Energy and Exergy Analysis of Vapor Compression Refrigeration System with Integrated Mechanical Subcooling Using R134a, R450a, R513a, and R515a

This study compares the performance of a vapor compression refrigeration system (VCRS) with an integrated mechanical subcooled vapor compression refrigeration system (IMS-VCRS) in water-cooled centrifugal chillers. Specifically, this study uses four different refrigerants R134a, R450a, R513a, and R515a. A mathematical model of IMS-VCRS is developed to determine the performance parameters at a fixed cooling capacity of 1750 kW. This study investigates that the energy consumption of an IMS-VCRS is reduced by 11.36% for R134a, 11.98% for R450a, 13.36% for R513a, and 11.89% for R515a. The mechanical subcooled system's COP is increased by 12.84% for R134a, 13.59% for R450a, 15.40% for R513a, and 13.48% for R515a due to the low power requirement. In addition, exergetic analysis is also used to determine the system's second law efficiencies, which in this study improved by 11.25%, 11.84%, 13.41%, and 11.77% for R134a, R450a, R513a, and R515a respectively. Furthermore, parametric analyses were performed to investigate the effects of various system parameters such as evaporator and condenser temperatures.