Abstract: A centrifugal compressor includes: an impeller; a main flow passage which receives the impeller and extends in a rotation axis direction of the impeller; an auxiliary flow passage which includes an upstream communication portion communicating to the main flow passage and a downstream communication portion communicating to the main flow passage at closer to the impeller than the upstream communication portion, and extends in a rotation direction of the impeller; a plurality of opening/closing portions which each have an opening portion and are arranged in the auxiliary flow passage; and a drive unit configured to move at least one of the plurality of opening/closing portions in the rotation direction.

Abstract: Provided is a centrifugal compressor, including: an impeller including blades; a main flow passage including a narrowing portion, which is formed on a front side of the impeller and has a diameter smaller than a diameter of each of the blades; an auxiliary flow passage, which has one end communicating to the main flow passage on the impeller side with respect to the narrowing portion and another end communicating to the main flow passage on a side away from the impeller with respect to the narrowing portion; and a movable portion which is movable between a first position and a second position, the second position being different from the first position in position in a rotation axis direction and a rotation direction of the impeller and in opening degree of the auxiliary flow passage.

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 includes: an impeller; a main flow passage which receives the impeller and extends in a rotation axis direction of the impeller; an auxiliary flow passage which includes an upstream communication portion communicating to the main flow passage and a downstream communication portion communicating to the main flow passage at closer to the impeller than the upstream communication portion, and extends in a rotation direction of the impeller; a plurality of opening/closing portions which each have an opening portion and are arranged in the auxiliary flow passage; and a drive unit configured to move at least one of the plurality of opening/closing portions in the rotation direction.

Abstract: Provided is a centrifugal compressor, including: an impeller including blades; a main flow passage including a narrowing portion, which is formed on a front side of the impeller and has a diameter smaller than a diameter of each of the blades; an auxiliary flow passage, which has one end communicating to the main flow passage on the impeller side with respect to the narrowing portion and another end communicating to the main flow passage on a side away from the impeller with respect to the narrowing portion; and a movable portion which is movable between a first position and a second position, the second position being different from the first position in position in a rotation axis direction and a rotation direction of the impeller and in opening degree of the auxiliary flow passage.

Abstract: A centrifugal compressor includes: a compressor impeller; a main flow passage in which the impeller is arranged, the main flow passage extending in a rotational axis direction of the impeller; a sub flow passage including an upstream communication passage communicating with the main flow passage and a downstream communication passage communicating with the main flow passage on the impeller side with respect to the upstream communication passage; N first partitions fixed to the sub flow passage and arranged while spaced apart from each other in a rotation direction of the impeller; and M second partitions (where N?4?M?N+4) fixed on the upstream communication passage side with respect to the first partitions in the sub flow passage, the M second partitions arranged while spaced apart from each other in the rotation direction.

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.