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1、第31卷第5期2011年2月15日中國電機工程學報ProceedingsoftheCSEEVol.31No.5Feb.15,2011?2011Chin.Soc.forElec.Eng.84文章編號:0258-8013(2011)05-0084-06中圖分類號:O359文獻標志碼:A學科分類號:470·10順列管束間氣液兩相流型及壓降特性研究洪文鵬,劉燕,任靜秋(東北電力大學能源與動力工程學院,吉林省吉林市132012)InvestigationonGas-liquidTwo-phaseFlowPatt
2、ernsandPressureDropAcrossanIn-lineTubeBundlesHONGWenpeng,LIUYan,RENJingqiu(NortheastDianliUniversity,SchoolofEnergyandPowerEngineering,Jilin132012,JilinProvince,China)ABSTRACT:Ahigh-speedvideocamerawasusedtostudytheflowpatternsintherectangularchannelofv
3、erticalupwardcross-flowofairandwaterinhorizontaltubebundles.Experimentswereconductedusingin-linetubebundleswithapitch-to-diameterratioof1.3and1.8.Bubblyflow,intermittentflowandmistflowwereidentifiedbyflowvisualization,andaflowmapwasconstructedasafunctio
4、nofgasandliquidsuperficialvelocities.Comparisonwithpreviousstudiesrevealedgoodagreementatlowgasandliquidvelocity.Acomparativeanalysisofpressuredropofdifferentflowpatternofbothtubebundleswasdone.Theresultsshowthat:thepressuredropofbubbleflowismaximum,whi
5、chisfollowedbyintermittentflowandmistflowbecomestheminimum.Whenthevoidfractionrangefrom0.15to0.67,thefluctuationpressuredropoftubebundleswhichwithapitch-to-diameterratioof1.3ishigherthantheonewithapitch-to-diameterratioof1.8,andwhenthevoidfractionisbigg
6、erthan0.67orsmallerthan0.15,thepressuredropoflargepitchratioislessthanthesmallpitchratio.Basedonthestatisticalanalysisofthedifferentpressuresignals,thepowerspectrumdensityversusfrequencyofthesignalsformajorflowpatternswasobtained.Itisfoundthattheflowpat
7、ternscanbeidentifiedinaccordancewiththepowerspectrumdensity.于P/D=1.3管束的壓降。含氣率a小于0.15和大于0.67時,大節(jié)距比管束的壓降反而小于小節(jié)距比管束的壓降。對壓差波動信號的功率譜特征進行分析的結(jié)果表明,利用壓差時域信號的功率譜特性可以鑒別流型。關(guān)鍵詞:氣液兩相流;順列管束;高速攝像;流型;壓降特性0引言在動力工程、石油化工、核能利用等領(lǐng)域廣泛存在氣液兩相流體繞流管束的流動現(xiàn)象,如冷凝器、蒸發(fā)器及核反應堆蒸汽發(fā)生器等管殼式換熱設(shè)
8、備[1-2]。管束間的氣液兩相流型對其繞流流動特性和傳熱規(guī)律有著重要的影響[3],尤其是動力、原子能工業(yè)的飛速發(fā)展,大容量高參數(shù)設(shè)備的引入,促使設(shè)備的結(jié)構(gòu)設(shè)計更加緊湊,對換熱器的綜合性能提出了更高的要求。這類問題的研究已經(jīng)成為多相流體動力學基礎(chǔ)研究和工程應用領(lǐng)域的一個重要研究課題。目前國內(nèi)外多位學者對管內(nèi)氣液兩相流型、壓降、含氣率及摩擦系數(shù)等進行了大量研究,而對氣液兩相流體橫掠管束流動特性的相關(guān)研究較少。Noghrehkar[4]等利用探針法研究了空氣-