Thermodynamic analysis of absorption refrigeration system based on entropy generation

Abstract

In this study, the first and second law thermodynamic analysis of a single-stage absorption refrigeration cycle with water/lithium bromide as working fluid pair is performed. Thermodynamic properties of each point in the cycle are calculated using related equations of state. Heat transfer rate of each component in the cycle and some performance parameters are calculated from the first law analysis. From the second law analysis, the entropy generation of each component (S-j) and the total entropy generation of all the system components (S-i) are obtained. Variation of the performance and entropy generation of the system are examined at various operating conditions. The results show that high coefficient of performance (COP) value is obtained at high generator and evaporator temperatures, and also at low condenser and absorber temperatures. With increasing generator temperature, total entropy generation of the system decreases. Whereas maximum entropy generation occurs in the generator at various operating conditions, entropy generation in the refrigerant heat exchanger, expansion valve and solution pump is negligibly small.