U.S. patent application number 14/669089 was filed with the patent office on 2016-09-29 for fuel nozzle with multiple flow divider air inlet.
This patent application is currently assigned to LUIZ CLAUDIO FERNANDES. The applicant listed for this patent is JUSTIN BOSNOIAN, NICOLAS DEMOUGEOT, LUIZ CLAUDIO FERNANDES, BRANDON HILL, CHILUWATA LUNGU, MARC PASKIN, KEVIN B. POWELL, BRIAN RICHARDSON, DAVID SCHLAMP, SUMIT SONI, PETER STUTTAFORD. Invention is credited to JUSTIN BOSNOIAN, NICOLAS DEMOUGEOT, LUIZ CLAUDIO FERNANDES, BRANDON HILL, CHILUWATA LUNGU, MARC PASKIN, KEVIN B. POWELL, BRIAN RICHARDSON, DAVID SCHLAMP, SUMIT SONI, PETER STUTTAFORD.
Application Number | 20160281978 14/669089 |
Document ID | / |
Family ID | 56975030 |
Filed Date | 2016-09-29 |
United States Patent
Application |
20160281978 |
Kind Code |
A1 |
FERNANDES; LUIZ CLAUDIO ; et
al. |
September 29, 2016 |
Fuel Nozzle With Multiple Flow Divider Air Inlet
Abstract
The present invention discloses a novel apparatus and way for
directing a supply of compressed air into a fuel nozzle assembly
for mixing with a fuel source. The apparatus comprises a fuel
nozzle assembly having one or more coaxial flow dividers and
radially-extending swirler vanes for directing a supply of fuel to
a mixing tube. Compressed air is directed to flow in a primarily
axial direction by passing through one or more coaxial flow
dividers spaced axially and radially about the air inlet region of
the fuel nozzle assembly so as to form a non-uniform radial
distribution of compressed air to the inlet region of the fuel
nozzle assembly.
Inventors: |
FERNANDES; LUIZ CLAUDIO;
(PALM BEACH GARDENS, FL) ; RICHARDSON; BRIAN;
(JUPITER, FL) ; STUTTAFORD; PETER; (JUPITER,
FL) ; SONI; SUMIT; (JUPITER, FL) ; SCHLAMP;
DAVID; (JUPITER, FL) ; LUNGU; CHILUWATA;
(Atlanta, GA) ; BOSNOIAN; JUSTIN; (JUNO BEACH,
FL) ; DEMOUGEOT; NICOLAS; (STUART, FL) ;
POWELL; KEVIN B.; (JUPITER, FL) ; HILL; BRANDON;
(JENSEN BEACH, FL) ; PASKIN; MARC; (PARKLAND,
FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FERNANDES; LUIZ CLAUDIO
RICHARDSON; BRIAN
STUTTAFORD; PETER
SONI; SUMIT
SCHLAMP; DAVID
LUNGU; CHILUWATA
BOSNOIAN; JUSTIN
DEMOUGEOT; NICOLAS
POWELL; KEVIN B.
HILL; BRANDON
PASKIN; MARC |
PALM BEACH GARDENS
JUPITER
JUPITER
JUPITER
JUPITER
Atlanta
JUNO BEACH
STUART
JUPITER
JENSEN BEACH
PARKLAND |
FL
FL
FL
FL
FL
GA
FL
FL
FL
FL
FL |
US
US
US
US
US
US
US
US
US
US
US |
|
|
Assignee: |
FERNANDES; LUIZ CLAUDIO
PALM BEACH GARDENS
FL
RICHARDSON; BRIAN
JUPITER
FL
STUTTAFORD; PETER
JUPITER
FL
SONI; SUMIT
JUPITER
FL
SCHLAMP; DAVID
JUPITER
FL
LUNGU; CHILUWATA
JUNO BEACH
FL
BOSNOIAN; JUSTIN
STUART
FL
DEMOUGEOT; NICOLAS
JUPITER
FL
POWELL; KEVIN B.
JENSEN BEACH
FL
HILL; BRANDON
PARKLAND
FL
PASKIN; MARC
|
Family ID: |
56975030 |
Appl. No.: |
14/669089 |
Filed: |
March 26, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F23R 3/14 20130101; F23D
11/38 20130101; F23R 3/28 20130101; F23R 3/286 20130101; F23R 3/26
20130101 |
International
Class: |
F23D 11/38 20060101
F23D011/38; F23R 3/28 20060101 F23R003/28 |
Claims
1. A fuel nozzle assembly comprising: a first tube extending along
a center axis and having a first passageway therein; a second tube
coaxial to and radially outward of the first tube and forming a
second passageway between the first tube and the second tube; a
third tube coaxial to and radially outward of the second tube and
forming a third passageway between the second tube and a portion of
the third tube and a portion of the first tube and the third tube;
a premix tube coaxial to and radially outward of the third tube,
the premix tube having an inlet end and an opposing outlet end, the
premix tube having a plurality of swirler vanes positioned between
the third tube and premix tube, the plurality of swirler vanes
configured to inject fuel and induce a swirl into a passing flow of
fuel and air; and, one or more coaxial flow dividers, each of the
coaxial flow dividers having a cylindrical portion and an inlet
region portion, where the inlet region portion is turned radially
outward from the center axis; wherein the one or more coaxial flow
dividers split and direct a passing airflow into the premix
tube.
2. The fuel nozzle assembly of claim 1, wherein the first tube
contains a cartridge for supplying purge through a first
passageway.
3. The fuel nozzle assembly of claim 2, wherein the first
passageway contains either liquid, gas, air, or a mixture
thereof.
4. The fuel nozzle assembly of claim 3, wherein the second
passageway contains air, fuel, or a mixture thereof.
5. The fuel nozzle assembly of claim 4, wherein the third
passageway is divided into a first portion and a second portion,
the first portion extending from proximate a base of the fuel
nozzle assembly to proximate the plurality of swirler vanes, while
the second portion extends from proximate the plurality of swirler
vanes to proximate a tip region of the fuel nozzle assembly, where
the first portion is not in fluid communication with the second
portion.
6. The fuel nozzle assembly of claim 5, wherein the first portion
of the third passageway contains gas and the second portion of the
third passageway contains air, gas, or a mixture thereof.
7. The fuel nozzle assembly of claim 1, wherein the inlet end of
the premix tube tapers radially outward from the center axis.
8. The fuel nozzle assembly of claim 1, further comprising a
plurality of struts extending between and secured to the one or
more coaxial flow dividers and the premix tube.
9. The fuel nozzle assembly of claim 8, wherein the plurality of
struts extend through a portion of the coaxial flow dividers and a
portion of the premix tube.
10. The fuel nozzle assembly of claim 8, wherein the plurality of
struts extend across the inlet region of each of the coaxial flow
dividers.
11. An air conditioning flow device for use in a fuel nozzle
assembly comprising: a premix tube having an inlet end turned
radially outward from a center axis of the fuel nozzle assembly;
and, one or more coaxial flow dividers positioned at an air inlet
region of the fuel nozzle assembly, each coaxial flow divider
having a cylindrical portion extending an axial length and an air
inlet portion turned radially outward, the one or more coaxial flow
dividers spaced axially and radially so as to form a plurality of
annular air inlet areas therebetween, so as to form an unequal
radial air flow distribution between the coaxial flow dividers.
12. The air conditioning flow device of claim 11, wherein the
plurality of coaxial flow dividers comprise a first and second flow
divider.
13. The air conditioning flow device of claim 12, wherein a first
air inlet area is formed between a third tube of the fuel nozzle
assembly and the first flow divider, a second air inlet flow area
is formed between the first and second flow dividers, and a third
air inlet area is formed between the second flow divider and the
inlet end of the premix tube.
14. The air conditioning flow device of claim 13, wherein the first
air inlet area has a different radial air flow distribution than
the second air inlet area.
15. The air conditioning flow device of claim 14, wherein the first
air inlet area has a similar radial air flow distribution to the
third air inlet area.
16. The air conditioning flow device of claim 15, wherein the first
air inlet area and third air inlet area each have a radial air flow
distribution that is greater than the second air inlet area.
17. The air conditioning flow device of claim 13 further comprising
a plurality of struts extending between and secured to the one or
more coaxial flow dividers and the premix tube.
18. A method of conditioning an incoming air stream entering a fuel
nozzle assembly comprising: providing the fuel nozzle assembly
having one or more coaxial flow dividers positioned at an air inlet
region of the fuel nozzle assembly and spaced axially and radially
at the air inlet region; providing a flow of compressed air to the
air inlet region of the fuel nozzle assembly; and, directing the
compressed air through each of a plurality of areas formed by the
one or more coaxial flow dividers and in a direction coaxial to a
center axis of the fuel nozzle assembly; wherein the plurality of
areas provide a non-uniform radial distribution of compressed air
to the air inlet region of the fuel nozzle assembly.
19. The method of claim 18, wherein the coaxial flow dividers
further comprise a plurality of radially extending support pins
positioned radially between adjacent coaxial flow dividers.
20. The method of claim 18, wherein the compressed air is oriented
in primarily an axial direction upon exiting the coaxial flow
dividers and entering the premix tube of the fuel nozzle assembly.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
TECHNICAL FIELD
[0002] The present invention relates generally to an apparatus and
method for directing a flow of compressed air into a fuel nozzle
assembly. More specifically, a fuel nozzle assembly is provided
with a flow directing device at an air inlet region.
BACKGROUND OF THE INVENTION
[0003] In an effort to reduce the amount of pollution emissions
from gas-powered turbine engines, governmental agencies have
enacted numerous regulations requiring reductions in the amount of
oxides of nitrogen (NOx) and carbon monoxide (CO) produced. Lower
combustion emissions can often be attributed to a more efficient
combustion process, with specific regard to fuel injector location,
airflow rates, and mixing effectiveness.
[0004] Early combustion systems utilized diffusion type nozzles,
where fuel is mixed with air external to the fuel nozzle by
diffusion, proximate the flame zone. Diffusion type nozzles
historically produce relatively high emissions due to the fact that
the fuel and air burn essentially upon interaction, without mixing,
and stoichiometrically at high temperature to maintain adequate
combustor stability and low combustion dynamics.
[0005] An enhancement in combustion technology is the concept of
premixing fuel and air prior to combustion to form a homogeneous
mixture that burns at a lower temperature than a diffusion type
flame and thereby produces lower NOx emissions. Premixing can occur
either internal to the fuel nozzle assembly or external thereto, as
long as it is upstream of the combustion zone. An example of a
premixing combustor has a plurality of fuel nozzle assemblies, each
injecting fuel into a premix chamber where fuel mixes with
compressed air from a plenum before entering a combustion chamber.
Premixing fuel and air together before combustion allows for the
fuel and air to form a more homogeneous mixture, which, when
ignited will burn more completely, resulting in lower emissions.
However, the thoroughness and completeness of the mixing and
resulting burning of the fuel-air mixture depends on the
effectiveness of the mixing.
SUMMARY
[0006] The present invention discloses an apparatus and method for
improving the air injection process for mixing with fuel injected
through a fuel nozzle assembly. More specifically, in an embodiment
of the present invention, a fuel nozzle assembly is disclosed
comprising a plurality of concentric tubes forming first, second
and third passageways. The fuel nozzle assembly also comprises a
premix tube coaxial to and radially outward of the third tube, the
premix tube having a plurality of swirler vanes contained therein
for inducing a swirl into a passing flow of air and fuel. The fuel
nozzle assembly further comprises one or more coaxial flow dividers
spaced axially and radially and extending around an inlet end of
the premix tube towards a base of the fuel nozzle. The one or more
coaxial flow dividers split and direct a passing airflow into the
premix tube of the fuel nozzle assembly.
[0007] In an alternate embodiment of the present invention, an air
conditioning device for use in a fuel nozzle assembly is disclosed.
The air conditioning device comprises a premix tube and one or more
coaxial flow dividers positioned at an air inlet region of the fuel
nozzle assembly. The one or more coaxial flow dividers each have a
cylindrical portion and an air inlet portion that is turned
radially outward from a center axis of the fuel nozzle assembly so
as to form a plurality of annular air inlets, with the air inlets
having unequal radial air flow distributions.
[0008] In yet another embodiment of the present invention, a method
of conditioning an incoming air stream entering a fuel nozzle
assembly is disclosed. The method generally comprises providing a
fuel nozzle assembly having one or more coaxial flow dividers
positioned at the air inlet region of the fuel nozzle assembly. A
flow of compressed air is provided to the air inlet region and the
coaxial flow dividers direct the compressed air through the areas
formed between the coaxial flow dividers, where the areas formed
generate a non-uniform radial distribution of compressed air to the
air inlet region of the fuel nozzle assembly.
[0009] Additional advantages and features of the present invention
will be set forth in part in a description which follows, and in
part will become apparent to those skilled in the art upon
examination of the following, or may be learned from practice of
the invention. The instant invention will now be described with
particular reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] The present invention is described in detail below with
reference to the attached drawing figures, wherein:
[0011] FIG. 1 is a cross section of a fuel nozzle assembly in
accordance with the prior art.
[0012] FIG. 2 is a perspective view of a fuel nozzle assembly in
accordance with an embodiment of the present invention.
[0013] FIG. 3 is a cross section of the fuel nozzle assembly of
FIG. 2 in accordance with an embodiment of the present
invention.
[0014] FIG. 4 is a perspective view of a portion of the fuel nozzle
assembly in accordance with an embodiment of the present
invention.
[0015] FIG. 5 is a cross section view through the portion of the
fuel nozzle assembly of FIG. 4 in accordance with an embodiment of
the present invention.
[0016] FIG. 6 is an exploded view of the fuel nozzle assembly of
FIG. 2 in accordance with an embodiment of the present
invention.
[0017] FIG. 7A is a perspective view of a fuel nozzle assembly in
accordance with an alternate embodiment of the present
invention.
[0018] FIG. 7B is a cross section of the fuel nozzle assembly of
FIG. 7A in accordance with an alternate embodiment of the present
invention.
[0019] FIG. 8A is a perspective view of a fuel nozzle assembly in
accordance with yet another alternate embodiment of the present
invention.
[0020] FIG. 8B is a cross section of the fuel nozzle assembly of
FIG. 8A in accordance with yet another alternate embodiment of the
present invention.
[0021] FIG. 9A is a perspective view of a fuel nozzle assembly in
accordance with a further alternate embodiment of the present
invention.
[0022] FIG. 9B is a cross section of the fuel nozzle assembly of
FIG. 9A in accordance with a further alternate embodiment of the
present invention.
[0023] FIG. 10 is a diagram depicting a method of conditioning an
incoming airflow entering a fuel nozzle assembly in accordance with
an embodiment of the present invention.
[0024] FIG. 11 is a cross section of an alternate embodiment of the
fuel nozzle assembly of FIG. 2.
DETAILED DESCRIPTION
[0025] The present invention discloses a fuel nozzle assembly for
use in a gas turbine combustion system for use in a premix
combustion system to help reduce emissions from the combustion
system as shown in detail in FIGS. 2-10. The fuel nozzle assembly
as shown in FIGS. 2-9B is not to scale but merely intended to
represent the present invention. As one skilled in the art
understands, a gas turbine engine typically incorporates a
plurality of combustors. Generally, for the purpose of discussion,
the gas turbine engine may include low emission combustors such as
those disclosed herein and may be arranged in a can-annular
configuration about the gas turbine engine. One type of gas turbine
engine (e.g., heavy duty gas turbine engines) may be typically
provided with, but not limited to, six to eighteen individual
combustors, each of them fitted with the components outlined above.
Accordingly, based on the type of gas turbine engine, there may be
several different fuel circuits utilized for operating the gas
turbine engine. Each combustor includes one or more fuel nozzle
assemblies for supplying the fuel for generating the hot combustion
gases.
[0026] Emissions from a combustion system are based in part on how
completely the fuel and air mix and then burn, or combust. In order
to minimize the emissions and maximize the burning of the fuel that
is being injected, it is preferable that the fuel and air are
thoroughly mixed. To ensure thorough mixing, one factor considered
is the condition of the air mixing with the fuel.
[0027] Referring initially to FIG. 1, a fuel nozzle assembly 100 of
the prior art is shown in cross section. The fuel nozzle assembly
100 is similar to that of U.S. Pat. No. 6,438,961 assigned to the
General Electric Co. The fuel nozzle assembly provides a swirler
102 for injecting fuel into a passing air flow and an inlet flow
conditioner 104 for directing the flow radially inward through a
series of holes 106. The inlet flow conditioner 104 comprises a
cylindrical wall portion and an end wall perpendicular to the
cylindrical portion. The flow, is turned axially through a
plurality of turning vanes 108. However improved conditioning of
the incoming airflow to the fuel nozzle assembly can be achieved
through a simpler geometry.
[0028] An improved way of treating the incoming air flow to a fuel
nozzle assembly is discussed below with respect to FIGS. 2-10. The
fuel nozzle assembly 200 is in accordance with an embodiment of the
invention. More specifically, referring to FIGS. 2 and 3, the fuel
nozzle assembly 200 comprises a first tube 202 extending along a
center axis A-A and having a first passageway 204 formed within the
first tube 202. The first passageway 204, depending upon the
operation of a combustion system contains a liquid, gas, air, or
mixture thereof for purging the first passageway 204, where the
contents of the first passageway 204 are directed towards a tip
region 205 of the fuel nozzle assembly 200. Depending on the
configuration of the fuel nozzle assembly, the first tube 202 can
also include a blank or dual fuel cartridge extending within the
first tube 202 and along the center axis A-A that may be purged
with air. The cartridge, although not depicted, is sized to then
also aid in establishing the correct size of the corresponding
first passageway 204 for the gas or purge air.
[0029] Coaxial to and radially outward of the first tube 202 is a
second tube 206. A second passageway 208 is formed between the
first tube 202 and the second tube 206. The second passageway 208
extends coaxial to the first passageway 204 to within approximately
swirler vanes 220, as discussed below. The second passageway 208
contains fuel, air, or a mixture thereof directed to the swirler
vanes 220, as discussed below.
[0030] The fuel nozzle assembly 200 also comprises a third tube 210
which is coaxial to and radially outward of the second tube 206,
thereby forming a third passageway between a portion of the second
tube 206 and the third tube 210 as well as between a portion of the
first tube 202 and the third tube 210. That is, the third
passageway is split into two portions, 212A and 212B, which do not
communicate with each other. A first portion 212A extends from a
base 224 of the fuel nozzle assembly 200 to proximate the swirler
vanes 220. A second portion 212B extends from proximate the swirler
vanes 220 to the tip region 205 of the fuel nozzle assembly 200.
Through the first portion 212A flows a gas, where the gas initially
travels axially through the first portion 212A and then radially
outward through the swirler vanes 220, where it is injected into a
surrounding air stream. The second portion 212B flows air, gas, or
a mixture thereof, which is drawn into the second portion 212B at
the region adjacent to the swirler vanes 220, through air inlet
holes 221. The air, fuel, or mixture thereof then passes axially
through the second portion 212B to the tip region 205 of the fuel
nozzle assembly 200, where it serves to mix with the liquid, air,
gas, or a mixture thereof from the first passageway 204 proximate
the tip region 205.
[0031] In an alternate embodiment of the present invention, a
fuel-air mixture can be provided to second portion 212B for
injection through the tip of the fuel nozzle assembly. This is
shown in FIGS. 3 and 6. The second portion 212B can flow a gaseous
fuel, air, or mixture thereof. In order to supply second portion
212B with a flow of fuel, it is necessary for the second portion
212B to be in fluid communication with the fuel-air mixture
resulting from the plurality of swirler vanes 220. A fuel mixture
can be supplied to the second portion 212B through one or more
holes 213 located in the third tube 210. The one or more holes 213
can be oriented at an angle or perpendicular to the surface of the
third tube 210.
[0032] Referring to FIG. 11, yet another alternate embodiment of
the fuel nozzle assembly is depicted. As discussed above, second
portion 212B can pass a fuel-air mixture to the tip region 205.
However, this fuel can be provided to second portion 212B through
an alternate means, such as through holes 211 in the first tube
202. As such, fuel from first passageway 204 passes through holes
211 and into second portion 212B.
[0033] Referring back to FIG. 3, the fuel nozzle assembly 200 also
comprises a premix tube 214 positioned coaxial to and radially
outward of the third tube 210. The premix tube 214 has an inlet end
216 and an opposing outlet end 218. A plurality of swirler vanes
220 extend radially between the third tube 210 and premix tube 214.
As it can be seen from FIGS. 3-5, the inlet end 216 of the premix
tube 214 has a flared edge directed generally radially outward from
the center axis A-A. The plurality of swirler vanes 220 are
positioned about the center core of coaxial tubes of the fuel
nozzle assembly 200 and provide a way of injecting and mixing fuel
and air together to induce a swirl, as discussed further below.
[0034] The fuel nozzle assembly 200 also comprises one or more
coaxial flow dividers 222 for dividing an incoming airflow stream,
as shown in FIG. 5. The exact quantity of coaxial flow dividers can
vary, but for the embodiment of the present invention depicted in
FIGS. 2-9, there are two coaxial flow dividers, a first flow
divider 222A and a second flow divider 222B that work together with
the inlet end 216 of the premix tube 214 and the base region 224 to
split and direct the flow of compressed air into the fuel nozzle
assembly 200. More specific features of the coaxial flow dividers
222 can be seen in FIGS. 4 and 5. For example, each coaxial flow
divider 222 (and therefore 222A and 222B) include a cylindrical
portion 226 having an axial length and an inlet region portion 228,
where the inlet region portion 228 is turned radially outward from
the center axis A-A.
[0035] As discussed above, the one or more coaxial flow dividers
direct a supply of compressed air into the fuel nozzle assembly
200. The coaxial flow dividers 222 are spaced apart in a radial and
axial positioning to create a series of annular openings through
which the air flows. The effective area of these openings, which
regulates the amount of air that can pass therethrough, is
controlled by this axial and radial positioning of the coaxial flow
dividers 222. More specifically, for the embodiment of the fuel
nozzle assembly depicted in FIG. 3, there are three air inlet areas
generated by the plurality of coaxial flow dividers 222 and the
premix tube 214. A first air inlet area 230 is formed between third
tube 210/base 224 of the fuel nozzle assembly 200 and the first
flow divider 222A. A second air inlet area 232 is formed between
the first flow divider 222A and the second flow divider 222B.
Finally, for the embodiment depicted in FIG. 3, a third air inlet
area 234 is formed between the second flow divider 222B and the
inlet end 216 of the premix tube 214.
[0036] The series of air inlets 230, 232, and 234 form a series of
co-annular flows of compressed air directed axially towards the
plurality of swirler vanes 220. However, the inlet areas 230, 232,
and 234 to do not provide a uniform radial air flow distribution
due to the size of the respective openings. More specifically, the
radial air flow distribution of the first air inlet 230 has a
different radial air flow distribution than that of the second air
inlet 232. However, for one embodiment of the present invention,
the radial air flow distribution of the first air inlet 230 is
similar to that of the radial air flow distribution for the third
air inlet 234. Accordingly, for an embodiment of the present
invention, the radial air flow distributions of the first air inlet
230 and third air inlet 234 are each greater than the second air
inlet area 232. The one or more coaxial flow dividers 222 generate
different volumes of air passing therethrough such that a greater
amount of air is biased to an inner diameter and outer diameter
regions of the premix tube 214. For example, for one embodiment of
the present invention, the second air inlet area 232 has a radial
air flow distribution that is approximately 85% of that of either
the first air inlet area 230 or third air inlet area 234. However,
the air inlet areas may vary based on downstream fuel input.
[0037] Another feature of the present invention is the ability to
expand the air flow after it has passed through the one or more
coaxial flow dividers 222 and corresponding air inlet areas (230,
232, and 234) and passes through premix tube 214. In an embodiment
of the invention depicted in FIGS. 3 and 5, the premix tube 214
tapers radially outward at a region 215 to increase the volume
within the premix tube 214. As such, the geometry of the premix
tube 214 provides a way of expanding or diffusing the compressed
air immediately downstream of the second flow divider 222B. The
exact geometry of the premix tube and coaxial flow dividers may
vary to avoid flow separation.
[0038] The overall shape of the coaxial flow dividers 222 and
premix tube 214 together provide a smooth way of transitioning the
airflow into a uniform axial flow direction. The shape and
orientation of the one or more coaxial flow dividers 222 provides a
way to change the flow direction of the compressed air while
minimizing pressure loss. As one skilled in the art understands,
flow passing through a screen, such as that of the prior art shown
in FIG. 1 undergoes a pressure loss. The present invention produces
a slight squeeze to the compressed air and then permits expansion
of the compressed air to the desired geometry of the premix tube
214 and plurality of swirler vanes 220.
[0039] Referring to FIGS. 4 and 5, another feature of the present
invention is a plurality of pins 240 positioned about and between
the one or more coaxial flow dividers 222. The plurality of pins
240 aid in holding the one or more coaxial flow dividers 222
together while also maintaining the air inlet areas 230, 232, and
234 previously discussed. The plurality of pins 240 are secured to
the one or more coaxial flow dividers 222 by a means such as
welding or brazing. As such, the pins are generally fabricated from
a material similar in thermal and mechanical properties to that of
the one or more coaxial flow dividers 222.
[0040] Alternate embodiments of the present invention are depicted
in FIGS. 7A-9D. Generally speaking, these alternate embodiments
provide additional ways of securing the one or more coaxial flow
dividers to the fuel nozzle assembly while also maintaining the air
inlet areas previously discussed. Referring initially to FIGS. 7A
and 7B, a fuel nozzle assembly 700 is disclosed, which is generally
similar in structure and operation to the fuel nozzle assembly of
FIGS. 2-6. The fuel nozzle assembly 700 includes a premix tube 714,
one or more coaxial flow dividers 722 and a plurality of pins 740.
To enhance the structural rigidity of the fuel nozzle assembly 700
and the one or more coaxial flow dividers 722, a plurality of
struts 742 are positioned extending between and secured to the one
or more coaxial flow dividers 722 at the radially outermost point
and the inlet end 716 of the premix tube 714. The plurality of
struts 742 are secured to the one or more coaxial flow dividers 722
and premix tube 714 by a means such as welding or brazing. The
exact size, quantity and spacing of the plurality of struts 742
will vary depending on a number of factors such as the size and
number of coaxial flow dividers 722 and size of the air inlet
areas.
[0041] An alternate embodiment of the fuel nozzle assembly having
improved structural integrity at the air inlet region is shown in
FIGS. 8A and 8B. A fuel nozzle assembly 800 is depicted in FIGS. 8A
and 8B, and is generally similar in structure and operation to the
fuel nozzle assembly 200 of FIGS. 2-6. The fuel nozzle assembly 800
includes a premix tube 814, one or more coaxial flow dividers 822
and a plurality of pins 840. To enhance the structural rigidity of
the fuel nozzle assembly 800 and the one or more coaxial flow
dividers 822, a plurality of struts 842 extend across the edge or
inlet region of each of the coaxial flow dividers 822, where the
plurality of struts 842 are secured to the one or more coaxial flow
dividers 822 and the inlet end 816 of the premix tube 814. The
plurality of struts 842 are secured to the coaxial flow dividers
822 and premix tube 814 preferably by a weld or braze. The exact
size, quantity and spacing of the plurality of struts 842 will vary
depending on a number of factors such as the size and number of
coaxial flow dividers 822 and size of the air inlet areas.
[0042] A further alternate embodiment of the present invention is
depicted in FIGS. 9A and 9B. This embodiment also provides a way of
improving the structural integrity at the air inlet of the fuel
nozzle assembly. A fuel nozzle assembly 900 is depicted in FIGS. 9A
and 9B, and is generally similar in structure and operation to the
fuel nozzle assembly 200 of FIGS. 2-6. The fuel nozzle assembly 900
includes a premix tube 914, one or more coaxial flow dividers 922
and a plurality of pins 940. To enhance the structural rigidity of
the fuel nozzle assembly 900 and the one or more coaxial flow
dividers 922, a plurality of struts 942 extend through a portion of
the flow dividers 922 and a portion of the premix tube 914. The
plurality of struts 942 extend through the coaxial flow dividers
922 by passing through one or more holes in the flow dividers 922.
The coaxial flow dividers 922 are then secured to the one or more
coaxial flow dividers 922 and the inlet end 916 of the premix tube
914 by a means such as brazing or welding. The exact size, quantity
and spacing of the plurality of struts 942 will vary depending on a
number of factors such as the size and number of coaxial flow
dividers 922 and size of the air inlet areas.
[0043] Referring now to FIG. 10, another embodiment of the present
invention is disclosed. A method 1000 of conditioning an incoming
air stream entering a fuel nozzle assembly is disclosed. In a step
1002, a fuel nozzle assembly is provided having one or more coaxial
flow dividers positioned at an air inlet region of the fuel nozzle
assembly with the coaxial flow dividers spaced axially and radially
at the air inlet region. The spacing of the coaxial flow dividers
creates a plurality of areas. In a step 1004, a flow of compressed
air is provided to the air inlet region of the fuel nozzle
assembly. Once the flow of compressed air is provided, in a step
1006, the compressed air is directed through each of the plurality
of areas formed by the coaxial flow dividers with the air flowing
in a direction that is coaxial to a center axis. The coaxial flow
dividers are spaced and oriented so as to provide a non-uniform
radial distribution of compressed air to the inlet region of the
fuel nozzle assembly. Upon exit from the coaxial flow divider
region, the compressed air is oriented in primarily an axial
direction.
[0044] While the invention has been described in what is known as
presently the preferred embodiment, it is to be understood that the
invention is not to be limited to the disclosed embodiment but, on
the contrary, is intended to cover various modifications and
equivalent arrangements within the scope of the following claims.
The present invention has been described in relation to particular
embodiments, which are intended in all respects to be illustrative
rather than restrictive.
[0045] From the foregoing, it will be seen that this invention is
one well adapted to attain all the ends and objects set forth
above, together with other advantages which are obvious and
inherent to the system and method. It will be understood that
certain features and sub-combinations are of utility and may be
employed without reference to other features and sub-combinations.
This is contemplated by and within the scope of the claims.
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