Research on Thermal Management System of New Energy Vehicles Based on Heat Pump Air Conditioner

With the popularity of electric vehicles, the application development of heat pump type automobile air conditioning system has been focused. Meanwhile, the traditional R134a needs to be replaced by more environmentally-friendly refrigerants under the Kigali Amendment. In this paper, a novel direct expansion heat pump air conditioning system with three circuit switching (DXACS) was proposed, and three low GWP refrigerants R1234yf, R1234ze(E) and R290 were carried out to evaluate the system performance. The results show that the winter range attenuation ratio of DXACS is 26.9%, significantly lower than the prototype EV360 (57.5%); the DXACS with R290 shows the best heating performance, COP_h and q_cv are 2.3% and 57.3% higher than R134a in extremely cold conditions, respectively. This study provides valuable insights for the development of efficient and green thermal management technology of new energy vehicles.