyintensivewithotherfactoriesorworkplacesinthesameindustryevaluatethe

possibilitytoimproveenergyef�iciencyortheachievementlevelofenergyconservationforafactory.

2.2.3.3.Energyef�iciencyanalysisbyhistoricaltrendandbenchmarking

Theenergyperformancewithintheplantsshouldbestudiedincludinghistoricalenergyconsumption

andtrendinthreerecentyears.

Energyintensityisoftenusedasindicatortoevaluatebywayofcomparisonwiththefollowings:

· Plannedvalue

·����Valueinthesameperiodofthepreviousyear

Elec

tric

ity

(kW

h)

180 000

160 000

140 000

120 000

100 000

80 000

60 000

40 000

20 000

0

0 50 100 150 200

Produc�on (tonnes)

26

Figure4.EPIforglassmelting

Figure5.Comparisonbetweenthemillandthebenchmarkandestimatedenergysavings

Source:EcoEnergy, 2008

· Otherfactoryorfacilitiesinthesameindustry

· Benchmarkbetweencompaniesanarea.

Historicaltrendofenergyconsumptioninthelastthreeyearswouldprovideapictureofenergy

practicesoftheplants,improvinginenergyef�iciencymaybeobservedshowingtheeffectivenessof

energymanagementapplication.

Anexampleofhistoricaltrendanalysisbasedonweeklydataofglassmeltingisillustratedinthe

Figure4.

ExistingregulatedEPI,orinternationalbestpracticesofthesimilarprocessorofthesameindustry

shouldbecollectedtoperformtheanalysis.

The gap inEPIbetweenexistenceplant and thebest practiceshelps to estimate energy savings

potentialfortheplant,asdemonstratedinFigure5.

Benchmarkingde�ineshigh-ef�iciencyequipmentinordertoidentifyandgivetheprioritytoimprove

low-ef�iciencyequipmentimmediately

EnergySaved

Range YourMill

ComparableBenchmark

EnergyGap

Gap A�erBest Prac�ces

Your Mill w’Best Prac�ces

27

Figure6.Flowchartofadying processwithenergyandmaterial�low

Energybalance,physicalbalancewouldbesetup forauditedobjects (blockdiagrama "blackbox");

operationalcharacteristicsofdevicesusingenergy.

Characteristicofkeyenergyconsumptionareaswouldbeidenti�ied,consistingof(butnotlimited)to:

· Thetypeandcharacteristicsoftheheatingboiler,andsteamsupplysystem

· The typeandcapacityof thecoolingsystem, the technical characteristics (refrigerationpressure,

temperature,�lowandtemperatureofcoolingwater,pressure,etc.)

· Type of air-conditioning systems, system components (pumps, fans, compressors, pipes, etc.),

operatingcharacteristics(�low,temperature,pressure,etc.)

· Thelevelofmobilizationofequipment,systemsandequipment

· The mechanism controlling the devices, system devices (controllers, devices Executive, sensors,

controllogic,etc.)

· Lightingequipmenttype,speci�icationandcontrolstructure

· Characteristicsoftheelectricitydistributionsystem.

Incaseofauditsofbuildings,auditorsneedtounderstand:

· Featuresofthebuilding

· Operating characteristicsof the system lifts, escalators (servicearea, typeofdrivemotor, control

system,etc.).

Comparisonsshouldbemadetoforkeyenergyconsumptionareasandequipmenttoidentifythelostand

savingpotentialsbyminimizingtheloss.Allcomparisonsincluded:

· BoilerEf�iciency,lossesinfuelcombustion

· Lossonheatsupplyingpipe(Pa/m)

· Theperformanceef�iciencyoftheengine(%)

2.2.3.4.Process�lowchartandkeyenergyconsumptionareaanalysis

The process �low chart of performing in the entire plant, line technology, key equipment, and

identifyingtheenergy�low,material�lowandproductin/outof"thebox"wouldbedrawn.Thekey

energyconsumptionareashouldbeidenti�iedinthe�lowchart.

Anexampleoftheprocess�lowchartispresentedinFigure6.

Yarn

Dyeing

process

Dyedyarn

Compressionair

Water

Steam

Rawmaterials

Wastewater

Condensate

Condensateandheatrecovery

28

· Theperformanceef�iciencyofthecoolingoperation

· Thecapacityofthesystemfanpower(kW/literofairsupply/sec)

· Theperformanceef�iciencyofthefan(%)

· PumpPerformanceef�iciency(%)

· Theperformanceef�iciencyofthecompressor(%)

· 2Lightingpowerdensity(W/m )

· Illuminanceofthelightingsystem(Lm/W)

· Lossoflightingcontrolsystems(W).

Forheatingsystems,ventilation,airconditioning(HVAC),wastedareacanbedeterminedfromthedata

recordkeepingontraf�icchangescorrespondingtochangesintemperatureandpressure.

Forpowersupplysystems,wasteareacanbedeterminedfromtherecordbookincurrent,voltage.

Intheabsenceoftherecordbook,themeasurementsaredonetodeterminetheequipment/system

devicesareworkinginef�iciently.

2.2.3.5.Energy�lowandenergybalance

Breakdownofenergyusebyareas/processes/functions….andidentifyingtheenergy�lowofeachpoint

areperformed.

Energybalanceisanalyzedandenergy�lowswouldbeidenti�iedintheformofSankeydiagramandpie

chart.

Sankeydiagram

TheSankeydiagramisan important tool in identifying inef�icienciesandpotential forsavingswhen

dealingwithresources.

Sankeydiagramrepresentsalltheprimaryenergy�lowsintofactory.Thewidthsofthebandsaredirectly

proportionaltoenergyproduction,utilizationandlosses.Theprimaryenergysourcesaregas,electricity

andcoal/oilandrepresentenergyinputsattheleft-handedsideoftheSankeydiagram.

TheSankeyshouldlooklikethepicturebelow–asteamsystemwithoutcondensaterecovery,nowaste

heatrecovery,allunitsinkg/day.

29

Figure7.Sankeydiagramfortheenergylossinsteamsystem

Figure8.Shareoftheenergyusers

100.0 72.0 66.3 60.3 51.3 41.0

6.0%

291 10.2%

5.8% 9.0% 500

281 441

28.0%

Fuel lossess (kg/day) 1,366 Total fuel lossess (kg/day)

2879/4879 (kg/day)

Example: using 2

ton/hr of steam, fuel

oil boiler with the

Fuel supply

Piechart

Piechartsshowingthedistributionoffuelsand�lowsgoingthroughtheselectedenergyconsumers.The

piechartscouldbeusedtopresent:

· Distributionoffuelspassingthroughthenode

· Distributionoftheenergycontentoftheincoming�lows

· Distributionoftheenergycontentoftheoutgoing�lows.

Water hea�ng23%

Cooking5%

Stand by5%

Ligh�ng11%

Other appliances24%

Hea�ng andcooling

20%

Refrigera�on12%

Heat transfer losses

Condensate lossesSteam leakage

Pipe heat losses

Boiler heat losses

Fuel flow 4,879 3,513 3,232 2,941 2,500 4,000 kg/day

- flue gas- radia�on- blow down, etc.

Usefulenergy

AreaBoilerheat

loss

Pipeheat

loss

Steam

leakage

Condensate

losses

Heat

transfer

losses

Losses>>> 28% 8% 9% 15% 20%

30

2.2.3.6.Energysavingopportunities

Thekeyenergyconsumptionareawouldbede�inedfromtheenergy�lowsdiagram(piechart)andthe

highsavingopportunitiesareawouldbeobservedfromtheSankeydiagramwherehighenergylossareas

areobserved.

Theauditteamshouldcomparetheoperationalcharacteristicsofthedevicewithdesigndataorwiththe

technicaldocumentationtodetectdifferences.Detectionareasareenergywastersandenergy-saving

potential.

2.2.3.7.Proposeenergysavingsolutions

Mostofthemeasuresaresimplegoodhousekeepingmeasureswhichcanbeimplementedimmediately.

Othermeasuresarelowcost(e.g.�ittingtimers,pipeinsulation,draughtproo�ing,etc.)andwillinvolve

someexpenditureand/orcontactingestates.

Energysavingsolutionsareclassi�iedintothreegroups:

Solutionswhichdonotrequireinvestmentcost

Includespracticalsolutionwithoutinvestmentcosts,doesnotaffectthenormaloperationofequipment/

technologyline:

· Changeproperlymanipulationofoperation

· Rationalizetheproductionline

· Arrangetidybuildingsandfacility

· Applysimplemeasures(airconditioningoff,turnoffthelights,stoppowertothedevicewhennotin

use,setthetemperatureofairconditioningintheroomproperly,etc.)

Solutionswithlowinvestmentcost

Includingsolutionswhichrequirelowinvestmentcosts,anddonotsigni�icantlydisrupttheoperationof

thedeviceorprocessline..Someexamplesare

· Installationofadditionaltimecontrollerstoon/offequipmentandopen/closedevicesintechnology

lines;

· Replacepower-savinglights;

· Equiponlinemeters,andmore...

Solutionswithhighinvestmentcost

Includessolutionswithhighinvestmentcosts,cansigni�icantlydisrupttheoperationofthedevice/line

technology

· Installationoftheinvertertothemotor

· Equipmentinstallationforpowerfactoradjustment

· Replacement,reconstructionofboiler

· Replacingthecoolers(chillers).

· Equipmentinstallationforwasteheatrecovery

Technicaland�inanceconstraintanalysisshouldbeperformedwhenproposingandanalyzingtheenergy

savingsolutions.Impracticalsolutionswithsigni�icantinvestmentcostshouldnotbeavoided.

Technicalfeasibilityanalysisshouldaddressthefollowingconditions

· Technologyavailability,space,skilledmanpower,reliability,service,etc.

· Theimpactofenergyef�iciencymeasureonsafety,quality,productionorprocess

· Themaintenancerequirementsandsparesavailability.

Economic feasibilitycanbeconductedbyusing thevarietymethodswhichareexplained in thenext

Section.

2.2.3.8.Financialandfeasibilityanalysis

Energysavingprojectsmustbecompetitivecomparedtootherprojectsbyincreaseofcostsavingsor

pro�itexpectations.

Financeanalysisisrequiredtodeterminetheappropriateinvestmentoptionsbycomparingtheoptionsto

achievetheobjectivesoftheorganization.

Theenergyef�iciencyprojectsinvolvingdifferenttypesofcosts.

Investmentcosts

Thescaleof the investment isavery important factor inthe�inancialevaluationofenergyef�iciency

projects.Thiscostareoftenexpressedinalargeamountofmoneyspendonprojectsbeingimplementedin

ayear.

Investmentcostsincludethefollowingcosts:

· Installationcosts(construction,installation)

· Equipmentexpenses

· Taxes,customsfees

· Thecostsofstafftraining

· Otherexpenses(Insurance,EngineeringandTransport).

Operationcost

Theoperatingcostsandmaintenanceassociatedwiththeoperationareanalyzed.Thedifferenttypesof

expensesincludinginoperationcostsinclude:

· Energyandrelatedcosts

· Laborcosts(salariesofoperatingpersonnelandmanagement,)

· Thecostofrepairsandmaintenance

· Otherexpenses(supplementarymaterial,administrativecosts,etc.).

Othercost

· Replacementcost:costtoremovethedeviceattheendoflifecycle

· Lost production due to stop productionwhile installing the equipment and put the system into

operation.

Pro�itscanbeearnedfromanenergyprojectmaybe

· Energysavings

· Incomefromthesaleofenergy

· Reducemaintenancecosts

31

· Incomefromimprovingquality

· Incomefromincreasedproductivity.

The�inancialcriteriatoevaluateproject

· Simplepaybacktime:

Thetimerequiredtorecovertheinvestmentfromcash�low.Thisisaquantitativemethodwhichiswidely

usedtoassessthecosteffectivenessofenergy-savinginvestments

Simplepayback=Costofinvestment/Netannualsavings

Whenapplyingthismethod,savingsafterpaybacktimeisnotcalculatedandthevariationinmoneyvalue

overtimeisnotconsidered.

· Rateofreturn(ROI)

ROI=(GainfromInvestment-CostofInvestment)/CostofInvestment

Description"annualbene�it" fromtheprojectcostasapercentageofcapital.Costcomparison isnot

considered.

· Netpresentvalue(NPV)

Allthesenetbene�itsaredepreciatedreturnatthelowestappealtodeterminetheequivalentpresent

value.

· Internalrateofreturn(IRR)

Thediscountrateatwhichthenetpresentvalueoftheaccruedbene�itsofaninvestmentequaltothe

investmentcosts.IftheIRRvalueishigher,projectismoreeffective.

· LifecycleanalysisForexample,considerthecomparisonoftraditional�luorescentlights(FL),spotlights,toCompact�luorescentlights(CFL)orlight-emittingdiode(LED)replaced.CFLlamplifeis5timeshigherthanhalogenlampandLEDlifespanatleast20timesmorethanhalogenlamps.

Thecalculationwilltakeintoaccountthelifecycletocomparetheoriginalequipmentandreplacement.

32

33

Table2.Summary ofenergysavingpotentialandestimationofinvestmentcost

No. Measures Energysavings ExpectedInvestment

(106VND)

Costsavings

(106VND/year)

PaybackPeriod(Year)Electricity

(kWh/year)

Fuel

(ton/year)

1

2

3

…

Total

3. STANDARDAUDITREPORTTEMPLATE

AuditreportformatshouldbestandardizedwiththecontentsregulatedbytheCircular09.Thischapter

recommendsastandardauditreporttemplate,consistingoftwomaincontents:

· Statusoftheorganizationincludingtheirgeneralinformation,descriptionproductionprocessand

energy�lows.Theenergyconsumptionstatus,annualEPI,andenergylossshouldbeincluded.

· Energysavingssolutionsconsistingof listofenergysavingsolutionsclassi�ied inthreegroupsas

mentioned in chapter2.Effectivenessof the energyaudit shouldbe evaluated in this report and

economicanalysisforeachenergysavingmeasuresshouldbereported.

Contentofthestandardauditreportshouldbeorganizedasbelow:

3.1. Summary

· Summaryofenergyconsumptionintheenterprise

· Summaryoftheenergysavingmeasureswithpriority

· Proposetheselectedmeasurestobeimplementedandinvested.

Thecontentshouldbesummarizedinthefollowingtable

3.2. Introduction

· Briefintroductionoftheauditorganization

· Objectiveandnecessaryoftheaudit

· Scopeoftheaudit

· Introductionoftheauditteam,andtheirtask

· Measurementmethodanddevice,listedinthetablebelow

34

Table3.Thelistofdedicatedequipmentusedintheenergyaudit

Table4.Rawmaterialandmainproducts

I Rawmaterialinyear…

Mainproductsinyear

Table5.Operatinghourperayearofenergyconsumptionareas/workshop

…

…

II

…

No. Name Code Quantity Origin

No. Item Unit Data

No. Area/Workshop Operationtime(hour/year)

3.3. GeneralInformationoftheauditorganization

· Developmenthistoryandtheirstatus

· Operationstructureandfrequencyofproduction,includingoperationhours

Therawmaterialandmainproductsisdescriptedbyfollowingtables:

3.4. Descriptionofoperationprocess

· Flow chart or black box description of the production process, including in/out �lows of energy,

materials,andwater

· Identifytheinef�iciencyenergyconsumersduringthesurvey

· Energysavingpotentials

35

Table6.Electricitytariff(appliedfrom…)

· Energydemandandconsumption

Table7.Electricityconsumptionandelectricitycostsinmonthly(…)

Table8.Fuelconsumptionandcostsinmonthly(…)

Amount(ton/yr)

Cost(103VND/yr)

Amount(ton/yr)

Cost(103VND/yr)

Amount(ton/yr)

Cost(103VND/yr)

Wholeyear

1

2

..

12

Fuel1 Fuel2 Fuel3 Totalcost(103VND/yr)

Monday–Saturday Sunday

Peakhours

(5hours)

Normalhours

(13hours)

Off-peakhours(6hours)

1

2

3

Tariff(VND/kWh)No. Item Appliedtime

3.5.Energydemand,supplyandconsumption

·Sourceofenergysupplyandcost,fuelcharacteristic

Normalhours

Peakhours

Off-peakhours

Total Normalhours

Peakhours

Off-peakhours

Wholeyear

Ratio(%)

1

…

12

Month Hourlyelectricconsumption(kWh) Electricitycost(VND)

36

· Waterdemandandconsumption

Table9.Waterconsumptioninmonthly(…)

Wholeyear

Table10.Energyconstrainsandstandards

1

2

…

12

Month Quantityofwater(m3) Watersource

Solidfuel

- Coal Kg

- Antracitecoal Kg

- Biomass(Wood/Ricehusk) m3

Liquidfuel

- DieselOilDO(ρ=0.86kg/dm3) Littre

- FuelOil(ρ=0.94kg/dm3) Kg

Gasfuel

- Natualgas–NG m3

- Liquidpetroliumgas–LPG Kg

Electricityconsumption MWh

Heatvalue/unit CO2emission

MJ/unit kWh Kg/MJ Kg/kWh

Energytypeandstandard Unit

3.6. Economicandtechnicalconstraints

· Energylossanalysis,andareawhichrequiredfurtheranalysis

· Technicalconstraintsbycomparingtheactualoperationstatuswithdesigncapacity

· Economicconstraints,costofenergy,andfuelandCO emissionconstraints2

· Theincreasingofenergycostandrequirementofenergysubstitutionshouldbeanalyzed

3.7. Energysavingmeasure

· Identifygroupofenergysavingmeasures,listofmeasuresineachgroupwithdetailsdescription

· Priorityofmeasurestobeimplemented

· Financialanalysisofselectedmeasures,amountofsavings,paybackperiodandenvironmental

aspectanalysis

· Conclusion and recommendations, proposing an energy management program for the

organization.

37

3.8. Conclusionandfutureplan

· Conclusionandrecommendationonenergyauditresult

· Proposedactionplanfortheenterprise:

-1-yearplan

-5-yearplan.

3.9. Annexes

· Primarydatatables:Summaryofproductionvolume,energy,etc.

· Actualloadpro�ile

· Energysavingcalculationsforproposedmeasuresmentionedintheenergyauditreport

· Energyprice

· Energytypeconversion

· Conversioncoef�icientofCO emission2

…

38

02 Recommendation For

Energy Audit Practices

39

Watt-hourMeter:Usedtomeasurethepowerused on the line by time cycle. The meterincludes a small motor running at speedsproportionaltothepowerused.

Wattmeter:Usedtomeasuretheusepowerofanelectricaldevice.Portablewattmeterallowsdirectreadingofelectricitydemand.Limitworkof300kWs,650Vand600A.Wattmetercanbeusedforbothlineonephaseandthreephase

Ampere meter: Used to measure the electric current. Portableclamp type ampere meter is very popular and convenient in theenergyauditwhenafixedmeterisnotrequired

Voltmeter:Usedtomeasurethevoltagebetweentwopointsofthepowerlines.Mostoftheactualmeasuredvoltageisbelow600V.

KiloWatt(kW)

Apparentpower

Powerfactor

PARTI.

RECOMMENDATIONFORENERGYAUDITPRACTICES

1. MEASUREMENTDEVICES

1.1. Electricitymeasurement

Measuringinstrumentsmainlyforelectricityaspower,powerfactor,reactivepower,electricalcurrent,

voltage.Someinstrumentsaremeasuredbothharmonics.

Thedevicesaregettingtotheline,wheretheenginesareworkingwithouthavingtostopthemotor.Hand-

heldmeasuringdevicescanbeusedforinstantmeasurements.Otheradvancedinstrumentscombining

datacanbereadwithprintsinacertaintimeperiod.

40

PowerFactorMeter:Initialmeasuringdeviceforpowerfactoristhree-phase.Canmeasurethepowerfactorearlyof 1.0 to delay 1.0 and accept the current to 1500A at600V. This range includes themajor applications in thelightIndustry.

Power Analyzer: The system analysis one phase andthreephase,Volt,Amps,Watts,VARs,VA,W,HzkWh

Clampautomatictypeusedto(20A,200A&1000A)

Lightingsystemmeasurementequipment

Luxmeter:

Illumination ismeasured by luxmeter, consisting of a photovoltaic cellsensitivity to emission light, converted into electrical pulses and areformattedtolux.

Clamp-onPower

These devices are getting up to lines to measure theelectrical parameters of themotor, transformer and theelectricheatingwithoutstoppingoperation.

Usedtomeasureparameters:

•Voltage:150Vto600V,

•Current:200Ato1000A,

•Voltage/currentpeak

• Effectivepower / reactive / apparent (onephaseorthree-phase):30kWto1200kW,14combination

Type

•Loadfactor

•Thephaseangle

•Frequency

•Thesynchronouslevelofvoltage/current

41

Dust filter

1.2.Thermalmeasurementequipment

Combustionef�iciencymeasurement

Oxygenmeasurement,�luegastemperature.The

heatvalueofthecommonfuelsisloadedintothe

processortocalculatethecombustionef�iciency.

Relativehumiditymeter

Wetanddrybulbwith�iltrationcombinedwith

mercurythermometers.

Quantity:150gms

Temperature:-5°Cto50°Cor20°Fto120°F

Fyritetube

Useamanualpumptosuckthesmokeintothe

deviceprocessor.Thechemicalreactionchanges

theliquidvolumeofthevolumeofairexpress.

ThedifferentFyritetubescanusedtomeasure

theO andCO2 2

Fluegasanalyzer(ORSAT)

TubeisarrangedinsidethedevicetomeasurechemicalgasessuchasO ,CO,NO andSO .Thisdeviceis2 X X

importantimplicatedfortheboilersystem,incalculatingtheamountofexcessairinthe�luegasesand

lossesduetouncompletedburnout.

42

Infraredthermometers

Range:upto1000°C

Readingaccuracywithin±1%

Contactthermometer:

This is a thermocouple to measure the �lue gas

temperature, hot air, hot water, etc. by bringing the

probeintothe�low.

Forsurfacetemperatures,leaftypeprobeisusedwith

thesamedevice.

The thermometer is attached to the pipe, used to

measurethetemperaturebothhotandcoldwater,and

steam,.

1.3.Pressure,velocityand�lowratemeasurementequipment

Pitotubeandmanometer

Measurewindspeedintubes,pressuregaugeattached

tocalculatethe�lowproperties

43

Speedmeasurement

Inanypublicenergyauditing,rotationspeedmeasurement is

importantbecausespeedmayvaryduetopowerfrequency,load

andunderloadskating.

Contacttypespeedmeterismaybeusedinareasaccessible.

Stroboscopic device is non- direct contact type, sophisticated

andsafer.

Leakdetectiontools

Ultrasonicinstrumentcandetectleaksoncompressedairpiping

andothergasesthatareusuallydif�iculttodetectbyeye.

Measurewater�lowrate:

Contactless �low measuring device use the Doppler effect/

ultrasoundprinciples(UltraSonic).Thereisatransmitterand

receiver set lying opposite pipe. The meter directly displays

water�lowor�luidinsidethetube.

Airvelocitymeter

Airvelocitymeterisadeviceusedformeasuringtheairvelocity

withfanbladessensor.Largefanbladeisusedforlargesurface

areatoensuretheaccuracyofthemeasurement.

Measuringrange:+0.3to+20m/s

Accuracy:±(0.1m/s+1.5%measuringvalue)

Resolution:0.01m/s

44

2. OVERALLENERGYCONSUMPTIONANDENERGYMANAGEMENTASSESSMENT

2.1. Generalinformation

Generalinformationoftheorganizationshouldconsistof:

· Nameandaddress

· Contactperson

· Mainactivities

· Startingyearofoperation

· Productioncapacity(design,actual)

· Numberofemployees(managers,technical,production)

· Organizationchartandlayout(ifavailable).

2.2. Materialconsumptionandproductvolume

Informationiscollected:

· Materialtypesandproducts

· Productquantityofenterprisesinrecentyears

From collected data can be analyzed by changing product trends, and production capacity of the

enterprises.

2.3. Powerandwaterconsumptiondata

Monthlypowerandwaterconsumptioninayearandthelast3yearsshouldbecollected.Fromcurrent

statusofenergyconsumptionandproductionvolume,itispossibletoidentify.

· Energy consumption status of the company in last years. Thus, the energy consumption of the

companycanbepredicted.

· Thetypeandcostofenergyconsumption.Thecostsavingpotentialandgreenhousegasemissionin

case the company use a new type of energywith lower cost and greenhouse gas emission (e.g.

renewableenergy)

Therearemanydifferentenergytypescanbeconsumedbyenterpriseinclude:electricity,coal,DOoil,FO

oil,LGPandnaturalgas,biomass,steam…andwater.

Theunitoffuelconsumptiondatawouldbeconvertedtobeconsistentwhenanalyzingandreporting.

Energydataanalysis

Dependonfueltypes,itisnecessarytocollecttheircalorific value of fuel, especially coal and biomass. Coal

and biomass have their calorific value, that can vary widely according to fuel type, percentage of moisture, ash in

the fuel. Thus,inordertoanalyzethetotalactualenergyconsumptionofenterprises,orconverttoTOE

unitAuditorcanaskenterprisesorcoal/biomasssupplierprovidesampletestingresultsofthesefuels

thatenterprisesareusing Innecessarycases,bringingthosesamplestotestingcentertochecktheir.

calori�icvalue.

45

Ap:Activepower(kWh)

Aq:Reactivepower(kVArh)

Priceforreactivepower:

Tq:Priceforreactivepower

Tp:Priceforactivepower.

k:Off-setpricefactorduetousingexcessreactivepower.

Determinekinbelowtable.

T =T xk%q p

With natural gas (NG) or compressed natural gas (CNG): Due to limited pipeline or limited

distribution,thosefuelsonlyprovideforsomefactoriesatindustrialareassuchasBaRia-VungTau

andDongNaiprovince.CNGcanprovidetoHCM,DongNai,BinhDuongprovince…

PowersupplycantakefromnationalGridorproducedbytheenterprises(bybackupgeneration,

cogenerationsystems,solar…).Now,nationalGridisthemostpopular.Cogenerationsystemscanbe

foundinlargeenterprisesandcompanysuchas:sugar,paperindustry…Otherpowersupplycanbe

generatedbyrecoverheatofcementorsteelindustry.

For national Grid, electricity price is different, depends on business types, voltage supply and

accordingtothetimeofuseinaday(normalhour,off-peakhour,peakhour).Theelectricitypricefor

enterprisesinrecentyearsisintheTable71.

Moreover,accordingtoCircular15/2014/TT-BCT,May28th,2014,prescribedaboutpurchaseand

saleofreactivepower.Theelectricitybuyerhastransformerorwithouttransformer,buthasthe

maximumpowerutilizationregisteredinpurchaseagreementfrom40KWormoreandthepower

factorlessthan0.9,havetobuyreactivepower.Thepowerfactorcanbecalculatedonthebasisofdata

measuredbytheelectricitymeterinrecordingcyclemeter,byfollowingformula:

46

Table11.Powerfactor

Therefore,whencollectingdataonpowerconsumption,takecareaboutthepriceofreactivepower,that

enterprisesmustpay,ifany.

TheconversionintoTOE,MGandemissionfactorsofsomeenergytypesisintheTable72.

2.4. Energyperformanceindicatorandbenchmarkingreferences

MethodologyofEPIcalculationandbenchmarkapproachhavebeenintroducedinprevioussections.In

thissection,energyconsumptioninenterprisesandenergyrateinsomeindustriesinVietNamwillbe

presentedasareferencetool.

Fromdataonproductqualityandenergyconsumption,willhelpdetermineenergyconsumptionforeach2productunit,orconsumptionpowerperaream atbuilding,commercialcenter,servicecenter….So,we

compareenergyconsumptionrateofthesectorinthecountryandintheworld.

AtVietNam,someindustrieswereruledtheirenergyconsumptionratebyMinistryofindustryTrade

suchas:steel,cement,drinks(beerorbeverage),chemistry(rubber,fertilizerNPK,paintwater,solvent).

Hereisshortlistaboutenergyconsumptionrateinthesector/sub-sectors:

k(%) k(%)

From0,9andabove

0,89

0,88

0,87

0,86

0,85

0,84

0,83

0,82

0,81

0,8

0,79

0,78

0,77

0,76

0,76

0

1,12

2,27

3,45

4,65

5,88

7,14

8,43

9,76

11,11

12,50

13,92

15,38

16,88

18,42

20,00

0,74

0,73

0,72

0,71

0,7

0,69

0,68

0,67

0,66

0,65

0,64

0,63

0,62

0,61

0,6

below0,6

21,62

23,29

25,00

26,76

28,57

30,43

32,35

34,33

36,36

38,46

40,63

42,86

45,16

47,54

50,00

52,54

PowerfactorCosϕ PowerfactorCosϕ

47

· Circulars19/2016/TT-BCT,publishedin14/09/2016,prescribedpowerconsumptionrateinbeer

andbeverageindustry.

Table12.Energyconsumptionrateuntil2020s.

TT Industry Powerscale(millionlitre) Rate(MJ/hl)

1 Beer >100 140

20–100 215

<20 306

Producttype

2 Beverage Sodaorbothsodaornonsoda. 55

Nonsoda 111

Table13.Energyconsumptionratefrom2021s–to2025s

TT Industry Powerscale(millionlitre) Rate(MJ/hl)

1 Beer >100 129

20-100 196

<20 286

Producttype

2 Beverage Sodaorbothsodaornonsoda. 52

Nonsoda 107

· Circulars 20/2016/TT-BCT, published in 20/09/2016, prescribe energy consumption rate in

steelindustry:

Table14.Energyconsumptionrateforsteelindustryuntil2020s

TT Productphase Units Rate

1 Sinteringofironore

Productionofcastironbyblastfurnace

Productionofsteelbilletby

Productionofsteelbilletbyelectricarcfurnace

Productionofsteelbilletbyinductionfurnace

Hotrollingoflongsteelproducts

Coldrollingofsteel

MJ/tonne 2,350

2 MJ/tonne 14,000

3 (top-blown)converter MJ/tonne 150

4 MJ/tonne 2,600

5 MJ/tonne 2,600

6 MJ/tonne 1,650

7 plates MJ/tonne 1,600

48

Table15.Energyconsumptionrateforsteelindustryfrom2021sto2025s.

TT Productphase Units Rate

1 Sinteringofironore MJ/tonne 1,960

12,400

100

2,500

2,500

1,600

1,500

2 Ironmakingbyblastfurnace MJ/tonne

3 Productionofsteelbilletby(top-blown)converter MJ/tonne

4 Productionofsteelbilletbyelectricarcfurnace MJ/tonne

5 Productionofsteelbilletbyinductionfurnace MJ/tonne

6 Hotrollingoflongsteelproducts MJ/tonne

7 Coldrollingofsteelplates MJ/tonne

Table16.Energyconsumpationrateinchemistryindustry

TT Industry Powerscale Rate(kOE/tons)

1 Rubber Designedpowerbelow5,000tons/year 44

Designedpowerfrom5,000to10,000tons/year 36

Designedpowerabove10,000tons/year 28

2 FertilizerNPK Designedpowerbelow4,000tons/year 14.8

Designedpowerfrom4,000to9,000tons/year 16.8

Designedpowerabove9,000tons/year. 19.7

3 Paintwater all 12.1kOE/tons

4 Solvent all 17.7kOE/tons

Factorieswhichonlyproduce a single product, calculate their energy consumption intensiveby

dividingdeterminedtotalenergyconsumptionwithtotalproduction.

Forfactorieswhichproducesvaryproductsorwhenanalyzingenergyconsumptionateachstage,itis

necessarytomeasureenergyconsumptionforparticularproductionorbyproductionstage.Youcan

alsousemultivariateregressionmethodstoanalyze, inthiscase,theaccuracyofdataaffectsthe

purityoftheanalyticalresults.

· Circulars 02/2014/TT-BCT, published in 16/01/2014, prescribe energy consumption rate in

chemistryindustry

49

Table17.Amatrixofenergymanagementevaluation

Ranking Energypolicy Assessment

4 Have energy policy, action plan, periodical checking,topmanagementcommitmentintheenergymanagementimplementation.

3 Thereisaformalpolicybutnotopcommitment.

2 Thereisapolicy, butitisnotyetimplemented

1 Thereareunwrittensetofguidelines.

0 Noenergypolicy

2.5. Energymanagementassessment

2.5.1. Objectives

This toolhelps theauditor to identify theenergymanagement statusof theenterpriseandpropose

solutionstoimproveenergyef�iciencyviamanagementimprovement.

2.5.2. Evaluationmethod

Inassessingthestatusofenergymanagement,auditormayusedifferentmethods.Inthismanual,onlythe

PDCAcycle(Plan–Do-Check-Act)isintroduced.Thisapproachprovidestheauditoranoverviewofthe

company's energy management system, starting from leaders' commitments to the performance

implementationandevaluation,aswellasimprovementactivities.

Belowisatableofcriteriatoevaluatethecurrentstatusofenergymanagement.Therearesixcriteriato

evaluatethecurrentstatusofenergymanagement,whicharedesignedbasedonthePlan-Do-Check-Act

model,including:

· Criteria1:Energypolicy(Planning)

· Criteria2:Organization(Planning)

· Criteria3:Training(Do)

· Criteria4:Informationexchange(Do)

· Criteria5:Checkingandevaluation(Check)

· Criteria6:Investment(Act)

Eachcriterionwillbescoredintheratingcolumn,thescorerangeisfrom0to4,inwhich0correspondsto

thelowestmanagementleveland4isthehighest.

50

Ranking Energymanagement Assessment

4

3

2

1

0 Thereisnoonewhoisinchargeofenergymonitoring.

Ranking Training Assessment

4

3 There are regularly trainings, awareness and sensitization campaigns onenergysavingbutonlyinsidetheenterprise.

2 There are trainings, awareness and sensitization campaigns on energysavingintheenterprisebutnotregularly.

1 There are trainings, awareness and sensitization campaigns on energysavingbutnotof�icially.

0 Thereisnotraining,awarenessandsensitizationcampaigns.

Ranking Motivation Assessment

4 There is information channel and all staff can exploit in order toknowenergyconsumptionstatusandresultsofenergysavingactivities.

3 Thereisanenergyboardandthisboardisthechanneltointeractwithallmainenergyusersintheenterprise.Thisboardisledbytopleader intheenterprise.

2 Interactions between some main energy users/staff is conducted byboard/team,organizationinchargeofenergy(headoforganization)

1

0 Thereisnothing

Energy management is fully integrated into company management;

Thereisclearenergyconsumptionregulation.

There is energy manager; there is energy board with head of board is top

leader of the enterprise.

There are regularly trainings, awareness and sensitization campaigns on

energy saving inside the enterprise and outside (equipment suppliers,

services, customers…) systematically, officially. There are regularly training

courses on energy saving in the enterprise.

There are only unof�icial interactions between factory engineers or

betweentechnicaldepartmentstaffwithsomemainenergyusers/staff

There is energy manager; there is energy board with head of board is head of

department [1]. (not top leader of the enterprise)

There is energy manager; but not official, the authority is limited. There is no

energy board.

51

Ranking Informationsystem Assessment

4 There is comprehensive information system of recording, analyzing,targeting,planning,costbene�itanalysis,investmentplan.

3 There is information system of recording, analyzing, reporting energyconsumption though at local level but results of energy saving activities,informationofenergysavingarenotannouncedtoenergyusers

2 Thereismonitoring,analyzingofenergydatasystembutmainlybasedonbills and some calculated data, there is not much data from measuringinstrument; but the energy manager has important role of budgetingenergycostandenergyinvestment

1 There is energy report but notmuch analysis, data is based on bills. Allenergydataisusedforinternaltechnicaldepartment.

0 Thereisnothing.

Ranking Investmentpolicy Assessment

4 Detailed investment plan with particular cost/ bene�it ratio given highpriority.

3 There is detailed investment planwith particular cost/ bene�it ratio, butonlyconsideringenergysavinginvestmentasnothighpriorityone.

2 Thereisdetailedinvestmentallegeandplanbutonlyconsideringmeasureswithshortpaybackperiod.

1 Thereisdetailedinvestmentplanbutonlyconsideringmeasureswithlowinvestmentcost.

0 Thereisnotinvestmentplan.

Aftercompletingtheassessment,theresultscanbereportedinvariousforms,suchascolumncharts,line

charts,orspiderwebcharts,etc.The�igurebelowshowsasampleofassessmentresultsrepresentedin

linechartatanenterprise

52

Figure9.Energymanagementassessmentchart

0

1

2

3

4

Energy policy Organiza�on Training Informa�on exchange Checking and evalua�on Investment

ASESSMENT ON STATUS OF ENERGY MANAGEMENT

Fromtheresultsofevaluation/graphshowsomestrengthsandweaknessesinenergymanagementofthe

enterprises. Auditors need to raise recommendation in short term and long term. The short-term

recommendationaimedat improvingtheweaknessmanagement,andlong-termrecommendationto

helpimprovecomprehensivemanagementlevelofwholeenterprises.

Belowaresometypicalassessmentresultsandrecommendationsforenergymanagementimprovement.

53

Table18.Assessmentresultsandimprovementactions

Shape Picture Description Results Action

1.High

balance

Scoreof3or

moreforall

columns

Excellent

performance

Maintainthislevel

2.Low

balance

Scoreunder3

forallcolumns

Allaspectsinenergy

managementshould

beimprove

Commitmentfromthe

leader.Setupanenergy

managementstrategy.

Setgoals,actionplans&

checkingprocess

3.Uform Twoouter

columnswith

scoresof3or

more

Havecommitmenton

energyef�iciency.

Highexpectation,but

theteamperforms

poorly

4.Nform Thetwoouter

columnsaretoo

low

Nocommitment.Have

anenergyspecialist

toperform.The

middlecolumngood

resultiswasted

Commitmentfrom

leaders

5.Gutter Themiddle

columnislower

thantheouter

columns

Theweaknessofthis

columncanreduce

thesuccessofother

columns

Focusmoreonthe

weakaspect

6.Peak Themiddle

columnis

higherthanthe

outercolumns.

Theeffortofthis

columncanbewasted

bythestagnationof

othercolumns.

Focusmoreonthe

weakaspect

7.Unbalance Twoormore

columnsare

higherorlower

thanaverage

Themorethe

imbalance,theharder

toperform.

Focusonthelower

aspectsandtrytolift

themup

Setupanenergy

managementboard,

establishaformal

communicationchannel

withallemployees.Set

goals,actionplans&

checkingprocess.

54

Figure10.Thetransformerinpowersystem

Table19describestheclassi�icationoftransformers:

Table19.Classi�icationoftransformers

Criteria Types Comment

Inputvoltage

stepup Convertlowvoltagetohighvoltage

stepdown Converthighvoltagetolowvoltage

(populartransformer)

Operation

Powertransformer Located at distribution station to increase voltage andtransmitlargepower

Distributiontransformer

Located at sub-distribution station to transmit lowpower.

3. COMMONENERGYCONSUMPTIONSYSTEMANALYSIS

Thissectionwillpresenttechnicalguidelinesfordatacollectionandanalysisatkeyandcommonenergy

consumersinfactoriesandbuildings.

Briefexplanationandcalculationforeachsystemwillbeintroduced.Standarddatacollectiontemplate

willbesuggested.SomecalculationtoolstoaccrueherequireddatawillalsobeintroducedinthisSection.

Keyenergyconsumptionsystemincluding;

· Energysupplysystem

· Keyelectricityconsumptionsystem:motors,pump,fan,aircompressionsystem,refrigerationsystem,

airconditioningsystem

· Keythermalenergyconsumptionsystems:boiler,furnace,steamdistribution.

3.1. Electricitysupplysystem

3.1.1. Introduction

3.1.1.1. Componentsofelectricaldistributionsystem

Transformer

Atransformerisastaticelectricaldevice,whichtransformselectricalenergyfromonevoltagelevelto

anothervoltagelevel.

55

Measuringtransformer

Usedtomeasurevoltageandcurrentwithmeasurementdevices.

Locationofinstallation

Outdoor Locatedoutdooronconcreteorironshelf

Indoor Locatedindooronconcreteorironshelf

Numberofphases

3phases Inputandoutputarethreephases(R,Y,andB)withorwithoutneutralwire.

1phase Inputandoutputareonephase

Source:BEE,2004

Figure11.Maindistributionswitchboard Figure12.Distributionboard

Distributionboard

Distributionboardistheimportantpartofanelectricitysupplysystemandisusedtodivideanelectrical

powerfeedintosubsidiarycircuits.Moreover,itisalsoaplaceforinstallationandprotectionofcircuit

breakerandcontrollerdevices.Twotypesofdistributionboardaremaindistributionswitchboard(MSB)

anddistributionboard(DB)inelectricalsystem.

Maindistributionswitchboardisinstalledrightafterstepdowntransformer.Itsmainfunctionistoshut

down to protect electrical consumption systems. There aremany cabinets insideMSBwith speci�ic

functionssuchasstoringmainACB/MCCB,storingMCCB/MCBoutput,storingcompensatescapacitor,or

storingATSsources.

DBisusedinlowvoltagenetworksanditisinstalledafterMSB.Itisthesmallestelectricalcabinetand

supplyelectricityforequipmentsuchaspumps,motorsandetc.

3.1.1.2. Singlelinediagramofsupplypowersystems

Singlelinediagramisdesignedtoanalyseelectricalsystem.Itcanhelpauditorunderstandthedesignand

structureofelectricaldistributionsystem.Then,theauditorcanhavesurveyplanstomeasuresystems

logicallyandeffectively.

56

Figure13.Exampleofsinglelinediagramofelectricalsupply

Figure14.Adailyloadcurve

0

100

200

300

400

500

600

700

800

900

1000

9:4

0

10:

40

11:

40

12:

40

13:

40

14:

40

15:

40

16:

40

17

:40

18

:40

19:

40

20:

40

21:

40

22:

40

23:

40

0:4

0

1:4

0

2:4

0

3:4

0

4:4

0

5:4

0

6:4

0

7:4

0

8:4

0

9:4

0

cap

acit

y (K

W)

TimeMBA 1 MBA 2

3.1.2. Loadgraphandelectricalloadmanagement

3.1.2.1.Loadcurve

ALoadcurveshowstheloaddemandofaconsumerversustime.Ifpowerconsumptionisplottedfor24

hoursofaday,itiscalled“hourlyloadcurve”andifpowerconsumptionisplottedfordaysofamonth,itis

called“dailyloadcurve”.

57

Table20.Strategytomanagepeakload

Solution Perform

ShiftingNon-Criticaland

Non-ContinuousProcess

LoadstoOff-Peaktime

SheddingofNon-

EssentialLoadsduring

PeakTime

OperatingAir

Conditioningunits

duringoff-peaktimes

andutilizingcool

thermalstorage

InstallationofPower

FactorCorrection

Equipment

Source:EnergyEf�iciencyManagementAgency,2004

Themaximumdemandcanalsobereducedat theplant levelbyusing

capacitor banks and maintaining the optimum power factor. These

systemsswitchonandoffthecapacitorbankstomaintainthedesired.

Powerfactorofsystemandoptimizemaximumdemandthereby.

Rescheduling of large electric loads and equipment operations, in

different shifts can be planned and implemented to minimize the

simultaneous maximum demand. For this purpose, it is advisable to

prepare an operation �low chart and a process chart. Analyzing these

chartsandwithanintegratedapproach,itwouldbepossibletoreschedule

theoperationsandequipmentinsuchawayastoimprovetheloadfactor

whichreducesthemaximumdemand.

Whenthemaximumdemandtendstoreachapresetlimit,sheddingsome

ofnon-essentialloadstemporarilycanhelptoreduceit.Itispossibleto

install direct demand monitoring systems, which will switch off

nonessentialloadswhenapresetdemandisreached.Simplesystemsgive

alarms,andtheloadsareshedmanually.Sophisticatedmicroprocessor

controlled systems are also available, which provide automatic load

sheddingoptions.

It is possible to reduce themaximumdemand by building up storage

capacityofproducts/materials,water,chilledwater/hotwater,using

electricityduringoffpeakperiods.Offpeakhouroperationsalsohelpto

save energy due to favorable conditions such as lower ambient

temperatureetc.

3.1.3. Harmoniceffects

Harmoniccurrentsarecausedbynon-linearloadsconnectedtothedistributionsystem.Aloadissaidto

benon-linearwhenthecurrentdoesnothavethesamewaveformasthesupplyvoltage.The�lowof

harmonic currents through system impedances in turn creates voltage harmonics,whichdistort the

supplyvoltage.

Theharmonicscausessuchthebeloweffectsinpowersystems:

·����Overheatingofelectricaldistributionequipment,cables,transformers,standbygenerators,etc.

ALoadcurveisusedtopredicthigh/lowdemandofpartoffactory,entirefactory,oradistributionsystem,

etc.Italsoshowspeakpower,off-peakpowerandaveragepowerofthefactory.Basedonthatinformation,

theauditorwillproposetheproperenergysavingsolutions.

3.1.2.2.Loadmanagement

Atthemacrolevel,thepowerconsumptionandelectricaldemandincreaseduringcertaintimesinaday

andthentheywillleadtoshortfallincapacitytomeetdemand.Thebetterloadmanagementattheuser

endhelpstominimizepeakdemandsontheutilityinfrastructureandimprovetheutilizationofpower

factorycapacity.Thefollowingtablelistssometechniquestohelpbetterloadmanagement:

58

Figure15.Waveformsofharmonics

· Meteringerrors

· Increasedinternalenergylossesinequipment,causingcomponentfailureandshortenedlifespan

· Falsetrippingofcircuitbreakers

· Lowersystempowerfactor,resultinginpenaltiesonmonthlyutilitybills

Source:www.hersheyenergy.com

Therearemanyoptionstoattenuateharmonics:

· AddAlternatingCurrentorDirectCurrentchokes

· Usepassive�iltering

· Uselowharmonicsdrive.

3.1.4. Datacollection

Theenergyauditorneedstocollectthefollowingdataforelectricitysystem:

· Single-linediagramofelectricalsystems

· Alltransformersdataandtheirpowercapacity

· Totalpowerconsumptionandannualcost

· Operatingcapacity:max,min,average

· Powerfactor

· Thebalancebetweenelectricalphases

· Powerconsumptionofeachsystemorarea

· Electricityrate

ElectricityrateisregularlyupdatedatthewebsiteofVietnamElectricity(EVN).Asthedifferentoperating

timebetweenfactories,theaverageelectricityrateshouldbecalculatedasthefollowingformula:

For equipment with unstable operating time, the average electricity rate will be used to calculate

electricitycost inenergysavingmeasures.Forequipmentwithstableoperating time,electricityrate

shouldbeusedaccordingtospeci�icperiod.

TotalelectricitycostAverageelectricityrate=Totalelectricityconsumption

Fundamentalrd

3 Harmonicth

5 Harmonicth

7 Harmonic

Resultant

HarmonicsA

mp

litu

de

Time

59

Table21.Applicationsofcolorrenderinggroups

Colorrenderinggroups

CIEgeneralcolorrenderingIndex

(Ra)

Typicalapplication

1A Ra>90

1B 80<Ra<90

2 60<Ra<80 Wherevermoderatecolorrenderingisrequired

3 40<Ra<60 Wherevercolorrenderingisof littlesigni�icancebutmarkeddistortionofcolorisunacceptable

4 20<Ra<40

Source:BureauofEnergyEf�iciency,2005

3.2. Lightingsystem

3.2.1. Introduction

De�initionsandcommonlyusedterms

Lumen(lm):isthephotometricequivalentofthewatt,weightedtomatchtheeyeresponseofthe

“standardobserver”.1watt=683lumensat555nmwavelength.Oneluxisequaltoonelumenper

squaremeter.

Luminaire:consistingofalamporlampstogetherwiththepartsdesignedtodistributethelight,

positionandprotectthelamps,andconnectthelampstothepowersupply.

Lux:isthemetricunitofmeasureforilluminanceofasurface.Averagemaintainedilluminanceisthe

averageofluxlevelsmeasuredatvariouspointsinade�inedarea.Oneluxisequaltoonelumenper

squaremeter.

LuminousIntensityandFlux:Onelumenisequaltotheluminous�lux,whichfallsoneachsquare2meter(m )ofasphereonemeter(1m)inradiuswhena1-candelaisotropiclightsource(onethat

radiatesequally inalldirections) isat thecenterof thesphere.The luminous �luxemittedbyan

isotropiclightsourceofintensityIisgivenby:

Luminous�lux(lm)=4π×luminousintensity(cd)

TheInverseSquareLaw:Theintensityoflightperunitareaisinverselyproportionaltothesquareof

thedistancefromthesource(essentiallytheradius):

2E=I/d

WhereE=illuminance,I=luminousintensityandd=distance

Distanceismeasuredfromthetestpointtothe�irstluminoussurface-the�ilamentofaclearbulb,or

theglassenvelopeofafrostedbulb.

ColorTemperature(K):isthecolorappearanceofthelampitselfandthelightitproduces.

ColorRenderingIndex:Theabilityofalightsourcetorendercolorsofsurfacesaccuratelycanbe

convenientlyquanti�iedbythecolor-renderingindex.Thisindexisbasedontheaccuracywithwhich

asetoftestcolorsisreproducedbythelampofinterestrelativetoatestlamp,perfectagreement

beinggivenascoreof100.

Wherever accurate color rendering is required e.g. color printing

inspection

Wherever accurate color judgments are necessary or good color

renderingisrequiredforreasonsofappearancee.g.displaylighting

Wherever color rendering is of no importance at all andmarked

distortionofcolorisacceptable

60

Table22.Luminousperformancecharacteristicsofcommonlyusedluminaries

TypeofLamp Lm/Watt

Colorrenderingindex

Typicalapplication Life

Range Avg. (Hours)

Incandescent 8-18 14 Excellent Homes,restaurants,generallighting,emergencylighting

1,000

Fluorescentlamps

46-60 50 Good w.r.tcoating

Of�ices,shops,hospitals,homes

5,000

Compact�luorescentlamps(CFL)

40-70 60 Verygood Hotels,shops,homes,of�ices

8,000-10,000

High pressuremercury(HPMV)

44-57-57 50 Fair Generallightinginfactories,garages,carparking,�loodlighting

5,000

Halogenlamps 18-24 20 Excellent Display,�loodlighting,stadiumexhibitiongrounds,constructionareas

2,000-4,000

High pressuresodium(HPSV)SON

67-121 90 Fair Generallightinginfactories,warehouses,streetlighting

6,000-12,000

Low pressuresodium(LPSV)SOX

101-175

150 Poor Roadways,tunnels,canals,streetlighting

6,000-12,000,

Source:AsiaEnergyEf�iciency

Characteristicsandapplications

Auditorsshouldunderstandthelampcharacteristicandapplicationtoproposeenergysavingsolutionfor

lightingsystem.

Thefollowingtabledescribesperformancecharacteristicsofcommonlyusedluminaries.

3.2.2. Energy�lowdiagramoflightingsystemsThelampisonlypartofthelightingsystem.Theentirelightedspaceshouldbealsoconsideredpartofthe

system,sincemanyfactorssuchaswallcolor,re�lectivity,windowdesignandinteriorpartitionscanhave

justasgreataneffectontheamountoflightthatisdeliveredtothetaskpoint.Theend-useofalighting

systemcanbemeasuredasthelightlevelatthetaskpoint(usefulillumination).Adetailedenergyaudit

should consider the various energy losses occurring in lighting systems, as indicated in the Sankey

diagrambelow:

61

Figure16.Sankeydiagramoflightingsystem

Source:Enerteam

ThevariouslossesintheaboveSankeydiagramarelistedbelow:

· Electric-to-Light-ConversionLosses: lightoutput(lumens)of lightsourceperunitof inputpower

(watts)

· FixtureLosses:Lighttrappedwithin�ixture

· Roomlosses:Lightlostbeforeitreachestaskduetophysicalroomcharacteristics

· VisibilityLosses:Excesslightsuppliedtoovercomelightingqualityproblems

· Over-IlluminanceLosses:Excesslightsuppliedtoovercomepoorlightingdistributionorconsistency

· OveruseLosses:Lightingleftswitchedonwhennotrequired.

3.2.3.Energysavingsmeasureforlightingsystem

3.2.3.1.Usenaturaldaylighting

Someofmethodstoincorporatedaylightingare:

· Innovativedesignsarepossiblewhicheliminatetheglareofdaylightandblendwellto illuminate

buildings,industrialworkshopsandwarehouses

· A good design incorporating sky lights with Fibre-reinforced plastic (FRP) material along with

transparentortranslucentfalseceilingcanprovidegoodglarefreelighting;thefalseceilingwillalso

cutouttheheatcomeswithnaturallights

· Useof atriumwithFRPdome in thebasic architecture can eliminate theuseof electric lights in

passagesoftallbuildings

Naturallightfromwindowshouldalsobeused.However,itshouldbewelldesignedtoavoidglare.Light

shelvescanbeusedtoprovidenaturallightwithoutglare.

ElectricEnergy

Input

ElectrictoLight

ConversionLosses

Useful

illumination

Overuse

LossesOver

illuminance

LossesVisibility

Losses

Room

LossesFixture

Losses

62

Figure17.Daylightingwithpolycarbonatedsheets Figure18.AtriumwithFRPdome

3.2.3.2. De-lampingtoreduceexcesslighting

Theamountoflightbulbcanbereducedby:

· Reducingthemountingheightoflamps

· Providingef�icientluminairesandthende-lampinghasensuredthattheilluminanceishardlyaffected

· De-lampingatemptyspacewhereactiveworkisnotbeingperformedisalsoausefulconcept

· Tasklighting.

Anothermethodtoreducetheamountoflightbulbistoprovidetherequiredgoodilluminanceonlyinthe

actualsmallareawherethetaskisbeingperformed.Theconceptoftasklightingifsensiblyimplemented,

canreducethenumberofgenerallighting�ixtures,reducethewattageoflamps,saveconsiderableenergy

andprovidebetterilluminanceandalsoprovideaestheticallypleasingambience.

3.2.3.3.Timer,twilightswitchesandoccupancysensors

Automaticcontrolforswitchingoffunnecessarylightscanleadtogoodenergysavings:

· Twilightswitchescanbeusedtoswitchthelightingdependingonavailabilityofdaylight

· Electronicdimmerissuitablefordimmingincandescentlamps.Dimmingof�luorescenttubelightsis

possible, if there are operated with electronic ballasts; these can be dimmed using motorized

autotransformersorelectronicdimmers(suitablefordimming�luorescentlamp;presently,thesehave

tobeimported).

3.2.3.4.Lightingmaintenance

Lightlevelsdecreaseovertimebecauseofaginglampsanddirton�ixtures,lampsandroomsurfaces.The

followingbasicmaintenancesuggestionscanhelppreventthis:

· Clean�ixtures,lamps,andlensesevery6to24months

· Replacelensesiftheyappearyellow

· Cleanorrepaintsmallroomseveryyearandlargerroomsevery2to3years.Dirtcollectsonsurfaces,

whichreducestheamountoflighttheyre�lect.

3.2.3.5.Selectionofhighef�iciencylampsandluminaries

Currently,LEDtechnologyhasbeendevelopedwithhighluminousef�icacy, longeroperatinglife,and

lower production cost. LED are gradually replacing all current conventional lights, including high

pressurelampintraf�iclighting.SomeadvantagesofLEDarelistedasfollows:

·����Generatehigherilluminationthanotherlamps

·����Lesserheat

63

· Notcontaintoxicsubstancessuchas:mercury,lead,cadmiumandharmfulradiation .

Figure19.LEDphaseandaroundlighting

ThetablebelowdescribestheenergysavingofLED:

Table23.EnergysavingbyusingLED

Currentlamp Replacedwith %Energysaving

Tungstenhalogenlamps

Fluorescentlamp

Mixedmercurylamp

Highpressuremercury(HPMV)

Metalhalidelamps

Highpressuresodium(HPSV)

LED 75to83

62to73

80

72

64

64

Table24.Energysavingcalculationtable

Items Unit Currentlamps LED

Powercapacity(+ballast) W/unit

Thenumberhoursinaday Hr/day

Thenumberdaysinayear Day/year

Numberofluminaires

Powerconsumptioninayear kWh/year

Energysavinginayear kWh/year

Averageelectricitypriceinaday VND/kWh

Moneysavinginayear MillionVND

Luminairesprice MillionVND

Totalinvestment MillionVND

Paybacktime Year

64

1

2

3

Table26.Lightingtransformer,ratedpowerandnumbers

No. Factorylocation

Ratedpoweroflightingtransformer(kVA)

Number Voltage/Ampe/kW/

1

2

3

3.2.4.Datacollection

· Step1:Prepareequipmentchecklistforlightingsystemandtransformers:

Table25.Ratedpower,numberandcurrentstatus

No. Factorylocation Lightingtypeandballast

Ratedpower Number ShiftI/II/II

date

· Step2:useluxmetertomeasureluxatvariousplantlocations

· Step3:measureandrecordpowerconsumptionatdifferentinputssuchasdistributionboard,lighting

transformer

· Step4:comparethemeasuredvaluewith luxstandard.Usethevaluesasareferenceandidentify

locationsofunderlitandoverlitareas

· Step5:Analyzethefailureratesoflamps,ballastsandtheactuallifeexpectancylevelsfromthepast

data

· Step6:Basedoncarefulassessmentandevaluation,identifyimprovementoptions.

65

Figure20.Squirrelcagerotormotor

Advantagesofsquirrelcagerotormotoraresimpledesign,inexpensive,easytooperate,lowmaintenance

cost,andhighreliability.

Figure21.Woundrotormotor

Thefollowingtabledescribesthebasicmotorloadtypes:

Table27.Thebasicmotorloadtypes

Loadtypes Description Example

Constanttorque Outputenergychangesbuttorqueisunchanged. Conveyors,rotatingovens,

vacuumpump

Changedtorque Torqueisproportionaltothesquareofspeed Centrifugalpumps,fans

Fixedload Torqueisinverselyproportionaltospeed Machinetool

3.3.2.Energy�lowformotor

Operatingcostandinvestmentinamotorarepresentedinthefollowingpiechart:

3.3. Motor

3.3.1. Introduction

Electricmotorisadevicethatconsumeselectricityandconvertselectricalenergyintomechanicalenergy.

TwomostpopularelectricmotorsinVietnamaresquirrelcagerotorandwoundrotor.

66

Figure22.Costdistributionofmotor

Source:PECSME

Energy cost 83%

Maintainance cosst3%

Investment14%

Basedontheabovechart,energycostsaccountforover80%ofthetotallifecyclecostofmotor.Therefore,

optimizingutilizationwillsigni�icantlyreducetheoperatingcostsofthemotor.

3.3.3. Theenergysavingmeasures

Therearesomeenergysavingsolutionsformotorsystem:

· Optimizetheoperatingcapacityandensurethatthesystemisoperatingatthehighestef�iciency

· Reducethepartialloadoperatingtimeofmotor

· Optimizetheoperatingconditionsofequipment

· Selectingpropermotor

· Usinghighperformancemotor

· Usinginverterformotor.

Themethodsforenergysavingsolutionsarediscussedinthefollowingsections.

3.3.3.1.Motorselection

Underloadmotors:Choosingamotorwithagreatercapacitythandemandwillreducetheperformance

ef�iciencyoftheengine

Motorselectionshouldbebasedontheperformancegraphandpercentageoffullload.Motoref�iciency

canbecalculatedasfollows:

Motoref�iciency(%)=outputpower/inputpowerx100%

67

Figure23.Ef�iciencyandfullloadpercent

Source:AsiaEnergyEf�iciency

Theabove�igureshowsthatthemotoref�iciencyissigni�icantlyreducedwhenthemotoroperatesat30-

40%ratedpower(%fullloadmeasuredwhenthemotoroperates).

Atthesameratedpower,higherspeedmotorhashigheref�iciency.

Figure24.Ef�iciencyandrotatingspeedofsquirrelcagerotor

Source:PECSME

Example:Calculationbene�itwhenchoosingrightmotorforloaddemand7,5hp.Thecalculationresults

arepresentedinthebelowtable:

68

Fromabove calculation, choosing rightmotormatch loaddemand,we can savepower consumption

aswellasoperatingcosts.

3.3.3.2.High-Ef�iciencymotor

Bene�itsofhigh-ef�iciencymotorselection:

Highperformanceandmotorlifetime

Reducepowerconsumption,reduceoperatingcosts

Reducedaffectpowerquality,increasepowerfactor,stableload.

Figure25.Standardef�iciencymotorvs.premiumef�iciencymotor

Source:PECSME

Table28.Operatingcostestimationofselectedmotors

(1)Requiredpower

(2)Designpower

(3)FullLoadEf�iciency

(4)Loadfactor

(5)Diminishingef�iciency

(6)Operationalef�iciency

(7)Operatinghours

(8)Electricityprice

(9)Operationalpower

(10)Electricityconsumption

(11)Annualcost

(12)Differentofoperatingcost

Requirement

SelectedMeasure

Result

hp 7,5

(A) (B)

hp 15 10

% 86,3% 86,0% Basedoncatalogue

% 50% 75% (1)/(2)

% 98,0% 100% Basedon%loadandef�iciencychart

% 84,6% 86,0% (3)x(5)

hours/year 7.920 7.920 (byactuallyoperationalhours)

VND/kWh 1.671 1.671 (byaverageelectricityprice)

kW 6,62 6,51 (2)x0,746x(4)/(6)

kWh 52.395 51.526 (7)x(9)

VND 87.551.754 86.100.024 (8)x(10)

VND/year 1.451.730 (A)-(B)

100

95

90

85

80

75

1 5 10 50 100 200

Premium Efficiency

Standard Efficiency

Input power (hp)

Effici

ency

(%

)

69

Table29.Standardef�iciencymotorvs.premiumef�iciencymotor

Source:AsiaEnergyEf�iciency

Thefollowingillustrationcomparestheenergysavingsandannualcostsbetweenenergyef�iciency

motortrandstandardmotor:

Table30.Motorinvestmentcomparison

HP kW

5

7,5

10

15

20

25

30

40

50

60

75

100

125

150

200

3,7 38,3 87,3 344

494

614

811

1.025

1.230

448

647

780

1.042

1.268

1.542

5,5 85,2 89,5

7,5 86,0 89,4

11,0 86,3 90,4

15,0 88,3 92,0

18,5 89,3 92,5

22 89,5 92,6 1.494 1.824

30 90,3 93,1 1.932 2.340

37,5 91 93,4 2.487 2.881

45 91,7 94,0 3.734 4.284

55 91,6 94,1 4.773 5.520

75 92,1 94,7 5.756 6.775

100 92,0 94,7 7.425 9.531

120 93,0 95,0 9.031 11.123

150 93,8 95,4 10.927 13.369

Power Efficiency (%) Price ($)

104

153

166

231

243

312

330

408

394

550

747

1.019

2.106

2.092

2.442

4,6

4,8

3,8

4,5

4,0

3,5

3,3

3,0

2,6

2,4

2,7

2,6

2,9

2,1

1,7

Standardmotors

High efficiencymotors

DiffirentDiffirentHigh efficiencymotors

Standardmotors

Thecostsofhighef�iciencymotorsarehigherthanthoseofstandardmotors.Thepaybackperiodwill

be rapid due to reducing operating costs, particularly in new applications or end-of-lifemotor

replacements.However,replacingexistingmotorsthathavenotreachedtheendoftheirusefullife

withenergyef�icientmotorsmaynotalwaysbe�inanciallyfeasible.Therefore,thereplacementis

recommendedwhentheexistingmotorisfailed.

Requirement

Power hp

Operatinghoursinday hours/year

Fullloadfactor %

Avarageelectricityprice VND/kWh

High-ef�iciencymodelef�iciency %

Normalmodelef�iciency %

Differentosprice VND

Annualelectricitysavings kWh

Annualsavings VND 9.846.334 12.704.947 19.851.480

Simplepaybackperiod months 6,4 6,0 7,2

Selectedmeasure

Result

5.892 7.603 11.880

75

7.920

80

1.6711.671

7.920

80

50

7.920

80

1.671

30

94,1

91,6

11.952.000

93,4

91,0

6.304.000

92,6

89,5

5.280.000

70

Figure26.Performancecurveofpumpwith�lowcontrolvalve

Source:AsiaEnergyEf�iciency

VSDimprovesenergyef�iciencybybalancingtherotationspeedwithvariableload.

Af�initylawsdescribetherelationshipsbetweenspeed,�lowrateandpower:

Q:Flowrate,P:Power,N:rotationspeed

Table31.Correlationbetweentherotationspeed,�low,andpowercapacity

Accordingtotheabovetable,themotorwithratingof50HPisthebestchoicesinceitcansave7,603

kWh/yearwhichisequivalentto13millionVND/yearanditspaybackperiodisshortest.

3.3.3.3.Variablespeeddrive

Forpumpsandfans:thevalvesystemandtheventdoorsmustnotbefullyopenedduringoperationdueto

overcapacitydesignorduetothenecessarychangesaccordingtoproductionstatus.

Thereasonformotorspeedcontrol:

· Mechanicalpoweriscontrolledbycycleoron/offaccordingtooutputpowerrequirements

· Infanorpumpsystem,�luid�lowisadjustedbycontrolvalvesatinletandoutletwhilethemotoris

operatingata�ixedrate.Thiscontrolstrategywillaffecttothepumpcharacteristicscurve.Inthis

method, the �low is reduced, while power consumption does not change, so that the total head

increases.Thefollowing�igureshowshowthesystemcurvemovesupwardsandtotheleftwhena

dischargevalveishalfclosed

Somemotorsandactuatordevicesusemechanicalcouplingandgearboxtoadjustspeed.

Asmallreductioninspeedwillresultinaverylargereductioninpowerconsumption.Thebelowtable

showsthecorrelationbetweentherotationspeed,�low,andpowercapacityofthecentrifugemachine.

Rotationspeed Flow Powercapacity

100% 100% 100%

90% 90% 73%

80% 80% 50%

70% 70% 34%

FLOW RATE

HEA

D

Flow 2 Flow 1

System Curvewith Fully Open Valve

Head Drop AcrossHalf Open valve

System Curve with Half Open Valve

71

60% 60% 22%

50% 50% 13%

40% 40% 6%

30% 30% 3%

Source:PECSME

Figure27.Loaddiagramofairconditioning

VSDcontrollerisappliedwellinthefollowingcases:

· Flowvariationsrequirethecontrolvalveandby-passvalve

· Motorratingismuchlargerthanpowerrequirement

· Thesystemhason/offcyclecontroller.

3.3.3.4.Optimizemotoroperation

Examplebasedonloadcurve:Loaddiagramofcompressorandcoolingwaterpump.Weseethatthe

compressor works intermittently while cooling water pump works continuously. So, operating

systemdoesn'tworkoptimally.

3.3.4. Datacollection

Inordertoevaluatetheoperationofmotorsystem,thefollowinginformationneedtobecollected:

· Loaddiagram:actualcapacity,thedifferencebetweenactualcapacityanddesigncapacity,operating

time

· Operationcontrolstrategy

· Parametersaffectingtheoperationofsystem.

Thedatacollectiontableformotorscanbereferencedbelow:

Coolingwaterpumpcompressor2

time

Inputpower(kW)

72

Table32.Motordatacollection

No. 1 2 …

-Name

-Code

-Ratedpower(motor) kW/hp

-Ef�iciency(motor) %

-Ratedspeed rpm

-Primaryspeed rpm

-Secondaryspeed rpm

-Voltage V

-Current A

-Cosj

-Operatingpower kW

-Operatingtime Hour/year

-Control(aperturevalve,VSD)

-Notes

3.4. Fans

3.4.1. Introduction

Basedonoperationpressure,classi�icationoffans,blowers,compressorsareasbelow:

· Fans:operatewithpressurebelow1,4mH O2

· Blowers:operatewithpressurefrom1,4mH Oto14mH O2 2

· Compressors:operatewithpressureabove14mH O.2

Therearetwotypesofindustrialfan:

· Axialfan:High�low,lowpressure

· Centrifugalfan:low�low,highpressure(normally,Δp<2,04mH O).2

3.4.1.1.Fansystem

Fansystemincludesthefollowingmaincomponents:

· Motor

· Propeller

Valves,ventscontrol�low.

73

P:Powercapacity(kW)

ΔpPressuredifference(Pa):

Q:Flow(m3/s):

(hisef�iciency(<0,85).Higherdifferentialpressurehasloweref�iciency)

Fanef�iciency

Table33.Ef�iciencyoftypesoffan

Typesoffans Minimumperformance Maximumperformance

Centrifugalfanwithhollowblades. 75% 86%

Centrifugalfanwithconvexblades 50% 73%

Centrifugalfanwithstraightblades 50% 60%

AxialFans 60% 86%

Source:PECSME

h Comparetheoricalpowerconsumptionandactualpowerconsumptionatthesamepointfan

H transmission:transmission ef�iciency. Transmission systems by cogged raw-edged belt with power

capacity above 10kW has ef�iciency of at least 95%. Transmission losses can be ignored if it is

directtransmissionsystems.

Hmotor:motoref�iciency.Checkmanufacturercatalogue

Theoreticalfancapacityiscalculatedasthefollowingdiagram:

Động cơ

Cánh quạt

Van

Engine

Propeller

Valve

3.4.1.2.Flowcontrol

Methodsusedfor�lowcontrolinclude:

· Circulation:apartofairvelocityiscirculatedtothefaninlet

· Airinlet:usedformitigatingairvelocityintheairinletoroutlet

· Flowchange:themotorspeedis�ixed,butpropellerspeedischangedbyusingembrayage.

· Inverter:invertercontrolunitisusedforchangingmotorandfanspeed.

3.4.1.3.Basicinformation

h=h .h .hfan transmission motor

74

Figure28.Fanpowercalculation

Source:PECSME

Totalpressure

Theorypower

Inletair�low

75

Figure29.Calculationoffancapaciy

Effectof�lowcontrolandsystemef�iciency:

Table34.Fanspeedvs.�low

Source:PECSME

Table35.Fanspeedvs.powercapacity

Source:PECSME

Table36.Percentageofpowerconsumprionby�lowpercentage

Source:PECSME

Fanspeed(round/minute) Flow(%)

800 55

900 62

1.000 69

1.100 76

1.200 83

1.450 100

Fanspeed(round/minute) Powercapacity(%rated)

800 17

900 24

1.000 33

1.100 44

1.200 57

1.450 100

Flow(%) Outputvents Inputvents Inverter

100 81 78 83

90 61 74 81

80 44 58 80

70 31 42 76

60 21 28 70

50 14 18 66

76

3.4.2.Energy�lowforfan

3.4.2.1.Costdistributionoffan

Operatingcostandinvestmentinafanarepresentedinthepiechart:

Figure30.Costdistributionoffan

Source:PECSME

Basedontheabovechart,wecanseeenergycostsaccountforover67%ofthetotallifecyclecostoffan.

Therefore,optimizingutilizationwillsigni�icantlyreducetheoperatingcostsofthefan.

Figure31.Sankeydiagramoffan

Source:Enerteam

AccordingtotheaboveSankeydiagram,theusefulenergyisonlyabout70%andtherestislossthrough

thevalves,leakages,piping,fanstructure…

EnergyConsumption;

87%

Investment;10%

Maintenance;3%

8.5% 36.0% 78.0%

8%

Useful power70%

4.5%

3.5%

2.5%

7%2.5%

2%

Power supply100%

Total losses: 30%

Loss due to transmissionand distribu�on

Loss through motor

Loss through driverLoss through fan

Loss through valves

Loss through pipingLoss through leakages

3.4.2.2.Sankeydiagramoffan

3.4.3. Energyef�iciencyforfan

3.4.3.1.Choosetherightfan

· Importantconsiderations:

-Noiselevel

-Rotatingspeed

-Air�lowcharacteristics

-Temperaturerange

-Operatingrange

-Spaceconstraintandsystemlayout

-Investmentcost/operationandoperatinglife.

· Avoidbuyingoversizedfan:

-Unabletooperateatthehighestef�iciency

-Riskofunstableoperation.

-Highnoiselevel.

3.4.3.2.Systemresistancereduction

Systemresistancewillreducefanef�iciency:

· Checkperiodically

· Checkafterrepairingsystem

· Reduceelbowsandremovedeadlegsofpipingsystem.

3.4.3.3.OperateclosetoBEP

· BestEf�iciencyPoint(BEP)

· Usuallyclosetoratedcapacity

· DeviationfromtheBEPwillresultinincreasedlossandinef�iciency.

3.4.3.4.Frequentmaintenance

· Inspectfancomponentsperiodically

· Lubricateandreplacebearingifnecessary

· Motorrepairorreplacementifnecessary

· Fancleaning.

3.4.3.5.Controlthefanair�low

· Pulleychange:reducedrivepulleysize->Reducespeedandenergyconsumption.

77

78

Figure32.Reducemotorspeedbydecreasingthepulleysize

Source:Enerteam

· VSDs:reducespeedofmotortomeetreduced�lowrequirements

-Classi�ication:mechanicaltype,electricaltype.

-Advantage:

o Mostimprovedandef�icient�lowcontrol

o Speedisadjustedinacontinuousrange.

o Highoperatingef�iciency.

-Disadvantage:highinvestmentcosts.

3.4.3.6. Operatingmultipleparallelfans(insteadonehighpowerfan)

-Advantage:

o Highef�iciencywithlargeloadrange

o Avoidoff-motorrisk

o Cheaperandbetterpropertiesthanonelargefan

o Combinedwithother�lowcontroller.

-Disadvantage:onlysuitableforsystemthathaslowresistance.

3.4.3.7. Operatingmultipleserialfans

-Advantage:

o Theaveragepressureof�luidpipeislower

o Lowernoise

o Lowerrequirementsforstructureandauxiliaryequipment

o Suitableforsystemthathaslongpipe,highresistance.

-Disadvantage:notsuitableforsystemthathaslowresistance.

3.4.4. Datacollection

Datacollectionforfansystem:

· Designparametersoffan,motor,andduct:

79

Table37.Datacollectiontemplateforfan

Order 1 2 3

-Name

-code

-Flowtype

-rated�low

-Ef�iciency(pump,fan)

m3/h

%

-Inletpressure bar(Kg/cm2)

-Outletpressure bar(Kg/cm2)

-Flowspeed m/s

-Pipesize mm

-Designed�low m3/h

-Operatingtime Hour/year

-Control(aperturevalve,VSD)

-Notes

-Ratedpower,maximum�low

-Controlscheme,open/closemodeofvents.

· Operatingpowerofmotors:

-Averageelectricalpower(kW)

-DCmotororACmotor

· Motorspeedandfanspeed.

· Collecttechnicalinformation,speci�icationsheets,characteristiccurve,and�lowdiagrams.

Measurementmethod:

· Electricalpowermeasurement

· Mechanicaldevicessuchas:anemometer,Pitottubes,temperatureindicator,pressuregauge.

80

3.5.1.3.Basicinformation

· Pumppower:

P–Power(kW)

H-statichead(m)

Q-�lowrate(m3/s)

r-Density(kg/m3),

h:Pumpef�iciency(0.7–0.85)

Pumpcapacityisshownasthefollowingdiagram:

3.5. Pump

3.5.1. Introduction

3.5.1.1. Pumpclassi�ication:

· Volumetricpump:low�low,highpressure(piston,gear,screw,roto)

· Bladepump:high�low,lowpressure(centrifugal,axialdirection).

3.5.1.2. Pumpsystemsinclude:

· Motors

· Pumps

· Valves

Pipingsystem

p.Q.HP=102.h

81

Figure33. Calculatepumppower

Source:PECSME

· Statichead(H,m):includesthedifferenceofhydrostaticpressure,highdifference,andresistanceon

thepipeline.

Figure34.ParametersofPumpsystem

RequirementpowerpumpStatichead

Flowrate

Theoricalrequirementpower

82

· Identifythepumpoperatingpoint:intersectionbetweenpumpcurvesandsystemcurves.

Figure35.PumpPerformanceCurve

· Pumpsinparalleloperation

Figure36.ParallelPumps&pumpscurve

- Staticheadofsystemisequaltoeachstaticheadofpump.

H=H1=H2

- Flowrateofsystemisequaltototal�lowrate.

Q =Q +QT 1 2

3.5.1.4.Control�lowrate

Methodof�lowratecontrolforpumpisillustratedbelow:

Figure37.Pumpcontrolmethods

A(Operatingpoint)

(n)Pumpcurves

Systemcurves

Ƞ

QA

HA

H

Q

Ƞmax

Pumpef�iciency

·Adjustingpipecharacteristicsbyvalves(keeppumpcharacteristics)

-Throttlevalvereducessystempressure,changesthesystemcharacteristics,andreducespump

ef�iciency(A)

-Circulation:thisisnotenergysavingstrategy(B).

83

Figure38.ON-OFFcontrolforpump

Figure39.PerformancecurveofpumpwithVSD

· Comparepumppowerconsumptionbetween�lowcontrolstrategies.

Figure40.PowerRequirementsforvariouspumpingcontroloptions

·Adjustingpumpcharacteristicsbyvalves(keeppipecharacteristics)(C,D)

·� � �UseVSDformotor:adjusttheelectricalfrequencyofpowersuppliedtoamotortochangethe

motor'srotationalspeed.

Fromtheabovegraph,withthesamepump�low,thepowerconsumptionpercentageintheVSDControl

solution(redline)islowerthanthatinValvecontrolsolution.

· Closedloopcontrol:

-Flowcanvaryfrom20%to100%ofmotorspeed

84

Figure41.Costdistributionofpump

Figure42.Sankeydiagramofpump

Energy cost 83%

Maintainance3%

Investment14%

8%

4.5%

3.5%

2.5%

7%2.5%

2%

· ThepumpisdesignedclosetotheBEPat100%�low

-OperationclosetoBEPpoint

· Flowcontrolforhighstaticpressuresystem

-The�lowrateshouldnotbeadjustedinthewholeoperationrange

-Usemultiplepumpstomeetthe�lowchangedemand.

3.5.2. Energy�lowforpump

3.5.2.1. Costdistributionofpump

Operatingcostandinvestmentofapumparepresentedinthefollowingpiechart:

Source:Enerteam

AccordingtotheaboveSankeydiagram,theusefulenergyisonlyabout70%andtherestislossthrough

thevalves,leakages,piping,pumpstructure…

Source:PECSME

Basedontheabovechart,wecanseeenergycostsaccountforover80%ofthetotallifecyclecostofpump.

Therefore,optimizingutilizationwillsigni�icantlyreducetheoperatingcostsofthepump.

3.5.2.2. Sankeydiagramofpump

Loss due to transmissionand distribu�on

Loss through motor

Useful power70%

Loss through driverLoss through pump

Loss through valves

Loss through pipingLoss through leakages

Total losses: 30%

Power supply100%

85

3.5.3. Energysavingsmeasures

3.5.3.1. Selecttherightpump

Thereasonofoversizedpumpfairlycommon:

· Ensuretheoperationhasamplecapacity

· Duetolimitedavailabilityfromsupplier

· Usesparepumpwithoutthepropersizeintheinventory.

Thepumpisaffectedwhentheselectedpumpisoversized

· Controlledwithdifferentmethodssuchasthrottlevalveorby-passline

· Increasetheheadduetofriction

· Thesystemcurvewillbeshiftedtotheleft

· Reducepumpef�iciency.

Solutionforpumpsinstock:

· UseVSDormultispeeddrives.

· Lowerrotatingspeed

· Trimtheimpeller.

3.5.3.2. Useadjustmentthe�lowrate

· Speedadjustmentoveracontinuousrange

· Reducepowerconsumption

· Twotypesofsystems:

-Mechanical:�luidcouplings,adjustablebelts

-ElectricalVFD:variablefrequencydrives(VFDs).

3.5.3.3. Installpumpsinparalleltochangeload

· Installofmultiplepumps:stopsomeofthemwhenlowload

· Systemcurvedoesnotchangebyrunningpumpsinparallel

· Thetotal�lowrateofparallelpumpsissmallerthanthesumofthe�lowratesofdifferentpumps.

· Tomatchthepumpwiththesamecharacteristics

3.5.3.4. Eliminate�lowcontrolvalve.

Effectsofcontrolvalve:

· Thepowerconsumptionisnotreducedasthetotalheadincreases

· Vibrationandcorrosionincreasemaintenancecostsandreducepump'slifetime.

3.5.3.5. Eliminateby-passcontrol

· Dischargepartisdividedintotwoseparatepipes:

-Onepipedeliversthe�luidtothedeliverypoint

-Thesecondpipereturnsthe�luidtothesource.

Energywastageisduetopartof�luidcirculatedunnecessarilybypump.

86

3.5.3.6.Start/stopcontrolofpump.

· Stoppumpwhennotneeded

· Pumpatnon-peakhours.

3.5.3.7.Impellertrimming

· Changingtheimpellerdiametergiveschangeintheimpeller'svelocity

· Notes:

-Cannotbeusedwherevarying�lowpatternexist

-Donottrimmorethan25%oforiginalimpellersize

-Trimdiameterallsides

-Changingimpellerismoreexpensive.

3.5.3.8.Completingthepumpsystem

Minimizestaticheadbythefollowingmethods:

· Uselargediameterpipe

· Uselongcurvebendratherthansharp-edgedbend.

3.5.4. Datacollection

Stepstoevaluatethepumpef�iciency

· Themeasurementtools:3phasespowermeter,pressuregaugemeter,andultrasonic�lowmeters

· Datacollection:nameplate,speci�icationsheet,pumpcurve,andprocess�lowsystem

· Measurementsteps:

-Measureinputpowerofmotorby3phasespowermeter

-Measurepressureatsuctionandpushingofpump

-Measurepressureandtemperatureattheinputandoutputofpump

· Measure�lowrate.If�lowrateisnotpossiblymeasured,itcanbeestimatedfromthepumpcurve

-Sitediscussionwithoperatorsandplantengineers

- Checkthrottlevalveandcontrolvalvesinentirepipingsystem.Ifitwasthrottled,measuring

pressureatitsinputoroutput

-Checkby-passlineofsystem

-Estimateoperatingtimeofpumpsandequipment.

87

-Ef�iciency %

-Inletpressure bar(Kg/cm2)

-Outletpressure bar(Kg/cm2)

-Flowspeed m/s

-Diameter mm

-Actual�lowrate m3/h

-Operatingtime Hour/year

-Controlmethod(aperturevalve,VSD)

-Notes

Table38.Datacollectiontoolforpump

Items 1 2 3

-Name

-Code

-Flowtype

-Flowrate

m3/h

88

Figure43.Aircompressionsystemillustration

Figure44.Typeofaircompressors

· Reciprocatingcompressor:

Typeofcompressor

DynamicPositive

displacement

Poston Screw Lobe Vane Centrifugal Axial

Atypicalcompressedairsystemcomponentsandnetwork

· Aircompressor

· Filter

· Intermediatecooling

· Compressorcooling

· Dryer

· Dehumidi�ier

· Tank.

3.6.1.1.Classi�icationofaircompressors:

3.6. Aircompressor

3.6.1. Introduction

Compressed air systems are commonly used inmost industries such as packaging systems, product

transfer,industrialhygiene,garmentprocessing,agriculturalproductsprocessing,heavyindustry,etc.

Themaincomponentsoftheaircompressorsystem:

89

P =suctionpressure1

P =dischargepressure2

· PowerN(kW):

R=Individualgasconstant(286.7J/kg.K).

T1=absoluteinitialtemperatureofgas(K).

m=mass�low(kg/s)

n=ratioofspeci�icheats

-Advantage:

o Highcapacity

o Highpressureratios

o Simpletooperate/repair.

-Disadvantage:

o lowcompressionratio

o Lowef�iciency

o Thelargesize,noise,highvibration

o Irregular�low.

· Screwaircompressor:

-Advantage:

o Highcompressionratio(max=25)

o Highfullloadef�iciency

o Lowcostoperating.

-Disadvantage:

o Expensive

o Morecomplexandgoodmaintenanceisveryimportant.

3.6.1.2.Compressionratio

Compressionratio

Thehigherthepressure,thelargerthepowerconsumption.Therelationshipbetweenthepressure

andpowerconsumptionisdescribedinthefollowingtable.

90

Table39.Relationshipbetweenpressureandpowerconsumption

Pressure Powerconsumption

3 2.08

4 2.73

5 3.06

6 3.71

7 4.11

Source:PECSME

· CapacityQ(m3tc/s)(at00C,1,013bar)

V=tankvolume(m3)

µ-airmassofonekmol(µ=29kg/kmol)

Dt-CompressortimefromP1toP2(s)

Ta,Pa–TemperatureandPressureatsuction(K),(Pa)

Tb,Pb–TemperatureandPressureatdischarge(K),(Pa)

3.6.1.3.Compressoref�iciency

· Isothermalef�iciency

Isothermal ef�iciency = isothermal power/ actual measured input power

Isothermalpower(kW)=

2P =absoluteinletpressure(kg/cm )1

3Q =freeairdelivered(m /hr)1

r=compressionratio.

· Volumetricef�iciency

Compressordisplacement=ΠxD2/4xLxSxχxn

D=cylinderbore,m

L=cylinderstroke,m

S=compressorRPM

x=1,forsingleacting,and2fordoubleactingcylinders

n=numberofcylinders

The calculation of isothermal power does not include power needed to overcome friction and

generallygivesanef�iciencythatislowerthanadiabaticef�iciency.Thereportedvalueofef�iciencyis

normallytheisothermalef�iciency.Thisisanimportantconsiderationwhenselectioncompressors

basedonreportedvaluesofef�iciency.

91

3.6.1.4.Typicalpressuredropincompressedairpipelinefordifferentpipesize

Thefollowingtabledescribestheenergylossofpipingwithdifferentdiameters:

Table40.Pressuredropfordifferentpipesize

PipeNominalBore

(mm)

Pressuredrop(bar)per100meters

Equivalentpowerloss

(kW)

40

50

65

80

100

1.80

0.65

0.22

0.04

0.02

9.5

3.4

1.2

0.2

0.1

Source:PECSME

3.6.1.5. Airleakage

· Consequence

-Wasting20to30percentofacompressor'soutput

-Pressuredropinsystem.

· Commonairleakagearea:

-Couplings,hoses,tubes,and�ittings

-Pressureregulators

-Opencondensatetrapsandshut-offvalves

-Pipejoints,disconnects,andthreadsealants.

· Thesystemleakageiscalculatedasfollows:

%leakage=(Tx100)/(T+t)

T–on-loadtime(s)

t–off-loadtime(s)

Goodmanagementsystemshasairleakageratelessthan10%

· Systemleakage

3Systemleakage(m /s)=QxT/(T+t)

3Q-actualcapacity(m /s)

3.6.1.6. Inletairtemperatureandpowerconsumption

Effectofinletairtemperatureonpowerconsumptionisdescribedinthebelowtable:

Forpracticalpurposes,themosteffectiveguideincomparingcompressoref�icienciesisspeci�icpower

consumptionkW/volume�lowrate,fordifferentcompressorsthatwouldprovideidenticalduty.

92

Table41.Inletairtemperaturevs.Powersaving

Source:PECSME

Every50Criseinletairtemperatureresultsinahigherenergyconsumptionby1.5%toachieveequivalent

output.

Figure45.Effectofinlettemperatureandpowerconsumption

Source:PECSME

3.6.2.Energy�lowdiagram

· Costdistributionofaircompressor

Figure46.Costdistributionofaircompressor

Source:UNIDO

· Sankeydiagram

Energycost75%

Investment15%

Maintenace10%

Inlettemperature

10,5 +1,4

15,5 0,0

21,1 -1,3

26,6 -2,5

32,2 -4,0

37,7 -5,0

43,3 -5,8

Powersaving(%)

93

Aircompressorsystemusuallyhaslowenergyef�iciency.Thepowerrangeofindustrialaircompressoris

from5toover50,000hp,but70to90percentofconsumedenergyislost.

Figure47.Sankeydiagramforcompressedairsystem

Source:VNEEP

Figure48.Energysavingspotentialforaircompressedsystem

Source:UNIDO

Power supply

100%

8%

Useful power10%

Loss through leakages

4%

5%

32%5%

16%

20%

3.6.3. Energysavingsmeasures

Theenergysavingsachievedwhenimplementingenergysavingsolutionsforthecompressorsystemare

showninthe�igurebelow:

3.6.3.1. Locationofaircompressor

Elevationof air compressorand thequalityof air: the altitudeof aplacehas adirect impacton the

volumetricef�iciencyandhigheraltitudeconsumesmorepower.

Loss due totransmission and

Loss through motor

Loss through driver

Loss through compressing air

Loss through storage tanks

Loss through piping and valves

Improving air

compressed

treatment

1% Orther

1%

Air trap

3%

New air compressor

2%

Improving air

compressed

distribution

2%

Installing inverter for

air compressor

6%

Reducing setting

presure

6%

Controlling air

compressor

7%

Reducing leakage

32%

Reducing compressed

air abuse

14%

Improving air

compressor

enficiency

14%

Heat recovery

12%

94

3.6.3.2.Airintake

· Preventaircontaminationfrommoisture,dust

Figure49.Effectofrelativehumidityandpowerconsumption

Figure50.Effectofsuctionpressureandpowerconsumption

Source:PECSME

Accordingtoabovegraph,thepowerconsumptionincreasesasthesuctionpressuredecreases.

Source:PECSME

· 0Maintaininletairatlowtemperature4 Criseininletairtemperatureresultsinahigherenergy

consumptionby1%

· Locatetheinletpipeofcompressoroutsidetheroomorbuildingsothattheinletairtemperature

canbekeptataminimum.

3.6.3.3.Thepressuredropinair�ilter

· Installtheair�ilteratthecoollocation

· Thepressuredropacrosstheintakeair�iltershouldbekeptataminimum.

Forevery250mmWCpressuredropincreaseacrossatthesuctionpathduetochoked�ilters,the

compressorpowerconsumptionincreasesbyabout2%.

100

98

96

100806040200

Po

we

r co

nsu

mp

�o

n (

%)

Rela�ve humidity (%)

Suctionpressure(mmH2O)

Powerconsumption

110

108

106

104

102

100

0-200-400-600-800-1000

95

3.6.3.4.Inter-coolersandAfter-coolers

· Theinletairtemperaturesatsubsequentstagesarehigherthanthenormallevelsresultinginhigher

powerconsumption

· Intercoolers:Heatexchangerstoremovetheheatofcompressionbetweenthestages

· After-coolersareinstalledafterthe�inalstageofcompressiontoreducetheairtemperature

· Useofcoolingwateratlowertemperaturereducesspeci�icpowerconsumption.

3.6.3.5.Pressuresetting

· Athigherdeliverypressures:compressorconsumesmorepowerforthesamecapacity,thevolumetric

ef�iciencyofacompressorislower.

· Reducingdeliverypressure

- Operatingacompressorat100PSIGinsteadof120PSIG,forinstance,requires10percentless

energyaswellasreducingtheleakagerate

-Areductioninthedeliverypressureby1barinacompressorwouldreducethepowerconsumption

by6–10%.

· Compressormodulationbyoptimumpressuresettings

-Ifallcompressorsaresimilar:onlyonecompressorhandlestheloadvariation,whereastheothers

operatemoreorlessatfullload

-Ifcompressorsareofdifferentsizes,thepressureswitchshouldbesetsuchthatonlythesmallest

compressorisallowedtomodulate(varyin�lowrate)

-Ifdifferenttypesofcompressorsareoperatedtogether:Thecompressorwithlowestnoloadpower

mustbemodulated.

· Segregatinghighandlowpressurerequirements:Usinglowpressureandhigh-pressureairseparately

andfeedtorespectivedemands.

· Minimumpressuredropindistributionline:

-Pressuredrop:thereductioninairpressurefromthecompressordischargetotheactualpoint-of-

use

-Aproperlydesignedsystemshouldhaveapressurelossofmuchlessthan10%ofthecompressor's

dischargepressure

-Usealoopsystemtoreducepressuredrop.

3.6.3.6.Minimizingleakage

· Useanultrasonicleakdetector

· Tighteningaconnectionandajoints

· Replacefaultyequipment.

3.6.3.7. Condensateremoval

· Watervaporiscondensedwhencompressor'safter-coolerreducesthedischargeairtemperature

· Installcondensateseparator-traptoremovethiscondensation.

3.6.3.8. Controlledusage

· Don't'suseforlow-pressureapplicationssuchasagitation,pneumaticconveyingorcombustionair

· Useablowerthatisdesignedforlowerpressureoperation.

96

Figure51.Heatrecovery

Source:UNIDO

3.6.3.9.Maintenance

· Lubrication:Inspectperiodically(checkoilleveldailyandchangeoil�iltermonthly)

· AirFilters:checkedandreplacedregularly

· CondensateTraps:Ensuretodrainanyaccumulated�luidandcompressedairisnotleaked.

· AirDryers:checkandreplacepre-�ilterordeliquescentdryers.

3.6.3.10.HeatRecovery

Average85%ofinputenergyisusedtoprovideheat.Heatrecoverydependson:

· Heatdemandoffactory

· Thecompatibilitybetweentheoperationandtheheatdemand

· Distancefromcompressorstationtouser/distributioncompressorpipeline.

· Temperature.

Theapplicationcanrecoverheatfromcompressorsuchas:

· Buildingservices:hotwater,heating

· Process:dryingandheating

· Preheatforboiler:intakewater,air.

Total electrical powerconsump�on 100%

Drive motor 9%

Fluid cooler 72%

Radiated heat loss of thecompressor package 2%

Heat in thecompressed air 4%

A�er cooler 15%

Approx. 95% forheat recovery

97

3.6.4.Datacollection

Table42.Basedatabasetocompressorsystem

Items 1 2 …

Compressortype

HasVSD?

No.ofcompressorstage

Ratedpower

Compressorcapacity

Intakepressure

Operatingpressure(Load-Unload)

Loadtime

Unloadtime

Loadpower

Unloadpower

Intakeairtemperature

Ambienttemperature

CondensateremovalType

Leakagepercent

kW

Nm3/min.

bar

bar

s

s

kW

kW

0C

0C

%

98

Table43.Currentcompressors

No.

Man

ufacturer/type

Model/

CoolingSystem

Compressor

Fluid

Rated

Motor

Power

Typeof

Control

(dual)

FAD

(m3)

Running/Load

Hours

Load

/Unload

PressureSettings

PowerConsumption

Load

/Unload

(kW)

1

/

/

/

/

/

2

/

/

/

/

/

3

/

/

/

/

/

Table44.Componentsofcompressor

Componen

t

Example:

FlowController,Conden

sateM

anagem

ent,

Dryer,D

rain,Filter

Man

ufacturer

Model

Cap

acity

3(m

)

Dew

Point

Tem

perature

(°C)

Rem

ark

99

Table45Tanksandreliefvalve

Tan

k1:V

olume:(m

3)

MWP:

(bar)

PressureGau

ge

Drain

(selectap

propriatetypebelow)

ReliefValve

SetPressure

ReliefValve

RatedCap

acity

(m3)

Yes

No

Auto

Man

ual

Both

Tan

k2:volume:(m

3)

MWP:

(bar)

PressureGau

ge

Drain

(selectap

propriatetypebelow)

ReliefValve

SetPressure

ReliefValve

RatedCap

acity

(m3)

Yes

No

Auto

Man

ual

Both

Table46.M

astercontrollersandairm

aincharging

MasterController

Man

ufacturer

Model

TypeofControl

(cascade,pressureban

d)

AirM

ain

ChargingSystem

Yes

No

Yes

No

PipeSize(in/m

m)

100

Table47.D

istributionsystem,pipe,connections,anddistributionairline

DistributionAirLine

DropPipe-Connections

System

Diameter

Material

Total

Len

gth

Connections

Doespipeextend

outside?

Number

of

Connections

Diameter

Dropsfromtopof

header?

Yes

N

o

Yes

N

o

Table48.Compressorroomm

easurements,open

ings

etc.

PowerSupply

(V)

(Hz)

(phase)

PowerCosts$/k

W-hr.

CoolingSystem

WaterInletTem

p.(°C)

WaterPressure[psig]

WaterCosts$/p

erliter

CompressorRoom

LxW

xH(m

)x(m

)x(m

)

NumberofInletOpen

ings:

CoolingAirExh

aust:Yes

No

HeatRecovery:Yes

N

o

101

Table49.A

irconditionatcompressorroom

Ambienttemp.

Elevationabovesea

level

Relativehumidity

RoomhasHeating

Roomhascooling

Qualityofintakeair

Min

(°C)

Max

(°C)

Curren

t

(°C)

(Avg.%

)(M

ax.%

)

(m)

Yes

No

Yes

No

Processofneigh

boringfacilities:

Table50.A

irrequirem

ents(Operatingtim

e,pressuredem

ands)

No.ofoperatinghours

Day

Ca1

Ca2

Ca3

Weekend

Ca1

Ca2

Ca3

Hr/day

Hr/day

Day

/week

Day

/week

Averagem

3/shift

Averm

3/ca

Theminim

umpressurereq

uired

atuser.

Curren

tpressureof

system

Doairsystemsturn

onduringunload

time

Averagecapacity.

m3duringunload

time

Req

uired

compressorquality

PressureDP

(oC)

Particle

(micron)

Oil

(mg/m

3)

Yes

No

Dep

endonseason:

102

Windowtype Splittype

Multi-splittypeCabinet

Figure52.Airconditionsystemtypes

3.7. Airconditioningsystem

3.7.1. Introduction

Airconditioningistheprocessusedtocontrolorimproveaircondition(temperature,humidity)ina

certainspace.

Thechoiceofwhichairconditionersystemtousedependsuponanumberoffactorsincludinghowlarge

theareaistobecooled,thetotalheatgeneratedinsidetheenclosedarea,etc.AnHVACdesignerwould

consideralltherelatedparametersandsuggestthesystemmostsuitableforyourspace.

3.7.1.1. Unitaryairconditionsystem

Unitaryairconditionsystemonlyadjustsairconditioninnarrowplace,suchasprivateroom,smallrooms.

Unitaryairconditionsystemhasfourcommontypes:

· Windowtype

· Splittype

· Multi-splittype

· Cabinet.

103

Figure53.Air-cooledchiller

Figure54.Water-cooledchiller

3.7.1.2.Centralairconditioningsystem

Centralairconditioningisusedforcoolingbigbuildings,of�ices,hotels,gyms,etc.Ifthewholebuildingis

tobeairconditioned,HVACengineers �ind thatputting individualunits ineachof therooms isvery

expensive making this a better option. A central air conditioning system is comprised of a huge

compressorthathasthecapacitytoproducehundredsoftonsofairconditioning.

104

Therefrigerationcycleisshownasbelow:

Figure55.OperatingPrinciplesofairconditioner

Source:BEE,2004

· 1-2:Compression:Thesuperheatedvapourentersthecompressorwhereitspressureisraised.The

temperaturealsoincreases

· 2-3:Condensation:Thehighpressuresuperheatedgasturnedbackintoliquidinthecondenser.The

refrigerantliquidissub-cooled

· 3-4Expansion:Thehigh-pressuresub-cooledliquidpassesthroughtheexpansiondevice,whichboth

reducesitspressureandcontrolsthe�lowintotheevaporator

· 4-1Evaporator:Lowpressureliquidabsorbsheatfromitssurrounding,changesitsstatefromaliquid

tolowpressuregas.

105

3.7.2.Assessmentofairconditioning

3.7.2.1.Coef�icientofperformance:

· The theoretical coef�icient of performance (Carnot), (COPcarnot a standard measure of refrigeration

ef�iciencyofanidealrefrigerationsystem):

Te:Evaporatortemperature

Tc:Condensertemperature

· ActualCOP:

Qeva=coolingeffect

Wc=powerinputtocompressor.

h1,h2,h3,h4=enthalpiesofrefrigerantatstates1,2,3,4.

Figure56.CalculationmethodofCOP

Figure57.HVACsystemdatacollection

COP=UsefulCooling(Qeva)/Power(P)

3.7.2.2. Assessactualcoolingperformancecooling:

· CollectinformationaboutHVACsystems(HVACtype,designcapacity,refrigerant,designCOP...)

· Collectoperating information(inletpressure,outletpressure,evaporationtemperature,condense

temperature,electricalconsumption).Datacanbecollectedthroughthescreenmonitorormeasured

byhandinstruments.

COP=(h -h )/(h -h )1 4 2 1

COPCarnot

ToCOP=T -Tk o

1PIC=COP

106

Figure58.Glassproperties

· Keepdoorsorwindowsclosed

3.7.3.2.Limitinternalheatsourcesinsidetheconditionedspace

Heatsourcescomefromthepowerconsumptiondevices:lighting,motors,orcooking…

Thedeterminationofheatsourcescanbedetectedbytheinfraredinstrument.

Figure59.DetectheatsourcesinsideHVACspace

· CalculatetheoreticalcoolingcapacityandCOP.Eachrefrigeranthasparticularthermodynamic

parameters.

3.7.3. Energysavingsmeasures

HVACsystemconsumesalotofenergyinbuildingorfactory.Therefore,therearemanyopportunitiesfor

energysaving.Somemethodsarelistedbelow:

3.7.3.1. Preventheatpenetrationfromoutside

Preventheatpenetrationfromoutsidebyusingdoublelayersofglassandre�lectiveglasslamination.

Whentheheatsourceisidenti�ied,removethemfromconditionedspacetoreducewasteenergy.

3.7.3.3.Maintaintheheatexchanger

Maintenance helps the air conditioner to operate ef�iciently. According to the below table, effective

maintenanceistheimportantkeyforoptimizedpowerconsumption:

107

Table51.Tableofeffectivemaintenanceforpowerconsumptionofthecompressor

Condition Evaporationtemp(oC)

Condensationtemp(oC)

Refrigerationcapacity(tons)

Speci�icpower

consumption(kW/ton)

Increasein

kW/ton(%)

Normal 7.2 40.5 17.0 0.69

Dirtycondenser 7.2 46.1 15.6 0.84 20.4

Dirtyevaporator 1.7 40.5 13.8 0.82 18.3

Dirtycondenserandevaporator 1.7 46.1 12.7 0.96 38.7

Source:AsiaEnergyEf�iciency

3.7.3.4.MatchingCapacitytoSystemLoad

During part-load operation, the evaporator temperature rises and the condenser temperature falls,

effectivelyincreasingtheCOP.Butatthesametime,deviationfromthedesignoperationpointandthefact

thatmechanicallossesformagreaterproportionofthetotalpowernegatetheeffectofimprovedCOP,

resulting in lower part- load ef�iciency. Therefore, consideration of part-load operation is important,

becausemostrefrigerationapplicationshavevaryingloads.

3.7.4. Datacollection

· CollectinformationaboutHVACsystems

-HVACtype

-Designcapacity

-Refrigerant

-DesignCOP...

· Collectoperatinginformation:

-Inletpressure,Outletpressure

-Evaporationtemperature

-Condensetemperature,

-Electricalconsumption

Datacanbecollectedthroughthescreenmonitorormeasuredbyhandinstruments.

108

Figure60.Therefrigerationcycle

Figure61.Basictypesofcompressors

Source:AsiaEnergyEf�iciency

3.8.1.2.Characteristicsofrefrigerationsystem

Thereare4maincomponentsinrefrigerationsystem:compressor,condenser,expansiondevice,and

evaporator.Therefrigerationcycleofrefrigerationsystemissimilartotheoneofairconditioning

system.Pleaserefertosection3.7formoredetails.

Themost commonly types of compressors in industrial refrigeration systems are reciprocating

compressor,screwcompressor,pistoncompressor,andcentrifugalcompressor.

The power consumption of compressor is almost 70% of the total power consumption of the

refrigeration system.Therefore, properdesign is thekey to reduce thepower consumptionand

improveitsef�iciencyofarefrigerationsystem.

3.8. Industryrefrigerationsystem

3.8.1. Introduction

3.8.1.1. Overviewofrefrigerationsystem

Therefrigerationsystemisusedtocooltheairoraproduct.Inordertomaintainthetemperatureofcool

air,theinputworkisrequiredtoremoveheatfromacoolareaandtransfertowarmarea.

Screw compressor

Scroll compressor

Piston compressor

Centrifugal compressor

HighTemperatureReservoir

LowTemperatureReservoir

HeatRejected

WorkInput

HeatAbsorbed

109

SpiralFreezer StraightFreezer ImpingementFreezer

·ContactFreezer&Air-BlastFreezeraredesignedtofreezeamountsofgoods,forinstancefoodproduction.

ContactFreezer Air-BlastFreezer

· ColdStorageisusedtostorefrozenfoodsproducts.

ColdStorage

· Icemachines:BlockIceMachineandFlakeIceMachine

3.8.1.3.Applicationofrefrigerationsystem

The industry refrigeration system is commonly used in the central air conditioning of building,

refrigerators,chilledwaterplants,etc.

Somecommonapplicationsare:

· IndividualQuickFreezer(IQF):which isusedto freezeproducts individuallyratherthan ina

group.Thespeedoftheconveyorcanbeadjustedtomeetactualdemand

110

BlockIceMachine FlakeIceMachine

Q(kW)=m*Cp*(ti–t0)

m:mass�lowrateofcoolant,kg/s.

Cp:coolantspeci�icheatinkJ/kg0C

ti:inlettemperatureofcoolanttoevaporator,0C.

t0:outlettemperatureofcoolantfromevaporator,0C.

COPCarnot=Te/(Tc-Te)

Teisevaporatortemperatureand

Tcisthecondensertemperature

Thespeci�icpowerconsumptionkW/TRisausefulindicatoroftheperformanceofarefrigeration

system.BymeasuringtherefrigerationdutyperformedinTRandthekWinputs,kW/TRisusedasan

energyperformanceindicator.

Inacentralizedchilledwatersystem,apartfromthecompressorunit,powerisalsoconsumedbythe

chilledwater(secondary)coolantpump,thecondenserwaterpump(forheatrejectiontocooling

tower)andthefaninthecoolingtower.Effectively,theoverallenergyconsumptionwouldbethesum

ofpowerconsumptionof:

-CompressorkW

-ChilledwaterpumpkW

-CondenserwaterpumpkW

-CoolingtowerfankW,forinduced/forceddrafttowers

-EvaporatorkW.

·���Coef�icientofPerformance

ThisequationalsoindicatesahigherCOP isachievedwithhigherevaporatortemperaturesandlowerCarnot

condensertemperatures.ButCOP isonlyaratiooftemperatures,anddoesnottakeintoaccounttheCarnot

typeofcompressor.HencetheCOPnormallyusedinindustryiscalculatedasfollows:

3.8.1.4. Basicdata

Thebasicparametersofarefrigerationsystem,whichneedtobecollectedaretheload,temperatureand

refrigerationtime. If theoperatingparametersofarefrigerationsystemarenotavailable, thedesign

parameterscanbeusedforassessment.

·���CoolingCapacity

Coolingeffect(kW)COP=Powerinputtocompressor(kW)+auxiliaries(kWe)

111

3.8.2.Energy�low

Thefollowing�iguredescribestherefrigerationcycleofindustrialrefrigerationsystem:

Figure62. Typicalheattransferloopinrefrigerationsystem

PistonCompressor ScrewCompressor

· TheInstallationofVSDforthecompressorswithvariableloadswouldreducethepowerconsumption

ofcompressorbutitalsoreducesthecompressoref�iciency

· Avoidpart-loadoperation:twocompressorsoperatingat60%offullloadconsumelesspowerthana

compressoroperatingat100%fullloadandacompressoroperatingat20%offullload.

· 0The temperature of coolant in piston compressor is usually greater than 100 C. Therefore, heat

exchangercanbeinstalledtoremovetheheatfromcoolantandusethisheatforprocess

Source:Enerteam

3.8.3. Energysavingsmeasures

3.8.3.1. Compressor

In order to generate energy savings the factory could consider either to replace the low ef�iciency

compressorwiththehighef�iciencycompressorortoinstallVSDforthecompressor.

· Replacingapistoncompressorwithscrewcompressor

Requiredenergy1.94kWh/RT

21% 8.3% 54% 8.3% 8.3%

Air condi�oner

112

Figure63.DiagramofHeatRecoveryfromdischargeoutletfromcompressor

Figure64.Comparisonofpowerconsumptionbydifferentregulationmethods(screwcompressor)

Accordingtothe�igureabove,highlightsthefact,powerconsumptionisstillrelativelyhigheventhough

thecapacityisreducedby50%usingaslidevalvecontrol.Thiscanbeavoidedbyusingapropercontrol

system.

Foraneworupdatedrefrigerationcompressor,thecontrolsystemsolutioncanberelevantunderthefollowingcircumstances:

· Theexistingsystemisoldandequippedwitholdcontrolsystem.

· Therefrigerationsystemhaschangedfromitsoriginaldesign(multiunits)

· Loadsoroperationpatternshavechanged.

· VSDhasbeeninstalledforsomeofthecompressors

· Therefrigerationplantconsistsofdifferenttypeand/orsizesofcompressors

· Thereisnofunctioningcompressorcontrolsystem.

· oReducecondensertemperature:the5.5 Creductionofcondensertemperaturewillreduce20-25%of

powerconsumption

· Applythecontrolsystemfortherefrigerationcompressor.

Operatingcompressorat thepartial loador improperlywillreducetheef�iciencyoftherefrigeration

system. It is obvious when the refrigeration system has multiple compressors or the demand of

refrigerationvarious.Theef�iciencyofascrewcompressorcanbereducedby30%whenitoperatesat

partialloadasillustratedinthefollowing�igure.

113

Figure65.Relationshipofthecondensationtemperatureandtheperformanceoftherefrigeration

h

1

2 3

4

h3,4 h1 h2

6

5

h6

7

P2,3,6

P7,5

P1,4

Lgp

h5

T1

T1’

T1

’ > T

1

3.8.3.2.Optimizetheevaporator

0Theinletpressureofacompressorisimportantforpowerconsumptionofrefrigerationsystem.A1 C

raiseinevaporatortemperaturecansavealmost3%ofthepowerconsumed.

Itisgenerallyobservedthattheevaporatorpressuresaremuchtoolowcomparedtotherequiredcooling

temperatureofanindustrialrefrigerationinVietnamThisiscausedbyanumberofreasons:

· Toosmallevaporators

· Plateheatexchangersarenotused(drums/spiralsoroldandpoortechnology)

· Moist(ice)hasbuiltupontheevaporator.

According to the above �igure, when the evaporation temperature rises, the required inputwork is

reduced(h –h <h –h )andthecoolingeffectisincreased(h –h <h –h ). Therefore,theCOPofthe6 5 2 1 1 4 5 7

refrigerationsystemwillbeincreased.TheCOPisverydependentontheevaporationtemperature.

Inpractice,thismeansthatifthetemperaturedifferenceofthetwomediumsatthecoolestpointisgreater

than2ºC(seebelow),thereisroomforimprovementssince2ºCdelta-Tistheoptimaldesign.

114

Figure66.Principleschematicoftworefrigerationsystemswiththedifferentofthecevaporatortemperature

Source:LCTU(MOIT)

Table52.Effectofvariationinevaporatortemperatureonthecompressorpowerconsumption

Evaporatortemperature(oC)

Refrigerationcapacity*(ton)

Speci�icpowerconsumption

IncreaseinkW/ton(%)

5,0 67,58

56,07

45,98

37,20

23,12

0,81

0,94

1,08

1,25

1,67

0,0 16,0

33,0

54,0

106,0

-5,0

-10,0

-20,0

oNote:*Condensatetemperatureat40 C

Source:AsiaEnergyEf�iciency

Inordertoimprovetheef�iciencyoftheevaporator,therearesomerequirements:

· Performperiodicmaintenanceforevaporator.Removeobstaclesonairfan.

· Inspecttheexpansiondevice.

· Replacethemanualvalvewithautomationvalve.

· Determinetheproperheattransferareasaswellasrationalizethetemperaturerequirementtohighest

possiblevalue.

3.8.3.3. Optimizethecondenser

oThe condensation temperature is also as important as the evaporation temperature. A 1 C raise in

condensationtemperatureconsumesadditional3%ofthepowerconsumptionofarefrigerationsystem.

Thecondensationtemperatureanditscorrespondingpressureofanyrefrigerantaredependentonthe

heattransferarea,theeffectivenessofheatexchangeandthetypeofcoolingchosen.Therequirementsto

improveef�iciencyofcondenseraresimilartotheonesofevaporator.Thebelowtableillustratestheeffect

ofvariationincondensertemperatureonthecompressorpowerconsumption.

Theonlydifferenceisthesizeoftheevaporator.Byincreasingthesizeoftheevaporatorthetemperatureincreasefrom-10ºC(leftpartof�igure)to-7ºC(rightpartof�igure),whichsavesmuchas9%ofthepowerconsumptionofthecompressor.

The table below illustrates the effect of the evaporator temperature on the compressor power

consumption:

115

Table53.:Effectofvariationincondensatetemperatureonthecompressorpowerconsumption

ItisgenerallyobservedthatcondenserpressuresofindustrialrefrigerationinVietnamistoohigh,whichiscausedbyanumberofreasons:

· Poorlymaintained(fouled)condensers

· Airinthecondensers

· Toosmallcondensers

· Inef�icientoperationofthecondensers.

Thesavingpotentialforthismeasureishighduetoin�luenceonallcoolingdevicesconnectedtothe

condenser.Ifallcondensersarechangedorremoveditispossibletosave5to15%ofthetotalelectricity

usedforrefrigeration.Investmentsinsuchmeasureswillhavemediumtohighpayback-periods

However, ifthemeasureis introducedatthesametimeasmorerefrigerationcapacityis introduced,

investmentsandpaybackperiodfortheextrasizeofthecondensermightbelow.

3.8.3.4. IQFFreezer

TheenergysavingcouldbeobtainedforIQFsystembythefollowingmeasures

· oBy Increasing theevaporationpressurewhilemaintain the required temperaturea5.5 Craise in

evaporatortemperaturecansave20-25%ofthepowerconsumed.

· Pre-cooltheproductbeforetheyarefrozen

· Use2-stageIQFfreezer

EnergylossintheIQFfreezerincludes:

· Lossesduetopoorinsulation

· Lossesduetomechanicalfrictionofthefanorthemotorofconveyor

· Lossthroughopeningsintherefrigerationsystem.

3.8.3.5. Contactfreezerandairblastfreezer

Theenergysavingcouldbeobtainedbythefollowingmeasures

· Ensurethefreezerisfullwithproducts

· InstalltheVariableFrequencyDrive(VFD)toslowevaporatorfansforlowdemands

· Pre-cooltheproductbeforetransferringintofreezer.

EnergylossintheAirBlastFreezerincludes:

· Lossduetopoorinsulation

· Lossduetoauxiliarydevicesinthefreezer.

3.8.3.6. Coldstorage

Energysavingcouldbeobtainedforcoldstoragesbyimplementingthebelowmeasures

· Closethedoorimmediatelyaftergoinginandgoingout.Installautomaticdoorcloser

116

· Ensuretheinsulationofstorageisstillgoodinservice.

· Keepmonitoringtheinsidetemperatureandoutsidetemperatureofstorage.

3.8.3.7. Flakeicemachine

Energysavingcouldbeobtainedfor�lakeicemachinesbyimplementingthebelowmeasures

· Operateatnon-peakschedule

· Pre-coolthewaterbeforetransferringintomachine

· Wellinsulated.

3.8.4. Datacollection

Inordertoassesstheperformanceoftherefrigerationsystem,atemplateofdatacollectiontoaudita

refrigerationsystemisproposedasbelow:

Sectionno. Refrigerationcompressor Unit Machinereference

1 2

3

4

1 Make

Type

Capacity(ofcooling)

2

3

TR

4

Chiller:

A No.oftubes ..

B Dia.oftubes m

C

Totalheattransferarea

m²

D

Chilledwater�low

m³/h

E

Chilledwatertemp.difference

⁰C

5 Condenser

A

No.oftubes

B

Dia.oftubes

C

Totalheattransferarea

m²

D

Condenserwater�low

m³/h

E Condenserwatertemp.difference ⁰C

6

Chilledwaterpump

A

Nos

..

B

Capacity

m³/h

C

Headdeveloped

mWC

D Ratedpower kW

E

Ratedef�iciency

%

7

Condenserwaterpump

A

Nos

..

B Capacity m³/h

C

Headdeveloped

mWC

D

Ratedpower

kW

E

Ratedef�iciency

%

8 Coolingtower

A Nos ..

B Coolingcapacity kCal/h

C Airvolume m³/h

D Ratedpowerfan

Inletcoolingwatertemp.

Outletcoolingwatertemp.

Ambientemp.

kW

E ⁰C

F ⁰C

G ⁰C

117

118

Table54.Propertiesofsaturatedwaterandsteam

Pressure Temperature Speci�icenthalpyofevaporation Volumedrysat.

Bar kPa oC Water

(kJ/kg)

Latentheat

(kJ/kg)

Saturatedsteam

(kJ/kg)

m3/kg

0

0.5

1.0

1.5

2.0

3.0

4.0

5.0

6.0

7.0

10.0

14.0

0

50

100

150

200

300

400

500

600

700

1000

1400

100

112

120

128

134

144

152

159

165

170

184

198

419

468

506

536

562

605

641

671

697

721

782

845

2257

2226

2201

2181

2163

2133

2108

2086

2066

2048

2000

1947

2676

2694

2702

2717

2725

2738

2749

2757

2763

2769

2782

2792

1.673

1.149

0.880

0.714

0.603

0.461

0.374

0.315

0.272

0.240

0.177

0.132

3.9. Boiler

3.9.1. Introduction

3.9.1.1. Steam

Steam is the commonmedium to transfer heat to a process. Usually it is produced by boilers and

distributedthroughdistributionsteamsystem.Advantagesofsteamare:

· Lowrisk

· Inexpensive

· Highheattransfercoef�icient

· Easytodistribute

· Easytocontrol.

Inordertodeterminethestateoftheheattransfer�luid(steam)threesystemsparameters: areusedto

de�inethestateofwater:Pressure,Temperature,Speci�icvolume.

Steamtable:

119

Figure67.Steamphasediagram

Figure68.SimplediagramofTubeboiler

Boilerexamples

FireTubeBoiler

Source:AsiaEnergyEf�iciency

Theabove�iguredescribestherelationshipbetweentheenthalpyandthetemperatureofwaterandsteam

atdifferentpressures.Theliquidregionorwaterregionisontheleftsideofsaturatedliquidlineandthe

superheatedregionorsuperheatedsteamregionisontherightsideofsaturatedvaporline.Thesaturated

vaporlineandsaturatedliquidlineintersectatthecriticalpointandcreateanenvelopeoftwophase

regions.

ThelineABCDdescribesthephasechangeofwaterattheconstantpressure.Initially,Waterisheatedfrom

subcooledliquidtemperature(pointA)tosaturationtemperature(pointB).Iffurtherheatcontinuestobe

added,liquidwaterwillbeconvertedgraduallyfromsaturatedliquid(pointB)tosaturatedvapor(point

C)atconstantsaturationtemperatureuntilitreaches100%vapor.Ifheatisstillheated,thesaturated

vapor(pointC)willbeconverted tosuperheatedvapor(pointC–pointD).The temperaturewillbe

increasedduringconvertingtosuperheatedsteam.

3.9.1.2. Boilerintroduction

Aboilerisanequipmentthattransfersheatenergyfromthecombustionoffuelstowaterinorderto

convertwatertosteam.Aboilerproducessteamatvariouspressurestosupplyfordifferentdemands.

steamoutlet

waterinlet

flueairandfuelinlet

combus�onchamber

watertubes

Enthalpy

Superheatregion

Two phase regionTe

mp

erat

ure

Liquidregion

Lines ofconstantpressure

Cri�calpoint

Saturatedvapour line

Saturatedliquid line

120

Figure69.Firetubeboiler

Table55.AdvantageanddisadvantageofFiretubeboiler

Advantages Disadvantages

Usedforsmallscale

Easytooperateandmaintain

Inexpensive

Requiretimeto�illwater

Requirelongertimetoincreasepressure

Steammightcontainwater

· Watertubeboiler:

Figure70.Watertubeboiler

Table56.Advantageanddisadvantageofwatertubeboiler

Advantages Disadvantages

Higherthermalef�iciency

Abletoproducesuperheatedsteam

Customizabledesign

Morecomplexconstruction

Complexcontrolsystemsrequired

· Watertubeboilerwithsteamdrum:

121

Figure71.Watertubeboilerwithsteamdrum

Table57.Advantageanddisadvantageofwatertubeboilerwithsteamdrum

Advantage Disadvantage

- Suitableforallfuels

- Highparameters(capacity,pressure,

abilitytoproducesuperheatedsteam).

- Goodcirculation.

- Bendedpipe:abletoself-expand.

-Bulkysize

-Longinstallationtime

-Highcapitalinvestment

-Highwaterqualityrequirements

-Complexoperation(blowdownat

multiplepositions)

-Dif�icultcleaningofpipesurface

Costofgeneratingsteamfromboilercanbeestimatedbythefollowingformula:

Sc (VND/kg) =)(

)'''(

GCVD

Rhh

´´

-

h

h’’:enthalpyofsteam(kcal/kg)

h’:enthalpyofboilerfeedwater(kcal/kg)

h:boileref�iciency(%)

R:fuelcost(VND/lit)

D:density(kg/lit)

GCV:GrossCalori�icValue(kcal/kg)

122

3.9.1.3.Boileref�iciencyevaluation

Boileref�iciencycanbeevaluatedbydatacollectionandcalculationasdecribedbelow:

· Boileref�iciencyiscalculateddirectlybyfollowingformula:

Q(kg/hr):Steamgeneratedperhour

hs(kcal/kg):Enthalpyofsaturatedsteam

hw(kcal/kg):Enthalpyoffeedwater

m(kg/hr):fuelusedperhour

GCV(kcal/kgoffuel):Grosscalori�icvalueoffuel

Example:

Steamgenerated:2.5ton/hr

QuantityofDieselFO :180liters/hour(density:0.95kg/liter)

Feedwatertemperature :850C

GCVofDieselFO:9.800kCal/kg

Enthalpyofsteamat8kg/cm2:666kCal/kg(saturatedsteam)

Enthalpyoffeedwater:85kCal/kg

Boileref�iciency:

%67,86100980095,0180

)85666(2500=´

´´

-´

Advantages Disadvantage

Fewrequiredparameters

Quickcalculation

Fewrequiredinstruments

Unabletode�inespeci�iclosses

Heatlossesdueto:

q1(%) :Dry�luegas

q2(%) :Hydrogeninfuelburnt

q3(%) :Moistureinfuel

q4(%) :Moistureinair

q5(%) :Unburntfuelin�lyash

q6(%) :Unburntfuelinbottomash

q7(%) :Radiationandotherunaccountedlosses.

Theheatlossthroughtheboilerisdeterminedbytheboilerheatbalance

BoilerEf�iciency=100%-(q +q +q +q +q +q +q )1 2 3 4 5 6 7

· Theboileref�iciencycanbecalculatedbyindirectmethod.Thismethodologyrequiresdataofthe

principlelosses:

Qx(hg-hf)Boileref�iciency= x100

qxGCV

123

Figure72.Typicallossesfromcoal�iredboiler

Source:AsiaEnergyEf�iciency

ThefollowingExceltemplateshowsanexampleofboileref�iciencybyusinganindirectmethod(including

formulas):

Heatlossduetodry�luegas

Heatlossduetosteamin�luegas

Heatlossduetomoistureinfuel

Heatlossduetomoistureinair

Heatlossduetounburntsinresidue

Heatlossduetoradiation&other

unaccountedloss

HeatinSteam

100,0%

Fuel

BOILER

12,7%

8,1%

1,7%

0,3%

2,4%

1,0%

73,8%

124

Table58.Boileref�iciencycalculation

# Parameter Unit

1 AbsoluteAnalysis Coal DieselFO

Carbon

Hydro

Oxy

Sulphur

Nitrogen

Moisture

Ash

% 46.15 82.7

% 3.06 10.9

% 10.21 0.5

% 0 3.5

% 1.58 0.4

% 7.2 0.1

% 31.8 0.1

2 GCVoffuel KCal/kg 4400 9856

3 O2 in�luegas % 9 7.8

4 CO2 in�luegas % 8.5 9.9

5 �luegastemperature(T )f0C 180.4 181

6 Ambienttemperature(T )a0C 31 31

7 Moistureinair Kg/kgdrygas 0.018 0.018

8 Ashcontent % 10 0

9 GCVofash KCal/kg 800 0

ExcessAir(EA)

(O2x100)/(21–O2)

TheoreticalAirRequirement(TAR)

[11.43xC+{34,5x(H2 –O2 /8)}+4,32xS]/100

Actualairsupplied(AAS)

{1+EA/100}xtheoreticalair

InputK

%heatlossduetoevaporationofwaterformedduetoH2

infuel

[9xH2{584+0,45(Tf –Ta )}]/GCVoffuel

%heatlossduetoevaporationofmoisturepresentinfuel

[Mx{584+0,45x(Tf –T)}]/GCVoffuel

%heatlossduetomoisturepresentinair

{AASxHumidityFactorx0,45(Tf –Ta)x100}/GCVfuel

%heatlossduetounburntfuelinash

{ashx(100–burntfuelinash)xGCVofash/100}/GCV

fuel18 heatlossduetoradiationandotheraccountedloss % 2.00 2.00

19 Totalloss % 24.05 17.24

20 Ef�iciency%

75.95 82.76

Value

6.48

0.01

10%

11.42

75

11kg/kgoffuel 5.89

10.3112

kg/kgoffuel

0.65

0.26

0.00

59

13.34

21.23

8.48

%

%

17

%

4.08

1.07

0.28

5.20

%

%

16

15

14

%heatlossduetodry�luegas

{kx(T –T )}/%CO2f a

Wherek

=0,65forcoal

=0,56forDiesel

=0,40forNaturalGas

13

125

Figure73.Sankeydiagramofboiler

Source:AsiaEnergyEf�iciency

3.9.3.Energysavingmeasures

3.9.3.1.Insulateheatedpipingsystemandusers

Heat losswilloccur if thepipingsystemandequipmentarenotwell insulated.Theamountofheat

lossisdescribedinthefollowingtables:

Table59.Heatlossduetouninsulation

Source:Enerteam

3.9.2.Energy�low

Sankeydiagram

ThefollowingSankeydiagramillustrateshowtheinputenergyfromthefuelistransformedintothesteam

energyandenergyloss�lows.Majorlossesarestackgaslosses,blowdownlosses,andlossesbyunburnt

fuelinstackandash.

56

67

78

89

100

111

125

139

153

167

180

194

W/m

Pipesize

15mm

20mm

25mm

32mm

40mm

50mm

65mm

80mm

100mm

150mm

54

68

83

99

116

134

159

184

210

241

274

309

65

82

100

120

140

164

191

224

255

292

329

372

79

100

122

146

169

198

233

272

312

357

408

461

103

122

149

179

208

241

285

333

382

437

494

566

108

136

166

205

234

271

285

333

382

437

494

566

132

168

203

246

285

334

394

458

528

602

676

758

155

198

241

289

337

392

464

540

623

713

808

909

188

236

298

346

400

469

555

622

747

838

959

1080

233

296

360

434

501

598

698

815

939

1093

1190

1303

324

410

500

601

696

816

969

1133

1305

1492

1660

1852

Temperature

difference

steamtoairOC

StoichiometricExcess AirUn burnt

Convec�on &Radia�on

BlowDown

Ash and Un-burntparts of Fuel in Ash

FUEL INPUT Stack Gas

STEAM OUTPUT

126

Table60.Heatlosscalculationduetouninsulation

Lengthofpiping 32 m

Heatloss 16,032 W

Steampressure 5 bar

Productioninformation Operatingtime 7,920 hr/year

Costofsteamgeneration 516,250 VND/ton

Equivalentsteamloss 20.94 kg/hr

Wastemoney 85,609,121 VND/year

Steamtemperature

Outerdiameter

Innerdiamete

Heattransfercoef�icient

Insulationtemperature

Heattransfercoef�icient

Unwantedheatloss

150.90C

100 mm

90 mm

50 W/m.C

500C

0.051 W/m.C

100 W/m

Insulation+B12:F41thickness 19 mm

Heatlossof1mpiping

REQUIREDINSULATIONTHICKNESS

Piping

Insulation

3.9.3.2. Installeconomizerstorecoverheatforfeed-waterpreheating

A�luegasofboilerisusuallydischargedathightemperature.Therefore,recoveringheatfrom�luegasto

preheatthefeedwaterisabene�icialenergysavingmeasure.Anadditionaleconomizerisanessential

equipmentforthismeasure.

501 W/m

127

Figure74.Heatrecovery�lowdiagram

Source:USDepartmentofEnergy

128

Moreover,theeconomizerisalsousedtodrytheair.

Figure75.Waterpre-heaterandairdryer

3.9.3.3.Optimizetheoperatingconditions

Theboileroperatingconditionsshouldbeoptimizedtoreducetheenergyloss,someproposedmeasures

are

· Controllingproperlytheamountratiooffuel/airwillmaintainthehighef�iciencyofcombustion

process

· Evaluatethesizeofboiler

· Automaticblowdowncontrol

· Installvariablespeedcontrolforairsupplyandexhaustfans.

3.9.3.4.UpgradeandReplacetheboiler

Anotheroptiontobene�itfromenergysavingistheupgradeorreplaceoftheboiler.Followingmeasures

arepossible:

· Installcombustionanalyzerforcontinuousmonitoring

· Recoverheatfrom�luegas

· Replacethelowef�iciencyboiler

· Replacefossilfuel�iredboilersbybiomass�iredboilers

129

Figure76.Typicalsteamtraps

Figure77.Functionsofsteamtraps

Classi�icationofsteamtraps:

Figure78.Classi�icationofsteamtraps

3.9.3.5. Installsteamtraptorecovercondensate

Asteamtraphasthefollowingmainfunctions:

· Dischargethecondensate

· Preventsteamloss

· Removeair.

MechanicalUse difference in

density between steamand condensate

Thermosta�cSense temperature

change of condensate

ThermodynamicSteam (flash) - velocity

difference

Trap types

Dischargecondensate

Func�on ofsteam traps

Prevent steamloss

Dischargeincondensable

gases

130

Mechanicalsteamtrap–Free�loat

· Structure:

Figure79.Mechanicalsteamtrap–Free�loat(source:TLV)

· OperatingPrinciples

Figure80.Operatingprinciplesofmechanicalsteamtrap–Free�loat

Table61.Advantagesanddisadvantagesofsteamtrap–free�loat

Advantages: Disadvantages:

-Continuouslydischargecondensateatsteamtemperature.

-Canhandleheavyorlightcondensate

-Largecapacity

-Resistanttowaterhammer

- Whenthetrapiscool,X-elementcontractsandAirVentValveopenstodischargeinitialair.After

coldcondensateentersthetrap,the�loatofsteamtrapwillrisetoallowdischargeofcondensate

fromori�ice.BothairandcondensatearealsodischargedfromAirventvalve

-Afterinitialairandcoldcondensatehavebeendischarged,hotcondensateheatstheX-elementand

closesAirVentValveinordertoavoidsteamloss.Atthistime,thecondensatecontinuestobe

dischargedthroughori�ice

-Ascondensatestops�lowingintothetrapandthesteamoccupiestheuppersection,the�loatwill

closetheori�iceandX-elementisalsoclosed.Therefore,thetrapiscompletelysealedtoprevent

steamleakage.

Trapsoperatingonhighdifferentialpressuresneedtohavesmallerori�ices

131

Mechanicalsteamtrap–invertedbucket

Structure:

Figure81.Mechanicalsteamtrap–invertedbucket(source:TLV)

· OperatingPrinciples

Figure82.OperatingPrinciplesofmechanicalsteamtrap–Invertedbucket

Table62.Advantagesanddisadvantagesofsteamtrap–Invertedbucket

Advantages Disadvantages

-Withstandhighpressures

Goodtolerancetowaterhammerconditions

Dischargeairveryslowly

Steammightbelostthroughdischargeportifthe

traploseswatersea

- Thetrapbodyisinitiallyfullofwaterfromlastoperationandthebucketisstillsettleddown.The

condensateispushedoutthroughtheopendischargeport

-Whentheair/steamleaksthroughventholeslowlyandthebucketrisesuptoclosethedischarge

port

-Trapiscloseduntilthesteaminsidethebucketiscondensedortheoutsidecondensate�lowsinto

thebucket.Thedischargevalvewillbepulledoff

-Accumulatedcondensateisreleasedandthecycleisrepeated.

132

ThermodynamicSteamTrap

· Structure

Figure83.Thermodynamicsteamtrap(source:TLV)

· Operatingprinciples

Figure84.Operatingprinciplesofthermodynamicsteamtrap

Table63.Advantagesanddisadvantagesofthermodynamicsteamtrap

Advantages Disadvantages

-Compact,simple,andlightweight

Largecondensatecapacity

Installhorizontallyorvertically

Removalcondensatealsocarriessteam

Lowef�iciency

Thedischargeofthetrapcanbenoisy

- On start-up, incoming pressure raises the disc, and cool condensate plus air is immediately

dischargedfromtheinnerringunderthedisc

- Thecondensatein�lowpushingopendisccausesthepressuredropandreleases�lashsteamwith

highvelocity.Thishighvelocitycreatesalowpressureareaunderthedisc,drawingittowardsits

seat

- Atthesametime,the�lashsteampressurebuildsupinsidethechamberabovethedisc,forcingit

downagainsttheincomingcondensateuntilitseatsontheinnerandouterrings.Atthispoint,the

�lashsteamistrappedintheupperchamber,andthepressureabovethediscequalsthepressure

beingappliedtotheundersideofthediscfromtheinnerring

-Eventuallythetrappedpressureintheupperchamberfallsasthe�lashsteamcondenses.Thediscis

raisedbythenowhighercondensatepressureandthecyclerepeats.

133

Thermostaticsteamtrap–Balancedpressure

· Structure:

Figure85.Thermostaticsteamtrap–Balancedpressure(source:TLV)

· OperatingPrinciples

Figure86.Operatingprinciplesofthermostaticsteamtrap–balancedpressure

Table64.Advantagesanddisadvantagesofthermostaticsteamtrap–balancedpressure

Advantages: Disadvantages

Compact,simple,andlightweight

Simplemaintenance

Largecapacity

Valve is not opened until the condensatetemperatureisbelowsteamtemperature.

Ascondensatepassesthroughthebalancedpressuresteamtrap,heatistransferredtotheliquidin

thecapsule.The liquidvaporisesbeforesteamreaches the trap.Thevapourpressurewithin the

capsule causes it to expand and the valve shuts. Heat loss from the trap then cools the water

surroundingthecapsule,thevapourcondensesandthecapsulecontracts,openingthevalveand

releasingcondensateuntilsteamapproachesagainandthecyclerepeats.

134

Steamtrapselectionnotices:

Table65 Steamtrapselection

Application Feature Suitabletrap

Steampiping Smallcapacity

Frequentchangeinpressure

Lowpressure–highpressure

Thermodynamic

Mechanical:�loat

Equipment

Reboiler

Heater

Dryer

Heatexchanger

Instrumentation Highreliability Thermodynamic

Thermostatic

Normaloperation Steamleakage

Figure87.Steamtrapoperation

Largecapacity

Variationinpressureandtemperatureis

undesirable

Ef�iciencyoftheequipmentisaproblem

Mechanical:�loat,bucket,

invertedbucket

· Temperaturetesting

-Useinfraredguns,surfacepyrometers,ortemperaturetapestomeasuretemperature

- Thesteamtrapoperateswellifthedifferencetemperaturebetweenthesteamandcondensateis

small.

· Ultrasonictesting:Usetheultrasonicleakdetectortodetermineifthetrapisfunctioningproperly

Twotypesoffailures:

· Failedinopenposition:steamlossincreasestheproductioncost

· Failedinclosedposition:waterhammercausesdamagetoequipment.

Therearefourwaystocheckforleaks,andcheckforsteamtraps

Visualtesting:Thismethodallowsustoobservetheoperationofsteamtrapwhenproductionisrunning.

Disadvantage:thesightglassneedsmaintenance,whichmightcauseincreasingproductioncost.

135

Figure88.Ultrasonictesting

· LeakdetectionbyusingSpira-tecequipment.

Figure89.Spira-tecmeasurement

SLDSSpira-tecmonitoringequipmentisusedtodetectifthereisleakofanysteamtrapduringitsoperation.

3.9.4.Datacollection

Necessaryparametersforboileref�iciencycalculation:

· Ultimateanalysisoffuel(%C,%H2,%O2,%S,moisturecontent,ashcontent)

· Fluegastemperature

· Ambienttemperature

· Humidityofair

· %O2or%CO2in�luegas

· GCVoffuel

· GCVofash

· Blowdownwater.

· Fueltemperature.

Touchsensor

Meter

Ampli�icationand�ilter

Headphone

136

Figure90.Typesoffurnaces

3.10. Furnace

3.10.1.Introduction

Afurnaceisanequipmentusedtomeltmetalsforcastingortoheatmaterialstochangetheirshape(e.g.

rolling,forging)orproperties(heattreatment).

3.10.1.1.Mainfurnacecomponents

· Heatingsystem:fuel�iredorelectricalheatingtype

-Fuel�ired:heatisproducedbyburninganappropriatemixtureofairandfuel

-Electricfurnace:heatisproducedbyresistance,inductionorarc.

· Refractory:preventheatlosstothesurrounding.Itshouldalsobechemicallyinerttotheprocess

· Loading–unloadingsystem:thematerial issuppliedandtakenoutof thefurnacethrougha

loadingandunloadingsystem.Energylossesoffurnacemightoccurduringsystemoperation

· Heatexchanger:useswasteheattopreheattheairandmaterialwhichisloadedinthefurnaceor

usedinexternalapplications

· Instrumentationandcontrol:thisincludessensorsandcontrollerstocontrolseveralprocesses

likefuelsupply,currentsupply,exhaust–gasanalysis,loadingandunloadingofmaterialetc.

Exhaust gas flue

Burner

Furnace chamber

Dischargedoor

Charge door Stock Hearth

137

3.10.1.2.Classi�ication

Table66.Classi�icationoffurnaces

Classi�icationmethod Types

Typeoffuelused Oil

Gas

Coal

Modeofchargingmaterials Batch

Periodical(Forging,re-rolling,pot)

Continuous(pusher,walkingbeam,walkingheart)

Modeofheattransfer Radiation

Convection

Modeofwasteheatrecovery recuperative

Regenerative

Heatinstock(Q)canbecalculatedwiththisequation:Q = m × Cp × (t2 − t1)

Q=quantityofheatinstockinkCal.

m=massofthestockinkg.

Cp=speci�icheatofstockinkCal/kg.0C

t2=�inaltemperatureofstockin0C

t1=initialtemperatureofthestockbeforeitentersthefurnacein0C

m=weightof�luegas(air+fuel)

Cp=speci�icheatof�luegas

rT=temperaturedifference

GCV=grosscalori�icvalueoffuel,kCal/kg.

3.10.1.3.Energyperformanceassessmentoffurnaces

Theef�iciencyofafurnaceincreaseswhenthepercentageofheatwhichistransferredtothestockorload

insidethefurnaceincreases.Theef�iciencyofthefurnacecanbecalculatedintwoways:

· Directmethod

Theef�iciencyofafurnacecanbedeterminedbymeasuringtheamountheatabsorbedbythestockand

dividingthisbythetotalamountoffuelconsumed.

· Indirectmethod

Furnaceef�iciencycanalsobecalculatedaftersubtractingsensibleheatlossin�luegas,heatlossdueto

moisture in �lue gas, heat lossdue toopenings in furnace, heat loss through furnace skin andother

unaccountedlossesfromtheinputtothefurnace.

- Heatlossin�luegas:

HeatinstockThermalef�iciencyofthefurnace=Heatinthefuelconsumed

138

- Heatlossfrommoistureinfuel:

m=%moistureofin1kgoffueloil

Tfg=�luegastemperature,0C.

Tamb=ambienttemperature,0C

- Heatlossduetohydrogeninfuel:

H2=%ofH2in1kgoffueloil.

- Heatlossduetoopeninginfurnace:

Thefactorofradiationthroughopeningsandtheblackbodyradiationfactorcanbeobtainedfromstandard

graphsasshownin�iguresbellows.

Figure91.Radiationfactorforheat

Source:BEE,2005

Figure92.Blackbodyradiationatdifferenttemperature

Source:BBE, 2005

139

- Heatlossthroughfurnaceskin:todeterminetheheatlossthroughthefurnaceskin,�irsttheheat

lossthroughtheroofandsidewallsandthroughotherareasmustbecalculatedseparately .

Figure93.Heatlossfromtheceiling,sidewallandhearthoffurnace

Source:BEE,2005

-Heatlossthroughroof/ceilingandsidewalls(=heatandsoakingzone).

Theaveragesurfacetemperaturet isestimatedfromdatapointsofpracticalmeasurementst

0 2Heatlossatt C(referto�igure39),kCal/m hr.st

2Totalareaofheating+soakingzone,m

0 2 2Sototalheatlossthroughfurnaceroof/ceilingis:Heatlossatt CkCal/m hr.xAream ,kCal/hr.st

-Heatlossfromareaotherthanheatingandsoakingzone.

Theaveragesurfacetemperaturet isestimatedfromdatapointsofpracticalmeasurementst

0 2Heatlossatt C(referto�igure39),kCal/m hr.ost

2Totalarea,m .

0 2 2Sototalheatlossthroughotherareasis:Heatlossatt CkCal/m hr.xAream ,kCal/hr.ost

The%heatlossthroughfurnaceskinis:

-UnaccountedLoss

Theselossescompriseofheatstorageloss,lossoffurnacegasesaroundchargingdoorandopening,heat

lossbyincompletecombustion,lossofheatbyconductionthroughhearth,lossduetoformationofscales.

Addingallofheatlossesabovegivethetotallossestoconstructaheatbalancefortypicalfurnace.

TemperatureofExternalSurfaceofFurnace(degC)

140

Figure94.Heatlossedinafurnace

Source:AsiaEnergyEf�iciency

Thesefurnaceheatlossesinclude:

· Fluegaslosses:partofheatremainsinthecombustiongasesinsidethefurnace

· Loss frommoisture in fuel: fuel usually contains somemoisture and some of the heat issued to

evaporatethemoistureinsidethefurnace

· Lossduetohydrogeninfuelwhichresultsintheformationofwater

· Lossthroughopeningsinthefurnace:radiationlossoccurswhenthereareopeningsinthefurnace

enclosureandtheselossescanbesigni�icant.Asecondlossisthroughairin�iltration

· Furnaceskin/surface losses:while temperatures inside their furnacearehigh,heat is conducted

throughtheroof,�loorandwallsandemittedtotheambientaironceitreachesthefurnaceskinor

surface.

Otherlosses:thereareseveralotherwaysinwhichheatislostfromafurnace,althoughquantifyingthese

isoftendif�icult.Someoftheseinclude:

· Storedheatlosses:whenfurnaceisstartedthefurnacestructureandinsulationisalsoheated,andthis

heatonlyleavesthestructureagainwhenthefurnaceshutsdown

· Coolingmedialosses:waterandairareusedtocooldownequipment,rolls,bearingandrolls,butheat

islossbecausethesemediaabsorbheat

· Incomplete combustion losses: heat is lost if combustion is incomplete because unburnt fuel or

particleshaveabsorbedheatbutthisheathasnotbeenputtouse

· Lossduetoformationofscales.

3.10.2.Heatlossesaffectingfurnaceperformance

Thetotalheatinputisprovidedintheformoffuelorpower.Thedesiredoutputistheheatsuppliedfor

heatingthematerialorprocess.Otherheatoutputsinthefurnacesareundesirableheatlosses.

Theenergy�lowisdepictedinthe�igurebelow:

141

Table67 Heatbalance

Heatinput Heatloss

Item kCal/kg % Item kCal/kg %

Combustionheatoffuel Fluegasloss

Electricity Moistureinfuelloss

Hydrogeninfuelloss

Coolingwaterloss

Heatlossduetoopening

Heatlossduetofurnaceskin

Heatlossin�luegas

Total

3.10.3.Energysavingsmeasures

Thegoalofanenergyauditoristominimizeheatlossandoptimizetheperformance.Potentialenergy

savingsareasinfurnacesarelistedbelow:

3.10.3.1.Completecombustionwithminimumexcessair

Tocompletecombustionoffuelwithminimumamountofair,itisnecessarytocontrol

· Airin�iltration

· Maintainpressureofcombustionair

· Fuelquality

· Excessairmonitoring

· Equippedanautomaticoxygen(air)/fuelratiocontroller.

3.10.3.2.Properheatdistribution

Afurnaceshouldbedesignedtoensurethatwithinagiventimethestockisheateduniformlytoadesired

temperaturewithminimumamountoffuel.

Whereburnersareusedto�irethefurnace,thefollowingshouldbeensuredforproperheatdistribution

· The�lameshouldnottouchorbeobstructedbyanysolidobject

· The�lameofdifferentburnersshouldstayclearofeachother

· Theburner�lamehasatendencytotravelfreelyinthecombustionspacejustabovethematerial.For

thisreason,theaxisoftheburnerinsmallfurnacesisneverplacedparalleltothehearthbutalwaysat

anupwardangle,butthe�lameshouldnothittheroof

· Insmallfurnacesusingoil,aburnerwithalong�lamewithagoldenyellowcolorimprovesuniform

heating.Butthe�lameshouldnotbetoolong,becauseheatislossofthe�lamereachesthechimneyor

thefurnacedoors

· Maintainingcleansurfacebyusingasootblower

· Completecombustionofcarbononradiantsurface

· Keepingheatexchangersclean

· Selectandlocateburnersandfanseffectively.

142

3.10.3.3.Wasteheatrecoveryfromfurnace�luegases

Wasteheatin�luegasescanberecoveredforpreheatingofthecharge,preheatingofcombustionair

orforotherprocesses.

· Chargepre-heating:

Whenrawmaterialsarepreheatedbyexhaustgasesbeforebeingplacedinaheatingfurnace,the

amountoffuelnecessarytoheattheminthefurnaceisreduced.

· Preheatingofcombustionair:

Theenergycontainedintheexhaustgasescanberecycledtopreheatthecombustionair.Sincethe

volume of combustion air increaseswhen it is preheated, it is necessary to consider thiswhen

modifyingairductdiametersandblowers.Itshouldbenotedthatpreheatingofcombustiongases

fromhighdensityoilswithahighsulphurcontent,couldcausecloggingwithdustorsulphidesand

corrosion.

· Utilizingwasteheatasaheatsourceforotherprocesses:

Thewasteheatcanbeusedtoproducesteamorhotwater.Sometimesexhaustgasheatcanbeusedfor

heatingpurposesinotherequipmentsuchastank,reactor,etc.

3.10.3.4.Minimizingfurnaceskinlosses

Thereareseveralwaystominimizeheatlossthroughthefurnaceskin:

· Choosingtheappropriaterefractorymaterials

· Increasingthewallthickness

· Installinginsulatingbricks

· Planningoperatingtimesoffurnaces.

3.10.3.5.Preventheatlossthroughopenings

Thereareseveralwaystominimizeheatlossthroughopening:

· Keeptheopeningassmallaspossibleandsealthem

· Openingthefurnacedoorslessfrequentandfortheshortesttimeperiodaspossible

· Checkairleakagefrequently.

3.10.3.6.Controloffurnacedraft

Ifnegativepressuresexistinsidethefurnace,aircanin�iltratethroughcracksandopeningsandaffect

theairfuelratiocontrol.Thisinturncancausemetaltonotreachthedesiredtemperatureornon-

uniformtemperatures.Toavoidthis, installingfurnacepressurecontrollershelpmaintaininside

positivefurnacepressure.

3.10.3.7.Operationattheoptimumfurnacetemperature

Itisimportanttooperatethefurnaceatitsoptimumtemperature.Operatingtemperaturesofvarious

furnacesaregivenintablebelow.Operatingattoohightemperaturescausesheat loss,excessive

oxidation,decarbonizationandstressonrefractories.Automaticcontrolofthefurnacetemperature

ispreferredtoavoidhumanerror.

143

Slabreheatingfurnaces 12000C

Rollingmillfurnaces 12000C

Barfurnaceforsheetmill 8000C

Bogietypeannealingfurnaces 6500C-7500C

3.10.3.8.Optimumcapacityutilization

Oneofthevitalfactorsaffectingef�iciencyisload.Thisincludestheamountofmaterialplacedinthe

furnace,thearrangementinsidethefurnaceandtheresidencetimeinsidethefurnace.

3.10.3.9.Optimumload

Ifthefurnaceisunderloaded,theproportionoftotalheatavailablethatwillbetakenupbyloadissmaller,

resultinginaloweref�iciency.Overloadingcanleadtotheloadnotheatedtorighttemperaturewithina

givenperiodoftime.

Thereisaparticularloadatwhichthefurnacewilloperateatmaximumthermalef�iciency,wherethe

amountoffuelperkgofmaterialislowest.

3.10.3.10.Optimumarrangementoftheload

Theloadingofmaterialsonthefurnacehearthshouldbearrangedsothat:

· Itreceivesthemaximumofradiationfromthehotsurfacesoftheheatingchambersand�lames

· Hotgasesareef�iciencycirculatedaroundtheheatreceivingsurfacesofthematerials.

3.10.3.11.Optimumresidencetimeoftheload

Fuelconsumptioniskeptataminimumandproductqualityisbestiftheloadonlyremainsinsidethe

furnaceuntil ithas therequiredphysicalandmetallurgicalproperties.Excessiveresidence timewill

increaseoxidationof thematerial surface,which can result in rejectionofproducts.Temperature is

increasedtomakeupforshorterresidencetime.Thehighertheworkingtemperature,thehigheristhe

lossperunitoftime.

Optimumutilizationoffurnacecanbeplannedatdesignstage,byselectingthesizeandtypethatmatches

theproductionschedule.

3.10.3.12.Useofceramiccoatings(highemissivitycoating)

Ceramiccoatinginthefurnacechamberpromotesrapidandef�icienttransferofheat,uniformheating

andextendedlifeofrefractories.Theemissivityofconventionalrefractoriesdecreaseswithincreasein

temperaturewhereas for ceramic coatings it increases slightly. Thisoutstandingpropertyhasbeen

exploitedbyusingceramiccoatinginhotfaceinsulation.Ceramiccoatingishighemissivitycoatinganda0havealonglifeattemperaturesupto1350 C.

3.10.3.13.Selectionofrefractories

Theselectionofrefractoriesaimstomaximizetheperformanceofthefurnace.Furnacemanufacturersor

usersshouldconsiderthefollowingpointsintheselectionofarefractory:

· Typeoffurnace

· Typeofmetalcharge

· Presenceofslag

· Areaofapplication

· Workingtemperature

· Extentofabrasionandimpact

144

Table68.Measuringinstruments

· Structuralloadofthefurnace

· Stressduetotemperaturegradientinthestructuresandtemperature�luctuations

· Chemicalcompatibilitytothefurnaceenvironment

· Heattransferandfuelconservation

· Costconsiderations.

3.10.4.Datacollection

3.10.4.1.Checklist

It isdif�icult tomakeachecklistofgeneraloptions for furnaces,becauseoptions to improveenergy

ef�iciencyvarybetweendifferenttypesoffurnaces.Butthemainoptionsthatareapplicabletomost

furnacesare:

· Checkagainstin�iltrationofair:usedoorsoraircurtains

· MonitorO ,CO ,COandcontrolexcessairtotheoptimumlevel2 2

· Improveburnerdesign,combustioncontrolandinstrumentation

· Ensurethatthefurnacecombustionchamberisunderslightpositivepressure

· Useceramic�ibersinthecaseofbatchoperations

· Matchtheloadtothefurnacecapacity

· Retro�itwithheatrecoverydevice

· Investigatecycletimesandreduce

· Providetemperaturecontrollers

· Ensurethat�lamedoesnottouchthestock.

3.10.4.2.Measuringinstrumentsforfurnace

No. Parameterstobemeasured LocationofMeasurement

Instrumentrequired

Value

1 Operatingtemperature Soakingzonesidewall Measuretemperature

oC

2 Measuretemperature

oC

3 Ambienttemperature(tamb) Aroundfurnace Measuretemperature andhumidity

oC,%RH

4 Fluegasanalyzer Measure the �luegas

5 Surfacefurnace Measuretemperature

oC

6 Average surface temperatureof areaotherthanheatingandsoakingzone

Surfaceothers Measuretemperature

oC

Averagesurfacetemperatureofheatingandsoakingzone

Exit�luegastemperatureafterpreheat(T )fg

Fluegasexitfromfurnace-chimney

Fluegasexitfromfurnace-chimney

OC,%ofOxygen,CO,CO2

145

3.10.4.3.Datacollectiontemplate

Table69.Datacollectiontemplateforfurnaceperformance

Items

Name

Model:

Fueltypes

Designedcapacity

Heatingzone

FuelLoadingdoor

Wallthickness

Coolingwater�lowrate(ifany)

Unit

tons/hr

m2

m2

mm

M3/hr

Measurement 1 2 3 1 2 3 1 2 3 1 2 3

Ambienttemperature OC

Operatingtemperature OC

Airtemperature OC

Surfacefurnacetemperature OC

Oxygen %

CO ppm

CO2 %

Note

4. SAFETYREQUIREMENTANDEQUIPMENT

Energyauditrequiresauditorstosurveyinmanyareasofthefactoryandbuildingssuchastransformers,

refrigerationsystem,boilers,wastewatertreatmentareas,etc.Eachareahasitsownrisksastheexposure

tospeci�ichazardscouldcauseseriousinjuries,ordiseases.Safetymanagersorsafetyspecialistsare

responsibleforensuringsafetyperformanceintheplant.Therefore,theenergyauditorneedstodiscuss

withthesestaffstode�inetheappropriatesafeworkpractices.Moreover,energyauditorsshouldbeaware

ofthebelowsafetyconcerns.

4.1. Electricalsafety

Electricityplaysanimportantroleinindustrialandresidentialenvironments,butitalsohashazardous

potentials.Electricitycancausemanyseriousaccidentsifitssafetystandardsarenotcomplied.Whenthe

electricpassesthroughbody,itcancausebraindamage,burns,pleurisyandorgansdamage.Themajor

task of energy auditor is to evaluate the ef�iciency of a lot of electrical equipment such asmotors,

transformers,andelectricitydistributionsystem.Therefore,theauditorhastobeawareoftheelectrical

safety.

Electricalaccidentscanoccurduetoelectricshocksorarc�lashes.Topreventelectricalaccidents,the

auditorshouldunderstandtheelectricalsystemdiagramsandde�inethehighvoltageareas.Then,the

auditor should discuss with managers to de�ine the appropriate safe work practices. The personal

protective equipment (PPE) should complywith the Vietnamese standards (TCVN) or international

standards.

Somepersonalprotectiveequipmentforworksrelatedtoelectricityarelistedasfollows:

146

Figure95.GHSPictograms

· Clothing shall be made of arc-rated �lame-resistant materials, have electrically non-conductive

properties,andhavelongsleevesandlongpants

· Hard hat has to comply with the International Safety Equipment Association Z89.1 Class E or

equivalentstandards

· Safetyglasseswithnon-conductivesideshields

· Safetyglovesorboots

· Sinceelectricalaccidentscanresultinhazardousnoiselevels,thehearingprotectionisrequired.

Somelegaldocumentsrelatedtoelectricitysafety:

· Degree 14/2014/NĐ-CP - Stipulating in detail the implementation of electricity law regarding

electricitysafety

· Circular31/2014/TT-BCT-Stipulatingcertaindetailsofelectricalsafety.

· Circular 39/2013 / TT-BLDTBXH promulgates national technical regulations on labor safety for

insulationshoeorboot.

4.2. Chemicalsafety

Theenergyauditorisnotrequiredtousechemicals,buttheymayenterareaswheretherearedangerous

chemicalsarehandled. Identi�icationofdangerouschemicalsby theirnamesandstructuresrequires

advancedknowledgeofchemicalsandlong-termtraining.However,theauditorscanrecognizethedanger

ofchemicalsfromitslabelinordertochooseanappropriatePPEwhenenteringhazardousareas.

Dependingupontheactualconditionsinafactory,thenecessaryPPEforchemicalsafetyareshownas

follows:

147

Imperviousgloves

Safetymasks

Safetyshoes

Figure96.Exampleofpressureequipment(boiler)

The common cause of exploded pressure equipment accident is operation under the overpressure

condition.Energysavingmeasuresshouldconsidernotonlytheef�iciencyofequipmentbutalsosafety

conditions. In order to satisfy both requirements, energy auditor needs to evaluate the drawing,

speci�icationsheet,inspectionsheet,andoperatingprocedurerelatedtoprocessequipment.Collecting

thedatafromthosedocumentsandcomparingdatawiththerequirementsoflocalregulations(TCVN,

QCVN…)or international standards (ISO,ASME…)will helpenergyauditor tode�ine theappropriate

operatingconditions.Moreover,theauditorcouldconsultatechnicalspecialistorequipmentsupplierfor

moreinformation.

Somelegaldocumentsrelatedtopressureequipmentsafety:

·� � �TCVN8366:2010-NationalTechnicalRegulationof pressure vessels-Requirementof design and

manufacture

PPE Purpose

Safetyglasseswithsideshields

Protecteyesfromsplashingchemicalssuchassolvents,toxicgases,etc.

Source:GlobalHarmonizedSystem

Somelegaldocumentsrelatedtoelectricitysafety:

· Circular04/2012/TT-BCT-Regulationsontheclassi�icationandlabellingofchemicals

· Circular20/2013/TT-BCT–Stipulatingtheplanandmeasuresforpreventionandresponseagainst

chemicalincidentsinindustry.

4.3. Pressureequipmentsafety

Pressureequipmentisusedtoconducthydraulicprocesses,thermalprocesses,chemicalprocesses,orto

storematerialsatthepressuregreaterthanatmosphericpressure.Accordingtothelocalregulations,the

equipmentwiththedesignpressureof0.7barisconsideredaspressureequipment.Forexample,boiler,

chillersystem,andcompressorsarethecommonpressureequipment.Energyauditorshouldpropose

theenergysavingmeasuressuchaschangingtheoperatingconditionsaswellasprocedures.Therefore,

understandingthesafetyparametersofpressureequipmentwillbene�itenergyauditorstoproposethe

appropriateenergysavingmeasures.

Protectagainstskinexposuretochemicalshazardwhenhandscontacttochemicalequipment

Protectagainstexposuretoair-bonedustorchemicalparticlesandprotectagainstnuisanceodorsfromsolventvapors

Protectagainstskinexposureinworklocationswhereliquidcontactwiththefeetislikely.

148

Figure98.Workingatheight

· QCVN01:2008/BLĐTBXH-NationalTechnicalregulationonsafeworkofsteamboilerandpressure

· 50/2015/TT-BLĐTBXH–Nationaltechnicalregulationonsafeworkofrefrigeratingsystem.

4.4. SafetyforworkingatHeights

Theenergyauditorsometimeshastoclimbuptheroofofbuildingorgouptothehighelevationtocollect

equipmentdata.Thereby,afallhazardexistsduetoanunintendedlossofbodybalancewhileworkingin

heights.ThereSomesafetymeasurescanreducethefallhazard:

· The�irstapproachshouldbetoreviewactivitiesrequireworkingatheightandtolookfortheother

alternativestocarryouttheworksuchasundertakingtheworkatgroundlevel

· Iffallhazardscan'tbecompletelyeliminated,installationofstairs,guardrails,barriers,andtravel

restrictionsystemscanleadtofallpreventionworkenvironment

·����Asalastlineofprotectionagainstfallfromheight,itisessentialtousefall-arrestingequipmentsuchas

harness,lanyards,shockabsorbers,lifelines,anchoragesetc.

Somelegaldocumentsrelatedtoworkingatheights:

· QCVN23:2014/BLDTBXH:Nationaltechnicalregulationofpersonalfall-arrestsystems

· TCVN7802:2007:Personalfallarrestsystems

· TCVN8207:2009:Personalequipmentforprotectionagainstfalls.

Inthesedocuments,somecommonissuesrelatedtosafetyforenergyauditarementioned.Toevaluate

exactlythesafetyforeachauditor, thefactoryhastoprovideanddiscussequipmentandproduction

processwiththeauditor.Thesafetymanagerorsafetyspecialistofafactoryneedstoprovideequipment

informationandinformaboutthehazardssothattheenergyauditorgets theappropriatesafework

practices.Moreover, it isnecessary toregularlyprovide trainingcoursesonOccupationalSafetyand

Health(OSH)forauditorsattrainingcentreswhichhavethepermitoftheMinistryofLabour-Invalids

andSocialAffairs.

149

APPENDIXES

Table70.Spreadsheetforenergysavingcalculation

Energysavingspreadsheetsaredividedintomanysheets,eachofwhich introduceaspeci�ictopicrelatedtoenergyef�iciency,including:

1. Electricitybill:foranalysis&calculationofelectricityconsumption,cost,powerfactor,...

2. Hourlyloadgraphs:todrawloadgraphsbasedonthepowerconsumptionrecordsperhour

3. Hourlyloadgraphs:todrawloadgraphsbasedonthepowerconsumptionrecordsperminute

4. Reactivepowercompensation:Supportsthecalculationofpowerfactor,compensationfactor,andreactivepowercapacitytobeused

5. Loadconversion:Supportsloadconversioncalculationssimply

6. Incandescentandcompactlamps:Supportscomputationalcomparisonsbetweenthesetwolamps

7. Ferromagnetic ballast & electronic ballast: supports the computational comparisonbetweentheuseof�luorescentlampswithdifferenttypesofballasts

8. Motorselection:supportstheevaluationofmotoref�iciencyperformance

9. HighEf�iciencyMotors:Comparetheef�iciencyofhighef�iciencymotors

10. VS-VSDmotor: Evaluate the result of the conversion fromVSmotors to themotorswithVSD

11. Pump-inverter:evaluatetheef�iciencyofthepumpsystemusinginverter

12. PumpEf�iciency:toassessandcalculatepumpef�iciency

13. BoilerEf�iciency–Directmethod:supportsthecalculationofboileref�iciencybydirectmethod

14. Boiler Ef�iciency – Indirect method: supports the calculation of boiler ef�iciency byindirectmethod

15. Insulation:Supportscalculationofpipeheatlossesandinsulationthickness

16. SteamLeaks:SupportssteamLeakageassessment

17. Chilleref�iciency

18. Coolingtower:Ef�iciencyofcoolingtower

19. OtherAppendix

150

Table71.T

heelectricitypricesforen

terprisesinrecentyears

Item

s01/0

1/2

007

01/0

3/2

009

01/0

3/2

010

01/0

3/2

011

20/1

2/2

011

01/0

7/2

012

22/1

2/2

012

01/0

8/2

013

01/0

6/2

014

Electricprice

forpro

duction

Above110kV.

a)Norm

alhour

785

898

1043

646

1862

1102

683

1970

1158

718

2074

1217

754

2177

1277

792

2284

b)Off-peakhour

425

496

c)Peakhour

1590

1758

From2

2k

Vto110

kV

a)Norm

alhour

815

445

1645

870

475

1755

920

510

1830

955

540

1900

935

518

1825

986

556

1885

1023

589

1938

1068

1128

710

2049

1164

727

2119

1216

767

2185

1184

746

2156

1225

773

2224

1278

814

2306

1243

783

2263

1286

812

2335

1339

854

2421

1305

822

2376

1350

852

2449

1406

897

2542

b)Off-peakhour

670

c)Peakhour

1937

From6kVto22kV

a)Norm

alhour

860

1093

b)Off-peakhour

480

683

c)Peakhour

1715

1999

Below6kV

a)Norm

alhour

895

1139

b)Off-peakhour

505

708

c)Peakhour

1775

2061

835

455

1690

1267

785

2263

16/0

3/2

015

1

1.1

1388

869

2459

1.2

1405

902

2556

1453

934

2637

1518

983

2735

1.3

1.4

1283

815

2354

1328

845

2429

1388

890

2520

151

2Electricityprice

forbusinessandservice

2.1

Above110kV.

a)Norm

alhour

1410

1540

1648

1713

1808

1909

2004

2104

2007

2125

1185

3699

b)Off-peakhour

770

835

902

968

1022

1088

1142

1199

1132

c)Peakhour

2615

2830

2943

2955

3117

3279

3442

3607

3470

2.2

From2

2k

Vto110

kV

a)Norm

alhour

1510

885

2715

1580

915

2855

1650

960

2940

1727

995

3100

1766

1037

3028

1846

1065

3193

1838

1939

2046

2148

2255

2158

2287

b)Off-peakhour

1093

1153

1225

1286

1350

1283

1347

c)Peakhour

3067

3226

3388

3557

3731

3591

3829

2.3

From6kVto22kV

a)Norm

alhour

1863

1965

2074

2177

2285

2188

2320

b)Off-peakhour

1142

1205

1279

1343

1410

1343

1412

c)Peakhour

3193

3369

3539

3715

3900

3742

3991

Note: -

Norm

alhour:from4h00–9h30;11h30–17h00;20h00–22h00fromMondaytoSaturdayandfrom4h00–22h00inSunday.

- Peakhour:from9h30–11h30andfrom17h00–20h00fromMondaytoSaturday.

- Off-peakhour:from22h00–4h00allofdayinaweek.

Electricitypricesforotherbusiness,organizations,pleasevisitEVNwebsite(

)toknow

moreinform

ation.

http

://w

ww

.evn

.com

.vn/

152

Table72.TheconversionintoTOE,MJandemissionfactorsofsomeenergytypes

Energytypes Units Energyconsumption(**)

(MJ/Unit)

TOEequivalent(*)

Emissionfactors(tonsCO2/unit)

Electricity

Cokecoal

Anthracitecoal1,2

Anthracitecoal3,4

Anthracitecoal5,6

DOoil

kWh

Tons

Tons

Tons

3.6

31,402.5

29,309.0

25,122.0

20,935.0

0.0001543

0.70-0.75

0.70

0.60

0.50

1.02

0.88

0.99

0.94

1.09

0.9

1.05

0.83

1.05

0.0006612

3.36

2.88

2.47

2.06

3.16

2.73

3.21

3.05

2.88

2.11

3.05

2.41

3.08

Tons

Tons 42,707.4

1.000litre 36,845.6

FOoil tons 41,451.3

1.000litre 39,357.8

LPG tons 45,638.3

Naturalgas(NG) 1000m3 37,683.0

Gasoline tons 43,963.5

1.000litre 34,752.1

JetFuel tons 43,963.5

Note:

(*)TOEcoef�icientsprescribedinOf�icialdispatchNo.3505/BCT-MOST,April19,2011

(**)Energy conversion coef�icient is calculated based on 1 TOE = 41,870 MJ by IPCC

((http://www.ipcc.ch/ipccreports/sres/emission/index.php?idp=167).Thisvalueisforreferenceonly,

recommendsusingresultsofcalori�icvalueistheactualfuel

153

Table73.Theemissionfactorofsomecommonenergytypes

Energytypes

(*)Electricitygrid

Cokecoal

Anthracitecoal

Value

0.6612

0.1070

0.0983

0.0741

0.0774

0.0631

0.0561

0.0693

0.070

0.112

0.100

Units

kgCO /kWh2

kgCO /MJ2

kgCO2/MJ

DO oil kgCO2/MJ

FOoil kgCO2/MJ

LPG kgCO2/MJ

NG kgCO2/MJ

Gasoline kgCO2/MJ

JetFuel kgCO2/MJ

Woodandwoodwaste kgCO2/MJ

Othersbiomass kgCO2/MJ

Source:IPCCguidelinesforNationalGreenhouseGasInventories”issuedin2006

Note:

(*)EmissionfactorofVNelectricitygridisissuedannuallybytheBureauofMeteorology,Hydrologyand

ClimateChange,MinistryofNaturalResourcesandEnvironment.

( )http://www.noccop.org.vn/modules.php?name=Airvariable_ldoc&menuid=33

WithCO emissionfactorforotherenergytypes,knowmoreatIPCCwebsite.2

( ).https://www.ipcc.ch/meetings/session25/doc4a4b/vol2.pdf

From the information on energy consumption and CO emission factor corresponding energy/ fuel2

consumptioncanbeconvertedCO emissionfactorofenergyconsumption(seeconversiontoolinexcel2

�ile).

154

- x - -

x x x x

x x x x

x x x x

x x x x

x x x x

- x x x

- x x x

- x x x

- x x -

x x x

- x x x

- x x x

- x x x

- x x x

- x x x

x x x x

x x x x

- x x x

Table74.Metrologicalcontrolmeasuresandinstrumentinspectionintervals

No. Measuringinstrument Metrologicalcontrolmeasures Inspectioninterval

Type

approval

Inspection

Once Periodi-cally

Afterrepair

(1) (2) (3) (4) (5) (6) (7)

Lengthmeasurements

1 Measuringtape

Volumeand�lowmeasurement

2 Mechanicalresidentialwatermeter 60months

3 Electronicresidentialwatermeter 36months

4 Oilandgasmeter 12months

5 LPGmeter x

6 Industrialair�lowmeter 12months

7 Commonvolumemeter 24months

Pressuremeasurement

8 Springmanometer 12months

9 Electronicmanometer 12months

Temperaturemeasurement

10 Macroscale electronic contact medicalthermometer

06months

11 In-earmedicalinfraredthermometer 12months

Physical-chemicalmeasurement

12 Seedmoisturemeter

Hydrometer

12months

13 24months

14 Vehicleexhaustgastester 12months

15 Equipment for measuring concentration ofSO2,CO2,CO,NOx inair

12months

16 Equipment for measuring pH, dissolvedoxygen, electrical conductance, wateropacity,totaldissolvedsolidsinwater

12months

Electricity&EMFmeasurement

17 1-phaseACelectricitymeter 60months

18 3-phaseACelectricitymeter 24months

Opticalmeasurement

19 Illuminancemeter 12months

Source:CircularNo.23/2013/TT-BKHCNdatedSeptember26,2013

Where:-“x”indicatesmandatorytasks;

-“-”indicatesoptionaltasks.

155

REFERENCE Date Content

LawNo.50/2010/QH12

17/6/2010 ECONOMICALANDEFFICIENTUSEOFENERGY

DecreeNo.21/2011/NĐ-CP

29/3/2011 DETAILING THE LAW ON ECONOMICAL AND EFFICIENTUSE OF ENERGY AND MEASURES FOR ITSIMPLEMENTATION

CircularNo.09/2012/TT-BCT

20/4/2012 PROVIDING FOR ELABORATION OF PLANS, REPORT ONIMPLEMENTATION OF PLANS ON ECONOMICAL ANDEFFICIENT ENERGY USE; IMPLEMENTATION OF ENERGYAUDIT

CircularNo.23/2013/TT-BKHCN

26/9/2013 GROUP2MEASURINGINSTRUMENTS

CircularNo.02/2014/TT-BCT

16/1/2014 Prescribedenergyconsumptionrateinchemistryindustry

CircularNo.19/2016/TT-BCT

14/9/2016 Prescribedenergyconsumptionrateinbeerandbeverageindustry

CircularNo.20/2016/TT-BCT

20/9/2016 PrescribedenergyconsumptionrateinSteelindustry

MoIT/GIZ Energy Support Progamme

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Unit042A,4thFloor,CocoBuilding, T+84(0)2439412605 Eof�ice.energy@giz.de

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