Bypass air volume control device for combustor used in gas turbine

Abstract

The invention applies to an air bypass control device which can bypass a portion of the compressed air in the space within the casing into the tail pipe connected to a combustion chamber via a control valve and a bypass channel. The invention includes a valve mechanism including a flat sliding ring, and a valve operating mechanism. The valve mechanism intersects a number of bypass air channels each of which is connected to a pipe located in the space inside the casing. A number of openings are arranged in the flat sliding ring for bypassing the air to the bypass air channels. The valve operating mechanism, one end of which is connected to the flat sliding ring, causes the flat sliding ring to rotate back and forth. When the operating mechanism rotates the flat sliding ring, the openings in the flat sliding ring rotate so as to coincide with or move away from the openings of the bypass channels. The control valve mechanism is made up of a flat sliding ring with a number of openings which corresponds to the number of bypass channels, and a ring supporting base which supports the flat sliding ring in such a way that the flat sliding ring can slide freely in the circumferential direction. One side of the openings of the flat sliding ring opens into the space in the casing, and the other side of the openings opens into the opening of the bypass channel when it is rotated.