Performance characteristics of an automobile air conditioning system with internal heat exchanger using refrigerant R1234yf

In this study, performance was assessed by charging the same automotive refrigeration systems with the refrigerants R134a and R1234yf, respectively, to compare the characteristics of the refrigeration cycle of the two refrigerants. The internal heat exchanger was installed in order to improve cooling performance of R1234yf and to investigate the level of performance improvement in comparison with conventional R134a system. Performance test by using R1234yf and R134a in the same system showed low power consumption and cooling capacity for using R1234yf, that is, up to 4% and 7%. In particular, performance comparison between the R1234yf and R134a for automotive air conditioning revealed that cooling capacity and COP of the 1234yf system without the IHX decreased by up to 7% and 4.5%, respectively, but those with the IHX decreased by up to 1.8% and 2.9%, respectively.