DETERMINATION OF CO-EFFICIENT OF PERFORMANCE (COP) OF A VAPOR COMPRESSION REFRIGERATION CYCLE USING DIFFERENT REFRIGERENTS

Abstract

Vapor compression refrigeration system was studied as it is the most widely used refrigeration system especially in small scale of refrigeration application such as in domestic application. Performance of the system becomes main issue and many researches are still ongoing to evaluate and improve efficiency of the system. By learning and understanding the basic vaporcompression refrigeration systems, the performance of refrigeration system can be determined using refrigerator test rig. This thesis deals with coefficient of performance testing under a vapor compression refrigerator using experimental setup for three different refrigerants. The main objective in this thesis was to obtain performance of the refrigeration system in term of refrigeration capacity, compressor work and coefficient of performance (COP) by determining three important parameters during operating mode which are temperature, pressure and refrigerant flowrate. The performance of the refrigerator test rig was analyzed using the actual pressure-enthalpy diagram of refrigeration cycle and by using the mathematical equation. This study may help the readers to analyze the performance of the refrigerator. Performance increases as the evaporating temperature increases, but reduces as the condensing temperature increases. We have found from the experiment that the average actual COP of R-12, R-22 and R-134a are 4.07, 3.97 and 3.80 respectively. Considering the overall assessment of the results and global warming potentials (GWPs) we can say that R134a will be a better alternative than other two refrigerants in the refrigeration system.