4669

4397

كارشناسي ارشد

تبديل انرژي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

1387

[هجده]،113، [II]ص.: مصور،جدول،نمودار

ص.ع. به فارسي و انگليسي

علي اكبر عالم رجبي

احمدصابونچي

88/7/13

محمدرضا سليم پور، محسن نصراصفهاني

مهندسي مكانيك

ID4397

به فارسي و انگليسي: قابل رويت در نسخه ديجبتالي

An Experimental investigation of the effect of inclined inserts on Heat transfer Ali Mohamadi Nasrabadi mohamadi@me iut ac ir December 12 2008 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language Farsi rajabi@cc iut ac ir Supervisor Dr A A Alem rajabiAdvisor A Saboonchi ahmadsab@cc iut ac ir AbstractHeat transfer enhancement has been used widely in recent years It results in heat exchangers towork at a lower fluid velocity and also reduction of driving force temperature and decrease insize of heat exchangers too Many ways exist to achieve these goals One of them is utilization ofinserts Both heat transfer and pressure drop increase by using of inserts There are many types ofinserts like twisted tape wire coil wire mesh etc In this study the effect of inclined inserts on enhancement of heat transfer and pressuredrop is investigated A Performance Evaluation Criterion P E C is introduced to evaluate theperformance of these insert In this project effect of inclined inserts on heat transfer and pressuredrop in a single shell and tube heat exchanger is investigated Steam is used as a heat source toobtain a uniform wall temperature and the working fluid in the tube is water The inserts used inthis project divide in two forms Some of them are solid inserts and some are inserts whit a hole In solid inserts the fluid water passes between the inserts and wall of tube The second form ofinserts is a circular disk with a hole in different shapes in this case fluid passes through the hole Another important parameter which is studied is the shape of the inserts The shape of the solid inserts or the shape of the hollow inserts can be square rectangle circle or elliptic Angel of inserts relative to axis of pipe and angle of insert relative to each otherare studied The angel between insert and pipe s axis is shown by and the angel of insertsrelative to each other is shown by The effects of these parameters on heat transfer andpressure drop are investigated in this study for different Reynolds numbers The results of experimental tests have shown that these inserts cause heat transfer andpressure drop to enhance They have shown that inserts with a hole perform better than solidinserts They also have demonstrated that 450 is the best angel for inserts however there is nojudgment for best angle It seems that the best angel depends on Prandtl number and shapesof inserts The highest P E C achieved was 1 85 which corresponds to inserts with rectangular hole at 450 and 00 for this case the nusselt number increased by a factor of 2 31 Key words internal flow inserts enhancement of heat transfer

علي اكبر عالم رجبي

احمدصابونچي

محمدرضا سليم پور، محسن نصراصفهاني