Centrifugal compressor having a casing with an adjustable clearance and connections for a variable flow rate cooling medium, impeller clearance control apparatus for centrifugal compressor, and impeller clearance control method for centrifugal compressor

摘要

A centrifugal compressor includes a casing, a first impeller, a motor, a cooling medium delivery structure, a shaft, and a first bearing. The casing has a first inlet portion and a first outlet portion. The first impeller is attached to the shaft and disposed between the first inlet portion and the first outlet portion. A first axial gap exists between the first impeller and the casing. The shaft is rotatably supported and axially moveable with respect to the casing by the first bearing. The motor is arranged inside the casing to rotate the shaft. The cooling medium delivery structure is configured to vary a supply of a cooling medium to the casing. An impeller clearance control apparatus for a centrifugal compressor includes a sensor and a controller. The controller controls a supply of a cooling medium to the casing based on a value detected by the sensor.