SEAL STRUCTURE OF TIP OF MOVING BLADE FOR GAS TURBINE

摘要

PURPOSE:To reduce a leakage gas quantity from a gap of the tip of a moving blade, by a method wherein static pressure of main flow gas at an inlet of a moving blade and leakage gas at the tip of the moving blade are measured and a seal material is moved up and down by varying pressure of compressed air. CONSTITUTION:A moving blade 14 is rotated at the lower part of a seal material 12 and a fin 16 is processed on the tip of the moving blade. A static pressure opening 21 is provided on a moving blade inlet side of the seal material, and a static pressure opening 22 is provided on the seal material which is confronted with the center of the tip of the moving blade. The seal material 12 is moved up and down through a bellows 18 as pressure of compressed air 29 can be increased or decreased by differential pressure measured by both the static pressure openings 21 and 22. Leakage gas quantity can be reduced and efficiency of a turbine is improved as a clearance quantity can be made minimum in this manner.