SUPPLEMENTAL SEAL FOR THE CHORDAL HINGE SEALS IN A GAS TURBINE

摘要

In a gas turbine having a chordal hinge seal between an inner rail of each nozzle segment and an annular axially facing sealing surface of a nozzle support ring, a supplemental seal is disposed between the support ring and inner band of the nozzle segment on a lower pressure side of the chordal hinge seal. The supplemental seal includes a flexible sheet metal seal having a margin secured in a groove of the inner rail of the nozzle segments with a bent-over edge to form a seal therewith. The opposite margin has an edge which bears against the axially opposed sealing surface of the nozzle support ring. Leakage flow past the chordal hinge seal exerts sealing pressure against the preloaded flexible seal to maintain the seal between the sealing surfaces of the support ring and segments. The supplemental seal extends circumferentially and spans the joint between adjacent nozzle segments.