Thermal performance of latent heat thermal energy storage units with fin optimization structure constructed based on the solid-liquid interface movement velocity

Abstract

A novel method is proposed to optimize the fin structure to improve the horizontally positioned shell-and-tube latent heat thermal energy storage systems' thermal performance. This approach is according to the variation law of movement velocity of the solid-liquid interface in melting for a horizontal bare tube latent heat thermal energy storage unit. By optimizing the internal fin structure, the method balances the heat transfer rates in all regions, resulting in shorter melting times and improved thermal performance. The enthalpy-porosity method is used to simulate the transient phase change process of the PCM. Compared to conventional uniform fin structures, the fin height optimization and fin angle optimization configuration of the number of basic fins constructed by this method can increase the average heat transfer rate by 87.2 % and 20.8 %, respectively. Furthermore, the fin comprehensive optimization structure established by the further developed coupling fin angle optimization method and fin height optimization method can increase the average heat transfer rate by more than 106 %. These results show that the proposed approach can remarkably enhance the thermal performance of latent heat energy storage units and provide new inspirations for the optimization of the fin structure of future phase change thermal energy storage units.