Heat flow management device for motor vehicles has a refrigerant circulation, a power train coolant circulation and a heating line heat carrier circulation. The refrigerant circulation includes a compressor, an indirect condenser, an expansion element, an ambient heat exchanger, an evaporator and a chiller. The power train coolant circulation includes a coolant pump, the chiller, an electric motor heat exchanger and a power train coolant radiator, wherein the heating line heat carrier circulation comprises a coolant pump, the indirect condenser and a heating heat exchanger, wherein the refrigerant circulation and the power train coolant circulation are directly thermally coupled with one another across the chiller. Refrigerant circulation and heating line heat carrier circulation are directly thermally coupled with one another across the indirect condenser. Power train coolant circulation and the heating line heat carrier circulation are only indirectly thermally coupled with one another across the refrigerant circulation.

A heat pump for a vehicle is provided in which the heat pump includes a compressor, an inner heat exchanger, an outer heat exchanger, a first expansion unit, a second expansion unit, an evaporator, an accumulator, a third heat exchanger, a first directional control valve, a second directional control valve, and a dehumidification line, and performs cooling, heating, defrosting, and dehumidifying operations according to the flow of a refrigerant.

A heat pump circuit has the following components when seen in the flow direction: a compressor; a condenser or gas cooler; a first coolant/air heat exchanger as a sub-cooler, via which the coolant dispenses heat; a first expansion element; a first coolant/air heat exchanger, via which the coolant absorbs heat from the ambient air; a second expansion element; and a third coolant/air heat exchanger, via which the coolant absorbs heat from the ambient air. The arrangement of the heat exchanger is in front of the drive engine relative to the travel direction. The danger of the ambient heat exchanger freezing is minimized. With this arrangement.

An acoustic wave generation unit oscillates working fluid of 35 atm or less so as to generate acoustic waves with a frequency in a range from 50 Hz or more and 500 Hz or less. A heat/acoustic wave conversion component has a partition wall of 5.0 W/mK or less between two end faces which defines a plurality of cells of 620 cells/cm.sup.2 or more and 3100 cells/cm.sup.2 or less. A heat exchanger disposed close to one end face receives heat from a first external air flowing into the heat exchanger and gives the heat to the one end face so as to flow out a cold air. Another heat exchanger disposed close to the other end face receives heat from the other end face and gives the heat to a second external air flowing into the another heat exchanger so as to flow out a warm air.

A vehicular heat management system includes: a refrigerant circuit; a first heat medium circuit in which a heat medium circulates and exchanges heat with a low-pressure side refrigerant of the refrigerant circuit; a second heat medium circuit in which a heat medium circulates and exchanges heat with a high-pressure side refrigerant of the refrigerant circuit; and a switching device configured to switch a mode between a communicating mode in which the first heat medium circuit and the second heat medium circuit are coupled and a non-communicating mode in which the first heat medium circuit and the second heat medium circuit are not coupled on the basis of a temperature of the heat medium in the first heat medium circuit.

A refrigeration cycle apparatus includes: an electric compressor that compresses and discharges refrigerant; a heating heat exchanger that heats a fluid by high pressure refrigerant discharged from the electric compressor as a heat source; a decompressor that decompresses the refrigerant flowing from the heating heat exchanger; an evaporator that evaporates the refrigerant decompressed by the decompressor; and a rotational speed controller that controls a rotational speed of the electric compressor. The rotational speed controller is configured to reduce an upper limit value of the rotational speed of the electric compressor in accordance with an increase in a pressure ratio of a high-pressure side refrigerant pressure of refrigerant within a range from a discharge port of the compressor to an inlet side of the decompressor to a low-pressure side refrigerant pressure of refrigerant within a range from an outlet side of the decompressor to a suction port of the compressor.

A method for defrosting a heat exchanger of a refrigeration circuit is provided. The method includes monitoring a compressor suction parameter at a suction line to a compressor of the refrigeration circuit. The method also includes determining a compressor suction parameter threshold. Also, the method includes initiating a defrost mode of the refrigeration circuit when the compressor suction parameter is less than or equal to the compressor suction parameter threshold.

There is disclosed a vehicle air conditioning device of a heat pump system which delays proceeding of frosting onto an outdoor heat exchanger, thereby eliminating or inhibiting deterioration of a heating capability due to the frosting. The vehicle air conditioning device executes a heating mode in which a controller lets a refrigerant discharged from a compressor 2 radiate heat in a radiator 4, decompresses the refrigerant by which heat has been radiated, and then lets the refrigerant absorb heat in an outdoor heat exchanger 7, and on the basis of a difference TXO=(TXObaseTXO) between a refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 in non-frosting and a refrigerant evaporation temperature TXO of the outdoor heat exchanger 7, the controller corrects a target subcool degree TGSC that is a target value of a subcool degree of the refrigerant in the radiator 4 in an increasing direction in accordance with increase of the difference TXO.

A vehicle air conditioner includes an air-heating switching portion that switches between a first air-heating mode of heating ventilation air by a heating heat exchanger and a second air-heating mode of heating the ventilation air by a condenser. The vehicle air conditioner includes a heat-exchange adjustment portion that adjusts an amount of heat exchange between the high-pressure refrigerant and the ventilation air in the condenser, and a heat-exchange control unit that controls the heat-exchange adjustment portion. The heat-exchange control unit controls the heat-exchange adjustment portion to decrease the amount of heat exchange between the high-pressure refrigerant and the ventilation air in the condenser if a condition satisfies in which temperature of the refrigerant in the condenser is equal to or lower than temperature of the ventilation air heated by a heating heat exchanger before passing through the condenser, when the air-heating switching portion switches from the first air-heating mode to the second air-heating mode.

A heater core for exchanging heat between a coolant and ventilation air to be blown into a vehicle interior is disposed in a high-pressure side heat-medium circulation circuit that allows for circulation of the coolant heated by a heat pump cycle. A radiator for exchanging heat between at least a part of the coolant flowing out of the heater core and a low-pressure refrigerant in the heat pump cycle is disposed in a low-pressure side heat-medium circulation circuit coupled to the high-pressure side heat-medium circulation circuit. Thus, excessive heat included in the coolant flowing out of the heater core and which is not used to heat the ventilation air can suppress frost formation on an exterior heat exchanger and can also defrost the exterior heat exchanger.