Performance Evaluation of Thermal Energy Storage with Phase Change Material in Smooth and Expanded Pipe Flow Using Numerical Simulation

Energy storage is needed in the renewable energy system due to the fluctuation nature of the energy source.Thermal energy storage with phase change material (PCM) has been proven to have higher performance due to its latent heat properties.In this study, heat transfer performance comparison of two geometric pipe profiles is performed to evaluate the effect of higher heat transfer area at same PCM volume using Computational Fluid Dynamics (CFD).Pressure drop in the heat transfer fluid (HTF) side is also evaluated.Base model of the smooth pipe is taken from existing experiment and a new pipe is modified by expanding the outer diameter of HTF side 50 bigger than the base model, resulting 14.9 higher heat transfer area.It is shown that at Reynolds number of 4162, there is only slightly higher heat transfer performance represent by slightly higher average liquid fraction and slightly lower outlet temperature in the expanded pipe compare to the smooth one over time.Meanwhile, the pressure drop of the HTF is increased by around 29.For current Reynolds number, increment of heat transfer area is not enough to increase the heat transfer performance.Other key factor related to the heat transfer performance need to be investigated. © 2023, Institute of Technology PETRONAS Sdn Bhd.