A transportation refrigeration unit TRU and power system. The TRU and power system including a compressor, an evaporator heat exchanger operatively coupled to the compressor, and an evaporator fan configured to provide return airflow over the evaporator heat exchanger. The system also includes a return air temperature RAT sensor disposed in the return airflow and configured measure the temperature of the return airflow, a TRU controller operably connected to the RAT sensor and configured to execute a process to determine an AC power requirement for the TRU based on at least the RAT; a generator power converter, configured to receive a first DC power from a generator and transmit a second three phase AC power to a power management system, the power management system configured to direct AC power to the TRU based on the AC power requirement.

A method for controlling torque of an air conditioner compressor is disclosed. In one example, the air conditioner compressor is a variable displacement compressor. The method may provide smooth transitions between different air conditioner compressor torques.

An air conditioner for a vehicle includes: a compressor that compresses a heat exchange medium; an internal heat exchanger that performs heat exchange between the heat exchange medium expelled from the compressor and air for air conditioning introduced inside a vehicle compartment; and an external heat exchanger that performs heat exchange between the heat exchange medium expelled from the internal heat exchanger and external air, wherein the air conditioner for a vehicle calculates a temperature difference between an external air temperature and a discharge port temperature of the external heat exchanger, calculates an average value of the temperature difference, and performs a defrosting operation which melts frost adhered to the external heat exchanger when an amount of change of the average value is equal to or greater than a first predetermined value.

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.

A method for controlling an air conditioner compressor of a vehicle is disclosed. The method includes adjusting a displacement command in response to an error between an expected air conditioner evaporator temperature and a measured or inferred air conditioner evaporator temperature, the displacement command is further adjusted via adding a value to the displacement command based on desired air conditioner evaporator temperature, the value determined apart from the error between the expected air conditioner evaporator temperature and the measured or inferred air conditioner evaporator temperature.

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.

An air conditioning system for use in a vehicle includes at least one compressor, a condenser disposed downstream of the at least one compressor and a plurality of evaporators disposed downstream of the condenser with first and second evaporators fluidly coupled to each other in parallel. The at least one compressor, the condenser, and the plurality of evaporators are fluidly connected by refrigerant lines to form a refrigerant circuit. The air conditioning system also includes a plurality of shut-off valves, with one shut-off valve installed at a refrigerant inlet and another shut-off valve installed at a refrigerant outlet of the first evaporator. The shut-off valves are controlled to prevent undesired collection of refrigerant in the first evaporator.

A cooling device for, for example, a cooling object has a refrigerant circuit with an evaporator, in which a cold air flow for the cooling object exchanges heat with the refrigerant, and a defrosting system for de-icing the evaporator. The defrosting system is controlled according to the degree of icing of the evaporator. The degree of icing of the evaporator is determined by the control unit of the defrosting system on the basis of the temperature of the cold air flow from the cooling object to the evaporator, the temperature and/or the operating pressure of the refrigerant upstream of the evaporator and at least one operating parameter 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.

A thermal management system for an electric vehicle that is used in the electric vehicle driven by an electric motor includes a refrigerant loop for an air conditioner, a refrigerant loop for a battery that allows a refrigerant for the battery to circulate among the battery, an evaporating unit and a heating device, and thermal management controlling means that, during charging of the battery, heats the refrigerant for the battery by using the heating device when temperature of the refrigerant for the battery is lower than target temperature of the refrigerant for the battery, and that allows the refrigerant for the air conditioner to circulate and to absorb heat from the refrigerant for the battery, in the evaporating unit, when the temperature of the refrigerant for the battery is higher than the target temperature of the refrigerant for the battery.