APPARATUS TO SEAL WITH A TURBINE BLADE STAGE IN A GAS TURBINE

• US 20120260670A1
• Filed: 04/18/2011
• Published: 10/18/2012
• Est. Priority Date: 04/18/2011
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (General Electric Company)
• Original Assignee: General Electric Company
• Inventors: Foster, Gregory Thomas, Garcia-Crespo, Andres Jose
• Granted Patent: US 8,998,565 B2
• Time in Patent Office: Days
• US Class Current: 60/798
• CPC Class Codes: F01D 11/08 for sealing space between rotor blade tips and stator specially-shaped blade tips therefor F01D5/20
• CPC Class Codes: F01D 25/246 Fastening of diaphragms or stator-rings

Abstract

Disclosed is an apparatus configured to seal with a turbine blade stage of a gas turbine. The apparatus includes an outer shroud coupled to an inner shroud and configured to circumferentially surround the turbine blade stage. The inner shroud is configured to circumferentially surround the turbine blade stage to seal with the turbine blade stage and includes an attachment element configured to be inserted into the outer shroud to couple the inner shroud to the outer shroud.

Claims

1. An apparatus configured to seal with a turbine blade stage of a gas turbine, the apparatus comprising:

an outer shroud configured to circumferentially surround the turbine blade stage; and

an inner shroud configured to circumferentially surround the turbine blade stage to seal with the turbine blade stage and comprising an attachment element configured to be inserted into the outer shroud to couple the inner shroud to the outer shroud.

2. The apparatus according to claim 1, wherein the outer shroud is configured to be coupled to a casing that at least partially encloses the gas turbine.

3. The apparatus according to claim 2, wherein the outer shroud and the inner shroud form a cavity configured to be cooled by gas purging in the casing, the cavity being in communication with the attachment element.

4. The apparatus according to claim 1, wherein the attachment element comprises a flange defining a hole therein.

5. The apparatus according to claim 4, wherein the outer shroud defines a hole that is configured to be in alignment with the hole defined by the flange when the inner shroud is inserted into the outer shroud.

6. The apparatus according to claim 5, further comprising a pin configured to be inserted into the hole defined by the outer shroud and the hole defined by the inner shroud.

7. The apparatus according to claim 6, wherein alignment comprises the hole defined by the outer shroud being offset an amount from the hole defined by the flange such that when the pin is inserted, the pin is elastically deformed to keep the inner shroud pressing against the outer shroud.

8. The apparatus according to claim 6, wherein the pin comprises a taper configured to press the inner shroud against the outer shroud when the pin is inserted into the hole defined by the outer shroud and the hole defined by the flange.

9. The apparatus according to claim 1, wherein the inner shroud defines a void internal to the inner shroud.

10. The apparatus according to claim 9, wherein a width of the void is greater than a height of the void.

11. The apparatus according to claim 9, wherein the inner shroud comprises a rib disposed in the void and configured to increase the rigidity of the inner shroud.

12. The apparatus according to claim 1, wherein the outer shroud comprises one or more contact pads configured to contact the inner shroud when the inner shroud is coupled to the outer shroud.

13. The apparatus according to claim 1, wherein the inner shroud comprises a plurality of inner shroud sections, each inner shroud section being configured to be disposed adjacent to another inner shroud section with each inner shroud section circumferentially surrounding a portion of the turbine blade stage.

14. The apparatus according to claim 1, wherein the inner shroud is made of at least one of ceramic matrix composite material or a refractory alloy configured to withstand an operating temperature in the turbine blade stage.

15. A gas turbine comprising:

a compressor section configured to compress intake air;

a combustion section configured to combust compressed intake air and fuel;

a turbine section comprising a turbine blade stage configured to rotate upon impingement of hot gas from the combustion section;

an outer shroud configured to circumferentially surround the turbine blade stage; and

an inner shroud configured to circumferentially surround the turbine blade stage to seal with the turbine blade stage and comprising an attachment element configured to be inserted into the outer shroud to couple the inner shroud to the outer shroud.

16. A gas turbine system comprising:

a gas turbine comprising;

a turbine blade stage;

an outer shroud configured to circumferentially surround the turbine blade stage; and

an inner shroud configured to circumferentially surround the turbine blade stage to seal with the turbine blade stage and comprising an attachment element configured to be inserted into the outer shroud to couple the inner shroud to the outer shroud;

a load coupled to the gas turbine;

a casing configured to be coupled to the outer shroud and to at least partially enclose the gas turbine; and

a purge system configured to purge one or more cavities formed by the outer shroud and the inner shroud with purge gas that purges an interior of the casing.

17. The system according to claim 16, wherein the load is an electric generator.