An Experimental Study on Convective Condensation of Steam in a Horizontal Tube at Low Pressure with Twisted Tape Inserts

Abstract: An experimental study is performed to investigate the enhancement of convective condensation heat transfer coefficient of steam at low pressure in a horizontal tube with helical twisted tape inserts. The results indicate substantial enhancement in the condensation heat transfer coefficient or the tape inserts with in the range 2.5 < HD < 10. Dimensionless correlation for design purposes are provided to predict the condensation heat transfer coefficient in terms of Nu, Nusselt number as a function of π-groups ReL, superficial liquid Reynolds, φL the friction multiplier of Lockhart and Martinelli, Pr Prandtl number of the condensate and, HD pitch to diameter ratio of the tape. The correlations could satisfy the data with an accuracy of ±4 % validating the correctness of the criteria employed in the regression analysis. 1 All correspondences to the first author