WO2016039716A1

WO2016039716A1 - Insulating system for surface of gas turbine engine component

Info

Publication number: WO2016039716A1
Application number: PCT/US2014/054467
Authority: WO
Inventors: Marco Claudio Pio Brunelli; Jan H. Marsh; Paul A. SANDERS; Ralph W. Matthews; Kenneth K. Landis; Jose L. Rodriguez; Gary B. Merrill; Samuel R. Miller, Jr.
Original assignee: Siemens Aktiengesellschaft; Siemens Energy, Inc.
Priority date: 2014-09-08
Filing date: 2014-09-08
Publication date: 2016-03-17
Also published as: TW201621153A

Abstract

An insulating system (10) for a gas turbine engine (12) configured to insulate a surface (14) to reduce thermal gradients within components (18) in the engine (12) is disclosed. The insulating system (10) may include one or more insulating components (18) positioned on a surface (14) of the component (18) within the gas turbine engine (12). The surface (14) may be on a component (18) within an internal cooling system in an airfoil or other appropriate location in the engine (12). The insulating component (18) may include one or more structures (24) configured to locally restrict flow of cooling fluid at the surface (14) of the component (18) within the engine (12), thereby isolating the surface (14) from the mainstream flow and effectively insulating it. Restricting the flow of fluids past the surface (14) will reduce the effective heat transfer at that location where the heating load is less than another location exposed to a cooling system, thereby reducing the thermal gradient and thermal stress and increasing the component life.

Description

INSULATING SYSTEM FOR SURFACE OF

GAS TURBINE ENGINE COMPONENT

FIELD OF THE INVENTION

This invention is directed generally to gas turbine engines, and more particularly to insulating systems for surfaces of components of gas turbine engines.

BACKGROUND

Typically, gas turbine engines include a compressor for compressing air, a combustor for mixing the compressed air with fuel and igniting the mixture, and a turbine blade assembly for producing power. Combustors often operate at high temperatures that may exceed 2,500 degrees Fahrenheit. Typical turbine combustor configurations expose turbine vane and blade assemblies and other components to these high temperatures. As a result, these components must be made of materials capable of withstanding such high temperatures. In addition, turbine vanes and blades and related components often contain cooling systems for prolonging the life of the vanes and blades and reducing the likelihood of failure as a result of excessive temperatures. These turbine engine components that are exposed to the heat generated by the combustors are typically not uniform in temperature. Rather, aspects of a component are colder than other aspects of the component. Typically, the cooling systems expose the cold and hot regions of a component to the cooling fluids alike. As such, the cold and hot regions are cooled, thereby protecting the hot region from overheating, but the thermal gradients and thermal stresses caused by the temperature differences between the cold and hot regions still exist. Thus, a need exists for reducing the thermal gradients and thermal stresses within turbine components to increase the useful life of those components.

SUMMARY OF THE INVENTION

An insulating system for a gas turbine engine configured to insulate a surface to reduce thermal gradients within components in the engine is disclosed. The insulating system may include one or more insulating components positioned on a surface of the component within the gas turbine engine. The surface may be on a component within an internal cooling system in an airfoil or other appropriate location in the engine. The insulating component may include one or more structures configured to locally restrict flow of cooling fluid at the surface of the component within the engine, thereby isolating the surface from the mainstream flow and effectively insulating it. Restricting the flow of fluids past the surface will reduce the effective heat transfer at that location where the heating load is less than another location exposed to a cooling system, thereby reducing the thermal gradient and thermal stress and increasing the component life.

In at least one embodiment, the insulating system for a gas turbine engine may include one or more insulating components positioned on a surface of a component within the gas turbine engine. The insulating component may include one or more structures configured to locally restrict flow of fluid at the surface of the component within the gas turbine engine. The structure forming the insulating component may include a plurality of pins extending from the surface. The pins may be spaced from each other no greater than three times a width each pin. The pins may extend orthogonally from the surface and may be parallel with each other. The pins may extend at an acute angle relative to the surface. In at least one

embodiment, the pins may be formed from a first group of pins extending at a first acute angle relative to the surface in a first direction and a second group of pins extending relative to the surface and in a second direction that is generally opposite to the first direction.

In at least one embodiment, the structure forming the insulating component may be formed from a plurality of nonlinear pins extending from the surface. The nonlinear pins are configured such that a distal tip of the nonlinear pin is positioned upstream of a base of the nonlinear pin. The plurality of pins may be configured such that distal tips of each nonlinear pin are positioned upstream of a base of each nonlinear pin. In at least one embodiment, the base of the nonlinear pin may extend linearly along the surface of the insulating component. In another embodiment, the base of the nonlinear pin may extend nonlinearly along the surface of the insulating component, thereby forming a cupped structure.

In at least one embodiment, one or more of the plurality of nonlinear pins may be configured such that a distal tip of the nonlinear pin is positioned downstream of a base of the nonlinear pin. The nonlinear pin is flexible such that the nonlinear pin is configured to bend such that the distal tip bends further downstream relative to the base when fluid flows past the distal tip. The nonlinear pin may be tapered such that the base is wider than the tip. In at least one embodiment, the nonlinear pin may be formed from a first section extending outwardly from the base and a second section extending outwardly from the first section, wherein the second section is nonparallel to the first section. The nonlinear pin may include a third section extending outwardly from the second section, wherein the third section is nonparallel to the second section.

In at least one embodiment, the structure forming the insulating component includes one or more recesses within the surface of the component of the gas turbine engine. In at least one embodiment, the recess may be formed from a concave dimple. One or more arms may partially covering an opening in the recess. In another embodiment, the recess may be formed from an inverted pyramid having a flat base and four sides nonparallel and nonorthogonal to the base and the surface of the component of the gas turbine engine. In at least one embodiment, the recess may have a smaller opening than a cross-sectional area of the recess taken parallel to the surface of the component of the gas turbine engine. The recess may be formed from linear sides that are generally orthogonal to the surface of the

component of the gas turbine engine.

In at least one embodiment, the recess may include two or more openings on the surface of the component of the gas turbine engine. The at least two openings may be separated each other forming a partially contained dead air pocket within the at least one recess between the at least two openings. In at least one embodiment, the recess may be formed from curved sides forming an elliptical recess viewed orthogonally to the surface of the component of the gas turbine engine. In another embodiment, the recess may have a cross-sectional configuration when view orthogonal to the surface of the component of the gas turbine engine formed from inverted fractal geometries. The surface of the component of the gas turbine engine may be nonlinear and broken up by a plurality of ridges and valleys formed from the inverted fractal geometries. In another embodiment, the structure of the at least one insulating component may be a plurality of honeycomb shaped structures. An advantage of the insulating system is that the insulating system includes components that lower the effective heat transfer at the surface of a turbine component, thereby reducing thermal stress and thermal gradients and increasing component life, either in conjunction with heat transfer enhancing features or alone.

Another advantage of the insulating system is that the insulating system is positioned on aspects of a component exposed to cooling fluids that are at a lower temperature, a cold region, than other aspects of the component that are hotter, a hot region. As such, the aspect the insulating system reduces the effective heat transfer in the cold region so that the thermal difference between the hot region and the cold region is less, thereby reducing thermal stress and thermal gradients.

Yet another advantage of the insulating system is that air that is exposed to the components of the insulating system have its heat load on the component reduced due to the cross-sectional area reduction at the true surface.

These and other embodiments are described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part of the specification, illustrate embodiments of the presently disclosed invention and, together with the description, disclose the principles of the invention.

Figure 1 is a cross-sectional view of a gas turbine engine with the insulating system.

Figure 2 is a perspective view of an airfoil of the gas turbine engine with the insulating system.

Figure 3 is a cross-sectional view of the airfoil taken along section line 3-3 in Figure 2.

Figure 4 is a side view of multiple embodiments of the insulating system. Figure 5 is a side view of another embodiment of the insulating system.

Figure 6 is a top view of another embodiment of the insulating system.

Figure 7 is a side view of another embodiment of the insulating system.

Figure 8 is a side view of another embodiment of the insulating system.

Figure 9 is a perspective view of the embodiment shown in Figure 8. Figure 10 is a perspective view of another embodiment of the insulating system.

Figure 1 1 is a side view of another embodiment of the insulating system. Figure 12 is a side view of another embodiment of the insulating system.

Figure 13 is a side view of another embodiment of the insulating system.

Figure 14 is a side view of another embodiment of the insulating system.

Figure 15 is a side view of another embodiment of the insulating system.

Figure 16 is a side view of another embodiment of the insulating system.

Figure 17 is a side view of another embodiment of the insulating system.

Figure 18 is a perspective view of another embodiment of the insulating system.

Figure 19 is an end view of the embodiment of the insulating system shown in Figure 6.

Figure 20 is a side view of another embodiment of the insulating system similar to the embodiment shown in Figure 6.

Figure 21 is an end view of the embodiment of the insulating system shown in Figure 20.

Figure 22 is a side view of the embodiment of the insulating system shown in Figure 20.

DETAILED DESCRIPTION OF THE INVENTION

As shown in Figures 1 -22, an insulating system 10 for a gas turbine engine 12 configured to insulate a surface 14 to reduce thermal gradients within components 16 in the engine 12 is disclosed. The insulating system 10 may include one or more insulating components 18 positioned on the surface 14 of the component 16 within the gas turbine engine 12. The surface 14 may be on a component 16 within an internal cooling system 20 in an airfoil 22 or other appropriate location in the engine 12. The insulating component 18 may include one or more structures 24 configured to locally restrict flow of fluid at the surface 14 of the component 16 within the engine 12, thereby isolating the surface from the mainstream flow and effectively insulating it. Restricting the flow of fluids past the surface 14 will reduce the effective heat transfer at that location where the heating load is less than another location exposed to a cooling system 20, thereby reducing the thermal gradient and thermal stress and increasing the component life.

The insulating system 10 may be positioned on an surface 14 in which the temperature of the surface 14 and component 16 is desired to change little, if at all, from exposure to fluid at a different temperature. In at least one embodiment, the insulating system 10 may be positioned on an surface 14 that is exposed to one or more cooling fluids, such as, but not limited to, air. As such, in at least one embodiment, the insulating system 10 may be positioned on an surface 14 exposed to an internal cooling system 20. In at least one embodiment, the surface 14 may be positioned within an internal cooling system 20 positioned in an airfoil 22 within the gas turbine engine 12. In at least one embodiment, as shown in Figures 2 and 3, the airfoil 22 may be a generally elongated hollow airfoil 70 formed from an outer wall 72, and having a leading edge 74, a trailing edge 76, a pressure side 78, a suction side 80, a root 82 at a first end 84 of the airfoil 22 and a tip 86 at a second end 88 opposite to the first end 84, and the internal cooling system 20 positioned within interior aspects of the generally elongated hollow airfoil 70. The airfoil 22 may be a compressor or turbine airfoil. The airfoil 22 may also be a vane or blade. The insulating system 10 is not limited to being placed within an airfoil 22, but may also be positioned on other surfaces 14 of an engine 12.

In at least one embodiment, the insulating system 10 may include one or more insulating components 18 positioned on a surface 14 of a component 16 within the gas turbine engine 12. The insulating component 18 may include one or more structures 24 configured to locally restrict flow of fluid at the surface 14 of the component 16 within the gas turbine engine 12. The structure 24 forming the insulating component 18 may include a plurality of pins 26 extending from the surface 14, as shown in Figure 4. The pins 26 may be spaced from each other no greater than three times a width each pin 26. The pins 26 may be separated from each other a distance equal to a width of the pins 26. The pins 26 may also have a length greater than about twice a width of the pins 26. In at least one embodiment, the pins 26 may have a length between about three times a width of the pins 26 and about ten times a width of the pins 26. The pins 26 may extend orthogonally from the surface 14 and may be parallel with each other. The pins 26 may extend at an acute angle relative to the surface 14. The pins 26 may be formed from a first group 28 of pins 26 extending at a first acute angle 30 relative to the surface 14 in a first direction 32 and a second group 34 of pins 26 extending at a second acute angle 31 relative to the surface 14 and in a second direction 36 that is generally opposite to the first direction 32.

As shown in Figures 8-10 and 13-15, the structure 24 forming the insulating component 18 may include a plurality of nonlinear pins 26 extending from the surface 14. One or more of the plurality of nonlinear pins 26 may be configured such that a distal tip 38 of the nonlinear pin 26 is positioned upstream of a base 40 of the nonlinear pin 26. In at least one embodiment, the plurality of pins 26 may be configured such that distal tips 38 of each nonlinear pin 26 is positioned upstream of a base 40 of each nonlinear pin 26. As shown in Figure 9, the base 40 of the nonlinear pin 26 may extend linearly along the surface 14 of the insulating component 18. In another embodiment, as shown in Figure 10, the base 40 of the nonlinear pin 26 may extend nonlinearly along the surface 14 of the insulating component 18, thereby forming a cupped structure 24. In at least one embodiment, the nonlinear pins 26 may form a cupped structure 24. One or more of the cupped structures 24 faces upstream.

In at least one embodiment, as shown in Figures 8 and 13-15, the one or more of the plurality of nonlinear pins 26 may be configured such that a distal tip 38 of the nonlinear pin 26 is positioned downstream of a base 40 of the nonlinear pin 26. The nonlinear pin 26 may be flexible such that the nonlinear pin 26 is

configured to bend such that the distal tip 38 bends further downstream relative to the base 40 when fluid flows past the distal tip 38. In at least one embodiment, the flexible, nonlinear pin 26 may bend to such an extent that the distal tip 38 may move further downstream than an upstream side 42 of an adjacent nonlinear pin 26. As shown in Figure 13, the nonlinear pin 26 may be tapered such that the base 40 is wider than the tip 38.

As shown in Figures 14 and 15, the nonlinear pin 26 may be formed from a first section 44 extending outwardly from the base 40 and a second section 46 extending outwardly from the first section 44. The second section 46 may be nonparallel to the first section 44. The nonlinear pin 26 may include a third section 48 extending outwardly from the second section 46, wherein the third section 48 may be nonparallel to the second section 46.

As shown in Figure 5, 1 1 , 12 and 16-18, the structure forming the insulating component 18 may include one or more recesses 50 within the surface 14 of the component 16 of the gas turbine engine 12. The recess 50 may be formed from a concave dimple. In at least one embodiment, as shown in Figure 5, the insulating system 10 may include one or more arms 52 partially covering an opening 54 in the recess 50. In at least one embodiment, the recess 50 may be formed from an inverted pyramid 51 attached to the surface 14, as shown in Figures 6, 7 and 19-22, having a flat base 54 and four sides 56 nonparallel and nonorthogonal to the base 54 and the surface 14 of the component 16 of the gas turbine engine 12. As shown in Figures 20-21 , the inverted pyramids 51 may be attached to each other via a bridge 53 in one direction to increase efficiency.

As shown in Figure 18, the structure 24 forming the insulating component 18 may include a recess 50 formed from a honeycomb shape. In at least one embodiment, a plurality of recesses 50 having a honeycomb shape may be positioned in close proximity such that only a thin wall separates each honeycomb shaped recess 50. In another embodiment, the honeycomb shaped structure 24 may be formed from a plurality of ribs 90 extending outwardly from the surface 14.

In another embodiment, as shown in Figures 1 1 and 12, the recess 50 may have a smaller opening 58 than a cross-sectional area of the recess 50 taken parallel to the surface 14 of the component 16 of the gas turbine engine 12. As shown in Figure 1 1 , the recess 50 may be formed from linear sides 56 that are generally orthogonal to the surface 14 of the component 16 of the gas turbine engine 12. The linear sides 56 may form a generally rectangular recess 50 viewed orthogonally to the surface 14 of the component 16 of the gas turbine engine 12. In another embodiment, as shown in Figure 16, the recess 50 may include at least two openings 58 on the surface 14 of the component 16 of the gas turbine engine 12. The two openings 58 may be separated from each other forming a partially contained dead air pocket 60 within the recess 50 between the two openings 58. In at least one embodiment, the openings 58 are located closer to ends 62 of the dead air pocket 60 than a midpoint 64. The openings 58 may have a diameter that is less than 1/5 of a length of the dead air pocket 60. In another embodiment, the openings 58 may have a diameter that is less than 1/10 of a length of the dead air pocket 60. As shown in Figure 12, the recess 50 may be formed from curved sides 56 forming an elliptical recess 50 viewed orthogonally to the surface 14 of the component 16 of the gas turbine engine 12.

In yet another embodiment, as shown in Figure 17, the recess 50 may have a cross-sectional configuration when view orthogonal to the surface 14 of the component 16 of the gas turbine engine 12 formed from inverted fractal geometries. The surface 14 of the component 16 of the gas turbine engine 12 may be nonlinear and broken up by a plurality of ridges 66 and valleys 68 formed from the inverted fractal geometries.

During use, cooling fluid is passed into the cooling system 20. The cooling fluid flows past the insulating system 10. The various embodiments of the insulating system 10 described above and shown in the figures limit exposure of a surface 14 to the cooling fluids. Rather, the embodiments of the insulating system 10 capture fluid, such as air, by the surface and slow the process of replacement of that fluid, thereby allowing that air to be heated and remain in place near the surface 14. As such, the effective heat transfer from the surface 14 is reduced.

The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of this invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of this invention.

Claims

CLAIMS I claim:

1 . An insulating system (10) for a gas turbine engine (12), characterized in that:

at least one insulating component (18) positioned on a surface (14) of a component (18) within the gas turbine engine (12);

wherein the at least one insulating component (18) includes at least one structure (24) configured to locally restrict flow of fluid at the surface (14) of the component (18) within the gas turbine engine (12).

2. The insulating system (10) of claim 1 , characterized in that the at least one structure (24) forming the at least one insulating component (18) comprises a plurality of pins (26) extending from the surface (14).

3. The insulating system (10) of claim 2, characterized in that the pins (26) are spaced from each other no greater than three times a width each pin (26).

4. The insulating system (10) of claim 2, characterized in that the pins (26) extend orthogonally from the surface (14) and are parallel with each other.

5. The insulating system (10) of claim 2, characterized in that the pins (26) extend at an acute angle relative to the surface (14).

6. The insulating system (10) of claim 5, characterized in that the pins (26) are formed from a first group (28) of pins (26) extending at a first acute angle (30) relative to the surface (14) in a first direction (32) and a second group (34) of pins (26) extending relative to the surface (14) and in a second direction (36) that is generally opposite to the first direction (32).

7. The insulating system (10) of claim 1 , characterized in that the at least one structure (24) forming the at least one insulating component (18) comprises a plurality of nonlinear pins (26) extending from the surface (14).

8. The insulating system (10) of claim 7, characterized in that at least one of the plurality of nonlinear pins (26) are configured such that a distal tip (38) of the at least one nonlinear pin (26) is positioned upstream of a base (40) of the at least one nonlinear pin (26).

9. The insulating system (10) of claim 8, characterized in that the base (40) of the at least one nonlinear pin (26) extends linearly along the surface (14) of the at least one insulating component (18).

10. The insulating system (10) of claim 8, characterized in that the base (40) of the at least one nonlinear pin (26) extends nonlinearly along the surface (14) of the at least one insulating component (18), thereby forming a cupped structure (24).

1 1 . The insulating system (10) of claim 7, characterized in that at least one of the plurality of nonlinear pins (26) are configured such that a distal tip (38) of the at least one nonlinear pin (26) is positioned downstream of a base (40) of the at least one nonlinear pin (26).

12. The insulating system (10) of claim 1 1 , characterized in that the at least one nonlinear pin (26) is flexible such that the at least one nonlinear pin (26) is configured to bend such that the distal tip (38) bends further downstream relative to the base (40) when fluid flows past the distal tip (38).

13. The insulating system (10) of claim 1 1 , characterized in that the at least one nonlinear pin (26) tapered such that the base (40) is wider than the tip (38).

14. The insulating system (10) of claim 1 1 , characterized in that at least one nonlinear pin (26) is formed from a first section (44) extending outwardly from the base (40) and a second section (46) extending outwardly from the first section (44), wherein the second section (46) is nonparallel to the first section (44).

15. The insulating system (10) of claim 14, characterized in that at least one nonlinear pin (26) includes a third section (48) extending outwardly from the second section (46), wherein the third section (48) is nonparallel to the second section (46).

16. The insulating system (10) of claim 1 , characterized in that the at least one structure (24) forming the at least one insulating component (18) comprises at least one recess (50) within the surface (14) of the component (18) of the gas turbine engine (12).

17. The insulating system (10) of claim 16, characterized in that the at least one recess (50) is formed from a concave dimple.

18. The insulating system (10) of claim 17, further characterized in that at least one arm (52) partially covering an opening (58) in the at least one recess (50).

19. The insulating system (10) of claim 16, characterized in that the at least one recess (50) has a smaller opening (58) than a cross-sectional area of the recess (50) taken parallel to the surface (14) of the component (18) of the gas turbine engine (12).

20. The insulating system (10) of claim 16, characterized in that the at least one recess (50) is formed from linear sides (56) that are generally orthogonal to the surface (14) of the component (18) of the gas turbine engine (12).

21 . The insulating system (10) of claim 16, characterized in that the at least one recess (50) includes at least two openings (58) on the surface (14) of the component (18) of the gas turbine engine (12) and wherein the at least two openings (58) are separated each other forming a partially contained dead air pocket (60) within the at least one recess (50) between the at least two openings (58).

22. The insulating system (10) of claim 16, characterized in that the at least one recess (50) is formed from curved sides forming an elliptical recess (50) viewed orthogonally to the surface (14) of the component (18) of the gas turbine engine (12).

23. The insulating system (10) of claim 16, characterized in that the at least one recess (50) has a cross-sectional configuration when view orthogonal to the surface (14) of the component (18) of the gas turbine engine (12) formed from inverted fractal geometries.

24. The insulating system (10) of claim 23, characterized in that the surface (14) of the component (18) of the gas turbine engine (12) is nonlinear and broken up by a plurality of ridges (66) and valleys (68) formed from the inverted fractal geometries.

25. The insulating system (10) of claim 16, characterized in that the at least one structure (24) forming the at least one insulating component (18) comprises at least one recess (50) attached to the surface (14) of the component (18) of the gas turbine engine (12), wherein the at least one recess (50) is formed from an inverted pyramid (51 ) having a flat base (54) and four sides (56) nonparallel and

nonorthogonal to the base (40).

26. The insulating system (10) of claim 25, characterized in that adjacent inverted pyramids (51 ) are coupled together via a bridge (51 ).

27. The insulating system (10) of claim 1 , characterized in that the at least one structure (24) of the at least one insulating component (18) is a plurality of honeycomb shaped structures (24).