Turbine engine and combustor for a turbine engine

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 have a combustor with a combustor liner at least partially defining a combustion chamber, and a fuel-air mixer including at least one set of mix tubes.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Indian Patent Application No. 202211003539, filed January 21, 2022, and U.S. Patent Application No. 17 / 685,883, filed March 3, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This topic generally relates to combustors with fuel assemblies for turbine engines, and more specifically, to fuel assemblies with fuel-air mixing arrangements. Background Technology

[0004] A turbine engine is driven by a flow of combustion gases through the engine, which rotates multiple turbine blades. These turbine blades, in turn, rotate a compressor to supply compressed air to a combustor for combustion. The combustor can be located within the turbine engine and fluidly connected to the turbine through which the combustion gases flow.

[0005] The use of hydrocarbon fuels in the combustors of turbine engines is known. Generally, air and fuel are supplied to the combustion chamber, mixed, and then the fuel is burned in the presence of air to produce hot gases. These hot gases are then supplied to the turbine, where they are cooled and expanded to generate power. Byproducts of fuel combustion typically include environmentally harmful byproducts such as nitrogen oxides and nitrogen dioxide (collectively known as NOx), carbon monoxide (CO), unburned hydrocarbons (UHCs) (e.g., methane and volatile organic compounds that contribute to the formation of atmospheric ozone), and other oxides, including oxides of sulfur (e.g., SO2 and SO3).

[0006] Various fuels are being explored for use in gas turbine engines. Hydrogen, or hydrogen mixed with another element or compound, can be used for combustion, but hydrogen or hydrogen-blended fuels can result in higher flame temperatures than conventional fuels. That is, hydrogen or hydrogen-blended fuels generally have a wider combustible range and faster combustion rates than conventional fuels such as petroleum-based fuels or mixtures of petroleum and synthetic fuels.

[0007] Standards governing air pollution problems worldwide regulate emissions of nitrogen oxides (NOx), unburned hydrocarbons (UHC), and carbon monoxide (CO) generated by turbine engine operation. Specifically, NOx is formed within the combustor due to the high flame temperature during operation. It is desirable to reduce NOx emissions while maintaining desired efficiency by adjusting the profile and / or pattern within the combustor. Attached Figure Description

[0008] In the attached diagram:

[0009] 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.

[0010] Figure 2 is a cross-sectional view of the combustion section of Figure 1 , along line II-II.

[0011] Figure 3 is a cross-sectional view of a combustor that can be used in the combustion section of Figure 2 , along line III-III.

[0012] Figure 4 is a perspective view of a fuel assembly that can be used in the combustor of Figure 3 , along line IV-IV.

[0013] Figure 5 is a side cross-sectional view of the fuel assembly of Figure 4 , along line V-V.

[0014] Figure 6 is a side cross-sectional view of the fuel assembly of Figure 4 , along line VI-VI.

[0015] Figure 7 is a side view of the fuel assembly of Figure 4 , along line VII-VII.

[0016] Figure 8 is a front cross-sectional view of the fuel assembly of Figure 7 , along line VIII-VIII.

[0017] Figure 9 is a cross-sectional view of another fuel assembly that can be used in the combustor of Figure 2 , along line IX-IX. DETAILED DESCRIPTION

[0018] The disclosed aspects described herein are directed to combustors having fuel nozzle assemblies. For illustrative purposes, the disclosure will be described with respect to turbine engines. It will be understood, however, that the disclosed aspects described herein are not so limited and that the combustors described herein can be implemented in engines including, but not limited to, turbojet engines, turboprop engines, turboshaft engines, and turbofan engines. The disclosed aspects discussed herein can have universal applicability within non-aircraft engines having combustors, such as within other mobile applications and non-mobile industrial, commercial, and residential applications.

[0019] 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, unless otherwise indicated, all embodiments described herein are to be considered exemplary in nature and not as limiting.

[0020] As used herein, the terms “first,” “second,” and “third” can be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.

[0021] 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.

[0022] As used herein, the term “upstream” refers to a direction opposite to that of fluid flow, while the term “downstream” refers to a direction the same as that 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 / rearwardly can mean downstream.

[0023] The term “fluid” can be a gas or a liquid. The terms “fluid communication” or “fluidly coupled” mean that a fluid connection can be established between designated areas.

[0024] 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.

[0025] 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 used only for identification and do not, unless specifically indicated, imply absolute direction or orientation. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and can include intermediate members between the elements being connected and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily imply that two elements are directly connected and in fixed relation to each other. The exemplary figures are for purposes of example only and the dimensions, positions, order and relative sizes reflected in the attached figures can vary.

[0026] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Further, as used herein, the term "or" can mean "and" unless the context clearly dictates otherwise. Additionally, the term "set" or "a set" of elements can be any number of elements, including only one.

[0027] Approximating language as used herein with respect to a given quantity should be interpreted in the context of the value to which it refers. For example, a phrase such as "about X" or "approximately X" with respect to a given quantity should be interpreted to mean that the quantity is within about 10% of the value of X, unless otherwise explicitly provided herein. As used herein in the specification and in the claims, "or" as used in a list of items prefaced by "comprising," "including," "carrying," "having," "containing," "characterized by," "comprised of," "defined herein as," "including by way of example," and

[0028] Figure 1 is a schematic view 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.

[0029] 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 spool can 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 can impart a driving force to the LP drive shaft, which in turn can cause the LP compressor 22 to rotate. A HP spool can 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 can impart a driving force to the HP drive shaft, which in turn can cause the HP compressor 24 to rotate.

[0030] 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 appreciated that the representation of the compressor section 12 is merely illustrative 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.

[0031] 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. 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 a 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 representative illustration. Further, it is contemplated that there can be any number of other components within the turbine section 16.

[0032] Combustion section 14 may be arranged in series between compressor section 12 and turbine section 16. Combustion section 14 may be fluidly coupled to at least a portion of compressor section 12 and turbine section 16, such that combustion section 14 at least partially fluidly couples compressor section 12 to turbine section 16. As a non-limiting example, combustion section 14 may be fluidly coupled to HP compressor 24 at its upstream end and to HP turbine 26 at its downstream end.

[0033] During operation of the turbine engine 10, ambient air 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 to define pressurized air. This pressurized air can then flow into the combustion section 14, where it mixes with fuel and is ignited to generate combustion gases. The HP turbine 26 extracts some work from these combustion gases, driving the HP compressor 24. The combustion gases are discharged into the LP turbine 28, which extracts additional work to drive the LP compressor 22, and the exhaust gas is ultimately discharged 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 to rotate the fan (not shown) and the LP compressor 22. The pressurized airflow and combustion gases together 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 Depicting along Figure 1 The image shows a cross-sectional view of combustion section 14 along line II-II. Combustion section 14 may include a burner 30, wherein annularly arranged fuel injectors 31 are positioned 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 burner 30 is located, the burner 30 may have a canister shape, a canister annulus, or annular arrangement. In a non-limiting example, the burner 30 may have a combined arrangement positioned together with the engine housing 29.

[0035] 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 a ring-like manner around the engine centerline or axis of rotation 20. In some examples, the burner liner 40 may have a ring-like 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 in a ring around the engine centerline or 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.

[0036] Figure 3 Depicting along Figure 2 The cross-sectional view taken along line III-III shows a portion of the combustion section 14. The burner 30 may include a fuel assembly 35 configured to supply fuel to the burner 30 at least partially. 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.

[0037] 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 around 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.

[0038] 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.

[0039] A fuel supply section 54 may be disposed within the dome assembly 44 to define a fuel outlet 58. It is contemplated that air may also be supplied or provided to the combustion chamber 50 via the fuel outlet 58. In this way, the fuel outlet 58 can provide a fuel-air mixture to the combustion chamber 50. Additionally, in some examples, multiple fuel injectors or premixers may be located on the dome wall 46. In some examples, multiple fuel injectors or premixers may be arranged in discrete clusters or groups on the dome wall 46.

[0040] In some examples, a flared cone 56 may be provided downstream of the fuel supply section 54. A swirler 60 may also be provided at the fuel assembly 35 to cause the incoming air to swirl near the fuel leaving the fuel supply section 54 and to provide a homogeneous mixture of air and fuel entering the burner 30.

[0041] A set of dilution holes 62 can be provided 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 provided 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 clusters, variable hole diameters, etc., or combinations thereof. It is also contemplated that the combustor 30 can be formed without any dilution holes. In one example, a plurality of premixers can be arranged on the dome wall 46 without using dilution holes.

[0042] Turning to Figure 4 A perspective view of a fuel assembly 35 is shown with one example implementation. The fuel assembly 35 can be in the form of a fuel-air mixer configured to provide a variety of customized mixtures of fuel and air into the combustion chamber 50 Figure 3 As shown, the fuel assembly 35 can include a body 70 aligned with the longitudinal axis 52. The body 70 can include a first collar 70A and a second collar 70B. In some examples, the body 70 can include the dome wall 46 and the fuel outlet 58 Figure 3 In the example shown, the dome wall 46 can at least partially form the first collar 70A, although this need not be the case.

[0043] The body 70 can include a plurality of internal channels or mixing tubes 75 for supplying or mixing air or fuel upstream of the combustion chamber 50 Figure 3 The mixing tubes 75 can extend through either or both of the first collar 70A or the second collar 70B. Additionally or alternatively, the first collar 70A or the second collar 70B can at least partially define the mixing tubes 75.

[0044] In the example shown, a first set 71 of mixing tubes 75, a second set 72 of mixing tubes 75, and a center mixing tube 75C are shown in the body 70 of the fuel assembly 35. Any number of mixing tubes 75 can be provided in the first set 71 or the second set 72. In some examples, a plurality of center mixing tubes 75C can be provided near the center of the body 70. In some examples, the mixing tubes 75, 75C can be identical to one another or have different properties, including different materials or different geometric properties.

[0045] In the illustrated example, the mixing tubes 75 of the first group 71 can be annularly arranged about the body 70. The mixing tubes 75 of the second group 72 can also be annularly arranged about the body 70 radially inward of the mixing tubes 75 of the first group 71 relative to the longitudinal axis 52. The central mixing tube 75C can extend through the body 70 radially inward of the mixing tubes 75 of the second group 72. In this manner, the mixing tubes 75 of the first group 71, the mixing tubes 75 of the second group 72, and the central mixing tube 75C can be concentrically arranged about the longitudinal axis 52. It will be understood that the mixing tubes 75 of the first group 71 or the mixing tubes 75 of the second group 72 can have any suitable pattern or arrangement of mixing tubes in the fuel assembly 35, including linear rows, circles, multiple concentric circles, irregular groupings, etc., or combinations thereof.

[0046] The mixing tubes 75 and the central mixing tube 75C can include at least one air inlet, at least one fuel inlet, and a mixture outlet. In the illustrated example, each mixing tube 75 in the first group 71 can include a first mixture outlet 81, each mixing tube 75 in the second group 72 can include a second mixture outlet 82, and the central mixing tube 75C can include a central mixture outlet 83. The first mixture outlets 81, the second mixture outlets 82, and the central mixture outlet 83 can face the combustion chamber 50 Figure 3 ) and collectively form the fuel outlet 58. The first mixture outlets 81 can be positioned rearward of the second mixture outlets 82 relative to the longitudinal axis 52. The central mixture outlet 83 can be forward of the first mixture outlets 81 relative to the longitudinal axis 52.

[0047] In some examples, the body 70 can include a protruding tip 85 at any of the first mixture outlets 81, the second mixture outlets 82, or the central mixture outlet 83. Such a protruding tip 85 can be configured to separate or isolate at least a portion of the fuel outlet 58 from the dome wall 46. In the illustrated example, protruding tips 85 are provided at the first mixture outlets 81 and the central mixture outlet 83. The protruding tips 85 can have any suitable geometric profile, including cylindrical, conical, symmetrical, irregular, etc., or combinations thereof.

[0048] In the illustrated example, the body 70 can include a mixing chamber 86 positioned radially inward of the mixing tubes 75 of the first group 71, as shown. The mixing chamber 86 can be fluidly coupled to any of the mixing tubes 75, 75C. In the illustrated example, the second mixture outlets 82 of the mixing tubes 75 of the second group 72 and the central mixture outlet 83 of the central mixing tube 75C are fluidly coupled to the mixing chamber 86, although this need not be the case.

[0049] Turning to Figure 5 , a cross-sectional view is shown along Figure 4a side cross-sectional view of the fuel assembly 35 taken along the line V-V. In this view, the interior portions of the first set 71 of mix tubes 75, the second set 72 of mix tubes 75, and the central mix tube 75C are shown. In the illustrated example, the mix tubes 75 are shown as integrally formed or unitarily formed with the first and second collars 70A, 70B, although this need not be the case. It is contemplated that the first or second collars 70A, 70B can be separate structures and coupled to the mix tubes 75.

[0050] The mixing chamber 86 can define a mixing length 87 and a width 88. In some non-limiting examples, the mixing length 87 can be between 0.2-10 times the width 88, including between 0.5-6 times the width 88. The width 88 can be constant or variable along the longitudinal axis 52 Figure 3 ). In some examples, the width 88 can increase, decrease, or remain constant along the longitudinal axis 52 Figure 4 ). In this way, the mixing chamber 86 can form a diverging, converging, or constant area mixing passage within the body 70 of the fuel assembly 35.

[0051] It is also contemplated that the central mix tube 75C can have a longer axial length than the mix tubes 75 of the second set 72. In the illustrated example, the central mix tube 75C includes a protruding tip 85 that extends into the mixing chamber 86 and forms the central mixture outlet 83. In this way, each of the first, second, and central mixture outlets 81, 82, 83 can be axially staggered within the body 70 relative to the longitudinal axis 52.

[0052] In non-limiting examples, it is also contemplated that the mixing chamber 86 can have a first converging portion followed by a second constant area portion, or an initial converging portion followed by a second diverging portion, or a first diverging portion followed by a second constant area portion, or a first diverging portion followed by a second converging portion. The mixing chamber 86 can be configured to mix the fuel and air flowing from the mix tubes 75 of the second set 72 and the central mix tube 75C. This arrangement can provide a more uniform fuel-air mixture in the center of the mixing chamber 86 for lower NO x emissions. The peripheral second set 72 of mix tubes 75 can be tangential to achieve high velocity on the mixing passage walls to avoid undesirable combustion dynamics. This tangential mix tube can also improve the fuel-air mixing in the mixing chamber 86 for lower NO x emissions.

[0053] Further, in the illustrated non-limiting example, each mix tube 75 in the first set 71 can include a first outer air inlet 90A, a first inner air inlet 91A, and a first fuel inlet 92A. The central mix tube 75C can include a central outer air inlet 90C Figure 6), a central inner air inlet 91C, and a central fuel inlet 92C. It is also contemplated that each mixing tube 75 in the second group 72 can include a second outer air inlet 90B, a second inner air inlet 91B, and a second fuel inlet 92B, as shown in Figure 6

[0054] It is further contemplated that tangential air inlets can be provided in at least some of the mixing tubes of the air-fuel mixer, including the mixing tubes 75 of the first group 71, the mixing tubes 75 of the second group 72, or the central mixing tube 75C. In the illustrated example of Figure 5 , a tangential air inlet 93 is provided for each mixing tube 75 in the first group 71, although this need not be the case.

[0055] During operation, in one example implementation, fuel can be supplied to the mixing tubes 75 of the first group 71, the mixing tubes 75 of the second group 72, or the central mixing tube 75C through the corresponding first fuel inlets 92A, second fuel inlets 92B, and central fuel inlets 92C. Air can also be supplied to the mixing tubes 75 of the first group 71, the mixing tubes 75 of the second group 72, or the central mixing tube 75C through the corresponding first outer air inlets 90A, first inner air inlets 91A, second outer air inlets 90B, second inner air inlets 91B, central outer air inlets 90C, or central inner air inlets 91C. In this manner, fuel-air mixtures can be formed within the mixing tubes 75, 75C.

[0056] The outer air inlets 90A, 90B, 90C can be positioned radially outward of the inner air inlets 91A, 91B, 91C. The fuel inlets 92A, 92B, 92C can be positioned radially between the corresponding outer air inlets 90A, 90B, 90C and inner air inlets 91A, 91B, 91C. In some examples, air can also be supplied to the mixing tubes 75 of the first group 71, the mixing tubes 75 of the second group 72, or the central mixing tube 75C through the tangential air inlets 93 and configured to further mix or swirl the fuel-air mixtures therein. In some examples, the mixing tubes 75 of the second group 72 and the central mixing tube 75C can form a pilot zone or pilot jet, while the mixing tubes 75 of the first group 71 can form a main zone or peripheral main jet for the combustor 30 Figure 3 .

[0057] ​In this manner, fuel and air from the second set 72 of mix tubes 75 and the center mix tube 75C can combine within the mixing chamber 86 upstream of the first mixture outlet 81. The fuel-air mixture can be provided to the first mixture outlet 81, the second mixture outlet 82, or the center mixture outlet 83 at an optional tangential velocity or swirl. This tangential velocity can provide an improved level of fuel-air mixing within each mix tube 75. Additionally, fuel injection sandwiched between outer and inner air streams can center the fuel stream along the passage and away from the sidewalls of the mix tube 75.

[0058] It is further contemplated that different fuels, fuel mixtures, or fuel-air mixtures can be provided to the mix tubes 75 of the first set 71, the mix tubes 75 of the second set 72, or the center mix tube 75C. In some examples, the mix tubes 75 of the first set 71, the mix tubes 75 of the second set 72, or the center mix tube 75C can include 100% hydrogen fuel, a fuel mixture with 50-100% hydrogen, a fuel mixture with 0-60% hydrogen, a fuel mixture with natural gas fuel, a fuel-air mixture with 0-50% fuel or fuel mixture and 0-50% air, etc., or combinations thereof. One example embodiment can include mix tubes 75 of the first set 71 having a higher concentration (e.g., “richer”) of fuel mixture as compared to the mix tubes 75 of the second set 72 or the center mix tube 75C. Another example embodiment can include mix tubes 75 of the first set 71 having a lower concentration (e.g., “leaner”) of fuel mixture as compared to the mix tubes 75 of the second set 72 or the center mix tube 75C. Another example embodiment can include mix tubes 75 of the first set 71 having a fuel mixture with 50-100% hydrogen, mix tubes 75 of the second set 72 having a fuel mixture with 0-60% hydrogen, and a center mix tube 75C having a fuel mixture with 0-60% hydrogen. Another example embodiment can include mix tubes 75 of the first set 71, mix tubes 75 of the second set 72, and a center mix tube 75C having 100% hydrogen fuel. Another example embodiment can include mix tubes 75 of the first set 71, mix tubes 75 of the second set 72, and a center mix tube 75C having 100% natural gas fuel. Another example embodiment can include mix tubes 75 of the first set 71 having a hydrocarbon fuel, mix tubes 75 of the second set 72 having a natural gas fuel, and a center mix tube 75C having a hydrogen fuel. Yet another example embodiment can include mix tubes 75 of the first set 71 having a first fuel-air ratio, mix tubes 75 of the second set 71 having a second fuel-air ratio, and a center mix tube 75C having a third fuel-air ratio, where the first, second, and third fuel-air ratios can be the same or different from one another.

[0059] Additional details of the fuel assembly 35 are shown in Figure 6 , Figure 6 Another cross-sectional view of the fuel assembly 35 along line VI-VI Figure 4 is shown in FIG. 6. In this view, the interior portions of the mixing tubes 75 of the second set 72 can be seen in more detail. It is contemplated that any of the mixing tubes 75 in the first set 71, the second set 72, or the central mixing tube 75C can have an internal cross-sectional width that can be constant or variable. In the example shown, the mixing tubes 75 of the second set 72 include a first cross-sectional width 94 and a second cross-sectional width 95. In some examples, the second cross-sectional width 95 can be less than the first cross-sectional width 94. In this case, the second set 72 can have a converging cross-sectional width in a direction toward the second mixture outlet 82. In some examples, the second cross-sectional width 95 can be greater than the first cross-sectional width 94 to form a diverging cross-sectional region. In some examples, the second cross-sectional width 95 can be the same as the first cross-sectional width 94.

[0060] Further, any of the first mixture outlet 81 Figure 5 , the second mixture outlet 82, or the central mixture outlet 83 can be configured to at least partially direct the outlet flow in a direction that is not aligned with the longitudinal axis 52. For example, the second mixture outlet 82 can be oriented or angled to provide a tangential or swirling flow within the mixing chamber 86. Such an arrangement can provide additional mixing of the exiting outlet flow. Combinations of swirling and non-swirling outlets can also be used in the first or second mixture outlets 81, 82 or the central mixture outlet 83. Some non-limiting example implementations include: a non-swirling outlet for each of the first and second mixture outlets 81, 82 and the central mixture outlet 83; a swirling outlet for each of the first and second mixture outlets 81, 82 and the central mixture outlet 83; a non-swirling second mixture outlet 82, a non-swirling central mixture outlet 83, and a swirling first mixture outlet 81; a swirling second outlet 82, a swirling central mixture outlet 83, and a non-swirling first mixture outlet 81; a first mixture outlet 81 with a non-swirling outlet, a second mixture outlet 82 with a first swirling direction, and a central mixture outlet 83 with a second swirling direction different from the first swirling direction; and the like, or combinations thereof.

[0061] Figure 7 A side view of the fuel assembly 35 is shown. The mixing tubes 75 of the first set 71 are shown with an outer air inlet 90A and a tangential air inlet 93. The outer air inlet 90A can provide air into the first set 71 at least partially aligned with the longitudinal axis 52. The tangential air inlet 93 can provide air into the mixing tubes 75 of the first set 71 in a direction substantially perpendicular to the longitudinal axis 52.

[0062] Figure 8 It shows the VIII-VIII line ( Figure 7 A front cross-sectional view of the fuel assembly 35 tangentially to the air inlet 93. In this view, fuel inlets 92A, 92B, 92C are visible adjacent to inner air inlets 91A, 91B, 91C, with the second ring 70B visible as shown. Each mixing tube 75 and the central mixing tube 75C may have access through the inner air inlets 91A, 91B, 91C and the outer air inlets 90A, 90B, 90C. Figure 6 The corresponding fuel inlets 92A, 92B, and 92C are positioned between two opposing air jets. In this way, fuel and air can be streamlined together within each mixing tube 75 and also tangentially mixed or swirled via the tangential air inlet 93. In some examples, the inlets for adjacent mixing tubes 75 can be staggered at an angle so that they do not face each other directly. This arrangement avoids potential flow insufficiency. In some examples, the inlets for adjacent mixing tubes 75 can be arranged opposite each other, such as in fuel assemblies where there is a large gap between adjacent mixing tubes 75.

[0063] Turn Figure 9 This shows that it can be done in burner 30 ( Figure 3 Another fuel assembly 135 used in ) . Fuel assembly 135 and Figures 4-8 The fuel assembly 35 is similar; therefore, similar parts will be identified by similar numbers incremented by 100. It should be understood that the description of similar parts of fuel assembly 35 applies to fuel assembly 135 unless otherwise stated.

[0064] Fuel assembly 135 may include a body 170 having a first collar 170A and a second collar 170B. Body 170 may also include a dome wall 146 and a fuel outlet 158. Body 170 may also include a plurality of mixing tubes 175. In the illustrated example, mixing tubes 175 of a first group 171, mixing tubes 175 of a second group 172, and a central mixing tube 175C are shown in the body 170 of fuel assembly 135. The mixing tubes 175 of the first group 171 are illustrated having a first external air inlet 190A, a first internal air inlet 191A, a first fuel inlet 192A, and a first mixture outlet 181. The mixing tubes 175 of the second group 172 are illustrated having a second mixture outlet 182. It will be understood that the mixing tubes 175 of the second group 172 may also include a second external air inlet similar to the second external air inlet 90B, a second internal air inlet similar to the second internal air inlet 91B, and a second fuel inlet 92B (…). Figure 8a second fuel inlet similar to the first fuel inlet 192A. The center mix tube 175C is illustrated as having a center fuel inlet 192C and a center mixture outlet 183. It will be understood that the center mix tube 175C can also include a center outer air inlet similar to the center outer air inlet 90C, and a center inner air inlet similar to the center inner air inlet 91C Figure 8 a center inner air inlet similar to the first fuel inlet 192A. In addition, tangential air inlets 193 can be provided in any or all of the mix tubes 175 of the first group 171, the mix tubes 175 of the second group 172, or the center mix tube 175C. As illustrated, a mixing chamber 186 can also be provided in the body 170.

[0065] One difference is that the first mixture outlet 181 can be formed directly on the dome wall 146. In this case, the combustion flame can seat directly on the dome wall 146 during operation. In addition, the protruding tip 185 is illustrated at the center mixture outlet 183, although this need not be the case. In some examples, the fuel assembly 135 can be formed without any tip at any of the mixture outlets, with the combustion flame seating directly on the corresponding face of the body 170 at each mixture outlet 181, 182, 183.

[0066] The above aspects provide a variety of benefits. The use of multiple mix tubes that are axially and radially staggered can provide a compact and shorter flame compared to conventional burners. The axially shorter center mix tube and mixing chamber within the body of the fuel assembly can provide an axially shortened burner, as well as improved mixing time and flow development before interaction with the outer / primary mix tube flow. The different lengths of each mix tube or group of mix tubes can provide a varying fuel mixture profile at the mixer outlet to reduce combustion dynamics. This arrangement can provide a reduction in undesirable combustion byproducts including NO x .

[0067] In examples where different mixing lengths are used within a group of mix tubes, a difference in fuel-air distribution can be provided downstream of the group of mix tubes. The mixing lengths between the first group of mix tubes and the second group of mix tubes can be arranged such that the fuel-air mixture from the first group of mix tubes and the fuel-air mixture from the second group of mix tubes can produce a radially varying distribution of fuel-air mixture as they mix downstream.

[0068] In examples where the fuel-air mixture varies circumferentially (e.g., lean fuel-air mixture at a first location and rich fuel-air mixture at a second location), this circumferential distribution of fuel concentration can provide for out-of-phase or in-phase alternating fuel-air mixture profiles at the mixer outlet, which can reduce undesirable combustion dynamics. An additional radial distribution of fuel concentration can further reduce such combustion dynamics. Varying fuel tube size or diameter can also create a varying fuel-air concentration profile, which can provide similar benefits to varying fuel-air mixture concentration while reducing undesirable combustion dynamics.

[0069] The use of peripheral primary jets can provide control over the diffusion of tangential or swirled flow from the center mixing plenum, which can control or reduce combustor liner temperatures. The interaction between the tangential or swirled center tube and the peripheral primary tube can create flow shear, providing for improved mixing post outlet.

[0070] Further, the use of a protruding surface can provide for shifting or moving the combustion flame away from the surface of the fuel assembly including the dome. Such an arrangement can provide for additional control over component temperatures including the dome plate or combustor liner.

[0071] While described with respect to a turbine engine, it should be understood that aspects of the present disclosure can have general applicability to any combustion device. In non-limiting examples, aspects of the disclosure described herein can also be applicable to an engine having a propeller section, a fan, and a booster section, a turbojet engine, or a turboshaft engine.

[0072] In areas not yet described, different features and structures of various embodiments can be used in combination or in the alternative as desired. The failure of one feature to be shown in all embodiments is not meant to imply that it cannot be, but that the that the description is for brevity. Embodiments are therefore mixed and matched as desired in order to result in new embodiments that are not expressly described. All combinations or permutations of features described herein fall within the scope of the present disclosure.

[0073] Further aspects of the present disclosure are provided by the following clauses:

[0074] 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 comprising: a combustor liner at least partially defining a combustion chamber; and a fuel-air mixer comprising a first set of mixing tubes and a second set of mixing tubes radially inward of the first set of mixing tubes, wherein each mixing tube of the first and second sets of mixing tubes comprises a fuel inlet, an air inlet, and a mixture outlet facing the combustion chamber.

[0075] The turbine engine of any of the preceding clauses, further comprising a center mixer tube positioned radially inward of the second set of mixer tubes and having a center fuel inlet, a center air inlet, and a center mixture outlet facing the combustion chamber.

[0076] The turbine engine of any of the preceding clauses, wherein the center mixture outlet is forward of the mixture outlets of the first set of mixer tubes.

[0077] The turbine engine of any of the preceding clauses, further comprising a mixing chamber within the body and positioned radially inward of the first set of mixer tubes.

[0078] The turbine engine of any of the preceding clauses, wherein the center mixture outlet is fluidly coupled to the mixing chamber.

[0079] The turbine engine of any of the preceding clauses, further comprising at least one circumferentially extending collar at least partially forming at least one of the first set of mixer tubes or the mixing chamber.

[0080] The turbine engine of any of the preceding clauses, wherein the at least one circumferentially extending collar at least partially defines a dome wall in the combustor.

[0081] The turbine engine of any of the preceding clauses, further comprising a protruding tip at each mixture outlet in the first set of mixer tubes and protruding from the dome wall.

[0082] The turbine engine of any of the preceding clauses, further comprising a second air inlet on a sidewall of each mixer tube in the first set of mixer tubes, wherein the second air inlet is spaced apart from the air inlet along the longitudinal axis.

[0083] The turbine engine of any of the preceding clauses, further comprising a protruding tip at the center mixture outlet, wherein each mixture outlet in the second set of mixer tubes is forward of the center mixture outlet along a longitudinal axis extending through the fuel-air mixer.

[0084] The turbine engine of any of the preceding clauses, wherein each mixture outlet in the first set of mixer tubes is rearward of the center mixture outlet relative to the longitudinal axis.

[0085] The turbine engine of any of the preceding clauses, wherein a mixing tube of the second set of mixing tubes comprises a decreasing cross-sectional width in a direction toward the mixture outlet.

[0086] The turbine engine of any of the preceding clauses, wherein the mixing chamber comprises one of an increasing width, a decreasing width, or a constant width in a direction along a longitudinal axis extending through the fuel-air mixer.

[0087] The turbine engine of any of the preceding clauses, further comprising a first fuel mixture of 50-100% hydrogen in the first set of mixing tubes, and a second fuel mixture of 0-60% hydrogen in the center mixing tube.

[0088] A combustor for a turbine engine, comprising: a combustor liner at least partially defining a combustion chamber; and a fuel-air mixer comprising a first set of mixing tubes and a second set of mixing tubes radially inward of the first set of mixing tubes, wherein each mixing tube of the first set of mixing tubes and the second set of mixing tubes comprises a fuel inlet, an air inlet, and a mixture outlet facing the combustion chamber.

[0089] The combustor of any of the preceding clauses, further comprising a center mixing tube positioned radially inward of the second set of mixing tubes and having a center fuel inlet, a center air inlet, and a center mixture outlet facing the combustion chamber.

[0090] The combustor of any of the preceding clauses, further comprising a mixing chamber within the body and positioned radially inward of the first set of mixing tubes.

[0091] The combustor of any of the preceding clauses, wherein the center mixture outlet is fluidly coupled to the mixing chamber.

[0092] The combustor of any of the preceding clauses, further comprising a circumferentially extending collar at least partially forming the mixing chamber and at least partially defining a dome wall in the combustor.

[0093] The combustor of any of the preceding clauses, further comprising a protruding tip at the mixture outlet and protruding from the dome wall.

[0094] The combustor of any of the preceding clauses, further comprising a center protruding tip at the center mixture outlet, wherein each mixture outlet in the second set of mixing tubes is forward of the center mixture outlet along a longitudinal axis extending through the fuel-air mixer, and wherein each mixture outlet in the first set of mixing tubes is rearward of the center mixture outlet relative to the longitudinal axis.

[0095] The combustor of any of the preceding clauses, further comprising a mixing chamber within the fuel-air mixer and positioned radially inward of the first set of mixing tubes and rearward of the mixture outlets of the second set of mixing tubes relative to the longitudinal axis.

[0096] The combustor of any of the preceding clauses, wherein the center mixing tube comprises a protruding tip that extends into the mixing chamber and forms the center mixture outlet.

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 burner, the burner comprising: A dome assembly and a circumferentially extending burner liner, together defining a combustion chamber at the front end; and A fuel-air mixer having a body extending rearward along a longitudinal axis and comprising: A first set of mixing pipes and a second set of mixing pipes, each of which is arranged circumferentially around the body, wherein the second set of mixing pipes is radially spaced inward from the first set of mixing pipes, and wherein each of the first set of mixing pipes and the second set of mixing pipes includes a fuel inlet, an air inlet and a mixture outlet; A circumferentially extending collar surrounds at least the first set of mixing tubes and includes a rear surface defining at least a portion of the dome wall in the dome assembly, wherein the mixture outlet of each mixing tube in the second set of mixing tubes is located in front of the dome wall. A mixing chamber, located within the fuel-air mixer and radially inward of the mixture outlet of each mixing tube in the first set of mixing tubes, wherein the mixture outlet of each mixing tube in the second set of mixing tubes discharges into the mixing chamber; and A central mixing tube is positioned radially inside the mixture outlet of each mixing tube in the second set of mixing tubes and has a central fuel inlet, a central air inlet, and a central mixture outlet facing the combustion chamber, wherein the central mixture outlet is located within the mixing chamber such that it is located in front of the mixture outlet of each mixing tube in the first set of mixing tubes and behind the mixture outlet of each mixing tube in the second set of mixing tubes.

2. The turbine engine according to claim 1, characterized in that, The mixing chamber includes a width that increases, decreases, or remains constant along the longitudinal axis.

3. The turbine engine according to claim 1, characterized in that, The circumferentially extending collar at least partially forms at least one of the first set of mixing tubes or the mixing chamber.

4. The turbine engine according to claim 1, characterized in that, It further includes a protruding tip located at the mixture outlet of each of the first set of mixing tubes and protruding from the dome wall.

5. The turbine engine according to claim 1, characterized in that, It further includes a second air inlet located on the sidewall of each of the first set of mixing tubes, wherein the second air inlet is spaced apart from the air inlet along the longitudinal axis.

6. The turbine engine according to claim 5, characterized in that, It further includes a protruding tip located at the central mixture outlet, wherein the mixture outlet of each of the second set of mixing tubes is located in front of the central mixture outlet along the longitudinal axis.

7. The turbine engine according to claim 2, characterized in that, The mixture outlet of each mixing tube in the first group of mixing tubes is located behind the central mixture outlet relative to the longitudinal axis.

8. The turbine engine according to claim 1, characterized in that, It further includes a first fuel mixture with 50-100% hydrogen in the first set of mixing tubes, and a second fuel mixture with 0-60% hydrogen in the central mixing tube.

9. The turbine engine according to claim 1, characterized in that, It further includes a central protruding tip located at the central mixture outlet, wherein the mixture outlet of each mixing tube in the second set of mixing tubes is located in front of the central mixture outlet relative to the longitudinal axis, and wherein the mixture outlet of each mixing tube in the first set of mixing tubes is located behind the central mixture outlet relative to the longitudinal axis.

10. A combustor for a turbine engine, characterized in that, include: A dome assembly and a circumferentially extending burner liner, together defining a combustion chamber at the front end; and A fuel-air mixer having a body extending rearward along a longitudinal axis and comprising: A first set of mixing pipes and a second set of mixing pipes, each of which is arranged circumferentially around the body, wherein the second set of mixing pipes is radially spaced inward from the first set of mixing pipes, and wherein each of the first set of mixing pipes and the second set of mixing pipes includes a fuel inlet, an air inlet and a mixture outlet; A circumferentially extending collar surrounds at least the first set of mixing tubes and includes a rear surface defining at least a portion of the dome wall in the dome assembly, wherein the mixture outlet of each mixing tube in the second set of mixing tubes is located in front of the dome wall. A mixing chamber, located within the fuel-air mixer and radially inward of the mixture outlet of each mixing tube in the first set of mixing tubes, wherein the mixture outlet of each mixing tube in the second set of mixing tubes discharges into the mixing chamber; and A central mixing tube is positioned radially inside the mixture outlet of each mixing tube in the second set of mixing tubes and has a central fuel inlet, a central air inlet, and a central mixture outlet facing the combustion chamber, wherein the central mixture outlet is located within the mixing chamber such that it is located in front of the mixture outlet of each mixing tube in the first set of mixing tubes and behind the mixture outlet of each mixing tube in the second set of mixing tubes.

11. The burner according to claim 10, characterized in that, The circumferentially extending collar at least partially forms the mixing chamber.

12. The burner according to claim 11, characterized in that, It further includes a protruding tip located at the mixture outlet of the mixing tube in one of the first or second sets of mixing tubes and protruding from the dome wall.

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