Heat pump cooling-heating-dehumidifying system for electric vehicle
A heat pump cooling-heating-dehumidifying system for an electric vehicle includes a compressor for compressing refrigerant, a refrigerant throttling device for achieving pressure reduction of the refrigerant, an out-room air-heat exchanger for heat-exchanging between the refrigerant and outside air, a first in-room air-heat exchanger for heat-exchanging between the refrigerant and air to be introduced into a car room, a second in-room air-heat exchanger provided downstream of the first in-room air-heat exchanger for selectively heat-exchanging between the refrigerant and the air which was heat-exchanged at the first in-room air-heat exchanger, and a four-way switching valve for switching a flow passage of the refrigerant. In each of the cooling operation and the dehumidifying-heating operation of the system, the refrigerant is circulated through the flow passage in order of the compressor, the second in-room air-heat exchanger, the four-way switching valve, the out-room air-heat exchanger, the refrigerant throttling device, the first in-room air-heat exchanger, the four-way switching valve and then the compressor. On the other hand, during the heating operation of the system, the refrigerant is circulated through the flow passage in order of the compressor, the second in-room air-heat exchanger, the four-way switching valve, the first in-room air-heat exchanger, the refrigerant throttling device, the out-room air-heat exchanger, the four-way switching valve and then the compressor.