The present invention primarily relates to a heat exchanger including a heat-exchange surface intended to be traversed by an air flow including at least one four-way valve that is able to adopt a first position in which the four-way valve fluidically connects one of the inlet orifices of a first inlet manifold to an inlet line and one of the outlets of a second outlet manifold to an outlet line, and at least a second position in which the four-way valve fluidically connects one of the inlet orifices of the first inlet manifold to the outlet line and one of the outlets of the second outlet manifold to the inlet line.

A heat pump includes a refrigerant loop. The refrigerant loop includes a first heat exchanger, a first region of a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a compressor, a vapor generator, an accumulator, a first expansion valve, and a first three-way valve. The compressor includes a low-pressure inlet, a mid-pressure inlet, and an outlet. The vapor generator is positioned downstream of the outlet of the compressor and upstream of both the low-pressure inlet and the mid-pressure inlet. The vapor generator includes a first region and a second region. The accumulator is positioned immediately upstream of the compressor. The accumulator includes an inlet and an outlet. The first expansion valve is positioned upstream of the accumulator. The first expansion valve includes an inlet and an outlet. The first three-way valve is positioned immediately downstream of the first expansion valve and immediately upstream of the accumulator.

A main core portion (6) performing heat exchange between air and a refrigerant, a receiver tank (8) into which the refrigerant having flowed through the main core portion flows, a sub-cool core portion (10) for sub-cooling a liquid refrigerant having flowed through the receiver tank by heat exchange with air, a first flow path (36b, 68, 78) through which a refrigerant flows in order of the main core portion, the receiver tank, and the sub-cool core portion, a second flow path (36a, 36c, 68, 72) through which the refrigerant flows in order of the main core portion and the sub-cool core portion by bypassing the receiver tank, and flow-path switching means (82) for switching between the first flow path and the second flow path.

There is disclosed an air-conditioning device of a so-called heat pump system which acquires comfortable heating of a vehicle interior by preventing or inhibiting frost formation to an outdoor heat exchanger. A controller calculates a maximum heating capability predicted value without frosting QmaxNfst as a target value of a maximum heating capability which can be generated by a radiator 4 in a range in which an outdoor heat exchanger 7 is not frosted, and controls heating by the radiator 4 and heating by a heating medium-air heat exchanger 40 of a heating medium circulating circuit 23 on the basis of the maximum heating capability predicted value without frosting QmaxNfst and a required heating capability Qtgt which is the heating capability required for the radiator 4 to achieve the required heating capability Qtgt without causing frost formation to the outdoor heat exchanger 7.

This air conditioning device for a vehicle comprises: a refrigeration cycle having a compressor, a condenser, an expansion valve, and an evaporator through which refrigerant sequentially flows; a high-temperature heat medium circuit in which a high-temperature heat medium that has been heat-exchanged with the refrigerant in the condenser circulates; a low-temperature heat medium circuit in which a low-temperature heat medium that has been heat-exchanged with the refrigerant in the evaporator circulates; a connection line for connecting the high-temperature heat medium circuit and the low-temperature heat medium circuit; a plurality of heat exchangers outside the vehicle that allow introduction of the heat medium; and a switching unit capable of switching modes for each of the plurality of heat exchangers outside the vehicle, among a mode for connecting to the high-temperature heat medium circuit, a mode for connecting to the low-temperature heat medium circuit, and a mode for not connecting to either of the high-temperature heat medium circuit and the low-temperature heat medium circuit.

A refrigerant cycle (16) for cooling as a prototype is provided with: an internal condenser (8) connected to a discharge circuit of an electric compressor (9) and disposed on a downstream of an internal evaporator (7) of an HVAC unit (2); a first heating circuit (18) connected to a receiver (11) through a switching unit (17) arranged on an inlet side of the external condenser (8); and a second heating circuit (23) connected between an outlet side of the receiver (11) and a suction side of the electric compressor (9) and provided with a second expansion valve (20) and an external evaporator (21). A heat pump cycle (24) for heating is formed by a second heating circuit (23) including the electric compressor (9), the internal condenser (8), the switching unit (17), the first heating circuit (18), the receiver (11), the second expansion valve (20), and the external evaporator (21).

A heat pump device includes an air conditioning control device configured to switch the heat pump device among a plurality of operation modes including an air-heating operation mode in which an indoor heat exchanger serves as a radiator and an outdoor heat exchanger serves as a heat absorber, and an air-cooling operation mode in which the indoor heat exchanger serves as a heat absorber and the outdoor heat exchanger serves as a radiator. The air conditioning control device switch a refrigerant pipe such that refrigerant is, in the air-cooling operation mode, supplied to part of the outdoor heat exchanger serving as a refrigerant inlet in the air-heating operation mode.

There is disclosed a vehicle air-conditioning device in which a heating qualification by gas injection can sufficiently be obtained. The vehicle air-conditioning device comprises a compressor 2 which compresses a refrigerant, an air flow passage 3 through which air to be supplied into a vehicle interior flows, a radiator 4 disposed in the air flow passage to let the refrigerant radiate heat, a heat absorber 9 disposed in the air flow passage to let the refrigerant absorb heat, an outdoor heat exchanger 7 disposed outside the vehicle interior to let the refrigerant radiate or absorb heat, and a controller. The controller executes a heating mode in which the refrigerant discharged from the compressor 2 radiates heat in the radiator 4 and the refrigerant by which heat has been radiated is decompressed and then absorbs heat in the outdoor heat exchanger 7. The vehicle air-conditioning device comprises an injection circuit 40 which distributes a part of the refrigerant flowing out from the radiator 4 to return the refrigerant to the middle of compression by the compressor 2, and the injection circuit 40 has an expansion valve 30, and a discharge side heat exchanger 35 which performs heat exchange between the refrigerant decompressed by the expansion valve 30 and the refrigerant discharged from the compressor 2 before flowing into the radiator 4.

There is disclosed a vehicle air-conditioning device in which a heating qualification by gas injection can sufficiently be obtained. The vehicle air-conditioning device comprises a compressor 2 which compresses a refrigerant, an air flow passage 3 through which air to be supplied into a vehicle interior flows, a radiator 4 disposed in the air flow passage to let the refrigerant radiate heat, a heat absorber 9 disposed in the air flow passage to let the refrigerant absorb heat, an outdoor heat exchanger 7 disposed outside the vehicle interior to let the refrigerant radiate or absorb heat, and a controller. The controller executes a heating mode in which the refrigerant discharged from the compressor 2 radiates heat in the radiator 4 and the refrigerant by which heat has been radiated is decompressed and then absorbs heat in the outdoor heat exchanger 7. The vehicle air-conditioning device comprises an injection circuit 40 which distributes a part of the refrigerant flowing out from the radiator 4 to return the refrigerant to the middle of compression by the compressor 2, and the injection circuit 40 has an expansion valve 30, and a discharge side heat exchanger 35 which performs heat exchange between the refrigerant decompressed by the expansion valve 30 and the refrigerant discharged from the compressor 2 before flowing into the radiator 4.

A vehicular air conditioner includes a dehumidifying and cooling mode, in which a heating capability of a radiator can be acquired without increasing a flow rate of a refrigerant into a heat absorber. The dehumidifying and cooling mode lets the refrigerant discharged from a compressor (2) radiate heat in a radiator (4) and an outdoor heat exchanger (7), decompress the refrigerant by which heat has been radiated, and then let the refrigerant absorb heat in a heat absorber (9). The vehicular air conditioner includes an injection circuit (40) which distributes a part of the refrigerant flowing out from the radiator (4) to return the part of the refrigerant to the compressor (2). In the dehumidifying and cooling mode, the injection circuit (40) is operated to return the refrigerant to the compressor (2) when there is a predetermined radiator capability shortage condition and/or predetermined low outdoor air temperature startup condition.