US20150345308A1

US20150345308A1 - Turbine component

Info

Publication number: US20150345308A1
Application number: US14/292,985
Authority: US
Inventors: Frederic Woodrow Roberts, JR.; Victor John Morgan; Glenn Curtis Taxacher; Jacob John Kittleson
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 2014-06-02
Filing date: 2014-06-02
Publication date: 2015-12-03
Also published as: CN105275513A; CH709761A2; DE102015107848A1; JP2015227661A; JP6979751B2; CH709761B1; CN105275513B

Abstract

A turbine component is disclosed. The turbine component includes an outer shroud and an inner shroud having a first hook region extending over a first portion of the outer shroud and a second hook region extending over a second portion of the outer shroud. A first hook gap, a second hook gap, a first radial gap, and a second radial gap are arranged and disposed to permit the inner shroud to deflect from the outer shroud under thermal loading. Additionally or alternatively, the inner shroud includes ceramic matrix composite fibers having a thermal conductivity of less than 200 W/m·k and greater than 10 W/m·k.

Description

FIELD OF THE INVENTION

The present invention is directed to turbine components. More particularly, the present invention is directed to turbine components having an inner shroud and an outer shroud.

BACKGROUND OF THE INVENTION

Higher temperature and pressure operation of turbine components in turbine engines and power generation systems permit improved efficiency and operation in new configurations. Selecting materials capable of operating at such higher temperatures and pressures is difficult. Such materials can be cost prohibitive, difficult to produce, or difficult to fabricate. In addition, use of such different materials can require modification to cooling mechanisms, which can produce other complications.
In general, using less material for similar or better operation is desirable. Using less material decreases weight, decreases costs associated with manufacturing, decreases material costs, and provides several other advantages. However, using less material can create complicated geometric requirements and/or can produce undesirable forces not previously generated, such as stress. In addition, as is the case for using different materials, using less materials can require complicated and/or expensive modifications to cooling mechanisms, which can produce other complications.
Thus, there is an ongoing need to produce materials that are capable of withstanding higher temperature and pressures, that are capable of being applied in lower amounts/weights, are capable of operation without producing undesirable forces, and are capable of use in operational conditions without employing complicated and/or expensive cooling mechanisms.
A turbine component that shows one or more improvements in comparison to the prior art would be desirable in the art.

BRIEF DESCRIPTION OF THE INVENTION

In an embodiment, a turbine component includes an outer shroud and an inner shroud having a first hook region extending over a first portion of the outer shroud and a second hook region extending over a second portion of the outer shroud. The first hook region and the first portion define a first hook gap and the second hook region and the second portion define a second hook gap. A first radial gap extends between the first hook region opposite the first hook gap and the outer shroud and a second radial gap extends between the second hook region opposite the second hook gap and the outer shroud. The first hook gap, the second hook gap, the first radial gap, and the second radial gap are arranged and disposed to permit the inner shroud to deflect from the outer shroud under thermal loading.
In another embodiment, a turbine component includes an outer shroud and an inner shroud having a first hook region extending over a first portion of the outer shroud and a second hook region extending over a second portion of the outer shroud. The inner shroud includes ceramic matrix composite fibers having a thermal conductivity of less than 200 W/m·k and greater than 10 W/m·k.
In another embodiment, a turbine component includes an outer shroud and an inner shroud having a first hook region extending over a first portion of the outer shroud and a second hook region extending over a second portion of the outer shroud. The first hook region and the first portion define a first hook gap and the second hook region and the second portion define a second hook gap, the first hook gap and the second hook gap being arranged and disposed to permit the inner shroud to deflect from the outer shroud under thermal loading. The inner shroud includes ceramic matrix composite fibers having a thermal conductivity of less than 200 W/m·k and greater than 10 W/m·k.
Other features and advantages of the present invention will be apparent from the following more detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of a component having an inner shroud and an outer shroud, according to the disclosure.

Wherever possible, the same reference numbers will be used throughout the drawings to represent the same parts.

DETAILED DESCRIPTION OF THE INVENTION

Provided is a turbine component. Embodiments of the present disclosure, for example, in comparison to concepts failing to include one or more of the features disclosed herein are capable of simpler repair or replacement, are capable of withstanding higher temperature and pressures, are capable of being applied in lower amounts/weights, are capable of operation without producing undesirable forces, are capable of use in operational conditions without employing complicated and/or expensive cooling mechanisms, and/or are capable of mechanical loading to reduce leakage, thereby enhancing engine operational efficiencies.
FIG. 1 shows an embodiment of a turbine component 100, for example, capable of being used in a power generation system, a turbine engine, or both. The turbine component 100 includes an outer shroud 101 and an inner shroud 103 having a first hook region 105 extending over a first portion 109 of the outer shroud 101, and a second hook region 107 extending over a second portion 111 of the outer shroud 101. The first hook region 105 and the first portion 109 define a first hook gap 113 and the second hook region 107 and the second portion 111 define a second hook gap 115. A first radial gap 114 extends between the first hook region 105 opposite the first hook gap 113 and the outer shroud 101 and a second radial gap 116 extends between the second hook region 107 opposite the second hook gap 115 and the outer shroud 101. The first hook gap 113, the second hook gap 115, the first radial gap 114, and the second radial gap 116 are arranged and disposed to permit the inner shroud 103 to deflect from the outer shroud 101 under thermal loading.
The first hook gap 113, the second hook gap 115, the first radial gap 114, and the second radial gap 116 are any suitable geometry permitting deflection to reduce or eliminate stress during operational use of the turbine component 100. For example, in one embodiment, a suitable geometry includes are cuboid channels extending above the inner shroud 103. Although the term “hook” is used and FIG. 1 shows a first curved portion 102, a first planar portion 104 proximal to the first curved portion 102, a second curved portion 106 proximal to the first planar portion 104, and a second planar portion 108 proximal to the second curved portion 106, with the second planar portion 108 extending substantially parallel to the inner shroud and a hot gas path 119, it shall be understood that an angled, arching, curling, curvilinear, or other arrangement that extends into at least three separate planes shall be considered within the term “hook.” Other suitable geometries include, but are not limited to, a rectangular prism, a slot, a portion of a cylinder (such as, a semi-cylinder), an arch with a planar or substantially planar border connecting ends of the arch, or any other geometry providing deflection.
The first hook region 105, the first radial gap 114, and the first portion 109 are proximal to a leading edge 127 in comparison to a trailing edge 129. The second hook region 107, the second radial gap 116, and the second portion 111 are proximal to the trailing edge 129 in comparison to the leading edge 127. The first hook region 105 and the second hook region 107 adjustably secure the inner shroud 103 to the outer shroud 101. In one embodiment, the inner shroud 103 and the outer shroud 101 are capable of being secured together without bolting by relying on the first hook region 105 extending over the first portion 109 of the outer shroud 101, and the second hook region 107 extending over the second portion 111 of the outer shroud 101. Any other suitable force-providing mechanisms are capable of being used to further secure the outer shroud 101 and the inner shroud 103, as well as additional inner shrouds in embodiments with a plurality of the inner shrouds 103.
In one embodiment, the arrangement of the outer shroud 101 and the inner shroud 103, in conjunction with the selected materials, permits selective removal, repair, and/or replacement of the inner shroud 103 from the outer shroud 101. For example, in one embodiment, the inner shroud 103 and the outer shroud 101 do not bind under suitable operational conditions of the turbine component 100. As used herein, the term “bind” refers to local yielding or deformation of the outer shroud 101, for example, above the second planar portion 108. Suitable operational conditions include, but are not limited to, from about 1200° F. to above 3200° F. (about 650° C. to above 1760° C.).
The inner shroud 103 and the outer shroud 101 include any suitable materials capable of use within the operational conditions of the power generation system, the turbine engine, or any other system utilizing the turbine component 100. In one embodiment, the outer shroud 101 includes a metal or metallic material, such as, a nickel-based alloy or stainless steel. In one embodiment, the inner shroud 103 includes a ceramic matrix composite. As used herein, the term “ceramic matrix composite” includes, but is not limited to, carbon-fiber-reinforced carbon (C/C), carbon-fiber-reinforced silicon carbide (C/SiC), silicon-carbide-fiber-reinforced silicon carbide (SiC/SiC), and silicon-carbide-fiber-reinforced oxide matrix composite. In one embodiment, the ceramic matrix composite material has increased elongation, fracture toughness, thermal shock, dynamical load capability, and anisotropic properties as compared to a monolithic ceramic structure. One suitable ceramic matrix composite includes a Si—C fiber and a SiC-matrix, for example, with the Si—C fiber at a concentration, by volume, in the ceramic matrix composite of at least about 20%, for example, at least about 23%, at least about 28%, at least about 30%, between about 23% and about 32%, or any suitable combination, subcombination, range, or sub-range therein.
The materials for the inner shroud 103 are selected to provide a select range of thermal conductivity for the turbine component 100. In one embodiment, the thermal conductivity of the inner shroud 103 and/or the material for the inner shroud 103 is less than 200 W/m·k, less than 150 W/m·k, less than 140 W/m·k, less than 130 W/m·k, or any suitable combination, sub-combination, range, or sub-range therein. Additionally or alternatively, in one embodiment, the thermal conductivity of the inner shroud 103 and/or the material for the inner shroud 103 is greater than 10 W/m·k, less than 50 W/m·k, greater than 100 W/m·k, less than 110 W/m·k, or any suitable combination, sub-combination, range, or sub-range therein. In one embodiment, the thermal conductivity is 120 W/m·k.
The inner shroud 103 and/or the outer shroud 101 include any other suitable features that do not adversely affect deflection under thermal loading. For example, in one embodiment, outer shroud 101 includes an internal cavity 117, permitting the flow of a fluid (for example, air or compressed air). The internal cavity 117 is capable of being sealed, for example, by spline seals on circumferential faces of the turbine component 100 as well as compliant seals on the leading edge 127 and/or on the trailing edge 129. In one embodiment, the internal cavity 117 is pressurized, for example, to or greater than the operational pressure and/or the pressure of the hot gas path 119 that traverses along the distal portion of the inner shroud 103 relative to the outer shroud 101. In one embodiment, a transverse gap 121 extends parallel, substantially parallel, or tangential between the inner shroud 103 and the outer shroud 101 from the first hook region 105 to the second hook region 107 and permits heat to be transferred to the outer shroud 101 from the inner shroud 103. In another embodiment, an impingement plate 123 is positioned between the inner shroud 103 and the outer shroud 101. The impingement plate 123 includes material identical, similar, or different from the inner shroud 103 and provides cooling by transferring heat to the internal cavity 117.
The inner shroud 103 includes any suitable features to respond to the operational parameters, such as temperature and pressure, resulting from being positioned to be contacted by the hot gasses within the hot gas path 119. For example, in one embodiment, the inner shroud 103 includes an environmental barrier coating 125 positioned on a portion or all surfaces of the inner shroud 103 positioned to be contacted with the hot gasses in the hot gas path 119. The environmental barrier coating 125 is any suitable coating capable of operation in the hot gas path 119. To accommodate blade tip clearance, in one embodiment, an abradable rub coat (not shown) is included on the inner shroud 103 within the hot gas path 119. Suitable materials for the environmental barrier coating 125 and/or the abradable rub coat include, but are not limited to, barium strontium alumino silicate, mullite, yttria-stabilized zirconia, yttria mono and disilicates, yterbium mono and disilicates, and combinations thereof.
While the invention has been described with reference to one or more embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

What is claimed is:

1. A turbine component, comprising:

an outer shroud; and

an inner shroud having a first hook region extending over a first portion of the outer shroud and a second hook region extending over a second portion of the outer shroud;

wherein the first hook region and the first portion define a first hook gap and the second hook region and the second portion define a second hook gap;

wherein a first radial gap extends between the first hook region opposite the first hook gap and the outer shroud and a second radial gap extends between the second hook region opposite the second hook gap and the outer shroud;

wherein the first hook gap, the second hook gap, the first radial gap, and the second radial gap are arranged and disposed to permit the inner shroud to deflect from the outer shroud under thermal loading.

2. The turbine component of claim 1, wherein the inner shroud includes a ceramic matrix composite material.

3. The turbine component of claim 2, wherein the ceramic matrix composite material includes a Si—C fiber and a SiC-matrix.

4. The turbine component of claim 3, wherein the Si—C fiber is at a concentration, by volume, in the ceramic matrix composite of at least 20%.

5. The turbine component of claim 1, wherein the outer shroud includes a metal or metallic material.

6. The turbine component of claim 1, wherein the inner shroud has a thermal conductivity of less than 200 W/m·k.

7. The turbine component of claim 1, wherein the inner shroud has a thermal conductivity of greater than 10 W/m·k.

8. The turbine component of claim 1, wherein the inner shroud has a thermal conductivity of about 120 W/m·k.

9. The turbine component of claim 1, wherein the inner shroud and the outer shroud do not bind during operation of the turbine component.

10. The turbine component of claim 1, further comprising an impingement plate positioned between the inner shroud and the outer shroud.

11. The turbine component of claim 10, wherein the impingement plate includes a metal.

12. The turbine component of claim 1, wherein the outer shroud includes an internal cavity.

13. The turbine component of claim 12, wherein the internal cavity is pressurized.

14. The turbine component of claim 13, wherein the internal cavity is pressurized to a pressure equal to or greater than the hot gas path pressure.

15. The turbine component of claim 1, further comprising a transverse gap extending parallel to at least a portion of the inner shroud between the first hook region and the second hook region.

16. The turbine component of claim 1, further comprising an additional inner shroud positioned abutting the inner shroud and extending over the first portion of the outer shroud and the second portion of the outer shroud.

17. The turbine component of claim 1, further comprising an environmental barrier coating positioned on at least a portion of the inner shroud to be contacted by the hot gas path.

18. The turbine component of claim 17, wherein the environmental barrier coating is an abradable rub coat.

19. A turbine component, comprising:

an outer shroud; and

wherein the inner shroud includes ceramic matrix composite fibers having a thermal conductivity of less than 200 W/m·k and greater than 10 W/m·k.

20. A turbine component, comprising:

an outer shroud; and

wherein the first hook region and the first portion define a first hook gap and the second hook region and the second portion define a second hook gap, the first hook gap and the second hook gap being arranged and disposed to permit the inner shroud to deflect from the outer shroud under thermal loading;