of technical, environmental and of tri generation …693637/fulltext01.pdfevaluation of technical,...

M.Sc. Thesis

EvaluationofTechnical,EnvironmentalandFinancialViabilityofTri–GenerationinApparel

SectorofSriLanka

By

WasanaChinthakaJagodaarachchi(830926–P132)AnuruddhaEkanayake(850801–P817)

MasterofScienceThesisKTHSchoolofIndustrialEngineeringandManagement

EnergyTechnologyEGI‐2013SE‐10044STOCKHOLM

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BachelorofScienceThesisEGI‐2013

Evaluation of Technical, EnvironmentalandFinancialViabilityofTri–GenerationinApparelSectorofSriLanka

WasanaChinthakaJagodaarachchi(830926–P132)AnuruddhaEkanayake(850801–P817)

Approved

Examiner

Prof.BjörnPalm

Supervisor

Dr.SadJarall

Commissioner

Contactperson

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ABSTRACTApparelindustryisthemainsourceofforeigncurrencyforSriLankaandistheonethatprovides most number of local employments. It has been severely affected by thecontinuousriseoffossilfuelprices.Industryisalsounderpressurebythegovernmentsandbuyers(majorretailchainsandglobalapparelbrandswhohastheirsupplychainemission reduction goals) tominimize the emissions aswell as to reduce the energyconsumption.Inviewofthat,thisstudywasfocusedontheviabilityofusingcombinedheating,coolingandpowergenerationortheTri‐Generation(TG)atfactorylevelwhichhasneverbeentriedintheapparelindustryinSriLanka.After the literature survey, local apparel sector was analyzed and then the factorieswere categorized in to fivemain groups out ofwhich themost affected groupby theenergycost,thefabricmanufacturing,wasselectedasthefocusgroup.Onefactoryfromthefocusgroup,TexturesJersey(TJ)wasselectedfortheinitialcasestudy.Afteradetailenergy audit at TJ, results were used to evaluate the environmental and economicalviability of two selected TG combinations. One with most favorable results wasoptimized and then studied in detail to see if it is environmentally, economically andtechnicallyviabletoTJ.ResultofthedetailanalysisoftheoptimalTGcombinationwasusedtocomeupwithgeneralguidelinestoimplementviableTGplantsforlocalapparelindustry.As per the results TJ can enjoy substantial benefits (15‐35% energy cost saving) byopting touseaTG, firedbyeithercoalorbiomass (sawdustbriquettesor firewood).Biomassispreferredovercoalduetolowpricesandreducedemissions.NotneedingofacomplicatedfuelpreparationandfeedingsystemasinacoalfiredTGsystemisalsoanadvantage of Bio‐mass. However biomass has relatively more supply chain issuescomparedtocoal.Auniversalsolutionthatcanbeusedbyanyapparelfactorycannotbearrived at, as economics of the TG is highly depended on local parameters. Howeverselecting the capacity of a TG based on the process heating demand of a factory isbeneficialifithasa24houroperation.IntermittentoperationofTGisnoteconomicalasfrequentstart‐upandshut‐downofaTGisnotpractical.Further,increasingelectricitygenerationinTGisnotveryattractiveowingtosubsidizedtariffs.

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ACKNOWLEDGMENTS

Firstofall,wearegratefultoourSupervisorsDr.MahinsasaNarayanaandDr.SadJarallfortheirguidanceandsupporttosuccessfullycompletethethesis.Wewouldalsoliketothank lecturers and staff of International College of Business & Technology, OpenuniversityofSriLankaandRoyalInstituteoftechnology,Swedenforthesupporttheyextendedbyfacilitatingandcoordinatingourthesisrelatedactivities.

Wetakethisopportunitytoacknowledgewithmuchappreciationthecrucialsupportbythemanagementand thestaffof theTextures Jersey forgivingpermission toconductthe energy audit and providing access to technical data and financial data for theanalysis. A special thank goes to tri generation plant equipment suppliers andcontractors for providing technical information and other literature relevant for thethesiswork.

Furthermorewewouldalso likeexpressthegratitudetoallwhodirectlyor indirectlyhavelenttheirhelpinghandforthesuccessoftheresearch.

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CONTENTABSTRACT ................................................................................................................................................. i

ACKNOWLEDGMENTS ............................................................................................................................. ii

NOMENCLATURE ..................................................................................................................................... 1

1 INTRODUCTION ............................................................................................................................. 2

1.1 Problem Statement and Methodology ......................................................................................... 2

1.2 Objectives of the Study ................................................................................................................. 4

2 Literature Survey .......................................................................................................................... 5

2.1 Theory and Technology ................................................................................................................ 5

3 Results of Energy Audit Conducted in Selected Factory ............................................................... 8

3.1 Factors Considered in Selecting the Facility ................................................................................. 9

3.2 Overview of the Selected Facility ............................................................................................... 10

3.2.1 General Overview ....................................................................................................................... 10

3.2.2 Energy Sources & Consumptions ................................................................................................ 11

3.3 Impact of Energy consumption ................................................................................................... 13

3.3.1 Economical Impact ..................................................................................................................... 13

3.3.2 Environmental Impact ................................................................................................................ 14

3.4 Energy System of the Factory ..................................................................................................... 15

3.4.1 Electrical System ......................................................................................................................... 16

3.4.2 Air Conditioning System ............................................................................................................. 17

3.4.3 Boiler and Steam System ............................................................................................................ 18

4 Possible Combinations for Tri‐Generation Plant ........................................................................ 20

4.1 Baseline Options for Plant Architecture ..................................................................................... 22

4.2 Capacity Estimation for Proposed Plant Architectures .............................................................. 24

4.2.1 Results of the Calculation done Based on Process Heating Demand ......................................... 25

5 Plant Optimization ...................................................................................................................... 33

5.1 Important Findings Plant Performance Simulations ................................................................... 33

5.2 Optimum Options ....................................................................................................................... 34

5.3 Technical Feasibility and Other Issues ........................................................................................ 35

5.3.1 Issues Related to Fuel Supply Chain ........................................................................................... 35

5.3.2 Issues Related to Fuel Storage .................................................................................................... 36

5.3.3 Issues Related to Fuel Preparation ............................................................................................. 37

5.3.4 Coal and biomass combustion technologies .............................................................................. 37

5.4 Detailed Schematic of Final Plant Architecture .......................................................................... 40

5.5 Detailed Economical and Environmental Analysis...................................................................... 41

5.5.1 Generator Capacity Estimation ................................................................................................... 41

5.5.2 Electricity Generation and Fuel Consumption by the Proposed Tri‐gen .................................... 42

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5.5.3 Net Present Value, IRR and Simple Payback ............................................................................... 45

5.5.4 Environmental Issues to be Tackled by Textures Jersey with Tri‐Gen ........................................ 51

5.6 General Guideline – What Local Apparel Sector can learn from this case ................................. 53

6 Conclusion .................................................................................................................................. 56

References ............................................................................................................................................ 59

Appendix A: Electricity Demand Variation with the Time of the Day .................................................. 60

Appendix B:EES Calculation Programs (Section 3.2.1 & 3.2.2) ............................................................. 63

Appendix C :NPV, IRR and Payback Calculation for Coal at 28bar and 350oC ...................................... 67

Appendix D :NPV, IRR and Payback Calculation for Saw Dust Briquettes at 28bar and 350oC ............. 69

Appendix E:NPV, IRR and Payback Calculation for Firewood at 28bar and 350oC ............................... 71

Appendix F : Calorific Value Test for Saw Dust Briquette ..................................................................... 73

ListofTablesTable 3.1: Comparison of Identified Factories of Different Categories .................................................. 8

Table 3.2 : Energy Sources and End‐Uses of Textured Jersey ............................................................... 11

Table 3.3 : Annual Consumption of Each Source of Energy in Textured Jersey .................................... 11

Table 3.4 : Financial Statement for Year 2011/2012 of Textured Jersey .............................................. 11

Table 3.5 : Expected Cost Increase of Furnace Oil in Sri Lanka ............................................................. 13

Table 3.6 : Expected Financial Statement for Year 2012/2013 with the FO Price Hike in TJ ................ 14

Table 3.7 : Equivalent CO2 Emission by Each Source in Textured Jersey ............................................. 14

Table 3.8 : Annual Average Amount of Refrigerant Charge to Compensate Leakages in TJ ................ 15

Table 3.9: Electricity Consumption of Last 6 Months in Textured Jersey ............................................. 17

Table 3.10 : Summary of AC Equipment in Textured Jersey ................................................................. 18

Table 3.11 : Specifications of Steam Boilers in Textured Jersey ........................................................... 18

Table 3.12 : Specifications of Thermic Oil Heaters in Textured Jersey ................................................. 18

Table 3.13: Process Steam Demand in Textured Jersey ....................................................................... 19

Table 4.1: Option 01 – Process Heating Base Calculation for 20T per hour (TPH) Boiler (F&A100C) ... 26

Table 4.2: Option 01 ‐ Process Heating Base Calculation for 25 TPH Boiler (F&A100C) ....................... 26





Table 5.1: Theoretical Design Turbine Capacities Calculated for Section 4.4 Design ........................... 41

Table 5.2 :Practical Turbine Capacities Calculated for Section 4.4 Design ........................................... 41

Table 5.3:Electricity Generation by Practical Turbine Capacities Calculated for Section 4.4 Design ... 42

Table 5.4: Electricity Use by Plant Equipment for Coal TG Plant .......................................................... 43

Table 5.5: Electricity Use by Plant Equipment for Biomass TG ............................................................. 43

Table 5.6: Fuel Consumption for Coal & Biomass Fired Systems .......................................................... 45

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ListofFigures Figure 1: Main Steps of the Analysis ....................................................................................................... 4

Figure 2 ‐ Energy Flow within Textured Jersey ..................................................................................... 12

Figure 3 ‐ Contribution of Each Energy Source to the Total in Textured Jersey ................................... 12

Figure 4 ‐ Variation of Fuel Oil Cost at Textured Jersey ........................................................................ 13

Figure 5‐ GHG (CO2e) Emission by Source in Textured Jersey ............................................................. 15

Figure 6 ‐ Percentage Energy Consumption by End‐use in Textured Jersey ......................................... 15

Figure 7‐ Daily Electricity Demand Variation in Textured Jersey .......................................................... 16

Figure 8‐ Monthly Cost and Consumption of Electricity in Textured Jersey ......................................... 16

Figure 9‐ Furnace Oil Consumption and Cost Variation in Textured Jersey ......................................... 19

Figure 10 ‐ Possible Electricity Generation Options.............................................................................. 21

Figure 11 ‐ Possible Heating Options .................................................................................................... 21

Figure 12‐ Baseline Option 01 Schematic Diagram ............................................................................... 23

Figure 13‐ Baseline Option 02 Schematic Diagram ............................................................................... 23

Figure 14‐ Theoretical Calculation Process ........................................................................................... 25

Figure 16‐ Cost of Energy, Option 01 ‐ Process Heating Base Calculation ............................................ 27

Figure 15‐ Electricity Generation Capacity, Option 01 ‐ Process Heating Base Calculation ................. 27

Figure 17‐ CO2e Emission for Coal Boiler, Option 01 ‐ Process Heating Base Calculation ................... 28

Figure 18 ‐ Electricity Generation Capacity, Option 02 – Process Heating Base Calculation................ 30

Figure 19‐ Cost of Energy, Option 02 ‐ Process Heating Base Calculation ............................................ 31

Figure 20‐ CO2e Emission for Coal Boiler, Option 02 ‐ Process Heating Base Calculation ................... 32

Figure 21 ‐ Moving Grate Combustor (Courtesy –Thermax, India ) ...................................................... 38

Figure 22 ‐ An Electrostatic Precipitator (Courtesy: Thermax) ............................................................. 39

Figure 23 ‐ Detailed Schematic of Coal Fired Tri‐Generation (Final) .................................................... 40

Figure 24‐ Investment and NPV of the Coal Fired Plant ....................................................................... 46

Figure 25‐ Internal Rate of Return of the Investment for Coal Fired Plant .......................................... 46

Figure 26‐Simple Payback Time of the Investment for Coal Fired Plant .............................................. 47

Figure 27‐ Investment and NPV of the Briquettes Fired Plant ............................................................. 49

Figure 28‐ Investment and NPV of the Firewood Fired Plant ............................................................... 49

Figure 29‐ Internal Rate of Return of the Investment for the Two types of Biomass .......................... 50

Figure 30‐Simple Payback Time of the Investment for the Types of Biomass ...................................... 50

Figure 31‐CO2 Emission by Three Options ........................................................................................... 53

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NOMENCLATURE

ListofAbbreviationsAFBC ‐AtmosphericFluidizedBedCombustionAPH ‐AirPreHeaterBFP ‐BoilerFeedWaterPumpBOI ‐BoardofInvestment,SriLankaCCHP ‐CombinedCoolingHeating&PowerCT ‐CoolingTowerCWP ‐CondenserWaterPumpDMWP ‐De‐mineralizedWaterPumpEES ‐EngineeringEquationSolverEfP ‐EffluentPumpESP ‐ElectroStaticPrecipitatorF&A ‐FromandAtFBC ‐FluidizedBedCombustorFD ‐ForcedDraftGHG ‐GreenhouseGasHFO ‐HeavyFuelOilHHV ‐HigherHeatValueID ‐InducedDraftIRR ‐InternalRateofReturnKTH ‐RoyalInstituteofTechnologyLHV ‐LowerHeatValueMSB ‐MainSwitchBoardNPV ‐NetPresentValuePA ‐PrimaryAirPPM ‐PartsperMillionPRV ‐PressureRegulatingValvePM ‐ParticulateMatterP&T ‐PressureandTemperatureRWP ‐RawWaterPumpSPB ‐SimplePaybackPeriodTG ‐Tri‐GenerationTPH ‐TonesperhoursTJ ‐TexturedJerseyLankaPLCWTP ‐WaterTreatmentPlant

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1 INTRODUCTIONIncreasingdemandforfossilfuelandtheconflictsinthemajoroilproducingcountrieshas ledfossil fuelpriceto increaseuptoa levelwhich isalmostunbearabletotheSriLankan industry. Among all, apparel manufacturing is one of the severely affectedindustriesbythesuddenfuelpricehikes.Asaresultoftheglobaltrendofsustainabledevelopment, pressure tominimize theemissionsby reducing theuseof fossil fuel&electricityconsumption,isanothermajorchallengefacedbythelocalapparelindustry.

ApparelindustryhaslongbeenthemainsourceofforeigncurrencyforSriLankaandisthe industry thatprovidesmostnumberof localemployments.Despite thesignificantgrowth of 13.8% in apparel manufacturing industry during 2011, overall productioncosthasbeenaffectedbyincreaseof furnaceoilpriceby80%,electricitycostby15%andsalaries&wagesby20%during2012.Amongallabove,thehighestandunexpected80% increase of furnace oil price has severely affected mainly to the knitting andweavingindustrywherefurnaceoilboilersareheavilyusedforsteamproduction.

Furthermore, the lower production cost associated with the apparel manufacturingindustries inneighboringcountries likeBangladesh,VietnamandthecountrieswithamassiveindustrialsectorlikeChina,hasmadeitmoredifficulttoSriLankatosustainitsmarket share in the internationalmarket. Hence, local manufactures are desperatelyseeking methods to reduce manufacturing cost, to keep their business runningsuccessfully. Since the lack of controllability over the production related costs likematerialcost,machinerycost,costoflabourandetc,themostviableoptionistoreducecost of energy incurred inprovidingutilities, such as air conditioning, lighting, steamgenerationandcompressedairgeneration.

Implementation of various energy efficiency methods and use of energy efficientequipmenthavebeenthetoppriorityactivitiestoreducetheenergyconsumption.ThisstudyisfocusingontheviabilityofusingTri‐GenerationatfactorylevelwhichhasneverbeentriedinSriLankanapparelmanufacturingindustry.

1.1 ProblemStatementandMethodology

A typical Sri Lankan apparel manufacturing factory requires electricity to run itsmachineries,airconditioning&Ventilationsystem,lightingsandutilityequipmentlikecompressors and pumps. Fossil fuels like Diesel and furnace oil are used to fulfillthermal energy requirements and to operate boilers to generate required steam formanufacturingprocess.Mainobjectiveofthisstudyistoanalyzingtheviabilityofself‐generation of required electricity while fulfilling the steam and cooling demand byimplementingacombineheating,coolingandpower(CCHP)plantwhichiscommonly

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knownasTri‐Generationintheindustry.TheTri‐Generationarrangementthathasbeenanalyzed in below chapters includes a high pressure steamboiler, a steam turbine, awasteheatrecoverysystemandabsorptionchillers.

AlthoughfossilfuelsuchasDieselandFurnaceoilarenoteconomicallyviableoptioninSri Lanka due to high price, same are commonly used in the apparel sector as it isreadily available and easy to use. Coal and biomass are the two identified candidatefuelsandthechallenges(economical,technicalandenvironmental)ofusingthosefuelsfor thecombinedcooling,heatingandpowerplantneedtobeanalyzed.Basedon theresults,plantequipmenthastobeselectedeithertypeoffuels.

Next is to study the viable options to supply of low pressure steam for themanufacturing process while maintaining the high pressure steam to the turbine.Directly taping thehighpressure steamanduseofpressure reductionmethodologiescan be identified as one option whereas the tapping steam from various workingpressure from the turbine is another option. Above two options and possible othermethodsneedbestudied to identify technicalcomplexitiesandeconomical feasibility.Installation of water treatment plant to meet boiler feed water standards andappropriate emission reduction methodologies to meet with country and board ofinvestment (BOI) environmental regulations also has to be evaluated. Suitable fuelstoragecapacityandfuelfeedingmechanismhastobechosentoensureuninterruptedfuelsupplytoboiler.

Feasibilityofrunninganabsorptionrefrigerationcyclechillerwhichutilizesthewasteheat of steam turbine need be evaluated, against running of a vapor compressionrefrigeration cycle chiller fromelectricity. In a typical apparel factory air conditionedload accounts for about 40 to 50% of the total electricity consumption. Use of anabsorption refrigeration cycle chiller that runswithwaste heat substantially reducesthe above electricity demand and it downsizes the required steam turbine capacity.Smallerturbineresultsinalessamountofwasteheatthatwouldnotbesufficienttorunthe absorption refrigeration cycle chiller of the required capacity. Therefore it isrequiredtostudytheoptimumcapacitiesofallplantequipment.Beingonlyself‐sustainwiththeelectricityandfeedingthegridwiththeexcesselectricityarealsotwooptionsthatneedtobestudied.

Toanalyzetheabovesaidvariousoption,bothmanualandcomputerbasedcalculationmethodsareused.EngineeringEquationSolver(EES)andMicrosoftExcelspreadSheetsare the main software used for the evaluations. EES and MS Excel are manuallyprogrammedforthecalculations.Resultisthenusedtosimulatethebuildingoperationsand energy consumption patterns to calculate the optimal economical andenvironmentalbenefits.

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2 LiteratureSurvey

Therearemanyoperatingtri‐generationfacilitiesintheworldandalsolotofresearchhasbeencarriedoutbyvariouspartiesaboutthetechnology.Howeverashighlightedinthe previous sections, main issues to be addressed in this research is the lack ofknowhowinlocalindustry,meetingprocessrelatedrequirementsotherthantheenergyrequirementsandevaluationofsustainabilityoftri‐generationinthelocalcontext.

A literature survey was carried out in order to find out the current status of Tri‐generationplantsofthesimilarcapacityandapplication.Widerangeofkeywordsandvarioustoolswereusedtocarryoutthesurveytoensurethatthemostrelevantpapers,articles and case studies about this topic are referred. Two main component of theproject, namely the combined heat & power component and the cooling component(boththermallydrivenandelectricallydriven)ofsamecapacityrange,werefocusedinthesearch.Furtherliteraturereviewswerecarriedoutastheresearchprogresstoplantdesign stage, to find out the technical data of the various products required for thefunctioningoftheplant.

SummaryofrelevanttheoreticalanalysisofTri‐Generation,availabletechnologiesandthe developments and the results case studies of similar plants listed below in thereport.

2.1 TheoryandTechnology

Generation of electricity, useful heat and cooling using fuel combustion or by othermean of heat source is commonly known as combined heating, cooling and powergenerationorTri‐generation.InatypicalTri‐Generationplant,gasorsteamturbineisruntogeneratetheelectricityusing high temperature / high pressure source and this result in relatively lowtemperature waste heat. This waste heat is then used for heating and to generatecooling by an absorption chiller. Advantage of this kind of system is the ability ofattaininghigheroverallefficiencycompared toother typeof traditionalpowerplants.Efficiencyofatri‐generationplantiscalculatedasshownbelow.

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ManypapersthattalksabouttheeconomicsoftheTri‐generationwerestudiedduringthesurveyastheanalysisofeconomicviabilityofthesuggestedplantisamajorpartofthestudy.Followingisasummaryoffewrelevantpapersforthisstudy.

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“Tri‐generationinfoodretail:anenergetic,economicandenvironmentalevaluationforasupermarketapplication”bySugiarthaetal[5],discusses theresultsofanevaluationofeconomic and environmental performance of a Tri‐Generation plant for supermarketapplications. Analysis is based on factors such as fraction of the heat output used todrivetheabsorptionchillers,thechillerCOPandthedifferencebetweenelectricityandgas prices. As per this analysis of Sugiartha et al, three is obvious economical andenvironmental benefits compared to the conventional system. Further, both theeconomical and environmental benefits are optimized by operating the plant at fullelectricityoutputratherthanfollowingtheheat load.Economicsof theplant ishighlydependsoncostofelectricity,costofgasandtheCOPofthecoolingsystem.Main difference between this system and the proposed system to be studied is thenatural gas turbine. Proposed systemhas a steam turbine and theNatural gas is notconsideredasanoptionasitisnotavailable.Smallgenerationcapacity(80kW)andtheapplication (supermarket) are also differing much from an industrial application.HowevertheeconomicalmodelusedfortheanalysisprovidegoodbasicframeworktodevelopamodeltoTri‐GenerationinapparelindustryinSriLanka.

Andrea Costa et al[1], discusses about an industrial application in their paper“Economics of tri‐generation in a Kraft pulp mill for enhanced energy efficiency andreduced GHG emissions”. The most important thing in this paper is the similaritycomparedtothecaseofanapparelfactory. Thepulpmillthathasbeenstudiedhasarequirement for cooling and steam at different pressure levels. Cooling ismet by anabsorptionchiller.AndreaCostaetalpropose threeoptionand theyconclude thatallthree have economical benefits. However results show that system without powergeneration(withonly theabsorptionchiller)has thehighestsimplepaybackwhereastheoptionwithtri‐generationhashighnetpresentvalues.

Unlike the caseof anapparel factory, “Economicalanalysisoftri‐generationsystem”bySüleyman Hakan et al[8], present results of a research carried out on tri‐generationapplicationinauniversitycampuswhereheatingisutilizedforbuildingheating(notforprocess heating). However one important objective of this paper is to come upwithmodeltodetermineoptimumcapacityofatri‐generationsystem.Moreoverit isaboutthe economics of embedding a tri‐generation system to existing systemwhich is thecaseinsystembeingstudied.

Thoughhavingahighenoughcapacitytosupplyallenergydemandsofthebuildingisthe requirement of the Tri‐Generation, research result indicates that meeting totalenergydemand could increase the investment thereby resultinghigherpayback time.Main reason behind this scenario is the non existence of the peak demand for longperiods. However the situation could be different in industrial facility located in atropicalclimate.

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Lozan et al present in their paper, “ThermoeconomicAnalysisofSimpleTri‐generationSystems”, a much generalized economical analysis of a simple tri‐generation system.UnlikemanypapersonTri‐generation,thisstudyisnotlimitedtoaspecificapplication.Thesystemisconnectedwith themainelectricitysupplygridallowingsystemsupplyexcesselectricitytogridandtoreceivetheshortage. Paperismoreorientedtowardstheeconomicsratherthanthetechnicalaspects.Lozanetal[4]haveusedalinearprogrammingmodeltoobtainthemodewiththelowestvariable cost, out of series of options available to meet a given demand of a user.Analysisusesthreedifferentapproachestocalculatethecostoffinalproductandeachapproach results in different costs. Thismeans that a universal approach cannot beusedforeconomicalevaluationofTri‐generationandtheviabilityiswidelydependsonthespecificapplication.

Fromthedatacollectedduring literaturereview, it isevident that this technologyhasbeenusedinapplicationwherethereisasubstantialdemandinelectricity,coolingandheating (process or comfort heating). Further themost of the applications hasmuchhigherdemandforall threeformofenergythanatypicalapparel factory inSriLankaand the demand has more of distributed form (Similar to district systems, militarycampsandcampuses)thanamediumscalemanufacturingfacility(SimilartotypicalSriLankanapparelfactory).Itisclearthatthesetwofactors,thedistributeddemandandthe substantially higher demand are key factors that affect the economics and thesustainabilityofaTri‐generationfacility[6],whichisnotthecaseofanapparelfactory.

Howevertheavailable literatureandthecasestudiessuggestthatthis technologycanbe used in applicationswhich do not exhibit above characteristics, depending on thestatusoftheotherparameters.Followingcanbeidentifiedastheparametersthatwillaffect the economical viability and the overall sustainability of a tri‐generationapplicationinanapparelfactory.

a) Cost,qualityandtheaccesstoavailableenergyb) Scaleofthefacilityandtheoperationhoursc) Environmentalconstrainsandtargets

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3 ResultsofEnergyAuditConductedinSelectedFactoryFirststepofthisstudywastoidentifyanapparelfactorywhereallthreeformofenergyuses namely; electricity, process steam (Heating) and air conditioning are used andconductadetailedenergyaudittoidentifytheconsumptionpatternoftheeachform.

In identifyinga facility, themanufacturingprocessesofvariousapparel factorieswerestudied and it was noted that those can be categorized in to several different typesbased on theirmanufacturingprocesses. Following are themain categories identifiedduringthestudy.

1) FabricManufacturinga. Knittingb. Weaving

2) FabricPrinting3) Cutting&Sewing4) Finishing5) Other(manufacturingofZippers,Hangers,Buttonsect…)

Fivefacilitieswereselectedineachcategoryforcomparisontoanalyzethepotentialoftrigeneration.

1) FabricManufacturing TexturedJerseyLanka,Avissawella2) FabricPrinting QuenbyLankaPrints,Avissawella3) Cutting&Sewing BrandixCasualwear,Avissawella4) Finishing BrandixFinishing,Rathmalana5) Other T&SButtons,Biyagama

FacilityElectricity**

(Monthlyavg.kWh)Steam**

(Monthlyavg.kg)ACCapacity**

(TR)TexturedJersey 1,933,000 63,475,000 610QuenbyLanka 227,000 975,000 40BrandixCasualwear 172,000 220,000 250BrandixFinishing 287,000 133,000 150T&SButtons 65,300 66,000 24**Dataobtainedfrommaintenancedepartmentofeachfactory

Table 3.1: Comparison of Identified Factories of Different Categories

From above categories, a fabric manufacturing facility (Textured Jersey Lanka,Avissawella) was selected for initial energy audit after studying factors that arepotentiallybeneficialforTri‐generationplant.Table3.1indicatesasummaryofenergyconsumptionandcoolingrequirementsofeachoftheindentifiedfacilities.

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3.1 FactorsConsideredinSelectingtheFacilityFromtheinformationfoundduringtheliteraturereviewsandthebackgroundsearch,itwas learned that there are many factors that would affect the viability of a tri‐generation plant. Based on that knowledge, severalmain factorswere identified andconsideredinselectingtheabovefacilitytoconductanenergyaudit,resultofwhichwillsubsequentlybeusedtoevaluateviabilityofthetri‐generation.Factorsconsideredarelistedbelow,

ImpactbytheEnergyCostIf a cheap source of energy is available, none of the activities such as self‐generation, use of renewable energy sources and investing on energy savingmethodmaynot paid back inmonetary terms. Therefore itwas considered toselectafacilitywherethecostofenergyisveryhighcomparedtootherswhichwill induce a higher possibility of economical attractiveness for the Tri‐Generation.

ExtensiveSteamUsageAsexplainedabove,tri‐generationplantsproduceelectricity,coolingandheatingsimultaneously.Therefore,forsuchaplanttobeviableitisessentialtohaveenduse that require above three form of energy. The only usewhere heat can beutilizedistheprocessrelatedapplications,sinceSriLankaisatropicalcountrywherespaceheatingorservicehotwaterisnotarequirement.Fabricmanufacturing factories require thermal energy fordyingmachines andStentormachines,whereasmostoftheothertypesuseonlyforironingpurpose(Generally this is based on steam generation). Since a substantial amount ofsteamisgoingtobeavailableafterthepowergenerationinsteamturbineitwasdecidedtoselectafacilitywithsubstantialsteamconsumption.

EnvironmentalTargetsAnother importantchallenge facedbytheapparelmanufactures inSriLanka ismeeting the environmental targets such as reduction of carbon foot print,enforcedbytheirinternationalbuyersandvariousregulatorybodies.Therehadbeenmanyinstancesintheindustrywheremanagementinvestingonmeasureswhichareeconomicallynotviable,tomeettheenvironmentaltargets.Therefore,it was assumed that a facility with environmental targets such as emissionreductionshouldbeconsideredfortheenergyaudithopingthatcertainmeasureof Tri‐Generation will be environmentally viable even if those are noteconomicallyattractive.

SubstantialElectricalEnergyUsageThemostessentialcomponentofaTri‐generationplantisasteamturbinewhichgeneratestheelectricity.Smallertheturbinethelesserthewasteheatavailable

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for subsequentuses[2].Therefore itwasassumed thataplantwithcomparablyhighenergyconsumptionhastobeselectedforthestudy.

SubstantialAirConditioningLoadOneoutcomeofTri‐generationisthewasteheatthatcanbeusedtooperateairconditioning systems, which operate with the absorption cycle. If the airconditioningloadisverysmallsuchwasteheatwouldnotbeadequatelyutilized.

ResourceAvailabilityforCogenerationPlantTri‐generation isnot viable if other required resource suchas space, access towater,transportationandetcatsitearenotavailable,regardlessofthestatusofthefactorsmentionedpreviously.

3.2 OverviewoftheSelectedFacility

3.2.1 GeneralOverviewTexturedJerseyisoneofSriLanka'smostsophisticatedfacilities,manufacturingknittedfabricsfortheintimateapparel(lingerie)andsportswearindustries.Specializedinthemanufacturing of high quality weft‐knitted and dyed stretch fabrics, it is a majorsuppliertoapparelmanufacturersthroughoutAsiaandend‐chainretailers.Amongstitsbuyers,thelargestareMarks&SpencerandVictoria'sSecret.Textured JerseywasawardedtheprestigiousOeko‐TexStandard100Certification,aninternationally recognized test forharmful substancespresent in textilemanufacture,which is now the benchmark for quality and safety amongst the textile industry inEurope.

TexturedJerseysuppliesitsproductstothetwolargestGroupcompaniesproducingitscore products, specializing in stretch fabrics. Infrastructure at the facility enables acapacity to knit, dye and finish up to 2.5millionmeters of fabrics amonth.With thecontribution of the annual turnover, TJ can be called as a backbone of Sri Lanka’sapparel sector. Textured Jersey’s contribution to the total annual turnover in wholeapparelsectorwas2.6%inlastfinancialyear.

Manufacturing process of the facility is of three‐steps which take place across threemajorproductionunits:

TheKnittingprocess‐convertstheyarn(Cotton,Viscose,ModalandPolyester)intogreigefabric.

TheDyeingprocess‐coloursthegriegeintothespecifiedcolour. TheFinishing‐Finalprocessthatensuresthedyedfabricisfinishedtotheexact

standards.

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3.2.2 EnergySources&ConsumptionsTexturedJerseyobtainsitenergydemandfromthreemainenergysourcesasshowninTable3.2andthecostincurredinyear2011&2012toobtaineachofthesourcesaregiven in the table3.2.Financial statementofTextured Jersey for theyearending31stMarch2012isgiveninfollowingTable3.4.

EnergySource Equipment/Area

GridElectricity

AirconditioningProductionmachinesSteamboilersThermicoilheaters(notforHeating)OfficeequipmentLightingfixtures

FurnaceOilSteamboilers

BulkdyingmachinesSampledyingmachinesBabydyingmachinesYarndyingmachinesDyemixingmachinesDyeheatingmachinesDryingmachines(Finishing)Compactors(Finishing)

Thermicoilheaters Stenators(Finishing)Diesel StandbyGenerators

Table 3.2 : Energy Sources and End‐Uses of Textured Jersey

Electricity**(kWh) FurnaceOil**(Ltrs) Diesel**(Ltrs)Year2011 24,367,540 8,945,009 45,836EquivalentGJ 87,723 368,534 2,053

Year2012 23,196,865 7,836,504 49,379.00EquivalentGJ 83,509 322,864 2,212**DataobtainedfrommaintenancedepartmentofTexturedJersey

Table 3.3 : Annual Consumption of Each Source of Energy in Textured Jersey

Description SriLankaRupees000’s**Sales 12,236,724Costofsales (10,906,806)Grossprofit 1,329,918SellingandAdminexpenses (501,874)Operatingprofit 828,044NetFinancecost (166,973)ProfitbeforeTax 661,071Tax (33,042)NetProfit 628,029**DataobtainedfromAccountsandFinancedepartmentofTexturedJersey

Table 3.4 : Financial Statement for Year 2011/2012 of Textured Jersey

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FlowofenergytoendusegiveninTable3.2fromthreeenergysourceisshowninbelowFigure 2. Out of three sources furnance oil contribute to the highest amoutwhich isabout~80%of the total as shown in Figure 3. Electricty consumption contributes torestofthe20%.Dieselinonlyusedasstandbyenergysourcehencethecontributionbythesameismearly1%.

ConversionFactorsUsed(1kWh0.0036GJ),(1FOLiter0.0412GJ),(1DieselLiter0.0428GJ)

20%

79%

1%

2012

Eletricity FurnaceOil Diesel

19%

80%

1%

2011

Eletricity FurnaceOil Diesel

MainGrid FurnaceOilDiesel

ProductionMachineriesAirConditioning Lighting

SteamBoilers ThermicHeaters

OfficeEquipment

Electricity Steam HeatedThermalOil

Figure 2 ‐ Energy Flow within Textured Jersey

Figure 3 ‐ Contribution of Each Energy Source to the Total in Textured Jersey

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3.3 ImpactofEnergyconsumption

3.3.1 EconomicalImpactTherecentamendmentof furnaceoilprice shown inFigure4 (fromLKR50 toLKR90perliter)hasseverelyaffectedtheoperationalcostwithanincreaseof55%.Accordingto the global fuel market, more hikes are anticipated in the future, rather thanmomentaryreductions.Hence,maintainingtheproductioncost isbecomingmoreandmorechallenging.

Figure 4 ‐ Variation of Fuel Oil Cost at Textured Jersey

2011 2012(Expected)

AnnualFuelConsumption(Liters) 8,900,000 8,900,000AnnualFuelCost(USD) 3,700,000 6,675,000CostIncrease(USD) 2,975,000

Table 3.5 : Expected Cost Increase of Furnace Oil in Sri Lanka

Note: Years are financial years from April to March

As per the Table 3.5, increase of furnace oil price has resulted in extra cost of LKR386,750,000 annually. Table 3.6 is a comparison of the financial figures, if the sameamount of sales, same amount of fuel consumption and no change in other cost areassumedforyearstocome.

‐

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

Jan

Feb

Mar

Apr

May Jun

Jul

Aug

Sep

Oct

Nov

Dec Jan

Feb

Mar

Apr

May Jun

Jul

Aug

Sep

Oct

Nov

Dec

LKR

2011 2012

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Table 3.6 : Expected Financial Statement for Year 2012/2013 with the FO Price Hike in Textured Jersey

Accordingtoabovefiguresfurnaceoilpricehikealonewillcontributeto58%decreaseofnetprofit.Moreoverthe15%fueladjustmentchargeimposedonelectricitytariffwillincreaseannualoperationalcostbyanotherLKR33million.

3.3.2 EnvironmentalImpact

Manufacturingfacilitycanadversely impacttheenvironmentbyvariousmeans.GreenHouseGas(GHG)emissionduetoenergyconsumption,landfillduetowastegeneration,use/pollutionofwaterresourcesandheatislandeffectaresomeofthemostcommonscenarios that adversely affect the surrounding of any factory or a manufacturingfacility.Onlytheenvironmentalimpactduetoenergyconsumptionisstudiedunderthissince a setting‐up of tri‐generation facility will only contribute to change in GHGemissionrelatedtoenergyconsumption.

Currently ‘Textured Jersey’ is using three energy sources; namely electricity,combustion of Furnace Oil to run Boilers / Oil heaters and Diesel for stand bygenerators. Another indirect contributor (related to energy consumption) isrefrigerantsusedinairconditioningsystem.

As per the records kept by the maintenance department of the facility, annualconsumptionofeachsourceofenergyisgivenintheTable3.7.

Source AverageConsumption TotalEnergy(MJ) CO2e(Mt/yr)

Electricity 23,960,000kWh/Yr 86,256,000 22,546[10]

FurnaceOil‐Boiler 5,340,000ltr/Yr 220,000,000 16,432[11]

FurnaceOil‐Oilheaters 3,560,000ltr/Yr 146,672,000 10,955[11]

Diesel** 50,000ltr/Yr 2,140,000 148[11]

Table 3.7 : Equivalent CO2 Emission by Each Source in Textured Jersey

**Dieselconsumptionlargelyvariesaccordingtothepowerfailures.Consumptionfigureisbasedonannualaveragedata

Description SriLankaRupees000’sSales 12,236,724 12,236,724Costofsales (10,906,806) (11,293,556)Grossprofit 1,329,918 943,168SellingandAdminexpenses (501,874) (501,874)Operatingprofit 828,044 441,294NetFinancecost (166,973) (166,973)ProfitbeforeTax 661,071 274,321Tax (33,042) (13,711)NetProfit 628,029 260,610

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AirconditioningsystemofthefacilityisequippedwiththecoolingequipmentsshowninTable3.8andastheamountrefrigerantchargedtocompensatetheleakagesaregiveninthesame.Figure5depictscontributionofeachsourcetothetotalGHGemission.

Typeofunit Qty Refrigerant AmountLeaked (kg) CO2e(Mt/yr)AirCooledChillers180TR 2 R22 36.2 54.3[11]

WaterCooledChillers180TR 2 R134a 13.6 17.7[11]

SplitType 23 R22 18.0 27[11]

Table 3.8 : Annual Average Amount of Refrigerant Charge to Compensate Leakages in Textured Jersey

3.4 EnergySystemoftheFactoryBelowFigure6showthepercentageenergyprovidedbyvarioussourcestothevariousenergysystemsofthefacility.

19.0%

48.3%

32.2%

0.5%

Electricity Furnace Oil ‐Boiler Furnace Oil ‐ Oil Heater Diesel

Figure 6 ‐ Percentage Energy Consumption by End‐use in Textured Jersey

Figure 5‐ GHG (CO2e) Emission by Source in Textured Jersey

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3.4.1 ElectricalSystem

The facility comprises of 6000 kVA transformer capacity and average maximumdemand is around 3400 kVA. As per the logged data, the demand for electricitythroughout the day is not fluctuating significantly, except the small drop during thenighttime.Figure7indicatestheaveragedailyvariationoftheelectricaldemandofthefacility. Since there are no seasonal variations this can be assumed as the averagethroughouttheyear.

Figure 7‐ Daily Electricity Demand Variation in Textured Jersey

ThemonthlytotalkWhrconsumptionandtotalelectricitycostbasedonhistoricaldataisshowninbelowFigure8.

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

0

500

1000

1500

2000

2500

3000

3500

4000

Demand PowerFactor

Power Factor

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

30,000,000

35,000,000

40,000,000

‐

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,000

Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov

kWh

Total kWh Consumption Electricity Cost

2011 2012

Cost (LKR)

Figure 8‐Monthly Cost and Consumption of Electricity in Textured Jersey

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Electricityconsumptionsofpast6monthsaregivenbelowinTable3.9.

Month(2012)

TariffCategory

Day OffPeak DayMax.

DemandTotalkWh

July I2‐3Part 292,027 526,418 958,963 3,098 1,777,408August I2‐3Part 273,987 492,881 823,913 2,962 1,590,781September I2‐3Part 299,138 533,943 939,183 3,152 1,772,264October I2‐3Part 450,894 821,040 1,497,843 3,369 2,769,777November I2‐3Part 327,653 593,467 1,071,530 3,394 1,992,650December I2‐3Part 335,376 611,782 1,089,254 3,489 2,036,412

Table 3.9: Electricity Consumption of Last 6 Months in Textured Jersey

Accordingtotheabovefigures,

MonthlyAverageElectricityConsumption(kWhr) 1,995,905AverageMax.Demand(kVA) 3,264AverageActiveDemand(kW) 2,772

3.4.2 AirConditioningSystemTheairconditioningsystemismainlytomaintain the thermalcomfort inofficeareas.Sincethecurrentsystemistobereplacedwithheatdrivencoolingsystem,itisessentialstudytheenergyconsumptionpatternofthecoolingsystem.ThereforeconsumptionofthemajorcomponentoftheACwasloggedusingdataloggersandconsumptionoftherest of the equipment was calculated using spot readings. Component of the totalinstalledairconditioningunitsareasgiveninTable3.10.

TypeofAirConditioningsystem Chillers/Package/Splittype/windowtype

TotalCoolingLoad(kWorTR) 610TR

Electricalpowerconsumption(kW) 750

AirCooledChillerunits

Manufacturer YORK

Model YEAJ99MW9

Noofunits 2(oneisonstandby)

Coolingloadofeachunit 180TR


Operatinghours 7Daysperweek 24hrsperday

AirCooledChillerunits

Manufacturer YORK

Model YCWS0663SC

Noofunits 2

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Coolingloadeachunit(kW) 180TR


Operatinghours 7Daysperweek 24hrsperday

SplitAC/windowtypeAC

Noofunits 23

Totalcoolingload(kw) 70TR

TotalElectricalpowerconsumption(kW)

115

Operatinghours 7Daysperweek 12hrsperdayTable 3.10 : Summary of AC Equipment in Textured Jersey

3.4.3 BoilerandSteamSystemCurrently the facility operates three furnace oil boilers and three furnace oil firedthermic oil heaters. Specification of boilers and thermic oil heaters are as shown inTable3.11&Table3.12.

Boiler01 Boiler02 Boiler03

Design Actual Design Actual Design Actual

Yearofinstallation 2001 2001 1994Make/Supplier Cochran Cochran LoosFueltype(Design) FurnaceOil FurnaceOil FurnaceOilNoofoperatingdaysperyear 360 360 360Nooperatinghoursperday 24 24 24BoilerSteampressurekg/cm2(g) 17.2 14.5 17.2 14.5 17.2 14.5BoilerSteamtemperature0C 208 199 208 199 208 199Drynessfraction 0.95 0.93 0.95 0.93 0.95 0.93Steamflowrate(average)kg/hr 9,200‐ 10,000 9,200‐ 10,000 9,200‐10,000SteamtoFuelratiokg/kgfuel 13.887 13.887 13.887FuelUsed FurnaceOil1500 FurnaceOil1500 FurnaceOil1500BoilerfeedwaterTemperature0C 94 94 94

Table 3.11 : Specifications of Steam Boilers in Textured Jersey

Heater01 Heater02 Heater03Yearofinstallation 2001 2004 2007Make/Supplier Thermtechnik Thermtechnik ThermtechnikFueltype(Design) FurnaceOil FurnaceOil FurnaceOilNoofoperatingdaysperyear 360 360 360Nooperatinghoursperday 24 24 24FuelUsed FurnaceOil1500 FurnaceOil1500 FurnaceOil1500

Table 3.12 : Specifications of Thermic Oil Heaters in Textured Jersey

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Outoftotalfurnaceoilconsumption,60%isconsumedforsteamboilersand40%isforthermic oil heaters. No significant fluctuation of process heating demand has beendetectedthroughouttheday.Table3.13indicatesthedetailsofsteamrequirement.

SteamrequirementbyDyeingandFinishingprocessesat6barand9barisshownintable3.13.Processsteamdemand

Pressure(kg/cm2)

Flow(kg/hr)

Finishing 9.0 5,000

Dyeing 6.0 10,000

Operatinghoursperday 24hours

Daysofoperations(annual) 360daysTable 3.13: Process Steam Demand in Textured Jersey

TotalfurnaceoilconsumptionandcostisshowninbelowFigure9.

‐

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

‐

500

1,000

1,500

2,000

2,500

3,000

Jan

Feb

Mar

Apr

May Jun Jul

Aug Sep

Oct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug Sep

Oct

Nov Dec

FunaceOil(MIllionLitres)

FOConsumption FOCost

2012

Cost (LKR M

illion)

2011

Figure 9‐ Furnace Oil Consumption and Cost Variation in Textured Jersey

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4 PossibleCombinationsforTri‐GenerationPlantBased on the result of the energy audit and historical data analysis of the “TexturesJersey”, it isobviousthatmeetingtheprocessheatingdemandof theFacilitybymoreeconomical mean is the most important aspect to increase the profitability of thefactories. Since this study is investigating viability of the Tri‐Generation, all possiblecombinationsforasuchplantwasstudiedtoidentifytheprospectiveoptionsthatwillbebotheconomicalandenvironmentalfriendly.Followingflowcharts(figure–10andFigure11)listallpossibleoptionofTri‐GenerationsuitableforTexuresJersey.

Figure 10 shown below indicates posible combinations available for electricitygeneration.Thethreemainoptionsforelectricitygenerationaretogeneratepartoftheexisting electricity demand, generate electricity to satisfy existing demand, andgeneratingelectricityinexcessofexistingdemand.

Capacity requirementof the firstelectricitygenerationoption is arrivedby sizing theplant to meet the existing process heating demand of the facility. In this option, thesteam requirements and the qualities will be considered to back calculate the boilercapcacity and threby the turbine capcity. Another possible sub option to be studiedsubsequentlyunderthisistoseeifthereisacapacitylessthantheabovewhichcangivemoreoptimumresults.

Viabilityoftwodifferentelectricitygenerationcapacitiesneedstobestudiedunderthesecondoptions.Onecapacitywillbecalculatedassumingtheplanttobeaco‐generationfacilityratherthanTri‐generation.Underthis,itisassumedthattheproposedplantwillmeet the existing electricity demand (including energy requirement by vaporcompression chillers). Next option is to size the steam turbine to meet the existingelectricity demand excluding the energy requirement by vapor compression chillers.Important thing to study under this option is to see if heating requirement of theAbsorption cycle chillers can be met economically with the reduced capacity of thesteamturbine.

Third electricity generating option as per figure 10 is to generate excess energycompared to the existing electricity demand. Two possibilities identified under thiscategoryistogenerateenoughelectricitytofeedthegridortogeneratetheelectrictyrequiredforoilheatinginThermicoilheaters.

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ProcessHeatingEnergyRequirement

SteamGeneration

HighPressureSteam

LowPressureSteam

FromHighPressureBolier

ViaPRV

TaptheTurbineatinermidiatePressure

USesteamfromTurbine

Exit

ThermicHeaters

AbsorptionCycleChillers

FromHighPressureBolier

ViaPRV

TaptheTurbineatinermidiatePressure

UsesteamfromTurbineExit

DirectFire

Electricity

ElectricityGeneration

(SteamTurbine)

GeneratePartoftheDemand

calculatedBasedonProcessheating

GenerateCurrentDemand

WiththeVCChiller

WithoutVCChiller

GenerateExcessEnergy

PowerThermicHeaters

FeedtheGrid

Figure 11 ‐ Possible Heating Options

Figure 10 ‐ Possible Electricity Generation Options

EndUsesofHeatEnergy

M

ainEndUses

SubEndUses

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As shown in the figure 11 the process heating requirement of the facility is of threeforms; namely steam formanufacturing process, oil heating for Thermic heaters andheat for absorption cycle chillers, if installed. Steam for manufacturing process isrequiredintwosubformsnamely;lowpressuresteamat6barandhighpressuresteamat10bar.

Thereare twopossiblecommonmethodsbywhich thesteamcanbeobtained for themanufacturingfacility.Oneistoobtainedsteamdirectlyfromthehighpressuresteamboiler (a high pressure boiler anyway has to be operated for a TG) and uses it formanufacturing process by reducing the pressure to suitable levels using a pressurereducing valves. Second commonmethod is to tap the steam turbineat suitable leveland obtain steam for the processes. In addition to these two commonmethods, lowpressuresteamcanbeobtainedbyusingthesteamexitingtheturbine.

Obtainingsteamdirectlyfromthehighpressuresteamboiler,tappingofsteamflowofturbineatanintermediatelevelanduseofsteamexitingtheturbinearethreepossibleoptionsthatcanbeusedforbothThermicoilheatersandforabsorptioncyclechillers.Inadditiontothesethreecommonoptions,Thermicoilheatingcanbedonebydirectfiringasit iscurrentlydoneoritcanbedoneusingtheelectricitygeneratedfromthesteamturbineoftheplant.

4.1 BaselineOptionsforPlantArchitectureWhenfigure10andfigure11areconsidereditisobviousthattherearemanyoptionsforthearchitectureofTri‐generationplant.Sinceevaluationofalloptionsinfigure10and figure 11 is not practical (some options are not worth evaluation for obviousreasons)twobaselinesystemarchitectureswereidentifiedtowhichothercombinationwouldbecompared.

Since it is unknown as to which combination would have the best viability at initialstage,several factorswereconsideredinarrivingatbaselinesystemarchitecture.Oneofthemainfactorsconsideredistheeconomicsoftheplantsthathavebeenevaluatedbyvariousauthorsinpreviousstudies.Manyofthosepaperssuggeststohaveabestnetpresent value it is necessary to include cooling (absorption cycle) to the chiller andmaximize electricity generation while meeting the heating requirement withoutgenerating excess heat. Plant architectures give in related case studies; heatingrequirementsandthequalityof therequiredheataretheotherparametersthatwereconsideredindesigningthetwobaselinecases.

Asshowninfigure12andfigure13bothbaselinecasesincludehighpressureboilers,steamturbineandanabsorptioncyclechiller.Thosetwodifferfromeachotherbyonlyoneaspect; thepointatwhich thehighpressuresteam isobtained. Inoption01highpressure steam is obtained directly from the boiler whereas in option 02 same isobtainedbytappingthesteamturbineatasuitableintermediatepressure.

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E

Cooling tower

To Production

From Production

Make Up water

Absorption Chiller

High Pressure Steam

for production

1

2

3 4

Flu Gas

1

2

3 4

Cooling tower

Flu Gas

To Production

From Production

To Production

From Production

Make Up water

Absorption Chiller

E

High Pressure Steam

Figure 13‐ Baseline Option 02 Schematic Diagram

Figure 12‐ Baseline Option 01 Schematic Diagram

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When heating requirement and the required quality of the heat is considered, it isobviousthattheabsorptioncyclechillerrequiredthelowestqualityheat.Inviewthat,absorptionchillerswerearrangedinbothaboveoptiontoreceivethesteamexistingtheturbineassumingthatitwouldhavethehighestviabilityoutofmanyoptions.Similarlylowpressuresteam(6bar)hasassumedtobeobtainedfroma intermediatepressurelevel from thegas turbine inbothoptions. Thisarrangement for lowpressure steamwasselectedassumingthatitismoreviabletoallowsteamfromtheboilertoreduceitpressure through the turbine rather than drastically reduce pressure directly from apressurereducingvalve.

Following section includes the theoretical calculations that have been preformed toevaluateabovetwooptions,resultofwhichhasbeenusedtoevaluatetheaccuracyofassumptionsmadeand to identify furtheroptions, if any, tobestudied fromtheoneslistedinfigure10and11.

4.2 CapacityEstimationforProposedPlantArchitecturesAsnotedearlieratrigenerationplantcanbedesignedeithertomeetagivenamountofelectricitywhilemeetingpartorallheatingrequirement(electricitybaseddesign)oritcan be designed tomeet a given amount of heatwhilemeeting part or all electricityrequirement(heatingbaseddesign).Sincetheobjectiveofthisstudyistofindoutthemost economical mean, two basic calculation approaches that represent the twoextremeoperatingconditionsoftheabovetwodesignoptions(electricitybaseddesign/Heatingbaseddesign)wereidentifiedtocarryoutthetheoreticalcalculation.ThetwobaselineTGoptions represented in Figures 12&13were then evaluatedusing thesetwo calculation approaches. Graphical representation of the calculation process isshowninfigure14andthedetailsoftheseapproachesaregivenbelow.

Approach01:FirstapproachistoevaluatetheperformanceofaTGplantdesignedbasedonagivenelectricitydemand.As the theoretical extremecondition, itwasassumed thatplant issized to have an electricity generation capacity that will be sufficient to meet theexisting demand of entire facility (excluding vapor compression chillers). Under this,effects (on boiler capacity) of various inlet pressures and temperatures of the inletsteamofturbineareevaluated.Sincetheresultsofthisevaluationrepresentthestatusin an extreme design condition, same was used to identify whether electricitygenerationcapacityshouldbeincreasedordecreasedtoimprovetheplanteconomics.

Approach02:SecondapproachistoevaluatetheperformanceofaTGplantdesignedbasedonagivenheatingdemand.Asthetheoreticalextremecondition,itwasassumedthattheplantissized to have a heating energy generation capacity that is sufficient to meet the

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productionrelatedsteamdemandandtheheatdemandoftheabsorptioncyclechillers.Under this also, effects (on turbine capacity) of various inlet pressures andtemperatures of the inlet steam of turbine are evaluated. Since the results of thisevaluation represent the status in an extreme design condition, same was used toidentifywhetherheatingenergygenerationcapacityshouldbeincreasedordecreasedtoimprovetheplanteconomics.

Figure 14‐ Theoretical Calculation Process

4.2.1 ResultsoftheCalculationdoneBasedonProcessHeatingDemand

4.2.1.1 CalculationBasedonOption01(HPSteamDirectlyfromBoiler)AcomputerprogramwrittenusingEngineeringEquationSolver(EES)hasbeenusedtocalculate the possible electricity generation capability for various standard boilercapacities and boiler operating conditions (Pressure and Temperature) when highpressure steam is directly taken from the boiler and low pressure steam is taken bytapping the turbine. EES Program and the calculation procedure are given in theAppendixB.

AssumptionsMadeforCalculation:Assumptions were made for calculation based on industry accepted norms, currentoperating conditions, values published is various papers and data provided byequipmentmanufactures.Followingarethelistofassumptionsmade.

Pressuredropinthesteamlinesgoingtoproductionis1bar Boilerfeedwatertemperatureisat70oC

Make‐upwaterrequirementis15%ofthetotalfeedwaterflowrate Make‐upwatertemperatureis30oC

Pressuredropinsteamlinesbetweenboilerandtheturbineisnegligible Temperaturedropinsteamlinesbetweenboilerandtheturbineisnegligible Isentropicefficiencyoftheturbineis85% Mechanicalefficiencyoftheturbineis65% Electricalefficiencyofgenerator98%

Calculations

BaselineOption01forTG

Approach‐01Electricitybased

Approach‐02ProcessHeatingbased

BaselineOption02forTG

Approach‐01Electricitybased

Approach‐02ProcessHeatingbased

T&PVariationtoTurbineinlet

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ResultsoftheCalculations(Table4.1,4.2&4.3):WithaBoilerof20tonsperhour(Fromandat1000C)capacity,Case Boiler

OperatingPressure(bar)

BoilerOperatingTemperature(0C)

Boiler HeatOutput(MW)

GrossElecPowerOut(kW)

Heatavailableforchiller(kW)

LowPSteamTemperature(0C)

1 28 350 17.65 783.6 2083 199.72 35 380 17.99 903.9 2101 201.83 42 400 18.22 996.0 2106 199.54 45 420 18.45 1055 2132 207.95 54 450 18.79 1169 2153 212.36 62 480 19.14 1274 2183 220.67 68 490 19.26 1323 2183 218.58 72 500 19.38 1362 2190 219.99 78 520 19.62 1431 2210 226.110 84 540 19.86 1499 2231 232.8

Table 4.1: Option 01 – Process Heating Base Calculation for 20 Toned per hour (TPH) Boiler (F&A100C)

WithaBoilerof25tonsperhour(Fromandat1000C)capacity,Case Boiler







1 28 350 22.06 1260 5438 199.72 35 380 22.48 1425 5466 201.83 42 400 22.77 1550 5466 199.54 45 420 23.06 1632 5519 207.95 54 450 23.49 1790 5557 212.36 62 480 23.93 1934 5614 220.67 68 490 24.08 2001 5608 218.58 72 500 24.23 2054 5621 219.99 78 520 24.52 2150 5661 226.110 84 540 24.82 2245 5704 232.8 Table 4.2: Option 01 ‐ Process Heating Base Calculation for 25 TPH Boiler (F&A100C)








1 28 350 26.47 1737 8792 199.72 35 380 26.98 1946 8830 201.83 42 400 27.32 2104 8825 199.54 45 420 27.67 2210 8906 207.95 54 450 28.19 2410 8960 212.36 62 480 28.72 2595 9044 220.67 68 490 28.89 2678 9034 218.58 72 500 29.07 2746 9051 219.99 78 520 29.43 2869 9112 226.110 84 540 29.79 2991 9176 232.8

Table 4.3: Option 01 ‐ Process Heating Base Calculation for 30 TPH Boiler (F&A100C)

Figure& 4.3.outputFurtherforagiinthertheheasystemaddres

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Sc. Thesis

| P a g e

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Sc. Thesis

| P a g e

withtheheplantnerationtcostofputforaedforandinginncreasethecostcreasedase thepresentificantly

s,useofeabove2ethannerationusedaspossibletcanbe

0

M.Sc. Thesis

29 | P a g e

4.2.1.2 CalculationBasedonOption02(HPSteamTappedfromTurbine)

SimilartoprevioussectionEngineeringEquationsolverhasbeenusedtocalculatethepossible electricity generation capability for various standard boiler capacities andboiler operating conditions (Pressure and Temperature) when both high pressuresteamandlowpressuresteamaretakenbytappingtheturbine.EESProgramandthecalculationprocedurehavebeengivenintheAppendixB.

AssumptionsMadeforCalculation:Assumptions are same as section 3.2.1.1 except the location of extraction of the highpressuresteamusedformanufacturingprocess.

ResultsoftheCalculations(Table4.4,4.5&4.6):WithaBoilerof20tonsperhour(Fromandat1000C)capacity,Case Boiler





HighPSteamTemperature(0C)


1 28 350 1015 2134 198.6 234.12 35 380 1192 2153 200.4 2363 42 400 1328 2156 197.9 233.34 45 420 1411 2183 206.1 242.25 54 450 1579 2206 210.3 246.66 62 480 1729 2236 218.3 255.17 68 490 1802 2235 216.1 252.78 72 500 1859 2243 217.4 254.19 78 520 1958 2264 223.4 260.610 84 540 2057 2286 229.9 267.5







HighPSteamTemperature(0C)


1 28 350 1494 5571 198.6 234.12 35 380 1715 5599 200.4 2363 42 400 1885 5597 197.9 233.34 45 420 1992 5653 206.1 242.25 54 450 2202 5692 210.3 246.66 62 480 2393 5751 218.3 255.17 68 490 2484 5744 216.1 252.78 72 500 2555 5757 217.4 254.19 78 520 2681 5799 223.4 260.610 84 540 2807 5843 229.9 267.5


WithaCase

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| P a g e

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(F&A100C)

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Sc. Thesis

| P a g e

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existinga 2‐6%

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M.S

32

Calculation

9 1

(F&A100C)

(F&A100C)

Sc. Thesis

| P a g e

0

M.Sc. Thesis

33 | P a g e

5 PlantOptimizationFollowing section describes the possible optimizations that would provide mostbenefits to the load pattern of the selected apparel factory. Optimization possibilitieshavebeenidentifiedbasedonthefindingoftheChapter‐04.

5.1 ImportantFindingsPlantPerformanceSimulations

Mainobjectiveoftheperformancecalculationoftheidentifiedplantarchitecturesintheprevioussectionwastoidentifythepossibleoptimizationmethodsandtoidentifythefurtheroptionforplantarchitectures,ifany,thatshouldbestudiedbeforearrivingatanoptimalsolution.Followingaresomeoftheimportantfindingsofthecalculations.

Oneofthemostimportantfindingisthedifferenceinenergycostsavingswhenhigh pressure steam is tapped off from the turbine compared to directlyobtaining steam from the steam boiler through a PRV. As per the abovecalculationsformercangenerate~20%moreelectricitywithoutadditionalfuelthanlaterwhichcontributestotheincreasedsavings.Inadditiontothatcapitalsavingcanbeachieved,asformerneedsasmallercapacityboilertogenerateagivenamountof electricity compared to the later. Thisobservationeliminatesthe requirement to analyze the further plant architectures (options base onfigure‐10and11)thatdirectlyobtainhighpressuresteamfromtheboileritself.

Each of the graphs that represent the calculation results indicates that theincreasedoperatingpressureandtemperatureofagivenboilercapacityresultsincreasedcostsavings.Furtherforagivenoperatingpressureandtemperaturelowest capacity boiler gives the highest savings, regardless of the higherelectricity generation by the higher capacity boiler. This is mainly due to theincreasedfuelcostingeneratingmoreelectricity.

Anotherprominentobservationissizingtheplanttomeettheelectricityresultsin lower energy cost saving than sizing the plant to meet process heatingdemand. This scenario is caused by the increased fuel cost as noted in thepreviouspoint.

If coal is used CO2 emissions are always higher than current emissions of thefactory,fortri‐genapplications.

M.Sc. Thesis

34 | P a g e

5.2 OptimumOptions

Steamexitingfromtheturbinehastobeat,atleast1atmtobeabletouseforabsorptionchiller.AccordingtotheChapter‐04calculations,itisevidentthatthesteamexitoftheturbinehas farmoreenergythanwhatabsorptionchillerrequired.Partof thisexcessenergyhastoberejectedviasuitablemeantocontinuethe thermodynamiccycle(eg:Coolingtower)whichcanbeconsideredasanenergywastagethatneedtobeavoidedforoptimumresults.

One Option to avoid the energy waste would be to tap out steam at a suitableintermediatepressure levelwhich is justsufficient tomeet theenergyrequirementofthechillerwhileallowingexcesssteamtofurtherexpandthroughtheturbinebyusingacondensingtypesteamturbine.Howevertheveryhighcapitalcostofcondensingtypeturbines(canbe50%to70%higherthanbackpressuretype)negatestheeconomicalbenefitsofeliminatedenergywastage.Henceforthissortofapplicationsitisbesttouseabackpressuretypeturbinewithminimumenergywastage.

Theonlyway that excess energyavailable for absorption chiller canbe reduced, at abackpressuretypeturbinesteamexit, isbyreducingthesteammass flowrate(smallboiler). Even when the result of Chapter‐04 and the observation mentioned in theprevious section are considered, it is obvious that smallest possible boilers has to beoperated in the suitable pressure (Operating Pressure shall be decided based oneconomical result of the economical analysis) to obtain optimum economical andenvironmentalresults.

However,theboilermusthaveacapacitytobesufficienttomeetthetotalprocesssteamrequirementofthefactory,whichisapproximatelyabout19TPH(6TPH+10TPH+3TPH).Henceforthepracticalapplication,theoptimumboilercapacitycanbeconsideredtobe20Trasoddcapacitysuchas19Trisnotusuallymanufactured.

Further the generating steam at high pressure and using them at a lower pressurethroughapressurereducingvalveisalsoleadstounnecessaryenergyuse.ThereforeitisevidentthattheplantarchitectureproposedinFigure12(BaselineOption02)isthemostsuitableforthissortofapplication.Detailedplantarchitecturedevelopedbasedonfigure12systemispresentedandanalyzedintheSection4.4.

M.Sc. Thesis

35 | P a g e

5.3 TechnicalFeasibilityandOtherIssues

Ifrequiredknow‐howisnotavailableorothertechnicalbarriersarepersisting,wholeTGbecomes infeasibleregardlessofeconomicalandenvironmentalviability.SinceTGplantsarenotbeingusedinSriLankaasofnow,itisimportanttoidentifythepossibletechnicalissues,ifany,thatmayariseinimplementingthesame.Thisisawellestablishtechnology where hundreds of researches have been carried out to improve theefficiencyovercomeothertechnicalissues.Henceitisobviousthatimplementingsuchasystemwon’t be hindered by fundamental technical issues.However there are issuesuniquetolocalconditionsandtothesectorthatneedtobesortedout.

Though not used before locally, combine heat, power and cooling systems have beensuccessfully installed and commissioned in theneighboring countries like India. Also,therearelocalexperts,suppliersandconsultantswhohaveundertakendesign,supply,installationandcommissioningofindividualcomponentoftheTGplantssuchassteamturbinepowerplants,chilledwatersystems,highpressuresteamboilersandetc.Hencetransferringtechnologycanbedoneeasilymakingtheimplementationoftri‐Generationsystemstechnicallyfeasible.Howevercertainissuesneedtobeaddressedifsuchplanttobeimplemented.

5.3.1 IssuesRelatedtoFuelSupplyChainHavingawell‐establishedandconsistentsupplychainforproposedfuels(coalandBio‐Mass)isuniqueissuefacedbythelocalindustrythatneedstobeaddressed

CoalSupplyCoalhastobeimportedasitisnotminedlocally.Importingcoalinsmallandmediumquantitiesisnoteconomicalduetoshippingandhandlingrelatedissues.Hencecoalhastobeimportedinbulkorders.Thereisverylimitednumberoflocalindustriesthatusecoal. Stateownedutility company, theCeylonElectricityBoard (CEB)and thebiggestlocal cementmanufacture, theHolcimLankaPLC are theonlybulk importers of coal.ThereforeanyonewhowishestousecoalinmediumquantitieslikeforTGplantshastocollaboratewitheitherofaboveparties.SinceCEBisagovernmententity,itisdifficultfor private sector institutes (like apparel factories) to enter in to collaboration.ThereforecomingintoagreementwithHolcimcanbeseenasthebestoptions.

Coal imported by Holcim arrives in vessels to Trincomalee port which is located inNorth East coast of the Country. Transportation from there to the site has to bearrangedbycoveredtrucks.

Bio‐MassSupplyAs per “The Biomass Energy Sector in Sri Lanka, Successes and Constraints” byJayasinghe P., 2,873,880 MT of bio mass is produced per year by waste of variousindustriesandcommerciallygrowntrees[7].Howevermostof thesearewastedduetonon‐availabilityofproperdemandandsupplymechanism.MostofthecurrentBiomassfuelsupplierssupplywoodlogsthoughsameisavailableinmanyformssuchaspaddy

M.Sc. Thesis

36 | P a g e

husk,sawdustandbriquettes.Furtherwiththedrastichikeoffurnaceoilprice,manyindustrieshavestartedmovingtowardsbiomassboilerstoreducethefuelcost.Thus,anew demand for biomass suppliers and a significant shortage of supply can also beobserved.

Therefore establishing consistent supply of Biomass has to be addressed at the verybeginningof theproject.Failing todosowill fail the totaleffortput in to theTG. SriLankaBoardofInvestmenthasintroducedaregistrationsystemofauthorizedbiomasssuppliers.Sowhoeveriswillingtousebiomassasfuelinindustrialscalehavetohaveagreements signed with minimum of three authorized biomass suppliers afore thepermission.

5.3.2 IssuesRelatedtoFuelStorageLiquid fossil fuel has a higher calorific value compared to coal and biomass and thecountryhasawell‐establishedsupplychainforthesame.Thereforelargestoragesthatwouldlastforweeksarenotrequired.Howeversolidfuelslikecoalandbiomassneedbiggerstoragesandmoreattentionduetocertaintechnicalmatters.

CoalStorageThemain technical issues related to coal storage are the finding of adequate storagespace, possiblemoisture contamination and environmental pollutions. Therefore, nothavingasuitablestoragespacecanfailtheentireproject.Around60Mtofcoalisrequiredondailybasisfortheplantdesignsubjectedtostudy,whichrequireapproximatelya40–50m3areafordailystorage.Therefore,asthefirststepofimplementingTG,astoringareashouldbeidentifiedtobothtruckunloadingandboilerfeeding.ThenasuitableshelteroracoveringmechanismhastobeimplementedtopreventstockpiledcoalabsorbingmoisturefromrainwhichwillreducetheLHVoftheCoal. It isalsovery importantto takeactiontopreventcoalgettingwashedoffbyrainandblownoffbywindtoavoidcoalwaste,contaminationofnearbywaterbodies,contaminationofsoilandair.

BiomassStorageBio‐massisrequiredinevenmorequantitiesthancoalandit facesthesameissuesasthecoalwhenitcomestostoring.Thereforesimilaractionshastobetakenavoidthese.Howeverthepollutionissuesarefarlesssevereforbiomasscomparedtocoal.

M.Sc. Thesis

37 | P a g e

5.3.3 IssuesRelatedtoFuelPreparationUnlikeliquidfossilfuels,coalandbio‐masshastobepreparedforcombustion.Thoughdirectlynotconnectedtotechnicalitiesoftheplant,fuelpreparationhassometechnicalissuestobesortedout.

CoalPreparationCoalhas tobe crusheddependingon the typeof combustorused in theboiler.Threemain combustionmethods have been studied for suitability. Coal crushing causes airpollutionaswellasnoisepollution.Hencethisprocessshouldbecarriedoutinenclosedenvironment,withspecialrespiratorsandheadphones.CoalcrushingsystemhastobedesignedtomeettherequirementsstipulatedbyBoardofInvestment.

BiomassPreparationIssuesrelatedtobiomasspreparationdependonthetypeoffuelused.Ifwoodlogs(firewood) are used as fuel it is very difficult to design an automatic or semi‐automaticfeedingsystemasfuelisfedaslogs.Theonlywayoutistousemanuallaborwhichcanbenotveryfeasibleforlargecapacityplants.

Otherformsofcommonsourceofbiomassaresawdust,sawdustbriquettesandwoodpellets.Theseformscanbeautomaticallyfedandneedverylesspreparations.

5.3.4 Coalandbiomasscombustiontechnologies

SelectionofCombustorSelectionofcombustorhastobedoneconsideringthetypeoffuelused.Movinggratetype,pulverizedandfluidizedbedcombustorarethethreemaintypestochoosefrom.MovingGrateCombustorMoving grate combustor is one of the oldest technologies which utilizegratefiringwherethecoal ismechanicallydistributedontoamovinggrateatthebottomofthe combustion chamber in partially crushed gravel like form. Air for combustion isblownupward through thegrate, so it carries the lighter ashandsmallerparticlesofunburnedcoalupwithit.Nospecificcrushingisneededforthistypeofcombustor,butsystemefficiencyislower.The main advantage of this technology is the ability to progressively move the fuelwithinthecombustionchamber. Itsabilitycombustwetfuels isadvantageousforbio‐massfiredTGplants.Asthefuelmovesforwardthoughamovinggrate,itgoesthroughdifferentstagesofcombustion.Atfirstthefuelentersthecombustionchamberandisimmediatelyexposedtotheheatofthecombustionchamber,atthisstagethewetfuelstartstodry.Thenthefuelsubjectscombustionandfinallyendsupinashpit.

PulverizedCoalCombustorPulverizedfuelboileristhemostcommonlyusedmethodinthermalpowerplants.Coalispulverized (ground) toa finepowderwith less than70–80µmparticle sizes.Thepulverizedcoalisblownwithpartofthecombustionairintotheboilerplantthrougha

seriesoSchema

FluidizeInFluidthecomaction,transfe10mm.

Em

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Figure 2

nozzles. Htypeofpla

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gnandtheflue gasmementalAuthParticulatehe commona scenartivetoredu

precipitatooves particltatic chargimally imp

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r,upwardbichresultsgfluid,proercombusti

combustioeet the reghorityofSre Matter (only used trioof coalucethePM

r as the onles from age. Electrospede the fl

Grate Combus

iscasecoainFigure2

blowingairaturbulenovidesmoreionefficien

onefficiencgulations sriLanka.ThPM). Bagtechnologiefiring, anEcontentin

ne showna flowing gstatic preclow of gas

stor (Courtesy

alneedsto21.

rjetssuspentmixingoeeffectivency.Thereq

cyofthesystipulated bheBOIregfilters, waes in Sri LElectrostatfluegasto

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stemhastoby Board oulationforater scrubbLanka in sticprecipita150ppmo

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M.S

38

dtofinepa

alparticlesfuel.Thistureactionsalparticles

obemaintaof Investmerfluegasebers andsolid fuelator (ESP)orless.

rticulate cong the forcefficient fice, and can

Sc. Thesis

| P a g e

articles.

sduringumblingndheatizeis1‐

ainedtoent andmissioncyclone(mostlywill be

ollectionce of aniltrationn easily

M.Sc. Thesis

39 | P a g e

removefineparticulatematterssuchasdustandsmokefromtheairstream.Incontrastto wet scrubbers which apply energy directly to the flowing fluid medium, an ESPapplies energy only to the particulate matter being collected and therefore is veryefficientinitsconsumptionofenergy(intheformofelectricity)

AspertheBOIregulations,theSO2emissionshallbecontrolledbyfuelqualityandstackheight.TheminimumstackheighthastobedefinedbyacceptableAirQualityModelingtool.Intheabsenceofsuchmodeling,followingequationshallbeappliedtodefinetheminimumstackheight. H(m)=14Q0.25(Where,QisSO2emissionrateinkg/hr.)

The bottom ash has to be collected to silos and only available option in Sri Lanka isusingasarawmaterialinCementmanufacturingandreadymixedconcrete.

Figure 22 ‐ An Electrostatic Precipitator (Courtesy: Thermax)

M.Sc. Thesis

40 | P a g e

5.4 DetailedSchematicofFinalPlantArchitecture

Figure 23 ‐ Detailed Schematic of Coal Fired Tri‐Generation (Final)

M.Sc. Thesis

41 | P a g e

5.5 DetailedEconomicalandEnvironmentalAnalysis

5.5.1 GeneratorCapacityEstimationCase BoilerOperating

Pressure(bar)BoilerOperatingTemperature(0C)


Poweravailableatturbineexit(kW)

1 28 350 1015 21342 35 380 1192 21533 42 400 1328 21564 45 420 1411 21835 54 450 1579 22066 62 480 1729 22367 68 490 1802 22358 72 500 1859 22439 78 520 1958 226410 84 540 2057 2286

Table 5.1: Theoretical Design Turbine Capacities Calculated for Section 4.4 Design

Result shown in theTable5.1abovehasbeenobtained for theplantdesignshown insection 5.4 by using the same calculation procedure used in Section 4.2.1.2. Theresultant gross electric power output indicates theoretical values that need to becorrectedforthecapacityofsteamturbinethatareavailableatthemarket(eg:1000kWturbine should be considered instead of theoretical value of 1015kW). In the caseswheretheoreticalgrosselectricpoweroutputhastoberoundedup(eg:11921200)operatingpressuretemperaturehastobeadjustedaccordingly.Highlightedcellsinthe

above table need to be adjusted suit the practical application. Table 5.2 indicates theactualturbinecapacities,adjustedtemperaturesandpressures.Case BoilerOperating

Pressure(bar)BoilerOperatingTemperature(0C)

Practical ElecPowerOut(kW)

Poweravailableatturbineexit(kW)

1 28 350 1000 21342 36 380 1200 21473 45 400 1350 21424 45 420 1400 21835 54 450 1550 22066 65 480 1750 22267 68 490 1800 22358 72 500 1850 22439 78 520 1950 226410 84 540 2050 2286

Table 5.2 :Practical Turbine Capacities Calculated for Section 4.4 Design

M.Sc. Thesis

42 | P a g e

5.5.2 ElectricityGenerationandFuelConsumptionbytheProposedTri‐gen

5.5.2.1 ElectricityGenerationSamecalculationprocedureusedinChapter04hasbeenusedwithamendmentforthecalculationof electricity generation. Practically available turbine capacitieshavebeenused for calculations instead of theoretical turbine capacities arrived in the samesectionforthecalculations.FurtherthreesetsofoperatingpressureandtemperatureshavebeenalteredtomeetthepracticallyavailableturbinecapacitiesasshowninTable5.1. In addition, two important factors have been considered in calculating total netelectricalenergygeneratedbyeachoftheturbinesidentifiedinTable5.2.

HoursOperated:inthiscaseplanthastobeoperated24hoursasthefactory

isrunning24hours.Howeverincalculatinghoursoperatedonemustconsider

thenumberofhoursinwhichtheplantneedstobeshutdownformaintenance.

Typically,plantsofthisnaturehasplantfactorof90%.

ElectricityRequirementof theTGPlant: As shown in the Schematic plantdesign, CCH plant comprises of various equipment such as blowers, fans,motors and pumps which are electric driven. Hence part of electricitygeneratedbytheplantwillbeoffsetbytheenergyconsumedbytheabovesaidequipment.

Total electricity generation by the turbines identified in Table 5.2, calculatedconsideringabovetwofactorsaregiveninTable5.3.

Case BoilerPressure(bar)

BoilerTemperature(0C)

possibleElecPowerOut(kW)

TotalElectricitynetGeneration(kWh)

1 28 350 1000 7,095,6002 36 380 1200 8,514,7203 45 400 1350 9,579,0604 45 420 1400 9,933,8405 54 450 1550 10,998,1806 65 480 1750 12,417,3007 68 490 1800 12,772,0808 72 500 1850 13,126,8609 78 520 1950 13,836,42010 84 540 2050 14,545,980

Table 5.3:Electricity Generation by Practical Turbine Capacities Calculated for Section 4.4 Design

5.5.2.2 ElectricityRequirementoftheTGPlant

Followingtable5.4indicatestheelectricalenergyconsumingequipmentoftheTGplantandtheexpectedannualenergyconsumptionsofthesame,whencoalisusedasfuel.

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Energyrequiredbythecoolingtower,chilledwater,andcondenserwaterpumpsoftheabsorptionchillershasbeenomittedfrombelowcalculationassumingthatitwilloffsettheenergyconsumedbythesameequipmentofthecurrentairconditioningsystem.

EquipmentType

Application Ratedpower(kW)

Count EnergyConsumption(kWh)

IDfan Flugassuction 75 1 532,170PAfan Createfluidizedbed 20 1 141,912FDfan Drawair 80 1 567,648RWpumps Pumpingrawwater 1.5 1 7,096DMWpump Pumpingtreatedwater 1.5 1 7,096BFpump Feedingwatertoboiler 95 1 674,082EFpump Dischargeeffluent 0.5 1 2,365Conveyormotor

SupplyCrushedcoaltoboiler

3 1 21,287

Coalcrusher Coalpreparation 35 1 110,376Absorptionchillers

Electricapplicationsinthechiller

10 2 110,376

TotalEnergyConsumption 2,174,407Table 5.4: Electricity Use by Plant Equipment for Coal TG Plant

Followingtable5.5indicatestheelectricalenergyconsumingequipmentoftheTG‐Plantand theexpectedannualenergyconsumptionsof thesame,whenBiomass isusedasfuel.

EquipmentType

Application Ratedpower(kW)

Count EnergyConsumption(kWh)

IDfan Flugassuction 15 1 106,434PAfan Createfluidizedbed 20 141,912RWpumps Pumpingrawwater 1.5 1 7,095DMWpump Pumpingtreated

water1.5

17,095

BFpump Feedingwatertoboiler

95 1 674,082

EFpump Dischargeeffluent 0.5 1 2,365Conveyormotor

SupplyCrushedcoaltoboiler 1 21,286

Absorptionchillers

Electricapplicationsinthechiller

10 2 110,376

TotalEnergyConsumption 1,070,647Table 5.5: Electricity Use by Plant Equipment for Biomass TG

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44 | P a g e

5.5.2.3 OperationalandLaborCostsSimilar to any industrial plant equipment Tri‐Generation plant will also incur anadditional cost to the owner in terms of operations and labor. Operation cost willincludeCostofspares,costofchemicals,costofwaterandadministrativecost.Itisverydifficult toaccuratelyestimatethesecostasmostof thesearecasespecific.Thereforethecost figuresused in the industryby the leadingTGplantequipmentsuppliershasbeen used for the calculation. Following are the list of such figures obtained from aleadingsupplier.

CostofSpares 0.0100 USD/kWh (AnnualEscalation‐07%) Costofwater 0.0050 USD/kWh (AnnualEscalation‐05%) CostofChemicals 0.0040 USD/kWh (AnnualEscalation‐05%)

Inadditiontoabovecostseveralstaffhasttobeemployedfortheoperationoftheplantwhichwill contribute to labor cost related to the TG plant. Since the plant has to beoperated24hours,foursupervisorylevelstaff,eighttechniciansandeightlaborerswillbe required at a minimum. Based on this manpower requirement following costcalculation has been done according to the current pay mechanism of the TexturesJersey

Supervisor– (2x600$/monthx12)=14,400$/Yr Technicians– (4x450$/monthx12)=21,600$\/Yr Admin– (3x350$/monthx12)=12,600$\/Yr Labourers– (4x250$/monthx12)=12,000$/Yr AnnualTotal– 60,600$/Yr

.

5.5.2.4 Fuel(Coal/BioMass)ConsumptionandAssociatedCostsBothcoalandbiomassconsumptionbyeachoperatingconditionshavebeencalculatedconsideringtheenergyinputtotheboiler.

24 365

M.Sc. Thesis

45 | P a g e

Following Table 5.6 indicates the fuel requirement in metric ton for each categorycalculatedusingtheaboveequation. Case Boiler

Pressure(bar)BoilerTemperature(0C)

coal (MT) Sawdustbriquettes(MT)

Firewood(MT)

1 28 350 20,199 30,859 45,3522 36 380 20,809 31,791 46,7213 45 400 20,994 32,074 47,1384 45 420 21,347 32,612 47,9285 54 450 21,553 32,926 48,3906 65 480 22,366 34,170 50,2197 68 490 22,523 34,409 50,5708 72 500 22,586 34,505 50,7119 78 520 22,920 35,016 51,46210 84 540 23,258 35,532 52,219

Table 5.6: Fuel Consumption for Coal & Biomass Fired Systems

5.5.3 NetPresentValue,IRRandSimplePaybackItisnormalpracticetoperformanetpresentvalueanalysisandcalculationofinternalrateofreturntoseeifinvestingmoneyonagivenprojectisworthwhile.Simplepayback(SPB)calculationindicateshowlongittakestorecovertheinvestment.

Above three economical parameters were calculated for the tri generation plantdesignedfortheTexturesJersey.Unlikemostoftheindustriesapparelindustryisveryvolatile and the future trends are highly unpredictable. Therefore apparel industrynormallydoesnotmake investmentsconsidering longperiods like20yrs.Consideringthisfactandthelifecycleofplantequipmentofthetri‐genplant,a10yearperiodwastakenfortheeconomicalanalysis.

Theeconomicalanalysiswasconductedforalltenselectedoperatingconditionsandforthreedifferentfuels,namely;coal,sawdustbriquettesandfirewood,whichresultsin30differentcases.SamplecalculationforeachfueltypeisgiveninAppendixC,D&E.

5.5.3.1 EconomicAnalysisforCoalFiredSystemPositiveNPVover10yearperiod(Figure25),IRRhigherthanthecurrentdiscountrate(Figure26)andthepaybackintherangeof4years(Figure27)indicatesthatinvestingon a tri‐generation plant is economically highly favorable. Though none of thecalculatedparameters(NPV,IRR,SPB)exhibitauniformtrend,itisevidentthathighertemperature and pressure points results in better values for all three parameters.Howeverchangeineachparameterwithvariousoperatingconditionsisnotsubstantialfor a management to take decision on an optimum condition. Hence capital in handplaysahugeroll inselectinganoperationconditionashigherpressure/temperaturesrequirehigherinvestments.Othernon‐economicalparameterssuchasemissions,Ashdisposal, coal storage, supply chain issues, safety requirement also may consider inselectingtheoperatingconditions.

3

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ure 25‐ Intern

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M.S

46

lant

Sc. Thesis

| P a g e

5.5.3.2

Same candfireinthesboiler.electriclowercmajorpThemathefirepracticrequirebriquetsystem

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M.S

47

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Sc. Thesis

| P a g e

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M.Sc. Thesis

48 | P a g e

1 2.447

ForBriquetteswith9.5%moisturecontent:19,924 1 0.095 2447 0.095 17,7985 /

Similarlyforthefirewood:

19,924 1 0.3 2447 0.3 13,2135 / Inadditiontoabovetheseverecontrastbetweenthepricesofthetwotypeofbiomasscontributestomajordifferencesineconomicparameters.AsshowninFigure28,inbriquettessystem,capitalrequirementforincreaseoperatingpressure and temperature steadily increase while NPV is maintained positive. Thisscenarioissameforthefirewoodboilers.NPVofbothcasesdoesnotindicatemuchofavariationwhereasNPVoffirewoodsystemveryhigh(~4timesthecapital)asshowninFigure29owingtothehighersavingresultedfromcheapfuelcost.

Simplepaybacksoftwosystemsalsodonotvarymuchwiththeoperatingpressureandtemperatures as shown in Figure 31. Here again the firewood system indicates paybacksassmallas1.6yrs(almosthalfofbriquettesandcoalsystems)duetoextremelylowfuelprices.AsshowninFigure30,IRRofbothBiomassfueltypesexhibitthesamepatterns.

Similar to coal powered systems economic parameters do not exhibit substantialvariation at different operating conditions. Therefore capital in hand should beconsidered in selecting a suitable operating condition. Other non‐economicalparameters also, such as Ash disposal, storage, supply chain issues and safetyrequirementhastobeconsideredinselectingtheoperatingconditions.

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M.S

49

Sc. Thesis

| P a g e

0

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50

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Sc. Thesis

| P a g e

M.Sc. Thesis

51 | P a g e

Whencomparedtoeachotherpurelyoneconomicterms,biomassfiredtri‐generationplant is economically attractive than the coal fired plant. Threemain contributors totheseeconomicallyattractiveresultsarethelowerpriceofbiomass,lowercapitalcostofbiomasstri‐genplantandhigherelectricityconsumptionbytheauxiliaryequipmentofthecoalfiredplants.

Ifuninterruptedsupplyofbiomasscanbeassured,economicallyoptimalsolutionistogoforabio‐massfiredTriGenerationplant.

5.5.4 EnvironmentalIssuestobeTackledbyTexturesJerseywithTri‐Gen

GreenhouseGas(GHG)EmissionsOne of themain reasons for implementing TG plants is to harness themaximumamount of energy thereby reduces the GHG emissions. Sri Lankan apparel sectoralsoisundergreatpressurefromtheirinternationalbuyersandthegovernmenttoreduce theemissions. However,as indicated in thebelowFigure32, it isevidentthatuseofcoalwillfurtherincreasetheemissionwhencomparedwiththecurrentemissionquantities.Thishappensduetooffsetofemissionreductionachievedbygenerating electricity and eliminating electricity requirement for chillers by theexcessive coal combustion. Coal combustion release CO2, N2O and CH4 thatcontributesto theglobalwarmingandtheFigure32 indicatestheequivalentCO2emissionbyallgreenhousegases.

However,theGHGemissioncanbedrasticallyreducedasshowninfigure32byuseof biomass (both briquettes and firewood) if the CO2 emission by the same isassumedtobezero.

SO2EmissionsCoal has a certain percentage of Sulphur. Coal is imported from Indonesia forcurrentmajor localapplicationssuchas coalpowerplants runby the localutilitycompanies. Hence same coal will have to be used by the tri‐gen plants ifimplemented.TypicalIndonesiancoalhaslowerSulphurcontentanditisabout1%as a fraction of mass. Therefore, 400 to 470MTs of SO2 will be released to theenvironment ifcoal isusedfortheTGplant,dependingontheoperatingpressureandtemperature.

CombustionAshAnysolidfuelfiredboilergeneratesbottomashafterthecombustionprocess.Coalandbiomassarenodifference. Locallyusedcoalhasapproximateash contentofabout 6% (source: Holcim test report) whereas bio mass has approximate ashcontent of about 4.3% (source: ITI test report). ThereforeTGplant fired by both

M.Sc. Thesis

52 | P a g e

fuel typeswill result in1,200 to1,800MTsof solidwaste (ash) annually. Properdisposalmethods such reuse in cementmanufacturing has to be implemented toavoid

AirborneParticlesWhen solid fuel like biomass or coal is combusted certain percentage of ash getairborne and exist the chimneywith the flu gas. This airborne particles then getcarriedbythewindandcangetdepositedintheneighboringarea.Unlike biomass, coal can create more airborne particles in form of dust duringloading,unloading,storing,crushingandconveying.

WaterandLandContaminatingThishappens if coal isused.Normally coal is stored inoutdoorbefore it isbeingused.During such time, rain fallson to stored coal canwashaway solidparticlesandcancontaminatethelocalwaterbodiesandthesurroundingland.

TransportRelatedEmissionsProposedplant thatwas subjected to studywill require20,000 to40,000MTsofsolid fuel (coal or biomass) depending on the fuel type and operatingpressure/temperature. Handling of these quantities will require lot oftransportationwhichagaincontributesharmfulemissions.

IndirectDeforestationInthisanalysisithasbeenassumedthatbiomasswouldcomefromwoodwasteorfromtreescommerciallygrownforfirewood.Howevercurrentlythereisnopropermechanism to check the actual source of the biomass. There have been manyincidentsofdeforesting for firewood. If thathappens,wholepurposeofusingbiomasswillbelost

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nvestmentutors areineandthefuelassou

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M.S

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ationalsoshowsthatcountlessctorandafusesofheaability of fpparelindu

onaTGPllow priceeelectricityurceofene

ntSystem

Sc. Thesis

| P a g e

hiscasenmentalameters.Lankanghours,ffect theniversalntify the

suggestcertainoptionsffecttheat,samefuel areustry.

lanthasof fuelysavingergyfor

M.Sc. Thesis

54 | P a g e

processheatingcanenjoyeconomicbenefitsbyshiftingtocoalorbiomassfiredTGplant. However NPV, IRR and the payback time will vary with the parametersuniquetotheplacewhereTGplantisimplemented.Thereforeitisadvisabletodoan economic analysis after doing a schematic design considering followingguidelines.

InfrastructureOnemustinvestigatewhetherthenecessaryinfrastructureisinplacetoimplementaTGPlant.First requirement is space.Normallymostof the localapparel factorybuildingsoccupiedmostof the landofthe locatedsite, leaving littlespaceforthiskind of projects. TG plants need adequate space for place the boilers, turbines,coolingtowers,watertreatmentplants,otherplantequipment,fuelstorageandetc.Eachof thesehas tobeplaceswithadequatemaintenanceaccessandwith safetyclearances.Furthertheavailabilityoftransportaccesstotransport&erecttheplantandtotransportfuelshouldalsobeconsidered.

PlantCapacityBoiler and the turbine are the twomain components in a TG plant, ofwhich thecapacityaffecttheeconomicsofthetotalplant.Restoftheplanthastobedesignedaccordingtothecapacitiesofthesetwocomponents.Itisalwaysimportanttosizethe plant considering the process heat requirement rather than considering theelectricitydemand,becausethereisnoalternativesourceforheating.Ontheotherhand,excesselectricitycanbe fedtothegrid, ifanyorelectricityshortagecanbeobtained from the grid, once the plant is sized tomeet process heating demand.Therefore,optimumboilercapacitycanbearrivedbyadditionofallprocesssteammassflowratesandthesteammassflowraterequiredbyabsorptionchillers(thisistheminimumboilercapacitypossible).Selectingaboilerwithhighercapacitythantheminimumsteamrequirementallowstheusertohaveabiggerturbineandtherebygeneratehigheramountofelectricity.Differencebetween costs of self‐generated kWhelectricity andpurchased kWh ismarginalasIndustrialelectricitypriceinSriLankaisheavilysubsidized.Thereforecost saving by increased self‐generations not substantial compared to the capitalcost incurred inpurchasinghighercapacityboilerand turbine.Howevereven thesubsidized grid electricity is not cheap enough to use for heatingpurposeswhencomparedwiththecostoffuelssuchasHFO,coalandbiomass.

PlantArchitecturePlant architecture depends mainly on how and at what point one is going toobtained process steam from the cycle.Main options are to directly obtain somesteamfromtheboilerthroughPRV,tappingtheboileratsuitablepressurelevelsorselecting the turbine to have an exit steam pressure at highest pressure levelrequired.Both firstandthirdoptionsreducetheelectricitygenerationcapacityofthe TG plant and require additional fuels as steam is obtained through PRVs.

M.Sc. Thesis

55 | P a g e

Thereforetappingtheturbineatsuitablepressurelevelgivestheoptimumbenefitstoagivenboilercapacity.

OptimumOperatingconditionsAtaminimum,anyselectedoperatingpressureandtemperatureshouldbeabletoprovideenoughsteamatsuitablequalityattheturbineexit toruntheabsorptionchillers. Further, as shown in the calculations, operating at higher pressures andtemperatures gives better economical and environmental performance. Since theprocess heating requirement is anyway met, increased P & T will increase thesavings only by offsetting electricity drawn from the grid. Further this increaserequires additional capital. As explained earlier designing the plant consideringelectricity generation is not very profitable. Therefore one must decide theminimum operating P&T considering energy availability to the absorption chillerandwhethertoincreasethepressurethantheminimumcanbedecidedconsideringtheavailablecapital.

OperatinghoursTexturesJersey,whichwassubjectedtoanalysisoperate24hoursaday.Thelongeroperatinghourshavecontributeda lot to theshorterpaybacksof the investment,extremelyattractiveNPVandIRR.Hadtheplantranontypical12hour,10hoursor8hourshiftthepaybacktimesbecomesnonattractiveasthereisnochangeintheinvestment. Negative NPVs will be resulted for certain operating conditions.Moreover,startingandshuttingoffthiskindofaplanteverydayisnotadvisableasthese plant are meant to run continuously. Options available for factories withshortershiftaretoeithertohaveanotherturbine(withouttapings)torunduringthe off hours or to run the existing turbineby rejecting heat via a cooling tower.Both these options seriously affects the economics and therefore case by caseeconomicalanalysisisrequired.

FuelSelectionFirewood,Sawdustbriquettesandcoalarepreferredas the fueloverHFO in therespectiveorder.Biomassispreferredovercoalowingtotwomainreasons.Firstisthereducecapital requirementasTGplantbecome lesscomplicatedcomparedtothe coal fired systemas itdoesnot require complex fuelpreparationand feedingsystem. This makes the Bio mass system more economically attractive. It alsocreatesmuchlowernetCO2emissioncomparedtoacoalfiredsystem.Ineconomic terms, firewood ispreferredoversawdustbriquettesdue to~40%lowercostperMJandlowercapitalcost.CostperMJofbiomassisslightlyhigherthanthatofthecoal,yet it iseconomicallyattractiveduetopreviouslymentionedreasons. However the main advantages of coal are the availability and the wellestablish supply chain. Whether large quantities of bio mass can be sourcedcontinuouslythroughouttheyearisdoubtful.Thereforeonemustnotventureintobio‐massfiredTGplantuntilcontinuoussupplyisensured.

M.Sc. Thesis

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6 Conclusion

Increaseddemandforfossil fuelandtheconflicts inthemajoroilproducingcountrieshas ledfossil fuelpriceto increaseuptoa levelwhich isalmostunbearabletotheSriLankan industry. Among all, apparel manufacturing is one of the severely affectedindustriesbythesuddenfuelpricehikes.Asaresultoftheglobaltrendofsustainabledevelopment,pressure fromvarious institutes tominimize theemissionsby reducingtheenergyconsumption,isanothermajorchallengefacedbythelocalapparelindustry.A typical Sri Lankan apparel manufacturing factory requires electricity to run itsmachineries,airconditioning&Ventilationsystem,lightingsandutilityequipmentlikecompressorsandpumps.FossilfuelslikeDieselandfurnaceoilareusedtorunboilerstogenerate steamrequired formanufacturingprocess.Tri‐generationhasneverbeenusedbythelocalapparelindustryasasolutionfortheeverincreasingenergycost.Themainobjectiveofthisresearchwastoevaluatethefeasibilityoftri‐generationifusedinapparelindustryandtherebyprovidesetofgeneralizedguidelinestothelocalapparelsector to identify the economical, environmental and technical challenges and thebenefitsthattheywouldcomeacrossinimplementingaTri‐Generationplant.Aspertheresearch results it is evident that apparel factories that utilize HFO can enjoyeconomicalbenefitsbyimplementingaTGplantrunbycoalorbiomass.

After the local apparel sector was studied it was found out that all factories can becategorizedintofivemaintypes.OutofthatknittingandweavingwasidentifiedasthemostsuitabletypetoimplementaTGplant.TexturesJerseyswhichisaknittingfacilitywas selected for the pilot study. After conducting a detail energy audit the end usequantitieswere estimated. Simultaneously, the possible combinations for a TG plantswere also identified based on the energy flow in the facility. Out of numerouscombinations,twomostpracticalsolutionswereevaluatedusingEngineeringEquationSolver.Thentheresultswereusedtoarriveatoptimalsolution.AfterdesigningadetailschematicoftheplantNPV,IRR,Paybackenvironmentalimpactanalysiswasconductedassumingthefuelascoal,sawdustbriquettesandfirewood.GeneralguidelinesonTGforlocalapparelsectorwerethendevelopedbasedonanalysisresult.

ResultsoftheenergyauditconductedatthetexturesjerseyispresentedintheChapter‐03.Ithasapeakelectricitydemandofabout3400kWandusesofstaggering8.9millionlitersofheavyfueloilannually.Facilityneedabout6MTofsteamat10barand10MTofsteamat6bar.Recentfueloilpriceincreasehasresultedinmorethan50%reductionin its net profit, making the facility good candidate to implement a Tri‐generationsystem. In thenext sectionall possible combinations forTri‐Generation systemhavebeenidentified.WhentheseoptionswereanalyzedusingmanualcalculationsandEESseveralimportantfactswererevealedthatultimatelyleadtotheoptimalsolution.Someofthemostprominentfactsrevealedareasfollows.

M.Sc. Thesis

57 | P a g e

Tappingoffhighpressuresteamfromthe turbine ismoreeconomicalcomparedtoobtainingsteamthroughaPRV.Capitalsavingispossibleasformerneedsasmallercapacityboilertogenerateagivenamountofelectricity.

Lower overall energy cost for Increased operating pressure and temperature of agivenboilercapacity

Lower overall energy cost achieved by lowest capacity boiler at a given operatingpressureandtemperature

Sizing the plant tomeet the electricity results in lower energy cost saving due toincreasedfuelcost

Steam exiting from the turbine has to be at, at least 1atm to be able to use forabsorption chiller. Availability of excess energy at exit indicates room foroptimization.

Usecondensingtypeturbinesnegatestheeconomicalbenefitsofeliminatedenergywastageduetocost

In a backpressure type turbine, Excess energy available for absorption chiller canonly be reduced by reducing the steammass flow rate. Hence, it is obvious that asmallest possible boiler has to be operated in the suitable pressure to obtainoptimumresults.

However boiler must have a capacity that at least is sufficient to meet the totalprocesssteamrequirementofthefactory.

Economical analysis conducted for the plant designed for Textures Jersey based onabove factors, exhibit veryattractive results for all three fuelsnamely; coal, sawdustbriquettes and firewood. Biomass fired systems indicates highly favorable GHGemissionreductionwhereascoalfiredsystemincreasestheoverallemissions.

Itwasfurthernotedthattheseeconomicalresultsarehighlydependedonthevariouslocalparametersunique toagiven facility.Henceuniversal approach toeconomicallyimplementaTGplantthatwouldsuitanygivenapparelfactoryisnotpossible.Howeverfollowinggenerallimitationscanbeimposed.

Any facility can enjoy economic benefits, by low cost heat source and electricitysavingbyTG.ButtheNPV,IRR&SPBdependonlocalparameters.

Sizetheplantconsideringprocessheatingrequirementaselectricitygenerationnotprofitableduetosubsidizedtariff.Henceselectthesmallestpossibleboiler

AvoidPRVs SelectP&TconsideringcapitalandenergyavailabletoAbsorptionchillers Suitableonlyfor24hoperations Firewood, Saw dust briquettes and coal are preferred as the fuel over HFO in therespectiveorder

Costofretrofittingismarginalcomparedtothetotalinvestment.

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Oneofthemostprominentfactsintheresultsistheextremelyfavorableeconomicandenvironment result of the bio mass fired Tri‐Generation plants. Such systems aretechnicallyalsosimplecomparedtocoalsystems.Paddyhusk,hey,commerciallygrownfirewood,municipalsolidwaste,timbermillwastesarethemostcommontypesofbiomassavailable.Furtherresearchshouldbecarriedoutonhowtoimprovethebiomasssupplychain,howtoefficientlyutilizetheavailablebiomass,howtocreateamarketforbiomassandhowtoavoidharvestingnaturalforestsforbiomass.Anotherimportantarea to study is how to create a certificate system or special tariff for self‐generatedelectricity that would encourage the industry to implement tri‐generation. Study onimplementingmethodologiestoobtainbenefitsfromcarboncreditsisalsoimportant.

FinallyitisevidentthatthelocalapparelsectorcanbebenefitedfromimplementingTr‐Generationplantsbymeetingeconomicalgoalsinsustainablemanner.

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References[1]AndreaC,JeanP,MichaelT,ThomasB,(2007).Economicsoftri‐generationinaKraftpulp mill for enhanced energy efficiency and reduced GHG emissions. Appliedthermalenergy,32:474‐481

[2]ArteconiA,BrandoniC,PolonaraF(2009).Distributedgenerationandtri‐generation:Energysavingopportunities in Italiansupermarketsector.Applied thermalenergy,29:1735‐1743

[3]Athanasovici V, Bitir I, Le Corre O,Minciuc E, Tazerout M,(2003). Thermodynamicanalysis of tri‐generation with absorption chilling machine. Applied ThermalEngineering,23:1391‐1405

[4]CarvalhM, LozanM.A, Ramos J.C, Serra L.M, (2009) Thermo economic Analysis ofSimple Tri‐generation Systems, International journal of thermodynamics, 12: 147‐153)

[5]ChaerI,MarriotM,SugiarthaN,TassouS.A,(2009).Tri‐generationinfoodretail:anenergetic, economic and environmental evaluation for a supermarket application.Appliedthermalenergy,29:2624‐2632

[6]FreschiF,GiacconeL,LazzeroniP,RepettoM,(2013).Economicandenvironmentalanalysisofa tri‐generationsystem for food‐industry:Acasestudy.AppliedEnergy,107:157‐172

[7]Parakrama Jayasinghe, (2004), TheBiomass Energy Sector In Sri Lanka, SuccessesAndConstraints

[8]Süleyman H.K, Onur S, (2011). Economical analysis of tri‐generation system.InternationalJournalofthePhysicalSciences,6:1068:1073

[9]TemirG,BilgeD,EmanetO(2004).AnApplicationoftri‐generationanditseconomicanalysis.EnergySources,26:857‐867.

[10]UnitedStatesDepartmentofEnergy, (2007).VoluntaryReportingofGreenhousegasses,EIA‐1605:123‐124

[11]United States Environmental Protection Agency, (2011). Emission Factors forGreenhouseGasInventories

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AppendixA:ElectricityDemandVariationwiththeTimeoftheDayFollowingarethedataobtainedduringtheenergyauditbyfixingdataloggerstothemainincomingbussbarsofthemainelectricalswitchboard.

Time Demand(kVA) PowerFactor ActivePower(kW)

12:00AM 2,545.1 0.94 2,394.8912:15AM 2,530.6 0.94 2,386.3312:30AM 2,494.4 0.93 2,319.8112:45AM 2,517.9 0.93 2,341.691:00AM 2,528.8 0.93 2,356.821:15AM 2,603.1 0.94 2,457.341:30AM 2,537.5 0.93 2,354.821:45AM 2,560.1 0.94 2,414.182:00AM 2,571.1 0.95 2,432.222:15AM 2,585.0 0.95 2,450.552:30AM 2,611.8 0.95 2,473.402:45AM 2,630.6 0.94 2,472.733:00AM 2,609.0 0.93 2,434.223:15AM 2,573.1 0.93 2,400.673:30AM 2,628.2 0.93 2,446.863:45AM 2,688.0 0.93 2,494.434:00AM 2,590.2 0.93 2,408.844:15AM 2,706.5 0.93 2,503.534:30AM 2,636.4 0.94 2,486.164:45AM 2,765.9 0.96 2,641.455:00AM 2,725.5 0.95 2,589.215:15AM 2,750.6 0.95 2,599.325:30AM 2,806.6 0.94 2,643.835:45AM 2,751.5 0.93 2,558.876:00AM 2,794.7 0.95 2,643.756:15AM 2,733.7 0.95 2,605.256:30AM 2,807.5 0.96 2,683.986:45AM 2,791.6 0.96 2,677.197:00AM 2,847.8 0.96 2,736.727:15AM 2,788.7 0.96 2,671.597:30AM 2,814.1 0.96 2,707.157:45AM 2,857.2 0.96 2,748.608:00AM 3,128.8 0.95 2,978.618:15AM 3,120.0 0.96 2,998.318:30AM 3,048.8 0.96 2,935.968:45AM 3,075.8 0.97 2,974.349:00AM 3,058.0 0.96 2,932.59

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9:15AM 3,090.3 0.96 2,951.199:30AM 3,291.0 0.94 3,093.569:45AM 3,195.2 0.95 3,022.6710:00AM 3,285.1 0.95 3,130.7310:15AM 3,222.7 0.95 3,071.2710:30AM 3,278.2 0.95 3,120.8010:45AM 3,238.4 0.95 3,076.4611:00AM 3,144.6 0.95 2,990.4911:15AM 3,390.2 0.95 3,227.4711:30AM 3,277.3 0.96 3,133.1211:45AM 3,195.9 0.96 3,052.1112:00PM 3,350.4 0.95 3,196.3212:15PM 3,293.8 0.95 3,132.4012:30PM 3,277.5 0.95 3,126.7512:45PM 3,282.1 0.95 3,117.991:00PM 3,277.5 0.95 3,107.041:15PM 3,221.3 0.95 3,066.671:30PM 3,181.2 0.95 3,031.641:45PM 3,066.7 0.96 2,931.752:00PM 3,173.0 0.95 3,001.672:15PM 3,265.4 0.95 3,085.802:30PM 3,315.0 0.95 3,139.302:45PM 3,282.9 0.95 3,102.353:00PM 3,301.9 0.95 3,149.993:15PM 3,292.8 0.95 3,131.423:30PM 3,221.2 0.95 3,066.583:45PM 3,233.5 0.95 3,084.734:00PM 3,307.1 0.95 3,138.394:15PM 3,239.5 0.95 3,077.484:30PM 3,342.7 0.95 3,185.594:45PM 3,243.5 0.95 3,091.045:00PM 3,291.7 0.96 3,150.195:15PM 3,177.5 0.96 3,053.565:30PM 2,989.0 0.96 2,857.535:45PM 2,965.9 0.96 2,844.256:00PM 2,902.0 0.97 2,803.306:15PM 2,934.0 0.95 2,793.166:30PM 2,893.2 0.95 2,739.846:45PM 2,931.4 0.94 2,764.347:00PM 2,957.1 0.95 2,818.077:15PM 2,996.1 0.95 2,855.277:30PM 2,925.1 0.96 2,793.487:45PM 2,946.6 0.95 2,805.20

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8:00PM 2,908.8 0.95 2,769.178:15PM 2,915.8 0.95 2,778.748:30PM 2,922.7 0.95 2,785.308:45PM 2,843.2 0.95 2,701.089:00PM 2,841.0 0.95 2,707.519:15PM 2,836.3 0.96 2,725.739:30PM 2,764.1 0.95 2,636.959:45PM 2,685.0 0.97 2,615.1610:00PM 2,653.7 0.95 2,507.7010:15PM 2,739.0 0.93 2,544.5210:30PM 2,706.7 0.94 2,549.6810:45PM 2,705.6 0.94 2,537.8411:00PM 2,652.0 0.94 2,484.9011:15PM 2,693.2 0.95 2,545.0411:30PM 2,691.2 0.94 2,540.4811:45PM 2,662.9 0.95 2,524.43

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AppendixB:EESCalculationPrograms(Section3.2.1&3.2.2)The EES simulation program was based on proposed schematic designs for each approach. Following

is the calculation procedure used in brief.

1. Selecting a F&A rated boiler capacity

2. Taking operating pressures and temperatures to a table, here operating points in

industrial applications were considered.

3. Enthalpy of Steam exits the boiler will be decided by operating point.

4. Supplying 6Tons of steam at 10bar for finishing process with keeping the room for

1bar pressure loss in distribution system.

5. Supplying 10Tons of steam at 7bar for dyeing process with keeping the room for

1bar pressure loss in distribution system.

6. Assuming 85% of steam will return as condensate at 700C. This has been assumed

according to the past factory data.

7. Boiler feed water temperature is calculated according to the percentage of

condensate and fresh water.

8. Boiler actual generation capacity is calculated according to the feed water

temperature.

9. “Turbine IN” steam enthalpy is calculated according to the steam temperature and

pressure. No pressure drop is taken into the account due to proximity of boiler and

the turbine‐generator.

10. “Turbine OUT” steam enthalpy is calculated assuming 1bar back pressure at turbine

out.

11. The “Power IN” to the turbine is calculated with change of enthalpy and flow rate in

each step whilst tapping steam at 10bar and 7bar to cater the Finishing and Dyeing

process. 0.85 of isentropic efficiency is considered for each step.

12. The “Gross Power Out” from turbine generator is calculated with 0.65 turbine

mechanical efficiency and 0.98 generator electrical efficiency.

13. The power available to run the absorption chiller is calculated with the waste heat.

14. Required coal consumption is calculated with 0.8 boiler efficiency and 26,000 kJ/kg

calorific value of coal. Coal calorific value is taken from a recent lab test report.

15. The annual CO2e is calculated with coal emission rates.

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"Option02:CalculationsBasedonProcessHeatingDemand(Approach02)" Cap_br= 30000 [kg/hr] Boiler rated capacity" h_b= Enthalpy (steam, P=P_b, T=T_b) "Enthalpy of steam exits boiler" "Finishing Process" P_f= 10 [bar] "+1 bar for line pressure drop" {T_f= Temperature (steam, P=P_f, X=1)} {h_f= Enthalpy (steam, P=P_f, T=T_f)} Cap_f= 6000 [kg/hr]"Finishing steam requirement with future expansion" "Dyeing Process" P_d= 7 [bar]"+1 bar for line pressure drop" {T_d= Temperature (steam, P=P_d, X=1)} {h_d= Enthalpy (steam, P=P_d, T=T_d)} Cap_d= 10000 [kg/hr]"Dyeing steam requirement" "Assume boiler feedwater temperature is at 70C and 85% condensate returns" T_cw= 70 [C] "Condensate at 70C" T_mw= 30 [C] "make-up water at 30C" h_cw= Enthalpy (Water, T=T_cw, X=0) "Enthalpy of condensate" h_mw= Enthalpy (Water, T=T_mw, X=0) "Enthalpy of make-up water" T_fw= 0.85 * T_cw + 0.15 * T_mw "Boiler feed water temperature" h_fw= 0.85 * h_cw + 0.15 * h_mw "Boiler feed water enthalpy" "Boiler Actual Generation Capacity" Cap_bg= Cap_br * (h_b - Enthalpy (Water, T=100[C], X=0)) / (h_b - h_fw) T_tur_in= T_b– 0 P_tur_in= P_b - 0 "Turbine IN steam enthalpy" h_tur_in= Enthalpy (Steam, T=T_tur_in, P=P_tur_in)S_tur_in "Turbine Tapping Point 1 - Finishing" "Enthalpy for Isentropic expansion through turbine" h_tap1_is = Enthalpy (Steam, P=P_f, S=S_tur_in) "Assuming 0.85 of isentropic efficiency" 0.85= (h_tur_in - h_tap1) / (h_tur_in - h_tap1_is) T_tap1= Temperature (Steam, P=P_f, H=h_tap1)"Tapped steam temperature" S_tap1= Entropy (Steam, P=P_f, T=T_tap1)"Tapped steam entropy" "Turbine Tapping Point 2 - Production" "Enthalpy for Isentropic expansion through turbine" h_tap2_is = Enthalpy (Steam, P=P_d, S=S_tap1) "Assuming 0.85 of isentropic efficiency" 0.85 = (h_tap1 - h_tap2) / (h_tap1 - h_tap2_is) T_tap2= Temperature (Steam, P=P_d, H=h_tap2)"Tapped steam temperature" S_tap2= Entropy (Steam, P=P_d, T=T_tap2) "Tapped steam entropy" "Turbine Out" P_tur_out= 1 [bar]"Turbine out pressure for Back-pressure turbine" "Enthalpy for Isentropic expansion through turbine" h_tur_out_is= Enthalpy (Steam, P=P_tur_out, S=S_tap2)

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"Assuming 0.85 of isentropic efficiency" 0.85= (h_tap2 - h_tur_out) / (h_tap2 - h_tur_out_is) "Exit steam temperature" T_tur_out= Temperature (Steam, P=P_tur_out, H=h_tur_out) S_tur_out= Entropy (Steam, P=P_tur_out, T=T_tur_out)"Exit steam entropy" "Turbine Out Put" Pw_tur_in = (Cap_bg*(h_b-h_tap1)+(Cap_bg-Cap_f)*(h_tap1-h_tap2)+(Cap_bg-Cap_f - Cap_d) * (h_tap2 - h_tur_out) ) / 3600 Eff_tur= 0.65"Turbine mechanical efficiency" Eff_ele= 0.98"Generator electrical efficiency" Pw_tur_out= Pw_tur_in * Eff_tur * Eff_ele"Gross power generation" "Power Availble to Chiller" P_Av_Ch = ((Cap_bg - Cap_f - Cap_d) * (h_tap1 - h_cw) ) / 3600 "Power Availble to Chiller" P_Av_Ch = ((Cap_bg - Cap_f - Cap_d) * (h_tap1 - h_cw) ) / 3600 B_eff = .80 "Boiler Efficiency" B_en=(Cap_bg/3600)* (h_b - h_fw) "Energy Output of Boiler" Coal_cal = 26000 [kJ/kg] "Calorific Value of Coal" M_coal=(B_en / (B_eff*Coal_cal) )*3600*24*26*12/1000 "Annual coal consumption" CO2_coal = M_coal*2.321 "CO2e emission per annum" E_annual= Pw_tur_out*24*26*12

"Option02:CalculationsBasedonProcessHeatingDemand(Approach02)" Cap_br= 30000 [kg/hr] Boiler rated capacity" h_b= Enthalpy (steam, P=P_b, T=T_b) "Enthalpy of steam exits boiler" "Finishing Process" P_f= 10 [bar] "+1 bar for line pressure drop" Cap_f= 6000 [kg/hr]"Finishing steam requirement with future expansion" "Dyeing Process" P_d= 7 [bar]"+1 bar for line pressure drop" {T_d= Temperature (steam, P=P_d, X=1)} {h_d= Enthalpy (steam, P=P_d, T=T_d)} Cap_d= 10000 [kg/hr]"Dyeing steam requirement" "Assume boiler feedwater temperature is at 70C and 85% condensate returns" T_cw= 70 [C] "Condensate at 70C" T_mw= 30 [C] "make-up water at 30C" h_cw= Enthalpy (Water, T=T_cw, X=0) "Enthalpy of condensate" h_mw= Enthalpy (Water, T=T_mw, X=0) "Enthalpy of make-up water" T_fw= 0.85 * T_cw + 0.15 * T_mw "Boiler feed water temperature"

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h_fw= 0.85 * h_cw + 0.15 * h_mw "Boiler feed water enthalpy" "Boiler Actual Generation Capacity" Cap_bg= Cap_br * (h_b - Enthalpy (Water, T=100[C], X=0)) / (h_b - h_fw) T_tur_in= T_b– 0 P_tur_in= P_b - 0 "Turbine IN steam enthalpy" h_tur_in= Enthalpy (Steam, T=T_tur_in, P=P_tur_in) S_tur_in "Turbine Tapping Point 1 - Dyeing" "Enthalpy for Isentropic expansion through turbine" h_tap1_is = Enthalpy (Steam, P=P_f, S=S_tur_in) "Assuming 0.85 of isentropic efficiency" 0.85= (h_tur_in - h_tap1) / (h_tur_in - h_tap1_is) T_tap1= Temperature (Steam, P=P_f, H=h_tap1)"Tapped steam temperature" S_tap1= Entropy (Steam, P=P_f, T=T_tap1)"Tapped steam entropy" "Turbine Out" P_tur_out= 1 [bar]"Turbine out pressure for Back-pressure turbine" "Enthalpy for Isentropic expansion through turbine" h_tur_out_is= Enthalpy (Steam, P=P_tur_out, S=S_tap1) "Assuming 0.85 of isentropic efficiency" 0.85= (h_tap1 - h_tur_out) / (h_tap1 - h_tur_out_is) "Exit steam temperature" T_tur_out= Temperature (Steam, P=P_tur_out, H=h_tur_out) S_tur_out= Entropy (Steam, P=P_tur_out, T=T_tur_out)"Exit steam entropy" "Turbine Out Put" Pw_tur_in = (Cap_bg-Cap_f)*(h_b-h_tap1)+(Cap_bg-Cap_f- Cap_d)*(h_tap1- h_tur_out) ) / 3600 Eff_tur= 0.65"Turbine mechanical efficiency" Eff_ele= 0.98"Generator electrical efficiency" Pw_tur_out= Pw_tur_in * Eff_tur * Eff_ele"Gross power generation" "Power Availble to Chiller" P_Av_Ch = ((Cap_bg - Cap_f - Cap_d) * (h_tap1 - h_cw) ) / 3600 "Power Availble to Chiller" P_Av_Ch = ((Cap_bg - Cap_f - Cap_d) * (h_tap1 - h_cw) ) / 3600 B_eff = .80 "Boiler Efficiency" B_en=(Cap_bg/3600)* (h_b - h_fw) "Energy Output of Boiler" Coal_cal = 26000 [kJ/kg] "Calorific Value of Coal" M_coal=(B_en / (B_eff*Coal_cal) )*3600*24*26*12/1000 "Annual coal consumption" CO2_coal = M_coal*2.321 "CO2e emission per annum" E_annual= Pw_tur_out*24*26*12

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AppendixC:NPV,IRRandPaybackCalculationforCoalat28barand350oC

CommonData

AverageElectricityTariff 0.0928 $/kWh

Demandcost 6.80 $/kVA

CurrentPriceofFuelOil 0.720 $/Ltr

AnnualElectricityRequirement 23,960,000 kWh

AverageElectricityDemand 3,400 kVA

ElectricityreusedbytheTri‐gen 2,174,407 kWh

ElectricitydemandbytheTri‐gen 332 kVA

ElectricityConsumptionByVCChillers 2,308,435 kWh

ElectricityDemandByVCChillers 439 kVA

FuelOilConsumption 5,340,000 Ltr

CurrentPriceofCoal 149 $/Tr

Plantfactor 90%

CaseSpecificData

ElectricityGeneratedbySteamTurbine 7,095,600 kWh

ElectricityDemandmetbyTri‐gen 1,000 kVA

CoalConsumptionbyTri‐Gen 20,199 TR

Capital 4,200,000 $

AnnualOperationalCost 0.0160 $/kWh

AnnualLabourCost 0.0085 $/kWh

Assumptions

AnnualDiscountrate 10.00%

AnnualAverageOperationalcostincrease 6.3%

AnnualLabourcostincrease 5.0%

AnnualFueloilpriceEscalation 10%

Annualelectricitycostescalation 5%

AnnualCoalcostescalation 10%

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AnnualCostSavingCalculationYear 0 1 2 3 4 5 6 7 8 9 10

EnergyCostwithCurrentSystem

Annualelectricitycost 2,500,928 2,625,974 2,757,273 2,895,137 3,039,894 3,191,888 3,351,483 3,519,057 3,695,010 3,879,760

AnnualFuelOilCost 3,844,800 4,229,280 4,652,208 5,117,429 5,629,172 6,192,089 6,811,298 7,492,428 8,241,670 9,065,837

CurrentTotalEnergyCost 6,345,728 6,855,254 7,409,481 8,012,566 8,669,065 9,383,977 10,162,780 11,011,484 11,936,680 12,945,597

EnergyCostWithTriGen

AnnualSupplementaryElectricityCost($) 1,739,671 1,826,655 1,917,987 2,013,887 2,114,581 2,220,310 2,331,326 2,447,892 2,570,286 2,698,801

AnnualSupplementaryFuelOilCost($) 384,480 422,928 465,221 511,743 562,917 619,209 681,130 749,243 824,167 906,584

AnnualCostofCoal 3,009,653 3,310,619 3,641,680 4,005,848 4,406,433 4,847,077 5,331,784 5,864,963 6,451,459 7,096,605

AnnualLaborcost($) 60,600 63,630 66,812 70,152 73,660 77,343 81,210 85,270 89,534 94,010

AnnualOperationCost($) 113,530 120,625 128,164 136,175 144,685 153,728 163,336 173,545 184,391 195,916

NewTotalEnergyCost 5,307,934 5,744,456 6,219,864 6,737,805 7,302,277 7,917,666 8,588,786 9,320,912 10,119,837 10,991,916

Investment (4,200,000)

NetProfit(Netsaving) (4,200,000) 1,037,794 1,110,798 1,189,617 1,274,761 1,366,789 1,466,311 1,573,995 1,690,572 1,816,842 1,953,682

Presentvalueofcashflow(Rs) ‐4,200,000 943,449 918,015 893,777 870,679 848,668 827,694 807,708 788,664 770,519 753,229

SimplePayback 4.05NPV 4,222,403IRR 27.54%

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AppendixD:NPV,IRRandPaybackCalculationforSawDustBriquettesat28barand350oC

CommonDataAverageElectricityTariff 0.0928 $/kWhDemandcost 6.80 $/kVACurrentPriceofFuelOil 0.720 $/LtrAnnualElectricityRequirement 23,960,000 kWhAverageElectricityDemand 3,400 kVAElectricityreusedbytheTri‐gen 1,070,642 kWhElectricitydemandbytheTri‐gen 157 kVAElectricityConsumptionByVCChillers 2,308,435 kWhElectricityDemandByVCChillers 439 kVAFuelOilConsumption 5,340,000 LtrCurrentPriceofBriquettes 104 $/TrPlantfactor 90%

CaseSpecificDataElectricityGeneratedbySteamTurbine 7,095,600 kWhElectricityDemandmetbyTri‐gen 1,000 kVACoal/BioMassConsumptionbyTri‐Gen 30,859 TRCapital 3,295,000 $AnnualOperationalCost 0.0160 $/kWhAnnualLabourCost 0.0085 $/kWh

AssumptionsAnnualDiscountrate 10.00%AnnualAverageOperationalcostincrease 6.3%AnnualLabourcostincrease 5.0%AnnualFueloilpriceEscalation 10%Annualelectricitycostescalation 5%BioMasscostescalation 10%

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AnnualCostofCoal/BioMass 3,209,348 3,530,283 3,883,311 4,271,642 4,698,806 5,168,687 5,685,555 6,254,111 6,879,522 7,567,474





NetProfit(Netsaving) (3,295,000) 954,850 1,013,722 1,076,704 1,144,120 1,216,327 1,293,707 1,376,680 1,465,703 1,561,273 1,663,930

Presentvalueofcashflow(Rs) ‐3,295,000 868,045 837,787 808,943 781,450 755,243 730,264 706,455 683,761 662,132 641,517


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AppendixE:NPV,IRRandPaybackCalculationforFirewoodat28barand350oC

CommonData

AverageElectricityTariff 0.0928 $/kWh

Demandcost 6.80 $/kVA

CurrentPriceofFuelOil 0.720 $/Ltr

AnnualElectricityRequirement 23,960,000 kWh

AverageElectricityDemand 3,400 kVA

ElectricityreusedbytheTri‐gen 1,070,642 kWh

ElectricitydemandbytheTri‐gen 157 kVA

ElectricityConsumptionByVCChillers 2,308,435 kWh

ElectricityDemandByVCChillers 439 kVAFuelOilConsumption 5,340,000 LtrCurrentPriceofFirewood 48 $/Tr

Plantfactor 90%

CaseSpecificData

ElectricityGeneratedbySteamTurbine 7,095,600 kWh

ElectricityDemandmetbyTri‐gen 1,000 kVA

FirewoodMassConsumptionbyTri‐Gen 45,352 TR

Capital 3,265,000 $

AnnualOperationalCost 0.0160 $/kWh

AnnualLabourCost 0.0123 $/kWh

AssumptionsAnnualDiscountrate 10.00%AnnualAverageOperationalcostincrease 6.3%AnnualLabourcostincrease 5.0%AnnualFueloilpriceEscalation 10%Annualelectricitycostescalation 5%Firewoodcostescalation 10%

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AnnualCostoffirewood 2,176,883 2,394,571 2,634,028 2,897,431 3,187,174 3,505,891 3,856,481 4,242,129 4,666,342 5,132,976





NetProfit(Netsaving) (3,265,000) 1,960,315 2,121,083 2,296,219 2,487,076 2,695,140 2,922,042 3,169,572 3,439,694 3,734,562 4,056,543

Presentvalueofcashflow(Rs) ‐3,265,000 1,782,104 1,752,961 1,725,183 1,698,706 1,673,470 1,649,417 1,626,492 1,604,642 1,583,819 1,563,973


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AppendixF:CalorificValueTestforSawDustBriquette

of technical, environmental and of tri generation …693637/fulltext01.pdfevaluation of technical,...

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