Study on the thermal storage performance of CaO/Ca(OH)2 thermochemical energy storage system integrated with molten salt

• Thermochemical energy storage system was coupled with molten salt. • The improvement of thermal storage and reaction performance was achieved. • The heat transfer was enhanced by porous media filled in molten salt. Thermochemical energy storage technology is considered as an important technical means to address energy intermittency. In this study, the thermochemical energy storage was integrated with molten salt to further improve thermal performance, the numerical simulation model was established using the finite element simulation. The variation of temperature and extent of reaction, as well as the heat storage characteristics were investigated. It is found that the introduction of porous media in the molten salt region is benefit to the heat transfer, and improves the reaction rate in the reaction bed. The heat storage capacity can be improved by 80%, and the increase in thermal storage time caused by molten salt in porous media is relatively limited. The porous media porosity of 0.8 was recommended for engineering applications. Increasing the external wall temperature enhanced the heat storage capacity of the system and reduced the reaction time by 52.41%. The heat storage capacity was increased by 18.25% due to the introduction of molten salt, and the heat storage rate of the system was increased by 14.72%. These results are expected to be helpful for the practical applications of thermochemical energy storage performance improvement.