U.S. patent application number 13/289146 was filed with the patent office on 2013-05-09 for bucket assembly for turbine system.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. The applicant listed for this patent is Sergio Daniel Marques Amaral, Mark Steven Honkomp, Jalindar Appa Walunj. Invention is credited to Sergio Daniel Marques Amaral, Mark Steven Honkomp, Jalindar Appa Walunj.
Application Number | 20130115060 13/289146 |
Document ID | / |
Family ID | 47142999 |
Filed Date | 2013-05-09 |
United States Patent
Application |
20130115060 |
Kind Code |
A1 |
Walunj; Jalindar Appa ; et
al. |
May 9, 2013 |
BUCKET ASSEMBLY FOR TURBINE SYSTEM
Abstract
A bucket assembly for a turbine system is disclosed. The bucket
assembly includes a main body having an exterior surface and
defining a main cooling circuit, and a platform surrounding the
main body and at least partially defining a platform cooling
circuit. The platform includes a forward portion and an aft portion
each extending between a pressure side slash face and a suction
side slash face and further includes a forward face, an aft face,
and a top face. The platform cooling circuit includes an upper
surface and a lower surface. The bucket assembly further includes a
passage extending between and providing fluid communication between
the main cooling circuit and the platform cooling circuit. An end
opening of the passage is defined in the lower surface of the
platform cooling circuit.
Inventors: |
Walunj; Jalindar Appa;
(Bangalore, IN) ; Honkomp; Mark Steven; (Taylors,
SC) ; Amaral; Sergio Daniel Marques; (Cambridge,
MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Walunj; Jalindar Appa
Honkomp; Mark Steven
Amaral; Sergio Daniel Marques |
Bangalore
Taylors
Cambridge |
SC
MA |
IN
US
US |
|
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
47142999 |
Appl. No.: |
13/289146 |
Filed: |
November 4, 2011 |
Current U.S.
Class: |
415/176 ;
416/97R |
Current CPC
Class: |
Y02T 50/60 20130101;
Y02T 50/673 20130101; F01D 5/187 20130101; F05D 2240/81 20130101;
Y02T 50/676 20130101; F01D 5/186 20130101 |
Class at
Publication: |
415/176 ;
416/97.R |
International
Class: |
F01D 5/18 20060101
F01D005/18; F01D 5/08 20060101 F01D005/08 |
Claims
1. A bucket assembly for a turbine system, comprising: a main body
having an exterior surface and defining a main cooling circuit; a
platform surrounding the main body and at least partially defining
a platform cooling circuit, the platform comprising a forward
portion and an aft portion each extending between a pressure side
slash face and a suction side slash face and further comprising a
forward face, an aft face, and a top face, the platform cooling
circuit comprising an upper surface and a lower surface; and a
passage extending between and providing fluid communication between
the main cooling circuit and the platform cooling circuit, wherein
an end opening of the passage is defined in the lower surface of
the platform cooling circuit.
2. The bucket assembly of claim 1, wherein the main cooling circuit
is a forward main cooling circuit.
3. The bucket assembly of claim 1, wherein the end opening is an
outlet.
4. The bucket assembly of claim 1, wherein at least a portion of
the passage extends in a generally radial direction.
5. The bucket assembly of claim 4, wherein the portion of the
passage extending in the radial direction defines the end
opening.
6. The bucket assembly of claim 1, wherein the platform cooling
circuit comprises a forward portion and an intermediate portion,
and wherein the end opening of the passage is defined in the
intermediate portion.
7. The bucket assembly of claim 1, wherein the platform cooling
circuit further comprises an outlet portion.
8. The bucket assembly of claim 1, wherein at least a portion of
the platform cooling circuit has a generally serpentine path.
9. The bucket assembly of claim 1, further comprising an exhaust
passage defined in the platform and in fluid communication with the
passage.
10. The bucket assembly of claim 9, wherein an outlet of the
exhaust passage is defined in the top face of the platform.
11. The bucket assembly of claim 9, wherein an outlet of the
exhaust passage is defined in the pressure side slash face of the
platform.
12. The bucket assembly of claim 1, wherein the main body comprises
a shank and an airfoil.
13. A turbine system, comprising: a compressor; a turbine coupled
to the compressor; and a plurality of bucket assemblies disposed in
at least one of the compressor or the turbine, at least one of the
bucket assemblies comprising: a main body having an exterior
surface and defining a main cooling circuit; a platform surrounding
the main body and at least partially defining a platform cooling
circuit, the platform comprising a forward portion and an aft
portion each extending between a pressure side slash face and a
suction side slash face and further comprising a forward face, an
aft face, and a top face, the platform cooling circuit comprising
an upper surface and a lower surface; and a passage extending
between and providing fluid communication between the main cooling
circuit and the platform cooling circuit, wherein an end opening of
the passage is defined in the lower surface of the platform cooling
circuit.
14. The turbine system of claim 14, wherein the main cooling
circuit is a forward main cooling circuit.
15. The turbine system of claim 14, wherein the end opening is an
outlet.
16. The turbine system of claim 14, wherein at least a portion of
the passage extends in a generally radial direction.
17. The turbine system of claim 14, wherein the platform cooling
circuit comprises a forward portion and an intermediate portion,
and wherein the end opening of the passage is defined in the
intermediate portion.
18. The turbine system of claim 14, wherein the platform cooling
circuit further comprises an outlet portion.
19. The turbine system of claim 14, wherein at least a portion of
the platform cooling circuit has a generally serpentine path.
20. The turbine system of claim 14, further comprising an exhaust
passage defined in the platform and in fluid communication with the
passage.
Description
FIELD OF THE INVENTION
[0001] The subject matter disclosed herein relates generally to
turbine systems, and more specifically to bucket assemblies for
turbine systems.
BACKGROUND OF THE INVENTION
[0002] 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.
[0003] 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.
[0004] Buckets are one example of a hot gas path component that
must be cooled. For example, various parts of the bucket, such as
the airfoil, the platform, the shank, and the dovetail, are
disposed in a hot gas path and exposed to relatively high
temperatures, and thus require cooling. Various cooling passages
and cooling circuits may be defined in the various parts of the
bucket, and cooling medium may be flowed through the various
cooling passages and cooling circuits to cool the bucket.
[0005] One specific component of a bucket that requires cooling is
the platform. Thus, a platform cooling circuit is provided in many
know buckets. A typical platform cooling circuit includes an inlet
portion that extends from the platform to the shank of the bucket
in a curvilinear fashion. Specifically, a curvilinear portion of
the inlet portion is typically located near an exterior
intersection between the platform and shank. Thus, during operation
of the bucket, when the platform and shank are subjected to
differing temperatures, this temperature differential may create
significant bending stresses at the curvilinear portion of the
inlet portion. These stresses can lead to a low thermal fatigue
life, and thus require frequent repair or replacement of
buckets.
[0006] Accordingly, an improved bucket assembly for a turbine
system is desired in the art. Specifically, a bucket assembly with
an improved platform cooling circuit would be advantageous.
BRIEF DESCRIPTION OF THE INVENTION
[0007] 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.
[0008] In one embodiment, a bucket assembly for a turbine system is
disclosed. The bucket assembly includes a main body having an
exterior surface and defining a main cooling circuit, and a
platform surrounding the main body and at least partially defining
a platform cooling circuit. The platform includes a forward portion
and an aft portion each extending between a pressure side slash
face and a suction side slash face and further includes a forward
face, an aft face, and a top face. The platform cooling circuit
includes an upper surface and a lower surface. The bucket assembly
further includes a passage extending between and providing fluid
communication between the main cooling circuit and the platform
cooling circuit. An end opening of the passage is defined in the
lower surface of the platform cooling circuit.
[0009] 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
[0010] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth in the specification, which makes
reference to the appended figures, in which:
[0011] FIG. 1 is a schematic illustration of a gas turbine system
according to one embodiment of the present disclosure;
[0012] FIG. 2 is a perspective view of a bucket assembly according
to one embodiment of the present disclosure;
[0013] FIG. 3 is a front view illustrating the internal components
of a bucket assembly according to one embodiment of the present
disclosure;
[0014] FIG. 4 is a partial perspective view illustrating the
internal components of a bucket assembly according to one
embodiment of the present disclosure; and
[0015] FIG. 5 is a perspective view of a platform cooling circuit
and passage according to one embodiment of the present
disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0016] 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.
[0017] 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.
[0018] 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 (not shown). 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.
[0019] 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.
[0020] One or more of the buckets in the turbine 16 and/or the
compressor 12 may comprise a bucket assembly 30, as shown in FIGS.
2 through 5. The bucket assembly 30 may include a main body 32 and
a platform 34. The main body 32 typically includes an airfoil 36
and a shank 38. The airfoil 36 may be positioned radially outward
from the shank 38. The shank 38 may include a root 40, which may
attach to a rotor wheel (not shown) in the turbine system 10 to
facilitate rotation of the bucket assembly 30.
[0021] In general, the main body 32 has an exterior surface. In
embodiments wherein the main body 32 includes an airfoil 36 and
shank 38, for example, the portion of the exterior surface defining
the airfoil 36 may have a generally aerodynamic contour. For
example, the airfoil 32 may have an exterior surface defining a
pressure side 42 and suction side 44 each extending between a
leading edge 46 and a trailing edge 48. Further, the portion of the
exterior surface of the shank 38 may include a pressure side face
52, a suction side face 54, a leading edge face 56, and a trailing
edge face 58.
[0022] The platform 34 may generally surround the main body 32, as
shown. A typical platform may be positioned at an intersection or
transition between the airfoil 36 and shank 38 of the main body 32,
and extend outwardly in the generally axial and tangential
directions. It should be understood, however, that a platform
according to the present disclosure may have any suitable position
relative to the main body 32 of the bucket assembly 30.
[0023] A platform 34 according to the present disclosure may
include a forward portion 62 and an aft portion 64. The forward
portion 62 is that portion of the platform 34 positioned proximate
the leading edge 46 of the airfoil 36 and the leading edge face 56
of the shank 38, while the aft portion 64 is that portion of the
platform 34 positioned proximate the trailing edge 48 of the
airfoil 36 and the trailing edge 58 of the shank 36. The forward
portion 62 and the aft portion 64 may further define a top face 66
of the platform 34, which may generally surround the airfoil 36 as
shown. Further, a peripheral edge may surround the forward portion
62, aft portion 64, and top face 66. The peripheral edge may
include a pressure side slash face 72 and suction side slash face
74, which each of the forward portion 62 and the aft portion 64 may
extend between. The peripheral edge may further include a forward
face 76, which may define a peripheral edge of the forward portion
62, and an aft face 78, which may define a peripheral edge of the
aft portion 64.
[0024] As shown in FIGS. 3 through 4, the main body 32 may define
one or more main cooling circuits therein. The main cooling
circuits may extend through portions of the main body 32 to cool
the main body 32. For example, in some embodiments as shown, the
main body 32 may define a forward main cooling circuit 82 and an
aft main cooling circuit 84. The main cooling circuits may have any
suitable shape and may extend along any suitable path. For example,
as shown each main cooling circuit may have various branches and
serpentine portions and may extend through the various portions of
the main body 32, such as through the airfoil 36 and shank 38. A
cooling medium may be flowed into and through the various main
cooling circuits 82 to cool the main body 32.
[0025] As further shown in FIGS. 3 through 5, one or more platform
cooling circuits 90 may be defined in the bucket assembly 30. In
general, the platform cooling circuit 90 may be defined at least
partially in the platform 34. For example, in exemplary
embodiments, a portion of the platform cooling circuit 90 is
defined in the platform 34, and extends through the platform 34 to
cool it. Other portions of the platform cooling circuit 90 may
extend into the main body 32 to inlet cooling medium into the
platform cooling circuit 90 (not shown) or exhaust the cooling
medium therefrom. In one embodiment, as shown in FIG. 3, a platform
cooling circuit 90 may include a forward portion 92 as discussed
below, an intermediate portion 94, and/or an outlet portion 96. The
outlet portion 96 may extend from the platform 34 into the main
body 32, and the forward portion 92 and intermediate portion 94 may
extend through the platform 34. Cooling medium may flow through the
forward portion 92 and intermediate portion 94, and be exhausted
through the outlet portion 96.
[0026] In many bucket assemblies 30, a platform cooling circuit 90
is in fluid communication with a main cooling circuit, such that
cooling medium is flowed from a main cooling circuit into the
platform cooling circuit 90 and/or is flowed from a platform
cooling circuit 90 to a main cooling circuit. For example, in the
embodiment shown in FIGS. 3 through 5, the outlet portion 96 is in
fluid communication with the aft main cooling circuit 84.
[0027] A platform cooling circuit 90, or any portion thereof, may
have any suitable path through the platform 34. For example, the
platform cooling circuit 90 or any portion thereof may be generally
linear or generally curvilinear. In some exemplary embodiments, the
platform cooling circuit 90, such as the intermediate portion 94
thereof, may have a generally serpentine path, as shown. Such
serpentine path may include alternating generally linear and
generally curvilinear portions, such that cooling medium may flow
back and forth through such portions as it flows through the
platform cooling circuit 90. It should be understood, however, that
a platform cooling circuit 90 according to the present disclosure
may have any suitable path through the platform 34.
[0028] A platform cooling circuit 90 according to the present
disclosure may further include an upper surface 102 and a lower
surface 104. In some embodiments, such as wherein the platform
cooling circuit 90, or any portion thereof, has a oval or circular
cross-section, the upper surface 102 and lower surface 104 may be
generally curvilinear, and may meet to fully define the platform
cooling circuit 90. In other embodiments, a platform cooling
circuit 90 may further include one or more sidewalls (not shown).
Each sidewall may extend between an upper surface 102 and a lower
surface 104. Upper surfaces 102 and lower surfaces 104 according to
the present disclosure may have any suitable shape and size. For
example, an upper surface 102 and/or lower surface may be planer,
may be curvilinear as discussed, or may include suitable bends or
other disruptions. An upper surface 102 and lower surface 104,
along with optional sidewalls, may define any suitable
cross-sectional profile for a platform cooling circuit, such as
rectangular, oval, triangular, or any other suitable polygonal
shape.
[0029] A bucket assembly 30 according to the present disclosure may
further advantageously include one or more passages 110, as shown
in FIGS. 3 through 5. Each passage 100 extends between a main
cooling circuit and a platform cooling circuit 90. In exemplary
embodiments, for example, a passage 110 may extend between a
forward main cooling circuit 62 and a platform cooling circuit 90.
Alternatively, however, a passage 110 may extend between an aft
main cooling circuit 64 and a platform cooling circuit 90. Each
passage 110 may provide fluid communication between such main
cooling circuit and such platform cooling circuit 90. Thus, in
exemplary embodiments, cooling medium may flow from the main
cooling circuit into the passage 110, and from the passage 110 to
the platform cooling circuit 90. Alternatively, however, cooling
medium may flow from the platform cooling circuit 90 into the
passage 110, and from the passage 110 into the main cooling
circuit.
[0030] As shown, a passage 110 according to the present disclosure
further includes end openings 112. The end openings 112 act as the
inlet and outlet for the passage 110 for flow to and from the main
cooling circuit and platform cooling circuit 90. Advantageously, an
end opening 112 of the passage 110, such as the end opening 112 for
flowing cooling medium between the passage 110 and platform cooling
circuit 90, is defined in the lower surface 104 of the platform
cooling circuit 90. In exemplary embodiments as shown, such end
opening 112 is an outlet, such that cooling medium flows through
the end opening 112 into the platform cooling circuit 90 from the
passage 110. Such design of the passage 110 and platform cooling
circuit 90 may advantageously reduce stresses at the intersection
between the platform cooling circuit 90 and passage 110. For
example, by designing the passage 110 and platform cooling circuit
90 such that an end opening 112 of the passage 110 is defined in
the lower surface 104 of the platform cooling circuit 90, the
intersection between the passage 110 and platform cooling circuit
90 may be spaced from the exterior intersection between the
platform 34 and shank 38. Thus, during operation of the turbine
system 10 when the platform 34 and shank 38 are subjected to
different temperatures, resulting bending stresses at the
intersection of the passage 110 and platform cooling circuit 90 may
be reduced or eliminated.
[0031] In some embodiments, as shown, at least a portion of a
passage 110 may extend in a generally radial direction. The radial
direction is the direction between the root 40 and airfoil 36 of
the bucket assembly, and may be shown as a vertical direction in
FIG. 3. Thus, as shown, at least a portion of a passage 110 may
extend in the generally radial direction. As shown, in exemplary
embodiments, such portion may be the portion that defines an end
opening 112, such as the end opening 112 that is defined in the
lower surface 104 of the platform cooling circuit 90. In
embodiments wherein such portion extends in the radial direction,
cooling medium flowing from the passage 110 into the platform
cooling circuit 90 may further advantageously impingement cool the
upper surface 102 of the platform cooling circuit 90, thus
providing improved cooling to the platform 34.
[0032] As discussed above and shown in FIGS. 3 through 5, in some
embodiments the platform cooling circuit 90 may include a forward
portion 92 and an intermediate portion 94. Further, the end opening
112 of the passage 110 that is defined in the lower surface 104 of
the platform cooling circuit 90 may be defined in the intermediate
portion 94. The forward portion 92 may thus be that portion of the
platform cooling circuit 90 that is generally upstream of such end
opening 112, such that the general flow path of cooling medium from
the passage 110 into and through the platform cooling circuit 90 is
away from the forward portion 92.
[0033] The arrows shown in FIG. 5 illustrate one embodiment of a
general flow path of cooling medium from the passage 110 into and
through the platform cooling circuit 90. As shown, a portion of the
cooling medium may, upon entering the platform cooling circuit 90,
flow upstream into the forward portion 92. This cooling medium may
then continue downstream, along the general flow path of the
cooling medium through the intermediate portion 94 of the platform
cooling circuit 90. In some embodiments as discussed above, the
cooling medium 90 may further flow through an outlet portion 96 and
be exhausted from the platform cooling circuit 90.
[0034] In some embodiments as shown, a bucket assembly 30 according
to the present disclosure may further include one or more exhaust
passages 120. Each exhaust passage 120 may be defined in the
platform 34, such as in the aft portion 64 of the platform 34
and/or in the forward portion 62 of the platform 34, and may be in
fluid communication with the platform cooling circuit 90. For
example, an exhaust passage 120 may be in fluid communication with
a forward portion 92, intermediate portion 94, outlet portion 96,
and/or any other suitable portion of a platform cooling circuit 90.
Thus, cooling medium flowing through the platform cooling circuit
90 may flow from the platform cooling circuit 90 into an exhaust
passage 120.
[0035] Each exhaust passage 120 may further include an outlet 122.
The outlet 122 may be defined in any suitable location on the
platform 34, such as on the aft portion 64 and/or forward portion
62 of the platform 34. For example, an outlet 122 may be defined in
the top face 66 as shown, or in the suction side slash face 74, or
in the pressure side slash face 72 as shown, or in the forward face
76, aft face 78, or any other suitable location on the platform 34,
such as on the aft portion 64 and/or forward portion 62 of the
platform 34. Cooling medium flowed through an exhaust passage 120
may thus be exhausted through the outlet 122 of that exhaust
passage 120. Additionally, in some embodiments, such exhausted
cooling medium may further advantageously act as a cooling film to
cool the exterior of the platform 34.
[0036] 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.
* * * * *