EP2581557A2

EP2581557A2 - Hot gas path component for turbine system

Info

Publication number: EP2581557A2
Application number: EP12179575.1A
Authority: EP
Inventors: Benjamin Paul Lacy; Brian Gene Brzek; Rebecca Christine Malish
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 2011-10-12
Filing date: 2012-08-07
Publication date: 2013-04-17
Also published as: CN103046973A; US20130094971A1

Abstract

A hot gas path component (30) for a turbine system is disclosed. The hot gas path component (30) includes a shell (32) having an exterior surface (36) and an interior surface (38). The hot gas path component (30) further includes a porous medium (70) having an exterior surface (72) and an interior surface (74), the exterior surface (72) positioned adjacent to the interior surface (38) of the shell (32). The porous medium (70) is configured for flowing a cooling medium therethrough.

Description

FIELD OF THE INVENTION

The subject matter disclosed herein relates generally to turbine systems, and more specifically to hot gas path components for turbine systems.

BACKGROUND OF THE INVENTION

Turbine systems are widely utilized in fields such as power generation. For example, a conventional gas turbine system includes a compressor, a combustor, and a turbine. During operation of the gas turbine system, various components in the system are subjected to high temperature flows, which can cause the components to fail. Since higher temperature flows generally result in increased performance, efficiency, and power output of the gas turbine system, the components that are subjected to high temperature flows must be cooled to allow the gas turbine system to operate at increased temperatures, increased efficiency, and/or reduced emissions.
Various strategies are known in the art for cooling various gas turbine system components. For example, a cooling medium may be routed from the compressor and provided to various components. In the compressor and turbine sections of the system, the cooling medium may be utilized to cool various compressor and turbine components.
Nozzles are one example of a hot gas path component that must be cooled. For example, various parts of the nozzle, such as the airfoil, are disposed in a hot gas path and exposed to relatively high temperatures, and thus require cooling.
One solution for cooling a nozzle is to include an impingement sleeve inside the airfoil. Cooling medium is flowed to the interior of the nozzle, and then flowed through the impingement sleeve and onto an interior surface of the airfoil. This approach facilitates impingement cooling of the airfoil. However, while impingement sleeves do provide adequate cooling of nozzles, increased cooling efficiency is desired. Such increased efficiency would allow for a reduction in the cooling medium required to cool the nozzles, and thus a reduction in emission and/or increase in firing temperature.
Accordingly, an improved hot gas path component, such as an improved nozzle, for a turbine system is desired in the art. For example, a hot gas path component with improved cooling features would be advantageous.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
In one aspect, the present invention resides in a hot gas path component for a turbine system. The hot gas path component includes a shell having an exterior surface and an interior surface. The hot gas path component further includes a porous medium having an exterior surface and an interior surface, the exterior surface positioned adjacent to the interior surface of the shell. The porous medium is configured for flowing a cooling medium therethrough.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 is a schematic illustration of a gas turbine system according to one embodiment of the present disclosure;
FIG. 2 is a perspective view of a nozzle according to one embodiment of the present disclosure;
FIG. 3 is a perspective view of an impingement sleeve according to one embodiment of the present disclosure;
FIG. 4 is a top cross-sectional view of a nozzle according to one embodiment of the present disclosure;
FIG. 5 is a top cross-sectional view of a nozzle according to another embodiment of the present disclosure;
FIG. 6 is a top cross-sectional view of a nozzle according to another embodiment of the present disclosure;
FIG. 7 is a close-up cross-sectional view of a hot gas path component according to one embodiment of the present disclosure; and
FIG. 8 is a close-up cross-sectional view of a hot gas path component according to another embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. 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 various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with 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.
FIG. 1 is a schematic diagram of a gas turbine system 10. The system 10 may include a compressor 12, a combustor 14, and a turbine 16. The compressor 12 and turbine 16 may be coupled by a shaft 18. The shaft 18 may be a single shaft or a plurality of shaft segments coupled together to form shaft 18.
The turbine 16 may include a plurality of turbine stages. For example, in one embodiment, the turbine 16 may have three stages. A first stage of the turbine 16 may include a plurality of circumferentially spaced nozzles and buckets. The nozzles may be disposed and fixed circumferentially about the shaft 18. The buckets may be disposed circumferentially about the shaft and coupled to the shaft 18. A second stage of the turbine 16 may include a plurality of circumferentially spaced nozzles and buckets. The nozzles may be disposed and fixed circumferentially about the shaft 18. The buckets may be disposed circumferentially about the shaft 18 and coupled to the shaft 18. A third stage of the turbine 16 may include a plurality of circumferentially spaced nozzles and buckets. The nozzles may be disposed and fixed circumferentially about the shaft 18. The buckets may be disposed circumferentially about the shaft 18 and coupled to the shaft 18. The various stages of the turbine 16 may be at least partially disposed in the turbine 16 in, and may at least partially define, a hot gas path. It should be understood that the turbine 16 is not limited to three stages, but rather that any number of stages are within the scope and spirit of the present disclosure.
Similarly, the compressor 12 may include a plurality of compressor stages (not shown). Each of the compressor 12 stages may include a plurality of circumferentially spaced nozzles and buckets.
An exemplary hot gas path component, which may be included in the turbine 16 and/or the compressor 12, is shown by reference numeral 30 in FIG. 2. In exemplary embodiments as shown, the hot gas path component 30 is a nozzle. Alternatively, however, a hot gas path component 30 according to the present disclosure may be a bucket, a shroud block, or any other suitable component that may be disposed in the path of hot gases flowing through a turbine system 10. The nozzle 30 may include a shell 32. In exemplary embodiments, the shell 32 may be an airfoil that extends between end caps 34. In embodiments wherein the shell 32 is an airfoil, it may have a generally aerodynamic contour. For example, the shell 32 may have an exterior surface 36 and an interior surface 38. In embodiments wherein the shell 32 is an airfoil, the exterior surface 36 may define a pressure side 42 and suction side 44 each extending between a leading edge 46 and a trailing edge 48, or any other suitable aerodynamic contour. One or more of the end caps 34 may define an opening (not shown). The opening may allow cooling medium 50 to flow to the interior 52 of the shell 32, def-med by the interior surface 38, as is generally known in the art.
In some embodiments, the hot gas path component 30 may further include an impingement sleeve 60, as shown in FIGS. 3, 4, 6 and 7. The impingement sleeve 60 may be disposed at least partially within the interior 52 of the shell 32, and spaced from the interior surface 38. The impingement sleeve may have an exterior surface 62 and interior surface 64, and may have a contour similar to that of the shell 32. Further, the impingement sleeve 60 may define one or more impingement passages 66 extending between the interior surface 64 and the exterior surface 62. Cooling medium 50 flowed into the interior 52 of the shell 32 may be flowed through these impingement passages 66. In other embodiments, the hot gas path component 30 may include any suitable sleeve therein. For example, a sleeve may include a plurality of spaced apart plates which allow cooling medium 50 to flow therebetween.
As shown in FIGS. 4 through 8, a hot gas path component 30 according to the present disclosure further includes one or more porous media 70. A porous medium 70 according to the present disclosure has an exterior surface 72 and an interior surface 74. The exterior surface 72 is positioned adjacent the interior surface 38 of the shell 32. In embodiments wherein the hot gas path component 30 includes an impingement sleeve 60 or other suitable sleeve, the porous media 70 are positioned between the hot gas path component 30 and impingement sleeve 60 or other suitable sleeve, such that the exterior surface 62 of the impingement sleeve 60 is positioned adjacent the interior surfaces 64 of the porous media 70.
The porous media 70 according to the present disclosure may advantageously allow improved cooling of the hot gas path component 30, such as of the shell 32. For example, in exemplary embodiments, the porous media 70 allow for conductive heat transfer from the shell 32 due to the cooling medium 50 flowing generally through the porous media 70. In further embodiments, as discussed below, the porous media 70 may additionally allow for impingement cooling of the shell 32, thus further improving cooling of the hot gas path component 30.
A porous medium 70 according to the present disclosure may be formed from any suitable porous material or materials having a matrix 76 and one or more voids 78. For example, in some embodiments, a porous medium 70, such as the matrix 76 thereof, may be formed from a metal or metal alloy foam, a ceramic foam, such as a ceramic matrix composite foam, or a carbon fiber foam. A foam is typically formed by mixing a material, such as a metal, ceramic, or carbon fiber, with another substance and then melting the substance away, leaving a porous foam. In other embodiments, the porous medium 70 may be formed from, for example, a plurality of packed together beads of a suitable material, or any other suitable material or materials. The porous medium 70 may thus be configured for flowing cooling medium 50 therethrough. The cooling medium 50 may flow through the voids 78 in a porous medium 70 before contacting the interior surface 38 of the shell 32, thus in exemplary embodiments facilitating convection cooling.
As shown in FIGS. 4 and 5, in some embodiments, the hot gas path component 30 may include one porous medium 70. In exemplary embodiments, the porous medium 70 is continuous in the direction of the contour, such as the aerodynamic contour, of the shell 32, such that substantially all of a cross-sectional profile of the interior surface 38 is adjacent to the porous medium 70. In other embodiments, only a portion of a cross-sectional profile of the interior surface 38 may be adjacent to the porous medium.
As shown in FIG. 6, in other embodiments, the hot gas path component 30 may include more than one porous medium 70. Each of the plurality of porous mediums 70 may be spaced apart from others of the plurality of porous mediums 70, such as in the direction of the contour, such as the aerodynamic contour, of the shell 32 as shown or in any other suitable direction, or may abut or otherwise contact others of the plurality of porous mediums 70.
As discussed above, in some embodiments as shown in FIGS. 4, 6 and 7, an impingement sleeve 60 may be positioned adjacent the interior surface 74 of a porous medium 70. In these embodiments, cooling medium 50 may be flowed through the impingement passages 66 of the impingement sleeve 60 to the porous medium 70. In other embodiments, as shown in FIGS. 5 and 8, no impingement sleeve 60 may be included in the hot gas path component 30.
As further shown in FIGS. 5 and 8, in some embodiments, the interior surfaces 74 of the porous media 70 may be treated. Such treating may seal the interior surface 74, such that voids 78 defined in a porous medium 70 do not extend to the interior surface 74. Passages, such as impingement passages, may then be formed through such treated interior surface 74, as discussed below, to allow cooling medium 50 to flow therethrough. Treating of the interior surface 74 may include grinding, filling, brazing, welding, soldering, or any other suitable treating technique that would suitably seal the interior surface 74.
In exemplary embodiments, as shown in FIGS. 4 through 8, a porous medium 70 may be in contact with the shell 32 and/or optional impingement sleeve 60. Thus, the exterior surface 72 of the porous medium 70 may contact the interior surface 38 of the shell 32. The interior surface 74 of the porous medium 70 may contact the exterior surface 62 of the impingement sleeve 60. In some embodiments wherein the porous medium 70 contacts the shell 32 and/or the impingement sleeve 60, the porous medium 70 may be press-fit, bonded such as through a suitable adhesive or bonding process, or otherwise connected to the shell 32 and/or impingement sleeve 60. In other embodiments, a porous medium 70 may be spaced from the shell 32 and/or the impingement sleeve 60. Thus, a porous medium 70 according to the present disclosure may be in contact with both an shell 32 and an impingement sleeve 60, may be spaced from both a shell 32 and an impingement sleeve 60, or may be in contact with one of an shell 32 or an impingement sleeve 60 and spaced from the other of an shell 32 or an impingement sleeve 60.
In further exemplary embodiments, as shown in FIGS. 7 and 8, one or more impingement passages 80 may be defined in a porous medium 70. The impingement passages 80 may extend between the interior surface 74 and the exterior surface 72 of the porous medium 70. Such impingement passages 80 may allow for cooling medium 50 to flow therethrough and impinge on the inner surface 38 of the shell 32, thus impingement cooling the shell 32. Further, portions of the cooling medium 50 may enter the impingement passages 80 and then flow from the impingement passages 80 through the voids 78 in the porous medium 70, thus otherwise facilitating cooling of the shell 32.
Such impingement passages 80 may have any suitable cross-sectional shape, such as circular or oval-shaped, square or rectangle shaped, triangular, or having any other suitable polygonal shape. For example, in some exemplary embodiments, the impingement passages 80 may have generally circular cross-sectional shapes, while in others the impingement passages 80 may have generally rectangular cross-sectional shapes and be characterized as slots. The impingement passages 80 may have cross-sectional areas that are larger than, identical to, or smaller than those of the impingement passages 66.
Further, the impingement passages 80 may have any suitable cross-sectional area, and this cross-sectional area may be constant throughout the length of the passage 80 or may vary. For example, in some embodiments, a passage 80 may taper, or may have a constricted portion or a relatively larger portion.
Still further, the impingement passages 80 may be linear, curvilinear, or have any other suitable path. For example, in some embodiments, an impingement passage 80 may be curvilinear, having a generally serpentine path. In other embodiments, an impingement passage 80 may simply have a linear path.
An impingement passage 80 according to the present disclosure may be drilled or otherwise formed into a porous medium 70. In embodiments wherein an impingement sleeve 60 is adjacent to the porous medium 70, the impingement passages 66 in the impingement sleeve 60 may generally align with the impingement passages 80 of the porous medium 70. In embodiments wherein the interior surface 74 of a porous medium 70 is treated, the impingement passages 80 may extend through this treated surface.
A shell 32 according to the present disclosure may further define one or more cooling passage 82, as shown in FIGS. 7 and 8. The cooling passages 80 may extend between the interior surface 38 and the exterior surface 36 of the shell 32. Such cooling passages 80 may have any suitable cross-sectional shape, cross-sectional area, and cross-sectional path, as discussed above. Further, in some embodiments, the cooling passages 80 may be film cooling passages, and may be angled and formed such that cooling medium 50 flowed therethrough and exhausted therefrom then provides film cooling to the exterior surface 36 of the shell 32.
A cooling passage 82 may be aligned with a porous medium 70, as shown, or with an impingement passage 80 defined therein. Cooling medium 50 flowing through the impingement passages 80 and porous medium 70 may flow into and through the cooling passage 82. In some embodiments, as shown in FIG. 7, a cooling passage 82 extends only through the shell 32 between the interior surface 38 and exterior surface 36. In other embodiments, as shown in FIG. 8, a cooling passage 82 may further extend at least partially into and be at least partially defined in a porous medium 70. For example, a cooling passage 82 may extend through the exterior surface 72 of a porous medium 70, as shown.
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

A hot gas path component (30) for a turbine system (10), comprising:
a shell (32) having an exterior surface (36) and an interior surface (38); and

a porous medium (70) having an exterior surface (72) )and an interior surface (74), the exterior surface (72) positioned adjacent to the interior surface (38) of the shell (32), the porous medium (70) configured for flowing a cooling medium (50) therethrough.
The hot gas path component of claim 1, further comprising an impingement sleeve (60) positioned adjacent the interior surface (74) of the porous medium (70).
The hot gas path component of claim 1 or 2, wherein the interior surface (74) of the porous medium (70) is treated.
The hot gas path component of any of claims 1 to 3, wherein the porous medium (70) defines an impingement passage (66) extending between the interior surface (74) and the exterior surface (72).
The hot gas path component of any of claims 1 to 4, wherein the exterior surface (72) of the porous medium (70) is in contact with the interior surface (38) of the shell (32).
The hot gas path component of any preceding claim, wherein the shell (32) defines a cooling passage (82) extending between the interior surface (38) and the exterior surface (36).
The hot gas path component of claim 6, wherein the cooling passage (82) further extends at least partially into the porous medium (70).
The hot gas path component of any preceding claim, wherein the porous medium (70) is formed from one of a metal foam, a ceramic foam, or a carbon fiber foam.
The hot gas path component of any preceding claim, further comprising a plurality of porous mediums (70), and wherein an exterior surface (72) of each of the plurality of porous mediums (70) is positioned adjacent to the interior surface (38) of the shell (32).
The hot gas path component of any preceding claim, wherein the hot gas path component (30) is a nozzle.
A turbine system (10), comprising:
a compressor (12);

a turbine (16) coupled to the compressor (12); and

a plurality of hot gas path components (30) disposed in at least one of the compressor (12) or the turbine (16), at least one of the hot gas path components (30) as recited in any of claim 1 to 10.