U.S. patent application number 15/555188 was filed with the patent office on 2018-02-22 for pre-mixing based fuel nozzle for use in a combustion turbine engine.
This patent application is currently assigned to SIEMENS ENERGY, INC.. The applicant listed for this patent is Siemens Energy, Inc.. Invention is credited to Joseph Meadows, Chunyang Wu.
Application Number | 20180051883 15/555188 |
Document ID | / |
Family ID | 52997554 |
Filed Date | 2018-02-22 |
United States Patent
Application |
20180051883 |
Kind Code |
A1 |
Meadows; Joseph ; et
al. |
February 22, 2018 |
PRE-MIXING BASED FUEL NOZZLE FOR USE IN A COMBUSTION TURBINE
ENGINE
Abstract
A pre-mixing type of fuel nozzle (10) for use in a combustion
turbine engine is provided. The nozzle includes an array of
pre-mixing conduits (20) that extends between an inlet end (14) and
an outlet end (16) of a body 12 of the nozzle. The nozzle may
further include an array of air flow conduits (22) disposed
radially inwardly relative to the array of pre-mixing conduits. The
nozzle may include an inter-conduit passageway 24 arranged to
aerodynamically reduce flow recirculation in the array of
pre-mixing conduits. A fuel-directing structure (26) may include
non-swirl elements (28) to direct fuel flow along a radial
direction, each non-swirl element including at least one orifice
(32) to inject the fuel flow directed along the radial direction
into a respective pre-mixing conduit to pre-mix air and fuel.
Inventors: |
Meadows; Joseph; (Charlotte,
NC) ; Wu; Chunyang; (Charlotte, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Siemens Energy, Inc. |
Orlando |
FL |
US |
|
|
Assignee: |
SIEMENS ENERGY, INC.
Orlando
FL
|
Family ID: |
52997554 |
Appl. No.: |
15/555188 |
Filed: |
April 1, 2015 |
PCT Filed: |
April 1, 2015 |
PCT NO: |
PCT/US2015/023849 |
371 Date: |
September 1, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F23D 14/58 20130101;
F23D 2206/10 20130101; F23R 3/286 20130101 |
International
Class: |
F23R 3/28 20060101
F23R003/28 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED DEVELOPMENT
[0001] Development for this invention was supported in part by
Contract No. DE-FC26-05NT42644, awarded by the United States
Department of Energy. Accordingly, the United States Government may
have certain rights in this invention.
Claims
21. A fuel nozzle comprising: a body having an inlet end and an
outlet end and defining a central axis that extends between the
inlet end and the outlet end along an axial direction of the fuel
nozzle; an array of pre-mixing conduits extending between the inlet
end and the outlet end of the body, the array of pre-mixing
conduits circumferentially disposed about the central axis of the
body, each pre-mixing conduit fluidly coupled to receive air at a
respective inlet; an array of air flow conduits disposed radially
inwardly relative to the array of pre-mixing conduits; means to
aerodynamically reduce flow recirculation in the array of air/fuel
pre-mixing conduits, wherein the means to aerodynamically reduce
the flow recirculation in a respective pre-mixing conduit comprises
an inter-conduit passageway arranged to provide fluid communication
between the respective pre-mixing conduit and a corresponding air
flow conduit; and a fuel-directing structure in the body comprising
a plurality of non-swirl elements, each non-swirl element including
a radially-extending passageway to direct fuel flow along a radial
direction, each non-swirl element including at least one orifice to
inject the fuel flow directed along the radial direction into a
respective pre-mixing conduit.
22. The fuel nozzle of claim 21, wherein the array of pre-mixing
conduits each comprises at least a respective pre-mixing conduit
segment having a cross-sectional area that increases as the
respective pre-mixing conduit segment extends from a location
between the inlet end and the outlet end towards a respective
outlet of the respective pre-mixing conduit.
23. The fuel nozzle of claim 22, wherein the respective pre-mixing
conduit segment includes at least one surface tilted radially
inwardly relative to the central axis as the segment extends
towards the respective outlet of the respective pre-mixing
conduit.
24. The fuel nozzle of claim 21, wherein the array of air flow
conduits each comprises at least a respective air flow conduit
segment having a cross-sectional area that decreases as the
respective air flow conduit segment extends from a respective inlet
towards a location between the inlet end and the outlet end.
25. The fuel nozzle of claim 21, wherein the array of air flow
conduits each comprises an outlet arranged radially inwardly
relative to the central axis.
26. The fuel nozzle of claim 25, wherein the fuel-directing
structure further comprises a central passageway arranged to direct
fuel along the axial direction.
27. The fuel nozzle of claim 26, wherein the fuel-directing
structure comprises a central outlet that in combination with the
respective outlets of the array of air flow conduits forms a
jet-assisted mixing stage.
28. A combustor in a combustion turbine engine comprising the fuel
nozzle of claim 21.
29. A fuel nozzle comprising: a body having an inlet end and an
outlet end and defining a central axis that extends between the
inlet end and the outlet end along an axial direction of the fuel
nozzle; an array of pre-mixing conduits circumferentially disposed
about the central axis of the body, each pre-mixing conduit fluidly
coupled to receive air at a respective inlet, wherein the array of
pre-mixing conduits each comprises at least a respective pre-mixing
conduit segment having a cross-sectional area that increases as the
respective pre-mixing conduit segment extends from a location
between the inlet end and the outlet end towards a respective
outlet of the respective pre-mixing conduit; an array of air flow
conduits disposed radially inwardly relative to the array of
pre-mixing conduits, wherein the array of air flow conduits each
comprises at least a respective air flow conduit segment having a
cross-sectional area that decreases as the respective air flow
conduit segment extends from a respective inlet towards a location
between the inlet end and the outlet end; and a fuel-directing
structure in the body, the fuel-directing structure comprising a
plurality of non-swirl elements each including a radially-extending
passageway to direct fuel flow along a radial direction, each
non-swirl element including at least one orifice to inject the fuel
flow directed along the radial direction into a respective
pre-mixing conduit.
30. The fuel nozzle of claim 29, further comprising means to
aerodynamically reduce flow recirculation in the array of
pre-mixing conduits.
31. The fuel nozzle of claim 31, wherein the means to
aerodynamically reduce the flow recirculation in a respective
pre-mixing conduit comprises an inter-conduit passageway arranged
to provide fluid communication between the respective pre-mixing
conduit and a corresponding air flow channel.
32. The fuel nozzle of claim 29, wherein the respective pre-mixing
conduit segment includes at least one surface tilted radially
inwardly relative to the central axis, as the segment extends
towards the respective outlet of the respective pre-mixing
conduit.
33. The fuel nozzle of claim 29, wherein the array of air flow
conduits each comprises an outlet arranged radially inwardly
relative to the central axis.
34. The fuel nozzle of claim 33, wherein the fuel-directing
structure further comprises a central passageway arranged to direct
fuel along the axial direction.
35. The fuel nozzle of claim 34, wherein the fuel-directing
structure comprises a central outlet that in combination with the
respective outlets of the array of air flow conduits forms a
jet-assisted mixing stage.
36. A combustor in a combustion turbine engine comprising the fuel
nozzle of claim 29.
37. A fuel nozzle comprising: a body having an inlet end and an
outlet end and defining a central axis that extends between the
inlet end and the outlet end along an axial direction of the fuel
nozzle; an array of pre-mixing conduits extending between the inlet
end and the outlet end of the body, the array of pre-mixing
conduits circumferentially disposed about the central axis of the
body, each pre-mixing conduit fluidly coupled to receive air at a
respective inlet, wherein the array of pre-mixing conduits each
comprises at least a respective pre-mixing conduit segment having a
cross-sectional area that increases as the respective pre-mixing
conduit segment extends from a location between the inlet end and
the outlet end towards a respective outlet of the respective
pre-mixing conduit; an array of air flow conduits disposed radially
inwardly relative to the array of pre-mixing conduits; an
inter-conduit passageway arranged to provide fluid communication
between a respective pre-mixing conduit and a corresponding air
flow conduit; and a fuel-directing structure in the body comprising
a plurality of non-swirl elements, each non-swirl element including
a radially-extending passageway to direct fuel flow along a radial
direction, each non-swirl element including at least one orifice to
inject the fuel flow directed along the radial direction into a
respective pre-mixing conduit.
Description
BACKGROUND
1. Field
[0002] Disclosed embodiments are generally related to a fuel nozzle
for use in a combustion turbine engine, such as a gas turbine
engine and, more particularly, to a pre-mixing type of fuel nozzle
that in one non-limiting application may be used in a distributed
combustion system (DCS) injection system.
2. Description of the Related Art
[0003] In gas turbine engines, fuel is delivered from a fuel source
to a combustion section where the fuel is mixed with air and
ignited to generate hot combustion products defining working gases.
The working gases are directed to a turbine section. The combustion
section may comprise one or more stages, each stage supplying fuel
to be ignited. See U.S. Pat. Nos. 8,281,594 and 8,752,386 in
connection with fuel nozzles involving pre-mixing of air and
fuel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is an isometric view that may be helpful for
visualizing an upstream end of one non-limiting embodiment of a
fuel nozzle embodying aspects of the invention that may be used in
a combustor of a combustion turbine engine.
[0005] FIG. 2 is a top view of the upstream end of the fuel nozzle
shown in FIG. 1.
[0006] FIG. 3 is a bottom view of a downstream end of the fuel
nozzle shown in FIG. 1.
[0007] FIG. 4 is a cross-sectional view illustrating a non-limiting
schematic representation of respective pre-mixing conduits and air
flow conduits constructed in the body of the fuel nozzle.
[0008] FIG. 5 is a cross-sectional view illustrating a non-limiting
schematic representation of fuel flow in a fuel-directing structure
constructed in the body of the fuel nozzle.
[0009] FIG. 6 is a top view illustrating a non-limiting schematic
representation of fuel-injecting locations in a given pre-mixing
conduit.
[0010] FIG. 7 is a simplified schematic of one non-limiting
embodiment of a combustion turbine engine, such as a gas turbine
engine, that can benefit from disclosed embodiments of the present
invention.
DETAILED DESCRIPTION
[0011] The inventors of the present invention have recognized
certain issues that can arise in the context of certain prior art
fuel nozzles involving pre-mixing of air and fuel, also referred in
the art as micro-mixing. These prior art fuel nozzles generally
involve a large number of point injection arrays having a
relatively small diameter, and the fabrication of such injection
arrays may involve costly fabrication techniques. In view of such a
recognition, the present inventors propose an improved fuel nozzle
that can benefit from more economical fabrication techniques while
providing appropriate levels of NO.sub.x emissions and enabling
practically a flashback-free operation, even on applications
involving a relatively high-content of hydrogen fuel.
[0012] In the following detailed description, various specific
details are set forth in order to provide a thorough understanding
of such embodiments. However, those skilled in the art will
understand that embodiments of the present invention may be
practiced without these specific details, that the present
invention is not limited to the depicted embodiments, and that the
present invention may be practiced in a variety of alternative
embodiments. In other instances, methods, procedures, and
components, which would be well-understood by one skilled in the
art have not been described in detail to avoid unnecessary and
burdensome explanation.
[0013] Furthermore, various operations may be described as multiple
discrete steps performed in a manner that is helpful for
understanding embodiments of the present invention. However, the
order of description should not be construed as to imply that these
operations need be performed in the order they are presented, nor
that they are even order dependent, unless otherwise indicated.
Moreover, repeated usage of the phrase "in one embodiment" does not
necessarily refer to the same embodiment, although it may. It is
noted that disclosed embodiments need not be construed as mutually
exclusive embodiments, since aspects of such disclosed embodiments
may be appropriately combined by one skilled in the art depending
on the needs of a given application.
[0014] The terms "comprising", "including", "having", and the like,
as used in the present application, are intended to be synonymous
unless otherwise indicated. Lastly, as used herein, the phrases
"configured to" or "arranged to" embrace the concept that the
feature preceding the phrases "configured to" or "arranged to" is
intentionally and specifically designed or made to act or function
in a specific way and should not be construed to mean that the
feature just has a capability or suitability to act or function in
the specified way, unless so indicated.
[0015] FIG. 1 is an isometric view of one non-limiting embodiment
of a fuel nozzle 10 embodying aspects of the invention that in one
non-limiting application may be used in a combustor of a combustion
turbine engine, such as a gas turbine engine. Fuel nozzle 10
includes a body 12 having an inlet end 14 and an outlet end 16 and
defines a central axis 18 that extends between inlet end 14 and
outlet end 16 along an axial direction of the fuel nozzle.
[0016] As may be appreciated in FIG. 1, an array of pre-mixing
conduits 20 extends between inlet end 14 and outlet end 16 of body
12. The array of pre-mixing conduits 20 is circumferentially
disposed about central axis 18. Each pre-mixing conduit 20 is
fluidly coupled to receive air at a respective inlet.
[0017] In one non-limiting embodiment, fuel nozzle 10 further
includes an array of air flow conduits 22 disposed radially
inwardly relative to the array of pre-mixing conduits 20. In one
non-limiting embodiment, fuel nozzle 10 may include means to
aerodynamically reduce flow recirculation (flow separation) in the
array of pre-mixing conduits 20. It will be appreciated that the
reduction of flow recirculation need not be limited to within the
array of pre-mixing conduits 20, since zones beyond outlet end 16
can also benefit from such flow recirculation reduction. As may be
appreciated in FIG. 4, in one non-limiting embodiment, the means to
aerodynamically reduce the flow recirculation in a respective
pre-mixing conduit 20 may comprise an inter-conduit passageway 24
arranged to provide fluid communication between the respective
pre-mixing conduit 20 and a corresponding air flow conduit 22. It
will be appreciated that the geometry of pre-mixing conduits 20 may
be optionally configured to reduce flow recirculation in
combination or in lieu of inter-conduit passageways 24.
[0018] As may be appreciated in FIG. 5, fuel nozzle 10 further
includes a fuel-directing structure 26 that in one-non-limiting
embodiment includes a plurality of non-swirl elements 28. Each
non-swirl element includes a radially-extending passageway to
direct fuel flow along a radial direction (schematically
represented by arrows 30). Each non-swirl element 28 includes at
least one orifice 32 arranged to inject the fuel that flows along
the radial direction into a respective air/fuel pre-mixing conduit.
Without limitation, orifices 32 may be located in regions of
relatively high axial flow velocity, thus increasing the static
pressure drop across orifices 32. See FIG. 6 that illustrates a
non-limiting example of fuel-injecting locations (schematically
represented by arrows 34) in a given pre-mixing conduit 20.
Fuel-directing structure 26 further includes a central passageway
36 (FIG. 5) arranged to direct fuel flow along the axial direction
(schematically represented by arrows 38) towards a central outlet
39.
[0019] In one non-limiting embodiment, the array of pre-mixing
conduits 20 each comprises at least a respective pre-mixing conduit
segment (schematically represented by line 40 (FIG. 4)) having a
cross-sectional area that increases as the respective pre-mixing
conduit segment extends from a location between inlet end 14 and
outlet end 16 towards a respective outlet 41 of the respective
pre-mixing conduit. This may be effective so that flow velocity is
increased without substantially increasing the overall pressure
drop. In one non-limiting embodiment, pre-mixing conduit segment 40
includes at least one surface 42 tilted radially inwardly relative
to central axis 18 as the segment extends towards the respective
outlet 41 of the respective pre-mixing conduit 20.
[0020] In one non-limiting embodiment, the array of air flow
conduits 22 each comprises at least a respective air flow conduit
segment (schematically represented by line 44 (FIG. 4) having a
cross-sectional area that decreases as the respective air flow
conduit segment 44 extends from a respective inlet 45 of the
respective air flow conduit 22 towards a location between inlet end
14 and outlet end 16. In one non-limiting embodiment, the array of
air flow conduits 22 each comprises an outlet 46 arranged radially
inwardly relative to central axis 18. In one non-limiting
embodiment, central outlet 39 of central passageway 36 in
combination with the respective outlets 46 of the array of air flow
conduits 22 forms a jet-assisted mixing stage. It will be
appreciated that the respective starting/end points and/or
respective geometries of the conduit segments schematically
represented by lines 40 and 44 should be construed in a
non-limiting sense since other starting/end points and/or
geometries may be arranged depending on the needs of a given
application.
[0021] FIG. 7 is a simplified schematic of one non-limiting
embodiment of a combustion turbine engine 50, such as gas turbine
engine, that can benefit from disclosed embodiments of the present
invention. Combustion turbine engine 50 may comprise a compressor
52, a combustor 54, a combustion chamber 56, and a turbine 58.
During operation, compressor 52 takes in ambient air and provides
compressed air to a diffuser 60, which passes the compressed air to
a plenum 62 through which the compressed air passes to combustor
54, which mixes the compressed air with fuel, and provides
combusted, hot working gas via a transition 64 to turbine 58, which
can drive power-generating equipment (not shown) to generate
electricity. A shaft 66 is shown connecting turbine 58 to drive
compressor 52. Disclosed embodiments of a fuel nozzle embodying
aspects of the present invention may be incorporated in combustor
54 of the combustion turbine engine to achieve superior pre-mixing
of fuel and air.
[0022] In operation and without limitation, disclosed embodiments
are expected to provide a cost-effective fuel nozzle including
arrays of fluid flow conduits that produce a substantially
homogenous mixture of fuel and air at the outlet end of the nozzle
and thus effective to produce appropriate pre-mixing of fuel and
air conducive to ultra-low levels of NO.sub.x emissions.
Additionally, disclosed embodiments need not involve swirler
elements, and thus flashback resistance is substantially high, even
for fuel blends comprising a high hydrogen content (e.g., at least
50% hydrogen content by volume).
[0023] Without limitation, practical embodiments of the disclosed
the nozzle may comprise fluid flow conduits having a minimum
diameter in a range from about 0.75 mm to about 1 mm and thus
capable of benefiting from relatively low-cost manufacturing
technologies, such as, without limitation, three-dimensional (3D)
printing, direct metal laser sintering (DLMS), etc., in lieu of
presently costlier manufacturing technologies.
[0024] While embodiments of the present disclosure have been
disclosed in exemplary forms, it will be apparent to those skilled
in the art that many modifications, additions, and deletions can be
made therein without departing from the spirit and scope of the
invention and its equivalents, as set forth in the following
claims.
* * * * *