脉动热管传热特性实验研究

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1、北京交通大学硕士学位论文脉动热管传热特性实验研究姓名：李燕申请学位级别：硕士专业：环境工程指导教师：贾力20081201北京交通大学硕士堂堡笙窒垒里璺里坠竺!——————二_———————————————————————————‘————————————。————————————————————一ABSTRACTPulsatingheatpipe(PHP)isanewtypeofheatpipes，especiallysuitedforthenlicro．ele咖11icscoolingofhighheatflux．Differentfrom

2、conventionalheatpipes，heatt舳sferofPHPincludeslatentheatandsensibleheat．Thetwo—phasesystemwhichembodiesmulti．disciplinaryphysicsisSOcomplicatedthattheinvestigationonPHPsisstillataprimarystage．OscillationmechaIljsmandheattransfercharacteristicsofpulsatingheatpipearesnJdiedint

3、hispaper．EffectsofsomefactorsinfluencingontheperformanceofPHPsareinvestigated．Andtheoscillationregularityisanalyzedpreliminarily．IIltllevisualizedexperimental，topheatmodevisualizingexperimentalsystemwasestablishedfirstly．Themainflowmodeintopheatmodeisbulkflowinsteadofannula

4、rflowwhichappearsinbottomheatmode．IntopheatmodetherearemanyTaylortypebubblesdistributinginevaporatorsectionwhileinbottomheatingmodetherearemanyglobetypebubblesdistributinginevaporatorsection．ItiseasiertOgeneratenewbubbleson吐Iewallaroundsmallglobebubblesinevaporatorsection·I

5、tmakesthestart．．upmuchharderfortopheatmode．FortheexperimentalofulleventunerdiameterPHP，itiseasiertOmaintainannularflowatthestablestate．‘TherunningandheattransferofcopperloopedandUll—loopedPHPsunderwatercoolingconditionwereinvestigated．Effectsoffillingratio，inputpower,workin

6、gfluid，协clineangleandturnsonheattransferperformancewerestudied．TheexperimentalresultsiIldicatethatfortheworkablefillingratiothermalresistanceincreaseswithfillingratio．Whenusingwater，ethanolandacetoneasworkingfluid，thethermalresistallceofPHPwithacetoneisthelowest,thestart·up

7、timeofPHPwithacetoneismeshortest．ThethermalresistanceofPHPinverticalbottomheatisthelowestforallinclineangles．andtheheattransferperformanceofloopedPHPisbetterthanun。loopedPHPsinceitiseasertOformcirculationflowinloopedP肿．KEYWORDS：pulsatingheatpipe；topheatmode；heattransferperf

8、ormance；affectingfactors；thermalresistance．CLASSN0：TKl24学位论文版权使用授权书本学位论文作者完全了解北京交通