板式換熱器畢業(yè)設(shè)計(jì)外文翻譯

DESIGNOFHEATEXCHANGERFORHEATRECOVERYINCHPSYSTEMSABSTRACTTheobjectiveofthisresearchistoreviewissuesrelatedtothedesignofheatrecoveryunitinCombinedHeatandPower(CHP)systems.TomeetspecificneedsofCHPsystems,configurationscanbealteredtoaffectdifferentfactorsofthedesign.Beforethedesignprocesscanbegin,productspecifications,suchassteamorwaterpressuresandtemperatures,andequipment,suchasabsorptionchillersandheatexchangers,needtobeidentifiedanddefined.TheEnergyEngineeringLaboratoryoftheMechanicalEngineeringDepartmentoftheUniversityofLouisianaatLafayetteandtheLouisianaIndustrialAssessmentCenterhasbeendonatedan800kWdieselturbineanda100tonabsorptionchillerfromindustries.ThisequipmentneedstobeintegratedwithaheatexchangertoworkasaCombinedHeatandPowersystemfortheUniversitywhichwillsupplementthechilledwatersupplyandelectricity.Thedesignconstraintsoftheheatrecoveryunitarethespecificationsoftheturbineandthechillerwhichcannotbealtered.INTRODUCTIONCombinedHeatandPower(CHP),alsoknownascogeneration,isawaytogeneratepowerandheatsimultaneouslyandusetheheatgeneratedintheprocessforvariouspurposes.Whilethecogeneratedpowerinmechanicalorelectricalenergycanbeeithertotallyconsumedinanindustrialplantorexportedtoautilitygrid,therecoveredheatobtainedfromthethermalenergyinexhauststreamsofpowergeneratingequipmentisusedtooperateequipmentsuchasabsorptionchillers,desiccantdehumidifiers,orheatrecoveryequipmentforproducingsteamorhotwaterorforspaceand/orprocesscooling,heating,orcontrollinghumidity.Basedontheequipmentused,CHPisalsoknownbyotheracronymssuchasCHPB(CoolingHeatingandPowerforBuildings),CCHP(CombinedCoolingHeatingandPower),BCHP(BuildingCoolingHeatingandPower)andIES(IntegratedEnergySystems).CHPsystemsaremuchmoreefficientthanproducingelectricandthermalpowerseparately.AccordingtotheCommercialBuildingsEnergyConsumptionSurvey,1995[14],therewere4.6millioncommercialbuildingsintheUnitedStates.Thesebuildingsconsumed5.3quadsofenergy,abouthalfofwhichwasintheformofelectricity.AnalysisofsurveydatashowsthatCHPmeetsonly3.8%ofthetotalenergyneedsofthecommercialsector.Despitethegrowingenergyneeds,theaverageefficiencyofpowergenerationhasremained33%since1960andtheaverageoverallefficiencyofgeneratingheatandelectricityusingconventionalmethodsisaround47%.Andwiththeincreaseinpricesinbothelectricityandnaturalgas,theneedforsettingupmoreCHPplantsremainsapressingissue.CHPisknowntoreducefuelcostsbyabout27%[15]COreleasedintotheatmosphere.TheobjectiveofthisresearchistoreviewissuesrelatedtothedesignofheatrecoveryunitinCombinedHeatandPower(CHP)systems.TomeetspecificneedsofCHPsystems,configurationscanbealteredtoaffectdifferentfactorsofthedesign.Beforethedesignprocesscanbegin,productspecifications,suchassteamorwaterpressuresandtemperatures,andequipment,suchasabsorptionchillersandheatexchangers,needtobeidentifiedanddefined.TheMechanicalEngineeringDepartmentandtheIndustrialAssessmentCenterattheUniversityofLouisianaLafayettehasbeendonatedan800kWdieselturbineanda100tonabsorptionchillerfromindustries.ThisequipmentneedstobeintegratedtoworkasaCombinedHeatandPowersystemfortheUniversitywhichwillsupplementthechilledwatersupplyandelectricity.Thedesignconstraintsoftheheatrecoveryunitarethespecificationsoftheturbineandthechillerwhichcannotbealtered.IntegratingequipmenttoformaCHPsystemgenerallydoesnotalwayspresentthebestsolution.Inourcasestudy,theabsorptionchillerisnotabletoutilizeallofthewasteheatfromtheturbineexhaust.Thisisbecausethecapacityofthechilleristoosmallascomparedtotheturbinecapacity.However,theneedforextraspaceconditioninginthebuildingsconsideredremainsanissuewhichcanberesolvedthroughtheuseofthisCHPsystem.BACKGROUNDLITERATUREThedecisionofsettingupaCHPsysteminvolvesahugeinvestment.Beforeplungingintoone,anyindustry,commercialbuildingorfacilityownerweighsitagainsttheoptionofconventionalgeneration.Adynamicstochasticmodelhasbeendevelopedthatcomparesthedecisionofanirreversibleinvestmentinacogenerationsystemwiththatofinvestinginaconventionalheatgenerationsystemsuchassteamboilercombinedwiththeoptionofpurchasingalltheelectricityfromthegrid[21].Thismodelisappliedtheoreticallybasedonexempts.Keepinginmindfactorssuchasrisingemissions,andtheavailabilityandsecurityofelectricitysupply,thebenefitsofacombinedheatandpowersystemaremany.CHPsystemsdemandthattheperformanceofthesystembewelltested.Theeffectsofvariousparameterssuchastheambienttemperature,inletturbinetemperature,compressorpressureratioandgasturbinecombustionefficiencyareinvestigatedontheperformanceoftheCHPsystemanddeterminesofeachoftheseparameters[1].FivemajorareaswhereCHPsystemscanbeoptimizedinordertomaximizeprofitshavebeenidentifiedasoptimizationofheattopowerratio,equipmentselection,economicdispatch,intelligentperformancemonitoringandmaintenanceoptimization[6].ManycommercialbuildingssuchasuniversitiesandhospitalshaveinstalledCHPsystemsformeetingtheirgrowingenergyneeds.BeforetheUniversityofDundeeinstalleda3MWCHPsystem,firsttheobjectivesforsettingupacogenerationsystemintheuniversitywerelaidandthenaccordinglytheequipmentwasselected.ConsiderationsforcompatibilityofthenewCHPsetupwiththeexistingdistrictheatingplantweretakencarebysomealterationsinpipeworksothatneithersystemcouldimposeanyoperationalconstraintsontheother[5].LouisianaStateUniversityinstalledaCHPsystembycontractingittoSempraEnergyServicestomeettheincreaseinchilledwaterandsteamdemands.Thenewcogenerationsystemwaslinkedwiththeexistingcentralpowerplanttosupplementchilledwaterandsteamsupply.Thisprojectsavestheuniversity$4.7millioneachyearinenergycostsaloneand2,200emissionsareequivalentto530annualvehicularemissions.AnotherexampleofacommercialCHPset-upistheMississippiBaptistMedicalCenter.FirsttheenergyrequirementofthehospitalwasassessedandthepotentialsavingsthataCHPsystemwouldgenerate[10].CHPapplicationsarenotlimitedtotheindustrialandcommercialsectoralone.CHPsystemsonamicro-scalehavebeenstudiedforuseinresidentialapplications.ThecostofUKresidentialenergydemandiscalculatedandastudyisperformedthatcomparestheoperatingcostforthefollowingthreemicroCHPtechnologies:Sterlingengine,gasengine,andsolidoxidefuelcell(SOFC)foruseinhomes[9].Thesearchfordifferenttypesoffuelcellsinresidentialhomesfindsthatadominantcosteffectivedesignoffuelcelluseinmicro–CHPexiststhatisquicklyemerging[3].Howeverfuelcellsfacecompetitionfromalternateenergyproductsthatarealreadyinthemarket.UseofalternateenergysuchasbiomasscombinedwithnaturalgashasbeentestedforCHPapplicationswherebiomassisusedasanexternalcombustorbyprovidingheattopartiallyreformthenaturalgasfeed[16].Asimilarstudywaspreformedwheresolidmunicipalwasteisintegratedwithnaturalgasfiredcombustioncycleforuseinawaste-to-energysystemwhichiscoupledwithaheatrecoverysteamgeneratorthatdrivesasteamturbine[4].SYSTEMDESIGNCONSIDERATIONSIntegrationofaCHPsystemisgenerallyattwolevels:thesystemlevelandthecomponentlevel.Certaintrade-offsbetweenthecomponentlevelmetricsandsystemlevelmetricsarerequiredtoachieveoptimalintegratedcooling,heatingandpowerperformance[18].AllCHPsystemscomprisemainlyofthreecomponents,apowergeneratingequipmentoraturbine,aheatrecoveryunitandacoolingdevicesuchasanabsorptionchiller.TherearevariousparametersthatneedtobeconsideredatthedesignstageofaCHPproject.Forinstance,thechillerefficiencytogetherwiththeplantsizeandtheelectricconsumptionofcoolingtowersandcondenserwaterpumpsareanalyzedtoachievetheoverallsystemdesign[20].Absorptionchillersworkgreatwithmicroturbines.AgoodexampleistheRolexRealitybuildinginNewYork,wherea150kWunitishookedupwithanabsorptionchillerthatprovideschilledwater.Anadvantageofabsorptionchillersisthattheydon’trequireanypermitsoremissiontreatment[2]Exhaustgasat800°Fcomesoutoftheturbineataflowrateof48,880lbs/h[7].OneimportantconstraintduringthedesignoftheCHPsystemwastocontrolthefinaltemperatureofthisexhaustgas.Thismeantutilizingasmuchheatasrequiredfromtheexhaustgasandsubsequentlybringingdowntheexittemperature.Afterrunningdifferentiterationsontemperaturecalculations,itwasdecidedtodivert35%oftheexhaustairtotheheatexchangerwhiletheremaining65%isdirectedtogoupthestack.Thisisachievedbyusingadiverterdamper.Inaddition,diverting35%ofthegasrelievestheproblemofbackpressurebuild-upattheendoftheturbine.Adivertervalvecanalsousedattheinletsideoftheheatexchangerwhichwoulddirecttheexhaustgaseithertotheheatexchangeroroutofthebypassstack.Thistakescareofvariableloadsrequirement.Insidetheheatexchanger,exhaustgasentertheshellsideandheatsupwaterrunninginthetubeswhichthengoestotheabsorptionchiller.Thesechillersrunoneithersteamorhotwater.TheabsorptionchillerdonatedtotheUniversityrunsonhotwaterandsupplieschilledwater.Acontinuouswatercircuitismadetorunthroughthechillertotakeawayheatfromtheheatinputsourceandalsofromthechilledwater.ThechilledwaterfromtheabsorptionchilleristhentransferredtotheexistingUniversitychillingsystemunitorforanotheruse.ThermallyActivatedDevicesThermallyactivatedtechnologies(TATs)aredevicesthattransformheatenergyforusefulpurposedsuchasheating,cooling,humiditycontroletc.ThecommonlyusedTATsinCHPsystemsareabsorptionchillersanddesiccantdehumidifiers.Absorptionchillerisahighlyefficienttechnologythatuseslessenergythanconventionalchillingequipment,andalsocoolsbuildingswithouttheuseofozone-depletingchlorofluorocarbons(CFCs).Thesechillerscanbepoweredbynaturalgas,steam,orwasteheat.Desiccantdehumidifiersareusedinspaceconditioningbyremovinghumidity.Bydehumidifyingtheair,thechillingloadontheACequipmentisreducedandtheatmospherebecomesmuchmorecomfortable.Hotaircomingfromanair-to-airheatexchangerremoveswaterfromthedesiccantwheeltherebyregeneratingitforfurtherdehumidification.ThismakesthemusefulinCHPsystemsastheyutilizethewasteheat.Anabsorptionchillerismechanicalequipmentthatprovidescoolingtobuildingsthroughchilledwater.Themainunderlyingprinciplebehindtheworkingofanabsorptionchilleristhatitusesheatenergyasinput,insteadofmechanicalenergy.Thoughtheideaofusingheatenergytoobtainchilledwaterseemstobehighlyparadoxical,theabsorptionchillerisahighlyefficienttechnologyandcosteffectiveinfacilitieswhichhavesignificantheatingloads.Moreover,unlikeelectricalchillers,absorptionchillerscoolbuildingswithoutusingozone-depletingchlorofluorocarbons(CFCs).Thesechillerscanbepoweredbynaturalgas,steamorwasteheat.Absorptionchillersystemsareclassifiedinthefollowingtwoways:1.Bythenumberofgenerators.i)Singleeffectchiller–thistypeofchiller,asthenamesuggests,usesonegeneratorandtheheatreleasedduringtheabsorptionoftherefrigerantbackintothesolutionisrejectedtotheenvironment.ii)Doubleeffectchiller–thischillerusestwogeneratorspairedwithasinglecondenser,evaporatorandabsorber.Someoftheheatreleasedduringtheabsorptionprocessisusedtogeneratemorerefrigerantvaportherebyincreasingthechiller’sefficiencyasmorevaporisgeneratedperunitheatorfuelinput.AdoubleeffectchillerrequiresahighertemperatureheatinputtooperateandthereforeitsuseinCHPsystemsislimitedbythetypeofelectricalgenerationequipmentitcanbeusedwith.iii)Tripleeffectchiller–thishasthreegeneratorsandevenhigherefficiencythanadoubleeffectchiller.Astheyrequireevenhigherheatinputtemperatures,thematerialchoiceandtheabsorbent/refrigerantcombinationislimited.2.Bytypeofinput:i)Indirect-firedabsorptionchillers–theyusesteam,hotwater,orhotgasesfromaboiler,turbine,enginegeneratororfuelcellasaprimarypowerinput.Indirect-firedabsorptionchillersfitwellintotheCHPschemeswheretheyincreasetheefficiencybyutilizingtheotherwisewasteheatandproducingchilledwaterfromit.ii)Direct-firedabsorptionchillers–theycontainburnerswhichusefuelsuchasnaturalgas.Heatrejectedfromthesechillersisusedtoprovidehotwaterordehumidifyairbyregeneratingthedesiccantwheel.Anabsorptioncycleisaprocesswhichusestwofluidsandsomeheatinputtoproducetherefrigerationeffectascomparedtoelectricalinputinavaporcompressioncycleinthemorefamiliarelectricalchiller.Althoughboththeabsorptioncycleandthevaporcompressioncycleaccomplishheatremovalbytheevaporationofarefrigerantatalowpressureandtherejectionofheatbythecondensationofrefrigerantatahigherpressure,themethodofcreatingthepressuredifferenceandcirculatingtherefrigerantremainstheprimarydifferencebetweenthetwo.Thevaporcompressioncycleusesamechanicalcompressorthatcreatesthepressuredifferencenecessarytocirculatetherefrigerant,whilethesameisachievedbyusingasecondaryfluidoranabsorbentintheabsorptioncycle[11].Theprimaryworkingfluidsammoniaandwaterinthevaporcompressioncyclewithammoniaactingastherefrigerantandwaterastheabsorbentarereplacedbylithiumbromide(LiBr)astheabsorbentandwater(H2O)astherefrigerantintheabsorptioncycle.Theprocessoccursintwoshells-theuppershellconsistingofthegeneratorandthecondenserandthelowershellconsistingoftheevaporatorandtheabsorber.HeatissuppliedtotheLiBr/H2Osolutionthroughthegeneratorcausingtherefrigerant(water)tobeboiledoutofthesolution,asinadistillationprocess.Theresultingwatervaporpassesintothecondenserwhereitiscondensedbackintotheliquidstateusingacondensingmedium.Thewaterthenenterstheevaporatorwhereactualcoolingtakesplaceaswaterispassesovertubescontainingthefluidtobecooled.HeatExchangerAverylowpressureismaintainedintheabsorber-evaporatorshell,causingthewatertoboilataverylowtemperature.Thisresultsinwaterabsorbingheatfromthemediumtobecooledandtherebyloweringitstemperature.TheheatedlowpressurevaporthenreturnstotheabsorberwhereitmixeswiththeLiBr/H2Osolutionlowinwatercontent.Duetothesolution’slowwatercontent,vaporgetseasilyabsorbedresultinginaweakerLiBr/H2Osolution.Thisweaksolutionispumpedbacktothegeneratorwheretheprocessrepeatsitself.Theheatrecoverysteamgenerator(HRSG)isprimarilyaboilerwhichgeneratessteamfromthewasteheatofaturbinetodriveasteamturbine.Theheatrecoveryboilerdesignforcogenerationprocessapplicationscoversmanyparameters.Theboilercouldbedesignedasafire-tube,watertubeorcombinationtype.Furtherforeachoftheseparameters,thereisavarietyoftubesizesandfinconfigurations.Foragivenboiler,asimplifiedmethodthatdeterminestheboilerperformancehasbeendeveloped[8].Theshellandtubeheatexchangeristhemostcommonandwidelyusedheatexchangerindifferentindustrialapplications[13].Itiscomparedtoaclassicinstrumentinaconcertplayingalltheimportantnodesindifferentcomplexsystemset-upsandcanbeimprovedbyusinghelicalbaffles.Thereareotherwaystoaugmenttheheattransferinashellandtubeexchangersuchasthroughtheuseofwall-radiation[25].Thedesignofashellandtubeheatexchangerforacombinedheatandpowersystembasicallyinvolvesdeterminingitssizeorgeometrybypredictingtheoverallheattransfercoefficient(U).Theprocessofobtainingtheheattransfercoefficientvaluesisobtainedfromliteraturebycorrelatingresultsfrompreviousfindingsinthedeterminationofheatexchangerdesigns.Thisinvolveslistingassumptionsatthebeginningoftheprocedure,obtainingfluidproperties,calculationofReynoldsnumberandtheflowareatoobtaintheshellandtubesizes.OnceUiscalculated,theheatbalancesarecalculated.ThisstudyalsocomparesthetheoreticalUvalueswiththeactualexperimentalonestoprovethetheoreticalassumptionsandtoobtaintheoptimumdesignmodel[18].Amathematicalsimulationforthetransientheatexchangeofashellandtubeheatexchangerbasedonenergyconservationandmassbalancecanbeusedtomeasuretheperformance.Thedesignoftheheatexchangerisoptimizedwiththeobjectivefunctionbeingthetotalentropygenerationrateconsideringtheheattransferandtheflowresistance[20].Onceaheatexchangerisdesigned,atotalcostequationfortheheatexchangeroperationisdeduced.Basedonthis,aprogramisdevelopedfortheoptimalselectionofshell-tubeheatexchanger[24].TheheatexchangertobeusedintheCHPsystemintheendneedstobetestedforitsperformance.AheatrecoverymoduleforcogenerationistestedbeforeuseforCHPapplicationthroughamicroprocessorbasedcontrolsystemtopresentthesystemdesignandperformancedata[19].ThebasisofaCHPsystemliesinefficientlycapturingthermalenergyandusingiteffectively.GenerallyinCHPsystems,theexhaustgasfromtheprimemoverisductedtoaheatexchangertorecoverthethermalenergyinthegas.ThecommonlyusedheatrecoverysystemsareheatexchangersandHeatRecoverySteamGeneratorsdependingonwhetherhotwaterorsteamisrequired.Theheatexchangeristypicallyanair-to-waterkindwheretheexhaustgasflowsoversomeformoftubeandfinheatexchangesurfaceandtheheatfromtheexhaustgasistransferredtomakehotwater.Sometimes,adiverteroraflapperdamperisusedtomaintainaspecificdesigntemperatureofthehotwaterorsteamgenerationratebyregulatingtheexhaustflowthroughtheheatexchanger.TheHRSGisessentiallyaboilerthatcapturestheheatfromtheexhaustofaprimemoversuchasacombustionturbine,gasordieselenginetomakesteam.Waterispumpedandcirculatedthroughthetubeswhichareheatedbyexhaustgasesattemperaturesrangingfrom800°Fto1200°F.Thewatercanthenbeheldunderhighpressuretotemperaturesof370°Forhighertoproducehighpressuresteam[21].TheDelawaremethodisaratingmethodregardedasthemostsuitableopen-literatureavailableforevaluatingshellsideperformanceandinvolvesthecalculationoftheoverallheattransfercoefficientandthepressuredropsonboththeshellandtubesideforsingle-phasefluids[12].Thismethodcanbeusedonlywhentheflowrates,inletandoutlettemperatures,pressuresandotherphysicalpropertiesofboththefluidsandaminimumsetofgeometricalpropertiesoftheshellandtubeareknown.EmissionControlEmissioncontroltechnologiesareusedintheCHPsystemstoremoveSO2(sulphurdioxide),SO3(sulphurtrioxide)NOx(nitrousoxide)andotherparticulatematterpresentintheexhaustofaprimemover.Somecommonemissioncontroltechnologiesare:1、DieselOxidationCatalyst(DOC)–Theyareknowtoreduceemissionsofcarbonmonoxideby70percent,hydrocarbonsby60percent,andparticulatematterby25percent(EmissionsControl:CHPTechnologiesGulfCoastCHP2007)whenusedwiththeultra-lowsulfurdiesel(ULSD)fuel.Reductionsarealsosignificantwiththeuseofregulardieselfuel.2、DieselParticulateFilter(DPF)-DPFcanreduceemissionsofcarbonmonoxide,hydrocarbons,andparticulatematterbyapproximately90to95percent(EmissionsControl:CHPTechnologiesGulfCoastCHP2007).However,DPFareusedonlyinconjunctionwithultra-lowsulfurdiesel(ULSD)fuel.3、ExhaustGasRecirculation(EGR)–TheyhaveagreatpotentialforreducingNOxemissions.4、SelectiveCatalyticReduction(SCR)–SCRcutsdownhighlevelsofNOxbyreducingNOxtonitrogen(N2)andoxygen(O2).5、NOxabsorbers–catalystsareusedwhichadsorbNOxintheexhaustgasanddissociatesittonitrogen.CONCLUSIONSThevariouscomponentsneededinaCHPsystemhavebeenpresented.Importantparameterssuchasthemassflowratesoftheexhaustgasandwatercanthenbedefined.TheCHPsystemhasbeenintegratedbytheuseofaheatrecoveryunit,thedesignofwhichhasbeendiscussed.Ashellandtubeconfigurationiscommonlyselectedbasedonliteraturesurvey.Thepressuredropsatboththeshellandthetubesidecanbecalculatedaftertheexchangerhasbeensized.IntegratingequipmenttoformaCHPsystemgenerallydoesnotalwayspresentthebestsolution.Inourcasestudy,theabsorptionchillerisnotabletoutilizeallofthewasteheatfromtheturbineexhaust.Approximately65%goesislefttogooutthestack.Thisisbecausethecapacityofthechilleristoosmallascomparedtotheturbinecapacity.However,theneedforextraspaceconditioninginthebuildingsconsideredremainsanissuewhichcanberesolvedthroughtheuseofthisCHPsystem.TheheatexchangerdesignedcaneitherbeconstructedfollowingtheTEMAstandardsoritcanbebuiltandpurchasedfromanindustrialfacility.ThedesignthatisusedisbasedonthemethodologyoftheBell-Delawaremethodandtheapproachispurelytheoretical,sothesizingmaybeslightlydifferentinindustrialdesign.Alsothemanufacturingfeasibilityneedstobechecked.Aftertheheatexchangerisconstructed,theCHPequipmentcanbehookedtogether.Againsincetheavailableequipmentisintegratedtoworkasasystem,theefficiencyoftheCHPsystemneedstobecalculated.Somekindofcontrolmoduleneedstobedevelopedthatcanmonitortheperformanceoftheentiresystem.Finally,thecostofrunningtheset-upneedstobedeterminedalongwiththeair-conditioningrequirements.關(guān)于在熱電聯(lián)產(chǎn)（CHP）系統(tǒng)中廢熱回收的熱交換器的設(shè)計(jì)

KozmanBimaldeepKaur吉姆·李研究助理教授副教授機(jī)械工程學(xué)系44170信箱,244房間CLR大廳拉斐特的路易斯安娜大學(xué)拉斐德,湖人70504-2250,美國(guó)摘要本次研究的目的是回顧熱電聯(lián)產(chǎn)（CHP）系統(tǒng)中廢熱回收裝置的設(shè)計(jì)的相關(guān)問題。為了滿足熱電聯(lián)產(chǎn)（CHP)系統(tǒng)的特殊需求，可以通過改變配置來影響設(shè)計(jì)的各種因素。在設(shè)計(jì)過程開始之前，產(chǎn)品參數(shù)(如蒸汽或水壓力、溫度)和設(shè)備(又如吸收式冷水機(jī)和熱交換器)需要被明確確定。實(shí)業(yè)公司向位于拉斐特的路易斯安那大學(xué)機(jī)械工程系的能源工程實(shí)驗(yàn)室和路易斯安那州的工業(yè)評(píng)估中心捐贈(zèng)一個(gè)800千瓦柴油渦輪機(jī)和100噸吸收式制冷機(jī)。該設(shè)備需要聯(lián)合熱交換器工作，作為一個(gè)聯(lián)合熱動(dòng)力系統(tǒng)，為大學(xué)供應(yīng)冷卻水和電力。不改變的渦輪機(jī)和制冷機(jī)的規(guī)格是熱回收裝置設(shè)計(jì)的約束條件。引言

熱電聯(lián)產(chǎn)（CHP）也稱為廢熱發(fā)電，是一種通過利用在使用過程中所產(chǎn)生的熱量來同時(shí)發(fā)電和發(fā)熱的方法。在機(jī)械或電氣能量中利用工業(yè)廢熱所產(chǎn)生的電能，可以被一個(gè)工業(yè)工廠完全消耗或被輸出到一個(gè)公用電網(wǎng)，從發(fā)電設(shè)備的排氣流中產(chǎn)生的熱能里得到的高溫回收熱能，被操作設(shè)備（如吸收冷水機(jī)、除濕設(shè)備）或是熱能回收裝置（用于生產(chǎn)蒸汽，熱水，空間或過程制冷、制熱，又或是控制濕度)所使用?；谒褂玫脑O(shè)備，CHP也有其它的縮寫，例如CHPB（冷卻建筑物的供暖和電力），CCHP（聯(lián)合冷熱電），BCHP（建筑冷熱電聯(lián)產(chǎn)）和IES（綜合能源系統(tǒng)）。熱電聯(lián)產(chǎn)（CHP）系統(tǒng)要比單獨(dú)的生產(chǎn)電力和火力發(fā)電的效率要高很多。根據(jù)商業(yè)建筑物能耗調(diào)查，1995年在美國(guó)有460萬的商業(yè)建筑[14]，這些建筑消耗能量是總能源四分之一的5.3倍，大約有一半來自電力。調(diào)查數(shù)據(jù)的分析表明，熱電聯(lián)產(chǎn)只滿足商業(yè)領(lǐng)域需要總能量的3.8%。盡管日益增長(zhǎng)的能源需求，自1960年以來，平均發(fā)電效率一直保持在33％，利用傳統(tǒng)方法發(fā)電和發(fā)熱的一般效率大約在47%左右。隨著電力和天然氣在價(jià)格上的增長(zhǎng)，對(duì)于設(shè)立更多的熱電聯(lián)產(chǎn)（CHP）設(shè)置的需求成為一個(gè)緊迫的課題.熱電聯(lián)產(chǎn)(CHP)被認(rèn)為是通過減少約27%[15]的CO釋放到大氣中,以降低燃料成本。本研究的目的是回顧熱電聯(lián)產(chǎn)（CHP）系統(tǒng)中廢熱回收裝置的設(shè)計(jì)的相關(guān)問題。為了滿足熱電聯(lián)產(chǎn)（CHP)系統(tǒng)的特殊需求，可以通過改變配置來影響設(shè)計(jì)的各種因素。在設(shè)計(jì)過程開始之前，產(chǎn)品規(guī)格(如蒸汽或水壓力、溫度）和設(shè)備（又如吸收冷水機(jī)和熱交換器）,需要被明確確定。實(shí)業(yè)公司向位于拉斐特的路易斯安那大學(xué)機(jī)械工程系的能源工程實(shí)驗(yàn)室和路易斯安那州的工業(yè)評(píng)估中心捐贈(zèng)一個(gè)800千瓦柴油渦輪機(jī)和100噸吸收式制冷機(jī)。該設(shè)備需要聯(lián)合熱交換器工作，作為一個(gè)聯(lián)合熱動(dòng)力系統(tǒng)為大學(xué)供應(yīng)冷卻水和電力。不改變的渦輪機(jī)和制冷機(jī)的規(guī)格是熱回收裝置設(shè)計(jì)的約束條件。為了構(gòu)成一個(gè)熱電聯(lián)產(chǎn)系統(tǒng)進(jìn)行設(shè)備的整合，通常并不總是能呈現(xiàn)最佳解決方案。在我們的案例研究中,吸收式制冷機(jī)不能利用所有的來自汽輪機(jī)排氣的余熱。這是由于與渦輪機(jī)的容量相比，機(jī)組的容量太小。然而,在建筑物中進(jìn)行額外空間的調(diào)節(jié)，變?yōu)橐粋€(gè)可以解決的問題，通過使用這種熱電聯(lián)產(chǎn)（CHP）系統(tǒng).文獻(xiàn)回顧

設(shè)立CHP系統(tǒng)的決定，涉及巨額的投資。暴跌到一個(gè)之前，任何工業(yè)、商業(yè)建筑物或者設(shè)施擁有者稱它是對(duì)傳統(tǒng)一代選擇的挑戰(zhàn).用已開發(fā)的動(dòng)態(tài)隨機(jī)模型來比較在熱電聯(lián)產(chǎn)系統(tǒng)中不可逆轉(zhuǎn)的投資和傳統(tǒng)熱生成系統(tǒng)的投資（如蒸汽鍋爐與從電網(wǎng)[21]購(gòu)買所有電力）。這種模式適用于理論上以免稅為基礎(chǔ)的。按照這個(gè)想法，如上升的排放量，電力供應(yīng)的可用性和安全因素，一個(gè)熱電聯(lián)產(chǎn)系統(tǒng)的好處是很多的。

熱電聯(lián)產(chǎn)系統(tǒng)需要系統(tǒng)的性能得到很好的測(cè)試。在熱電聯(lián)產(chǎn)系統(tǒng)的性能中，各種參數(shù)的影響（如環(huán)境溫度、進(jìn)氣渦輪溫度、壓縮機(jī)壓力比和燃?xì)廨啓C(jī)燃燒效率）要被研究，并對(duì)于各參數(shù)[1]進(jìn)行確定。熱電聯(lián)產(chǎn)系統(tǒng)，為了實(shí)現(xiàn)利潤(rùn)最大化，可以優(yōu)化的五個(gè)主要領(lǐng)域被確定為熱功率比的優(yōu)化，設(shè)備選型，經(jīng)濟(jì)調(diào)度，智能化性能監(jiān)控和維護(hù)優(yōu)化[6]。例如大學(xué)和醫(yī)院的很多商業(yè)樓宇安裝熱電聯(lián)產(chǎn)系統(tǒng)，以滿足其日益增長(zhǎng)的能源需求。蘇格蘭丹地大學(xué)之前安裝