U.S. patent application number 13/674255 was filed with the patent office on 2014-05-15 for system for cooling a hot gas component for a combustor of a gas turbine.
This patent application is currently assigned to General Electric Company. The applicant listed for this patent is GENERAL ELECTRIC COMPANY. Invention is credited to Wei Chen, Roy Marshall Washam.
Application Number | 20140130504 13/674255 |
Document ID | / |
Family ID | 49596068 |
Filed Date | 2014-05-15 |
United States Patent
Application |
20140130504 |
Kind Code |
A1 |
Chen; Wei ; et al. |
May 15, 2014 |
SYSTEM FOR COOLING A HOT GAS COMPONENT FOR A COMBUSTOR OF A GAS
TURBINE
Abstract
A system for cooling a hot gas path component for a combustor
generally includes an impingement sleeve that circumferentially
surrounds an outer surface of the hot gas path component. A first
cooling chamber is defined between the impingement sleeve and a
first portion of the outer surface of the hot gas path component. A
second cooling chamber is disposed downstream from the first
cooling chamber. The second cooling chamber is defined between the
impingement sleeve and a second portion of the outer surface of hot
gas path component. An inlet extends through the impingement sleeve
so as to define a first flow path into the first cooling chamber.
An outlet defines a second flow path between the first cooling
chamber and the second cooling chamber.
Inventors: |
Chen; Wei; (Greer, SC)
; Washam; Roy Marshall; (Clinton, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GENERAL ELECTRIC COMPANY |
Schenectady |
NY |
US |
|
|
Assignee: |
General Electric Company
Schenectady
NY
|
Family ID: |
49596068 |
Appl. No.: |
13/674255 |
Filed: |
November 12, 2012 |
Current U.S.
Class: |
60/772 ;
60/754 |
Current CPC
Class: |
F05D 2240/35 20130101;
F01D 25/12 20130101; F05D 2260/205 20130101; F23R 3/002 20130101;
F01D 9/023 20130101; F05D 2260/201 20130101 |
Class at
Publication: |
60/772 ;
60/754 |
International
Class: |
F23R 3/00 20060101
F23R003/00 |
Claims
1. A system for cooling a hot gas path component for a combustor,
comprising: a. an impingement sleeve that circumferentially
surrounds an outer surface of the hot gas path component; b. a
first cooling chamber defined between the impingement sleeve and a
first portion of the outer surface of the hot gas path component;
c. a second cooling chamber downstream from the first cooling
chamber, the second cooling chamber being defined between the
impingement sleeve and a second portion of the outer surface of hot
gas path component; and d. an inlet that extends through the
impingement sleeve to define a first flow path into the first
cooling chamber, and an outlet that defines a second flow path
between the first cooling chamber and the second cooling
chamber.
2. The system as in claim 1, wherein the hot gas path component is
one of a combustion liner or a transition duct.
3. The system as in claim 1, wherein the inlet is configured to
impinge a cooling medium onto the first portion of the outer
surface of the hot gas path component.
4. The system as in claim 1, wherein the outlet is configured to
re-impinge the cooling medium from the first cooling chamber onto
the second portion of the outer surface of the hot gas path
component.
5. The system as in claim 1, wherein the impingement sleeve
includes an upper portion radially separated from a lower
portion.
6. The system as in claim 5, further comprising a cooling channel
defined between the upper and the lower portions of the impingement
sleeve.
7. The system as in claim 5, wherein the inlet extends through the
upper portion of the impingement sleeve and the outlet extends
through the lower portion of the impingement sleeve.
8. The system as in claim 1, further comprising a transversely
extending rail member disposed along the outer surface of the hot
gas path component, the rail member at least partially separating
the first cooling chamber from the second cooling chamber.
9. The system as in claim 8, further comprising an exhaust passage
downstream from the outlet, the exhaust passage being defined
between the impingement sleeve and the second portion of the outer
surface of the hot gas path component.
10. A combustor for a gas turbine, comprising: a. an outer casing;
and b. an annular hot gas path component circumferentially
surrounded by the casing, the hot gas path component being radially
separated from the casing so as to define a flow passage
therebetween, the hot gas path component comprising: i. a main body
defining a first cooling chamber and a second cooling chamber along
an outer surface of the main body, the second cooling chamber being
downstream from the first cooling chamber; ii. an impingement
sleeve circumferentially surrounding the first and the second
cooling chambers; iii. an inlet extending through the impingement
sleeve, the inlet defining a first flow path between the flow
passage and the first cooling chamber; and iv. an outlet extending
through the impingement sleeve downstream from the inlet, the
outlet defining a second flow path between the first cooling
chamber and the second cooling chamber.
11. The combustor as in claim 10, wherein the hot gas component is
one of a combustion liner or a transition duct.
12. The combustor as in claim 10, wherein the inlet is configured
to impinge a cooling medium from the flow passage of the combustor
onto a first portion of the outer surface of the main body.
13. The combustor as in claim 12, wherein the outlet is configured
to impinge the cooling medium from the first cooling chamber onto a
second portion of the outer surface of the main body.
14. The combustor as in claim 10, further comprising a transversely
extending rail member disposed along an outer surface of the main
body of the hot gas path component, the rail member at least
partially separating the first cooling chamber from the second
cooling chamber.
15. The combustor as in claim 10, further comprising an exhaust
flow path defined between the impingement sleeve and the second
cooling chamber, the exhaust flow path being downstream from the
second cooling passage of the impingement sleeve.
16. The combustor as in claim 10, wherein the impingement sleeve
includes an upper portion radially separated from a lower portion,
and a cooling channel defined therebetween.
17. The combustor as in claim 16, wherein the inlet extends through
the upper portion of the impingement sleeve and the outlet extends
through the second portion of the impingement sleeve.
18. A method for cooling a portion of an outer surface of a hot gas
path component disposed within a combustor of a gas turbine, the
method comprising: a. routing a cooling medium through an inlet
extending through an impingement sleeve; b. impinging the cooling
medium onto a first portion of the outer surface of the hot gas
path component; c. routing the cooling medium through an outlet
that extends through the impingement sleeve; and d. re-impinging
the cooling medium onto a second portion of the outer surface of
the hot gas path component.
19. The method as in claim 18, further comprising routing the
cooling medium through an exhaust passage of the hot gas path
component onto an inner surface of a second hot gas path
component.
20. The method as in claim 18, further comprising routing the
cooling medium from the second portion of the outer surface of the
hot gas path component into a hot gas path defined within the
combustor.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to a hot gas path
component disposed within a combustor of a gas turbine. More
particularly, this invention relates to impingement cooling a
portion of the hot gas component.
BACKGROUND OF THE INVENTION
[0002] Gas turbines are widely used in industrial and power
generation operations. A typical gas turbine includes a compressor
section, a combustion section downstream from the compressor
section, and a turbine section downstream from the combustor. The
combustion section generally includes a combustor having various
annular shaped hot gas path components such as a combustion liner
and/or a transition duct that at least partially define a hot gas
path that extends between the combustion section and the turbine
section. Each of the hot gas path components generally includes an
inner surface and an outer surface. Typically, the combustion
section further includes a casing that surrounds the hot gas path
components and defines a plenum that is in fluid communication with
the compressor section.
[0003] In operation, a compressed working fluid such as ambient air
is routed from the compressor section into the plenum of the
combustion section. A portion of the compressed working fluid is
mixed with a fuel to form a combustible mixture in a combustion
chamber that is typically defined within the combustion liner. The
combustible mixture is burned to produce a high temperature and
high velocity hot gas that flows through the hot gas path and into
the turbine section. A portion of the compressed working fluid is
used as a cooling medium to cool the outer surfaces and other hot
segments of the various hot gas path components. For example, the
cooling medium may be directed across the outer surfaces of the
various hot gas path components so as to convectively and/or
conductively cool those surfaces.
[0004] Certain areas of the hot gas path components such as an aft
end of the combustion liner or an aft end of the transition duct
may be particularly sensitive to thermal stress. As a result, those
areas gain significant benefit from focusing a jet of the cooling
medium onto the outer surface of the hot gas path component,
thereby significantly increasing the rate of heat transfer or
cooling effectiveness between the cooling medium and the hot gas
path component. This method of cooling is known in the industry as
impingement or jet impingement cooling.
[0005] In current impingement cooling configurations, the cooling
medium is routed through one or more cooling passages that are
configured to impinge/focus the compressed working fluid onto a
particular area of the outer surface of one of the hot gas path
components. Generally, the cooling medium impinges on the outer
surface of one of the hot gas path components and is then routed
directly into the hot gas path and/or it is reintroduced back into
the stream of the compressed working fluid where it may be mixed
with the fuel for combustion.
[0006] Although this cooling method is generally effective at
cooling the specific area in which the cooling air is impinged, a
substantial amount of cooling capability of the cooling air is not
utilized. For example, further cooling of the hot gas component
could be realized using the same cooling medium. Accordingly, an
improved hot gas path component and an improved method for cooling
the hot gas path component would be useful in the art.
BRIEF DESCRIPTION OF THE INVENTION
[0007] Aspects 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.
[0008] One embodiment of the present invention is a system for
cooling a hot gas path component for a combustor. The system
generally includes an impingement sleeve that circumferentially
surrounds an outer surface of the hot gas path component. A first
cooling chamber is defined between the impingement sleeve and a
first portion of the outer surface of the hot gas path component. A
second cooling chamber is disposed downstream from the first
cooling chamber. The second cooling chamber is defined between the
impingement sleeve and a second portion of the outer surface of hot
gas path component. An inlet extends through the impingement sleeve
so as to define a first flow path into the first cooling chamber.
An outlet defines a second flow path between the first cooling
chamber and the second cooling chamber.
[0009] Another embodiment of the present invention is a combustor
for a gas turbine having an outer casing and an annular hot gas
path component circumferentially surrounded by the casing. The hot
gas path component is radially separated from the casing so as to
at least partially define a flow passage therebetween. The hot gas
path component includes a main body that defines a first cooling
chamber and a second cooling chamber along an outer surface of the
main body. The second cooling chamber being downstream from the
first cooling chamber. An impingement sleeve circumferentially
surrounds the first and the second cooling chambers. An inlet
extends through the impingement sleeve. The inlet defines a first
flow path between the flow passage and the first cooling chamber.
An outlet extends through the impingement sleeve downstream from
the inlet. The outlet defines a second flow path between the first
cooling chamber and the second cooling chamber.
[0010] Another embodiment of the present invention includes a
method for cooling a portion of an outer surface of a hot gas path
component disposed within a combustor of a gas turbine. The method
includes routing a cooling medium through an inlet that extends
through an impingement sleeve. The cooling medium is impinged onto
a first portion of the outer surface of the hot gas path component.
The cooling medium is routed through an outlet that extends through
the impingement sleeve. The cooling medium is re-impinged onto a
second portion of the outer surface of the hot gas path
component.
[0011] Those of ordinary skill in the art will better appreciate
the features and aspects of such embodiments, and others, upon
review of the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] 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:
[0013] FIG. 1 is a simplified cross-section view of an exemplary
combustor within the scope of various embodiments of the present
disclosure;
[0014] FIG. 2 is a perspective, partial cut-away view of a portion
of the combustor shown in FIG. 1;
[0015] FIG. 3 is an enlarged cross section of a system for cooling
an aft end portion of a hot gas path component as shown in FIG. 2,
according to one embodiment of the present disclosure;
[0016] FIG. 4 is an enlarged cross section perspective view of an
impingement sleeve portion of the system for cooling the hot gas
path component, as shown in FIG. 3;
[0017] FIG. 5 is an enlarged cross section perspective view of an
aft end of a combustion liner as shown in FIG. 3, according to at
least one embodiment of the present invention; and
[0018] FIG. 6 is an enlarged cross section of the system for
cooling an aft end portion of a hot gas path component as shown in
FIG. 3, according to one embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0019] 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. As used
herein, the terms "first", "second", and "third" may be used
interchangeably to distinguish one component from another and are
not intended to signify location or importance of the individual
components. In addition, the terms "upstream" and "downstream"
refer to the relative location of components in a fluid pathway.
For example, component A is upstream from component B if a fluid
flows from component A to component B. Conversely, component B is
downstream from component A if component B receives a fluid flow
from component A.
[0020] 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.
[0021] Various embodiments of the present disclosure include a
system for cooling a portion of a combustor hot gas path component
such as a combustion liner or a transition duct. The system
generally includes an impingement sleeve that circumferentially
surrounds the hot gas component. A first cooling chamber is
positioned upstream from a second cooling chamber. The first and
the second cooling chambers are surrounded by the impingement
plate. A cooling medium flows through an inlet into the first
cooling chamber and is impinged onto a portion of an outer surface
of the hot gas path component. The cooling medium is then routed
through an outlet that extends through the impingement plate. The
cooling medium is re-focused and impinged onto a second portion of
the outer surface of the hot gas path component, thereby further
utilizing the cooling medium for cooling the hot gas path
component.
[0022] Referring now to the drawings, FIG. 1 provides a simplified
cross-section of an exemplary combustion section 10, such as may be
included in a gas turbine, and FIG. 2 provides a perspective,
partial cut-away view of a portion of a combustor 12 of the
combustion section as shown in FIG. 1. As shown in FIG. 1, the
combustion section 10 generally includes a casing 14 that surrounds
the combustor 12. An end cover 16 is connected to a portion of the
casing 14 at one end of the combustor 12. At least one fuel nozzle
18 extends axially downstream from the end cover 16. The at least
one fuel nozzle 18 extends through a cap assembly 20 that extends
radially within the casing 14.
[0023] Various hot gas path components 22 extend downstream from
the cap assembly 20 so as to define a hot gas path 24 through the
combustor 12. The hot gas path components 22 generally include an
annular combustion liner 26 and an annular transition duct 28. The
combustion liner 26 extends downstream from the cap assembly 20. A
combustion chamber 30 is at least partially defined within the
combustion liner 26 downstream from the at least one fuel nozzle
18. The transition duct 28 extends downstream from the combustion
liner 26 and terminates adjacent to a first stage nozzle 32 that is
disposed adjacent to an inlet 34 of a turbine 36.
[0024] A first flow sleeve 38 at least partially surrounds the
transition duct 28, and a second flow sleeve 40 at least partially
surrounds the combustion liner 26. An annular flow passage 42 is
defined between the first flow sleeve 38 and the transition duct
28, and the second flow sleeve 40 and the combustion liner 26. The
first flow sleeve 38 generally includes a plurality of cooling
passages 44 that define a flow path between a plenum 46 defined
within the combustion section casing 14 and the annular flow
passage 42. In addition, the second flow sleeve 40 may include one
or more cooling passages 48 that define a flow path between the
plenum 46 and the annular flow passage 42.
[0025] In operation, a working fluid such as compressed air 50 is
routed into the plenum 46 of the combustion section 10 from a
compressor (not shown) such as an axial compressor positioned
upstream from the combustion section 10. As shown in FIG. 1, a
primary portion of the compressed air 50 is routed through the
cooling passages 44, 48 into the annular flow passage. In this
manner, the compressed air 50 is used as a cooling medium 52 to
provide impingement, convective, and/or conductive cooling to an
outer surface 54 (FIG. 2) of the transition duct 28 and/or to an
outer surface 56 (FIG. 2) of the combustion liner 26.
[0026] As shown in FIG. 1, the cooling medium 52 travels along the
annular flow passage 42 before reversing direction at the end cover
16. The cooling medium 52 then flows past the one or more fuel
nozzles 18 and through the end cap 20 where it is mixed with a fuel
and burned in the combustion chamber 30, thereby producing a hot
gas 58 that flows through the hot gas path 24, across the first
stage nozzle 32 and into the inlet 34 of the turbine 36. The hot
gas 58 results in high thermal stresses on the combustion liner 26
and/or the transition duct 28, thereby limiting the mechanical life
of those hot gas path components 22. More specifically, as shown in
FIG. 2, an aft end 60 of the combustion liner 26 and/or an aft end
62 of the transition duct 28 may be particularly sensitive to the
high thermal stresses produced by the hot gas 58.
[0027] As shown in FIG. 2, the combustion liner 26 generally
includes an annular main body 64 and a forward end 66 that is
axially separated from the aft end 60. The outer surface 56 of the
combustion liner generally extends between the forward and aft ends
66, 60. The transition duct 28 generally includes an annular main
body 68 and a forward end 70 that is upstream from the aft end 62.
As shown in FIG. 2, the aft end 60 of the combustion liner 26 is
generally seated within the forward end 70 of the transition duct
28.
[0028] FIG. 3 illustrates a cross section side view of a system for
cooling the various hot gas path components 72, herein referred to
as "the system 72", according to one embodiment of the present
disclosure. FIG. 4 illustrates a cross section perspective view of
an impingement sleeve 74 portion of the system 72 as shown in FIG.
3, and FIG. 5 illustrates a cross section perspective view of a
portion of the aft end 60 of the combustion liner 26 as shown in
FIG. 2, according to one embodiment of the present disclosure. As
shown in FIG. 2, the system 72 may be deployed at the aft end 60 of
the combustion liner and/or on the transition duct 28.
[0029] In one embodiment, as shown in FIG. 3, the system 72 is
deployed at the aft end 60 of the combustion liner 26. As shown,
the system 72 generally includes an impingement sleeve 74 having an
upper portion 76 and a lower portion 78. The impingement sleeve 74
at least partially circumferentially surrounds the outer surface 56
of the combustion liner 26. A first cooling chamber 80 is defined
between the upper portion 76 of the impingement sleeve 74 and a
first portion 82 of the outer surface 56 of the combustion liner
26. A second cooling chamber 84 is defined downstream from the
first cooling chamber 80 between the lower portion 78 of the
impingement sleeve 74 and a second portion 86 of the outer surface
56 of the combustion liner 26. The second cooling chamber 84 is
disposed generally adjacent to the aft end 60 of the combustion
liner 26.
[0030] In particular embodiments, as shown in FIGS. 3 and 5, the
annular main body 64 of the combustion liner 26 at least partially
defines at least one of the first cooling chamber 80 or the second
cooling chamber 84. For example, at least one of the first or the
second cooling chambers 80, 84 may be cast and/or machined into the
main body 64 of the combustion liner 26. In alternate embodiments,
the system 72 may comprise of separate components such as a liner
extension that at least partially defines at least one of the first
or the second cooling chambers 80, 84. The separate components may
be welded or otherwise joined to the aft end 60 of the combustion
liner 26.
[0031] In particular embodiments, as shown in FIGS. 3 and 5, a
transversely extending rail member 88 at least partially separates
the first cooling chamber 80 from the second cooling chamber 84.
The rail member 88 may at least partially provide a seating surface
for supporting and/or joining the impingement sleeve 74 to the main
body 64 of the combustion liner 26.
[0032] In various embodiments, as shown in FIG. 3, a first radially
extending support member 90 extends between the first portion 80 of
the outer surface 56 and the upper portion 76 of the impingement
sleeve 74. The first support member 90 provides radial separation
between the upper portion 76 of the impingement sleeve 74 and the
rail member 88. The first support member 90 may at least partially
define a seating surface for supporting and/or joining the
impingement sleeve 74 to the main body 64 of the combustion liner
26. A second radially extending support member 92 extends between
the second portion 86 of the outer surface 56 of the combustion
liner 26 and an end portion 94 of the impingement sleeve 74. As
shown in FIG. 3, the second support member 92 may provide radial
separation between the lower portion 78 and/or the end portion 94
of the impingement sleeve 74 and the second portion 86 of the outer
surface 56. The second support member 92 may at least partially
provide a seating surface for supporting and/or joining the
impingement sleeve 74 to the combustion liner 26.
[0033] As shown in FIGS. 3 and 4, the lower portion 78 of the
impingement sleeve 74 is radially separated from the upper portion
76 of the impingement sleeve 74. In particular embodiments, as
shown in FIG. 3, the lower portion 78 extends substantially axially
downstream from the rail member 88 and is generally parallel to the
upper portion 76 of the impingement sleeve 74. A flow channel 95 is
at least partially defined between the upper portion 76 and the
lower portion 78 of the impingement sleeve 74.
[0034] As shown in FIGS. 3 and 4, an inlet or cooling passage 96
extends through the upper portion 76 of the impingement sleeve 74.
As shown in FIG. 3, the inlet 96 defines a cooling flow path 98
between the annular flow passage 42 and the first cooling chamber
80. In operation, the annular flow passage 42 is generally held at
a higher pressure than the first cooling chamber 80. As a result,
the cooling medium 52 flows along the cooling flow path 98 and into
the first cooling chamber 80. In particular embodiments, as shown
in FIGS. 3 and 4, the inlet is configured to focus or impinge the
cooling medium 52 onto a small area of the first portion 82 of the
outer surface 56 of the combustion liner 26 at a high velocity,
thereby increasing the heat transfer rate of the cooling medium 52.
For example, as shown in FIG. 3, the inlet 96 may be tapered,
chamfered or concaved from a top surface 100 of the upper portion
76 of the impingement sleeve 74. In this manner, the cooling medium
52 may be concentrated into a cooling jet to more effectively cool
the first portion 82 of the outer surface 56 within the first
cooling chamber 80.
[0035] In alternate embodiments, as shown in FIG. 4, a scoop or
other flow catching device 102 may extend radially outward from and
at least partially surround the inlet 96. The scoop 102 generally
faces the direction of flow of the cooling medium 52 flowing
through the annular flow passage 42 (FIG. 3). As the cooling medium
52 flows through the annular passage 42, friction reduces the
velocity of a portion of the cooling medium 52 flowing closest to
the outer surfaces 54, 56 of the transition duct 28 and/or the
combustion liner 26. The scoop 102 captures a portion of the
cooling medium 52 that is radially separated from those surfaces
54, 56, thereby increasing the velocity of the cooling medium 52
flowing into the first cooling chamber 80 (FIG. 3). As a result,
the heat transfer rate of the cooling medium 52 is increased,
thereby providing improved cooling to the first portion 82 of the
outer surface 56 of the combustion liner 26 disposed within the
first cooling chamber 80.
[0036] As shown in FIGS. 3 and 4, an outlet or cooling passage 104
extends through the lower portion 78 of the impingement sleeve 74.
As shown in FIG. 3, the outlet 104 defines a cooling flow path 106
that extends between the first cooling chamber 80 and the second
cooling chamber 84. In operation, the first cooling chamber 80 is
generally at a higher pressure than the second cooling chamber 84.
As a result, the cooling medium 52 flows from the first cooling
chamber 80 along the cooling flow path 106 and into the second
cooling chamber 84.
[0037] In particular embodiments, as shown in FIGS. 3 and 5, the
outlet 104 is configured to focus or impinge the cooling medium 52
from the first cooling chamber 80 onto a small or concentrated area
of the second portion 86 of the outer surface 56 of combustion
liner 26, thereby increasing the heat transfer rate of the cooling
medium 52. For example, as shown in FIG. 3 the outlet 104 may be
tapered, chamfered or concaved radially inward from an outer
surface 107 (FIG. 4) of the lower portion 78 of the impingement
sleeve 74. In this manner, the cooling medium 52 may be
concentrated into a cooling jet and re-impinged on the second
portion 86 of the outer surface 56 within the second cooling
chamber 84 so as to further utilize the cooling capability of the
cooling medium 52 routed from the first cooling chamber 80.
[0038] As shown in FIG. 3, an exhaust outlet 108 is at least
partially defined between the end portion 94 and/or the lower
portion 78 of the impingement sleeve 74 and the second portion 86
of the outer surface 56 of the combustion liner 26. In particular
embodiments, the exhaust outlet 108 defines a flow path 110 between
the second cooling chamber 84 and the transition duct 28. In this
manner, the cooling medium 52 is routed from the exhaust passage
110 along an inner surface 112 of the transition duct 28 so as to
provide film cooling to the transition duct 28 inner surface
112.
[0039] In alternate embodiments, wherein the system 72 is deployed
at the aft end of the transition duct, the exhaust outlet 108
routes the cooling medium 52 from the second cooling chamber 84 to
the first stage of stationary vanes 32 (FIG. 1) disposed at the aft
end 62 of the transition duct 28. In this manner, the cooling
medium 52 may provide film cooling to the first stage of stationary
nozzles 32 (FIG. 1).
[0040] In operation, as shown in FIG. 6, the cooling medium 52
flows from the annular flow passage 42 along the flow path 98
through the inlet 98 that extends through the upper portion 76 of
the impingement sleeve 74. The cooling medium 52 is impinged onto
the first portion 82 of the outer surface 56 of the combustion
liner 26 and heat is transferred from the first portion 82 of the
outer surface 56 to the cooling medium 52. The cooling medium 52 is
then routed from the first cooling chamber 80 along the flow path
106 that extends between the first cooling chamber 80 and the
second cooling chamber 84. As the cooling medium 52 flows through
the outlet 104 of the lower portion 78 of the impingement sleeve 74
and into the second cooling chamber 84, the cooling medium 52 is
focused so that it is re-impinged onto the second portion 86 of the
outer surface 56 of the combustion liner 26. In this manner, heat
is transferred from the second portion 86 of the outer surface 56
to the cooling medium 52. The cooling medium 52 is then routed
through the exhaust passage 108 and into the hot gas path 24 and/or
along the inner surface 112 of the transition duct 28, thereby
providing a cooling film that flows along the inner surface 112 of
the transition duct 28.
[0041] The various embodiments presented in FIGS. 3 through 6 also
provide a method for cooling an aft portion of various hot gas path
components 22 such as the combustion liner 26 and/or the transition
duct 28. The method generally includes routing the cooling medium
52 through the inlet 96 extending through the impingement sleeve 74
and into the first cooling chamber 80. The cooling medium 52 is
then impinged onto the first portion 82 of the outer surface 56 of
the hot gas path component 22. The cooling medium 52 is then routed
from the first cooling chamber and through the outlet 104 that
extends through the impingement sleeve 74. The cooling medium 52 is
then impinged onto the second portion 86 of the outer surface 56 of
the hot gas path component 22 disposed within the second cooling
chamber 84. The method may further include routing the cooling
medium 52 through the exhaust passage 108 and filming the cooling
medium 52 onto an inner surface of a second hot gas path component
22. The method may further include routing the cooling medium 52
from the second cooling chamber 84 through the exhaust passage 108
and into the hot gas path 24.
[0042] 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 and 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 language of the claims.
* * * * *