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 arranged in serial flow along an engine centerline. A combustion section for a turbine engine has a primary combustor liner that includes an inner liner and an outer liner that are annular about an engine centerline. A dome wall extends between the inner liner and the outer liner. A set of primary dome inlets is located in the dome wall and circumferentially arranged about the engine centerline. A set of secondary combustors is fluidly coupled to the primary combustion chamber, the set of secondary combustors including a first small combustor and a second small combustor.

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 sulfur oxides (e.g., SO 2 and SO 3 ) other oxides.

[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 The combustion section of a turbine engine is depicted along Figure 1A cross-sectional view along line II-II of the combustion section is at least partially defined by an outer liner and has a set of secondary burners.

[0009] Figure 3 is from Figure 2 Schematic portion of the outer lining seen along line III-III.

[0010] Figure 4 It is along Figure 3 A cross-sectional view taken along line IV-IV of FIG. 1 shows a schematic diagram of the combustion section viewed in a first radial plane.

[0011] Figure 5 It is along Figure 3 FIG. 1 is a cross-sectional view taken along line VV of FIG. 1 , showing a schematic diagram of the combustion section viewed in a second radial plane circumferentially spaced apart from the first radial plane.

[0012] Fig. 6A is with Figure 2 The same cross-sectional view shows the arrangement of the first stage small burners.

[0013] Figure 6B It is along Figure 3 A cross-sectional view taken along line BB shows the arrangement of the second stage small burner.

[0014] Fig. 7A Is from Fig. 6A A variation of the arrangement of the first stage small burners.

[0015] Figure 7B Is from Figure 6B A variation of the arrangement of the second stage small burner.

[0016] Figure 8 According to another aspect disclosed herein, Figure 3 Schematic diagram of a variation of a portion of the outer liner 40 .

[0017] Fig. 9 According to another aspect disclosed herein, Figure 3 FIG. 4 is a schematic diagram of another variation of a portion of an outer liner 40 .

[0018] Fig.10 According to another aspect disclosed herein, Figure 3 FIG. 4 is a schematic diagram of yet another variation of a portion of the outer liner 40 .

[0019] Fig.11 According to another aspect disclosed herein, Figure 3 Schematic diagrams of additional variations of a portion of the outer liner 40 .

[0020] Fig.12 According to another aspect disclosed herein, Figure 3 FIG. 4 is a schematic diagram of yet another variation of a portion of the outer liner 40 .

[0021] Fig.13 According to another aspect disclosed herein, Figure 3 FIG. 4 is a schematic diagram of another variation of a portion of an outer liner 40 .

[0022] Fig.14 According to another aspect disclosed herein, Figure 3 FIG. 4 is a schematic diagram of another variation of a portion of an outer liner 40 . DETAILED DESCRIPTION

[0023] Aspects of the disclosure described herein relate to combustion sections, particularly combustion sections having a primary burner and a set of secondary burners, wherein the set of secondary burners are arranged to discharge gases into the primary burner in different orientations. For illustrative purposes, the 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 sections described herein can be implemented in engines (including but not limited to turbojets, turboprops, turboshafts, and turbofans). The disclosed aspects discussed herein can be in non-aircraft engines with burners, such as in other mobile applications and non-mobile industrial, commercial, and residential applications, and have general applicability.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] Figure 1 is a schematic diagram of a turbine engine 10. As a non-limiting example, the turbine engine 10 may be used within an aircraft. The turbine engine 10 may include at least a compressor section 12, a combustion section 14, and a turbine section 16. A drive shaft 18 rotationally couples the compressor section 12 and the turbine section 16 so that rotation of one affects rotation of the other, and defines an axis of rotation or engine centerline 20 of the turbine engine 10.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] Figure 2 The combustion section 14 is depicted along Figure 1 2, which defines a transverse plane (denoted as "TP"). The combustion section 14 may include a primary combustor 32, which is annular about the engine centerline 20 and has a primary combustor liner 38. The primary combustor liner 38 includes an outer liner 40 and an inner liner 42 that are concentric with each other. A dome wall 44 extends between the outer liner 40 and the inner liner 42. A primary combustion chamber 46 is at least partially defined by the dome wall 44 and the primary combustor liner 38. A set of primary dome inlets 66 are arranged circumferentially within the dome wall 44 about the engine centerline 20. A set of primary fuel injectors 30 are fluidly coupled to the primary combustion chamber 46 via the set of primary dome inlets 66. It should be understood that the annular arrangement of the primary dome inlets 66 can be fluidly coupled to one or more fuel injectors, and one or more primary fuel injectors 30 can have different characteristics. Depending on the type of engine in which the primary combustor 32 is located, the primary combustor 32 can have a can shape, a can annular or annular arrangement. In a non-limiting example, an annular arrangement is shown and disposed within housing 36 .

[0040] The combustion section 14 also includes a circumferential arrangement of small burners 34 defining a set of secondary burners 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 (i.e., the small burner 34 is smaller than the primary burner 32). Each small burner 34 in the set of secondary burners 50 is defined by a secondary burner liner 52 extending generally perpendicularly from the primary burner liner 38. The secondary burner liner 52 defines at least a portion of a secondary combustion chamber 54 circumferentially spaced about the engine centerline 20. The set of secondary burners 50 is fluidly coupled to the primary burner 32 by a set of openings 57 extending through the outer liner 40. More specifically, the secondary combustion chamber 54 terminates at the set of openings 57 to define a secondary burner outlet 58. In a non-limiting example, each secondary combustion chamber 54 in the set of secondary burners 50 is radially aligned with the primary fuel injector 30. The set of primary dilution openings 72 may include a plurality of dilution openings 59 arranged circumferentially about the engine centerline 20 and located in the liner 42 .

[0041] The primary burner 32 generates a primary exhaust gas (indicated as “G1”) in the primary combustion chamber 46. The set of secondary burners 50 generates 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 to form a secondary combustion chamber 54. 2 The level is insufficient and reduces the temperature in the primary combustion chamber 46. This causes NO xReduction in Emissions. A dilution flow (designated “D”) enters the primary combustion chamber 46 via the set of primary dilution openings 72 to shape the exit temperature profile and complete combustion if any unburned products are present downstream of the set of secondary combustors 50 .

[0042] The group of secondary burners 50 includes at least a first small burner 34a, a second small burner 34b ( Figure 5 ) and the third small burner 34c. The first-stage small burner 65 includes at least the first and third small burners 34a, 34c, and the remaining small burners 34 shown. The group of openings 57 is a plurality of openings including at least the first opening 57a and the third opening 57c. The first opening 57a corresponds to the first small burner 34a, and the third opening 57c corresponds to the third small burner 34c. The primary fuel injector 30 includes at least the first primary fuel injector 30a, the second primary fuel injector 30b and the third primary fuel injector 30c.

[0043] Figure 3 is from Figure 2 Schematic diagram of a portion of the outer liner 40 as seen along line III-III in FIG. The axial direction (denoted as "AD") is parallel to the engine centerline 20 ( Figure 1 ), a radial direction (denoted as "RD") extends into the page and is perpendicular to the axial direction AD, and a circumferential direction (denoted as "CD") is perpendicular to the radial direction RD and the axial direction AD. The circumferential direction CD surrounds the engine centerline 20 and extends up and down the page when oriented in two dimensions as shown.

[0044] As can be more clearly seen, the set of openings 57 in the outer liner 40 has a rectangular shape (indicated as "RS"). The second opening 57b is located between the first opening 57a and the third opening 57c. The first opening 57a includes a first geometric center 90a. The second opening 57b includes a second geometric center 90b and corresponds to the second small burner 34b ( Figure 5 ). The third opening 57c includes a third geometric center 90c. The first opening 57a and the third opening 57c are oriented so that the first geometric center 90a and the third geometric center 90c are aligned in the circumferential direction CD and are located at a first axial position A1. The second opening 57b is located at a second axial position A2, upstream of the first opening 57a and the third opening 57c. The first geometric center 90a and the second geometric center 90b are axially spaced apart from each other by an axial distance (denoted as "Ad"). The axial distance Ad is defined as the axial measurement between the first geometric center 90a and the second geometric center 90b.

[0045] The secondary burner group 50 ( Figure 2) can be staged to align with the first, second and third openings 57a, 57b, 57c. The first and third small burners 34a, 34c ( Figure 2 ) are angled so that the secondary exhaust gas G2 discharged through the first and third openings 57a, 57c flows downstream away from the corresponding first and third primary fuel injectors 30a, 30c. The second small burner 34b ( Figure 5 ) are angled so that the secondary exhaust gas G2 discharged through the second openings 57b flows upstream toward the corresponding second primary fuel injector 30b.

[0046] Figure 4 Depicts the Figure 3 A cross-sectional view taken along line IV-IV of is shown, showing a schematic diagram of the combustion section 14 observed in a first radial plane (denoted as "RP1"). The primary burner 32 extends between the dome wall 44 and the primary burner outlet 48. The first dome assembly 60a includes the dome wall 44 and accommodates the first primary fuel injector 30a. The first primary fuel injector 30a can be fluidly coupled to the first fuel inlet 62a via a first fuel passage 64a, and the first fuel passage 64a can be suitable for receiving a primary fuel flow (denoted as "F1"). The first primary fuel injector 30a can terminate at a fuel outlet (also referred to herein as the first primary dome inlet 66a). In some embodiments, the first primary fuel injector 30a may include a first swirler 68a arranged circumferentially around the first primary dome inlet 66a. The first opening 57a is located downstream of the first primary dome inlet 66a.

[0047] The first primary igniter 61a is fluidly coupled to the primary combustion chamber 46. The first secondary igniter 63a is fluidly coupled to the first small burner 34a, and more specifically, to the first secondary combustion chamber 54a.

[0048] A compressed air passage 70 may surround the primary combustor 32 and be at least partially defined by the casing 36. Compressed air (indicated as “C”) may be drawn from the compressor section 12 ( Figure 1 ) is provided to the combustion section 14. The set of primary dilution openings 72 connects the compressed air passage 70 and the primary combustion chamber 46.

[0049] A set of first secondary dilution openings 74a may be provided in the first secondary combustor liner 52a for connecting the compressed air passage 70 and the first secondary combustion chamber 54a. As a non-limiting example, when the primary combustor 32 is a rich combustion system, the set of first secondary dilution openings 74a is located at a rear position of the first small combustor 34a for shaping the combustor outlet temperature distribution and mode factor associated with the first small combustor 34a and the primary combustor 32.

[0050] The 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 60% to 90% of the compressed air C from the compressor section 12 while the set of secondary combustors 50 receives between 10% and 40% of the compressed air C.

[0051] The first small burner 34a includes a first small dome assembly 80a, which includes a first small dome wall 82a and accommodates a first small fuel injector 84a. The first small fuel injector 84a can be fluidly connected to a first secondary fuel passage 86a, and the first secondary fuel passage 86a can be suitable for receiving a secondary fuel flow (denoted as "F2"). The first small fuel injector 84a terminates at a secondary fuel outlet (also referred to herein as a first small dome inlet 88a leading to the first secondary combustion chamber 54a). In some embodiments, the first small fuel injector 84a may include a first low swirl number swirler 89a arranged circumferentially around the first small dome inlet 88a, that is, having a number less than 1 and having a low tangential velocity. It is further envisioned that the group of secondary burners 50 does not include a swirler, but may have a non-swirl air passage.

[0052] The first primary dome inlet 66a defines a first primary centerline (designated "CLa"). The first mini-dome inlet 88a defines a first centerline CL1 extending toward the first secondary burner outlet 58a. The first secondary burner outlet 58a intersects the first centerline CL1 to define a first geometric center 90a of the first secondary burner outlet 58a.

[0053] The total burner length (denoted as "L1") extends parallel to the first primary centerline CLa from the dome wall 44 to the primary burner outlet 48. The first burner length (denoted as "La") extends parallel to the first primary centerline CLa from the dome wall 44 to the first geometric center 90a. The first burner length La is 5% to 80% of the total burner length L1. In other words: 0.05L1 < La < 0.80L1.

[0054] When the secondary exhaust gas G2 is directed toward the primary burner outlet 48, the outlet temperature distribution and flame mode factor are improved for the primary burner 32. The secondary exhaust gas G2 trims the existing temperature distribution and forces any unburned products from the first small burner 34a to be completely burned. Mixing the combustion products produced by the group of secondary burners 50 with the combustion products of the primary burner 32 helps improve the temperature distribution within the primary combustion chamber 46 due to the higher turbulence generated by the products colliding with each other.

[0055] Figure 5 Depicts the Figure 3The cross-sectional view taken along the line VV of FIG. 1 shows the first radial plane RP1 ( Figure 4 ) is a schematic diagram of the combustion section 14 observed in a second radial plane (denoted as "RP2") circumferentially spaced apart from the primary burner 32. The primary burner 32 extends between the dome wall 44 and the primary burner outlet 48. The second dome assembly 60b includes the dome wall 44 and accommodates the second primary fuel injector 30b. The second primary fuel injector 30b can be fluidly connected to the second fuel inlet 62b via the second fuel passage 64b, and the second fuel passage 64b can be suitable for receiving the primary fuel flow (denoted as "F1"). The second primary fuel injector 30b can terminate at a fuel outlet, also referred to herein as the second primary dome inlet 66b. In some embodiments, the second primary fuel injector 30b may include a second swirler 68b arranged circumferentially around the second primary dome inlet 66b. The second opening 57b is located downstream of the second primary dome inlet 66b. The second opening 57b is fluidly connected to the second small burner 34b to define a second secondary burner outlet 58b.

[0056] The second primary igniter 61b is fluidly coupled to the primary combustion chamber 46. The second secondary igniter 63b is fluidly coupled to the second small burner 34b, and more specifically, to the second secondary combustion chamber 54b.

[0057] A set of second secondary dilution openings 74b may be provided in the second secondary combustor liner 52b for connecting the compressed air passage 70 and the second secondary combustion chamber 54b. As a non-limiting example, when the set of second secondary dilution openings 74b is located at a front position of the second small combustor 34b, it is used to provide additional mixing associated with the second small combustor 34b and the primary combustor 32.

[0058] The second small burner 34b includes a second small dome assembly 80b, which includes a second small dome wall 82b and accommodates a second small fuel injector 84b. The second small fuel injector 84b can be fluidly connected to a second secondary fuel passage 86b, and the second secondary fuel passage 86b can be suitable for receiving a secondary fuel flow (denoted as "F2"). The second small fuel injector 84b terminates at a secondary fuel outlet, also referred to herein as a second small dome inlet 88b leading to the second secondary combustion chamber 54b. In some embodiments, the second small fuel injector 84b may include a second low swirl number swirler 89b arranged circumferentially around the second small dome inlet 88b, that is, having a number less than 1 and having a low tangential velocity. It is further envisioned that the group of secondary burners 50 does not include a swirler, but may have a non-swirl air channel.

[0059] The second primary dome inlet 66b defines a second primary centerline (designated "CLb"). The second mini-dome inlet 88b defines a second centerline CL2 extending toward the second secondary burner outlet 58b. The second secondary burner outlet 58b intersects the second centerline CL2 to define a second geometric center 90b of the second secondary burner outlet 58b.

[0060] The second burner length (denoted as "Lb") extends parallel to the second primary centerline CLb from the dome wall 44 to the second geometric center 90b. The second burner length L2 is 5% to 80% of the total burner length L1. In other words: 0.05L < Lb < 0.80L1. From Figure 4 The first geometric center 90a and the second geometric center 90b are axially spaced apart from each other by an axial distance (denoted as "Ad"). The axial distance Ad is 0% to + / - 60% of the total combustor length L1. In other words: -0.60L1 < Ad < 0.60L1.

[0061] From Figure 4 The first geometric center 90a and the first centerline CL1 are shown to help define the orientation angle β. The orientation angle β is the first small burner 34a ( Figure 4 ) and the second small burner 34b. The orientation angle β can range from 0° to 120°.

[0062] When the secondary exhaust gas G2 is directed away from the primary burner outlet 48, the primary exhaust gas G1 and the secondary exhaust gas G2 mix, which reduces the O 2 levels and reduced NO x The amount of secondary exhaust gas G2 recirculated in the primary combustion chamber 46 may be in the range of 0.1% to 100% to reduce NO x emission.

[0063] During operation, refer to Figure 4 and Figure 5, compressed air C can 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 first and second primary fuel injectors 30a, 30b together with the first and second primary igniters 61a, 61b define a primary combustion system having a primary flame. The first and second primary fuel injectors 30a, 30b can distribute a premixed or partially premixed primary fuel / air mixture FA1. In addition, the primary fuel flow F1 can be a diffusion fuel that does not contain an air mixture before entering the primary combustion chamber 46. The primary combustion system can 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. The rich burn system for the primary burner 32 will produce a higher temperature in 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 first and second secondary combustion chambers 54a, 54b. x .

[0064] 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 first and second primary fuel injectors 30a, 30b or the first and second mini-fuel injectors 84a, 84b will need to be fuel-rich to provide flame stability. Similarly, both the primary burner 32 and the set of secondary burners 50 can have a rich-burning system, wherein reducing the NO x The O in the primary burner 32 is made by staging the fuel and the products released from the group of secondary burners 50. 2 Insufficient NO x To achieve.

[0065] The compressed air C may be fed into the first and second small fuel injectors 84a, 84b and mixed with the secondary fuel flow F2 to define a secondary fuel / air mixture (denoted as "FA2"). The first and second small fuel injectors 84a, 84b together with the first and second secondary igniters 63a, 63b may define a small combustion system including a secondary flame that may be premixed, partially premixed, or diffused. The small combustion system may be a rich combustion system or a lean combustion system. The fuel provided to the first and second primary fuel injectors 30a, 30b and the first and second small fuel injectors 84a, 84b may include injection fuel natural gas or a more reactive fuel such as H 2 and H 2 In some embodiments, the turbine engine 10 ( Figure 1 ) can be started on conventional fuel using the set of secondary burners 50, wherein the secondary exhaust gas G2 propagates toward the primary combustion chamber 46, which can use conventional fuel or H 2 Fuel to provide fuel.

[0066] The fuel staging between the primary combustion chamber 46 and the set of secondary burners 50 reduces the combustion section 14 ( Figure 1 ) of the fuel / air ratio in these stages, which helps to further reduce the temperature 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 emission.

[0067] Fig. 6A is with Figure 2 Same and along Figure 3 The first stage small burner 65 is arranged so that the secondary exhaust gas G2 is introduced in a first circumferential direction CD (as a non-limiting example, in a clockwise direction (denoted as "CW")).

[0068] Figure 6B It is along Figure 3 BB, the housing 36 and most of the reference numerals are removed for clarity. The second-stage small burner 67 is located upstream of the first-stage small burner 65. The second-stage small burner 67 is arranged so that the secondary exhaust gas G2 discharged from the second-stage small burner 67 is introduced in the same direction as the first circumferential direction CD (as a non-limiting example, in the clockwise direction CW). The second-stage small burner 67 includes at least the second small burner 34b and the remaining small burners 34 shown.

[0069] Fig. 7A Is from Fig. 6A , showing an alternative version of a cross-sectional view of the first stage small burner 165 arranged so that the secondary exhaust gas G2 is introduced in a first direction (as a non-limiting example, in a clockwise direction CW).

[0070] Figure 7B Is from Figure 6B , showing a second stage small burner 167 located upstream of the first stage small burner 165. The second stage small burner 167 is arranged so that the secondary exhaust gas G2 discharged from the second stage small burner 167 is introduced in a second circumferential direction CD opposite to the first direction. As a non-limiting example, the second direction is a counterclockwise direction (denoted as "CCW").

[0071] Although the first direction disclosed herein is a clockwise direction CW, it should be understood that the first direction may be a counterclockwise direction CCW, and the second direction may be a clockwise direction CW.

[0072] Figure 8 According to another aspect disclosed herein, Figure 3 Schematic diagram of a variation of a portion of the outer liner 40. The outer liner 140 is similar to Figure 3 therefore, like parts will be identified by like numerals increased by 100, it should be understood that the description of like parts of the outer liner 40 applies to the outer liner 140 unless otherwise specified.

[0073] A set of openings 157 may include a first opening 157a, a second opening 157b, and a third opening 157c. The first opening 157a includes a first geometric center 190a. The second opening 157b includes a second geometric center 190b, and the third opening 157c includes a third geometric center 190c. The first, second, and third openings 157a, 157b, 157c are oriented so that the first, second, and third geometric centers 190a, 190b, 190c are aligned in the circumferential direction CD and are all located at a third axial position A3. The third axial position A3 may be aligned with the first axial position A1 or the second axial position A2 ( Figure 3 )same.

[0074] Fig. 9 According to another aspect disclosed herein, Figure 3 Schematic diagram of a variation of a portion of the outer liner 40. The outer liner 240 is similar to Figure 3 therefore, like parts will be identified by like numerals increased by 200, it should be understood that the description of like parts of the outer liner 40 applies to the outer liner 240 unless otherwise specified.

[0075] A set of openings 257 may include a first opening 257a, a second opening 257b, and a third opening 257c. The first opening 257a includes a first geometric center 290a. The second opening 257b includes a second geometric center 290b, and the third opening 257c includes a third geometric center 290c. The first and third openings 257a, 257c are oriented so that the first and third geometric centers 290a, 290c are aligned in the circumferential direction CD and are located at a fourth axial position A4. The second opening 257b is located at a fifth axial position A5 downstream of the first and third openings 257a, 257c. The fourth axial position A4 may be aligned with the first axial position A1, the second axial position A2 ( Figure 2 ) or the third axial position A3( Figure 8 The axial distance Ad is defined as the axial measurement between the fourth axial position A4 and the fifth axial position A5.

[0076] Fig.10 According to another aspect disclosed herein, Figure 3 Schematic diagram of a variation of a portion of the outer liner 40. The outer liner 340 is similar to Figure 3 therefore, like parts will be identified by like numerals increased by 300, it should be understood that the description of like parts of the outer liner 40 applies to the outer liner 340 unless otherwise specified.

[0077] A group of openings 357 may include a first opening 357a, a second opening 357b, a third opening 357c, and a fourth opening 357d. The first opening 357a includes a first geometric center 390a, the second opening 357b includes a second geometric center 390b, the third opening 357c includes a third geometric center 390c, and the fourth opening includes a fourth geometric center 390d. The first and fourth openings 357a, 357d are oriented so that the first and fourth geometric centers 390a, 390d are aligned in the circumferential direction CD and are located at a sixth axial position A6. The second and third openings 357b, 357c are upstream of the first and fourth openings 357a, 357d and are located between the first and fourth openings 357a, 357d at a seventh axial position A7. The sixth axial position A6 may be aligned with the first axial position A1, the second axial position A2 ( Figure 2 )、third axial position A3( Figure 8 ), the fourth axial position A4 or the fifth axial position A5 ( Fig. 9 The axial distance Ad is defined as the axial measurement between the sixth axial position A6 and the seventh axial position A7.

[0078] A set of secondary burners (not visible) may be staged to align with the first, second, third, and fourth openings 357a, 357b, 357c, 357d. The corresponding small burners (not visible) for the first and fourth openings 357a, 357d may be angled so that the secondary exhaust gas G2 discharged through the first and fourth openings 357a, 357d flows downstream away from the corresponding first and fourth primary fuel injectors 330a, 330d. The corresponding small burners (not visible) for the second and third openings 357b, 357c may be angled so that the secondary exhaust gas G2 discharged through the second and third openings 357b, 357c flows upstream toward the corresponding second and third primary fuel injectors 330b, 330c.

[0079] Fig.11 According to another aspect disclosed herein, Figure 3 Schematic diagram of a variation of a portion of the outer liner 40. The outer liner 440 is similar to Figure 3 therefore, like parts will be identified by like numerals increased by 400, it should be understood that unless otherwise stated, the description of like parts of the outer liner 40 applies to the outer liner 440.

[0080] Thus far, all examples of the arrangement of openings in the outer liner have shown each opening axially aligned and located at the same circumferential position as a corresponding primary fuel injector. It is further contemplated that a set of openings 457 and corresponding primary fuel injectors 430 may be axially staggered and located at different circumferential positions.

[0081] A group of openings 457 may include a first opening 457a, a second opening 457b, a third opening 457c, and a fourth opening 457d. The first opening 457a includes a first geometric center 490a and is located at a first circumferential position C1. The second opening 457b includes a second geometric center 490b and is located at a second circumferential position C2. The third opening 457c includes a third geometric center 490c and is located at a third circumferential position C3. The fourth opening 457d includes a fourth geometric center 490d and is located at a fourth circumferential position C4. All of the first, second, third, and fourth openings 457a, 457b, 457c, 457d may be located at an eighth axial position A8.

[0082] The primary fuel injector 430 may include a first primary fuel injector 430a, a second primary fuel injector 430b, and a third primary fuel injector 430c. The first primary fuel injector 430a is located at a fifth circumferential position C5 between the first and second circumferential positions C1, C2. The second primary fuel injector 430b is located at a sixth circumferential position C6 between the second and third circumferential positions C2, C3. The third primary fuel injector 430c is located at a seventh circumferential position C7 between the third and fourth circumferential positions C3, C4.

[0083] The eighth axial position A8 may be aligned with the first axial position A1 ( Figure 2 ), the second axial position A2 ( Figure 2 )、third axial position A3( Figure 8 )、The fourth axial position A4( Fig. 9 )、The fifth axial position A5( Fig. 9 )、the sixth axial position A6( Fig.10 ) or the seventh axial position A7( Fig.10 )same.

[0084] A set of secondary burners (not visible) may be staged to align with the first, second, third, and fourth openings 457a, 457b, 457c, 457d. The corresponding small burners (not visible) for the first and fourth openings 457a, 457d may be angled so that the secondary exhaust gas G2 discharged through the first and fourth openings 457a, 457d flows downstream away from the corresponding first and fourth primary fuel injectors 430a, 430d. The corresponding small burners (not visible) for the second and third openings 457b, 457c may be angled so that the secondary exhaust gas G2 discharged through the second and third openings 457b, 457c flows upstream toward the corresponding second and third primary fuel injectors 430b, 430c.

[0085] Fig.12 According to another aspect disclosed herein, Figure 3 Schematic diagram of a variation of a portion of the outer liner 40. The outer liner 540 is similar to Figure 3 therefore, like parts will be identified by like numerals increased by 500, it should be understood that the description of like parts of the outer liner 40 applies to the outer liner 540 unless otherwise specified.

[0086] A set of openings 557 may include a first opening 557a, a second opening 557b, and a third opening 557c. The first opening 557a includes a first geometric center 590a, the second opening 557b includes a second geometric center 590b, and the third opening 557c includes a third geometric center 590c. The first and third openings 557a, 557c are oriented so that the first and third geometric centers 590a, 590c are aligned in the circumferential direction CD and are located at a ninth axial position A9. The second opening 557b is downstream of the first and third openings 557a, 557c and is located between the first and third openings 557a, 557c at a tenth axial position A10. The ninth axial position A9 may be aligned with the first axial position A1 ( Figure 2 ), the second axial position A2 ( Figure 2 )、third axial position A3( Figure 8 )、The fourth axial position A4( Fig. 9 )、The fifth axial position A5( Fig. 9 )、the sixth axial position A6( Fig.10 )、The seventh axial position A7( Fig.10 ) or the eighth axial position A8 ( Fig.11 The axial distance Ad is defined as the axial measurement between the ninth axial position A9 and the tenth axial position A10.

[0087] In addition, the first, second and third openings 557a, 557b, 557c are rotated from the axial direction AD toward the circumferential direction CD to define an opening angle (denoted as "α"). In one aspect, the first and third openings 557a, 557c are rotated clockwise (denoted as "CW"), and the second opening 557b is rotated counterclockwise (denoted as "CCW").

[0088] A set of secondary burners (not visible) may be staged to align with the first, second, and third openings 557a, 557b, 557c. The corresponding small burners (not visible) for the first and third openings 557a, 557c may be angled so that the secondary exhaust gas G2 discharged through the first and second openings 557a, 557c flows generally upstream toward the corresponding first and third primary fuel injectors 530a, 530c at an opening angle α. The corresponding small burner (not visible) for the second opening 557b may be angled so that the secondary exhaust gas G2 discharged through the second opening 557b flows generally downstream away from the corresponding second primary fuel injector 530b at an opening angle α.

[0089] Fig.13 According to another aspect disclosed herein, Figure 3 Schematic diagram of a variation of a portion of the outer liner 40. The outer liner 640 is similar to Figure 3Thus, similar parts will be identified by similar numbers increased by 600, and it should be understood that the description of similar parts of the outer liner 40 applies to the outer liner 640 unless otherwise specified. The outer liner 640 includes a set of openings 657, including a first opening 657a, a second opening 657b, and a third opening 657c, which are oriented so that the opening angle α is relative to Figure 8 The plurality of openings 157a, 157b, 157c shown in FIG. 1 are at an angle of 90 degrees. In other words, the opening angle α may be in the range of -90 degrees to 90 degrees.

[0090] Fig.14 According to another aspect disclosed herein, Figure 3 Schematic diagram of a variation of a portion of the outer liner 40. The outer liner 740 is similar to Figure 3 thus, like parts will be identified by like numerals increased by 700, it being understood that the description of like parts of outer liner 40 applies to outer liner 740 unless otherwise noted. Outer liner 740 includes a plurality of openings 757a, 757b, 757c having an oval shape (designated as "OS").

[0091] Any combination of positions and orientations of the openings 57, 57a, 57b, 57c, 157a, 157b, 157c, 257a, 257b, 257c, 357a, 357b, 357c, 357d, 457a, 457b, 457c, 457d, 557a, 557b, 557c, 657a, 657b, 657c, 757a, 757b, 757c described herein is contemplated. In addition, although three or four openings are shown, it should be understood that any number of openings and an appropriate corresponding number of small burners 34, 34a, 34b are contemplated. The position, orientation, number and shape can be adjusted to achieve adequate mixing between the two exhaust gases G1, G2. It is also contemplated that any opening described herein can be square or circular. For a rectangular or oval / elliptical shape, the shape may extend along the main burner axis, or be transverse or inclined relative to the main burner axis.

[0092] The method for controlling nitrogen oxides present in the combustion section 14 described herein includes generating a primary exhaust gas G1 in the primary combustion chamber 46 and generating a secondary exhaust gas G2 in the set of secondary burners 50 including the secondary combustion chambers 54a, 54b. The method also includes injecting the secondary exhaust gas G2 into the primary combustion chamber 46. The method also includes introducing the secondary exhaust gas G2 in an upstream direction toward the primary fuel injectors 30a, 30b, 30c, 130a, 130b, 130c, 230a, 230b, 230c, 330a, 330b, 330c, 330d, 430a, 430b, 430c, 530a, 530b, 530c, 630a, 630b, 630c, 730a, 730b, 730c 2, and introduces the secondary exhaust gas G2 in a downstream direction away from the primary fuel injectors 30a, 30b, 30c, 130a, 130b, 130c, 230a, 230b, 230c, 330a, 330b, 330c, 330d, 430a, 430b, 430c, 530a, 530b, 530c, 630a, 630b, 630c, 730a, 730b, 730c.

[0093] 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 with heated 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 O 2 levels, thereby further reducing NO x The combustion section described herein can use 100% H 2 Fuel to operate.

[0094] Additionally, directing some stages forward and some stages rearward toward the outlet can help burn soot from the main stage. Both stages will achieve lower main burner zone temperatures due to fuel staging and flame temperature reduction. The discrete small stages tilted toward the main burner disrupt the main burner flow, thereby reducing O 2 levels, and thus reduce NO x Discharge. A small rearward facing stage can help control the outlet temperature distribution / pattern.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] Further aspects are provided by the subject matter of the following clauses:

[0099] A combustion section for a turbine engine, the combustion section comprising: a primary combustor liner, the primary combustor liner comprising an inner liner and an outer liner annularly arranged around a centerline of the engine, wherein the outer liner defines a group of openings including at least a first opening and a second opening; a dome wall extending between the inner liner and the outer liner; a group of primary dome inlets, the group of primary dome inlets being located in the dome wall and arranged circumferentially around the centerline of the engine, the group of primary dome inlets being located upstream of the group of openings and including at least a first primary dome inlet and a second 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, and extending between the dome wall and a primary combustor outlet to define a total burner length; a group of secondary burners, the group of secondary burners being fluidly connected to the primary combustion chamber at the group of openings, the group of secondary burners comprising at least: a first small burner, the first small burner being oriented away from the first primary dome inlet and having a first small dome inlet defining a first centerline, the first centerline extending away from the first primary dome inlet through the first opening; and a second small burner, the second small burner being oriented toward the second primary dome inlet and having a second small dome inlet defining a second centerline, the second centerline extending toward the second primary dome inlet through the second opening; wherein the orientation difference between the first centerline and the second centerline defines an orientation angle ranging from 0° to 120°.

[0100] A combustion section as in any preceding clause, wherein the first small burner and the second small burner are arranged to exhaust gases in the same circumferential direction.

[0101] A combustion section as in any preceding clause, wherein the first small burner and the second small burner are arranged to exhaust gases in opposite circumferential directions.

[0102] A combustion section as described in any preceding clause, wherein the set of openings is a plurality of openings arranged circumferentially about the engine centerline.

[0103] A combustion section as in any preceding clause, wherein the set of primary dome inlets and the set of openings are located at the same circumferential position.

[0104] A combustion section as described in any preceding clause, wherein the first opening is located at the same axial position as the second opening.

[0105] A combustion section as in any preceding clause, wherein the first opening is located at a different axial position than the second opening.

[0106] A combustion section as described in any preceding clause, further comprising a third opening located at the same axial position as the second opening.

[0107] A combustion section as in any preceding clause, further comprising a fourth opening located at the same axial position as the first opening, wherein the second opening and the third opening are located between the first opening and the fourth opening.

[0108] A combustion section as in any preceding clause, wherein the set of primary dome inlets and the set of openings are located at different circumferential locations.

[0109] A combustion section as described in any preceding clause, wherein the first opening is located at the same axial position as the second opening.

[0110] A combustion section as described in any preceding clause, wherein the set of openings are rotated from an axial direction towards a circumferential direction to define an opening angle.

[0111] A combustion section as in any preceding clause, wherein the first opening rotates in a clockwise direction and the second opening rotates in a counter-clockwise direction.

[0112] A combustion section as in any preceding clause, wherein the first opening is located at a different axial position than the second opening.

[0113] A combustion section as described in any preceding clause wherein the opening angle ranges from -90 degrees to 90 degrees.

[0114] A combustion section as described in any preceding clause, wherein the set of openings are rectangular in shape.

[0115] A combustion section as described in any preceding clause, wherein the set of openings are oval in shape.

[0116] A combustion section as in any preceding clause, wherein the first opening defines a first geometric center and the second opening defines a second geometric center spaced an axial distance from the first geometric center.

[0117] A combustion section according to any preceding clause, wherein a first burner length extends from the dome wall to the first geometric center, and a second burner length extends from the dome wall to the second geometric center, wherein the first burner length and the second burner length both range from 5% to 80% of the total burner length.

[0118] A combustion section as in any preceding clause, wherein the axial distance ranges from -60% to 60% of the total combustor length.

[0119] A method for controlling nitrogen oxides, comprising: generating a primary exhaust gas in a primary combustion chamber, and generating a secondary exhaust gas in a group of secondary burners, each secondary burner including a secondary combustion chamber; injecting a first secondary exhaust gas from a first small burner into a main combustion zone of the primary combustion chamber in a first direction along a first center line; and injecting a second secondary exhaust gas from a second small burner into the main combustion zone of the primary combustion chamber in a second direction along a second center line oriented in a different orientation.

[0120] A method as in any preceding clause, further comprising introducing the first secondary exhaust gas and the second secondary exhaust gas in the same circumferential direction.

[0121] A method as described in any preceding clause, further comprising introducing the first secondary exhaust gas and the second secondary exhaust gas in opposite circumferential directions.

Claims

1. A combustion section for a turbine engine, characterized in that: The combustion section comprises: a primary combustor liner including an inner liner and an outer liner annularly disposed about a centerline of the engine, wherein the outer liner defines a set of openings including at least a first opening and a second opening; a dome wall extending between the inner liner and the outer liner; a set of primary dome inlets located in the dome wall and arranged circumferentially about the engine centerline, the set of primary dome inlets located upstream of the set of openings and including at least a first primary dome inlet and a second 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 and extending between the dome wall and a primary combustor outlet to define an overall combustor length; a set of secondary burners, the set of secondary burners being fluidly coupled to the primary combustion chamber at the set of openings, the set of secondary burners comprising at least: a first small burner oriented away from the first primary dome inlet and having a first small dome inlet defining a first centerline extending away from the first primary dome inlet through the first opening; and a second small burner oriented toward the second primary dome inlet and having a second small dome inlet defining a second centerline extending through the second opening toward the second primary dome inlet; Wherein the orientation difference between the first centerline and the second centerline defines an orientation angle ranging from 0° to 120°.

2. The combustion section according to claim 1, characterized in that: in, The first small-sized burner and the second small-sized burner are arranged to discharge gas in the same circumferential direction.

3. The combustion section according to claim 1, characterized in that: in, The first small-sized burner and the second small-sized burner are arranged to exhaust gas in opposite circumferential directions.

4. The combustion section according to claim 1, characterized in that: in, The set of openings is a plurality of openings arranged circumferentially about a centerline of the engine.

5. The combustion section according to claim 1, characterized in that: in, The set of primary dome inlets and the set of openings are located at the same circumferential position.

6. The combustion section according to claim 5, characterized in that in, The first opening is located at the same axial position as the second opening.

7. The combustion section according to claim 5, characterized in that in, The first opening is located at a different axial position than the second opening.

8. The combustion section according to claim 7, characterized in that Further included is a third opening located at the same axial position as the second opening.

9. The combustion section according to claim 8, characterized in that Further comprising a fourth opening located at the same axial position as the first opening, wherein the second opening and the third opening are located between the first opening and the fourth opening.

10. The combustion section according to claim 1, characterized in that in, The set of primary dome inlets and the set of openings are located at different circumferential locations.

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