| 摘要 |
A centrifugal compressor includes an impeller, a casing, an impeller housing portion for housing the impeller, an inlet port provided coaxially with the impeller, an annular flow passage provided so as to surround the impeller, a discharge port communicated with the annular flow passage, an annular chamber provided around the inlet port, a downstream slot communicating a downstream end of the annular chamber with the impeller housing portion, and an upstream slot communicating an upstream end of the annular chamber with the inlet port. The downstream slot draws a one-cycle curved line that pulsates in an axial direction of the inlet port with a predetermined amplitude. A most upstream point on a center line of the downstream slot is located at an upstream end portion of the impeller blades when seen along a direction perpendicular to a direction of a rotary shaft of the impeller. According to the centrifugal compressor, it becomes possible to expand its operating range by improving a surging restriction effect brought by more effective casing treatment. |
