热泵的应用英汉互译翻译.docx

热泵的应用英汉互译翻译.docx

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热泵的应用英汉互译翻译

外文翻译

TheApplicationsofHeatpumps

1.Heatpumpsinindustry

1）.Systems

Relativelyfewheatpumpsarecurrentlyinstalledinindustry.However,asenvironmentalregulationsbecomestricter,industrialheatpumpscanbecomeanimportanttechnologytoreduceemissions,improveefficiency,andlimittheuseofgroundwaterforcooling

Toensurethesoundapplicationofheatpumpsinindustry,processesshouldbeoptimisedandintegrated.Throughprocessintegrationimprovedenergyefficiencyisachievedbythermodynamicallyoptimisingtotalindustrialprocesses.Animportantinstrumentforprocessintegrationispinchanalysis,atechnologytocharacteriseprocessheatstreamsandidentifypossibilitiesforheatrecovery.Suchpossibilitiesmayincludeimprovedheatexchangernetworks,cogenerationandheatpumps.Pinchanalysisisespeciallypowerfulforlarge,complexprocesseswithmultipleoperations,andisanexcellentinstrumenttoidentifysoundheatpumpopportunities.

Industrialapplicationsshowagreatvariationinthetypeofdriveenergy,heatpumpsize,operatingconditions,heatsourcesandthetypeofapplication.Theheatpumpunitsaregenerallydesignedforaspecificapplication,andarethereforeunique.

Themajortypesofindustrialheatpumpsare:

oMechanicalvapourrecompressionsystems（MVRs）,classifiedasopenorsemi-openheatpumps.Inopensystems,vapourfromanindustrialprocessiscompressedtoahigherpressureandthusahighertemperature,andcondensedinthesameprocessgivingoffheat.Insemi-opensystems,heat

fromtherecompressedvapouristransferredtotheprocessviaaheatexchanger.Becauseoneortwoheatexchangersareeliminated（evaporatorand/orcondenser）andthetemperatureliftisgenerallysmall,theperformanceofMVRsystemsishigh,withtypicalcoefficientsofperformance（COPs）of10to30.CurrentMVRsystemsworkwithheat-sourcetemperaturesfrom70-80篊,anddeliverheatbetween110and150篊,insomecasesupto200篊.Wateristhemostcommon'workingfluid'（i.e.recompressedprocessvapour）,althoughotherprocessvapoursarealsoused,notablyinthe（petro-）chemicalindustry.

oClosed-cyclecompressionheatpumpsaredescribedinthesectionHeatpumptechnology.Currentlyappliedworkingfluidslimitthemaximumoutputtemperatureto120篊.

oAbsorptionheatpumps（TypeI）arenotwidelyusedinindustrialapplications.Somehavebeenrealisedtorecoverheatfromrefuseincinerationplants,notablyinSwedenandDenmark.Currentsystemswithwater/lithiumbromideasworkingpairachieveanoutputtemperatureof100篊andatemperatureliftof65篊.TheCOPtypicallyrangesfrom1.2to1.4.Thenewgenerationofadvancedabsorptionheatpumpsystemswillhavehigheroutputtemperatures（upto260篊）andhighertemperaturelifts.

oHeattransformers（TypeII）havethesamemaincomponentsandworkingprincipleasabsorptionheatpumps.Withaheattransformerwasteheatcanbeupgraded,virtuallywithouttheuseofexternaldriveenergy.Wasteheatofamediumtemperature（i.e.betweenthedemandlevelandtheenvironmentallevel）issuppliedtotheevaporatorandgenerator.Usefulheatofahighertemperatureisgivenoffintheabsorber.Allcurrentsystemsusewaterandlithiumbromideasworkingpair.Theseheattransformerscanachieveadeliverytemperaturesupto150篊,typicallywithaliftof50篊.COPsundertheseconditionsrangefrom0.45to0.48.

o

ReverseBrayton-cycleheatpumpsrecoversolventsfromgasesinmanyprocesses.Solventloadenairiscompressed,andthenexpanded.Theaircoolsthroughtheexpansion,andthesolventscondenseandarerecovered.Furtherexpansion（withtheassociatedadditionalcooling,condensationandsolventrecovery）takesplaceinaturbine,whichdrivesthecompressor.

2）.Applications

Industrialheatpumpsaremainlyusedfor:

ospaceheating;

oheatingandcoolingofprocessstreams;

owaterheatingforwashing,sanitationandcleaning;

osteamproduction;

odrying/dehumidification;

oevaporation;

odistillation;

oconcentration.

Whenheatpumpsareusedindrying,evaporationanddistillationprocesses,heatisrecycledwithintheprocess.Forspaceheating,heatingofprocessstreamsandsteamproduction,heatpumpsutilise（waste）heatsourcesbetween20篊and100篊.

Themostcommonwasteheatstreamsinindustryarecoolingwater,effluent,condensate,moisture,andcondenserheatfromrefrigerationplants.Becauseofthefluctuationinwasteheatsupply,itcanbenecessarytouselargestoragetanksforaccumulationtoensurestableoperationoftheheatpump.

oSpaceheating:

Heatpumpscanutiliseconventionalheatsourcesforheatingofgreenhousesandindustrialbuildings,ortheycanrecoverindustrialwasteheatthatcould

notbeuseddirectly,andprovidealow-tomediumtemperatureheatthatcanbeutilisedinternallyorexternallyforspaceheating.Mainlyelectricclosed-cyclecompressionheatpumpsareused.

oProcesswaterheatingandcooling:

Manyindustriesneedwarmprocesswaterinthetemperaturerangefrom40-90篊,andoftenhaveasignificanthotwaterdemandinthesametemperaturerangeforwashing,sanitationandcleaningpurposes.Thiscanbemetbyheatpumps.Heatpumpscanalsobeapartofanintegratedsystemthatprovidesbothcoolingandheating.Mainlyelectricclosed-cyclecompressionheatpumpsareinstalled,butafewabsorptionheatpumpsandheattransformersarealsoinuse.

oSteamproduction:

Industryconsumesvastamountsoflow-,medium-andhigh-pressuresteaminthetemperaturerangefrom100-200篊.Steamisuseddirectlyinindustrialprocesses,andforheatdistribution.Currenthightemperatureheatpumpscanproducesteamupto150篊（aheatpumpprototypehasachieved300篊）.Bothopenandsemi-openMVRsystems,closed-cyclecompressionheatpumps,cascade（combination）systemsandafewheattransformersareinoperation.

oDryingprocess:

Heatpumpsareusedextensivelyinindustrialdehumidificationanddryingprocessesatlowandmoderatetemperatures（maximum100）.Themainapplicationsaredryingofpulpandpaper,variousfoodproductswoodandlumber.Dryingoftemperature-sensitiveproductsisalsointeresting.Heatpumpdryersgenerallyhavehighperformance（COP5-7）,andoftenimprovethequalityofthedriedproductsascomparedwithtraditionaldryingmethods.Becausethedryingisexecutedinaclosedsystem,odoursfromthedryingoffoodproductsetc.arereduced.Bothclosed-cycle

compressionheatpumpsandMVRsystemsareused.

oEvaporationanddistillationprocesses:

Evaporationanddistillationareenergy-intensiveprocesses,andmostheatpumpsareinstalledintheseprocessesinthechemicalandfoodindustries.Inevaporationprocessestheresidueisthemainproduct,whilethevapour（distillate）isthemainproductindistillationprocesses.Mostsystemsareopenorsemi-openMVRs,butclosed-cyclecompressionheatpumpsarealsoapplied.SmalltemperatureliftsresultinhighperformancewithCOPsrangingfrom6to30.

2．Heatpumpsinresidentialandcommercialbuildings

1）.Functions

Heatpumpsforheatingandcoolingbuildingscanbedividedintofourmaincategoriesdependingontheiroperationalfunction:

oHeating-onlyheatpumps,providingspaceheatingand/orwaterheating.

oHeatingandcoolingheatpumps,providingbothspaceheatingandcooling.

Themostcommontypeisthereversibleair-to-airheatpump,whicheitheroperatesinheatingorcoolingmode.Largeheatpumpsincommercial/institutionalbuildingsusewaterloops（hydronic）forheatandcolddistribution,sotheycanprovideheatingandcoolingsimultaneously.

oIntegratedheatpumpsystems,providingspaceheating,cooling,waterheatingandsometimesexhaustairheatrecovery.

Waterheatingcanbebydesuperheatingonly,orbydesuperheatingand

condenserheating.Thelatterpermitswaterheatingwhennospaceheatingorcoolingisrequired.

oHeatpumpwaterheaters,fullydedicatedtowaterheating.

Theyoftenuseairfromtheimmediatesurroundingsasheatsource,butcanalsobeexhaust-airheatpumps,ordesuperheatersonair-to-airandwater-to-airheatpumps.Heatpumpscanbebothmonovalentandbivalent,wheremonovalentheatpumpsmeettheannualheatingandcoolingdemandalone,whilebivalentheatpumpsaresizedfor20-60%ofthemaximumheatloadandmeetaround50-95%oftheannualheatingdemand（inaEuropeanresidence）.Thepeakloadismetbyanauxiliaryheatingsystem,oftenagasoroilboiler.Inlargerbuildingstheheatpumpmaybeusedintandemwithacogenerationsystem（CHP）.

Inresidentialapplicationsroomheatpumpscanbereversibleair-to-airheatpumps（ductlesspackagedorsplittypeunits）.Theheatpumpcanalsobeintegratedinaforced-airductsystemorahydronicheatdistributionsystemwithfloorheatingorradiators（centralsystem）.

Incommercial/institutionalbuildingstheheatpumpsystemcanbeacentralinstallationconnectedtoanairductorhydronicsystem,oramulti-zonesystemwheremultipleheatpumpunitsareplacedindifferentzonesofthebuildingtoprovideindividualspaceconditioning.Efficientinlargebuildingsisthewater-loopheatpumpsystem,whichinvolvesaclosedwaterloopwithmultipleheatpumpslinkedtothelooptoprovideheatingandcooling,withacoolingtowerandauxiliaryheatsourceasbackup.

ThedifferentheatsourcesthatcanbeusedforheatpumpsinresidentialandcommercialbuildingsaredescribedinthesectionHeatsources.Thenextparagraphdescribesthetypesofheatandcolddistributionsystemsthatcanbeusedinbuildings.

2）.Heatandcolddistributionsystems

Airisthemostcommondistributionmedi