Abstract: With the continuous optimization of the energy supply structure, energy storage technology has gradually become a research hotspot. Direct fixed-bed reactors, as an important thermochemical energy storage device, face challenges such as low energy input efficiency and heat storage efficiency constrained by mass transfer capacity, which limit their industrial application. To address these issues, a novel thermochemical energy storage direct fixed-bed reactor has been designed. This device integrates the ventilation pipeline as an electric heating element for internal heating, improving energy input efficiency. Additionally, the multi-channel design effectively enhances mass transfer performance. To evaluate the heat storage performance of the device, three-dimensional numerical simulation methods were employed to study the distribution of physical fields such as gas-solid chemical reactions, heat transfer, mass transfer, and fluid flow within the porous medium, and to analyze the effects of parameters such as pressure, porosity, and heating power on the heat storage process. The results indicate that the reactor bed exhibits high symmetry, with a distinct temperature gradient within the bed. Factors such as vapor pressure, porosity, and heat release power influence the reaction progress and equilibrium from different perspectives. This study reveals the coupling mechanism of multiple physical fields within the calcium-based thermochemical energy storage fixed bed, clarifying the interaction effects of various operational conditions, and providing a theoretical basis for the design of fixed-bed reactors.

Key words: reactors, numerical analysis, chemical reaction, Ca(OH)₂, electric heating