Experimental characterization of a reversible heat pump for hybrid and electric vehicles

The most performant system for heating in electric and hybrid vehicles is the heat pump. This study proposes a heating system with a reversible heat pump, which works as a conventional air conditioning system in cooling mode and in heating mode it uses a secondary circuit with water/glycol to transfer the heat from the condenser to the heater core located in the air conditioning module. This system was experimentally validated with 61 tests in heating mode and 19 tests in cooling mode. In the heating mode, there is a test which was developed with an ambient temperature of -1ºC with the air circulating through the outdoor unit at a velocity of 3.2m /s , an air flow rate of 388 kg/h supplied to the cabin and the compressor running at 2866 r/min. At these conditions, the air is supplied to the cabin at 41.5ºC, the heating power is 4.2kW and the COP is 1.9. In the cooling mode, there are tests developed at a condenser supply air temperature of 45.4ºC with a velocity of 5.7m/s . The air is supplied to the vehicle cabin with a temperature of 14.6ºC with a flow rate of 508 kg/h , with a cooling capacity of 3.88 kW and a coefficient of performance of 1.8.