Performance Characteristics of Automobile Air Conditioning Using the R134a/R1234yf Mixture

Abstract

In this study, the energy and exergy of an automobile refrigeration system using R134a and R134a/R1234yf were analyzed experimentally with respect to outdoor air temperature and compressor speed. As outdoor air temperature increased from 32.5 °C to 37.5 °C, the coefficient of performance (COP) and total exergy destruction rate of the refrigeration system using Mix30 decreased by 5.19% and 25.8% on average, compared to that of the system using R134a. The exergy efficiency of the Mix30 refrigeration system was on average 21.8% higher than that of the R134a system. As the compressor rotating speed increased from 1000 to 2000 rpm, the cooling capacity of the refrigeration system using R134a and R134a/R1234yf increased, while the COP decreased. The COP and total exergy destruction rate of the refrigeration system using Mix30 decreased by 4.82% and 19.5%, compared to that of the system using R134a. The exergy efficiency of the Mix30 refrigeration system increased on average by 20.7%, compared to that of the R134a system. The total exergy destruction rate of the automobile refrigeration system using R134a/R1234yf decreased with increase in R1234yf, while exergy efficiency increased. In addition, the exergy destruction rate of the automobile refrigeration system decreased as the amount of R1234yf in the R134a/R1234yf automobile refrigeration system increased.

Application of Refrigerant Cooling in a Battery Thermal Management System under High Temperature Conditions: A Review

“…It is noteworthy that flammability issues are avoided when R134a (mass ratio of 11%) is included. Scholars , use R134a mass ratios of 5%, 10%, and 15% in R1234yf.…”

An Experimental Study on the Cooling Performance of Refrigerant (R134a/R1234yf) in Automobile HVAC System

“…Similarly, the cooling capacity and the exergy efficiency of the air conditioning system using the refrigerant mixture increased compared to that of the R134a system while the COP decreased with an increase in the compressor rotating speed. So, the presence of R1234yf in the R134a-R1234yf mixture decreases the total exergy destruction rate of the automobile refrigeration system and increases the exergy efficiency [7]. In an experiment done by Zilio et al, an automotive air conditioning system with baseline components which uses conventional R134a has been replaced with a drop-in R1234yf and the experimental results indicate low COP of R1234yf systems than the R134a system.…”