Jagodaarachchi Wasana_Ekanayake Anuruddha_EGI-2014-009MSC $(function(){PrimeFaces.cw("Tooltip","widget_formSmash_items_resultList_26_j_idt799_0_j_idt801",{id:"formSmash:items:resultList:26:j_idt799:0:j_idt801",widgetVar:"widget_formSmash_items_resultList_26_j_idt799_0_j_idt801",showEffect:"fade",hideEffect:"fade",target:"formSmash:items:resultList:26:j_idt799:0:fullText"});});

Jagodaarachchi Wasana_Ekanayake Anuruddha_EGI-2014-009MSC $(function(){PrimeFaces.cw("Tooltip","widget_formSmash_items_resultList_26_j_idt799_0_j_idt801",{id:"formSmash:items:resultList:26:j_idt799:0:j_idt801",widgetVar:"widget_formSmash_items_resultList_26_j_idt799_0_j_idt801",showEffect:"fade",hideEffect:"fade",target:"formSmash:items:resultList:26:j_idt799:0:fullText"});});
M.Sc. Thesis EvaluationofTechnical,Environmentaland
FinancialViabilityofTri–GenerationinApparel
SectorofSriLanka
By
WasanaChinthakaJagodaarachchi(830926–P132)
AnuruddhaEkanayake(850801–P817) MasterofScienceThesis
KTHSchoolofIndustrialEngineeringandManagement
EnergyTechnologyEGI‐2013
SE‐10044STOCKHOLM
M.Sc. Thesis BachelorofScienceThesisEGI‐2013
Evaluation of Technical, Environmental
and Financial Viability of Tri – Generation
inApparelSectorofSriLanka
WasanaChinthakaJagodaarachchi(830926–P132)
AnuruddhaEkanayake(850801–P817)
Approved
Examiner
Supervisor
Prof.BjörnPalm
Dr.SadJarall
Commissioner
Contactperson
ii | P a g e M.Sc. Thesis ABSTRACT
ApparelindustryisthemainsourceofforeigncurrencyforSriLankaandistheonethat
provides most number of local employments. It has been severely affected by the
continuousriseoffossilfuelprices.Industryisalsounderpressurebythegovernments
andbuyers(majorretailchainsandglobalapparelbrandswhohastheirsupplychain
emission reduction goals) to minimize the emissions as well as to reduce the energy
consumption.Inviewofthat,thisstudywasfocusedontheviabilityofusingcombined
heating,coolingandpowergenerationortheTri‐Generation(TG)atfactorylevelwhich
hasneverbeentriedintheapparelindustryinSriLanka.
After the literature survey, local apparel sector was analyzed and then the factories
were categorized in to five main groups out of which the most affected group by the
energycost,thefabricmanufacturing,wasselectedasthefocusgroup.Onefactoryfrom
thefocusgroup,TexturesJersey(TJ)wasselectedfortheinitialcasestudy.Afteradetail
energy audit at TJ, results were used to evaluate the environmental and economical
viability of two selected TG combinations. One with most favorable results was
optimized and then studied in detail to see if it is environmentally, economically and
technicallyviabletoTJ.ResultofthedetailanalysisoftheoptimalTGcombinationwas
usedtocomeupwithgeneralguidelinestoimplementviableTGplantsforlocalapparel
industry.
As per the results TJ can enjoy substantial benefits (15‐35% energy cost saving) by
opting to use a TG, fired by either coal or biomass (saw dust briquettes or firewood).
Biomassispreferredovercoalduetolowpricesandreducedemissions.Notneedingof
acomplicatedfuelpreparationandfeedingsystemasinacoalfiredTGsystemisalsoan
advantage of Bio‐mass. However biomass has relatively more supply chain issues
comparedtocoal.Auniversalsolutionthatcanbeusedbyanyapparelfactorycannotbe
arrived at, as economics of the TG is highly depended on local parameters. However
selecting the capacity of a TG based on the process heating demand of a factory is
beneficialifithasa24houroperation.IntermittentoperationofTGisnoteconomicalas
frequentstart‐upandshut‐downofaTGisnotpractical.Further,increasingelectricity
generationinTGisnotveryattractiveowingtosubsidizedtariffs.
i | P a g e M.Sc. Thesis ACKNOWLEDGMENTS
Firstofall,wearegratefultoourSupervisorsDr.MahinsasaNarayanaandDr.SadJarall
fortheirguidanceandsupporttosuccessfullycompletethethesis.Wewouldalsoliketo
thank lecturers and staff of International College of Business & Technology, Open
universityofSriLankaandRoyalInstituteoftechnology,Swedenforthesupportthey
extendedbyfacilitatingandcoordinatingourthesisrelatedactivities.
Wetakethisopportunitytoacknowledgewithmuchappreciationthecrucialsupportby
the management and the staff of the Textures Jersey for giving permission to conduct
the energy audit and providing access to technical data and financial data for the
analysis. A special thank goes to tri generation plant equipment suppliers and
contractors for providing technical information and other literature relevant for the
thesiswork.
Furthermorewewouldalsolikeexpressthegratitudetoallwhodirectlyorindirectly
havelenttheirhelpinghandforthesuccessoftheresearch.
ii | P a g e M.Sc. Thesis CONTENT
ABSTRACT ................................................................................................................................................. 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 iii | P a g e M.Sc. Thesis 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 ListofTables
Table 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 4.3: Option 01 ‐ Process Heating Base Calculation for 30 TPH Boiler (F&A100C) ....................... 26 Table 4.4: Option 02 ‐ Process Heating Base Calculation for 20 TPH Boiler (F&A100C) ....................... 29 Table 4.5: Option 02 ‐ Process Heating Base Calculation for 25 TPH Boiler (F&A100C) ....................... 29 Table 4.6: Option 02 ‐ Process Heating Base Calculation for 30 TPH Boiler (F&A100C) ....................... 30 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 iv | P a g e M.Sc. Thesis 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 v | P a g e M.Sc. Thesis NOMENCLATURE
ListofAbbreviations
AFBC ‐AtmosphericFluidizedBedCombustion
APH ‐AirPreHeater
BFP ‐BoilerFeedWaterPump
BOI ‐BoardofInvestment,SriLanka
CCHP ‐CombinedCoolingHeating&Power
CT
‐CoolingTower
CWP ‐CondenserWaterPump
DMWP
‐De‐mineralizedWaterPump
EES ‐EngineeringEquationSolver
EfP ‐EffluentPump
ESP ‐ElectroStaticPrecipitator
F&A ‐FromandAt
FBC ‐FluidizedBedCombustor
FD
‐ForcedDraft
GHG ‐GreenhouseGas
HFO ‐HeavyFuelOil
HHV ‐HigherHeatValue
ID
‐InducedDraft
IRR ‐InternalRateofReturn
KTH ‐RoyalInstituteofTechnology
LHV ‐LowerHeatValue
MSB ‐MainSwitchBoard
NPV ‐NetPresentValue
PA
‐PrimaryAir
PPM ‐PartsperMillion
PRV ‐PressureRegulatingValve
PM ‐ParticulateMatter
P&T ‐PressureandTemperature
RWP ‐RawWaterPump
SPB ‐SimplePaybackPeriod
TG
‐Tri‐Generation
TPH ‐Tonesperhours
TJ
‐TexturedJerseyLankaPLC
WTP ‐WaterTreatmentPlant
1 | P a g e M.Sc. Thesis 1 INTRODUCTION
Increasingdemandforfossilfuelandtheconflictsinthemajoroilproducingcountries
hasledfossilfuelpricetoincreaseuptoalevelwhichisalmostunbearabletotheSri
Lankan industry. Among all, apparel manufacturing is one of the severely affected
industriesbythesuddenfuelpricehikes.Asaresultoftheglobaltrendofsustainable
development, pressure to minimize the emissions by reducing the use of fossil fuel &
electricityconsumption,isanothermajorchallengefacedbythelocalapparelindustry.
ApparelindustryhaslongbeenthemainsourceofforeigncurrencyforSriLankaandis
the industry that provides most number of local employments. Despite the significant
growth of 13.8% in apparel manufacturing industry during 2011, overall production
costhasbeenaffectedbyincreaseoffurnaceoilpriceby80%,electricitycostby15%
andsalaries&wagesby20%during2012.Amongallabove,thehighestandunexpected
80% increase of furnace oil price has severely affected mainly to the knitting and
weavingindustrywherefurnaceoilboilersareheavilyusedforsteamproduction.
Furthermore, the lower production cost associated with the apparel manufacturing
industriesinneighboringcountrieslikeBangladesh,Vietnamandthecountrieswitha
massiveindustrialsectorlikeChina,hasmadeitmoredifficulttoSriLankatosustainits
market share in the international market. Hence, local manufactures are desperately
seeking methods to reduce manufacturing cost, to keep their business running
successfully. Since the lack of controllability over the production related costs like
materialcost,machinerycost,costoflabourandetc,themostviableoptionistoreduce
cost of energy incurred in providing utilities, such as air conditioning, lighting, steam
generationandcompressedairgeneration.
Implementation of various energy efficiency methods and use of energy efficient
equipmenthavebeenthetoppriorityactivitiestoreducetheenergyconsumption.This
studyisfocusingontheviabilityofusingTri‐Generationatfactorylevelwhichhasnever
beentriedinSriLankanapparelmanufacturingindustry.
1.1 ProblemStatementandMethodology
A typical Sri Lankan apparel manufacturing factory requires electricity to run its
machineries,airconditioning&Ventilationsystem,lightingsandutilityequipmentlike
compressors and pumps. Fossil fuels like Diesel and furnace oil are used to fulfill
thermal energy requirements and to operate boilers to generate required steam for
manufacturingprocess.Mainobjectiveofthisstudyistoanalyzingtheviabilityofself‐
generation of required electricity while fulfilling the steam and cooling demand by
implementingacombineheating,coolingandpower(CCHP)plantwhichiscommonly
2 | P a g e M.Sc. Thesis knownasTri‐Generationintheindustry.TheTri‐Generationarrangementthathasbeen
analyzed in below chapters includes a high pressure steam boiler, a steam turbine, a
wasteheatrecoverysystemandabsorptionchillers.
AlthoughfossilfuelsuchasDieselandFurnaceoilarenoteconomicallyviableoptionin
Sri Lanka due to high price, same are commonly used in the apparel sector as it is
readily available and easy to use. Coal and biomass are the two identified candidate
fuelsandthechallenges(economical,technicalandenvironmental)ofusingthosefuels
for the combined cooling, heating and power plant need to be analyzed. Based on the
results,plantequipmenthastobeselectedeithertypeoffuels.
Next is to study the viable options to supply of low pressure steam for the
manufacturing process while maintaining the high pressure steam to the turbine.
Directly taping the high pressure steam and use of pressure reduction methodologies
can be identified as one option whereas the tapping steam from various working
pressure from the turbine is another option. Above two options and possible other
methods need be studied to identify technical complexities and economical feasibility.
Installation of water treatment plant to meet boiler feed water standards and
appropriate emission reduction methodologies to meet with country and board of
investment (BOI) environmental regulations also has to be evaluated. Suitable fuel
storagecapacityandfuelfeedingmechanismhastobechosentoensureuninterrupted
fuelsupplytoboiler.
Feasibilityofrunninganabsorptionrefrigerationcyclechillerwhichutilizesthewaste
heat of steam turbine need be evaluated, against running of a vapor compression
refrigeration cycle chiller from electricity. In a typical apparel factory air conditioned
load accounts for about 40 to 50% of the total electricity consumption. Use of an
absorption refrigeration cycle chiller that runs with waste heat substantially reduces
the above electricity demand and it downsizes the required steam turbine capacity.
Smallerturbineresultsinalessamountofwasteheatthatwouldnotbesufficienttorun
the absorption refrigeration cycle chiller of the required capacity. Therefore it is
requiredtostudytheoptimumcapacitiesofallplantequipment.Beingonlyself‐sustain
withtheelectricityandfeedingthegridwiththeexcesselectricityarealsotwooptions
thatneedtobestudied.
Toanalyzetheabovesaidvariousoption,bothmanualandcomputerbasedcalculation
methodsareused.EngineeringEquationSolver(EES)andMicrosoftExcelspreadSheets
are the main software used for the evaluations. EES and MS Excel are manually
programmedforthecalculations.Resultisthenusedtosimulatethebuildingoperations
and energy consumption patterns to calculate the optimal economical and
environmentalbenefits.
3 | P a g e M.SSc. Thesis Followiing Figure 1 indicatees the main
n stages of the study that are to
o be condu
ucted to
analyzeetheissuessmentioneedabove.
•StudyaaboutLocalA
ApparelIndusstry
•Identiffycanditatefaactoryforcassestudy
Step0
01 •conducctanenergyA
AuditinIden
ntifiedplant
(Chapter02)
Step0
02
(Chapter03)
Step0
03
(Chapter04)
•Useressultsoftheau
udittoidentiifyenergycon
nsumptionpaatternofapparelfactoriess
•Identiffypossibleco
ombinationsfforTGplant
•Capaciityestimation
nandeconom
micanalysiso
ofselctedcom
mbinations
•OptimiizationoftheeTGbasedon
ntheResulto
ofstep‐02
•Idnetiffyeconomic,environmenttalandtechniicalchangeso
ofoptimalplaant
combin
nation
•CreateGeneralguid
delineforloccalapparelin
ndustryonT
TG
Figure 1: M
Main Steps of the Analysis 1.2 Objectives
O
softheStu
udy
The maain objectiv
ve of this research iss to provid
de set of generalized
g
guideliness to the
localap
pparelsecttortoidenttifytheeco
onomical,eenvironmen
ntalandtechnicalchaallenges
and thee benefits that
t
they would
w
com
me across in
n implemen
nting a Trii‐generation plant.
(Combin
nedCoolinggHeatandpowerplantt).
Thespeecificobjecctivesoftheeresearchare:
 DoaapreliminaarydesignofaTri‐Generationplant(TG)fo
oraselecteedfacility
 Anaalyzingofteechnical,en
nvironmen
ntalandeco
onomicalfeeasibilityo
of
o Coalfireedboileran
ndBiomassBoilerfiredboilerfo
ortheTGp
plant
o Use of vapor com
mpression chiller run
ns using ellectricity in
nstead of using a
vaporab
bsorptioncchillerrunssusingreco
overedheaatfromthepowerplan
nt.
o Requireedplantequ
uipmentcaapacities
o Generattingelectriccitytobesself‐sufficieentagainst feedingthegridwith
hexcess
capacity
y
 Evaaluationof possiblem
methodtosupplysteaamtomanu
ufacturingp
processat various
pressures
o Directtaapingfrom
mhighpresssureboilerrandsendthroughp
pressurereduction
valvesfo
orhighpreessureandlowpressu
uresteamrrequiremen
nts
o Extractiingsteamfr
fromtheTu
urbineatvaariouspresssurelevelssforhighp
pressure
andlow
wpressuresteamrequ
uirements
 Opttimize the design bassed on find
dings abovee and geneeralize it to
o be used in other
man
nufacturinggfacilities
4 | P a g e M.Sc. Thesis 2 LiteratureSurvey
Therearemanyoperatingtri‐generationfacilitiesintheworldandalsolotofresearch
hasbeencarriedoutbyvariouspartiesaboutthetechnology.Howeverashighlightedin
the previous sections, main issues to be addressed in this research is the lack of
knowhowinlocalindustry,meetingprocessrelatedrequirementsotherthantheenergy
requirementsandevaluationofsustainabilityoftri‐generationinthelocalcontext.
A literature survey was carried out in order to find out the current status of Tri‐
generationplantsofthesimilarcapacityandapplication.Widerangeofkeywordsand
varioustoolswereusedtocarryoutthesurveytoensurethatthemostrelevantpapers,
articles and case studies about this topic are referred. Two main component of the
project, namely the combined heat & power component and the cooling component
(boththermallydrivenandelectricallydriven)ofsamecapacityrange,werefocusedin
thesearch.Furtherliteraturereviewswerecarriedoutastheresearchprogresstoplant
design stage, to find out the technical data of the various products required for the
functioningoftheplant.
SummaryofrelevanttheoreticalanalysisofTri‐Generation,availabletechnologiesand
the developments and the results case studies of similar plants listed below in the
report.
2.1 TheoryandTechnology
Generation of electricity, useful heat and cooling using fuel combustion or by other
mean of heat source is commonly known as combined heating, cooling and power
generationorTri‐generation.
InatypicalTri‐Generationplant,gasorsteamturbineisruntogeneratetheelectricity
using high temperature / high pressure source and this result in relatively low
temperature waste heat. This waste heat is then used for heating and to generate
cooling by an absorption chiller. Advantage of this kind of system is the ability of
attaining higher overall efficiency compared to other type of traditional power plants.
Efficiencyofatri‐generationplantiscalculatedasshownbelow.
ƞ
ManypapersthattalksabouttheeconomicsoftheTri‐generationwerestudiedduring
thesurveyastheanalysisofeconomicviabilityofthesuggestedplantisamajorpartof
thestudy.Followingisasummaryoffewrelevantpapersforthisstudy.
5 | P a g e M.Sc. Thesis “Tri‐generationinfoodretail:anenergetic,economicandenvironmentalevaluationfora
supermarketapplication” by Sugiartha et al[5], discusses the results of an evaluation of
economic and environmental performance of a Tri‐Generation plant for supermarket
applications. Analysis is based on factors such as fraction of the heat output used to
drivetheabsorptionchillers,thechillerCOPandthedifferencebetweenelectricityand
gas prices. As per this analysis of Sugiartha et al, three is obvious economical and
environmental benefits compared to the conventional system. Further, both the
economical and environmental benefits are optimized by operating the plant at full
electricityoutputratherthanfollowingtheheatload.Economicsoftheplantishighly
dependsoncostofelectricity,costofgasandtheCOPofthecoolingsystem.
Main difference between this system and the proposed system to be studied is the
natural gas turbine. Proposed system has a steam turbine and the Natural gas is not
consideredasanoptionasitisnotavailable.Smallgenerationcapacity(80kW)andthe
application (supermarket) are also differing much from an industrial application.
Howevertheeconomicalmodelusedfortheanalysisprovidegoodbasicframeworkto
developamodeltoTri‐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 and
reduced GHG emissions”. The most important thing in this paper is the similarity
comparedtothecaseofanapparelfactory.Thepulpmillthathasbeenstudiedhasa
requirement for cooling and steam at different pressure levels. Cooling is met by an
absorption chiller. Andrea Costa et al propose three option and they conclude that all
three have economical benefits. However results show that system without power
generation (with only the absorption chiller) has the highest simple payback whereas
theoptionwithtri‐generationhashighnetpresentvalues.
Unlike the case of an apparel factory, “Economicalanalysisoftri‐generationsystem” by
Süleyman Hakan et al[8], present results of a research carried out on tri‐generation
applicationinauniversitycampuswhereheatingisutilizedforbuildingheating(notfor
process heating). However one important objective of this paper is to come up with
modeltodetermineoptimumcapacityofatri‐generationsystem.Moreoveritisabout
the economics of embedding a tri‐generation system to existing system which is the
caseinsystembeingstudied.
Thoughhavingahighenoughcapacitytosupplyallenergydemandsofthebuildingis
the requirement of the Tri‐Generation, research result indicates that meeting total
energy demand could increase the investment thereby resulting higher payback time.
Main reason behind this scenario is the non existence of the peak demand for long
periods. However the situation could be different in industrial facility located in a
tropicalclimate.
6 | P a g e M.Sc. Thesis Lozan et al present in their paper, “ThermoeconomicAnalysisofSimpleTri‐generation
Systems”, a much generalized economical analysis of a simple tri‐generation system.
UnlikemanypapersonTri‐generation,thisstudyisnotlimitedtoaspecificapplication.
The system is connected with the main electricity supply grid allowing system supply
excesselectricitytogridandtoreceivetheshortage.Paperismoreorientedtowards
theeconomicsratherthanthetechnicalaspects.
Lozanetal[4]haveusedalinearprogrammingmodeltoobtainthemodewiththelowest
variable cost, out of series of options available to meet a given demand of a user.
Analysisusesthreedifferentapproachestocalculatethecostoffinalproductandeach
approach results in different costs. This means that a universal approach cannot be
usedforeconomicalevaluationofTri‐generationandtheviabilityiswidelydependson
thespecificapplication.
Fromthedatacollectedduringliteraturereview,itisevidentthatthistechnologyhas
beenusedinapplicationwherethereisasubstantialdemandinelectricity,coolingand
heating (process or comfort heating). Further the most of the applications has much
higherdemandforallthreeformofenergythanatypicalapparelfactoryinSriLanka
and the demand has more of distributed form (Similar to district systems, military
campsandcampuses)thanamediumscalemanufacturingfacility(SimilartotypicalSri
Lankanapparelfactory).Itisclearthatthesetwofactors,thedistributeddemandand
the substantially higher demand are key factors that affect the economics and the
sustainabilityofaTri‐generationfacility[6],whichisnotthecaseofanapparelfactory.
Howevertheavailableliteratureandthecasestudiessuggestthatthistechnologycan
be used in applications which do not exhibit above characteristics, depending on the
statusoftheotherparameters.Followingcanbeidentifiedastheparametersthatwill
affect the economical viability and the overall sustainability of a tri‐generation
applicationinanapparelfactory.
a) Cost,qualityandtheaccesstoavailableenergy
b) Scaleofthefacilityandtheoperationhours
c) Environmentalconstrainsandtargets
7 | P a g e M.Sc. Thesis 3 ResultsofEnergyAuditConductedinSelectedFactory
Firststepofthisstudywastoidentifyanapparelfactorywhereallthreeformofenergy
uses namely; electricity, process steam (Heating) and air conditioning are used and
conductadetailedenergyaudittoidentifytheconsumptionpatternoftheeachform.
Inidentifyingafacility,themanufacturingprocessesofvariousapparelfactorieswere
studied and it was noted that those can be categorized in to several different types
based on their manufacturing processes. Following are the main categories identified
duringthestudy.
1) FabricManufacturing
a. Knitting
b. Weaving
2) FabricPrinting
3) Cutting&Sewing
4) Finishing
5) Other(manufacturingofZippers,Hangers,Buttonsect…)
Fivefacilitieswereselectedineachcategoryforcomparisontoanalyzethepotentialof
trigeneration.
1)
2)
3)
4)
5)
FabricManufacturing
FabricPrinting
Cutting&Sewing Finishing
Other TexturedJerseyLanka,Avissawella
QuenbyLankaPrints,Avissawella
BrandixCasualwear,Avissawella
BrandixFinishing,Rathmalana
T&SButtons,Biyagama
Electricity**
Steam**
(Monthlyavg.kWh) (Monthlyavg.kg)
TexturedJersey
1,933,000
63,475,000
QuenbyLanka
227,000
975,000
BrandixCasualwear
172,000
220,000
BrandixFinishing
287,000
133,000
T&SButtons
65,300
66,000
**Dataobtainedfrommaintenancedepartmentofeachfactory Facility
ACCapacity**
(TR)
610
40
250
150
24
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 are
potentiallybeneficialforTri‐generationplant.Table3.1indicatesasummaryofenergy
consumptionandcoolingrequirementsofeachoftheindentifiedfacilities.
8 | P a g e M.Sc. Thesis 3.1 FactorsConsideredinSelectingtheFacility
Fromtheinformationfoundduringtheliteraturereviewsandthebackgroundsearch,it
was learned that there are many factors that would affect the viability of a tri‐
generation plant. Based on that knowledge, several main factors were identified and
consideredinselectingtheabovefacilitytoconductanenergyaudit,resultofwhichwill
subsequentlybeusedtoevaluateviabilityofthetri‐generation.Factorsconsideredare
listedbelow,
 ImpactbytheEnergyCost
If a cheap source of energy is available, none of the activities such as self‐
generation, use of renewable energy sources and investing on energy saving
method may not paid back in monetary terms. Therefore it was considered to
selectafacilitywherethecostofenergyisveryhighcomparedtootherswhich
will induce a higher possibility of economical attractiveness for the Tri‐
Generation.
 ExtensiveSteamUsage
Asexplainedabove,tri‐generationplantsproduceelectricity,coolingandheating
simultaneously.Therefore,forsuchaplanttobeviableitisessentialtohaveend
use that require above three form of energy. The only use where heat can be
utilizedistheprocessrelatedapplications,sinceSriLankaisatropicalcountry
wherespaceheatingorservicehotwaterisnotarequirement.
Fabric manufacturing factories require thermal energy for dying machines and
Stentormachines,whereasmostoftheothertypesuseonlyforironingpurpose
(Generally this is based on steam generation). Since a substantial amount of
steamisgoingtobeavailableafterthepowergenerationinsteamturbineitwas
decidedtoselectafacilitywithsubstantialsteamconsumption.
 EnvironmentalTargets
AnotherimportantchallengefacedbytheapparelmanufacturesinSriLankais
meeting the environmental targets such as reduction of carbon foot print,
enforcedbytheirinternationalbuyersandvariousregulatorybodies.Therehad
beenmanyinstancesintheindustrywheremanagementinvestingonmeasures
whichareeconomicallynotviable,tomeettheenvironmentaltargets.Therefore,
it was assumed that a facility with environmental targets such as emission
reductionshouldbeconsideredfortheenergyaudithopingthatcertainmeasure
of Tri‐Generation will be environmentally viable even if those are not
economicallyattractive.
 SubstantialElectricalEnergyUsage
ThemostessentialcomponentofaTri‐generationplantisasteamturbinewhich
generatestheelectricity.Smallertheturbinethelesserthewasteheatavailable
9 | P a g e M.Sc. Thesis for subsequent uses[2]. Therefore it was assumed that a plant with comparably
highenergyconsumptionhastobeselectedforthestudy.
 SubstantialAirConditioningLoad
OneoutcomeofTri‐generationisthewasteheatthatcanbeusedtooperateair
conditioning systems, which operate with the absorption cycle. If the air
conditioningloadisverysmallsuchwasteheatwouldnotbeadequatelyutilized.
 ResourceAvailabilityforCogenerationPlant
Tri‐generation is not viable if other required resource such as space, access to
water,transportationandetcatsitearenotavailable,regardlessofthestatusof
thefactorsmentionedpreviously.
3.2 OverviewoftheSelectedFacility
3.2.1 GeneralOverview
TexturedJerseyisoneofSriLanka'smostsophisticatedfacilities,manufacturingknitted
fabricsfortheintimateapparel(lingerie)andsportswearindustries.Specializedinthe
manufacturing of high quality weft‐knitted and dyed stretch fabrics, it is a major
suppliertoapparelmanufacturersthroughoutAsiaandend‐chainretailers.Amongstits
buyers,thelargestareMarks&SpencerandVictoria'sSecret.
Textured Jersey was awarded the prestigious Oeko‐TexStandard 100 Certification, an
internationally recognized test for harmful substances present in textile manufacture,
which is now the benchmark for quality and safety amongst the textile industry in
Europe.
TexturedJerseysuppliesitsproductstothetwolargestGroupcompaniesproducingits
core products, specializing in stretch fabrics. Infrastructure at the facility enables a
capacity to knit, dye and finish up to 2.5 million meters of fabrics a month. With the
contribution of the annual turnover, TJ can be called as a backbone of Sri Lanka’s
apparel sector. Textured Jersey’s contribution to the total annual turnover in whole
apparelsectorwas2.6%inlastfinancialyear.
Manufacturing process of the facility is of three‐steps which take place across three
majorproductionunits:



TheKnittingprocess‐convertstheyarn(Cotton,Viscose,ModalandPolyester)
intogreigefabric.
TheDyeingprocess‐coloursthegriegeintothespecifiedcolour.
TheFinishing‐Finalprocessthatensuresthedyedfabricisfinishedtotheexact
standards.
10 | P a g e M.Sc. Thesis 3.2.2 EnergySources&Consumptions
TexturedJerseyobtainsitenergydemandfromthreemainenergysourcesasshownin
Table3.2andthecostincurredinyear2011&2012toobtaineachofthesourcesare
given in the table 3.2. Financial statement of Textured Jersey for the year ending 31st
March2012isgiveninfollowingTable3.4. EnergySource
Equipment/Area
Airconditioning
Productionmachines
Steamboilers
GridElectricity
Thermicoilheaters(notforHeating)
Officeequipment
Lightingfixtures
Bulkdyingmachines
Sampledyingmachines
Babydyingmachines
Yarndyingmachines
Steamboilers
FurnaceOil
Dyemixingmachines
Dyeheatingmachines
Dryingmachines(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
45,836
EquivalentGJ
87,723
368,534
2,053
Year2012
23,196,865
7,836,504
EquivalentGJ
83,509
322,864
**DataobtainedfrommaintenancedepartmentofTexturedJersey 49,379.00
2,212
Table 3.3 : Annual Consumption of Each Source of Energy in Textured Jersey Description
SriLankaRupees000’s**
Sales
12,236,724
Costofsales
(10,906,806)
Grossprofit
1,329,918
SellingandAdminexpenses
(501,874)
Operatingprofit
828,044
NetFinancecost
(166,973)
ProfitbeforeTax
661,071
Tax
(33,042)
NetProfit
628,029
**DataobtainedfromAccountsandFinancedepartmentofTexturedJersey Table 3.4 : Financial Statement for Year 2011/2012 of Textured Jersey 11 | P a g e M.Sc. Thesis FlowofenergytoendusegiveninTable3.2fromthreeenergysourceisshowninbelow
Figure 2. Out of three sources furnance oil contribute to the highest amout which is
about ~80% of the total as shown in Figure 3. Electricty consumption contributes to
restofthe20%.Dieselinonlyusedasstandbyenergysourcehencethecontribution
bythesameismearly1%.
MainGrid
Diesel
FurnaceOil
SteamBoilers
Electricity
ThermicHeaters
Steam
HeatedThermalOil
AirConditioning
OfficeEquipment
Lighting
ProductionMachineries
Figure 2 ‐ Energy Flow within Textured Jersey
ConversionFactorsUsed
(1kWh0.0036GJ),(1FOLiter0.0412GJ),(1DieselLiter0.0428GJ)
1%
1%
19%
20%
79%
80%
Eletricity
FurnaceOil
Diesel
Eletricity
FurnaceOil
Diesel
2012
2011
Figure 3 ‐ Contribution of Each Energy Source to the Total in Textured Jersey
12 | P a g e M.Sc. Thesis 3.3 ImpactofEnergyconsumption
3.3.1 EconomicalImpact
The recent amendment of furnace oil price shown in Figure 4 (from LKR50 to LKR90
perliter)hasseverelyaffectedtheoperationalcostwithanincreaseof55%.According
to the global fuel market, more hikes are anticipated in the future, rather than
momentaryreductions.Hence,maintainingtheproductioncostisbecomingmoreand
morechallenging.
100.0 90.0 80.0 70.0 LKR
60.0 50.0 40.0 30.0 20.0 10.0 Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
‐
2012
2011
Figure 4 ‐ Variation of Fuel Oil Cost at Textured Jersey
2011
AnnualFuelConsumption(Liters)
AnnualFuelCost(USD)
CostIncrease(USD)
2012(Expected)
8,900,000
3,700,000
8,900,000
6,675,000
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 LKR
386,750,000 annually. Table 3.6 is a comparison of the financial figures, if the same
amount of sales, same amount of fuel consumption and no change in other cost are
assumedforyearstocome.
13 | P a g e M.Sc. Thesis Description
SriLankaRupees000’s
12,236,724
12,236,724
(10,906,806)
(11,293,556)
1,329,918
943,168
(501,874)
(501,874)
828,044
441,294
(166,973)
(166,973)
661,071
274,321
(33,042)
(13,711)
628,029
260,610
Sales
Costofsales
Grossprofit
SellingandAdminexpenses
Operatingprofit
NetFinancecost
ProfitbeforeTax
Tax
NetProfit
Table 3.6 : Expected Financial Statement for Year 2012/2013 with the FO Price Hike in Textured Jersey Accordingtoabovefiguresfurnaceoilpricehikealonewillcontributeto58%decrease
ofnetprofit.Moreoverthe15%fueladjustmentchargeimposedonelectricitytariffwill
increaseannualoperationalcostbyanotherLKR33million.
3.3.2 EnvironmentalImpact
Manufacturingfacilitycanadverselyimpacttheenvironmentbyvariousmeans.Green
HouseGas(GHG)emissionduetoenergyconsumption,landfillduetowastegeneration,
use/pollutionofwaterresourcesandheatislandeffectaresomeofthemostcommon
scenarios that adversely affect the surrounding of any factory or a manufacturing
facility.Onlytheenvironmentalimpactduetoenergyconsumptionisstudiedunderthis
since a setting‐up of tri‐generation facility will only contribute to change in GHG
emissionrelatedtoenergyconsumption.
Currently ‘Textured Jersey’ is using three energy sources; namely electricity,
combustion of Furnace Oil to run Boilers / Oil heaters and Diesel for stand by
generators. Another indirect contributor (related to energy consumption) is
refrigerantsusedinairconditioningsystem.
As per the records kept by the maintenance department of the facility, annual
consumptionofeachsourceofenergyisgivenintheTable3.7.
Source
Electricity
AverageConsumption
TotalEnergy(MJ)
CO2e(Mt/yr)
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]
50,000ltr/Yr
2,140,000
148[11]
Diesel**
Table 3.7 : Equivalent CO2 Emission by Each Source in Textured Jersey **Dieselconsumptionlargelyvariesaccordingtothepowerfailures.Consumptionfigureisbasedonannual
averagedata
14 | P a g e M.Sc. Thesis Airconditioningsystemofthefacilityisequippedwiththecoolingequipmentsshownin
Table3.8andastheamountrefrigerantchargedtocompensatetheleakagesaregiven
inthesame.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 Figure 5‐ GHG (CO2e) Emission by Source in Textured Jersey 3.4 EnergySystemoftheFactory
BelowFigure6showthepercentageenergyprovidedbyvarioussourcestothevarious
energysystemsofthefacility.
48.3%
19.0%
32.2%
0.5%
Electricity
Furnace Oil ‐Boiler
Furnace Oil ‐ Oil Heater
Diesel
Figure 6 ‐ Percentage Energy Consumption by End‐use in Textured Jersey 15 | P a g e M.Sc. Thesis 3.4.1 ElectricalSystem
4000
1.00
3500
0.95
3000
0.90
2500
0.85
2000
Demand
0.80
PowerFactor
1500
0.75
1000
0.70
500
0.65
0
0.60
Power Factor
The facility comprises of 6000 kVA transformer capacity and average maximum
demand is around 3400 kVA. As per the logged data, the demand for electricity
throughout the day is not fluctuating significantly, except the small drop during the
nighttime.Figure7indicatestheaveragedailyvariationoftheelectricaldemandofthe
facility. Since there are no seasonal variations this can be assumed as the average
throughouttheyear.
Figure 7‐ Daily Electricity Demand Variation in Textured Jersey ThemonthlytotalkWhrconsumptionandtotalelectricitycostbasedonhistoricaldata
isshowninbelowFigure8.
7,000,000 40,000,000
6,000,000 35,000,000
25,000,000
4,000,000 20,000,000
3,000,000 2,000,000 1,000,000 15,000,000
10,000,000
5,000,000
‐
Cost (LKR)
kWh
30,000,000
5,000,000 0
Jan Mar May Jul
Sep Nov Jan Mar May Jul
2011
Total kWh Consumption
Sep Nov
2012
Electricity Cost
Figure 8‐ Monthly Cost and Consumption of Electricity in Textured Jersey 16 | P a g e M.Sc. Thesis Electricityconsumptionsofpast6monthsaregivenbelowinTable3.9.
Month
(2012)
Tariff
Category
July
August
September
October
November
December
I2‐3Part
I2‐3Part
I2‐3Part
I2‐3Part
I2‐3Part
I2‐3Part
Day
292,027
273,987
299,138
450,894
327,653
335,376
OffPeak
526,418
492,881
533,943
821,040
593,467
611,782
Day
958,963
823,913
939,183
1,497,843
1,071,530
1,089,254
Max.
Demand
3,098
2,962
3,152
3,369
3,394
3,489
TotalkWh
1,777,408
1,590,781
1,772,264
2,769,777
1,992,650
2,036,412
Table 3.9: Electricity Consumption of Last 6 Months in Textured Jersey Accordingtotheabovefigures,
MonthlyAverageElectricityConsumption(kWhr)
AverageMax.Demand(kVA)
AverageActiveDemand(kW)
1,995,905
3,264
2,772
3.4.2 AirConditioningSystem
The air conditioning system is mainlyto maintain the thermal comfort in office areas.
Sincethecurrentsystemistobereplacedwithheatdrivencoolingsystem,itisessential
studytheenergyconsumptionpatternofthecoolingsystem.Thereforeconsumptionof
themajorcomponentoftheACwasloggedusingdataloggersandconsumptionofthe
rest of the equipment was calculated using spot readings. Component of the total
installedairconditioningunitsareasgiveninTable3.10.
TypeofAirConditioningsystem
Chillers/Package/Splittype/windowtype
TotalCoolingLoad(kWorTR)
610TR
Electricalpowerconsumption(kW)
750
AirCooledChillerunits
Manufacturer
YORK
Model
YEAJ99MW9
Noofunits
2(oneisonstandby)
Coolingloadofeachunit
180TR
Electricalpowerconsumption(kW)
394
Operatinghours
7Daysperweek
24hrsperday
AirCooledChillerunits
Manufacturer
YORK
Model
YCWS0663SC
Noofunits
2
17 | P a g e M.Sc. Thesis Coolingloadeachunit(kW)
180TR
Electricalpowerconsumption(kW)
241
Operatinghours
7Daysperweek
SplitAC/windowtypeAC
Noofunits
23
Totalcoolingload(kw)
TotalElectricalpowerconsumption
(kW)
Operatinghours
70TR
24hrsperday
115
7Daysperweek
12hrsperday
Table 3.10 : Summary of AC Equipment in Textured Jersey 3.4.3 BoilerandSteamSystem
Currently the facility operates three furnace oil boilers and three furnace oil fired
thermic oil heaters. Specification of boilers and thermic oil heaters are as shown in
Table3.11&Table3.12.
Boiler01
Boiler02
Design Actual Design
Yearofinstallation
Make/Supplier
Fueltype(Design)
Noofoperatingdaysperyear
Nooperatinghoursperday
BoilerSteampressurekg/cm2(g)
BoilerSteamtemperature0C
Drynessfraction
Steamflowrate(average)kg/hr
SteamtoFuelratiokg/kgfuel
FuelUsed
BoilerfeedwaterTemperature0C
Actual
Boiler03
Design Actual
2001
2001
Cochran
Cochran
FurnaceOil
FurnaceOil
360
360
24
24
17.2
14.5
17.2
14.5
208
199
208
199
0.95
0.93
0.95
0.93
9,200‐ 10,000 9,200‐ 10,000
13.887
13.887
FurnaceOil1500 FurnaceOil1500
94
94
1994
Loos
FurnaceOil
360
24
17.2
14.5
208
199
0.95
0.93
9,200‐10,000
13.887
FurnaceOil1500
94
Table 3.11 : Specifications of Steam Boilers in Textured Jersey Yearofinstallation
Make/Supplier
Fueltype(Design)
Noofoperatingdaysperyear
Nooperatinghoursperday
FuelUsed
Heater01
2001
Thermtechnik
FurnaceOil
360
24
FurnaceOil1500
Heater02
Heater03
2004
2007
Thermtechnik
Thermtechnik
FurnaceOil
FurnaceOil
360
360
24
24
FurnaceOil1500 FurnaceOil1500
Table 3.12 : Specifications of Thermic Oil Heaters in Textured Jersey 18 | P a g e M.Sc. Thesis Outoftotalfurnaceoilconsumption,60%isconsumedforsteamboilersand40%isfor
thermic oil heaters. No significant fluctuation of process heating demand has been
detectedthroughouttheday.Table3.13indicatesthedetailsofsteamrequirement.
Steamrequirementby
DyeingandFinishing
processesat6barand9
barisshownintable
3.13.Processsteamdemand
Operatinghoursperday
Daysofoperations(annual)
Finishing
Pressure
(kg/cm2)
9.0
Flow
(kg/hr)
5,000
6.0
10,000
Dyeing
24hours
360days
Table 3.13: Process Steam Demand in Textured Jersey
TotalfurnaceoilconsumptionandcostisshowninbelowFigure9. 80,000
3,000
FunaceOil(MIllionLitres)
70,000
2,500
60,000
2,000
50,000
1,500
40,000
30,000
1,000
20,000
500
10,000
‐
‐
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Cost (LKR Million)
2012
2011
FOConsumption
FOCost
Figure 9‐ Furnace Oil Consumption and Cost Variation in Textured Jersey 19 | P a g e M.Sc. Thesis 4 PossibleCombinationsforTri‐GenerationPlant
Based on the result of the energy audit and historical data analysis of the “Textures
Jersey”,itisobviousthatmeetingtheprocessheatingdemandoftheFacilityby more
economical mean is the most important aspect to increase the profitability of the
factories. Since this study is investigating viability of the Tri‐Generation, all possible
combinationsforasuchplantwasstudiedtoidentifytheprospectiveoptionsthatwill
bebotheconomicalandenvironmentalfriendly.Followingflowcharts(figure–10and
Figure11)listallpossibleoptionofTri‐GenerationsuitableforTexuresJersey.
Figure 10 shown below indicates posible combinations available for electricity
generation.Thethreemainoptionsforelectricitygenerationaretogeneratepartofthe
existing electricity demand, generate electricity to satisfy existing demand, and
generatingelectricityinexcessofexistingdemand.
Capacity requirement of the first electricity generation option is arrived by sizing the
plant to meet the existing process heating demand of the facility. In this option, the
steam requirements and the qualities will be considered to back calculate the boiler
capcacity and threby the turbine capcity. Another possible sub option to be studied
subsequentlyunderthisistoseeifthereisacapacitylessthantheabovewhichcangive
moreoptimumresults.
Viabilityoftwodifferentelectricitygenerationcapacitiesneedstobestudiedunderthe
secondoptions.Onecapacitywillbecalculatedassumingtheplanttobeaco‐generation
facilityratherthanTri‐generation.Underthis,itisassumedthattheproposedplantwill
meet the existing electricity demand (including energy requirement by vapor
compression chillers). Next option is to size the steam turbine to meet the existing
electricity demand excluding the energy requirement by vapor compression chillers.
Important thing to study under this option is to see if heating requirement of the
Absorption cycle chillers can be met economically with the reduced capacity of the
steamturbine.
Third electricity generating option as per figure 10 is to generate excess energy
compared to the existing electricity demand. Two possibilities identified under this
categoryistogenerateenoughelectricitytofeedthegridortogeneratetheelectricty
requiredforoilheatinginThermicoilheaters.
20 | P a g e M.Sc. Thesis GeneratePartof
theDemand
calculatedBasedon
Processheating
WiththeVCChiller
GenerateCurrent
Demand
ElectricityGeneration
(SteamTurbine)
WithoutVCChiller
PowerThermic
Heaters
GenerateExcess
Energy
FeedtheGrid
Figure 10 ‐ Possible Electricity Generation Options ProcessHeatingEnergy
Requirement
SteamGeneration
AbsorptionCycle
Chillers
Thermic
Heaters
LowPressure
Steam
FromHigh
PressureBolier
ViaPRV
Tapthe
Turbineat
inermidiate
Pressure
USesteam
fromTurbine
Exit
FromHigh
PressureBolier
ViaPRV
TaptheTurbine
atinermidiate
Pressure
Usesteamfrom
TurbineExit
DirectFire
EndUsesofHeatEnergy
MainEndUses
SubEndUses
HighPressure
Steam
Electricity
Figure 11 ‐ Possible Heating Options
21 | P a g e M.Sc. Thesis As shown in the figure 11 the process heating requirement of the facility is of three
forms; namely steam for manufacturing process, oil heating for Thermic heaters and
heat for absorption cycle chillers, if installed. Steam for manufacturing process is
requiredintwosubformsnamely;lowpressuresteamat6barandhighpressuresteam
at10bar.
There are two possible common methods by which thesteam canbe obtained for the
manufacturingfacility.Oneistoobtainedsteamdirectlyfromthehighpressuresteam
boiler (a high pressure boiler anyway has to be operated for a TG) and uses it for
manufacturing process by reducing the pressure to suitable levels using a pressure
reducing valves. Second common method is to tap the steam turbine at suitable level
and obtain steam for the processes. In addition to these two common methods, low
pressuresteamcanbeobtainedbyusingthesteamexitingtheturbine.
Obtainingsteamdirectlyfromthehighpressuresteamboiler,tappingofsteamflowof
turbineatanintermediatelevelanduseofsteamexitingtheturbinearethreepossible
optionsthatcanbeusedforbothThermicoilheatersandforabsorptioncyclechillers.
Inadditiontothesethreecommonoptions,Thermicoilheatingcanbedonebydirect
firingasitiscurrentlydoneoritcanbedoneusingtheelectricitygeneratedfromthe
steamturbineoftheplant.
4.1 BaselineOptionsforPlantArchitecture
Whenfigure10andfigure11areconsidereditisobviousthattherearemanyoptions
forthearchitectureofTri‐generationplant.Sinceevaluationofalloptionsinfigure10
and figure 11 is not practical (some options are not worth evaluation for obvious
reasons)twobaselinesystemarchitectureswereidentifiedtowhichothercombination
wouldbecompared.
Since it is unknown as to which combination would have the best viability at initial
stage,severalfactorswereconsideredinarrivingatbaselinesystemarchitecture.One
ofthemainfactorsconsideredistheeconomicsoftheplantsthathavebeenevaluated
byvariousauthorsinpreviousstudies.Manyofthosepaperssuggeststohaveabestnet
present value it is necessary to include cooling (absorption cycle) to the chiller and
maximize electricity generation while meeting the heating requirement without
generating excess heat. Plant architectures give in related case studies; heating
requirementsandthequalityoftherequiredheataretheotherparametersthatwere
consideredindesigningthetwobaselinecases.
Asshowninfigure12andfigure13bothbaselinecasesincludehighpressureboilers,
steamturbineandanabsorptioncyclechiller.Thosetwodifferfromeachotherbyonly
one aspect; the point at which the high pressure steam is obtained. In option 01 high
pressure steam is obtained directly from the boiler whereas in option 02 same is
obtainedbytappingthesteamturbineatasuitableintermediatepressure.
22 | P a g e M.Sc. Thesis 2
High Pressure Steam for production E
1 Flu Gas 3
4
Absorption Chiller To Production
From Production
Cooling tower
Make Up water
Figure 12‐ Baseline Option 01 Schematic Diagram
1
E
2
Flu Gas 3 4
High Pressure Steam To Production
Absorption Chiller From Production
To Production
From Production
Cooling tower
Make Up water Figure 13‐ Baseline Option 02 Schematic Diagram
23 | P a g e M.Sc. Thesis When heating requirement and the required quality of the heat is considered, it is
obviousthattheabsorptioncyclechillerrequiredthelowestqualityheat.Inviewthat,
absorptionchillerswerearrangedinbothaboveoptiontoreceivethesteamexistingthe
turbineassumingthatitwouldhavethehighestviabilityoutofmanyoptions.Similarly
lowpressuresteam(6bar)hasassumedtobeobtainedfromaintermediatepressure
level from the gas turbine in both options. This arrangement for low pressure steam
wasselectedassumingthatitismoreviabletoallowsteamfromtheboilertoreduceit
pressure through the turbine rather than drastically reduce pressure directly from a
pressurereducingvalve.
Following section includes the theoretical calculations that have been preformed to
evaluateabovetwooptions,resultofwhichhasbeenusedtoevaluatetheaccuracyof
assumptions made and to identify further options, if any, to be studied from the ones
listedinfigure10and11.
4.2 CapacityEstimationforProposedPlantArchitectures
Asnotedearlieratrigenerationplantcanbedesignedeithertomeetagivenamountof
electricitywhilemeetingpartorallheatingrequirement(electricitybaseddesign)orit
can be designed to meet a given amount of heat while meeting part or all electricity
requirement(heatingbaseddesign).Sincetheobjectiveofthisstudyistofindoutthe
most economical mean, two basic calculation approaches that represent the two
extremeoperatingconditionsoftheabovetwodesignoptions(electricitybaseddesign
/Heatingbaseddesign)wereidentifiedtocarryoutthetheoreticalcalculation.Thetwo
baseline TG options represented in Figures 12 & 13 were then evaluated using these
two calculation approaches. Graphical representation of the calculation process is
showninfigure14andthedetailsoftheseapproachesaregivenbelow.
Approach01:
FirstapproachistoevaluatetheperformanceofaTGplantdesignedbasedonagiven
electricity demand. As the theoretical extreme condition, it was assumed that plant is
sized to have an electricity generation capacity that will be sufficient to meet the
existing demand of entire facility (excluding vapor compression chillers). Under this,
effects (on boiler capacity) of various inlet pressures and temperatures of the inlet
steamofturbineareevaluated.Sincetheresultsofthisevaluationrepresentthestatus
in an extreme design condition, same was used to identify whether electricity
generationcapacityshouldbeincreasedordecreasedtoimprovetheplanteconomics.
Approach02:
SecondapproachistoevaluatetheperformanceofaTGplantdesignedbasedonagiven
heatingdemand.Asthetheoreticalextremecondition,itwasassumedthattheplantis
sized to have a heating energy generation capacity that is sufficient to meet the
24 | P a g e M.Sc. Thesis productionrelatedsteamdemandandtheheatdemandoftheabsorptioncyclechillers.
Under this also, effects (on turbine capacity) of various inlet pressures and
temperatures of the inlet steam of turbine are evaluated. Since the results of this
evaluation represent the status in an extreme design condition, same was used to
identifywhetherheatingenergygenerationcapacityshouldbeincreasedordecreased
toimprovetheplanteconomics.
BaselineOption01
forTG
Calculations
BaselineOption02
forTG
Approach‐01
Electricitybased
Approach‐02
ProcessHeatingbased
Approach‐01
Electricitybased
T&PVariation
toTurbineinlet
Approach‐02
ProcessHeatingbased
Figure 14‐ Theoretical Calculation Process 4.2.1 ResultsoftheCalculationdoneBasedonProcessHeatingDemand
4.2.1.1 CalculationBasedonOption01(HPSteamDirectlyfromBoiler)
AcomputerprogramwrittenusingEngineeringEquationSolver(EES)hasbeenusedto
calculate the possible electricity generation capability for various standard boiler
capacities and boiler operating conditions (Pressure and Temperature) when high
pressure steam is directly taken from the boiler and low pressure steam is taken by
tapping the turbine. EES Program and the calculation procedure are given in the
AppendixB.
AssumptionsMadeforCalculation:
Assumptions were made for calculation based on industry accepted norms, current
operating conditions, values published is various papers and data provided by
equipmentmanufactures.Followingarethelistofassumptionsmade.









Pressuredropinthesteamlinesgoingtoproductionis1bar
Boilerfeedwatertemperatureisat70oC
Make‐upwaterrequirementis15%ofthetotalfeedwaterflowrate
Make‐upwatertemperatureis30oC
Pressuredropinsteamlinesbetweenboilerandtheturbineisnegligible
Temperaturedropinsteamlinesbetweenboilerandtheturbineisnegligible
Isentropicefficiencyoftheturbineis85%
Mechanicalefficiencyoftheturbineis65%
Electricalefficiencyofgenerator98%
25 | P a g e M.Sc. Thesis ResultsoftheCalculations(Table4.1,4.2&4.3):
WithaBoilerof20tonsperhour(Fromandat1000C)capacity,
Case Boiler
Operating
Pressure
(bar)
1
2
3
4
5
6
7
8
9
10
28
35
42
45
54
62
68
72
78
84
Boiler
Boiler Heat
Operating
Output
Temperature
(MW)
(0C)
350
17.65
380
17.99
400
18.22
420
18.45
450
18.79
480
19.14
490
19.26
500
19.38
520
19.62
540
19.86
Gross
Elec
PowerOut
(kW)
783.6
903.9
996.0
1055
1169
1274
1323
1362
1431
1499
Heat
LowPSteam
available
Temperature
forchiller (0C)
(kW)
2083
199.7
2101
201.8
2106
199.5
2132
207.9
2153
212.3
2183
220.6
2183
218.5
2190
219.9
2210
226.1
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
Operating
Pressure
(bar)
1
28
2
35
3
42
4
45
5
54
6
62
7
68
8
72
9
78
10
84
Boiler
Boiler Heat GrossElec
Operating
Output
PowerOut
Temperature
(MW)
(kW)
0
( C)
350
22.06
1260
380
22.48
1425
400
22.77
1550
420
23.06
1632
450
23.49
1790
480
23.93
1934
490
24.08
2001
500
24.23
2054
520
24.52
2150
540
24.82
2245
Heat
LowPSteam
available
Temperature
forchiller (0C)
(kW)
5438
199.7
5466
201.8
5466
199.5
5519
207.9
5557
212.3
5614
220.6
5608
218.5
5621
219.9
5661
226.1
5704
232.8
Table 4.2: Option 01 ‐ Process Heating Base Calculation for 25 TPH Boiler (F&A100C) WithaBoilerof30tonsperhour(Fromandat1000C)capacity,
Case Boiler
Operating
Pressure
(bar)
1
28
2
35
3
42
4
45
5
54
6
62
7
68
8
72
9
78
10
84
Boiler
Boiler Heat GrossElec
Operating
Output
PowerOut
Temperature
(MW)
(kW)
(0C)
350
26.47
1737
380
26.98
1946
400
27.32
2104
420
27.67
2210
450
28.19
2410
480
28.72
2595
490
28.89
2678
500
29.07
2746
520
29.43
2869
540
29.79
2991
Heat
LowPSteam
available
Temperature
forchiller (0C)
(kW)
8792
199.7
8830
201.8
8825
199.5
8906
207.9
8960
212.3
9044
220.6
9034
218.5
9051
219.9
9112
226.1
9176
232.8
Table 4.3: Option 01 ‐ Process Heating Base Calculation for 30 TPH Boiler (F&A100C) 26 | P a g e M.SSc. Thesis 3500
for 20 TPH B
Boiler (F&A100C)
for 25 TPH B
Boiler (F&A100C)
for 30 TPH B
Boiler (F&A100C)
Electrical Power (kW)
3000
2500
2000
1500
1000
500
0
2
1
3
4
5
6
7
Cases (( Boiler out ‐T
T & P Variation)
8
9
10
Figure 15‐ EElectricity Gen
neration Capaacity, Option 0
01 ‐ Process H
Heating Base C
Calculation
Figure15comparresresultan
ntelectricittygenerationcapacitiiespresenttedintable4.1,4.2
& 4.3. As per thaat, it is ob
bvious thatt the higheer temperaature and p
pressure at boiler
output results in
n higher ellectricity generation
g
capacity for
f a given
n boiler capacity.
Furtherr,increased
dboilercap
pacityalsoresultsinahigherellectricitygeenerationccapacity
foragiiventempeeratureand
dpressure atboileroutput.Two
oimportantfactstob
benoted
intherresultsisth
hetemperaatureoftheetappedou
utlowpresssuresteam
moftheboilerand
theheaatavailableeforthech
hiller.Both theseareiinexcesso
ofwhatisrrequiredforactual
system
m to run. This
T
indicaates a posssible optiimization in system which haas been
addressedintheffinalstageo
ofthestudy
y.
AnnualEnergyCostUS$
Thousands
BasicE
EconomicssAnalysis:
10,000
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
1
2
3
4
5
6
7
Cases‐ Boilerout‐ T&Pvariatiion
CurreentEnergyCo
ost(US$)
for25
5TPHBoiler(F&A100C)
8
9
10
for20
0TPHBoiler((F&A100C)
for30
0TPHBoiler((F&A100C)
Figgure 16‐ Cost of Energy, Op
ption 01 ‐ Proccess Heating Base Calculattion 27 | P a g e M.SSc. Thesis Figure 16shown above,com
mparescosstofenerggyofthecu
urrentarraangementw
withthe
expecteedenergy costvariattionwhenssystemdessignedfor option‐01 andsizeth
heplant
for pro
ocess heatting demaand. As peer the graaph it is evident aall tri gen
neration
combin
nationsred
ducetheenergycostb
byabout10
0‐17%.Furrtheritisevidentthattcostof
energy reducesw
withtheinccreasingpreessureand
dtemperatu
ureofthetturbineinp
putfora
givenb
boilerandw
whereasco
ostofenerggyincreasewhenboilercapacityyisincreasedfora
giventturbineinp
putpressurreandtemp
perature. Thisisoneeoftheim
mportantfin
ndingin
this caalculation that
t
should
d be consiidered in plant optimization. A
Also the increase
electriccity generaation capaccity shown in figure 15
1 has no significant
s
effect on the
t cost
reductiion as incrrease electrricity geneeration req
quire more coal. Furtther the increased
pressurre, increassed temperrature and
d the increease boilerr capacity will increase the
capital costoftheeplantasw
well.Thereeforethesim
mplepaybaacktimean
ndthenetpresent
value will
w not bee attractivee as increaase in elecctricity gen
neration iss not signiificantly
contrib
butingtosaavings.
AnnualCO2EmmisonMT
Thousands
Enviro
onmentalImpact:CO
O2eEmissio
on:
100
90
80
70
60
50
40
30
20
10
0
1
2
3
4
5
6
7
Cases‐ Boilerout‐ T&Pvariatio
on
8
9
10
0
CurreentEnergyCo
ost(US$)
for20TPHBoiler((F&A100C)
for25
5TPHBoiler(F&A100C)
for30TPHBoiler((F&A100C)
Figure 17‐ CO2e Emissio
on for Coal Bo
oiler, Option 0
01 ‐ Process H
Heating Base C
Calculation Byusin
ngaTrigen
nerationplant,theCO
O2eemissio
onbyburningfueloillforboilerss,useof
electriccityfromth
hegridand
dbythereefrigerants canbeavo
oided.ButtAspertheeabove
figure1
17,anycom
mbinationo
ofthetri‐ggeneration proposedaaboveemittsmoreCO2ethan
the exiisting systeem if coal is used fo
or boiler. The higheer the elecctricity gen
neration
capacittyoftheTrri‐Genplan
ntthehigheertheCO2emission. Thereforeeifcoalis usedas
the fueel, least em
mission can
n be achiev
ved by opeerating the boiler witth lowest possible
p
capacittyatlowestpossible temperatu
ureandpreessure.IfBio‐massis feasible,ittcanbe
usedto
oreducetheeemissionssignifican
ntly.
28 | P a g e M.Sc. Thesis 4.2.1.2 CalculationBasedonOption02(HPSteamTappedfromTurbine)
SimilartoprevioussectionEngineeringEquationsolverhasbeenusedtocalculatethe
possible electricity generation capability for various standard boiler capacities and
boiler operating conditions (Pressure and Temperature) when both high pressure
steamandlowpressuresteamaretakenbytappingtheturbine.EESProgramandthe
calculationprocedurehavebeengivenintheAppendixB.
AssumptionsMadeforCalculation:
Assumptions are same as section 3.2.1.1 except the location of extraction of the high
pressuresteamusedformanufacturingprocess.
ResultsoftheCalculations(Table4.4,4.5&4.6):
WithaBoilerof20tonsperhour(Fromandat1000C)capacity,
Case Boiler
Operating
Pressure
(bar)
1
28
2
35
3
42
4
45
5
54
6
62
7
68
8
72
9
78
10
84
Boiler
Operating
Temperature
(0C)
350
380
400
420
450
480
490
500
520
540
Gross
Heat
HighPSteam LowPSteam
Elec
availablefor Temperature Temperature
Power
chiller(kW) (0C)
(0C)
Out(kW)
1015
2134
198.6
234.1
1192
2153
200.4
236
1328
2156
197.9
233.3
1411
2183
206.1
242.2
1579
2206
210.3
246.6
1729
2236
218.3
255.1
1802
2235
216.1
252.7
1859
2243
217.4
254.1
1958
2264
223.4
260.6
2057
2286
229.9
267.5
Table 4.4: Option 02 ‐ Process Heating Base Calculation for 20 TPH Boiler (F&A100C) WithaBoilerof25tonsperhour(Fromandat1000C)capacity,
Case Boiler
Operating
Pressure
(bar)
1
28
2
35
3
42
4
45
5
54
6
62
7
68
8
72
9
78
10
84
Boiler
Operating
Temperature
(0C)
350
380
400
420
450
480
490
500
520
540
Gross
Heat
HighPSteam LowPSteam
Elec
availablefor Temperature Temperature
Power
chiller(kW) (0C)
(0C)
Out(kW)
1494
5571
198.6
234.1
1715
5599
200.4
236
1885
5597
197.9
233.3
1992
5653
206.1
242.2
2202
5692
210.3
246.6
2393
5751
218.3
255.1
2484
5744
216.1
252.7
2555
5757
217.4
254.1
2681
5799
223.4
260.6
2807
5843
229.9
267.5
Table 4.5: Option 02 ‐ Process Heating Base Calculation for 25 TPH Boiler (F&A100C) 29 | P a g e M.SSc. Thesis WithaBoilerof30tonsperhour(From
mandat10
000C)capaccity,
Case Boiler
Operating
Pressure
(bar)
1
28
2
35
3
42
4
45
5
54
6
62
7
68
8
72
9
78
10
84
Boiler
Operatingg
Temperatture
(0C)
350
380
4
400
4
420
4
450
4
480
4
490
500
520
540
Grosss
Heat
H
HighPSteam
m LowPSteam
Elec
avaiilablefor Temperatur
T
re Tempeerature
Poweer
chilller(kW) (0C)
(0C)
Out(k
kW)
1972
9009
198
8.6
234.1
2238
9046
200
0.4
236
2441
9038
197
7.9
233.3
2572
9123
206
6.1
242.2
2826
9178
210
0.3
246.6
3057
9265
218
8.3
255.1
3165
9253
216
6.1
252.7
3251
9271
217
7.4
254.1
3404
9334
223
3.4
260.6
3557
9401
229
9.9
267.5
Table 4.6
6: Option 02 ‐ Process Heatting Base Calculation for 30
0 TPH Boiler (F&A100C) 4000
for 20 TPH B
Boiler (F&A10
00C)
3500
for 25 TPH B
Boiler (F&A10
00C)
Electrical Power (kW)
for 30 TPH B
Boiler (F&A10
00C)
3000
2500
2000
1500
1000
500
0
1
2
3
4
5
6
7
8
9
10
0
Cases ( Boiler out ‐T
T & P Variatio
on)
Figure 18 ‐ EElectricity Gen
neration Capaacity, Option 0
02 – Process H
Heating Base Calculation
Similarr to figure 15, figure 18 indicattes that the higher teemperature and presssure at
boilero
outputresu
ultsinhigh
herelectriccitygenerationcapaciityforagivveboilercapacity.
Furtherr,increased
dboilercap
pacityalsoresultsinahigherellectricitygeenerationccapacity
foragiiventempeeratureand
dapressurreatboilerroutput.Th
hissystem alsoindicaatesthe
potentiial optimizzations as temperatu
ure of the two tappeed out steam, and th
he heat
availab
bleforthe chillerare inexcess oftheactu
ualrequirem
ment.Elecctricitygen
neration
capacittyis20%higherinav
veragecomp
paredtoth
hefigure15
5results.
30 | P a g e M.SSc. Thesis AnnualEnergyCostUS$
Thousands
BasicE
EconomicssAnalysis:
1
10,000
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
1
2
3
4
5
6
7
8
9
10
0
Cases‐ Boilerout‐ T&Pvariatio
on
CurreentEnergyCo
ost(US$)
for20TPHBoiler((F&A100C)
for25
5TPHBoiler(F&A100C)
for30TPHBoiler((F&A100C)
Figgure 19‐ Cost of Energy, Op
ption 02 ‐ Proccess Heating Base Calculattion Similarr to Figurre 16, figu
ure 19 sh
hown abov
ve, indicattes that aall tri gen
neration
combin
nationsred
ducetheenergycostb
byabout12
2‐22%.Furrtheritiseevidentthattcostof
energy reducesw
withtheinccreasingpreessureand
dtemperatu
ureofthetturbineinp
putfora
given boiler
b
and the cost of
o energy in
ncreases when
w
boilerr capacity is increaseed for a
given turbine
t
in
nput pressu
ure and temperaturre. Due to the 20%
% more eleectricity
generattion,there isaddition
nalcostsav
vingcompaaretotheo
option01w
whichvariesfrom
2‐6%o
ofallcases..Thereforeeitcanbe safelyassu
umethattaapingallsteeamrequirrements
from th
he turbine is more economical
e
in terms of savings. However impact off capital
needto
obestudied
dindetailaafteroptim
mizingthesy
ystem.
Enviro
onmentalImpact:CO
O2eEmissiion
Asshow
wninfigurre20,inth
hissetupallso,theCO2eemissio
onishigherrthanthe existing
setup. Pattern off emissionss are same as the above
a
option 01 butt there is a 2‐6%
reductiionofCO2emissioncomparedto
othesame.
31 | P a g e M.SSc. Thesis Annual CO2 Emmison MTThousands
Annual CO2 Emmison MT
100
90
80
70
60
50
40
30
20
10
0
1
2
3
4
5
6
7
Cases ‐ Boiler out ‐ T&
&P variation
8
9
10
Currrent Energy Co
ost (US$)
for 20 TPH Boiler ((F&A100C)
for 2
25 TPH Boiler (F&A100C)
for 30 TPH Boiler ((F&A100C)
Figure 20‐ CO2e Emissio
on for Coal Bo
oiler, Option 0
02 ‐ Process H
Heating Base C
Calculation 32 | P a g e M.Sc. Thesis 5 PlantOptimization
Following section describes the possible optimizations that would provide most
benefits to the load pattern of the selected apparel factory. Optimization possibilities
havebeenidentifiedbasedonthefindingoftheChapter‐04.
5.1 ImportantFindingsPlantPerformanceSimulations
Mainobjectiveoftheperformancecalculationoftheidentifiedplantarchitecturesinthe
previoussectionwastoidentifythepossibleoptimizationmethodsandtoidentifythe
furtheroptionforplantarchitectures,ifany,thatshouldbestudiedbeforearrivingatan
optimalsolution.Followingaresomeoftheimportantfindingsofthecalculations.

Oneofthemostimportantfindingisthedifferenceinenergycostsavingswhen
high pressure steam is tapped off from the turbine compared to directly
obtaining steam from the steam boiler through a PRV. As per the above
calculationsformercangenerate~20%moreelectricitywithoutadditionalfuel
thanlaterwhichcontributestotheincreasedsavings.Inadditiontothatcapital
savingcanbeachieved,asformerneedsasmallercapacityboilertogeneratea
given amount of electricity compared to the later. This observation eliminates
the requirement to analyze the further plant architectures (options base on
figure‐10and11)thatdirectlyobtainhighpressuresteamfromtheboileritself.

Each of the graphs that represent the calculation results indicates that the
increasedoperatingpressureandtemperatureofagivenboilercapacityresults
increasedcostsavings.Furtherforagivenoperatingpressureandtemperature
lowest capacity boiler gives the highest savings, regardless of the higher
electricity generation by the higher capacity boiler. This is mainly due to the
increasedfuelcostingeneratingmoreelectricity.

Anotherprominentobservationissizingtheplanttomeettheelectricityresults
in lower energy cost saving than sizing the plant to meet process heating
demand. This scenario is caused by the increased fuel cost as noted in the
previouspoint.

If coal is used CO2 emissions are always higher than current emissions of the
factory,fortri‐genapplications.
33 | P a g e M.Sc. Thesis 5.2 OptimumOptions
Steamexitingfromtheturbinehastobeat,atleast1atmtobeabletouseforabsorption
chiller.AccordingtotheChapter‐04calculations,itisevidentthatthesteamexitofthe
turbinehasfarmoreenergythanwhatabsorptionchillerrequired.Partofthisexcess
energy hasto be rejected via suitable mean to continuethe thermodynamic cycle (eg:
Coolingtower)whichcanbeconsideredasanenergywastagethatneedtobeavoided
foroptimumresults.
One Option to avoid the energy waste would be to tap out steam at a suitable
intermediatepressurelevelwhichisjustsufficienttomeettheenergyrequirementof
thechillerwhileallowingexcesssteamtofurtherexpandthroughtheturbinebyusinga
condensingtypesteamturbine.Howevertheveryhighcapitalcostofcondensingtype
turbines(canbe50%to70%higherthanbackpressuretype)negatestheeconomical
benefitsofeliminatedenergywastage.Henceforthissortofapplicationsitisbesttouse
abackpressuretypeturbinewithminimumenergywastage.
The only way that excess energy available for absorption chiller can be reduced, at a
backpressuretypeturbinesteamexit,isbyreducingthesteammassflowrate(small
boiler). Even when the result of Chapter‐04 and the observation mentioned in the
previous section are considered, it is obvious that smallest possible boilers has to be
operated in the suitable pressure (Operating Pressure shall be decided based on
economical result of the economical analysis) to obtain optimum economical and
environmentalresults.
However,theboilermusthaveacapacitytobesufficienttomeetthetotalprocesssteam
requirementofthefactory,whichisapproximatelyabout19TPH(6TPH+10TPH+3TPH).
Henceforthepracticalapplication,theoptimumboilercapacitycanbeconsideredtobe
20Trasoddcapacitysuchas19Trisnotusuallymanufactured.
Further the generating steam at high pressure and using them at a lower pressure
throughapressurereducingvalveisalsoleadstounnecessaryenergyuse.Thereforeit
isevidentthattheplantarchitectureproposedinFigure12(BaselineOption02)isthe
mostsuitableforthissortofapplication.Detailedplantarchitecturedevelopedbasedon
figure12systemispresentedandanalyzedintheSection4.4.
34 | P a g e M.Sc. Thesis 5.3 TechnicalFeasibilityandOtherIssues
Ifrequiredknow‐howisnotavailableorothertechnicalbarriersarepersisting,whole
TG becomes infeasible regardless of economical and environmental viability. Since TG
plantsarenotbeingusedinSriLankaasofnow,itisimportanttoidentifythepossible
technicalissues,ifany,thatmayariseinimplementingthesame.Thisisawellestablish
technology where hundreds of researches have been carried out to improve the
efficiencyovercomeothertechnicalissues.Henceitisobviousthatimplementingsucha
system won’t be hindered by fundamental technical issues. However there are issues
uniquetolocalconditionsandtothesectorthatneedtobesortedout.
Though not used before locally, combine heat, power and cooling systems have been
successfully installed and commissioned in the neighboring countries like India. Also,
therearelocalexperts,suppliersandconsultantswhohaveundertakendesign,supply,
installationandcommissioningofindividualcomponentoftheTGplantssuchassteam
turbinepowerplants,chilledwatersystems,highpressuresteamboilersandetc.Hence
transferringtechnologycanbedoneeasilymakingtheimplementationoftri‐Generation
systemstechnicallyfeasible.Howevercertainissuesneedtobeaddressedifsuchplant
tobeimplemented.
5.3.1 IssuesRelatedtoFuelSupplyChain
Havingawell‐establishedandconsistentsupplychainforproposedfuels(coalandBio‐
Mass)isuniqueissuefacedbythelocalindustrythatneedstobeaddressed
 CoalSupply
Coalhastobeimportedasitisnotminedlocally.Importingcoalinsmallandmedium
quantitiesisnoteconomicalduetoshippingandhandlingrelatedissues.Hencecoalhas
tobeimportedinbulkorders.Thereisverylimitednumberoflocalindustriesthatuse
coal. State owned utility company, the Ceylon Electricity Board (CEB) and the biggest
local cement manufacture, the Holcim Lanka PLC are the only bulk importers of coal.
ThereforeanyonewhowishestousecoalinmediumquantitieslikeforTGplantshasto
collaboratewitheitherofaboveparties.SinceCEBisagovernmententity,itisdifficult
for 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 in
North East coast of the Country. Transportation from there to the site has to be
arrangedbycoveredtrucks.
 Bio‐MassSupply
As per “The Biomass Energy Sector in Sri Lanka, Successes and Constraints” by
Jayasinghe P., 2,873,880 MT of bio mass is produced per year by waste of various
industriesandcommerciallygrowntrees[7].Howevermostofthesearewasteddueto
non‐availabilityofproperdemandandsupplymechanism.MostofthecurrentBiomass
fuelsupplierssupplywoodlogsthoughsameisavailableinmanyformssuchaspaddy
35 | P a g e M.Sc. Thesis husk,sawdustandbriquettes.Furtherwiththedrastichikeoffurnaceoilprice,many
industrieshavestartedmovingtowardsbiomassboilerstoreducethefuelcost.Thus,a
new demand for biomass suppliers and a significant shortage of supply can also be
observed.
Therefore establishing consistent supply of Biomass has to be addressed at the very
beginning of the project. Failing to do so will fail the total effort put in to the TG. Sri
LankaBoardofInvestmenthasintroducedaregistrationsystemofauthorizedbiomass
suppliers.Sowhoeveriswillingtousebiomassasfuelinindustrialscalehavetohave
agreements signed with minimum of three authorized biomass suppliers afore the
permission.
5.3.2 IssuesRelatedtoFuelStorage
Liquid fossil fuel has a higher calorific value compared to coal and biomass and the
countryhasawell‐establishedsupplychainforthesame.Thereforelargestoragesthat
wouldlastforweeksarenotrequired.Howeversolidfuelslikecoalandbiomassneed
biggerstoragesandmoreattentionduetocertaintechnicalmatters.
 CoalStorage
The main technical issues related to coal storage are the finding of adequate storage
space, possible moisture contamination and environmental pollutions. Therefore, not
havingasuitablestoragespacecanfailtheentireproject.
Around60Mtofcoalisrequiredondailybasisfortheplantdesignsubjectedtostudy,
whichrequireapproximatelya40–50m3areafordailystorage.Therefore,asthefirst
stepofimplementingTG,astoringareashouldbeidentifiedtobothtruckunloadingand
boilerfeeding.Thenasuitableshelteroracoveringmechanismhastobeimplemented
topreventstockpiledcoalabsorbingmoisturefromrainwhichwillreducetheLHVof
theCoal.Itisalsoveryimportanttotakeactiontopreventcoalgettingwashedoffby
rainandblownoffbywindtoavoidcoalwaste,contaminationofnearbywaterbodies,
contaminationofsoilandair.
 BiomassStorage
Bio‐massisrequiredinevenmorequantitiesthancoalanditfacesthesameissuesas
thecoalwhenitcomestostoring.Thereforesimilaractionshastobetakenavoidthese.
Howeverthepollutionissuesarefarlesssevereforbiomasscomparedtocoal.
36 | P a g e M.Sc. Thesis 5.3.3 IssuesRelatedtoFuelPreparation
Unlikeliquidfossilfuels,coalandbio‐masshastobepreparedforcombustion.Though
directlynotconnectedtotechnicalitiesoftheplant,fuelpreparationhassometechnical
issuestobesortedout.
 CoalPreparation
Coal has to be crushed depending on the type of combustor used in the boiler. Three
main combustion methods have been studied for suitability. Coal crushing causes air
pollutionaswellasnoisepollution.Hencethisprocessshouldbecarriedoutinenclosed
environment,withspecialrespiratorsandheadphones.Coalcrushingsystemhastobe
designedtomeettherequirementsstipulatedbyBoardofInvestment.
 BiomassPreparation
Issuesrelatedtobiomasspreparationdependonthetypeoffuelused.Ifwoodlogs(fire
wood) are used as fuel it is very difficult to design an automatic or semi‐automatic
feedingsystemasfuelisfedaslogs.Theonlywayoutistousemanuallaborwhichcan
benotveryfeasibleforlargecapacityplants.
Otherformsofcommonsourceofbiomassaresawdust,sawdustbriquettesandwood
pellets.Theseformscanbeautomaticallyfedandneedverylesspreparations.
5.3.4 Coalandbiomasscombustiontechnologies
 SelectionofCombustor
Selectionofcombustorhastobedoneconsideringthetypeoffuelused.Movinggrate
type,pulverizedandfluidizedbedcombustorarethethreemaintypestochoosefrom.
MovingGrateCombustor
Moving grate combustor is one of the oldest technologies which utilizegrate
firingwherethecoalismechanicallydistributedontoamovinggrateatthebottomof
the combustion chamber in partially crushed gravel like form. Air for combustion is
blown upward through the grate, so it carries the lighter ash and smaller particles of
unburnedcoalupwithit.Nospecificcrushingisneededforthistypeofcombustor,but
systemefficiencyislower.
The main advantage of this technology is the ability to progressively move the fuel
withinthecombustionchamber.Itsabilitycombustwetfuelsisadvantageousforbio‐
massfiredTGplants.Asthefuelmovesforwardthoughamovinggrate,itgoesthrough
differentstagesofcombustion.Atfirstthefuelentersthecombustionchamberandis
immediatelyexposedtotheheatofthecombustionchamber,atthisstagethewetfuel
startstodry.Thenthefuelsubjectscombustionandfinallyendsupinashpit.
PulverizedCoalCombustor
Pulverizedfuelboileristhemostcommonlyusedmethodinthermalpowerplants.Coal
is pulverized (ground) to a fine powder with less than 70 – 80 µm particle sizes. The
pulverizedcoalisblownwithpartofthecombustionairintotheboilerplantthrougha
37 | P a g e M.SSc. Thesis serieso
ofburnern
nozzles.Henceinthiiscasecoaalneedsto becrushed
dtofinepaarticles.
SchemaaticofthistypeofplantisgiveninFigure2
21.
Figure 2
21 ‐ Moving G
Grate Combusstor (Courtesyy –Thermax, India )
Fluidize
edBedCom
mbustor
InFluid
dizedbedccombustorr,upwardb
blowingairrjetssuspeendthecoaalparticlessduring
thecom
mbustionp
processwhiichresults aturbulen
ntmixingofgasandffuel.Thistu
umbling
action, muchlike abubblinggfluid,pro
ovidesmoreeeffective chemicalrreactionsandheat
ncy.Thereq
quiredcoalparticlesizeis1‐
transfeer,hencehaavingbetteercombustiionefficien
10mm.

Em
missionCon
ntrol
FlueGa
as
Properrstackdesiggnandthecombustio
onefficienccyofthesysstemhasto
obemaintaainedto
ensure that the flue
f
gas meeet the reggulations stipulated by
b Board o
of Investmeent and
CentrallEnvironm
mentalAuth
horityofSrriLanka.Th
heBOIregulationforrfluegasemission
is 200 ppm of Particulate
P
e Matter (PM). Bag filters, waater scrubb
bers and cyclone
separattors are th
he commo
only used technologie
t
es in Sri Lanka
L
in ssolid fuel (mostly
biomasss) firing. In a scenarrio of coal firing, an Electrostat
E
tic precipitaator (ESP) will be
muchm
moreeffecttivetoredu
ucethePMcontentinfluegasto 150ppmo
orless.
r as the on
An elecctrostatic precipitato
p
ne shown in figure 22
2 is a parrticulate co
ollection
device that remo
oves particlles from a
a flowing gas
g (such as
a air) usin
ng the forcce of an
induced
d electrosttatic chargge. Electrosstatic precipitators are
a highly efficient fiiltration
devicess that minimally imp
pede the fllow of gases through
h the devicce, and can
n easily
38 | P a g e M.Sc. Thesis removefineparticulatematterssuchasdustandsmokefromtheairstream.Incontrast
to wet scrubbers which apply energy directly to the flowing fluid medium, an ESP
applies energy only to the particulate matter being collected and therefore is very
efficientinitsconsumptionofenergy(intheformofelectricity)
Figure 22 ‐ An Electrostatic Precipitator (Courtesy: Thermax)
AspertheBOIregulations,theSO2emissionshallbecontrolledbyfuelqualityandstack
height.TheminimumstackheighthastobedefinedbyacceptableAirQualityModeling
tool.Intheabsenceofsuchmodeling,followingequationshallbeappliedtodefinethe
minimumstackheight.
H(m)=14Q0.25(Where,QisSO2emissionrateinkg/hr.)
The bottom ash has to be collected to silos and only available option in Sri Lanka is
usingasarawmaterialinCementmanufacturingandreadymixedconcrete.
39 | P a g e M.Sc. Thesis 5.4 DetailedSchematicofFinalPlantArchitecture
Figure 23 ‐ Detailed Schematic of Coal Fired Tri‐Generation (Final) 40 | P a g e M.Sc. Thesis 5.5 DetailedEconomicalandEnvironmentalAnalysis
5.5.1 GeneratorCapacityEstimation
Case
1
2
3
4
5
6
7
8
9
10
BoilerOperating
Pressure(bar)
28
35
42
45
54
62
68
72
78
84
BoilerOperating
Temperature(0C)
350
380
400
420
450
480
490
500
520
540
GrossElec
PowerOut(kW)
Poweravailableat
turbineexit(kW)
1015
1192
1328
1411
1579
1729
1802
1859
1958
2057
2134
2153
2156
2183
2206
2236
2235
2243
2264
2286
Table 5.1: Theoretical Design Turbine Capacities Calculated for Section 4.4 Design Result shown in the Table 5.1 above has been obtained for the plant design shown in
section 5.4 by using the same calculation procedure used in Section 4.2.1.2. The
resultant gross electric power output indicates theoretical values that need to be
correctedforthecapacityofsteamturbinethatareavailableatthemarket(eg:1000kW
turbine should be considered instead of theoretical value of 1015kW). In the cases
wheretheoreticalgrosselectricpoweroutputhastoberoundedup(eg:11921200)
operatingpressuretemperaturehastobeadjustedaccordingly.Highlightedcellsinthe
above table need to be adjusted suit the practical application. Table 5.2 indicates the
actualturbinecapacities,adjustedtemperaturesandpressures.
Case
1
2
3
4
5
6
7
8
9
10
BoilerOperating
Pressure(bar)
28
36
45
45
54
65
68
72
78
84
BoilerOperating
Temperature(0C)
350
380
400
420
450
480
490
500
520
540
Practical Elec
PowerOut(kW)
Poweravailableat
turbineexit(kW)
1000
1200
1350
1400
1550
1750
1800
1850
1950
2050
2134
2147
2142
2183
2206
2226
2235
2243
2264
2286
Table 5.2 :Practical Turbine Capacities Calculated for Section 4.4 Design 41 | P a g e M.Sc. Thesis 5.5.2 ElectricityGenerationandFuelConsumptionbytheProposedTri‐gen
5.5.2.1 ElectricityGeneration
SamecalculationprocedureusedinChapter04hasbeenusedwithamendmentforthe
calculation of electricity generation. Practically available turbine capacities have been
used for calculations instead of theoretical turbine capacities arrived in the same
sectionforthecalculations.Furtherthreesetsofoperatingpressureandtemperatures
havebeenalteredtomeetthepracticallyavailableturbinecapacitiesasshowninTable
5.1. In addition, two important factors have been considered in calculating total net
electricalenergygeneratedbyeachoftheturbinesidentifiedinTable5.2.

HoursOperated:inthiscaseplanthastobeoperated24hoursasthefactory
isrunning24hours.Howeverincalculatinghoursoperatedonemustconsider
thenumberofhoursinwhichtheplantneedstobeshutdownformaintenance.
Typically,plantsofthisnaturehasplantfactorof90%.

Electricity Requirement of the TG Plant: As shown in the Schematic plant
design, CCH plant comprises of various equipment such as blowers, fans,
motors and pumps which are electric driven. Hence part of electricity
generatedbytheplantwillbeoffsetbytheenergyconsumedbytheabovesaid
equipment.
Total electricity generation by the turbines identified in Table 5.2, calculated
consideringabovetwofactorsaregiveninTable5.3.
Case
1
2
3
4
5
6
7
8
9
10
Boiler
BoilerTemperature
Pressure(bar) (0C)
28
36
45
45
54
65
68
72
78
84
possibleElecPower TotalElectricitynet
Out(kW)
Generation(kWh)
350
380
400
420
450
480
490
500
520
540
1000
1200
1350
1400
1550
1750
1800
1850
1950
2050
7,095,600
8,514,720
9,579,060
9,933,840
10,998,180
12,417,300
12,772,080
13,126,860
13,836,420
14,545,980
Table 5.3:Electricity Generation by Practical Turbine Capacities Calculated for Section 4.4 Design 5.5.2.2 ElectricityRequirementoftheTGPlant
Followingtable5.4indicatestheelectricalenergyconsumingequipmentoftheTGplant
andtheexpectedannualenergyconsumptionsofthesame,whencoalisusedasfuel.
42 | P a g e M.Sc. Thesis Energyrequiredbythecoolingtower,chilledwater,andcondenserwaterpumpsofthe
absorptionchillershasbeenomittedfrombelowcalculationassumingthatitwilloffset
theenergyconsumedbythesameequipmentofthecurrentairconditioningsystem.
Equipment
Type
Application
Rated
power(kW)
Count Energy
Consumption(kWh)
IDfan
PAfan
FDfan
RWpumps
DMWpump
BFpump
EFpump
Conveyor
motor
Flugassuction
Createfluidizedbed
Drawair
Pumpingrawwater
Pumpingtreatedwater
Feedingwatertoboiler
Dischargeeffluent
SupplyCrushedcoalto
boiler
75
20
80
1.5
1.5
95
0.5
3
1
1
1
1
1
1
1
1
532,170
141,912
567,648
7,096
7,096
674,082
2,365
21,287
Coalcrusher Coalpreparation
Absorption
Electricapplicationsin
chillers
thechiller
TotalEnergyConsumption
35
10
1
2
110,376
110,376
2,174,407
Table 5.4: Electricity Use by Plant Equipment for Coal TG Plant Followingtable5.5indicatestheelectricalenergyconsumingequipmentoftheTG‐Plant
and the expected annual energy consumptions of the same, when Bio mass is used as
fuel.
Equipment
Type
IDfan
PAfan
RWpumps
DMWpump
Application
Flugassuction
Createfluidizedbed
Pumpingrawwater
Pumpingtreated
water
BFpump
Feedingwaterto
boiler
EFpump
Dischargeeffluent
Conveyor
SupplyCrushedcoal
motor
toboiler
Absorption
Electricapplications
chillers
inthechiller
TotalEnergyConsumption
Rated
Count
power(kW)
15
1
20
1.5
1
1.5
1
95
0.5
Energy
Consumption(kWh)
106,434
141,912
7,095
7,095
1
1
1
10
2
674,082
2,365
21,286
110,376
1,070,647
Table 5.5: Electricity Use by Plant Equipment for Biomass TG 43 | P a g e M.Sc. Thesis 5.5.2.3 OperationalandLaborCosts
Similar to any industrial plant equipment Tri‐Generation plant will also incur an
additional cost to the owner in terms of operations and labor. Operation cost will
includeCostofspares,costofchemicals,costofwaterandadministrativecost.Itisvery
difficulttoaccuratelyestimatethesecostasmostofthesearecasespecific.Therefore
the cost figures used in the industry by the leading TG plant equipment suppliers has
been used for the calculation. Following are the list of such figures obtained from a
leadingsupplier.



CostofSpares
Costofwater
CostofChemicals
0.0100 USD/kWh (AnnualEscalation‐07%)
0.0050 USD/kWh (AnnualEscalation‐05%)
0.0040 USD/kWh (AnnualEscalation‐05%)
Inadditiontoabovecostseveralstaffhasttobeemployedfortheoperationoftheplant
which will contribute to labor cost related to the TG plant. Since the plant has to be
operated24hours,foursupervisorylevelstaff,eighttechniciansandeightlaborerswill
be required at a minimum. Based on this manpower requirement following cost
calculation has been done according to the current pay mechanism of the Textures
Jersey





Supervisor–
Technicians–
Admin–
Labourers–
AnnualTotal–
(2x600$/monthx12)=14,400$/Yr
(4x450$/monthx12)=21,600$\/Yr
(3x350$/monthx12)=12,600$\/Yr
(4x250$/monthx12)=12,000$/Yr
60,600$/Yr
.
5.5.2.4 Fuel(Coal/BioMass)ConsumptionandAssociatedCosts
Bothcoalandbiomassconsumptionbyeachoperatingconditionshavebeencalculated
consideringtheenergyinputtotheboiler.
365
24
44 | P a g e M.Sc. Thesis Following Table 5.6 indicates the fuel requirement in metric ton for each category
calculatedusingtheaboveequation. Case
1
2
3
4
5
6
7
8
9
10
Boiler
Boiler
Pressure(bar) Temperature(0C)
28
36
45
45
54
65
68
72
78
84
350
380
400
420
450
480
490
500
520
540
coal (MT)
20,199
20,809
20,994
21,347
21,553
22,366
22,523
22,586
22,920
23,258
Sawdust
briquettes(MT)
30,859
31,791
32,074
32,612
32,926
34,170
34,409
34,505
35,016
35,532
Firewood(MT)
45,352
46,721
47,138
47,928
48,390
50,219
50,570
50,711
51,462
52,219
Table 5.6: Fuel Consumption for Coal & Biomass Fired Systems 5.5.3 NetPresentValue,IRRandSimplePayback
Itisnormalpracticetoperformanetpresentvalueanalysisandcalculationofinternal
rateofreturntoseeifinvestingmoneyonagivenprojectisworthwhile.Simplepayback
(SPB)calculationindicateshowlongittakestorecovertheinvestment.
Above three economical parameters were calculated for the tri generation plant
designedfortheTexturesJersey.Unlikemostoftheindustriesapparelindustryisvery
volatile and the future trends are highly unpredictable. Therefore apparel industry
normally does not make investments considering longperiods like 20yrs. Considering
thisfactandthelifecycleofplantequipmentofthetri‐genplant,a10yearperiodwas
takenfortheeconomicalanalysis.
Theeconomicalanalysiswasconductedforalltenselectedoperatingconditionsandfor
threedifferentfuels,namely;coal,sawdustbriquettesandfirewood,whichresultsin
30differentcases.SamplecalculationforeachfueltypeisgiveninAppendixC,D&E.
5.5.3.1 EconomicAnalysisforCoalFiredSystem
PositiveNPVover10yearperiod(Figure25),IRRhigherthanthecurrentdiscountrate
(Figure26)andthepaybackintherangeof4years(Figure27)indicatesthatinvesting
on a tri‐generation plant is economically highly favorable. Though none of the
calculatedparameters(NPV,IRR,SPB)exhibitauniformtrend,itisevidentthathigher
temperature and pressure points results in better values for all three parameters.
Howeverchangeineachparameterwithvariousoperatingconditionsisnotsubstantial
for a management to take decision on an optimum condition. Hence capital in hand
plays a huge roll in selecting an operation condition as higher pressure/temperatures
requirehigherinvestments.Othernon‐economicalparameterssuchasemissions,Ash
disposal, coal storage, supply chain issues, safety requirement also may consider in
selectingtheoperatingconditions.
45 | P a g e M.SSc. Thesis 5
5000
USDollar($Thaousands)
4
4800
Capital
NPV
4
4600
4
4400
4
4200
4
4000
3
3800
OperatingT&P
Figure 2
24‐ Investmen
nt and NPV of the Coal Fire
ed Plant 29%
29%
28%
IRR
28%
27%
27%
26%
26%
25%
OperratingT&P
Figure 25‐ Intern
nal Rate of Re
eturn of the In
nvestment forr Coal Fired Plant 46 | P a g e M.SSc. Thesis 4.2
20
4.0
00
3.8
80
Years
3.6
60
3.4
40
3.2
20
3.0
00
O
OperatingP
&T
Figure 26‐Simp
ple Payback Tiime of the Invvestment for Coal Fired Plaant 5.5.3.2 EconomiicalAnalyssisforBiom
massFired
d System
Same calculation
c
proceduree used for coal was used
u
for biiomass (saw
w dust briiquettes
andfireewood)fireedsystemanalysis.A
Asshownin
nschematiccdesignsth
hemaindiffference
inthessystemcom
mparedtoccoalisthe fuelpreparrationsysttemandtheelesscomp
plicated
boiler. Hence bio
o mass sy
ystems req
quire less capital an
nd the plan
nt consum
mes less
biomassbo
oilers,loweerLHVofb
biomass,
electriccity.Aparttfromthat,,lowereffiiciencyofb
lowerccostofbiom
massandlowerself‐eelectricitycconsumptio
onofbiomaasssystem
marethe
majorp
parameterssthatcontrributetodiifferentresultforecon
nomicanallysis.
Themaaindifferen
ncebetweeentheplanttarchitectu
uresofsaw
wdustbriquettessysttemand
thefireewoodsysttemistheffuelfeedingsystem.A
Automatic feedingbyyaconveyo
orisnot
practicalasfirew
woodcomessinlogs.Thereforeadditionallaabouris(aatleast9p
persons)
requireed for the operation and hencee the labou
ur cost per kWh high
her comparred to a
briquetttesystem..Also,optin
ngtofirew
woodsaveo
oncapitalaastheauto
omaticfuel feeding
system
misnotrequ
uired.
A samp
ple of saw
w dust briq
quette was tested in Industrial Technologgy institutee of Sri
Lanka, toestimatethecalorificvalue.A
Asperthe results,(atttachedinA
AppendixF
F)ithas
9.5% moisture
m
content and
d a higherr heating value
v
(HHV
V) of 4,759kCal/kg (19,924
kJ/kg).Followingequationw
wasusedto
ocalculatethelowerh
heatingvalue(LHV).
47 | P a g e M.Sc. Thesis 1
2.447 ForBriquetteswith9.5%moisturecontent:
19,924 1
0.095
2447
Similarlyforthefirewood:
19,924 1 0.3
2447
0.095
0.3
17,7985 /
13,2135 /
Inadditiontoabovetheseverecontrastbetweenthepricesofthetwotypeofbiomass
contributestomajordifferencesineconomicparameters.
AsshowninFigure28,inbriquettessystem,capitalrequirementforincreaseoperating
pressure and temperature steadily increase while NPV is maintained positive. This
scenarioissameforthefirewoodboilers.NPVofbothcasesdoesnotindicatemuchofa
variationwhereasNPVoffirewoodsystemveryhigh(~4timesthecapital)asshownin
Figure29owingtothehighersavingresultedfromcheapfuelcost.
Simplepaybacksoftwosystemsalsodonotvarymuchwiththeoperatingpressureand
temperatures as shown in Figure 31. Here again the fire wood system indicates pay
backsassmallas1.6yrs(almosthalfofbriquettesandcoalsystems)duetoextremely
lowfuelprices.AsshowninFigure30,IRRofbothBiomassfueltypesexhibitthesame
patterns.
Similar to coal powered systems economic parameters do not exhibit substantial
variation at different operating conditions. Therefore capital in hand should be
considered in selecting a suitable operating condition. Other non‐economical
parameters also, such as Ash disposal, storage, supply chain issues and safety
requirementhastobeconsideredinselectingtheoperatingconditions.
48 | P a g e M.SSc. Thesis 4
4,100
USDollar($Thousands)
3
3,900
Capitaal
NPV
3
3,700
3
3,500
3
3,300
3
3,100
2
2,900
2
2,700
2
2,500
Operatin
ngT&P
Figure 27‐ Investment aand NPV of th
he Briquettes Fired Plant
16
6,000
Cap
pital
NPV
USDollar($Thousands)
14
4,000
12
2,000
10
0,000
8
8,000
6
6,000
4
4,000
2
2,000
0
OperatingP
P&T
he Firewood FFired Plant Figure 28‐‐ Investment and NPV of th
49 | P a g e M.SSc. Thesis 80
0.00%
IRR‐Briquetttes
IRR‐firewood
70
0.00%
60
0.00%
IRR
50
0.00%
40
0.00%
30
0.00%
20
0.00%
10
0.00%
0
0.00%
Operatin
ngP&T
Figure 29‐ Internal Raate of Return of the Investment for the Two types off Biomass 4.0
00
SimplePaayBack‐Briqu
uettes
SiimplePayBack‐ Fierwood
d
3.5
50
3.0
00
2.5
50
Years
2.0
00
1.5
50
1.0
00
0.5
50
0.0
00
O
OperatingP&
&T
e of the Investment for the
e Types of Bio
omass Figurre 30‐Simple Payback Time
50 | P a g e M.Sc. Thesis Whencomparedtoeachotherpurelyoneconomicterms,biomassfiredtri‐generation
plant is economically attractive than the coal fired plant. Three main contributors to
theseeconomicallyattractiveresultsarethelowerpriceofbiomass,lowercapitalcost
ofbiomasstri‐genplantandhigherelectricityconsumptionbytheauxiliaryequipment
ofthecoalfiredplants.
Ifuninterruptedsupplyofbiomasscanbeassured,economicallyoptimalsolutionisto
goforabio‐massfiredTriGenerationplant.
5.5.4 EnvironmentalIssuestobeTackledbyTexturesJerseywithTri‐Gen

GreenhouseGas(GHG)Emissions
One of the main reasons for implementing TG plants is to harness the maximum
amount of energy thereby reduces the GHG emissions. Sri Lankan apparel sector
alsoisundergreatpressurefromtheirinternationalbuyersandthegovernmentto
reduce the emissions. However, as indicated in the below Figure 32, it is evident
thatuseofcoalwillfurtherincreasetheemissionwhencomparedwiththecurrent
emissionquantities.Thishappensduetooffsetofemissionreductionachievedby
generating electricity and eliminating electricity requirement for chillers by the
excessive coal combustion. Coal combustion release CO2, N2O and CH4 that
contributestotheglobalwarmingandtheFigure32indicatestheequivalentCO2
emissionbyallgreenhousegases.
However,theGHGemissioncanbedrasticallyreducedasshowninfigure32byuse
of biomass (both briquettes and firewood) if the CO2 emission by the same is
assumedtobezero.

SO2Emissions
Coal has a certain percentage of Sulphur. Coal is imported from Indonesia for
current major local applications such as coal power plants run by the local utility
companies. Hence same coal will have to be used by the tri‐gen plants if
implemented.TypicalIndonesiancoalhaslowerSulphurcontentanditisabout1%
as a fraction of mass. Therefore, 400 to 470 MTs of SO2 will be released to the
environmentifcoalisusedfortheTGplant,dependingontheoperatingpressure
andtemperature.

CombustionAsh
Anysolidfuelfiredboilergeneratesbottomashafterthecombustionprocess.Coal
and biomass are no difference. Locally used coal has approximate ash content of
about 6% (source: Holcim test report) whereas bio mass has approximate ash
content of about 4.3% (source: ITI test report). Therefore TG plant fired by both
51 | P a g e M.Sc. Thesis fuel types will result in 1,200 to 1,800 MTs of solid waste (ash) annually. Proper
disposal methods such reuse in cement manufacturing has to be implemented to
avoid

AirborneParticles
When solid fuel like biomass or coal is combusted certain percentage of ash get
airborne and exist the chimney with the flu gas. This airborne particles then get
carriedbythewindandcangetdepositedintheneighboringarea.
Unlike biomass, coal can create more airborne particles in form of dust during
loading,unloading,storing,crushingandconveying.

WaterandLandContaminating
This happens if coal is used. Normally coal is stored in outdoor before it is being
used. During such time, rain falls on to stored coal can wash away solid particles
andcancontaminatethelocalwaterbodiesandthesurroundingland.

TransportRelatedEmissions
Proposed plant that was subjected to study will require 20,000 to 40,000 MTs of
solid fuel (coal or biomass) depending on the fuel type and operating
pressure/temperature. Handling of these quantities will require lot of
transportationwhichagaincontributesharmfulemissions.

IndirectDeforestation
Inthisanalysisithasbeenassumedthatbiomasswouldcomefromwoodwasteor
fromtreescommerciallygrownforfirewood.Howevercurrentlythereisnoproper
mechanism to check the actual source of the biomass. There have been many
incidents of deforesting for firewood. If that happens, whole purpose of using bio
masswillbelost
52 | P a g e M.SSc. Thesis 8
85.00
CoalTri‐Geen
Biom
massTri‐Gen
Curren
ntSystem
CO2Emmisions(MT)
7
75.00
6
65.00
5
55.00
4
45.00
3
35.00
2
25.00
1
15.00
Ope
eratingP&T
T
F
Figure 31‐CO2
2 Emission by Three Option
ns 5.6 GeneralGu
G
uideline––WhatLo
ocalApparrelSectorrcanlearn
nfromth
hiscase
Regard
dless of thee similarity
y in the app
plication itt is used, economic
e
and environ
nmental
benefitts of a Tri‐G
Generation
n plant dep
pends heav
vily on the prevailing local paraameters.
SriLan
nkanappareelssectorisalsonoexception.A
Asmention
nedinChap
pter03,SriLankan
apparelsectorhassfivemain
ncategoriessandtheirenergycon
nsumptionss,operatingghours,
producction proceesses,coolin
ng requirementand many otheer parametters that afffect the
viabilitty of a TG plant larggely differ from
f
each other. Theerefore creeating a un
niversal
approaach is not possible, that
t
would
d enable th
he local ap
pparel sector to iden
ntify the
viabilittyofaTGplantifimpllementedo
ontheirfacilities.
Resultssofmanyo
oftheprev
viousreseaarchescarrriedouton Tri‐Generationalso suggest
theeacchcasehassuniqueou
utcomes.H
Howeverresultofthissanalysissshowsthat certain
generallimitation
nscanbeim
mposedthaatwillhelp
ptonarrow
wdownthecountless options
availab
bleforaTG
Gplant.Facctorsthataarecommontolocalaapparelsecctorandafffectthe
viabilittyoftheTrri‐Generatio
onsuchas sameenerrgytariffs, sameendu
usesofheaat,same
weatheer conditio
ons, similarr manufactturing procedures, same availaability of fuel
f
are
usedto
ocomeupw
withthegenerallimitaationofTG
Gapplicableetolocalap
pparelindu
ustry.

Eco
onomicBe
enefits
As per the caalculation done
d
for th
he Texturess Jersey, in
nvestment on a TG Pllant has
ve econom
mical ben
nefits. Maiin contribu
utors are low price of fuel
verry attractiv
com
mparedto HFO,electtricitygeneeratedbystteamturbiineandtheeelectricity
ysaving
on VCchillerss.Thereforreanyoneu
usingHFO orsimilarfuelassou
urceofeneergyfor
53 | P a g e M.Sc. Thesis processheatingcanenjoyeconomicbenefitsbyshiftingtocoalorbiomassfiredTG
plant. However NPV, IRR and the payback time will vary with the parameters
uniquetotheplacewhereTGplantisimplemented.Thereforeitisadvisabletodo
an economic analysis after doing a schematic design considering following
guidelines.

Infrastructure
Onemustinvestigatewhetherthenecessaryinfrastructureisinplacetoimplement
a TG Plant. First requirement is space. Normally most of the local apparel factory
buildingsoccupiedmostofthelandofthelocatedsite,leavinglittlespaceforthis
kind of projects. TG plants need adequate space for place the boilers, turbines,
coolingtowers,watertreatmentplants,otherplantequipment,fuelstorageandetc.
Each of these has to be places with adequate maintenance access and with safety
clearances.Furthertheavailabilityoftransportaccesstotransport&erecttheplant
andtotransportfuelshouldalsobeconsidered.

PlantCapacity
Boiler and the turbine are the two main components in a TG plant, of which the
capacityaffecttheeconomicsofthetotalplant.Restoftheplanthastobedesigned
accordingtothecapacitiesofthesetwocomponents.Itisalwaysimportanttosize
the plant considering the process heat requirement rather than considering the
electricitydemand,becausethereisnoalternativesourceforheating.Ontheother
hand,excesselectricitycanbefedtothegrid,ifanyorelectricityshortagecanbe
obtained from the grid, once the plant is sized to meet process heating demand.
Therefore,optimumboilercapacitycanbearrivedbyadditionofallprocesssteam
massflowratesandthesteammassflowraterequiredbyabsorptionchillers(this
istheminimumboilercapacitypossible).
Selectingaboilerwithhighercapacitythantheminimumsteamrequirementallows
theusertohaveabiggerturbineandtherebygeneratehigheramountofelectricity.
Difference between costs of self‐generated kWh electricity and purchased kWh is
marginalasIndustrialelectricitypriceinSriLankaisheavilysubsidized.Therefore
cost saving by increased self‐generations not substantial compared to the capital
cost incurred in purchasing higher capacity boiler and turbine. However even the
subsidized grid electricity is not cheap enough to use for heating purposes when
comparedwiththecostoffuelssuchasHFO,coalandbiomass.

PlantArchitecture
Plant architecture depends mainly on how and at what point one is going to
obtained process steam from the cycle. Main options are to directly obtain some
steamfromtheboilerthroughPRV,tappingtheboileratsuitablepressurelevelsor
selecting the turbine to have an exit steam pressure at highest pressure level
required.Bothfirstandthirdoptionsreducetheelectricitygenerationcapacityof
the TG plant and require additional fuels as steam is obtained through PRVs.
54 | P a g e M.Sc. Thesis Thereforetappingtheturbineatsuitablepressurelevelgivestheoptimumbenefits
toagivenboilercapacity.

OptimumOperatingconditions
Ataminimum,anyselectedoperatingpressureandtemperatureshouldbeableto
provideenoughsteamatsuitablequalityattheturbineexittoruntheabsorption
chillers. Further, as shown in the calculations, operating at higher pressures and
temperatures gives better economical and environmental performance. Since the
process heating requirement is anyway met, increased P & T will increase the
savings only by offsetting electricity drawn from the grid. Further this increase
requires additional capital. As explained earlier designing the plant considering
electricity generation is not very profitable. Therefore one must decide the
minimum operating P&T considering energy availability to the absorption chiller
andwhethertoincreasethepressurethantheminimumcanbedecidedconsidering
theavailablecapital.

Operatinghours
TexturesJersey,whichwassubjectedtoanalysisoperate24hoursaday.Thelonger
operating hours have contributeda lot to the shorter paybacks of the investment,
extremelyattractiveNPVandIRR.Hadtheplantranontypical12hour,10hoursor
8hourshiftthepaybacktimesbecomesnonattractiveasthereisnochangeinthe
investment. Negative NPVs will be resulted for certain operating conditions.
Moreover,startingandshuttingoffthiskindofaplanteverydayisnotadvisableas
these plant are meant to run continuously. Options available for factories with
shortershiftaretoeithertohaveanotherturbine(withouttapings)torunduring
the off hours or to run the existing turbine by rejecting heat via a cooling tower.
Both these options seriously affects the economics and therefore case by case
economicalanalysisisrequired.

FuelSelection
Firewood, Saw dust briquettes and coal are preferred as the fuel over HFO in the
respectiveorder.Biomassispreferredovercoalowingtotwomainreasons.Firstis
the reduce capital requirement as TG plant become less complicated compared to
the coal fired system as it does not require complex fuel preparation and feeding
system. This makes the Bio mass system more economically attractive. It also
createsmuchlowernetCO2emissioncomparedtoacoalfiredsystem.
In economic terms, fire wood is preferred over saw dust briquettes due to ~40%
lowercostperMJandlowercapitalcost.CostperMJofbiomassisslightlyhigher
thanthatofthecoal,yetitiseconomicallyattractiveduetopreviouslymentioned
reasons. However the main advantages of coal are the availability and the well
establish supply chain. Whether large quantities of bio mass can be sourced
continuouslythroughouttheyearisdoubtful.Thereforeonemustnotventureinto
bio‐massfiredTGplantuntilcontinuoussupplyisensured.
55 | P a g e M.Sc. Thesis 6 Conclusion
Increaseddemandforfossilfuelandtheconflictsinthemajoroilproducingcountries
hasledfossilfuelpricetoincreaseuptoalevelwhichisalmostunbearabletotheSri
Lankan industry. Among all, apparel manufacturing is one of the severely affected
industriesbythesuddenfuelpricehikes.Asaresultoftheglobaltrendofsustainable
development, pressure from various institutes to minimize the emissions by reducing
theenergyconsumption,isanothermajorchallengefacedbythelocalapparelindustry.
A typical Sri Lankan apparel manufacturing factory requires electricity to run its
machineries,airconditioning&Ventilationsystem,lightingsandutilityequipmentlike
compressorsandpumps.FossilfuelslikeDieselandfurnaceoilareusedtorunboilers
to generate steam required for manufacturing process. Tri‐generation has never been
usedbythelocalapparelindustryasasolutionfortheeverincreasingenergycost.The
mainobjectiveofthisresearchwastoevaluatethefeasibilityoftri‐generationifusedin
apparelindustryandtherebyprovidesetofgeneralizedguidelinestothelocalapparel
sector to identify the economical, environmental and technical challenges and the
benefitsthattheywouldcomeacrossinimplementingaTri‐Generationplant.Asperthe
research results it is evident that apparel factories that utilize HFO can enjoy
economicalbenefitsbyimplementingaTGplantrunbycoalorbiomass.
After the local apparel sector was studied it was found out that all factories can be
categorizedintofivemaintypes.Outofthatknittingandweavingwasidentifiedasthe
mostsuitabletypetoimplementaTGplant.TexturesJerseyswhichisaknittingfacility
was selected for the pilot study. After conducting a detail energy audit the end use
quantities were estimated. Simultaneously, the possible combinations for a TG plants
were also identified based on the energy flow in the facility. Out of numerous
combinations,twomostpracticalsolutionswereevaluatedusingEngineeringEquation
Solver.Thentheresultswereusedtoarriveatoptimalsolution.Afterdesigningadetail
schematicoftheplantNPV,IRR,Paybackenvironmentalimpactanalysiswasconducted
assumingthefuelascoal,sawdustbriquettesandfirewood.GeneralguidelinesonTG
forlocalapparelsectorwerethendevelopedbasedonanalysisresult.
ResultsoftheenergyauditconductedatthetexturesjerseyispresentedintheChapter‐
03.Ithasapeakelectricitydemandofabout3400kWandusesofstaggering8.9million
litersofheavyfueloilannually.Facilityneedabout6MTofsteamat10barand10MTof
steamat6bar.Recentfueloilpriceincreasehasresultedinmorethan50%reduction
in its net profit, making the facility good candidate to implement a Tri‐generation
system. In the next section all possible combinations for Tri‐ Generation system have
beenidentified.WhentheseoptionswereanalyzedusingmanualcalculationsandEES
severalimportantfactswererevealedthatultimatelyleadtotheoptimalsolution.Some
ofthemostprominentfactsrevealedareasfollows.
56 | P a g e M.Sc. Thesis  Tapping off high pressure steam from the turbine is more economical compared to
obtainingsteamthroughaPRV.Capitalsavingispossibleasformerneedsasmaller
capacityboilertogenerateagivenamountofelectricity.
 Lower overall energy cost for Increased operating pressure and temperature of a
givenboilercapacity
 Lower overall energy cost achieved by lowest capacity boiler at a given operating
pressureandtemperature
 Sizing the plant to meet the electricity results in lower energy cost saving due to
increasedfuelcost
 Steam exiting from the turbine has to be at, at least 1atm to be able to use for
absorption chiller. Availability of excess energy at exit indicates room for
optimization.
 Usecondensingtypeturbinesnegatestheeconomicalbenefitsofeliminatedenergy
wastageduetocost
 In a back pressure type turbine, Excess energy available for absorption chiller can
only be reduced by reducing the steam mass flow rate. Hence, it is obvious that a
smallest possible boiler has to be operated in the suitable pressure to obtain
optimumresults.
 However boiler must have a capacity that at least is sufficient to meet the total
processsteamrequirementofthefactory.
Economical analysis conducted for the plant designed for Textures Jersey based on
above factors, exhibit very attractive results for all three fuels namely; coal, saw dust
briquettes and firewood. Biomass fired systems indicates highly favorable GHG
emissionreductionwhereascoalfiredsystemincreasestheoverallemissions.
Itwasfurthernotedthattheseeconomicalresultsarehighlydependedonthevarious
local parameters unique to a given facility. Hence universal approach to economically
implementaTGplantthatwouldsuitanygivenapparelfactoryisnotpossible.However
followinggenerallimitationscanbeimposed.
 Any facility can enjoy economic benefits, by low cost heat source and electricity
savingbyTG.ButtheNPV,IRR&SPBdependonlocalparameters.
 Sizetheplantconsideringprocessheatingrequirementaselectricitygenerationnot
profitableduetosubsidizedtariff.Henceselectthesmallestpossibleboiler
 AvoidPRVs
 SelectP&TconsideringcapitalandenergyavailabletoAbsorptionchillers
 Suitableonlyfor24hoperations
 Firewood, Saw dust briquettes and coal are preferred as the fuel over HFO in the
respectiveorder
 Costofretrofittingismarginalcomparedtothetotalinvestment.
57 | P a g e M.Sc. Thesis Oneofthemostprominentfactsintheresultsistheextremelyfavorableeconomicand
environment result of the bio mass fired Tri‐Generation plants. Such systems are
technicallyalsosimplecomparedtocoalsystems.Paddyhusk,hey,commerciallygrown
firewood,municipalsolidwaste,timbermillwastesarethemostcommontypesofbio
massavailable.Furtherresearchshouldbecarriedoutonhowtoimprovethebiomass
supplychain,howtoefficientlyutilizetheavailablebiomass,howtocreateamarketfor
biomassandhowtoavoidharvestingnaturalforestsforbiomass.Anotherimportant
area to study is how to create a certificate system or special tariff for self‐generated
electricity that would encourage the industry to implement tri‐generation. Study on
implementingmethodologiestoobtainbenefitsfromcarboncreditsisalsoimportant.
FinallyitisevidentthatthelocalapparelsectorcanbebenefitedfromimplementingTr‐
Generationplantsbymeetingeconomicalgoalsinsustainablemanner.
58 | P a g e M.Sc. Thesis References
[1]AndreaC,JeanP,MichaelT,ThomasB,(2007).Economicsoftri‐generationinaKraft
pulp mill for enhanced energy efficiency and reduced GHG emissions. Applied
thermalenergy,32:474‐481
[2]ArteconiA,BrandoniC,PolonaraF(2009).Distributedgenerationandtri‐generation:
Energy saving opportunities in Italian supermarket sector. Applied thermal energy,
29:1735‐1743
[3]Athanasovici V, Bitir I, Le Corre O,Minciuc E, Tazerout M,(2003). Thermodynamic
analysis of tri‐generation with absorption chilling machine. Applied Thermal
Engineering,23:1391‐1405
[4]Carvalh M, Lozan M.A, Ramos J.C, Serra L.M, (2009) Thermo economic Analysis of
Simple Tri‐generation Systems, International journal of thermodynamics, 12: 147‐
153)
[5]ChaerI,MarriotM,SugiarthaN,TassouS.A,(2009).Tri‐generationinfoodretail:an
energetic, economic and environmental evaluation for a supermarket application.
Appliedthermalenergy,29:2624‐2632
[6]FreschiF,GiacconeL,LazzeroniP,RepettoM,(2013).Economicandenvironmental
analysis of a tri‐generation system for food‐industry: A case study. Applied Energy,
107:157‐172
[7]Parakrama Jayasinghe, (2004), The Biomass Energy Sector In Sri Lanka, Successes
AndConstraints
[8]Süleyman H.K, Onur S, (2011). Economical analysis of tri‐generation system.
InternationalJournalofthePhysicalSciences,6:1068:1073
[9]TemirG,BilgeD,EmanetO(2004).AnApplicationoftri‐generationanditseconomic
analysis.EnergySources,26:857‐867.
[10]United States Department of Energy, (2007). Voluntary Reporting of Green house
gasses,EIA‐1605:123‐124
[11]United States Environmental Protection Agency, (2011). Emission Factors for
GreenhouseGasInventories
59 | P a g e M.Sc. Thesis AppendixA:ElectricityDemandVariationwiththeTimeof
theDay
Followingarethedataobtainedduringtheenergyauditbyfixingdataloggerstothe
mainincomingbussbarsofthemainelectricalswitchboard.
Time
12:00AM
12:15AM
12:30AM
12:45AM
1:00AM
1:15AM
1:30AM
1:45AM
2:00AM
2:15AM
2:30AM
2:45AM
3:00AM
3:15AM
3:30AM
3:45AM
4:00AM
4:15AM
4:30AM
4:45AM
5:00AM
5:15AM
5:30AM
5:45AM
6:00AM
6:15AM
6:30AM
6:45AM
7:00AM
7:15AM
7:30AM
7:45AM
8:00AM
8:15AM
8:30AM
8:45AM
9:00AM
Demand(kVA)
2,545.1
2,530.6
2,494.4
2,517.9
2,528.8
2,603.1
2,537.5
2,560.1
2,571.1
2,585.0
2,611.8
2,630.6
2,609.0
2,573.1
2,628.2
2,688.0
2,590.2
2,706.5
2,636.4
2,765.9
2,725.5
2,750.6
2,806.6
2,751.5
2,794.7
2,733.7
2,807.5
2,791.6
2,847.8
2,788.7
2,814.1
2,857.2
3,128.8
3,120.0
3,048.8
3,075.8
3,058.0
PowerFactor
0.94
0.94
0.93
0.93
0.93
0.94
0.93
0.94
0.95
0.95
0.95
0.94
0.93
0.93
0.93
0.93
0.93
0.93
0.94
0.96
0.95
0.95
0.94
0.93
0.95
0.95
0.96
0.96
0.96
0.96
0.96
0.96
0.95
0.96
0.96
0.97
0.96
ActivePower(kW)
2,394.89
2,386.33
2,319.81
2,341.69
2,356.82
2,457.34
2,354.82
2,414.18
2,432.22
2,450.55
2,473.40
2,472.73
2,434.22
2,400.67
2,446.86
2,494.43
2,408.84
2,503.53
2,486.16
2,641.45
2,589.21
2,599.32
2,643.83
2,558.87
2,643.75
2,605.25
2,683.98
2,677.19
2,736.72
2,671.59
2,707.15
2,748.60
2,978.61
2,998.31
2,935.96
2,974.34
2,932.59
60 | P a g e M.Sc. Thesis 9:15AM
9:30AM
9:45AM
10:00AM
10:15AM
10:30AM
10:45AM
11:00AM
11:15AM
11:30AM
11:45AM
12:00PM
12:15PM
12:30PM
12:45PM
1:00PM
1:15PM
1:30PM
1:45PM
2:00PM
2:15PM
2:30PM
2:45PM
3:00PM
3:15PM
3:30PM
3:45PM
4:00PM
4:15PM
4:30PM
4:45PM
5:00PM
5:15PM
5:30PM
5:45PM
6:00PM
6:15PM
6:30PM
6:45PM
7:00PM
7:15PM
7:30PM
7:45PM
3,090.3
3,291.0
3,195.2
3,285.1
3,222.7
3,278.2
3,238.4
3,144.6
3,390.2
3,277.3
3,195.9
3,350.4
3,293.8
3,277.5
3,282.1
3,277.5
3,221.3
3,181.2
3,066.7
3,173.0
3,265.4
3,315.0
3,282.9
3,301.9
3,292.8
3,221.2
3,233.5
3,307.1
3,239.5
3,342.7
3,243.5
3,291.7
3,177.5
2,989.0
2,965.9
2,902.0
2,934.0
2,893.2
2,931.4
2,957.1
2,996.1
2,925.1
2,946.6
0.96
0.94
0.95
0.95
0.95
0.95
0.95
0.95
0.95
0.96
0.96
0.95
0.95
0.95
0.95
0.95
0.95
0.95
0.96
0.95
0.95
0.95
0.95
0.95
0.95
0.95
0.95
0.95
0.95
0.95
0.95
0.96
0.96
0.96
0.96
0.97
0.95
0.95
0.94
0.95
0.95
0.96
0.95
2,951.19
3,093.56
3,022.67
3,130.73
3,071.27
3,120.80
3,076.46
2,990.49
3,227.47
3,133.12
3,052.11
3,196.32
3,132.40
3,126.75
3,117.99
3,107.04
3,066.67
3,031.64
2,931.75
3,001.67
3,085.80
3,139.30
3,102.35
3,149.99
3,131.42
3,066.58
3,084.73
3,138.39
3,077.48
3,185.59
3,091.04
3,150.19
3,053.56
2,857.53
2,844.25
2,803.30
2,793.16
2,739.84
2,764.34
2,818.07
2,855.27
2,793.48
2,805.20
61 | P a g e M.Sc. Thesis 8:00PM
8:15PM
8:30PM
8:45PM
9:00PM
9:15PM
9:30PM
9:45PM
10:00PM
10:15PM
10:30PM
10:45PM
11:00PM
11:15PM
11:30PM
11:45PM
2,908.8
2,915.8
2,922.7
2,843.2
2,841.0
2,836.3
2,764.1
2,685.0
2,653.7
2,739.0
2,706.7
2,705.6
2,652.0
2,693.2
2,691.2
2,662.9
0.95
0.95
0.95
0.95
0.95
0.96
0.95
0.97
0.95
0.93
0.94
0.94
0.94
0.95
0.94
0.95
2,769.17
2,778.74
2,785.30
2,701.08
2,707.51
2,725.73
2,636.95
2,615.16
2,507.70
2,544.52
2,549.68
2,537.84
2,484.90
2,545.04
2,540.48
2,524.43
62 | P a g e M.Sc. Thesis 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. 63 | P a g e M.Sc. Thesis "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)
64 | P a g e M.Sc. Thesis "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_bgCap_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"
65 | P a g e M.Sc. Thesis 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_tap1h_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
66 | P a g e M.Sc. Thesis AppendixC:NPV,IRRandPaybackCalculationforCoalat28barand350oC
CommonData
AverageElectricityTariff
Demandcost
CurrentPriceofFuelOil
AnnualElectricityRequirement
0.0928 $/kWh
6.80 $/kVA
0.720 $/Ltr
23,960,000 kWh
AverageElectricityDemand
ElectricityreusedbytheTri‐gen
ElectricitydemandbytheTri‐gen
ElectricityConsumptionByVCChillers
ElectricityDemandByVCChillers
FuelOilConsumption
CurrentPriceofCoal
Plantfactor
3,400
2,174,407
332
2,308,435
439
5,340,000
149
90%
kVA
kWh
kVA
kWh
kVA
Ltr
$/Tr
CaseSpecificData
ElectricityGeneratedbySteamTurbine
ElectricityDemandmetbyTri‐gen
CoalConsumptionbyTri‐Gen
Capital
AnnualOperationalCost
AnnualLabourCost
7,095,600
1,000
20,199
4,200,000
0.0160
0.0085
kWh
kVA
TR
$
$/kWh
$/kWh
Assumptions
AnnualDiscountrate
AnnualAverageOperationalcostincrease
AnnualLabourcostincrease
AnnualFueloilpriceEscalation
Annualelectricitycostescalation
AnnualCoalcostescalation
10.00%
6.3%
5.0%
10%
5%
10%
67 | P a g e M.Sc. Thesis AnnualCostSavingCalculation
Year
0
1
2
3
4
5
6
7
8
Annualelectricitycost
2,500,928
2,625,974
2,757,273
2,895,137
3,039,894
3,191,888
3,351,483
3,519,057
3,695,010
3,879,760
AnnualFuelOilCost
3,844,800
4,229,280
4,652,208
5,117,429
5,629,172
6,192,089
6,811,298
7,492,428
8,241,670
9,065,837
6,345,728
6,855,254
7,409,481
8,012,566
8,669,065
9,383,977
10,162,780
11,011,484
11,936,680
12,945,597
EnergyCostWithTriGen
AnnualSupplementaryElectricityCost($)
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
10
EnergyCostwithCurrentSystem
CurrentTotalEnergyCost
9
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
‐4,200,000
943,449
918,015
893,777
870,679
848,668
827,694
807,708
788,664
770,519
753,229
Presentvalueofcashflow(Rs)
SimplePayback
NPV
IRR
4.05
4,222,403
27.54%
68 | P a g e M.Sc. Thesis AppendixD:NPV,IRRandPaybackCalculationforSawDustBriquettesat
28barand350oC
CommonData
AverageElectricityTariff
Demandcost
CurrentPriceofFuelOil
AnnualElectricityRequirement
AverageElectricityDemand
ElectricityreusedbytheTri‐gen
ElectricitydemandbytheTri‐gen
ElectricityConsumptionByVCChillers
ElectricityDemandByVCChillers
FuelOilConsumption
CurrentPriceofBriquettes
Plantfactor
0.0928
6.80
0.720
23,960,000
3,400
1,070,642
157
2,308,435
439
5,340,000
104
90%
$/kWh
$/kVA
$/Ltr
kWh
kVA
kWh
kVA
kWh
kVA
Ltr
$/Tr
CaseSpecificData
ElectricityGeneratedbySteamTurbine
ElectricityDemandmetbyTri‐gen
Coal/BioMassConsumptionbyTri‐Gen
Capital
AnnualOperationalCost
AnnualLabourCost
7,095,600
1,000
30,859
3,295,000
0.0160
0.0085
kWh
kVA
TR
$
$/kWh
$/kWh
Assumptions
AnnualDiscountrate
AnnualAverageOperationalcostincrease
AnnualLabourcostincrease
AnnualFueloilpriceEscalation
Annualelectricitycostescalation
BioMasscostescalation
10.00%
6.3%
5.0%
10%
5%
10%
69 | P a g e M.Sc. Thesis AnnualCostSavingCalculation
Year
0
1
2
3
4
5
6
7
8
Annualelectricitycost
2,500,928
2,625,974
2,757,273
2,895,137
3,039,894
3,191,888
3,351,483
3,519,057
3,695,010
3,879,760
AnnualFuelOilCost
3,844,800
4,229,280
4,652,208
5,117,429
5,629,172
6,192,089
6,811,298
7,492,428
8,241,670
9,065,837
6,345,728
6,855,254
7,409,481
8,012,566
8,669,065
9,383,977
10,162,780
11,011,484
11,936,680
12,945,597
EnergyCostWithTriGen
AnnualSupplementaryElectricityCost($)
1,622,921
1,704,067
1,789,270
1,878,734
1,972,670
2,071,304
2,174,869
2,283,613
2,397,793
2,517,683
AnnualSupplementaryFuelOilCost($)
384,480
422,928
465,221
511,743
562,917
619,209
681,130
749,243
824,167
906,584
AnnualCostofCoal/BioMass
3,209,348
3,530,283
3,883,311
4,271,642
4,698,806
5,168,687
5,685,555
6,254,111
6,879,522
7,567,474
AnnualLaborcost($)
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
10
EnergyCostwithCurrentSystem
CurrentTotalEnergyCost
9
NewTotalEnergyCost
5,390,878
5,841,533
6,332,778
6,868,445
7,452,739
8,090,270
8,786,100
9,545,781
10,375,407
11,281,667
Investment
(3,295,000)
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
SimplePayback
NPV
IRR
3.4508
4,180,597
31.91%
70 | P a g e M.Sc. Thesis AppendixE:NPV,IRRandPaybackCalculationforFirewoodat28barand
350oC
CommonData
AverageElectricityTariff
0.0928 $/kWh
Demandcost
6.80 $/kVA
CurrentPriceofFuelOil
0.720 $/Ltr
AnnualElectricityRequirement
AverageElectricityDemand
23,960,000 kWh
3,400 kVA
ElectricityreusedbytheTri‐gen
ElectricitydemandbytheTri‐gen
1,070,642 kWh
157 kVA
ElectricityConsumptionByVCChillers
2,308,435 kWh
ElectricityDemandByVCChillers
FuelOilConsumption
CurrentPriceofFirewood
439 kVA
5,340,000 Ltr
48 $/Tr
Plantfactor
90%
CaseSpecificData
ElectricityGeneratedbySteamTurbine
ElectricityDemandmetbyTri‐gen
FirewoodMassConsumptionbyTri‐Gen
Capital
7,095,600 kWh
1,000 kVA
45,352 TR
3,265,000 $
AnnualOperationalCost
0.0160 $/kWh
AnnualLabourCost
0.0123 $/kWh
Assumptions
AnnualDiscountrate
AnnualAverageOperationalcostincrease
AnnualLabourcostincrease
AnnualFueloilpriceEscalation
Annualelectricitycostescalation
Firewoodcostescalation
10.00%
6.3%
5.0%
10%
5%
10%
71 | P a g e M.Sc. Thesis AnnualCostSavingCalculation
Year
0
1
2
4
5
6
7
8
9
10
EnergyCostwithCurrentSystem
Annualelectricitycost
2,500,928
2,625,974
2,757,273
2,895,137
3,039,894
3,191,888
3,351,483
3,519,057
3,695,010
3,879,760
AnnualFuelOilCost
3,844,800
4,229,280
4,652,208
5,117,429
5,629,172
6,192,089
6,811,298
7,492,428
8,241,670
9,065,837
6,345,728
6,855,254
7,409,481
8,012,566
8,669,065
9,383,977
10,162,780
11,011,484
11,936,680
12,945,597
CurrentTotalEnergyCost
3
EnergyCostWithTriGen
AnnualSupplementaryElectricityCost($)
1,622,921
1,704,067
1,789,270
1,878,734
1,972,670
2,071,304
2,174,869
2,283,613
2,397,793
2,517,683
AnnualSupplementaryFuelOilCost($)
384,480
422,928
465,221
511,743
562,917
619,209
681,130
749,243
824,167
906,584
AnnualCostoffirewood
2,176,883
2,394,571
2,634,028
2,897,431
3,187,174
3,505,891
3,856,481
4,242,129
4,666,342
5,132,976
AnnualLaborcost($)
87,600
91,980
96,579
101,408
106,478
111,802
117,392
123,262
129,425
135,896
AnnualOperationCost($)
113,530
120,625
128,164
136,175
144,685
153,728
163,336
173,545
184,391
195,916
NewTotalEnergyCost
4,385,413
4,734,171
5,113,262
5,525,490
5,973,925
6,461,935
6,993,208
7,571,791
8,202,118
8,889,054
Investment
(3,265,000)
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
‐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
Presentvalueofcashflow(Rs)
SimplePayback
NPV
IRR
1.6655
13,395,768
67.56%
72 | P a g e M.Sc. Thesis AppendixF:CalorificValueTestforSawDustBriquette
73 | P a g e 
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Related manuals

Download PDF

advertisement