Cooling circuit for platform of stator vane assembly

Abstract

To provide a cooling circuit for a platform of a stator vane assembly.SOLUTION: A platform for a stator vane assembly comprises a main body that extends between a forward end and an aft end. The main body defines an opening configured to receive an airfoil segment of the stator vane assembly. A hook rail extends from the main body and across the opening. A cooling circuit defined within the platform comprises: a first plenum disposed in the forward portion of the body; a reuse plenum disposed in the aft portion of the body and separated from the first plenum; and a connecting channel disposed at least partially in the hook rail and fluidly connecting the first plenum and the reuse plenum. A stator vane assembly comprises such a platform and an airfoil segment.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates generally to a platform for multi-piece stator vane assemblies and, more particularly, to a platform defining a cooling circuit having interconnected forward and aft plenums. [Background technology]

[0002] Turbomachines are used in various industries and applications for energy transfer. For example, a gas turbine engine typically includes a compressor section, a combustion section, a turbine section, and an exhaust section. The compressor section gradually increases the pressure of the working fluid entering the gas turbine engine and supplies the compressed working fluid to the combustion section. The compressed working fluid and fuel (such as natural gas) are mixed in the combustion section and burned in the combustion chamber to generate high-pressure and high-temperature combustion gases. The combustion gases flow from the combustion section to the turbine section, where they expand to produce work. For example, the expansion of the combustion gases in the turbine section rotates a rotor shaft connected to a generator, for example, to generate electricity. The spent combustion gases leave the gas turbine engine through the exhaust section.

[0003] During turbomachine operation, various hot gas path components in the system are exposed to high temperature flows, which can stress the hot gas path components and cause premature failure. Generally, higher temperatures lead to increased turbomachine performance, efficiency, and power output, so hot gas path components exposed to high temperature flows must be cooled to enable the gas turbine system to operate with high temperature flows.

[0004] Forced air cooling becomes necessary when the maximum localized temperatures of hot gas path components approach the melting temperature of the hot gas path components. For this reason, turbine rotor blades and static nozzle airfoils often require complex cooling schemes in which air (usually bleed air from the compressor section) is forced through internal cooling passages in the airfoil and exhausted through cooling holes in the airfoil surface to transfer heat from the hot gas path components.

[0005] Many complex cooling schemes use small cooling passages, or microchannels, to deliver cooling fluid through the airfoil (e.g., near the surface or wall of the airfoil). Such cooling schemes pose significant fabrication challenges to the cores and castings and can significantly increase the manufacturing costs of hot gas path components that use such known near-wall cooling systems. To address the manufacturing challenges due to the complex cooling flow paths and / or small cooling flow paths near the part surface, many hot gas path components with such features can be additively manufactured. Additive manufacturing can produce parts with complex and diverse cooling features. However, additively manufacturing hot gas path components, such as rotor blades and stator vanes, as single parts can be costly and time consuming. Furthermore, a manufacturing error in one portion of a hot gas path component can result in the entire part being scrapped.

[0006] As such, it may be advantageous to fabricate hot gas path components as multiple subcomponents. However, fabricating hot gas path components as multiple subcomponents creates cooling challenges because the cooling microchannels in each subcomponent cannot be fluidly coupled. Furthermore, if not properly cooled, the joints formed between the subcomponents may be particularly weak and / or fail when exposed to the hot combustion gases generated during turbomachine operation.

[0007] Thus, an improved hot gas path component having one or more subcomponents joined together and capable of being exposed to hot combustion gases without risk of joint failure would be desirable and appreciated in the art. Summary of the Invention

[0008] Aspects and advantages of the platform and stator vanes according to the present disclosure will be set forth in part in the description which follows, or will be obvious from the description, or may be learned by practice of the art.

[0009] According to one embodiment, a platform for a stator vane assembly is provided. The platform includes a body extending between a forward end and an aft end. The platform further includes an opening defined in the body. The opening is configured to receive an airfoil segment of the stator vane assembly. A forward portion of the body extends between the forward end and the opening. An aft portion of the body extends between the opening and the aft end. A cooling circuit is defined in the platform. The cooling circuit includes a first plenum defined in the forward portion and at least one reuse plenum defined in the aft portion and separated from the first plenum. The cooling circuit further includes a communication flow passage providing fluid communication between the first plenum and the at least one reuse plenum.

[0010] According to another embodiment, a stator vane assembly is provided. The stator vane assembly includes a platform and an airfoil segment. The airfoil segment includes an airfoil and a boss. The platform includes a body extending between a forward end and an aft end. The platform further includes an opening defined in the body. The opening is configured to receive the airfoil segment of the stator vane assembly. A forward portion of the body extends between the forward end and the opening. An aft portion of the body extends between the opening and the aft end. A cooling circuit is defined in the platform. The cooling circuit includes a first plenum defined in the forward portion and at least one reuse plenum defined in the aft portion and separated from the first plenum. The cooling circuit further includes a communication flow passage providing fluid communication between the first plenum and the at least one reuse plenum.

[0011] These and other features, aspects, and advantages of the present platform and stator vane assembly will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present technology and, together with the description, serve to explain the principles of the technology. [Brief description of the drawings]

[0012] A full and enabling disclosure of the present platform and stator vanes, including the best mode of making and using the present systems and methods, directed to those skilled in the art, is set forth in this specification, which makes reference to the accompanying drawings. [Figure 1] 1 is a schematic diagram of a turbomachine (e.g., a gas turbine engine) according to an embodiment of the present disclosure. [Diagram 2] 2 is a partial cross-sectional side view of a turbine section of the gas turbine engine shown in FIG. 1 according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is an exploded perspective view of a stator vane assembly according to an embodiment of the present disclosure. [Figure 4]4 illustrates a schematic cross-sectional view of a platform of a stator vane assembly taken along line 4-4 shown in FIG. 3 according to an embodiment of the present disclosure. [Diagram 5] 5A and 5B are schematic diagrams illustrating a cross-sectional view of a platform of a stator vane assembly taken along line 5-5 shown in FIG. 3 according to an embodiment of the present disclosure. [Figure 6] 4 illustrates a schematic top-down plan view of a platform of the stator vane assembly of FIG. 3 according to an embodiment of the present disclosure. [Figure 7] FIG. 2 is a perspective view of an aft portion of a platform of a stator vane assembly according to an embodiment of the present disclosure. [Figure 8] 2 is a schematic cross-sectional view of a cooling circuit disposed within a platform of a stator vane assembly according to an embodiment of the present disclosure; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Reference will now be made in detail to embodiments of the platform and stator vanes of the present invention, one or more examples of which are illustrated in the drawings. Each example is provided for purposes of explanation, not limitation of the technology. Indeed, it will be apparent to those skilled in the art that modifications and variations can be made to the technology without departing from the scope or spirit of the claimed technology. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a further embodiment. Thus, the present disclosure is intended to cover such modifications and variations as come within the scope of the appended claims and their equivalents.

[0014] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Moreover, unless otherwise specified, all embodiments described herein should be considered exemplary.

[0015] The detailed description uses numbers and letters to refer to features in the drawings. Like or similar designations in the drawings and description are used to refer to like or similar parts of the invention. In this specification, the terms "first", "second", and "third" may be used interchangeably to distinguish one component from another, and are not intended to imply the position or importance of the individual components.

[0016] The term "fluid" may be a gas or a liquid. The term "fluid communication" means that two or more regions defining a flow path therein are joined to one another such that fluid can communicate between the defined regions.

[0017] As used herein, the terms "upstream" (or "forward") and "downstream" (or "aft") refer to relative directions with respect to fluid flow in a fluid pathway. For example, "upstream" refers to the direction in which the fluid flows, and "downstream" refers to the direction in which the fluid flows. The term "radial" refers to relative directions that are substantially perpendicular to an axial centerline of a particular part, the term "axial" refers to relative directions that are substantially parallel and / or coaxially aligned with an axial centerline of a particular part, and the term "circumferential" refers to relative directions that extend around an axial centerline of a particular part.

[0018] Approximate terms such as "about," "approximately," "generally," and "substantially" are not limited to the exact value specified. In at least some examples, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of a method or machine for constructing or manufacturing the component and / or system. In at least some examples, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of a method or machine for constructing or manufacturing the component and / or system. For example, it may refer to being within a margin of 1, 2, 4, 5, 10, 15, or 20 percent at any of the individual values, ranges of values, and / or endpoints defining the range of values. When used in the context of angles or directions, such terms include within 10 degrees greater or less than the stated angle or direction. For example, "approximately vertical" includes a direction within 10 degrees of vertical in any direction, such as clockwise or counterclockwise.

[0019] Terms such as "coupled," "fixed," "attached," and the like, unless otherwise specified herein, refer to both direct coupling, fixing, or attachment, and indirect coupling, fixing, or attachment through one or more intermediate components or features. Terms such as "directly coupled," "directly fixed," "directly attached," and the like, refer to the attachment of two components without any intermediate components or features.

[0020] As used herein, the terms "comprises," "comprising," "includes," "has," "having," or other variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus consisting of a list of features is not necessarily limited to only those features, but may include other features not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, unless expressly stated to the contrary, "and / or" refers to a condition that is satisfied by any one of the following: A is true (or present) and B is false (or absent), A is false (or absent) and B is true (or present), and both A and B are true (or present).

[0021] Throughout this specification and claims, where range limitations are combinable and interchangeable, unless the context or language indicates otherwise, such ranges are specified and include all subranges contained therein. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.

[0022] The term "proximate to" refers to being closer to an object or feature than to an opposing object or feature. For example, when used with first and second ends, high and low pressure sides, leading and trailing edges, etc., the phrases "proximate to the first end," or "proximate to the high pressure side," or "proximate to the leading edge" refer to a position closer to the first end than to the second end, or closer to the high pressure side than the low pressure side, or closer to the leading edge than the trailing edge, respectively.

[0023] As used herein, the term "solid" may refer to a component that has no voids, cavities, holes, or other openings, such that the component is impermeable and does not allow air or other fluids to pass therethrough.

[0024] Referring now to the drawings, Figure 1 is a schematic diagram of one embodiment of a turbomachine, which in the illustrated embodiment is a gas turbine engine 10. Although industrial or land-based gas turbine engines are shown and described herein, the present disclosure is not limited to industrial or land-based gas turbine engines unless otherwise specified in the claims. For example, the invention described herein may be used with any type of turbomachine, including, but not limited to, a steam turbine, an aircraft gas turbine, or a marine gas turbine.

[0025] As shown in Figure 1, a gas turbine engine 10 generally includes a compressor section 12. The compressor section 12 includes a compressor 14. The compressor 14 includes an inlet 16 disposed at an upstream end of the gas turbine engine 10. The gas turbine engine 10 further includes a combustion section 18 having one or more combustors 20 disposed downstream from the compressor section 12. The gas turbine engine 10 further includes a turbine section 22 (i.e., an expansion turbine) downstream from the combustion section 18. A shaft 24 extends generally axially within the gas turbine engine 10.

[0026] The compressor section 12 may generally include a number of rotor disks 21 and a number of rotor blades 23 extending radially outward from and coupled to each rotor disk 21. Each rotor disk 21 may in turn be coupled to or form a part of a shaft 24 extending through the compressor section 12. The rotor blades 23 of the compressor section 12 may include turbomachine airfoils defining an airfoil (e.g., having a leading edge, a trailing edge, and a sidewall extending between the leading edge and the trailing edge). Additionally, in many embodiments, the compressor section 12 may include stator vanes 19 disposed between the rotor blades 23. The stator vanes 19 may extend from and be coupled to a compressor casing 11 that circumferentially surrounds an upstream portion of the shaft 24.

[0027] The turbine section 22 may generally include a number of rotor disks 27 and a number of rotor blades 28 extending radially outward from and interconnected to each rotor disk 27. Each rotor disk 27 may in turn be coupled to or form a part of a shaft 24 extending through the turbine section 22. The turbine section 22 further includes an outer casing 32 circumferentially surrounding a downstream portion of the shaft 24 and the rotor blades 28. The turbine section 22 may include stator vanes or static nozzles 26 extending radially inward from the outer casing 32. The rotor blades 28 and the stator vanes 26 may be alternately arranged in a stepped manner along an axial centerline 30 of the gas turbine 10. Both the rotor blades 28 and the stator vanes 26 may include turbomachine airfoils defining an airfoil shape (e.g., having a leading edge, a trailing edge, and sidewalls extending between the leading edge and the trailing edge).

[0028] During operation, ambient air 36 or other working fluid is drawn into the inlet 16 of the compressor 14 and gradually compressed to provide compressed air 38 (or other working fluid) to the combustion section 18. The compressed air 38 enters the combustion section 18 and is mixed with fuel to form a combustible mixture. The combustible mixture is combusted in a combustion chamber 40 of the combustor 20 to generate combustion gases 42 that enter the combustion chamber 40 and enter the turbine section 22. Energy (kinetic and / or thermal energy) is transferred from the combustion gases 42 to the rotor blades 28, which rotate the shaft 24 to generate mechanical work. The spent combustion gases 42 (also referred to as "exhaust gases") exit the turbine section 22 and flow through the exhaust diffuser 34, traversing a number of struts or main airfoils 44 disposed within the exhaust diffuser 34.

[0029] Gas turbine engine 10 may define a cylindrical coordinate system having an axial direction A extending along axial centerline 30, a radial direction R perpendicular to axial centerline 30, and a circumferential direction C extending around axial centerline 30.

[0030] 2 is a partial cross-sectional side view of turbine section 22 of gas turbine engine 10 according to an embodiment of the present disclosure. Turbine section 22 may include one or more stages 50 each including a set of rotor blades 28 coupled to a rotor disk 27, which may be rotatably mounted to shaft 24. One or more stages 50 may further include a set of stator vanes 26. The stator vanes 26 described herein may be employed in a first stage, second stage, third stage, fourth stage, or multiple stages thereof, where "first" refers to the stage immediately downstream of combustion section 18.

[0031] Each stator vane 26 may include an airfoil segment 206 having an airfoil 56 extending in a radial direction R between an inner platform or endwall 202 and an outer platform or endwall 204. Circumferentially adjacent outer platforms 204 of each stator vane 26 may be joined to form an outer annular ring extending around an inner annular ring formed by circumferentially adjacent inner platforms 202 of each stator vane 26. At least one airfoil 56 may extend between the two annular rings formed by the platforms 202, 204. The turbine section 22 may also include a shroud segment 58 disposed downstream of the outer platforms 204 to direct the combustion gases 42 flowing through the stator vanes 26 to the rotor blades 28.

[0032] As shown, the platforms 202, 204 may each include a body 210 and one or more hook rails 212 extending radially outward from the body 210. The one or more hook rails 212 may couple the platforms 202, 204 to the turbine section 22 (and thus couple the stator vane assembly 26). In particular, the hook rails 212 may be coupled to a stationary structure of the turbine section 22, such as the turbine casing 32 described above with reference to FIG.

[0033] Structures or components disposed along the flow path of the combustion gases 42 may be referred to as hot gas path components. In one example, the hot gas path components may be the stator vanes 26 and / or rotor blades 28. In some embodiments, cooling features such as impingement sleeves, cooling channels, cooling holes, etc., may be disposed within the hot gas path components to cool them, as indicated by dashed lines 78. For example, cooling air, as indicated by arrow 79, may be routed from the compressor section 12 or elsewhere and directed through the cooling features, as indicated by arrow 81.

[0034] FIG. 3 illustrates an exploded view of a stator vane assembly 200 that may be representative of a stator vane 19 of the compressor section 12 and / or a stator vane 26 of the turbine section 22. However, in an exemplary embodiment, the stator vane assembly 200 may be a stator vane 26 of the turbine section 22. As shown in FIG. 3, the stator vane assembly 200 includes a platform 201 and an airfoil segment 206. For example, the stator vane assembly 200 may include an inner platform 202, an outer platform 204, and an airfoil segment 206 that are separated from one another along an axial centerline 55 of the stator vane assembly 200 (i.e., shown in an exploded view) to illustrate various features of the stator vane assembly 200 that are not otherwise visible when the assembly is constructed. The axial centerline 55 may be generally parallel to a radial direction of the gas turbine 10 when the stator vane assembly 200 is installed in the turbine section 22. The airfoil segment 206 may include an airfoil 56 that generally defines an aerodynamic shape or contour. For example, the airfoil 56 may include a leading edge 60 that engages the flow of combustion gases and sidewalls that guide the combustion gases along the airfoil 56 to a trailing edge 62. For example, the airfoil 56 may include a pressure sidewall 64 and a suction sidewall 66 that each extend from the leading edge 60 to the trailing edge 62. Additionally, the airfoil 56 may extend radially between a base 68 and a tip 70.

[0035] In an exemplary embodiment, the inner platform 202, the airfoil portion 56, and the outer platform 204 may be separate components (e.g., manufactured as separate components) that are each coupled (e.g., via a mechanical retention device and / or via a fixed coupling) to the airfoil segment 206. The inner platform 202 may be coupled to the inner boss 75 of the airfoil segment 206, and the outer platform 204 may be coupled to the outer boss 73. In certain embodiments, the inner platform 202, the airfoil segment 206, and the outer platform 204 may each be additively manufactured (e.g., 3D printed) separately and then coupled to one another. Forming the stator vane assembly 200 as three separate components advantageously increases the repairability of the stator vane assembly 200. For example, if a portion of the airfoil segment 206 is damaged, the entire stator vane assembly 200 does not need to be replaced. Rather, the mechanical connections may be released (eg, the mechanical retention devices removed) to decouple the airfoil segment 206 from the platforms 202, 204, and a new airfoil segment 206 may be employed or the old airfoil may be repaired.

[0036] Furthermore, when additive manufacturing is used to manufacture some or all of the stator vane assembly 200, the build time (i.e., printing) of the airfoil segments 206 as separate components from the inner and outer platforms 202, 204 is significantly shorter as compared to the build time of a unitary nozzle in which the inner and outer platforms 202, 204 are printed along with the airfoil segments 206. Additionally, forming the stator vane assembly 200 from three separate components allows for different manufacturing techniques and / or different materials to be used for the various components.

[0037] 3, the airfoil segment 206 may include a camber axis 57 that may extend from the leading edge 60 to the trailing edge 62 and be defined intermediate the pressure sidewall 64 and the suction sidewall 66 of the airfoil 56. The camber axis 57 may be curved and / or contoured to correspond to the curvatures of the pressure sidewall 64 and the suction sidewall 66. A lateral direction T may be defined as perpendicular to the camber axis 57.

[0038] 3, the airfoil segment 206 may further include a boss 216 extending from at least one of the base 68 or tip 70 of the airfoil 56. For example, the stator vane assembly 200 may include an inner boss 73 extending radially inward from the airfoil 56 at the base 68 and an outer boss 75 extending radially outward from the airfoil 56 at the tip 70. Each boss 73, 75 may extend generally perpendicularly from the pressure sidewall 64 and the suction sidewall 66 in the lateral direction T.

[0039] Both the inner platform 202 and the outer platform 204 may define an opening 102. The boss 216 is disposed within the opening 102 of the platforms 202, 204. The opening 102 may be sized and shaped to correspond to the respective bosses 73, 75 such that the respective bosses 73, 75 may be inserted into the opening 102 and then connected (e.g., via a mechanical retention device and / or a fixed connection) to the respective platforms 202, 204. In particular, the inner boss 73 may be inserted into the opening 102 of the inner platform 202 (and then connected to the inner platform 202) and the outer boss 75 may be inserted into the opening 102 of the outer platform 204 (and then connected to the outer platform 204).

[0040] 3 , the inner platform 202 and / or the outer platform 204 may include a body 210 extending between a forward end 214 and an aft end 215. The body 210 defines a hot gas boundary surface 208. The hot gas boundary surface 208 may extend generally perpendicular to the airfoil 56. The hot gas boundary surface 208 of the inner platform 202 may define a radially inward flow boundary for the combustion gases in the turbine section 22. Similarly, the hot gas boundary surface 208 of the outer platform 204 may define a radially outer flow boundary for the combustion gases in the turbine section 22.

[0041] Additionally, the body 210 of the inner platform 202 and the outer platform 204 can at least partially define the respective opening 102. In an exemplary embodiment, one or both of the inner platform 202 and / or the outer platform 204 can include one or more protrusions 80 extending radially from the body 210. The one or more protrusions 80 can at least partially define the opening 102. In many embodiments, the boss 216 can be coupled to the one or more protrusions 80. In many embodiments, the body 210 can further include one or more hook rails 212 extending from the body 210 opposite the hot gas interface 208. In many embodiments, the at least one hook rail 212 can extend across the opening 102.

[0042] In certain embodiments, the boss 216 extending from the base 68 of the airfoil 56 may extend into the opening 102 of the inner platform 202. Similarly, the boss 216 extending from the tip 70 of the airfoil 56 may extend into the opening 102 of the outer platform 204. As shown, in some embodiments, the boss 216 may extend into the airfoil 56 and at least partially define a cavity 92 further defined in the airfoil 56. The cavity 92 may be exposed by the opening 102 of the platform 54 such that air (e.g., bleed air from the compressor 14) may enter the cavity 92. In other embodiments (not shown), the boss 216 may be solid (i.e., no voids, cavities, or openings defined therein).

[0043] During operation, the platforms 202, 204 may be exposed to extremely hot combustion gases and it is necessary to cool the platforms 202, 204 to prevent them from being damaged or from experiencing unacceptable thermal deformation due to the high temperatures.

[0044] 4 and 5, Fig. 4 illustrates a cross-sectional view of the outer platform 204 taken along line 4-4 as shown in Fig. 3, and Fig. 5 illustrates a cross-sectional view of the inner platform 202 taken along line 5-5 as shown in Fig. 3, in accordance with an embodiment of the present disclosure. As shown, the platforms 202, 204 each include a body 210 extending between a forward end 214 and an aft end 215.

[0045] In many embodiments, the platforms 202, 204 may each define an opening 102 in the body 210. The opening 102 may be configured to receive the airfoil segment 206, as described above with reference to FIG. 3. For example, the opening 102 may be airfoil shaped (e.g., having a leading edge boundary, a trailing edge boundary, a suction side boundary, and a pressure side boundary) to receive the boss 216 of the airfoil segment 206. The opening 102 may divide or separate the body 210 into a forward portion 218 and an aft portion 220. The forward portion 218 of the body 210 may extend between the forward end 214 and the opening 102, and the aft portion 220 of the body 210 may extend between the aft end 215 and the opening 102. In this manner, the opening 102 may separate the forward portion 218 from the aft portion 220.

[0046] In the exemplary embodiment, a cooling circuit 222 may be defined within each of the platforms 202, 204. The cooling circuit 222 may include a first or forward plenum 224 defined in the forward portion 218 of the body 210 and at least one reuse or aft plenum 226 defined in the aft portion 220 of the body 210. Although only one reuse plenum 226 is shown in the illustrated embodiment, the cooling circuit 222 may include any number of reuse plenums and should not be limited to a particular number of reuse plenums unless otherwise recited in the claims. The aft plenum 226 may be separated from the forward plenum 224 (e.g., by the opening 102). In this manner, the forward plenum 224 is not directly fluidly coupled to the aft plenum 226 (i.e., coolant cannot pass directly from the forward plenum 224 to the aft plenum 226). In various embodiments, the cooling circuit 222 may further include a connecting channel 228 that fluidly couples the forward plenum 224 and the aft plenum 226. In particular, cooling water may flow from the forward plenum 224, through the communicating passages 228, and to the aft plenum 226.

[0047] In certain embodiments, the body 210 may further include a boundary wall 230 that defines the hot gas interface 208. The hot gas interface 208 may be directly exposed to combustion gases during operation of the gas turbine engine 10, such that the boundary wall 230 may have a locally elevated temperature relative to other portions of the body 210. As shown, the boundary wall 230 may include a first impingement surface 232 at a forward portion 218 of the body 210 (opposite the hot gas interface 208). The first impingement surface 232 may at least partially define the forward plenum 224. Additionally, in many embodiments, the forward portion 218 of the body 210 may include a first impingement wall 234 that defines a first plurality of impingement openings 236. The first plurality of impingement openings 236 may extend through the first impingement wall 234 to provide fluid communication to the forward plenum 224. In the exemplary embodiment, first plurality of impingement openings 236 may be an inlet to cooling circuit 222 such that coolant enters cooling circuit 222 at first plurality of impingement openings 236 .

[0048] In an exemplary embodiment, the first plurality of impingement openings 236 may be sized and oriented to direct coolant (such as compressed air from the compressor section 12) across the forward plenum 224 to impinge on the first impingement surface 232. More specifically, the impingement openings 236 may be sized and oriented to direct pre-impingement air in discrete jets to impinge on the impingement surface 232 of the boundary wall 230. The discrete jets of air impinge on (or strike) the impingement surface 232 to form a thin boundary layer of air on the impingement surface 232 to enable optimal heat transfer between the boundary wall 230 and the air. For example, the impingement openings 236 may direct the pre-impingement air to be perpendicular to a surface against which the air impinges (e.g., the impingement surface 232 of the boundary wall 230).

[0049] Once the air impacts the impingement face 232, it has different properties due to the energy transfer that it has undergone and may be referred to as "post-impingement air" and / or "spent cooling air." For example, the spent cooling air may have a higher temperature and lower pressure than the pre-impingement air due to the removal of heat from the platforms 202, 204 during the impingement process. However, as described below, the post-impingement air from the forward plenum 224 may advantageously travel through the connecting channel 228 and be reused in the aft plenum 226 (e.g., the air may be utilized for impingement again in the aft plenum 226).

[0050] In various embodiments, the aft portion 220 of the body 210 may further include a second impingement wall 238 and a solid wall 240. The second impingement wall 238 may be spaced (e.g., radially) from the solid wall 240 and the boundary wall 230. In this manner, the second impingement wall 238 may separate the aft plenum 226 into a first portion 242 and a second portion 244. The first portion 242 of the aft plenum 226 may be defined (e.g., radially) between the solid wall 240 and the second impingement wall 238, and the second portion 244 may be defined (e.g., radially) between the second impingement wall 238 and a second impingement surface 246 of the boundary wall 230. In the exemplary embodiment, the connecting channel 228 may fluidly couple (extend between) the forward plenum 224 and a first portion 242 of the aft plenum 226 .

[0051] As described above, the boundary wall 230 may include a second impingement surface 246 at the aft portion 220 of the body 210. The second impingement surface 246 may at least partially define the second portion 244 of the aft plenum 226. Additionally, the second impingement wall 238 may define a second plurality of impingement openings 248 fluidly coupling the first portion 242 and the second portion 244. The second plurality of impingement openings 248 may be sized and oriented to direct cooling water across the second portion 244 of the aft plenum and impinge against the second impingement surface 246. More specifically, the impingement openings 248 may be sized and oriented to direct reused impingement air (e.g., air already used once for impingement) in discrete jets to impinge against the second impingement surface 246 of the boundary wall 230. The multiple impingement openings 248 may be oriented generally perpendicular to the impingement face 246 .

[0052] In many embodiments, the boundary wall 230 may define film cooling channels 252 that extend from an inlet fluidly coupled to one of the forward plenum 224 or the aft plenum 226 to an outlet on the hot gas interface 208. For example, the forward portion 218 of the body 210 may include a plurality of film cooling channels 252, each extending from a respective inlet fluidly coupled to the forward plenum 224 to a respective outlet on the hot gas interface 208. Similarly, the aft portion 220 of the body 210 may include a plurality of film cooling passages 252, each extending from a respective inlet fluidly coupled to the second portion 244 of the aft plenum 226 to a respective outlet on the hot gas interface 208.

[0053] In many embodiments, the outlet of the film cooling passages 252 may be aft (or downstream) of the inlet such that the film cooling passages 252 are oblique to (i.e., form an oblique angle with) the hot gas interface 208. The film cooling channels 252 may establish a layer of air between the hot combustion gases and the hot gas interface 208 during operation of the gas turbine engine 10. That is, the film cooling channels 252 may eject air from the cooling circuit 222, which creates a film of cool air that flows over the hot gas interface 208. This air absorbs some of the heat from the hot combustion gases and helps maintain the temperature of the platforms 202, 204 within a safe operating range.

[0054] In various embodiments, the platforms 202, 204 may further include a number of internal supports 258 extending across at least one of the forward plenum 224 and / or the aft plenum 224. The number of internal supports 258 do not completely block the flow of coolant in the plenums 224, 226 as the coolant may flow around the internal supports 258. Each of the number of internal supports 258 may extend radially within one of the plenums 224, 226 to provide additional structural support. For example, the support 258 in the forward plenum may extend radially between (e.g., directly between) the boundary wall 230 and the first impingement wall 234. The supports 258 in the aft plenum 226 may extend radially between the solid wall 240 and the second impingement wall 238, or between the solid wall 240 and the boundary wall 230, or between the boundary wall 230 and the second impingement wall 238.

[0055] In various embodiments, the platforms 202, 204 may each include one or more hook rails 212 extending radially from the body 210. In particular, the platforms 202, 204 may each include a forward hook rail 211 extending radially from a forward portion 218 of the body 210. Additionally, the platforms 202, 204 may each include an aft hook rail 213 extending radially from an aft portion 220 of the body 210. The forward hook rail 211 may include a radial portion 264 extending from the body 210 and an axial protrusion 266 extending from the radial portion 262. As shown, in various embodiments, the forward plenum 224 may be at least partially defined in the radial portion 262 of the forward hook rail 211. The aft hook rail 213 of the inner platform 202 may include an axial tab 260 and a radial body 262. The axial tabs 260 may extend from the solid wall 240 to a radial body 262 .

[0056] 6, a top-down plan view of a platform 201 (which may be the inner platform 202 and / or the outer platform 204 described above) of a stator vane assembly 200 is illustrated in accordance with an embodiment of the present disclosure. As illustrated, the platform 201 may include a body 210 and one or more hook rails 212 (e.g., a forward hook rail 211 and an aft hook rail 213) extending from the body 210. As illustrated, the aft hook rail 213 may extend across the opening 102.

[0057] The body 210 may define a leading edge surface 276 and a trailing edge surface 278 spaced apart from and generally parallel to the leading edge surface 276. Additionally, the body 210 defines a pressure side slashface 280 and a suction side slashface 282 spaced apart from and generally parallel to one another. The suction side slashface 282 and the pressure side slashface 280 may each extend between the leading edge surface 276 and the trailing edge surface 278. The hook rail 212 may extend between the pressure side slashface 280 and the suction side slashface 282. Additionally, the body 210 may define an opening 102, as previously discussed, which may be an airfoil such that the body 210 defines a leading edge boundary 268, a trailing edge boundary 270, a suction side boundary 272, and a pressure side boundary 274 of the opening 102.

[0058] In the exemplary embodiment, the platform 201 may include a cooling circuit 222 defined within the body 210 and / or the hook rail 212 of the platform 201. For example, the cooling circuit 222 may include a forward plenum 224 and an aft plenum 226 defined within the body 210. The forward plenum 224 and the aft plenum 226 may be spaced apart from one another such that the opening 102 is disposed between the forward plenum 224 and the aft plenum 226 (i.e., the opening 102 separates the plenums 224, 226). The forward plenum 224 may extend along (or adjacent to) the leading edge surface 276, a small portion of the suction side slashface 282, and a large portion (e.g., larger than the small portion) of the pressure side slashface 280. Additionally, the forward plenum 224 may extend along (or adjacent to) a minor portion of the suction side boundary 272 , the leading edge boundary 268 , and a majority (e.g., greater than a minor portion) of the pressure side boundary 274 of the opening 102 .

[0059] The aft plenum 226 may extend along (or adjacent to) the trailing edge surface 278, a majority of the suction side slashface 282, and a minor portion (e.g., smaller than the large portion) of the pressure side slashface 280. Additionally, the aft plenum 226 may extend along (or adjacent to) a majority of the suction side boundary 272, the trailing edge interface 270, and a minor portion (e.g., smaller than the large portion) of the pressure side boundary 274.

[0060] In an exemplary embodiment, the connecting channel 228 may be defined at least partially within the hook rail 212. In particular, the connecting channel 228 may extend through the aft hook rail 213 and across the opening 102 to fluidly connect the forward plenum 224 to the aft plenum 226. In many embodiments, the connecting channel 228 may include one or more supply passages 284, a main connecting portion 286, and one or more outlet passages 288. The one or more supply passages 284 may extend (and be in fluid communication) between the forward plenum 224 and the main connecting portion 286. The one or more outlet passages 288 may extend (and be in fluid communication) between the main connecting portion 286 and the aft plenum 226. Additionally or alternatively, the main connection portion 286 of the connecting channel 228 may extend between a first end 290 fluidly coupled to the forward plenum 224 and a second end 292 fluidly coupled to the aft plenum 226. The first end 290 is proximate the pressure side slashface 280 and the second end 292 is proximate the suction side slashface 282.

[0061] 7 and 8, various views of the platform 201 of the stator vane assembly 200 are illustrated in accordance with an embodiment of the present disclosure. In particular, FIG. 7 illustrates a perspective view of a portion of the platform 201, and FIG. 8 illustrates a cross-sectional view of the platform 201. Of note, the cross-sectional view shown in FIG. 8 includes separation, and thus FIG. 8 illustrates features of the platform 201 in the same plane when these features are separated from one another, which is done for purposes of discussion and clarity. In particular, the hook rail 212 shown in FIG. 8 may extend into and out of the page, as shown in FIG. 7. As shown, the platform 201 may include a body 210 that defines an opening 102, and the hook rail 212 may extend from the body 210 (e.g., radially from the body 210) across the opening 102.

[0062] As shown, a cooling circuit 222 may be defined within the platform 201. The cooling circuit 222 may include a first or forward plenum 224 defined in the forward portion 218 of the body 210 and at least one reuse or aft plenum 226 defined in the aft portion 220 of the body 210. The aft plenum 226 may be separated from the forward plenum 224 (e.g., by the opening 102). In this manner, the forward plenum 224 is not in direct fluid communication with the aft plenum 226 (i.e., coolant cannot pass directly from the forward plenum 224 to the aft plenum 226). In various embodiments, the cooling circuit 222 may further include a connecting channel 228 fluidly coupling the forward plenum 224 and the aft plenum 226. In particular, the coolant may flow from the forward plenum 224 through the communicating channel 228 to the aft plenum 226. In the exemplary embodiment, as shown, the communication passage 228 may be defined in the hook rail 212.

[0063] Further, as shown, the connecting channel 228 may include one or more supply passages 284, a main connection portion 286, and one or more exhaust passages 288. The one or more supply passages 284 may extend (in fluid communication) between the forward plenum 224 and the main connection portion 286. The one or more outlet passages 288 may extend (in fluid communication) between the main connection portion 286 and the aft plenum 226. The one or more supply passages 284 and the one or more exhaust passages 288 may be angled relative to the radial direction R (e.g., oblique to the radial direction R). The main communication portion 286 may extend between the one or more supply passages 284 on a first side of the opening 102 and the one or more exhaust passages 288 on a second side of the opening 102. For example, the one or more supply passages 284 may be disposed proximate to the pressure side slashface 280 and the one or more exhaust passages 288 may be disposed proximate to the suction side slashface 282.

[0064] The stator vane assemblies described herein advantageously provide a multi-piece assembly that is easier to manufacture at reduced cost and time compared to single piece assemblies. Additionally, the platforms described herein advantageously include cooling circuits that utilize coolant at multiple locations for impingement and film cooling purposes, thereby extending the overall hardware life of the stator vane assemblies and platforms.

[0065] This specification uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems, and performing the incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they contain structural elements that do not differ from the literal language of the claims, or if they contain equivalent structural elements that do not differ insubstantially from the literal language of the claims.

[0066] Further aspects of the invention are provided by the subject matter of the following clauses: [Embodiment 1] 1. A platform for a stator vane assembly, comprising: a main body extending between a forward end and an aft end; an opening defined within the main body, the opening configured to receive an airfoil segment of the stator vane assembly, wherein a forward portion of the main body extends between the forward end and the opening, and wherein an aft portion of the main body extends between the opening and the aft end; a cooling circuit defined within the platform; The cooling circuit includes: a first plenum defined in the forward portion; at least one re-use plenum defined in the aft portion and separated from the first plenum; a connecting channel fluidly coupling the first plenum and the at least one re-use plenum. [Embodiment 2] 13. The platform of any preceding embodiment, further comprising a hook rail extending from the main body and across the opening. [Embodiment 3] 11. The platform of any preceding embodiment, wherein the connecting channel is at least partially defined within the hook rail. [Embodiment 4] The platform of any preceding embodiment, wherein the main body further comprises a boundary wall that defines a hot gas boundary surface. [Embodiment 5] A platform as described in any of the preceding embodiments, wherein the forward portion of the main body further comprises a first impingement wall disposed within the first plenum, the first impingement wall defining a first plurality of impingement apertures. [Embodiment 6] 11. The platform of any of the preceding embodiments, wherein the boundary wall includes a first impingement surface at the forward portion of the main body, the first impingement surface at least partially defining the first plenum, and the first plurality of impingement apertures is sized and oriented to direct coolant across the first plenum to impinge upon the first impingement surface. [Embodiment 7] The platform of any of the preceding embodiments, wherein the boundary wall defines a film cooling channel that extends from an inlet fluidly coupled to one of the first plenum or the at least one re-use plenum to an outlet on the hot gas boundary surface, and the outlet is offset from the inlet such that the film cooling channel is oblique to the hot gas boundary surface. [Embodiment 8] 2. The platform of claim 1, wherein the aft portion of the main body includes a second impingement wall disposed within the at least one re-use plenum, the second impingement wall separating the at least one re-use plenum into a first portion and a second portion, and the second impingement wall defining a second plurality of impingement apertures fluidly coupling the first portion and the second portion. [Embodiment 9] A platform as described in any of the preceding embodiments, wherein the connecting channel fluidly couples the first plenum to the first portion of the at least one re-use plenum. [Embodiment 10] 11. The platform of any of the preceding embodiments, wherein the aft portion of the main body includes a boundary wall having a second impingement surface, the second impingement surface at least partially defining the second portion of the at least one re-use plenum, and the second plurality of impingement apertures is sized and oriented to direct coolant across the second portion of the at least one re-use plenum to impinge upon the second impingement surface. [Embodiment 11] The platform of any of the preceding embodiments, further comprising a support extending within at least one of the first plenum and the at least one re-use plenum. [Embodiment 12] 1. A stator vane assembly comprising: an airfoil segment having an airfoil and a boss; A platform, The platform includes: a main body extending between a forward end and an aft end; an opening defined within the main body; the boss disposed in the opening of the platform; a forward portion of the main body extends between the forward end and the opening; an aft portion of the main body extends between the opening and the aft end; the platform includes a cooling circuit defined within the platform; The cooling circuit includes: a first plenum defined in the forward portion; at least one re-use plenum defined in the aft portion and separated from the first plenum; a connecting channel fluidly coupling the first plenum and the at least one re-use plenum; Stator vane assembly. [Embodiment 13] a hook rail extending from the main body and across the opening; 5. The stator vane assembly of any preceding embodiment, wherein the connecting channel is at least partially defined within the hook rail. [Embodiment 14] 5. The stator vane assembly of any preceding embodiment, wherein the main body further comprises a boundary wall that defines a hot gas boundary surface. [Embodiment 15] A stator vane assembly as described in any of the preceding embodiments, wherein the forward portion of the main body further comprises a first impingement wall disposed within the first plenum, the first impingement wall defining a first plurality of impingement apertures. [Embodiment 16] 11. A stator vane assembly as described in any of the preceding embodiments, wherein the boundary wall includes a first impingement surface at the forward portion of the main body, the first impingement surface at least partially defining the first plenum, and the first plurality of impingement apertures is sized and oriented to direct coolant across the first plenum to impinge upon the first impingement surface. [Embodiment 17] 11. A stator vane assembly as described in any of the preceding embodiments, wherein the boundary wall defines a film cooling channel that extends from an inlet fluidly coupled to one of the first plenum or the at least one re-use plenum to an outlet on the hot gas boundary surface, and the outlet is aft of the inlet such that the film cooling channel is oblique to the hot gas boundary surface. [Embodiment 18] 11. A stator vane assembly as described in any of the preceding embodiments, wherein the aft portion of the main body includes a second impingement wall disposed within the at least one re-use plenum, the second impingement wall separating the at least one re-use plenum into a first portion and a second portion, and the second impingement wall defining a second plurality of impingement apertures fluidly coupling the first portion and the second portion. [Embodiment 19] A stator vane assembly as described in any of the preceding embodiments, wherein the connecting channel fluidly couples the first plenum to the first portion of the at least one re-use plenum. [Embodiment 20] 11. A stator vane assembly as in any of the preceding embodiments, wherein the aft portion of the main body includes a boundary wall having a second impingement surface, the second impingement surface at least partially defining the second portion of the at least one re-use plenum, and the second plurality of impingement apertures is sized and oriented to direct coolant across the second portion of the at least one re-use plenum to impinge upon the second impingement surface. [Explanation of symbols]

[0067] 10: Gas turbine engine 11: Compressor casing 12: Compressor section 14: Compressor 16: Inlet 18: Combustion section 19: Stator vanes / static nozzles 20: Combustor 21: Rotor disk 22: Turbine section 23: Rotor blades 24: Shaft 25: Combustion chamber 26: Stator vanes / static nozzles 27: Rotor disk 28: Rotor blades 30: Axial centerline 32: Outer casing 34: Exhaust diffuser 35: Compressed air 36: Ambient air 37: Shank 38: Mounting 40: Airfoil 41: Combustion gases 42: Platform 43: Strut / main airfoil 44: Pressure sidewall 46: Suction sidewall 48: Root 50: Stage 55: Axial centerline 56: Airfoil 57: Cambered axis 58: Shroud segment 60: Leading edge 62: trailing edge 64: pressure sidewall 66: suction sidewall 68: base 70: tip 73: inner boss 75: outer boss 78: dashed line 79, 81: arrows 80: protrusion 92: cavity 102: opening 200: stator vane assembly 201: platform 202: inner platform / inner endwall 204: outer platform / outer endwall 206: airfoil segment 208: hot gas interface 210: body 211: forward hook rail 212: hook rail 213: aft hook rail 214: forward end 215: aft end 216: boss 218: forward section 220: aft section 222: cooling circuit 224: first plenum / forward plenum 226: reuse plenum / aft plenum 228: connecting channel 230: boundary wall 232: first impingement surface 234: first impingement wall 236: first plurality of impingement openings 238: second impingement wall 240: solid wall 242: first portion 244: second portion 246: second impingement surface 248: impingement openings 252: film cooling channel 258: internal support 260: axial tab 262: radial portion / radial body 264: radial portion 266: axial protrusion 268: leading edge boundary 270: trailing edge boundary 272: suction side boundary 274: pressure side boundary 276: leading edge surface 278: trailing edge surface 280: pressure side slash face282: Suction side slash face 284: Supply passage 286: Main connection portion 288: Outlet passage 290: First end 292: Second end A: Axial direction C: Circumferential direction R: Radial direction T: Lateral direction 228

Claims

1. A platform (201) for a stator vane assembly (200), comprising: a body (210) extending between a forward end (214) and a rearward end (215); an opening (102) defined in a body (210), the opening being configured to receive an airfoil segment (56) of a stator vane assembly (200), a forward portion (218) of the body (210) extending between a forward end (214) and the opening (102), and an aft portion (220) of the body (210) extending between the opening (102) and an aft end (215); a hook rail (212) extending from the body (210) across the opening (102); a cooling circuit (222) at least partially defined within said platform (201); Including, The cooling circuit (222) a first plenum (224) defined in the forward portion (218); at least one reuse plenum (226) defined within the aft portion (220) and separated from the first plenum (224); a connecting channel (228) fluidly connecting the first plenum (224) and the at least one reuse plenum (226); Including, The connecting channel (228) is defined at least partially within the hook rail (212), the platform (201).

2. The platform (201) of claim 1, wherein the body (210) further comprises a boundary wall (230) defining the hot gas interface (208).

3. 3. The platform (201) of claim 2, wherein the forward portion (218) of the body (210) further includes a first impingement wall (234) disposed in the first plenum (224), the first impingement wall (234) defining a first plurality of impingement openings (236).

4. 4. The platform (201) of claim 3, wherein the boundary wall (230) includes a first impingement surface (232) at a forward portion (218) of the body (210), the first impingement surface (232) at least partially defining a first plenum (224), and the first plurality of impingement openings (236) are sized and oriented to direct coolant across the first plenum (224) to impinge on the first impingement surface (232).

5. 3. The platform (201) of claim 2, wherein the boundary wall (230) defines a film cooling channel (252) extending from an inlet fluidly coupled to one of the first plenum (224) or the at least one reuse plenum (226) to an outlet on the hot gas interface (208), the outlet being offset from the inlet such that the film cooling channel (252) is oblique to the hot gas interface (208).

6. 2. The platform (201) of claim 1, wherein the aft portion (220) of the body (210) includes a second impingement wall (238) disposed within the at least one reuse plenum (226), the second impingement wall (238) separating the at least one reuse plenum (226) into a first portion (242) and a second portion (244), the second impingement wall (238) defining a second plurality of impingement openings (248) fluidly coupling the first portion (242) and the second portion (244).

7. The platform (201) of claim 6, wherein the connecting channel (228) fluidly couples the first plenum (224) to a first portion (242) of the at least one reuse plenum (226).

8. 7. The platform (201) of claim 6, wherein the aft portion (220) of the body (210) includes a boundary wall (230) having a second impingement surface (246), the second impingement surface (246) at least partially defining a second portion (244) of the at least one reuse plenum (226), and the second plurality of impingement openings (248) are sized and oriented to direct the coolant across the second portion (244) of the at least one reuse plenum (226) to impinge against the second impingement surface (246).

9. The platform (201) of any preceding claim, further comprising a support (258) extending into at least one of the first plenum (224) and the at least one reuse plenum (226).

10. A stator vane assembly (200) comprising: A platform (201) according to any one of claims 1 to 9, arranged as an inner platform (202) or an outer platform (204); an airfoil segment (56) disposed within the opening (102) and having a boss (216) connected to the opening (102); A stator vane assembly (200) configured for use in a gas turbine engine (10).

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