Bucket mounted multi-stage turbine interstage seal and method of assembly

Patent metadata

Field	Value
Publication number	US-10337345-B2
Application number	US-201514627431-A
Country	US
Kind code	B2
Filing date	Feb 20, 2015
Priority date	Feb 20, 2015
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

A sealing system for a multi-stage turbine includes multiple interstage seal segments disposed circumferentially about a turbine rotor wheel assembly and extending axially between a forward turbine stage and an aft turbine stage. Each of the interstage seal segments includes a forward end portion including an outer seal surface and an inner support face, an aft end portion, including an outer seal surface and an inner support face and a main body portion extending axially from the forward end portion to the aft end. The main body portion includes at least two support webs coupling the outer seal surfaces and the inner support faces. The outer seal surfaces are configured to be retained in a radial direction by a land support on each of a forward and aft stage turbine buckets, such that substantially all the centrifugal load from the multiple interstage seal segments is transferred to the forward and aft stage turbine buckets. A method of assembling the sealing system is disclosed.

First claim

The invention claimed is:

1. A sealing system for a multi-stage turbine, the sealing system comprising:
an interstage seal disposed circumferentially about a turbine rotor wheel assembly of the multi-stage turbine and extending axially between a forward turbine stage and an aft turbine stage of the multi-stage turbine, wherein the interstage seal comprises:
a plurality of near flow path seal segments, wherein each of the plurality of near flow path seal segments comprises:
outer seal surfaces and inner support faces extending from at least one downstream region of the forward turbine stage to at least one upstream region of the aft turbine stage such that substantially all the centrifugal load from the interstage seal is transferred to a plurality of forward stage buckets and a plurality of aft stage buckets; and
at least two support webs coupling the outer seal surfaces and the inner support faces,

wherein each of the plurality of near flow path seal segments extends from an angel wing region of the plurality of forward stage buckets to an angel wing region of the plurality of aft stage buckets, the inner support faces extend from the angel wing region of the plurality of forward stage buckets to the angel wing region of the plurality of aft stage buckets, an aft portion of the interstage seal and the plurality of aft stage buckets comprise a plurality of cooperatively engaged retention features enabling at least one of radial and circumferential constraining of the interstage seal, the plurality of cooperatively engaged retention features comprise a plurality of recessed roundcuts that allow locking with a plurality of protruding tabs located on an aft portion of the interstage seal; and
a forward stage turbine rotor wheel of the forward turbine stage and an aft stage turbine rotor wheel of the aft turbine stage, wherein the forward stage turbine rotor wheel comprises a plurality of dovetail slots configured for operatively coupling the plurality of forward stage buckets and the aft stage turbine rotor wheel comprises a plurality of dovetail slots configured for operatively coupling the plurality of aft stage buckets.

2. The system of claim 1 , further comprising a plurality of intersegment spline seals located at both sides of each of the plurality of near flow path seal segments for preventing intersegment gap leakages.

3. The system of claim 1 , wherein the outer seal surface at the angel wing region of the plurality of forward stage buckets is configured to be constrained in the radial direction by a support land of the plurality of forward stage buckets and wherein the outer seal surface at the angel wing region of the plurality of aft stage buckets is configured to be constrained in a radial direction by a land support of the plurality of aft stage buckets.

4. The system of claim 1 , further comprising a seal wire or a seal rope disposed in a seal groove of the interstage seal and located one of axially and radially between the interstage seal and the plurality of aft stage buckets for isolating the aft turbine rotor wheel from a flow of hot gas path.

5. The system of claim 1 , wherein the plurality of cooperatively engaged retention features comprise a plurality of scalloped hooks located on an aft portion of the interstage seal and a plurality of L-shaped seats and landing faces at the angel wing region of the aft stage bucket.

6. The system of claim 5 , further comprising a capture means disposed between the plurality of L-shaped seats and landing faces at the angel wing region of the aft stage buckets and the plurality of scalloped hooks of the interstage seal for locking the interstage seal to the aft stage bucket.

7. The system of claim 6 , wherein the capture means comprises one of a retention ring, a lock wire and one or more fasteners.

Assignees

• Gen Electric

Inventors

• Samudrala Omprakash
• Casanova Fernando Jorge
• Sevincer Edip
• Webster Jonathan Michael

Classifications

• F05D2230/60

  Assembly methods · CPC title

• F01D11/02

  by non-contact sealings, e.g. of labyrinth type (for sealing space between rotor blade tips and stator F01D11/08) · CPC title

• F01D11/006 Primary

  Sealing the gap between rotor blades or blades and rotor · CPC title

• F01D11/005

  Sealing means between non relatively rotating elements · CPC title

• F01D11/003 Primary

  by packing rings; Mechanical seals · CPC title