The disclosure relates to gas turbine engines, and more particularly to heat shields used in gas turbine engines.
Gas turbine engines operate according to a continuous-flow, Brayton cycle. A compressor section pressurizes an ambient air stream, fuel is added and the mixture is burned in a central combustor section. The combustion products expand through a turbine section where bladed rotors convert thermal energy from the combustion products into mechanical energy for rotating one or more centrally mounted shafts. The shafts, in turn, drive the forward compressor section, thus continuing the cycle. Gas turbine engines are compact and powerful power plants, making them suitable for powering aircraft, heavy equipment, ships and electrical power generators. In power generating applications, the combustion products can also drive a separate power turbine attached to an electrical generator.
For many stator vane assemblies, a fairing is disposed about a frame in order to define a main gas flow path for the gas turbine engine. As the fairing is directly exposed to gas flow, including combustion gases, the fairing can be heated to high temperatures during operation. Heat from the fairing can heat the frame in an undesirable manner.
An assembly for a gas turbine engine includes a first casing, a fairing, and a multi-piece heat shield assembly. The fairing is disposed adjacent the first casing. The multi-piece heat shield assembly includes a first shield mounted to the first casing and extending between the first casing and the fairing, and a second shield mounted to the fairing and extending between the fairing and the first casing.
A gas turbine engine includes a frame, an annularly shaped fairing, and a multi-piece heat shield. The frame has an inner casing, an outer casing, and struts that extend between the inner casing and outer casing. The annularly shaped fairing is disposed adjacent the frame between the inner casing and the outer casing. The multi-piece heat shield is connected to the frame and the fairing. The multi-piece heat shield includes a first shield that extends between the inner casing and the fairing, a second shield that is spaced from and extends across a portion of the first shield and extends between the fairing and the inner casing, and a third shield that extends between the outer radial casing and the fairing.
A method includes connecting a first shield to an upstream portion of an inner radial casing, connecting a second shield to a downstream portion of a fairing, and disposing a third shield comprised of a plurality of arcuate segments within an outer radial casing between a plurality of struts that extend between the inner radial casing and outer radial casing.
This application discloses a multi-piece heat shield that is easily assembled within a frame. The multiple pieces of the heat shield overlap with one another or are joined together to eliminate line-of-sight from the fairings. The heat shield design blocks or reduces radiation heating from the frame, including the inner casing and outer casing, and therefore, allows less expensive materials (steel) to be used for those components.
An exemplary industrial gas turbine engine 10 is circumferentially disposed about a central, longitudinal axis or axial engine centerline axis 12 as illustrated in
In gas turbines, incoming ambient air 30 becomes pressurized air 32 in compressors 16 and 18. Fuel mixes with pressurized air 32 in combustor section 20, where it is burned to produce combustion gases 34 that expand as they flow through turbine sections 22, 24 and power turbine 26. Turbine sections 22 and 24 drive high and low pressure rotor shafts 36 and 38 respectively, which rotate in response to the combustion products and thus attached compressor sections 18, 16. Free turbine section 26 may, for example, drive an electrical generator, pump, or gearbox (not shown).
It is understood that
Frame 42 comprises a stator component of gas turbine engine 10 (
As illustrated in
Fairing 46 is adapted to be disposed within frame 42 between outer radial casing 48 and inner radial casing 50. Outer radial platform 54 of fairing 46 has a generally conical shape. Similarly, inner radial platform 56 has a generally conical shape. Inner radial platform 56 is spaced from outer radial platform 54 by strut liners 58. Strut liners 58 are adapted to be disposed around struts 52 of frame 42.
As illustrated in
Fairing 46 is adapted to be disposed within frame 42 between outer radial casing 48 and inner radial casing 50. Strut liners 58 are adapted to be disposed around struts 52 of frame 42 as well as strut shields 60A and 60B of heat shield 44 when fairing 46 is assembled on frame 42 as illustrated in
Heat shield 44 is disposed between frame 42 and fairing 46 in
Strut shields 60A and 60B extend about struts 52 and are disposed between strut liner 58 and struts 52. Each strut shield 60A and 60B extends generally radially and is connected to outer radial shield 62. Outer radial shield 62 is disposed between outer radial casing 48 and outer radial platform 54. Strut shields 60A and 60B can initially be divided (as illustrated in
Aft shield 64 has a conical shape when assembled and is spaced from but generally extends along inner radial platform 56. In the embodiment of
Together, forward shield 66 and aft shield 64 block line-of-sight from fairing 46 to inner radial casing 50. This reduces or blocks radiant heat transfer from fairing 46 to inner radial casing 50. Additionally, spacing forward shield 66 from aft shield 64 so that the components overlap axially but do not make contact allows for ease of installation and removal of heat shield assembly 44 from frame 42. For example, during assembly forward shield 66 can be inserted in and connected to inner radial casing 50, and then fairing 46 and aft shield 64 can be insert into frame 42 and connected without having forward shield 66 interfere with the assembly process.
In the embodiment shown in
Strut shields 160A and 160B extend about struts 52 and are disposed between strut liner 58 and struts 52. Each strut shield 160A and 160B extends generally radially and is connected to outer radial shield 62. Strut shield 160A does not contact forward shield 166. Strut shield 160B is connected to aft shield 164 along an inner radial portion thereof.
Aft shield 164 has a conical shape when assembled and is spaced from but generally extends along inner radial platform 56. In the embodiment of
Together, forward shield 166 and aft shield 164 block all line-of-sight from fairing 46 to inner radial casing 50. This reduces or blocks radiant heat transfer from fairing 46 to inner radial casing 50. Additionally, spacing forward shield 166 from aft shield 164 so that the components overlap axially but do not make contact due to radial spacing allows for ease of installation and removal of heat shield assembly 144 from frame 42. For example, during assembly forward shield 166 can be inserted in and connected to inner radial casing 50, and then fairing 46 and aft shield 164 can be insert into frame 42 and connected without having forward shield 166 interfere with the assembly process.
Strut shields 260A and 260B extend about struts 52 and are disposed between strut liner 58 and struts 52. Each strut shield 260A and 260B extends generally radially and is connected to outer radial shield 62. Strut shield 260A is spaced from and does not contact forward shield 66. Strut shield 260B is spaced from and does not contact aft shield 264.
Aft shield 264 has a conical shape when assembled and is spaced from but generally extends along inner radial platform 56. In the embodiment of
Together, forward shield 66 and aft shield 264 block all line-of-sight from fairing 46 to inner radial casing 50. This reduces or blocks radiant heat transfer from fairing 46 to inner radial casing 50. Additionally, spacing forward shield 66 from aft shield 264 so that the components overlap axially but do not make contact due to radial spacing allows for ease of installation and removal of heat shield assembly 244 from frame 42. For example, during assembly forward shield 66 can be inserted in and connected to inner radial casing 50, and then fairing 46 and aft shield 264 can be insert into frame 42 and connected without having forward shield 66 interfere with the assembly process.
Strut shields 360A and 360B extend about struts 52 and are disposed between strut liner 58 and struts 52. Each strut shield 360A and 360B extends generally radially and is connected to outer radial shield 62. Strut shield 360A does not contact forward shield 366. Strut shield 360B is connected to aft shield 364 along an inner radial portion thereof.
Aft shield 364 has a conical shape when assembled and is spaced from but generally extends along inner radial platform 56. Aft shield 364 is supported by member 376. Member 376 extends generally radially from and is connected to forward shield 366. Member 376 extends to abut and connect with a middle portion of aft shield 364. Aft shield 364 additionally extends to connect with forward shield 366 along a forward end thereof. In the embodiment of
Forward shield 366 is connected to inner radial casing 50 by flange 368 and bolts. In other embodiments, flange 368 can be connected to inner radial casing 50 by welding, brazing, riveting, or another type of connection. Forward shield 366 is spaced from but extends along a forward portion of inner radial casing 50.
Together, forward shield 366 and aft shield 364 block all line-of-sight from fairing 46 to inner radial casing 50. This reduces or blocks radiant heat transfer from fairing 46 to inner radial casing 50. Additionally, the arrangement of forward shield 366 and aft shield 364 disclosed allows for easy installation and removal of heat shield assembly 344 from frame 42. For example, during assembly forward shield 366 can be inserted in and connected to inner radial casing 50, and then fairing 46 and aft shield 364 can be inserted into frame 42 and connected. Once inserted, aft shield 364 can be welded or otherwise attached to forward shield 366 at a forward end. Member 376 can then be inserted and welded or otherwise attached to both aft shield 364 and forward shield 366.
Strut shields 460A and 460B extend about struts 52 and are disposed between strut liner 58 and struts 52. Each strut shield 460A and 460B extends generally radially and is connected to outer radial shield 62. Both strut shields 460A and 460B are connected to and extend past shield 464F and 464A, respectively. This is accomplished by slots in shield 464F and 464A that receive tabs in strut shield 460A and 460B in one embodiment.
Shields 464A and 464F have a conical shape when assembled and are spaced from but generally extend along inner radial platform 56. In the embodiment of
This application discloses a multi-piece heat shield that is easily assembled within the frame. The multiple pieces of the heat shield overlap with one another or are joined together to eliminate line-of-sight from the fairings. The heat shield design blocks or reduces radiation heating from the frame, including the inner casing and outer casing, and therefore, allows less expensive materials (steel) to be used for those components.
The following are non-exclusive descriptions of possible embodiments of the present invention.
An assembly for a gas turbine engine includes a first casing, a fairing, and a multi-piece heat shield assembly. The fairing is disposed adjacent the first casing. The multi-piece heat shield assembly includes a first shield mounted to the first casing and extending between the first casing and the fairing, and a second shield mounted to the fairing and extending between the fairing and the first casing.
The assembly of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
struts extending from the first casing and supporting a second casing;
the first shield and the second shield include apertures adapted to receive the struts;
a third shield extending between the second casing and the fairing, the third shield includes apertures adapted to receive the struts;
the third shield is comprised of a plurality of connected arcuate segments.
a fourth shield disposed about the struts and extending between the struts and the fairing;
the first shield includes a flange adapted to interface with the casing;
the first shield includes a cylindrical portion that is disposed within the casing;
the second shield is attached to a rib of the fairing;
the second shield is attached to an inner radial platform of the fairing;
second shield is spaced from and extends across the first shield such that a portion of the second shield is disposed between the fairing and a portion of the first shield;
the first shield is connected to the second shield; and
the first shield is intermittently circumferentially connected to the second shield.
A gas turbine engine includes a frame, an annularly shaped fairing, and a multi-piece heat shield. The frame has an inner casing, an outer casing, and struts that extend between the inner casing and outer casing. The annularly shaped fairing is disposed adjacent the frame between the inner casing and the outer casing. The multi-piece heat shield is connected to the frame and the fairing. The multi-piece heat shield includes a first shield that extends between the inner casing and the fairing, a second shield that is spaced from and extends across a portion of the first shield and extends between the fairing and the inner casing, and a third shield that extends between the outer radial casing and the fairing.
The gas turbine engine of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
the first shield, the second shield, and the third assembly include apertures adapted to receive the struts; and
a fourth shield disposed about the struts and extending between the struts and the fairing.
A method includes disposing the plurality of heat shield segments adjacent a casing and between a plurality of struts that extend from the casing, connecting the segments to the casing, and attaching the segments together to form a heat shield having a first portion positioned adjacent the casing and a second portion extending away from the casing.
The method of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
attaching the segments of the third shield together to form a generally conically shaped heat shield;
joining the first shield to the second shield; and
disposing the second shield such that a portion of the second shield is spaced from and extends across a portion of the first shield.
While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art 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 material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/US2013/076392 | 12/19/2013 | WO | 00 |
Number | Date | Country | |
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61747239 | Dec 2012 | US |