Thermodynamic optimization and analysis of 3E performance for irreversible absorption energy storage heating system

This study analyzes the performance of an absorption energy storage (AES) system based on finite-time thermodynamics. A thermodynamic model of the system is established by accounting for system irreversibility, energy storage and release time ratio, thermal resistance, and heat leakage. The study focuses on three evaluation criteria: the exergy-based ecological criterion (E), the exergetic performance criterion (EPC), and the thermo-economic criterion (k₂f). The effects of irreversibility factors, energy storage and release time ratio, heat leakage, thermo-economic parameter, heat source temperature, and heat transfer coefficients on these criteria are systematically analyzed and discussed. Additionally, methods for improving system performance are thoroughly examined. The results indicate that relative to the maximum heat release rate point, the maximum k₂f criterion point and the maximum E criterion point can significantly enhance energy storage efficiency (ESE) at the cost of a certain reduction in heat release rate. Increasing the system’s irreversibility factor and time ratio can substantially improve ESE and k₂f criterion, albeit at the expense of ecological performance and a decrease in heat release capacity. Although the heat source temperature has a negligible effect on k₂f criterion, increasing the absorber heat source temperature significantly enhances the E criterion. Moreover, raising the heat transfer coefficient of the energy storage tank by 0.4 kW/(K·m²) increases the maximum value of the E criterion function by 8.6 % and expands the upper bound of the system’s heat release rate by 65.1 %. These findings offer theoretical insights for the design of AES systems.