Melting performance optimization and economic evaluation in rotating thermal energy storage system with partially filled porous structure

The current work introduces a hybrid enhancement approach that incorporates rotation and partially filled metal foam, aiming to achieve a balance between the cost and thermal performance of the latent heat thermal energy storage (LHTES) system. Based on the user-defined functions and enthalpy-porosity method, the effects of the filling position, the number of porous fins, and rotational speed on the melting process are numerically examined. Besides, the response surface methodology (RSM) and economic evaluation index are introduced to optimize the filling ratios at different positions and comprehensively compare the thermal performance and system cost. The results indicate that the structure with metal foam arranged simultaneously near the inner tube, outer shell, and radial positions achieves the best thermal performance, effectively shortening the melting time by 54.65 %. At a rotational speed of 0.50 RPM, five porous fins are identified as the optimal choice. Compared to the basic case, the optimal structure determined by RSM achieves a 73.02 % reduction in melting time and a 276.22 % increase in thermal energy storage rate (TESR). Additionally, it has better economic feasibility and heat transfer enhancement per unit mass of metal foam. The hybrid enhancement measures proposed in this paper can enhance the thermal performance of latent heat thermal energy storage unit (LHTESU) at a low cost, which is conducive to the realization of efficient and low-carbon clean production.