A refrigerant cycle device includes a compressor, a radiator, a first expansion valve, a second expansion valve, a first evaporator, a second evaporator, and a controller. The controller is configured to switch between a first evaporator priority control and a second evaporator priority control. During the first evaporator priority control, the controller controls a throttle opening of the second expansion valve based on at least one of a temperature of a first evaporator, a temperature of a refrigerant flowing through the first evaporator, and a temperature of an air having exchanged heat in the first evaporator. During the second evaporator priority mode, the controller controls the throttle opening based on a refrigerant state of the second evaporator. When the at least one of the temperatures is equal to or greater than a switching temperature, the second priority mode is switched to the first priority mode.

An apparatus and method for measuring air conditioning output temperature to ensure the proper amount of refrigerant for recharging or servicing a coolant system, such as an automobile coolant system, are disclosed. In one embodiment, the apparatus includes a measurement display for viewing the temperature of air conditioning output inside a vehicle while the user is outside the vehicle recharging or servicing a coolant system. The measurement display is in communications with a temperature sensor measuring the air temperature at a vent inside the vehicle to allow a user to ensure proper recharging of the coolant system.

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.

A vehicle air conditioner capable of making a determination that the dehumidification is unnecessary in a vehicle interior early to make a prompt transition from a dehumidifying mode to a heating mode and reduce power consumption is provided. A control device executes a heating mode to let a refrigerant discharged from a compressor 2 radiate heat in a radiator, decompress the refrigerant, and then let the refrigerant absorb heat in an outdoor heat exchanger 7, and a dehumidifying mode to let the refrigerant flow into the outdoor heat exchanger without flowing to the radiator to radiate heat therein, decompress the refrigerant, and then let the refrigerant absorb heat in a heat absorber 9 and let an auxiliary heater 23 generate heat. The control device shifts from the dehumidifying mode to the heating mode on the basis of the heat absorber suction air temperature Tevain being lowered more than a target heat absorber temperature TEO.

A refrigeration system includes a generator, a power generation engine, a refrigerator, an electric power converter, an output control unit, and a characteristic estimation unit that estimates a refrigerator characteristic of a refrigerator according to an outside air temperature and a temperature of a cooling target space. The refrigeration system includes an output calculation unit that calculates a drive output as a target drive output that optimizes an energy efficiency of the entire system based on the refrigerator characteristic estimated by the characteristic estimation unit, an engine characteristic of the power generation engine, and a generator characteristic of the generator. Further, the output control unit controls the drive output to approach the target drive output calculated by the output calculation unit.

A vehicle air-conditioning apparatus is provided which is capable of efficiently eliminating or suppressing fogging of a window while comfortably heating a vehicle interior. A controller changes and executes a heating mode to let a refrigerant discharged from a compressor 2 radiate heat in a radiator 4, and a dehumidifying and heating mode to let the refrigerant discharged from the compressor radiate heat in the radiator and let the refrigerant absorb heat in a heat absorber 9. When the temperature of air blown out to the vehicle interior is not capable of reaching a target outlet temperature in the dehumidifying and heating mode, the controller actuates a window heater 35 heating a front window 30 and shifts to the heating mode.

A transportation refrigeration unit TRU (26) and power system. The TRU (26) and power system including a compressor (58) configured to compress a refrigerant, an evaporator heat exchanger (76) operatively coupled to the compressor (58), and an evaporator fan (98) configured to provide return airflow and flow the return airflow over the evaporator heat exchanger (76). The system also includes a return air temperature RAT sensor (142) disposed in the return airflow and configured measure the temperature of the return airflow, a TRU controller (82) operably connected to the RAT sensor (142) and configured to execute a process to determine an AC power requirement for the TRU (26) based on at least the RAT (142), a generator power converter (164a) configured to provide a second DC power (165b), an energy storage system (150) configured to receive the second DC power (165) and provide a three phase AC power (157) to a power management system (124).

A transportation refrigeration unit TRU and power system. The TRU (26) and power system including a compressor (58), an evaporator heat exchanger (76) operatively coupled to the compressor (58), and an evaporator fan (98) configured to provide return airflow over the evaporator heat exchanger (76). The system also includes a return air temperature RAT sensor (142) disposed in the return airflow (134) and configured measure the temperature of the return airflow (134), a TRU controller (82) operably connected to the RAT sensor (142) and configured to execute a process to determine an AC power requirement for the TRU (26) based on at least the RAT (142); a generator power converter (164), configured to receive a first DC power (163a) from a generator and transmit a second three phase AC power (165) to a power management system (124), the power management system (124) configured to direct AC power the TRU (26) based on the AC power requirement.

An air conditioning system, a vehicle and a method of controlling the vehicle with a vehicle air conditioning system are provided. The vehicle air conditioning system has a refrigeration circuit having a compressor, a condenser, and an evaporator in sequential fluid communication, with a valve assembly and a battery chiller positioned for parallel flow with the evaporator. A cooling circuit in the vehicle has a chiller. A controller is configured to, in response to a temperature of the evaporator being less than a first predetermined value and the compressor operating at a predetermined speed, open the valve assembly to divert a portion of refrigerant through the chiller and away from the evaporator. The refrigerant may be diverted, for example, to raise the temperature of the evaporator and/or prevent cycling of the compressor.

Methods and systems are provided for an air conditioning system. An example method of determining current through a compressor suction valve in a vehicle air conditioning (AC) system is provided, the AC system comprises an evaporator fan and the method includes determining the speed of the evaporator fan and determining the current through the suction valve based on the speed of the evaporator fan.