Dynamic simulation and analysis of a SrBr2-H2O high-temperature thermochemical heat transformer for continuous industrial heating

Thermochemical heat transformer utilizes reversible gas-solid chemical reactions to upgrade low-grade thermal energy to a higher temperature level. It can recover low-grade industrial waste heat to provide high-temperature heating, which is a promising solution for heating decarbonization. However, existing researches mainly focused on low-temperature operating conditions, and performed steady-state analysis that overlooking the inherent intermittency of gas-solid reactions, contradicting the industrial requirement for continuous high-temperature heating. In this study, a dynamic model of a high-temperature strontium bromide-water system was established, which incorporated reaction kinetics and energy conservation. Moreover, a dual-reactor alternating operational strategy was also proposed and improved based on the results of thermodynamic analysis. Results demonstrated that with a minimum driving temperature of 143 °C, the system effectively upgrades waste heat from 85 °C to a high-grade output of 205 °C, achieving a significant temperature lift of 120 °C. Under typical conditions, the coefficient of performance and exergy efficiency reached 0.43 and 0.54, respectively. The investigation into dynamic characteristics established a robust foundation to surmount the inherent intermittency of gas-solid reactions, and bridged the gap between dynamic reaction mechanisms and system-level continuous operation, unlocking new pathways for integrating thermochemical heat transformers into industrial processes.