A device for centrifugal compression of a working gas comprising a plurality of centrifugal compressors forming a plurality of compression stages and a plurality of drive motors for driving the compressors, the device comprising a gas circuit comprising a first pipe for supplying gas to be compressed into the first compressor, the gas circuit comprising a second pipe for discharging the gas compressed therein, the second pipe being connected to an inlet of a second compressor in order to carry out a second compression, the gas circuit comprising a third, cooling, pipe for transferring a fraction of the gas compressed in said compressor into said at least one first motor in order to limit heating thereof, the gas circuit comprising a fourth pipe for recovering the gas that has circulated in the first motor and a downstream end connected to an inlet of a second motor for transferring the gas into same in order to limit the heating of second motor.

An electric compressor motor includes a stator ring having a plurality of stator winding slots and a plurality of stator windings. Each of said stator windings is received in a stator winding slot of the plurality of stator winding slots. The stator ring also includes a plurality of cooling slots. Each cooling slot in the plurality of coolant slots is defined along an axial length of at least one corresponding stator winding slot of the plurality of stator winding slots such that a shared opening between each stator winding slot and at least one corresponding coolant slot is defined. The cooling slots are configured to allow coolant to directly contact at least one stator winding in the corresponding at least one stator winding slot.

The reversed single-working-medium vapor combined cycle of the present invitation belongs to the field of thermodynamics, refrigeration and heat pump. A reversed single-working-medium vapor combined cycle method consists of nine processes: a heat-absorption vaporization process 1-2 of the M.sub.1 kg of working medium, a heat-absorption process 2-3 of the (M.sub.1+M.sub.2) kg of working medium, a pressurization process 3-4 of the (M.sub.1+M.sub.2) kg of working medium, a heat-releasing process 4-5 of the (M.sub.1+M.sub.2) kg of working medium, a depressurization process 5-2 of the M.sub.2 kg of working medium, a heat-releasing process 5-6 of the M.sub.1 kg of working medium, a pressurization process 6-7 of the M.sub.1 kg of working medium, a heat-releasing and condensation process 7-8 of the M.sub.1 kg of working medium, a depressurization process 8-1 of the M.sub.1 kg of working medium.

A refrigerant compressor according to an exemplary aspect of the present disclosure includes, among other things, a first stage and a second stage downstream of the first stage, and a cooling line configured to cool power electronics. The cooling line is configured to be switched between a first mode and a second mode. The first mode is configured to dump refrigerant between the first stage and the second stage, and the second mode is configured to dump refrigerant upstream of the first stage.

A 3000-20000 rpm RS-SR motor (RS-SR) and adjustable speed drive (ASD), with a cooling and lubrication system that is independent of the existing chiller lubrication and refrigerant cooling circuits. Product is configured as a direct replacement for motor, starter(drive), and gearbox solutions historically and currently used by OEM's on chillers. Oil containment and low motor cavity pressure is achieved with Axial Carbon Ceramic seals. Using an inner shell suspended in an outer shell: a coolant path is created, and vibration is abated, as well as meeting pressure vessel requirements. These features enable precise qualification of product independent of the chiller system over range of speeds and loads on a calibrated test stand. Specific information derived from qualification tests enables integration of optimization subroutines into the ASD that improve efficiency and increase ability to operate at or near compressor surge boundary.

In some aspects, the techniques described herein relate to a refrigerant compressor, including: an impeller; a shaft; a motor configured to rotate the impeller via the shaft, wherein the motor includes a stator and a rotor; and a housing surrounding the motor, wherein the housing includes a first inlet configured to permit fluid to enter the housing and flow along a stator cooling line and a second inlet configured to permit fluid to enter the housing and flow a rotor cooling line, and wherein the first inlet is separate from the second inlet.

A power electronics unit, a vapor compression system incorporating the power electronics unit, and a method of cooling a power electronics unit are provided. The power electronics unit includes a semiconductor portion and an inductor portion. Approximately 80% of the heat generated by the power electronics unit may be derived from the semiconductor portion. Approximately 20% of the heat generated by the power electronics unit may be derived from the inductor portion. The semiconductor portion is cooled using at least one fan. The inductor portion is cooled using a working fluid (e.g., a refrigerant). The working fluid may be provided from upstream of the evaporator in the vapor compression system. Limiting the use working fluid to only cool the inductor portion of the power electronics unit may minimize the impact of the power electronics unit on the vapor compression system.

A refrigeration cycle apparatus in which a refrigerant having potential for disproportionation reaction circulates a first refrigerant flow path connected between a discharge side of the compressor and the condenser; a second refrigerant flow path connected between the condenser and the expansion valve; a third refrigerant flow path connected between the expansion valve and a suction side of the compressor; a jetting unit; a pressure measuring unit; and a temperature measuring unit. The jetting unit is configured to jet the refrigerant drawn from the second refrigerant flow path or the third refrigerant flow path to at least one of the compressor, the first refrigerant flow path and the second refrigerant flow path when at least one of a measured value of the pressure measuring unit and a measured value of the temperature measuring unit exceeds an allowed value.

A compressor operates within a system having a cooling capacity below 60 tons. The compressor includes a hermetically sealed housing and a drive module and aero module within the housing. The drive module includes a motor, a rotor, and oil free bearings. The aero module has a centrifugal impeller driven by the drive module to compress a working fluid. The compressor is arranged such that the working fluid flows through the drive module before reaching the aero module.

In an embodiment of the present disclosure, a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a variable speed drive (VSD) enclosure. The VSD enclosure includes a main drive line variable speed drive (VSD) configured to supply power to a motor, and an oil pump variable speed drive (VSD) configured to supply power to a pump. The pump is configured to supply oil to one or more moving parts of the HVAC&R system. Additionally or in the alternative to the oil pump VSD, the VSD enclosure includes a magnetic bearing controller and/or a magnetic bearing controller power supply. The magnetic bearing controller is configured to control magnetic bearings of the HVAC&R system.