Simulation-driven optimization of adsorption bed structure and experimental validation: A pathway to elevate energy storage in continuous solar drying systems

Abstract The sorption thermal energy storage solar drying system (STES-SDS) effectively mitigates the intermittency of solar energy supply. However, the heat and mass transfer performance of the adsorption bed remains the principal factor constraining overall system efficiency. Herein, we propose a rectangular-wave-honeycomb adsorption bed employing ACF-CA-1/1 as the adsorbent, designed to simultaneously enhance heat and mass transfer performance while maintaining practical manufacturability. A three-dimensional (3D) non-equilibrium transient model was developed to systematically evaluate how key structural parameters shape the temperature distribution, moisture capacity, mass transfer resistance, and adsorption efficiency. Simulations identified the optimal adsorption bed configuration as a length-to-width ratio of 2.5, a thickness of 2 mm, and a height of 270 mm. The optimized bed also exhibited strong adaptability across diverse operating conditions, with its adsorption kinetic parameters varying by less than 0.4 over five humidity levels. Experimental validation of adsorption performance was conducted to corroborate the simulation results. Relative to the original bed, the optimized structure increased the instantaneous adsorption rate by 30.8% (no-load), enhanced moisture capacity by 12.6% (load), and improved total adsorption during continuous operation by 13.1% (1508.3 g vs. 1333.3 g). Overall, this study establishes an optimization framework integrating modeling with experiments, reveals how the structural parameters affect adsorption behavior under multi-field coupling, and provides theoretical and experimental foundations for the engineering design of high-performance STES-SDS adsorption bed.