Improving heat transfer in a triplex tube heat exchanger containing phase-change materials by modifications of length and position of fins

Heat thermal energy storage is a technique to improve thermal efficiency through reducing discrepancy between energy demand and supply. Latent heat thermal energy storage as a kind of thermal energy storage method has drawn considerable attention from researchers due to its high thermal energy density and constant operating temperature. This study numerically investigates the melting process in a triplex tube heat exchanger containing phase change material (PCM) RT82. A two-dimensional numerical model has been generated using the Ansys Fluent 16 software program to simulate melting process. In this study, conduction and natural convection have been considered. Selected arrangements of rectangular fins, including lengths and positions, were selected according to heat distribution while the total area of fins was kept constant. This new strategy was done to improve heat transfer in PCM which would result in decreasing its melting time. The select optimized model in this article reduces meting time to 28.4% in comparison with the model in Ref. [1]. Numerical results have been validated by numerical and experimental results of this reference and there has been a proper agreement between them.