U.S. patent application number 15/739819 was filed with the patent office on 2018-07-05 for gas turbine transition duct with late lean injection having reduced combustion residence time.
This patent application is currently assigned to Siemens Aktiengesellschaft. The applicant listed for this patent is Siemens Aktiengesellschaft. Invention is credited to Timothy A. Fox, Walter Ray Laster, Juan Enrique Portillo Bilbao, Grant L. Powers.
Application Number | 20180187563 15/739819 |
Document ID | / |
Family ID | 53785745 |
Filed Date | 2018-07-05 |
United States Patent
Application |
20180187563 |
Kind Code |
A1 |
Laster; Walter Ray ; et
al. |
July 5, 2018 |
GAS TURBINE TRANSITION DUCT WITH LATE LEAN INJECTION HAVING REDUCED
COMBUSTION RESIDENCE TIME
Abstract
An improved combustion system having a reduced combustion
residence time in a combustion turbine engine is provided. The
combustor system may include a flow-accelerating structure (16, 51)
having an inlet (26) and an outlet (28). The inlet of the
flow-accelerating structure is fluidly coupled to receive a flow of
combustion gases from a combustor outlet. At least one fuel
injector (32, 64, 66) is disposed between the inlet and the outlet
of the flow-accelerating structure. The flow-accelerating structure
causes an increasing speed to the flow of combustion gases, and, as
a result, the flow of combustion gases in the flow-accelerating
structure experiences a decreased static temperature and a reduced
combustion residence time, each of which is effective to reduce NOx
emissions at the high firing temperatures of the turbine
engine.
Inventors: |
Laster; Walter Ray; (Oviedo,
FL) ; Portillo Bilbao; Juan Enrique; (Oviedo, FL)
; Fox; Timothy A.; (Hamilton, CA) ; Powers; Grant
L.; (Orlando, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Siemens Aktiengesellschaft |
Munchen |
|
DE |
|
|
Assignee: |
Siemens Aktiengesellschaft
Munchen
DE
|
Family ID: |
53785745 |
Appl. No.: |
15/739819 |
Filed: |
July 24, 2015 |
PCT Filed: |
July 24, 2015 |
PCT NO: |
PCT/US2015/041948 |
371 Date: |
December 26, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01D 9/023 20130101;
F23R 3/346 20130101; F23R 3/425 20130101; F23R 3/46 20130101; F23R
3/06 20130101; F23R 3/286 20130101 |
International
Class: |
F01D 9/02 20060101
F01D009/02; F23R 3/06 20060101 F23R003/06; F23R 3/28 20060101
F23R003/28; F23R 3/34 20060101 F23R003/34; F23R 3/42 20060101
F23R003/42; F23R 3/46 20060101 F23R003/46 |
Claims
1-20. (canceled)
21. A combustion system comprising: a flow-accelerating structure
defining a flow-accelerating cone between an inlet and an outlet of
the flow-accelerating structure, the inlet of the flow-accelerating
structure fluidly coupled to receive a flow of combustion gases
from a combustor outlet; and at least one fuel injector disposed
between the inlet and the outlet of the flow-accelerating
structure, wherein the flow-accelerating structure causes an
increasing speed to the flow of combustion gases, and, as a result,
the flow of combustion gases in the flow-accelerating structure
experiences a decreased static temperature and a reduced combustion
residence time, wherein a circular cross-sectional profile of the
flow-accelerating cone narrows in diameter as the flow of
combustion gases travels between inlet and outlet.
22. The combustion system of claim 21, wherein the
flow-accelerating structure comprises a single-piece
flow-accelerating cone.
23. The combustion system of claim 21, wherein the
flow-accelerating cone comprises two interconnected cone
sections.
24. The combustion system of claim 23, wherein a portion of the two
interconnected cone sections comprises a non-varying
cross-sectional profile.
25. The combustion system of claim 24, wherein said at least one
fuel injector is disposed in the portion having the non-varying
cross-sectional profile.
26. The combustion system of claim 21, wherein said at least one
fuel injector is arranged to provide jet in cross-flow
injection.
27. The combustion system of claim 21, wherein said at least one
fuel injector is arranged without providing jet in cross-flow
injection.
28. The combustion system of claim 21, wherein the outlet of the
flow-accelerating structure is fluidly coupled to supply the flow
of combustion gases to a turbine section of a turbine engine.
29. The combustion system of claim 28, wherein the
flow-accelerating structure is part of a ducting arrangement
configured to supply the flow of combustion gases to the turbine
section of a turbine engine without a first stage of flow-directing
vanes in the turbine section of the turbine engine.
30. A gas turbine engine comprising: a combustion system comprising
a ducting arrangement having a plurality of flow paths, each flow
path arranged to receive a flow of combustion gases from a
combustor outlet and to supply the flow of combustion gases to a
turbine section of the gas turbine engine; each flow path
comprising a flow-accelerating structure defining a
flow-accelerating cone between an inlet and an outlet of the
flow-accelerating structure, the inlet of the flow-accelerating
structure fluidly coupled to receive the flow of combustion gases
from the combustor outlet; and at least one fuel injector disposed
between the inlet and the outlet of the flow-accelerating
structure, wherein the flow-accelerating structure causes an
increasing speed to the flow of combustion gases, and, as a result,
the flow of combustion gases in the flow-accelerating structure
experiences a decreased static temperature and a reduced combustion
residence time in the flow paths, wherein a circular
cross-sectional profile of the flow-accelerating cone narrows in
diameter as the flow of combustion gases travels between inlet and
outlet.
31. The gas turbine engine of claim 30, wherein the
flow-accelerating structure comprises a single-piece cone.
32. The gas turbine engine of claim 30, wherein the
flow-accelerating cone comprises two interconnected cone
sections.
33. The gas turbine engine of claim 32, wherein a portion of the
two interconnected cone sections comprises a non-varying
cross-sectional profile, and further wherein said at least one fuel
injector is disposed in the portion having the non-varying
cross-sectional profile.
34. The gas turbine engine of claim 30, wherein said at least one
fuel injector is arranged to provide jet in cross-flow
injection.
35. The gas turbine engine of claim 30, wherein said at least one
fuel injector is arranged without having to provide jet in
cross-flow injection.
36. The gas turbine engine of claim 30, wherein the ducting
arrangement is configured to supply the flow of combustion gases to
the turbine section of the turbine engine without a first stage of
flow-directing vanes.
Description
BACKGROUND
1. Field
[0001] Disclosed embodiments are generally related to combustion
turbine engines, such as gas turbine engines and, more
particularly, to a combustion system having a reduced combustion
residence time.
2. Description of the Related Art
[0002] In gas turbine engines, fuel is delivered from a fuel source
to a combustion section where the fuel is mixed with air and
ignited to generate hot combustion products that define working
gases. The working gases are directed to a turbine section where
they effect rotation of a turbine rotor. It is known that
production of NOx emissions from the burning fuel in the combustion
section may be reduced by providing a portion of the fuel to be
ignited downstream from a main combustion zone. This approach is
referred to in the art as a distributed combustion system (DCS).
See, for example, U.S. Pat. Nos. 8,375,726 and 8,752,386.
[0003] It is also known that certain ducting arrangements in a gas
turbine engine may be configured to appropriately align the flow of
working gases, so that, for example, such flow alignment may be
tailored to avoid the need of a first stage of flow-directing vanes
in the turbine section of the engine. See for example U.S. Pat.
Nos. 7,721,547 and 8,276,389. Each of the above-listed patents is
herein incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a fragmentary schematic representation of one
non-limiting embodiment of a ducting arrangement with fuel
injectors disposed at a location in a flow-accelerating structure,
such as a flow-accelerating cone, characterized by a relatively
lower static temperature and a reduced combustion residence time,
each of which is conducive to reduce NOx emissions at the high
firing temperatures of a combustion turbine engine.
[0005] FIG. 2 illustrate non-limiting plots of decreasing static
temperatures as a function of increasing flow speed between the
cone inlet and the cone outlet in the flow-accelerating cone shown
in FIG. 1.
[0006] FIGS. 3 and 4 illustrate further non-limiting embodiments of
ducting arrangements with fuel injectors disposed at respective
flow-accelerating cones.
[0007] FIG. 5 is a schematic of a Ili& injector, which in one
non-limiting embodiment may be arranged to provide jet in
cross-flow injection,
[0008] FIG. 6 is a schematic of a fuel injector, which in another
non-limiting embodiment may be arranged without providing jet in
cross-flow injection
DETAILED DESCRIPTION
[0009] The inventors of the present invention have recognized
synergies that result from an innovative integration of what up to
the present invention have been perceived as seemingly independent
combustor design approaches, such as may involve a distributed
combustion system (DCS) approach, and an advanced ducting approach
in the combustor system of a combustion turbine engine, such as a
gas turbine engine. With the integration of these design
approaches, in certain non-limiting embodiments, it is now feasible
to achieve a decreased static temperature and a reduced combustion
residence time, each of which is conducive to reduce NOx emissions
to be within acceptable levels at turbine inlet temperatures of
approximately 1700.degree. C. (3200.degree. F.) and above.
[0010] In the following detailed description, various specific
details are set forth in order to provide a thorough understanding
of such embodiments. However, those skilled in the art will
understand that embodiments of the present invention may be
practiced without these specific details, that the present
invention is not limited to the depicted embodiments, and that the
present invention may be practiced in a variety of alternative
embodiments. In other instances, methods, procedures, and
components, which would be well-understood by one skilled in the
art have not been described in detail to avoid unnecessary and
burdensome explanation.
[0011] Furthermore, various operations may be described as multiple
discrete steps performed in a manner that is helpful for
understanding embodiments of the present invention. However, the
order of description should not be construed as to imply that these
operations need be performed in the order they are presented, nor
that they are even order dependent, unless otherwise indicated.
Moreover, repeated usage of the phrase "in one embodiment" does not
necessarily refer to the same embodiment, although it may. It is
noted that disclosed embodiments need not be construed as mutually
exclusive embodiments, since aspects of such disclosed embodiments
may be appropriately combined by one skilled in the art depending
on the needs of a given application.
[0012] The terms "comprising", "including", "having", and the like,
as used in the present application, are intended to be synonymous
unless otherwise indicated. Lastly, as used herein, the phrases
"configured to" or "arranged to" embrace the concept that the
feature preceding the phrases "configured to" or "arranged to" is
intentionally and specifically designed or made to act or function
in a specific way and should not be construed to mean that the
feature just has a capability or suitability to act or function in
the specified way, unless so indicated.
[0013] FIG. 1 is a fragmentary schematic representation of an
advanced ducting arrangement 10 in one non-limiting embodiment of a
combustor system of a combustion turbine engine, such as a gas
turbine engine. In advanced ducting arrangement 10, a plurality of
flow paths 12 blends smoothly into a single, annular chamber 14. In
one non-limiting embodiment, each flow path 12 may be configured to
deliver combustion gases formed in a respective combustor to a
turbine section of the engine without a need of a first stage of
flow-directing vanes in the turbine section of the engine.
[0014] In one non-limiting embodiment, each flow path 12 includes a
cone 16 and an integrated exit piece (IEP) 18. In one non-limiting
embodiment, each cone 16 has a cone inlet 26 having a circular
cross section and configured to receive the combustion gases from a
combustor outlet (not shown). The cross-sectional profile of cone
16 narrows toward a cone outlet 28 that is associated with an IEP
inlet 30 in fluid communication with each other.
[0015] Based on the narrowing cross-sectional profile of cone 16,
as the flow travels from cone inlet 26 to cone outlet 28, the flow
of combustion gases is accelerated to a relatively high subsonic
Mach (M) number, such as without limitation may comprise a range
from approximately 0.3 M to approximately a 0.8 M, and thus cone 16
may be generally conceptualized as a non-limiting embodiment of a
flow-accelerating structure. Accordingly, the combustion gases may
flow through cone 16 with an increasing flow speed, and as a
result, this flow of combustion gases can experience a decreasing
static temperature in cone 16.
[0016] For example, see FIG. 2 that illustrates a non-limiting plot
40 of decreasing static temperature as a function of increasing
flow speed between the cone inlet and the cone outlet in cone 16,
as illustrated in FIG. 1. By way of comparison, FIG. 2 further
illustrates a plot 42 of total temperature, which is essentially
independent of the increasing flow speed between the cone inlet and
the cone outlet.
[0017] The inventors of the present invention have cleverly
recognized that by injecting fuel and air at locations of the cone
having a relatively lower static temperature, such as a location
between cone inlet 26 and cone outlet 28, it is feasible to
effectively bring the reaction temperature below the NOx formation
threshold even though, in certain non-limiting embodiments, the
firing temperature may be approximately 1700.degree. C. and higher.
That is, the injector location is in a location where the static
temperature is lower compared to the static temperature at cone
inlet 26. For the sake of simplicity of illustration, FIG. 1
illustrates a single injector 32, as may comprise an assembly of an
air scoop and a fuel nozzle, in connection with each of the cones
illustrated in FIG. 1; it will be appreciated, however, that
multiple injectors may be circumferentially distributed in each
cone 16.
[0018] FIG. 3 illustrates another non-limiting embodiment of a
ducting arrangement 50 where a flow-accelerating cone 51 may be
made up of two or more interconnected cone sections, in lieu of a
single-piece flow-accelerating cone, as described above. In one
non-limiting embodiment, a first cone section 52 may be arranged to
receive the combustion gases from a combustor outlet 54, and a
second. cone section 56, affixed at one end to first cone section
52, may be arranged to supply the combustion gases to a
corresponding IEP inlet 58. In one non-limiting embodiment, cone
sections 52, 54 may each include a respective flattened portion 60
defining a non-varying cross sectional profile where the injectors
32 may be located.
[0019] As illustrated in FIG. 4, in one non-limiting embodiment, a
respective manifold 34 (e.g., a ring manifold) is fluidly coupled
to the fuel injectors 32. In one non-limiting embodiment, manifold
34 may be affixed (e.g., bolted) between respective interconnecting
flanges 33, 35. It will be appreciated that aspects of the present
invention are not limited to any specific configuration regarding
the mechanical design of the flow-accelerating cone; or regarding
mechanical arrangements for affixing the fuel injectors to the
flow-accelerating cone since such mechanical design and/or
arrangements can be readily tailored based on the needs of a given
application.
[0020] Returning to FIG. 2, one can appreciate a further
non-limiting plot 44 of static temperature as a function of flow
speed between the cone inlet and the cone outlet in the context of
flow-accelerating cone 51, as shown in FIG. 3. A portion 46 of plot
44 corresponds to flattened portion 60 of cone 51, where, although
the flow speed may be constant over flattened portion 60, such flow
speed would be lower compared to the static temperature at cone
inlet 26.
[0021] It will be appreciated that in one non-limiting embodiment
injectors 64 may be disposed to provide jet in cross-flow
injection, as schematically illustrated in FIG. 5, Alternatively,
injectors 66 may be positioned normal to a wall 62 of the
flow-accelerating cone, as schematically illustrated in FIG. 6,
where arrow 68 schematically represents flow direction. It will be
appreciated that one can use injector angles relative to the flow
direction other than those illustrated in FIGS. 5 and 6, and thus
aspects of the present invention are not limited to injector angles
normal to the flow or normal to the wall. That is, aspects of the
present invention are not limited to any particular modality of
injectors or to any particular injector angle relative to the flow
direction.
[0022] In operation, disclosed embodiments are expected to be
conducive to a combustion system capable of realizing approximately
a 65% combined cycle efficiency or greater in a gas turbine engine.
Disclosed embodiments are also expected to realize a combustion
system capable of maintaining stable operation at turbine inlet
temperatures of approximately 1700.degree. C. and higher while
maintaining a relatively low level of NOx emissions, and acceptable
temperatures in components of the engine without an increase in
cooling air consumption.
[0023] While embodiments of the present disclosure have been
disclosed in exemplary forms, it will he apparent to those skilled
in the art that many modifications, additions, and deletions can be
made therein without departing from the spirit and scope of the
invention and its equivalents, as set forth in the following
claims.
* * * * *