Abstract: A compressor (22) has a housing assembly (50) with a suction port (24) and a discharge port (26). An impeller (54) is supported by a shaft (70) which is mounted for rotation to be driven in at least a first condition so as to draw fluid in through the suction port (24) and discharge the fluid from the discharge port (26). A magnetic bearing system (66, 67, 68) supports the shaft (70). A controller (84) is coupled to an axial position sensor (80) and is configured to control impeller position.

Abstract: A centrifugal compressor (20) comprises: a housing (26); an impeller (34) having an axial inlet (70) and a radial outlet (72); a diffuser (82); and a control ring (90) mounted for shifting between an inserted position and a retracted position. The control ring comprises means (150, 160, 162, 166) for absorbing pulsations.

Abstract: A system (20; 300) comprises: a vapor compression loop (38; 338); a low-pressure or medium-pressure refrigerant in the loop; a centrifugal compressor (42) along the vapor compression loop and comprising: a housing (120); an inlet (44); an outlet (46); an impeller (140); an electric motor (122) coupled to the impeller to drive rotation of the impeller; and one or more refrigerant-lubricated bearings (130, 132).

Abstract: A vapor compression system comprises a compressor (22). The compressor comprises an inlet (40) and an outlet (42) and an electric motor (28). The motor has a stator (30) and a rotor (32). A plurality of bearings (36) support the rotor. A fluid flowpath (126) extends to the plurality of bearings. A branch (310) from the fluid flowpath extends to the compressor. A liquid sensor (330) is along the branch.

Abstract: A compressor (22) has a housing assembly (50) with a suction port (24) and a discharge port (26). A shaft (70) is mounted for rotation about an axis (500) and an impeller (44) is mounted to the shaft to be driven in at least a first condition so as to draw fluid in through the suction port and discharge the fluid from the discharge port. A mag netic bearing system (66, 67, 68) supports the shaft. A controller (84) is coupled to a sensor (80, 82) and configured to detect at least one of surge and pre-surge rotating stall and, responsive to said detection, take action to prevent or counter surge.

Abstract: A vapor compression system (20) has: a centrifugal compressor (22) having an inlet (40) and an outlet (42); and an electric motor (28) having a stator (30) and a rotor (32). A plurality of bearings (36) support the rotor. A refrigerant charge comprises a base refrigerant and one or more oils. The one or more oils are present at a total concentration of 80-5000 parts per million (ppm) by weight.

Abstract: A seal configured for use in a chiller refrigeration system is provided including a first flange and a second flange. The first flange and the second flange are coaxially aligned and in direct contact. The second flange includes at least one groove within which a first sealing mechanism and a second sealing mechanism are positioned. The first sealing mechanism and the second sealing mechanism are separated by a distance such that a chamber configured to receive a pressurized gas is formed between the first and second sealing mechanisms.

Abstract: A vapor compression system comprising a centrifugal compressor (22) having: an inlet (24); an outlet (26); a first impeller stage (28); a second impeller stage (30); and a motor (34) coupled to the first impeller stage and second impeller stage. A first heat exchanger (38) is downstream of the outlet along a refrigerant flowpath. An expansion device (56) and a second heat exchanger (64) are upstream of the inlet along the refrigerant flowpath. A bypass flowpath (120; 320) is positioned to deliver refrigerant from the compressor bypassing the first heat exchanger. A valve (128) is positioned to control flow through the bypass flowpath, wherein: the bypass flowpath extends from a first location (140) intermediate the inlet and outlet to a second location (142; 342) downstream of the first heat exchanger along the refrigerant flowpath.

Abstract: A method of positioning an inlet guide vane assembly before start-up of a chiller system including a compressor, a condenser, and a cooler is provided including receiving a first input form sensors located in the cooler and the condenser. A saturation temperature is calculated based on the input from the sensors. A second input indicative of a minimum speed of a motor coupled to the compressor at start-up is received. Using the calculated saturation temperature and the second input, an allowable position of the inlet guide vane assembly is determined. The inlet guide vane assembly is then moved to the determined allowable position.

Abstract: A motor cooling system for a simply supported compressor includes a rotor shaft 24 having a first end 26 and a second end 28. The rotor shaft 24 includes an axial bore 60 and a plurality of shaft radial holes 64 extending from a first end of the axial bore 60, wherein a cooling medium is supplied to the axial bore 60. The cooling system further includes a rotor 22 coupled to the rotor shaft 24 and having a plurality of rotor axial holes 25 and a plurality of rotor radial holes 27. The plurality of rotor radial holes 27 extends from the plurality of rotor axial holes 25. A refrigerant dam 70 is arranged adjacent a first end of the rotor 22 and includes a plurality of dam axial holes 74 fluidly coupled to an interior cavity 72. The dam axial holes 74 align with the rotor axial holes 25 and the interior cavity 72 aligns with the shaft radial holes 64 to form a flow path between the rotor shaft 24 and the rotor 22.

Abstract: A centrifugal compressor (22) comprises: a case (160) having a suction port (24) and a discharge port (26); an impeller (162, 164) mounted for rotation about an impeller axis (500) by a plurality of bearings (80, 82); and a motor (34) coupled to the impeller to drive rotation of the impeller about the impeller axis. The bearings each comprise: an inner race (200); an outer race (202); and rolling elements (204) between the inner race and outer race. The outer race of each bearing is mounted for radial displacement relative to the case and is surrounded by an associated chamber (224); and the chambers are coupled to a port (92) on the compressor.

Abstract: In one embodiment, a compressor assembly is provided. The compressor assembly includes a compressor having an inlet, an outlet, and at least one bearing, the compressor configured to compress a first refrigerant. The assembly further includes a lubrication supply conduit fluidly coupled to the compressor and configured to supply a lubricant to the at least one bearing. The lubricant is a second refrigerant.

Abstract: A seal configured for use in a chiller refrigeration system is provided including a first flange and a second flange. The first flange and the second flange are coaxially aligned and in direct contact. The second flange includes at least one groove within which a first sealing mechanism and a second sealing mechanism are positioned. The first sealing mechanism and the second sealing mechanism are separated by a distance such that a chamber configured to receive a pressurized gas is formed between the first and second sealing mechanisms.

Abstract: A compressor (22) has a housing assembly (40) with a suction port (24), a discharge port (26), and a motor compartment (60). An electric motor (42) has a stator (62) within the motor compartment and a rotor (64) within the stator. The rotor is mounted for rotation about a rotor axis (500). One or more working impellers (44) are coupled to the rotor to be driven by the rotor in at least a first condition so as to draw fluid in through the suction port and discharge the fluid from the discharge port. An inlet guide vane (IGV) array (174) is between the suction port (24) and the one or more impellers (44). One or more bearings (66, 68) support the rotor (64) and/or the one or more impellers (44). A purge unit (400) has a vapor inlet line (410) for receiving a refrigerant flow and a return line (414, 417A, 417B) for returning a contaminant-depleted refrigerant flow. A supply flowpath (407A, 407B) for supplying refrigerant to the bearings extends from the purge unit.

Abstract: A vapor compression system (20) comprises a compressor (22) having one or more bearing systems (66, 68) supporting a rotor and/or one or more working elements (44). One or more bearing feed passages (114) are coupled to the bearings to pass fluid along a supply flowpath to the bearings. A mechanical pump (130; 330) is positioned to drive fluid along the supply flowpath. An ejector (140, 150) has a motive flow inlet (142, 152) coupled to the mechanical pump to receive refrigerant from the mechanical pump.

Abstract: A compressor (22) has a housing assembly (40) with a suction port (24), a discharge port (26), and a motor compartment (60). An electric motor (42) has a stator (62) within the motor compartment and a rotor (64) within the stator. The rotor is mounted for rotation about a rotor axis (500). One or more working impellers (44) are coupled to the rotor to be driven by the rotor in at least a first condition so as to draw fluid in through the suction port and discharge the fluid from the discharge port. An inlet guide vane (IGV) array (174) is between the suction port (24) and the one or more impellers (44). One or more bearing systems (66, 68) support the rotor (64) and/or the one or more impellers (44). One or more main drain passages (120, 234 206; 120, 232, 202, 206) are coupled to the bearings to pass fluid along a drain flowpath from the bearings to a location (172) upstream of the impeller and downstream of the IGV array.

Abstract: An inlet guide vane assembly (60) is provided including a plurality of vane subassemblies (62) configured to rotate relative to a blade ring housing (64) to control a volume of air flowing there through. The inlet guide vane assembly (60) also includes a plurality of drive mechanisms (80). Each drive mechanism (80) is operably coupled to one of the plurality of vane subassemblies (62). The vane subassemblies (62) may be rotated independently.

Abstract: A method of positioning an inlet guide vane assembly before start-up of a chiller system including a compressor, a condenser, and a cooler is provided including receiving a first input form sensors located in the cooler and the condenser. A saturation temperature is calculated based on the input from the sensors. A second input indicative of a minimum speed of a motor coupled to the compressor at start-up is received. Using the calculated saturation temperature and the second input, an allowable position of the inlet guide vane assembly is determined. The inlet guide vane assembly is then moved to the determined allowable position. and determine which is greater.

Abstract: A motor cooling system for a simply supported compressor includes a rotor shaft 24 having a first end 26 and a second end 28. The rotor shaft 24 includes an axial bore 60 and a plurality of shaft radial holes 64 extending from a first end of the axial bore 60, wherein a cooling medium is supplied to the axial bore 60. The cooling system further includes a rotor 22 coupled to the rotor shaft 24 and having a plurality of rotor axial holes 25 and a plurality of rotor radial holes 27. The plurality of rotor radial holes 27 extends from the plurality of rotor axial holes 25. A refrigerant dam 70 is arranged adjacent a first end of the rotor 22 and includes a plurality of dam axial holes 74 fluidly coupled to an interior cavity 72. The dam axial holes 74 align with the rotor axial holes 25 and the interior cavity 72 aligns with the shaft radial holes 64 to form a flow path between the rotor shaft 24 and the rotor 22.

Abstract: A compressor, as well as a lightweight and strong casting for a compressor, are disclosed. The compressor, which may be a reciprocating compressor for use in compressing high-pressure refrigerants such as CO2, includes substantially reduced wall thicknesses (t) compared to prior art castings. The side walls of the compressor can be manufactured to such reduced thicknesses (t) through the use of a bridge spanning across the crankcase. This not only allows the opposing side walls to be manufactured of a thinner material, but the bottom cover removably mounted to the crankcase can be manufactured from a thinner and lighter material as well. Through the use of such a bridge, the resulting compressor is not only able to satisfy current strength requirements, but at significant weight, size and cost savings as well.