A method of controlling injection into a compressor in a refrigeration cycle is described. A refrigeration cycle may comprise at least an economizer heat exchanger, a heat rejection heat exchanger, a first expansion device, and a compressor. A discharge port of the compressor is connected to the heat rejection heat exchanger via a discharge line and an injection port of the compressor is connected to the means for compressing. The economizer heat exchanger comprises a first path having an input connected to the heat rejection heat exchanger and an output connected to the first expansion device, and a second path having an input connected to the heat rejection heat exchanger via an economizer valve and an output connected to the injection port of the compressor via an injection line. The economizer valve is regulated based on a superheat level of the refrigerant in the economizer heat exchanger.

An air-conditioning apparatus includes a suction-injection pipe that introduces a refrigerant in a liquid or two-phase state into a suction side of a compressor, an expansion device that is arranged at the suction-injection pipe, and a controller that regulates the suction-injection flow rate of a refrigerant introduced into the suction side of the compressor through the suction-injection pipe by controlling the opening degree of the expansion device.

Refrigeration systems and control methods therefor are described. The refrigeration systems include a main circuit to connect, through a pipeline, a multi-stage compressor, a condenser, an economizer, a main throttling element, and an evaporator. An air supply branch is configured to connect to the air outlet of the economizer and the intermediate stage air inlet of the multi-stage compressor. A liquid injection branch is configured to connect to the intermediate stage air inlet of the multi-stage compressor from a section having a high-pressure liquid-phase refrigerant in the main circuit. Through the design of the liquid injection branch, the liquid-phase refrigerant can be introduced when vibration or noise of the unit exceeds a limit. The liquid-phase refrigerant, in the form of droplets, can effectively absorb the sound wave energy in the compressor pipeline to reduce an overall discharge pulsation of the compressor and reduce the noise and vibration of the condenser.

A compressor includes: a stator core including a plurality of teeth around which an aluminum winding wire is wound in a concentrated manner; a rotor core disposed on an inner diameter side of the stator core and including a plurality of magnet insertion holes; and a plurality of ferrite magnets inserted in the magnet insertion holes, in which when a width of a winding wire portion formed in each of the teeth is represented as A, a length in an axis direction of the stator core is represented as L, and the number of slots is represented as S, the stator core has a shape that satisfies a relation of 0.3<S×A÷L<2.2.

A refrigeration apparatus, including a main circuit for a loop circulation of a main flow of refrigerant, the main circuit including a compressor, a condenser, an expansion valve and an evaporator. The refrigeration apparatus comprises a lubrication branch, for deriving a lubrication flow from the main flow for feeding the compressor for lubrication. The main circuit includes a low-temperature part, consisting in the evaporator, the compressor inlet, and any part of the main circuit between the evaporator and the compressor inlet. The lubrication branch further includes a subcooling heat exchanger, which is configured for enabling an exchange of heat between the lubrication flow circulating through the lubrication branch and the main flow of refrigerant circulating through the low-temperature part, so that the lubrication flow may be cooled by the main flow of refrigerant circulating through the low-temperature part, within the subcooling heat exchanger.

A centrifugal compressor includes a casing, an inlet guide vane, an impeller, a motor, a diffuser and a cooling medium delivery structure. The motor includes a rotor mounted on the shaft and a stator disposed radially outwardly of the rotor to form a gap between the rotor and the stator. The cooling medium delivery structure includes inlet and outlet conduits located to supply and discharge a cooling medium to and from the motor. The shaft has an external shape different than an internal shape of the rotor to form at least one axial passageway between the shaft and the rotor. The cooling medium is supplied through the gap and the at least one axial passageway to cool the rotor.

A system for cooling a hermetic motor includes a housing of the hermetic motor that is configured to be disposed along a motor cooling refrigerant flow path. The housing is configured to surround at least a portion of a stator of the hermetic motor and includes an annular cavity configured to receive refrigerant from a refrigerant loop. The system also includes a sleeve configured to be positioned between the annular cavity and the stator, where the sleeve includes a plurality of discharge ports oriented generally parallel to a central axis of the stator. The plurality of discharge ports is configured to discharge the refrigerant from the annular cavity toward the stator.

A method for providing supplemental flow control of working fluid through a transport climate control circuit during a start-stop cooling operation mode is provided. The method includes closing a main liquid suction solenoid valve disposed between a condenser and an evaporator of the transport climate control circuit when the compressor is OFF. The method also includes monitoring a climate controlled space temperature within a climate controlled space. When the climate controlled space temperature is greater than or equal to a setpoint temperature, the method includes turning a compressor ON, and opening the main liquid suction solenoid valve when a suction pressure at the suction port of the compressor is less than or equal to a predetermined suction pressure threshold. When the climate controlled space temperature is less than or equal to the setpoint temperature, the method includes turning the compressor OFF, and closing the main liquid suction solenoid valve.

A compressor may include a shell, a first scroll, and a second scroll. The shell may include a first inlet, a second inlet, and an outlet. The first scroll may include a first end plate and a first spiral wrap. The second scroll may include a second end plate and a second spiral wrap, the first and second spiral wraps cooperating to define a series of moving compression pockets therebetween. The moving compression pockets decrease in volume as the moving compression pockets move from a radially outer position to a radially inner position. The moving compression pockets may receive working fluid from the first inlet at the radially outer position and provide working fluid to the outlet at the radially inner position. The second end plate may include a fluid cavity receiving working fluid from the second inlet and fluidly isolated from working fluid within the moving compression pockets.

A heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system includes a refrigerant loop having a compressor configured to circulate a refrigerant therethrough, a motor configured to drive rotation of the compressor, wherein the motor is a permanent magnet assisted synchronous reluctance (PMASR) motor, and a motor cooling system configured to direct a portion of the refrigerant from the refrigerant loop and through a housing of the PMASR motor to place the portion of the refrigerant in thermal communication with components of the PMASR motor.