R410A Based Automotive Heat Pump System That Hits Cabin Heating Goal Successfully in -30 °C Extreme Ambient

To meet low ambient challenges on Battery based Electric Vehicles (BEV), it is necessary to employ heat pump systems on the HVAC systems. However, due to the boiling points limitation of the regular refrigerant R134A/R1234YF, even with Vapor Injection cycle (VI) added, due to -26°C Boiling Temperature (BT) limitation, it is still encountering serious challenges to meet -30 °C or lower ambient needs, although VI Heat Pump (VI H/P) may reach COP>=1.7 at ambient -18 °C. An alternative low BT refrigerant, R410A, plus VI participation, the combination provides potentials to operate in extreme low ambient like -30 °C. In order to find out the actual heating performance of R410A+VI, a demonstration fleet of three vehicles had been built up for road tests to compare each other, which consists of a traditional vehicle (ICE gas heating), a BEV with PTC water heating system (R134A) and a BEV with VI heat pump system (R410A). The testing area covers the coldest city in China such as Harbin, (-20°C), Yakeshi (-39 °C), The road tests have exhibited positive results that the R410A based VI H/P cabin heating system fulfills requirements essentially both for passengers comfort and defrosting/demising. This paper is to summarize the information of the experiments related, including vehicle information, H/P thermal loop, the components applied etc. Meanwhile, it opens some environmental concerns of R410A application on vehicular HVAC systems.