Experimental and Numerical Investigation to Evaluate the Performance of Helical Coiled Tube Heat Exchanger

Abstract

Experimental and Numerical investigation of heat transfer enhancement in shell and helical coil tube heat exchanger is carried out in the present work. Experimental work included design of helical coil heat exchanger with different curvature ratio and coil pitch. Three helical coil tube heat exchangers with different curvature ratio (D/d) 12/1, 15/1, 17/1, 20/1 and 24/1 are studied to choose the optimum one. Four helical coils with different coil pitch 1.8d, 2d, 3d, and 5d has been chosen to study the effect of coil pitch on heat transfer coefficient. From experimental results the curvature ratio 17/1 gives optimum helical coil. Experimental results show increases of coil pitch lead to increasing in heat transfer coefficient of the shell side and indicate that convective heat transfer is increased by Reynolds number as well as Dean Number.Numerical geometry has been built using ansys fluent package 14.1 commercial copy with solid work and gambit software program depends on the optimum design . Numerical results show that the temperature decreases along the coil and the temperature difference effect on heat flow along helical coiled. Also there is different in temperature between each turn. Empirical correlation has been developed to predict Nusselt number at helical coil. The comparison between numerical and experimental results show good agreement.