Comparative performance between R134a and R152a in an air conditioning system of a passenger car

Abstract

The present study investigates numerically the performances of an automotive air conditioning (A/C) system using R134a and R152a as working fluids for various engine running speeds. There are three engine rotation variations, i.e., 1000 rpm, 2000 rpm and 3000 rpm that represent idle, city and high speed conditions, respectively. The compressor volumetric efficiencies for 1000 rpm, 2000 rpm and 3000 rpm are 0.75, 0.65 and 0.55, respectively. The results show that the cooling capacities of R152a are slightly lower than that of R134a at the condensing temperatures of 40oC and 45°C. However, at the condensing temperature of 50°C, the cooling capacity of R152a is higher than that of R134a up to 5.0%. In addition, COPs of R152a are higher than that of R134a for all the condensing temperature. The increase of condensing temperature is more dominant to the COP improvement rather than the increase in engine rotation. The highest COP improvement is 13.5%.