Seal structure for gas turbine flange contact surfaces

Abstract

A steam-cooled type gas turbine has flange contact surfaces between adjacent rotor disks in which buffering sheets such as gaskets and the like can not be inserted. Further, the contact surfaces have a large diameter, making it difficult or impossible to ensure sufficient surface contact pressure for sealing. Yet preventing the leakage of coolant steam from these flange contact surfaces presents a very important problem. The present invention provides a seal structure for flange contact surfaces of a gas turbine which can enhance the sealability at these portions. The seal structure for flange contact surfaces includes a plurality of labyrinth-like grooves (8) which are formed in at least one of the flange contact surfaces (7). The seal structure of the present invention provides a gas turbine with high reliability and enhanced sealability. Further, a high surface contact pressure is obtained by reducing the area of the flange contact surfaces.

Dependencies are inferred from the claim text.