Computational energy and exergy analysis of R134a, R1234yf, R1234ze and their mixtures in vapour compression system

Abstract

Due to the European Communities motor vehicle directive (2006) refrigerants with a GWP higher than 150 are not allowed from January 1, 2017 in new passenger cars. Thus, a replacement for R134a is needed. This paper presents a simulation analysis of vapour compression system for finding a drop-in replacement of R134a. The various parameters computed are pressure ratio, mass flow rate, relative volumetric cooling capacity, relative coefficient of performance, cooling capacity, exergetic efficiency, exergy destruction and efficiency defect. A total of thirty one refrigerants was tested taking R134a as a baseline. The results showed that among all tested refrigerants R290 has the highest value of the relative coefficient of performance and exergy efficiency, but the least value of efficiency defect whereas refrigerant mixture 40%R134a/22%R1234yf/38%R1234ze has the relative volumetric cooling capacity nearly similar as that of R134a. Overall, results indicate that refrigerant mixture 40%R134a/22%R1234yf/38%R1234ze is the best alternative for R134a.