Turbomachine nozzle with tabs having a rounded trailing edge

Abstract

The invention is entitled Turbomachine nozzle with airfoil having a rounded trailing edge. A gas turbine engine (10) is defined that defines an axial direction (A), a radial direction (R) perpendicular to the axial direction (A), and a circumferential direction (C) extending concentrically about the axial direction (A). The gas turbine engine (10) includes a nozzle (202) having an inner platform (208), an outer platform (210), and an airfoil (212). The airfoil (212) includes a leading edge (218), a trailing edge (220) downstream of the leading edge (218), a pressure side surface (224), and a suction side surface (226) opposite the pressure side surface (224). The trailing edge (220) defines a circular arc between the inner platform (208) and the outer platform (210).

Description

Technical Field

[0001] This disclosure relates in its entirety to turbines. More specifically, this disclosure relates to stator blades for turbines. Background Technology

[0002] A gas turbine engine typically comprises 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 this compressed working fluid to the combustion section. The compressed working fluid and fuel (e.g., natural gas) mix in the combustion section and burn in the combustion chamber to produce high-pressure, high-temperature combustion gases. The combustion gases flow from the combustion section into the turbine section, where they expand to do work. For example, the expansion of the combustion gases in the turbine section can rotate a rotor shaft connected to, for example, a generator to produce electricity. The combustion gases then exit the gas turbine via the exhaust section.

[0003] The turbine section typically comprises multiple stator blades, sometimes also referred to as nozzles. Each stator blade includes an airfoil positioned within the combustion gas flow. The stator blade airfoil typically extends radially outward from the inner platform to the outer platform.

[0004] Airfoils can extend from the leading edge to the trailing edge downstream of the leading edge, and can define aerodynamic surfaces, such as pressure-side and suction-side surfaces, between them. The intersections of these aerodynamic surfaces with the inner and outer platforms can create regions of relatively high secondary losses. Some airfoils are designed with curved shapes to reduce such secondary losses; however, known curved shapes can lead to other inefficiencies, such as those due to increased throat spacing between the blades.

[0005] Therefore, such a blade for stator blades would be useful, providing both reduced secondary losses and effective overall aerodynamic performance at the external platform. Additionally, there is a need in the art for blades that facilitate the installation of internal components. Summary of the Invention

[0006] The various aspects and advantages of this technology will be partly set forth in the following description, or may be apparent from the description, or may be understood through practice of this technology.

[0007] According to one embodiment, a vane for a stator blade of a turbine is provided. The turbine defines an axial direction, a radial direction perpendicular to the axial direction, and a circumferential direction extending concentrically about the axial direction. The vane extends radially between an inner platform and an outer platform of the stator blade. The vane includes a leading edge extending along the flow direction from the inner platform to the outer platform and a trailing edge downstream of the leading edge. A trailing edge extends along the vane from the inner platform to the outer platform. The vane also includes a pressure-side surface extending between the inner and outer platforms and between the leading and trailing edges. The vane also includes a suction-side surface extending between the inner and outer platforms and between the leading and trailing edges. The suction-side surface is opposite to the pressure-side surface. The trailing edge defines an arc between the inner and outer platforms.

[0008] According to another embodiment, a turbine is provided. The turbine defines an axial direction, a radial direction perpendicular to the axial direction, and a circumferential direction extending concentrically about the axial direction. The turbine includes a compressor, a combustor disposed downstream of the compressor, and a turbine disposed downstream of the combustor. The turbine includes stator blades having an inner platform, an outer platform, and vanes. The vanes of the stator blades include a leading edge extending along the flow direction from the inner platform to the outer platform and a trailing edge downstream of the leading edge. A trailing edge extends along the vane from the inner platform to the outer platform. The vane also includes a pressure-side surface extending between the inner and outer platforms and between the leading and trailing edges. The vane also includes a suction-side surface extending between the inner and outer platforms and between the leading and trailing edges. The suction-side surface is opposite to the pressure-side surface. The trailing edge defines an arc between the inner and outer platforms.

[0009] These and other features, aspects, and advantages of the present technology will become more readily understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present technology and, together with the description, serve to explain the principles of the present technology. Attached Figure Description

[0010] The specification with reference to the accompanying drawings sets forth a full and implementable disclosure of the present technology for those skilled in the art, including its best mode.

[0011] Figure 1 This is a schematic diagram of an exemplary gas turbine engine according to one or more exemplary embodiments of the present disclosure;

[0012] Figure 2 This is a perspective view of an exemplary turbine nozzle that may be incorporated into one or more embodiments of this disclosure;

[0013] Figure 3This is a side view of the trailing edge of a stator blade according to one or more exemplary embodiments of the present disclosure;

[0014] Figure 4 This is a trailing edge view taken from upstream of a stator blade according to one or more exemplary embodiments of this disclosure;

[0015] Figure 5 This is a trailing edge view taken from upstream of a stator blade according to one or more exemplary embodiments of this disclosure;

[0016] Figure 6 This is a side view of a stator blade according to one or more exemplary embodiments of the present disclosure;

[0017] Figure 7 yes Figure 6 A perspective view of the trailing edge of the stator blades;

[0018] Figure 8 This is a perspective view of a stator blade airfoil according to one or more exemplary embodiments of the present disclosure; and

[0019] Figure 9 This is a perspective view of a stator blade airfoil according to one or more exemplary embodiments of the present disclosure.

[0020] Reference characters are used repeatedly in this specification and drawings to indicate the same or similar features or elements of the technology. Detailed Implementation

[0021] Reference will now be made in detail to embodiments of the present technology, one or more examples of which are illustrated in the accompanying drawings. Detailed descriptions use numerical and letter names to refer to characteristic structures in the drawings. Similar or analogous names in the drawings and specification have been used to refer to similar or analogous parts of the present technology. As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of individual components. The terms “upstream” and “downstream” refer to the relative directions of fluid flow in a fluid passage. For example, “upstream” refers to the direction from which fluid flows, and “downstream” refers to the direction from which fluid flows.

[0022] As used herein, approximations such as “generally” or “about” include values ​​that are greater than or less than ten percent of the stated value. When used in the context of angles or directions, such terms include values ​​that are greater than or less than ten degrees of the stated angle or direction. For example, “generally vertical” includes directions that are within ten degrees of vertical in any direction (e.g., clockwise or counterclockwise).

[0023] Each example is provided by way of explanation of the technology and not as a limitation thereof. Indeed, it will be apparent to those skilled in the art that modifications and variations may be made to the technology without departing from the scope or spirit of this disclosure. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, the technology is intended to cover such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0024] Although industrial or land-based gas turbines are shown and described herein, the techniques of the invention as shown and described herein are not limited to land-based and / or industrial gas turbines, unless otherwise specified in the claims. For example, the techniques described herein can be used in any type of turbine, including but not limited to aviation gas turbines (e.g., turbofans, etc.), steam turbines, and marine gas turbines.

[0025] Referring now to the accompanying drawings, in which the same numerals indicate the same elements throughout all the drawings. Figure 1 A gas turbine engine 10 is schematically illustrated. It should be understood that the gas turbine engine 10 of this disclosure need not be a gas turbine engine, but can be any suitable turbine, such as a steam turbine engine or other suitable engine. The gas turbine engine 10 may include an inlet section 12, a compressor section 14, a combustion section 16, a turbine section 18, and an exhaust section 20. The compressor section 14 and the turbine section 18 may be connected by a shaft 22. The shaft 22 may be a single shaft or multiple shaft segments connected together to form the shaft 22.

[0026] During operation, a working fluid, such as air 24, flows through inlet section 12 and into compressor 14, where it is gradually compressed, thereby supplying compressed air 26 to combustor 16. At least a portion of the compressed air 26 mixes with fuel 28 within combustor 16 and is burned to produce combustion gas 30. Combustion gas 30 flows from combustor 16 into turbine 18, where energy (kinetic and / or thermal energy) is transferred from combustion gas 30 to rotor blades, causing shaft 22 to rotate. This mechanical rotational energy can then be used for various purposes, such as powering compressor 14 and / or generating electricity. Combustion gas 30 exiting turbine 18 can then be discharged from gas turbine 10 via exhaust section 20.

[0027] like Figures 3 to 9 As shown, the gas turbine 10 may define, for example, an axial direction A along or parallel to the shaft 22, a radial direction R perpendicular to the axial direction A, and a circumferential direction C extending concentrically around the axial direction.

[0028] Figure 2 Provided, for example, in various embodiments of this disclosure, can be incorporated into Figure 1A perspective view of an exemplary turbine nozzle 202 in the turbine 18 shown. Figure 2 As shown, in some embodiments, the turbine nozzle 202 includes an inner platform 208 and an outer platform 210, for example, radially spaced from the inner platform 208 along a radial direction R. The outer platform may extend along an axial direction A between a front sidewall 214 and a rear sidewall 216.

[0029] exist Figure 2 In the illustrative example, a pair of flaps 212 extend from the inner platform 208 across the outer platform 210. In this respect, Figure 2 The exemplary turbine nozzle 202 shown is referred to in the industry as a doublet. However, the turbine nozzle 202 may have only one blade 212 (i.e., a singlet), three blades 212 (i.e., a triplet), or more blades 212.

[0030] Each blade 212 includes a leading edge 218 at the front end of the blade 212 and a trailing edge 220 at the rear end of the blade 212. The nozzle 202 may also include one or more rear hooks 222 configured to engage with an adjacent cover (not shown) of a turbine (e.g., a gas turbine 10). For example, the nozzle 202 may include a rear hook 222 corresponding to each blade 212; for instance, a dual-blade assembly may have two rear hooks 222.

[0031] Each vane 212 includes a pressure-side surface 224 and an opposing suction-side surface 226. The pressure-side surface 224 and the suction-side surface 226 are joined together or interconnected at the leading edge 218 of the vane 212, which is oriented to enter the flow of combustion gases 30. Figure 1 The pressure-side surface 224 and the suction-side surface 226 are also joined together or interconnected at the trailing edge 220 of the vane 212, which is spaced downstream of the leading edge 218. The pressure-side surface 224 and the suction-side surface 226 are continuous around the leading edge 218 and the trailing edge 220. The pressure-side surface 224 is generally concave, and the suction-side surface 226 is generally convex.

[0032] Figure 3 This is a side view of the trailing edge portion of the airfoil 212 of the stator blade 202, where portions of the inner platform 208 and the outer platform 210 are shown in cross section. The trailing edge portion may be the downstream half of the airfoil 212 at and around the trailing edge 220 of the airfoil 212.

[0033] As in Figure 3 As can be seen, the trailing edge 220 intersects with the inner platform 208 at point 228 and forms an interior angle B with the inner platform 208 at point 228. From Figure 3It can also be seen that the trailing edge 220 intersects with the outer platform 210 at the second point 230 and forms an exterior angle α with the outer platform 210 at the second point 230. The second point 230 may be located downstream of the first point 228. Specifically, the second point 230 may be located downstream of the radial projection line 1000, which extends along the radial direction R through the first point 228, as shown below. Figure 3 As shown.

[0034] Additionally, as in Figure 3 As can be seen, the projection of the trailing edge 220 in the axial-radial direction defines a curved line in the downstream flow direction, wherein the outer platform intersection 230 is not upstream of the inner platform intersection 228. Conversely, as... Figure 3 As shown, the outer platform intersection 230 is located downstream of the inner platform intersection 228 or axially aligned in other embodiments (not shown). In some embodiments, the trailing edge 220 may be orthogonal to the outer platform 210 and inclined to the inner platform 208. For example, the outer angle α may be approximately 90° and the inner angle β may not be equal to 90°; for example, the inner angle β may be less than 90°.

[0035] Figure 4 This is a trailing edge view taken upstream of the blade 212 of the stator blade 202, according to one or more exemplary embodiments. Figure 4 and Figure 5 An embodiment of the blade 212 is shown as seen in a plane perpendicular to the axial direction A (e.g., a radial-circumferential plane defined by the radial direction R and the circumferential direction C). Figure 4 As can be seen, in some embodiments, the trailing edge 220 may be bent relative to the radial direction R in such a way as to be bent relative to the radial projection line 1000 extending through the intersection 228 of the trailing edge 220 and the inner platform 208, in such a way that the pressure side surface 224 of each profile segment is positioned at an angle relative to the adjacent profile segment at a lower radius (e.g., closer to the inner platform 208) toward the center of the engine (e.g., toward the shaft 22 and / or its axial centerline).

[0036] In some implementation schemes, such as Figure 4 As shown, the inner portion of the trailing edge 220 may be tangent to the radial direction R, wherein the intersection 230 of the trailing edge 220 and the outer platform 210 is circumferentially offset from the radial projection line 1000. In other embodiments, such as Figure 5 As shown, the trailing edge 220 may be inclined relative to the radial direction R. For example, the inner portion of the trailing edge 220 may be tangent to the second line 1002, which is inclined at an angle Θ relative to the radial direction R, for example, forming an angle Θ with the radial projection line 1000.

[0037] Figure 6 and Figure 7Additional examples of fins 212 for stator blades 202 according to various embodiments of this disclosure are provided. For simplicity and to depict the shape of the fins 212 more clearly, the inner platform 208 and the outer platform 210 are not shown. Figure 6 and Figure 7 As shown in the image. For example, Figure 6 and Figure 7 An embodiment of a winglet 212 with a curved trailing edge 220 is shown, which is radially stacked such that the pressure sides 224 of each profile segment are positioned at an angle toward the center of the engine, for example, as described above relative to... Figure 4 The downstream arcuate portion, curved at the trailing edge 220, for example, as described above relative to... Figure 3 As mentioned above, it can also be found in Figure 6 and Figure 7 As seen in the exemplary implementation shown.

[0038] Now go to Figure 8 and Figure 9 The trailing edge 220 of the wing 212 can be circular. For example, as... Figure 8 and Figure 9 As shown, trailing edge 220 may define arc 2020, which is along imaginary circle 2000, for example, a portion of imaginary circle.

[0039] Specifically, go to Figure 8 The trailing edge 220 can be connected from the first point T1 on the circle 2000 at the innermost point of the trailing edge 220 (e.g., the first point 228 where the trailing edge 220 intersects with the inner platform 208, such as...). Figure 3 As shown, a second point T2 extends onto circle 2000, which may be the mid-span point on the winglet (e.g., at or approximately halfway between the inner platform 208 and the outer platform 210), and extends from the second mid-span point T2 to an outer point T3, which may be the outermost point on the trailing edge 220 (e.g., the second point 230 where the trailing edge 220 intersects the outer platform 210, as shown). Figure 3 (As shown).

[0040] like Figure 8 As shown, the first point T1 on circle 2000 lies on radial projection line 1000, while subsequent points are offset from the first point T1, and therefore also offset from radial projection line 1000. More specifically, the second point T2 can be offset along the axial direction A from the midpoint T1′ on radial projection line 1000 by a first axial distance 1004 and along the circumferential direction C by a first circumferential distance 1006. Figure 8 As shown, in some implementations, the first axial distance 1004 is not equal to the first circumferential distance 1006.

[0041] Furthermore, the third point T3 on circle 2000 can be offset by a second axial distance 1008 from the outermost point T1” on radial projection line 1000 along the axial direction A and by a second circumferential distance 1010 along the circumferential direction C. For example... Figure 8 As shown, the trailing edge 220 is further separated from the radial direction R, for example, from the radial projection line 1000 that moves outward along the trailing edge 220. Therefore, the second axial distance 1008 may be greater than the first axial distance 1004, and the second circumferential distance 1010 may be greater than the first circumferential distance 1006. For example, the trailing edge 220 may be axially and circumferentially offset from the radial direction R.

[0042] like Figure 9 As shown, a circle 2000 on which the trailing edge 220 lies (e.g., a circle 2000 whose part is an arc 2020 defined by the trailing edge 220) may lie in a plane 2002. The plane 2002 in which the circle 2000 lies may be an inclined plane relative to the turbine (e.g., gas turbine 10). For example, as in... Figure 9 As can be seen, plane 2002 may not be parallel to any of the Cartesian planes defined by the machine's axis. For example, plane 2002 may not be parallel to the radial direction R, the axial direction A, or the circumferential direction C. Therefore, plane 2002 may be neither an axial-radial plane nor a circumferential-radial plane.

[0043] A circular trailing edge 220 can offer numerous advantages. For example, a circular trailing edge 220 can provide aerodynamic benefits such as improved efficiency and reduced losses, for example, due to the relatively short axial distance between the nozzle and the downstream rotor blades. Furthermore, a circular trailing edge 220 can facilitate the easy installation of internal components of the stator blade 202. For instance, the stator blade 212 (and specifically its vane 212) may include internal cooling structures, such as one or more baffles, defining cooling channels for coolant (e.g., air) to flow through and within the vane 212, as commonly understood by those skilled in the art. Such internal cooling structures may be formed separately from the vane 212 and can be inserted into the vane 212 by rotating the internal cooling structure along the circle 2000.

[0044] This written description uses examples to disclose the technology, including best practices, and also enables any person skilled in the art to practice the technology, including making and using any device or system and performing any combined methods. The patentable scope of the technology is defined by the claims and may include other examples that would occur to a person skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

Claims

1. A stator blade (202) for a gas turbine engine (10), the gas turbine engine (10) defining an axial direction (A), a radial direction (R) perpendicular to the axial direction (A), and a circumferential direction (C) extending concentrically about the axial direction (A), the stator blade comprising: Internal platform (208); External platform (210); as well as A winglet (212) extending radially between the inner platform (208) and the outer platform (210), the winglet (212) comprising: Leading edge (218), which extends from the inner platform (208) to the outer platform (210) on the winglet (212); The trailing edge (220), located downstream of the leading edge (218) along the flow direction, extends across the flap (212) from a first point (T1) intersecting the inner platform (208) through a midspan point to a second point (T3) intersecting the outer platform (210), wherein a radial projection line extends through the first point (T1), wherein the trailing edge deviates from the radial projection line both axially and circumferentially from the first point (T1) to the second point (T3), such that the midspan point is closer to the radial projection line in both the axial and circumferential directions than the second point (T3), and wherein as the trailing edge extends from the first point (T1) to the second point (T3), the trailing edge deviates further from the radial projection line in the circumferential direction than the trailing edge deviates further from the radial projection line in the axial direction; A pressure-side surface (224) extending between the inner platform (208) and the outer platform (210) and between the leading edge (218) and the trailing edge (220), wherein the entire pressure-side surface is angled toward the inner platform; and A suction-side surface (226) extends between the inner platform (208) and the outer platform (210) and between the leading edge (218) and the trailing edge (220), the suction-side surface (226) being opposite to the pressure-side surface (224), wherein the entire suction-side surface is angled toward the outer platform; The trailing edge (220) defines an arc (2020) between the inner platform (208) and the outer platform (210), wherein the arc (2020) is part of a circle (2000) and the circle (2000) lies in a plane (2002) that is not parallel to the axial-radial plane or the circumferential-radial plane of the turbine.

2. The stator blade (202) according to claim 1, wherein the trailing edge (220) is inclined relative to the inner platform (208) in the axial-radial plane.

3. The stator blade (202) according to claim 2, wherein the trailing edge (220) and the inner platform (208) form an angle of less than ninety degrees in the axial-radial plane.

4. The stator blade (202) according to claim 1, wherein the trailing edge (220) bends outward along the flow direction between the first point (T1) and the second point (T3).

5. The stator blade (202) according to claim 1, wherein the second point (T3) is not located upstream of the first point (T1).

6. The stator blade (202) according to claim 1, wherein the second point (T3) is located downstream of the first point (T1).

7. A gas turbine engine (10) defining an axial direction (A), a radial direction (R) perpendicular to the axial direction (A), and a circumferential direction (C) extending concentrically about the axial direction (A), the gas turbine engine (10) comprising: Compressor (14); A burner (16) is disposed downstream of the compressor (14); as well as A turbine (18) disposed downstream of the burner (16) includes stator blades (202) according to any one of claims 1 to 6.

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