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 having an inner liner and an outer liner. A dome wall and a dome inlet are located in the dome wall. At least one opening is located in the outer liner downstream of the 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 profile and / or 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 the Figure 1 Cross-sectional view of line II-II

[0009] Figure 3 is along Figure 2 A cross-sectional view of the burners in the combustion section and the small burners 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 the primary exhaust gas and the secondary fuel / air mixture and the secondary exhaust gas.

[0011] Figure 5 According to the aspects disclosed herein Figure 2 Variation of the combustion section.

[0012] Figure 6 According to another aspect disclosed herein Figure 2 Variation of the combustion section.

[0013] Figure 7 According to another aspect disclosed herein Figure 2 Variation of the combustion section. DETAILED DESCRIPTION

[0014] The disclosed aspects described herein relate to combustion sections, in particular, combustion sections having primary burners and secondary burners. For illustrative purposes, 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 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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 centerline 20 of the turbine engine 10.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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 an annular arrangement of primary fuel injectors 30 disposed around 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 one or more primary fuel injectors 30 may have different characteristics. Depending on the type of engine in which the primary combustor 32 is located, the primary combustor 32 may have a can shape, a can annular or annular arrangement. In a non-limiting example, an annular arrangement is shown and is 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 44, together with the primary combustor liner 38, defines a primary combustion chamber 46 annularly around the centerline 20.

[0031] 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 centerline 20. The set of secondary burners 50 is fluidly coupled to the primary burner 32 by at least one opening 57 extending through the outer liner 40. More specifically, the secondary combustion chamber 54 terminates at the at least one opening 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 secondary combustion chamber 54 may define a secondary centerline (designated “CL2”) extending toward the secondary combustor outlet 58. A radial line (designated “R”) extends from the centerline 20 and is aligned with the secondary centerline CL2 in a transverse plane TP.

[0032] 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 Reduction of emissions.

[0033] 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 dome inlet 66). In some embodiments, the primary fuel injector 30 may include a swirler 68 arranged circumferentially around the dome inlet 66. At least one opening 57 is located downstream of the dome inlet 66.

[0034] 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 provided from the compressor section 12 to the combustion section 14 via the compressed air passage 70. A set of primary dilution openings 72 may be provided in the primary combustor liner 38 at a position downstream of the small combustor 34 for connecting the compressed air passage 70 and the primary combustion chamber 46. The primary combustor liner 38 has no dilution openings at any position upstream of the small combustor 34. 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 is 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. A primary igniter 76 may be fluidly coupled to the primary combustion chamber 46. The secondary igniter 78 may be fluidly coupled to the secondary combustion chamber 54. 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.

[0035] 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, that is, 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.

[0036] The dome inlet 66 defines a primary centerline (designated as "CL1"). The primary burner length (designated as "L1") is measured parallel to the primary centerline CL1 between the dome wall 44 and the leading edge 53 of the nozzle assembly 56. The small dome inlet 88 can define a secondary centerline CL2 extending toward the secondary burner outlet 58. The secondary burner outlet 58 intersects the secondary centerline CL2 to define a geometric center 90 of the secondary burner outlet 58. The primary combustion zone 94 is defined as the volume between the dome inlet 66 and the geometric center 90. The primary combustion length (designated as "L1") is measured parallel to the primary centerline CL1 between the dome wall 44 and the leading edge 53 of the nozzle assembly 56. M ”) is measured parallel to the primary centerline CL1 from the dome wall 44 to the geometric center 90. The main combustion length L M It is 5% to 90% of the primary burner length L1. M It can be 5% to 50% of the primary burner length L1. The combustion residence time of the primary combustion zone 94 can be in the range of 1.0 ms to 12 ms, including the end points. The combustion residence time of the secondary combustion chamber can be in the range of 0.1 ms to 8 ms, including the end points. The total combustion residence time of the combustion section 14 can be in the range of 1.1 ms to 20 ms, including the end points.

[0037] The primary centerline CL1 and the secondary centerline CL2 intersect to define a primary burner angle (denoted as "α") in the radial plane RP. The set of secondary burners 50 can be angled toward the dome inlet 66 so that the primary burner angle α is 90° or less. When angled toward the dome inlet 66, the set of secondary burners 50 has a primary burner angle α that can vary from 25° to 90°. It is further contemplated that the set of secondary burners 50 can be angled away from the dome inlet 66 so that the primary burner angle α is greater than 90°. When angled away from the dome inlet 66, the set of secondary burners 50 has a primary burner angle α that can vary from 90° to 165°. It should be understood that the set of secondary burners 50 can include at least one small burner 34 angled toward the dome inlet 66 and another at least one small burner 34 angled away from the dome inlet 66, or any combination thereof. Radial line R intersects geometric center 90 and secondary centerline CL2 to define a second burner angle (denoted as "β") in radial plane RP. Geometrically, primary burner angle α and secondary burner angle β are complementary angles.

[0038] refer to Figure 4 During 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 76, 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 xEmissions 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.

[0039] 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 78 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.

[0040] 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.

[0041] In addition, the arrangement described herein improves the outlet temperature distribution and mode factor of the primary burner 32. Mixing the combustion products produced by the set of secondary burners 50 with the combustion products of the primary burner 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 burner chamber 94 can range from 0.1% to 100% to reduce NO x emission.

[0042] Figure 5 FIG. 1 shows a combustion section 114 having a set of secondary combustors 150 oriented circumferentially around the primary combustor 132 according to another aspect disclosed herein. The combustion section 114 is similar to Figure 2-4 Thus, like parts will be identified with like numbers increased by 100, and it should be understood that the description of like parts of the combustion section 14 applies to the combustion section 114 unless otherwise specified. In addition, although four small burners 134 are shown as the set of secondary burners 150, it should be understood that any number of small burners 134 is contemplated. Likewise, any number of associated primary fuel injectors 130 and small fuel injectors (not shown) are contemplated, including that they can be the same or different quantities, and the numbers depicted herein are non-limiting examples.

[0043] The combustion section 114 includes an annular arrangement of primary fuel injectors 130 disposed about the engine centerline 120. Each of the primary fuel injectors 130 is fluidly coupled to a primary combustor 132. The primary combustor 132 is defined by a primary combustor liner 138 that includes an outer liner 140 and an inner liner 142 that are concentric relative to each other and annularly around the engine centerline 120. The dome wall 144 together with the primary combustor liner 138 defines a primary combustion chamber 146 that annularly around the engine centerline 120.

[0044] The combustion section 114 also includes a circumferential arrangement of small burners 134 defining the set of secondary burners 150. Each small burner 134 in the set of secondary burners 150 is defined by a secondary burner liner 152 extending generally perpendicularly from the primary burner liner 138. The secondary burner liner 152 defines at least a portion of a secondary combustion chamber 154 circumferentially spaced about the engine centerline 120. The set of secondary burners 150 is fluidly coupled to the primary burner 132 via at least one opening 157 extending through the outer liner 140. More specifically, the secondary combustion chamber 154 terminates at the at least one opening 157 to define a secondary burner outlet 158. In a non-limiting example, each secondary combustion chamber 154 in the set of secondary burners 150 is aligned with the primary fuel injector 130.

[0045] The radial line R intersects the secondary centerline CL2 at the geometric center 190 of the secondary burner outlet 158. The radial line R forms an orientation angle with the secondary centerline CL2, and more specifically, forms a first orientation angle θ1 with the secondary centerline CL2 in the transverse plane TP. The first orientation angle θ1 is measured from the secondary centerline CL2 to the radial line R in a clockwise direction (denoted as "CW").

[0046] The primary burner 132 generates a primary exhaust gas G1 in the primary combustion chamber 146, which is recirculated in a first direction (as a non-limiting example, a clockwise direction (denoted as "CW")) generated by the swirler 68. The set of secondary burners 50 generates a secondary exhaust gas G2 in the secondary combustion chamber 54, which flows into the primary combustion chamber 146 and is recirculated in the same direction as the first direction (clockwise direction CW). The secondary exhaust gas G2 circulates in the primary combustion chamber 146, deficiencies in the O2 level, and reduces the temperature in the primary combustion chamber 146. This causes NO x In another embodiment, it is further contemplated that the primary exhaust gas G1 may be rotated in a counterclockwise direction (denoted as "CCW") ( Figure 6 ), and the secondary exhaust G2 is in the clockwise CW direction.

[0047] Figure 6 A combustion section 214 having a set of secondary combustors 250 oriented circumferentially around a primary combustor 232 is shown according to another aspect disclosed herein. The combustion section 214 is similar to Figure 2-4 Thus, similar parts will be identified with similar numbers increased by 200, and it should be understood that the description of similar parts of the combustion section 14 applies to the combustion section 214 unless otherwise specified. In addition, although four small burners 234 are shown as the set of secondary burners 250, it should be understood that any number of small burners 234 can be envisioned. Likewise, any number of associated primary fuel injectors 230 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.

[0048] The combustion section 214 includes an annular arrangement of primary fuel injectors 230 disposed about the engine centerline 220. Each of the primary fuel injectors 230 is fluidly coupled to a primary combustor 232. The primary combustor 232 is defined by a primary combustor liner 238, which includes an outer liner 240 and an inner liner 242 that are concentric relative to each other and annularly around the engine centerline 120. The dome wall 244, together with the primary combustor liner 238, defines a primary combustion chamber 146 that annularly around the engine centerline 220.

[0049] The combustion section 214 also includes a circumferential arrangement of small burners 234 defining the set of secondary burners 250. Each small burner 234 in the set of secondary burners 250 is defined by a secondary burner liner 252 extending generally perpendicularly from the primary burner liner 238. The secondary burner liner 252 defines at least a portion of a secondary combustion chamber 254 circumferentially spaced about the engine centerline 220. The set of secondary burners 250 is fluidly coupled to the primary burner 232 via at least one opening 257 extending through the outer liner 240. More specifically, the secondary combustion chamber 254 terminates at at least one opening 257 to define a secondary burner outlet 258. In a non-limiting example, each secondary combustion chamber 254 in the set of secondary burners 250 is aligned with the primary fuel injector 230.

[0050] The radial line R intersects the secondary center line CL2 at the geometric center 290 of the secondary burner outlet 258. The radial line R and the secondary center line CL2 form a second orientation angle θ2 in the transverse plane TP. The first orientation angle θ1 ( Figure 5 ) and the second orientation angle θ2 may be the same value, or different values. The second orientation angle θ2 is measured from the secondary center line CL2 to the radial line R in the counterclockwise direction CW.

[0051] The primary burner 232 generates a primary exhaust gas G1 in the primary combustion chamber 246, which is recirculated in a first direction (as a non-limiting example, a clockwise direction CW). The set of secondary burners 250 generates a secondary exhaust gas G2 in the secondary combustion chamber 254, which flows into the primary combustion chamber 246 and is recirculated in a direction opposite to the first direction (as a non-limiting example, a counterclockwise direction CCW). The secondary exhaust gas G2 circulates in the primary combustion chamber 246, deficiencies in the O2 level, and reduces the temperature in the primary combustion chamber 246. This results in NO x Reduction of emissions.

[0052] Figure 7 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 Figure 2-4 The combustion section 14 and Figure 5 Similar parts will be identified with similar numbers increased by 300 relative to the combustion section 14. It should be understood that the description of similar parts of the combustion section 14 applies to the combustion section 314 unless otherwise stated. In addition, although four small burners 334 are shown as the group of secondary burners 350, it should be understood that any number of small burners 334 is contemplated.

[0053] 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. 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.

[0054] The combustion section 314 also includes a plurality of small burners 334, and more specifically, a circumferential arrangement of differently oriented small burners 335. The differently oriented small burners 335 may define the set of secondary burners 350. As a non-limiting example, the differently oriented small burners 335 may include the following: Figure 2 The first plurality of small burners 334a are similarly angled with the small burners 34, wherein the radial line R extends from the centerline 320 and is aligned with the secondary centerline CL2 in the transverse plane TP. The differently oriented small burners 335 may further include the first plurality of small burners 334a with the radial line R extending from the centerline 320 and aligned with the secondary centerline CL2 in the transverse plane TP. Figure 5 The second plurality of small burners 334b ​​are similarly angled with the small burners 134, wherein the radial line forms a fifth burner angle θ5 with the secondary centerline CL2 in the transverse plane TP. The fifth burner angle θ5 is measured in the clockwise direction CW from the secondary centerline CL2 to the radial line R. Although the group of secondary burners 350 shown is Figure 2-4 Small burners 34 and Figure 5 However, it should be understood that the small burners 34, 134, 234 ( Figure 6 )、334( Figure 7 ) can define small burners 335 of different orientations.

[0055] In addition, although Figure 2 The combustion section 14 is shown as having eight small burners 34, and Figure 5-7 The combustion sections 114, 214, and 314 are shown as having four small burners 134, 234, 334, 334a, 334b, respectively, but any number of small burners at any burner angles α, β, θ3, θ4, θ5 described herein can be envisioned. The number and orientation angles of the small burners can be adjusted to achieve adequate mixing between the two exhaust gases G1, G2.

[0056] For control Figure 2-7The method of reducing nitrogen oxides present in the combustion section 14, 114, 214, 314 described includes generating a primary exhaust gas G1 in the primary combustion chamber 46, 146, 246, 346, and generating a secondary exhaust gas G2 in the group of secondary burners 50, 150, 250, 350 including the secondary combustion chamber 54, 154, 254, 354. The method also includes injecting the secondary exhaust gas G2 into the primary combustion zone 94 of the primary combustion chamber 46, 146, 246, 346. By not including dilution holes in the primary combustion zone 94, the method also includes making the primary combustion zone 94 O2 deficient.

[0057] The method may further include flowing compressed air C into the primary combustion chamber 46, 146, 246, 346 and the secondary combustion chamber 54, 154, 254, 354. Wherein, flowing the compressed air C includes receiving 60% to 90% of the compressed air C in the primary combustion chamber 46, 146, 246, 346, and receiving 10% to 40% of the compressed air C in at least one secondary combustion chamber 54, 154, 254, 354. The method may further include starting the turbine engine 10 using the set of secondary combustors 50, 150, 250, 350.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] Further aspects are provided by the subject matter of the following clauses:

[0063] 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; a dome wall, the dome wall extending between the inner liner and the outer liner; a dome inlet, the dome inlet being located in the dome wall; at least one opening, the at least one opening being located in the outer liner, downstream of the 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 a group of secondary combustors, the group of secondary combustors 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; wherein the outer liner has no dilution opening upstream of the at least one opening.

[0064] The combustion section of any preceding clause, further comprising a set of dilution openings located in the outer liner downstream of the at least one opening.

[0065] A combustion section as described in any preceding clause, wherein the at least one secondary combustion chamber is directed towards the dome inlet.

[0066] 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.

[0067] The combustion section of any preceding clause, further comprising a primary fuel injector fluidly coupled to the dome inlet and a mini-fuel injector fluidly coupled to the mini-dome inlet.

[0068] A combustion section as in any preceding clause, wherein the domed inlet defines a primary centerline and the mini-dome inlet defines a secondary centerline that intersects the primary centerline to define a primary burner angle α.

[0069] A combustion section as described in any preceding clause, wherein the primary burner angle is in the range of 25 degrees to 90 degrees.

[0070] A combustion section according to any preceding clause, wherein a radial line extending from an engine centerline of the turbine engine intersects the geometric center of the at least one opening and forms a second burner angle β with the secondary centerline in a radial plane, the secondary burner angle β being complementary to the primary burner angle α.

[0071] A combustion section as in any preceding clause, wherein a radial line extending from the engine centerline intersects a geometric center of the at least one opening and forms an orientation angle with the secondary centerline in a transverse plane.

[0072] A combustion section as in any preceding clause, wherein the orientation angle is a first orientation angle measured in a clockwise direction from the secondary centerline to the radial line.

[0073] A combustion section as in any preceding clause, wherein the orientation angle is a second orientation angle measured in a counter-clockwise direction from the secondary centerline to the radial line.

[0074] A combustion section as described in any preceding clause, wherein the primary combustion chamber produces a primary exhaust gas which is recirculated in a first direction.

[0075] A combustion section as claimed in any preceding clause, wherein the at least one secondary combustion chamber produces a secondary exhaust gas which flows into the primary combustion chamber in a second direction different from the first direction.

[0076] A combustion section as claimed in any preceding clause, wherein the at least one secondary combustion chamber produces a secondary exhaust gas which flows into the primary combustion chamber in the same direction as the first direction.

[0077] A combustion section according to any preceding clause, wherein the at least one opening is a plurality of openings spaced circumferentially around the outer liner, and wherein the set of secondary burners includes a plurality of small burners, and the plurality of small burners are fluidly connected to the primary combustion chamber at corresponding openings in the plurality of openings.

[0078] A combustion section as described in any preceding clause, further comprising a main combustion zone extending a main combustion length between the dome inlet and a geometric center of the at least one opening.

[0079] A combustion section as in any preceding clause, wherein the primary burner extends a primary burner length between the dome inlet and a primary burner outlet, and the main combustion length is 5% to 90% of the primary burner length, inclusive.

[0080] A combustion section as described in any preceding clause, wherein the combustion residence time of the main combustion zone is in the range of 1.0 ms to 12 ms, inclusive.

[0081] A combustion section as described in any preceding clause, wherein the combustion residence time of the at least one secondary combustion chamber is in the range of 1.1 ms to 20 ms, inclusive.

[0082] A combustion section as in any preceding clause, wherein the at least one opening is radially aligned with the primary fuel injector.

[0083] The combustion section of any preceding clause, further comprising a secondary combustor liner extending from the at least one opening to define a secondary combustor outlet, the secondary combustor liner defining at least a portion of the secondary combustion chamber.

[0084] A combustion section as in any preceding clause, wherein the at least one opening is a plurality of openings spaced circumferentially about the outer liner.

[0085] A combustion section as in any preceding clause, wherein the set of secondary burners comprises a plurality of small burners fluidly coupled to the primary combustion chamber at a corresponding plurality of openings.

[0086] A combustion section as in any preceding clause, further comprising a primary fuel injector fluidly coupled to the dome inlet.

[0087] 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: an inner liner, the inner liner being arranged circumferentially about the engine centerline; an outer liner, the outer liner being radially spaced outward from the inner liner and concentric with the inner liner; a dome wall, the dome wall extending between the inner liner and the outer liner; a dome inlet, the dome inlet being located in the dome wall; at least one opening, the at least one opening being located in the outer liner, downstream of the dome inlet; a primary burner outlet, the primary burner outlet being located axially downstream of the dome inlet a primary burner having a primary combustion chamber at least partially defined by the inner liner, the outer liner and the dome wall and extending between the dome inlet and the primary burner outlet; and a set of secondary burners including at least one secondary combustion chamber fluidly coupled to the primary combustion chamber at the at least one opening to define a secondary burner outlet directed toward the dome inlet; wherein the outer liner has no dilution opening upstream of the secondary burner outlet.

[0088] A turbine engine according to any preceding clause, further comprising a set of dilution openings located in the outer liner downstream of the secondary combustor outlet.

[0089] A method for controlling nitrogen oxides present in a combustor of a turbine engine, the method comprising: generating a primary exhaust gas in a primary combustion chamber; generating a secondary exhaust gas in a group of secondary combustors including at least one secondary combustion chamber; injecting the secondary exhaust gas into a main combustion zone of the primary combustion chamber; and starving the main combustion zone of O2.

[0090] A method as in any preceding clause, further comprising flowing compressed air into said primary combustion chamber and said at least one secondary combustion chamber.

[0091] A method as in any preceding clause, wherein flowing the compressed air comprises receiving 60% to 90% of the compressed air in the primary combustion chamber and receiving 10% to 40% of the compressed air in the at least one secondary combustion chamber.

[0092] A method as in any preceding clause, further comprising starting the turbine engine using the set of secondary combustors.

Claims

1. A combustion section for a turbine engine, It is 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 dome entrance located in the dome wall; at least one opening located in the outer liner downstream of the 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 a set of secondary burners, the set of secondary burners comprising at least one secondary combustion chamber, the at least one secondary combustion chamber fluidly coupled to the primary combustion chamber at the at least one opening; Wherein the outer liner has no dilution opening upstream of the at least one opening.

2. The combustion section according to claim 1, It is characterized in that Further included is a set of dilution openings located in the outer liner downstream of the at least one opening.

3. The combustion section according to claim 1, It is characterized in that in, The at least one secondary combustion chamber is directed toward the dome inlet.

4. The combustion section according to claim 1, It is 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.

5. The combustion section according to claim 4, It is characterized in that Further included is a primary fuel injector fluidly coupled to the dome inlet and a mini-fuel injector fluidly coupled to the mini-dome inlet.

6. The combustion section according to claim 4, It is characterized in that in, The dome inlet defines a primary centerline and the mini-dome inlet defines a secondary centerline that intersects the primary centerline to define a primary burner angle α.

7. The combustion section according to claim 6, It is characterized in that in, The primary burner angle is in the range of 25 degrees to 90 degrees.

8. The combustion section according to claim 7, It is characterized in that in, A radial line extending from an engine centerline of the turbine engine intersects the geometric center of the at least one opening and forms with the secondary centerline a second burner angle β in a radial plane, the secondary burner angle β being complementary to the primary burner angle α.

9. The combustion section according to claim 7, It is characterized in that in, A radial line extending from the engine centerline intersects the geometric center of the at least one opening and forms an orientation angle with the secondary centerline in the transverse plane.

10. The combustion section according to claim 9, It is characterized in that in, The orientation angle is a first orientation angle measured in a clockwise direction from the secondary centerline to the radial line.

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