Fuel nozzles and swirlers

Abstract

An engine may utilize a burner to combust fuel to drive the engine. A fuel nozzle assembly may supply fuel to the burner for combustion or ignition of the fuel. The fuel nozzle assembly may include a swirler and a fuel nozzle to supply a fuel and air mixture for combustion, which may supply a primary fuel supply and a secondary fuel supply. Increased efficiency and reduced emissions require the use of alternative fuels that burn at higher temperatures or at faster burn rates than conventional fuels, requiring improved fuel introduction without flame holding or flashback.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Indian Provisional Patent Application No. 202111059707, filed on December 21, 2021, and U.S. Patent Application No. 17 / 682,373, filed on February 28, 2022, both of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present subject matter generally relates to a combustor for a turbine engine having one or both of a fuel nozzle and a swirler. Background Art

[0004] An engine, such as a turbine engine including a turbine, is driven by the combustion of a combustible fuel within the engine's combustor. The engine utilizes a fuel nozzle to inject the combustible fuel into the combustor. A swirler provides mixing of the fuel and air for efficient combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] In the description with reference to the accompanying drawings, a full and enabling disclosure of the present disclosure, including the best mode thereof, is set forth to those skilled in the art, wherein:

[0006] Figure 1 is a schematic cross-sectional view of an engine according to an exemplary embodiment of the present disclosure.

[0007] Figure 2 is a method for implementing an exemplary embodiment of the present disclosure Figure 1 Schematic cross-sectional view of a burner of an engine.

[0008] Figure 3 is a cross-sectional view of a fuel nozzle assembly including a swirler having a separator with a fuel passage having an outlet on a radially outer surface of the separator according to an exemplary embodiment of the present disclosure.

[0009] Figure 4 is a cross-sectional view of another fuel nozzle assembly including a swirler having a separator with a fuel passage having an outlet on a radially inner surface of the separator according to an exemplary embodiment of the present disclosure.

[0010] Figure 5 is a cross-sectional view of another fuel nozzle assembly including a swirler having a separator with a fuel passage having outlets on both a radially outer surface and a radially inner surface according to an exemplary embodiment of the present disclosure.

[0011] Figure 6is a cross-sectional view of yet another fuel nozzle assembly including a fuel nozzle having nozzle wall passages with external outlets that discharge into a swirler, according to an exemplary embodiment of the present disclosure.

[0012] Figure 7 is a cross-sectional view of yet another fuel nozzle assembly including a fuel nozzle having nozzle wall passages with an outer outlet that discharges to a swirler and an inner outlet that discharges within the fuel nozzle according to an exemplary embodiment of the present disclosure.

[0013] Figure 8 is a cross-sectional view of a fuel nozzle assembly having an axial swirler with fuel passages extending through the axial vanes of the axial swirler according to an exemplary embodiment of the present disclosure.

[0014] Figure 9 is a cross-sectional view of a fuel nozzle assembly having a radial swirler with fuel passages extending through the vanes of the radial swirler according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0015] Aspects disclosed herein are directed to fuel nozzles and swirler structures located within engine components, and more specifically, to fuel nozzle structures configured for use with fuels operating at elevated combustion temperatures and combustion velocities (such as hydrogen or hydrogen-based fuels), which can provide reduced NOx or carbon emissions. Efficiency and emission requirements require fuels that burn hotter and faster than conventional fuels. Such fuels can present challenges associated with flame holding or flashback due to the higher flame speeds of high-temperature fuels. Existing burners include durability risks when using high-temperature fuels due to flame holding or flashback on burner components. For illustrative purposes, the present disclosure will be described with respect to turbine engines, while other residential or commercial applications are contemplated.

[0016] Reference will now be made in detail to fuel nozzle and swirler architectures, and in particular to fuel nozzle and swirler architectures for use with engines, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and the description have been used to refer to like or similar parts of the disclosure.

[0017] The word "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 preferred or advantageous over other implementations. Furthermore, all embodiments described herein are to be considered exemplary unless expressly stated otherwise.

[0018] The terms "front" and "rear" refer to relative positions within an engine or vehicle and refer to the normal operating attitude of the engine or vehicle. For example, with respect to a turbine engine, front refers to a position closer to the engine inlet, and rear refers to a position closer to the engine nozzle or exhaust.

[0019] As used herein, the term "upstream" refers to a direction opposite to the direction of fluid flow, while the term "downstream" refers to a direction in the same direction as the direction of fluid flow. The terms "forward" or "front" mean in front of something, and "rearward" or "rear" mean behind something. For example, when used in relation to fluid flow, forward / front can refer to upstream, and rearward / rear can refer to downstream.

[0020] The term "fluid" may be a gas or a liquid. The term "fluid communication" means that a fluid is able to establish a connection between designated areas.

[0021] The terms "front" and "rear" refer to relative positions within an engine or vehicle and refer to the normal operating attitude of the engine or vehicle. For example, with respect to a turbine engine, front refers to a position closer to the engine inlet, and rear refers to a position closer to the engine nozzle or exhaust.

[0022] The term "flame holding" relates to a condition of continued combustion of fuel such that a flame is maintained along or near a component, and typically along or near a portion of a fuel nozzle assembly as described herein, and "flashback" relates to the retreat of a combustion flame in an upstream direction.

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

[0024] All directional references (e.g., radial, axial, proximal, distal, up, down, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, front, rear, etc.) are for identification purposes only to assist the reader in understanding the present disclosure and do not impose limitations, particularly with respect to the position, orientation, or use of the disclosed aspects described herein. Connection references (e.g., attach, couple, connect, and join) are to be interpreted broadly and may include intermediate structural elements between a collection of elements and relative movement between elements, unless otherwise indicated. Thus, a connection reference does not necessarily mean that two elements are directly connected and fixed relative to each other. The exemplary figures are for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the accompanying figures may vary.

[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 group of" elements may refer to any number of elements, including only one.

[0026] As used herein throughout the specification and claims, approximating language is applied to modify any quantitative representation that can be allowed to vary without causing its related basic function to change. Therefore, the value modified by one or more terms such as "approximately", "approximately", "substantially" is not limited to the specified exact value. In at least some cases, approximate language can correspond to the accuracy of the instrument used to measure the value, or the accuracy of the method or machine used to construct or manufacture components and / or systems. For example, approximate language can refer to a margin of 1%, 2%, 4%, 5%, 10%, 15% or 20% of the endpoint of a single value, a range of values ​​and / or a range of limited values. Here and throughout the specification and claims, range limitations are combined and interchanged, and such ranges are identified and include all subranges contained therein, unless the context or language indicates otherwise. For example, all ranges disclosed herein include endpoints, and the endpoints can be combined independently of each other.

[0027] The combustor introduces fuel from the fuel nozzle, which mixes with air provided by the swirler and then burns within the combustor to drive the engine. Increased efficiency and reduced emissions have driven the use of fuels that burn cleaner or at higher temperatures, which can also include increased combustion velocities. There is a need to improve the durability of the combustor under these operating parameters, such as improving flame control to prevent flame retention on the fuel nozzle and swirler components.

[0028] Figure 1 is a schematic diagram of a turbine engine 10. As a non-limiting example, the turbine engine 10 may be used within an aircraft. The turbine engine 10 may 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 so that rotation of one affects rotation of the other and defines an axis of rotation 20 of the turbine engine 10.

[0029] The compressor section 12 may include a low-pressure (LP) compressor 22 and a high-pressure (HP) compressor 24 fluidly coupled in series with each other. The turbine section 16 may include an LP turbine 28 and an HP turbine 26 fluidly coupled in series with each other. The drive shaft 18 may operably couple the LP compressor 22, the HP compressor 24, the LP turbine 28, and the HP turbine 26 together. Alternatively, the drive shaft 18 may include an LP drive shaft (not shown) and an HP drive shaft (not shown). The LP drive shaft may couple the LP compressor 22 to the LP turbine 28, and the HP drive shaft may couple the HP compressor 24 to the HP turbine 26. The LP spool may be defined as the combination of the LP compressor 22, the LP turbine 28, and the LP drive shaft, such that rotation of the LP turbine 28 may apply driving force to the LP drive shaft, which in turn may rotate the LP compressor 22. The HP spool may be defined as the combination of the HP compressor 24, the HP turbine 26, and the HP drive shaft, such that rotation of the HP turbine 26 may apply driving force to the HP drive shaft, which in turn may rotate the HP compressor 24.

[0030] The compressor section 12 may 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. The compressor blades for a stage of the compressor section 12 may be mounted to a disk, which is mounted to the drive shaft 18. Each set of blades for a given stage may have its own disk. The vanes of the compressor section 12 may be mounted to a casing, which may extend circumferentially around the turbine engine 10. It should be understood that the representation of the compressor section 12 is merely schematic and that there may be any number of stages. Further, it is contemplated that there may be any other number of components within the compressor section 12.

[0031] Similar to the compressor section 12, the turbine section 16 may 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 may be mounted to disks, which are mounted to the drive shaft 18. Each set of blades for a given stage may have its own disk. The vanes of the turbine section may be mounted to the casing in a circumferential manner. It should be noted that there may 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 may be any other number of components within the turbine section 16.

[0032] The combustion section 14 may be disposed in series between the compressor section 12 and the turbine section 16. The combustion section 14 may 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 may be fluidly coupled to the HP compressor 24 at an upstream end of the combustion section 14 and to the HP turbine 26 at a downstream end of the combustion section 14.

[0033] 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, where it is compressed, defining pressurized air. The pressurized air may then flow into the combustion section 14, where it is mixed with fuel and ignited, thereby generating combustion gases. The HP turbine 26 extracts some work from these combustion gases, which drives the HP compressor 24. The combustion gases are exhausted to the LP turbine 28, which extracts additional work to drive the LP compressor 22, and the exhaust gases are ultimately exhausted from the turbine engine 10 via an exhaust section (not shown) downstream of the turbine section 16. The drive of the LP turbine 28 drives the LP spool, which rotates the fan (not shown) and the LP compressor 22. Together, the pressurized airflow and the combustion gases may define the working airflow flowing through the fan, compressor section 12, combustion section 14, and turbine section 16 of the turbine engine 10.

[0034] Figure 2 Describes a suitable Figure 1 FIG3 is a cross-sectional view of a generic combustor 36 of a combustion section 14 of FIG3. The combustor 36 may include an annularly arranged fuel nozzle assembly 38 for supplying fuel to the combustor. It should be understood that the fuel nozzle assembly 38 may be organized, for example, in an annular arrangement including multiple fuel injectors. Depending on the type of engine in which the combustor 36 is located, the combustor 36 may have a can shape, a can annular shape, or an annular arrangement. The combustor 36 may include an annular inner combustor liner 40 and an annular outer combustor liner 42, and a dome assembly 44 including a dome 46 and a flow guide 48, which together define a combustion chamber 50 about a longitudinal axis 52. At least one fuel supply 54 is fluidly coupled to the combustion chamber 50 to supply fuel to the combustor 36. The fuel supply 54 may be disposed within the dome assembly 44, upstream of the flared cone 56, to define a fuel outlet 58. A swirler may be provided at the fuel nozzle assembly 38 to swirl the incoming air around the fuel exiting the fuel supply 54 and provide a uniform mixture of air and fuel entering the combustor 36.

[0035] Figure 3A fuel nozzle assembly 130 is shown, suitable for use as the fuel nozzle assembly 38 in the combustor 36, for example, including a fuel nozzle 132 having an outer wall 126 surrounding a fuel passage 124 defining a longitudinal axis 128, a swirler 134, and a flared cone 136. The fuel nozzle 132 may be a cylindrical conduit, although non-cylindrical conduits are contemplated, including a nozzle cover 138 preceding a nozzle tip 140. The nozzle cover 138 may include a set of openings 142 that may or may not impart a swirl or tangential component to the fuel discharged from the nozzle tip 140. As shown, the openings 142 are tangentially oriented so that they appear to terminate within the cover 138, however, it should be understood that the openings 142 extend completely through the cover 138 so that fuel can pass through the openings 142. The nozzle cover 138 may be spaced apart from the nozzle tip 140. This spacing provides for a stable axial component of the fuel supplied from the fuel passage 124 prior to discharge from the nozzle tip 140. The fuel nozzle 132 and swirler 134 may be coupled together or formed as a single unitary component, such as by additive manufacturing.

[0036] The swirler 134 may be annular, surrounding the fuel nozzle 132, and may include an air passage 144 extending from an inlet 146 to an outlet 148. A set of vanes 150 are circumferentially arranged within the air passage 144 to impart a swirl or tangential component to the airflow passing through the air passage 144. The vanes 150 may extend between a leading wall 152 and an aft wall 154.

[0037] Splitter 156 extends from vanes 150 in a downstream direction. Splitter 156 can separate air passage 144 into a radially outer passage 158 and a radially inner passage 160. It should be understood that swirler 134 can alternatively be described as two sets of swirlers, with a first swirler defined between front wall 152 and splitter 156, and a second swirler defined between splitter 156 and rear wall 154. The first swirler can include different angles for the vanes within the first swirler, as opposed to the vanes of the second swirler, which can be used to define different velocity profiles along different portions of the swirler. Additionally, radially inner passage 160 and radially outer passage 158, or the first swirler and the second swirler, can be sized differently to provide different velocities at the passage exits while reducing or eliminating flow separation.

[0038] A fuel passage 170 extends through the wall of the fuel nozzle 132 and into the front wall 152 of the swirler 134. In one example, the fuel passage 170 may be an annular passage, although it is contemplated that the fuel passage 170 may be arranged as a set of discrete passages in an annular arrangement. In a non-limiting example, the fuel passage 170 or discrete fuel passages may have any cross-sectional shape, such as a circular or elliptical shape. The fuel passage 170 may further extend through the vanes 150 at the front wall 152 and then extend through the vanes 150 into the separator 156. The fuel passage 170 may discharge into the radially outer passage 158 at an outlet 172. Although an inlet is not shown, the fuel passage 170 may be supplied from a fuel source shared with the fuel nozzle 132, or even directly from the fuel nozzle 132, or the fuel passage 170 may be supplied from a separate fuel manifold that is separate from or shared with the main fuel supply to the fuel nozzle 132.

[0039] The fuel nozzle 132 may define a primary fuel circuit, while the fuel passage 170 may define a secondary fuel circuit. The primary fuel circuit may provide a swirling fuel flow from the nozzle tip 140, and the secondary fuel circuit may provide a non-swirling fuel flow, with either swirling or non-swirling flow contemplated for any of the primary fuel supply, the secondary fuel supply, the radially outer passage 158, and the radially inner passage 160. The swirling flow at the nozzle tip 140 may provide for reducing or eliminating flashback or flame holding at the nozzle tip 140, while the non-swirling fuel flow may provide for limited radial dispersion of the fuel while maintaining the primary fuel flow centrally. The swirling flow may further enable the generation and maintenance of a stable flame in the combustor while avoiding flashback, while the secondary fuel flow may provide for better control of the radial supply of fuel, which may reduce or eliminate flame holding or flame scrubbing on the flared cone or combustor liner. Additionally, the air provided in the radially outer passage 158 directs the fuel away from the flared cone 136 while still providing increased fuel dispersion. Improved fuel distribution and control thereof in the primary zone of the combustor results in greater fuel mixing, thereby leading to reduced NOx or carbon emissions.

[0040] It is further contemplated that the outlet 172 may be arranged at an angle 174 relative to the surface of the separator 156 at the outlet 172. More specifically, in one example, the angle may be defined relative to a line or plane 178 between a longitudinal axis 176 defined along the outlet 172, the line or plane 178 being perpendicular to a line or plane passing through the surface defined by the outlet 172. In one example, the angle may be oriented in a downstream direction relative to the air flow within the swirler 134. In one example, the angle may be between 10 and 70 degrees, with a wider range of angles contemplated, or even angular orientations in an upstream direction, a circumferential direction, a tangential direction, or a combination thereof. In one example, the outlet 172 may include a tangential component so that the fuel discharged from the outlet 172 is aligned with the swirling air from the swirler 134. It will be appreciated that customizing the outlet angle for the secondary fuel supply may be used to influence or limit the influence on the swirling airflow. For example, injecting the fuel at a higher angle may provide increased radial dispersion of the fuel and increased turbulence for improved mixing. Injecting the secondary fuel at a lower angle may provide reduced shear, which may limit radial spread of the fuel and reduce flame scrubbing on the combustor liner. Furthermore, directing the injection at a tangential angle may further reduce shear relative to the swirling airflow from the swirler 134.

[0041] Figure 4 An alternative fuel nozzle assembly 200 is shown defining a longitudinal axis 216 that may be used with Figure 3 The fuel nozzle assembly 130 is substantially similar to the fuel nozzle assembly 130, wherein the fuel nozzle assembly 200 includes an annular secondary fuel circuit 202 including an outlet 204 on an inner surface 206 of a separator 208. The fuel injection from the inner surface 206 provides a greater radial spread of the fuel than using the primary fuel supply alone, while the primary fuel discharged from the fuel nozzle 210 reduces flame holding and flashback and provides fuel along the centerline of the fuel nozzle assembly 200. Figure 3 Similar to the example in FIG. , the swirling flow can further allow for the generation and maintenance of a stable flame in the combustor while avoiding flashback, while the secondary fuel flow can provide for better control of the radial supply of fuel, which can reduce or eliminate flame holding or flame scrubbing on the flared cone or combustor liner. The airflow within the radial outer passage 212 directs the secondary fuel discharged from the outlet 204 away from the flared cone 214, providing a greater volume of air discharged from the swirler between the flared cone 214 and the secondary fuel supply, which can increase the durability of the flared cone. It is also contemplated that the outlet 204 can be disposed on the outer surface 218 of the separator 208.

[0042] Figure 5Another alternative fuel nozzle assembly 230 is shown that can be used with Figure 3 and 4 The fuel nozzle assemblies 130, 200 are substantially similar, with the fuel nozzle assembly 230 including a secondary fuel passage 232 having a first outlet 234 on an exterior surface 236 of a separator 238 and a second outlet 240 on an interior surface 242 of the separator 238. As such, the secondary fuel passage 232 may be split or otherwise separated to supply both the first and second outlets 234, 240.

[0043] Injecting fuel on both the inner and outer portions of the separator 238 provides further fuel spreading for the secondary flow while maintaining a high velocity profile along the central fuel nozzle passage 244, which can reduce flame holding and flashback while providing increased radial fuel spreading. The increased fuel spreading in the primary combustion zone increases uniform fuel distribution and reduces NOx emissions while lowering component temperatures by reducing flame holding or flashback.

[0044] It should be understood that the outlets 234, 240 may be aligned or misaligned relative to the axial extent or circumferential direction of the fuel nozzle assembly 230. Furthermore, the outlets 234, 240 may be staggered relative to one another, such as axially, radially, or circumferentially. It is further contemplated that the outlets may be arranged in circumferential rows relative to the circumferential arrangement of the separator 238, with the outlets being formed as circumferential slots or a series of slots formed in the separator 238. It is further contemplated that more than two groups of outlets may be used, such that any number of outlets in any arrangement is contemplated. Furthermore, the outlets may be arranged in multiple groups of rows while being constrained by the radially outer wall or the radially inner wall of the swirler, with further combinations contemplated. Different outlet arrangements may be used to control different fuel spread profiles, velocity profiles, or combinations thereof, which may be used to increase radial fuel spread while minimizing or eliminating the occurrence of flame holding or flashback on the fuel nozzle assembly 230. For example, the outlets 234, 240 may discharge with a tangential component that can be tailored to the local swirl from the swirler.

[0045] Figure 6 Another exemplary fuel nozzle assembly 270 is shown that includes a fuel nozzle 272 and a swirler 274. The swirler 274 may include a separator 276 that divides a swirler air passage 278 into a radially inner passage 280 and a radially outer passage 282, wherein the radially inner passage 280 is adjacent to a front wall 284 and the radially outer passage 282 is adjacent to an aft wall 286. The front wall 284 includes a foot 287 that extends along the fuel nozzle 272 as the swirler 274 turns from a radial direction to an axial direction.

[0046] Fuel nozzle wall passages 288 may extend through wall 290 of fuel nozzle 272 and discharge at outlet 292. Fuel nozzle wall passages 288 may discharge through an exterior surface of fuel nozzle wall 290 or through the exterior surface and into foot 287, discharging into radially inner passage 280.

[0047] Figure 7 Yet another exemplary fuel nozzle assembly 300 is shown including a fuel nozzle 302 and a swirler 304. A fuel nozzle wall passage 306 may extend through a wall 308 of the fuel nozzle 302. The fuel nozzle wall passage 306 may include a set of inner outlets 310 that discharge into the fuel nozzle 302 behind a nozzle cover 314, while a set of outer outlets 312 discharge into a swirler air passage 316.

[0048] about Figure 6-7 It will be appreciated that a secondary fuel passageway may be provided within the wall of the primary fuel nozzle. The outlet for discharging the secondary fuel may be internal to the fuel nozzle, external to the fuel nozzle, or both. The radially outer outlet 312 provides for discharging the secondary fuel, which may improve restricted fuel distribution. The radially inner outlet 310 may impinge upon the primary fuel stream, which may focus and maintain the primary fuel stream, thereby providing reduced flame holding along the tip of the fuel nozzle 302. The radially inner outlet 310 may provide additional localized control of fuel distribution between the primary fuel supply via the fuel nozzle 272 and the swirler 274, and may expand the operating range of the fuel supply without increasing the size of the fuel nozzle 272.

[0049] Regarding the outlet on the interior of the fuel nozzle, the outlet can be positioned downstream of the nozzle cover so that the secondary fuel flow is imparted to the primary fuel flow after the nozzle cover has acted on the primary fuel flow (such as imparting a swirl component to the flow). Similarly, it is contemplated that the outlet from the secondary fuel nozzle can have a tangential component so that the secondary fuel is imparted with a swirl or tangential component that can be in the same direction as the primary fuel flow, which can reduce shear between the two flows. Similarly, the external outlet can include a tangential component that is in the same direction as the swirler airflow or opposite to the airflow to improve radial fuel dispersion.

[0050] It should be further understood that Figure 6-7 The secondary fuel channel can be connected with Figure 3-5 The secondary fuel passages may be combined or integrated such that there are multiple secondary fuel passages or circuits, with multiple outlet locations or arrangements, or a combination thereof.

[0051] Figure 8Another arrangement of a fuel nozzle assembly 330 is schematically shown, comprising a swirler 332 positioned around a fuel nozzle 334. The swirler 332 can be either an axial swirler that receives an axial air supply and imparts a tangential component to the axial supply, or a radial swirler that receives a radial air supply and turns the air into an axial orientation, imparting a tangential component. It should be understood that the fuel nozzle 334 can be a cylindrical supply duct, only a portion of which is shown in the cross-sectional view. The swirler 332 includes a set of circumferentially arranged axial vanes 336 dedicated to axial swirling and a set of circumferentially arranged radial vanes 338 dedicated to radial swirling, although arrangements without radial vanes are contemplated. It should be understood that the swirlers described herein can be either or both axial and radial swirlers.

[0052] The secondary fuel passage 340 can extend through the axial vanes 336 and discharge into the airflow passage 342 downstream of the radial vanes 338. The secondary fuel can be injected into the airflow passage 342 at an angle such that the longitudinal axis defined by the secondary fuel passage 340 at the outlet 344 is offset from perpendicular to the wall of the swirler 332 at the outlet 344. It should be understood that while two flow paths are shown for the outlet 344, with two different injection angles, only one outlet, or more additional outlets than shown, as well as any variation in injection angles are possible. It should be further understood that, in non-limiting examples, any outlet arrangement is contemplated, such as aligned rows or groups, offset rows or groups, or other arrangements, and the outlets can have axial, radial, or tangential components.

[0053] The angled injection can provide for spreading the secondary fuel supply into the airflow while minimizing any flow disruption caused by the injection. In addition, the injection can include a tangential or circumferential component so that the secondary fuel supply is aligned with the swirl of the airflow within the airflow channel 342. The swirl imparted to the secondary fuel supply can be minimal, which can provide an increased velocity component along the front wall, thereby reducing or eliminating flashback or flame holding along the fuel nozzle or fuel nozzle tip. In addition, the inner axial swirler with a lower swirl component can produce a high axial velocity component on both swirler channels, which can eliminate flame holding on both the flared cone and the fuel nozzle or swirler. The relative swirl between the radial swirler and the axial swirler can improve the control of turbulence in the primary zone of the combustor to increase uniform mixing of the fuel and air, which results in a uniform temperature distribution in the primary zone, thereby reducing NOx emissions. It is further contemplated that the axial vanes can produce higher swirl than the swirler to increase mixing with the primary fuel supply. It is further contemplated that the radial and axial vanes may have equal or opposite swirl, which may provide a balance between reducing flame holding and reducing NOx emissions.

[0054] Figure 9 Another exemplary fuel nozzle assembly 360 is shown, including a fuel nozzle 362 and a swirler 364. The swirler 364 includes a front wall 366 and an aft wall 368, with a set of circumferentially arranged vanes 370 extending between the front wall 366 and the aft wall 368. A secondary fuel passage 372 may extend radially outward relative to the fuel nozzle 362 into the front wall 366. The secondary fuel passage 372 may then pass through the vanes 370 and into the aft wall 368. The secondary fuel passage 372 may extend through the aft wall 368 in a downstream direction relative to the flow through the swirler 364. The secondary fuel supply may be injected through an outlet 374, which may be arranged perpendicular to the aft wall 368 or may be arranged at an angle relative to the vertical, such as with an axially aft angle or a tangential component, to impart a swirl component to the secondary fuel supply, which may be co-swirling or counter-swirling with the air supply from the swirler 364. Injecting fuel from the radially outer aft wall 368 provides increased fuel spread while maintaining the primary fuel supply centered.

[0055] It should be understood that fuels with higher combustion temperatures and higher combustion velocities, or lighter weight relative to air or other fuels, can provide reduced or eliminated emissions, or improve efficiency without increasing emissions. In one example, hydrogen fuel or hydrogen-based fuels can be used, which can eliminate carbon emissions without negatively impacting efficiency. Such fuels, including hydrogen, require better flame control to prevent flame holding or flashback on the burner hardware. The various aspects described herein can increase burner durability, which current burners cannot provide using such fuels.

[0056] It should be understood that the examples used herein are not specifically limited to those shown, and those skilled in the art should understand that aspects from one or more examples may be mixed with one or more aspects from other examples to define examples that may differ from those shown.

[0057] 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 may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they 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 language of the claims.

[0058] Further aspects are provided by the subject matter of the following clauses, a turbine engine comprising: a compressor section, a combustor section, and a turbine section in a serial flow arrangement, the combustor section including a fuel nozzle assembly, the fuel nozzle assembly comprising: a fuel nozzle including an outer wall surrounding a fuel passage and defining a longitudinal axis; a swirler surrounding the fuel nozzle and defining a swirler passage; a set of vanes disposed within the swirler passage; and a secondary fuel passage extending at least partially within the swirler.

[0059] Turbine engine according to any of the preceding clauses, wherein the secondary fuel passage comprises an outlet at the swirler passage.

[0060] Turbine engine according to any of the preceding clauses, wherein the swirler comprises a front wall and a rear wall.

[0061] A turbine engine according to any of the preceding clauses, wherein the outlet is provided on the rear wall.

[0062] Turbine engine according to any of the preceding clauses, wherein the secondary fuel passage passes through the leading wall and at least one vane of the set of vanes to be fluidly coupled to the outlet on the trailing wall.

[0063] Turbine engine according to any of the preceding clauses, further comprising a separator dividing the swirler channel into a radially outer channel and a radially inner channel.

[0064] Turbine engine according to any of the preceding clauses, wherein the secondary fuel passage extends through the separator.

[0065] A turbine engine according to any of the preceding clauses, wherein the outlet is provided on the separator.

[0066] A turbine engine according to any of the preceding clauses, wherein the outlet discharges into both the radially inner passage and the radially outer passage.

[0067] Turbine engine according to any of the preceding clauses, wherein the fuel passage is configured to supply hydrogen or a hydrogen-based fuel.

[0068] Turbine engine according to any of the preceding clauses, wherein the secondary fuel passage passes through the outer wall of the fuel nozzle.

[0069] A turbine engine according to any of the preceding clauses, wherein the secondary fuel passage comprises a tangential aspect, arranged at least partially tangentially to a radius extending from the longitudinal axis, configured to impart swirl to a secondary fuel supply through the secondary fuel passage.

[0070] A turbine engine according to any of the preceding clauses, wherein the swirler is a radial swirler; wherein the fuel nozzle assembly further comprises an axial swirler having a set of axial vanes; and wherein the secondary fuel passage passes through the set of axial vanes.

[0071] A turbine engine according to any of the preceding clauses, wherein the secondary fuel passages are arranged as a plurality of secondary fuel passages in an annular arrangement around the fuel nozzle assembly.

[0072] Turbine engine according to any of the preceding clauses, wherein the secondary fuel passage extends through the set of blades.

[0073] A fuel nozzle assembly includes: a fuel nozzle including an outer wall surrounding a fuel passage and defining a longitudinal axis; an annular swirler surrounding the fuel nozzle and defining a swirler passage; a set of vanes disposed within the swirler passage; and a secondary fuel passage extending at least partially through the outer wall of the fuel nozzle.

[0074] A fuel nozzle assembly according to any of the preceding clauses, wherein the secondary fuel passage comprises an outlet at the swirler passage.

[0075] A fuel nozzle assembly according to any of the preceding clauses, wherein the secondary fuel passage comprises a second outlet at the fuel passage.

[0076] A fuel nozzle assembly according to any of the preceding clauses, wherein the fuel nozzle comprises a nozzle cover having a set of openings, and wherein the outlet at the fuel passage is arranged downstream of the nozzle cover relative to a flow direction through the fuel passage.

[0077] A method of injecting fuel into a fuel nozzle assembly includes discharging a primary fuel flow through a fuel nozzle and providing a secondary fuel flow through a secondary fuel passage and discharging the secondary fuel flow through the secondary fuel passage.

[0078] A method according to any of the preceding clauses, wherein the secondary fuel passage at least partially passes through the swirler.

[0079] A method according to any of the preceding clauses, wherein the secondary fuel passage at least partially passes through the fuel nozzle.

[0080] A turbine engine comprising: a compressor section, a combustor section, and a turbine section in a serial flow arrangement, the combustor section including a fuel nozzle assembly, the fuel nozzle assembly comprising: a fuel injector terminating in a fuel tip; a first swirler including a first swirler passage having a first outlet adjacent to and surrounding the fuel tip, and a first set of vanes within the first swirler passage; and a second swirler including a second swirler passage having a second outlet adjacent to and surrounding the first outlet, and a second set of vanes within the second swirler passage; wherein the first set of vanes imparts a first tangential swirl velocity to a flow passing through the first outlet, and the second set of vanes imparts a second tangential swirl velocity to a flow passing through the second outlet, the second tangential flow velocity being greater than the first tangential flow velocity.

[0081] A turbine engine comprises: a compressor section, a combustor section, and a turbine section in a serial flow arrangement, the combustor section including a fuel nozzle assembly, the fuel nozzle assembly comprising: a fuel nozzle including an outer wall surrounding a fuel passage and defining a longitudinal axis; a swirler surrounding the fuel nozzle and defining a swirler passage; and a secondary fuel passage.

[0082] Turbine engine according to any of the preceding clauses, wherein the secondary fuel passage extends through the swirler.

[0083] Turbine engine according to any of the preceding clauses, wherein the secondary fuel passage passes through the outer wall of the fuel nozzle.

[0084] Turbine engine according to any of the preceding clauses, wherein the secondary fuel passage comprises a second outlet along the outer wall.

[0085] Turbine engine according to any of the preceding clauses, wherein the second outlet is formed as a set of outlets arranged both on the outer surface of the outer wall and on the inner surface of the outer wall.

[0086] A turbine engine comprises: a compressor section, a combustor section, and a turbine section in a serial flow arrangement, the combustor section including a fuel nozzle assembly, the fuel nozzle assembly comprising: a fuel nozzle including an outer wall surrounding a fuel passage and defining a longitudinal axis; a swirler surrounding the fuel nozzle and defining a swirler passage, the swirler including a set of axial vanes and a set of radial vanes; and a secondary fuel passage extending through the set of axial vanes.

[0087] Turbine engine according to any of the preceding clauses, wherein the secondary fuel passage discharges into the swirler passage downstream of the set of radial vanes.

[0088] A turbine engine according to any of the preceding clauses, wherein the secondary fuel passage branches into a plurality of secondary fuel passages.

[0089] Turbine engine according to any of the preceding clauses, wherein the secondary fuel passage extends through the outer wall of the fuel nozzle.

Claims

1. A turbine engine, characterized in that: include: A compressor section, a combustor section, and a turbine section in a serial flow arrangement, the combustor section including a fuel nozzle assembly comprising: a fuel nozzle including an outer wall surrounding a fuel passage and defining a longitudinal axis; a swirler surrounding the fuel nozzle, the swirler including a front wall and a rear wall defining a swirler passage therebetween; a set of vanes disposed in the swirler passage, each vane in the set of vanes extending between the front wall and the rear wall; a separator extending from the set of vanes, the separator dividing the swirler passage into a radially outer passage and a radially inner passage; and A secondary fuel passage extends at least partially through the outer wall of the fuel nozzle and includes an outlet on the separator.

2. The turbine engine according to claim 1, characterized in that The secondary fuel passage includes an outlet at the swirler passage.

3. The turbine engine according to claim 1, characterized in that wherein the outlet discharges into both the radially inner passage and the radially outer passage.

4. The turbine engine according to any one of claims 1 to 2, characterized in that: The fuel channel is configured to supply hydrogen or a hydrogen-based fuel.

5. The turbine engine according to any one of claims 1 to 2, characterized in that: The secondary fuel passage passes through the outer wall of the fuel nozzle.

6. The turbine engine according to any one of claims 1 to 2, characterized in that: The secondary fuel passages are arranged as a plurality of secondary fuel passages in an annular arrangement around the fuel nozzle assembly.

7. The turbine engine according to any one of claims 1 to 2, characterized in that: Wherein the secondary fuel passage extends through the set of vanes.

8. The turbine engine according to any one of claims 1 to 2, characterized in that: Wherein the secondary fuel passage includes a second outlet at the fuel passage.

9. The turbine engine according to claim 8, characterized in that Wherein the fuel nozzle includes a nozzle cover having a set of openings, and wherein the second outlet at the fuel passage is disposed downstream of the nozzle cover relative to a direction of flow through the fuel passage.

10. A fuel nozzle assembly, characterized in that: include: a fuel nozzle including an outer wall surrounding a fuel passage and defining a longitudinal axis; an annular swirler surrounding the fuel nozzle, the annular swirler including a front wall and a rear wall defining a swirler passage therebetween; a set of vanes disposed in the swirler passage, each vane in the set of vanes extending between the front wall and the rear wall; a separator extending from the set of vanes, the separator dividing the swirler passage into a radially outer passage and a radially inner passage; and A secondary fuel passage extends at least partially through the outer wall and includes an outlet on the separator.

11. The fuel nozzle assembly according to claim 10, wherein: The secondary fuel passage includes an outlet at the swirler passage.

12. A method of injecting fuel into a fuel nozzle assembly, characterized in that The method comprises: discharging a primary fuel flow through a fuel nozzle, the fuel nozzle having an outer wall; Expelling the swirling airflow through a swirler having a set of vanes surrounding the fuel nozzle, the swirler including a separator extending from the set of vanes; and discharging a secondary fuel flow through a secondary fuel passage; The secondary fuel passage extends at least partially through the outer wall and includes an outlet on the separator.

13. The method according to claim 12, characterized in that The secondary fuel passage at least partially passes through a swirler forming part of the fuel nozzle assembly.

14. The method according to claim 13, characterized in that The secondary fuel passage at least partially passes through the fuel nozzle.

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