CFD analysis on the performance of PCM thermal energy storage incorporating a double-pipe heat exchanger with longitudinal fins

This study presents a Computational Fluid Dynamics (CFD) analysis of a Phase Change Material (PCM) based Thermal Energy Storage (TES). The PCM-TES employs a double-pipe heat exchanger with longitudinal fins to enhance its heat transfer performance. The research aims to investigate the feasibility of the of PCM-TES for mitigating renewable energy curtailment that has been a growing concern in the sector coupling and power-to-heat transitions. This study also evaluates how the inclusion of a double-pipe heat exchanger with longitudinal fins within the PCM can enhance the heat transfer rate during charging and discharging processes, making the TES system more effective for sector coupling applications, particularly in scenarios where excess renewable energy is converted to heat (power-to-heat). The CFD model is developed to simulate the thermal behaviour and performance of the PCM TES system under charging and discharging conditions. It specifically investigates the impact of the longitudinal fins on the melting and solidification processes of the PCM. These fins are designed to increase the surface area for heat exchange, thereby enhancing the heat transfer rate between the heat transfer fluid (HTF) in the double-pipe and the PCM. The simulation results demonstrate a significant improvement in the energy density and heat transfer rate with the inclusion of longitudinal fins. This enhancement leads to a faster charging and discharging cycle of the TES system, thereby making it more capable of handling the intermittent nature of renewable energy sources. The study also explores the optimal fin design and configuration for maximum efficiency.