U.S. patent application number 14/288974 was filed with the patent office on 2015-12-03 for systems and methods for coherence reduction in combustion system.
This patent application is currently assigned to General Electric Company. The applicant listed for this patent is General Electric Company. Invention is credited to Joseph Vincent Citeno, Sarah Lori Crothers.
Application Number | 20150345794 14/288974 |
Document ID | / |
Family ID | 54481590 |
Filed Date | 2015-12-03 |
United States Patent
Application |
20150345794 |
Kind Code |
A1 |
Crothers; Sarah Lori ; et
al. |
December 3, 2015 |
SYSTEMS AND METHODS FOR COHERENCE REDUCTION IN COMBUSTION
SYSTEM
Abstract
A system includes a gas turbine engine having a first combustor
and a second combustor. The first combustor includes a first set of
fuel nozzles and a first plurality of injection pegs. The first
plurality of injection pegs are disposed in a first configuration
upstream of the first set of fuel nozzles, along a first fuel path,
and the first plurality of injection pegs are configured to route a
fuel to the first set of fuel nozzles. The system further includes
a second combustor having a second set of fuel nozzles and a second
plurality of injection pegs. The second plurality of injection pegs
are disposed in a second configuration upstream of the second set
of fuel nozzles, along a second fuel path, and the second plurality
of injection pegs are configured to route the fuel to the second
set of fuel nozzles. The second configuration has at least one
difference relative to the first configuration.
Inventors: |
Crothers; Sarah Lori;
(Greenville, SC) ; Citeno; Joseph Vincent;
(Greenville, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Assignee: |
General Electric Company
Schenectady
NY
|
Family ID: |
54481590 |
Appl. No.: |
14/288974 |
Filed: |
May 28, 2014 |
Current U.S.
Class: |
60/773 ;
60/725 |
Current CPC
Class: |
F23R 2900/00014
20130101; F23R 3/46 20130101; F23R 3/286 20130101; F23R 3/42
20130101; F23R 3/346 20130101 |
International
Class: |
F23R 3/34 20060101
F23R003/34; F23R 3/42 20060101 F23R003/42 |
Claims
1. A system, comprising: a gas turbine engine, comprising: a first
combustor having a first set of fuel nozzles and a first plurality
of injection pegs, wherein the first plurality of injection pegs
are disposed in a first configuration upstream of the first set of
fuel nozzles, along a first fuel path, and the first plurality of
injection pegs are configured to route a fuel to the first set of
fuel nozzles; and a second combustor having a second set of fuel
nozzles and a second plurality of injection pegs, wherein the
second plurality of injection pegs are disposed in a second
configuration upstream of the second set of fuel nozzles, along a
second fuel path, and the second plurality of injection pegs are
configured to route the fuel to the second set of fuel nozzles, and
the second configuration has at least one difference relative to
the first configuration.
2. The system of claim 1, wherein the at least one difference is
configured to reduce coherence between the first combustor and the
second combustor by varying a first convective time of the first
set of injection pegs relative to a second convective time of the
second set of injection pegs.
3. The system of claim 1, wherein the at least one difference is
configured to vary combustion dynamics between the first combustor
and the second combustor by varying a first ratio of an air-fuel
mixture of the first set of fuel nozzles relative to a second ratio
of the air-fuel mixture of the second set of fuel nozzles.
4. The system of claim 1, wherein the at least one difference
between the first plurality of injection pegs and the second
plurality of injection pegs comprises a difference between at least
one injection peg of the first plurality of injection pegs and at
least one injection peg of the second plurality of injection
pegs.
5. The system of claim 4, wherein the at least one difference
between the first plurality of injection pegs and the second
plurality of injection pegs comprises at least one of a different
axial configuration, a different circumferential configuration, or
a different geometry, or any combination thereof.
6. The system of claim 5, wherein the different axial configuration
comprises at least one of a different axial placement, a different
axial location, a different axial position, or a different axial
arrangement, or any combination thereof, between one or more axes
of the first or second combustor.
7. The system of claim 5, wherein the different circumferential
configuration comprises at least one of a different circumferential
placement, a different circumferential location, a different
circumferential position, or a different circumferential
arrangement, or any combination thereof, between a first axis of
the first and second combustor.
8. The system of claim 5, wherein the different geometry comprises
at least one of a different angle, a different size, or a different
shape, or any combination thereof, between the first plurality of
injection pegs and the second plurality of injection pegs.
9. The system of claim 1, wherein the first set of fuel nozzles are
arranged into one or more fuel circuits, and wherein a first
injection peg and a second injection peg of the first plurality of
injection pegs are associated with a first fuel circuit and a
second fuel circuit of the one or more fuel circuits,
respectively.
10. The system of claim 9, wherein the first injection peg
comprises at least one difference relative to the second injection
peg, and wherein the at least one difference comprises a different
axial configuration, a different circumferential configuration, a
different geometry, or any combination thereof.
11. A system, comprising: a first turbine combustor, comprising: a
first plurality of fuel nozzles configured to route an air-fuel
mixture to a combustion chamber of the first turbine combustor,
wherein the first plurality of fuel nozzles comprises a first set
of fuel nozzles and a second set of fuel nozzles; and a first
plurality of injection pegs configured to route a fuel to the first
plurality of fuel nozzles, wherein the first plurality of injection
pegs comprises a first set of injection pegs associated with the
first set of fuel nozzles and a second set of injection pegs
associated with the second set of fuel nozzles, and the first set
of injection pegs has at least one difference relative to the
second set of injection pegs.
12. The system of claim 11, wherein the at least one difference is
configured to reduce coherence between the first combustor and the
second combustor by varying a first convective time of the first
set of injection pegs relative to a second convective time of the
second set of injection pegs.
13. The system of claim 11, comprising a second turbine combustor
comprising: a second plurality of fuel nozzles configured to route
the air-fuel mixture to a second combustion chamber of the second
turbine combustor, wherein the second plurality of fuel nozzles
comprises a third set of fuel nozzles and a fourth set of fuel
nozzles; and a second plurality of injection pegs configured to
route the fuel to the second plurality of fuel nozzles, wherein the
second plurality of injection pegs comprises a third set of
injection pegs associated with the third set of fuel nozzles and a
fourth set of injection pegs associated with the fourth set of fuel
nozzles.
14. The system of claim 13, wherein the first set of injection pegs
or the second set of injection pegs comprises at least one
difference relative to the third set of injection pegs or the
fourth set of injection pegs.
15. The system of claim 14, wherein the at least one difference is
configured to vary combustion dynamics between the first combustor
and the second combustor by varying a first ratio of an air-fuel
mixture of the first set of fuel nozzles relative to a second ratio
of the air-fuel mixture of the second set of fuel nozzles.
16. The system of claim 11, wherein the at least one difference
between the first set of injection pegs and the second set of
injection pegs comprises a different axial configuration, a
different circumferential configuration, a different geometry, or
any combination thereof.
17. The system of claim 11, wherein the first set of injection pegs
or the second set of injection pegs comprises a set of zero
injection pegs.
18. A method, comprising: controlling a first combustion dynamic of
a first combustor or a first convective time of a first set of
injection pegs of the first combustor with a first configuration of
a first plurality of injection pegs disposed upstream of the first
set of fuel nozzles along a first fuel path; and controlling a
second combustion dynamic of a second combustor or a second
convective time of a second set of injection pegs of the second
combustor with a second configuration of a second plurality of
injection pegs disposed upstream of the second set of fuel nozzles
along a second fuel path, wherein the second plurality of injection
pegs has at least one difference relative to the first plurality of
injection pegs.
19. The method of claim 18, wherein the at least one difference
comprises a different axial configuration, a different
circumferential configuration, a different geometry, or any
combination thereof.
20. The method of claim 18, wherein the at least one difference
between the first plurality of injection pegs and the second
plurality of injection pegs is configured to reduce modal coupling
between the first combustor and the second combustor.
Description
BACKGROUND
[0001] The disclosed subject matter relates generally to gas
turbine systems, and more particularly, to a system and method for
controlling combustion dynamics, and more specifically, for
reducing modal coupling of combustion dynamics.
[0002] Gas turbine systems generally include a gas turbine engine
having a compressor section, a combustor section, and a turbine
section. The combustor section may include one or more combustors
(e.g., combustion cans) with fuel nozzles configured to inject a
fuel and an oxidant (e.g., air) into a combustion chamber within
each combustor. In each combustor, a mixture of the fuel and
oxidant combusts to generate hot combustion gases, which then flow
into and drive one or more turbine stages in the turbine section.
Each combustor may generate combustion dynamics, which occur when
the flame dynamics (also known as the oscillating component of the
heat release) interact with, or excite, one or more acoustic modes
of the combustor, to result in pressure oscillations in the
combustor.
[0003] Combustion dynamics can occur at multiple discrete
frequencies or across a range of frequencies, and can travel both
upstream and downstream relative to the respective combustor. For
example, the pressure and/or acoustic waves may travel downstream
into the turbine section, e.g., through one or more turbine stages,
or upstream into the fuel system. Certain downstream components of
the turbine section can potentially respond to the combustion
dynamics, particularly if the combustion dynamics generated by the
individual combustors exhibit an in-phase and coherent relationship
with each other, and have frequencies at or near the natural or
resonant frequencies of the components. As discussed herein,
"coherence" may refer to the strength of the linear relationship
between two dynamic signals, and may be strongly influenced by the
degree of frequency overlap between them. In some situations,
"coherence" is a measure of the modal coupling, or
combustor-to-combustor acoustic interaction, exhibited by the
combustion system. Accordingly, a need exists to control the
combustion dynamics, and/or modal coupling of the combustion
dynamics, to reduce the possibility of any unwanted sympathetic
vibratory response (e.g., resonant behavior) of components in the
turbine system.
BRIEF DESCRIPTION
[0004] Certain embodiments commensurate in scope with the
originally claimed invention are summarized below. These
embodiments are not intended to limit the scope of the claimed
invention, but rather these embodiments are intended only to
provide a brief summary of possible forms of the invention. Indeed,
the invention may encompass a variety of forms that may be similar
to or different from the embodiments set forth below.
[0005] In a first embodiment, a system includes a gas turbine
engine having a first combustor and a second combustor. The first
combustor includes a first set of fuel nozzles and a first
plurality of injection pegs. The first plurality of injection pegs
are disposed in a first configuration upstream of the first set of
fuel nozzles, along a first fuel path, and the first plurality of
injection pegs are configured to route a fuel to the first set of
fuel nozzles. The system further includes a second combustor having
a second set of fuel nozzles and a second plurality of injection
pegs. The second plurality of injection pegs are disposed in a
second configuration upstream of the second set of fuel nozzles,
along a second fuel path, and the second plurality of injection
pegs are configured to route the fuel to the second set of fuel
nozzles. The second configuration has at least one difference
relative to the first configuration.
[0006] In a second embodiment, a system includes a first turbine
combustor. The first combustor includes a first plurality of fuel
nozzles configured to route an air-fuel mixture to a combustion
chamber of the first turbine combustor. The first plurality of fuel
nozzles comprises a first set of fuel nozzles and a second set of
fuel nozzles. The system also includes a first plurality of
injection pegs configured to route a fuel to the first plurality of
fuel nozzles. The first plurality of injection pegs comprises a
first set of injection pegs associated with the first set of fuel
nozzles and a second set of injection pegs associated with the
second set of fuel nozzles. The first set of injection pegs has at
least one difference relative to the second set of injection
pegs.
[0007] In a third embodiment, a method includes controlling a first
combustion dynamic of a first combustor or a first convective time
of a first set of injection pegs of the first combustor with a
first configuration of a first plurality of injection pegs disposed
upstream of the first set of fuel nozzles along a first fuel path.
The method further includes controlling a second combustion dynamic
of a second combustor or a second convective time of a second set
of injection pegs of the second combustor with a second
configuration of a second plurality of injection pegs disposed
upstream of the second set of fuel nozzles along a second fuel
path. The second plurality of injection pegs has at least one
difference relative to the first plurality of injection pegs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] These and other features, aspects, and advantages of the
present invention will become better understood when the following
detailed description is read with reference to the accompanying
drawings in which like characters represent like parts throughout
the drawings, wherein:
[0009] FIG. 1 is a schematic of an embodiment of a gas turbine
system having a plurality of combustors with a respective fuel
circuit configuration configured to control combustion dynamics
and/or modal coupling of combustion dynamics to reduce the
possibility of unwanted vibratory responses in downstream
components;
[0010] FIG. 2 is a cross-sectional schematic of an embodiment of
one of the combustors of FIG. 1, wherein the combustor includes a
first quaternary fuel circuit configuration with an axial
staggering of injection pegs;
[0011] FIG. 3 is a cross-sectional schematic of an embodiment of
one of the combustors of FIG. 1, wherein the combustor includes a
second quaternary fuel circuit configuration with a circumferential
arrangement of injection pegs;
[0012] FIG. 4 is a cross-sectional schematic of an embodiment of
the combustor of FIG. 3 taken along line 4-4, illustrating a
plurality of quat pegs arranged around an axis and biased to a
first fuel circuit; and
[0013] FIG. 5 is a cross-sectional schematic of an embodiment of
the gas turbine system of FIG. 1, taken along line 5-5,
illustrating a plurality of combustors with respective quaternary
fuel circuit configurations configured to control combustion
dynamics and/or modal coupling of combustion dynamics to reduce the
possibility of unwanted vibratory responses in downstream
components.
DETAILED DESCRIPTION
[0014] One or more specific embodiments of the present invention
will be described below. In an effort to provide a concise
description of these embodiments, all features of an actual
implementation may not be described in the specification. It should
be appreciated that in the development of any such actual
implementation, as in any engineering or design project, numerous
implementation-specific decisions must be made to achieve the
developers' specific goals, such as compliance with system-related
and business-related constraints, which may vary from one
implementation to another. Moreover, it should be appreciated that
such a development effort might be complex and time consuming, but
would nevertheless be a routine undertaking of design, fabrication,
and manufacture for those of ordinary skill having the benefit of
this disclosure.
[0015] When introducing elements of various embodiments of the
present invention, the articles "a," "an," "the," and "said" are
intended to mean that there are one or more of the elements. The
terms "comprising," "including," and "having" are intended to be
inclusive and mean that there may be additional elements other than
the listed elements.
[0016] The disclosed embodiments are directed toward reducing
combustion dynamics and/or modal coupling of combustion dynamics
(e.g., reduce unwanted vibratory responses in downstream
components) in a gas turbine system by varying a fuel circuit
configuration, such as the configuration of a quaternary fuel
circuit or manifold. In particular, the disclosed embodiments are
directed towards varying the configuration of a plurality of
injection pegs (e.g., quat pegs) within one or more quaternary fuel
circuits associated with one or more combustors of the gas turbine
system, such that the arrangement of the quat pegs are configured
to reduce combustion dynamics and/or unwanted vibratory responses
within the system.
[0017] As noted above, a gas turbine combustor (or combustor
assembly) may generate combustion dynamics due to the combustion
process, characteristics of intake fluid flows (e.g., fuel,
oxidant, diluent, etc.) into the combustor, and various other
factors. The combustion dynamics may be characterized as pressure
fluctuations, pulsations, oscillations, and/or waves at certain
frequencies. The fluid flow characteristics may include velocity,
pressure, fluctuations in velocity and/or pressure, variations in
flow paths (e.g., turns, shapes, interruptions, etc.), or any
combination thereof. Collectively, the combustion dynamics can
potentially cause vibratory responses and/or resonant behavior in
various components upstream and/or downstream from the combustor.
For example, the combustion dynamics (e.g., at certain frequencies,
ranges of frequencies, amplitudes, combustor-to-combustor phases,
etc.) can travel both upstream and downstream in the gas turbine
system. If the gas turbine combustors, upstream components, and/or
downstream components have natural or resonant frequencies that are
driven by these pressure fluctuations (e.g., combustion dynamics),
then the pressure fluctuations can potentially cause vibration,
stress, fatigue, etc. The components may include combustor liners,
combustor flow sleeves, combustor caps, fuel nozzles, turbine
nozzles, turbine blades, turbine shrouds, turbine wheels, bearings,
fuel supply assemblies, or any combination thereof. The downstream
components are of specific interest, as they are more sensitive to
combustion tones that are in-phase and coherent. Thus, reducing
coherence specifically reduces the possibility of unwanted
vibrations in downstream components.
[0018] As discussed in detail below, the disclosed embodiments may
equip one or more gas turbine combustors with a particular fuel
circuit arrangement (e.g., quaternary fuel circuit arrangement)
configured to modify the combustion dynamics of the gas turbine
combustor, e.g., varying the frequency, amplitude,
combustor-to-combustor coherence, range of frequencies, or any
combination thereof. In particular, the arrangement of a plurality
of quaternary pegs or quat pegs (e.g., injection pegs) of each
quaternary fuel circuit system associated with a particular
combustor may alter the convective time for one or more quat pegs,
and/or fuel-air ratio at the nozzle level, which may alter the
combustion dynamics, in a way to substantially reduce or eliminate
any unwanted vibratory response of components upstream and/or
downstream of the turbine combustor, as well as the gas turbine
combustors. Varying the fuel-air ratio at the nozzle level may
modify the distribution of the heat release, which alters the flame
dynamics, and therefore the combustion dynamics. In addition,
convective time is an important factor in combustion dynamics
frequencies and/or amplitudes. The convective time refers to the
delay between the time that the fuel is injected through the fuel
ports of the gas turbine combustor and the time when the fuel
reaches the combustion chamber and ignites. Altering the axial
position of the quat pegs, alters the travel time for the fuel
between the quat pegs and the flame zone, and therefore alters the
convective time. Generally, there is an inverse relationship
between convective time and frequency. That is, when the convective
time increases, the frequency of the combustion instability
decreases, and when the convective time decreases, the frequency of
the combustion instability increases. In addition, varying the
convective time between the quat pegs may encourage destructive
interference of the combustion dynamics generated by, or
contributed to, by the quat pegs, which may reduce the amplitudes
of the combustion dynamics and/or alter the frequency of the
combustion dynamics. For example, varying the configuration (e.g.,
placement, arrangement, position, location, etc.) of quat pegs
axially and/or circumferentially around the head end of the
combustor may facilitate the tuning of convective time for one or
more quat pegs, and/or the fuel-air ratio at the nozzle level, and
may result in combustion dynamics with reduced amplitudes, and/or
frequencies that are different, and/or spread out over a greater
frequency range, or any combination thereof, relative to any
resonant frequencies of the components in the gas turbine system.
In addition, varying the geometries of the quat pegs (e.g., size,
shape, angle, etc.) may introduce a variation in convective time
for one or more quat pegs, and/or fuel-air ratio at the nozzle
level, and may result in combustion dynamics with reduced
amplitudes, and/or frequencies that are different and/or spread out
over a greater frequency range, relative to any resonant
frequencies of the components in the gas turbine system.
[0019] In addition to modifications on a combustor level (i.e.,
individual turbine combustor), the disclosed embodiments may vary
the configuration (e.g., arrangement, location, position, etc.)
and/or the geometry (e.g., angle, size, shape, etc.) of the quat
pegs within each quaternary fuel circuit among a plurality of gas
turbine combustors, thereby varying the combustion dynamics, from
combustor-to-combustor, in a manner to reduce the combustion
dynamics amplitudes and/or modal coupling of the combustion
dynamics among the plurality of gas turbine combustors. For
example, varying the configuration of the quat pegs (e.g.,
placement, location, position, arrangement, etc.) axially and/or
circumferentially between or among combustors of the system may
result in combustor-to-combustor variations in the combustion
dynamics frequencies (e.g., frequencies that are different, spread
out over a greater frequency range, or any combination thereof),
thereby reducing the possibility of modal coupling of the
combustors, particularly at frequencies that are aligned with
resonant frequencies of the components of the gas turbine system.
Likewise, the geometries of the quat pegs (e.g., size, shape,
angle, etc.) may be varied between or among combustors of the
system to help reduce unwanted vibratory responses.
[0020] With the forgoing in mind, FIG. 1 is a schematic of an
embodiment of a gas turbine system 10 having a plurality of
combustors 12, where each combustor 12 is associated with one or
more quaternary fuel circuits 13 (e.g., quat fuel circuit 13). Each
quat fuel circuit 13 may include a plurality of quaternary pegs 14
(e.g., injection pegs, quat pegs), where each quat peg 14 may be
configured to inject fuel into the combustor 12 upstream of the
fuel nozzles 18 in the combustor 12. For example, each quat fuel
circuit 13 may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more quat
pegs 14 that are arranged around the circumference of the combustor
12 upstream of the fuel nozzles 18 (e.g., primary fuel nozzles 18).
The configuration and/or the geometries of the quat pegs 14 of each
quat fuel circuit 13 may be varied within and/or among the
combustors 12 to change the combustion dynamics in a particular
combustor 12 and/or between the combustors 12, thereby helping to
reduce any unwanted vibratory responses in components downstream of
the system 10, as will be further described in detail below.
Specifically, varying the configuration and/or the geometries of
the quat pegs 14 within the combustor 12 and/or among the
combustors 12 may vary the convective time between the quat pegs,
and/or fuel-air ratio between the fuel nozzles 18 associated with
the quat pegs 14, thereby decreasing combustion dynamics amplitudes
and/or varying the combustion dynamics frequencies within a
particular combustor 12, and/or between adjacent combustors 12,
and/or among a plurality of combustors 12, which is expected to
reduce the coherence of the combustors 12, as further described in
detail below.
[0021] In the illustrated embodiment, the gas turbine system 10
includes one or more combustors 12 each having the quat fuel
circuit 13, a compressor 11, and a turbine 16. Each quat fuel
circuit 13 may include one or more quat pegs 14, which may be
configured to direct a fuel from one or more fuel sources into the
combustor 12 upstream of one or more fuel nozzles 18 (e.g., 1, 2,
3, 4, 5, 6, or more) within the combustor 12. The combustors 12
ignite and combust a pressurized oxidant (e.g., air) and fuel
mixture (e.g., an air-fuel mixture) within the combustion chambers
19, and then pass resulting hot pressurized combustion gases 24
(e.g., exhaust) into the turbine 16. In certain embodiments, the
fuel nozzles 18 may grouped into one or more primary fuel circuits
(e.g., 1, 2, 3, 4, 5, or more fuel circuits), where each primary
fuel circuit includes one or more fuel nozzles 18. Each primary
fuel circuit may be associated with a fuel source. The fuel nozzles
18 associated with one or more primary fuel circuits may also be
associated with one or more quat pegs 14, i.e. one or more quat
pegs 14 may inject fuel into the flow passage 64 (as shown in FIG.
2), where it mixes with the airflow 67 from the compressor
discharge 68 (as shown in FIG. 2), prior to entering one or more
fuel nozzles 18 associated with one or more fuel circuits, creating
a fuel-air mixture that then enters the fuel nozzles 18, where
additional fuel will be injected by the fuel nozzles 18. In certain
embodiments, varying the configuration and/or geometries of the
quat pegs 14 may tune the convective time of one or more quat pegs
and/or the air/fuel ratio of the one or more fuel nozzles 18
associated with the quat pegs 14, thereby altering the combustion
dynamics amplitudes and/or frequencies within the combustor 12
and/or among the combustors 12 of the system 10.
[0022] In particular, varying the configuration and/or geometries
of the quat pegs 14 may vary convective time for one or more quat
pegs, and/or fuel-air ratio for one or more fuel nozzles 18.
Accordingly, varying the convective time for one or more quat pegs,
and/or fuel-air ratio of one or more fuel nozzles 18 via the
configuration and/or geometries of the quat pegs 14 may modify the
resulting combustion dynamics of the combustor 12 and/or among the
combustors 12 of the system 10. Modifying the combustion dynamics,
in turn, may reduce the possibility of unwanted vibratory responses
in the combustor 12, and/or downstream components. For example, in
certain embodiments, the combustors 12 of the system 10 may be
identical except for variations in the configuration and/or
geometries of the quat pegs 14 within each combustor 12.
Accordingly, the variations in the configuration and/or geometries
of the quat pegs 14 between the combustors 12 may help modify or
reduce modal coupling of the combustion dynamics between the
combustors 12.
[0023] Turbine blades within the turbine 16 are coupled to a shaft
26 of the gas turbine system 10, which may also be coupled to
several other components throughout the turbine system 10. As the
combustion gases 24 flow against and between the turbine blades of
the turbine 16, the turbine 16 is driven into rotation, which
causes the shaft 26 to rotate. Eventually, the combustion gases 24
exit the turbine system 10 via an exhaust outlet 28. Further, in
the illustrated embodiment, the shaft 26 is coupled to a load 30,
which is powered via the rotation of the shaft 26. The load 30 may
be any suitable device that generates power via the torque of the
turbine system 10, such as an electrical generator, a propeller of
an airplane, or other load.
[0024] The compressor 11 of the gas turbine system 10 includes
compressor blades. The compressor blades within the compressor 11
are coupled to the shaft 26, and will rotate as the shaft 26 is
driven to rotate by the turbine 16, as discussed above. As the
compressor blades rotate within the compressor 11, the compressor
11 compresses air (or any suitable oxidant) received from an air
intake 32 to produce pressurized air 34. The pressurized air 34 is
then fed into the fuel nozzles 18 of the combustors 12. As
mentioned above, the fuel nozzles 18 mix the pressurized air 34 and
fuel to produce a suitable mixture ratio for combustion. In the
following discussion, reference may be made to an axial direction
or axis 42 (e.g., a longitudinal axis) of the combustor 12, a
radial direction or axis 44 of the combustor 12, and a
circumferential direction or axis 46 of the combustor 12.
[0025] In certain embodiments, varying the configuration of the
quat pegs 14 of the quat fuel circuit 13 axially and/or
circumferentially and/or varying the geometries of the quat peg 14
(e.g., shapes, sizes, angles, etc.) may help reduce unwanted
vibratory responses within the combustor 12 and/or downstream
turbine components in the system 10. For example, in the
illustrated embodiment, the system 10 includes a first combustor 17
associated with a first quat fuel circuit 13 and a second combustor
21 associated with a second quat fuel circuit 13. Each quat fuel
circuit 13 may be associated with a plurality of quat pegs 14
configured to route the fuel and/or the air/fuel mixture to the
fuel nozzles 18. In certain embodiments, the configuration of the
plurality of quat pegs 14 associated with a particular combustor 12
may be different than the configuration of the plurality of quat
pegs 14 associated with an adjacent or non-adjacent combustor 12.
For example, a first set of quat pegs 14 associated with the first
combustor 17 may be disposed approximately along a first axis 48
along the circumferential direction 46 of the system 10. In the
illustrated embodiment, a second set of quat pegs 15 associated
with the second combustor 21 may be disposed approximately along a
second axis 50 approximately parallel to the first axis 48. In
particular, the second set of quat pegs 15 may be axially staggered
relative to the first set of quat pegs 14, such that a first
configuration of the quat pegs 14 is different from a second
configuration of the quat pegs 15.
[0026] While the illustrated embodiment depicts varying the
configuration of the quat pegs 14 via axial staggering of the quat
pegs 14 between adjacent combustors 12 of the system 10, it should
be noted that the configuration of the quat pegs 14 may be varied
by axially staggering the quat pegs 14 between 2, 3, 4, 5, 6, or
more combustors 12 within the system 10 along 1, 2, 3, 4, 5, 6, or
more axial positions along the circumferential direction 46. In
certain embodiments, the configuration of the quat pegs 14 may be
varied within a particular combustor 12 (as further described in
FIG. 2), by axially staggering the quat pegs 14 along 1, 2, 3, 4,
5, 6 or more axial positions along the circumferential direction 46
within the particular combustor 12. In addition, in certain
embodiments, it should be noted that the configuration of the quat
pegs 14 among one or more combustors 12 may be varied by
circumferentially distributing the quat pegs 14 in various
configurations, as further described with respect to FIGS. 3-5.
[0027] FIG. 2 is a cross-sectional schematic of an embodiment of
the combustor 12 in the system 10 of FIG. 1, wherein the combustor
12 includes a first quaternary fuel circuit configuration where the
quat pegs 14 (e.g., injection pegs) are staggered axially, at 1, 2,
3, 4, 5, 6 or more axial positions along the circumferential
direction 46. As noted above with respect to FIG. 1, the
configurations of the quat pegs 14 may be varied by axially
staggering the quat pegs 14 among one or more combustors 12 at one
or more axial positions 48, 50. In the illustrated embodiment, the
quat pegs 14 are varied within a single combustor 12, such that the
quat pegs 14 are axially staggered along the first axial position
48, the second axial position 50, and a third axial position 52
along the circumferential direction 46 of the system 10. As noted
above, varying the configuration and/or geometries of the quat pegs
14 within the combustor 12 may vary the convective time for one or
more quat pegs, and/or the fuel-air ratio of the fuel nozzles 18
associated with the quat pegs 14, thereby decreasing combustion
dynamics amplitudes within the combustor, which is expected to
reduce unwanted vibratory responses within the gas turbine system
10.
[0028] In the illustrated embodiment, the combustor 12 includes a
head end 54 and the combustion chamber 19. The head end 54 of the
combustor 12 generally encloses a cap assembly 56 and the fuel
nozzles 18, such as 1, 2, 3, 4, 5, 6, 7 or more fuel nozzles 18. In
certain embodiments, the fuel nozzles 18 route fuel, air, fuel-air
mixtures, and sometimes other fluids to the combustion chamber 19.
In particular, the fuel nozzles 18 may be grouped or arranged into
one or more different fuel circuits, such that each fuel circuit
contains one or more fuel nozzles 18 and where each fuel circuit
may route a fuel and/or an air/fuel mixture from one or more fuel
sources. The combustor cap assembly 56 is disposed along a portion
of the length of the fuel nozzles 18, housing the fuel nozzles 18
within the combustor 12. Each fuel nozzle 18 facilitates the mixing
of pressurized air and fuel and directs the mixture through the
combustor cap assembly 56 and into the combustion chamber 19. The
air-fuel mixture may then combust in a primary combustion zone 57
of the chamber 19, thereby creating hot pressurized exhaust gases
that flow in a downstream direction 69. These pressurized exhaust
gases drive the rotation of blades within the turbine 16. The
combustor 12 has one or more walls extending circumferentially 46
around the combustion chamber 19 and the axis 42 of the combustor
12, and generally represents one of a plurality of combustors 12
that are disposed in a spaced arrangement circumferentially about a
rotational axis (e.g., shaft 26) of the gas turbine system 10.
[0029] Each combustor 12 includes an outer wall (e.g., flow sleeve
58) disposed circumferentially about an inner wall (e.g., combustor
liner 60) to define an intermediate flow passage or space 64, while
the combustor liner 60 extends circumferentially about the
combustion chamber 19. The inner wall 60 also may include a
transition piece 66, which generally converges toward a first stage
of the turbine 16. The impingement sleeve 59 is disposed
circumferentially about the transition piece 66. The liner 60
defines an inner surface of the combustor 12, directly facing and
exposed to the combustion chamber 19. The flow sleeve 58 and
impingement sleeve 59 include a plurality of perforations 61, which
direct an airflow 67 from a compressor discharge 68 into the flow
passage 64 while also impinging air against the liner 60 and the
transition piece 66 for purposes of impingement cooling. The flow
passage 64 then directs the airflow 67 in an upstream direction
toward the head end 54 (e.g., relative to a downstream direction 69
of the hot combustion gases), such that the airflow 67 further
cools the liner 60 before flowing through the combustor cap
assembly 56, through the fuel nozzles 18, and into the combustion
chamber 19.
[0030] In certain embodiments, the combustor 12 may include the
quaternary fuel circuit 13 having a plurality of quat pegs 14 in
various configurations and/or geometries. Specifically, the quat
pegs 14 may be disposed circumferentially around the combustor 12
near the head end 54. In certain embodiments, the airflow 67
flowing through the combustor cap assembly 56 may encounter the
quat pegs 14 associated with the fuel nozzles 18. Specifically, the
quat pegs 14 may be configured as fuel injectors that inject a
portion of a fuel into the airflow 67 upstream of the fuel nozzles
18. In particular, one or more quat pegs 14 may be associated with
one or more respective fuel nozzles 18. In certain embodiments,
each fuel nozzle 18 may be associated with one or more quat pegs
14. Further, in some embodiments, one or more quat pegs 14 may be
associated with a group of fuel nozzles 18, such as a group of fuel
nozzles 18 within a particular fuel circuit, as further explained
with respect to FIG. 5. The fuel injected by the quat pegs 14 may
be provided by one or more fuel sources coupled to the quat fuel
circuit 13 via a fuel manifold. In certain embodiments, the quat
pegs 14 may include one or more fuel openings (not shown) facing
and/or angled approximately perpendicular to the downstream
direction 69 of the combustor 12. The fuel provided by the quat
pegs 14 may mix with the airflow 67 flowing towards the fuel
nozzles 18 to form an air/fuel mixture that is then routed to the
combustion chamber 19 via the fuel nozzles 18.
[0031] As noted above, varying the configuration (e.g., position,
location, arrangement, placement, axial staggering, circumferential
variations, etc.) and/or geometries (e.g., sizes, shapes, angles,
etc.) of the quat pegs 14 among combustors 12 may vary the
convective time for one or more quat pegs, and/or the fuel-air
ratio of the fuel nozzles 18 associated with the quat pegs 14 among
the combustors 12, thereby decreasing combustion dynamics
amplitudes, and/or varying combustion dynamics frequencies among
the combustors, which is expected to reduce modal coupling of
combustion dynamics. For example, in the illustrated embodiment of
the combustor 12, a first set of quat pegs 14 are disposed
approximately along the first axial position 48, a second set of
quat pegs 15 are disposed approximately along the second axial
position 50, and a third set of quat pegs 23 are disposed
approximately along the third axial position 52, such that each set
of quat pegs 14, 15, and 23 are axially staggered proximal to the
head end 54 and around the circumference of the combustor 12. Each
set of quat pegs 14 may include 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or
more quat pegs 14 configured to route a fuel toward one or more
particular fuel nozzles 18. In some embodiments, axially staggering
the quat pegs 14 may vary the convective time for one or more quat
pegs, and/or may vary the air/fuel ratio of one or more fuel
nozzles 18. For example, in the illustrated embodiment, the
air/fuel ratio of the one or more fuel nozzles 18 associated with
the first set of quat pegs 14 (having 3 quat pegs 14) may be
different than the air/fuel ratio of the one or more fuel nozzles
18 associated with the third set of quat pegs 14 (having 4 quat
pegs 14), thereby varying the combustion dynamics of the combustor
12 to reduce unwanted vibratory response within the combustor
and/or in downstream components.
[0032] While the illustrated embodiment depicts each set of quat
pegs 14, 15, and 23 with approximately the same size and/or shape,
it should be noted that in some embodiments, each quat peg 14
and/or each set of quat pegs 14, 15, or 23 may be a different
geometry (e.g., size, shape, angle, etc.). For example, in certain
embodiments, the first set of quat pegs 14 may be different in size
relative to the second set of quat pegs 15 (e.g., ratio of 1:1,
1.5:1, 2:1, 2.5:1, etc.). Likewise, the first set of quat pegs 14
may be different in shape relative to the second set of quat pegs
15 (e.g., square, conical, etc.), approximately, or may be at
different angles relative to the second set of quat pegs 15,
thereby varying the combustion dynamics of the combustor 12 to
reduce unwanted vibratory response in the gas turbine system 10.
For example, the quat pegs 14 may include one or more fuel openings
(not shown) facing and/or angled approximately perpendicular to the
downstream direction 69 of the combustor 12. In certain
embodiments, the angle of the fuel openings to the downstream
direction 69 on a particular quat peg 14 may be different (e.g.,
greater than or less than) compared to the angle of the fuel
openings to the downstream direction 69 on another quat peg 14
(e.g., approximately 1, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 60, 70,
80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180 degrees more or
less). In other embodiments, the entire quat peg 14 may be angled
approximately perpendicular to the downstream direction 69, such
that the angle of a particular quat peg 14 is different from the
angle of another quat peg 14 (e.g., approximately 1, 2, 3, 4, 5,
10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140,
150, 160, 170, 180 degrees more or less).
[0033] In some embodiments, the configuration of the quat pegs 14
may be varied within a particular combustor 12 at a single axial
position (e.g., the first axial position 48, the second axial
position 50, or the third axial position 52), by circumferentially
distributing the quat pegs 14 along a particular axial position in
the circumferential direction 46 in various configurations, as
further described with respect to FIG. 3. Further, in some
embodiments, the configuration of the quat pegs 14 may be varied
between adjacent combustors 12 and/or among a plurality of
combustors 12 within the system 10 by circumferentially
distributing the quat pegs 14 at a particular axial position in
various configurations differently in one combustor 12 compared to
at least one other combustor 12, as further described with respect
to FIG. 5.
[0034] FIG. 3 is a cross-sectional schematic of an embodiment of
the combustor 12 in the system 10 of FIG. 1, wherein the combustor
12 includes a second quaternary fuel circuit configuration having a
circumferential distribution (i.e. along the circumferential axis
46) of the quat pegs 14 (e.g., injection pegs) at a particular
axial position. For example, in the illustrated embodiment, a
fourth set of quat pegs 25 comprising five quat pegs 14 and a fifth
set of quat pegs 27 comprising three quat pegs 14 are
circumferentially disposed (e.g., arranged, configured, etc.)
approximately along the second axial position 50 along the
circumferential axis 46. In particular, each set of quat pegs 25,
27 may be configured to route a fuel to one or more particular fuel
nozzles 18 and/or a particular group of fuel nozzles 18 (e.g., a
fuel circuit comprising one or more fuel nozzles 18). As noted
above, varying the configuration of the quat pegs 14 within the
combustor 12 may vary the convective time of one or more quat pegs
14 and/or vary the fuel-air ratio of one or more fuel nozzles 18
associated with one or more quat pegs 14, thereby decreasing
coherence and reducing unwanted vibratory responses within the
combustor 12 as well as in downstream components.
[0035] In some embodiments, the quat pegs 14 may be approximately
disposed at a single axial position (e.g., the second axial
position 50), such that the quat pegs 14 are circumferentially
arranged in various configurations and associated with various fuel
nozzles 18 and/or various groups of fuel nozzles 18 (e.g., fuel
circuits comprising one or more fuel nozzles 18). For example, in
the illustrated embodiment, the fourth set 25 of quat pegs 14
comprising five quat pegs 14 may be spatially disposed and/or
grouped away from the fifth set 27 of quat pegs 14 comprising three
quat pegs 14. In such embodiments, each set of the quat pegs 14
(e.g., the fourth set 25 and/or the fifth set 27) may be associated
with one or more fuel nozzles 18, such as a single fuel nozzle 18
and/or a group of fuel nozzles 18 grouped into a single fuel
circuit, as further described with respect to FIG. 4. Each set of
quat pegs 14 may include 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more
quat pegs 14 configured to increase or decrease the fuel-air ratio
for a particular fuel nozzle 18 or a particular group of fuel
nozzles 18. In some embodiments, circumferentially disposing the
quat pegs 14 at a particular axial position in various
circumferential configurations may vary the air-fuel ratio of the
one or more fuel nozzles 18 associated with one or more quat pegs
14. For example, in the illustrated embodiment of FIG. 3, the
air/fuel ratio of the fuel nozzles 18 associated with the fourth
set of quat pegs 25 (having 5 quat pegs 14) may be different than
the air-fuel ratio of the one or more fuel nozzles 18 associated
with the fifth set of quat pegs 27 (having 3 quat pegs 14).
Further, the air-fuel ratio of the one or more fuel nozzles not
associated with either the fourth set of quat pegs 25 or the fifth
set of quat pegs 27 may also be different, thereby varying the
combustion dynamics of the combustor 12 to reduce unwanted
vibratory response, either within the combustor 12 or within
downstream components.
[0036] In some embodiments, in addition to various quat peg 14
configurations (e.g., circumferential arrangements at a particular
axial position 48, 50, or 52), each quat peg 14 and/or each set of
quat pegs 25 or 27 may have a different geometry (e.g., size,
shape, angle, etc.). For example, in certain embodiments, the
fourth set of quat pegs 25 may be different in size relative to the
fifth set of quat pegs 25 (e.g., ratio of approximately 1:1, 1.5:1,
2:1, 2.5:1, etc.), such that one or more quat pegs 14 from the
fourth set 25 is greater than or less than the size of one or more
quat pegs 14 from the fifth set 27. Likewise, the fourth set of
quat pegs 25 may be different in shape relative to the fifth set of
quat pegs 25 (e.g., square, conical, etc.), or may have different
angles relative to the fifth set of quat pegs 27, thereby varying
the combustion dynamics of the combustor 12 to reduce unwanted
vibratory response, either within the combustor 12 or within
downstream components. For example, the quat pegs 14 may include
one or more fuel openings (not shown) facing and/or angled
approximately perpendicular to the downstream direction 69 of the
combustor 12. In certain embodiments, the angle of the fuel
openings to the downstream direction 69 on a particular quat peg 14
may be greater than or less than the angle of the fuel openings to
the downstream direction 69 on another quat peg 14 (e.g.,
approximately 1, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80,
90, 100, 110, 120, 130, 140, 150, 160, 170, 180 degrees more or
less).
[0037] FIG. 4 is a cross-sectional schematic of an embodiment 69 of
the combustor 12 of FIG. 3, illustrating the quat pegs 14 arranged
circumferentially at the second axial position 50 and biased to a
first fuel circuit 72. In certain embodiments, the combustor 12 may
include four or more fuel circuits, such as the first fuel circuit
72, a central fuel circuit 74, a second fuel circuit 76, and one or
more quat fuel circuits 13. Specifically, the first fuel circuit 72
may comprise three fuel nozzles 18 (e.g., a first fuel nozzle 73, a
second fuel nozzle 75, and a third fuel nozzle 77). In addition,
the central fuel circuit 74 may comprise a single fuel nozzle, and
the second fuel circuit 76 may comprise two fuel nozzles 18 (e.g.,
a fourth fuel nozzle 79 and a fifth fuel nozzle 81). In particular,
each fuel nozzle 18 and/or each fuel circuit (e.g., the first fuel
circuit 72, the central fuel circuit 74, or the second fuel circuit
76) may be associated with one or more quat pegs 14 configured to
route the fuel to the respective fuel nozzle 18 and/or the
respective fuel circuit (e.g., one or more fuel nozzles 18).
Accordingly, the quat pegs 14 may be configured to vary the
air/fuel ratio of the fuel nozzles 18 and/or the fuel circuits
associated with the quat pegs 14, thereby decreasing coherence and
reducing unwanted vibratory responses within the combustor 12
and/or downstream components.
[0038] In some embodiments, the plurality of quat pegs may be
associated with one or more fuel nozzles 18 of the combustor 12.
For example, in the illustrated embodiment, the fourth set of quat
pegs 25 and the fifth set of quat pegs 27 are associated with the
first fuel circuit 72. Specifically, the fourth set of quat pegs 25
and the fifth set of quat pegs 27 may be associated with the first
fuel nozzle 73, the second fuel nozzle 75, and the third fuel
nozzle 77. Accordingly, the fourth set of quat pegs 25 and the
fifth set of quat pegs 27 may be configured as fuel injectors to
route and/or inject a portion of the fuel into the airflow 67
upstream of the fuel nozzles 18 associated with the first fuel
circuit 72. In this manner, the quat pegs 14 associated with the
first fuel circuit 72 may be configured to change, or bias, the
air/fuel ratio of the first fuel circuit 72 relative to the second
fuel circuit 76 and/or the central fuel circuit 74. Furthermore, as
noted above, varying the air/fuel ratio of the fuel nozzles 18 may
decrease the combustion dynamics amplitudes and/or coherence and
may therefore reduce unwanted vibratory responses within the
combustor 12 and/or downstream components.
[0039] In some embodiments, the quat pegs 14 (e.g., one or more
quat pegs 14 and/or one or more sets of quat pegs 14) may be
arranged to bias fuel flow towards any of the fuel nozzles 18
and/or the fuel circuits (e.g., the second fuel circuit 76 and/or
the central fuel circuit 74), such that the air/fuel ratio between
the fuel circuits, and therefore the fuel nozzles 18, are different
within and/or among the combustors 12. Further, in addition to
varying the axial and circumferential configurations of the quat
pegs 14 such that the quat pegs 14 bias the quat circuit fuel flow
through certain fuel nozzles 18 and/or certain fuel circuits, in
certain embodiments, the geometries of the quat pegs 14 may be
different among each fuel nozzle 18 and/or each fuel circuit. For
example, the size, shape and/or angles of the quat pegs 14
associated with the first fuel circuit 72 may be different from
those associated with the second fuel circuit 76 or the central
fuel circuit 74, such that the convective time and/or the air/fuel
ratio between the fuel circuits, and therefore the fuel nozzles 18,
may be different within and/or among the combustors 12.
[0040] FIG. 5 is cross-sectional schematic of an embodiment of the
gas turbine system 10 of FIG. 1, taken along line 5-5, illustrating
a plurality of combustors 12 each having a respective quat peg 14
configuration configured to control combustion dynamics and/or
modal coupling of combustion dynamics, to reduce the possibility of
unwanted vibratory responses in downstream components. In
particular, it should be noted that each quat peg 14 configuration
may include any variation technique (e.g., axial staggering,
circumferential placement, and/or variations in size, shape,
angles, etc.) and/or may include any combination of variation
techniques. Each variation technique, either alone or in
combination with other variation techniques, may be configured to
help decrease combustion dynamics amplitudes and/or reduce
coherence to reduce unwanted vibratory responses in downstream
components within the system 10. Furthermore, the quat peg 14
configurations may be varied in different patterns or groupings
within the system 10, as further described below.
[0041] In some embodiments, configurations of quat pegs 14 may bias
the quat fuel towards one or more fuel circuits, such that adjacent
combustors 12 have quat pegs 14 biasing fuel to different fuel
circuits. For example, in the illustrated embodiment, a first
configuration 70 of quat pegs 14 in the first combustor 17 are
configured to bias quat fuel flow to the first fuel circuit 72,
such that the fuel nozzles 73, 75, and 77 of the first combustor 17
have an air/fuel ratio that is biased differently from other fuel
circuits of the first combustor 17. In addition, the quat pegs 14
of a second configuration 78 are arranged to bias quat fuel flow to
the second fuel circuit 76, such that fuel nozzles 79 and 81 of the
second combustor 21 have an air/fuel ratio that is biased
differently from other fuel circuits of the second combustor 21.
Moreover, the first configuration 70 of quat pegs 14 may be
different than the second configuration 78 of quat pegs 14 in the
second combustor 21, such that the first combustor 17 has different
combustion dynamics frequencies relative to the second combustor
21, thereby decreasing coherence and reducing unwanted vibratory
responses in the gas turbine system 10.
[0042] In some embodiments, geometries of quat pegs 14 may be
varied between combustors 12, such that a particular combustor 12
has different combustion dynamics frequencies relative to at least
one other combustor 12. For example, in the illustrated embodiment,
the first configuration 70 of quat pegs 14 in the first combustor
17 includes a quat peg 14 shape (e.g., circular) that is different
from the quat peg 14 shape (e.g., square) of a third configuration
80 of quat pegs 14 in a third combustor 83. In certain embodiments,
the size of the quat pegs 14 may be varied between combustors 12.
For example, a fourth configuration 82 in a fourth combustor 85
includes quat pegs 14 that are different in size compared to the
quat pegs 14 of a fifth configuration 84 in a fifth combustor 87.
Specifically, the quat pegs 14 of the fourth configuration 82 may
be smaller in size, such that the ratio between the quat pegs of
the fourth and fifth configurations 82, 84 may be approximately
1:1, 1.5:1, 2:1, 2.5:1, and so forth.
[0043] In some embodiments, in addition to a variation related to
geometry, the configurations of quat pegs 14 (e.g., the third
configuration 80 relative to the first configuration 70) may
include variations related to axial staggering along various axes
and/or circumferential positioning of the quat pegs 14 to bias quat
fuel to other fuel circuits. In this manner, a combination of
different parameters may be used to help decrease coherence and
reduce unwanted vibratory responses in downstream components within
the system 10. Furthermore, in certain embodiments, a particular
combustor 12 may not have any variations in quat pegs 14 relative
to other combustors 12 and/or may not have any quat pegs 14. For
example, in the sixth configuration 86 in the sixth combustor 89,
no quat pegs 14 are disposed within the combustor 89. In this
manner, the sixth combustor 89 may have a combustion dynamics
frequency that is different than the first combustor 17, the second
combustor 21, the third combustor 83, the fourth combustor 85,
and/or the fifth combustor 87.
[0044] In some embodiments, the system 10 may include one or more
groupings (e.g., 1, 2, 3, 4, 5, or more) of combustors 12, where
each group of combustors 12 includes one or more combustors 12
(e.g., 1, 2, 3, 4, 5, or more). In some situations, each group of
combustors 12 may include identical combustors 12 that differ from
one or more other groups of combustors 12 within the system 10. For
example, a first group of combustors 12 may include identical
combustors 12 having a first configuration of quat pegs 14, and a
second group of combustors 12 may include identical combustors 12
have a second configuration of quat pegs 14. Further, the first
configuration of quat pegs 14 may be different from the second
configuration of quat pegs 14 in one or more ways, as described
above (e.g., axial staggering, circumferential placement, and/or
variations in size, shape, angles, etc). Accordingly, the first
group of combustors 12 may produce a combustion dynamics frequency
that is different from the combustion dynamics frequency of the
second group of combustors 12 within the system 10.
[0045] Technical effects of the invention include reducing
combustion dynamics and/or modal coupling of combustion dynamics
(e.g., reduce unwanted vibratory responses in downstream
components) in a gas turbine system 10 by varying the configuration
of a plurality of injection pegs 14 (e.g., quat pegs 14) associated
with one or more combustors 12 of the gas turbine system 10. The
arrangement of a plurality of quat pegs 14 associated with a
particular combustor 12 may alter the combustion dynamics, in a way
to substantially reduce or eliminate any unwanted vibratory
response of the combustor and/or components downstream of the
combustors 12. For example, varying the configuration (e.g.,
placement, arrangement, position, location, etc.) of quat pegs 14
axially and/or circumferentially may facilitate the tuning of
convective time for one or more quat pegs and/or the fuel-air ratio
at the fuel nozzle 18 level, and may result in combustion dynamics
frequencies that are different, spread out over a greater frequency
range, or any combination thereof, relative to any resonant
frequencies of the components in the gas turbine system 10, and/or
the combustion dynamics of one or more of the other combustors 12
in the gas turbine system 10. In addition, varying the geometries
of the quat pegs 14 (e.g., size, shape, angle, etc.) may introduce
a variation in convective time between two or more quat pegs and/or
the fuel-air ratio between two or more fuel nozzles 18, and
therefore may help decrease combustion dynamics amplitudes, and/or
modal coupling of the combustion dynamics, which may reduce
unwanted vibratory responses within the combustor 12, and/or
downstream components within the system 10.
[0046] 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 have 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.
* * * * *