U.S. patent application number 13/398630 was filed with the patent office on 2013-08-22 for late lean injection system.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. The applicant listed for this patent is Patrick Benedict Melton. Invention is credited to Patrick Benedict Melton.
Application Number | 20130213046 13/398630 |
Document ID | / |
Family ID | 47709980 |
Filed Date | 2013-08-22 |
United States Patent
Application |
20130213046 |
Kind Code |
A1 |
Melton; Patrick Benedict |
August 22, 2013 |
LATE LEAN INJECTION SYSTEM
Abstract
A late lean injection system includes at least one fuel injector
disposed proximate a combustion zone. Also included is at least one
guide for directing an airflow from a region proximate a compressor
discharge exit to the at least one fuel injector.
Inventors: |
Melton; Patrick Benedict;
(Horse Shoe, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Melton; Patrick Benedict |
Horse Shoe |
NC |
US |
|
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
47709980 |
Appl. No.: |
13/398630 |
Filed: |
February 16, 2012 |
Current U.S.
Class: |
60/740 |
Current CPC
Class: |
F23R 3/346 20130101;
F23R 3/04 20130101 |
Class at
Publication: |
60/740 |
International
Class: |
F23R 3/28 20060101
F23R003/28 |
Claims
1. A late lean injection system comprising: at least one fuel
injector disposed proximate a combustion zone; and at least one
guide for directing an airflow from a region proximate a compressor
discharge exit to the at least one fuel injector.
2. The late lean injection system of claim 1, further comprising a
transition duct.
3. The late lean injection system of claim 2, wherein the at least
one fuel injector is disposed proximate the transition duct and is
configured to inject a fuel into the combustion zone.
4. The late lean injection system of claim 2, further comprising a
liner duct, wherein the at least one fuel injector is disposed
proximate the liner duct and is configured to inject a fuel into
the combustion zone.
5. The late lean injection system of claim 1, wherein the at least
one guide includes a first end disposed proximate the compressor
discharge exit and a second end disposed proximate the at least one
fuel injector.
6. The late lean injection system of claim 1, wherein the at least
one guide comprises a bend proximate the at least one fuel
injector.
7. The late lean injection system of claim 6, wherein the at least
one guide comprises at least one straightening vane proximate the
bend.
8. The late lean injection system of claim 1, wherein the at least
one guide is operably connected to a compressor discharge
casing.
9. The late lean injection system of claim 1, further comprising a
plurality of fuel injectors, wherein the plurality of fuel
injectors are circumferentially spaced at a single axial
location.
10. The late lean injection system of claim 1, further comprising a
plurality of fuel injectors, wherein the plurality of fuel
injectors are circumferentially spaced a plurality of axial
locations.
11. A late lean injection system comprising: a transition duct
defining a transition interior, the transition duct having an end
adapted for connection to a first turbine zone, and an opposite
end; a sleeve spaced radially outward of the transition duct and
extending circumferentially around the transition duct; at least
one fuel injector configured to inject fuel into the transition
interior; and at least one guide for directing an airflow to the at
least one fuel injector.
12. The late lean injection system of claim 11, wherein the at
least one guide includes a first end disposed proximate a
compressor discharge exit and a second end disposed proximate the
at least one fuel injector.
13. The late lean injection system of claim 12, further comprising
a liner duct disposed proximate the opposite end of the transition
duct.
14. The late lean injection system transition piece of claim 11,
wherein the at least one guide comprises a bend proximate the at
least one fuel injector.
15. The late lean injection system transition piece of claim 14,
wherein the at least one guide comprises at least one straightening
vane proximate the bend.
16. The late lean injection system transition piece of claim 12,
wherein the at least one guide is operably connected to a
compressor discharge casing.
17. A late lean injection system comprising: a transition duct
having an upstream end and a downstream end; a liner duct disposed
proximate the upstream end of the transition duct; a flowsleeve
spaced radially outward of the liner duct and extending
circumferentially around the liner duct; at least one fuel injector
disposed proximate at least one of the transition duct and the
liner duct; and at least one guide for directing an airflow from a
region proximate a compressor discharge exit to the at least one
fuel injector.
18. The late lean injection system of claim 17, wherein the at
least one guide includes a first end disposed proximate the
compressor discharge exit and a second end disposed proximate the
at least one fuel injector.
19. The late lean injection system of claim 17, wherein the at
least one guide comprises a bend proximate the at least one fuel
injector.
20. The late lean injection system of claim 17, wherein the at
least one guide is operably connected to a compressor discharge
casing.
Description
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to turbines, and
more particularly to late lean injection systems.
BRIEF DESCRIPTION OF THE INVENTION
[0002] According to one aspect of the invention, a late lean
injection system includes at least one fuel injector disposed
proximate a combustion zone. Also included is at least one guide
for directing an airflow from a region proximate a compressor
discharge exit to the at least one fuel injector.
[0003] According to another aspect of the invention, a late lean
injection system includes a transition duct defining a transition
interior, the transition duct having an end adapted for connection
to a first turbine zone, and an opposite end. Also included is a
sleeve spaced radially outward of the transition duct and extending
circumferentially around the transition duct. Further included is
at least one fuel injector configured to inject fuel into the
transition interior. Yet further included is at least one guide for
directing an airflow to the at least one fuel injector.
[0004] According to yet another aspect of the invention, a late
lean injection system includes a transition duct having an upstream
end and a downstream end. Also included is a liner duct disposed
proximate the upstream end of the transition duct. Further included
is a flowsleeve spaced radially outward of the liner duct and
extending circumferentially around the liner duct. Yet further
included is at least one fuel injector disposed proximate at least
one of the transition duct and the liner duct. Also included is at
least one guide for directing an airflow from a region proximate a
compressor discharge exit to the at least one fuel injector.
[0005] These and other advantages and features will become more
apparent from the following description taken in conjunction with
the drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0006] The subject matter, which is regarded as the invention, is
particularly pointed out and distinctly claimed in the claims at
the conclusion of the specification. The foregoing and other
features and advantages of the invention are apparent from the
following detailed description taken in conjunction with the
accompanying drawings in which:
[0007] FIG. 1 is an elevational, side view of a first embodiment of
a late lean injection system having at least one fuel injector;
[0008] FIG. 2 is an elevational, side view of a second embodiment
of the late lean injection;
[0009] FIG. 3 is an elevational, side view of a third embodiment of
the late lean injection system;
[0010] FIG. 4 is a cross-sectional view of the late lean injection
system having at least one guide;
[0011] FIG. 5 is a simplified view of an airflow penetration
profile resulting from the at least one guide of FIG. 4;
[0012] FIG. 6 is a cross-sectional view of the late lean injection
system having at least one guide of another embodiment; and
[0013] FIG. 7 is a simplified view of an airflow penetration
profile resulting from the at least one guide of FIG. 6.
[0014] The detailed description explains embodiments of the
invention, together with advantages and features, by way of example
with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Referring to FIG. 1, a late lean injection system 10 of a
first embodiment is illustrated. The late lean injection system 10
includes a transition piece assembly 11 of a gas turbine system
that is operably connected between a combustor (not labeled) and a
first turbine stage (not illustrated) and includes an interior 21
defined by a transition duct 12. The transition duct 12 carries hot
combustion gases from the combustor, which is typically upstream of
the transition duct 12, to an inlet of the turbine. At least a
portion of the transition duct 12 may be surroundingly enclosed by
an impingement sleeve 14 that is spaced radially outward of the
transition duct 12. Upstream of the transition piece assembly 11 is
a liner duct 16. The interior region of the liner duct 16 and the
transition duct 12 comprises a combustion zone, wherein combustion
of the hot gases occurs and is directed toward the turbine. At
least a portion of the liner duct 16 is surroundingly enclosed by a
flowsleeve 17 that is spaced radially outward of the liner duct 16.
A compressor discharge casing 32 is illustrated and includes a
compressor discharge exit 34.
[0016] The combustor of the gas turbine is late lean injection
(LLI) compatible. An LLI compatible combustor is any combustor with
either an exit temperature that exceeds 2500.degree. F. or handles
fuels with components that are more reactive than methane with a
hot side residence time greater than 10 milliseconds (ms).
[0017] Referring to FIG. 2, the late lean injection system 10 of a
second embodiment is illustrated. The late lean injection system 10
of the second embodiment is similar to that of the first
embodiment, however, does not include an impingement sleeve 14 that
surroundingly encloses the transition duct 12.
[0018] Referring to FIG. 3, the late lean injection system 10 of a
third embodiment is illustrated. The late lean injection system 10
of the third embodiment comprises merely a single duct, that being
the transition duct 12 that extends upstream to a region that
included the liner duct 16 in the first and second embodiments.
Furthermore, a single sleeve, referred to generally as a sleeve 19
surroundingly encloses the transition duct 12 at a location
radially outward of the transition duct 12.
[0019] Irrespective of the embodiment employed in the gas turbine
system, a plurality of fuel injectors 18 are each integrated with
or structurally supported by a plurality of housings that extend
radially into at least one of the transition duct 12 or the liner
duct 16. The plurality of fuel injectors 18 extend through the
respective duct, i.e., the transition duct 12 or the liner duct 16,
to varying depths. That is, the fuel injectors 18 are each
configured to supply a second fuel (i.e., LLI fuel) to the
combustion zone through fuel injection in a direction that is
generally transverse to a predominant flow direction through the
transition duct 12 and/or the liner duct 16. For each of the
above-described embodiments, it is emphasized that the plurality of
fuel injectors 18 may be disposed proximate the transition duct 12
or the liner duct 16, in spite of the illustrated embodiments
showing disposal of the plurality of fuel injectors 18 disposed in
connection with only one of the transition duct 12 and the liner
duct 16. Furthermore, the plurality of fuel injectors 18 may be
disposed in connection with both the transition duct 12 and the
liner duct 16. The plurality of fuel injectors 18 may be disposed
in a single axial circumferential stage that includes multiple
currently operating fuel injectors 18 respectively disposed around
a circumference of a single axial location of the transition duct
12 and/or the liner duct 16. It is also conceivable that the
plurality of fuel injectors 18 may be situated in a single axial
stage, multiple axial stages, or multiple axial circumferential
stages. A single axial stage includes a currently operating single
fuel injector 18. A multiple axial stage includes multiple
currently operating fuel injectors 18 that are respectively
disposed at multiple axial locations. A multiple axial
circumferential stage includes multiple currently operating fuel
injectors 18, which are disposed around a circumference of the
transition duct 12 and/or the liner duct 16 at multiple axial
locations thereof.
[0020] Airflow from a compressor enters into a compressor discharge
casing 32. A high pressure dynamic airflow 20 exits the compressor
discharge casing 32 proximate a compressor discharge exit 34 and
rushes downstream toward the transition duct 12 and/or the liner
duct 16 to locations proximate the fuel injectors 18. To reduce the
pressure drop of airflow within the fuel injectors 18, where mixing
of the air and LLI fuel occurs and penetrates into the transition
duct 12 and/or the liner duct 16, it is advantageous to harness the
high pressure dynamic airflow 20 into the fuel injectors 18.
[0021] Referring to FIG. 4, a cross-sectional view of an axial
location of the late lean injection system 10 is illustrated. The
impingement sleeve 14 and/or the flowsleeve 17, or the transition
duct 12 in the case of the embodiment illustrated in FIG. 2,
includes one or more guides 22 to redirect the high pressure
dynamic airflow 20 into the fuel injectors 18. In the illustrated
example, the guides 22 are in the form of scoops that are
positioned to correspond to the fuel injectors 18. Based on this
correspondence to the fuel injectors 18, the guides may be disposed
in a single axial circumferential stage, a single axial stage, a
multiple axial stage, or a multiple axial circumferential stage, as
is the case with the fuel injectors 18. The impingement sleeve 14
and/or the flowsleeve 17 include apertures 24 that correspond to
the fuel injectors 18 and the guides 22 are positioned proximate
the apertures 24. A typical scoop can either fully or partially
surround each aperture 24 or partially or fully cover the aperture
24 and be generally part-spherical in shape. For example, the scoop
may be in the shape of a half cylinder with or without a top.
Alternatively, the guides 22 may take the form of various other
shapes that provide a similar functionality, specifically
harnessing of the high pressure dynamic airflow 20. Furthermore,
the guides 22 may be disposed radially inward of the impingement
sleeve 14 and/or the flowsleeve 17 and may be in direct connection
with the plurality of fuel injectors 18 in embodiments where a
sleeve is not present.
[0022] Irrespective of the exact shape of the guide 22, the guides
22 may be attached individually proximate the impingement sleeve 14
and/or flowsleeve 17, or the transition duct 12 in the case of the
embodiment illustrated in FIG. 2, so as to direct the compressor
discharge air radially inboard, through the guides 22, apertures
24, into the fuel injectors 18, and projecting into the transition
duct 12 and/or the liner duct 16. As the high pressure dynamic
airflow 20 rushes into the guides 22, the airflow 20 is quickly
turned and redirected inboard. Such a redirection may lead to
turning vortices within the airflow, thereby hindering the flow
into the fuel injector 18. To reduce the formation of such turning
vortices, each guide 22 may include one or more straightening vanes
26 proximate a bend 28 in the guide 22.
[0023] Referring to FIG. 5, a penetration profile of the mixed
airflow and LLI fuel is illustrated. The harnessing of the high
pressure dynamic airflow 20 allows deeper penetration of the late
lean injection into the combustion zone.
[0024] In operation, airflow is channeled toward the fuel injectors
18 by the guides 22 that project out into the high pressure dynamic
airflow 20 passing the impingement sleeve 14 and/or the flowsleeve
17 of the transition duct 12 and/or the liner duct 16. The guides
22, by a combination of stagnation and redirection, catch air that
would previously have passed the apertures 24 aligned with the fuel
injectors 18 due to the lack of static pressure differential to
drive the flow through them, and directs the airflow 20 inward into
the fuel injectors 18 to mix with LLI fuel, and into the transition
duct 12 and/or the liner duct 16, thus producing deeper penetration
into the combustion zone.
[0025] Referring now to FIG. 6, another embodiment of the guides
122 is illustrated. The guides 122 are substantially longer than
the above-described guides 22 in the form of scoops or the like.
The guides 122 function similarly to guides 22, such that high
pressure dynamic airflow 120 is directed from a compressor
discharge exit 133 to one or more fuel injectors 118. The guides
122 include a first end 130 disposed proximate the compressor
discharge exit 133 and a second end 132 disposed proximate an
aperture 124 of an impingement sleeve 114 and/or a flowsleeve 117,
where the aperture 124 is relatively aligned with an inlet 134 of
each fuel injector 118. The guides 122 function as passages that
take the high pressure dynamic airflow 120 to the fuel injectors
118. Each guide 122 may be mounted to numerous components within
the gas turbine assembly including, but not limited to, a
compressor discharge casing 131 or various other combustion
hardware components.
[0026] The contour of the guides 122 as they extend from the first
end 130 to the second end 132 may vary based on the specific
application of use. One typical contour comprises a substantially
elongated straight portion 136 extending from a region proximate
the first end 130 and a bend portion 128 that functions to
transition the airflow 120 from the substantially elongated
straight portion 136 to the inlet 134 of the fuel injector 118. As
with the scoop guides 22, such a bend portion 128 may impose
turning vortices on the airflow. To reduce the occurrence of such
vortices, the bend portion 128 may include one or more
straightening vanes 126.
[0027] Referring to FIG. 7, a penetration profile of the mixed
airflow and LLI fuel is illustrated. The harnessing of the high
pressure dynamic airflow 120 allows deeper penetration of the late
lean injection into the combustion zone.
[0028] While the invention has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the invention is not limited to such
disclosed embodiments. Rather, the invention can be modified to
incorporate any number of variations, alterations, substitutions or
equivalent arrangements not heretofore described, but which are
commensurate with the spirit and scope of the invention.
Additionally, while various embodiments of the invention have been
described, it is to be understood that aspects of the invention may
include only some of the described embodiments. Accordingly, the
invention is not to be seen as limited by the foregoing
description, but is only limited by the scope of the appended
claims.
* * * * *