Centrifugal compressor

A centrifugal compressor having a revolving shaft, an impeller mounted to the rotating shaft, a casing for housing the impeller, a diffuser section connected to the downstream of the impeller, and a volute section connected to the downstream of the diffuser section for compressing fluid by applying a centrifugal force to the fluid by rotating the impeller, the centrifugal compressor comprising:

• a parting member for dividing a flow channel in the diffuser section and the volute section into a plurality of channels in the direction of circulation of the fluid so as to define a hub-side flow channel and a shroud-side flow channel;
• and
• a flow rate adjuster for lowering the flow rate of the fluid flowing in the shroud-side flow channel and allowing the fluid to flow in the hub-side flow channel at a high flow rate when the flow rate of the fluid compressed by the impeller is low and not lowering the flow rate of the fluid flowing the shroud-side flow channel to allow the fluid to flow both in the shroud-side flow channel and the hub-side flow channel when the flow rate of the fluid compressed by the impeller is high.