A method for controlling a thermal conditioning system is disclosed. The thermal conditioning system includes a refrigerant unit configured to circulate a refrigerant. The refrigerant circuit includes a main loop and a first bypass branch. The main loop includes a compression device, a first heat exchanger configured to exchange heat with a first heat transfer fluid, a first expansion device, and a first evaporator configured to exchange heat with an element of a powertrain of a motor vehicle via a second heat transfer fluid. The method includes determining a pressure of the refrigerant at the outlet of the first evaporator and controlling, depending on the determined pressure, at least one parameter so that the pressure of the refrigerant at the outlet of the first evaporator is below a predetermined pressure threshold.

There is disclosed a vehicular air-conditioning device of a so-called heat pump system which eliminates or decreases noise generated when an opening/closing valve opens at a changing time of an operation mode. The vehicular air-conditioning device executes a heating mode to let a refrigerant discharged from a compressor 2 radiate heat in a radiator 4, decompress the refrigerant by which heat has been radiated, and then let the refrigerant absorb heat in an outdoor heat exchanger 7, and a dehumidifying and heating mode to open a solenoid valve 22 in a state of the heating mode, decompress at least a part of the refrigerant flowing out from the radiator and then let the refrigerant absorb heat in a heat absorber 9. When the heating mode changes to the dehumidifying and heating mode, the controller decreases a radiator pressure or a pressure difference before and after the solenoid valve to a predetermined value or less, and then opens the solenoid valve 22.

The present invention relates to an air-conditioner system for a vehicle and a method for controlling the same, and more particularly, to an air-conditioner system for a vehicle and a method for controlling the same which can change a target superheat degree depending on variation in an amount of refrigerant discharged from a compressor, namely, gradually decrease the target superheat degree by stages as the amount of refrigerant discharged from the compressor decreases, and control an electronic expansion valve based on the target superheat degree dropping by stages, thereby preventing performance degradation of an air conditioner and stabilizing the system by restraining a change in the superheat degree in an area where an amount of refrigerant discharged from a compressor varies.

There is disclosed a vehicle air conditioner which is capable of enlarging an effective range of a dehumidifying and heating mode to environmental conditions and smoothly dehumidifying and heating a vehicle interior. A vehicle air conditioner 1 executes a dehumidifying and heating mode in which a controller lets a refrigerant discharged from a compressor 2 radiate heat in a radiator 4, and decompresses the refrigerant by which heat has been radiated and then lets the refrigerant absorb heat in a heat absorber 9 and an outdoor heat exchanger 7, the controller decreases an outdoor blower voltage FANVout of an outdoor blower 15 and decreases an air volume into the outdoor blower 15 in a case where a temperature Te of the heat absorber 9 is high even when the controller adjusts a valve position of an outdoor expansion valve 6 into a lower limit of controlling in a situation in which a temperature TCI of the radiator 4 is satisfactory.

There is disclosed a refrigeration device which is capable of inexpensively improving durability of an electronic expansion valve (an outdoor expansion valve) for use in a refrigerant circuit. A vehicle air conditioner 1 has a refrigerant circuit R including an outdoor expansion valve 6. The vehicle air conditioner includes a controller which controls energization to a coil of the outdoor expansion valve 6, and this controller executes operation limit control to limit an operation of the outdoor expansion valve 6 so that a temperature of the coil of the outdoor expansion valve 6 is not in excess of a predetermined value. The controller lengthens a control period of the outdoor expansion valve 6 and suppresses an operation amount of the outdoor expansion valve 6 within a predetermined limit value to limit a duty factor, in the operation limit control.

A vapor compression cooling system includes a centrifugal compressor(s) for compressing a primary fluid in a cycle including at least two compressions, and a control module for controlling the centrifugal compressor dependent upon at least a condition of a secondary fluid. The module controls a power of the centrifugal compressor by adjusting a speed of the motor driving the compressor and/or an opening of guide vanes associated with at least one impeller. The module may also control a pressure drop of a primary fluid moving through at least one expansion device. The at least two compressions may be made in parallel or in series. A related method includes compressing a primary fluid in a first and a second compression cycle and adjusting a parameter of the compressor dependent upon a calculated desired power of the compressor.

The present disclosure provides a method of controlling an air conditioning system of a vehicle. The method includes controlling a compressor to adjust a flow of refrigerant discharged from the compressor to obtain a target refrigerant pressure responsive to an actual refrigerant pressure upstream an inlet of an electric expansion valve. The method also includes controlling the valve to adjust the flow entering an evaporator to obtain a target evaporator surface temperature responsive to an actual evaporator temperature.

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.

Methods and systems for controlling a transport refrigeration system are provided. In one instance, the method includes identifying an operational mode change request for a heat exchanger unit of the transport refrigeration system. The method also includes preparing the transport refrigeration system for the operational mode change of the heat exchanger unit, wherein preparing the transport refrigeration system for the operational mode change of the heat exchanger unit includes performing a load control action, the load control action preventing a power source of the transport refrigeration system from at least one of operating outside of a predefined revolutions per minute (RPM) bandwidth and exceeding a predefined power limit of the power source. Also, the method includes changing the operational mode of the heat exchanger unit; and removing the load control action.

The present invention relates to a vehicular heat management system capable of inducing an increase in refrigerant superheat degree without unconditionally turning off a compressor when the refrigerant superheat degree on the discharge side of a chiller is less than or equal to a lower limit value. The vehicular heat management system includes: a compressor; a condensing heat exchanger; an expansion valve; an evaporation heat exchanger; and a control part configured to, when a refrigerant superheat degree on a discharge side of the evaporation heat exchanger is lowered to a predetermined lower limit value or less, control, step by step, at least two devices directly involved in the increase and decrease of the refrigerant superheat degree to increase the refrigerant superheat degree until the refrigerant superheat degree exceeds the lower limit value.