Performance analysis of ammonia-based vapour absorption refrigeration system

Abstract

In the past few years, absorption refrigeration systems (ARS) have captivated increasing research interests as it is a promising alternative and tenable solution to replace vapour compression refrigeration systems (CRS). Also, the refrigerants used in this system are environmentally friendly. NH3/H2O and H2O/LiBr are the most commonly used working fluids in ARS. However, the NH3/H2O ARS has a limitation in that it requires additional components such as a rectifier and analyzer. The proposed work focuses on improving the performance of the ARS by using other ammonia-based working fluids, namely NH3/LiNO3 and NH3/NaSCN. Various correlations are used to determine the thermodynamic properties of these working fluids and are later used in the thermodynamic simulation. NH3/H2O, NH3/LiNO3 and NH3/NaSCN ARS performance analyses are carried out using a computer program written in Python 3.0. The coefficient of performance of these systems is compared at different operating parameters, i.e., evaporator, condenser, generator, and absorber temperature. The results indicate that the working fluids, NH3/LiNO3 and NH3/NaSCN, perform better than the NH3/H2O ARS. Thus, NH3/LiNO3, NH3/NaSCN ARS provide better performance in more significant value of COP and do not require additional components such as a rectifier and analyzer. Hence, NH3/LiNO3 and NH3/NaSCN can be considered suitable alternatives to NH3/H2O in a vapour ARS.