COMBUSTOR AND A METHOD FOR REPAIRING A COMBUSTOR
A combustor includes an end cover with a borehole through the end cover. The combustor further includes an insert in the borehole in the end cover and at least one continuous passage through the end cover and the insert. A ring is fixedly connected to the end cover with a seal between the ring and the insert. A method for repairing a combustor includes fixedly connecting a ring to an end cover and installing a replacement insert in the end cover. The method further includes installing a seal between the ring and the replacement insert.
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The present invention generally involves a combustor and a method for repairing a combustor. In particular, various embodiments of the present invention provide a system or method for modifying or repairing an end cover in the combustor.
BACKGROUND OF THE INVENTIONCombustors are known in the art for igniting fuel with air to produce combustion gases having a high temperature and pressure. For example, gas turbine systems, aircraft engines, and numerous other combustion-based systems may include one or more combustors that mix a working fluid, such as air, with fuel and ignite the mixture to produce high temperature and pressure combustion gases. The combustion gases may then be used to rotate a turbine, provide thrust, or perform various other forms of work.
Each combustor generally includes an end cover and a liner that surround and define a combustion chamber, and the working fluid may flow along the outside of the liner to remove heat from the liner before flowing into the combustion chamber through one or more nozzles. The nozzles may be radially arranged in or connected to the end cover, and fuel may be supplied to the nozzles through the end cover for injection into the combustion chamber. For example, passages through the end cover may connect to complementary passages in the nozzles to provide fluid communication through the end cover and nozzles to the combustion chamber. An insert between the end cover and each nozzle may enable a single end cover design to accommodate several different passages to supply air, fuel, and/or other fluids to the fuel nozzle. The insert may be attached to the end cover by bolts, brazing, or weld joints, and each nozzle may then be bolted or otherwise attached to the insert and/or the end cover to complete the fluid pathway through the end cover, insert, and each nozzle.
Temperature changes associated with the combustor may produce uneven expansion between the end cover and the insert. Over time, the braze or weld joints between the end cover and the insert may crack or fail, possibly resulting in internal leakage between the various passages in the end cover and/or insert. For some end cover designs, the braze or weld joints may be removed and replaced by one or more seals between the end cover and the insert, as disclosed in U.S. Pat. No. 7,134,287, assigned to the same assignee as the present invention. However, geometric constraints preclude adequate seating surfaces for the replacement seals in some end cover designs. Therefore, a new combustor design that allows for replacement or repair of one or more braze or weld joints in the end cover would be useful.
BRIEF DESCRIPTION OF THE INVENTIONAspects and advantages of the invention are set forth below in the following description, or may be obvious from the description, or may be learned through practice of the invention.
One embodiment of the present invention is a combustor that includes an end cover with a borehole through the end cover. The combustor further includes an insert in the borehole in the end cover and at least one continuous passage through the end cover and the insert. A ring is fixedly connected to the end cover with a seal between the ring and the insert.
Another embodiment of the present invention is a combustor that includes an end cover and a nozzle connected to the end cover. The combustor further includes an insert between the end cover and the nozzle and at least one continuous passage through the end cover and the insert. A ring is fixedly connected to the end cover with a seal between the ring and the insert.
The present invention also includes a method for repairing a combustor. The method includes fixedly connecting a ring to an end cover and installing a replacement insert in the end cover. The method further includes installing a seal between the ring and the replacement insert.
Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the specification.
A full and enabling disclosure of the present invention, including the best mode thereof to one skilled in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:
Reference will now be made in detail to present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention.
Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
During transient or extended operations, temperature gradients between the end cover 18 and the insert 34 may weaken or damage the braze 36 or weld joints between the end cover 18 and the insert 34. As a result, leaks may develop between the borehole 30 and the passages 32, allowing co-mingling or mixing of the fluids in the borehole 30 and/or passages 32. Although the combustor 10 may continue to operate with some amount of leakage between the borehole 30 and various passages 32, any leakage may compromise the combustor operation by altering the designed fluid flow through the nozzle 14. The weakened or damaged braze 36 or weld joints may be difficult to inspect and detect, and once detected, the spatial or geometric limitations inside the borehole 30 may make conventional repairs difficult or impractical without replacing the entire end cover 18. Various embodiments of the present invention provide a system and method for modifying a new or existing end cover 18 that replaces or repairs one or more existing braze 36 or weld joints with a ring 40. The ring 40 typically has a lower stiffness than the original insert 34, resulting in lower tensile stresses between the ring 40 and the end cover 18. In addition, due to the removal or repair of one or more braze 36 or weld joints, the ring 40 may be more accessible to subsequent inspection and repairs, if necessary. As a result, the end cover 18 may be modified or repaired to couple the end cover 18 to the nozzle 14 without requiring a redesigned or replacement end cover 18, producing substantial savings in repair or replacement costs.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
Claims
1. A combustor comprising:
- a. an end cover;
- b. a borehole through the end cover;
- c. an insert in the borehole in the end cover;
- d. at least one continuous passage through the end cover and the insert;
- e. a ring fixedly connected to the end cover; and
- f. a seal between the ring and the insert.
2. The combustor as in claim 1, wherein the borehole through the end cover is stepped in an axial direction.
3. The combustor as in claim 1, wherein the ring is at least one of brazed or welded to the end cover.
4. The combustor as in claim 1, further comprising a plurality of continuous passages through the end cover and the insert.
5. The combustor as in claim 1, further comprising a nozzle connected to the end cover downstream of the insert.
6. The combustor as in claim 1, further comprising a plurality of rings fixedly connected to the end cover.
7. The combustor as in claim 6, further comprising a seal between each of the plurality of rings and the insert.
8. A combustor comprising:
- a. an end cover;
- b. a nozzle connected to the end cover;
- c. an insert between the end cover and the nozzle;
- d. at least one continuous passage through the end cover and the insert;
- e. a ring fixedly connected to the end cover; and
- f. a seal between the ring and the insert.
9. The combustor as in claim 8, further comprising a plurality of nozzles radially arranged in the end cover.
10. The combustor as in claim 8, wherein the ring is at least one of brazed or welded to the end cover.
11. The combustor as in claim 8, further comprising a plurality of continuous passages through the end cover and the insert.
12. The combustor as in claim 8, further comprising a plurality of rings fixedly connected to the end cover.
13. The combustor as in claim 12, further comprising a seal between each of the plurality of rings and the insert.
14. A method for repairing a combustor comprising:
- a. fixedly connecting a ring to an end cover;
- b. installing a replacement insert in the end cover; and
- c. installing a seal between the ring and the replacement insert.
15. The method as in claim 14, further comprising removing at least a portion of an original insert from the end cover.
16. The method as in claim 14, further comprising brazing or welding the ring to the end cover.
17. The method as in claim 14, further comprising connecting a nozzle to the end cover downstream of the replacement insert.
18. The method as in claim 14, further comprising fixedly connecting a plurality of rings to the end cover.
19. The method as in claim 18, further comprising installing a seal between each of the plurality of rings and the replacement insert.
Type: Application
Filed: Jan 18, 2011
Publication Date: Jul 19, 2012
Applicant: GENERAL ELECTRIC COMPANY (Schenectady, NY)
Inventor: Keith C. Belsom (Laurens, SC)
Application Number: 13/008,051
International Classification: F23R 3/60 (20060101); B21D 53/00 (20060101);