Research Progress of Solid-Gas Two-Phase Chemical Heat Storage Technology for Solar Thermal Power Generation

As a heat storage method with high heat storage density, long storage time and long transportation distance, the chemical heat storage has been widely studied in recent years. This article firstly summarized the basic principles and research progress of several existing solid-gas two-phase chemical heat storage reaction systems, mainly involving the metal hydroxide reaction, metal oxide reaction, carbonate reaction, and hydration salt reaction. Then, according to the moving state of solid phase reactant in the reactor, the reactor was divided into three types: the fixed bed reactor, fluidized bed reactor and moving bed reactor. Moreover, their research progress was summarized respectively. Finally, based on the current deficiencies in the research of chemical heat storage, the future development trend of chemical heat storage was analyzed. At present, the storage still needs further research, and there are still technical difficulties in strengthening and matching the chemical reaction rate and heat transfer. The cyclic stability of chemical heat storage under long-term operation condition still needs to be further explored.