U.S. patent application number 13/453320 was filed with the patent office on 2013-10-24 for combustor cap mounting structure for a turbine engine.
The applicant listed for this patent is Christopher Paul Kenner, Jason Stewart. Invention is credited to Christopher Paul Kenner, Jason Stewart.
Application Number | 20130276449 13/453320 |
Document ID | / |
Family ID | 48139843 |
Filed Date | 2013-10-24 |
United States Patent
Application |
20130276449 |
Kind Code |
A1 |
Kenner; Christopher Paul ;
et al. |
October 24, 2013 |
COMBUSTOR CAP MOUNTING STRUCTURE FOR A TURBINE ENGINE
Abstract
A mounting structure for mounting a combustor cap in a combustor
of a turbine engine includes support struts that are connected
between the combustor cap and a concentric combustor cap barrel
flange. The support struts may have an airfoil shape to minimize
wakes created in a flow of compressed air that is passing over the
support struts. Also, the support struts may have an interior
passageway that allows a portion of the compressed air to flow
though the support strut. The flow of air passing through the
support struts may also pass through corresponding vent apertures
in the combustor cap barrel flange so that the flow of air passing
through the support struts is delivered into a space between the
exterior of the combustor cap barrel flange and a forward casing of
the combustor.
Inventors: |
Kenner; Christopher Paul;
(Woodruff, SC) ; Stewart; Jason; (Greer,
SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kenner; Christopher Paul
Stewart; Jason |
Woodruff
Greer |
SC
SC |
US
US |
|
|
Family ID: |
48139843 |
Appl. No.: |
13/453320 |
Filed: |
April 23, 2012 |
Current U.S.
Class: |
60/722 |
Current CPC
Class: |
F23R 3/283 20130101;
F23R 3/002 20130101 |
Class at
Publication: |
60/722 |
International
Class: |
F23R 3/00 20060101
F23R003/00 |
Claims
1. A combustor cap assembly for a turbine engine, comprising: a
generally cylindrical combustor cap configured to receive at least
one fuel nozzle; a generally cylindrical combustor cap barrel
flange that surrounds an outer circumference of the combustor cap;
and a plurality of support struts that mount the combustor cap to
the combustor cap barrel flange and which extend between the outer
circumference of the combustor cap and an inner circumference of
the combustor cap barrel flange, wherein an interior passageway
extends through an interior of each support strut.
2. The combustor cap assembly of claim 1, wherein vent apertures
are formed in the combustor cap barrel flange at locations
corresponding to where the support struts are attached to the
combustor cap barrel flange, and wherein each vent aperture
operatively communicates with the interior passageway of a
corresponding support strut.
3. The combustor cap assembly of claim 2, wherein the interior
passageway in each support strut extends between an entrance
aperture located on a side surface of the support strut and an exit
aperture that is formed on a portion of the support strut that
abuts the combustor cap barrel flange.
4. The combustor cap assembly of claim 3, wherein the entrance
aperture of each support strut is located on a leading edge portion
of the support strut which is impacted by a flow of compressed
air.
5. The combustor cap assembly of claim 3, wherein the support
struts are mounted to the combustor cap barrel flange such that a
flow of air can pass from the entrance aperture of each support
strut, through the interior passageway, out the exit aperture of
the support strut and through a corresponding vent aperture of the
combustor cap barrel flange to a location adjacent an exterior
circumference of the combustor cap barrel flange.
6. The combustor cap assembly of claim 1, wherein each support
strut has an airfoil shape with a rounded leading edge and a
tapered trailing edge.
7. The combustor cap assembly of claim 1, wherein a leading edge of
each support strut is angled with respect to the outer
circumference of the combustor cap and the inner circumference of
the combustor cap barrel flange such that the portion of the
leading edge that is coupled to the combustor cap is located
further forward than the portion of the leading edge that is
coupled to the combustor cap barrel flange.
8. The combustor cap assembly of claim 7, wherein each support
strut has an airfoil shape with a rounded leading edge and a
tapered trailing edge.
9. A support strut configured to mount a combustor cap to a
combustor cap barrel flange of a combustor of a turbine engine,
comprising: a main body having an inner end that is configured to
be attached to the outer circumference of a combustor cap and an
outer end that is configured to be attached to an inner
circumference of a combustor cap barrel flange; and an interior
passageway that extends through the main body between an entrance
aperture and an exit aperture.
10. The support strut of claim 9, wherein the entrance aperture is
located on a sidewall of the main body and the exit aperture is
located on the outer end of the support strut.
11. The support strut of claim 10, wherein the entrance aperture is
located on a leading edge of the main body.
12. The support strut of claim 9, wherein the main body has an
airfoil shape with a rounded leading edge and a tapered trailing
edge.
13. The support strut of claim 9, wherein the inner and outer ends
are substantially parallel to one another, wherein a leading edge
of the main body forms an oblique angle with the inner end, and
wherein a trailing edge of the main body forms an acute angle with
the inner end.
14. The support strut of claim 13, wherein the main body has an
airfoil shape with a rounded leading edge and a tapered trailing
edge.
15. The support strut of claim 14, wherein the entrance aperture is
located on the leading edge of the main body and the exit aperture
is located on the outer end of the main body.
Description
BACKGROUND OF THE INVENTION
[0001] A combustor for a turbine engine used in the power
generation industry can include a combustor cap that is mounted
adjacent a forward end of the combustor. A plurality of fuel
nozzles are typically mounted to an end cover and pass through the
combustor cap. Compressed air flows around the exterior periphery
of the combustor cap, makes a 180.degree. turn, and then flows
through the fuel nozzles, where the air is mixed with fuel. The
air-fuel mixture is then ignited downstream from the combustor
cap.
[0002] FIGS. 1 and 2 illustrate a typical background art combustor
cap assembly mounted in a combustor. As illustrated in these
Figures, a combustor cap 110 having openings 112 to receive a
plurality of fuel nozzles is mounted to a combustor cap barrel
flange 118 by a plurality of A-frame spacers 116. The A-frame
spacers 116 are typically formed from flat metal strips. Center
portions of the A-frame spacers are mounted to the inner
circumference of the combustor cap barrel flange 118, and ends of
the A-frame spacers 116 are attached to the outer circumference 114
of the combustor cap 110. The combustor cap barrel flange 118
includes a protruding flange 120. The protruding flange 120 is
mounted between a flange 106 of an outer casing 105 and a flange
132 of a forward casing 130.
[0003] A flow sleeve 102 is positioned inside the outer casing 106.
A combustor liner 104 is mounted concentrically inside the flow
sleeve 102. A forward end of the combustor liner 104 engages a hula
seal 117 on the exterior circumference 114 of the combustor cap
110. A flow of compressed air from the compressor section of the
turbine engine flows through the annular space 103 between the flow
sleeve 102 and the combustor liner 104, as illustrated by the
arrows appearing in FIG. 1. This flow of compressed air also flows
through the annular space between the outer circumference 114 of
the combustor cap 110 and the inner circumference of the combustor
cap barrel flange 118. Because the A-frame spacers 116 are
positioned between the outer circumference 114 of the combustor cap
110 and the inner circumference of the combustor cap barrel flange
118, the A-frame spacers 116 tend to impede and/or disrupt the flow
of compressed air, resulting in flow losses and separation.
[0004] In addition, the combustor cap design illustrated in FIG. 1
can result in a step located between the outer circumferential
surface of the combustor cap barrel flange 118 and the inner
circumferential surface of the forward casing 130. This step can
cause disturbances in the flow of compressed air and a low pressure
cavity 133 in the volume between the outer circumferential surface
of the combustor cap barrel flange 118 and the inner
circumferential surface of the forward casing 130. In designs where
fuel is introduced through a fuel peg 135 located downstream from
the combustor cap, such as with a quaternary fuel circuit, the
disturbances caused by this step can provide a path for fuel to
migrate upstream from the fuel peg 135. Other obstacles in the
compressed air flow path, such as cross fire tubes, can also cause
fuel to migrate upstream. If the fuel enters the low pressure
cavity 133 in the volume between the outer circumferential surface
of the combustor cap barrel flange 118 and the inner
circumferential surface of the forward casing 130, it can lead to a
flame holding event. All of which is undesirable.
BRIEF DESCRIPTION OF THE INVENTION
[0005] In one aspect, the invention may be embodied in a combustor
cap assembly for a turbine engine that includes a generally
cylindrical combustor cap configured to receive at least one fuel
nozzle, a generally cylindrical combustor cap barrel flange that
surrounds an outer circumference of the combustor cap, and a
plurality of support struts that mount the combustor cap to the
combustor cap barrel flange. The support struts extend between the
outer circumference of the combustor cap and an inner circumference
of the combustor cap barrel flange. An interior passageway extends
through an interior of each support strut.
[0006] In another aspect, the invention may be embodied in a
support strut that is configured to mount a combustor cap to a
combustor cap barrel flange of a combustor of a turbine engine. The
support strut includes a main body having an inner end that is
configured to be attached to the outer circumference of a combustor
cap and an outer end that is configured to be attached to an inner
circumference of a combustor cap barrel flange. Also, an interior
passageway extends through the main body between an entrance
aperture and an exit aperture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a diagram of a background art mounting structure
for mounting a combustor cap in a combustor of a turbine
engine;
[0008] FIG. 2 is a diagram illustrating how a background art
combustor cap is mounted to a combustor cap barrel flange;
[0009] FIG. 3 is a perspective view of a first embodiment of a
support strut that is used to mount a combustor cap to a combustor
cap barrel flange;
[0010] FIG. 4 is a cross-sectional view of a support strut mounted
to a combustor cap barrel flange;
[0011] FIG. 5 is a diagram illustrating how support struts as
illustrated in FIGS. 3 and 4 are used to mount a combustor cap to a
combustor cap barrel flange;
[0012] FIG. 6 is a diagram, illustrating how a combustor cap and
combustor cap barrel flange assembly that includes support struts
as illustrated in FIGS. 3 and 4 is mounted to a combustor of a
turbine engine;
[0013] FIG. 7 is a cross-sectional view of an alternate embodiment
of a support strut that can be used to mount a combustor cap to a
combustor cap barrel flange; and
[0014] FIG. 8 is a diagram, illustrating how another embodiment of
a combustor cap and combustor cap barrel flange assembly that
includes support struts as illustrated in FIGS. 3 and 4 is mounted
to a combustor of a turbine engine.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] FIGS. 3 and 4 illustrate a support strut 160 which can be
used to mount a combustor cap to a combustor cap barrel flange. The
support strut 160 replaces the A-frame spacers 116 used for this
purpose in the background art combustor cap assembly illustrated in
FIGS. 1 and 2. The support strut 160 has an airfoil shape, with a
rounded leading edge 161 and a tapered trailing edge 163. In
addition, an interior passageway extends through the interior of
the support strut 160 between an entrance aperture 162 and an exit
aperture 164.
[0016] FIG. 4, which is a cross-sectional view of a support strut
160 attached to a combustor cap barrel flange 150, illustrates that
the inner end 166 and outer end 168 of the support strut 160 are
substantially parallel to one another. In alternate embodiment,
however, the inner and outer ends could be angled relative to one
another. In some embodiments, the leading edge 161 and trailing
edge 163 of each support strut 160 may be angled with respect to
the inner end 166 and outer end 168. FIG. 4 also illustrates that
an interior passageway 165 passes between an entrance aperture 162
and an exit aperture 164 of the support strut. The exit aperture
164 is in communication with a vent aperture 152 in the combustor
cap barrel flange 150. As a result, air entering the entrance
aperture 162, flowing through the interior passageway 165 and
exiting the exit aperture 164 can pass through the vent aperture
164 of the combustor cap barrel flange 150.
[0017] FIG. 5 illustrates how a plurality of support struts 160 are
used to mount a combustor cap 110 to a combustor cap barrel flange
150. Inner ends 166 of each support strut 160 are mounted to an
exterior circumference 114 of the combustor cap 110. Outer ends 168
of each support strut 160 are mounted to an interior
circumferential surface 154 of the combustor cap barrel flange 150.
In some embodiments, the inner and outer ends of the support struts
160 may be integral to the combustor cap 110 and combustor cap
barrel flange 150, respectively. In alternate embodiments,
additional structure may be provided to help attach the support
struts 160 to one or both of the combustor cap 110 and combustor
cap barrel flange 150. FIG. 5 presents a view which shows the
leading edges of the support struts 160. As a result, one can see
the entrance apertures 162 on the leading edges of the support
struts 160.
[0018] FIG. 6 illustrates a side view of the combustor assembly,
which shows how the support struts 160 are mounted between the
combustor cap 110 and the combustor cap barrel flange 150. FIG. 6
also illustrates that the leading edge 161 of the support struts
are positioned so that the flow of compressed air exiting the
annular space 103 between the flow sleeve 102 and the combustor
liner 104 impinges directly on the leading edges 161 of the support
struts 160. As a result, a portion of the compressed air flows into
the entrance aperture 162, through the interior passageway 165, out
the exit aperture 164 of the support strut 160, and then through
the vent aperture 152 in the combustor cap barrel flange 150, as
illustrated by the arrows in FIG. 6. The flow of air passing
through the interior of the support struts 160 is delivered into
the low pressure cavity 133 between the outer circumferential
surface of the combustor cap barrel flange 150 and the inner
circumferential surface of the forward casing 130. Thus, the flow
of air continuously purges the low pressure cavity 133 that existed
in the background art design.
[0019] The airfoil shape of the support struts 160 also help to
minimize any flow losses that result from the flow of compressed
air impinging on the structure used to attach the combustor cap 110
to the combustor cap barrel flange 150. Another benefit of the
airfoil shape is that it helps to minimize wakes if the flow of
compressed air has a tangential component (swirl). If the air
coming from the annular space 103 is swirling, the background art
A-frames tended to cause a large wake, as they essentially act like
flat plates with an angle of attack. In contrast, when airfoil
shapes are used for the support struts the air will tend to stay
attached to the airfoil in moderate angles of attack (swirl)
thereby minimizing wakes or flow deficits from the structure.
[0020] FIG. 7 illustrates an alternate embodiment of a support
strut 190 that can be used to attach a combustor cap 110 to a
combustor cap barrel flange 150. In this embodiment, the interior
passageway 175 makes a smooth curve between the entrance aperture
162 on the leading edge 161 of the support strut and the exit
aperture 164 that is in communication with the vent aperture 152 in
the combustor cap barrel flange 150. The smoothly curved interior
passageway 175 also serves to minimize flow losses and maximize the
flow of air that is used to purge the dead cavity.
[0021] In alternate embodiments, the entrance aperture of a support
strut could be located on portions of the sidewall of the support
strut other than the leading edge. For example, the entrance
aperture could be located on a portion of the sidewall between the
leading and trailing edges.
[0022] In still other embodiments, multiple entrance apertures
could be provided on multiple portions of the sidewall of the
support strut. For example, multiple entrance apertures could be
formed on the leading edge 161 of a support strut. In some
embodiments, all of the entrance apertures would lead to the same
interior passageway. In alternate embodiments, each entrance
aperture could lead to a separate interior passageway.
[0023] Also, in the embodiments described above, the exit aperture
is located on the outer end of the support struts. In alternate
embodiments, the exit aperture could be located in different
locations. Also, multiple exit apertures could be provided.
[0024] In an embodiment of a support strut having multiple entrance
apertures and/or multiple exit apertures, multiple interior
passageways may be provided.
[0025] In the embodiments described above, the support struts have
a cross-sectional shape with a rounded leading edge and a tapered
trailing edge. In alternate embodiments, the support strut could
have alternate cross-sectional shapes. For example, the support
struts could have a rectangular cross-sectional shape, with or
without rounded edges. Alternatively, the support struts could have
a circular or oval cross-sectional shape. Still other
cross-sectional shapes are also possible, depending on design
considerations.
[0026] In the embodiments described above, the leading and trailing
edges of the support struts were angled with respect to the inner
and outer ends. In alternate embodiments, the inner and outer ends
could form right angles with the leading and trailing edges of the
support struts. Also, in alternate embodiments, the leading and
trailing edges may be angled such that the inner ends of the
support struts extend further rearward than the outer ends.
[0027] FIG. 8 illustrates another embodiment of a combustor
assembly where support struts 160 are mounted between a combustor
cap 110 and a combustor cap barrel flange 150. In this embodiment,
a slot 137 is cut in the forward casing 130, and the combustor cap
barrel flange 150 is mounted in the slot 137. A cavity 139 is
formed between the inner circumference of the slot 137 and the
outer circumference of the combustor cap barrel flange 150. A
portion of the compressed air exiting the annular space 103 flows
into the entrance aperture of the support strut 160, through the
interior passageway, out the exit aperture of the support strut
160, and then through a vent aperture in the combustor cap barrel
flange 150 and into the cavity 139, as illustrated by the arrows in
FIG. 6. Thus, a flow of air continuously purges the cavity 139. The
flow of air exiting the cavity 139 through the gap 151 prevents
fuel delivered from a downstream fuel peg 135 from migrating
upstream into the location adjacent the trailing edges of the
support struts 160.
[0028] While the invention has been described in connection with
what is presently considered to be the most practical and preferred
embodiments, it is to be understood that the invention is not to be
limited to the disclosed embodiments, but on the contrary, is
intended to cover various modifications and equivalent arrangements
which are encompassed within the spirit and scope of the appended
claims.
* * * * *