CFD analysis for heat transfer comparison in circular, rectangular and elliptical tube heat exchangers filled with PCM

Abstract

A two-dimensional computational fluid dynamics (CFD) investigation of the melting of phase change material (PCM) and heat transfer characteristics of a heat exchanger of shell and tube type having circular, rectangular and elliptical tubes are analyzed in this study. Gallium in the rectangular shell of heat exchange is considered as the working fluid in this present study. A fixed temperature boundary condition is applied at the circumference of the tubes and a standard k-epsilon turbulence model is used for the simulation. The variation in the shape of the tubes at a fixed temperature of 60 °C has been utilized for the analysis and the effect of the shape of these tubes on melting of PCM in terms of liquid proportion and melting time has been analyzed. The melting duration of PCM is 745 s for a configuration with circular tubes, 650 s for a configuration with rectangular tubes, and 740 s for a configuration with elliptical tubes and the duration by the PCM to reach 60 °C for a configuration with circular tubes is 800 s, for a configuration with rectangular tubes is 725 s, and for a configuration with elliptical tubes is 770 s. Hence it is indicated by the results that the lowest melting time of PCM can be obtained by the heat exchanger having rectangular tubes followed by elliptical tubes and circular tubes at a temperature of 60 °C.