三维翅片管外螺旋流动传热强化.pdf

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1、第57卷第11期化工学报Vol.57No.11Z006年11月JournalofChemicalIndustryandEngineering(China)NovemberZ006妥、妥妥妥妥、妥妥研究论文妥三维翅片管外螺旋流动传热强化妥、妥妥妥妥、妥张正国!余昭胜!方晓明!高学农(华南理工大学传热强化与过程节能教育部重点实验室9广东广州510640)摘要2流体在螺旋隔板换热器的壳程类似于塞状流流动9几乎没有返混和流动死区.在相同压降下9其传热系数比普通的弓形隔板换热器高得多.以润滑油作为实验介质9研究了润滑油在螺旋隔板单管换热

2、器的壳程传热和压降性能9并与光滑管进行了性能对比.采用Wilson图解法分别分离出了螺旋隔板花瓣管和光滑管单管换热器的管程传热系数9并计算出各自的壳程传热系数9壳程传热系数相对误差为3.实验结果表明9在相同Reynolds数下9螺旋隔板花瓣管单管换热器的Nusselt数和压降AP分别是螺旋隔板光滑管单管换热器的Z~Z.7倍和1.3~1.4倍.与螺旋隔板光滑管单管换热器相比9螺旋隔板花瓣管单管换热器的传热性能的提高远高于压降的提高9证明在螺旋流条件下9花瓣管具有很好的传热强化性能.关键词!花瓣管3螺旋隔板3传热强化中图分类号!T

3、K1Z4文献标识码!A文章编号!0438-1157(Z006)11-Z531-05HeattransferenhancementforhelicalfloWin9outsidethree-dimensionalfintubeZHANGZhen99uo"YUZhaoshen9"FANGXiaomin9"GAOXuenon9(KeSLaboratorSofEnhanced~eatTransferandEnergSConseruation9MinistrSofEducation9SouthChinaUniuersitSofTechn

4、ologS9Guangzhou5106409Guangdong9China)Abstract!ThefloWpatternontheshellsideofahelicallybaffledheatexchangerisnearplugfloWconditions9Whichalmosteliminatesbackmixinganddeadspaceontheshellside.Theheattransfercoefficientofthehelicallybaffledheatexchangerismuchhigherthan

5、thatofconventionalsegmentalbaffleheatexchangeratthesamepressuredrop.Inthispaper9experimentsWereconductedforcoolingWaterfloWinginthetubesideonthehelicallybaffledheatexchangerWithlubricatingoilastheWorkingmediumfloWingontheshellside.Thetestedtubesincludedonepetal-shap

6、edfinnedtubeandonesmoothtubeselectedforperformancecomparison.TheheattransfercoefficientsWereobtainedbyusingtheWilsonplotmethodandpressuredropontheshellsideWasdirectlymeasuredforthetWoheatexchangers.TherelativeerrorofheattransfercoefficientontheshellsideWasWithin3.Th

7、eresultsshoWedthattheNusseltnumbersandpressuredropsontheshellsideofthehelicallybaffledheatexchangerWithpetal-shapedfinnedtubeWereZZ.7and1.31.4timeslargerthanthoseofthehelicallybaffledheatexchangerWithsmoothtubeatconstantReynoldsnumber9respectively.Thepetal-shapedfin

8、nedtubecouldsignificantlyimprovetheshellsideheattransferperformanceforthehelicallybaffledheatexchanger.KeyWords!petal-shapedfinnedtube3hel