An experimental study on the binary hydrated salt composite zeolite for improving thermochemical energy storage performance

Thermochemical energy storage is a promising approach in thermal energy storage because of its advantages in high heat storage density, low heat loss and long period stability. The hydrated salt is a commonly used material in low temperature heat storage. A thermochemical energy storage experiment is conducted based on the material of MgCl₂ and CaCl₂ binary hydrated salt composite zeolite. In the preparation of binary hydrated salt, it's found that the optimum concentration is 15 wt% and the better mass ratio of MgCl₂ to CaCl₂ is 1:1.5. The metal mesh net packed method is adopted for further improvement of thermal performance. The results of energy release process show that the binary hydrated salt composite zeolite can increase the temperature rise up to 45.8 °C at the air velocity of 0.18 m/s. It can achieve the highest energy storage density of 719 kJ/kg and thermal efficiency of 41.9% at the air velocity of 0.32 m/s. Also, the combination with metal mesh packed nets can further improve the temperature rise peak, energy storage density and the thermal efficiency to 52.7 °C, 918 kJ/kg and 46.1%, respectively. This study provides references for multicomponent composite material preparation and thermochemical reactor improvement.