Entropy generation of R513A condensation flow inside the horizontal microfin tubes

Abstract

It is well known that the pressure drop of heat exchanger tube increases when heat transfer is enhanced, entropy generation analysis is an effective way to comprehensively analyze the heat transfer and pressure drop. In this paper, the refrigerants R513A and R134a are used in a horizontal single tube to carry out an experimental study of in-tube condensation heat transfer in six test tubes, the test tubes are divided into smooth and microfin tubes with outer diameters of 9.52 mm and 12.7 mm, where microfin tubes are available in two tube types with 60 and 65 fin, respectively. Helix angles of 18 degrees. The experimental conditions: mass flow rate of 50-300kg/m2·s, condensation temperatures of 35°C, 38°C and 40°C. The results show that it is feasible to replace R134a by R513A. It is analyzed that the comprehensive heat transfer performance of 9.52mm microfin tube is better than that of 12.7mm microfin tube, and the comprehensive heat transfer performance of 65-fin microfin tube is significantly lower than that of 60-fin microfin tube, i.e., microfin tubes with small pipe diameters and reasonable number of fin are conducive to the enhancement of condensation heat transfer performance.