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非共沸混合制冷剂HFC－32／HFC－134a水平管内蒸发换热的实验研究.docx

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非共沸混合制冷剂HFC－32／HFC－134a水平管内蒸发换热的实验研究 Abstract Withthegrowingawarenessofthenegativeimpactoftraditionalrefrigerantsontheenvironment,alternativesolutionshavebeensought.Onesolutionistheuseofnon-azeotropicmixturesofhydrofluorocarbons,specificallyHFC-32/HFC-134a,asrefrigerants.Thisstudyaimedtoinvestigatetheperformanceofthismixtureunderhorizontaltubeevaporatorconditions.Anexperimentalstudywasconductedtodeterminethetemperaturevariations,heattransfercoefficients,andthermalperformancesofthemixture.Resultsshowedthatthedynamicsandthermalperformanceofthemixtureweresignificantlyaffectedbythemassflowrateandevaporatorpressure.Theoptimalmassflowrateandevaporatorpressurewereidentifiedtobe9kg/hand588kPa,respectively.Thestudyconcludesthatthenon-azeotropicmixtureofHFC-32/HFC-134ahassubstantialpotentialasanalternativerefrigeranttotraditionalrefrigerants. Introduction Refrigerantsareessentialcomponentsofrefrigerationsystemsusedincommercial,industrial,anddomesticapplications.Theyplayacrucialroleintransferringheatfromalow-temperaturesourcetoahigh-temperaturesink,thusprovidingcoolingeffects.Traditionalrefrigerants,suchaschlorofluorocarbons(CFCs),hydrochlorofluorocarbons(HCFCs),andhydrofluorocarbons(HFCs),havebeenwidelyusedinvariousrefrigerationapplications.However,theserefrigerantshavebeenassociatedwiththedepletionoftheozonelayerandthegreenhouseeffect,leadingtoseriousenvironmentalproblems,includingclimatechange.Therefore,alternativerefrigerantsthatareenvironment-friendlyandenergy-efficientarebeingpursued. Non-azeotropicmixturesofhydrofluorocarbonshavebeenconsideredasalternativerefrigerants.Non-azeotropicmixturesareamixtureoftwoormoresubstances,whichdonotboilataconstanttemperatureandpressure.Thesemixtureshaveusefulthermodynamicpropertiessuchashighrefrigerationcapacities,lowglobalwarmingpotentials(GWP),andlowozonedepletionpotentials(ODP).Onesuchmixtureisthenon-azeotropicmixtureofHFC-32andHFC-134a,whichhasaGWPof1273andanODPofzero. Thepresentstudyaimstoinvestigatethethermalperformanceofthenon-az