Preparation and parameter optimization of thermochemical heat storage materials with high cyclic stability

Abstract

Thermochemical heat storage technology is a highly promising one, with high heat storage density and the ability to store heat across seasons. Thermochemical heat storage materials are mainly solid powders, which usually have a low heat transfer coefficient, a wide particle size distribution and poor mobility. Hence, their application in fixed-bed as well as fluidized-bed reactors is difficult. In this paper, core shell structure (CSS) pellets were prepared with silicon carbide as shell and Ca(OH)2 as core. The pellets were of uniform size, stable in shape and have good cyclic stability. The experimental validation and simulation of the heat storage properties and mechanical strength of the prepared pellets were carried out. The experimental results show that after 25 cycles of heat storage and release, the heat storage density of the pellet decreases within 20% and no cracking or crushing occurs. The simulation results show that the shell structure parameters affect both the heat storage performance and the mechanical strength of the pellets. In this paper, the shell structure parameters are optimized through simulations, which provide a reference for the preparation of CSS pellets.