Experimental investigation of performance and exergy analysis of automotive air conditioning systems using refrigerant R1234yf at various compressor speeds

This paper presents an experimental performance investigation and exergy analysis using R1234yf in an automotive air conditioning system. The R1234yf system with an internal heat exchanger (IHX) was compared with an R1234yf system without the IHX and an R134a system. The R1234yf system had 4.0-7.0% smaller cooling capacity and 3.6-4.5% lower COP compared to the R134a system. With the IHX, the R1234yf system showed almost equivalent cooling capacity to the R134a system. The COP of the R1234yf system with the IHX is lower than that of the R134a system by 0.3-2.9% for a compressor speed of 800-1800 rpm. The COP increased by 0.9% at a compressor speed of 2500 rpm. The second law efficiency of the R1234yf system was 3.4-4.6% lower than that of the R134a system at all compressor speeds. The second law efficiency of R1234yf with the IHX was improved by 1.5-4.6% compared to the R1234yf system without the IHX. The EDR of the R1234yf system was 0.5-3.3% higher than that of the R134a system in the range of 800-1800 rpm. However, the R1234yf system with the IHX had 1.2% lower EDR than the R134a system at a compressor speed of 2500 rpm.