A vehicle thermal management system including a refrigerant circuit, a coolant circuit, a chiller, and a controller is provided. The refrigerant circuit may include an electric air conditioning (eAC) compressor and a pressure sensor. The coolant circuit may include a high-voltage battery. The chiller selectively thermally links the circuits. The controller may be programmed to, responsive to receipt of a sensor signal indicating refrigerant pressure exiting the eAC compressor is greater than a high threshold, output a pressure sensor fault error indicating the pressure sensor is faulty. The system may further include a timer to monitor operational timing of the eAC compressor. The controller may be further programmed to direct the system to operate without monitoring the eAC compressor responsive to the timer indicating the eAC compressor has been off for a time-period less than a time threshold reflective of the eAC compressor not being in an at rest state.

A vehicle air-conditioning device is provided which is capable of eliminating or suppressing vibration and noise generated due to the application of a counterpressure to an opening/closing valve. The vehicle air-conditioning device includes a refrigerant circuit R having a compressor 2, a radiator 4 to perform heat exchange between a refrigerant and air, an outdoor heat exchanger 7, a heat absorber 9, and a solenoid valve 40. The compressor 2 and the solenoid valve 40 are controlled to air-condition a vehicle interior. A decompression speed at a refrigerant inflow side of the solenoid valve when the compressor 2 is stopped and the solenoid valve 40 is closed is faster than that at a refrigerant outflow side thereof. When operation is stopped from a state in which the compressor 2 is operating with the solenoid valve 40 being in an opened state, the opened state of the solenoid valve 40 is maintained even after the compressor 2 is stopped.

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.

Systems and methods for heating and cooling a vehicle are disclosed herein. In one embodiment, a method for heating and cooling the vehicle includes: running a compressor of an air-conditioning system; and sensing the temperature inside the cab of the vehicle. The method further includes, closing a path of refrigerant to the compressor by a solenoid valve, pumping-down refrigerant by the compressor, and deactivating the compressor when a lower set point of the temperature inside the cab is reached. The method also includes opening the path of refrigerant to the compressor by a solenoid valve, sensing pressure of refrigerant at an inlet of the compressor by a pressure sensor, and activating the compressor based on a signal from the pressure sensor when an upper set point of temperature inside cab is reached.

In at least one embodiment, a vehicle climate control system including a compressor, at least one sensor, and at least one controller is provided. The compressor is configured to circulate fluid about a refrigerant loop. The at least one sensor is configured to provide a signal indicative of a pressure of the fluid in the refrigerant loop. The at least one controller is programmed to control a first valve to open to enable the fluid to flow to an evaporator for a battery responsive to the pressure of the fluid being greater than a predetermined pressure level to reduce the pressure of the fluid.

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 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 vehicle air conditioner which is capable of inhibiting liquid return to a compressor and generation of noise due to bumping in an accumulator. There are executed a heating mode to close a solenoid valve 17, open a solenoid valve 21, let a refrigerant radiate heat in a radiator 4, decompress the refrigerant through an outdoor expansion valve 6, let the refrigerant absorb heat in an outdoor heat exchanger 7, and send the refrigerant to an accumulator 12, and a dehumidifying and heating mode to open the solenoid valve 17, close the solenoid valve 21, decompress the refrigerant through an indoor expansion valve 8, let the refrigerant absorb heat in a heat absorber, and generate heat in an auxiliary heater 23. A valve position of the outdoor expansion valve 6 is reduced for a predetermined period of time before shifting from the heating mode to the dehumidifying and heating mode.

There is disclosed a vehicle air conditioning device which is capable of judging, as early as possible, refrigerant shortage, for example, due to leakage of refrigerant with elapse of time, and protecting a compressor. The vehicle air conditioning device includes a compressor 2, a radiator 4, an outdoor expansion valve 6, and a heat absorber 9. A control device possesses normal time data indicating a relation between a suction refrigerant temperature Ts and a discharge refrigerant temperature Td of the compressor when a refrigerant circuit R is charged with a sufficient amount of the refrigerant. The control device calculates, from the normal time data, a discharge refrigerant temperature estimated value Tdst at normal time on the basis of the current suction refrigerant temperature Ts, and compares the value and the current discharge refrigerant temperature Td, thereby judging refrigerant shortage of the refrigerant circuit.

Provided is a control device that performs protection control of a compressor without malfunction. The control device activates protection control on a compressor included in a refrigerant circuit based on a pressure value detected by a pressure sensor that is installed at a low-pressure side of the refrigerant circuit and a change over time of the pressure value.