Methods and systems for providing control of a heat pump of a motor vehicle are presented. In one operating mode, speed of a heat pump compressor is controlled responsive to an outlet pressure of the heat pump compressor. In a second operating mode, speed of the heat pump compressor is controlled responsive to a pressure ratio between an inlet and an outlet of the heat pump compressor.

A method of controlling an air conditioner including activating a refrigeration cycle by driving an compressor; detecting a high pressure and a low pressure when the refrigeration cycle is activated; adjusting an operating frequency of the compressor based on the detected high pressure or low pressure of the refrigeration cycle; determining a current load of an inside space through a load detecting unit; determining a load level of the inside space by comparing the current load with a reference load; and determining the operating frequency of the compressor based on the determined load level.

A diagnostic instrument failure prediction and remediation system may include a compressed air system and a computer configured to analyze stored information regarding the compressed air system to predict likely failures of the compressed air system. Such analysis may utilize information such as duty cycle information for a compressor comprised by the compressed air system and pressure information for a pressure sensor for a compressed air system.

A diagnostic instrument failure prediction and remediation system may include a compressed air system and a computer configured to analyze stored information regarding the compressed air system to predict likely failures of the compressed air system. Such analysis may utilize information such as duty cycle information for a compressor comprised by the compressed air system and pressure information for a pressure sensor for a compressed air system.

The invention provides an air conditioner control method and device and an air conditioner. The air conditioner control device acquires a current temperature of a chilled water of a unit at a preset period; determine a target load of the unit, a target temperature of a chilled water and a target temperature of a cooling water based on a temperature of the chilled water set by a user and the current temperature of the chilled water; determine an evaporating parameter and a condensing parameter of the unit based on the target load of the unit, the target temperature of the chilled water and the target temperature of the cooling water; and determine operation parameters of a compressor based on the target load of the unit, the evaporation parameter and the condensation parameter. Therefore, the unit can operate based on the operation parameters.

A method of operating a heat exchanger system in which a compressor, which is drivable by a motor, is fluidly interposed between an evaporator and a condenser following receipt of a shutdown command is provided. The method includes positioning inlet guide vanes (IGVs) of the compressor in a first position in the event of at least one of a first precondition being in effect and the first and a second precondition both not being in effect. The method further includes positioning the IGVs in a second position in an event the first precondition is not in effect but the second precondition is in effect, ramping a speed of the compressor down until a third precondition takes effect, removing power from the motor and positioning the IGVs in the first position once power is removed from the motor.

There is provided a starting method for a cryocooler, the cryocooler including a compressor, a cold head, a high pressure line, and a low pressure line, the method including increasing a volume of the high pressure line when the cold head is at a room temperature, cooling the cold head from the room temperature to a cryogenic temperature while controlling an operation frequency of the compressor based on a pressure of the high pressure line or a differential pressure between the high pressure line and the low pressure line, after the volume of the high pressure line has been increased, decreasing the volume of the high pressure line after the cold head has been cooled to the cryogenic temperature, and maintaining the cold head at the cryogenic temperature after the volume of the high pressure line has been decreased.

If a first condition that an intermediate pressure corresponding to a pressure of an intermediate flow path is greater than a predetermined value is satisfied in an operation in which first, second, and third compressors are operated, the control unit executes a first action of increasing the number of revolutions of the third compressor.

A refrigeration circuit for a vehicle system includes a compressor, an evaporator, an accumulator, an inlet tube, an outlet tube, and a bypass valve. The inlet tube is configured to deliver refrigerant from the evaporator to the accumulator. The outlet tube is configured to deliver refrigerant from the accumulator to the compressor. The bypass valve is in fluid communication with the inlet and outlet tubes. The bypass valve has an open position and a closed position. The bypass valve is configured to direct refrigerant flow from the inlet tube to the outlet tube to bypass the accumulator when in the open position. The bypass valve is configured to restrict refrigerant from flowing from the inlet tube to the outlet tube when in the closed position.

A refrigeration cycle apparatus in which a refrigerant having potential for disproportionation reaction circulates a first refrigerant flow path connected between a discharge side of the compressor and the condenser; a second refrigerant flow path connected between the condenser and the expansion valve; a third refrigerant flow path connected between the expansion valve and a suction side of the compressor; a jetting unit; a pressure measuring unit; and a temperature measuring unit. The jetting unit is configured to jet the refrigerant drawn from the second refrigerant flow path or the third refrigerant flow path to at least one of the compressor, the first refrigerant flow path and the second refrigerant flow path when at least one of a measured value of the pressure measuring unit and a measured value of the temperature measuring unit exceeds an allowed value.