TECHNICAL FIELD
[0001] The present application and the resultant patent relate generally to gas turbine
engines and more particularly relate to a turbine shroud impingement system with an
impingement box in communication with a feed tube and a bellows for effective sealing,
low leakage, and improved production.
BACKGROUND OF THE INVENTION
[0002] Generally described, a gas turbine includes a number of turbine blades rotating in
a hot gas pathway. This hot gas pathway may be enclosed and defined in part by a turbine
shroud. Specifically, a number of turbine shroud segments may be fixed in an annular
array adjacent to the turbine blades. The turbine shroud thus protects an outer turbine
casing and inhibits leakage of the hot combustion gases past the turbine blades without
producing useful work therein.
[0003] Because the turbine shroud defines the hot gas pathway in part, the turbine shroud
may be cooled with a cooling air flow from the compressor or other source. This cooling
air flow is required to maintain the structural integrity of the turbine shroud and
maintain the clearances in the hot gas pathway. Because this cooling air flow is a
parasitic loss on the overall gas turbine engine, reducing the leakage of such cooling
air flow about the turbine shroud and elsewhere should promote overall gas turbine
efficiency and performance.
[0004] There is thus a desire for an improved turbine shroud cooling system. Preferably,
such an improved turbine shroud cooling system should provide a cooling air flow to
the turbine shroud for sufficient cooling therein while limiting overall leakage losses
and the like.
SUMMARY OF THE INVENTION
[0005] The present invention resides in a turbine shroud impingement system. The turbine
shroud impingement system may include a turbine shroud segment, an impingement box
positioned within the turbine shroud segment, a feed tube in communication with the
impingement box, and a bellows positioned about the feed tube.
[0006] The present invention resides in a method of cooling a shroud segment. The method
may include the steps of positioning an impingement box within the shroud segment,
positioning a feed tube with a bellows within an inlet of the impingement box, maintaining
the feed tube within the inlet of the impingement box by the axial compression of
the bellows, and delivering a flow of air through the feed tube to the impingement
box to cool the shroud segment.
[0007] The present invention resides in a turbine shroud impingement system. The turbine
shroud impingement system may include a turbine shroud segment, an impingement box
with a number of impingement holes positioned within the turbine shroud segment, a
feed tube in communication with the impingement box, and a bellows with a number of
convolutions positioned about feed tube.
[0008] These and other features and improvements of the present application and the resultant
patent will become apparent to one of ordinary skill in the art upon review of the
following detailed description when taken in conjunction with the several drawings
and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Embodiments of the present invention will now be described, by way of example only,
with reference to the accompanying drawings in which:
Fig. 1 is a schematic diagram of a gas turbine engine with a compressor, a combustor,
and a turbine.
Fig. 2 is a schematic diagram of portions of a number of stages of the turbine.
Fig. 3 is a side view of a turbine shroud impingement system as may be described herein.
Fig. 4 is a side view of an alternative embodiment of a turbine shroud impingement
system as may be described herein.
DETAILED DESCRIPTION
[0010] Referring now to the drawings, in which like numerals refer to like elements throughout
the several views, Fig. 1 shows a schematic view of gas turbine engine 10 as may be
used herein. The gas turbine engine 10 may include a compressor 15. The compressor
15 compresses an incoming flow of air 20. The compressor 15 delivers the compressed
flow of air 20 to a combustor 25. The combustor 25 mixes the compressed flow of air
20 with a pressurized flow of fuel 30 and ignites the mixture to create a flow of
combustion gases 35. Although only a single combustor 25 is shown, the gas turbine
engine 10 may include any number of combustors 25. The flow of combustion gases 35
is in turn delivered to a turbine 40. The flow of combustion gases 35 drives the turbine
40 so as to produce mechanical work. The mechanical work produced in the turbine 40
drives the compressor 15 via a shaft 45 and an external load 50 such as an electrical
generator and the like.
[0011] The gas turbine engine 10 may use natural gas, various types of syngas, and/or other
types of fuels. The gas turbine engine 10 may be any one of a number of different
gas turbine engines offered by General Electric Company of Schenectady, New York,
including, but not limited to, those such as a 7 or a 9 series heavy duty gas turbine
engine and the like. The gas turbine engine 10 may have different configurations and
may use other types of components. Other types of gas turbine engines also may be
used herein. Multiple gas turbine engines, other types of turbines, and other types
of power generation equipment also may be used herein together.
[0012] Fig. 2 shows a number of the components of the turbine 40. Specifically, a stage
one bucket 55 and a stage two nozzle 60 are shown. The stage one bucket 55 may be
surrounded by a stage one shroud 65. The stage one shroud 65 may be in communication
with a flow of air 20 from the compressor 15 or other source. Known systems for delivering
this flow of air 20 to the shroud 65 may include metered holes, spoolie systems, and
the like. (Cooling systems are not limited to stage one use.) As described above,
such known shroud cooling systems, however, may be subject to leakage therein.
[0013] Fig. 3 shows a shroud 100 as may be described herein. Specifically, Fig. 3 shows
a shroud segment 110. Any number of shroud segments 110 may be used in the overall
shroud 100 in a circumferential array. As described above, the shroud segments 110
surround the buckets 55 and define the hot gas pathway therethrough. A lower surface
120 of the shroud segment 110 may face the buckets 55 and the flow of combustion gases
35 therein. Other components and other configurations may be used herein.
[0014] Each shroud segment 110 may include a shroud impingement system 130 positioned therein.
The shroud impingement system 130 may include an impingement box 140. A bottom surface
150 of impingement box 140 may have a number of impingement holes 160 therein. The
impingement holes 160 may have any desired size, shape, or configuration. Any number
of impingement holes 160 may be used herein. The impingement holes 160 face the lower
surface 120 of the shroud segment 110 for cooling purposes. The impingement box 140
also may include an offset inlet 170. The offset inlet 170 may be positioned about
a conical or an axial load face 180. The offset inlet 170 may have a substantial tube
like shape 190. The offset inlet 170 may extend about the axial load face 180 into
an interior 200 of the impingement box 140. Other components and other configurations
may be used herein.
[0015] The shroud impingement system 130 also may include a feed tube 220. The feed tube
220 may be in communication with the flow of air 20 from the compressor 15 or elsewhere
and with the impingement box 140. The feed tube 220 may have any desired size, shape,
or configuration. The shroud impingement system 130 also may include a bellows 230.
In this example, the bellows 230 may be part of the feed tube 220. The bellows 230
may include a number of convolutions 240 and the like. The bellows 230 as a whole
and the convolutions 240 may have any size, shape, or configuration. The bellows 230
acts as a type of expansion joint. Other types of deflection and sealing means may
be used herein. The bellows 230 can withstand the internal pressure of the flow of
air 20 within the feed tube 220 while also being flexible enough to accept axial,
lateral, and/or angular deflections. Likewise, the bellows 230 may compensate for
thermal movement, manufacturing and assembly variations, and the like. The configuration
of the bellows 230 may vary with the configuration of the stages and the overall gas
turbine engine and the output thereof. The feed tube 220 and the bellows 230 may be
made out of any type of high temperature resistant materials and alloys. Other components
and other configurations also may be used herein.
[0016] The bellows 230 may be positioned between a first section 250 and a second section
260 of the feed tube 220 or otherwise. The second section 260 may have any type of
geometry and may be sized to accommodate the offset inlet 170 of the impingement box
140. For example, the second tube 260 may have an expanded spherical shape to accommodate
the offset inlet 170. The feed tube 220 and the sections 250, 260 thereof may be sized
with a predetermined diameter depending upon the desired flow rate of the flow of
air 20 therein. The respective lengths of the sections 250, 260 and the bellows 230
may vary. Other components and other configurations also may be used herein.
[0017] The shroud impingement system 130 may be positioned within an impingement box aperture
270 of the shroud segment 110. The impingement box aperture 270 may be sized and shaped
to accommodate the intended impingement box 140. Standoffs tend to maintain a certain
distance between the impingement box 140 and the shroud segment 110. Likewise, the
lower surface 120 of the shroud segment 110 may face the bottom surface 150 and the
impingement holes 160 of the impingement box 140 for impingement cooling therein.
A feed tube aperture 290 also may extend through the shroud segment 110. The feed
tube aperture 290 may be sized and shaped to accommodate the feed tube 220 and the
bellows 230 securely therein. Other components and other configurations also may be
used herein.
[0018] Fig. 4 shows an alternative embodiment of a shroud impingement system 300 as may
be described herein. In this example, the bellows 230 may be attached directly to
the offset inlet 170 of the impingement box 140 instead of the feed tube 220 described
above. The bellow 230 extends directly to the first section 250 of the feed tube 220
without the use of the second section 260. A flange 310 and the like also may be attached
to the bellows 230. Other components and other configurations also may be used herein.
[0019] In use, the feed tube 220 of the shroud impingement system 130 extends through the
feed tube aperture 290 of the shroud segment 110. The second section 260 of the feed
tube 220 may be positioned within the offset inlet 170 about the axial load face 180
of the impingement box 140. The connection between the feed tube 220 and the impingement
box 140 may be maintained by the axial compression of the bellows 230. The bellows
230 thus reduces the leakage in the flow of air 20 by maintaining a sealing surface
in spite of relative movement between the feed tube 220 and the impingement box 140.
The sealing surface may be maintained regardless of slight relative movement therein.
Additional sealing means also may be used herein. The shroud impingement system 130
thus delivers the flow of air 20 to the impingement box 140 so as to cool the lower
surface 120 of the shroud segment 110 in an efficient manner. Alternatively, the bellows
230 may be attached to the offset inlet 170 of the impingement box 140 or elsewhere
and may receive the feed tube 220 therein.
[0020] The bellows 230 of the shroud impingement system 130 thus may reduce the need for
tight machining tolerances that otherwise would be required for a rigid connection
between the impingement box 140 and the feed tube 220. The bellows 230 therefore provides
a constant sealing surface in a low cost, efficient sealing system with high reliability.
[0021] It should be apparent that the foregoing relates only to certain embodiments of the
present application and the resultant patent. Numerous changes and modifications may
be made herein by one of ordinary skill in the art without departing from the general
spirit and scope of the invention as defined by the following claims and the equivalents
thereof.
[0022] Various aspects and embodiments of the present invention are defined by the following
numbered clauses:
- 1. A turbine shroud impingement system, comprising:
a turbine shroud segment;
an impingement box with a plurality of impingement holes positioned within the turbine
shroud segment;
a feed tube in communication with the impingement box; and
a bellows with a plurality of convolutions positioned about feed tube.
- 2. The turbine shroud impingement system of clause 1, wherein the shroud segment comprises
a lower surface and wherein the impingement box comprises a bottom surface adjacent
to the lower surface of the shroud segment.
- 3. The turbine shroud impingement system of clause 1, wherein the feed tube comprises
a first section and a second section and wherein the bellows is positioned between
the first section and the second section.
- 4. The turbine shroud impingement system of clause 1, wherein the bellows is attached
to the impingement box.
1. A turbine shroud impingement system (130), comprising:
a turbine shroud segment (110);
an impingement box (140) positioned within the turbine shroud segment (110);
a feed tube (220) in communication with the impingement box (14); and
a bellows (230) positioned about feed tube (220).
2. The turbine shroud impingement system (130) of claim 1, wherein the shroud segment
(110) comprises a lower surface (120) and wherein the impingement box (140) comprises
a bottom surface (150) adjacent to the lower surface (120) of the shroud segment (110).
3. The turbine shroud impingement system (130) of claim 2, wherein the bottom surface
(150) of the impingement box (140) comprises a plurality of impingement holes (160)
therein.
4. The turbine shroud impingement system (130) of any of claims 1 to 3, wherein the impingement
box (140) comprises axial load face (1800 thereon.
5. The turbine shroud impingement system (130) of claim 4, wherein the shroud segment
(110) comprises a segment axial load face (280) and wherein the axial load face (180)
of the impingement box (1400 is positioned about the segment axial load face (280).
6. The turbine shroud impingement system (130) of claim 4 or 5, wherein the impingement
box (140) comprises an offset inlet (170) positioned about the axial load face (180).
7. The turbine shroud impingement system (130) of claim 6, wherein the offset inlet (170)
comprises a tube-like shape (190).
8. The turbine shroud impingement system (130) of any preceding claim, wherein the bellows
(230) comprises a plurality of convolutions (240).
9. The turbine shroud impingement system (130) of any preceding claim, wherein the feed
tube (220) comprises a first section (250) and a second section (260) and wherein
the bellows (230) is positioned between the first section (250) and the second section
(260).
10. The turbine shroud impingement system (130) of any preceding claim, wherein the bellows
(230) is attached to the impingement box (140).
11. The turbine shroud impingement system (130) of any preceding claim, wherein the shroud
segment (110) comprises an impingement box aperture (270) therein.
12. The turbine shroud impingement system (130) of any preceding claim, wherein the shroud
segment (110) comprises a feed tube aperture (240) therein.
13. The turbine shroud impingement system (130) of any preceding claim, further comprising
a plurality of shroud segments (110).
14. A method of cooling a shroud segment (110), comprising:
positioning an impingement box (140) within the shroud segment (110);
positioning a feed tube (220) with a bellows (230) within an inlet (170) of the impingement
box (140);
maintaining the feed tube (220) within the inlet (170) of the impingement box (140)
by axial compression of the bellows (230); and
flowing a flow of air (20) through the feed tube (220) to the impingement box (140)
to cool the shroud segment (110).