U.S. patent application number 11/841053 was filed with the patent office on 2009-02-26 for leakage reducing venturi for dry low nitric oxides (nox) combustors.
This patent application is currently assigned to General Electric Company. Invention is credited to Neal William Grooms, Jeffrey Scott Lebegue, Derrick Walter Simons.
Application Number | 20090053054 11/841053 |
Document ID | / |
Family ID | 40280466 |
Filed Date | 2009-02-26 |
United States Patent
Application |
20090053054 |
Kind Code |
A1 |
Grooms; Neal William ; et
al. |
February 26, 2009 |
LEAKAGE REDUCING VENTURI FOR DRY LOW NITRIC OXIDES (NOx)
COMBUSTORS
Abstract
Disclosed is a leakage reducing venturi for a dry low nitric
oxides (NOx) emissions combustor, the venturi including a
substantially annular outer liner, a substantially annular inner
liner, a venturi channel defined by the annular inner liner and the
annular outer liner, the venturi channel including a forward end
and an aft end, a forward weld disposed in proximity to the forward
end of the venturi channel, the forward weld being configured to
connect the annular outer liner with the annular inner liner, and
an aft weld disposed in proximity to the aft end of the venturi
channel, the aft weld being configured to connect the annular outer
liner with the annular inner liner.
Inventors: |
Grooms; Neal William;
(Simpsonville, SC) ; Lebegue; Jeffrey Scott;
(Simpsonville, SC) ; Simons; Derrick Walter;
(Greer, SC) |
Correspondence
Address: |
CANTOR COLBURN, LLP
20 Church Street, 22nd Floor
Hartford
CT
06103
US
|
Assignee: |
General Electric Company
Schenectady
NY
|
Family ID: |
40280466 |
Appl. No.: |
11/841053 |
Filed: |
August 20, 2007 |
Current U.S.
Class: |
415/208.1 |
Current CPC
Class: |
F23R 3/04 20130101; F23R
3/002 20130101; F23R 3/286 20130101 |
Class at
Publication: |
415/208.1 |
International
Class: |
F01D 1/02 20060101
F01D001/02 |
Claims
1. A leakage reducing venturi for a dry low nitric oxides (NOx)
emissions combustor, the venturi comprising: a substantially
annular outer liner; a substantially annular inner liner; a venturi
channel defined by said annular inner liner and said annular outer
liner, said venturi channel including a forward end and an aft end;
a forward weld disposed in proximity to said forward end of said
venturi channel, said forward weld being configured to connect said
annular outer liner with said annular inner liner; and an aft weld
disposed in proximity to said aft end of said venturi channel, said
aft weld being configured to connect said annular outer liner with
said annular inner liner.
2. The venturi of claim 1, wherein a forward extent of said venturi
channel terminates at said forward weld, and wherein an aft extent
of said venturi channel terminates at said aft weld.
3. The venturi of claim 2, wherein said forward weld and said aft
weld are disposed at substantially opposite ends of said venturi
channel.
4. The venturi of claim 1, wherein said outer annular liner
includes a plurality of inlets configured to inlet a cooling fluid
into said venturi channel.
5. The venturi of claim 1, wherein said annular inner liner and
said annular outer liner are integrated into a parent liner of the
dry low nitric oxides (NOx) emissions combustor.
6. The venturi of claim 5, wherein said forward weld includes a
welding of said outer annular liner and said inner annular liner to
opposing ends of a y-joint that is connected to said parent
liner.
7. The venturi of claim 5, wherein said aft weld includes a welding
of said outer annular liner and said inner annular liner to
opposing ends of a y-joint that is connected to said parent liner.
Description
FIELD OF THE INVENTION
[0001] The disclosure relates generally to a venturi for a dry low
nitric oxides (NOx) emissions combustor, and more particularly to a
leakage reducing venturi for a dry low nitric oxides (NOx)
emissions combustor.
BACKGROUND OF THE INVENTION
[0002] The riveted joints located at the venturi of current dry low
nitric oxides (NOx) emissions combustor (DLN combustors) allow a
variable air leakage into the combustion chamber. This air leakage
has been identified as a key contributor to combustion emissions,
as well as combustor-to-combustor variation. Accordingly, a leakage
reducing means for associating the venturi with the liner of DLN
combustors would be desirable.
SUMMARY
[0003] Disclosed is a leakage reducing venturi for a dry low nitric
oxides (NOx) emissions combustor, the venturi including a
substantially annular outer liner, a substantially annular inner
liner, a venturi channel defined by the annular inner liner and the
annular outer liner, the venturi channel including a forward end
and an aft end, a forward weld disposed in proximity to the forward
end of the venturi channel, the forward weld being configured to
connect the annular outer liner with the annular inner liner, and
an aft weld disposed in proximity to the aft end of the venturi
channel, the aft weld being configured to connect the annular outer
liner with the annular inner liner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The following descriptions should not be considered limiting
in any way. With reference to the accompanying drawings, like
elements are numbered alike:
[0005] FIG. 1 is a simplified representation of a cross section of
a combustor including an exemplary embodiment of a leakage reducing
venturi; and
[0006] FIG. 2 is a simplified cross section of the leakage reducing
venturi of the combustor of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
[0007] Referring of FIG. 1, a portion of a dry low nitric oxides
(NOx) emissions combustor 10 ("dry low NOx" meaning less than 9 ppm
NOx) for a gas turbine is illustrated. The combustor 10 includes
generally a combustion chamber 12, fuel nozzles 14 (some gas
turbines, as illustrated here, employ multiple nozzles in each
combustor), an annual premixing chamber 16, and a leakage reducing
venturi 18 (the venturi being described in greater detail below). A
turbine compressor (which is not shown) provides airflow into the
premixing chamber 16. Fuel 20 is provided to the chamber 16 via the
fuel nozzles 14, which are controlled a fuel flow controller 26.
Air is introduced to the chamber 16 via one or more entry ports
28.
[0008] The combustion chamber 12 is generally cylindrical in shape
about a combustor centerline 30, and is enclosed by a wall 32 and a
parent liner or wall 34. The fuel-air mix that enters the
combustion chamber 12 from the premixing chamber 16 travels in a
downstream direction, as indicated by arrows 36. Upon leaving the
premixing chamber 16, the fuel-air mix is constricted by
convergent/divergent walls 38 and 40 of the venturi 18. The flow
re-circulation introduced by the venturi 18 acts as a bluff body
flame holder. This causes the fuel-air mix to accelerate into the
combustion chamber 12, where it will combust and create enormous
amounts of heat flux on the venturi 18.
[0009] As shown in FIGS. 1 and 2, the leakage reducing venturi 18
includes a substantially annular outer liner 42, a substantially
annular inner liner 44, which are integrated into the parent liner
34 of the combustor 10. The outer liner 42 and inner liner 44
define a venturi channel 46, which includes a forward end 48 and an
aft end 50. The venturi channel 46 is designed to ingest cooling
air (compressed air) through inlets 51 that are disposed in the
outer liner 44, and in fluid communication with the venturi channel
46. This cooling/compressed air is provided by the turbine
compressor (which is not illustrated), and creates a cooling effect
on the venturi 18. It should be appreciated that, for purposes of
this disclosure, the venturi 18 is defined to include the extents
of the venturi channel 46 (i.e. the forward end 48 of the channel
46 to aft end 50 of the channel 46) as illustrated in FIGS. 1 and
2.
[0010] Referring to FIG. 2 in particular, the venturi 18 also
includes a forward weld 52 and an aft weld 54. The forward weld 52
is disposed at the forward end 48 of the venturi channel 46, such
that a forward extent of the channel 46 terminates at the forward
weld 52. Conversely, the aft weld 54 is disposed at the aft end 50
of the venturi channel 46, such that and aft extent the channel 46
terminates at the forward weld 52. Thus, in the exemplary
embodiment of FIGS. 1 and 2, the forward weld 52 and aft weld 54
are disposed at opposite ends of the venturi channel 46. In
addition, both the forward weld 52 and aft weld 54 connect the
annular outer liner 42 with the annular inner liner 44. In the
exemplary embodiment of FIGS. 1 and 2, the forward weld 52 and aft
weld 54 provide these connections via a welding of the inner
annular liner 42 and outer annular liner 44 to a forward y-joint 60
and aft y-joint 62 respectively. The y-joints 60 and 62 allow for a
continuous leak free path in the channel 46, which minimizes air
leakage through venturi joints, provides a cavity for impingement
cooling, and allows the venturi 18 to be constructed with
acceptable stresses. As is shown in the Figures, these y-joints 60
and 62 include a generally "y" like shape, which includes three
prongs 70, 72, and 74. Prongs 70 and 72 connect the joints 60 and
62 to the two walls of the channel 46 (via welds 52 and 54), while
prong 74 connects each joint 60 and 62 to the parent liner 34.
Associating the venturi 18 with the parent liner 34 of the
combustor 10 via these forward and aft welds 52 and 54 (and
y-joints 60 and 62) renders any riveted venturi joints unnecessary,
and minimizes air leakage variation from combustor to combustor.
This welding thus reduces emissions causing leakage into the
combustion chamber 12.
[0011] It will be noted that while the invention has been described
with reference to an exemplary embodiment, it should be understood
that various changes may be made and equivalents may be substituted
for elements thereof without departing from the scope of the
invention. In addition, many modifications may be made to adapt a
particular situation or substance to the teachings of the invention
without departing from the scope thereof. Therefore, it is
important that the invention not be limited to the particular
embodiment disclosed as the best mode contemplated for carrying out
this invention, but that the invention will include all embodiments
falling within the scope of the apportioned claims. Moreover, it
will be further noted that unless specifically stated any use of
the terms first, second, etc. do not denote any order or
importance, but rather the terms first, second, etc. are used to
distinguish one element from another.
* * * * *