Lattice Boltzmann modelling on pore-scale reactive transport in exothermic reactions of solid blocks for thermochemical energy storage

In this study, a pore-scale numerical model of plate-type reactor is developed to simulate and analyze the coupled CaO/Ca(OH)(2) thermochemical heat storage processes based on the lattice Boltzmann method. In the research, the fluid flow, chemical adsorption, mass and heat transfer during hydration reaction are considered. Three different structures with the same porosity of solid particles are designed: in-line, staggered and random patterns. The heterogeneous reaction model with the Langmuir adsorption kinetics is implemented on gas-solid interfaces. The interparticle and intraparticle mass transfer processes are both involved with the help of the lattice Boltzmann method. The distributions of concentration in the gas phase and adsorbed amount in the solid phase are obtained in detail. The conversion rates under three different structures with similar porosity are also compared. Moreover, conjugate heat transfer is applied to simulate the transient temperature distributions in these structures. Heat is released from the solid particles and diffuse to the surrounding area along with the fluid flow. The maximum temperatures of the three structures are 550?. Besides, the trends of characteristic temperatures over time are also obtained, and the durations above 500? are calculated, reflecting the heat storage performances of the different structures. The heat release of three different structures is also compared. It is proved that the structure with staggered blocks is recommended.