Turbine seal system and method

Patent metadata

Field	Value
Publication number	US-9624784-B2
Application number	US-201313937109-A
Country	US
Kind code	B2
Filing date	Jul 8, 2013
Priority date	Jul 8, 2013
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A system includes a multi-stage turbine that includes a first turbine stage having a first wheel having a plurality of first blade segments spaced circumferentially about the first wheel. The turbine also includes a second turbine stage having a second wheel having a plurality of second blade segments spaced circumferentially about the second wheel. The turbine also includes a seal assembly extending axially between the first and second turbine stages. The seal assembly includes a first coverplate coupled to the first turbine stage. The first coverplate includes a first air director. The seal assembly also includes a second coverplate coupled to the second turbine stage. The second coverplate comprises a second air director. The seal assembly also includes an interstage seal. The first coverplate, the second coverplate, or both are configured to support the interstage seal.

First claim

The invention claimed is:

1. A system, comprising:
a multi-stage turbine, comprising:
a first turbine stage comprising a first wheel having a plurality of first blade segments spaced circumferentially about the first wheel;
a second turbine stage comprising a second wheel having a plurality of second blade segments spaced circumferentially about the second wheel; and
a seal assembly extending axially between the first and second turbine stages, comprising:
a first coverplate coupled to the first turbine stage, wherein the first coverplate comprises a first seal;
a second coverplate coupled to the second turbine stage, wherein the second coverplate comprises a second seal; and
an interstage seal comprising a radially outermost surface, wherein the interstage seal is supported by the first coverplate, the second coverplate, or both at the radially outermost surface of the interstage seal, wherein the first coverplate comprises a first seal wing and/or the second coverplate comprises a second seal wing, and the radially outermost surface of the interstage seal contacts the first seal wing and/or the second seal wing.

2. The system of claim 1 , wherein the interstage seal comprises one or more seal teeth protruding from the radially outermost surface of the interstage seal and configured to block interstage axial leakage between the first turbine stage and the second turbine stage.

3. The system of claim 1 , comprising a forward sealing element, an aft sealing element, or both, wherein the forward sealing element is configured to block a flow of gases between the first coverplate and at least one of the first blade segments, the first wheel, or any combination thereof, and the aft sealing element is configured to block the flow of gases between the second coverplate and at least one of the second blade segments, the second wheel, or any combination thereof.

4. The system of claim 3 , wherein the forward sealing element, the aft sealing element, or a combination thereof, is disposed in at least one notch formed in at least one of the first coverplate, the first blade segments, or the first wheel, or any combination thereof.

5. The system of claim 1 , wherein the first coverplate comprises a first lip and the second coverplate comprises a second lip, wherein the first lip and second lip are configured to support the interstage seal.

6. The system of claim 1 , wherein the interstage seal is integrally formed with the first coverplate or the second coverplate.

7. The system of claim 1 , wherein the interstage seal assembly comprises an anti-rotation tab configured to restrict circumferential movement of at least one of the first coverplate with respect to the first turbine stage, the second coverplate with respect to the second turbine stage, or any combination thereof.

8. The system of claim 1 , wherein the first seal is disposed at a first radial seal distance that is greater than an outermost radial wheel distance of the interstage seal, and the second seal is disposed at a second radial seal distance that is greater than the outermost radial wheel distance of the interstage seal.

9. The system of claim 1 , comprising a nozzle disposed between the first turbine stage and the second turbine stage.

10. The system of claim 1 , wherein the interstage seal is configured to engage with the first coverplate and the second coverplate at a radial engagement distance that is greater than a radius of the first wheel, the second wheel, or any combination thereof.

11. The system of claim 1 , comprising cooling passages configured to direct a cooling fluid through the first turbine stage, the second turbine stage, or any combination thereof, wherein the first coverplate, the second coverplate, or any combination thereof, are configured to block the cooling fluid from escaping the cooling passages.

12. The system of claim 1 , wherein the seal assembly comprises a plurality of seal assemblies arranged circumferentially about the first turbine stage and the second turbine stage.

13. A method of installing a seal assembly between a first turbine stage and a second turbine stage of a multi-stage turbine, comprising:
installing a first coverplate comprising a first seal wing into a first wheel of the first turbine stage, wherein the first seal wing extends axially away from the first coverplate;
installing a first blade segment around a first circumferential rim of the first wheel, wherein the first blade segment is configured to secure the first coverplate;
installing a second coverplate comprising a second seal wing into a second wheel of the second turbine stage, wherein the second seal wing extends axially away from the second coverplate; and
installing an interstage seal between the first coverplate and the second coverplate, wherein the interstage seal comprises a radially outermost surface, the interstage seal is supported by the first seal wing with the radial outermost surface at a first radial engagement or the second seal wing with the radial outermost surface at a second radial engagement, and the interstage seal is secured between the first coverplate and the second coverplate; and
installing a second blade segment around a second circumferential rim of the second wheel.

14. The method of claim 13 , comprising integrally forming the interstage seal with the first coverplate or the second coverplate before installing the interstage seal.

15. The method of claim 13 , comprising installing at least one anti-rotation tab configured to restrict circumferential movement of at least one of the first coverplate with respect to the first turbine stage, the second coverplate with respect to the second turbine stage, or any combination thereof.

16. The method of claim 13 , wherein installing the first coverplate comprises installing the first coverplate into a recess in the first wheel.

17. A seal assembly for use in a multi-stage turbine, comprising:
a first coverplate configured to be coupled to a first turbine stage of the multi-stage turbine, wherein the first coverplate comprises a first seal;
a second coverplate configured to be coupled to a second turbine stage of the multi-stage turbine, wherein the second coverplate comprises a second seal;
an interstage seal comprising a radially outermost surface having a curved shape along an axial direction, wherein the first coverplate, the second coverplate, or both are configured to support the interstage seal at the radially outermost surface of the interstage seal; and one or more seal wings attached to the first coverplate or the second coverplate, wherein the one or more seal wings extend axially away from the coverplate and are configured to support the interstage seal at a first or a second radial engagement at the radially outermost surface of the interstage seal.

18. The seal assembly of claim 17 , wherein the interstage seal is integrally formed with one of the first coverplate or the second coverplate.

19. The system of claim 1 , wherein the interstage seal comprises a curved shape from a first end of the interstage seal to a second end of the interstage seal in an axial direction.

20. The system of claim 1 , wherein the first coverplate and/or the second coverplate comprises one or more support arms that are cantilever mounted from the coverplate and extends axially away from the coverplate.

Assignees

• Gen Electric

Inventors

• Hafner Matthew Troy

Classifications

• Y10T29/49245

  Vane type or other rotary, e.g., fan · CPC title

• F01D11/006

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

• F01D11/008

  by spacer elements between the blades, e.g. independent interblade platforms · CPC title

• F01D11/001 Primary

  for sealing space between stator blade and rotor · CPC title

• F01D5/3015

  with side plates · CPC title