Advanced exergy analysis of an NH3-LiNO3 single-stage absorption cooling system

This paper presents an advanced exergy analysis applied to a theoretical absorption cooling system working with the ammonia-lithium nitrate mixture. The analysis was realized for real, ideal, and unavoidable cycles. The mathematical model was compared with theoretical and experimental results obtained from the literature. A case base was established and analyzed, and then a parametric analysis was conducted based on the first and second laws of thermodynamics, determining the coefficient of performance, as well as the avoidable and unavoidable exergy destruction for each component and the overall system, as a function of the main system parameters. It was found that the highest values of the exergy destruction were obtained for the real cycle, followed by the unavoidable cycle and the ideal cycle. The advanced exergy analysis revealed that 90.8% of the total exergy destruction is unavoidable, while only 9.2% is avoidable. From the analysis of the case base, it was found that the highest values of the exergy destruction occurred in the generator ( ≈ 39.3 % ), followed by the absorber ( ≈ 34.3 % ). The lowest values were obtained in the condenser, contributing just 2.3% of the total exergy destruction. From the parametric analysis, it was found that the exergy destruction of the entire system increases linearly with the increase in the generator temperature and exponentially with the increase in the condenser and absorber temperatures.