Numerical study of CaO/Ca(OH)2 dehydration process with a porous channel

Thermochemical energy storage is an effective method of energy storage with high energy density and little heat loss. The physicochemical model of dehydration process is established based on the chemical kinetic regulation of dehydration process, coupling with fluid flow and heat transfer. The dehydration process of CaO/Ca(OH)2 in an undirected cylindrical reaction unit with constant wall temperature is studied. Mechanism of chemical reaction combined with heat transfer and fluid flow is analyzed first. Then, dehydration processes at different wall temperature and outlet pressure conditions are studied. Results indicate that higher wall temperature can significantly shorten reaction time while change of outlet pressure here has little impact on reaction time. To enhance the equilibrium of dehydration process, porous channels, of different permeability and solid frame thermal conductivity, are inserted into the reaction unit. Porous channel not only promotes the flow of vapour but also improves heat transfer and the corresponding reaction time is significantly reduced.