Patent Application
20210040866
This disclosure generally relates to a turbine nozzle for a gas turbine engine, and more specifically to an angled inner band flange of the turbine nozzle.
At least some known rotary machines include a compressor, a combustor coupled downstream from the compressor, a turbine coupled downstream from the combustor, and a rotor shaft rotatably coupled between the compressor and the turbine. Some known turbines include at least one rotor disk coupled to the rotor shaft, and a plurality of circumferentially-spaced turbine blades that extend outward from each rotor disk to define half of a stage of the turbine. The other half of the turbine stage includes a row of stationary, circumferentially-spaced turbine nozzles axially positioned between adjacent rows of turbine blades. Each turbine nozzle includes an airfoil that extends radially outward from an inner band towards a turbine casing.
At least some known turbine nozzles include an inner band that includes an axially-extending platform portion and a radially-extending flange portion. The airfoil is coupled to the platform portion and the flange portion couples the turbine nozzles to retaining rings within the turbine. In at least some known turbine engines, the position of the flange portion is determined by the configuration of the retaining ring and how the retaining ring attaches to the turbine nozzle. As such, in at least some known turbine engines, the flange portion of the inner band is not axially aligned with the throat location of the turbine nozzle due to space limitations within the turbine.
Furthermore, in some known configurations, the flange portion is radially oriented and both the platform portion and the flange portion include slots defined therein that receive a strip seal. Such designs may not satisfy positive back flow margin design specifications due to increased leakage areas at the intersection of the strip seals in the platform portion and flange portion.
In one aspect, the disclosure relates to inner band assembly for a turbine nozzle of a rotary machine that includes a centerline axis, the inner band assembly comprising a platform portion. a first flange coupled to the platform portion wherein the first flange is obliquely oriented with respect to the centerline axis, and a second flange coupled to the first flange wherein the second flange is obliquely oriented with respect to the first flange, wherein the platform portion and the first flange intersect at a point that is axially aligned with a throat location that is at least partially defined by the turbine nozzle.
In another aspect, the disclosure relates to a turbine nozzle for a rotary machine including a centerline axis, the turbine nozzle comprising an airfoil comprising a leading edge and a trailing edge wherein the airfoil defines a throat location proximate to the trailing edge, and an inner band assembly comprising a platform portion coupled to the airfoil, and a first flange coupled to the platform portion wherein the first flange is obliquely oriented with respect to the platform portion, wherein the platform portion and the first flange intersect at a point axially aligned with the throat location.
In yet another aspect, the disclosure relates to a method of manufacturing a turbine nozzle for a rotary machine including a centerline axis, the method comprising coupling an airfoil to a platform portion of an inner band assembly, coupling a first flange of the inner band assembly to the platform portion such that the first flange is obliquely oriented with respect to the centerline axis, and such that the first flange and the platform portion intersect at a throat location at least partially defined by the airfoil, and coupling a second flange of the inner band assembly to the first flange such that the second flange is obliquely oriented with respect to the first flange.
These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Unless otherwise indicated, the drawings provided herein are meant to illustrate features of embodiments of the disclosure. These features are believed to be applicable in a wide variety of systems comprising one or more embodiments of the disclosure. As such, the drawings are not meant to include all conventional features known by those of ordinary skill in the art to be required for the practice of the embodiments disclosed herein.
Embodiments of the present disclosure relate to a turbine nozzle for a rotary machine having an angled flange at least partially aligned with a throat of the turbine nozzle. More specifically, the turbine nozzle includes an airfoil that defines a throat location proximate a trailing edge. The turbine nozzle also includes an inner band assembly including a platform portion coupled to the airfoil, and a first flange coupled to the platform portion. The first flange is obliquely oriented with respect to the platform portion, and the platform portion and the first flange intersect at a point axially aligned with the throat location. The inner band assembly also includes a second flange coupled to the first flange such that the second flange is obliquely oriented with respect to the first flange. The design features include positioning an intersection of the platform portion and the first flange at the throat location while also offsetting the second flange from the throat location. Such a configuration may be used in smaller sized rotary machines where spaced for the inner band assembly is limited. Furthermore, the slanted first flange creates a pressurization area inward of the platform portion that maintains a positive backflow margin up to the throat location. More specifically, axial alignment of a high static pressure area and the pressurization area forward of the first flange reduces or prevents purge air from leaking across platform portions of adjacent turbine nozzles and intermixing with the hot combustion gases in the combustion gas path.
In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings.
The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
“Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.
Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about”, “approximately”, and “substantially”, are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged. Such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.
As used herein, the terms “axial” and “axially” refer to directions and orientations that extend substantially parallel to a centerline of the turbine engine. Moreover, the terms “radial” and “radially” refer to directions and orientations that extend substantially perpendicular to the centerline of the turbine engine. In addition, as used herein, the terms “circumferential” and “circumferentially” refer to directions and orientations that extend arcuately about the centerline of the turbine engine. As used herein, the terms “oblique” and “obliquely” refer to orientations that extend in both non-parallel and non-perpendicular directions from a respective component or surface. More specifically, “oblique” and “obliquely” refer to an angle of orientation between two components or surfaces that is not 0 degrees, 90 degrees, or 180 degrees.
Additionally, unless otherwise indicated, the terms “first,” “second,” etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to, for example, a “second” item does not require or preclude the existence of, for example, a “first” or lower-numbered item or a “third” or higher-numbered item. As used herein, the term “upstream” refers to a forward or inlet end of a gas turbine engine, and the term “downstream” refers to an aft or nozzle end of the gas turbine engine.
In operation, air entering rotary machine 10 through intake 32 is channeled through fan assembly 12 towards booster compressor assembly 14. Compressed air is discharged from booster compressor assembly 14 towards high-pressure compressor assembly 16. Highly compressed air is channeled from high-pressure compressor assembly 16 towards combustor assembly 18, mixed with fuel, and the mixture is combusted within combustor assembly 18. High temperature combustion gas generated by combustor assembly 18 is channeled towards turbine assemblies 20 and 22. Combustion gas is subsequently discharged from rotary machine 10 via exhaust 34.
Airfoil 124 includes a pressure-side sidewall 126 and a suction-side sidewall 128 that are connected at a leading edge 130 and at a chordwise-spaced trailing edge 132 such that sidewalls 126 and 128 are defined between edges 130 and 132. Sidewalls 126 and 128 each extend radially between inner band assembly 120 and outer band assembly 122. In one embodiment, sidewall 126 is generally concave and sidewall 128 is generally convex. Airfoil 124 also at least partially defines a throat location 134 proximate trailing edge 132. As used herein, the term “throat location” identifies an axial location of the throat between circumferentially adjacent airfoils 124 in row 102 of turbine nozzles 104. Further, the term “throat” is used herein to indicate the minimum restriction distance between circumferentially adjacent airfoils 124. Specifically, the throat is the minimum distance from the pressure-side sidewall 126, and more specifically, from the trailing edge 132 of the pressure-side sidewall 126 on one airfoil 124 to the suction-side sidewall 128 of the adjacent airfoil 124. Throat location 134 occurs where combustion gases 118 (shown in
In the exemplary embodiment, outer band assembly 122 includes a platform portion 136 coupled to airfoil 124 and a flange portion 138 extending radially outward from platform portion 136. At least one of platform portion 136 and flange portion 138 is coupled to turbine casing 116. Similarly, inner band assembly 120 includes a platform portion 140, a first flange 142, and a second flange 144. As shown in
As shown in
In the exemplary embodiment, first flange 142 includes a first end 152 coupled to platform portion 140 and a second end 154 coupled to second flange 144. First flange 142 also includes a forward surface 156 extending between first end 152 and second end 154 and an aft surface 158 extending between first end 152 and second end 154. As best shown in
In the exemplary embodiment, as best shown in
As shown in
In the embodiment shown in
Embodiments of the present disclosure relate to a turbine nozzle for a rotary machine having an angled flange at least partially aligned with a throat of the turbine nozzle. More specifically, the turbine nozzle includes an airfoil that defines a throat location proximate a trailing edge. The turbine nozzle also includes an inner band assembly including a platform portion coupled to the airfoil, and a first flange coupled to the platform portion. The first flange is obliquely oriented with respect to the platform portion, and the platform portion and the first flange intersect at a point axially aligned with the throat location. The inner band assembly also includes a second flange coupled to the first flange such that the second flange is obliquely oriented with respect to the first flange.
The design features include positioning an intersection of the platform portion and the first flange at the throat location while also offsetting the second flange from the throat location. Such a configuration may be used in smaller sized rotary machines where spaced for the inner band assembly is limited. Furthermore, the slanted first flange creates a pressurization area inward of the platform portion that maintains a positive backflow margin up to the throat location. More specifically, axial alignment of a high static pressure area and the pressurization area forward of the first flange reduces or prevents purge air from leaking across platform portions of adjacent turbine nozzles and intermixing with the hot combustion gases in the combustion gas path.
Exemplary embodiments of a turbine nozzle having an angled flange on the inner band assembly are described above in detail. The turbine nozzle is not limited to the specific embodiments described herein, but rather, components and steps may be utilized independently and separately from other components and/or steps described herein. For example, the embodiments may also be used in combination with other systems and methods, and are not limited to practice with only the gas turbine engine assembly as described herein. Rather, the exemplary embodiment may be implemented and utilized in connection with many other turbine applications.
Although specific features of various embodiments of the device may be shown in some drawings and not in others, this is for convenience only. Moreover, references to “one embodiment” in the above description are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. In accordance with the principles of the device, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.
This written description uses examples to disclose the device, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the device 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 have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 174616045 | Sep 2017 | EP | regional |
This application is a continuation of U.S. patent application Ser. No. 16/057,908, filed on Aug. 8, 2018, now allowed, which takes priority to European Patent Application No. 17461604, filed on Sep. 15, 2017, all of which are hereby incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16057908 | Aug 2018 | US |
| Child | 17083565 | US |
