Turbine engine fuel premixer

Abstract

A turbine engine can include a compressor section, a combustion section, and a turbine section in a serial flow arrangement. The combustion section can include a combustor having a fuel premixer. The fuel premixer can include an annular shroud defining an interior, a center body located within the interior, and an annular swirler located within the interior.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 295,015, filed December 30, 2021, and U.S. Patent Application No. 17 / 699,735, filed March 21, 2022, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present subject matter relates generally to turbine engine combustors, and more specifically, to fuel premixers for combustors. BACKGROUND

[0004] Gas turbine engines include turbines that are driven by the combustion of a combustible fuel within a combustion chamber of the turbine engine. Fuel nozzles inject the combustible fuel into a combustor while swirler mixes the fuel with air for more efficient combustion. BRIEF DESCRIPTION OF DRAWINGS

[0005] In the description of the specification, the complete disclosure of the present disclosure is set forth, including its preferred mode and combinations, for the generic skilled person in the art, wherein:

[0006] Figure 1 is a schematic illustration of a turbine engine having a compression section, a combustion section, and a turbine section, in accordance with various aspects described herein.

[0007] Figure 2 is a cross-sectional view of the combustion section of Figure 1 along line II-II, in accordance with various aspects described herein.

[0008] Figure 3 is a cross-sectional view of the combustion section of Figure 2 along line III-III, showing a combustor, in accordance with various aspects described herein.

[0009] Figure 4 is a cross-sectional view of a fuel premixer that can be used in the combustor of Figure 3 , in accordance with various aspects described herein.

[0010] Figure 5 is a cross-sectional view of another fuel premixer that can be used in the combustor of Figure 3 , in accordance with various aspects described herein.

[0011] Figure 6 is a cross-sectional view of another fuel premixer that can be used in the combustor of Figure 3 , in accordance with various aspects described herein.

[0012] Figure 7Based on the various aspects described in this article, it is possible to... Figure 3 A cross-sectional view of another fuel premixer used in the burner.

[0013] Figure 8 Based on the various aspects described in this article, it is possible to... Figure 3 A cross-sectional view of another fuel premixer used in the burner.

[0014] Figure 9 Based on the various aspects described in this article, it is possible to... Figure 3 A cross-sectional view of another fuel premixer used in the burner.

[0015] Figure 10 Based on the various aspects described in this article, it is possible to... Figure 3 A cross-sectional view of another fuel premixer used in the burner. Detailed Implementation

[0016] The aspects disclosed herein relate to fuel premixers located within engine components, and more specifically, to fuel premixers configured for use with elevated combustion engine temperatures, such as those using hydrogen fuel. For illustrative purposes, this disclosure will be described in relation to turbine engines for aircraft with combustors that drive turbines. However, it will be understood that the aspects disclosed herein are not limited thereto and can have general applicability within engines, including but not limited to turbojet engines, turboprop engines, turboshaft engines, and turbofan engines. The aspects of the disclosure discussed herein can also have general applicability within non-aircraft engines with combustors, such as in other mobile applications and non-mobile industrial, commercial, and residential applications.

[0017] Reference will now be made in detail to combustor architectures, particularly to fuel premixers used to supply fuel to combustors located within a turbine engine, one or more examples of which are shown in the accompanying drawings. Detailed descriptions use numbers and letter reference numerals to denote features in the drawings. Similar or analogous reference numerals in the drawings and description have been used to denote similar or analogous parts of this disclosure.

[0018] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as superior or better than other implementations. Furthermore, unless expressly stated otherwise, all aspects described herein should be considered exemplary.

[0019] 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 the individual components.

[0020] The terms "forward" and "aft" refer to relative positions within a gas turbine engine or vehicle and refer to the normal operating attitude of the gas turbine engine or vehicle. For example, for a gas turbine engine, forward refers to a position closer to the engine inlet, and aft refers to a position closer to the engine nozzle or exhaust.

[0021] As used herein, the term "upstream" refers to a direction opposite to the direction of fluid flow, and the term "downstream" refers to a direction the same as the direction of fluid flow. The terms "forward" or "forwardly" mean in front of something, and "rearward" or "rearwardly" mean behind something. For example, when used in relation to fluid flow, forward / forwardly can mean upstream, and rearward / aft can mean downstream.

[0022] The term "fluid" can be a gas or a liquid. The term "fluid communication" means that a fluid is able to establish a connection between designated areas.

[0023] Additionally, as used herein, the term "radial" or "radially" refers to a direction away from a common center. For example, in the overall context of a turbine engine, radial refers to a direction along a ray extending between a central longitudinal axis of the engine and an outer periphery of the engine.

[0024] All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, aft, etc.) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of the disclosure described herein. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and will be given their ordinary and accustomed meaning to

[0025] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Also, as used herein, the term "set" or "a set" of elements can be any number of elements, including only one.

[0026] Approximating language, as used herein throughout the specification and claims, is applied to modify any quantitative representation that could permissibly vary without resulting in a change of the basic function to which it is directed. Accordingly, a value modified by a term or terms, such as "about", "approximately”, “substantially”, and "approximately”, is not limited to the precise value specified. In at least some instances, an approximation can correspond to the precision of an instrument for measuring the value, or the precision of the method or machine for constructing or manufacturing the item and / or system providing the value. In at least some instances, an approximation can correspond to the precision of an instrument for measuring the value, or the precision of the method or machine for constructing or manufacturing the item and / or system providing the value. For example, an approximation can refer to a margin of error within 1%, 2%, 4%, 5%, 10%, 15%, or 20% of a single value, a range of values, and / or an endpoint of a range of values. Ranges are combined and interchanged, such ranges are identified and include all subranges therein unless context or language indicates otherwise. For example, all ranges disclosed herein encompass end points, and end points are combinable with each other independently of other end points.

[0027] With respect to a duct or flow path, such as a duct or flow path in which a heat exchanger is positioned, “substantially annular” refers to a duct or flow path that is completely annular (i.e., extends continuously and uninterrupted in a circumferential direction except for the heat exchanger alone), or a duct or flow path that is partially annular with at least 50% volume percent voids (such as at least 60%, such as at least 70%, such as at least 80%, such as at least 90% volume percent voids) except for the heat exchanger.

[0028] In certain example aspects of the present disclosure, a turbine engine defining a centerline and a circumferential direction is provided. The gas turbine engine can generally include a turbine and a rotor assembly. The rotor assembly can be driven by the turbine. The turbine, the rotor assembly, or both can define a substantially annular flow path relative to the centerline of the gas turbine engine. The turbine engine includes a combustor positioned upstream of the turbine configured to drive the turbine.

[0029] The combustor introduces fuel from a fuel nozzle that mixes with swirled turbulent air generated by a swirler and then burns within a combustion chamber to produce combustion gases that drive the turbine. Increases in efficiency and reductions in emissions have driven the need to use fuels that burn cleaner or at higher temperatures, such as the use of hydrogen fuels. There is a need to improve durability of the combustor at these operating parameters, such as improved flame control to prevent the flame from staying on the fuel nozzle and swirler components. The inventors’ practice has been to design the fuel nozzle and swirler in ways that meet the durability requirements of increased engine temperatures and hydrogen fuels.

[0030] Figure 1is a schematic illustration of a turbine engine 10. As a non-limiting example, the turbine engine 10 can be used within an aircraft. The turbine engine 10 can include at least a compressor section 12, a combustion section 14, and a turbine section 16. A drive shaft 18 rotationally couples the compressor section 12 and the turbine section 16 such that rotation of one affects rotation of the other and defines an axis of rotation 20 of the turbine engine 10.

[0031] The compressor section 12 can include a low pressure (LP) compressor 22 and a high pressure (HP) compressor 24 fluidly coupled in series with one another. The turbine section 16 can include a HP turbine 26 and a LP turbine 28 fluidly coupled in series with one another. The drive shaft 18 can operably couple the LP compressor 22, the HP compressor 24, the HP turbine 26, and the LP turbine 28 together. Alternatively, the drive shaft 18 can include a LP drive shaft (not shown) and a HP drive shaft (not shown). The LP drive shaft can couple the LP compressor 22 to the LP turbine 28, and the HP drive shaft can couple the HP compressor 24 to the HP turbine 26. A LP train can be defined as a combination of the LP compressor 22, the LP turbine 28, and the LP drive shaft such that rotation of the LP turbine 28 can impart a driving force to the LP drive shaft, which in turn can cause the LP compressor 22 to rotate. A HP train can be defined as a combination of the HP compressor 24, the HP turbine 26, and the HP drive shaft such that rotation of the HP turbine 26 can impart a driving force to the HP drive shaft, which in turn can cause the HP compressor 24 to rotate.

[0032] The compressor section 12 can include a plurality of axially spaced stages. Each stage includes a set of circumferentially spaced rotating blades and a set of circumferentially spaced stationary vanes. Compressor blades for a stage of the compressor section 12 can be mounted to a disk, which is mounted to the drive shaft 18. Each set of blades for a given stage can have its own disk. The vanes of the compressor section 12 can be mounted to a casing, which can extend circumferentially around the turbine engine 10. It should be understood that the representation of the compressor section 12 is merely schematic and there can be any number of blades, vanes, and stages. Further, it is contemplated that there can be any number of other components within the compressor section 12.

[0033] Similar to the compressor section 12, the turbine section 16 can include a plurality of axially spaced stages, with each stage having a set of circumferentially spaced rotating blades and a set of circumferentially spaced stationary vanes. The turbine blades for a stage of the turbine section 16 can be mounted to a disk, which is mounted to the drive shaft 18. Each set of blades for a given stage can have its own disk. The vanes of the turbine section can be mounted to the casing in a circumferential manner. It is noted that there can be any number of blades, vanes, and turbine stages, as the illustrated turbine section is merely a schematic representation. Further, it is contemplated that there can be any number of other components within the turbine section 16.

[0034] The combustion section 14 can be serially disposed between the compressor section 12 and the turbine section 16. The combustion section 14 can be fluidly coupled to at least a portion of the compressor section 12 and the turbine section 16, such that the combustion section 14 at least partially fluidly couples the compressor section 12 to the turbine section 16. As a non-limiting example, the combustion section 14 can be fluidly coupled to the HP compressor 24 at an upstream end of the combustion section 14, and fluidly coupled to the HP turbine 26 at a downstream end of the combustion section 14.

[0035] During operation of the turbine engine 10, ambient or atmospheric air is drawn into the compressor section 12 via a fan (not shown) upstream of the compressor section 12, the air is compressed at the compressor section 12, defining pressurized air. The pressurized air can then flow into the combustion section 14, where the pressurized air is mixed with fuel and ignited, generating combustion gases. The HP turbine 26 extracts some work from these combustion gases, the HP turbine 26 driving the HP compressor 24. The combustion gases are exhausted into the LP turbine 28, which extracts additional work to drive the LP compressor 22, and the exhaust is ultimately exhausted from the turbine engine 10 via an exhaust section (not shown) downstream of the turbine section 16. The driving of the LP turbine 28 drives the LP spool to rotate the fan (not shown) and the LP compressor 22. The pressurized air stream and the combustion gases can together define a working airflow that flows through the fan, the compressor section 12, the combustion section 14, and the turbine section 16 of the turbine engine 10.

[0036] Figure 2 depicted along Figure 1The image shows a cross-sectional view of combustion section 14 along line II-II. Combustion section 14 may include a combustor 30, wherein annularly arranged fuel injectors 31 are disposed around the centerline or axis of rotation 20 of the turbine engine 10. It should be understood that the annularly arranged fuel injectors 31 may be one or more fuel injectors, and one or more of the fuel injectors 31 may have different characteristics. Depending on the type of engine in which the combustor 30 is located, the combustor 30 may have a canister-shaped, canister-annular, or annular arrangement. In a non-limiting example, the combustor 30 may have a combined arrangement positioned together with the engine housing 29.

[0037] The burner 30 may be at least partially defined by the burner liner 40. In some examples, the burner liner 40 may include an outer liner 41 and an inner liner 42 arranged concentrically with respect to each other and in an annular manner about the engine centerline or axis of rotation 20. In some examples, the burner liner 40 may have an annular structure with respect to the burner 30. In some examples, the burner liner 40 may include multiple segments or portions that together form the burner liner 40. The dome assembly 44, together with the burner liner 40, may at least partially define a combustion chamber 50 arranged annularly about the axis of rotation 20. The compressed air passage 32 may be at least partially defined by both the burner liner 40 and the housing 29.

[0038] Figure 3 Depicting along Figure 2 The cross-sectional view taken along line III-III shows the burner 30. The burner 30 may include a fuel assembly 35 configured to supply fuel to the burner 30. The fuel assembly 35 may at least partially form a fuel injector 31. In some examples, the fuel assembly 35 may include annularly arranged fuel nozzles. It should be understood that such fuel nozzles may be organized in any suitable arrangement, pattern, grouping, etc.

[0039] The dome assembly 44 may include a dome wall 46 and a diffuser 48. The burner liner 40 and the dome assembly 44 may together define the combustion chamber 50 at least partially with respect to a longitudinal axis 52. The longitudinal axis 52 may extend between a forward direction 52F and a rearward direction 52A, as shown in the figure.

[0040] At least one fuel supply unit 54 may be fluidly connected to the combustion chamber 50 to supply fuel to the burner 30. In a non-limiting example, the fuel may include any suitable fuel, including hydrocarbon fuels, hydrogen fuels, or mixtures of different fuel types.

[0041] The fuel supply 54 can be disposed within the dome assembly 44 to define a fuel outlet 58. It is contemplated that air can also be supplied or provided to the combustion chamber 50 through the fuel outlet 58. In this manner, the fuel outlet 58 can provide a fuel-air mixture to the combustion chamber 50. Additionally, in some examples, multiple fuel injectors or premixers can be located on the dome wall 46. In some examples, the multiple fuel injectors or premixers can be arranged in discrete clusters or groups on the dome wall 46.

[0042] In some examples, a flared cone 56 can be disposed downstream of the fuel supply 54. An annular swirler 60 (or "swirler 60") can also be disposed at the fuel assembly 35. The swirler 60 can be an annular swirler located within an interior of an annular shroud. The swirler 60 can include static vanes, angled passages, etc. The swirler 60 can be configured to swirl incoming air around the fuel exiting the fuel supply 54. The swirler 60 can also provide a mixture of air and fuel into the combustor 30.

[0043] A set of dilution holes 62 can be disposed in the combustor liner 40 and configured to direct air into the combustion chamber 50 for temperature control, flame shaping, fuel-air mixing, etc. Any number of dilution holes can be disposed in the set of dilution holes 62. The set of dilution holes 62 can have any suitable pattern or arrangement on the combustor liner 40, including straight rows, irregular groups, variable hole diameters, etc., or combinations thereof. It is also contemplated that the combustor 30 can be formed without any dilution holes.

[0044] A fuel premixer 100 can also be disposed in the combustor 30. The fuel premixer 100 can form a mixture of fuel and air and can also supply the mixture to the combustion chamber 50. Turning to Figure 4 , a cross-sectional view of the fuel premixer 100 is shown. The fuel premixer 100 can define an upstream end 103, a downstream end 104, and a central longitudinal axis LI extending between the upstream end 103 and the downstream end 104. In some examples, the central longitudinal axis LI can be aligned with the longitudinal axis 52 Figure 3 ), although this need not be the case. It will be appreciated that Figure 4 only a portion of the fuel premixer 100 is shown in FIG. 1 1 and that the fuel premixer 100 can have an annular form about the central longitudinal axis LI.

[0045] The fuel premixer 100 can include an annular shroud 120 (or "shroud 120") defining an interior 121. The shroud 120 can define or bound a mixing chamber 122 within the interior 121. A central body 125 can also be located within the interior 121. The central body 125 can also be aligned with the central longitudinal axis LI.

[0046] An annular swirler 102 having a set of vanes 106 can be positioned within the interior 121 and encircle the center body 125. As shown, each vane of the set of vanes 106 can extend between an upstream leading edge 107 and a downstream trailing edge 108. As shown, the swirler 102 can include a first annular wall 130 and a second annular wall 140. The first annular wall 130 can be positioned radially outward of the second annular wall 140 relative to the central longitudinal axis LI.

[0047] The swirler 102 can be spaced apart from the shroud 120. As shown, an outer annular passage, referred to herein as a "first annular passage" 127, can be defined between the shroud 120 and the first annular wall 130. A second annular passage 128 can be defined within the swirler 102, between the first annular wall 130 and the second annular wall 140. The swirler 102 can also be spaced apart from the center body 125. As shown, an inner annular passage, referred to herein as a "third annular passage" 129, can be defined between the second annular wall 140 and the center body 125.

[0048] A compressed gas flow C can be provided to the fuel premixer 100. Portions of the compressed gas flow C can be provided to respective portions of the fuel premixer 100. In the illustrated example, the compressed gas flow C can include a first portion forming a first non-swirled gas flow PI, a second portion forming a second non-swirled gas flow P2, and a third portion forming a third non-swirled gas flow P3. The first non-swirled gas flow PI, the second non-swirled gas flow P2, and the third non-swirled gas flow P3 can be provided to the first annular passage 127, the third annular passage 129, and the second annular passage 128, respectively.

[0049] The fuel premixer 100 can further include at least a first fuel nozzle 151 and a set of second fuel nozzles 152. The first fuel nozzle 151 can be disposed in the center body 125. The first fuel nozzle 151 can include a first fuel passage 153 and a nozzle outlet 157. In non-limiting aspects, the first fuel nozzle 151 can include a nozzle cover 155 defining a set of fuel orifices 180 therethrough. In such cases, the set of fuel orifices 180 can at least partially define the nozzle outlet 157.

[0050] In some examples, the set of second fuel nozzles 152 can be circumferentially spaced apart or radially spaced apart from one another. In the illustrated, non-limiting example, the set of second fuel nozzles 152 can be positioned at the vanes 106, upstream of the trailing edges 108. It is contemplated that the set of second fuel nozzles 152 can inject fuel from a surface of the vanes 106. In some examples, the first fuel nozzle 151 can form a pilot, while a main fuel supply for the combustor 30( Figure 3 ) can be supplied through the set of second fuel nozzles 152.

[0051] The shroud 120 can also define or limit an exhaust flow passage 119 at the downstream end 104 of the fuel premixer 100. The exhaust flow passage 119 can be arranged to have a converging cross-sectional profile at the downstream end 104. For example, the outer housing can include a converging portion at the downstream end 104 that defines the exhaust flow passage 119. The exhaust flow passage 119 can be downstream of and in fluid communication with the first fuel nozzle 151, the set of second fuel nozzles 152, the first annular passage 127, the second annular passage 128, and the third annular passage 129.

[0052] During operation, the first fuel nozzle 151 can be configured to emit a first fuel flow Fl of received fuel into the exhaust flow passage 119. In some examples, the first fuel nozzle 151 can include angled or offset openings to form a swirled first fuel flow Fl. While illustrated as a swirled flow, in some examples, the first fuel flow Fl can also include a non-swirled flow. For example, the first fuel nozzle 151 can include openings that are aligned with the exhaust flow passage 119 such that the first fuel flow Fl is not swirled as it exits.

[0053] The set of second fuel nozzles 152 can be configured to emit a second fuel flow F2 of received fuel into the exhaust flow passage 119. In some examples, the set of second fuel nozzles 152 can include angled or offset openings to form a swirled second fuel flow Fl. In other examples, the set of second fuel nozzles 152 can include straight openings, non-angled openings, or the like, to form a non-swirled second fuel flow Fl. While illustrated as a non-swirled flow, in some examples, the second fuel flow F2 can also include a swirled flow, or a combination of swirled and non-swirled flows.

[0054] Further, in the illustrated example, the first fuel nozzle 151 can provide the first fuel flow Fl downstream of the swirler 102. In some examples, this arrangement can prevent a flame from holding on the swirler 102. Further, the swirl created by the set of fuel orifices 180 on the nozzle cover 155 can prevent low velocity flow from occurring at the first fuel nozzle 151, which reduces the chance of a flame holding or backfiring on the first fuel nozzle 151.

[0055] Additionally, during operation, the first non-swirling gas stream P1 can be delivered through the first annular passage 127 to the exhaust flow passage 119. In some examples, the first non-swirling gas stream P1 can form a first gas film positioned along the shroud 120 so as to provide cooling or to avoid flame holding. The third non-swirling gas stream P3 can be delivered to the second passage 128 and the swirler 102. The swirler 102 can impart a tangential or spiral swirl to the second non-swirling gas stream P2 and emit a first swirling gas stream S1 so as to be delivered to the exhaust flow passage 119. The second non-swirling gas stream P2 can be delivered through the third annular passage 129 to the mixing chamber 122. In some examples, the second non-swirling gas stream P2 can create a second gas film positioned along the center body 125 so as to provide cooling or to avoid flame holding. In this manner, a stratified flow mixture of fuel and air can be provided to the exhaust flow passage 119 with a centrally located swirling first fuel stream Fl, a second non-swirling gas stream P2 surrounding the first fuel stream Fl, a first swirling air stream S1 mixed with the second fuel stream F2 and surrounding the second non-swirling gas stream P2, and a non-swirling first gas stream Pl forming an outermost layer along the shroud 120.

[0056] In this manner, the first non-swirling gas stream Pl can be emitted from the outer first annular passage 127 along the shroud 120 into the mixing chamber 122, the second non-swirling gas stream P2 can be emitted from the inner third annular passage 129 along the center body 125, the swirling gas stream S1 can be emitted from the swirler 102 between the first non-swirling gas stream Pl and the second non-swirling gas stream P2 into the mixing chamber 122, and the swirling fuel stream Fl can be emitted from the center body 125 into the mixing chamber 122.

[0057] It can be appreciated that the co-swirling among the fuel and air streams can avoid high shear forces between the streams. This shear reduction can reduce shear layer separation between the gas and fuel streams, provide improved distribution of the radial velocity profile, and maintain high axial velocities for both the fuel and gas streams. The high axial velocities can reduce or eliminate the occurrence of flame holding on the fuel premixer 100, allowing the use of higher temperature fuels, such as hydrogen fuel. Additionally, the co-swirling of the air and fuel prevents mixing of the air and fuel, which provides better mixing control, as well as a reduction or elimination of flashback and flame holding at high temperature operation.

[0058] Referring now to Figure 5 , another fuel premixer 200 is shown. The fuel premixer 200 is similar to the fuel premixer 100; therefore, similar parts will be identified with like numbers increased by 100, and it should be understood that the description of the similar parts of the fuel premixer 100 apply to the fuel premixer 200, unless otherwise noted.

[0059] The fuel premixer 200 can define a shroud 220, an upstream end 203, a downstream end 204, a center body 225, an exhaust flow passage 219, and a central longitudinal axis LI. The shroud 220 can define an interior 221. The shroud 220 can define or bound a mixing chamber 222 within the interior 221.

[0060] A swirler 202 having a set of vanes 206 can be disposed in the fuel premixer 200. The swirler 202 can include a first annular wall 230 and a second annular wall 240. The swirler 202 can be spaced apart from the shroud 220 to define a first annular passage 227. A second annular passage 228 can be defined within the swirler 202. The swirler 202 can also be spaced apart from the center body 225 to define a third annular passage 229.

[0061] A compressed gas flow C can be provided to the fuel premixer 200. The compressed gas flow C can include a first non-swirled gas flow PI, a second non-swirled gas flow P2, and a third non-swirled gas flow P3 provided to the first annular passage 227, the third annular passage 229, and the second annular passage 228, respectively. The shroud 220 can bound or bound the exhaust flow passage 219 at the downstream end 204 of the fuel premixer 200.

[0062] The fuel premixer 200 can further include at least a first fuel nozzle 251 and a set of second fuel nozzles 252. The first fuel nozzle 251 can be disposed in the center body 225 and include a first fuel passage 253. In some examples, the set of second fuel nozzles 252 can be spaced apart circumferentially or radially from one another. One distinction compared to the fuel premixer 100 is that the fuel premixer 200 can include a second fuel passage 256 fluidly coupled to the set of second fuel nozzles 252. The second fuel passage 256 can be communicatively coupled to a fuel source or supply on the aircraft, e.g., via a fuel line (not shown), to receive a flow of fuel therefrom in a known manner, such as via a fuel pump (not shown). In non-limiting aspects, the second fuel passage 256 can define an annular shape. The second fuel passage 256 can include a tubular member. In some aspects, a portion of the second fuel passage 256 can be substantially concentric with the center body 225. The set of second fuel nozzles 252 can be further fluidly coupled to the second annular passage 228 and configured to supply the received fuel as a second fuel flow F2 to the second annular passage 228 and the exhaust flow passage 122. In non-limiting aspects, each second fuel nozzle 252 can include a respective orifice or nozzle.

[0063] During operation, the first fuel nozzle 251 can be configured to emit a first fuel stream Fl of received fuel to the exhaust flow passage 219. A set of second fuel nozzles 252 can be configured to emit a second fuel stream F2 of received fuel to the exhaust flow passage 219. A first non-swirl air stream Pl can be delivered to the mixing chamber 222 through the first annular passage 227. In some examples, the first non-swirl air stream Pl can form a first air film positioned along the shroud 220 so as to provide cooling or avoid flame holding. The swirler 202 can impart a tangential or helical swirl to a third non-swirl air stream P3 and emit a first swirl air stream SI so as to be delivered to the exhaust flow passage 219. A second non-swirl air stream P2 can be delivered to the mixing chamber 222 through the third annular passage 229. In some examples, the second non-swirl air stream P2 can create a second air film positioned along the center body 225 so as to provide cooling or avoid flame holding. In this manner, a stratified flow mixture of fuel and air can be provided to the exhaust flow passage 219 with a centrally located swirl of the first fuel stream Fl, the second non-swirl air stream P2 surrounding the first fuel stream Fl, the first swirl air stream SI mixed with the second fuel stream F2 and surrounding the second non-swirl air stream P2, and the first non-swirl air stream Pl forming an outermost layer along the shroud 220.

[0064] Referring now to Figure 6 , another fuel premixer 300 is shown. The fuel premixer 300 is similar to the fuel premixers 100, 200; therefore, similar parts will be identified with like numbers further incremented 100, and it should be understood that the description of similar parts of the fuel premixers 100, 200 apply to the fuel premixer 300, unless otherwise noted.

[0065] The fuel premixer 300 can define a shroud 320, an upstream end 303, a downstream end 304, a center body 325, an exhaust flow passage 319, and a central longitudinal axis LI. The annular shroud 320 can define an interior 321. The shroud 320 can define or bound a mixing chamber 322 within the interior 321.

[0066] A swirler 302 having a set of vanes 306 can be disposed in the fuel premixer 300. The swirler 302 can include a first annular wall 330 and a second annular wall 340. The swirler 302 can be spaced apart from the shroud 320 to define a first annular passage 327. A second annular passage 328 can be defined within the swirler 302. The swirler 302 can also be spaced apart from the center body 325 to define a third annular passage 329.

[0067] The compressed air stream C can be provided to the fuel premixer 300. The compressed air stream C can include a first non-swirl air stream PI, a second non-swirl air stream P2, and a third non-swirl air stream P3 provided to the first annular passage 327, the third annular passage 329, and the second annular passage 328, respectively. The shroud 320 can define or limit the exhaust flow passage 319 at the downstream end 304 of the fuel premixer 300.

[0068] The fuel premixer 300 can further include at least a first fuel nozzle 351 and a set of second fuel nozzles 352. The first fuel nozzle 351 can be disposed in the center body 325 and include a first fuel passage 353 and a nozzle outlet 357. In some examples, the set of second fuel nozzles 352 can be spaced apart circumferentially or radially from one another, or a combination thereof. A second fuel passage 356 can be disposed in the fuel premixer 300 and fluidly coupled to the set of second fuel nozzles 352. One difference compared to the fuel premixer 100, 200 is that the second fuel passage 356 can be positioned downstream of the trailing edge 308 of the set of vanes 306.

[0069] Another difference compared to the fuel premixer 100, 200 is that the fuel premixer 300 can include one or more third fuel nozzles 359. The third fuel nozzles 359 can be arranged or defined on a periphery of the center body 325. The third fuel nozzles 359 can be positioned upstream of the nozzle outlet 357. For example, in non-limiting aspects, the third fuel nozzles 359 can be defined by holes defined through the center body 325. In some non-limiting examples, the third fuel nozzles 359 can be spaced apart axially or circumferentially from one another along the center body 325. The third fuel nozzles 359 can be in fluid communication with the first fuel passage 353 to receive fuel therefrom.

[0070] During operation, the first fuel nozzle 351 can be configured to emit a first fuel stream FI of received fuel to the exhaust flow passage 319. The set of second fuel nozzles 352 can be configured to emit a second fuel stream F2 of received fuel to the exhaust flow passage 319. The first non-swirl air stream PI can be conveyed to the exhaust flow passage 319 through the first annular passage 327. In some examples, the first non-swirl air stream PI can form a first air film positioned along the shroud 320 to provide cooling or avoid flame holding. The swirler 302 can impart a tangential or helical swirl to the third non-swirl air stream P3 and emit a first swirl air stream SI to be conveyed to the exhaust flow passage 319. The second non-swirl air stream P2 can be conveyed to the exhaust flow passage 319 through the third annular passage 329. In some examples, the second non-swirl air stream P2 can create a second air film positioned along the center body 325 to provide cooling or avoid flame holding.

[0071] Further, during operation, the third fuel nozzle 359 can deliver received fuel as a third fuel stream F3 radially outward to the exhaust flow passage 319. The third fuel stream F3 can form a film on the center body 325 and subsequently mix with the swirled first fuel stream Fl. This injection of the third fuel stream F3 at the periphery of the center body 325 upstream of the nozzle exit 357 can provide additional time for fuel and air mixing prior to combustion, while allowing at least a portion of the third fuel stream F3 to mix with air radially outward of the first fuel stream Fl. This arrangement can enhance or increase the overall mixing and distribution of fuel and air at the downstream end 304 of the fuel premixer 300. This improved mixing of fuel and air can result in reduced NOx emissions compared to conventional technology. x emissions.

[0072] A portion of the third fuel stream F3 can also flow on the outer diameter or periphery of the center body 325 and mix with fuel on the trailing edge of the center body 325, creating a fuel-rich mixture on the trailing edge of the center body 325 to prevent flame holding on the trailing edge of the center body 325.

[0073] Referring now to Figure 7 , another fuel premixer 400 is shown. The fuel premixer 400 is similar to the fuel premixers 100, 200, 300; therefore, similar parts will be identified with like numbers further incremented by 100, and it should be understood that the description of similar parts of the fuel premixers 100, 200, 300 apply to the fuel premixer 400, unless otherwise noted.

[0074] The fuel premixer 400 can define a shroud 420, an upstream end 403, a downstream end 404, a center body 425, an exhaust flow passage 419, and a central longitudinal axis LI. The annular shroud 420 can define an interior 421. The shroud 420 can define or limit a mixing chamber 422 within the interior 421.

[0075] A swirler 402 having a set of vanes 406 can be disposed in the fuel premixer 400. The swirler 402 can include a first annular wall 430 and a second annular wall 440. The swirler 402 can be spaced apart from the shroud 420 to define a first annular passage 427. A second annular passage 428 can be defined within the swirler 402. The swirler 402 can also be spaced apart from the center body 425 to define a third annular passage 429.

[0076] The compressed air flow C can be provided to the fuel premixer 400. The compressed air flow C can include a first non-swirl air flow PI, a second non-swirl air flow P2, and a third non-swirl air flow P3 provided to the first annular passage 427, the third annular passage 429, and the second annular passage 428, respectively. The shroud 420 can define or limit the exhaust flow passage 419 at the downstream end 404 of the fuel premixer 400.

[0077] The fuel premixer 400 can further include at least a first fuel nozzle 451 and a set of second fuel nozzles 452. The first fuel nozzle 451 can be disposed in the center body 425 and include a first fuel passage 453. In some examples, the set of second fuel nozzles 452 can be circumferentially spaced apart or radially spaced apart from one another. A second fuel passage 456 can be disposed in the fuel premixer 400 and fluidly coupled to the set of second fuel nozzles 452. The second fuel passage 456 is illustrated as being positioned downstream of the set of vanes 406, although this need not be the case.

[0078] One difference compared to the fuel premixers 100, 200, 300 is that the fuel premixer 400 can include cooling apertures 474 defined through the shroud 420 in fluid communication with the exhaust flow passage 419. The cooling apertures 474 can be axially disposed downstream of the first fuel nozzle 451 and the set of second fuel nozzles 452. Some example cooling apertures 474 are illustrated, and any number of cooling apertures 474 can be provided. The cooling apertures 474 can be circumferentially spaced apart from one another. Additionally or alternatively, the cooling apertures 474 can be axially spaced apart from one another. In non-limiting aspects, the cooling apertures 474 can include a tangential or compound angle component. In operation, the cooling apertures 474 can provide respective second air flows C2 to the exhaust flow passage 419. In some examples, the second air flows C2 can be separate from the compressed air flow C. In some examples, the second air flows C2 can also be part of the compressed air flow C.

[0079] During operation, the first fuel nozzle 451 can be configured to emit a first fuel stream Fl of received fuel to the exhaust flow passage 419. A set of second fuel nozzles 452 can be configured to emit a second fuel stream F2 of received fuel to the exhaust flow passage 419. A first non-swirl air stream Pl can be delivered to the exhaust flow passage 419 through the first annular passage 427. In some examples, the first non-swirl air stream Pl can form a first air film positioned along the shroud 420 so as to provide cooling or to avoid flame holding. The swirler 402 can impart a tangential or helical swirl to a third non-swirl air stream P3 and emit a first swirled air stream SI so as to be delivered to the exhaust flow passage 419. A second non-swirl air stream P2 can be delivered to the exhaust flow passage 419 through the third annular passage 429. In some examples, the second non-swirl air stream P2 can create a second air film positioned along the center body 425 so as to provide cooling or to avoid flame holding.

[0080] Further, during operation, the cooling aperture 474 can emit a second air stream C2 such that the second air stream C2 can form or enhance the first air film along the shroud 420. Such an arrangement can further prevent or reduce flame holding along the shroud 420.

[0081] Referring now to Figure 8 , another fuel premixer 500 is shown. The fuel premixer 500 is similar to the fuel premixers 100, 200, 300, 400; therefore, similar parts will be identified with like numbers further increasing 100, and it should be understood that the description of similar parts of the fuel premixers 100, 200, 300, 400 apply to the fuel premixer 500, unless otherwise noted.

[0082] The fuel premixer 500 can define a shroud 520, an upstream end 503, a downstream end 504, a center body 525, an exhaust flow passage 519, and a central longitudinal axis LI. The shroud 520 can define an interior 521. The shroud 520 can define or limit a mixing chamber 522 within the interior 521.

[0083] A swirler 502 having a set of vanes 506 can be disposed in the fuel premixer 500. The swirler 502 can include a first annular wall 530 and a second annular wall 540. The swirler 502 can be spaced apart from the shroud 520 to define a first annular passage 527. A second annular passage 528 can be defined within the swirler 502. The swirler 502 can also be spaced apart from the center body 525 to define a third annular passage 529.

[0084] Compressed airflow C can be provided to fuel premixer 500. Compressed airflow C may include a first non-swirling airflow P1, a second non-swirling airflow P2, and a third non-swirling airflow P3 provided to the first annular passage 527, the third annular passage 529, and the second annular passage 528, respectively. Shield 520 may define or restrict exhaust flow passage 119 at the downstream end 104 of fuel premixer 100.

[0085] The fuel premixer 500 may further include at least a first fuel nozzle 551 and a set of second fuel nozzles 552. The first fuel nozzle 551 may be disposed in the central body 525 and include a first fuel passage 553. In some examples, the set of second fuel nozzles 552 may be circumferentially or radially spaced apart from each other. A second fuel passage 556 may be disposed in the fuel premixer 500 and fluidly connected to the set of second fuel nozzles 552. The second fuel passage 556 is illustrated as being positioned downstream of a set of impellers 506, although this is not necessarily the case.

[0086] One difference compared to fuel premixers 100, 200, 300, and 400 is that a portion of the second fuel passage 556, or at least one subgroup of the second fuel nozzles 552, or both, may extend radially outward beyond the second annular passage 528. In other words, at least a portion of the subgroup of the second fuel nozzles 552 may be positioned outside the swirling airflow S1. In this way, at least a portion of the second fuel flow F2 may be initially delivered outside the swirling airflow S1. In some non-limiting examples, this portion of the second fuel flow F2 may be injected or delivered from the first annular wall 530, either toward or parallel to the swirling airflow S1. In a non-limiting aspect, at least a portion of the subgroup of the second fuel nozzles 552 may be arranged upstream of the first fuel nozzle 551. Compared to conventional technologies, injecting a portion of the second fuel stream F2 radially outward relative to the remainder of the second fuel stream F2 allows for a distribution of the second fuel stream F2 over a relatively large radial span, achieving improved fuel-air mixing and a better radial distribution of the fuel profile at the outlet of the exhaust flow passage 519. It will be understood that this improved fuel-air mixing, compared to conventional technologies, can lead to a reduction in NOx. x Emissions. In some non-limiting aspects, a portion of the second fuel stream F2 may be injected from the first annular wall 530.

[0087] In other non-limiting aspects, a portion of the second fuel stream F2 may be injected from a set of second fuel nozzles 552, thereby creating a radial distribution of fuel to achieve lower NO levels compared to conventional techniques. xBetter discharge of the fuel-air mixture. In some non-limiting aspects, the second fuel nozzles 552 can be circumferentially or axially staggered relative to one another to achieve increased circumferential spread of the fuel, or to achieve a predetermined fuel-air mixing length, or both.

[0088] Referring now to Figure 9 , another fuel premixer 600 is shown. The fuel premixer 500 is similar to the fuel premixers 100, 200, 300, 400, 500; thus, similar parts will be identified with like numbers further increasing 100, and it should be understood that the description of similar parts of the fuel premixers 100, 200, 300, 400, 500 applies to the fuel premixer 600, unless otherwise noted.

[0089] The fuel premixer 600 can define a shroud 620, an upstream end 603, a downstream end 604, a center body 625, an exhaust flow passage 619, and a central longitudinal axis LI. The annular shroud 620 can define an interior 621. The shroud 620 can define or bound a mixing chamber 622 within the interior 621.

[0090] A swirler 602 having a set of vanes 606 can be disposed in the fuel premixer 600. The swirler 602 can include a first annular wall 630 and a second annular wall 640. The swirler 602 can be spaced apart from the shroud 620 to define a first annular passage 627. A second annular passage 628 can be defined within the swirler 602. The swirler 602 can also be spaced apart from the center body 625 to define a third annular passage 629.

[0091] A compressed gas stream C can be provided to the fuel premixer 600. The compressed gas stream C can include a first non-swirled gas stream PI, a second non-swirled gas stream P2, and a third non-swirled gas stream P3 provided to the first annular passage 627, the third annular passage 629, and the second annular passage 628, respectively. The shroud 620 can define or bound the exhaust flow passage 619 at the downstream end 604 of the fuel premixer 600.

[0092] The fuel premixer 600 can further include at least a first fuel nozzle 651 and a set of second fuel nozzles 652. The first fuel nozzle 651 can be disposed in the center body 625 and include a first fuel passage 653. In some examples, the set of second fuel nozzles 652 can be circumferentially spaced apart or radially spaced apart from one another. A second fuel passage 656 can be disposed in the fuel premixer 600 and fluidly coupled to the set of second fuel nozzles 652. The second fuel passage 656 is illustrated as being positioned downstream of the set of vanes 606, although this need not be the case.

[0093] One difference compared to the fuel premixers 100, 200, 300, 400, 500 is that the first fuel passage 653 can receive a fourth portion of the compressed gas flow C as a fourth non-swirl gas flow P4, rather than supplying fuel. In this manner, the first fuel passage 653 can be configured to supply air alone to the mixing chamber 622, to supply fuel alone to the mixing chamber 622, or to supply a mixture of air and fuel to the mixing chamber 622.

[0094] During operation, the set of second fuel nozzles 652 can be configured to emit a second fuel flow F2 of received fuel to the exhaust flow passage 619. The first non-swirl gas flow Pl can be conveyed to the exhaust flow passage 619 through the first annular passage 627. In some examples, the first non-swirl gas flow Pl can form a first gas film positioned along the shroud 620 so as to provide cooling or to avoid flame holding. The swirler 602 can impart a tangential or helical swirl to the third non-swirl gas flow P3 and emit a first swirl air flow SI so as to be conveyed to the exhaust flow passage 619. The second non-swirl gas flow P2 can be conveyed to the exhaust flow passage 619 through the third annular passage 629. In some examples, the second non-swirl gas flow P2 can create a second gas film positioned along the center body 625 so as to provide cooling or to avoid flame holding.

[0095] Further, during operation, the fourth non-swirl gas flow P4 can be conveyed to the nozzle outlet 657 as a second swirl gas flow S2. In non-limiting aspects, the third non-swirl gas flow P3 can be disposed radially outward of the second swirl gas flow S2. In this sense, the second swirl gas flow S2 can be surrounded by the third non-swirl gas flow P3. In operation, this arrangement can have the effect of biasing fuel away from a central region of the exhaust flow passage 619, resulting in a reduction or elimination of center body flame holding.

[0096] Referring now to Figure 10 , another fuel premixer 700 is shown. The fuel premixer 500 is similar to the fuel premixers 100, 200, 300, 400, 500, 600; therefore, similar parts will be identified with like numbers further increasing 100, and it should be understood that the description of similar parts of the fuel premixers 100, 200, 300, 400, 500, 600 applies to the fuel premixer 700, unless otherwise noted.

[0097] The fuel premixer 700 can define a shroud 720, an upstream end 703, a downstream end 704, a center body 725, an exhaust flow passage 719, and a central longitudinal axis LI. The annular shroud 720 can define an interior 721. The shroud 720 can define or limit a mixing chamber 722 within the interior 721.

[0098] A swirler 702 having a set of vanes 706 can be disposed in the fuel premixer 700. The swirler 702 can include a first annular wall 730 and a second annular wall 740. The swirler 702 can be spaced apart from the shroud 720 to define a first annular passage 727. A second annular passage 728 can be defined within the swirler 702. The swirler 702 can also be spaced apart from the center body 725 to define a third annular passage 729.

[0099] A compressed gas stream C can be provided to the fuel premixer 700. The compressed gas stream C can include a first non-swirling gas stream PI, a second non-swirling gas stream P2, and a third non-swirling gas stream P3 provided to the first annular passage 727, the third annular passage 729, and the second annular passage 728, respectively. The shroud 720 can define or limit an exhaust flow passage 719 at the downstream end 704 of the fuel premixer 700.

[0100] The fuel premixer 700 can further include a first fuel nozzle 751 and a set of second fuel nozzles 752. The first fuel nozzle 751 can be disposed in the center body 725 and include a first fuel passage 753. The first fuel nozzle 751 can further include a nozzle outlet 757. In non-limiting aspects, the first fuel nozzle 751 can include a nozzle cover 755 defining a set of fuel orifices 780 therethrough. In such cases, the set of fuel orifices 780 can at least partially define the nozzle outlet 757.

[0101] A second fuel passage 756 can be disposed in the fuel premixer 700. The second fuel passage 756 is illustrated as being positioned in a separate fuel conduit downstream of the set of vanes 706, although this need not be the case. In some non-limiting examples, the second fuel passage 756 and the set of second fuel nozzles 752 can be disposed in the set of vanes 706, or through a plurality of discrete fuel conduits, or a combination thereof. Further, the set of second fuel nozzles 752 can be fluidly coupled to the second fuel passage 756.

[0102] One difference compared to the fuel premixers 100, 200, 300, 400, 500, 600 is that one or both of the first annular wall 730 or the second annular wall 740 can include an internal passage fluidly coupled to the second fuel passage 756. In the illustrated non-limiting example, the first annular wall 730 can include a first wall passage 771 and the second annular wall 740 can include a second wall passage 772. One or both of the first wall passage 771 or the second wall passage 772 can include a straight portion, a curved portion, a branched portion, etc.

[0103] Another difference compared to the fuel premixers 100, 200, 300, 400, 500, 600 is that a second set of fuel nozzles 752 can include outlets on one or both of the first annular wall 730 or the second annular wall 740. In the illustrated non-limiting example, the second set of fuel nozzles 752 can include a first outlet 761 on the first side 730A of the first annular wall 730, a second outlet 762 on the second side 730B of the first annular wall 730, a third outlet 763 on the first side 740A of the second annular wall 740, and a fourth outlet 764 on the second side 740B of the second annular wall 740. Any number of outlets can be provided in the second set of fuel nozzles 752.

[0104] Further, in the illustrated non-limiting example, a first wall passage 771 can extend from the second fuel passage 756 to the first outlet 761 and the second outlet 762. A second wall passage 772 can extend from the second fuel passage 756 to the third outlet 763 and the fourth outlet 764.

[0105] During operation, the first fuel nozzles 751 can be configured to emit a first fuel flow Fl of received fuel into the exhaust flow passage 719. While illustrated as a swirling flow, in some examples, the first fuel flow Fl can also include a non-swirling flow. Further, in the illustrated example, the first fuel nozzles 751 can provide the first fuel flow Fl downstream of the swirler 702. In some examples, this arrangement can prevent flame holding on the swirler 102. Further, the swirl generated by the set of fuel orifices 780 on the nozzle cover 755 can prevent low velocity flow from occurring at the first fuel nozzles 751, which reduces the chance of flame holding or flashback on the first fuel nozzles 751.

[0106] A first non-swirling air flow Pl can be delivered to the exhaust flow passage 719 through the first annular passage 727. In some examples, the first non-swirling air flow Pl can form a first air film positioned along the shroud 720 in order to provide cooling or avoid flame holding. A third non-swirling air flow P3 can be delivered to the second passage 728 and the swirler 702. The swirler 702 can impart a tangential or helical swirl to the third non-swirling air flow P3 and emit a first swirling air flow SI to be delivered to the exhaust flow passage 719. A second non-swirling air flow P2 can be delivered to the mixing chamber 722 through the third annular passage 729. In some examples, the second non-swirling air flow P2 can create a second air film positioned along the center body 725 in order to provide cooling or avoid flame holding.

[0107] Further, during operation, the second set of fuel nozzles 752 can be configured to emit a second fuel flow F2 of received fuel. While illustrated as a non-swirled flow, in some examples, the second fuel flow F2 can also include a swirled flow. The second fuel flow F2 can be emitted into any or all of the first annular passage 727, the second annular passage 728, or the third annular passage 729. The second fuel flow F2 can be equally or unequally divided among the second set of fuel nozzles 752. In this way, during operation, the second set of fuel nozzles 752 can provide a secondary fuel circuit that injects fuel into any or all of the first non-swirled flow Pl, the third non-swirled flow P3, or the first swirled flow Sl.

[0108] The features included herein provide improved fuel supply to a turbine engine combustor that provides for reduced or eliminated flame holding or flashback at a fuel premixer. This reduction or elimination provides for the use of higher temperature fuels, such as hydrogen fuel, which provides for improved efficiency while reducing or eliminating emissions.

[0109] This written description uses examples to disclose the disclosure, 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 disclosure is defined by the claims, and can 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 include 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.

[0110] Further aspects of the disclosure are provided in the following clauses:

[0111] A turbine engine comprising a compressor section, a combustion section, and a turbine section in a serial flow arrangement, and the combustion section having a combustor with a fuel premixer comprising: an annular shroud defining an interior with a mixing chamber; a center body within the interior and having a first fuel nozzle that emits fuel into the mixing chamber; and an annular swirler within the interior, encircling the center body, wherein the annular swirler is spaced apart from the shroud to define an outer annular passage, and also spaced apart from the center body to define an inner annular passage, wherein: the outer annular passage is configured to emit a first non-swirling airflow into the mixing chamber as a first gas film positioned along the shroud; the inner annular passage is configured to emit a second non-swirling airflow into the mixing chamber as a second gas film positioned along the center body; the annular swirler is configured to emit a swirling airflow into the mixing chamber between the first non-swirling airflow and the second non-swirling airflow; and the first fuel nozzle is configured to emit a swirling fuel flow into the mixing chamber.

[0112] The turbine engine of any of the preceding clauses, further comprising a set of second fuel nozzles configured to emit a second fuel flow into the swirling airflow.

[0113] The turbine engine of any of the preceding clauses, further comprising a second fuel passage within the interior and fluidly coupled to the set of second fuel nozzles.

[0114] The turbine engine of any of the preceding clauses, wherein the annular swirler comprises a set of vanes, wherein the set of second fuel nozzles are positioned on the set of vanes.

[0115] The turbine engine of any of the preceding clauses, wherein the set of vanes comprises a trailing edge, wherein the second fuel passage is one of downstream or upstream of the trailing edge.

[0116] The turbine engine of any of the preceding clauses, wherein the second fuel passage extends to at least one outlet on at least one wall of the annular swirler, wherein the at least one outlet fluidly couples the second fuel passage to at least one of the inner annular passage or the outer annular passage.

[0117] The turbine engine of any of the preceding clauses, wherein the second fuel passage extends into a wall of the annular swirler, wherein the set of second fuel nozzles are configured to emit the second fuel flow out of the annular swirler.

[0118] The turbine engine of any of the preceding clauses, wherein the center body includes a nozzle cover and a set of fuel orifices in the nozzle cover configured to emit the swirled fuel flow.

[0119] The turbine engine of any of the preceding clauses, further comprising a third fuel nozzle in the center body fluidly coupling a first fuel passage in the first fuel nozzle to the inner annular passage.

[0120] The turbine engine of any of the preceding clauses, further comprising a cooling aperture in the shroud downstream of the annular swirler and fluidly coupled to the mixing chamber.

[0121] A combustor for a turbine engine, comprising: a combustor liner at least partially defining a combustion chamber; and a fuel premixer fluidly coupled to the combustion chamber and comprising: an annular shroud defining an interior having a mixing chamber; a center body within the interior and having a first fuel nozzle; and an annular swirler within the interior, encircling the center body, wherein the annular swirler is spaced apart from the shroud to define an outer annular passage, and further spaced apart from the center body to define an inner annular passage, wherein: the outer annular passage is configured to emit a first non-swirled gas flow into the mixing chamber as a first gas film along the shroud; the inner annular passage is configured to emit a second non-swirled gas flow into the mixing chamber as a second gas film positioned along the center body; the annular swirler is configured to emit a swirled gas flow into the mixing chamber between the first non-swirled gas flow and the second non-swirled gas flow; and the first fuel nozzle is configured to emit at least one of a fuel flow or an air flow into the mixing chamber.

[0122] The combustor of any of the preceding clauses, further comprising a set of second fuel nozzles configured to emit a second fuel flow into the swirled gas flow.

[0123] The combustor of any of the preceding clauses, wherein the annular swirler includes a set of vanes, wherein the set of second fuel nozzles are positioned on the set of vanes.

[0124] The combustor of any of the preceding clauses, further comprising a second fuel passage within the interior and having the set of second fuel nozzles.

[0125] A method of mixing fuel in a combustor of a turbine engine, the method comprising: emitting a first non-swirl flow of air into a mixing chamber within the combustor; emitting a second non-swirl flow of air into the mixing chamber and spaced apart from the first non-swirl flow of air; emitting a first swirl flow of air into the mixing chamber between the first non-swirl flow of air and the second non-swirl flow of air; and emitting a first fuel flow into the combustor adjacent the second non-swirl flow of air.

[0126] The method of any of the preceding clauses, wherein the first fuel flow is swirled.

[0127] The method of any of the preceding clauses, further comprising emitting a second fuel flow into the first swirl flow of air.

[0128] The method of any of the preceding clauses, wherein the second fuel flow is non-swirled.

[0129] The method of any of the preceding clauses, wherein the second fuel flow is emitted from at least one vane of a swirler.

[0130] The method of any of the preceding clauses, wherein the second fuel flow is emitted from a fuel orifice upstream of a trailing edge of the at least one vane.

[0131] A combustor for a turbine engine, comprising: a combustor liner at least partially defining a combustion chamber; and a fuel premixer fluidly coupled to the combustion chamber and comprising: an annular shroud defining an interior having a mixing chamber; a centerbody within the interior and having a first fuel nozzle to emit fuel into the mixing chamber; and an annular swirler within the interior, encircling the centerbody, wherein the swirler is spaced apart from the shroud to define an outer annular passage and is also spaced apart from the centerbody to define an inner annular passage, wherein the outer annular passage is configured to emit a first non-swirl flow of air as a first air film positioned along the shroud into the mixing chamber; the inner annular passage is configured to emit a second non-swirl flow of air as a second air film positioned along the centerbody into the mixing chamber; the swirler is configured to emit a swirl flow of air into the mixing chamber between the first non-swirl flow of air and the second non-swirl flow of air; and the first fuel nozzle is configured to emit at least one of a fuel flow or an air flow into the mixing chamber.

[0132] The combustor of any of the preceding clauses, further comprising a second fuel nozzle configured to emit a second fuel flow into the swirl flow of air.

[0133] The combustor of any of the preceding clauses, wherein the annular swirler comprises a set of vanes, wherein the set of second fuel nozzles are positioned on the set of vanes.

[0134] The combustor of any of the preceding clauses, further comprising a second fuel passage located within the interior and having the second fuel nozzles.

[0135] The combustor of any of the preceding clauses, wherein the second fuel passage extends to at least one outlet on at least one wall of the annular swirler, wherein the at least one outlet fluidly couples the second fuel passage to at least one of the inner annular passage or the outer annular passage.

[0136] The combustor of any of the preceding clauses, wherein the first fuel nozzles are configured to emit the flow of air as a second swirling flow into the mixing chamber.

[0137] The combustor of any of the preceding clauses, wherein the second fuel nozzles are configured to emit the flow of second fuel into the first swirling flow.

[0138] A method of mixing fuel in a combustor of a turbine engine, the method comprising: emitting a first non-swirling flow of air into a mixing chamber within the combustor; emitting a second non-swirling flow of air into the mixing chamber and spaced apart from the first non-swirling flow of air; between the first non-swirling flow of air and the second non-swirling flow of air, emitting a first swirling flow of air into the mixing chamber; and emitting a first flow of fuel into the combustor adjacent the second non-swirling flow of air.

[0139] The method of any of the preceding clauses, wherein the first flow of fuel is swirling.

[0140] The method of any of the preceding clauses, further comprising emitting a second flow of fuel into the first swirling flow of air.

[0141] The method of any of the preceding clauses, wherein the second flow of fuel is non-swirling.

[0142] The method of any of the preceding clauses, wherein the second flow of fuel is emitted from at least one vane of a swirler.

[0143] The method of any of the preceding clauses, wherein the second flow of fuel is emitted from a fuel orifice upstream of a trailing edge of the at least one vane.

[0144] A turbine engine including a compressor section, a combustion section, and a turbine section in a serial flow arrangement, and the combustion section having a combustor with a fuel premixer including an annular shroud defining an interior with a mixing chamber, a center body within the interior and having a first fuel nozzle that emits fuel into the mixing chamber, an annular swirler within the interior, annular about the center body, an outer annular passage defined between the annular swirler and the annular shroud, and an inner annular passage defined between the center body and the annular swirler.

[0145] The turbine engine according to any of the preceding clauses, further including a first non-swirling air flow emitted from the outer annular passage into the mixing chamber and forming a first air film positioned along the shroud.

[0146] The turbine engine according to any of the preceding clauses, further including a second non-swirling air flow emitted from the inner annular passage into the mixing chamber and forming a second air film positioned along the center body.

[0147] The turbine engine according to any of the preceding clauses, further including a swirling air flow emitted from the annular swirler into the mixing chamber between the first non-swirling air flow and the second non-swirling air flow.

[0148] The turbine engine according to any of the preceding clauses, further including a third non-swirling air flow that flows through the annular swirler and forms the swirling air flow.

[0149] The turbine engine according to any of the preceding clauses, further including a swirling fuel flow emitted from the first fuel nozzle into the mixing chamber.

[0150] The turbine engine according to any of the preceding clauses, further including a second swirling air flow emitted from the first fuel nozzle into the mixing chamber.

Claims

1. A turbine engine, characterized in that, include: A compressor section, a combustion section, and a turbine section are arranged in a series flow configuration, wherein the combustion section has a combustor with a fuel premixer, the fuel premixer comprising: An annular shield defining an interior having a mixing chamber; A central body, located within the interior, having a first fuel nozzle for ejecting fuel into the mixing chamber; and An annular cyclone is located within the interior, surrounding the central body, wherein the annular cyclone is spaced apart from the shroud to define an outer annular channel, and also spaced apart from the central body to define an inner annular channel, wherein: The outer annular channel is configured to launch a first non-swirling airflow as a first air film positioned along the shield into the mixing chamber; The inner annular channel is configured to launch a second non-swirling airflow as a second air film positioned along the central body into the mixing chamber; The annular cyclone separator is configured to inject swirling airflow into the mixing chamber between the first and second non-swirling airflows; and The first fuel nozzle is configured to deliver a swirling fuel stream into the mixing chamber.

2. The turbine engine according to claim 1, characterized in that, It further includes a set of second fuel nozzles configured to deliver a second fuel stream into the swirling airflow.

3. The turbine engine according to claim 2, characterized in that, It further includes a second fuel passage located within the interior and fluidly connected to the set of second fuel nozzles.

4. The turbine engine according to claim 3, characterized in that, The annular cyclone includes a set of blades, and a set of second fuel nozzles is positioned on the set of blades.

5. The turbine engine according to claim 4, characterized in that, The set of blades includes a trailing edge, wherein the second fuel passage is located downstream or upstream of the trailing edge.

6. The turbine engine according to claim 4, characterized in that, The second fuel passage extends to at least one outlet on at least one wall of the annular cyclone, wherein the at least one outlet fluidly connects the second fuel passage to at least one of the inner annular channel or the outer annular channel.

7. The turbine engine according to claim 4, characterized in that, The second fuel passage extends into the wall of the annular cyclone, wherein a set of second fuel nozzles is configured to eject the second fuel stream outside the annular cyclone.

8. The turbine engine according to any one of claims 1-4, characterized in that, The central body includes a nozzle cap and a set of fuel orifices in the nozzle cap, the set of fuel orifices being configured to emit the swirling fuel stream.

9. The turbine engine according to any one of claims 1-4, characterized in that, It further includes a third fuel nozzle in the central body, the third fuel nozzle fluidly connecting the first fuel passage in the first fuel nozzle to the inner annular passage.

10. The turbine engine according to any one of claims 1-4, characterized in that, It further includes cooling pores in the shroud, which are downstream of the annular cyclone and fluidly connected to the mixing chamber.

11. A combustor for a turbine engine, characterized in that, include: A burner liner that at least partially defines a combustion chamber; and A fuel premixer, fluidly connected to the combustion chamber and comprising: An annular shield defining an interior having a mixing chamber; A central body, located within the interior and having a first fuel nozzle; and An annular cyclone is located within the interior, surrounding the central body, wherein the annular cyclone is spaced apart from the shroud to define an outer annular channel, and also spaced apart from the central body to define an inner annular channel, wherein: The outer annular channel is configured to emit a first non-swirling airflow as a first air film along the shield into the mixing chamber; The inner annular channel is configured to launch a second non-swirling airflow as a second air film positioned along the central body into the mixing chamber; The annular cyclone separator is configured to inject swirling airflow into the mixing chamber between the first and second non-swirling airflows; and The first fuel nozzle is configured to inject at least one of a fuel stream or an air stream into the mixing chamber.

12. The burner according to claim 11, characterized in that, It further includes a set of second fuel nozzles configured to deliver a second fuel stream into the swirling airflow.

13. The burner according to any one of claims 11-12, characterized in that, The annular cyclone includes a set of blades, and a set of second fuel nozzles is positioned on the set of blades.

14. The burner according to claim 12, characterized in that, It further includes a second fuel passage located within the interior and having the set of second fuel nozzles.

15. A method for mixing fuel in the combustor of a turbine engine, characterized in that, The method includes: The first non-swirling gas flow is launched into the mixing chamber within the burner; A second non-swirling airflow is launched into the mixing chamber and spaced apart from the first non-swirling airflow; Between the first non-swirling airflow and the second non-swirling airflow, the first swirling airflow is injected into the mixing chamber; and The adjacent second non-swirling airflow launches the first fuel stream into the burner.

16. The method according to claim 15, characterized in that, The first fuel stream is a swirling stream.

17. The method according to claim 16, characterized in that, It further includes launching a second fuel stream into the first swirling gas stream.

18. The method according to claim 17, characterized in that, The second fuel stream is non-swirling.

19. The method according to claim 17, characterized in that, The second fuel stream is emitted from at least one blade of the cyclone separator.

20. The method according to claim 19, characterized in that, The second fuel stream is emitted from a fuel orifice upstream of the trailing edge of the at least one blade.

Images