Development of an empirical correlation for condensation heat transfer coefficient on a vertical tube in the presence of a noncondensable gas

Abstract

In this study, condensation heat transfer coefficients are measured in the presence of noncondensable gas (i.e., air) on a vertical tube with a 10-mm outer diameter. Experiments are conducted at pressures ranging from 2 to 5 bar and an air-mass fraction from 10 to 75 %. The experimental results are compared to the heat transfer coefficients obtained on a 40-mm O.D. tube, researched by Lee et al. Using the consolidated data from this study and Lee's and Dehbi's tests, a new empirical correlation for the condensation heat transfer coefficient of an air-steam mixture is developed. The proposed correlation is assessed against Kawakubo's experimental results, and the mean standard deviation is -27 %. © 2018 The Korean Society of Mechanical Engineers.