Exergy analysis of a novel air-cooled non-adiabatic absorption refrigeration cycle with NH3–NaSCN and NH3–LiNO3 refrigerant solutions

• We analyze an absorption refrigeration cycle driven by low grade energy.
• Modified Methodology in entropy calculation is presented.
• New exergy calculation method of ammonia/salt solution is presented.
• Exergy analysis under air-cooled condition is carried out.
• Influence of non-adiabatic absorber to exergetic efficiency is analyzed.

This paper presents a methodology of exergy analysis for ammonia-lithium nitrate and ammonia-sodium thiocyanate absorption refrigeration cycle which applies a novel air-cooled type non-adiabatic absorber to improve both the coefficient of performance and exegetic efficiency of the system under air cooling condition. A modified entropy calculation method for NH3/NaSCN and NH3/LiNO3 solutions is presented in this literature and different results are obtained comparing to previous research. In addition to the variation of solution temperature and pressure from specific working state to the reference state, the variation of solution concentration, which was always neglected by previous researchers in ammonia/salt solution exergy calculation, has been taken into account while analyzing the least potential of ammonia/salt solution for doing useful work, and a corresponding approach for specific exergy calculation is presented. The effects of generator temperature, absorber outlet temperature, absorber efficiency and other system parameters on system exergetic efficiency have been discussed in this study. Analysis results indicate that relatively high system performance can be obtained by air-cooled type ammonia/salt absorption refrigeration cycles when non-adiabatic absorbers are applied in these systems.

A methodology based on the second law of thermodynamic has been carried out in the analysis of an air-cooled type ammonia/salt absorption refrigeration system. Simulation results show that Low grade energy is applicable for NH3/NaSCN and NH3/LiNO3 absorption refrigeration system under air cooling condition and relatively high exergetic efficiency can be obtained.Figure optionsDownload as PowerPoint slide