A fluid injection control system, a fluid injection control method and a fluid circulation system including the fluid injection control system are provided. The fluid injection control system includes an injection valve, control apparatus and energy storage apparatus. The injection valve is arranged in a path along which a fluid flows into a device; the energy storage apparatus is configured to supply, in response to the control apparatus being powered off, power to the control apparatus so as to maintain an operation of the control apparatus.

A temperature control system includes: first and second refrigerator units; a first fluid flow apparatus that allows a first fluid to flow therethrough and that is cooled by the first refrigerator unit; a second fluid flow apparatus that allows a second fluid to flow therethrough and that is cooled by the second refrigerator unit; and a valve unit that is configured to allow the first fluid or the second fluid to selectively flow out therefrom. The first refrigerator unit has, in a medium-temperature-side refrigerator, a medium-temperature-side first expansion valve and a medium-temperature-side second expansion valve. A medium-temperature-side second evaporator corresponding to the medium-temperature-side second expansion valve and a low-temperature-side condenser of a low-temperature-side refrigerator constitute a cascade condenser. The first fluid is cooled by a medium-temperature-side first evaporator corresponding to the medium-temperature-side first expansion valve, and is then cooled by a low-temperature-side evaporator of the low-temperature-side refrigerator.

An electric motor for a vapor compression system is disclosed. The electric motor is provided with a working fluid. The electric motor includes a housing forming cavity therein. The housing includes a rotor, a stator, and a shaft. The rotor is secured to the shaft and the stator surrounds at least a portion of the rotor. An airgap is formed between the rotor and the stator. An inlet of the housing receives the working fluid and is in fluid communication with the airgap. An outlet of the housing is in fluid communication with the airgap and receives the working fluid from the airgap. The electric motor further includes an impeller that induces flow of the working fluid between the inlet and the outlet.

An air conditioner, in which a liquid-pressure adjustment expansion valve that decompresses a refrigerant so that the refrigerant flowing through a liquid-refrigerant connection pipe is in a gas-liquid two-phase state is provided in an outdoor liquid-refrigerant pipe that connects a liquid-side end of an outdoor heat exchanger to the liquid-refrigerant connection pipe, properly transports the refrigerant in a two-phase state while suppressing an increase in a discharge temperature of a compressor. A liquid injection pipe that branches part of a refrigerant flowing through an outdoor liquid-refrigerant pipe and feeds the branched refrigerant to a compressor is connected to a portion of the outdoor liquid-refrigerant pipe on a side of an outdoor heat exchanger with respect to a liquid-pressure adjustment expansion valve.

A variable orifice flow device controls the flow of refrigerant into a compressor motor housing in a compressor. The variable orifice flow device may include, for example, an electronic expansion valve, a thermal expansion valve, or a shuttling valve controlling the flow of refrigerant into a compressor motor housing. One or more flows of refrigerant may be through a fixed orifice, a valve seat of the variable orifice flow device, or leakage through a seal of the compressor motor housing, providing a baseline refrigerant flow to the inside of the compressor motor housing in addition to the flow through the variable orifice flow device.

A refrigerant composition, including trifluoroiodomethane (CF.sub.3I); 1,1,1,2-tetrafluoropropene (HFO-1234yf); difluoromethane (HFC-32); and carbon dioxide (CO.sub.2), for use in a heat exchange system, including refrigeration applications and in particular aspects to the use of such compositions as a replacement of the refrigerant R-404A for heating and cooling applications and to retrofitting heat exchange systems, including systems designed for use with R-404A.

A compressor with a touchdown bearing and a supply line for injecting a working fluid toward the touchdown bearing, and a vapor compression system incorporating the same are provided. The supply line injects working fluid approximately continuously when the compressor is operational. The compressor includes a magnetic bearing for levitating the rotating shaft when the compressor is operational. The touchdown bearing is used to support the rotating shaft when the compressor is shutdown. The touchdown bearing may be disposed, at least partially, between a pair of races. The injecting of the working fluid may cause the touchdown bearing to rotate between the races. The injecting of the working fluid may help mitigate a buildup of a debris between the touchdown bearing and the races.

Systems and methods are provided for controlling compressor systems to ensure sufficient pressure differentials to provide cooling. A compressor system includes a compressor, a suction pressure sensor at a suction of the compressor, a discharge pressure sensor, a condenser, an expansion device, a liquid line, a liquid line pressure sensor, an evaporator, a condenser blower and a controller. The method includes determining a pressure target based on an intermediate pressure within the compressor and a threshold cooling differential pressure value, determining a pressure ratio setpoint based on the pressure target and a liquid line pressure measured by the liquid line pressure sensor, controlling the condenser blower to operate based on the determined pressure ratio setpoint, determining a subcooling setpoint based on the pressure target and the liquid line pressure in the compressor system, and controlling the expansion device to operate based on the subcooling setpoint.

A hybrid cooling system for a hermetic motor includes an annular cavity in a motor housing that receives a vapor flow and an annulus in the motor housing that receives a liquid flow. The hybrid cooling system includes a sleeve disposed adjacent to the annular cavity and the annulus, where a radial opening is defined through the sleeve. The hybrid cooling system includes a stator at least partially surrounded by the sleeve, a gap defined between the stator and a rotor, and a vent slot of the stator configured to receive the vapor flow from the annular cavity through the radial opening of the sleeve and direct the vapor flow to the gap. The hybrid cooling system includes an exit path in the motor housing configured to direct an evaporated vapor flow, generated from the liquid flow contacting the stator, and the vapor flow out of the motor housing.

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.