多级梯度孔隙钙基热化学储能反应床结构优化OA

Mass transfer limitations constitute a critical bottleneck affecting performance in calcium-based thermochemical energy storage systems.In this study,we propose a composite-structured reaction bed integrating gradient pore distribution with multilevel pore channels to synergistically optimise heat and mass transfer pathways within the bed.By establishing a three-dimensional numerical model,the heat storage reaction during Ca(OH)2 dehydration was simulated to systematically investigate the coupled enhancement mechanisms of heat transfer,mass transfer,and reaction kinetics driven by gradient porosity and multilevel pore channels.Further,we elucidate the influence patterns of pore volume fraction and inlet temperature on energy storage performance.Results indicate that within the studied 1-4-level pore channel range,heat/mass transfer performance and reaction rate exhibit a sustained upward trend with increasing level number.Compared with conventional uniform pore structures,the four-level gradient pore channel model with an 8%pore channel volume fraction achieved an approximately 16.6%increase in bed average temperature and a 27.98%reduction in the time required for complete conversion.This study elucidates the synergistic mechanism by which gradient porosity optimizes heat transfer pathways while multilevel channels enhance water vapor transport.It provides theoretical foundations and engineering guidance for the structural design and parameter optimization of high-performance calcium-based thermochemical energy storage reactors.