CENTRIFUGAL COMPRESSOR WITH VARIABLE DIFFUSER AND ITS CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To provide a centrifugal compressor with a variable diffuser and its control method, capable of completely burying/protruding a guide blade in/from a diffuser part, completely preventing a leak of compressed fluid from a gap between the guide blade and a diffuser wall, and keeping high efficiency in a wide flow rate range. SOLUTION: This centrifugal compressor has the guide blade 12 coming in and out of the diffuser wall 11; a hollow air-chamber 13 installed within the diffuser wall; and an elastic partition member 14 (a diaphragm) airtightly dividing the air-chamber and movable in the axial direction. The guide blade is fixed to the elastic partition member. A fluid driving mechanism comprising an energizing means 16 energizing the elastic partition member in the axial direction; a first opening and closing valve 17a communicating a diffuser side and an anti-diffuser side of the air-chamber; and a second opening and closing valve 17b communicating the anti-diffuser side of the air-chamber and the outside is installed. The guide blade comes in and out by the opening and closing of these valves.