Gas turbine fuel nozzle end cover using Au—Ni braze and method producing same

Patent metadata

Field	Value
Publication number	US-10131010-B2
Application number	US-201213536577-A
Country	US
Kind code	B2
Filing date	Jun 28, 2012
Priority date	Jun 28, 2012
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

A brazed end cover assembly for a gas turbine combustor using Au—Ni braze is disclosed. The end cover assembly may include an end cover with openings, a flow insert, first and second gaps between the end cover and the flow insert, and first and second braze joints formed at the first and second gaps, wherein the braze materials used comprises Au and Ni. A method of brazing a flow insert into an end cover is also disclosed. The method may include providing an end cover and a flow insert with first and second gaps therebetween; applying a braze material to an outer surface of the flow insert, wherein the braze material comprises Au and Ni; inserting the flow insert into the end cover; heating the assembly to a brazing temperature for some time; and cooling the resulting brazed assembly to room temperature.

First claim

What is claimed is:

1. A brazed end cover assembly for a gas turbine combustor, comprising:
an end cover having first and second surfaces and having a plurality of openings for receiving a flow insert extending between said surfaces, said opening having a stepped inner hole so as to have at least first and second inner diameters;
a flow insert for being received in said stepped inner hole, said flow insert having first and second ends and a nozzle hole defined therethrough, and an outer surface of said flow insert being stepped so as to have at least first and second outer diameters generally corresponding to said inner diameters of said inner hole of said end cover;
a first gap between said first inner diameter of said inner hole and said first outer diameter of said flow insert;
a second gap between said second inner diameter of said inner hole and said second outer diameter of said flow insert;
a first braze joint formed at said first gap using a first braze material, said first braze material consists of Au and Ni or Au, Ni, Cu, Cr and B, said first braze material including no less than 65% Au and having a melting range between about 1742 F and 1814 F; and
a second braze joint formed at said second gap using a second braze material, said second braze material consists of Au and Ni, or Au, Ni, Cu, Cr and B, said second braze material including no less than 65% Au and having a melting range between about 1742 F and about 1814 F.

2. The brazed end cover assembly of claim 1 , wherein said flow insert and said end cover are formed from stainless steel.

3. The brazed end cover assembly of claim 1 , further comprising at least first and second fluid inlets extending from said second surface.

4. The brazed end cover assembly of claim 3 , further comprising:
a first manifold which is in fluid communication with said first fluid inlet; and a second manifold which is in fluid communication with said second fluid inlet.

5. The brazed end cover assembly of claim 1 , wherein said first and second braze materials comprise no more than 35% Ni.

6. The brazed end cover assembly of claim 1 , wherein said first and second braze materials comprise no less than 75% Au and no more than 25% Ni.

7. A gas turbine engine comprising: a compressor;
a plurality of combustors; and a turbine;
wherein said combustor has a brazed end cover assembly, said brazed end cover assembly comprising:
an end cover having first and second surfaces and having a plurality of openings for receiving a flow insert extending between said surfaces, said opening having a stepped inner hole so as to have at least first and second inner diameters;
a flow insert for being received in said stepped inner hole, said flow insert having first and second ends and a nozzle hole defined therethrough, and an outer surface of said flow insert being stepped so as to have at least first and second outer diameters generally corresponding to said inner diameters of said inner hole of said end cover;
a first gap between said first inner diameter of said inner hole and said first outer diameter of said flow insert;
a second gap between said second inner diameter of said inner hole and said second outer diameter of said flow insert;
a first braze joint formed at said first gap using a first braze material, said first braze material consists of Au and Ni or Au, Ni Cu, Cr and B, said first braze material including no less than 65% Au and having a melting range between about 1742 F and about 1814 F; and
a second braze joint formed at said second gap using a second braze material, said second braze material consists of Au and Ni or Au, Ni Cu, Cr and B, said second braze material including no less than 65% Au and having a melting range between about 1742 F and about 1814 F.

8. The gas turbine engine of claim 7 , wherein said flow insert and said end cover are formed from stainless steel.

9. The gas turbine engine of claim 7 , said brazed end cover assembly further comprising at least first and second fluid inlets extending from said second surface.

10. The gas turbine engine of claim 9 , said brazed end cover assembly further comprising:
a first manifold which is in fluid communication with said first fluid inlet; and
a second manifold which is in fluid communication with said second fluid inlet.

11. The gas turbine engine of claim 7 , wherein said first and second braze materials comprise no more than 35% Ni.

12. The gas turbine engine of claim 7 , wherein said first and second braze materials comprise no less than 75% Au and no more than 25% Ni.

13. A method for brazing a flow insert into an end cover to form a brazed assembly, comprising:
providing an end cover having first and second surfaces and having a plurality of openings for receiving an insert structure extending between said surfaces, said opening having a stepped inner hole so as to have at least first and second inner diameters;
providing a flow insert for being received in a respective said hole, said flow insert having first and second ends and a nozzle hole defined therethrough, and an outer surface of said flow insert being stepped so as to have at least first and second outer diameters generally corresponding to said inner diameters of said inner hole of said end cover;
wherein there is a first gap between said first inner diameter of said inner hole and said first outer diameter of said flow insert, and,
wherein there is a second gap between said second inner diameter of said inner hole and said second outer diameter of said flow insert;
cleaning said end cover and said flow insert;
applying a braze material to pre-determined circumferential portions of said outer surface of said flow insert, said braze material consists of Au and Ni or Au, Ni Cu, Cr and B, the braze material comprising no less than 65% Au and having a melting range between about 1742 F and about 1814 F;
inserting said flow insert with said braze material applied thereto into said respective inner hole of said end cover;
heating the assembly of said flow insert and said end cover to a brazing temperature;
maintaining said brazing temperature for a pre-determined time; and
cooling said assembly of said flow insert and said end cover from said brazing temperature to a predetermined end temperature at a pre-determined rate.

14. The method of claim 13 , wherein said cleaning comprises vacuum heating at least the surfaces to be razed to remove surface oxide.

15. The method of claim 13 , wherein said braze material is a braze wire.

16. The method of claim 13 , wherein said braze material is selected from a group consisting of a braze foil, a braze paste, and combinations thereof.

17. The method of claim 13 , wherein said braze material comprises no more than 45% Ni.

18. The method of claim 13 , wherein said braze material comprises no less than 75% Au and no more than 25% Ni.

19. The method of claim 13 , further comprising inspecting the brazed joints of said assembly, determining defective braze joints, and repairing said defective braze joints by re-applying said braze material and re-brazing said assembly.

20. The method of claim 19 , wherein said inspecting comprises X-ray inspection.

Assignees

• Dillard Gary J
• United Technologies Corp

Inventors

• Dillard Gary J

Classifications

• B23K1/008

  Soldering within a furnace (B23K1/012 takes precedence) · CPC title

• B23K1/206

  Cleaning · CPC title

• B23K1/0018 Primary

  Brazing of turbine parts · CPC title

• F23R3/46

  Combustion chambers comprising an annular arrangement of {several essentially tubular} flame tubes within a common annular casing or within individual casings · CPC title

• B23K2103/05

  Stainless steel · CPC title