SEALING STRUCTURE FOR FIRST STAGE STATOR BLADE OF GAS TURBINE

摘要

A gas turbine first-stage stator blade sealing structure for preventing the sealing air from leaking from the inside even if the blade falls due to a thermal stress. A rear flange 12 of a first-stage stator blade 31 is formed into an arcuate shape having a straight rib 10, with which a stator blade support ring 13 contacts to form a sealing face. When the rear flange 12 and the stator blade support ring 13 fall relative to each other, as indicated by 13a and 13b, due to a thermal stress during operation, the upper end or lower end of the horizontal rib 10 contacts straight with the face of the circular stator blade support ring 13 so that no clearance is established to inhibit leakage of the sealing air. In the prior art where the horizontal rib 10 is absent, an arcuate clearance is established between the stator blade support ring 13 and the rear flange 12 as the support ring 13 inclines, to allow the sealing air to leak from the inside to the gas passages. This leakage can be prevented.