Predictive thermal performance analysis of T-wall based adsorption thermal battery for solar building heating

Moisture-based adsorption thermal battery (ATB) holds great potential for addressing energy storage and utilization challenges. In this work, a proof-of-concept solar harvesting building envelope using the Trombe-wall (Twall) based ATB design is proposed and investigated, featuring a developed composite sorbent as the porous wall for effective heat storage and utilization. To demonstrate the feasibility of employing the ATB-based building envelope for day-and-night space heating, a 3-dimensional simulation model of the ATB wall is meticulously designed and comprehensively studied. Parametric analyses of various working conditions, including examining the effects of solar radiation intensity, air temperature, air humidity, and airflow velocity on the heat charging and discharging performances of the ATB wall, are conducted using the numerical model. Simulation results indicate that, under a solar irradiance level of 700 W m- 2 during the daytime, an average output air temperature of 42.4 C and an average heating power density of 2.5 kW m- 3 are achieved. Extending the heat charging time to 8 h and 12 h significantly improves the desorption efficiency, which is able to reach 47.2% and 75.0%, respectively. In terms of heat discharging performances, various working conditions investigated in the ATB wall model will lead to different thermal output performances.