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1、第63卷第4期化工學(xué)報(bào)Vol.63No.42012年4月CIESCJournalApril2012檭檭檭檭檭殐殐檭檭研究論文檭多熔點(diǎn)相變材料堆積蓄熱床蓄熱性能分析檭殐殐檭檭檭檭檭楊磊,張小松(東南大學(xué)能源與環(huán)境學(xué)院,江蘇南京210096)摘要:對(duì)采用多種不同熔點(diǎn)相變材料(PCM)構(gòu)成的堆積蓄熱床進(jìn)行了數(shù)值分析。熱水作為換熱流體(HTF)自上而下流經(jīng)蓄熱床,熔化相變材料、蓄積相變潛熱。石蠟作為相變材料被注射入聚碳酸酯球殼內(nèi)形成相變膠囊,根據(jù)熔點(diǎn)高低依次排放在蓄熱床的不同位置,熔點(diǎn)越高距離熱水進(jìn)口越近。假定流場(chǎng)穩(wěn)定,采用一維S
2、chumann模型計(jì)算HTF溫度,相變模擬采用顯熱容法。分別對(duì)兩種排列方式下采用2種、3種以及4種相變材料的蓄熱床的蓄熱過(guò)程進(jìn)行了基于熱力學(xué)第一及第二定律的性能分析,并將結(jié)果與單相變材料蓄熱床進(jìn)行比較?;跓崃W(xué)第一定律分析結(jié)果表明,采用多種相變材料構(gòu)成的蓄熱堆積床蓄熱速度更快,能量效率更高。基于熱力學(xué)第二定律分析表明,平均熔點(diǎn)更高的蓄熱床能夠儲(chǔ)存更高的。結(jié)果表明采用多熔點(diǎn)相變材料構(gòu)成的堆積蓄熱床能夠顯著地縮短蓄熱時(shí)間,改進(jìn)蓄熱性能。關(guān)鍵詞:堆積蓄熱床;相變膠囊;多熔點(diǎn);能量;DOI:10.3969/j.issn.0438
3、-1157.2012.04.006中圖分類(lèi)號(hào):TK512文獻(xiàn)標(biāo)志碼:A文章編號(hào):0438-1157(2012)04-1032-06ChargeperformanceofpackedbedthermalstorageunitwithphasechangematerialhavingdifferentmeltingpointsYANGLei,ZHANGXiaosong(SchoolofEnergyandEnvironment,SoutheastUniversity,Nanjing210096,Jiangsu,China)Abs
4、tract:Anumericalstudyonapackedbedthermalstorageunitwithphasechangematerial(PCM)havingdifferentmeltingpointsispresented.ParaffinisusedasPCMandinjectedintopolycarbonatespheresasphasechangecapsules.Hotwaterisusedasheattransferfluid(HTF)flowingfromthetopdowntomeltPCMa
5、ndstorelatentheat.Thecapsulesareplacedinseriesinthetankbasedonmeltingpoints.PCMhavinghighermeltingtemperatureisplacedcloserwithhotwaterinlet.One-dimensionalSchumann’smodelwithsteady-stateflowfieldassumptionisadoptedtocalculateHTFtemperature,whilethephasechangeofPC
6、Missimulatedusingapparentheatcapacitymethod.Theenergyandexergyperformanceinchargingprocessoftwoarrangementmodescontainingtwo,threeandfourkindsdifferentPCMsareinvestigatedandcomparedwiththoseofpackedbedusingonlyonekindofPCM.Theenergycomparisonresultsindicatethatthe
7、thermalstorageunitwithmultiplePCMshasmuchhigherchargerateandhigherthermalefficiencythansinglePCMstoragebed.Intheexergycomparison,thestoragebedwithhigheraveragemeltingpointcanstoremoreexergythanthathasloweraveragemeltingpoint.TheutilizationofmultiplePCMscandramatic
8、allyreducechargetime,improvingthestorageperformance.Keywords:packedbed;phasechangecapsule;differentmeltingpoints;energy;exergy2011-08-26收到初稿,2011-09-26收