In a method for operating a compressor (22) having an inlet (26) and an outlet (28), the method includes: running the compressor to compress a fluid; shutting down (422) the compressor; determining (420) a condition-dependent threshold restart pressure difference (threshold) across the compressor; relieving the pressure difference to reach the threshold; and, after the threshold is reached, restarting (434) the compressor.

The present disclosure provides a system and a method for monitoring an operation of a vapor compression cycle. The method comprises collecting digital representation of observed variables of the operation of the vapor compression cycle over multiple instances of time and executing a constrained ensemble Kalman smoother for each instance of time to estimate the state variables of the vapor compression cycle for each instance of time. The constrained ensemble Kalman smoother updates the state variables over a sequence of time instances within a smoothing window by solving a series of constrained optimization problems in a range of a covariance, for which constraints are enforced for every variable in the smoothing window for every instance of the constrained optimization problems. The method further comprises outputting, based on the estimates of the state variables, estimates of variables of the vapor compression cycle at each instance of time.

A system and method of controlling temperature of a medium by refrigerant vaporization, the system including a container, at least one a refrigerant reservoir having at least one reservoir section that includes a wall with an exterior surface structured to be thermally coupled with a volume of the medium in the container and to provide a volume of medium thermal coverage in the container, a vapor pressure apparatus to provide regulation of refrigerant vapor pressure in the at least one refrigerant reservoir, whereby the refrigerant reservoir forms a vapor space in each of the at least one reservoir section in response to receiving refrigerant and to the vapor pressure apparatus regulation of vapor pressure above the refrigerant to enable refrigerant vaporization at or near a selected temperature of the volume of medium in the container that is thermally coupled to the respective reservoir section.

The present disclosure relates to a heating, ventilation, and air conditioning (HVAC) unit having a vapor compression circuit including a compressor and a heat exchanger. The HVAC unit includes a controller configured to provide a first signal to control the compressor, and provide a second signal to control a variable speed fan associated with the heat exchanger based on a target speed. The HVAC unit further includes a pressure activated device coupled between the controller and the compressor, wherein the pressure activated device is configured to temporarily block the first signal from the controller while a refrigerant pressure within the vapor compression circuit is greater than a threshold value. In response to determining that the pressure activated device has blocked the first signal for at least a threshold time period, the controller is configured to both deactivate the first signal and provide the second signal for an equilibration time.

Methods and systems for detecting and correcting improper operation of a compressor in a refrigeration system and/or an HVAC system include a component level detection and prevention and a system level detection and prevention. The system level detection and prevention can be a backup or a confirmation of the component level detection and prevention. The component level detection and prevention can detect and prevent improper compressor operation within a predetermined time so that the compressor's operation period in an improper direction can be minimized, thereby minimizing wear and damage to the 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.

Provided is a refrigeration apparatus capable of, even in occurrence of a refrigerant leak, suppressing the extent of the refrigerant leak in continuously operating a usage unit other than a usage unit at which the refrigerant leak occurs. When one of a first usage unit and a second usage unit connected in parallel via a liquid-refrigerant connection pipe and a gas-refrigerant connection pipe is in a refrigerant leak situation satisfying a predetermined condition, a controller closes an on-off valve of a leak unit, the on-off valve being disposed on the side of the liquid-refrigerant connection pipe with respect to a usage-side heat exchanger, continues to open an on-off valve of a non-leak unit, the on-off valve being disposed on the side of the liquid-refrigerant connection pipe with respect to a usage-side heat exchanger, and reduces a refrigerant pressure at a portion on the side of the liquid-refrigerant connection pipe with respect to each on-off valve below a refrigerant pressure at the portion at a time when the refrigerant leak situation satisfies the predetermined condition.

A method for controlling a vapour compression system (1) is disclosed, the vapour compression system (1) comprising at least one compressor (2, 16), a heat rejecting heat exchanger (3), a high pressure expansion device (4, 15, 17), a receiver (5), an evaporator expansion device (6), an evaporator (7) and a gas bypass valve (8), arranged in a refrigerant path. It is registered that the gas bypass valve (8) is malfunctioning or saturated, and a pressure value for a pressure prevailing inside the receiver (5) is obtained. Finally, the vapour compression system (1) is controlled in order to control a gaseous refrigerant supply to the receiver (5) to adjust the pressure prevailing inside the receiver (5) to reach a target pressure level.

An economizer control system includes a compressor including a compression area, a piston chamber, and an economizer inlet configured to receive economizer vapor into the compression area via a flow path that extends between the economizer inlet and the compression area. At least a portion of the flow path traverses the piston chamber. The economizer control system also includes a piston disposed within the piston chamber and configured to contact the economizer vapor. The piston is moveable between an open position that opens the flow path and a closed position that closes the flow path. Additionally, the economizer control system includes a biasing system configured to apply force to the piston to bias the piston toward the closed position.

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.