Abstract: A vapor compression system and method for operating the vapor compression system are provided. The vapor compression system includes a first compressor, a second compressor, a condenser, and at least one check valve disposed between the first compressor and the condenser. The method provides for the transmitting of a shutdown command to at least one of the first compressor and the second compressor, at least one of the first compressor and the second compressor including a rotating shaft and a magnetic bearing, the magnetic bearing having an active mode and an inactive mode, the magnetic bearing levitating the rotating shaft in the active mode. The method further provides for the monitoring of at least one of a rotational speed of the rotating shaft and a differential pressure over the check valve for a preset time, wherein the magnetic bearing remains in the active mode at least during the preset time.

Abstract: A vapor compression system and method for operating the vapor compression system are provided. The vapor compression system includes a first compressor, a second compressor, a condenser, and at least one check valve disposed between the first compressor and the condenser. The method provides for the transmitting of a shutdown command to at least one of the first compressor and the second compressor, at least one of the first compressor and the second compressor including a rotating shaft and a magnetic bearing, the magnetic bearing having an active mode and an inactive mode, the magnetic bearing levitating the rotating shaft in the active mode. The method further provides for the monitoring of at least one of a rotational speed of the rotating shaft and a differential pressure over the check valve for a preset time, wherein the magnetic bearing remains in the active mode at least during the preset time.

Abstract: An exemplary compressor system includes a compressor having a fluid inlet and a fluid outlet. An isolation valve connects the fluid outlet of the compressor to a condenser. A controller is communicatively coupled to the isolation valve and the compressor. The controller includes a memory storing instructions configured to cause the controller to detect one of a surge event and a surge event precursor and restrict an opening in the isolation valve in response.

Abstract: A vapor compression system includes a compressor that has a suction port and a discharge port. A heat rejection heat exchanger is coupled to the discharge port to receive compressed refrigerant. A heat absorption heat exchanger is coupled to the suction port. A lubricant flowpath goes from the heat absorption heat exchanger to the compressor. A side channel pump is located in the lubricant flowpath.

Abstract: A refrigerant compressor assembly (20A, 20B, 20C) includes an axial compressor (22B, 22C, 22) that includes at least one axial stage. A downstream compressor (24) is located fluidly downstream of the axial compressor (22B, 22C, 22) and includes one of a mixed-flow impeller (46) or a centrifugal impeller (96). At least one motor (26, 27) is in driving engagement with at least one of the axial compressor (22B, 22C, 22) and the downstream compressor (24).

Abstract: 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.

Abstract: A centrifugal compressor and a method of operating a centrifugal compressor. The centrifugal compressor includes: an impeller configured to suction a gas to be compressed; a diffuser disposed downstream of the impeller to pressurize the gas, the diffuser comprising a movable ring, a main passage in which the gas flows past the ring, and an openable branch passage; and a circulation loop comprising an inlet and an outlet, the outlet being in communication with an inlet of the impeller; the branch passage is disposed to be in communication with the main passage and the circulation loop when the ring moves into the main passage so that a portion of the gas in the main passage passes through the circulation loop and returns to the impeller so as to be suctioned, and to be closed when the ring is withdrawn from the main passage.

Abstract: 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.

Abstract: An example centrifugal compressor includes a housing that defines an inlet chamber and includes first and second openings that define a recirculation passage in fluid communication with the inlet chamber. An impeller is disposed within the housing and is rotatable about a longitudinal axis to draw fluid into the inlet chamber. The first and second openings are at different axial locations along the longitudinal axis. A plurality of inlet guide vanes are rotatable and situated in the inlet chamber. The centrifugal compressor includes a ring and a controller for moving the ring along the longitudinal axis between a first position and a second position when rotating the inlet guide vanes. The ring obstructs at least one of the first and second openings more in the second position than in the first position.

Abstract: A coolant system includes a multistage compressor having a plurality of surge detection sensors. A condenser is connected to an outlet of the multistage compressor. An economizer is connected to an outlet of the condenser and has a gaseous coolant outlet and a liquid coolant outlet. The liquid coolant outlet is connected to a cooler and the gaseous coolant outlet is connected to a second or later stage of the multistage compressor via a controllable valve. A controller is communicatively coupled to the surge detection sensors and the controllable valve. The controller includes a non-transitory medium storing instructions for causing the controller to detect an occurrence of a surge and restricting a flow through the controllable valve until the surge has ceased.

Abstract: A centrifugal compressor includes an impeller configured to drive fluid along a fluid flowpath via a plurality of discrete passages. Each of the discrete passages includes a discrete passage exit. A diffuser portion is disposed circumferentially about the impeller. The diffuser portion includes a plenum connected to each exit of the discrete passages via a plurality of diffuser inlets and an equalization plenum defined adjacent to the impeller. The equalization plenum is fluidly connected to each discrete passage exit via a corresponding slot.

Abstract: A bearing support (26) for a compressor (10) includes an annular body. The annular body includes a circle opening (28) that is configured to receive a bearing (21) and a shaft (20). A tapered portion (30) is tapered away from the circular opening. The tapered portion (30) includes a passage (32). A vibration sensor (34) is situated in the passage. A compressor and a method of sensing vibration adjacent a bearing in a compressor are also disclosed.

Abstract: An illustrative example embodiment of a compressor includes an inlet defining an intake passage, a plurality of inlet guide vanes, an impeller, and a plurality of swirl nozzles. Fluid flow through the plurality of inlet guide vanes into the intake passage is selectively adjustable to control fluid flow through at least the portion of the intake passage downstream of the swirl nozzles. The impeller includes a plurality of blades and directs fluid from the intake passage toward an outlet. The swirl nozzles have outlets positioned downstream of the plurality of inlet guide vanes and upstream of the impeller. The swirl nozzles are configured to introduce fluid into the intake passage to cause swirl of fluid in the intake passage between the plurality of inlet guide vanes and the impeller.

Abstract: An illustrative example embodiment of a multistage compressor includes a first compressor stage, a second compressor stage downstream of the first compressor stage, and a motor section between the first compressor stage and the second compressor stage. The motor section includes a housing and a motor within the housing. A space between the motor and the housing establishes a flow path for fluid to flow from the first compressor stage to the second compressor stage. A plurality of ribs within the space have a curvature along at least a portion of a length of the ribs that changes a direction of fluid flow within the space such that the fluid flows downstream of the curvature in a direction parallel to a longitudinal axis of the housing.

Abstract: An illustrative example embodiment of a compressor assembly includes a compressor housing having a suction inlet and a discharge outlet. A flow restricting valve allows unrestricted fluid flow in a first direction into the housing through the suction inlet and out of the discharge outlet during a first operating condition. The flow restricting valve allows a restricted fluid flow in a second, opposite direction into the housing through the discharge outlet in a second operating condition.

Abstract: A compressor includes a housing having an inlet and an outlet and a fluid flow path extending between the inlet and the outlet. An impeller is mounted within the housing and is movable to move a fluid from the inlet along the fluid flow path to the outlet. A plurality of flow interference elements is arranged within the housing at one or more locations along the fluid flow path. When a fluid flows through the fluid flow path in a backwards direction of flow, a disturbance is generated in the fluid adjacent each of the plurality of flow interference elements.

Abstract: A method of controlling, by a controller for a compressor (200), pressure at plurality of magnetic motor thrust bearings (360, 370) for a motor (280) disposed within a housing (220) for the compressor (200), wherein the motor (280) and an impeller (270) are disposed on a compressor shaft (260) within the housing, the method including: monitoring current at each of the plurality of magnetic motor thrust bearings (360, 370), controlling a flow regulator (400) in a bypass loop (380) for the impeller (270) to decrease flow through the bypass loop when a first current in a first of the plurality of magnetic motor thrust bearings (360, 370) exceeds a second current in a second of the plurality of magnetic motor thrust bearings (360, 370), and controlling the flow regulator (400) to increase flow through the bypass loop (380) when the second current exceeds the first current.

Abstract: A mixed-flow compressor includes an impeller attached to a shaft and rotatable about a shaft axis. A vaneless diffuser is located axially downstream of the impeller and has a converging portion and a diverging portion. A vaned diffuser is located axially downstream of the vaneless diffuser.

Abstract: An illustrative example embodiment of a compressor includes an inlet defining an intake passage, a plurality of inlet guide vanes, an impeller, and a plurality of swirl nozzles. Fluid flow through the plurality of inlet guide vanes into the intake passage is selectively adjustable to control fluid flow through at least the portion of the intake passage downstream of the swirl nozzles. The impeller includes a plurality of blades and directs fluid from the intake passage toward an outlet. The swirl nozzles have outlets positioned downstream of the plurality of inlet guide vanes and upstream of the impeller. The swirl nozzles are configured to introduce fluid into the intake passage to cause swirl of fluid in the intake passage between the plurality of inlet guide vanes and the impeller.

Abstract: A centrifugal compressor includes a casing. An impeller is arranged within the casing. The impeller is rotatable about an axis. A diffuser section is arranged within the casing. The diffuser section is positioned axially downstream from an outlet of the impeller and includes a forward portion fixed relative to the impeller and an aft portion distinct from the forward portion.