There is disclosed a vehicle air conditioner device of a so-called heat pump system to accurately perform efficient and comfortable heating of a vehicle interior. The vehicle air conditioner device includes a heating medium circulating circuit 23 which heats air to be supplied from an air flow passage 3 to a vehicle interior. A controller calculates a required heating capability TGQhtr of the heating medium circulating circuit to complement a shortage of an actual heating capability Qhp to a required heating capability TGQ of a radiator 4. The controller calculates a decrease amount ΔQhp of the actual heating capability Qhp from a difference ΔTXO between a refrigerant evaporation temperature TXO of an outdoor heat exchanger 7 and a refrigerant evaporation temperature TXObase in non-frosting, and adds the decrease amount ΔQhp to the required heating capability TGQhtr to execute the heating by the heating medium circulating circuit.

A refrigeration cycle device has a compressor, a radiator, a decompressor, an evaporator, a heat medium cooling evaporator, a cooling target device, a detector, and a controller. The heat medium cooling evaporator cools a cooling heat medium by performing a heat exchange between the refrigerant decompressed in the decompressor and the cooling heat medium. The cooling heat medium cools the cooling target device. The detector detects a subcooling state of the cooling target device having a temperature lower than or equal to a reference temperature. Upon the detection of the subcooling state in the cooling target device by the detector, the controller increases the degree of superheat of the refrigerant flowing out of the heat medium cooling heat exchanger as compared to the degree of superheat of the refrigerant flowing out of the heat medium cooling heat exchanger when the detector does not detect the subcooling state.

A vehicle air-conditioning device is a heat pump type vehicle air-conditioning device including an external heat exchanger that performs heat exchange between refrigerant flowing the inside thereof and outside air. With the vehicle air-conditioning device, a controller functions as a temperature-difference calculation unit that calculates the temperature difference ΔT between the refrigerant in a refrigerant flow path on the exit side of the external heat exchanger and the outside air, and in addition, the controller functions as a frost formation determination unit that determines that frost formation is caused on the external heat exchanger on the basis of the elapsed time to of a state in which the temperature difference ΔT is equal to or larger than a frost-formation temperature difference at which the frost formation may be caused on the external heat exchanger.

A refrigeration cycle device includes a compressor, a radiator, an air-conditioning heat exchanger, a cooling heat exchanger, an air-conditioning decompression unit, a cooler-unit decompression unit, a refrigerant flow rate detector, and a controller. The radiator is configured to radiate heat of refrigerant discharged from the compressor. The air-conditioning heat exchanger absorbs heat from air to evaporate the refrigerant. The cooling heat exchanger is arranged in parallel with the air-conditioning heat exchanger in the flow of refrigerant. The air-conditioning decompression unit adjusts a decompression amount of the refrigerant flowing into the air-conditioning heat exchanger. The cooler-unit decompression unit adjusts a decompression amount of the refrigerant flowing into the cooling heat exchanger. The controller controls the operation of the cooler-unit decompression unit so that the flow rate of the refrigerant detected by the refrigerant flow rate detector exceeds a predetermined reference flow rate.

A first evaporator cools air-conditioning air. A second evaporator cools an object. A first orifice unit and a second orifice unit are capable of changing a refrigerant amount of the first evaporator and the second evaporator, respectively. A control unit controls both the first orifice unit and the second orifice unit so that a temperature of the second evaporator approaches a target temperature. The control unit, in a first mode, performs control not to evaporate a refrigerant at the first evaporator and to evaporate the refrigerant at the second evaporator. The control unit, in a second mode, performs control to evaporate the refrigerant at both the first evaporator and the second evaporator. The control unit sets the target temperature in a first mode higher than that in a second mode.

Embodiments of the present invention provide a lubricant management system (100) in a heat flux management system for an electric vehicle (150), comprising a vehicle air conditioning circuit comprising a refrigeration cycle refrigerant circuit (6) comprising at least a heat pump condenser (17) in thermal communication with a heat source (19), first and second evaporators (31, 131) each associated with an expansion valve (29, 129), and a refrigerant compressor (11), wherein the components are fluidly connected to one another by a refrigerant line (9,45), an accumulator (37) having a lubricant storage capacity and comprising lubricant delivery means (38), the accumulator being fluidly coupled in the refrigerant line downstream of the first and second evaporators (31, 131) and upstream of the refrigerant compressor (11),

wherein the first evaporator and the second evaporator are fluidly connected in parallel downstream of the heat pump condenser (17) and upstream of the accumulator (37) and the associated expansion valves (29, 129) are operable to control a refrigerant flow rate through the first and the second evaporators (31, 131) sequentially to flush lubricant from the first and second evaporators to the lubricant storage capacity of the accumulator (37).

Embodiments of the present invention provide a heat recovery system for an electric vehicle (1), comprising first and second switchable heat sources (65, 19) and a control means (20) operable to selectively switch one of the heat sources into thermal communication with a compressor (11) in a thermodynamic cycling system (12), the thermodynamic cycling system being in thermal communication with a heat sink (59, 159); and a detection means (39, 71, T3) operable to detect a temperature differential between each of the switchable heat sources and a fluid entering the compressor; wherein the control means is operable (adapted, arranged) to switch one of the first and second switchable heat sources into thermal communication with the thermodynamic cycling system when a temperature differential is detected between the fluid entering the compressor in the thermodynamic cycling system and the heat available from the switchable heat source, the temperature differential being such that the compressor (11) is operable to upgrade low grade heat from the switchable heat source (65, 19) to a higher grade heat upon operation of the compressor (11).

Embodiments of the present invention provide a refrigerant management system (10) in a heat flux management system (1) for an electric vehicle (150) and a method of refrigerant management, the system comprising a vehicle air conditioning circuit comprising a heat pump circuit (4) with a heating function and a refrigeration cycle refrigerant circuit (6), the air conditioning circuit comprising a heat pump condenser (17) in thermal communication with a heat source (19), a refrigerant evaporator (25) in thermal communication with the heat source (19), an evaporator (31) associated with an expansion valve (29), and a refrigerant compressor (11), wherein the components are fluidly connected to one another by a refrigerant line (9), an accumulator (37) fluidly coupled in the refrigerant line downstream of the heat pump condenser (17), the refrigerant evaporator (25) and evaporator (31) and upstream of the refrigerant compressor (11),

wherein the air conditioning circuit is switchable between a heating mode in which the heat pump circuit (4) is in fluid communication with the compressor (11) and the heat pump condenser (17) is isolated from fluid communication with the compressor (11) and a cooling mode wherein the refrigerant circuit (6) is in fluid communication with the compressor by actuation of at least one valve (15, 21, 41, 47);
wherein the air conditioning circuit comprises a sensor (39) at the compressor inlet (239) operable to monitor refrigerant temperature and pressure; and
wherein when the system is in the heating mode, a shut off valve 41 in line between the heat pump condenser (17) and the accumulator (37) is operable to open to initiate a cold start mode in which a temporary fluid communication is provided between the heat pump condenser (17) and the accumulator in the heat pump circuit when:
the sensor (39) detects one or both of: a superheated refrigerant at the compressor inlet (239) and a temperature gradient of more than 3 Kelvin between ambient (T3) and the compressor inlet (239).

A control method of an air conditioning system for a vehicle includes a process A of determining whether arrival at a destination is imminent based on data detected from a data detecting unit by a controller and comparing a target temperature of an evaporator with an actual temperature of the evaporator in a state of cooling a vehicle interior while the vehicle is running. A process B includes controlling a blow motor, a compressor, and a vent discharge control unit by determining whether the evaporator is cleaned by the controller through process A, and controlling an outdoor air/indoor air mode operation unit by detecting external humidity and internal humidity. A process C includes controlling the blow motor and the outdoor air/indoor air mode operation unit by comparing an external temperature with the temperature of the evaporator.

This disclosure relates to a vehicle configured to prevent oil entrapment within a refrigerant system of the vehicle. This disclosure also relates to a corresponding method. An example vehicle includes a refrigerant system configured to circulate fluid including a mixture of refrigerant and oil relative to an evaporator, a controller, and an electronic expansion valve upstream of the evaporator. The electronic expansion valve is responsive to instructions from the controller, and the controller is configured to instruct the electronic expansion valve to open to prevent entrapment of oil within the evaporator or refrigerant lines.