Abstract:

Compared to sensible and latent heat storage, thermochemical heat storage has high heat storage density and can achieve seasonal heat storage at ambient temperature. In order to design the reactor and choose optimal reaction condition, the exothermic process of CaO-Ca(OH)2 heat storage system must be examined. Based on the thermal behavior of CaO-Ca(OH)2 heat storage system, a 2D axisymmetric time dependent model is developed to study the exothermic process, and the effect of different reaction conditions and reaction bed parameters on exothermic process of CaO-Ca(OH)2 heat storage system is investigated systematically. The results indicate that there is a rapid reaction zone in the reaction bed and the exothermic reaction moves from the inlet to the outlet. The outlet temperature is mainly influenced by steam pressure and the reaction exothermic power is mainly influenced by flow rate. Low porosity has little effect on the maximum exothermic power and the height of reaction bed has no effect on the maximum reaction exothermic power. The result of this study provides systematical insight into the application of Cao-Ca(OH)2 thermochemical heat storage system.

Key words: thermochemical heat storage, calcium hydroxide, numerical computation