A compressor system includes a screw compressor and a controller. The screw compressor includes a slide valve selectively actuatable between a first position and a second position to facilitate modulating a capacity of the screw compressor between fully-loaded and fully-unloaded. The controller is communicably coupled to the slide valve. The controller is configured to receive a chilled fluid temperature setpoint for a fluid in heat transfer communication with a refrigerant of the refrigeration circuit; receive temperature data indicative of a chilled fluid temperature of the fluid; determine a difference between the chilled fluid temperature and the chilled fluid temperature setpoint; and provide one of a load command and an unload command to the slide valve based the difference between the chilled fluid temperature and the chilled fluid temperature setpoint. According to an embodiment, the controller does not receive feedback from the screw compressor regarding a position of the slide valve.

This method for controlling asynchronous electrical motors of a compressor system, comprises: —receiving an order to start a first asynchronous electrical motor and a second asynchronous electrical motor of a compressor system; —unloading said first and second motors, by operating respectively a first load control unit of the first motor and a second load control unit of the second motor, in order to reduce the mechanical load associated to said motors; —starting the first motor and, only once the first motor is running at nominal speed, starting the second motor, —loading both the first and second electrical motor only once the second motor has started and is running at nominal speed, by operating the first load control unit and the second load control unit, in order to increase the mechanical load associated to said motors.

An air conditioner system is disclosed. The air conditioner system includes: a compressor; a four-way valve configured to provide a refrigerant circulation path depending on an operation mode of the air conditioner system; a blocking valve disposed between the compressor and the four-way valve; a circulation line configured to provide a path for introducing a refrigerant discharged from the compressor back into the compressor, when the blocking valve is in a closed state; and a controller configured to control the blocking valve based on a pressure of the refrigerant discharged from the compressor.

A heat source system that optimizes a load on compressors in multiple heat source machines with respective independent refrigeration cycles that are situated in series. This is accomplished by using an information acquisition unit that acquires measurement values of operation frequencies of compressors from the respective heat source machines, a load distribution change unit that changes a load distribution currently assigned to each of the heat source machines, and a temperature setting unit that sets the hot/chilled water outlet temperatures of respective heat source machines.

This method for controlling asynchronous electrical motors of a compressor system, comprises: receiving an order to start a first asynchronous electrical motor and a second asynchronous electrical motor of a compressor system; unloading said first and second motors, by operating respectively a first load control unit of the first motor and a second load control unit of the second motor, in order to reduce the mechanical load associated to said motors; starting the first motor and, only once the first motor is running at nominal speed, starting the second motor, loading both the first and second electrical motor only once the second motor has started and is running at nominal speed, by operating the first load control unit and the second load control unit, in order to increase the mechanical load associated to said motors.

Controls for chillers with variable speed and variable geometry compressors are disclosed. In exemplary embodiments, a centrifugal compressor equipped with a variable frequency drive and variable inlet guide vanes may be utilized. A controller is operable to determine a chiller capacity command, a speed command, and a vane position command. The speed command and vane position command may maintain system operation at or near a surge control boundary over one or more capacity ranges to enhance efficiency and deviate from the surge control boundary over certain capacity ranges to improve controllability or avoid control aberrations.

Systems and methods to manage power consumption of a building and storage by controlling a refrigeration system within the building are disclosed. Exemplary implementations may: receive input defining an average power target and a time interval; determine system information characterizing a refrigeration system; determine build information characterizing power usage of a building that includes the refrigeration system; determine precooling control actions based on the system information, the average power target, and the time interval; determine load shedding control actions based on the system information, the average power target, and the time interval; generate a control schedule for the refrigeration system to effectuate the precooling control actions and/or load shedding control actions based on the average power target, the time interval, and the building information; and effectuate the precooling control actions and/or load shedding control actions for the refrigeration system in accordance with the control schedule.

A climate-control system may include a first compressor, a second compressor, a suction manifold, and a flow restrictor. The first and second compressors each include a shell and a compression mechanism. The shells define suction chambers from which the compression mechanisms draw working fluid. The shells include suction inlet fittings through which working fluid is drawn into the suction chambers. The suction inlet fittings are fluidly connected to the suction manifold. The suction manifold provides suction-pressure working fluid to the suction inlet fittings of the first and second compressors. The flow restrictor may be at least partially disposed within the suction manifold.

A compressor system includes a screw compressor (48) and a controller (100). The screw compressor includes a slide valve (49) selectively actuatable between a first position and a second position to facilitate modulating a capacity of the screw compressor between fully-loaded and fully-unloaded. The controller is communicably coupled to the slide valve. The controller is configured to receive a chilled fluid temperature setpoint for a fluid in heat transfer communication with a refrigerant of the refrigeration circuit; receive temperature data indicative of a chilled fluid temperature of the fluid; determine a difference between the chilled fluid temperature and the chilled fluid temperature setpoint; and provide one of a load command and an unload command to the slide valve based the difference between the chilled fluid temperature and the chilled fluid temperature setpoint. According to an example embodiment, the controller (100) does not receive feedback from the screw compressor (48) regarding a position of the slide valve (49).

A cooler system includes a plurality of cooler units; a condensed water flow path, an aqueous medium in the condensed water flow path sequentially flowing through each of the cooler units; a cooling water flow path, an aqueous medium in the cooling water flow path sequentially flowing through each of the cooler units in a flow direction opposite to a flow direction of the aqueous medium in the condensed water flow path; a plurality of current sensors used for detecting working currents of the cooler units; water temperature sensors used for detecting an entering water temperature and a leaving water temperature of the cooling water flow path; at least one virtual temperature sensor arranged between the cooler units and used for acquiring a middle water temperature between the cooler units; and a controller.