Abstract: An actuator assembly includes a first actuator, a second actuator, and a moving piece that is disposed between the first actuator and the second actuator. The moving piece is positionable to close a gap in the compressor.

Abstract: An example refrigerant system according to an exemplary aspect of this disclosure includes, among other things, a refrigerant loop having at least a condenser, an evaporator, and a compressor. The compressor includes a motor in communication with a variable speed drive. The system further includes a cooling circuit including a pressure regulator downstream of a heat exchanger, the heat exchanger absorbing heat from the variable speed drive.

Abstract: An actuator assembly includes a first actuator, a second actuator, and a moving piece that is disposed between the first actuator and the second actuator. The moving piece is positionable to close a gap in the compressor.

Abstract: This disclosure relates to a centrifugal compressor. In a first example, the compressor includes a first impeller provided in a main refrigerant flow path, a second impeller provided in the main refrigerant flow path downstream of the first impeller, and a recirculation flow path. In the first example, the recirculation flow path is provided between a first location and a second location along the main refrigerant flow path. The first location is downstream of the second location, and the second location is downstream of the first impeller. In a second example, the compressor includes an impeller provided in a main refrigerant flow path, and a recirculation flow path provided between a first location and a second location along the main refrigerant flow path. In the second example, the recirculation flow path includes a recirculation volute. Further disclosed is a method for operating a centrifugal compressor.

Abstract: A refrigeration system includes a chiller having a refrigerant loop. A compressor is part of and in fluid communication with the refrigerant loop. The compressor has two stages, one with a variable geometry diffuser and one with a fixed geometry diffuser.

Abstract: A centrifugal refrigerant compressor system includes an impeller connected to a shaft. A diffuser is arranged on a downstream side of the impeller and is configured to regulate refrigerant flow exiting the impeller. A magnetic bearing supports the shaft. A sensing element is configured to produce an output relating to a shaft condition. A controller is configured to receive the output and determine an undesired impeller operating condition based upon the shaft condition. The controller is configured to command the diffuser to a desired state in response to the undesired impeller operating condition.

Abstract: An example refrigerant system according to an exemplary aspect of this disclosure includes, among other things, a refrigerant loop having at least a condenser, an evaporator, and a compressor. The compressor includes a motor in communication with a variable speed drive. The system further includes a cooling circuit including a pressure regulator downstream of a heat exchanger, the heat exchanger absorbing heat from the variable speed drive.

Abstract: This disclosure relates to a centrifugal compressor. In a first example, the compressor includes a first impeller provided in a main refrigerant flow path, a second impeller provided in the main refrigerant flow path downstream of the first impeller, and a recirculation flow path. In the first example, the recirculation flow path is provided between a first location and a second location along the main refrigerant flow path. The first location is downstream of the second location, and the second location is downstream of the first impeller. In a second example, the compressor includes an impeller provided in a main refrigerant flow path, and a recirculation flow path provided between a first location and a second location along the main refrigerant flow path. In the second example, the recirculation flow path includes a recirculation volute. Further disclosed is a method for operating a centrifugal compressor.

Abstract: This disclosure relates to a centrifugal compressor. In a first example, the compressor includes a first impeller provided in a main refrigerant flow path, a second impeller provided in the main refrigerant flow path downstream of the first impeller, and a recirculation flow path. In the first example, the recirculation flow path is provided between a first location and a second location along the main refrigerant flow path. The first location is downstream of the second location, and the second location is downstream of the first impeller. In a second example, the compressor includes an impeller provided in a main refrigerant flow path, and a recirculation flow path provided between a first location and a second location along the main refrigerant flow path. In the second example, the recirculation flow path includes a recirculation volute. Further disclosed is a method for operating a centrifugal compressor.

Abstract: A centrifugal refrigerant compressor system includes an impeller connected to a shaft. A diffuser is arranged on a downstream side of the impeller and is configured to regulate refrigerant flow exiting the impeller. A magnetic bearing supports the shaft. A sensing element is configured to produce an output relating to a shaft condition. A controller is configured to receive the output and determine an undesired impeller operating condition based upon the shaft condition. The controller is configured to command the diffuser to a desired state in response to the undesired impeller operating condition.

Abstract: A refrigeration system includes a chiller having a refrigerant loop. A compressor is part of and in fluid communication with the refrigerant loop. The compressor has two stages, one with a variable geometry diffuser and one with a fixed geometry diffuser.

Abstract: This disclosure relates to a centrifugal compressor. In a first example, the compressor includes a first impeller provided in a main refrigerant flow path, a second impeller provided in the main refrigerant flow path downstream of the first impeller, and a recirculation flow path. In the first example, the recirculation flow path is provided between a first location and a second location along the main refrigerant flow path. The first location is downstream of the second location, and the second location is downstream of the first impeller. In a second example, the compressor includes an impeller provided in a main refrigerant flow path, and a recirculation flow path provided between a first location and a second location along the main refrigerant flow path. In the second example, the recirculation flow path includes a recirculation volute. Further disclosed is a method for operating a centrifugal compressor.