Investigation on bi-salt chemisorption system for long term energy storage

In this study, a bi-salt sorbent was observed to exhibit better adaptability to the heating and cooling temperatures than conventional single-salt sorbents. A reactor filled with the bi-salt sorbent of CaCl2 and MnCl2 was designed, and the performance for long-term thermal energy storage, which included several months of seasonal energy storage and a few days of exhaust gas heat storage in winter, was analyzed. The thermal energy charging rate under both working conditions increased with the heating temperature; however, the COPh exhibited a downward trend. The COPh of seasonal energy storage was maintained above 0.5, and the COPh of exhaust gas heat storage was slightly higher at approximately 0.7. For both working conditions, the average heat-producing power in 50 min increased to approximately 9 kW, and the energy-storage density increased to approximately 1900 kJ.kg(-1), which was approximately 100% higher than that of existing resorption systems with single-salt sorbents. (C) 2020 Elsevier Ltd. All rights reserved.