用于高效热化学储能与释能的多盐分层反应器性能分析

Abstract Thermochemical energy storage offers high-density seasonal storage for solar heat, yet conventional single-salt reactors suffer from low charging efficiency and short discharging durations. To overcome these limitations, this study proposes a multi-salt tiered reactor in which three hydrated salts—strontium bromide, vermiculite–calcium chloride composite, and potassium carbonate—are arranged in order of decreasing charging temperature. The layered configuration uses the distinct thermodynamic properties of each salt to achieve staged energy storage and extended heat release. A coupled heat and mass transfer model is established in COMSOL Multiphysics to simulate the reactor performance under variable solar-driven inlet temperatures. Under these conditions, the reactor reaches an average salt conversion of 90 % and a charging thermal efficiency of 85.30 %, both higher than those of the single-salt configurations. The discharging process lasts for 1400 min, more than double the duration of the single-salt reactor, and exhibits two temperature peaks with a maximum outlet temperature of 52.20 °C. The tiered arrangement also reduces the risk of deliquescence by creating a humidity gradient from top to bottom. Adjusting the thicknesses of the salt layers to 21 cm for SrBr 2 , 13 cm for CaCl 2 , and 5 cm for K 2 CO 3 further increases the effective discharging period to 778 min. Overall, the results show that the multi-salt tiered design provides a balanced improvement in energy density, heat delivery duration, and temperature stability, with potential for application in building heating systems.