Dynamic performance analysis and climate zone-based design of a seasonal solar thermochemical energy storage and heating system in China

Abstract

The prospects of solar heating in China are promising, but solar energy’s intermittency and variability challenge its alignment with winter heating demands. Seasonal thermochemical energy storage (TCES) offers a viable solution by enabling the temporary storage of thermal energy in summer for subsequent winter use. However, the practical application of seasonal TCES technology is limited due to a lack of dynamic performance analysis, control method formulation, and comprehensive system evaluation. Therefore, the study investigated a seasonal TCES system coupled with solar collectors for space heating, with MATLAB and TRNSYS for joint simulation. The dynamic performance of the system and its application in different climate zones in China was explored. Results indicated that the system could effectively store solar heat in summer and provide continuous heating in winter. Based on the climatic divisions of China, the relationships among the system heat release, mass flow rate and the volumetric heat transfer rates were fitted and summarized. Additionally, for the target building located in Changsha of China, the optimal supply–demand ratio of the system was determined to be 1.5:1, achieving an annual heating capacity of 1565.22 kWh, a System Coefficient of Performance (SCOP) of 1.492, and an hourly room temperature satisfaction rate of 96.97%. It was expected that the system could reduce CO₂ emissions by approximately 52.16% compared with traditional coal heating. All the results indicated that the system had great application potential, and the proposed design methods for different climate zones could promote its widespread use.