U.S. patent application number 13/940723 was filed with the patent office on 2015-01-15 for air flow conditioner for fuel injector of gas turbine engine.
The applicant listed for this patent is Solar Turbines Inc.. Invention is credited to Daniel William Carey, Jonathan Duckers, Robert James Fanella.
Application Number | 20150013342 13/940723 |
Document ID | / |
Family ID | 51924589 |
Filed Date | 2015-01-15 |
United States Patent
Application |
20150013342 |
Kind Code |
A1 |
Carey; Daniel William ; et
al. |
January 15, 2015 |
AIR FLOW CONDITIONER FOR FUEL INJECTOR OF GAS TURBINE ENGINE
Abstract
A fuel injector for a gas turbine engine is provided. The fuel
injector includes a central body, an air inlet duct, a mixing duct,
a swirler, and a flow conditioner. The air inlet duct and the
mixing duct are positioned around the central body to define an air
flow passage. The swirler is positioned between the air inlet duct
and the mixing duct. The flow conditioner is disposed in the air
flow passage upstream with respect to the swirler. The flow
conditioner has a perforated plate configured to uniformly
distribute air circumferentially within the air inlet duct.
Inventors: |
Carey; Daniel William; (San
Diego, CA) ; Duckers; Jonathan; (San Diego, CA)
; Fanella; Robert James; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Solar Turbines Inc. |
San Diego |
CA |
US |
|
|
Family ID: |
51924589 |
Appl. No.: |
13/940723 |
Filed: |
July 12, 2013 |
Current U.S.
Class: |
60/776 ;
60/735 |
Current CPC
Class: |
F23C 2900/07001
20130101; F23R 3/14 20130101; F23R 3/286 20130101 |
Class at
Publication: |
60/776 ;
60/735 |
International
Class: |
F23D 14/64 20060101
F23D014/64 |
Claims
1. A fuel injector for a gas turbine engine, the fuel injector
comprising: a central body; an air inlet duct and a mixing duct
positioned around the central body to define an air flow passage; a
swirler positioned between the air inlet duct and the mixing duct;
and a flow conditioner disposed in the air flow passage upstream
with respect to the swirler, the flow conditioner having a
perforated plate configured to uniformly distribute air
circumferentially within the air inlet duct.
2. The fuel injector of claim 1, wherein the flow conditioner
comprises a cylindrical body to fit inside the air inlet duct and
around the central body of the fuel injector.
3. The fuel injector of claim 2, wherein the perforated plate is
located at a downstream end of the cylindrical body.
4. The fuel injector of claim 2, wherein the cylindrical body
comprises an outer surface defining openings thereon.
5. The fuel injector of claim 1, wherein the perforated plate
comprises round perforations.
6. The fuel injector of claim 1, wherein the perforated plate
comprises curved rectangular perforations.
7. The fuel injector of claim 1, wherein the swirler comprises a
plurality of vanes that extend outward from the central body and
into the air flow passage.
8. The fuel injector of claim 7, wherein the vane comprises a
plurality of fuel jets.
9. The fuel injector of claim 1, wherein the central body comprises
a pilot fuel injector configured to inject a pilot stream of
fuel.
10. A gas turbine engine comprising: a combustion chamber; one or
more fuel injectors comprising: a central body; an air inlet duct
and a mixing duct positioned around the central body to define an
air flow passage; a swirler positioned between the air inlet duct
and the mixing duct; and a flow conditioner disposed in the air
flow passage upstream with respect to the swirler, the flow
conditioner including a perforated plate configured to uniformly
distribute air circumferentially within the air inlet duct.
11. The gas turbine engine of claim 10, wherein the flow
conditioner comprises a cylindrical body to fit inside the air
inlet duct and around the central body of the fuel injector.
12. The gas turbine engine of claim 11, wherein the perforated
plate is located at a downstream end of the cylindrical body.
13. The gas turbine engine of claim 11, wherein the cylindrical
body comprises an outer surface defining openings thereon.
14. The gas turbine engine of claim 10, wherein the perforated
plate comprises round perforations.
15. The gas turbine engine of claim 10, wherein the perforated
plate comprises curved rectangular perforations.
16. The gas turbine engine of claim 10, wherein the swirler
comprises a plurality of vanes that extend outward from the central
body and into the air flow passage.
17. The gas turbine engine of claim 16, wherein the vane comprises
a plurality of fuel jets.
18. The gas turbine engine of claim 10, wherein the central body
comprises a pilot fuel injector configured to inject a pilot stream
of fuel.
19. A method of delivering air-fuel mixture into a combustor
chamber of a gas turbine engine, the method comprising: receiving
pilot fuel from pilot fuel injectors into a central body of the
fuel injector; receiving fuel from vanes on a swirler into a mixing
duct of the fuel injector; receiving air from an air inlet duct
into the mixing duct; and uniformly distributing the air
circumferentially within an air inlet duct of the fuel injector by
a perforated plate of a flow conditioner disposed upstream with
respect to the swirler; and mixing fuel with the distributed air in
the mixing duct; receiving air-fuel mixture from the mixing duct
together with the pilot fuel from the central body at the
combustion chamber.
20. The method of claim 19, wherein uniformly distributing the air
circumferentially within an air inlet duct further comprises
passing the air through one of round and curved rectangular
perforations of the perforated plate.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a fuel injector for gas
turbine engines and more particularly to fuel injectors for
uniformly mixing air and fuel in gas turbine engines.
BACKGROUND
[0002] In recent years, emission norms for engines have become
increasingly stringent. In order to meet the stringent emission
norms, engine manufacturers are continually striving to achieve
emission levels that may be well below the permissible limits
specified in the emission norms. Some commonly known pollutants
resulting from combustion of fuels are carbon monoxide (CO), carbon
dioxide (CO.sub.2), and NO.sub.x.
[0003] In some cases, the permissible limits for pollutants, given
in parts per million (ppm), may be met by varying air-fuel ratios
in the engines during operation. Previously known systems
accomplished variation to the air-fuel ratios. However, these
systems may not evenly distribute the air and fuel to accomplish an
uniform mixing pattern of the air and fuel and hence, may produce a
heterogeneous air-fuel mixture for use in combustion.
[0004] U.S. Pat. No. 8,186,162 relates to a fuel nozzle for a
turbine engine. The fuel nozzle has a central body member with a
pilot, a surrounding barrel housing, a mixing duct and an air inlet
duct. The fuel nozzle additionally has a main fuel injection device
located between the air inlet duct and the mixing duct. The main
fuel injection device is configured to introduce a flow of fuel
into the barrel member to create a fuel/air mixture which is then
premixed with a swirler. The fuel/air mixture then further mixes in
the mixing duct and exits the nozzle into a combustor for
combustion.
SUMMARY
[0005] In one aspect, the present disclosure discloses a fuel
injector for a gas turbine engine. The fuel injector includes a
central body, an air inlet duct, a mixing duct, a swirler, and a
flow conditioner. The air inlet duct and the mixing duct are
positioned around the central body to define an air flow passage.
The swirler is positioned between the air inlet duct and the mixing
duct. The flow conditioner is disposed in the air flow passage
upstream with respect to the swirler. The flow conditioner has a
perforated plate configured to uniformly distribute air
circumferentially within the air inlet duct.
[0006] In another aspect, the present disclosure discloses a gas
turbine engine including a combustion chamber, and one or more fuel
injectors associated with the combustion chamber. The fuel
injectors include a central body, an air inlet duct, a mixing duct,
a swirler, and a flow conditioner. The air inlet duct and the
mixing duct are positioned around the central body to define an air
flow passage. The swirler is positioned between the air inlet duct
and the mixing duct. The flow conditioner is disposed in the air
flow passage upstream with respect to the swirler. The flow
conditioner has a perforated plate configured to uniformly
distribute air circumferentially within the air inlet duct.
[0007] In another aspect, the present disclosure discloses a method
of delivering air-fuel mixture into a combustor chamber of a gas
turbine engine. The method includes receiving pilot fuel from pilot
fuel injectors into a central body of the fuel injector. The method
further includes receiving fuel from vanes on a swirler into a
mixing duct of the fuel injector. The method further includes
receiving air from an air inlet duct into the mixing duct. The
method further includes uniformly distributing the air
circumferentially within an air inlet duct of the fuel injector by
a perforated plate of a flow conditioner disposed upstream with
respect to the swirler. The method further includes mixing fuel
with the distributed air in the mixing duct. The method further
includes receiving air-fuel mixture from the mixing duct together
with the pilot fuel from the central body at the combustion
chamber.
[0008] Other features and aspects of this disclosure will be
apparent from the following description and the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a cutaway view of an exemplary gas turbine engine
in accordance with an embodiment of the present disclosure;
[0010] FIG. 2 is a front sectional view of a fuel injector employed
in the exemplary gas turbine engine of FIG. 1;
[0011] FIGS. 3-5 are front perspective views of a flow conditioner
in accordance with various exemplary embodiments of the present
disclosure; and
[0012] FIG. 6 is a method of delivering air-fuel mixture into a
combustor chamber of the exemplary gas turbine engine.
DETAILED DESCRIPTION
[0013] The present disclosure relates to air flow conditioners for
fuel injectors used in gas turbine engines. Although, the present
disclosure focusses on gas turbine engines, structures, processes,
and methods disclosed herein may be similarly applicable to fuel
injectors used in other types of engines such as internal
combustion engines. FIG. 1 shows a cutaway view of an exemplary gas
turbine engine 100. The gas turbine engine 100 may be of any type.
In one embodiment, the gas turbine engine 100 may be used to drive
a generator for power generation, or other mechanical assemblies
such as a compressor. In other embodiments, the gas turbine engine
100 may be employed in mobile machines such as but not limited to
earth moving machines, passenger vehicles, marine vessels, or any
other mobile machine known in the art.
[0014] The gas turbine engine 100 may include a compressor section
102, a combustor section 104, a turbine section 106, and an exhaust
section 108. The compressor section 102 may include a series of
compressor blades 110 fixedly connected about a central shaft 112.
The compressor blades 110 may be rotatable to compress air. As the
central shaft 112 is rotated, the compressor blades 110 may draw
air into the gas turbine engine 100 and pressurize the air. This
pressurized air may then be directed towards the combustor section
104. It is contemplated that compressor section 102 may further
include compressor blades (not shown) that are separate from
central shaft 112 and remain stationary during operation of turbine
engine.
[0015] The combustor section 104 may mix a liquid and/or gaseous
fuel with the compressed air from compressor section 102 and
combust the mixture to produce a mechanical work output. The
combustor section 104 may include a combustion chamber 114, and one
or more fuel injectors 116 associated with the combustion chamber
114. In an embodiment as shown in FIG. 1, the fuel injectors 116
may be annularly arranged about the central shaft 112. The
combustion chamber 114 may house the combustion process. The fuel
injectors 116 may inject one or both of liquid and gaseous fuel
into the flow of compressed air from the compressor section 102 for
ignition within the combustion chamber 114. As the fuel/air mixture
combusts, the heated molecules may expand and move at high speed
into the turbine section 106.
[0016] The turbine section 106 may include a series of rotatable
turbine rotor blades 118 fixedly connected to the central shaft
112. As the turbine rotor blades 118 are bombarded with high-energy
molecules from the combustor section 104, the expanding molecules
may cause central shaft 112 to rotate, thereby converting
combustion energy into useful rotational power. This rotational
power may then be drawn from the gas turbine engine 100 and used
for a variety of purposes. In addition to powering various external
devices, the rotation of the turbine rotor blades 118 and the
central shaft 112 may drive the rotation of the compressor blades
110. The exhaust section 108 may direct the exhaust from combustor
and turbine sections 104, 106 to the atmosphere.
[0017] As illustrated in FIG. 2, the fuel injector 116 may include
components that cooperate to inject gaseous and liquid fuel into
the combustion chamber 114. Each fuel injector 116 includes an air
inlet duct 120, and a mixing duct 122. The air inlet duct 120 and
the mixing duct 122 together define a barrel housing 124 configured
to receive compressed end and supply the fuel-air mixture to the
combustion chamber 114.
[0018] In an embodiment as shown in FIG. 2, the barrel housing 124
may include a plurality of air jets 126 configured to receive
compressed air from the compressor section 102 by way of one or
more fluid passageways (not shown) external to the barrel housing
124. The air inlet duct 120 may be configured to axially direct
compressed air from the compressor section 102 (referring to FIG.
1) to the barrel housing 124, and to divert a portion of the
compressed air to the air jets 126.
[0019] The mixing duct 122 may be configured to axially direct the
fuel/air mixture from fuel injector 116 into the combustion chamber
114. The mixing duct 122 may include a central opening 128 that
fluidly communicates the barrel housing 124 with the combustion
chamber 114. The fuel injector 116 further includes a central body
130. The central body 130 may be disposed radially inward of the
barrel housing 124 and aligned along a common axis 131.
[0020] The air inlet duct 120 and the mixing duct 122 are
positioned around the central body 130 to define an air flow
passage 132 therebetween. The air flow passage 132 is configured to
receive compressed air from the compressor section 102. The fuel
injector 116 may also include a pilot fuel injector 134 located
within the central body 130. The pilot fuel injector 134 may be
configured to inject a pilot stream of pressurized fuel through a
tip end 136 of the central body 130 into the combustion chamber 114
to facilitate engine starting, idling, cold operation, and/or lean
burn operations of the gas turbine engine 100.
[0021] The fuel injector 116 further includes a swirler 138
positioned between the air inlet duct 120 and the mixing duct 122.
In an embodiment as shown in FIG. 2, the swirler 138 may be
annularly disposed between the barrel housing 124 and the central
body 130 and may be configured to radially redirect an axial flow
of compressed air from the air inlet duct 120.
[0022] In an embodiment as shown in FIG. 2, the swirler 138 may
include vanes 140 that extend outward from the central body 130 and
into the air flow passage 132. These vanes 140 are disposed in an
axial flow path of the compressed air and may be configured to
divert the compressed air in a radially inward direction. The vanes
140 disclosed herein, may be arranged in the barrel housing 124
around the common axis 131 or, alternatively, to a point centered
off-center from the common axis 131. Further, the vanes 140 may be
straight or twisted in shape, and may be tilted at an angle
relative to the common axis 131.
[0023] One or more vanes 140 may include a liquid fuel jet 142 and
a plurality of gaseous fuel jets 144 to facilitate fuel injection
within the barrel housing 124. It is contemplated that any number
or configuration of vanes 140 may include the liquid fuel jets 142.
The location of vanes 140 along the common axis 131 and the
resulting axial fuel introduction point within the fuel injector
116 may vary depending on specific requirements of an application.
The gaseous fuel jets 144 may be associated with the vane to
receive gaseous fuel from an external source (not shown).
[0024] The fuel injector 116 further includes a flow conditioner
146 disposed in the air flow passage 132 upstream with respect to
the swirler 138. In an embodiment as shown in FIG. 3, the flow
conditioner 146 may include a cylindrical body 148 to fit inside
the air inlet duct 120 and around the central body 130 of the fuel
injector 116. In an embodiment, the cylindrical body 148 may
include a peripheral flange 149 at an upstream end 151 such that
the flow conditioner 146 may be welded or placed in secure abutment
with the air inlet duct 120. In an embodiment, the cylindrical body
148 comprises an outer surface 150 defining openings 152
thereon.
[0025] Further, the flow conditioner 146 has a perforated plate 154
configured to uniformly distribute the air circumferentially within
the air inlet duct 120 (referring to FIG. 2). The perforated plate
154 is located at a downstream end 156 of the cylindrical body 148.
The perforated plate 154 includes perforations 158. These
perforations 158 may be of varying configurations, and sizes such
that compressed air is allowed to flow past the perforated plate
154, deflect in one or more pre-determined paths, and mix with the
injected fuel at the mixing duct 122. In one exemplary embodiment
as shown in FIG. 3, the perforated plate 154 of the flow
conditioner 146 may include round perforations 158. In other
exemplary embodiments as shown in FIGS. 4-5, the perforated plate
154 may include curved rectangular perforations 158 of different
sizes. The perforations 158 may be may be formed by commonly known
manufacturing processes such as, but not limited to, stamping,
blanking, casting, or assembling multiple cut-outs from a blanked
material.
[0026] In one embodiment, the perforations 158 may be chosen such
that uniform mixing pattern of fuel and air is achieved across the
mixing duct 122. However, a shape, size, number and configuration
of the perforations 158 may vary based on various factors such as
but not limited to a distribution of air required within the air
flow passage 132, mixing pattern required in the air-fuel mixture,
wake associated with operation of the gas turbine engine 100, or
emission requirements to be met by the gas turbine engine 100.
Therefore, although a specific number, size, shape and
configuration of the perforations 158 are shown on the perforated
plate 154 of FIGS. 3-5, it is to be noted that the perforations 158
are merely exemplary in nature, and hence non-limiting of this
disclosure. Any known shape, size, configuration, and number of
perforations 158 may be used depending on specific application
requirements.
INDUSTRIAL APPLICABILITY
[0027] Typically, gas turbine engines experience wake that may
disrupt a mixing pattern of the air and fuel at a mixing duct of a
fuel injector. In some cases, wake occurring in gas turbine engines
may further lead to a heterogeneous mixing of air and fuel within
the fuel injectors. Use of such heterogeneous air-fuel mixture may
increase a possibility of incomplete combustion and promote the
production of pollutants. Hence, pollutants may be produced by the
gas turbine engine even if the air-fuel ratios are varied to suit
one or more operating parameters of the gas turbine engine.
[0028] The flow conditioner 146 of the present disclosure may serve
to reduce any wake occurring upstream of the flow conditioner 146.
The flow conditioner 146 may be formed to include any number of
perforations 158 of various sizes, shapes, and configurations such
that wake is reduced and a pre-determined mixing pattern of the
air-fuel mixture is achieved. With implementation of the flow
conditioner 146 disclosed herein, the flow conditioner 146 may
present a required amount of restriction and deflection to the air
in the air flow passage 132 such that the mixing pattern of the air
and fuel is uniform across the mixing duct 122 of the fuel injector
116. The uniform mixing pattern of the air and fuel to form the
homogenous air-fuel mixture may entail complete combustion of the
air-fuel mixture at the combustion chamber 114. Consequently, the
level of emissions from the gas turbine engine 100 may reduce and
may be equal to or lesser than the permissible limit determined by
the emission requirements for the gas turbine engine 100. Moreover,
the openings 152 provided on the cylindrical body 148 may avoid
creation of any dead spaces upon installation of the flow
conditioner 146 into the fuel injector 116 thus, preventing fuel to
inadvertently migrate and combust at the dead spaces.
[0029] Prolonged use of the flow conditioner 146 in conjunction
with fuel injectors 116 may improve fuel economy of the gas turbine
engines 100 and save fuel costs. Therefore, the flow conditioner
146 disclosed herein may increase profitability associated with
operation of the gas turbine engine 100.
[0030] FIG. 6 shows a method 600 of delivering the air-fuel mixture
into the combustor chamber 114 of the gas turbine engine 100. At
step 602, the method 600 includes receiving the pilot fuel from the
pilot fuel injectors 134 into the central body 130 of the fuel
injector 116. At step 604, the method 600 further includes
receiving the fuel from the vanes 140 on the swirler 138 into the
mixing duct 122 of the fuel injector 116. At step 606, the method
600 further includes receiving the air from the air inlet duct 120
into the mixing duct 122.
[0031] At step 608, the method 600 further includes uniformly
distributing the air circumferentially within the air inlet duct
120 of the fuel injector 116 by the perforated plate 154 of the
flow conditioner 146 disposed upstream with respect to the swirler
138. In an embodiment, the step 608 of uniformly distributing the
air circumferentially within the air inlet duct 120 further
comprises passing the air through the round perforations 158 of the
perforated plate 154. In another embodiment, the step of the step
608 of uniformly distributing the air circumferentially within the
air inlet duct 120 further comprises passing the air through the
curved rectangular perforations 158 of the perforated plate
154.
[0032] At step 610, the method 600 further includes mixing the fuel
with the distributed air in the mixing duct 122. At step 612, the
method 600 further includes receiving the air-fuel mixture from the
mixing duct 122 together with the pilot fuel from the central body
130 at the combustion chamber 114.
[0033] While aspects of the present disclosure have been
particularly shown and described with reference to the embodiments
above, it will be understood by those skilled in the art that
various additional embodiments may be contemplated by the
modification of the disclosed machine, systems and methods without
departing from the spirit and scope of what is disclosed. Such
embodiments should be understood to fall within the scope of the
present disclosure as determined based upon the claims and any
equivalents thereof.
* * * * *