U.S. patent application number 14/469029 was filed with the patent office on 2016-03-03 for corrugated cyclone mixer assembly to facilitate reduced nox emissions and improve operability in a combustor system.
The applicant listed for this patent is General Electric Company. Invention is credited to Joel Meier Haynes, Narendra Digamber Joshi, Junwoo Lim, Sarah Marie Monahan, Krishna Kumar Venkatesan, David James Walker.
Application Number | 20160061452 14/469029 |
Document ID | / |
Family ID | 55402038 |
Filed Date | 2016-03-03 |
United States Patent
Application |
20160061452 |
Kind Code |
A1 |
Walker; David James ; et
al. |
March 3, 2016 |
CORRUGATED CYCLONE MIXER ASSEMBLY TO FACILITATE REDUCED NOX
EMISSIONS AND IMPROVE OPERABILITY IN A COMBUSTOR SYSTEM
Abstract
A corrugated cyclone mixer for use in a fuel injection assembly
of a turbine engine. The corrugated cyclone mixer generally
includes an annular housing including a flange portion and a lip
portion configured downstream of the flange portion. The mixer
further including a swirler disposed therein the annular housing
for inducing a cyclonic motion in the corrugated cyclone mixer. The
swirler is configured upstream of the flange portion and including
a plurality of swirler vanes to produce a swirling air flow. The
lip portion forming an outlet downstream of the swirler and
including a plurality of corrugations at an aft end. The plurality
of corrugations are configured to mix the swirling air flow and an
injected fuel stream flowing therethrough the corrugated cyclone
mixer. Additionally disclosed is a fuel injection assembly and a
turbine assembly including the corrugated cyclone mixer.
Inventors: |
Walker; David James; (Burnt
Hills, NY) ; Haynes; Joel Meier; (Niskayuna, NY)
; Joshi; Narendra Digamber; (Schenectady, NY) ;
Lim; Junwoo; (Lynnfield, MA) ; Venkatesan; Krishna
Kumar; (Clifton Park, NY) ; Monahan; Sarah Marie;
(Latham, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Family ID: |
55402038 |
Appl. No.: |
14/469029 |
Filed: |
August 26, 2014 |
Current U.S.
Class: |
60/737 |
Current CPC
Class: |
F23R 2900/00014
20130101; F23R 3/286 20130101 |
International
Class: |
F23R 3/28 20060101
F23R003/28 |
Claims
1. A corrugated cyclone mixer assembly for use in a fuel injection
assembly of a turbine engine, the assembly comprising: an annular
housing comprising a flange portion and a lip portion configured
downstream of the flange portion; and a swirler disposed therein
the annular housing for inducing a cyclonic motion in the
corrugated cyclone mixer assembly, the swirler configured upstream
of the flange portion and including a plurality of swirler vanes to
produce a swirling air flow, the lip portion forming an outlet
downstream of the swirler and including a plurality of corrugations
at an aft end, the plurality of corrugations configured to mix the
swirling air flow and an injected fuel stream flowing therethrough
the corrugated cyclone mixer assembly.
2. The corrugated cyclone mixer assembly as claimed in claim 1,
wherein the plurality of corrugations comprise a plurality of
purely radially extending corrugations.
3. The corrugated cyclone mixer assembly as claimed in claim 1,
wherein the plurality of corrugations comprise a plurality of
purely axially extending corrugations.
4. The corrugated cyclone mixer assembly as claimed in claim 1,
wherein the plurality of corrugations comprise a plurality of
radially and tangentially extending corrugations.
5. The corrugated cyclone mixer assembly as claimed in claim 1,
wherein the plurality of corrugations comprise a plurality of
radially outwardly extending corrugations.
6. The corrugated cyclone mixer assembly as claimed in claim 1,
wherein the plurality of corrugations comprise a plurality of
radially inwardly extending corrugations.
7. The corrugated cyclone mixer assembly as claimed in claim 1,
wherein the plurality of corrugations are configured substantially
uniformly spaced circumferentially about the lip portion.
8. The corrugated cyclone mixer assembly as claimed in claim 1,
wherein the plurality of corrugations are configured having a
uniform length, extending from an apex to a base, in at least one
of a radial or axial direction.
9. The corrugated cyclone mixer assembly as claimed in claim 1,
wherein the plurality of corrugations are configured as at least
one of sinusoidal corrugations or substantially triangular
corrugations.
10. A fuel injection assembly for use in a combustor of a turbine
engine, the fuel injection assembly comprising: a fuel nozzle
assembly including a main housing and defining an annular cavity,
the fuel nozzle assembly comprising; a fuel manifold in fluid
communication with a source of fuel; and a plurality of fuel
injection ports, each fuel injection port configured to introduce a
fuel column into the annular cavity; and a corrugated cyclone mixer
assembly disposed about the fuel nozzle, the corrugated cyclone
mixer assembly comprising; an annular housing comprising a flange
portion and a lip portion configured downstream of the flange
portion; and a swirler disposed therein the annular housing for
inducing a cyclonic motion in the corrugated cyclone mixer
assembly, the swirler configured upstream of the flange portion and
including a plurality of swirler vanes to produce a swirling air
flow, the lip portion forming an outlet downstream of the swirler
and including a plurality of corrugations at an aft end, the
plurality of corrugations configured to mix the swirling air flow
and an injected fuel stream flowing therethrough the corrugated
cyclone mixer assembly.
11. The fuel injection assembly as claimed in claim 10, wherein the
plurality of corrugations comprise at least one of a plurality of
purely radially extending corrugations or a plurality of purely
axially extending corrugations.
12. The fuel injection assembly as claimed in claim 10, wherein the
plurality of corrugations include a plurality of radially and
tangentially extending corrugations.
13. The fuel injection assembly as claimed in claim 10, wherein the
plurality of corrugations comprise at least one of a plurality of
radially outwardly extending corrugations or a plurality of
radially inwardly extending corrugations.
14. The fuel injection assembly as claimed in claim 10, wherein the
plurality of corrugations are configured substantially uniformly
spaced circumferentially about the lip portion.
15. The fuel injection assembly as claimed in claim 10, wherein the
plurality of corrugations are configured having a uniform length,
extending from an apex to a base, in at least one of a radial or
axial direction.
16. The fuel injection assembly as claimed in claim 10, wherein the
plurality of corrugations are configured as at least one of
sinusoidal corrugations or substantially triangular
corrugations.
17. A turbine engine assembly comprising: a compressor section; a
combustor section; and a turbine section, wherein the compressor
section, the combustor section and the turbine section are
configured in a downstream axial flow relationship, the combustor
section comprising: a combustion chamber; and a fuel injection
assembly disposed in the combustion chamber, the fuel injection
assembly comprising: a fuel nozzle assembly including a main
housing and defining an annular cavity, the fuel nozzle assembly
comprising; a fuel manifold in fluid communication with a source of
fuel; and a plurality of fuel injection ports, each fuel injection
port configured to introduce a fuel column into the annular cavity;
and a corrugated cyclone mixer assembly disposed about the fuel
nozzle, the corrugated cyclone mixer assembly comprising; an
annular housing comprising a flange portion and a lip portion
configured downstream of the flange portion; and a swirler disposed
therein the annular housing for inducing a cyclonic motion in the
corrugated cyclone mixer assembly, the swirler configured upstream
of the flange portion and including a plurality of swirler vanes to
produce a swirling air flow, the lip portion forming an outlet
downstream of the swirler and including a plurality of corrugations
at an aft end, the plurality of corrugations configured to mix the
swirling air flow and an injected fuel stream flowing therethrough
the corrugated cyclone mixer assembly.
18. The turbine engine assembly as claimed in claim 17, wherein the
plurality of corrugations comprise at least one of a plurality of
purely radially extending corrugations, a plurality of purely
axially extending corrugations, a plurality of radially and
tangentially extending corrugations, a plurality of radially
outwardly extending corrugations or a plurality of radially
inwardly extending corrugations.
19. The turbine engine assembly as claimed in claim 18, wherein the
plurality of corrugations are configured as at least one of
sinusoidal corrugations or substantially triangular
corrugations.
20. The turbine engine assembly as claimed in claim 17, wherein the
assembly comprises a gas turbine engine.
Description
BACKGROUND
[0001] The embodiments described herein relate generally to
combustion systems, and more specifically, to systems that
facilitate optimal mixing of liquid and gaseous fuels with oxidizer
in a turbine combustor, such as gas turbine engine or liquid fuel
aero-engine.
[0002] Combustors are commonly used in industrial, power generation
and aero operations to ignite fuel to produce combustion gases
having a high temperature and pressure. For example, turbo-machines
such as gas turbine engines or aero-engines, may include one or
more combustors to generate power or thrust. A typical turbine
system includes an inlet section, a compressor section, a
combustion section, a turbine section, and an exhaust section. The
inlet section cleans and conditions a working fluid (e.g., air) and
supplies the working fluid to the compressor section. The
compressor section increases the pressure of the working fluid and
supplies a compressed working fluid to the combustion section. The
combustion section mixes fuel with the compressed working fluid and
ignites the mixture to generate combustion gases having a high
temperature and pressure. The combustion gases flow to the turbine
section where they expand to produce work. For example, expansion
of the combustion gases in the turbine section may rotate a shaft
connected to a generator to produce electricity.
[0003] The combustion section may include one or more combustors
annularly arranged between the compressor section and the turbine
section, and the temperature of the combustion gases directly
influences the thermodynamic efficiency, design margins, and
resulting emissions of the combustor. For example, higher
combustion temperatures generally improve the thermodynamic
efficiency of the combustor. However, higher combustion
temperatures also promote flame holding conditions in which the
combustion flame migrates towards the fuel being supplied by
nozzles, possibly causing accelerated damage to the nozzles in a
relatively short amount of time. In addition, higher combustion
temperatures generally increase the disassociation rate of diatomic
nitrogen, increasing the production of nitrogen oxides (NOx) for
the same residence time in the combustor. Conversely, a lower
combustion 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 for the same residence
time in the combustor.
[0004] In a particular combustor design, the combustor may include
a cap assembly that extends radially across at least a portion of
the combustor, and one or more fuel nozzles may be radially
arranged across the cap assembly to supply fuel to the combustor.
The combustor may also include at least one annular liner that
extends downstream from the cap assembly. The liner at least
partially defines a combustion chamber within the combustor. The
liner further defines a hot gas path that extends between the
combustion chamber and an inlet to the turbine. The fuel nozzles
may include swirler vanes and/or other flow guides to enhance
mixing between the fuel and the compressed working fluid to produce
a lean fuel-air mixture for combustion. The swirling fuel-air
mixture flows into the combustion chamber where it ignites to
generate the hot combustion gases. The hot combustion gases are
routed through the hot gas path to the inlet of the turbine.
[0005] Although generally effective at enabling higher operating
temperatures, the overall effectiveness of the engine is at least
partially dependent upon how well the fuel-air combination that
flows from the injector mixes with the swirling fuel-air mixture in
the combustion chamber and/or with the hot combustion gases flowing
through the liner generally downstream from the combustion chamber.
In general, increased levels of premixing tend to increase
autoignition risk and increase dynamics. In addition, mixing of
fuel and air in a high temperature environment is very challenging
because the fuel/air mixture can preignite/autoignite in the fuel
nozzle and damage the hardware.
[0006] Attempts at increasing fuel air mixing in the fuel nozzle
have come in various forms including number of fuel orifices,
orifice diameter, mixer geometry, and axial placement of fuel
orifices.
[0007] As a result, an improved mixing apparatus for supplying fuel
to a combustor that enhances mixing of the fuel-air combination
that flows from the fuel injectors would be useful.
BRIEF DESCRIPTION OF THE DISCLOSURE
[0008] Aspects and advantages of the disclosure are set forth below
in the following description, or may be obvious from the
description, or may be learned through practice of the
disclosure.
[0009] In one aspect, corrugated cyclone mixer assembly for use in
a fuel injection assembly of a turbine engine is provided. The
corrugated cyclone mixer assembly includes an annular housing, a
swirler. The annular housing comprises a flange portion and a lip
portion configured downstream of the flange portion. The swirler is
disposed therein the annular housing for inducing a cyclonic motion
in the corrugated cyclone mixer assembly. The swirler is configured
upstream of the flange portion and includes a plurality of swirler
vanes to produce a swirling air flow. The lip portion forms an
outlet downstream of the swirler and includes a plurality of
corrugations at an aft end. The plurality of corrugations are
configured to mix the swirling air flow and an injected fuel.
[0010] In another aspect, a fuel injection assembly for use in a
combustion chamber of a turbine engine assembly is provided. The
fuel injection assembly including a fuel nozzle including a main
housing and defining an annular cavity and a corrugated cyclone
mixer disposed about the fuel nozzle. The fuel nozzle including a
fuel manifold and a plurality of fuel injection ports. The fuel
manifold is in fluid communication with a source of fuel. Each of
the plurality of fuel injection ports is configured to introduce a
fuel column into the annular cavity. The corrugated cyclone mixer
assembly includes an annular housing and a swirler disposed therein
the annular housing for inducing a cyclonic motion in the
corrugated cyclone mixer assembly. The annular housing comprising a
flange portion and a lip portion configured downstream of the
flange portion. The swirler is configured upstream of the flange
portion and includes a plurality of swirler vanes to produce a
swirling air flow. The lip portion forms an outlet downstream of
the swirler and includes a plurality of corrugations at an aft end.
The plurality of corrugations are configured to mix the swirling
air flow and an injected fuel stream flowing therethrough the
corrugated cyclone mixer assembly.
[0011] In yet another aspect, a turbine engine assembly is
provided. The turbine engine assembly including a compressor
section, a combustor section and a turbine section configured in a
downstream axial flow relationship. The combustor section including
a combustion chamber and a fuel injection assembly disposed in the
combustion chamber. The fuel injection assembly including a fuel
nozzle including a main housing and defining an annular cavity and
a corrugated cyclone mixer assembly disposed about the fuel nozzle.
The fuel nozzle including a fuel manifold in fluid communication
with a source of fuel and a plurality of fuel injection ports. Each
fuel injection port is configured to introduce a fuel column into
the annular cavity. The corrugated cyclone mixer assembly including
an annular housing and a swirler disposed therein the annular
housing for inducing a cyclonic motion in the corrugated cyclone
mixer assembly. The annular housing comprising a flange portion and
a lip portion configured downstream of the flange portion. The
swirler is configured upstream of the flange portion and including
a plurality of swirler vanes to produce a swirling air flow. The
lip portion forms an outlet downstream of the swirler and includes
a plurality of corrugations at an aft end. The plurality of
corrugations are configured to mix the swirling air flow and an
injected fuel stream flowing therethrough the corrugated cyclone
mixer assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A full and enabling disclosure of the present disclosure,
including the best mode thereof to one skilled in the art, is set
forth more particularly in the remainder of the specification,
including reference to the accompanying figures, in which:
[0013] FIG. 1 is schematic diagram of an exemplary turbine engine
assembly including a combustion section, according to one or more
embodiments disclosed herein;
[0014] FIG. 2 is a simplified side cross-section view of a portion
of an exemplary combustor, according to one or more embodiments
disclosed herein;
[0015] FIG. 3 is a simplified side cross-section view of a fuel
injection assembly including a corrugated cyclone mixer assembly,
according to one or more embodiments disclosed herein;
[0016] FIG. 4 is an enlarged simplified diagram illustrating a
portion of the corrugated cyclone mixer assembly for use in the
fuel injection assembly of FIG. 3, according to one or more
embodiments disclosed herein;
[0017] FIG. 5 is an enlarged simplified isometric view illustrating
a portion of the corrugated cyclone mixer assembly of FIG. 3,
according to one or more embodiments disclosed herein;
[0018] FIG. 6 is an enlarged simplified isometric view of an
alternate embodiment of a portion of a corrugated cyclone mixer
assembly for use in the fuel injection assembly of FIG. 3,
according to one or more embodiments disclosed herein;
[0019] FIG. 7 is an enlarged simplified side view of an alternate
embodiment of a portion of a corrugated cyclone mixer assembly for
use in the fuel injection assembly of FIG. 3, according to one or
more embodiments disclosed herein;
[0020] FIG. 8 is an enlarged simplified side view of an alternate
embodiment of a portion of a corrugated cyclone mixer assembly for
use in the fuel injection assembly of FIG. 3, according to one or
more embodiments disclosed herein;
[0021] FIG. 9 is an enlarged simplified isometric view of an
alternate embodiment of a portion of a corrugated cyclone mixer
assembly for use in the fuel injection assembly of FIG. 3,
according to one or more embodiments disclosed herein; and
[0022] FIG. 10 is an enlarged simplified isometric view of an
alternate embodiment of a portion of a corrugated cyclone mixer
assembly for use in the fuel injection assembly of FIG. 3,
according to one or more embodiments disclosed herein.
[0023] Corresponding reference characters indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0024] The exemplary methods and systems described herein overcome
the structural disadvantages of known fuel injectors by providing
optimal mixing of liquid and gaseous fuels with oxidizer in the
combustor. It should also be appreciated that the term "first end"
is used throughout this application to refer to directions and
orientations located upstream in an overall axial flow direction of
fluids with respect to a center longitudinal axis of a combustion
chamber. It should be appreciated that the terms "axial" and
"axially" are used throughout this application to refer to
directions and orientations extending substantially parallel to a
center longitudinal axis of a combustion chamber. It should also be
appreciated that the terms "radial" and "radially" are used
throughout this application to refer to directions and orientations
extending substantially perpendicular to a center longitudinal axis
of the combustion chamber. It should also be appreciated that the
terms "upstream" and "downstream" are used throughout this
application to refer to directions and orientations located in an
overall axial flow direction with respect to the center
longitudinal axis of the combustion chamber.
[0025] Each example is provided by way of explanation of the
disclosure, not limitation of the disclosure. In fact, it will be
apparent to those skilled in the art that modifications and
variations can be made in the present disclosure 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 disclosure covers such modifications and
variations as come within the scope of the appended claims and
their equivalents. Although exemplary embodiments of the present
disclosure will be described generally in the context of a mixer
assembly for 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 disclosure may
be applied to any combustor assembly incorporated into any
turbomachine, and not limited to gas turbine engines.
[0026] Referring now to the drawings, wherein identical numerals
indicate the same elements throughout the figures, FIG. 1 provides
a diagram of an exemplary turbine engine assembly 10 that may
incorporate various embodiments of the present disclosure. As
described in detail below, the disclosed turbine engine assembly 10
(e.g., a gas turbine engine, a liquid fueled aero-engine, etc.) may
employ one or more fuel nozzles (e.g., turbine fuel nozzles) and
one or more corrugated cyclone mixer assemblies (described
presently), with an improved design to enhance premixing of the
fuel, and control over the fuel-air profile, while reducing
emissions (e.g., NOx) in the turbine engine assembly 10.
[0027] FIG. 1 depicts in diagrammatic form an exemplary turbine
engine assembly 10 (high bypass type engine) utilized with aircraft
having a longitudinal or axial centerline axis 11 therethrough for
reference purposes. Assembly 10 preferably includes a core turbine
engine, generally identified by numeral 12, and a fan section 14
positioned upstream thereof. Core engine 12 typically includes a
generally tubular outer casing 16 that defines an annular inlet 18.
Outer casing 16 further encloses and supports a booster compressor
20 for raising the pressure of the air that enters core engine 12
to a first pressure level. A high pressure, multi-stage, axial-flow
high pressure compressor 21 receives pressurized air from booster
20 and further increases the pressure of the air. The pressurized
air flows to a combustor 22, generally defined by a combustion
liner 23, and including a fuel injection assembly 24, where fuel is
injected into the pressurized air stream, via one or more fuel
nozzles and corrugated cyclone mixer assemblies, to raise the
temperature and energy level of the pressurized air. The high
energy combustion products flow from combustor 22 to a first (high
pressure) turbine 26 for driving high pressure compressor 21
through a first (high pressure) drive shaft 27, and then to a
second (low pressure) turbine 28 for driving booster compressor 20
and fan section 14 through a second (low pressure) drive shaft 29
that is coaxial with first drive shaft 27. After driving each of
turbines 26 and 28, the combustion products leave core engine 12
through an exhaust nozzle 30 to provide propulsive jet thrust.
[0028] Fan section 14 includes a rotatable, axial-flow fan rotor 32
that is surrounded by an annular fan casing 34. It will be
appreciated that fan casing 34 is supported from core engine 12 by
a plurality of substantially radially-extending,
circumferentially-spaced outlet guide vanes 36. In this way, fan
casing 34 encloses the fan rotor 32 and a plurality of fan rotor
blades 38. A downstream section 40 of fan casing 34 extends over an
outer portion of core engine 12 to define a secondary, or bypass,
airflow conduit 42 that provides additional propulsive jet
thrust.
[0029] From a flow standpoint, it will be appreciated that an
initial air flow, represented by arrow 43, enters the turbine
engine assembly 10 through an inlet 44 to fan casing 34. Air flow
43 passes through fan blades 38 and splits into a first compressed
air flow (represented by arrow 45) and a second compressed air flow
(represented by arrow 46) which enters booster compressor 20. The
pressure of the second compressed air flow 46 is increased and
enters high pressure compressor 21, as represented by arrow 47.
After mixing with fuel and being combusted in combustor 22
combustion products 48 exit combustor 22 and flow through the first
turbine 26. Combustion products 48 then flow through the second
turbine 28 and exit the exhaust nozzle 30 to provide thrust for the
turbine engine assembly 10.
[0030] During operation, the one or more fuel injection assemblies
24, intake the fuel from a fuel supply (e.g., liquid and/or gas
fuel), mix the fuel with air, and distribute the air-fuel mixture
into the one or more combustors 22 in a suitable ratio for optimal
combustion, emissions, fuel consumption, and power output. As
disclosed herein, the turbine engine assembly 10, and more
particularly the fuel injection assembly 24, includes a mixer
assembly having a corrugated cyclone mixer geometry (described
presently).
[0031] Referring to the drawings and in particular to FIG. 2,
illustrated is an exemplary combustor 50, generally similar to
combustors 22 of FIG. 1. The combustor 50 includes a combustion
chamber 52 in which combustor air is mixed with fuel and burned.
The combustor 50 includes an outer liner 54 and an inner liner 56.
The outer liner 54 defines an outer boundary of the combustion
chamber 52, and the inner liner 56 defines an inner boundary of the
combustion chamber 52. An annular dome, generally designated by 58,
mounted upstream from the outer liner 54 and the inner liner 56
defines an upstream end of the combustion chamber 52. One or more
fuel injector assemblies of the present disclosure, generally
designated by 60, and generally similar to fuel injection assembly
24 of FIG. 1, are positioned on the dome 58. According to this
disclosure, each of the fuel injector assemblies 60 includes a fuel
nozzle assembly and a corrugated cyclone mixer assembly (described
presently), disposed thereabout the fuel nozzle assembly. The
corrugated cyclone mixer assembly 62 includes a corrugated geometry
(described presently) for delivery of a mixture of fuel and air to
the combustion chamber 52. Other features of the combustion chamber
52 are conventional and will not be discussed in further
detail.
[0032] Illustrated in FIG. 3 is a first embodiment of a fuel
injector assembly according to the disclosure. According to this
disclosure, the fuel injector assembly 60 generally comprises a
fuel nozzle assembly 61 and a corrugated cyclone mixer assembly 62
(generally shown as a shaded portion), disposed thereabout the fuel
nozzle assembly 61. As illustrated, each fuel nozzle assembly 61
comprises a pilot mixer, generally designated by 63, and a main
mixer, generally designated by 64, surrounding the pilot mixer 63.
The pilot mixer 63 includes an annular pilot housing 66 having a
hollow interior 68. A pilot fuel nozzle, generally designated by
70, is mounted in the annular pilot housing 66 along an axial
centerline axis 71 of the fuel injector assembly 60. The fuel
injector assembly 60 is axisymmetric about the axial centerline
axis 71. The pilot fuel nozzle 70 includes a fuel injector 72
adapted for dispensing droplets of fuel into the hollow interior 68
of the pilot housing 66. It is envisioned that the fuel injector 72
may include an injector such as described in U.S. Pat. No.
5,435,884, which is hereby incorporated by reference.
[0033] In the illustrated embodiment, the pilot mixer 63 also
includes a pair of concentrically mounted axial swirlers, generally
designated by 76, 78, having a plurality of vanes 80, 82,
respectively positioned upstream from the pilot fuel nozzle 70. The
swirlers 76, 78 may have the same or different numbers of vanes 80,
82 without departing from the scope of the disclosure. Each of the
vanes 80, 82 is skewed relative to the centerline 71 of the fuel
injector assembly 60 for swirling air traveling through the pilot
swirlers 76, 78 so it mixes with the droplets of fuel dispensed by
the pilot fuel nozzle 70 to form a fuel-air mixture selected for
optimal burning during ignition and low power settings of the
engine. Although the pilot mixer 63 of the disclosed embodiment has
two axial swirlers 76, 78, those skilled in the art will appreciate
that the pilot mixer 63 may include more or less swirlers without
departing from the scope of the present disclosure. As will further
be appreciated by those skilled in the art, when more than one
swirler is included in the pilot mixer, such as the illustrated
swirlers 76, 78, the swirlers 76, 78 may be configured to swirl air
in the same direction or in opposite directions. Further, the pilot
interior 68 may be sized and the pilot inner and outer swirlers 76,
78 airflows and swirl angles may be selected to provide good
ignition characteristics, lean stability and low CO and HC
emissions at low power conditions.
[0034] A cylindrical barrier 84 is positioned between the swirlers
76, 78 for separating airflow traveling through the inner swirler
76 from that flowing through the outer swirler 78. The barrier 84
has a converging-diverging inner surface 86 which provides a fuel
filming surface to aid in low power performance. Further, the
housing 66 includes a generally diverging inner surface 88 adapted
to provide controlled diffusion for mixing the pilot air with the
main mixer airflow. The diffusion also reduces the axial velocities
of air passing through the pilot mixer 63 and allows recirculation
of hot gasses to stabilize the pilot flame.
[0035] The main mixer 64 includes a fuel injection assembly 60,
including a fuel manifold 96, mounted in a fuel injection housing
98 between the pilot housing 66 and the corrugated cyclone mixer
assembly 62. The fuel manifold 96 has a plurality of fuel injection
ports 100 for introducing a fuel column 102, comprised of droplets
of fuel, into a cavity 92 of the main mixer 64 defined between the
fuel injection housing 98 and the corrugated cyclone mixer assembly
62. The fuel manifold 96 may have any number of fuel injection
ports 100 without departing from the scope of the present
disclosure. In one embodiment the fuel manifold 96 has a single
circumferential row consisting of 10 evenly spaced ports. Although
the ports 100 are arranged in a single circumferential row in the
embodiment shown in FIG. 3, those skilled in the art will
appreciate that they may be arranged in other configurations
without departing from the scope of the present disclosure.
[0036] In an embodiment, by positioning the fuel injection housing
98 of the fuel manifold 96 between the pilot mixer 63 and the main
mixer 64, the mixers are physically separated. As will also be
appreciated by those skilled in the art, the distance between the
pilot mixer 63 and the main mixer 64 may be selected to improve
ignition characteristics, combustion stability at high and lower
power and low CO and HC emissions at low power conditions.
[0037] As best illustrated in FIG. 3, and as previously described,
the corrugated cyclone mixer assembly 62 is disposed about the fuel
nozzle assembly 61. The corrugated cyclone mixer assembly 62
generally includes an annular housing 90 having disposed therein a
swirler 110 positioned upstream from the plurality of fuel
injection ports 100, a flange portion 91 and a corrugated lip
portion 93 forming an outlet 94 downstream of the swirler 110.
Although the swirler 110 may have other configurations without
departing from the scope of the present disclosure, in one
embodiment the swirler 110 is a radial swirler 111 having a
plurality of radially skewed vanes 112 for swirling air traveling
through the swirler 110 and mixing the swirled air passing
therethrough with the droplets of fuel dispensed by the fuel ports
100 in the fuel injection housing 98 to form a fuel-air mixture
selected for optimal burning during high power settings of the
engine. Although the swirler 110 may have a different number of
vanes 112 without departing from the scope of the present
disclosure, in one embodiment the swirler has 40 vanes. The main
mixer 64 is primarily designed to achieve low NO.sub.x under high
power conditions by operating with a lean air-fuel mixture and by
maximizing the fuel and air pre-mixing. The swirler 110 provides
swirling of the incoming air through the radial vanes 112 to
produce an upstream swirling air stream 114, as illustrated by
directional arrow, and establishes the basic flow field of the
combustor 50 (FIG. 2). During operation, fuel droplets are injected
radially outward via fuel injection ports 100 into the swirling air
stream 114 downstream from the swirler 110 as a fuel injection
column 102, to produce a fuel/air stream 116.
[0038] As previously indicated, in contrast to known fuel injection
assemblies, the novel fuel injection assembly 60 described herein
includes the corrugated cyclone mixer assembly 62, disposed about
the fuel nozzle assembly 61, and including lip portion 93 including
a plurality of corrugations disposed at an aft end 95. The lip
portion 93 is configured to include corrugations (described
presently) that provide a multi-dimensional physical surface
capable of introducing three dimensional vorticity to the fuel/air
stream 116 passing therethrough the fuel injection assembly 60. The
introduced three dimensional vorticity enhances the mixing process
and can lead to lower NO.sub.x emissions. The corrugated lip
portion 93 may also provide an improvement in operability and
reduce combustion dynamics by shifting the frequencies at which
unsteady pressure waves exit the fuel nozzle assembly 61. This
shifting of frequencies, in turn, may prevent the unsteady pressure
fluctuations from coupling to heat release oscillations.
[0039] Referring now to FIGS. 4-10, illustrated in schematic
illustrations, are various embodiments for the corrugated cyclone
mixer assembly 62, and more particularly the lip portion 93 of the
corrugated cyclone mixer assembly 62 according to various
embodiments disclosed herein. In an embodiment, the corrugated
cyclone mixer assembly 62 is constructed of a carbon steel. In an
alternate embodiment, the corrugated cyclone mixer assembly 62 may
be constructed of any sufficiently durable material capable of
withstanding the high temperatures, pressures and abrasions
encountered during the mixing process. Alternate materials may
include, but are not limited to plastics such as polycarbonates and
urethanes, metals such as aluminum, steel, stainless steel and
ferro-nickel alloys and ceramics. In an embodiment, the cyclone
mixer assembly 92 is fabricated using additive manufacturing
techniques.
[0040] Referring more specifically to FIGS. 4 and 5, illustrated
are embodiments of a portion of a corrugated cyclone mixer assembly
120 and 122, respectively, generally similar to corrugated cyclone
mixer assembly 62 of FIG. 3. In this particular embodiment, the
corrugated cyclone mixer assemblies 120, 122 are configured as
purely radial extending corrugated cyclone mixers 121. More
specifically, each of the corrugated cyclone mixer assemblies 120,
122 includes a lip portion 124, 126, respectively.
[0041] Referring more specifically to FIG. 4, in the illustrated
embodiment, the lip portion 124 includes a plurality of sinusoidal
radial extending corrugations 128. In this particular embodiment,
the corrugations 128 are generally uniformly spaced,
circumferentially about the lip portion 124 as indicated at "A". In
an alternate embodiment, the corrugations 128 are not uniformly
spaced, circumferentially about the lip portion 124. In addition,
as illustrated, the corrugations 128 are configured to extend
radially, as indicated at "B". In this particular embodiment, the
corrugations 128 are illustrated as extending a uniformly radial
amount "B", circumferentially and radially about the lip portion
124. In an alternate embodiment, the corrugations 128 do not extend
a uniformly a radially amount, circumferentially about the lip
portion 124, and may extend various radial dimensions. As
previously indicated, the corrugations 128 are configured as
sinusoidal configured elements. In an alternate embodiment,
described presently, the corrugations 128 may be configured to
include sharp peaks and valley, and described as "shark teeth",
circumferentially about the lip portion 124. In yet another
embodiment, the radial corrugations 128 may include a mix of
sinusoidal corrugations and shark teeth corrugations.
[0042] Referring more particularly to FIG. 5, as illustrated, in
this particular embodiment, the corrugated cyclone mixer assembly
122 is configured as including a plurality of sinusoidal, radial
extending corrugations 128, similar to the embodiment of FIG. 4. In
this particular embodiment, the radial corrugations 128 are
configured uniformly circumferentially about only a portion of the
lip portion 126 as a means for enhancing the turbulent air/fuel
mixing. As illustrated the corrugated cyclone mixer assembly 122 is
configured axisymmetric about an axial centerline axis 125.
[0043] Referring now to FIG. 6, illustrated is an alternate
embodiment of a corrugated cyclone mixer assembly 130, generally
similar to the corrugated cyclone mixer assembly 62 of FIG. 3,
configured axisymmetric about an axial centerline axis 136. In this
particular embodiment, and in contrast to the embodiments of FIGS.
4 and 5, the corrugated cyclone mixer assembly 130 is configured as
a radial/tangential corrugated cyclone mixer, and described as
including both radial and tangential directional components to the
corrugations. More specifically, as illustrated the corrugated
cyclone mixer assembly 130 includes a lip portion 132 including a
plurality of sinusoidal radially/tangentially extending
corrugations 134, and more specifically including a radial and
tangential component as indicated by the directional arrows 137 and
138, respectively. In this particular embodiment, the corrugations
134 are generally uniformly spaced, circumferentially about the lip
portion 132, but may be non-uniformly spaced as previously
indicated with regard to FIGS. 4 and 5. Similarly, the corrugations
134 may be configured circumferentially about only a portion of the
lip portion 132 as indicated in FIG. 5. The corrugations 134 of
FIG. 6 may be described as radial/tangential corrugations.
[0044] Referring now to FIGS. 7 and 8, illustrated are side
schematic views of alternate embodiments of a corrugated cyclone
mixer assembly, designated 140 and 150, generally similar to the
corrugated cyclone mixer assembly 62 of FIG. 3. In this particular
embodiment, and in contrast to the embodiments of FIGS. 4-6, the
corrugated cyclone mixer assemblies 140 and 150 are configured as
purely axial corrugated cyclone mixers. More specifically, as best
illustrated in FIG. 7, the corrugated cyclone mixer assembly 140
includes a lip portion 142 including a plurality of sinusoidal
axially extending corrugations 144 configured extending axially
relative to a longitudinal axis 146. In this particular embodiment,
the corrugations 144 are configured in an alternating pattern,
extending axially upstream and including a downstream cooperating
corrugation and generally uniformly spaced, circumferentially about
the lip portion 142, but may be non-uniformly spaced as previously
indicated with regard to FIGS. 4-6. Similarly, the plurality of
sinusoidal purely axially extending corrugations 144 may be
non-uniformly configured about the lip portion 142 as described in
FIG. 5. The corrugations 144 of FIG. 7 may be described as purely
axial corrugations. As illustrated, the plurality of sinusoidal
axially extending corrugations 144 are integrally disposed at an
aft end of the lip portion 142. In an embodiment, each sinusoidal
axially extending corrugation 144 includes an apex 141, and a pair
of circumferentially or laterally opposite trailing edges or sides
145 converging from a base 143 to the respective apex 141 in one of
the downstream, aft direction or as a cutout in an upstream,
forward direction. Each sinusoidal axially downstream extending
corrugation 144 also includes a radially outer or first
substantially semi-circular surface 147, and a radially opposite
inner or substantially semi-circular surface 148 bounded by the
trailing edges 145 and base 143. The adjacent corrugations 144 are
spaced circumferentially or laterally about at least a portion of
the lip portion 142, and disposed in flow communication with the
inside of the corrugated cyclone mixer assembly 140 for channeling
flow radially therethrough. In an embodiment, each sinusoidal
axially downstream extending corrugation 144 may not be formed as
"purely axial" and include a concave contour axially between the
respective bases 143 and apexes 141 and/or a concave contour
circumferentially or laterally between the trailing edges 145. In
another embodiment not formed as "purely axial", each of the
sinusoidal axially downstream extending corrugation 144 may include
a compound, three-dimensional flow surface contour defining a
shallow concave depression or bowl for promoting mixing
effectiveness. Each sinusoidal axially extending corrugation 144
has an axial length "C" measured perpendicularly from its base 143
to its apex 141, and a lateral width "D" varying from a maximum
value at the base to a minimum value at the apex.
[0045] In contrast to the sinusoidal purely axial corrugations of
FIG. 7, in FIG. 8, illustrated is the corrugated cyclone mixer
assembly 150 including a plurality of non-sinusoidal or shark teeth
configured, axial corrugations 154, being substantially triangular
in configuration. More specifically, as best illustrated in FIG. 8,
the corrugated cyclone mixer assembly 150 includes a lip portion
152 including the plurality of shark teeth configured, axial
corrugations 154 configured extending axially relative to a
longitudinal axis 156. As illustrated, the plurality of axial
corrugations 154 are integrally disposed at an aft end of the lip
portion 152, that in combination define the shark-tooth
configuration. In an embodiment, each axial corrugation 154
includes an apex 151, and a pair of circumferentially or laterally
opposite trailing edges or sides 155 converging from a base 153 to
the respective apex 151 in the downstream, aft direction. Each
axial corrugation 154 also includes a radially outer or first
triangular surface 157, and a radially opposite inner or second
triangular surface 158 bounded by the trailing edges 155 and base
153. The trailing edges 155 of adjacent corrugations 154 are spaced
circumferentially or laterally apart from the bases 153 to apexes
151 to define respective slots or cut-outs 159 diverging laterally
and axially, and disposed in flow communication with the inside of
the corrugated cyclone mixer assembly 150 for channeling flow
radially therethrough. In the exemplary embodiment illustrated in
FIG. 8, the slots 159 are also triangular and complementary with
the triangular axial corrugations 154 and diverge axially aft from
a slot base, which is circumferentially coextensive with the bases
153, to the corrugation apexes 151. In an embodiment, each
corrugation 154 may not be formed as "purely axial" and include a
concave contour axially between the respective bases 153 and apexes
151 and/or a concave contour circumferentially or laterally between
the trailing edges 155. In another embodiment not formed as "purely
axial", each of the axial corrugations 154 may include a compound,
three-dimensional flow surface contour defining a shallow concave
depression or bowl for promoting mixing effectiveness. Each axial
corrugations 154 has an axial length "E" measured perpendicularly
from its base 153 to its apex 151, and a lateral width "F" varying
from a maximum value at the base to a minimum value at the
apex.
[0046] Referring now to FIGS. 9 and 10, illustrated are yet
additional embodiments of a corrugated cyclone mixer assembly
including a plurality of corrugations about an aft end of the lip
portion, generally referenced 160 and 170, respectively. In the
embodiment of FIG. 9, the corrugated cyclone mixer assembly 160
includes a plurality of non-sinusoidal or shark teeth configured,
radially outward extending corrugations 164. More specifically, as
best illustrated in FIG. 9, the corrugated cyclone mixer assembly
160 includes a lip portion 162 including the plurality of shark
teeth configured, radially outward corrugations 164 configured
extending radially outward relative to a longitudinal axis 166. As
illustrated, the plurality of axial corrugations 164 include a
plurality of apexes 168 and a plurality of bases 169, such as those
previously described with regard to FIG. 8, that in combination
define the shark-tooth configuration. In an alternate embodiment,
the corrugations 164 may be configured having a sinusoidal geometry
as previously described.
[0047] In contrast to the radially outward corrugations of FIG. 9,
in FIG. 10, illustrated is the corrugated cyclone mixer assembly
170 including a plurality of non-sinusoidal or shark teeth
configured, radially inward extending corrugations 174. More
specifically, as best illustrated in FIG. 10, the corrugated
cyclone mixer assembly 170 includes a lip portion 172 including the
plurality of shark teeth configured, radially inward extending
corrugations 174 configured extending radially inward relative to a
longitudinal axis 176. As illustrated, the plurality of radially
inward corrugations 174 include a plurality of apexes 178 and a
plurality of bases 179 that in combination define the shark-tooth
configuration. In an alternate embodiment, the corrugations 174 may
be configured having a sinusoidal geometry as previously
described.
[0048] As emissions regulations tighten, hardware known for lower
emissions will become increasingly important. Accordingly, as
disclosed herein and as illustrated in FIGS. 1-10 provided are
various technological advantages and/or improvements over existing
fuel injection assemblies, and in particular mixer assemblies and
fuel/air mixing. The disclosure provides an improved corrugated
cyclone mixer assembly to enhance the mixing of the fuel flowing
from a fuel injector with air supplied via a swirler to the
combustion chamber and thus reduces production of undesirable
emissions such as oxides of nitrogen or NO.sub.x. In addition, the
improved corrugated cyclone mixer provides increased premixing that
is downstream of the corrugated cyclone mixer without increasing
the risk of autoignition that may lead to improved durability of
the hardware, and thereby a reduction in the need for maintenance
or replacement.
[0049] A further benefit of the disclosure lies in the many
variable corrugation configurations of the corrugated cyclone
mixer, including, but not limited to, purely radial corrugations,
purely axial corrugations, axial and tangential corrugations,
sinusoidal corrugations, sharp "shark teeth" like corrugations,
radial inward extending corrugations, radially outward extending
corrugations, uniform and non-uniform corrugations configurations,
flat or contoured corrugations, or combinations of any of the above
listed corrugation geometries, etc. In addition, the corrugations
as disclosed herein may be configured having a substantially
uniform thickness which may also be equal to the thickness of the
flange portion 91 of the annular housing 90 from which they extend,
and may be formed of one or more thin walled members or plates.
Alternatively, the corrugations may vary in thickness to allow for
structural rigidity and flow surface blending. Although the
individual corrugations, for example, could be flat components, as
previously mentioned, the corrugations may include a compound
curvature for cooperating with the fluid flow for promoting mixing
effectiveness while at the same time providing an aerodynamically
smooth and non-disruptive profile for minimizing losses in
aerodynamic efficiency and performance. In the disclosed
embodiment, each corrugation has an axial length measured
perpendicularly from its base to its apex or outermost point and a
lateral width varying from a maximum value at the base to a minimum
value at the apex or outermost point. Additionally, the
corrugations preferably have equal axial lengths from the bases to
the apexes, however, the corrugation lengths may be unequal and
vary as desired.
[0050] The many varied configurations provide that the NO.sub.x
performance can be optimized. As a result of the above, various
embodiments of the present disclosure may allow extended combustor
operating conditions, extend the life and/or maintenance intervals
for various combustor components, maintain adequate design margins
of flame holding, and/or reduce undesirable emissions. In addition,
improved fuel-air mixing is also expected to yield better
efficiency at a cruise condition.
[0051] This written description uses examples to disclose the
disclosure, including the best mode, and also to enable any person
skilled in the art to practice the disclosure, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the disclosure 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 include structural elements that do not
differ from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal language of the claims.
[0052] Exemplary embodiments of a corrugated cyclone mixer are
described in detail above. The corrugated cyclone mixers are not
limited to use with the specified turbine containing systems
described herein, but rather, the corrugated cyclone mixers can be
utilized independently and separately from other turbine containing
system components described herein. Moreover, the present
disclosure is not limited to the embodiments of the corrugated
cyclone mixers described in detail above. Rather, other variations
of corrugated cyclone mixers embodiments may be utilized within the
spirit and scope of the claims.
[0053] While the disclosure has been described in terms of various
specific embodiments, those skilled in the art will recognize that
the disclosure can be practiced with modification within the spirit
and scope of the claims.
* * * * *