Two-phase flow condensation heat transfer characteristic of R-600a inside the horizontal smooth and dimpled helical coiled tube in shell type heat exchanger

Abstract

This paper presents an experimental study on condensation heat transfer of R-600a inside smooth and dimpled helical coiled tubes. The experiments were executed at saturation temperature of 35°, and 45 °C with mass fluxes of 75, 115, 156 and 191 kg m−2s−1. The effect of vapor quality, mass flux and saturation temperature on the heat transfer coefficient is examined. The experiments have been carried out for smooth and dimpled helical tube. The dimpled helical coiled tube showed higher heat transfer coefficient compared to the smooth helically coiled tube. The heat transfer data of R-600a are compared with R-134a from a previous study with the same operating condition for both tubes. We developed correlations to predict the condensation heat transfer coefficients in smooth and dimpled tubes that predict data within ±20%.