Flow Rate Control in a Two-stage Adsorption Cycle for Stable Outlet Temperature in Thermal Energy Storage

In this study, we integrated a double adsorption cycle structure with a flow control strategy to maintain a constant outlet temperature during the release phase and enhance thermal performance. We compared a single conventional cycle with two types of double cycles (Cascade) and analyzed how constant temperature output (CTO) affected useful energy storage density and heat output. Our analysis was based on a numerical model and included simulations that accounted for seasonal variations in feed water temperature. The results indicated that the Cascade system outperformed the Conventional system, with Cascade 2 achieving the highest performance. Under CTO conditions, Cascade 1 demonstrated the best performance, while Cascade 2 had the highest overall useful energy storage density. Additionally, when comparing our proposed system to phase change material (PCM) storage systems, we found that it offered a greater energy storage density than PCM.