BACKGROUND

[0001] An industrial gas turbine engine typically includes a compressor section, a turbine section, and a combustion section disposed therebetween. The compressor section includes multiple stages of rotating compressor blades and stationary compressor vanes. The combustion section typically includes a plurality of combustors.

[0002] The turbine section includes multiple stages of rotating turbine blades and stationary turbine vanes. Turbine blades and vanes often operate in a high temperature environment and are internally cooled.

BRIEF SUMMARY

[0003] A guide vane in a gas turbine engine includes: an inner platform; an outer platform; and a vane airfoil extending between the inner platform and the outer platform, the vane airfoil including a leading edge and a trailing edge with respect to a flow direction, the vane airfoil including a bow shape such that the outermost portion and the innermost portion of the leading edge are positioned upstream of the middle portion of the leading edge and the outermost portion of the trailing edge and the innermost portion of the trailing edge are positioned upstream of the middle portion of the trailing edge.

[0004] A guide vane in a gas turbine engine includes: an inner platform; an outer platform including a side surface; a vane airfoil extending between the inner platform and the outer platform; a first outer seal slot disposed on the side surface of the outer platform; and a second outer seal slot disposed on the side surface of the outer platform spaced apart from the first outer seal slot.

[0005] A guide vane in a gas turbine engine includes: an inner platform; an outer platform including a front hook and a rear hook; a vane airfoil extending between the inner platform and the outer platform; and a radiation shield coupled to the outer platform.

[0006] A guide vane in a gas turbine engine includes: an inner platform; an outer platform; a vane airfoil extending between the inner platform and the outer platform; and an inter stage seal coupled to the inner platform, the inner stage seal including a base plate and a rail extending between the inner platform and the base plate forming a T-shape, the base plate including a stepped shape.

[0007] A guide vane positioned adjacent to and downstream of a row of rotating turbine blades, the row of rotating turbine blades defining an annular groove, the guide vane includes: an inner platform; an outer platform; a vane airfoil extending between the inner platform and the outer platform; and an extension coupled to the inner platform and extending in an upstream direction toward the row of rotating blades, the extension at least partially positioned within the annular groove, the extension and the annular groove cooperating to aerodynamically damp vibrations of the guide vane during operation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0009] FIG. 1 is a longitudinal cross-sectional view of a gas turbine engine taken along a plane that contains a longitudinal axis or central axis.

[0010] FIG. 2 is a perspective view of a guide vane. [0011] FIG. 3 is an enlarged view of an outer part of the guide vane of FIG. 2.

[0012] FIG. 4 is an enlarged view of an inner part of the guide vane of FIG. 2.

[0013] FIG. 5 is a longitudinal cross-sectional view of a portion of a turbine section.

DETAILED DESCRIPTION

[0014] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in this description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0015] Various technologies that pertain to systems and methods will now be described with reference to the drawings, where like reference numerals represent like elements throughout. The drawings discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged apparatus. It is to be understood that functionality that is described as being carried out by certain system elements may be performed by multiple elements. Similarly, for instance, an element may be configured to perform functionality that is described as being carried out by multiple elements. The numerous innovative teachings of the present application will be described with reference to exemplary non-limiting embodiments. [0016] Also, it should be understood that the words or phrases used herein should be construed broadly, unless expressly limited in some examples. For example, the terms “including”, “having”, and “comprising”, as well as derivatives thereof, mean inclusion without limitation. The singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. The term “or” is inclusive, meaning and/or, unless the context clearly indicates otherwise. The phrases “associated with” and “associated therewith” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like. Furthermore, while multiple embodiments or constructions may be described herein, any features, methods, steps, components, etc. described with regard to one embodiment are equally applicable to other embodiments absent a specific statement to the contrary.

[0017] Also, although the terms “first”, “second”, “third” and so forth may be used herein to refer to various elements, information, functions, or acts, these elements, information, functions, or acts should not be limited by these terms. Rather these numeral adjectives are used to distinguish different elements, information, functions or acts from each other. For example, a first element, information, function, or act could be termed a second element, information, function, or act, and, similarly, a second element, information, function, or act could be termed a first element, information, function, or act, without departing from the scope of the present disclosure.

[0018] In addition, the term “adjacent to” may mean that an element is relatively near to but not in contact with a further element or that the element is in contact with the further portion, unless the context clearly indicates otherwise. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Terms “about” or “substantially” or like terms are intended to cover variations in a value that are within normal industry manufacturing tolerances for that dimension. If no industry standard is available, a variation of twenty percent would fall within the meaning of these terms unless otherwise stated.

[0019] FIG. 1 illustrates an example of a gas turbine engine 100 including a compressor section 102, a combustion section 104, and a turbine section 106 arranged along a central axis 112. The compressor section 102 includes a plurality of compressor stages 114 with each compressor stage 114 including a set of rotating compressor blade 116 and a set of stationary compressor vane 118 or adjustable guide vanes. A rotor 134 supports the rotating compressor blade 116 for rotation about the central axis 112 during operation. In some constructions, a single one- piece rotor 134 extends the length of the gas turbine engine 100 and is supported for rotation by a bearing at either end. In other constructions, the rotor 134 is assembled from several separate spools that are attached to one another or may include multiple disk sections that are attached via a bolt or plurality of bolts.

[0020] The compressor section 102 is in fluid communication with an inlet section 108 to allow the gas turbine engine 100 to draw atmospheric air into the compressor section 102. During operation of the gas turbine engine 100, the compressor section 102 draws in atmospheric air and compresses that air for delivery to the combustion section 104. The illustrated compressor section 102 is an example of one compressor section 102 with other arrangements and designs being possible.

[0021] In the illustrated construction, the combustion section 104 includes a plurality of separate combustors 120 that each operate to mix a flow of fuel with the compressed air from the compressor section 102 and to combust that air-fuel mixture to produce a flow of high temperature, high pressure combustion gases or exhaust gas 122. Of course, many other arrangements of the combustion section 104 are possible.

[0022] The turbine section 106 includes a plurality of turbine stages 124 with each turbine stage 124 including a number of rotating turbine blades 126 and a number of stationary turbine vanes 128. The turbine stages 124 are arranged to receive the exhaust gas 122 from the combustion section 104 at a turbine inlet 130 and expand that gas to convert thermal and pressure energy into rotating or mechanical work. The turbine section 106 is connected to the compressor section 102 to drive the compressor section 102. For gas turbine engines 100 used for power generation or as prime movers, the turbine section 106 is also connected to a generator, pump, or other device to be driven. As with the compressor section 102, other designs and arrangements of the turbine section 106 are possible.

[0023] An exhaust portion 110 is positioned downstream of the turbine section 106 and is arranged to receive the expanded flow of exhaust gas 122 from the final turbine stage 124 in the turbine section 106. The exhaust portion 110 is arranged to efficiently direct the exhaust gas 122 away from the turbine section 106 to assure efficient operation of the turbine section 106. Many variations and design differences are possible in the exhaust portion 110. As such, the illustrated exhaust portion 110 is but one example of those variations.

[0024] A control system 132 is coupled to the gas turbine engine 100 and operates to monitor various operating parameters and to control various operations of the gas turbine engine 100. In preferred constructions the control system 132 is typically micro-processor based and includes memory devices and data storage devices for collecting, analyzing, and storing data. In addition, the control system 132 provides output data to various devices including monitors, printers, indicators, and the like that allow users to interface with the control system 132 to provide inputs or adjustments. In the example of a power generation system, a user may input a power output set point and the control system 132 may adjust the various control inputs to achieve that power output in an efficient manner.

[0025] The control system 132 can control various operating parameters including, but not limited to variable inlet guide vane positions, fuel flow rates and pressures, engine speed, valve positions, generator load, and generator excitation. Of course, other applications may have fewer or more controllable devices. The control system 132 also monitors various parameters to assure that the gas turbine engine 100 is operating properly. Some parameters that are monitored may include inlet air temperature, compressor outlet temperature and pressure, combustor outlet temperature, fuel flow rate, generator power output, bearing temperature, and the like. Many of these measurements are displayed for the user and are logged for later review should such a review be necessary.

[0026] FIG. 2 is a perspective view of a guide vane 200. The guide vane 200 is one of a plurality of guide vanes 200 that are arranged next to each other circumferentially in the gas turbine engine 100 to define a row of stationary guide vanes 200.

[0027] The guide vane 200 includes an inner platform 202, an outer platform 204, and a vane airfoil 206 extending between the inner platform 202 and the outer platform 204 in a radial direction 212. The vane airfoil 206 has a leading edge 208 and a trailing edge 210 in a longitudinal direction 214 that is parallel to the flow direction of the exhaust gas 122. The leading edge 208 has a concave shape looking normal to the longitudinal direction 214. The trailing edge 210 has a convex shape looking normal to the longitudinal direction 214. The concave shaped leading edge 208 and the convex shaped trailing edge 210 form a bow shaped vane airfoil 206 towards the upstream in the longitudinal direction 214. The vane airfoil 206 is bow shaped such that the outermost portion and the innermost portion of the leading edge 208 are positioned upstream of the middle portion of the leading edge 208. The trailing edge 210 has the same arrangement such that the outermost portion of the trailing edge 210 and the innermost of the trailing edge 210 are positioned upstream of the middle portion of the trailing edge 210.

[0028] A curvature of the leading edge 208 is defined based on design requirements of the gas turbine engine 100. A curvature of the trailing edge 210 is also defined based on design requirements of the gas turbine engine 100. The curvature of the leading edge 208 may be the same as the curvature of the trailing edge 210. The curvature of the leading edge 208 may be different from the curvature of the trailing edge 210. [0029] More than one vane airfoil 206 may be disposed between the inner platform 202 and the outer platform 204. In the illustrated construction, two vane airfoils 206 extend between the inner platform 202 and the outer platform 204. The vane airfoils 206 are spaced apart from each other in a circumferential direction. The vane airfoils 206 may have the same geometry or may have different geometries.

[0030] FIG. 3 is an enlarged view of an outer part of the guide vane 200 of FIG. 2. The guide vane 200 has an upstream side 302 and a downstream side 304 in the longitudinal direction 214 that is parallel to the flow direction of the exhaust gas 122. The outer platform 204 includes an outer surface 306 facing away from the inner platform 202, and a side surface 308 extending between the upstream side 302 and the downstream side 304. The side surface 308 is the surface between an adjacent guide vane 200 that is arranged in the circumferential direction.

[0031] The side surface 308 includes a first outer seal slot 310 extending between the upstream side 302 and the downstream side 304. The side surface 308 includes a second outer seal slot 312 extending between the upstream side 302 and the downstream side 304. The first outer seal slot 310 and the second outer seal slot 312 are spaced apart from each other in the radial direction 212. The outer platform 204 includes a third outer seal slot 314 that connects the first outer seal slot 310 and the second outer seal slot 312 at the upstream side 302.

[0032] At least one of the first outer seal slot 310 and the second outer seal slot 312 has a straight shape. In the illustrated construction in FIG. 3, the first outer seal slot 310 and the second outer seal slot 312 have straight shapes. It is possible that at least one of the first outer seal slot 310 and the second outer seal slot 312 has a curved shape. It is also possible that the first outer seal slot 310 and the second outer seal slot 312 may have any suitable configurations.

[0033] The outer platform 204 includes a front hook 316 and a rear hook 318 disposed at a front end and a rear end of the guide vane 200, respectively, with respect to the longitudinal direction 214. The front hook 316 is generally C-shaped. The rear hook 318 has a general C-shape. The outer surface 306 has a general curved shape looking towards the outer surface 306. The curved shaped outer surface 306 may tangentially intersect the front hook 316 and the rear hook 318.

[0034] The guide vane 200 includes a radiation shield 320 attached to the outer platform 204. The radiation shield 320 is a thin flat plate. A front end 322 of the radiation shield 320 bends away from the outer surface 306 of the outer platform 204. A rear end 324 of the radiation shield 320 bends towards the outer surface 306 of the outer platform 204. It is possible that the radiation shield 320 may have any suitable configurations.

[0035] The front end 322 of the radiation shield 320 is attached to the front hook 316. The rear end 324 is attached to the rear hook 318. A gap exists between the radiation shield 320 and the outer surface 306 of the outer platform 204. Tabs 326 are attached to the front hook 316 and the rear hook 318, respectively. The tabs 326 limit movements of the radiation shield 320 to hold the radiation shield 320 in place.

[0036] FIG. 4 is an enlarged view of an inner part of the guide vane 200 of FIG. 2. The guide vane 200 includes an inter stage seal 402 coupled to the inner platform 202. The inter stage seal 402 has a base plate 404 and a rail 406 extending between the base plate 404 and the inner platform 202. The base plate 404 and the rail 406 form a general T-shaped inter stage seal 402. The base plate 404 has an inner surface 408 facing away from the inner platform 202.

[0037] A seal (not shown in FIG. 4), such as a labyrinth seal, is disposed between the guide vane 200 and the rotor 134 (not shown in FIG. 4). The labyrinth seal includes a sealing surface and a seal ring coupled to the rotor 134 that interfaces with the sealing surface. The sealing ring has seal tips. By coupling the inter stage seal 402 to the inner platform 202 of the guide vane 200, the inner surface 408 of the base plate 404 of the inter stage seal 402 forms the sealing surface of the labyrinth seal. The inner surface 408 has a stepped shape that steps down towards the sealing ring. A diameter of the sealing ring or the seal tips interfaces with the inner surface 408 of the inter stage seal 402 is reduced in comparison toa diameter of the sealing ring interfacing with inner platform 202 as a sealing surface. In the illustrated construction in FIG. 4, the inner surface 408 has three steps. It is possible that the inner surface 408 may have any suitable numbers of steps or no steps at all.

[0038] The inner platform 202 has a side surface 410. The side surface 410 is the surface between an adjacent guide vane 200 that is arranged in the circumferential direction. The side surface 410 of the inner platform 202 includes a first seal slot 412 extending between the upstream side 302 and the downstream side 304. The base plate 404 has a side surface 418. The side surface 418 of the base plate 404 includes a second seal slot 414 extending between the upstream side 302 and the downstream side 304. The rail 406 has a side surface 420. The side surface 420 of the rail 406 includes a third seal slot 416 extending between the first seal slot 412 and the second seal slot 414. In the illustrated construction in FIG. 4, the first seal slot 412, the second seal slot 414, and the third seal slot 416 have straight shape. It is possible that the first seal slot 412, the second seal slot 414, and the third seal slot 416 may have any suitable shapes.

[0039] FIG. 5 is a longitudinal cross-section view of a part of a turbine sections 500. The turbine section 500 includes a turbine blade 502 of one turbine stage 124 and an adjacent guide vane 200 of a downstream turbine stage 124 in the longitudinal direction 214. The turbine blade 502 includes an inner platform 504. An upstream side of the inner platform 202 of the guide vane 200 includes an extension 508 that interfaces with a downstream side of the inner platform 504 of the upstream turbine blade 502. The downstream side of the inner platform 504 has a groove 506. The groove 506 may refer to a damping cavity. The upstream side of the inner platform 202 of the guide vane 200 extends to the groove 506 of the inner platform 504 of the turbine blade 502.

[0040] In use, the curved shaped vane airfoil 206 may reduce losses. The first outer seal slot 310 and the second outer seal slot 312 on the side surface 308 of the outer platform 204 may reduce leakage. The straight shaped first outer seal slot 310 and the second outer seal slot 312 may improve surface contact and improve sealing. The radiation shield 320 attached on the outer platform 204 may reduce stator temperature. The T-shaped inter stage seal 402 may reduce hot gas ingestion.

[0041] In addition, the extension 508 is sized and positioned to be positioned at least partially within the groove 506 or near enough to the groove 506 for the extension 508 and the groove 506 to interact. In some circumstances, this interaction can include an aerodynamic interaction that acts to counteract undesired movement and vibration of the guide vane 200. Thus, this arrangement can provide damping for the guide vane 200 during operation.

[0042] It should be noted that Figs. 1-5 illustrate many features of a guide vane 200 and these features can be used together or separate from one another on any guide vane 200. Thus, there is no requirement that the guide vane 200 includes any or all of the features and there is no limit to the combinations of features for a particular design.

[0043] Although an exemplary embodiment of the present disclosure has been described in detail, those skilled in the art will understand that various changes, substitutions, variations, and improvements disclosed herein may be made without departing from the spirit and scope of the disclosure in its broadest form.

[0044] None of the description in the present application should be read as implying that any particular element, step, act, or function is an essential element, which must be included in the claim scope: the scope of patented subject matter is defined only by the allowed claims. Moreover, none of these claims are intended to invoke a means plus function claim construction unless the exact words “means for” are followed by a participle.

LISTING OF DRAWING ELEMENTS

100 gas turbine engine

102 compressor section combustion section turbine section inlet section exhaust portion central axis compressor stage rotating compressor blade stationary compressor vane combustor exhaust gas turbine stage rotating turbine blade stationary turbine vane turbine inlet control system rotor guide vane inner platform outer platform vane airfoil leading edge trailing edge radial direction longitudinal direction upstream side downstream side outer surface side surface first outer seal slot second outer seal slot third outer seal slot front hook rear hook radiation shield front end rear end tabs inter stage seal base plate rail inner surface side surface first seal slot second seal slot third seal slot side surface side surface turbine section turbine blade inner platform groove extension