U.S. patent application number 13/349886 was filed with the patent office on 2013-07-18 for system and method for supplying a working fluid to a combustor.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. The applicant listed for this patent is Patrick Benedict Melton, Lucas John Stoia, Roy Marshall Washam. Invention is credited to Patrick Benedict Melton, Lucas John Stoia, Roy Marshall Washam.
Application Number | 20130180253 13/349886 |
Document ID | / |
Family ID | 47631263 |
Filed Date | 2013-07-18 |
United States Patent
Application |
20130180253 |
Kind Code |
A1 |
Stoia; Lucas John ; et
al. |
July 18, 2013 |
SYSTEM AND METHOD FOR SUPPLYING A WORKING FLUID TO A COMBUSTOR
Abstract
A system for supplying a working fluid to a combustor includes a
fuel nozzle, a combustion chamber, and fuel injectors
circumferentially arranged around the combustion chamber. A
combustor casing surrounds the combustion chamber. A distribution
manifold encloses the fuel injectors, and a plenum passes through
the combustor casing. A method for supplying a working fluid to a
combustor includes flowing a working fluid from a compressor
through a combustion chamber, diverting a portion of the working
fluid into a plenum, and flowing the diverted portion of the
working fluid outside of the compressor and the combustor. The
method further includes flowing the diverted portion of the working
fluid through a combustor casing and through a distribution
manifold that encloses fuel injectors circumferentially arranged
around the combustion chamber.
Inventors: |
Stoia; Lucas John; (Taylors,
SC) ; Melton; Patrick Benedict; (Horse Shoe, NC)
; Washam; Roy Marshall; (Clinton, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Stoia; Lucas John
Melton; Patrick Benedict
Washam; Roy Marshall |
Taylors
Horse Shoe
Clinton |
SC
NC
SC |
US
US
US |
|
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
47631263 |
Appl. No.: |
13/349886 |
Filed: |
January 13, 2012 |
Current U.S.
Class: |
60/772 ;
60/739 |
Current CPC
Class: |
F23R 3/04 20130101; F23R
3/346 20130101 |
Class at
Publication: |
60/772 ;
60/739 |
International
Class: |
F23R 3/28 20060101
F23R003/28 |
Claims
1. A system for supplying a working fluid to a combustor,
comprising: a. a fuel nozzle; b. a combustion chamber downstream
from said fuel nozzle; c. a plurality of fuel injectors
circumferentially arranged around said combustion chamber
downstream from said fuel nozzle; d. a combustor casing that
circumferentially surrounds at least a portion of said combustion
chamber; e. a distribution manifold that encloses said plurality of
fuel injectors; and f. a plenum that passes through said combustor
casing to provide fluid communication for a working fluid to flow
to said distribution manifold.
2. The system as in claim 1, wherein said distribution manifold
circumferentially surrounds said combustion chamber inside of said
combustor casing.
3. The system as in claim 1, wherein said plenum comprises a
plurality of branch lines in fluid communication with said
distribution manifold.
4. The system as in claim 1, wherein said plenum separates into a
plurality of branch lines after passing through said combustor
casing.
5. The system as in claim 1, wherein said plenum includes an
upstream portion configured to receive the working fluid from a
compressor.
6. The system as in claim 1, wherein said plenum includes an
upstream portion that passes through a compressor casing.
7. The system as in claim 1, wherein said plenum includes an
upstream portion that passes through a compressor casing and at
least a portion of said plenum extends outside of the
combustor.
8. A system for supplying a working fluid to a combustor,
comprising: a. a compressor; b. a combustor downstream from said
compressor, wherein said combustor comprises a combustion chamber
and a plurality of fuel injectors circumferentially arranged around
said combustion chamber; c. a combustor casing that surrounds at
least a portion of said combustor to contain a working fluid
flowing from said compressor to said combustor; d. a distribution
manifold that encloses said plurality of fuel injectors; and e. a
plenum that passes through said combustor casing to provide fluid
communication for a portion of the working fluid to flow to said
distribution manifold.
9. The system as in claim 8, wherein said distribution manifold
circumferentially surrounds said combustion chamber inside said
combustor casing.
10. The system as in claim 8, wherein said plenum comprises a
plurality of branch lines in fluid communication with said
distribution manifold.
11. The system as in claim 8, wherein said plenum separates into a
plurality of branch lines after passing through said combustor
casing.
12. The system as in claim 8, wherein said plenum includes an
upstream portion configured to receive the portion of the working
fluid from said compressor.
13. The system as in claim 8, wherein said plenum includes an
upstream portion that passes through a compressor casing.
14. The system as in claim 8, wherein said plenum includes an
upstream portion that passes through a compressor casing and at
least a portion of said plenum extends outside of said compressor
and said combustor.
15. A method for supplying a working fluid to a combustor,
comprising: a. flowing a working fluid from a compressor through a
combustion chamber; b. diverting a portion of the working fluid
into a plenum; c. flowing the diverted portion of the working fluid
outside of the compressor and the combustor; d. flowing the
diverted portion of the working fluid through a combustor casing
that circumferentially surrounds at least a portion of the
combustion chamber; and e. flowing the diverted portion of the
working fluid through a distribution manifold that encloses a
plurality of fuel injectors circumferentially arranged around the
combustion chamber.
16. The method as in claim 15, further comprising flowing the
diverted portion of the working fluid circumferentially around the
combustion chamber inside of the distribution manifold.
17. The method as in claim 15, further comprising separating the
diverted portion of the working fluid into a plurality of branch
lines in fluid communication with the distribution manifold.
18. The method as in claim 15, further comprising separating the
diverted portion of the working fluid into a plurality of branch
lines after passing through the combustor casing.
19. The method as in claim 15, further comprising flowing the
diverted portion of the working fluid through a compressor
casing.
20. The method as in claim 15, further comprising flowing the
diverted portion of the working fluid through a compressor casing
and outside of the combustor.
Description
FIELD OF THE INVENTION
[0001] The present invention generally involves a system and method
for supplying a working fluid to a combustor.
BACKGROUND OF THE INVENTION
[0002] Combustors are commonly used in industrial and power
generation operations to ignite fuel to produce combustion gases
having a high temperature and pressure. For example, gas turbines
typically include one or more combustors to generate power or
thrust. A typical gas turbine used to generate electrical power
includes an axial compressor at the front, one or more combustors
around the middle, and a turbine at the rear. Ambient air may be
supplied to the compressor, and rotating blades and stationary
vanes in the compressor progressively impart kinetic energy to the
working fluid (air) to produce a compressed working fluid at a
highly energized state. The compressed working fluid exits the
compressor and flows through one or more nozzles into a combustion
chamber in each combustor where the compressed working fluid mixes
with fuel and ignites to generate combustion gases having a high
temperature and pressure. The combustion gases expand in the
turbine to produce work. For example, expansion of the combustion
gases in the turbine may rotate a shaft connected to a generator to
produce electricity.
[0003] Various design and operating parameters influence the design
and operation of combustors. For example, higher combustion gas
temperatures generally improve the thermodynamic efficiency of the
combustor. However, higher combustion gas temperatures also promote
flashback or flame holding conditions in which the combustion flame
migrates towards the fuel being supplied by the nozzles, possibly
causing severe damage to the nozzles in a relatively short amount
of time. In addition, higher combustion gas temperatures generally
increase the disassociation rate of diatomic nitrogen, increasing
the production of nitrogen oxides (NO.sub.X). Conversely, a lower
combustion gas temperature associated with reduced fuel flow and/or
part load operation (turndown) generally reduces the chemical
reaction rates of the combustion gases, increasing the production
of carbon monoxide and unburned hydrocarbons.
[0004] In a particular combustor design, one or more fuel
injectors, also known as late lean injectors, may be
circumferentially arranged around the combustion chamber downstream
from the nozzles. A portion of the compressed working fluid exiting
the compressor may flow through the fuel injectors to mix with fuel
to produce a lean fuel-air mixture. The lean fuel-air mixture may
then be injected into the combustion chamber for additional
combustion to raise the combustion gas temperature and increase the
thermodynamic efficiency of the combustor.
[0005] The late lean injectors are effective at increasing
combustion gas temperatures without producing a corresponding
increase in the production of NO.sub.X. However, the pressure and
flow of the compressed working fluid exiting the compressor may
vary substantially around the circumference of the combustion
chamber. As a result, the fuel-air ratio flowing through the late
lean injectors can vary considerably, mitigating the beneficial
effects otherwise created by the late lean injection of fuel into
the combustion chamber. Previous attempts have been made to achieve
a more uniform flow of working fluid through the late lean
injectors. For example, scoops or shrouds have been installed over
a portion of the fuel injectors to more evenly regulate the flow of
working fluid through the fuel injectors. However, an improved
system and method for reducing the variation in the pressure and/or
flow of the working fluid flowing through the late lean injectors
would be useful.
BRIEF DESCRIPTION OF THE INVENTION
[0006] 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.
[0007] One embodiment of the present invention is a system for
supplying a working fluid to a combustor that includes a fuel
nozzle and a combustion chamber downstream from the fuel nozzle. A
plurality of fuel injectors are circumferentially arranged around
the combustion chamber downstream from the fuel nozzle. A combustor
casing circumferentially surrounds at least a portion of the
combustion chamber. A distribution manifold encloses the plurality
of fuel injectors, and a plenum passes through the combustor casing
to provide fluid communication for a working fluid to flow to the
distribution manifold.
[0008] Another embodiment of the present invention is a system for
supplying a working fluid to a combustor that includes a compressor
and a combustor downstream from the compressor. The combustor
includes a combustion chamber and a plurality of fuel injectors
circumferentially arranged around the combustion chamber. A
combustor casing surrounds at least a portion of the combustor to
contain a working fluid flowing from the compressor to the
combustor. A distribution manifold encloses the plurality of fuel
injectors, and a plenum passes through the combustor casing to
provide fluid communication for a portion of the working fluid to
flow to the distribution manifold.
[0009] The present invention may also include a method for
supplying a working fluid to a combustor. The method includes
flowing a working fluid from a compressor through a combustion
chamber, diverting a portion of the working fluid into a plenum,
and flowing the diverted portion of the working fluid outside of
the compressor and the combustor. The method further includes
flowing the diverted portion of the working fluid through a
combustor casing that circumferentially surrounds at least a
portion of the combustion chamber and flowing the diverted portion
of the working fluid through a distribution manifold that encloses
a plurality of fuel injectors circumferentially arranged around the
combustion chamber.
[0010] 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
[0011] 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:
[0012] FIG. 1 is a simplified side cross-section view of a system
according to one embodiment of the present invention; and
[0013] FIG. 2 is a simplified side view of the combustor shown in
FIG. 1 according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] 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.
[0015] 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.
[0016] Various embodiments of the present invention include a
system and method for supplying a working fluid to a combustor. In
general, the system includes multiple late lean injectors that
circumferentially surround a combustion chamber. The system diverts
or flows a portion of the working fluid from a common location and
routes the diverted portion of the working fluid to a distribution
manifold that surrounds the late lean injectors. By drawing the
working fluid from one common location and delivering it to the
distribution manifold, the system reduces variations in the
pressure and/or flow rate of the diverted working fluid at each
late lean injector to produce a more uniform fuel-air mixture
injected into the combustion chamber. Although exemplary
embodiments of the present invention will be described generally in
the context of a combustor incorporated into a gas turbine for
purposes of illustration, one of ordinary skill in the art will
readily appreciate that embodiments of the present invention may be
applied to any combustor and are not limited to a gas turbine
combustor unless specifically recited in the claims.
[0017] FIG. 1 provides a simplified cross-section view of a system
10 according to one embodiment of the present invention. As shown,
the system 10 may be incorporated into a gas turbine 12 having a
compressor 14 at the front, one or more combustors 16 radially
disposed around the middle, and a turbine 18 at the rear. The
compressor 14 and the turbine 18 typically share a common rotor 20
connected to a generator 22 to produce electricity.
[0018] The compressor 14 may be an axial flow compressor in which a
working fluid 24, such as ambient air, enters the compressor 14 and
passes through alternating stages of stationary vanes 26 and
rotating blades 28. A compressor casing 30 contains the working
fluid 24 as the stationary vanes 26 and rotating blades 28
accelerate and redirect the working fluid 24 to produce a
continuous flow of compressed working fluid 24. The majority of the
compressed working fluid 24 flows through a compressor discharge
plenum 32 to the combustor 16.
[0019] The combustor 16 may comprise any type of combustor known in
the art. For example, as shown in FIG. 1, a combustor casing 34 may
circumferentially surround some or all of the combustor 16 to
contain the compressed working fluid 24 flowing to the combustor
16. One or more fuel nozzles 36 may be radially arranged in an end
cover 38 to supply fuel to a combustion chamber 40 downstream from
the fuel nozzles 36. Possible fuels include, for example, one or
more of blast furnace gas, coke oven gas, natural gas, vaporized
liquefied natural gas (LNG), hydrogen, and propane. The compressed
working fluid 24 may flow from the compressor discharge plenum 32
along the outside of the combustion chamber 40 before reaching the
end cover 38 and reversing direction to flow through the fuel
nozzles 36 to mix with the fuel. The mixture of fuel and compressed
working fluid 24 flows into the combustion chamber 40 where it
ignites to generate combustion gases having a high temperature and
pressure. The combustion gases flow through a transition piece 42
to the turbine 18.
[0020] The turbine 18 may include alternating stages of stators 44
and rotating buckets 46. The first stage of stators 44 redirects
and focuses the combustion gases onto the first stage of turbine
buckets 46. As the combustion gases pass over the first stage of
turbine buckets 46, the combustion gases expand, causing the
turbine buckets 46 and rotor 20 to rotate. The combustion gases
then flow to the next stage of stators 44 which redirects the
combustion gases to the next stage of rotating turbine buckets 46,
and the process repeats for the following stages.
[0021] FIG. 2 provides a simplified side view of the combustor 16
shown in FIG. 1 according to one embodiment of the present
invention. As shown, the combustor 16 includes a plurality of fuel
injectors 50 circumferentially arranged around the combustion
chamber 40 downstream from the fuel nozzles 36. The fuel injectors
50 may receive the same or a different fuel than supplied to the
fuel nozzles 36 and mix the fuel with a portion of the compressed
working fluid 24 before injecting the mixture into the combustion
chamber 40. In this manner, the fuel injectors 50 supply a lean
mixture of fuel and air for additional combustion to raise the
temperature, and thus the efficiency, of the combustor 16.
[0022] A distribution manifold 52 encloses the fuel injectors 50 to
shield the fuel injectors 50 from direct impingement by the
compressed working fluid 24 flowing out of the compressor 14. As
shown in FIG. 2, the distribution manifold 52 may circumferentially
surround at least a portion of the combustion chamber 40 inside of
the combustor casing 34 to contain a portion of the compressed
working fluid 24 diverted from a common source and supplied to the
fuel injectors 50. A plenum 54 may connect the distribution
manifold 52 to a common source of the diverted compressed working
fluid 24 to provide fluid communication for the diverted working
fluid 24 to flow to the distribution manifold 52. For example, as
shown more clearly in FIG. 1, the plenum 54 may include an upstream
portion 56 configured to receive or divert a portion of the working
fluid 24 from the compressor 14. The upstream portion 56 may pass
through the compressor casing 30 so that at least a portion of the
plenum 54 extends outside of the compressor 14 and combustor 16
before passing through the combustor casing 32 to connect to the
distribution manifold 52. In particular embodiments, as shown in
FIG. 2, the plenum 54 may separate into a plurality of branch lines
58 before or after passing through the combustor casing 34. The
branch lines 58 may include, for example, piping or flexible hoses
so that each branch line 58 provides a separate fluid communication
with the distribution manifold 52. In this manner, the plenum 54
may divert a portion of the compressed working fluid 24 at or close
to the discharge pressure of the compressor 14 and deliver this
diverted compressed working fluid 24 directly to the fuel injectors
50 inside the distribution manifold 52 with little or no pressure
drop in the compressed working fluid 24.
[0023] The system 10 shown and described with respect to FIGS. 1
and 2 may also provide a method for supplying the working fluid 24
to the combustor 16. The method may include flowing the working
fluid 24 from the compressor 14 through the combustion chamber 40
and diverting a portion of the working fluid 24 into the plenum 54.
The method may further include flowing the diverted portion of the
working fluid 24 outside of the compressor 14 and the combustor 16,
through the combustor casing 34 that circumferentially surrounds at
least a portion of the combustion chamber 40, and through the
distribution manifold 52 that encloses the fuel injectors 50
circumferentially arranged around the combustion chamber 40. In
particular embodiments, the method may further include flowing the
diverted portion of the working fluid 24 through the compressor
casing 30, circumferentially around at least a portion of the
combustion chamber 40 inside of the distribution manifold 52,
and/or separating the diverted portion of the working fluid 24 into
the branch lines 58 before or after passing through the combustor
casing 34.
[0024] The various embodiments of the present invention may provide
one or more technical advantages over existing late lean injection
systems. For example, the systems and methods described herein may
reduce variations in the pressure and/or flow of the working fluid
24 through each fuel injector 50. As a result, the various
embodiments require less analysis to achieve the desired fuel-air
ratio through the fuel injectors 50 and enhance the intended
ability of the fuel injectors 50 achieve the desired efficiency and
reduced emissions from the combustor 16.
[0025] 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 languages of the claims.
* * * * *