U.S. patent application number 13/209698 was filed with the patent office on 2013-02-21 for ignition system for a combustor.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. The applicant listed for this patent is Albert B. Costa, Abdul Khaliq. Invention is credited to Albert B. Costa, Abdul Khaliq.
Application Number | 20130045452 13/209698 |
Document ID | / |
Family ID | 46826239 |
Filed Date | 2013-02-21 |
United States Patent
Application |
20130045452 |
Kind Code |
A1 |
Costa; Albert B. ; et
al. |
February 21, 2013 |
IGNITION SYSTEM FOR A COMBUSTOR
Abstract
A combustor ignition system includes an igniter assembly adapted
for installation at least partially inside a combustor. A first
ignition lead is electrically connected to the igniter assembly and
includes a terminal end remote from the igniter assembly. A second
ignition lead is electrically connected to the first ignition lead.
The combustor ignition system further includes means for releasably
connecting the first and second ignition leads.
Inventors: |
Costa; Albert B.;
(Simpsonville, SC) ; Khaliq; Abdul; (Manama,
BH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Costa; Albert B.
Khaliq; Abdul |
Simpsonville
Manama |
SC |
US
BH |
|
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
46826239 |
Appl. No.: |
13/209698 |
Filed: |
August 15, 2011 |
Current U.S.
Class: |
431/254 |
Current CPC
Class: |
F02C 7/264 20130101;
H01T 13/04 20130101; F02C 7/266 20130101; F23Q 3/006 20130101 |
Class at
Publication: |
431/254 |
International
Class: |
F23Q 3/00 20060101
F23Q003/00 |
Claims
1. A combustor ignition system, comprising: a. an igniter assembly
adapted for installation at least partially inside a combustor; b.
a first ignition lead electrically connected to said igniter
assembly, wherein said first ignition lead comprises a terminal end
remote from said igniter assembly; c. a second ignition lead
electrically connected to said first ignition lead; and d. means
for releasably connecting said first and second ignition leads.
2. The combustor ignition system as in claim 1, further comprising
an exciter electrically connected to said second ignition lead.
3. The combustor ignition system as in claim 1, wherein said means
for releasably connecting said first and second ignition leads
comprises a ferrule surrounding said terminal end.
4. The combustor ignition system as in claim 3, wherein at least a
portion of said second ignition lead surrounds said ferrule.
5. The combustor ignition system as in claim 3, further comprising
a threaded engagement between said ferrule and said second ignition
lead.
6. The combustor ignition system as in claim 3, further comprising
an insulator between said ferrule and said terminal end.
7. The combustor ignition system as in claim 1, further comprising
means for biasing at least a portion of said second ignition lead
toward at least a portion of said first ignition lead.
8. A combustor ignition system, comprising: a. an igniter assembly
adapted for installation at least partially inside a combustor; b.
a first ignition lead electrically connected to said igniter
assembly, wherein said first ignition lead comprises a terminal end
remote from said igniter assembly; c. a ferrule surrounding said
terminal end; and d. a second ignition lead releasably connected to
said ferrule.
9. The combustor ignition system as in claim 8, further comprising
an exciter electrically connected to said second ignition lead.
10. The combustor ignition system as in claim 8, wherein at least a
portion of said second ignition lead fits inside said ferrule.
11. The combustor ignition system as in claim 8, wherein at least a
portion of said second ignition lead surrounds said ferrule.
12. The combustor ignition system as in claim 8, further comprising
a threaded engagement between said ferrule and said second ignition
lead.
13. The combustor ignition system as in claim 8, further comprising
an insulator between said ferrule and said terminal end.
14. The combustor ignition system as in claim 8, further comprising
means for biasing at least a portion of said second ignition lead
toward at least a portion of said first ignition lead.
15. An ignition system, comprising: a. a combustor; b. an igniter
assembly adapted for installation at least partially inside said
combustor; c. a first ignition lead electrically connected to said
igniter assembly, wherein said first ignition lead comprises a
terminal end remote from said igniter assembly; d. a ferrule
surrounding said terminal end; and e. a second ignition lead
releasably connected to said first ignition lead.
16. The ignition system as in claim 15, wherein at least a portion
of said second ignition lead fits inside said ferrule.
17. The combustor ignition system as in claim 15, wherein at least
a portion of said second ignition lead surrounds said ferrule.
18. The combustor ignition system as in claim 15, further
comprising a threaded engagement between said ferrule and said
second ignition lead.
19. The combustor ignition system as in claim 15, further
comprising an insulator between said ferrule and said terminal
end.
20. The combustor ignition system as in claim 15, further
comprising means for biasing at least a portion of said second
ignition lead toward at least a portion of said first ignition
lead.
Description
FIELD OF THE INVENTION
[0001] The present invention generally involves an ignition system
for a combustor. In particular embodiments, the system includes one
or more ignition leads that facilitate maintenance and repairs to
the combustor and/or an associated gas turbine.
BACKGROUND OF THE INVENTION
[0002] Commercial gas turbines are known in the art for generating
power. A typical gas turbine used to generate electrical power
includes an axial compressor at the front, one or more combustors
around the middle, and a turbine at the rear. Ambient air may be
supplied to the compressor, and rotating blades and stationary
vanes in the compressor progressively impart kinetic energy to the
working fluid (air) to produce a compressed working fluid at a
highly energized state. The compressed working fluid exits the
compressor and flows through one or more nozzles into a combustion
chamber in each combustor where the compressed working fluid mixes
with fuel and ignites to generate combustion gases having a high
temperature and pressure. The combustion gases expand in the
turbine to produce work. For example, expansion of the combustion
gases in the turbine may rotate a shaft connected to a generator to
produce electricity.
[0003] The combustion may be initiated by an ignition circuit in
one or more combustors. The ignition circuit may include, for
example, an exciter located outside of the combustor and an igniter
located proximate to or inside of the combustor. The exciter
generates a desired electrical pulse used by the igniter to produce
a spark or other source of ignition inside of the combustor. In
many cases, the exciter may be located remotely from the igniter by
distances exceeding 25-35 feet, and an ignition lead may thus be
used to provide electrical continuity from the exciter to the
igniter, while also isolating the exciter from the high
temperatures and pressures associated with the combustor.
[0004] The ignition lead must often be removed during maintenance
or repair outages to enable removal of the casing surrounding the
combustor and/or for replacement of the igniter. Due to the length
of the ignition lead and difficulty in accessing the igniter, the
removal process is often both time consuming and labor intensive,
increasing the cost and duration of the outage. Therefore, an
improved system and method for igniting a combustor that
facilitates improved maintainability and/or removal of the ignition
lead would be useful.
BRIEF DESCRIPTION OF THE INVENTION
[0005] Aspects and advantages of the invention are set forth below
in the following description, or may be obvious from the
description, or may be learned through practice of the
invention.
[0006] One embodiment of the present invention is a combustor
ignition system that includes an igniter assembly adapted for
installation at least partially inside a combustor. A first
ignition lead is electrically connected to the igniter assembly and
includes a terminal end remote from the igniter assembly. A second
ignition lead is electrically connected to the first ignition lead.
The combustor ignition system further includes means for releasably
connecting the first and second ignition leads.
[0007] Another embodiment of the present invention is a combustor
ignition system that includes an igniter assembly adapted for
installation at least partially inside a combustor. A first
ignition lead is electrically connected to the igniter assembly and
includes a terminal end remote from the igniter assembly. A ferrule
surrounds the terminal end, and a second ignition lead is
releasably connected to the ferrule.
[0008] The present invention may also include an ignition system
that includes a combustor and an igniter assembly adapted for
installation at least partially inside the combustor. A first
ignition lead is electrically connected to the igniter assembly and
includes a terminal end remote from the igniter assembly. A ferrule
surrounds the terminal end, and a second ignition lead is
releasably connected to the first ignition lead.
[0009] Those of ordinary skill in the art will better appreciate
the features and aspects of such embodiments, and others, upon
review of the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A full and enabling disclosure of the present invention,
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:
[0011] FIG. 1 is a simplified cross-section view of an exemplary
combustor according to one embodiment of the present invention;
[0012] FIG. 2 is a cross-section view of a combustor ignition
system according to one embodiment of the present invention;
[0013] FIG. 3 is an enlarged view of a portion of a first ignition
lead shown in FIG. 2; and
[0014] FIG. 4 is an enlarged view of a connection between the first
and second ignition leads shown in FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Reference will now be made in detail to present embodiments
of the invention, one or more examples of which are illustrated in
the accompanying drawings. The detailed description uses numerical
and letter designations to refer to features in the drawings. Like
or similar designations in the drawings and description have been
used to refer to like or similar parts of the invention.
[0016] Each example is provided by way of explanation of the
invention, not limitation of the invention. In fact, it will be
apparent to those skilled in the art that modifications and
variations can be made in the present invention 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 invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
[0017] Various embodiments of the present invention include an
ignition system for a combustor. In particular embodiments, the
combustor ignition system may include multiple ignition leads in
which a first ignition lead connects to an igniter assembly located
proximate to or inside of the combustor and a second ignition lead
connects to an exciter located outside of the combustor. The first
and second ignition leads may releasably connect to one another to
complete the ignition circuit while also facilitating easier
removal of one of the ignition leads for maintenance and
repair.
[0018] FIG. 1 provides a simplified cross-section view of an
exemplary combustor 10, such as may be included in a gas turbine,
according to one embodiment of the present invention. A casing 12
may surround the combustor 10 to contain the compressed working
fluid flowing to the combustor 10. As shown, the combustor 10 may
include one or more nozzles 14 radially arranged between a cap 16
and an end cover 18. The cap 16 and a liner 20 generally surround a
combustion chamber 22 located downstream from the nozzles 14, and a
transition piece 24 downstream from the liner 20 connects the
combustion chamber 22 to a turbine inlet 26. As used herein, the
terms "upstream" and "downstream" refer to the relative location of
components in a fluid pathway. For example, component A is upstream
from component B if a fluid flows from component A to component B.
Conversely, component B is downstream from component A if component
B receives a fluid flow from component A. An impingement sleeve 28
with flow holes 30 may surround the transition piece 24 to define
an annular passage 32 between the impingement sleeve 28 and the
transition piece 24. The compressed working fluid may pass through
the flow holes 30 in the impingement sleeve 28 to flow through the
annular passage 32 to provide convective cooling to the transition
piece 24 and liner 20. When the compressed working fluid reaches
the end cover 18, the compressed working fluid reverses direction
to flow through the one or more nozzles 14 where it mixes with fuel
before igniting in the combustion chamber 22 to produce combustion
gases having a high temperature and pressure.
[0019] As shown in FIG. 1, the combustor 10 may further include a
combustor ignition system 40 for igniting the fuel-air mixture
inside the combustion chamber 22. The ignition system 40 may
comprise, for example, an igniter assembly 42, a sparkplug, or a
laser adapted for installation at least partially inside the
combustor 10 to project a spark or beam into the combustion chamber
22. Alternately, or in addition, the ignition system 40 may
comprise a crossfire tube 44 that provides a flame, for example
from an adjacent combustor, to the combustion chamber 22. In either
event, the ignition system 40 may be located through the breach of
the combustor 10 or along a side of the combustor 10, as shown in
FIG. 1, so that the ignition system 40 may project the spark, beam,
or flame into the combustion chamber 22 approximately coincident
with the fuel-air mixture to enhance the reliability of the
ignition system 40.
[0020] FIG. 2 provides a cross-section view of the combustor
ignition system 40 shown in FIG. 1 according to one embodiment of
the present invention. As shown, the ignition system 40 generally
comprises the igniter assembly 42, a first ignition lead 46, a
second ignition lead 48, and an exciter 50. The igniter assembly 42
may comprise any suitable instrument known in the art for
generating a spark or ignition source. The first and second
ignition leads 46, 48 generally comprise a conductor 52 insulated
to withstand the anticipated temperatures inside the turbine
compartment and to contain the high electrical energy from the
exciter 50. For example, the conductor 52 may comprise 14 gauge
nickel plated copper encased in an insulator 54 such as glass
reinforced polyether ether ketone capable of continuous exposure to
temperatures greater than approximately 400.degree. F. A contact
assembly 56 and disk 58 may be used to provide electrical
conductivity between the conductor 52 included in the first and
second ignition leads 46, 48. The contact assembly 56 may be
formed, for example, from 304 stainless steel, and the disk 58 may
be formed, for example, from thoriated tungsten to enhance the
conductivity and wear resistance between the first and second
ignition leads 46, 48. The first ignition lead 46 is electrically
connected to the igniter assembly 42 at a first terminal end 60 and
to the second ignition lead 48 at a second terminal end 62. The
exciter 50 in turn is electrically connected to the second ignition
lead 48 and may comprise any suitable electrical circuit capable of
producing a desired electrical pulse to fire the igniter assembly
42. In this manner, the exciter 50 generates the desired electrical
pulse which is transmitted through the second ignition lead 48 and
first ignition lead 46 to the igniter assembly 42 to complete the
electrical circuit for the ignition system 40.
[0021] FIG. 3 provides an enlarged view of the second terminal end
62 of the first ignition lead 46 shown in FIG. 2. As shown, the
second terminal end 62 is remote from the igniter assembly 42 and
may include the conductor 52, insulator 54, contact assembly 56,
and disk 58 as previously described. In addition, a ferrule 64 may
surround the second terminal end 62 so that the insulator 54 is
between the ferrule 64 and the second terminal and 62. The ferrule
64 may be formed from 416 stainless steel or other suitable
material having suitable heat and wear resistance. A portion of the
ferrule 64 may include threads 66 or other mechanical fittings for
engaging with the second ignition lead 48.
[0022] FIG. 4 provides an enlarged view of a releasable connection
between the first and second ignition leads 46, 48 shown in FIG. 2.
As shown, the ignition system 40 may include means for releasably
connecting the first and second ignition leads 46, 48. The means
for releasably connecting the first and second ignition leads 46,
48 may comprise any suitable mechanical device known to one of
ordinary skill in the art for releasably connecting components
together. For example, the means may comprise a clamp, a latch and
hasp, a ratchet and pawl assembly, an adhesive, a quick release
fitting or coupling, or a threaded engagement. Alternately, or in
addition, the means may comprise a threaded collar 68 connected to
the second ignition lead 48, as shown in FIG. 4. At least a portion
of the second ignition lead 48 may be inserted inside the ferrule
64 to allow the conductor 52 of the second ignition lead 48 to
electrically connect with the conductor 52 of the first ignition
lead 46. At least a portion of the second ignition lead 48, for
example the collar 68, may surround the ferrule 64 to provide a
threaded engagement between the ferrule 64 and the second ignition
lead 48. In alternate embodiments, the collar 68 and ferrule 64 may
be press fit together to provide a releasable connection between
the first and second ignition leads 46, 48.
[0023] As further shown in FIG. 4, the ignition system 40 may
further include means for biasing at least a portion of the second
ignition lead 48 toward at least a portion of the first ignition
lead 46. The means for biasing at least a portion of the second
ignition lead 48 toward at least a portion of the first ignition
lead 46 may comprise any suitable mechanical device known to one of
ordinary skill in the art for biasing components. For example, the
means may comprise a spring clip, expansion joint, or angled
surface between the first and second ignition leads 46, 48.
Alternately, or in addition, as shown in FIG. 4, the means may
comprise a spring 70 engaged with the insulator 54 or other portion
of the second ignition lead 48 to apply force to at least a portion
of the second ignition lead 48 in the direction of the first
ignition lead 46.
[0024] Referring again to FIGS. 1 and 2, the various embodiments of
the ignition system 40 thus enhance the removal of the first
ignition lead 46 to facilitate maintenance and repair to the
igniter assembly 42 and/or combustor 10. Specifically, the first
ignition lead 46 may have a length substantially shorter than the
combined length of the first and second ignition leads 46, 48. For
example, although specific lengths of the first and second ignition
leads 46, 48 are not limitations of the present invention unless
specifically recited in the claims, the first ignition lead 46 may
be approximately 6 feet in length, and the second ignition lead 48
may have a substantially longer length, such as greater than
approximately 25 feet in length. As a result, maintenance and
repairs to the igniter assembly 42, the conductor 52 at the
connection point between the igniter assembly 42 and first ignition
lead 46, and/or the combustor 10 may be accomplished by
disconnecting and/or removing only the first ignition lead 46
instead of the entire ignition lead connecting the igniter assembly
42 to the exciter 50, producing substantial savings in labor and
reduction in the time of the outage associated with the maintenance
and repair. A failure of the igniter seal resulting in anticipated
temperatures and pressures associated with the combustion chamber
22 entering the first ignition lead 46 will be prevented from
entering the second ignition lead 48 to the exciter 50, preventing
subsequent failures of the exciter 50 and need to replace the
entire ignition lead connecting the igniter assembly 42 to the
exciter 50.
[0025] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other and 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 languages of the claims.
* * * * *