Exergy analysis of the absorption refrigeration cycle using economizers

Abstract

This paper presents the study of a simple effect absorption refrigeration system (SRA) using the ammonia-water working couple, with the incorporation of three economizers and their analysis of the first and second law of thermodynamics, emphasizing the effect of the operating temperatures and the efficiency of the exchangers on the refrigerant circulation ratio (RC), the coefficient of performance (COP) of the system and the destruction of exergy. In order to determine the thermodynamic properties at each point of the system and evaluate the performance of the SRA, was programmed a tool in MATLAB with the governing equations. The results show that: the exergy efficiency increases when the temperature in the evaporator decreases; and RC decreases with increasing temperature in the generator. As conclusion, an increase in the effectiveness of heat exchangers cannot only decrease the refrigerant circulation rate, but also increase the inlet temperature of the solution to the generator, so that the temperature difference between the solution and the heat source decreases, causing a decrease in the rate of exergy destruction in the generator and the increase in COP.