Combustion section having primary burner and set of secondary burners

Abstract

A turbine engine has a compressor section, a combustion section, and a turbine section in a serial flow arrangement along an engine centerline. The combustion section includes a primary combustor liner including an inner liner and an outer liner. A dome wall and a primary dome inlet are located in the dome wall. The outer liner defines at least one opening downstream of the primary dome inlet. The primary combustion chamber and the set of secondary combustors are fluidly coupled to the primary combustion chamber at at least one opening.

Description

Technical Field

[0001] The present subject matter relates generally to a combustion section of a turbine engine and, more particularly, to a combustion section having a primary combustor and a secondary combustor. Background Art

[0002] The turbine engine is driven by the flow of combustion gases through the engine to rotate a plurality of turbine blades, which in turn rotate the compressor, thereby providing compressed air to the combustor for combustion. The combustor may be disposed within the turbine engine and fluidly coupled to the turbine into which the combustion gases flow.

[0003] It is known to use hydrocarbon fuels in the combustors of turbine engines. Typically, air and fuel are fed into a combustion chamber, the air is mixed with the fuel, and the fuel is then burned in the presence of the air to produce hot gases. The hot gases are then fed into a turbine where they are cooled and expanded to produce power. The byproducts of the combustion of the fuel typically include byproducts that are harmful to the environment, such as nitrogen oxides and nitrogen dioxide (collectively referred to as NO x ), carbon monoxide (CO), unburned hydrocarbons (UHC) (e.g., methane and volatile organic compounds that contribute to the formation of atmospheric ozone), and other oxides including sulfur oxides (e.g., SO2 and SO3).

[0004] Various fuels are being explored for combustion turbine engines. Hydrogen or hydrogen mixed with another element or compound can be used for combustion. However, hydrogen or hydrogen mixed fuels can result in higher flame temperatures than traditional fuels. That is, hydrogen or hydrogen mixed fuels generally have a wider flammable range and faster burning speed than traditional fuels (such as petroleum-based fuels, or petroleum and synthetic fuel mixtures).

[0005] Standards stemming from global air pollution issues regulate NOx generated by turbine engine operation. x , UHC and CO emissions. In particular, NO is formed in the burner due to the high burner flame temperature during operation. x It is expected that NOx can be reduced by adjusting the temperature distribution and / or flame pattern within the burner. x emissions while still maintaining desired efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In the attached picture:

[0007] Figure 1 It is a schematic diagram of a turbine engine.

[0008] Figure 2 Depicts a combustion section of a turbine engine having a set of secondary combustors along Figure 1 A cross-sectional view along line II-II.

[0009] Figure 3 is along Figure 2 A cross-sectional view of a burner having a dilution opening and located in the combustion section and a small burner in the group of secondary burners, taken along line III-III.

[0010] Figure 4 is with Figure 3 The same cross-sectional view showing the interaction of the primary fuel / air mixture and primary exhaust gas, the secondary fuel / air mixture and secondary exhaust gas, and the dilution flow.

[0011] Figure 5 Multiple orientations of small burners and dilution openings (including Figure 3 Schematic diagram of the orientation).

[0012] Figure 6 According to another aspect disclosed herein Figure 4 Another embodiment of a combustion section of.

[0013] Figure 7 According to another aspect disclosed herein Figure 4 Another embodiment of a combustion section of.

[0014] Figure 8 According to another aspect disclosed herein Figure 2 Another embodiment of a combustion section of.

[0015] Fig. 9 According to another aspect disclosed herein Figure 2 Another embodiment of a combustion section of.

[0016] Fig.10 According to another aspect disclosed herein Figure 2 Another embodiment of a combustion section of.

[0017] Fig.11 According to the aspects disclosed herein, Fig.10 A cross-sectional view of the small burner taken along line XI-XI shows the shape of the small burner.

[0018] Fig.12 According to another aspect disclosed herein Fig.11 Another embodiment of a small burner is shown, showing an alternative shape of the small burner.

[0019] Fig.13 According to another aspect disclosed herein Fig.11 Another embodiment of a small burner is shown, showing another alternative shape of the small burner.

[0020] Fig.14 According to another aspect disclosed herein Fig.11 Another embodiment of a small burner is shown, showing another alternative shape of the small burner. DETAILED DESCRIPTION

[0021] The disclosed aspects described herein relate to a combustion section, in particular a combustion section having a primary burner and a secondary burner, wherein the primary burner includes a set of dilution openings. For the purpose of illustration, the present disclosure will be described with respect to a turbine engine. However, it will be understood that the disclosed aspects described herein are not limited thereto, and the combustion section described herein can be implemented in an engine (including but not limited to a turbojet engine, a turboprop engine, a turboshaft engine, and a turbofan engine). The disclosed aspects discussed herein can be in a non-aircraft engine with a burner, such as in other mobile applications and non-mobile industrial, commercial and residential applications, and have general applicability.

[0022] As used herein, the word "exemplary" means "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 expressly stated otherwise, all embodiments described herein are to be considered exemplary.

[0023] As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of each component.

[0024] The terms "front" and "rear" 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, front refers to a position closer to the engine inlet, while rear refers to a position closer to the engine nozzle or exhaust.

[0025] As used herein, the term "upstream" refers to the direction opposite to the direction of fluid flow, while the term "downstream" refers to the 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 may mean upstream, and rearward / rear may mean downstream.

[0026] The term "fluid" may be a gas or a liquid. The terms "fluid coupling" and "fluidly coupled" refer to the ability of a fluid to establish a connection between designated areas.

[0027] 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 a central longitudinal axis of the engine and an outer periphery of the engine.

[0028] All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, transverse, front, rear, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, backward, etc.) may be used for identification purposes to help the reader understand the present disclosure and do not create limitations, particularly limitations on the position, orientation, or use of the disclosed aspects described herein. Connection references (e.g., attachment, coupling, connection, and engagement) may be used and will be interpreted broadly and may include intermediate structural elements between sets of elements and relative movement between elements unless otherwise indicated. Therefore, a connection reference does not necessarily mean that two elements are directly connected and fixed relative to each other. The exemplary drawings are for illustration purposes only, and the dimensions, positions, orders, and relative sizes reflected in the attached drawings may vary.

[0029] Unless the context clearly dictates otherwise, the singular forms "a," "an," and "the" include plural references. Also, as used herein, the term "set" or "a group of" elements may include any number of elements, including only one.

[0030] Approximate language as used in the entire specification and claims herein is applied to modify any quantitative representation that can allow variation without causing its related basic function to change. Therefore, the value modified by one or more terms such as "approximately", "approximately", "substantially" and "substantially" is not limited to the specified precise value. In at least some cases, the approximate language may 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 parts and / or systems. In at least some cases, the approximate language may 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 parts and / or systems. For example, approximate language may refer to 1%, 2%, 4%, 5%, 10%, 15% or 20% of the end point of a single value, a range of values ​​and / or a range of limited values. Here and throughout the specification and claims, range restrictions are combined and interchanged, and such ranges are identified and include all sub-ranges contained therein, unless otherwise indicated by context or language. For example, all ranges disclosed herein include endpoints, and the endpoints can be combined independently of each other.

[0031] Figure 1is 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 or centerline 20 of the turbine engine 10.

[0032] The compressor section 12 may include a low pressure (LP) compressor 22 and a high pressure (HP) compressor 24 that are serially fluidly coupled to each other. The turbine section 16 may include an LP turbine 28 and an HP turbine 26 that are serially fluidly coupled to 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 a combination of the LP compressor 22, the LP turbine 28, and the LP drive shaft, such that the rotation of the LP turbine 28 may apply a driving force to the LP drive shaft, which in turn may rotate the LP compressor 22. The HP spool may be defined as a combination of the HP compressor 24, the HP turbine 26, and the HP drive shaft, such that the rotation of the HP turbine 26 may apply a driving force to the HP drive shaft, which in turn may rotate the HP compressor 24.

[0033] 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 fixed vanes. The compressor blades for one stage of the compressor section 12 may be mounted to a disk that 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 that may extend circumferentially around the turbine engine 10. It should be understood that the representation of the compressor section 12 is merely schematic and 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.

[0034] 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 one stage of the turbine section 16 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 turbine section 16 may be mounted to the housing in a circumferential manner. It is 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.

[0035] 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 fluidly coupled to the HP turbine 26 at a downstream end of the combustion section 14.

[0036] 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 the air 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 into 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 to rotate the fan (not shown) and the LP compressor 22. The pressurized airflow and the combustion gases may together define a working airflow through the fan, compressor section 12, combustion section 14, and turbine section 16 of the turbine engine 10.

[0037] Figure 2 The combustion section 14 is depicted along Figure 1 1-1, which defines a transverse plane (denoted as "TP"). The combustion section 14 may include an annular arrangement of primary fuel injectors 30 disposed about the centerline 20 of the turbine engine 10. Each primary fuel injector 30 is fluidly coupled to a primary combustor 32. It should be understood that the annular arrangement of fuel injectors may be one or more fuel injectors, and that the one or more primary fuel injectors 30 may have different characteristics.

[0038] The primary combustor 32 may have a can shape, a can annular shape, or an annular arrangement, depending on the type of engine in which the primary combustor 32 is located. In a non-limiting example, an annular arrangement is shown and disposed within a casing 36. The primary combustor 32 is defined by a primary combustor liner 38, which includes an outer liner 40 and an inner liner 42 that are concentric relative to each other and annularly around the centerline 20. The dome wall T together with the primary combustor liner 38 defines a primary combustion chamber 46 that annularly around the centerline 20.

[0039] The combustion section 14 also includes a circumferential arrangement of small combustors 34 defining a set of secondary combustors 50. As used herein, "small" means that the component referenced by the term small is smaller than a corresponding similar component without the term small (e.g., the small combustor 34 is smaller than the primary combustor 32). Each small combustor 34 in the set of secondary combustors 50 is defined by a secondary combustor liner 52 extending generally perpendicularly from the primary combustor liner 38. The term "generally perpendicular" is defined as an angle equal to 85 degrees, 95 degrees, or between 85 degrees and 95 degrees. Although shown as a 90 degree angle, it is contemplated that in different and non-limiting examples, the secondary combustor liner 52 may extend from the primary combustor liner 38 at any angle.

[0040] The secondary combustor liner 52 defines at least a portion of a secondary combustion chamber 54 that is circumferentially spaced about the centerline 20. The set of secondary combustors 50 is fluidly coupled to the primary combustor 32 via at least one opening 57 extending through and defined by the outer liner 40. More specifically, the secondary combustion chamber 54 terminates at the at least one opening 57 to define a secondary combustor outlet 58. In a non-limiting example, each secondary combustion chamber 54 in the set of secondary combustors 50 is radially aligned with the primary fuel injector 30. The secondary combustion chamber 54 may define a second centerline (designated as "CL2") extending toward the secondary combustor outlet 58. A radial line (designated as "R") extends from the centerline 20 and overlaps and is aligned with the second centerline CL2 in the transverse plane TP.

[0041] A set of primary dilution openings 72 includes a plurality of dilution openings 59 arranged circumferentially about the centerline 20 and located in the liner 42. At least one dilution opening 59 in the set of primary dilution openings 72 is positioned opposite at least one of the small combustors 34 and is aligned with the second centerline CL2 and the radial line R. The at least one dilution opening 59 may be the entire set of primary dilution openings 72, with each dilution opening 59 positioned opposite each small combustor 34, as shown.

[0042] The primary burner 32 produces a primary exhaust gas (indicated as "G1") in the primary combustion chamber 46. The set of secondary burners 50 produces a secondary exhaust gas (indicated as "G2") in the secondary combustion chamber 54 that flows into the primary combustion chamber 46. The secondary exhaust gas G2 circulates in the primary combustion chamber 46, depleting the O2 level and reducing the temperature in the primary combustion chamber 46. This causes NO x Emissions Reduction. A dilution flow (designated “Df”) enters the primary combustion chamber 46 through the set of primary dilution openings 72 to shape the exit temperature profile and complete combustion in the event of any unburned products downstream of the set of secondary combustors 50 .

[0043] Figure 3 Depicted along Figure 2 , taken along line III-III of , showing the combustion section 14 as viewed in a radial plane (denoted as “RP”). ​​The primary burner 32 extends between the primary burner outlet 48 at the dome wall 44 and the nozzle assembly 56, which defines an inlet 51 to the turbine section 16. The dome assembly 60 includes the dome wall 44 and accommodates the primary fuel injector 30. The primary fuel injector 30 can be fluidly coupled to the fuel inlet 62 via a fuel passage 64, which can be suitable for receiving a primary fuel flow (denoted as “F1”). The primary fuel injector 30 can terminate at a fuel outlet (also referred to herein as a primary dome inlet 66). In some embodiments, the primary fuel injector 30 may include a swirler 68 arranged circumferentially around the primary dome inlet 66. At least one opening 57 is located downstream of the primary dome inlet 66.

[0044] The primary igniter 61 is fluidly coupled to the primary combustion chamber 46. The secondary igniter 63 is fluidly coupled to the secondary combustion chamber 54.

[0045] The compressed air passage 70 may surround the primary combustor 32 and be at least partially defined by the casing 36. Compressed air (denoted as "C") may be provided from the compressor section 12 to the combustion section 14 via the compressed air passage 70. The set of primary dilution openings 72 connect the compressed air passage 70 and the primary combustion chamber 46. At least one dilution opening 59 is located at a first position (denoted as "L1") within the liner 42. At least one dilution opening 59 has a diameter (denoted as "D"). A dilution centerline (denoted as "CL3") extends through the center of the at least one dilution opening 59 to define the orientation of the at least one dilution opening 59. In one non-limiting example, the dilution centerline CL3 and the second centerline CL2 are not aligned, as shown. An axial distance (denoted as "A") is measured from the rearward face 76 of the small combustor 34 to the forward face 78 of the at least one dilution opening 59. The axial distance A may range from -10D to +20D, where 0D will indicate that the rearward face 76 is aligned with the forward face 78. Any number of dilution openings (not shown) may be located in the outer and inner liners 42 downstream of the mini-combustor 34 .

[0046] A set of secondary dilution openings 74 may be provided in the secondary combustor liner 52 for connecting the compressed air passage 70 and the secondary combustion chamber 54. As a non-limiting example, when the primary combustor 32 is a rich combustion system, the set of secondary dilution openings 74 are located at a rear position of the small combustor 34 for shaping the combustor exit temperature distribution and mode factors associated with the small combustor 34 and the primary combustor 32.

[0047] Compressed air C may be split between the primary combustor 32 and the set of secondary combustors 50 such that the primary combustor 32 receives approximately 60% to approximately 90% of the compressed air C from the compressor section 12 while the set of secondary combustors 50 receives between approximately 10% and approximately 40% of the compressed air C.

[0048] Each small burner 34 includes a small dome assembly 80, which includes a small dome wall 82 and accommodates a small fuel injector 84. The small fuel injector 84 can be fluidly connected to a secondary fuel passage 86, which can be suitable for receiving a secondary fuel flow (denoted as "F2"). The small fuel injector 84 terminates at a secondary fuel outlet (also referred to herein as a small dome inlet 88 leading to the secondary combustion chamber 54). In some embodiments, the small fuel injector 84 may include a low swirl number swirler 89 arranged circumferentially around the small dome inlet 88, for example, having a number less than 1 and having a low tangential velocity. It is further envisioned that the group of secondary burners does not include a swirler, but may have a non-swirl air passage.

[0049] The fuel provided to the primary fuel injector 30 and the small fuel injector 84 may include injection fuel natural gas or a more reactive fuel, such as a mixture of hydrogen (H2) and H2. Figure 1 ) can be started on conventional fuel using the set of secondary burners 50, wherein the secondary exhaust gas G2 ( Figure 2 ) propagates toward a primary combustion chamber 46, which may be fueled using either conventional fuel or H2 fuel.

[0050] The primary dome inlet 66 defines a first centerline (designated as "CL1"). The mini-dome inlet 88 may define a second centerline CL2 extending toward the secondary burner outlet 58. The secondary burner outlet 58 intersects the second centerline CL2 to define a geometric center 90 of the secondary burner outlet 58. As discussed herein, the geometric center refers to the arithmetic mean position of all points along the surface defining the at least one opening 57 of the secondary burner outlet 58 in a plane parallel to the outer liner 42.

[0051] The first centerline CL1 and the second centerline CL2 intersect to define a first primary burner angle (denoted as "α1") in the radial plane RP. The small burner 34 can be angled toward the primary dome inlet 66 so that the first primary burner angle α1 is 90° or less. When angled toward the primary dome inlet 66, the small burner 34 has a first primary burner angle α1 that can vary from 25° to 90°.

[0052] The first centerline CL1 and the dilution centerline CL3 intersect to define a first dilution angle (denoted as "β1") in the radial plane RP. The at least one dilution opening 59 can be angled away from the primary dome inlet 66 such that the first dilution angle β1 is greater than 90°. When angled away from the primary dome inlet 66, the at least one dilution opening 59 has a first dilution angle β1 that can vary from 90° to 165°.

[0053] refer to Figure 4During operation, compressed air C may be fed into the primary fuel injector 30 and mixed with the primary fuel flow F1 to define a primary fuel / air mixture (indicated as "FA1"). The primary fuel injector 30, together with the primary igniter 61, defines a primary combustion system having a primary flame. The primary fuel injector 30 may distribute a premixed or partially premixed primary fuel / air mixture FA1. In addition, the fuel flow F1 may be a diffusion fuel that does not contain an air mixture before entering the primary combustion chamber 46. The primary combustion system may be a rich burn system or a lean burn system. A rich burn combustion system includes a fuel / air ratio that is higher than the stoichiometric fuel / air ratio, while a lean burn combustion system includes a fuel / air ratio that is lower than the stoichiometric fuel / air ratio. A rich burn system for the primary burner 32 will produce a higher temperature within the primary combustion chamber 46, thereby providing flame stability for the entire combustion system. When combined with a lean burn system for the group of secondary burners 50, NO is reduced from the secondary combustion chamber 54. x Similarly, the primary burner 32 may be used to reduce NO from the primary combustion chamber 46. x The primary burner 32 and the secondary burner 50 can both be a rich burn system or a lean burn system. Since both have a lean burn system, NO x Emissions are greatly reduced. However, at least one or more of the primary fuel injectors 30 or the mini-fuel injectors 84 will need to be fuel-rich to provide flame stability. Likewise, both the primary burner 32 and the set of secondary burners 50 can have a rich-burning system, wherein reducing the NO x The lower NO is produced by staging the fuel and by the products released from the set of secondary burners 50 to starve the primary burner 32 of O2. x To achieve.

[0054] Compressed air C can be fed into a small fuel injector 84 and mixed with a secondary fuel flow F2 to define a secondary fuel / air mixture (denoted as "FA2"). The small fuel injector 84 together with the secondary igniter 63 can define a small combustion system including a secondary flame that can be premixed, partially premixed or diffused. The small combustion system can be a rich combustion system or a lean combustion system. The fuel supplied to the primary fuel injector 30 and the small fuel injector 84 can include injection fuel natural gas or a more reactive fuel, such as a mixture of H2 and H2. In some embodiments, the turbine engine 10 can be started on conventional fuel using the group of secondary burners 50, wherein the secondary exhaust G2 propagates toward the primary combustion chamber 46, and the primary combustion chamber 46 can be fueled using conventional fuel or H2 fuel.

[0055] The equivalence ratio of the primary combustion zone 94 may be between 0.5 and 2, inclusive. The equivalence ratio of the secondary combustion chamber may be between 0.4 and 1.5, inclusive.

[0056] The dilution flow Df is defined by the compressed air C passing through the at least one dilution opening 59. The dilution flow Df guides the secondary exhaust gas G2 and causes the secondary exhaust gas to flow back into the primary combustion zone 94.

[0057] When the secondary exhaust gas G2 is directed to the primary combustion chamber 46, the primary exhaust gas G1 and the secondary exhaust gas G2 are mixed, which reduces the O2 level in the primary combustion chamber 46, thereby reducing NO x Fuel staging between the primary combustion chamber 46 and the secondary combustion chamber 54 reduces the fuel / air ratio in these stages of the combustion section 14, which helps to further reduce temperatures and NO x In contrast, a single-stage burner will have a relatively high fuel / air ratio and higher temperatures, which results in higher NO x The process of directing the secondary exhaust gas G2 from the small burner 34 into the primary combustion chamber 46 at the primary burner angle α increases the level of turbulence. The turbulence helps to thoroughly mix the primary exhaust gas G1 and the secondary exhaust gas G2, which improves the uniform temperature distribution, again resulting in NO x reduction.

[0058] In addition, the arrangement improves the outlet temperature distribution and mode factor of the primary burner 32. The dilution flow Df trims the outlet temperature distribution and forces complete combustion of any unburned products from the small burners 34. Mixing the combustion products produced by the set of secondary burners 50 with the combustion products of the primary burners 32 helps to improve the temperature distribution within the primary combustion chamber 46 due to the higher turbulence generated by the products colliding with each other. The amount of secondary exhaust gas G2 recirculated in the primary or main combustion zone 94 can range from 0.1% to 100% to reduce NO x emission.

[0059] Go to Figure 5 , showing Figure 3 and Figure 4 3 and at least one dilution opening 59. Each orientation is represented by a plurality of second center lines CL2a, CL2b and dilution center lines CL3a, CL3b, CL3c relative to the first center line CL1. For clarity, all parts have been removed.

[0060] Small burner 34( Figure 3 ) is represented by a first alternative second centerline CL2a. Figure 3 ) from the outer lining 40( Figure 3) extends orthogonally to define a second primary burner angle α2, which is equal to 90° and is measured between the first alternative second centerline CL2a and the first centerline CL1.

[0061] Small burner 34( Figure 3 ) is represented by a second alternative second centerline CL2b. Figure 3 ) away from the primary dome entrance 66 ( Figure 3 ) are angled to define a third primary burner angle α3, the third primary burner angle α3 varies from 90° to 165° and is measured between the second alternative second centerline CL2b and the first centerline CL1.

[0062] At least one dilution opening 59 ( Figure 3 ) is represented by a first alternative dilution centerline CL3a. At least one dilution opening 59 ( Figure 3 ) extends orthogonally through the liner 42 to define a second dilution angle β2, which is equal to 90° and is measured between the first alternative dilution centerline CL3a and the first centerline CL1.

[0063] Small burner 34( Figure 3 A first alternative position (designated as "L2") of the liner 42 is located in the liner 42 and defines a second alternative dilution centerline CL3b that is parallel to the dilution centerline CL3 and intersects the first centerline CL1. The first alternative position L1 is Figure 3 upstream of the location depicted in .

[0064] At least one dilution opening 59 ( Figure 3 A second alternative position (denoted as "L3") of the first alternative position L2 is located in the liner 42 and defines a third alternative dilution centerline CL3c that is parallel to the dilution centerline CL and intersects the first centerline CL1. The second alternative position L2 is upstream of the first alternative position L1.

[0065] Although the first alternative position L2 and the second alternative position L3 are shown as having Figure 3 3. The original orientation of the at least one dilution opening 59 is shown, but it should be understood that a third alternative orientation O3 of either the first or second alternative positions L2, L3 is also conceivable.

[0066] It should be understood that the set of secondary burners 50 may include at least one small burner 34 angled toward the primary dome inlet 66 and another at least one small burner 34 angled away from the primary dome inlet 64, or any combination thereof. Depending on the desired results in the combustion section 14, it is contemplated that Figure 3Any combination of the original orientation depicted in , the first, second and third alternative orientations O1, O2, O3, the first position L1, and the first and second alternative positions L2, L3.

[0067] Go to Figure 6 , another embodiment of the combustion section 14 is shown according to another aspect disclosed herein. The combustion section 114 is similar to Figure 4 therefore, like parts will be identified by like numerals increased by 100, it being understood that the description of like parts of the combustion section 14 applies to the combustion section 114 unless otherwise stated.

[0068] The combustion section 114 may be disposed in series between the compressor section 112 and the turbine section 116. The combustion section 114 includes a set of secondary combustors 150, the set of secondary combustors 150 including at least one small combustor 134. The primary fuel injector 130 is fluidly coupled to the primary combustor 132. The compressed air passage 170 surrounds the primary combustor 172 and is at least partially defined by the casing 136. A primary combustor liner 138 including an outer liner 140 and an inner liner 142 defines at least a portion of the primary combustor. The dome assembly 160 includes a dome wall 144. The dome wall 144 together with the primary combustor liner 138 defines a primary combustion chamber 146 of the primary combustor 132. The primary combustor 132 extends between the dome wall 144 and a primary combustor outlet 148 at a nozzle assembly 156, which defines an inlet 151 of the turbine section 116. At least one opening 157 extends through the outer liner 140.

[0069] In a first non-limiting example, the small burner 134 has a secondary combustion chamber 154 and is Figure 3In the orientation shown, the secondary combustion chamber 154 is at least partially defined by the secondary combustor liner 152. The small burner 134 is fluidly coupled to the primary combustion chamber 146 at at least one opening 157 to define a secondary combustor outlet 158. The secondary combustion chamber 154 may define a second centerline (indicated as "CL2") extending toward the secondary combustor outlet 158. The secondary combustor outlet 158 ​​intersects the second centerline CL2 to define a geometric center 190 of the secondary combustor outlet 158. A set of secondary dilution openings 174 are provided in the secondary combustor liner 152 for connecting the compressed air passage 170 and the secondary combustion chamber 154. The primary igniter 161 is fluidly coupled to the primary combustion chamber 146. The secondary igniter 163 is fluidly coupled to the secondary combustion chamber 154. The primary fuel injector 130 is fluidly coupled to the fuel inlet 162 via a fuel passage 164, which may be adapted to receive a primary fuel flow (indicated as "F1"). The primary fuel injector 130 may terminate in a fuel outlet (also referred to herein as a primary dome inlet 166 ). In some embodiments, the primary fuel injector 130 may include a swirler 168 disposed circumferentially about the primary dome inlet 166 .

[0070] The small burner 134 includes a small dome assembly 180, which includes a small dome wall 182 and accommodates a small fuel injector 184. The small fuel injector 184 is fluidly connected to a secondary fuel passage 186, which can be suitable for receiving a secondary fuel flow (denoted as "F2"). The small fuel injector 184 terminates at a secondary fuel outlet (also referred to herein as a small dome inlet 188 leading to the secondary combustion chamber 154). In some embodiments, the small fuel injector 184 may include a low swirl number swirler 189 arranged circumferentially around the small dome inlet 188, for example, having a number less than 1 and having a low tangential velocity. It is further contemplated that the group of secondary burners does not include a swirler, but may have a non-swirling air passage.

[0071] At least one dilution opening 159 is located Figure 3 At the first alternative position L2, at least one dilution opening 159 is positioned at Figure 3 At least one dilution opening 159 is positioned directly opposite the small burner 134 .

[0072] Go to Figure 7 , another embodiment of the combustion section 14 is shown according to aspects disclosed herein. The combustion section 214 is similar to Figure 4 therefore, like parts will be identified by like numerals increased by 200, it being understood that the description of like parts of the combustion section 14 applies to the combustion section 214 unless otherwise stated.

[0073] The combustion section 214 may be disposed in series between the compressor section 212 and the turbine section 216. The combustion section 214 includes a group of secondary combustors 250, the group of secondary combustors 250 including at least one small combustor 234. The small combustor 234 includes a small dome assembly 280, the small dome assembly 280 including a small dome wall 282 and accommodating a small fuel injector 284. The small fuel injector 284 is fluidly coupled to a secondary fuel passage 286, which may be adapted to receive a secondary fuel flow F2. The small fuel injector 284 terminates at a secondary fuel outlet (also referred to herein as a small dome inlet 288 leading to the secondary combustion chamber 254). In some embodiments, the small fuel injector 184 may include a low swirl number swirler 289 arranged circumferentially around the small dome inlet 288, for example, having a number less than 1 and having a low tangential velocity. It is further contemplated that the group of secondary combustors does not include a swirler, but may have a non-swirling air passage.

[0074] The primary fuel injector 230 is fluidly coupled to the primary combustor 232. A compressed air passage 270 surrounds the primary combustor 232 and is at least partially defined by a casing 236. A primary combustor liner 238, including an outer liner 240 and an inner liner 242, defines at least a portion of the primary combustor. The dome assembly 260 includes a dome wall 244. The dome wall 244, together with the primary combustor liner 238, defines a primary combustion chamber 246 of the primary combustor 232. The primary combustor 232 extends between the dome wall 244 and a primary combustor outlet 248 at a nozzle assembly 256, which defines an inlet 251 of the turbine section 216. At least one opening 257 extends through the outer liner 240.

[0075] In a second non-limiting example, the small combustor 234 is at least partially defined by a secondary combustor liner 252 and is positioned in a first alternative orientation O1 ( Figure 5) is oriented on the secondary combustion chamber 254. The small burner 234 is fluidly coupled to the primary combustion chamber 246 at at least one opening 257 to define a secondary burner outlet 258. The secondary combustion chamber 254 may define a second centerline (denoted as "CL2") extending toward the secondary burner outlet 258. The secondary burner outlet 158 ​​intersects the second centerline CL2 to define a geometric center 290 of the secondary burner outlet 258. A set of secondary dilution openings 274 are provided in the secondary combustor liner 252 for connecting the compressed air passage 270 and the secondary combustion chamber 254. The primary igniter 261 is fluidly coupled to the primary combustion chamber 246. The secondary igniter 263 is fluidly coupled to the secondary combustion chamber 254. The primary fuel injector 230 is fluidly coupled to the fuel inlet 262 via a fuel passage 264, which may be adapted to receive a primary fuel flow (denoted as "F1"). The primary fuel injector 230 may terminate at a fuel outlet (also referred to herein as a primary dome inlet 266). In some embodiments, the primary fuel injector 230 may include a swirler 268 disposed circumferentially about the primary dome inlet 266 .

[0076] At least one dilution opening 259 is located at the first position L1 and in a third alternative orientation O3 ( Figure 5 At least one dilution opening 259 is positioned directly opposite the small burner 234. In addition, a set of additional dilution openings 273 are located in the outer liner 240, downstream of the small burner 234.

[0077] like Figure 6 and Figure 7 As shown, the small burner 134, 234 is arranged directly opposite to the at least one dilution opening 159, 259 so that the first part G2a of the secondary exhaust gas G2 from the small burner 134, 234 is circulated back to the main combustion zone 194, 294. The first part Da of the dilution flow Df is mixed in the main combustion zone 194, 294. The remaining part G2b of the secondary exhaust gas G2 flows backward toward the primary burner outlet 148, 248 together with the second part Db of the dilution flow Df.

[0078] Figure 8 A combustion section 314 is shown having a set of secondary combustors 350 oriented circumferentially around a primary combustor 332 according to another aspect disclosed herein. The combustion section 314 is similar to Figure 2Thus, similar parts will be identified with similar numbers increased by 300, and it should be understood that the description of similar parts of the combustion section 14 applies to the combustion section 314 unless otherwise specified. Although eight small burners 334 are shown as the set of secondary burners 350, it should be understood that any number of small burners 334 can be envisioned. Likewise, any number of associated primary fuel injectors 330 and small fuel injectors (not shown) can be envisioned, including that they can be the same or different quantities, and the numbers depicted herein are non-limiting examples.

[0079] The combustion section 314 includes an annular arrangement of primary fuel injectors 330 disposed about the engine centerline 320. Each of the primary fuel injectors 330 is fluidly coupled to a primary combustor 332. In a non-limiting example, an annular arrangement is shown and disposed within a casing 336. The primary combustor 332 is defined by a primary combustor liner 338, which includes an outer liner 340 and an inner liner 342 that are concentric relative to each other and annularly around the engine centerline 320. The dome wall 344, together with the primary combustor liner 338, defines a primary combustion chamber 346 that annularly around the engine centerline 320.

[0080] The combustion section 314 also includes a circumferential arrangement of small burners 334 defining the set of secondary burners 350. Each small burner 334 in the set of secondary burners 350 is defined by a secondary burner liner 352 extending generally perpendicularly from the primary burner liner 338. The secondary burner liner 352 defines at least a portion of a secondary combustion chamber 354 circumferentially spaced about the engine centerline 320. The set of secondary burners 350 is fluidly coupled to the primary burner 332 by at least one opening 357 extending through the outer liner 340. More specifically, the secondary combustion chamber 354 terminates at at least one opening 357 to define a secondary burner outlet 358. In a non-limiting example, each secondary combustion chamber 354 in the set of secondary burners 350 is aligned with the primary fuel injector 330.

[0081] A set of primary dilution openings 372 includes a plurality of dilution openings 359 arranged circumferentially about the engine centerline 320 and located in the liner 342. At least one dilution opening 359 in the set of primary dilution openings 372 is offset from at least one of the small combustors 334. At least one dilution opening 359 may be the entire set of primary dilution openings 372, wherein each dilution opening 359 is misaligned relative to the small combustor 334. In other words, each dilution opening 359 is staggered relative to the sequential secondary combustion chambers 354, as shown.

[0082] Positioning at least one dilution opening 359 between the small burners 334 can form a low pressure zone (denoted as "LPZ") between the secondary exhaust gas G2 from the small burners 334. The low pressure zone LPZ creates an exhaust gas flow moving in a lateral direction (denoted as "LD"), increasing the diffusion of the primary exhaust gas G1 and the secondary exhaust gas G2 and the recirculation of the gases G1, G2. The recirculation in the primary combustion chamber 346 makes the O2 level insufficient and reduces the temperature in the primary combustion chamber 346. This causes NO x Reduction of emissions.

[0083] Fig. 9 A combustion section 414 having a set of secondary combustors 450 oriented circumferentially around a primary combustor 432 is shown according to another aspect disclosed herein. The combustion section 414 is similar to Figure 2 Thus, similar parts will be identified with similar numbers increased by 400, and it should be understood that the description of similar parts of the combustion section 14 applies to the combustion section 414 unless otherwise specified. Although eight small burners 434 are shown as the set of secondary burners 450, it should be understood that any number of small burners 434 can be envisioned. Likewise, any number of associated primary fuel injectors 430 and small fuel injectors (not shown) can be envisioned, including that they can be the same or different quantities, and the numbers depicted herein are non-limiting examples.

[0084] The combustion section 414 includes an annular arrangement of primary fuel injectors 430 disposed about an engine centerline 420. Each of the primary fuel injectors 430 is fluidly coupled to a primary combustor 432. In a non-limiting example, an annular arrangement is shown and disposed within a casing 436. The primary combustor 432 is defined by a primary combustor liner 438, which includes an outer liner 440 and an inner liner 442 that are concentric relative to each other and annularly around the engine centerline 420. The dome wall 444, together with the primary combustor liner 438, defines a primary combustion chamber 446 that annularly around the engine centerline 420.

[0085] The combustion section 414 also includes a circumferential arrangement of small burners 434 defining the set of secondary burners 450. Each small burner 434 in the set of secondary burners 450 is defined by a secondary burner liner 452 extending generally perpendicularly from the primary burner liner 438. The secondary burner liner 452 defines at least a portion of a secondary combustion chamber 454 circumferentially spaced about the engine centerline 420. The set of secondary burners 450 is fluidly coupled to the primary burner 432 by at least one opening 457 extending through the outer liner 440. More specifically, the secondary combustion chamber 454 terminates at at least one opening 457 to define a secondary burner outlet 458. In a non-limiting example, each secondary combustion chamber 454 in the set of secondary burners 450 is aligned with the primary fuel injector 430.

[0086] A set of primary dilution openings 472 includes a plurality of dilution openings 459 arranged circumferentially about the engine centerline 420 and located in the liner 442. At least one dilution opening 459 in the set of primary dilution openings 472 extends between the inlet 496 and the outlet 498. A fourth centerline (designated as "CL4") extends from the geometric center 497 of the inlet 496 through the at least one dilution opening 459 and through the geometric center 499 of the outlet 498. A second radial line (designated as "R2") extends from the engine centerline 420 through the geometric center 499 of the outlet 498 of the at least one dilution opening 459. The at least one dilution opening 459 is tangentially angled such that the fourth centerline CL4 and the second radial line R2 define a tangential angle θ. The at least one dilution opening 359 may be the entire set of primary dilution openings 372, wherein each dilution opening 359 is tangentially angled, as shown.

[0087] Angling the at least one dilution opening 459 tangentially creates exhaust gas flow in a circumferential direction (denoted as "CD"). Flowing the primary exhaust gas G1 and the secondary exhaust gas G2 in the circumferential direction CD creates a uniform temperature distribution. The tangential angle θ can vary from 0° to + / -180°. The varying angles can create swirling flows of the primary gas G1 and the secondary gas G2 in the same direction or in opposite directions.

[0088] Fig.10 A combustion section 514 is shown having a set of secondary combustors 550 oriented circumferentially around a primary combustor 532 according to another aspect disclosed herein. The combustion section 514 is similar to Figure 2Thus, similar parts will be identified with similar numbers increased by 500, and it should be understood that the description of similar parts of the combustion section 14 applies to the combustion section 514 unless otherwise specified. Although eight small burners 534 are shown as the set of secondary burners 550, it should be understood that any number of small burners 534 can be envisioned. Likewise, any number of associated primary fuel injectors 530 and small fuel injectors (not shown) can be envisioned, including that they can be the same or different quantities, and the numbers depicted herein are non-limiting examples.

[0089] The combustion section 514 includes additional features that may be implemented in any of the combustion sections 14, 114, 214, 314, 414 discussed herein. An exhaust wall 591 may extend into the primary combustion chamber 546. The exhaust wall 591 may provide hardware protection and define the secondary burner outlet 558.

[0090] In addition, a group of primary dilution openings 572 includes a plurality of dilution openings 559 arranged circumferentially around the centerline 520 of the combustion section 514. At least one dilution opening 559 in the group of dilution openings 572 includes a dilution component 592. The dilution component 592 may be a hot side feature that improves the penetration of the dilution flow Df into the core of the primary burner 532, thereby enabling air to reach the middle of the primary burner 532 and reduce the temperature in the primary combustion chamber 546. The dilution component 592 may include a metal extension facing the primary combustion chamber 546 or the hot side, or facing the compressed air passage 570 or the cold side, to provide a flow direction of the dilution flow Df. Controlling the direction of the dilution flow Df controls the mixing of the exhaust gas from the secondary combustion chamber 554 and makes the temperature within the primary burner 532 as uniform as possible. The dilution component 592 may also be an insert for controlling the direction of the dilution flow Df. At least one dilution opening 559 may be the entire group of primary dilution openings 572, wherein each dilution opening 559 includes a dilution component 592, as shown.

[0091] Fig.11 , Fig.12 , Fig.13 and Fig.14 Various shapes of small burners 34, 134, 234, 334, 434, 534 described herein are shown.

[0092] Fig.11 It is along Fig.10 The cylindrical shape (denoted as “CS”) defined by the secondary combustor liner 552 of the secondary combustion chamber 554 is intercepted by the line XI-XI.

[0093] Fig.12 yes Fig.11Another embodiment of a small combustor is defined by a secondary combustor liner 652 of a secondary combustion chamber 654 having a rectangular shape (designated “RS”).

[0094] Fig.13 yes Fig.11 Another embodiment of a small combustor of the invention is defined by a secondary combustor liner 752 of a secondary combustion chamber 754 having an elliptical shape (designated “OS”).

[0095] Fig.14 yes Fig.11 Another embodiment of a small combustor is defined by a secondary combustor liner 852 of a secondary combustion chamber 854 having a rounded rectangular shape (denoted as “RRS”).

[0096] Any combination of the positions and orientations described herein relative to at least one dilution opening 59, 159, 259, 359, 459, 559 and the small burner 34, 134, 234, 334, 434, 534 is contemplated. In addition, the number of dilution openings 59, 159, 259, 359, 459, 559 and the small burner 34, 134, 234, 334, 434, 534 may vary. Furthermore, the shape of the small burner 34, 134, 234, 334, 434, 534 may vary. The position, orientation, number and shape are adjusted to achieve adequate mixing between the two exhaust gases G1, G2.

[0097] A method for controlling nitrogen oxides present in a combustion section 14, 114, 214, 314, 414, 514 described herein includes generating a primary exhaust gas G1 in a primary combustion chamber 46, 146, 246, 346, 446, 546, and generating a secondary exhaust gas G2 in the group of secondary burners 50, 150, 250, 350, 450, 550 including the secondary combustion chamber 54, 154, 254, 354, 454, 554, 654, 754. The method also includes injecting the secondary exhaust gas G2 into the main combustion zone 94, 194, 294 of the primary combustion chamber 46, 146, 246, 346, 446, 546. The method also includes introducing a dilution flow Df into the primary combustion chamber 46, 146, 246, 346, 446, 546.

[0098] The method may also include introducing a dilution flow Df downstream of the secondary combustion chamber 54, 154, 254, 354, 454, 554, 654, 754. The method may include directing all of the secondary exhaust gas G2 to the primary combustion zone 94, 194, 294 using the dilution flow Df.

[0099] The method may also include introducing a dilution flow Df directly opposite the secondary combustion chamber 54, 154, 254, 354, 454, 554, 654, 754. The method may include directing a portion of the secondary exhaust gas G2 to the primary combustion zone 94, 194, 294 using the dilution flow Df.

[0100] The benefit associated with the set of secondary burners in combination with the primary burner and method described herein is that NOx can be reduced even in severe cycles with higher operating air pressures, higher temperatures, higher fuel / air ratios and heating fuel. x Emissions. Typically, higher fuel / air ratios within a combustion system result in higher flame temperatures, which results in higher NO x By having two combustion chambers within the combustion system, the fuel can be split between these chambers, thereby reducing the fuel / air ratio in each chamber, thereby achieving lower temperatures and therefore lower NO x By directing the combustion products from the secondary combustion into the primary combustion chamber, the O2 level in the primary combustion chamber can be reduced, thereby further reducing NO x Emissions. The combustion section herein can be operated using 100% H2 fuel.

[0101] Although described with respect to a turbine engine, it should be understood that the combustor described herein may be used with a turbine engine having NOx emissions. x It should be understood that the application of the various aspects of the disclosure discussed herein may also be applied to engines having a propeller section or a fan and supercharger section, as well as turbojets and turbine engines.

[0102] To the extent not yet described, the different features and structures of the various embodiments may be used in combination or in place of one another as desired. The fact that a feature is not shown in all embodiments does not mean that it cannot be shown as such, but is done so for the sake of brevity of description. Thus, the various features of the different embodiments may be mixed and matched as desired to form new embodiments, whether or not the new embodiments are explicitly described. All combinations or permutations of the features described herein are covered by the present disclosure.

[0103] This written description uses examples to describe the aspects of the disclosure described herein, including the best mode, and also to enable any person skilled in the art to practice aspects of the disclosure, including making and using any device or system and performing any combined methods. The patentable scope of the various aspects of the disclosure is defined by the claims, and may include other examples that occur to one skilled in the art. These other examples are intended to fall within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims.

[0104] Further aspects are provided by the subject matter of the following clauses:

[0105] A combustion section for a turbine engine, the combustion section comprising: a primary combustor liner, the primary combustor liner including an inner liner and an outer liner; a dome wall, the dome wall extending between the inner liner and the outer liner; a primary dome inlet, the primary dome inlet located in the dome wall and defining a first centerline, wherein the outer liner defines at least one opening downstream of the primary dome inlet; a primary combustor, the primary combustor having a primary combustion chamber, the primary combustion chamber being at least partially defined by the inner liner, the outer liner and the dome wall; a set of secondary combustors, the set of secondary combustors including at least one secondary combustion chamber, the at least one secondary combustion chamber being fluidly coupled to the primary combustion chamber at the at least one opening; and at least one dilution opening, the at least one dilution opening being located in the inner liner and defining a dilution centerline, the dilution centerline intersecting the first centerline to define a dilution angle β, the dilution angle β being away from the primary dome inlet opening and being in the range of 25° to 165°.

[0106] The combustion section according to any preceding clause, further comprising a mini-dome wall and a mini-dome inlet, wherein the mini-dome wall is radially spaced from the outer liner and further defines the at least one secondary combustion chamber, and the mini-dome inlet is located in the mini-dome wall and fluidly connected to the at least one secondary combustion chamber.

[0107] The combustion section of any preceding clause, further comprising a primary fuel injector fluidly coupled to the primary dome inlet and a mini-fuel injector fluidly coupled to the mini-dome inlet.

[0108] A combustion section according to any preceding clause, wherein the mini-dome inlet defines a second centerline that intersects the first centerline to define a primary burner angle α that is away from the primary dome inlet opening and is in the range of 25° to 165°.

[0109] A combustion section as described in any preceding clause, wherein the mini-dome inlet defines a second centerline that intersects the first centerline to define a primary burner angle α that is away from the primary dome inlet opening and is in the range of 25° to 90°.

[0110] A combustion section according to any preceding clause, wherein the primary burner angle α is equal to 90°.

[0111] A combustion section according to any preceding clause, wherein the mini-dome inlet defines a second centerline that intersects the first centerline to define a primary burner angle α that is away from the primary dome inlet opening and is in the range of 90° to 165°.

[0112] A combustion section as in any preceding clause, wherein the dilution centerline and the second centerline are not aligned.

[0113] A combustion section as in any preceding clause, wherein the dilution centreline is downstream of the second centreline.

[0114] A combustion section as in any preceding clause, wherein the dilution centreline is upstream of the second centreline.

[0115] A combustion section as in any preceding clause, wherein the at least one secondary combustion chamber is directed towards the primary dome inlet.

[0116] A combustion section as described in any preceding clause wherein the primary burner angle α is less than 90°.

[0117] A combustion section as in any preceding clause, wherein the at least one secondary combustion chamber is directed away from the primary dome inlet.

[0118] A combustion section as described in any preceding clause, wherein the primary burner angle α is greater than 90°.

[0119] A combustion section as described in any preceding clause, wherein the at least one secondary combustion chamber and the at least one dilution opening are positioned directly opposite each other.

[0120] The combustion section of any preceding clause, wherein a radial line extending from an engine centerline of the turbine engine intersects a geometric center of the at least one dilution opening in a transverse plane, and the radial line and the dilution centerline overlap and are aligned.

[0121] The combustion section of claim 1, wherein a radial line extending from an engine centerline of the turbine engine intersects a geometric center of the at least one dilution opening in a transverse plane, and wherein the radial line and the dilution centerline are angled relative to each other to form a tangential angle θ, wherein the tangential angle θ is in the range of -180° to 180°.

[0122] The combustion section of claim 1, wherein the at least one secondary combustion chamber is a plurality of secondary combustion chambers arranged circumferentially around the outer liner, and the at least one dilution opening is a plurality of dilution openings arranged circumferentially around the inner liner.

[0123] The combustion section of claim 14, wherein the plurality of dilution openings are circumferentially staggered relative to the plurality of secondary combustion chambers.

[0124] The combustion section of claim 15, wherein the plurality of dilution openings are staggered midway between sequential secondary combustion chambers.

[0125] The combustion section of claim 1, wherein the at least one dilution opening comprises a dilution member.

[0126] The combustion section of claim 1, wherein the set of secondary burners includes a rearward facing surface, and the at least one dilution opening defines a diameter (D) and includes a forward facing surface, the forward facing surface being spaced apart from the rearward facing surface by an axial distance of -10D to +20D.

[0127] The combustion section of claim 1, further comprising an exhaust wall extending into the primary burner and bordering the at least one opening to define at least a portion of a secondary burner outlet.

[0128] A turbine engine includes a compressor section, a combustion section, and a turbine section in a serial flow arrangement along an engine centerline, the combustion section including: a primary combustor liner, the primary combustor liner including an inner liner and an outer liner; a dome wall, the dome wall extending between the inner liner and the outer liner; a primary dome inlet, the primary dome inlet located in the dome wall and defining a first centerline, wherein the outer liner defines at least one opening downstream of the primary dome inlet; a primary combustor, the primary combustor having a primary combustion chamber, the primary combustion chamber being at least partially defined by the inner liner, the outer liner, and the dome wall; a set of secondary combustors, the set of secondary combustors including at least one secondary combustion chamber, the at least one secondary combustion chamber being fluidly coupled to the primary combustion chamber at the at least one opening; and at least one dilution opening, the at least one dilution opening being located in the inner liner and defining a dilution centerline, the dilution centerline intersecting the first centerline to define a dilution angle β, the dilution angle β being away from the primary dome inlet opening and being in the range of 25° to 165°.

[0129] A method for controlling nitrogen oxides comprises: generating a primary exhaust gas in a primary combustion chamber and generating a secondary exhaust gas in a group of secondary burners including a secondary combustion chamber; injecting the secondary exhaust gas into a main combustion zone of the primary combustion chamber; and introducing a dilution flow into the primary combustion chamber.

[0130] A method as in any preceding clause, further comprising introducing the dilution flow at a location downstream of the secondary combustion chamber.

[0131] A method as in any preceding clause, further comprising directing all of the secondary exhaust gas towards the primary combustion zone using the dilution flow.

[0132] A method as in any preceding clause, further comprising introducing the dilution flow directly opposite the secondary combustion chamber.

[0133] A method as in any preceding clause, further comprising directing a portion of the secondary exhaust gas towards the primary combustion zone using the dilution flow.

Claims

1. A combustion section for a turbine engine, characterized in that: The combustion section comprises: a primary combustor liner, the primary combustor liner comprising an inner liner and an outer liner; a dome wall extending between the inner liner and the outer liner; a primary dome inlet located in the dome wall and defining a first centerline, wherein the outer liner defines at least one opening downstream of the primary dome inlet; a primary combustor having a primary combustion chamber defined at least in part by the inner liner, the outer liner, and the dome wall; a set of secondary burners, the set of secondary burners comprising at least one secondary combustion chamber, the at least one secondary combustion chamber being fluidly coupled to the primary combustion chamber at the at least one opening; and At least one dilution opening is located in the liner and defines a dilution centerline that intersects the first centerline to define a dilution angle β that is away from the primary dome inlet opening and is in a range of 25° to 165°.

2. The combustion section according to claim 1, characterized in that: Further included is a mini-dome wall radially spaced from the outer liner and further defining the at least one secondary combustion chamber, and a mini-dome inlet located in the mini-dome wall and fluidly coupled to the at least one secondary combustion chamber.

3. The combustion section according to claim 2, characterized in that Further included is a primary fuel injector fluidly coupled to the primary dome inlet and a mini-fuel injector fluidly coupled to the mini-dome inlet.

4. The combustion section according to claim 3, characterized in that in, The mini-dome inlet defines a second centerline that intersects the first centerline to define a primary burner angle α that is away from the primary dome inlet opening and is in a range of 25° to 165°.

5. The combustion section according to claim 4, characterized in that in, The primary burner angle α is equal to 90°.

6. The combustion section according to claim 4, characterized in that in, The dilution centerline and the second centerline are not aligned.

7. The combustion section according to claim 6, characterized in that in, The dilution centerline is downstream of the second centerline.

8. The combustion section according to claim 6, characterized in that in, The dilution centerline is upstream of the second centerline.

9. The combustion section according to claim 4, characterized in that in, The at least one secondary combustion chamber is directed towards the primary dome inlet, and the primary burner angle α is less than 90°.

10. The combustion section according to claim 4, characterized in that in, The at least one secondary combustion chamber is directed away from the primary dome inlet, and the primary burner angle α is greater than 90°.

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