Enhancement of Heat Transfer in a Tube with Swirl Generators
Enhancement of Heat Transfer in a Tube with Swirl Generators
摘要
Influence of strip self-rotating plastic spiral elements inserted in a tube on heat transfer enhancement is studied experimentally. The strip consists of 100 self-rotating spiral elements made of plastic polycarbonate inserted in the inner tube of a concentric tube heat exchanger with a view to generating swirl flow that helps to increase the heat transfer rate of the tube. Cold water flows in the annulus whereas the hot water flows in the inner tube. The obtained experimental data are compared with the data obtained from plain tube .Experimental results confirmed that the use of self-rotating plastic spiral elements leads to higher overall heat transfer coefficient than the plain tube. This technology is not only useful for heat transfer enhancement but also can be used for self cleaning deposition fouling in heat exchanger when the flow velocity is higher than 0.2 m/sec.
Influence of strip self-rotating plastic spiral elements inserted in a tube on heat transfer enhancement is studied experimentally. The strip consists of 100 self-rotating spiral elements made of plastic polycarbonate inserted in the inner tube of a concentric tube heat exchanger with a view to generating swirl flow that helps to increase the heat transfer rate of the tube. Cold water flows in the annulus whereas the hot water flows in the inner tube. The obtained experimental data are compared with the data obtained from plain tube .Experimental results confirmed that the use of self-rotating plastic spiral elements leads to higher overall heat transfer coefficient than the plain tube. This technology is not only useful for heat transfer enhancement but also can be used for self cleaning deposition fouling in heat exchanger when the flow velocity is higher than 0.2 m/sec.
参考文献10
-
1Manglik R M,Bergles A E.Heat transfer and pressuredrop correlations for twisted-tape inserts in isothermal tubes: part II: transition and turbulent flows[].Journal of Heat Transfer.1993
-
2Plessis J P,Kroeger D G.Friction factor prediction for fully-developed laminar twisted-tape flow[].International Journal of Heat Mass Transfer.1984
-
3Yunus A Cengel.Heat transfer[].nd ed : McGraw-Hill.2003
-
4Adrian Bejan,Allan D Kraus.Heat transfer handbook[]..2003
-
5Zhang Zhengguo,Xu Tao,Fang Xiaoming.Experimental study on heat transfer enhancement of a helically baffled heat exchanger combined with three- dimensional finned tubes[].Applied Thermal Engineering.2004
-
6Liao Q,Xin M D.Augmentation of convective heat transfer inside tubes with three-dimensional internal extended surfaces and twisted-tape inserts[].Chemical Engineering Journal.2000
-
7Al-Fahed S,Chamra L M,Chakroun W.Pressure drop and heat transfer comparison for both microfin tube and twisted-tape inserts in laminar flow[].Experimental Thermal and Fluid Science.1999
-
8Agarwal S K,Rao R M.Heat-transfer augmentation for the flow of a viscous liquid in circular tubes using twisted tape inserts[].International Journal of Heat Mass Transfer.1996
-
9Hsieh Shou-shing,Liu Ming-ho and Wu Feng-yu.Developing turbulent mixed convection in a horizontal circular tube with strip-type inserts[].International Journal of Heat Mass Transfer.1984
-
10Hong S W,Bergles A E.Augmentation of laminar flow heat transfer in tubes by means of twisted-tape inserts[].Transactions ASME Journal of Heat Transfer.1976
