Solidification performance enhancement of a latent heat thermal energy storage system: A novel discontinuous fin configuration for vertical shell-and-tube design

This study investigates the critical challenge of low heat release rates in vertical latent heat thermal energy storage units, proposing an innovative discontinuous fin configurations. A numerical model of the wax solidification process was developed using the enthalpy-porosity method, with a focus on analyzing how the discontinuous fin structure regulates temperature field distribution and solidification rate. The results demonstrate that optimizing the fin geometric parameters leads to a significant enhancement in thermal energy storage performance. The main fin length (L1) has a critical value of 15 mm. Variations in L1 below 15 mm result in negligible differences in solidification performance, while further increases in L1 lead to a gradual increase in the total solidification time. Additionally, the dimensionless bifurcation angle α has an optimal range of 0.45–0.6, which yields the shortest solidification time. The optimized discontinuous fin configuration (L1 = 15 mm, α = 0.45) achieves a 22.14 % reduction in solidification time and a 28.45 % increase in heat release rate compared to conventional longitudinal fins. This study elucidates the mechanism by which discrete fins enhance the solidification process, providing a robust theoretical foundation and critical design parameters for the development of next-generation high-efficiency thermal energy storage units.