Abstract: A centrifugal compressor is equipped with a housing including a suction passage which accommodates an impeller. The suction passage is provided with a first opening portion formed at a position facing the impeller, a second opening portion formed on an upstream side of the first opening portion, a circulation flow path which allows the first opening portion and the second opening portion to communicate with each other and extends in an annular shape around a rotational axis of the impeller, and a plurality of guide vanes disposed in the circulation flow path. The circulation flow path includes a first region in which a plurality of guide vanes is disposed at intervals in a circumferential direction, and a second region in which no guide vane is disposed. The second region extends over a wider range in the circumferential direction than the interval between the guide vanes in the first region.

Abstract: A centrifugal compressor is equipped with a housing including a suction passage which accommodates an impeller. The suction passage is provided with a first opening portion formed at a position facing the impeller, a second opening portion formed on an upstream side of the first opening portion, a circulation flow path which allows the first opening portion and the second opening portion to communicate with each other and extends in an annular shape around a rotational axis of the impeller, and a plurality of guide vanes disposed in the circulation flow path. The circulation flow path includes a first region in which a plurality of guide vanes is disposed at intervals in a circumferential direction, and a second region in which no guide vane is disposed. The second region extends over a wider range in the circumferential direction than the interval between the guide vanes in the first region.