Patent ID: 6152685
Filing Date: 2000-11-28
Classification: F01D

Abstract:
A seal clearance control apparatus for a gas turbine stationary blade, comprising:a sensor to be mounted on a gas turbine stationary blade seal ring so as to confront a rotor disc face, said sensor being adapted to measure a clearance between a face of the gas turbine stationary blade seal ring and the rotor disc face, and to generate a clearance signal based on the measured clearance;a sealing feed air line for conveying air from a compressor through the gas turbine stationary blade and into a cavity in the gas turbine stationary blade, said sealing feed air line including a cooling passage portion and a bypass passage portion;a cooler disposed in said cooling passage portion of said sealing feed air line so as to cool the air conveyed through said cooling passage portion of said sealing feed air line;a flow regulator valve disposed in said bypass passage portion of said sealing feed air line, said bypass passage portion of said sealing feed air line being arranged parallel to said cooling passage portion of said sealing feed air line so as to form a bypass around said cooler; anda control unit for receiving said clearance signal from said sensor and for controlling said flow regulator valve based on said clearance signal, wherein said control unit opens said flow regulator valve when said clearance signal is greater than a preset clearance value, and wherein said control unit closes said flow regulator valve when said clearance signal is less than said preset clearance value.