空调热水器系统研究毕业论文外文文献翻译.docx

空调热水器系统研究毕业论文外文文献翻译.docx

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空调热水器系统研究毕业论文外文文献翻译

外文翻译（英文原文）

ABSTRACT

Theworkingprinciplesandthebasicfeaturesofairconditioningwaterheater（ACWH）systemareintroducedinthispaper.Theairconditioningwaterheatersystemcanoperateinfivemodes:

water-heatingonly,space-coolingandwater-heating,space-heatingandwater-heating,space-cooling,space-heating.Comparatively,thesystemcanprovidemuchbetterenergyperformanceandhigherequipmentutilizationthroughoutayear,andcauselessthermalpollutionthanheatpumpwaterheaterandcommonairconditioner.Aprototypewithfivemodeswasassembledandtestedattheambienttemperaturefrom-7℃to43℃,especiallywhenfrosting.Whenitworksinthewater-heatingmode,itcansupply55℃hotwaterwithintwominutes,andthecondensingpressureisjustsamewithcommonairconditioner.Whensomemodesswitch,thetemperatureoftheoutlethotwaterisconstant.TheoreticalanalysisandexperimentalstudyweredonetotheACWHinthisthesis:

1.Theprototypewastestedintheair-conditionerlaboratoryofGREE.Thetestingdataindicatethattheprototypeaccordswellwiththenationalstandardsofairconditionerandheatpumpwaterheater.

2.Basedontheexperimentalresults,analysiswasdoneontheACWHinmainoperatingmodesandsomeimportantconclusionsweregiven，Theresultsindicatethatthenewsystemcansaveenergythroughmulti-duties,anditcanworkstablyinfiveworkmodeswithhighefficiency.Comparedwithothermodels,thenewsystemalsoincludesair-conditioningunitandwaterheaterunit,butwithfewercomponentsandhigherreliability.Basedoncommonairconditioner,thissystemcanofferapracticablesolutioncouplingairconditionerandwaterheater.Itmustbechangingthemarketsofbothairconditionerandwaterheater.

1.INTRODUCTION

Theheatpumpwaterheater（HPWH）hasbeenusedsince1950s,mainlyforhouseholdapplications.Itabsorbsheatenergyfromtheambientairtoacquirehotwater.Inthelast20years,thestudyintendstodesignheatpumpwaterheaterwithhighreliabilityandpracticability,andmanymanufacturersturntoofferthisproductionbasedonenvironmentalprotectionandenergysaving.InSouthAfrica,HPWHhaspenetrated16percentofthemarketshareforcommercialwaterheaters.Becauseofthehighlyprimarycost,itisdifficulttobecomethealternativetothecommonwaterheater.However,ifwecanofferanairconditionercoupledwithHPWHsystem,whichcanactasairconditionerandwaterheaterwith

themaincomponentssuchasheatexchangers,compressor,four-wayvalve,andcapillarytube,theprimarycostwillbereducedanditcanrealizemultifunctioneasily.Insummer,withtherecoveryofthewasteheatofcondensation,itcanoffer“free”hotwater,andalsocanimprovethecoefficientofperformance（COP）oftheairconditioner.Whenairconditionerisnotrequiredinspringandautumn,itcanoperateinHPWHmode.Astheenhancementoftheyearroundutilization,itcanbemoreefficientandisexpectedtobecomeastrategysolvingtheairconditioningandhotwaterapplications.Herewedemonstrateanairconditioningwaterheater（ACWH）system,andtheperformanceanalysisisdescribedinthisarticle.

1.THEPRINCIPLEOFACWH

TheschematicdiagramofairconditioningwaterheatersystemisshowninFigure1.Thesystemcanofferthefollowingfiveoperatingmodes.Mode1isonlyforheatingwater;mode2canactasspace-coolingandwaterheating;mode3canrealizebothspace-heatingandwater-heating;theothertwomodesarethesamewiththecommonair-conditioningcircles.Theswitchingamongallthesemodesisbymeansofon-offcontrolsofthesolenoidvalvesandfour-wayvalve.Eachmodewillbedemonstratedasfollows.

1.1WaterHeatingMode

2.1WaterHeatingMode

Thesystemcanoperateintwoheatingmodes.Theoneisdirectheatingwater;theotherisheatingwaterwithwaterrecycleintheadiabaticwatertank.Thecontrollercanadjusttheoperatingmodeaccordingtothewaterlevelsensorsinthetank.Awatervalveisplacedatthehotwateroutletwhichcanbeadjustedtocontrolthewaterflowandkeep

thecondensingpressureconstant.Whenthetapwatergoesintothewater-refrigerantheatexchanger（WRHE）,itwillbeheatedto50-55directlywithintwominutes.Ifneeded,℃theoutletwatertemperaturecanbesetbyadjustingthewatervalve.AsshowninFigure1,whenthepowerison,thecompressorsuckslow-pressurerefrigerantgasandthendischargeshigh-pressuregasintowater-refrigerantheatexchanger（WRHE）,whererefrigerantiscondensedandwaterisheated

directly.Afterheatexchanges,theliquidrefrigerantflowsacrossfour-wayvalve,thenitisthrottledtolowtemperatureandlow-pressureliquidandgasbyanelectronicexpansionvalve.Refrigerantflowsintooutdooraircooledcondenserwhereitisevaporatedandbecomeslow-pressuregas.Whenthelow-pressuregasreturnstothecompressor,thecirclebeginsagain.Inthismode,valve1isclosedandvalve2isopen.Whenheatingwater,theoutdoorair-cooledunitactsasevaporator,andtheindoorfandoesn’trun.TheCOPwispresentedasafunctionofpowerQwandtheelectricpowerWasshowninEquation

（1）.

COPw=Qw/W=MC△T

（1）

WhereMisthemassflowofwater;Cisthespecificheatofwater;△Tisthewatertemperaturedifferencebetweenoutletandinletofthewater-refrigerantheatexchanger（WRHE）.

1.2Space-coolingandWater-heating（SCWH）Mode

Insummer,withtherecoveryofcondensingheat,theindoorairiscooleddownatthesametime.Comparedwithwater-heatingmode,thehigh-temperaturerefrigerantisalsocondensedintheWRHEdirectly,andthengoesthroughtheair-cooledcondensertobesuper-cooledwheretheoutdoorfandoesn’trun.Itisthrottledbycapillary1tolow-temperatureliquidandgas,andtheindoorairexchangesheatwithreturnedrefrigerant.Inthismode,valve1isopenandvalve2isclosed.Thismodecanactasspacecoolingandwaterheatingatthesametime.However,itisnotnecessarytorecovertheentirecondensingheatwhichcanbereleasedintheair-cooledcondenser.ThetotalcapacityisthesumofcoolingcapacityQcandheatingcapacityQw,andthentotalCOPcwcanbeshownasthe

Equation

（2）.

COPcw=（Qc＋Qw）/W

（2）

2.3Space-heatingandWater-heatingMode

RefrigerantflowsacrossWRHE,evaporator,capillary2,capillary1,andair-cooledcondenserinturn.Space-heatingandWater-heatingcanrealizeintheory.Thismodesometimesmaynotmeetcustomers’expectations,sothatitmustoperatecombinedwiththewater-heatingmodeandspacing-heatingmode.Ifneeded,anelectricheaterisavailable

2.4Space-coolingModeandSpace-heatingMode

Inthesetwomodes,refrigerantdoesn’tflowacrossWRHEorthewaterpumpandinletvalveareclosed,andthecondensingheatiscompletelyreleasedbytheoutdoororindoorheatexchanger.Infact,itisthesamewithanormalairconditioner,andisnotdescribedanymoreasabove.Insummer,space-coolingmodecanbereplacedbytheSCWHmode,whichcanusethewater-cooledandair-cooledheatexchangersatthesametime.Theperformanceofthesystemwillbeimprovedsignificantlywiththeenhancementofheattransfer.

3.EXPERIMENTS

Experimentalresearchwasperformedatanair-enthalpytestlaboratorywhichcanalsosupplywaterwithrequiredtemperatureandmassflow.Thelaboratoryincludesoutdoorchamber,indoorchamberandcontrolroom.Itconsistsofinsulatedwalls,air-handlingequipments,temperatureandhumiditycollectionsystem,airvolumetestingequipment,electriccontrolsystemandcomputerhandlingunit.Thecoolingandheatingcapacitycanbetestedbyair-enthalpytest.Airhandlingequipmentsareprovidedinbothtestchamberstocontrolthedrybulbandwetbulbtemperatures,aswellashumidity.Theindoorunitofairconditioningwasplacedinonechamber;theoutdoorunitandadiabaticstoragetankwereplacedinanotherchamber.T-typethermocoupleswereplacedateachtemperature

testpointandpressuresweretestedbythepressuresensors.Allthetestingdatacanbecollectedanddisplayedbythecomputerhandlingsystem.

3.1PrototypeDesign

Theprototypeincludesoutdoorunit,indoorunit,andanadiabaticstoragetank.Basedonacommonairconditioner,thesystemaddsawater-refrigerantheaterexchanger,astoragetank,severalsolenoidvalves,andwaterpump.Thestoragetankisaninsulatedcylinderandwatercapacityisabout800L.TheprototypewasdesignedbasedontheschematicdiagramshowninFigure

3.2ExperimentalTestConditions

Inmode1,theambienttemperaturewasfrom-7℃to43℃,andtheinflowwatertemperaturewasfrom9℃to30℃.Theoutletwatertemperaturewassetto55℃byadjustingthewatervalve.Theotherfourmodesoperatedonlyinthenominaltestconditionsaccordingtothenationalstandardsofairconditionerandheatpumpwaterheater.TheexperimentaltestconditionsareshowninTable

4.RESULTS

Thisstudyemphasizesonthedirectheatingwater.Mode1wastestedintemperatureconditions,whilemode2justoperatedinthestandardtestingconditionshownintable1.Theprototypeisdifferentfromacommonheatpumpwaterheater,whichcanofferhotwaterwithin2minutesbymeansofheattransferoflargetemperaturedifference.Theexperimentalresultswerediscussedcombinedwiththefirsttwomodesasfollows.

4.1HotWaterOutput

ThecurvesofhotwateroutputareshowninFigure2atdifferentinflowwaterandambienttemperatures.AsshowninFigure2,thehotwateroutputtendstorisemorerapidlyathigherambienttemperatureorinflowwatertemperature.Itcanofferabout400Lhotwatereachhourwhentheinflowwatertemperatureis15℃andambienttemperatureis20℃.Fromthisfigure,wecanknowthatthehotwateroutputisrelativetotheparametersoftheinflow