Title:
Turbine vane with divided turbine vane platform
Kind Code:
A1


Abstract:
A turbine vane with endwalls, wherein at least one endwall is formed from two or more sections configured such that the sections form releasable joints with a generally elongated airfoil of the turbine vane. The sections may be configured to both support the generally elongated airfoil and to establish cooling fluid flowpaths between the sections and the generally elongated airfoil to cool the aspects of the turbine vane proximate to the intersection of the endwalls and the generally elongated airfoil. In addition, the joints between the generally elongated airfoil and the sections may be formed from a connection system that enables forces to be transmitted from the generally elongated airfoil to the endwalls without creating stresses found in conventional turbine vane fillets at the intersection between the generally elongated airfoil and the endwalls.



Inventors:
Marini, Bonnie D. (Oviedo, FL, US)
Application Number:
11/807390
Publication Date:
12/04/2008
Filing Date:
05/29/2007
Assignee:
Siemens Power Generation, Inc.
Primary Class:
International Classes:
F01D5/14
View Patent Images:
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Primary Examiner:
VERDIER, CHRISTOPHER M
Attorney, Agent or Firm:
Siemens Corporation;Intellectual Property Department (170 Wood Avenue South, Iselin, NJ, 08830, US)
Claims:
I claim:

1. A turbine vane, comprising: a generally elongated airfoil formed from an outer wall, and having a leading edge, a trailing edge, a pressure side, and a suction side, a first endwall at a first end, a second endwall at a second end opposite the first end; wherein the first endwall is formed from at least first and second sections positioned adjacent to each other and to the airfoil such that each section forms a releasable joint with the generally elongated airfoil; wherein the first section includes a hot gas path surface generally orthogonal to the generally elongated airfoil, a cold side surface opposite to the hot gas path surface, an upstream edge, a downstream edge opposite to the upstream edge, and first and second side edges opposite to each other, wherein the first side edge of the first section is positioned in close proximity with the generally elongated airfoil; wherein the first section includes a first section attachment system on the first side edge of the first section, the first section attachment system being formed from at least one loading bearing surface for transferring loads from the generally elongated airfoil to the first section so that the first section supports and positions the turbine vane within a turbine engine and including at least one cooling fluid channel on the first side edge that is defined by the first side edge of the first section and the outer surface of the generally elongated airfoil to cool a region of the airfoil at an intersection between the generally elongated airfoil and the first section, wherein the at least one cooling fluid channel creates a cooling fluid pathway for cooling fluids to flow between the first section and the generally elongated airfoil.

2. The turbine vane of claim 1, wherein the second section includes a hot gas path surface generally orthogonal to the generally elongated airfoil, a cold side surface opposite to the hot gas path surface, an upstream edge, a downstream edge opposite to the upstream edge, and first and second side edges opposite to each other, wherein the first side edge of the second section is positioned in close proximity with the generally elongated airfoil. wherein the second section includes a second section attachment system on the first side edge of the second section, the second section attachment system being formed from at least one loading bearing surface for transferring loads from the generally elongated airfoil to the second section so that the second section supports and positions the turbine vane within a turbine engine and including at least one cooling fluid channel on the first side edge that is defined by the first side edge of the second section and the outer surface of the generally elongated airfoil to cool a region of the airfoil at an intersection between the generally elongated airfoil and the second section, wherein the at least one cooling fluid channel creates a cooling fluid pathway for cooling fluids to flow between the second section and the generally elongated airfoil.

3. The turbine vane of claim 2, wherein the at least one load bearing surface of the first section attachment system is positioned on a projection extending from the first side edge of the first section that is received within a groove in the generally elongated airfoil.

4. The turbine vane of claim 3, wherein the projection extends along the first side edge of the first section a length generally equal to a distance between the leading and trailing edges of the generally elongated airfoil.

5. The turbine vane of claim 3, wherein the projection extends along the first side edge of the first section a length generally equal to a distance between the upstream edge to the downstream edge of the first section and wherein the projection is received within the groove in the generally elongated airfoil and within grooves in the first side edge of the second section.

6. The turbine vane of claim 1, wherein the second side edge of the first section is shaped with a cutaway section that fits around an outer surface of the generally elongated airfoil.

7. The turbine vane of claim 1, wherein the second endwall is formed from at least first and second sections positioned adjacent to each other such that each section forms a releasable joint with the generally elongated airfoil.

8. The turbine vane of claim 7, wherein the first section of the second endwall includes a hot gas path surface generally orthogonal to the generally elongated airfoil, a cold side surface opposite to the hot gas path surface, an upstream edge, a downstream edge opposite to the upstream edge, and first and second side edges opposite to each other, wherein the first side edge of the first section of the second endwall is positioned in close proximity with the generally elongated airfoil; wherein the first section of the second endwall includes a third section attachment system on the first side edge of the first section, the third section attachment system being formed from at least one loading bearing surface for transferring loads from the generally elongated airfoil to the first section so that the first section supports and positions the turbine vane within a turbine engine and including at least one cooling fluid channel on the first side edge that is defined by the first side edge of the first section of the second endwall and the outer surface of the generally elongated airfoil to cool a region of the airfoil at an intersection between the generally elongated airfoil and the first section, wherein the at least one cooling fluid channel creates a cooling fluid pathway for cooling fluids to flow between the first section of the second endwall and the generally elongated airfoil.

9. The turbine vane of claim 8, wherein the second section of the second endwall includes a hot gas path surface generally orthogonal to the generally elongated airfoil, a cold side surface opposite to the hot gas path surface, an upstream edge, a downstream edge opposite to the upstream edge, and first and second side edges opposite to each other, wherein the first side edge of the second section of the second endwall is positioned in close proximity with the generally elongated airfoil; wherein the second section of the second endwall includes a fourth section attachment system on the first side edge of the second section, the fourth section attachment system being formed from at least one loading bearing surface for transferring loads from the generally elongated airfoil to the second section of the second endwall so that the second section of the second endwall supports and positions the turbine vane within a turbine engine and including at least one cooling fluid channel on the first side edge that is defined by the first side edge of the second section of the second endwall and the outer surface of the generally elongated airfoil to cool a region of the airfoil at an intersection between the generally elongated airfoil and the second section, wherein the at least one cooling fluid channel creates a cooling fluid pathway for cooling fluids to flow between the second section of the second endwall and the generally elongated airfoil.

10. The turbine vane of claim 9, wherein the at least one load bearing surface of the third section attachment system is positioned on a projection extending from the first side edge of the first section that is received within a groove in the generally elongated airfoil.

11. The turbine vane of claim 9, wherein the projection extends along the first side edge of the first section of the second endwall a length generally equal to a distance between the leading and trailing edges of the generally elongated airfoil.

12. The turbine vane of claim 9, wherein the projection extends along the first side edge of the first section of the second endwall a length generally equal to a distance between the upstream edge to the downstream edge of the first section and wherein the projection is received within the groove in the generally elongated airfoil and within grooves in the first side edge of the second section of the second endwall.

13. The turbine vane of claim 8, wherein the second side edge of the first section of the second endwall is shaped with a cutaway section that fits around an outer surface of the generally elongated airfoil.

14. A turbine vane, comprising: a generally elongated airfoil formed from an outer wall, and having a leading edge, a trailing edge, a pressure side, and a suction side, a first endwall at a first end, a second endwall at a second end opposite the first end; wherein the first endwall is formed from at least first and second sections positioned adjacent to each other such that each section forms a releasable joint with the generally elongated airfoil, and wherein the second endwall is formed from at least first and second sections positioned adjacent to each other such that each section forms a releasable joint with the generally elongated airfoil; wherein the first and second sections of the first and second endwalls each include a hot gas path surface generally orthogonal to the generally elongated airfoil, a cold side surface opposite to the hot gas path surface, an upstream edge, a downstream edge opposite to the upstream edge, and first and second side edges opposite to each other, wherein the first side edge is positioned in close proximity with the generally elongated airfoil; wherein the first section of the first endwall includes a first section attachment system on the first side edge of the first section of the first endwall, the first section attachment system being formed from at least one loading bearing surface for transferring loads from the generally elongated airfoil to the first section of the first endwall so that the first section supports and positions the turbine vane within a turbine engine and including at least one cooling fluid channel on the first side edge that is defined by the first side edge of the first section of the first endwall and the outer surface of the generally elongated airfoil to cool a region of the airfoil at an intersection between the generally elongated airfoil and the first section, wherein the at least one cooling fluid channel creates a cooling fluid pathway for cooling fluids to flow between the first section and the generally elongated airfoil; wherein the second section of the first endwall includes a second section attachment system on the first side edge of the second section of the first endwall, the second section attachment system being formed from at least one loading bearing surface for transferring loads from the generally elongated airfoil to the second section of the first endwall so that the first section supports and positions the turbine vane within a turbine engine and including at least one cooling fluid channel on the first side edge that is defined by the first side edge of the second section of the first endwall and the outer surface of the generally elongated airfoil to cool a region of the airfoil at an intersection between the generally elongated airfoil and the second section, wherein the at least one cooling fluid channel creates a cooling fluid, pathway for cooling fluids to flow between the second section of the first endwall and the generally elongated airfoil; wherein the first section of the second endwall includes a third section attachment system on the first side edge of the first section of the second endwall, the third section attachment system being formed from at least one loading bearing surface for transferring loads from the generally elongated airfoil to the first section of the second endwall so that the first section supports and positions the turbine vane within a turbine engine and including at least one cooling fluid channel on the first side edge that is defined by the first side edge of the first section of the second endwall and the outer surface of the generally elongated airfoil to cool a region of the airfoil at an intersection between the generally elongated airfoil and the first section, wherein the at least one cooling fluid channel creates a cooling fluid pathway for cooling fluids to flow between the first section and the generally elongated airfoil; wherein the second section of the second endwall includes a fourth section attachment system on the first side edge of the second section of the second endwall, the fourth section attachment system being formed from at least one loading bearing surface for transferring loads from the generally elongated airfoil to the second section of the second endwall so that the first section supports and positions the turbine vane within a turbine engine and including at least one cooling fluid channel on the first side edge that is defined by the first side edge of the second section of the second endwall and the outer surface of the generally elongated airfoil to cool a region of the airfoil at an intersection between the generally elongated airfoil and the second section, wherein the at least one cooling fluid channel creates a cooling fluid pathway for cooling fluids to flow between the second section of the second endwall and the generally elongated airfoil.

Description:

FIELD OF THE INVENTION

This invention is directed generally to stationary turbine vanes, and more particularly to platforms of turbine vanes.

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 to high temperatures. As a result, turbine vanes and blades must be made of materials capable of withstanding such high temperatures, or must include cooling features to enable the component to survive in an environment which exceeds the capability of the material. Turbine engines typically include a plurality of rows of stationary turbine vanes extending radially inward from a shell and include a plurality of rows of rotatable turbine blades attached to a rotor assembly for turning the rotor.

Typically, the turbine vanes 4 are formed from inner and outer endwalls attached to an airfoil extending therebetween. The endwalls extend generally orthogonally outward from a longitudinal axis of the turbine vanes. Typically, advanced turbine vanes are made by investment casting which are then put through a series of machining processes and assembly processes to incorporate the cooling circuit. Fillets are formed at the intersection between the airfoil and the endwalls. Turbine vanes may be cantilevered and supported at the ID and OD ends of the turbine vanes which is typical of stages beyond the first stage vane, or may be simply supported, which is typical of a first stage vane. Such support schemes for turbine vanes provide fail-safe support structures operable under extreme structural and thermal loading. The endwalls of the turbine vanes are typically butted together at joints that are remote from the airfoils of the turbine vanes, as shown in FIG. 1. Typically, cooling fluids leak through these joints. The cooling fluid leakage does not ordinarily provide significant benefit to the turbine engine in which the turbine vane is positioned. Rather, the cooling fluid leakage negatively effects the efficiency of the turbine engine. During use, high temperatures and high stresses are typically found at the fillets at the intersection of the airfoil and the endwalls. Traditionally, cooling the fillet has proven to be very difficult. The high temperature and high stresses in this region often cause cracking of the vane shroud thereby causing reduced part life and increased expense. Thus, a need exists for a turbine vane with a cooling scheme for cooling the region at the intersection between the turbine airfoil and the endwalls.

SUMMARY OF THE INVENTION

This invention relates to a turbine vane with endwalls formed from two or more sections having joints along the airfoils. The sections may be configured such that the sections form releasable joints with a generally elongated airfoil of the turbine vane. The airfoil may incorporate a serpentine cooling circuit and internal impringement cooling of any variety of cooling circuits used to cool turbine airfoils. The sections may be configured to support the generally elongated airfoil and to establish cooling fluid flowpaths between the sections and the generally elongated airfoil to cool the aspects of the turbine vane proximate to the intersection of the endwalls and the generally elongated airfoil. In addition, the joints between the generally elongated airfoil and the sections may be formed from a connection system that enables forces to be transmitted from the generally elongated airfoil to the endwalls without creating thermal stresses found in conventional turbine vane fillets at the intersection between the generally elongated airfoil and the endwalls.

The turbine vane may be formed from a generally elongated airfoil formed from an outer wall, and having a leading edge, a trailing edge, a pressure side, and a suction side, a first endwall at a first end, and a second endwall at a second end opposite the first end. The first and second endwalls may be formed from at least first and second sections positioned adjacent to each other such that each section forms a releasable joint with the generally elongated airfoil. The first and second sections of the first and second endwalls may each include a hot gas path surface that is generally orthogonal to the generally elongated airfoil, a cold side surface opposite to the hot gas path surface, an upstream edge, a downstream edge opposite to the upstream edge, and first and second side edges opposite to each other. The first side edge of the first section and the second side edge of the second section may be positioned in close proximity with the generally elongated airfoil.

The first section may include a first section attachment system on the first side edge of the first section. The first section attachment system may be formed from at least one loading bearing surface for transferring loads from the generally elongated airfoil to the first section so that the first section supports and positions the turbine vane within a turbine engine. The first section attachment system may include at least one cooling fluid channel on the first side edge that is defined by the first side edge of the first section and the outer surface of the generally elongated airfoil to cool a region of the airfoil at an intersection between the generally elongated airfoil and the first section. Alternately, the airfoil may be the load bearing member and the first section may be attached to the airfoil transferring load from the section, to the airfoil. The at least one cooling fluid channel may create a cooling fluid pathway for cooling fluids to flow between the first section and the generally elongated airfoil. The first section attachment system does not include cooling fluid channels between the upstream edge and the leading edge of the airfoil and between the trailing edge of the airfoil and the downstream edge of the section. Alternatively, the design may be created such that a seal is placed in the region of the joint to minimize leakage in the region between the upstream edge and the leading edge of the airfoil and between the trailing edge of the airfoil and the downstream edge of the section.

At least one load bearing surface of the first section attachment system may be positioned on a projection extending from the first side edge of the first section that is received within a groove in the generally elongated airfoil. The projection may extend along the first side edge of the first section a length generally equal to a distance between the leading and trailing edges of the generally elongated airfoil. In another embodiment, the projection may extend along the first side edge of the first section a length generally equal to a distance between the upstream edge to the downstream edge of the first section. The projection may be received within the groove in the generally elongated airfoil and within grooves in the second side edge of the second section. The second side edge of the first section may be shaped with a cutaway section that fits around an outer surface of the generally elongated airfoil. In an alternate embodiment, the at least one load bearing surface may be attached to the airfoil with bolts, clamps or other mechanical means which employ a protrusion from the lower part of the section which is mechanically attached to the airfoil through bolts, hooks, clamps, or other mechanical means.

The second section of the first endwall may include a second section attachment system configured similarly to the first section attachment system. In addition, the first and second section attachment systems may be configured to attach together in regions upstream from the leading edge of the turbine airfoil and downstream from the trailing edge of the turbine airfoil where the adjacent sections contact each other. Similarly, the first and second sections of the second endwall may include third and fourth section attachment systems, thereby forming a single component with a plurality of airfoils.

An advantage of this invention is that the joint between adjacent endwalls for turbine vanes is positioned at the intersections of a turbine airfoil and the endwalls. Such a configuration enables the cooling fluids to be exhausted at the intersection of the turbine airfoil of the turbine vane and the endwalls, thereby cooling a region that has been traditionally difficult to cool.

Another advantage of this invention is that the attachment system for attaching the endwalls to the turbine airfoil includes one or more cooling channels for providing cooling fluid pathways through the load bearing surfaces at the joints to provide cooling fluids to form film cooling while enabling loads to be transferred from the endwalls airfoil and vice versa. The cooling channels may be individually sized and configured to optimize cooling of the adjacent region of the airfoil.

Yet another advantage of this invention is that by forming an endwall from a plurality of sections that are releasably joined together, components of the turbine vane, such as the sections and airfoil, may be easily replaced in a cost effective manner.

Another advantage of this invention is that the turbine vane uses cooling fluids that were previously wasted in conventional systems by being exhausted through joints positioned in a non-optimized region between adjacent turbine vanes.

Still another advantage of this invention is that the turbine vane eliminates stresses because a rigid connection such as that which exists in a single piece casting as the welded intersection is not required between the airfoil and endwall of conventional systems.

Another advantage of this invention is that the configuration of the turbine vane may be easily changed. For instance, the angle of position of the turbine vane may be easily changed by removing the sections of the turbine vane and replacing them with alternate sections that cause the vane to be oriented in a different angle in the gas path. Because the turbine airfoil of the turbine vane may be so easily replaced, the turbine vane may be easily customized to a particular load application for increased efficiency.

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.

FIG. 1 is an end view of conventional turbine vanes positioned adjacent one another in a turbine engine with joints of adjacent endwalls between,the airfoils.

FIG. 2 is an end view of turbine vanes of the instant invention.

FIG. 3 is a perspective view of a turbine vane of this invention with first and second endwalls.

FIG. 4 is a perspective view of a partial turbine vane of this invention with only a first sidewall.

FIG. 5 is a perspective view of a partial turbine vane of this invention with a first section forming a portion of the first endwall.

FIG. 6 is a detailed cross-section of an attachment system taken at detail line 6-6 in FIG. 3 usable to attach the endwalls to the generally elongated airfoil of the turbine vane.

FIG. 7 is a partial detail view of an attachment system formed from a protrusion with cooling fluid channels.

FIG. 8 is a partial detail view of another embodiment of the attachment system formed from a protrusion with cooling fluid channels.

FIG. 9 is a detailed cross-section of another embodiment of the attachment system shown in FIG. 6.

FIG. 10 is a front view of a side edge of a section with a protrusion having load bearing surfaces and cooling channels taken at line 10-10 in FIG. 7.

FIG. 11 is a front view of a side edge of a section with a protrusion having an alternative configuration of load bearing surfaces and cooling channels taken at line 11-11 in FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 2-11, this invention is directed to a turbine vane 10 with endwalls 12 formed from two or more sections 14. The sections 14 may be configured such that the sections 14 form releasable joints 18 with a generally elongated airfoil 16 of the turbine vane 10 at the airfoil 16. The sections 14 may be configured 14 to both support the generally elongated airfoil 16 and to establish cooling fluid flowpaths between the sections 14 and the generally elongated airfoil 16 to cool the aspects of the turbine vane 10 proximate to the intersection of the endwalls 12 and the generally elongated airfoil 16. In addition, the joints 18 between the generally elongated airfoil 16 and the sections 14 may be formed from a connection system that enables forces to be transmitted from the generally elongated airfoil 16 to the endwalls 12 without creating stresses found in conventional turbine vane fillets at the intersection between the generally elongated airfoil 16 and the endwalls 12.

As shown in FIGS. 4 and 5, the turbine vane 10 may be formed from a generally elongated airfoil 16 formed from an outer wall 20, and having a leading edge 22, a trailing edge 24, a pressure side 26, and a suction side 28, a first endwall 30 at a first end 32, and a second endwall 34 at a second end 36 opposite the first end 32. The generally elongated airfoil 16 may have any appropriate profile configured for use in a turbine engine.

The endwalls 12 of the turbine vane 10 support and position the generally elongated airfoil 16 within a turbine engine. The endwalls 12 are thus configured to transfer loads (forces) from the generally elongated airfoil 16 to the endwalls 12. In particular, one or both of the endwalls 12 may be formed from two or more sections 14. As shown in FIG. 2-4, an endwall 12, such as the first endwall 30, may be formed from a first section 38 and a second section 40. The sections 38, 40 may each include a hot gas path surface 42, 44 positioned generally orthogonal to the generally elongated airfoil 16, a cold side surface 46, 48 opposite to the hot gas path surface 42, 44, an upstream edge 50, 52, a downstream edge 54, 56 opposite to the upstream edge 50, 52, and a first side edge 58, 60 and a second side edge 62, 64 opposite to each other, respectively. The first and second sections 38, 40 may be configured such that the upstream edges 50, 52 are positioned upstream from the leading edge 22, and the downstream edges 54, 56 are positioned downstream from the trailing edge 24. As such, the first and second sections 38, 40 may contact each other upstream from the leading edge 22 and downstream of the trailing edge 24 of the generally elongated airfoil 16. The first and second sections 38, 40 may include cutaway airfoil sections 66, 68 that correspond to the pressure and suction sides 26, 28 of the generally elongated airfoil 16, respectively. The cutaway airfoil sections 66, 68 enable the generally elongated airfoil 16 to fit within the cutaway airfoil sections 66, 68 and for the first and second sections 38, 40 to form joints 18 with each other upstream and downstream from the generally elongated airfoil 16. The joints 18 upstream and downstream from the generally elongated airfoil 16 may be aligned with a midline of the turbine vane 10, as shown in FIG. 2.

The first side edge 58 of the first section 38 may be positioned in close proximity with pressure side 26 of the generally elongated airfoil 16 and the second side edge 64 of the second section 40 may be positioned in close proximity with the suction side 28 of the generally elongated airfoil 16. The first side edges 58, 60 and the second side edges 62, 64 of the first and second sections 38, 40 may be configured to form joints 18 with the generally elongated airfoil 16, as described in more detail below.

The turbine vane 10 may also include a first section attachment system 70 on the first side edge 58 of the first section 38, the first section attachment system 70 may be formed from at least one load bearing surface 72 for transferring loads from the generally elongated airfoil 16 to the first section 38 so that the first section 38 supports and positions the turbine vane 10 within a turbine engine. The load bearing surface 72 may be formed from one or more load bearing surfaces 72 positioned at the cutaway section 66. The first section attachment system 70 may include at least one cooling fluid channel 74 on the first side edge 58 that is defined by the first side edge 58 of the first section 38 and the outer surface 20 of the generally elongated airfoil 16 to cool a region of the airfoil 16 at an intersection between the generally elongated airfoil 16 and the first section 38. The cooling fluid channel 74 may create a cooling fluid pathway for cooling fluids to flow between the first section 38 and the generally elongated airfoil 16.

The cooling fluid channel 74 may be formed from various appropriate configurations. For instance, the cooling fluid channel 74 may have a semicircular cross-sectional shape, as shown in FIG. 7 and 10, a slight depression in the first side edge 58, as shown in FIG. 8 and 11, or have another appropriate shape enabling cooling fluids to move from an internal cooling system to the hot gas path. The size of the cooling fluid channel 74 may be used to control the flow of cooling fluids through the cooling fluid channel 74. The load bearing surface 72 may extend across the entire cutaway airfoil section 66 with cooling fluid channels 74 interspersed along the length of the cutaway airfoil section 66 to enable cooling fluids to flow between the first side edge 58 and the generally elongated airfoil 16.

In one embodiment, as shown in FIG. 6, the first section attachment system 70 may be formed from a projection 76 extending from the first side edge 58 and a groove 78 in the generally elongated airfoil 16 for receiving the projection 76. The load bearing surface 72 may be positioned on the projection 76 where the projection 76 contacts the generally elongated airfoil 16 in the groove 78. The cooling fluid channels 74 may be positioned on the lower surface 80 of the projection 76 to create a cooling fluid pathway enabling cooling fluids to pass from a cooling fluid supply source into the hot gas path. In one embodiment, as shown in FIG. 4, the projection 76 may extend along the first side edge 58 of the first section 38 a length generally equal to a distance between the upstream edge 50 to the downstream edge 54 of the first section 38. The projection 76 may be received within the groove 78 in the generally elongated airfoil 16 and within grooves 78 in the second side edge 64 of the second section 40 upstream and downstream from the cutaway airfoil section 68.

The second section 40 may include a second section attachment system 82 for attaching the second section 40 to the generally elongated airfoil 16. The second section attachment system 82 may configured similarly to the first attachment system 82. In particular, the second section attachment system 82 may include a projection 76 on the second side edge 64 of the second section 40. The projection 76 may be received within a groove 78 in the generally elongated airfoil 16. The projection 76 may extend only within the cutaway airfoil section 68. Sections of the second side edge 64 between the cutaway airfoil section 68 and the upstream edge 52 and between the cutaway airfoil section 68 and the downstream edge 56 may include grooves 78 to receive the projection 76 extending from the first side edge 58 of the first section 38. In another embodiment, the configuration of the first and second sections 38, 40 may be reversed such that the projection 76 extends entirely down the second section 40 and only down a portion of the first side edge 58 of the first section 38.

The second endwall 34 may be formed in a configuration similar to the first endwall 30. In particular, the second endwall 34, may be formed from a first section 90 and a second section 92. The sections 90, 92 may each include a hot gas path surface 94, 96 positioned generally orthogonal to the generally elongated airfoil 16, a cold side surface 98, 100 opposite to the hot gas path surface 94, 96, an upstream edge 102, 104, a downstream edge 106, 108 opposite to the upstream edge 102, 104, and a first side edge 110, 112 and a second side edge 114, 116 opposite to each other, respectively. The first and second sections 90, 92 may be configured such that the upstream edges 102, 104 are positioned upstream from the leading edge 22, and the downstream edges 106, 108 are positioned downstream from the trailing edge 24. As such, the first and second sections 90, 92 may contact each other upstream from the leading edge 22 and downstream of the trailing edge 24 of the generally elongated airfoil 16. The first and second sections 90, 92 may include cutaway airfoil sections 118, 120 that correspond to the pressure and suction sides 26, 28 of the generally elongated airfoil 16, respectively. The cutaway airfoil sections 118, 120 enable the generally elongated airfoil 16 to fit within the cutaway airfoil sections 118, 120 and for the first and second sections 90, 92 to form joints 18 with each other upstream and downstream from the generally elongated airfoil 16. The joints 18 upstream and downstream from the generally elongated airfoil 16 may be aligned with a midline of the turbine vane 10, as shown in FIG. 2.

The first side edge 110 of the first section 90 may be positioned in close proximity with pressure side 26 of the generally elongated airfoil 16 and the second side edge 116 of the second section 92 may be positioned in close proximity with the suction side 28 of the generally elongated airfoil 16. The first side edges 110, 112 and the second side edges 114, 116 of the first and second sections 90, 92 may be configured to form joints 18 with the generally elongated airfoil 16, as described in more detail below.

The turbine vane 10 may also include a third section attachment system 122 on the first side edge 110 of the first section 90, the third section attachment system 122 may be formed from at least one load bearing surface 124 for transferring loads from the generally elongated airfoil 16 to the first section 90 so that the first section 90 supports and positions the turbine vane 10 within a turbine engine. The load bearing surface 124 may be formed from one or more load bearing surfaces 124 positioned at the cutaway section 118. The third section attachment system 122 may include at least one cooling fluid channel 126 on the first side edge 110 that is defined by the first side edge 110 of the first section 90 and the outer surface 20 of the generally elongated airfoil 16 to cool a region of the airfoil 16 at an intersection between the generally elongated airfoil 16 and the first section 90. The cooling fluid channel 126 may create a cooling fluid pathway for cooling fluids to flow between the first section 90 and the generally elongated airfoil 16.

The cooling fluid channel 126 may be formed from various appropriate configurations. For instance, the cooling fluid channel 126 may have a semicircular cross-sectional shape, as shown in FIGS. 7 and 10, a slight depression in the first side edge 110, as shown in FIGS. 8 and 11, or have another appropriate shape enabling cooling fluids to move from an internal cooling system to the hot gas path. The size of the cooling fluid channel 126 may be used to control the flow of cooling fluids through the cooling fluid channel 126. The load bearing surface 124 may extend across the entire cutaway airfoil section 118 with cooling fluid channels 126 interspersed along the length of the cutaway airfoil section 118 to enable cooling fluids to flow between the first side edge 110 and the generally elongated airfoil 16.

In one embodiment, as shown in FIG. 6, the third section attachment system 122 may be formed from a projection 128 extending from the first side edge 110 and a groove 130 in the generally elongated airfoil 16 for receiving the projection 128. The load bearing surface 124 may be positioned on the projection 128 where the projection 128 contacts the generally elongated airfoil 16 in the groove 130. The cooling fluid channels 126 may be positioned on the upper surface 80 of the projection 128 to create a cooling fluid pathway enabling cooling fluids to pass from a cooling fluid supply source into the hot gas path. In one embodiment, as shown in FIG. 4, the projection 128 may extend along the first side edge 110 of the first section 90 a length generally equal to a distance between the upstream edge 102 to the downstream edge 106 of the first section 90. The projection 128 may be received within the groove 130 in the generally elongated airfoil 16 and within grooves 130 in the second side edge 116 of the second section 92 upstream and downstream from the cutaway airfoil section 120.

The second section 92 may include a fourth section attachment system 132 for attaching the second section 92 to the generally elongated airfoil 16. The fourth section attachment system 132 may configured similarly to the third attachment system 122. In particular, the fourth section attachment system 132 may include a projection 128 on the second side edge 116 of the second section 92. The projection 128 may be received within a groove 130 in the generally elongated airfoil 16. The projection 128 may extend only within the cutaway airfoil section 120. Sections of the second side edge 116 between the cutaway airfoil section 120 and the upstream edge 104 and between the cutaway airfoil section 120 and the downstream edge 108 may include grooves 130 to receive the projection 128 extending from the first side edge 110 of the first section 90. In another embodiment, the configuration of the first and second sections 90, 92 may be reversed such that the projection 128 extends entirely down the second section 92 and only down a portion of the first side edge 110 of the first section 90.

During use, the turbine vane 10 and corresponding first and second sections 38, 40, 90, 92 forming the first and second endwalls 30, 34, respectively, form an efficient cooling system that eliminates stress related problems that are created at fillets in conventional turbine vanes at the intersection between endwalls and the airfoil. During use, the generally elongated airfoil 16 is held stationary in the turbine engine. The outboard endwall 34 supports the airfoil 16, which in turn supports the inboard endwall 30 and inner support ring (not shown). During use, cooling fluids are passed through internal aspects of the airfoil 16 to cool the airfoil and to supply cooling fluids to the rotor assembly. Cooling fluids may be leaked through the cooling fluid channels 74, 126 in the inner and outer endwalls 30, 34. The cooling fluids may be released at the intersection between the airfoil 16 and the endwalls 30, 34, thereby providing film cooling in a region that traditionally has been very difficult to cool. The efficiency of the turbine engine for a particular load application may be optomized by testing the engine with turbine vanes having different angles of alignment relative to the flow path of hot combustion gases. Such testing may be accomplished relatively inexpensively.

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.