Injector, combustor and method of mixing fuel and air in a combustor

Abstract

An injector (100) for a combustor of a gas turbine engine has a plurality of first vanes (116) radially arranged about a central axis of the injector and a plurality of second vanes (120) radially arranged about the central axis of the injector and disposed radially inward of the plurality of first vanes. A plurality of fuel injection holes (126) are disposed more aft (128) than a leading edge of the second vanes for injecting fuel into compressed air passing through the second vanes. An aft edge of each of the second vanes includes a non-planar profile configured to induce turbulence in the compressed air to mix the fuel with the compressed air and reduce surfaces where undesirable flame anchoring can occur.

Description

Technical Field

[0001] This disclosure relates generally to gas turbine engines, and more specifically to injectors for injecting a mixture of compressed air and fuel into a combustor in a gas turbine engine. Background Technology

[0002] Gas turbine engines are used to generate mechanical energy by burning a fuel / air mixture within a combustor. Fuel and compressed air are delivered to the combustor via one or more fuel injectors. In one type of annular injector, spaced-apart blades define a passage through which compressed air flows and mixes with fuel injected into the compressed air's flow path. Under certain operating conditions, the trailing edges of the injectors and blades can provide an undesirable flame-holding surface, through which the combustion flame can anchor and cause a spontaneous combustion or flashback event, which can potentially damage the hardware in the gas turbine engine. While various types of protection devices are used to detect spontaneous combustion or flashback and react to it, for example, by increasing airflow or by shutting down the gas turbine engine, these methods can result in increased undesirable NOx emissions or significant downtime before the gas turbine engine is brought back online. Therefore, it is necessary to reduce or prevent spontaneous combustion or flashback in the first case. Summary of the Invention

[0003] This brief description is provided to introduce, in a simplified form, a series of concepts that will be further described in the detailed description below. This brief description is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. Other aspects and advantages of this disclosure will be apparent from the following detailed description and accompanying drawings of the embodiments.

[0004] Various aspects of this disclosure relate to gas turbine engines, including combustors having one or more fuel injectors. More specifically, aspects relate to injectors including blades with irregular trailing edge geometry, which reduces flame retention while improving fuel-compressed air mixing.

[0005] In one aspect, this disclosure relates to an injector for a combustor of a gas turbine engine, the injector comprising: a plurality of first blades arranged radially about a central axis of the injector; and a plurality of second blades arranged radially about the central axis of the injector and disposed radially inside the plurality of first blades. Each of the plurality of second blades includes: a leading edge and a trailing edge; a plurality of fuel injection orifices disposed closer to the trailing edge than the leading edge and configured to inject fuel into compressed air passing over the second blade; and a fuel supply orifice in fluid communication with the plurality of fuel injection orifices and configured to supply fuel to the plurality of fuel injection orifices, wherein the trailing edge includes a non-planar profile configured to induce turbulence in the compressed air, thereby mixing the fuel with the compressed air.

[0006] In another aspect, this disclosure relates to a combustor for a gas turbine engine, the combustor including a combustion bushing defining a combustion zone therein and a first injector surrounding the combustion bushing. The first injector includes: a plurality of first blades radially arranged about a central axis of the injector, each of the first blades being separated from an adjacent first blade by a first channel of a plurality of first channels forming part of a radially outer flow path; and a plurality of second blades radially arranged about the central axis of the injector and disposed radially inside the plurality of first blades, each of the second blades being separated from an adjacent second blade by a second channel of a plurality of second channels forming part of a radially inner flow path. Each of the plurality of second blades includes: a leading edge and a trailing edge; a plurality of fuel injection holes arranged closer to the trailing edge than the leading edge and configured to inject fuel into compressed air passing through the radially internal flow path; and a fuel supply hole fluidly communicating with the plurality of fuel injection holes and configured to supply fuel to the plurality of fuel injection holes, wherein the trailing edge includes a non-planar profile configured to induce turbulence in the compressed air passing through the radially internal flow path, thereby mixing the fuel with the compressed air upstream of the combustion chamber.

[0007] In another aspect, this disclosure relates to a method of mixing fuel and air in a combustor of a gas turbine engine. The method includes: passing compressed air through an injector, wherein: the injector includes: a plurality of first blades arranged radially about a central axis of the injector; and a plurality of second blades arranged radially about the central axis of the injector and disposed radially inside the plurality of first blades. Passing the compressed air through the injector includes: directing a first portion of the compressed air onto the plurality of first blades and directing a second portion of the compressed air onto the plurality of second blades, and each of the plurality of second blades having a trailing edge comprising a non-planar profile, thereby generating at least one compressed air vortex at each respective trailing edge. The method further includes: injecting fuel into at least one compressed air vortex at each trailing edge, thereby mixing the fuel with the second portion of the compressed air. Attached Figure Description

[0008] The present technology is described in detail below with reference to the accompanying drawings, in which similar numbers denote the same parts, and wherein: Figures 1 to 2 It is a cross-sectional view of a gas turbine combustor according to various aspects of this disclosure; Figures 3A to 3B It is based on various aspects of this disclosure for use in gas turbine combustors (such as...) Figures 1 to 2 A partial close-up view of a first embodiment of the injector of the burner shown; Figure 4 It is based on various aspects of this disclosure for use in gas turbine combustors (such as...) Figures 1 to 2 A perspective view of a second embodiment of the injector of the burner shown; Figures 5A to 5C yes Figure 4 A close-up partial view of the injector shown; Figures 6A to 6C It is based on various aspects of this disclosure for use in gas turbine combustors (such as...) Figures 1 to 2 A partial close-up view of a third embodiment of the injector of the burner shown; Figures 7A to 7C It is based on various aspects of this disclosure for use in gas turbine combustors (such as...) Figures 1 to 2 A partial close-up view of a fourth embodiment of the injector of the burner shown; Figures 8A to 8C It is based on various aspects of this disclosure for use in gas turbine combustors (such as...) Figures 1 to 2 A partial close-up view of a fifth embodiment of the injector of the burner shown; Figures 9A to 9B It is based on various aspects of this disclosure for use in gas turbine combustors (such as...) Figures 1 to 2A partial close-up view of a sixth embodiment of the injector of the burner shown; Figure 10 Is adopted Figures 9A to 9B A close-up partial view of the combustor of a gas turbine engine with an injector shown in the image; Figures 11A to 11B It is based on various aspects of this disclosure for use in gas turbine combustors (such as...) Figures 1 to 2 A partial close-up view of the seventh embodiment of the injector of the burner shown; and Figure 12 yes Figures 4 to 5C A close-up view of the cross-section of the injector shown. Detailed Implementation

[0009] Now turn to the accompanying drawings for more details, and first turn to... Figure 1 The combustor of the gas turbine engine according to various aspects of this disclosure is generally designated by the numeral 100. The combustor 100 generally includes a first or radially outward injector 102, a second or radially inward injector 104, a generally cylindrical flow sleeve 106, and a generally cylindrical combustion bushing 108 positioned radially inward from the flow sleeve 106 and generally defining a combustion zone 110. The first injector 102 is generally annular in shape and surrounds the combustion bushing 108 and is positioned at the downstream end of the flow sleeve 106. The second injector 104 is positioned radially inward of the combustion bushing 108 at the inlet end of the combustion zone 110.

[0010] For reference Figure 2Best understood, during the use of burner 100, compressed air is supplied to both the first injector 102 and the second injector 104, where it is mixed with the fuel source and then ignited to support the flame within combustion chamber 110. Compressed air following a radially outer path 112 along the radially outer surface of flow sleeve 106 passes through radially outward blades and / or openings in the first injector 102 without mixing with fuel therein, and continues downstream to a portion of burner 100 where it is diverted and passes through the second injector 104. Here, the compressed air mixes with the fuel source and is ignited to support the flame near the central axis of burner 100. Compressed air following a radially inner path 114 between flow sleeve 106 and combustion bushing 108 passes through different (i.e., radially inward) blades and / or openings in the first injector 102, where it mixes with the fuel source. The fuel / air mixture then travels to dome plate 130 or a similar structure, where it is turned substantially 180 degrees to enter combustion chamber 110, where it is ignited to support a radially outward flame supported by a second injector 104. In some embodiments, the first injector 102 is referred to as the “master” injector, and the second injector 104 as the “lead injector.”

[0011] Figures 3A to 3B A portion of one embodiment of a first or main injector 102 for mixing fuel and air through a radially internal path 114 is shown. In this embodiment, the first injector 102 includes a plurality of radially outward first blades 116 arranged radially about a central axis of the combustor 100, wherein adjacent first blades of the plurality of first blades 116 define a plurality of first channels 118 therebetween. Figure 3A As can be seen, the first blade 116 and the passage 118 do not contain any fuel injection openings or similar structures, and thus the compressed air in the radially outer path 112 passes through the opening 118 without mixing with any fuel and continues downstream to the second injector 104.

[0012] However, the first injector 102 also includes a plurality of second blades 120 arranged radially inside the plurality of first blades 116 and similarly about the central axis of the combustor 100. Adjacent second blades of the plurality of second blades 120 define a plurality of second channels 122 therebetween through which compressed air traveling along the radially inner path 114 passes. Each blade of the blades 120 generally includes a planar leading edge (not shown) and a planar trailing edge 128, wherein the planar leading edge and planar trailing edge 128 extend in a direction substantially perpendicular to or cross-flowing with the airflow direction within the injector 102. Furthermore, each blade of the blades 120 includes a plurality of fuel injection holes 126 disposed at the trailing edge 128 (in this case, in a flat surface located at the trailing edge 128), which are in fluid communication with a plurality of fuel delivery holes 124. Fuel from a manifold or similar structure (not shown) is fed to the compressed air traveling along the radially inner path 114 via the fuel delivery holes 124 and the fuel injection holes 126. More specifically, as compressed air passes through the second channel 122 and over the blades 120, the air mixes with fuel exiting the fuel injection orifice 126, which is located near the trailing edge 128 of each blade 120. Thereafter, the fuel / air mixture continues along the radially inner path 114 to the dome plate 130 positioned at the inlet end of the combustion zone 110. Figure 2 (or a similar structure.) The dome plate 130 reverses the flow direction of the fuel / air mixture and delivers it to the inlet end of the combustion zone 100 for ignition.

[0013] In this embodiment, the flat surface of the trailing edge 128 of each blade 120 provides a surface for flame anchoring during operation of the burner 100. Flame anchored at this portion of the radially inner path 114 may be undesirable, as an anchored flame can lead to premature ignition of the fuel / air mixture, damage to the first fuel injector 102 or other components, or other undesirable disadvantages. Therefore, according to some embodiments of the technology described below, the leading or trailing edge of the blades of the first injector 102 includes an irregular or non-planar profile, thereby reducing the surface area that could lead to flame anchoring, while improving fuel and air mixing along the radially outer path 112 and / or inner path 114, resulting in more efficient combustion and reduced emissions, among other benefits.

[0014] Figure 4An embodiment of an improved first injector 202 according to various aspects of this disclosure is shown. In this embodiment, the first (or alternatively, main) injector 202 is generally annular in shape and includes a radial array of first blades 216 located radially outside a radial array of second blades 220. Adjacent first blades of the plurality of first blades 216 define a plurality of first channels 218, while adjacent second blades of the plurality of second blades 220 define a plurality of second channels 222. Additionally, as per [context missing] Figure 3A As discussed in the embodiment of the first injector 102 shown in Figure 3C, when installed in and used in the burner 100, compressed air delivered to the second injector 104 along the radially outer path 112 passes through a plurality of first openings 218 and over a plurality of first blades 220 without mixing with fuel, and continues downstream to the second injector 104, while compressed air delivered along the radially inner path 114 passes through a plurality of second channels 222, through second channels 122 and over a plurality of second blades 220, and mixes with fuel. In this respect, the first injector 202 includes a plurality of fuel delivery holes 224, each fuel delivery hole communicating with a plurality of fuel injection holes 226, which are disposed on the trailing edge 228 of each second blade 220 or disposed closer to the trailing edge 228 than the leading edge 230. Figure 5C ).

[0015] like Figures 5A to 5CBest viewed in the image, a close-up portion of the first injector 202 is shown, with the trailing edge 228 of each radially inner blade 220 comprising a stepped profile. More specifically, in this embodiment, the trailing edge 228 comprises three distinct portions 228a, 228b, and 228c. The radially outer first portion 228a and the radially inner third portion 228c of the trailing edge 228 are offset circumferentially from the intermediate second portion 228b. In this embodiment, each blade 220 includes two fuel injection holes 226 disposed on the second portion 228b of the trailing edge 228. However, in other embodiments, without departing from the scope of this disclosure, the blade 220 may include more or fewer fuel injection holes 226, and / or one or more of the fuel injection holes 226 may be located elsewhere (i.e., on one of the first portion 228a or the third portion 228c of the trailing edge 228). Furthermore, in this embodiment, the radially inner fuel injection holes 226 are larger than the radially outer fuel injection holes 226 (i.e., have a larger diameter). For example, in a non-limiting example, the inner fuel injection orifice 226 has a diameter of approximately 0.112 inches, while the outer fuel injection orifice 226 has a diameter of approximately 0.059 inches. In other embodiments, without departing from the scope of this disclosure, the fuel injection orifices 226 may have the same dimensions, the radially outer fuel injection orifice 226 may be larger than the radially inner fuel injection orifice 226, and / or the fuel injection orifices 226 may have different shapes or configurations.

[0016] For example Figure 3A Compared to the embodiment of the first injector 102 shown in Figure 3C, Figure 4 and Figures 5A to 5C The profile of the blade 220 shown can exhibit mixing and flame retention mitigation benefits. That is, the leading edge 230 of each blade 220 ( Figure 5C The leading edge 230 is rounded, similar to the leading edge of an airfoil, thus providing enhanced flow and aerodynamic benefits; that is, the rounded leading edge 230 reduces the pressure loss of compressed air flowing around blade 220. The stepped profile of the trailing edge 228 increases mixing at the trailing edge 228 of blade 220 because the irregular profile induces turbulence, causing the compressed air crossing the trailing edge 228 to swirl and mix with the fuel leaving the fuel injection orifice 226. In this respect, the fuel injection orifice 226 is positioned and configured such that fuel exiting from the fuel injection orifice is injected into and captured by the swirling compressed air generated by the stepped profile of the trailing edge 228, thereby enhancing fuel-compressed air mixing.

[0017] Furthermore, because a flat surface substantially perpendicular to the compressed airflow is not provided at the trailing edge 228 (as opposed to the flat surface provided at the trailing edge 128 of blade 120), there is no surface conducive to flame anchoring. In other words, there is no rearward-facing base region of blade 220, thereby reducing or eliminating flame retention at the first injector 202. Therefore, the stepped profile of the trailing edge 228 of blade 220 reduces undesirable flame anchoring upstream of combustion zone 110.

[0018] exist Figures 5A to 5C In the illustrated embodiment, the second portion 228b of the trailing edge 228 is longer than the third portion 228c in the radial direction, and both the second portion 228b and the third portion 228c are longer than the first portion 228a. In other embodiments, without departing from the scope of this disclosure, the blade 220 may be otherwise configured such that two or more of the stepped portions 228a, 228b, and 228c have the same length in the radial direction, or that one or two of the stepped portions 228a and 228c are longer than the stepped portion 228b. Furthermore, in some embodiments, without departing from the scope of this disclosure, the blade 220 may include a portion at the trailing edge 228 that is longer than the third portion 228c. Figure 4 and Figures 5A to 5C The diagram depicts more or fewer stepped sections, such as, for example, two stepped sections or four or more stepped sections. In such embodiments, the distal ends of adjacent stepped sections are spaced apart and alternate in the circumferential direction, similar to... Figure 4 and Figures 5A to 5C The construction of the stepped portions 228a and 228b in the middle.

[0019] like Figures 6A to 8C As shown in the embodiments depicted, the trailing edges 228 of the plurality of second blades 220 can be alternatively constructed, while providing similar benefits without departing from the scope of this disclosure. Figures 6A to 8C In the illustrated embodiment, the depicted blades 320, 420, and 520 respectively form part of the first or main injector 302, 402, and 502, similar to Figure 4 The first injector 202 is shown. In this respect, although not shown, injectors 302, 402, 502 will include a second radial array of blades located radially outside the depicted blades 320, 420, 520, which will be similarly configured. Figure 4 The blade 216 is shown in the figure and will therefore not be discussed further for the sake of convenience.

[0020] Figures 6A to 6CThe blade 320 of the first injector 302 is shown, which includes a wavy trailing edge 328 profile of the blade 320. The wavy trailing edge 328 profile may generally follow a sine wave or similar wave profile, along which one or more fuel injection holes 326 (two in the depicted embodiment) are provided.

[0021] Figures 7A to 7C The injector 402 shown includes a trailing edge 428 profile of blade 420, which includes both a stepped portion and a wavy portion located radially inward of the stepped portion. However, in other embodiments, instead of or in addition to the wavy portion located radially inward of the stepped portion, the trailing edge profile 428 may include a wavy portion located radially outward of the stepped portion. Additionally, in this embodiment, the stepped portion has three fuel injection holes 426. The holes 426 may have equal or varying sizes. In the depicted embodiment, the two radially inward holes have approximately equal cross-sectional areas, while the radially outward fuel injection hole 426 is smaller. However, in other embodiments, without departing from the scope of this disclosure, the holes 426 may be otherwise sized and configured, for example, in a configuration where the largest fuel injection hole 426 is located at least at the radially outermost position.

[0022] Figures 8A to 8C The trailing edge 528 profile of the blade 520 in the first injector 502 is shown, which is wavy but irregular. That is, the profile does not typically follow a sine wave or a similar wave, but rather comprises a smooth arc oscillating in a circumferential direction, with a pair of fuel injection holes 526 disposed on the ridges of the wave. In some embodiments, the trailing edge 528 profile of this embodiment may be described as an angled sine wave, an irregular sine wave, a deflected sine wave, or a similar wave. Furthermore, without departing from the scope of this disclosure, more or fewer fuel injection holes 526 and fuel injection holes 526 with different diameters may be implemented. Figures 8A to 8C This disclosure indicates that various aspects include a wide range of trailing edge geometries, even irregular waveforms and similar shapes, which provide benefits such as enhanced blending at the trailing edge and reduced flame anchoring.

[0023] Figures 9A to 9B Another embodiment of the first injector 602 according to various aspects of this disclosure is shown. In this embodiment, a plurality of first blades 616 are substantially elliptical in cross-section; that is, the leading and trailing edges of the blades 616 are rounded, thereby providing a more streamlined flow and thus providing enhanced airflow characteristics, such as a reduced pressure drop, thereby allowing compressed air to flow freely along the radially external flow path 112 to the second injector, such as... Figure 10 As best illustrated in the diagram. The plurality of second blades 620 in this embodiment are structurally similar to... Figure 4 and Figures 5A to 5CThe second blade 220 shown is therefore not discussed in detail hereafter. However, in this embodiment, the circumferential stepped portion of the trailing edge 628 includes rounded or rounded transition edges 632 that separate the stepped portions. These rounded or rounded transition edges 632 reduce thermal and other stresses at the transition between the circumferential stepped portions, thereby improving the lifespan of the injector 602 and its plurality of second blades 620. Furthermore, the rounded or rounded transition edges 632 improve the aerodynamic mixing of compressed air and fuel supplied by the fuel injection orifices, thereby providing a more homogeneous mixture to the combustion zone.

[0024] in addition, Figure 10 A partial cross-sectional view of a burner 100 employing a first injector 602 is shown, illustrating how compressed air flows along a radially outer flow path 112 and a radially inner flow path 114. Furthermore, as... Figure 10 As can be seen, the improved hybrid and similar benefits of the injector described herein allow the injector to be included in the burner 100 without requiring tear strips, sealing platforms, embossing, finger seals, or similar features on the outer surface of the combustion bushing 108. That is, as Figure 10 As shown, the radially outer surface of the combustion bushing 108 downstream of the first injector 602 is exposed, unlike known burners that employ tear strips, sealing platforms, embossing, finger seals, or similar features. This, in turn, reduces the use of surfaces upstream of the combustion zone 110 that would otherwise contribute to flame retention or flame anchoring.

[0025] Figures 11A to 11B Another exemplary embodiment of the first injector 702 is shown. In this embodiment, the plurality of first blades 716 are constructed similar to Figure 4 In addition to the flat surface embodiments shown in other figures, in other embodiments, the plurality of first blades 716 may include an elliptical or similar cross-section, such as Figures 9A to 10 The plurality of first blades 616 are shown. However, in this embodiment, the transition region between the circumferential stepped portions of the trailing edges 728 of the plurality of second blades 720 includes a pressure relief cutout 732, as shown. Figure 11B Best visible in the middle. Similar to Figures 9A to 10 The rounded or chamfered transition area 632 shown in this embodiment reduces thermal and other stresses on the plurality of second blades 720, while providing enhanced mixing of compressed air and fuel at the trailing edge 728 of the blades 720.

[0026] In some implementations, additive manufacturing can be used to achieve the complex and irregular geometry of the trailing edge of the second blade, which might otherwise be difficult to manufacture using conventional manufacturing techniques such as casting. This can be referred to... Figure 12 Easier to understand Figure 12It is a combination of the above Figures 4 to 5C A partial cross-sectional view of the plurality of second blades 220 in the first injector 202 discussed herein. The manufacturing techniques discussed herein are equally applicable to each embodiment of the embodiments discussed and contemplated in this disclosure.

[0027] It should be understood that additive manufacturing involves building an article layer by layer, typically following multiple essentially 2D "slices" of a 3D model of the article. In this embodiment, the first injector 202 and / or its blades 220 are built from the leading edge 230 to the trailing edge 228, as... Figure 12 The build direction arrow 134 shown in the diagram roughly indicates this. This allows for the inclusion of complex and irregular trailing edge geometries discussed herein without the need for expensive and cumbersome molds, while simultaneously reducing or eliminating post-manufacturing processing or similar processes.

[0028] When additive manufacturing is performed on injector 202 and / or blade 220, internal channels (such as fuel feed orifice 224 and fuel injection orifice 226) forming cooling or fuel passages are integrally formed within injector 202. In some embodiments, these channels may include non-circular cross-sections to facilitate the additive manufacturing process. For example, as Figure 12 As shown, the fuel feed orifice 224 includes a generally teardrop-shaped cross-sectional profile. This profile aids the additive manufacturing process by reducing the amount of material extending over the material voids left during the formation of the previous 2D slices of the 3D model. In other words, the additive manufacturing process may not be able to readily accommodate overhangs greater than 45 degrees or similar angles without causing the manufactured part itself to collapse. In this embodiment, the fuel feed orifice 224 (and in some embodiments, other internal channels) includes a teardrop-shaped cross-section to reduce overhangs in the upper half of the cross-sectional profile, thereby managing the printed top plate of the fuel feed orifice 224 in the printing direction and thus increasing the manufacturability of the first injector 202 and / or the plurality of second blades 220.

[0029] The injectors discussed herein can be additively manufactured (or otherwise manufactured, such as by machining, casting, forging, etc.) from any desired material. For example, in some embodiments, the injectors are made of superalloys such as Inconel 718 (i.e., an alloy primarily composed of nickel and chromium, with the remainder formed of many other metals) or similar materials that provide high strength and corrosion resistance. Any desired and suitable material may be used without departing from the scope of this disclosure.

[0030] In summary, the designs and embodiments discussed herein provide increased fuel-air mixing while offering improved flame holding or anchoring mitigation. For example, the stepped, sinusoidal, or other irregular profiles of the trailing edge of the injector blades can generate one or more downstream vortices at the trailing edge, thereby providing enhanced mixing without the need for crossflow flat surfaces that could additionally provide surfaces for flame anchoring. By increasing fuel-air mixing at the injector, the injector embodiments discussed herein result in improved combustor emissions, while being streamlined and constructed for flame holding resistance, leading to improved injector life and a reduced risk of injector and / or combustor failure.

[0031] As will be seen from the foregoing, this disclosure is highly suitable for achieving all the aforementioned objectives and purposes, as well as other obvious and inherent advantages of the system and method. It should be understood that certain features and sub-combinations are useful and can be used without reference to other features and sub-combinations.

[0032] Additional considerations

[0033] In this specification, references to "one embodiment," "implementation," or "multiple embodiments" mean that one or more features referenced are included in at least one embodiment of the present technology. Individual references to "one embodiment," "implementation," or "multiple embodiments" in this specification do not necessarily refer to the same embodiment and are not mutually exclusive, unless so stated and / or otherwise readily apparent to those skilled in the art based on this specification. For example, features, structures, actions, etc., described in one embodiment may be included in other embodiments, but are not necessarily included in other embodiments. Therefore, the present technology may include various combinations and / or integrations of the embodiments described herein.

[0034] In the specification and claims, several terms will be referenced and defined as having the following meanings. The singular forms “an,” “a,” and “the” include plural references unless the context clearly indicates otherwise. “Optional” or “optionally” means that the event or situation subsequently described may or may not occur, and the description includes instances in which the event occurs and instances in which the event does not occur.

[0035] As used herein throughout the specification and claims, approximate language may be used to modify any quantitative expression, which may be permitted to vary without altering the essential function it relates to. Therefore, values ​​modified by one or more terms such as “about,” “approximate,” and “substantially” are not limited to the specified precise values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value. Range limitations may be combined and / or interchanged. Such ranges are identified and include all subranges contained therein, unless otherwise indicated by context or language.

[0036] As used herein, the terms “axial” and “axially” refer to a direction and orientation extending substantially parallel to the central longitudinal axis of the burner. The terms “radial” and “radially” refer to a direction and orientation extending substantially perpendicular to the central axis. Furthermore, directional references such as “top,” “bottom,” “front,” “rear,” “side,” and similar terms are used herein for convenience only and should be understood only relative to each other. For example, components may be oriented in practice such that the surfaces referred to herein as “top” and “bottom” are, in practice, laterally, angularly, inverted, etc., relative to a chosen frame of reference.

[0037] The terms “connection,” “fixation,” “attachment,” etc., refer to direct connection, fixation, or attachment, as well as indirect connection, fixation, or attachment via one or more intermediate components or features, unless otherwise stated herein.

[0038] Although this application sets forth detailed descriptions of many different embodiments, it should be understood that the legal scope of such description is defined by the language of the claims and equivalents. The detailed descriptions should be construed as exemplary only and do not describe every possible embodiment, as it would be impractical to describe every possible embodiment. Numerous alternative embodiments may be implemented using current technology or technology developed after the filing date of this patent, and they will still fall within the scope of the claims.

[0039] Throughout this specification, multiple instances may implement components, operations, or structures described as single instances. Although a single operation of one or more methods is illustrated and described as a separate operation, one or more of the single operations may be performed simultaneously, and these operations are not required to be performed in the order described or illustrated. Structures and functions presented as independent components in exemplary configurations may be implemented as combined structures or components. Similarly, structures and functions presented as single components may be implemented as single components. These and other variations, modifications, additions, and improvements fall within the scope of the subject matter herein. Unless so stated in the specification and / or as will be readily apparent to those skilled in the art based on the specification, the foregoing statements in this paragraph shall apply.

[0040] As used herein, the terms “comprising,” “including,” “having,” or any other variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, article, or apparatus that includes a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0041] Although this disclosure has been described with reference to embodiments illustrated in the accompanying drawings, it should be noted that equivalents and substitutions made herein may be used without departing from the scope of this disclosure as set forth in the claims.

Claims

1. A first injector (102) for a combustor (100) of a gas turbine engine, the first injector (102) comprising: A plurality of first blades (116) are arranged radially around the central axis of the first injector (102); A plurality of second blades (120) are arranged radially around the central axis of the first injector (102) and disposed radially inside the plurality of first blades (116), each of the plurality of second blades (120) comprising: Previous relationship; Trailing edge (128), the trailing edge including a stepped profile, the stepped profile including: The radially outer first portion (228a) has a first length in the radial direction; The second radially intermediate portion (228b) has a second length in the radial direction; The radially inner third part (228c) has a third length in the radial direction; The radially intermediate second portion (228b) includes a second rear end offset circumferentially from the first rear end of the radially outer first portion and the third rear end of the radially inner third portion; A plurality of fuel injection holes (126) are arranged on the radially intermediate second portion (228b) closer to the trailing edge (128) than the leading edge, and are configured to inject fuel into compressed air passing over the second blade (120); and A fuel delivery orifice (124) is in fluid communication with the plurality of fuel injection orifices (126) and is configured to deliver fuel to the plurality of fuel injection orifices (126). The stepped profile of the trailing edge (128) is configured to induce turbulence in the compressed air, thereby mixing the fuel with the compressed air.

2. The first injector (102) according to claim 1, the first injector further includes a first pressure relief cut and a second pressure relief cut, the first pressure relief cut being disposed between the radially outer first portion (228a) and the radially intermediate second portion (228b), and the second pressure relief cut being disposed between the radially intermediate second portion (228b) and the radially inner third portion (228c).

3. The first injector (102) according to claim 1, wherein the third rear end of the radially inner third portion includes a portion of a generally sinusoidal rear end.

4. The first injector (102) according to claim 1, wherein the fuel delivery orifice (124) has a teardrop-shaped cross-sectional profile.

5. The first injector (102) according to claim 1, wherein each of the plurality of first blades (116) comprises an elliptical cross-sectional profile.

6. A combustor for a gas turbine engine, the combustor comprising: A combustion bushing that defines a combustion zone therein; and A first injector (102) surrounds the combustion liner and includes: A plurality of first blades (116) are arranged radially around the central axis of the first injector (102), each of the first blades (116) being separated from the adjacent first blade by a first channel of a plurality of first channels forming part of a radially external flow path; A plurality of second blades (120) are arranged radially around the central axis of the first injector (102) and disposed radially inside the plurality of first blades (116). Each of the plurality of second blades (120) is separated from its adjacent second blade by a second channel of a plurality of second channels forming part of a radially internal flow path. Each of the plurality of second blades (120) includes: Leading and trailing edges (128); A plurality of fuel injection orifices (126) are provided closer to the trailing edge (128) than the leading edge and are configured to inject fuel into compressed air passing through the radially internal flow path; and A fuel delivery orifice (124) is in fluid communication with the plurality of fuel injection orifices (126) and is configured to deliver fuel to the plurality of fuel injection orifices (126). The trailing edge (128) includes a non-planar profile configured to induce turbulence in the compressed air flowing through the radially internal flow path, thereby mixing the fuel with the compressed air upstream of the combustion zone. The first portion of the non-planar profile of the trailing edge (128) comprises a stepped profile, the stepped profile comprising a plurality of stepped segments, wherein the rear end of the first stepped segment is offset circumferentially from the rear end of the second stepped segment, and wherein the second portion of the non-planar profile of the trailing edge (128) comprises a portion of the rear end in a generally sinusoidal shape. A second injector (104) is located downstream of the first injector (102) along the radial outer flow path. The second injector (104) is configured to mix fuel with compressed air passing through the radial outer flow path, thereby mixing the fuel with the compressed air upstream of the combustion zone.

7. The burner according to claim 6, wherein the non-planar profile of the trailing edge (128) comprises a stepped profile, the stepped profile comprising a plurality of stepped segments, wherein the rear end of a first stepped segment is offset circumferentially from the rear end of a second stepped segment.

8. The burner according to claim 7, further comprising a pressure relief cutout disposed between the first stepped section and the second stepped section.

9. The burner of claim 6, wherein the non-planar profile of the trailing edge (128) comprises a sinusoidal profile, the sinusoidal profile comprising a generally sinusoidal rear end.

10. The burner according to claim 6, wherein the fuel feed orifice (124) has a teardrop-shaped cross-sectional profile.

11. The burner of claim 6, wherein each of the plurality of first blades (116) comprises an elliptical cross-sectional profile.

12. A method for mixing fuel and air in a combustor of a gas turbine engine, the method comprising: Compressed air is passed through the first injector (102), wherein: The first injector (102) includes: a plurality of first blades (116) arranged radially around a central axis of the first injector (102); and a plurality of second blades (120) arranged radially around the central axis of the first injector (102) and disposed radially inside the plurality of first blades (116). Passing the compressed air through the first injector (102) includes directing a first portion of the compressed air onto the plurality of first blades (116) and directing a second portion of the compressed air onto the plurality of second blades (120), and The trailing edge (128) of each of the plurality of second blades (120) includes a stepped profile, the stepped profile comprising: The radially outer first portion (228a) has a first length in the radial direction; The second radially intermediate portion (228b) has a second length in the radial direction; The radially inner third part (228c) has a third length in the radial direction; The second length is greater than the third length, and the third length is greater than the first length; The radially intermediate second portion (228b) includes a second rear end offset circumferentially from the first rear end of the radially outer first portion (228a) and the third rear end of the radially inner third portion (228c); This generates at least one compressed air vortex at each corresponding trailing edge (128); and Fuel is injected into the at least one compressed air vortex at each trailing edge (128), thereby mixing the fuel with the second portion of the compressed air.

13. The method of claim 12, wherein the stepped profile generates at least two compressed air vortices at each respective trailing edge (128).

14. The method of claim 13, wherein each of the plurality of second blades (120) includes a first fuel injection port and a second fuel injection port, the first fuel injection port and the second fuel injection port being configured to be closer to the trailing edge (128) on the radially intermediate second portion (228b) than to the leading edge of each of the plurality of second blades (120), the method further comprising: At each of the plurality of second blades (120): Fuel is injected into the first vortex of the at least two compressed air vortices via the first fuel injection orifice; as well as Fuel is injected into the second vortex of the at least two compressed air vortices via the second fuel injection orifice.

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