Research on the Application of an HFO1234yf/HFC134a Mixture in a Vehicle Air-Conditioner System with an Internal Heat Exchanger

[Image: see text] The application of a mixed refrigerant HFO1234yf/HFC134a (89:11, by mass) of GWP 144 in a vehicle air-conditioner system with and without an internal heat exchanger was studied under refrigerating and heating conditions, and it was compared with an R134a original system. The results show that under refrigerating conditions, the refrigerating capacity of the HFO1234yf/HFC134a system with an internal heat exchanger is increased by 2–4%, which is slightly larger than that of R134a system. The refrigerating COP of the HFO1234yf/HFC134a system with an internal heat exchanger is increased not largely. However, it tends to decrease at high-temperature conditions. In heating conditions, the heat capacity of the HFO1234yf/HFC134a system with an internal heat exchanger is improved by 2–5%, basically equal to that of the R134a system. The heating COP of HFO1234yf/HFC134a with an internal heat exchanger is increased with a maximum of 6% at low-temperature conditions. HFO1234yf/HFC134a can be used as an environmental alternative to R134a as an introduction of an internal heat exchanger into an automobile air-conditioning systems.