U.S. patent application number 11/104549 was filed with the patent office on 2006-10-19 for combustor and cap assemblies for combustors in a gas turbine.
This patent application is currently assigned to General Electric Company. Invention is credited to Mark Bailey, Stewart W. Beitz, Robert R. Berry, Jere A. Johnson, James C. Monaghan.
Application Number | 20060230763 11/104549 |
Document ID | / |
Family ID | 37107140 |
Filed Date | 2006-10-19 |
United States Patent
Application |
20060230763 |
Kind Code |
A1 |
Johnson; Jere A. ; et
al. |
October 19, 2006 |
Combustor and cap assemblies for combustors in a gas turbine
Abstract
The cap assembly of a turbine combustor includes a plurality of
burner tubes sealed against fuel nozzles extending in the tubes.
These piston seals are coated with a high velocity oxygen fuel
coating to extend their service life. The outer cap body assembly
includes concentric seal rings each with cantilevered convex
fingers circumferentially offset from one another to seal between
the cap assembly casing and the inner liner. The cap assembly
casing is provided with a plurality of holes at predetermined
locations about the casing to minimize or eliminate response to
combustion dynamics.
Inventors: |
Johnson; Jere A.;
(Greenville, SC) ; Bailey; Mark; (Simpsonville,
SC) ; Berry; Robert R.; (Anderson, SC) ;
Beitz; Stewart W.; (Greenville, SC) ; Monaghan; James
C.; (Moore, SC) |
Correspondence
Address: |
NIXON & VANDERHYE P.C.
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Assignee: |
General Electric Company
Schenectady
NY
|
Family ID: |
37107140 |
Appl. No.: |
11/104549 |
Filed: |
April 13, 2005 |
Current U.S.
Class: |
60/740 ;
60/752 |
Current CPC
Class: |
F23R 3/60 20130101; F23R
3/10 20130101; F23R 3/46 20130101 |
Class at
Publication: |
060/740 ;
060/752 |
International
Class: |
F23R 3/42 20060101
F23R003/42 |
Claims
1. A cap assembly for a turbine combustor comprising: a plurality
of burner tubes; a fuel nozzle in each burner tube; and seals
between the burner tubes and the fuel nozzles, each seal including
a ring having a high velocity oxygen fuel coating on a surface
thereof.
2. A cap assembly according to claim 1 wherein said seal is formed
of HAST-X.
3. A combustor comprising: a combustor liner; a cap assembly in
part received within an end of the liner; and a seal between the
cap assembly and said liner including pair of generally annular
rings, each said ring having a plurality of spring fingers at
circumferentially spaced locations thereabout, said rings being
concentrically disposed relative to one another with the spring
fingers of one ring circumferentially offset from the spring
fingers of another ring enabling the spring fingers of each ring to
register with gaps between the spring fingers of said another
ring.
4. A combustor according to claim 3 wherein each ring has a margin
along an edge thereof with the spring fingers cantilevered from
said edge.
5. A combustor according to claim 4 wherein the spring fingers are
arcuate with each spring finger following the arcuate contour of
registering portions of a pair of spring fingers of said another
ring.
6. A combustor according to claim 5 wherein the spring fingers are
secured to a casing of the cap assembly, said spring fingers of an
outermost ring having radially outward cantilevered convex portions
for sealing about an inner surface of the liner.
7. A combustor according to claim 6 wherein said radially outward
convex portions have a high velocity oxygen fuel coating.
8. A cap assembly for a turbine combustor comprising: a plurality
of burner tubes; a fuel nozzle in each burner tube; an outer body
sleeve surrounding said plurality of burner tubes and having a
plurality of openings sized and located to protect against onset of
a mode of combustion dynamics.
Description
[0001] The present invention relates to combustors and cap
assemblies for combustors having increased service life and
particularly relates to combustors and cap assemblies therefor for
converting combustors and cap assemblies having a predetermined
life cycle to combustors and cap assemblies having extended life
cycles.
BACKGROUND OF THE INVENTION
[0002] In gas turbines, a plurality of combustors are typically
arranged in an annular array about the axis of the turbine. For
example, in one known turbine, eighteen combustors are
circumferentially spaced about the turbine axis. Each combustor
combines fuel and compressor discharge air into an fuel/air mixture
which is then combusted with the resulting gases expanded through
the blades of the turbine whereby work is extracted from the
turbine.
[0003] Combustors including cap assemblies are typically rated for
a predetermined number of hours of operation before requiring
service. For example, a cap assembly may be rated for 8,000 hours
of operation before requiring servicing New versions of the cap
assembly, however, are capable of extended hours of operation, e.g.
24,000 hours. This has led to an excess supply of cap assembly
hardware having the lower rated hours of operation. These excess
cap assemblies thus constitutes stranded assets since the lower
rated cap assemblies would not be utilized in upgraded or providing
new cap assemblies in new turbines. Accordingly, there has been a
need to convert the lower rated cap assemblies which are otherwise
stranded assets to the higher rated cap assemblies with extended
hours of service whereby the lower rated cap assemblies can be
utilized for turbine upgrades or provided in new turbines.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In a preferred embodiment of the present invention there is
provided a cap assembly for a turbine combustor comprising: a
plurality of burner tubes; a fuel nozzle in each burner tube; and
seals between the burner tubes and the fuel nozzles, each seal
including a ring having a high velocity oxygen fuel coating on a
surface thereof.
[0005] In a further preferred embodiment of the present invention
there is provided a combustor comprising: a combustor liner; a cap
assembly in part received within an end of the liner; a seal
between the cap assembly part and said liner including pair of
generally annular rings with each said ring having a plurality of
spring fingers at circumferentially spaced locations thereabout,
said rings being concentrically disposed relative to one another
with the spring fingers of one ring circumferentially offset from
the spring fingers of another ring enabling the spring fingers of
each ring to register with gaps between the spring fingers of said
another ring.
[0006] In another preferred embodiment of the present invention
there is provided a cap assembly for a turbine combustor
comprising: a plurality of burner tubes; a fuel nozzle in each
burner tube; an outer body sleeve surrounding said plurality of
burner tubes and having a plurality of openings sized and located
to protect against onset of a mode of combustion dynamics.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a cross-sectional view of a combustor containing a
cap assembly upgraded in accordance with a preferred embodiment of
the present invention;
[0008] FIG. 2 is an enlarged end elevational view of the cap
assembly for the combustor of FIG. 1;
[0009] FIG. 3 is a cross-sectional view through an axis of the cap
assembly;
[0010] FIG. 4 is a fragmentary enlarged view of a seal between the
burner tubes and fuel nozzles within the cap assembly;
[0011] FIG. 5 is an elevational view of a seal between the cap
assembly and combustor liner in accordance with the prior art;
[0012] FIG. 6 is a similar view of a seal between the cap assembly
and liner in accordance with a preferred embodiment of the present
invention;
[0013] FIG. 7 is a cross-sectional view of the seal of FIG. 6 taken
about on line 7-7 in FIG. 6;
[0014] FIG. 8 is a fragmentary enlarged end view in an axial
direction of the seal of FIG. 6;
[0015] FIG. 9 is an enlarged fragmentary cross-sectional view of a
flange of the cap assembly fitting into the forward casing of the
combustor;
[0016] FIG. 10 is an axial view of the outer casing of the cap
assembly; and
[0017] FIG. 11 is a side elevational view thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Referring now to the drawings, particularly to FIG. 1, there
is illustrated a combustor generally designated 10 for a gas
turbine. Combustor 10 includes a cap assembly generally designated
12 at a forward end of the combustor. As is conventional, combustor
10 includes a flow sleeve 14, a combustor liner 16 and a transition
piece 18. Additionally, the cap assembly 12 includes a plurality of
burner tubes 20 which form an annular array of tubes about the axis
of the combustor and about a central fuel nozzle 22. Each burner
tube 20 also houses a fuel nozzle 24 illustrated in FIG. 1.
Typically, compressor discharge air is supplied to the burner tubes
and fuel nozzle for mixing with fuel to enable combustion, the
combustion gases flowing through the transition piece 18 into the
turbine to extract work from the gases.
[0019] The burner tubes 20 typically have piston seals 28 for
sealing about the burner tubes and to the fuel nozzle which is
received within the burner tubes. Prior burner tube piston seals
constituted a limiting factor in the service life of the cap
assembly of the combustor. In accordance with a preferred
embodiment of the present invention, to extend the service life of
the cap assembly in this aspect of the invention, a high velocity
oxygen fuel coating 30 is provided on each piston seal 28 to extend
the service life of the piston seal. The material of the seal per
se is conventional and may comprise HAST-X and the coating is
identified FSX-414. The coating may be applied to a thickness of
approximately 7-9 mils whereby superior wear properties are
provided to the piston seal 28.
[0020] Referring now to FIGS. 3 and 5-8, there is provided an outer
cap body assembly seal for sealing the cap assembly to the liner in
a manner which will extend the life of the outer cap body assembly
seal. Referring to FIG. 5, prior seals typically included a single
annular seal, generally designated 32, having a plurality of
segments 34 extending from a seal base 36 secured to the outer
housing of the cap assembly. The segments 34 are thus cantilevered
from the base 36 with gaps 38 therebetween. Service life for this
seal constituted a limiting factor for the overall service life of
the cap assembly. To extend the service life of the cap assembly,
an outer cap body assembly seal in the form of a pair of concentric
rings is provided. Particularly, and referring to FIGS. 6-8, the
seal assembly, generally designated 39, includes a pair of
concentric outer and inner rings 40 and 42 respectively. Each ring
included a base 44 and 46 respectively secured to one another and
to the outer casing of the cap assembly. Each ring includes a
plurality of fingers 48, 50 respectively with gaps 52 and 54
respectively between the fingers. The concentrically arranged rings
40 and 42 are circumferentially offset relative to one another.
Thus, the spring fingers of one ring circumferentially offset from
the spring fingers of the other seal ring enable the spring fingers
of each ring to register with the gaps between the spring fingers
of the other seal ring. The offset double seal ring, as illustrated
in FIG. 3, is secured to the outer casing 60 (FIG. 1) of the outer
cap body assembly and extends in a forward direction from its
securement to the outer cap body casing. Thus, the seal rings are
convex and cantilevered in a forward direction and are biased
against the interior surface of the liner 16 (FIG. 1) to provide a
seal between the liner and the outer cap body assembly. As a
consequence, the service life of the seal between the outer cap
body assembly and the liner has been extended correspondingly to
the uprated service life of new cap assemblies.
[0021] Referring to FIG. 9, a flange is provided on the cap
assembly and the flange has a chamfer.
[0022] Referring now to FIGS. 10 and 11, there is illustrated an
outer casing 60 for the cap assembly. It has been found that in
certain turbines, the outer casing has limited service life due to
its response to certain combustion dynamics within the combustor.
That is, vibratory action of the casing may occur at frequencies
deleterious to extended service life. Therefore to extend the
service life of the casing, a plurality of holes or openings 62 are
provided at predetermined locations about the casing. For example,
as illustrated in FIGS. 10 and 11, the holes 62 are provided in
pairs in quadrants of the casing. By providing these holes, the
vibratory response of the casing to combustion dynamics is
substantially minimized or eliminated thereby extending the service
life of the casing.
[0023] While the invention has been described in connection with
what is presently considered to be the most practical and 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
included within the spirit and scope of the appended claims.
* * * * *