Centrifugal compressor diffuser control
AssigneeDanfoss A/S
InventorsLin Sun, Jose Alvares, Mogens Rasmussen
Life of this patent
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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.
Claims16
A centrifugal refrigerant compressor control system comprising:
- an impeller connected to a shaft;
- a diffuser arranged on a downstream side of the impeller and configured to regulate refrigerant flow exiting the impeller;
- a magnetic bearing system supporting the shaft;
- a sensing element from the magnetic bearing system configured to produce an output relating to a shaft condition;
- and
- a controller configured to receive the output and determine an undesired impeller operating condition based upon the shaft condition only when a predetermined minimum impeller speed is reached with the diffuser in a fully open state, the controller configured to command the diffuser to a desired state in response to the undesired impeller operating condition.
A method of controlling a centrifugal refrigerant compressor comprising:
- sensing a shaft condition of a shaft supporting an impeller;
- determining whether an undesired impeller operating condition exists based upon the sensed shaft condition, wherein the determining step is initiated only after reaching a predetermined minimum impeller speed with the diffuser in a fully effectively open state;
- and
- effectively closing a diffuser on a downstream side of the impeller in response to a detected undesired impeller operating condition.
Dependencies are inferred from the claim text.