A screw compressor system for a utility vehicle has at least one screw compressor, at least one screw compressor drive, at least one temperature probe and at least one control and regulation unit. The control and/or regulation unit is connected to the screw compressor drive and to the temperature probe and is designed and configured such that it controls, in accordance with a temperature threshold signal obtained from the temperature probe, the screw compressor drive with respect to a rotational speed.

A cooling system includes a subcooling heat exchange assembly, which controls magnitude of subcooling of refrigerant circulated through the cooling system. The subcooling heat exchange assembly includes a first fluid line fluidly coupled to an output of a condenser to enable a first portion of the refrigerant output from the condenser to flow through the first fluid line; a second fluid line fluidly coupled to the output of the condenser to enable a second portion of the refrigerant output from the condenser to flow through the second fluid line; and an expansion valve disposed along the second fluid line, in which the expansion valve exerts a first pressure drop on the second portion of the refrigerant that facilitates extracting heat from the first portion of the refrigerant flowing through the first fluid line using the second portion of the refrigerant flowing through the second fluid line when valve position of the expansion valve is greater than a threshold position. Additionally the cooling system includes a plurality of capillary expansion tubes fluidly coupled in parallel to an output of the first fluid line and that to exert a second pressure drop on the refrigerant circulated through the cooling system.

A cooling system includes an expansion valve configured to exert a first pressure drop on refrigerant circulated through the cooling system. The cooling system also includes a plurality of capillary expansion tubes fluidly coupled in parallel to an output of the expansion valve and configured to exert a second pressure drop on the refrigerant circulated through the cooling system. The cooling system also includes a controller communicatively coupled to the expansion valve, wherein the controller is configured to control magnitude of the first pressure drop by instructing the expansion valve to adjust the valve position based at least in part on refrigerant mass flow expected to be supplied to the expansion valve to facilitate substantially uniformly distributing the refrigerant mass flow between each of the plurality capillary expansion tubes.

The present disclosure provides a control method, apparatus, and device for a compressor, a storage medium, and a refrigerator system. The control method includes: obtaining an electrical parameter, a return air parameter, and a first frequency of the compressor during operation of the compressor; determining a first fitting formula corresponding to the first frequency; obtaining an exhaust pressure by inputting the electrical parameter and the return air parameter into the first fitting formula for calculation; and controlling the compressor based on the exhaust pressure. In this way, the pressure sensor disposed on an exhaust side of an air conditioner can be omitted, hence cost is saved; or for the air conditioner with the pressure sensor on the exhaust side, the above manner for calculation can be an alternative to obtaining the exhaust pressure, which ensures a user's normal use and thus improves the user experience.

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.

A method for monitoring a compressor includes measuring a power factor of a motor of a compressor. The method includes selectively detecting an occurrence of a fault event of an electrical grid based on the power factor. The method includes, in response to detecting that the fault event has occurred, switching the compressor from a first state to a second state. The compressor consumes less power in the second state than in the first state. The method includes identifying an apparent conclusion of the fault event. The method includes, in response to the apparent conclusion of the fault event, waiting for a first delay period before switching the motor of the compressor back to the first state.

A system and method for flooded start control of a compressor having a crankcase heater are provided. A control module receives sensed data from a sensor, determines a current rate of liquid migration into the compressor, and compares the current rate with first and second predetermined thresholds. The control module operates the compressor in a flooded-start control mode, including operating the compressor according to at least one cycle with a first time period when the compressor is on and a second time period when the compressor is off. The control module operates the compressor in the flooded start control mode when the current rate is greater than the first predetermined threshold, activates the crankcase heater when the current rate is between the first and second predetermined thresholds, and operates the compressor without the flooded start control mode when the current rate is less than the second predetermined threshold.

The air conditioner has a configuration such that, in an air-warming operation: the average refrigerant exit temperature, which is obtained by averaging the temperature of the refrigerant exits of indoor heat exchangers 7 in a plurality of indoor units 10, as detected by heat-exchanger-refrigerant-exit temperature probes 34 in the indoor units 10, is determined; the temperature difference between the average refrigerant exit temperature and the refrigerant exit temperatures of the indoor heat exchangers 7 of each of the indoor units 10 is determined; and the degree to which indoor expansion valves 9 of the indoor units 10 are open is controlled such that the determined temperature difference falls within a predetermined temperature difference range.

A refrigerant compressor for refrigeration plants having a compressor unit driven by a drive unit. At least one of the compressor and drive units has a control unit which is controllable by delivery rate control system to control the refrigerant compressor at different delivery rates. An external delivery rate setpoint value is communicated to the delivery rate control system to prevent critical operating states. The delivery rate control system is configured to acquire, via a sensor, a compressor unit reference temperature. The delivery rate control system is configured to ascertain an operating state value group to acquire an operating state of the refrigerant compressor, and specify a delivery rate for operation of the refrigerant compressor outside of the critical operating states, if the value of the ascertained operating state value group based upon the compressor reference temperature permits a critical operating state of the refrigerant compressor.

A predictive HVAC control apparatus and method, the predictive HVAC control apparatus having an input/output interface connected to a gain amplifier and a thermocouple amplifier, the gain amplifier connected to a first plurality of sensors disposed on an HVAC system, the HVAC system having HVAC system controls, and the temperature amplifier connected to a second plurality of sensors disposed on an HVAC system, a central processing unit connected to the input/output interface, and an HVAC control relay, connected to the input/output interface and the HVAC system controls.