Analytical modeling of sorption thermal energy storage systems

This study presents the development of a transient one-dimensional analytical model for a novel shell-and-tube sorption reactor designed for thermal energy storage (TES) applications. The governing equations are solved using the Laplace transform method, enabling relatively fast and accurate predictions of transient temperature and uptake profiles in sorbent composites. Model validation was performed through gravimetric large temperature jump experiments, showing good agreement with experimental data (average relative difference ∼ 11%). A comprehensive parametric study examined the influence of cycle time, sorbent thickness, thermal diffusivity, and convective heat transfer coefficient on key performance indicators (KPIs), including specific heating/cooling power (SHP/SCP), coefficient of performance (COP), and energy storage density (ESD). Analysis of variance (ANOVA) identified that the cycle time has a significant effect on the main KPIs (45%, 35%, and 50% in SCP, COP, and ESD, respectively). This analytical modeling can serve as a computationally efficient design tool for optimizing sorption reactor geometry, material properties, and operating conditions in heating, cooling, and thermal energy storage applications.