An air-conditioning system, in particular for a motor vehicle, having a refrigerant circuit, which has an evaporator and a condenser, and a coolant circuit, wherein the refrigerant circuit and the coolant circuit are thermally coupled to each other, in particular in the region of the evaporator and in the region of the condenser, wherein the coolant circuit has a line system having junctions, wherein a heating body, a cooling body, an outside heat exchanger, an additional heat source, a first bypass line, and a second bypass line are integrated into the line system, wherein the first bypass line bypasses the additional heat source from the cooling body to the outside heat exchanger, and/or the second bypass line bypasses the additional heat source from the heating body to the outside heat exchanger.

A vehicle heat management device that includes: a pump that circulates cooling water around a cooling water circulation path; an air blower that blows air through a radiator toward an exterior heat exchanger of an air-conditioning device of a vehicle; and a de-icing controller that, in a case in which an estimated ice adhesion amount on the exterior heat exchanger is a predetermined value or greater, starts first de-icing control by using a pump to circulate cooling water in a flow path including a second flow path, in the state in which a first flow path and the second flow path are isolated from each other by a first switching section, and using the air blower to blow air through the radiator toward the exterior heat exchanger.

There is disclosed an air conditioning device for vehicle in which in a defrosting mode to defrost an outdoor heat exchanger, the defrosting of the outdoor heat exchanger can be achieved without hindrance while maintaining heating of a vehicle interior. A refrigerant discharged from a compressor 2 radiates heat in a radiator 4 and the refrigerant by which heat has been radiated is decompressed and then absorbs heat in an outdoor heat exchanger 7 to heat the vehicle interior. The air conditioning device for vehicle includes an injection circuit 40 which distributes a part of the refrigerant flowing out from the radiator 4 to return the part to the compressor 2. When a controller 32 passes the high-temperature refrigerant through the outdoor heat exchanger 7 to perform defrosting, the controller operates the injection circuit 40 to return the refrigerant to the compressor 2.

A vehicle air conditioner comprising a heat pump device including a compressor that compresses refrigerant, first and second heat exchangers disposed inside the vehicle cabin within an interior air-conditioning unit, and a pressure reducing valve. The vehicle air conditioner further comprises an air-conditioning controller which controls the heat pump device and interior air-conditioning unit, an exterior heat exchanger temperature sensor and a degree-of-heating requested detecting section. If the quantity of heat absorbed by the exterior heat exchanger has decreased, the controller operates the heat pump device to operate in a mode in which a refrigerant discharged from the compressor flows through the first and second heat exchangers, bypasses the exterior heat exchanger, and then is sucked into the compressor, and a second mode in which the refrigerant is flow throughs the first heat exchanger and is bypassed around the second and exterior heat exchanger after pressure has been reduced.

A heat pump vehicle air conditioning system passes hot gas to a condenser and a vaporizer for the vehicle cabin exterior. Even with low outside air temperature, it can efficiently defrost using the cooling cycle. The system includes a cabin-interior condenser downstream of a cabin-interior vaporizer within an HVAC unit connected via refrigerant switching means to a cooling cycle. Cooling is accomplished by a compressor, cabin-exterior condenser, first decompression unit with on-off valve function, the cabin-interior vaporizer, and an accumulator. A cabin-exterior vaporizer disposed outside of the vehicle cabin is connected with a second decompression unit via an on-off valve function and to the exit-side liquid refrigerant pipe of the cabin-exterior condenser. A bypass circuit having a third decompression unit with on-off function is connected between the accumulator and the exit-side liquid refrigerant pipe of the cabin-exterior condenser.

There is disclosed a vehicle air conditioner of a heat pump system in which there is prevented or inhibited frosting to an outdoor heat exchanger when heating in a vehicle interior is beforehand performed during plug-in, thereby achieving comfortable heating in the vehicle interior during running and also extending a running distance. The vehicle air conditioner includes an injection circuit 40 which distributes a refrigerant flowing out from a radiator 4 to return the refrigerant to the middle of compression by a compressor 2, a controller has frosting estimation means for estimating the frosting to an outdoor heat exchanger 7, and when a heating mode is executed in a state where a power is supplied from an external power source to the compressor 2 or to a battery which supplies the power to drive the compressor 2, the injection circuit 40 performs gas injection to the compressor 2 in a case where the frosting to the outdoor heat exchanger 7 is predicted.

An air conditioning device has a blower, a compressor, a radiator, a decompressor, a heat absorber, and a controller. The compressor compresses and discharges a refrigerant. The radiator dissipates a heat of the refrigerant to the air thereby heating the air. The decompressor decompresses the refrigerant after the heat of the refrigerant is dissipated in the radiator. The refrigerant decompressed in the decompressor absorbs heat from outside air in the heat absorber. The controller determines whether the heat absorber is in a frosted state in which a frost is formed on the heat absorber or whether the heat absorber is in an estimated frosted state in which a frost is possibly formed on the heat absorber. The controller performs a frost delay control to delay a formation of the frost when the controller determines that the heat absorber is in the frosted state or the estimated frosted state.

A transport refrigeration unit includes a combustion engine system having a turbo-charger constructed and arranged to receive air in a cold state and expel the air in a compressed hot state, an evaporator, and a defrost heat exchanger constructed and arranged to receive the air in the compressed hot state and expel the air in a compressed cooled state for defrosting the evaporator. In operation, the unit may be capable of controlling a defrost temperature and/or controlling the temperature of the air entering a combustion engine of the engine system for combustion by controlling the volume of air flow between the defrost heat exchanger and a charge air cooler of the engine system.

A transport refrigeration unit (26) includes a dedicated combustion engine system (56), an evaporator (50), and a de-frost heat exchanger (78) constructed and arranged to flow engine coolant in a heated state for defrosting the evaporator (50) when the dedicated combustion engine system (56) is not running. A method of operation may include running a defrost cycle of the unit (26) utilizing the heated coolant whether or not an associated internal combustion engine (66) of the unit (26) is running.

If an exterior heat exchanger is sensed to be frosted while a heat pump device is operating in a first heating operation mode in which two interior heat exchangers are used, the operation modes are switched into a second heating operation mode in which one interior heat exchanger is used, and then switched into a defrosting operation mode.