Performance regulation characteristics of bi-halide sorbents in the thermochemical sorption system for cold/heat storage

Thermochemical sorption is a promising technology for cold and heat storage. The performance regulation characteristics of bi-halide sorbents composed of CaCl2 and MnCl2 in different mixing ratios in the sorption energy storage system are investigated and compared by simulation and experiments in this paper. The simulation results show that the bi-halide sorbent can effectively reduce the reaction hysteresis temperature difference. The output energy becomes more concentrated, the start-up time is effectively shortened, and the stability of the energy output is ameliorated as the ratio of MnCl2 increases. Moreover, the experimental results corroborate the analysis in the simulation, and the maximum average cold and heat storage capacity of 2.7 kW and 1.6 kW, and their COP of 0.32 and 0.19 are obtained when the ratio of CaCl2 and MnCl2 is 6:1. In addition, the refrigerating power becomes concentrated in the early stage of the reaction with the mixing ratio of 1:3, and the time for rising to the average refrigerating capacity is significantly shortened from 900 s to 100 s. The consistency between simulation and experiments in the regulation characteristics illustrates that the bi-halide sorbent can improve the applicability of the sorption energy storage system in practical scenarios with different requirements.