WO2019156666A1

WO2019156666A1 - Transition-to-turbine seal assembly and method for manufacturing same

Info

Publication number: WO2019156666A1
Application number: PCT/US2018/017333
Authority: WO
Inventors: Robert H. Bartley; Richard L. SLOBODA; Daniel CASSAR
Original assignee: Siemens Aktiengesellschaft; Siemens Energy, Inc.
Priority date: 2018-02-08
Filing date: 2018-02-08
Publication date: 2019-08-15

Abstract

A transition-to-turbine seal assembly, and method for manufacturing same are provided. The method allows forming an arcuate seal piece (110) including a first sealing flange (112) and a second sealing flange (114). Each sealing flange defining a respective sealing surface (116, 118). The method further allows forming an arcuate fastening piece (120) including circumferentially spaced fastening hooks (122) interspersed between circumferentially extending gap-sections (124). The fastening piece may be affixed to the seal piece by way of a joint 130 to form the transition-to-turbine seal assembly. The simplicity of the proposed design is conducive to manufacturing-friendly and time-efficient operations that improve manufacturability, dimensional accuracy and repeatability, while reducing costs of the transition-to-turbine seal assembly.

Description

TRANSITION-TO-TURBINE SEAL ASSEMBLY AND METHOD FOR MANUFACTURING SAME

[0001] BACKGROUND

[0002 j 1. Field

[0003] Disclosed embodiments are generally related to turbomaehinery, such as gas turbine engines and, more particularly, to a seal assembly between a transition and a turbine stage of such engine, referred to herein as a transition-to-turbine seal assembly, and method for manufacturing same.

[0004] 2. Description of the Related Art

[0005 j In turbomachinery, such as a gas turbine engine, a number of combustion chambers combust fuel mixed with compressed air, and a hot working gas flowing from these combustion chambers is passed via respective transitions (also referred to by some in the art as ducts and tail tubes) to respective entrances of a turbine stage of the engine. More specifically, a plurality of combustion chambers may be arranged radially about a longitudinal axis of the gas turbine engine, and likewise radially arranged transitions comprise outlet ends that converge to form an annular inflow_^ of working gas to the turbine stage entrance. Each transition exit is joined by a number of seals each of which bridges a gap between a portion of the exit and one or more turbine components, such as turbine vane carrier. A number of factors—such as adjacent component growth, variances due to thermal expansion, mechanical loads, vibrational forces from combustion dynamics, etc.— can present challenges regarding durability and performance of such seals.

[0006] Disclosed embodiments offer an improved design solution for a transition-to- turbine seal assembly and method for manufacturing same. See US patents 8,142, 142 and 8,118,549 for examples of transition ducts for a gas turbine involving seal apparatuses. BRIEF DESCRIPTION

[0008] One disclosed embodiment is directed to a method for manufacturing a

transition-to-turbine seal assembly. The method allows forming an arcuate seal piece including a first sealing flange and a second sealing flange. Each sealing flange defining a respective sealing surface. The method further allows forming an arcuate fastening piece including a plurality of circumferentially spaced fastening hooks interspersed between a plurality of circumferentially extending gap-sections disposed between mutually adjacent hooks. The arcuate fastening piece may he affixed to a backend surface of one of the sealing flanges by way of a joint to form the transition-to-turbine seal assembly.

[0009] Another disclosed embodiment is directed to a transition-to-turbine seal

assembly that includes an arcuate seal piece formed by a first sealing flange and a second sealing flange. Each sealing flange defining a respective sealing surface. An arcuate fastening piece includes a plurality of circumferentially spaced fastening hooks interspersed between a plurality of circumferentially extending gap-sections between adjacent hooks. A joint allo ws affixing the arcuate fastening piece to a backend surface of one of the sealing flanges.

[0010] Reduced complexity in the proposed design for an improved transition-to- turbine seal assembly is believed to be conducive to manufacturing-friendly and time-efficient operations that substantially improve manufacturability, dimensional accuracy and repeatability, while reducing costs of transition-to- turbine seal assemblies.

[0011] BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is an isometric view of disclosed transition-to-turbine seal assemblies as may be annul arly interconnected to an annular array of gas turbine transition ducts to seal an outer diameter and an inner diameter of a transition- to-turbine interface. [0013] FIG. 2 is an exploded, isometric view of disclosed transition-to-turbine seal assemblies with respect to an outlet end of a gas turbine transition duct.

[0014] FIG 3 is an exploded, isometric view of a disclosed seal piece and a disclosed fastening piece that may joined by way of a joint to form a disclosed transition-to-turbine seal assembly.

[0015] FIG. 4 is an assembled, isometric view of the disclosed seal piece and the disclosed fastening piece to form a transition-to-turbine seal assembly shown in FIG. 3.

[0016] FIG. 5 is a cross-sectional view of a disclosed transition-to-turbine seal

assembly.

[0017] FIG. 6 is an isometric view of an alternative embodiment of a disclosed seal piece and a disclosed fastening piece.

[0018] FIG. 7 is a side vie of a disclosed transition-to-turbine seal assembly as may be interconnected between a transition and a first stage turbine vane structure disposed at an entrance of a turbine stage of the gas turbine engine.

[0019] DETAILED DESCRIPTION

[0020] The inventors of the present invention have recognized some practical

limitations regarding certain known transition-to-turbine seal assemblies. For example, such seal assemblies may involve a somewhat complicated mechanical design with a concomitant increase in manufacturing complexities and costs. Moreover, the manufacturing complexities involved with these known designs can lead to dimensional inconsistencies. Often, such known transition-to-turbine seal assemblies may involve a relatively stiff, singular piece that integrates affixing and sealing functionality but may lack a sufficient level of flexibility, and this can lead to, for example, a premature wear of the sealing surfaces and/or the affixing surfaces. [0021] In view of such recognition, the present inventors propose an innovative design solution for a transition-to-turbine seal assembly and method for manufacturing same. Disclosed embodiments, in a cost-effective and reliable manner, involve separate pieces that can be manufactured in a simplified manner for respectively providing the affixing and the sealing functionality. These pieces can then be joined in a straightforward manner to form a relatively flexible transition-to-turbine seal assembly. The joining of the separate pieces may be performed by way of a suitable joint such as, without limitation, a bonding joint, a welding joint, a brazing joint, etc. This separate forming is conducive to manufacturing-friendly and time-efficient operations that substantially improve manufacturability, dimensional accuracy and repeatability, and reduce costs.

[0022] In the following detailed description, various specific details are set forth in order to provide a thorough understanding of such embodiments. However, those skilled in the art will understand that disclosed embodiments may be practiced without these specific details that the aspects of the present invention are not limited to the disclosed embodiments, and that aspects of the present invention may be practiced in a variety of alternative embodiments. In other instances, methods, procedures, and components, which would be well- understood by one skilled in the art have not been described in detail to avoid unnecessary and burdensome explanation.

[0023] Furthermore, various operations may be described as multiple discrete steps performed in a manner that is helpful for understanding embodiments of the present invention. However, the order of description should not be construed as to imply that these operations need be performed in the order they are presented, nor that they are even order dependent, unless otherwise indicated. Moreover, repeated usage of the phrase“in one embodiment” does not necessarily refer to the same embodiment, although it may. It is noted that disclosed embodiments need not be construed as mutually exclusive embodiments, since aspects of such disclosed embodiments may be appropriately combined by one skilled in the art depending on the needs of a given application. [0024] The terms“comprising”,“including”,“having”, and the like, as used in the present application, are intended to be synonymous unless otherwise indicated.

Lastly, as used herein, the phrases“configured to” or“arranged to” embrace the concept that the feature preceding the phrases“configured to” or“arranged to” is intentionally and specifically designed or made to act or function in a specific way and should not be construed to mean that the feature just has a capability or suitability to act or function in the specified way, unless so indicated.

[0025] FIG. 1 is an isometric view of one non-limiting embodiment of a plurality of disclosed transition-to-turbine seal assemblies, such as may involve outer diameter seal assemblies 102 and inner diameter seal assemblies 104 that may be annulariy interconnected to an annular array of transitions 100 to respectively seal an outer diameter and an inner diameter of a transition-to- turbine interface. For example, it is envisioned that in one non-limiting embodiment the enhanced mechanical flexibility achieved with the disclosed seal assemblies can provide an effective and thorough sealing functionality, even at sea! locations not typically expected to do so, such as the respective boundaries between neighboring transitions.

[0026] FIG. 2 is an exploded, isometric view of disclosed transition-to-turbine seal assemblies 102, 104 with respect to an outlet end 106 of a gas turbine transition 100. The description below will focus on structural and/or operational relationships in connection the seal assemblies.

[0027] FIG. 3 is an exploded, isometric view of constituent pieces—that can be joined to form a disclosed transition-to-turbine seal assembly— such as without limitation, an arcuate seal piece 110 and an arcuate fastening piece 120. Seal piece 110 and fastening piece 120 may be joined to one another by way of a joint (schematically represented by dots 130 in FIG. 5) to form a disclosed transition-to-turbine seal assembly, such as seal assemblies 102, 104. Without limitation, joint 130 may be a bonding joint, a welding joint, a brazing joint or any other joint suitable for metallurgically joining two metal surfaces designed to operate in the hot temperature environment of a gas turbine engine.

[0028] In one non-limiting embodiment, arcuate seal piece 110 includes a first sealing flange 112 and a second sealing flange 114 that may be mutually orthogonal. Each sealing flange may define a respective sealing surface 116, 118 (FIG. 5).

[0029] In one non-limiting embodiment, arcuate fastening piece 120 includes a

plurality of circumferentially spaced fastening hooks 122 interspersed between a plurality of circumferentially extending gap-sections (schematically represented by twin- headed arrows 124) disposed between mutually adjacent hooks. These circumferentially extending gap-sections 124 are effective for improved mechanical flexibility, which in turn is effective for improved sealing and durability of disclosed transition-to-turbine seal assemblies.

Without limitation, circumferentially extending gap-sections 124 may provide respective degrees of freedom to the transition-to-turbine seal assembly along an axial direction (indicated by arrow 106 (FIG. 3), and in certain applications this may be particularly beneficial to outer diameter seals 102); and a radial direction (indicated by arrow 108 and in certain applications this may be particularly beneficial to inner diameter seals 104). In one non-limiting application, at least some of the plurality of circumferentially extending gap- sections (designated as 124’) may be circumferentially arranged to correspond to a location of a respective alignment pin. [0030] In one non-limiting embodiment, arcuate fastening piece 120 may include a mounting flange 121, and fastening piece 120 may be fastened by way of joint 130 (FIG. 5) formed between mounting flange 121 and a backend surface 119 of one of the sealing flanges (e.g., sealing flange 112) to form the transition- to-turbine seal assembly.

[0031] As may be appreciated in FIG. 3, in one non-limiting embodiment all (or at least some) of the plurality of circumferentially spaced fastening hooks 122 are constructed to form an integral structure. Thus, in this embodiment, the affixing of arcuate fastening piece 120 to backend surface 119 of sealing flange 112 would involve individually affixing the integral structure onto such backend surface. FIG 4 is an isometric view of seal piece 110 and fastening piece 120 assembled (e.g., joined) to form one disclosed transition-to-turbine seal assembly 105.

[0032] In one non-limiting alternative embodiment, as may be appreciated in FIG. 6, all (or at least some) of the plurality of circumferentially spaced fastening hooks 122 may be made up of a plurality of discrete hooks (in lieu of an integral multi-hook piece, as described above in the context of FIG. 3). Thus, in this embodiment, the affixing of arcuate fastening piece 122 to backend surface 119 of sealing flange 112 would involve individually affixing the plurality of discrete hooks onto such backend surface.

[0033] FIG. 7 is a side view of a disclosed transition-to-turbine seal assembly

including outer diameter seal assembly 102 and inner diameter seal assembly 102, as may be interconnected between the outlet of transition 100 and a first stage turbine vane structure 140 disposed at an entrance of the turbine stage of the gas turbine engine. [0034] In operation, disclosed embodiments of transition-to-turbine seal assemblies in a cost-effective and reliable manner involve separate pieces that can be manufactured in a simplified manner. This is believed to be conducive to manufacturing-friendly and time-efficient operations that substantially improve manufacturability, dimensional accuracy and repeatability, while reducing costs of such transition-to-turbine seal assemblies.

[0035] While embodiments of the present disclosure have been disclosed in

exemplary forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the scope of the invention and its equivalents, as set forth in the following claims.

Claims

What is claimed is:

1. A method for manufacturing a transition-to-turbine seal assembly, the method comprising:

forming an arcuate seal piece (110) including a first sealing flange (112) and a second sealing flange(l 14), each sealing flange defining a respective sealing surface (116, 118);

forming an arcuate fastening piece (120) including a plurality of

circumferentially spaced fastening hooks (122) interspersed between a plurality of circumferentially extending gap-sections (24) disposed between mutually adjacent hooks; and

affixing the arcuate fastening piece to a backend surface (119) of one of the sealing flanges to form the transition-to-turbine seal assembly.

2. The method of claim 1, wherein at least some of the plurality of circumferentially spaced fastening hooks (122) comprises an integral structure, and the affixing comprises individually affixing the integral structure onto the backend surface of the one of the sealing flanges.

3. The method of claim 1 , wherein at least some of the plurality of

circumferentially spaced hooks (122) comprises a plurality of discrete hooks, and the affixing comprises individually affixing the plurality of discrete hooks onto the backend surface of the one of the sealing flanges.

4. The method of claim 2, wherein the arcuate fastening piece comprises a

mounting flange (121) in the integral structure, and wherein the affixing comprises forming a joint (130) between the mounting flange in the integral structure and the backend surface of the one of the sealing flanges.

5. The method of claim 4, wherein the joint (130) is selected from the group consisting of a bonding joint, a welding joint and a brazing joint.

6. The method of claim 3, wherein the arcuate fastening piece comprises respective mounting flanges (121) in respective ones of the plurality of discrete hooks, and wherein the affixing comprises forming respective joints between the respective mounting flanges in the respective ones of the plurality of discrete hooks and the backend surface of the one of the sealing flanges.

7. The method of claim 6, wherein the respective joints (130) are selected from the group consisting of a bonding joint, a welding joint and a brazing joint.

8. The method of claim 1, configuring the plurality of circumferentially extending gap-sections (122) to provide respective degrees of freedom to the transition-to- turbine seal assembly along an axial direction (107) and a radial direction (108).

9. The method of claim 1, further comprising annularly interconnecting a first

plurality of transition-to-turbine seal assemblies (102) to seal an outer diameter of a transition-to-turbine interface, and annularly interconnecting a second plurality of transition-to-turbine seal assemblies (104) to seal an inner diameter of the transition-to-turbine interface.

10. The method of claim 1, circumferentially disposing at least some of the plurality of circumferentially extending gap-sections (124’) to receive a corresponding alignment pin.

11. A transition-to-turbine seal assembly comprising:

an arcuate seal piece (110) formed by a first sealing flange (112) and a second sealing flange (114), each sealing flange defining a respective sealing surface (116, 118);

an arcuate fastening piece (120) comprising a plurality of circumferentially spaced fastening hooks (122) interspersed between a plurality of circumferentially extending gap-sections (124) between adjacent hooks; and

a joint (13) to affix the arcuate fastening piece to a backend surface (119) of one of the sealing flanges.

12. The transition-to-turbine seal assembly of claim 11, wherein at least some of the plurality of circumferentially spaced fastening hooks (122) comprise an integral structure, and the integral structure is individually affixed by the joint onto the backend surface of the one of the sealing flanges.

13. The transition-to-turbine seal assembly of claim 11, wherein at least some of the plurality of circumferentially spaced hooks comprises a plurality of discrete hooks (122), and the plurality of discrete hooks is individually affixed by respective joints onto the backend surface of the one of the sealing flanges.

14. The transition-to-turbine seal assembly of claim 12, wherein the arcuate fastening piece comprises a mounting flange (121) in the integral structure, wherein the joint is formed between the mounting flange in the integral structure and the backend surface of the one of the sealing flanges.

15. The transition-to-turbine seal assembly of claim 14, wherein the joint (130) is selected from the group consisting of bonding joint, a welding joint and a brazing joint.

16. The transition-to-turbine seal assembly of claim 13, wherein the arcuate fastening piece comprises respective mounting flanges in respective ones of the plurality of discrete hooks, and wherein the respective joints are formed between the respective mounting flanges in the respective ones of the plurality of discrete hooks and the backend surface of the one of the sealing flanges.

17. The transition-to-turbine seal assembly of claim 16, wherein the respective joints are selected from the group consisting of bonding joint, a welding joint and a brazing joint.

18. The transition-to-turbine seal assembly of claim 11, wherein the plurality of circumferentially extending gap-sections (124) is effective to provide respective degrees of freedom to the transition-to-turbine seal assembly along an axial direction (107) and a radial direction (108).

19. A transition-to-turbine interface comprising a first plurality of the transition- to-turbine seal assemblies recited in claim 11 annularly interconnected to seal an outer diameter of the transition-to-turbine interface, and a second plurality of the transition-to-turbine seal assemblies to seal an inner diameter of the transition-to- turbine interface.