畢業(yè)設(shè)計(jì)（論文）相關(guān)資料題目：灌裝生產(chǎn)線上灌裝閥的設(shè)計(jì)信機(jī)系機(jī)械工程及自動(dòng)化專業(yè)學(xué)號(hào)：學(xué)生姓名：指導(dǎo)教師：（職稱：副教授）（職稱：）2012年5月25日英文原文DishwasherandwashingmachineheatedbyahotwatercirculationloopTomasPersson*SolarEnergyResearchCenterSERC,HogskolanDalarna,78188Borlange,SwedenReceived14November2005；accepted6May2006Availableonline30June2006AbstractElectricenergy(7090%)usedbyelectricallyheateddishwashersandwashingmachinesisusedforheatingthewater,thecrockery,thelaundryandthemachineandcouldaswellbereplacedbyheatfromothersourcesthanelectricity.Thisarticleevaluatesprototypesofadishwasherandawashingmachine,wherethemachinesareheatedbyahotwatercirculationloopandtheheatistransferredtothemachinesviaaheatexchanger.Themachinethereforeuseswaterfromthecoldwaterpipe.Measurementsandsimulationshavebeenperformedshowingthatallenergyforheatingcanbereplacedifthesupplywatertemperatureis6570_C.Analternativeandcommonwaytosaveelectricityistoconnectthemachinestothedomestichotwaterpipe,buttheelectricalsavingswiththismeasurearemuchsmaller,especiallyforthedishwasher.Computermodellinghasbeenperformedandthemodelhasprovedtohaveahighagreementwithmeasureddata.Howevercomparisonwithmanufacturersdataindicatesthatthecomputermodelsoverestimatetheenergydemandbyabout10%.2006ElsevierLtd.Allrightsreserved.Keywords:Dishwasher；Clotheswasher；Washingmachine；Domesticappliances；Heatexchanger1.IntroductionInordertosaveelectricityfordishwashersandwashingmachinesitiscommontoconnectthemtothehotwaterpipe(hotwater-fedmachines).Asmodernmachinesuseverylittlewatertheheatingofthecrockery/clothesandthemachineitselfrequirealargepartoftheelectricityforheating.Thusnotallelectricityforheatingcanbereplacedbyhotwater-fedmachines.Inadditionthewashingperformancewillbeworsebecausealbuminoidalsubstancesarebetterremovedincoldwater8.Inthisarticleprototypesaremeasuredandsimulationmodelsaredevelopedandverifiedforadishwasherandawashingmachineconnectedtothecoldwaterpipethatisheatedbyacirculatinghotwatercircuitviaaheatexchangerbuiltintothemachine(heat-fedmachines).Prototypesofawashingmachineandatumbledryerwheretheheatistransferredtothemachinebyacirculatinghotwatercircuitandaheatexchangerbuiltinthemachinehavebeendevelopedandevaluatedby18.Thewashingmachinehasatubeheatexchangerbuiltinthebottomofthewashdrum.Accordingtofieldtestsby18theelectricitydemandforthewashingmachinecouldbebroughtdownfrom3.78MJ(conventional)to0.83MJforonecycle,howeverthetubepacketincreasedthewaterconsumptionandtherebytheenergydemandforheating.Themachinesusedinthisstudyareequippedwithapipeinpipeheatexchangeranddoesnotneedanyextrawater.Accordingto8amoderndishwasheruse3.78MJ(1.05kWh)percycle,where3.33MJ(0.924kWh)iselectricityforheating.Awashingmachine(on60_C)use3.42MJ(0.95kWh),where2.74MJ(0.76kWh)iselectricityforheating.Accordingtotheenergydeclarationby12,adishwasherisassumedtobeused220times/yrandawashingmachine200times/yr11,thustheannualelectricitydemandforthedishwasherandthewashingmachineis1516MJwhere1280MJisusedforheating.InSweden,forexample,with9millioninhabitantsthereare1.3milliondishwashersand2.1millionwashingmachinesinhouseholds9.Withthefiguresabovethetotaluseofelectricityforheatingwouldbe2.5PJ(0.7TWh)correspondingto0.5%ofthetotalelectricityusedinSweden16.InAustriawith8millioninhabitantsthedishwashersandthewashingmachinesareestimatedtousein1.1TWhin19997.2.Theprototypes2.1.ThedishwasherAdishwasherforhouseholds(CylindaDW20.1)wasrebuiltaccordingtoFig.1.Theheatexchanger(Fig.2)isapipeinpipeheatexchangermadefromaninternalcopperpipeof22mmandanexternalcopperpipewithdiameter28mm.Thepipegoingtotheuppersprayarmisreplacedbytheheatexchangerandthewashingwaterispumpedthroughtheinnerpipeoftheheatexchanger.Theflowrateintheinternalpipeishigh(roughly0.6kg/s).Thehotwaterfromtheheatingcircuitwithaflowrateofroughly0.03kg/sflowsinthegapbetweentheinnerandtheouterpipesintheheatexchanger.Tomaximisetheheattransferandtokeeptheinnerpipecentred,whentheheatexchangerisbent,a1.5mmcopperwirewaswoundroundtheinnerpipe(Fig.2).Thelengthoftheheatexchangerwas1.47m.Thecontrolstrategywasmodifiedsowhenthemachinecalledforheatthehotthesolenoidvalve(SV1,Fig.1)openedandwaterfromabufferstoragetankstartedtocirculatethroughtheheatexchanger.Whenthetemperatureinthebufferstoragetankwas5_Cwarmerthanthewaterinthedishwasher,thecirculationstoppedandtheelectricFig.1.Outlinediagramofthedishwasherandwashingmachineprototypes.Inthedishwasherthepipegoingtotheuppersprayarmisreplacedbytheheatexchanger.InthewashingmachineanewpumpP2pumpsthewashwaterthroughtheheatexchanger.Twoexistingconnectionswereusedtoconnecttheheatexchangertothewashdrum.ThehotwaterflowrateduringtheheatingphasesiscontrolledbythesolenoidvalvesSV1andSV2.NomenclatureeWrelativeerrorintransferredenergythroughthemotorortheheatexchanger%ePrelativeerrorintransferredheatratethroughtheheatexchanger%Ppower,heatrateWPmmeasuredheatratethroughtheheatexchangerWPccalculatedheatratethroughtheheatexchangerWttime,timeforthewashingsequencesTtemperatureK,_CTDHWdomestichotwatertemperatureK,_CTflowflowtemperature(supplywatertemperature)K,_CWenergyJWccalculatedtransferredenergythroughtheheatexchangerJWmmeasuredtransferredenergythroughtheheatexchangerJHotwater(fromtheheatsource)HotwaterreturnWashwaterfromthepumpP1/P225mmFig.2.Theconstructionoftheheatexchanger.Theouterpipeisremovedandthespiralbetweenthepipesisvisible.T.Persson/AppliedThermalEngineering27(2007)120128121auxiliaryheaterinthemachinecontinuedtheheatingprocessuntiltherequiredtemperaturehadbeenreached.2.2.ThewashingmachineAwashingmachineforhouseholds,aCylinda