Improving heat transfer in a triplex tube heat exchanger containing phase-change materials by modi cations of length and position of ns

Abstract

Heat thermal energy storage is a technique used to improve thermal eciency by reducing the discrepancy between energy demand and supply. Latent heat thermal energy storage as a kind of the thermal energy storage method has drawn considerable attention from researchers due to its high thermal energy density and a constant operating temperature. This study numerically investigated the melting process in a triplex tube heat exchanger containing Phase-Change Material (PCM) RT82. A two-dimensional numerical model was generated using the Ansys Fluent 16 software program to simulate the melting process. In this study, conduction and natural convection were considered. Certain arrangements of rectangular ns including lengths and positions were selected according to heat distribution, while the total area of ns was kept constant. This new strategy was done to improve heat transfer in PCM, which would result in decreasing its melting time. The selected optimized model in this article reduced the melting time to 28.4% in comparison with the model in [Mat, S., Al-Abidi, A.A., Sopian, K., et al. "Enhance eat transfer for PCM melting in triplex tube with internal-external ns", Energy Conversion and Management, 74, pp. 223{236 (2013)]. Numerical results were in agreement with the numerical and experimental results of the above-mentioned reference, thus verifying the validity of the obtained results.