Combustion section having a primary burner and a set of secondary burners

Abstract

A turbine engine having a compressor section, a combustion section, and a turbine section in 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. A primary combustion chamber and a set of secondary burners are fluidly coupled to the primary combustion chamber at the at least one opening.

Description

Technical Field

[0001] This topic generally relates to the combustion section of a turbine engine, and more specifically, to the combustion section having a primary burner and a secondary burner. Background Technology

[0002] A turbine engine is driven by a flow of combustion gases through the engine to rotate multiple turbine blades, which in turn rotate a compressor, thereby supplying compressed air to a combustor for combustion. The combustor can be located within the turbine engine and fluidly connected to the turbine through which the combustion gases flow.

[0003] Hydrocarbon fuels are known to be used in the combustors of turbine engines. Typically, air and fuel are fed into the combustion chamber, where the air mixes with the fuel, and the fuel is then burned in the presence of air to produce hot gases. These hot gases are then fed into the turbine, where they are cooled and expanded to generate power. Byproducts of fuel combustion typically include environmentally harmful byproducts such as nitrogen oxides and nitrogen dioxide (collectively known as 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 for combustion in turbine engines are being explored. Hydrogen, or hydrogen mixed with another element or compound, can be used for combustion; however, hydrogen or hydrogen-blended fuels can result in higher flame temperatures than conventional fuels. That is, hydrogen or hydrogen-blended fuels generally have a wider combustible range and faster combustion rates than conventional fuels such as petroleum-based fuels or mixtures of petroleum and synthetic fuels.

[0005] Standards originating from global air pollution problems specify the NO generated by turbine engine operation x Emissions of UHC and CO. In particular, due to the high burner flame temperature during operation, NO is formed within the burner. x The aim is to reduce NO by adjusting the profile and / or mode within the burner. x Emissions can be reduced while maintaining the desired efficiency. Attached Figure Description

[0006] In the attached diagram:

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

[0008] Figure 2 The combustion section of a turbine engine with a set of secondary combustors is depicted along... Figure 1 Cross-sectional view of line II-II

[0009] Figure 3 It is along Figure 2 A cross-sectional view of the burner in the combustion zone and the small burner in the group of secondary burners, taken from line III-III.

[0010] Figure 4 Is with Figure 3 The same cross-sectional view shows the interaction between the primary fuel / air mixture and the primary exhaust gas, as well as the secondary fuel / air mixture and the secondary exhaust gas.

[0011] Figure 5 It is based on the aspects disclosed in this article. Figure 2 The combustion zone is modified.

[0012] Figure 6 This is based on another aspect disclosed in this article. Figure 2 The combustion zone is modified.

[0013] Figure 7 This is based on another aspect disclosed in this article. Figure 2 The combustion zone is modified. Detailed Implementation

[0014] The aspects disclosed herein relate to combustion sections, particularly combustion sections having primary and secondary combustors. For illustrative purposes, this disclosure will be described in relation to turbine engines. However, it will be understood that the aspects disclosed herein are not limited thereto, and the combustion sections described herein can be implemented in engines (including, but not limited to, turbojet engines, turboprop engines, turboshaft engines, and turbofan engines). The aspects disclosed herein are generally applicable to non-aircraft engines with combustors, such as in other mobile applications and non-mobile industrial, commercial, and residential applications.

[0015] The term "exemplary" as used herein means "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as superior to or advantageous to other implementations. Furthermore, unless explicitly stated otherwise, all embodiments described herein should be considered exemplary.

[0016] As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of the individual components.

[0017] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle, and specifically to the normal operating posture of the gas turbine engine or vehicle. For example, in the case of a gas turbine engine, "front" refers to the position closer to the engine inlet, while "rear" refers to the position closer to the engine nozzle or exhaust port.

[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 fluid flow. The terms "forward" or "front" indicate what is in front of something, and "backward" or "rear" indicate what is behind something. For example, when used in relation to fluid flow, forward / front can indicate upstream, and backward / rear can indicate downstream.

[0019] The term "fluid" can refer to either a gas or a liquid. The terms "fluid connection" and "fluid geoconnection" refer to the ability of fluids to establish a connection between specified areas.

[0020] Furthermore, as used herein, the term "radial" or "radially" refers to a direction away from a common center. For example, in the overall context of a turbine engine, radial refers to the direction along a ray extending between the engine's central longitudinal axis and the engine's outer perimeter.

[0021] All directional references (e.g., radial, axial, proximal, distal, up, down, upward, downward, left, right, lateral, front, rear, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, backward, etc.) may be used for identification purposes to aid the reader's understanding of this disclosure and do not impose limitations, particularly regarding the location, orientation, or use of aspects of the disclosure described herein. Connecting references (e.g., attachment, connection, joint, 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 connecting reference does not necessarily mean that two elements are directly connected and fixed relative to each other. Exemplary figures are for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the accompanying figures may vary.

[0022] Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” include plural references. Furthermore, as used herein, the term “group” or “set” of elements can be any number of elements, including only one.

[0023] As used herein and throughout the specification and claims, approximate language is applied to modify any quantitative representation that may allow for variation without altering its associated essential function. Therefore, values ​​modified by one or more terms such as “about,” “approximately,” “substantially,” and “basically” are not limited to the specified precise values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or system. For example, approximate language may refer to a margin of 1%, 2%, 4%, 5%, 10%, 15%, or 20% of the endpoints of a single value, a range of values, and / or a range of defined values. Scope limitations are combined and interchanged herein and throughout the specification and claims; such scope is identified and includes all subscopes contained herein, unless otherwise indicated by context or language. For example, all scopes disclosed herein include endpoints, and endpoints can be combined independently of each other.

[0024] Figure 1 This is a schematic diagram of a turbine engine 10. As a non-limiting example, the turbine engine 10 can 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 rotatably connects the compressor section 12 and the turbine section 16 such that rotation of one affects rotation of the other, and defines the axis of rotation or centerline 20 of the turbine engine 10.

[0025] Compressor section 12 may include a low-pressure (LP) compressor 22 and a high-pressure (HP) compressor 24 fluidly connected in series with each other. Turbine section 16 may include an LP turbine 28 and an HP turbine 26 fluidly connected in series with each other. Drive shaft 18 may operatively connect the LP compressor 22, HP compressor 24, LP turbine 28, and HP turbine 26 together. Alternatively, drive shaft 18 may include an LP drive shaft (not shown) and an HP drive shaft (not shown). The LP drive shaft may connect the LP compressor 22 to the LP turbine 28, and the HP drive shaft may connect the HP compressor 24 to the HP turbine 26. The LP spool may be defined as a combination of the LP compressor 22, LP turbine 28, and LP drive shaft, such that 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, HP turbine 26, and HP drive shaft, such that 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] Compressor section 12 may include multiple axially spaced stages. Each stage includes a set of circumferentially spaced rotating blades and a set of circumferentially spaced stationary blades. Compressor blades for a stage of compressor section 12 may be mounted to a disc, which is mounted to drive shaft 18. Each set of blades for a given stage may have its own disc. The blades of compressor section 12 may be mounted to a housing that may extend circumferentially around turbine engine 10. It should be understood that the representation of compressor section 12 is merely illustrative and any number of stages may be present. Furthermore, it is contemplated that any other number of components may be present within compressor section 12.

[0027] Similar to compressor section 12, turbine section 16 may include multiple axially spaced stages, each stage having a set of circumferentially spaced rotating blades and a set of circumferentially spaced stationary blades. Turbine blades for one stage of turbine section 16 may be mounted to a disc, which is mounted to drive shaft 18. Each set of blades for a given stage may have its own disc. The blades of turbine section 16 may be circumferentially mounted to the housing. It should be noted that any number of blades, blades, and turbine stages can be present, as the illustrated turbine section is merely schematic. Furthermore, it is contemplated that any other number of components may be present within turbine section 16.

[0028] Combustion section 14 may be arranged in series between compressor section 12 and turbine section 16. Combustion section 14 may be fluidly coupled to at least a portion of compressor section 12 and turbine section 16, such that combustion section 14 at least partially fluidly couples compressor section 12 to turbine section 16. As a non-limiting example, combustion section 14 may be fluidly coupled to HP compressor 24 at its upstream end and to HP turbine 26 at its downstream end.

[0029] During operation of the turbine engine 10, ambient air or atmospheric air is drawn into the compressor section 12 via a fan (not shown) upstream of the compressor section 12, where it is compressed to define pressurized air. This pressurized air can then flow into the combustion section 14, where it mixes with fuel and is ignited to generate combustion gases. The HP turbine 26 extracts some work from these combustion gases, driving the HP compressor 24. The combustion gases are discharged into the LP turbine 28, which extracts additional work to drive the LP compressor 22, and the exhaust gas is ultimately discharged from the turbine engine 10 via an exhaust section (not shown) downstream of the turbine section 16. The drive of the LP turbine 28 drives the LP spool to rotate the fan (not shown) and the LP compressor 22. The pressurized airflow and combustion gases together define the working airflow flowing through the fan, compressor section 12, combustion section 14, and turbine section 16 of the turbine engine 10.

[0030] Figure 2 The combustion section 14 is depicted. Figure 1 The image shows a cross-sectional view along line II-II, which defines a transverse plane (denoted as "TP"). 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 the primary combustor 32. It should be understood that the annular arrangement of fuel injectors may be one or more fuel injectors, and the 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 canister-shaped, canister-annular, or annular arrangement. In a non-limiting example, an annular arrangement is shown disposed within a housing 36. The primary combustor 32 is defined by a primary combustor bushing 38, which includes an outer liner 40 and an inner liner 42 that are concentric with each other and annularly surrounding the centerline 20. A dome wall 44, together with the primary combustor bushing 38, defines an annular primary combustion chamber 46 surrounding the centerline 20.

[0031] Combustion section 14 also includes a circumferential arrangement of miniature burners 34 defining a group of secondary burners 50. As used herein, “miniature” means that a component referred to by the term miniature is smaller than a corresponding similar component without the term miniature (i.e., miniature burner 34 is smaller than primary burner 32). Each miniature burner 34 in the group of secondary burners 50 is defined by a secondary burner bushing 52 extending substantially perpendicularly from primary burner bushing 38. The secondary burner bushing 52 defines at least a portion of secondary combustion chambers 54 circumferentially spaced around a centerline 20. The group of secondary burners 50 is fluidly connected to the primary burner 32 via at least one opening 57 extending through the outer liner 40. More specifically, the secondary combustion chambers 54 terminate at at least one opening 57 to define a secondary burner outlet 58. In a non-limiting example, each secondary combustion chamber 54 in the group of secondary burners 50 is radially aligned with the primary fuel injector 30. The secondary combustion chamber 54 may define a secondary centerline (denoted as "CL2") extending toward the secondary burner outlet 58. A radial line (denoted as "R") extends from the centerline 20 and is aligned with the secondary centerline CL2 in the transverse plane TP.

[0032] Primary burner 32 produces primary exhaust gas (denoted as "G1") in primary combustion chamber 46. The set of secondary burners 50 produces secondary exhaust gas (denoted as "G2") in secondary combustion chamber 54 that flows into primary combustion chamber 46. Secondary exhaust gas G2 circulates in primary combustion chamber 46, resulting in insufficient O2 levels and lowering the temperature within primary combustion chamber 46. This leads to NO... x Emissions reduction.

[0033] Figure 3 Depicting along Figure 2 A cross-sectional view taken along line III-III shows the combustion section 14 as viewed in a radial plane (denoted as "RP"). A primary combustor 32 extends between a dome wall 44 and a primary combustor outlet 48 at a nozzle assembly 56, which defines an inlet 51 leading to the turbine section 16. A dome assembly 60 includes the dome wall 44 and houses a primary fuel injector 30. The primary fuel injector 30 may be fluidly coupled to a fuel inlet 62 via a fuel passage 64, which may be adapted to receive a primary fuel flow (denoted as "F1"). The primary fuel injector 30 may terminate at a fuel outlet (also referred to herein as the 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 burner 32 and be at least partially defined by the housing 36. Compressed air (denoted as "C") may be supplied 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 burner bushing 38 downstream of the miniature burner 34 for connecting the compressed air passage 70 and the primary combustion chamber 46. The primary burner bushing 38 has no dilution openings anywhere upstream of the miniature burner 34. A set of secondary dilution openings 74 may be provided in the secondary burner bushing 52 for connecting the compressed air passage 70 and the secondary combustion chamber 54. As a non-limiting example, when the primary burner 32 is a fuel-rich system, this set of secondary dilution openings 74 is located downstream of the miniature burner 34 for adjusting the burner outlet temperature distribution and mode factor associated with the miniature burner 34 and the primary burner 32. A primary igniter 76 may be fluidly coupled to the primary combustion chamber 46. The secondary igniter 78 can be fluidly connected to the secondary combustion chamber 54. Compressed air C can be split between the primary burner 32 and the set of secondary burners 50, such that the primary burner 32 receives 60% to 90% of the compressed air C from the compressor section 12, while the set of secondary burners 50 receives between 10% and 40% of the compressed air C.

[0035] Each miniature burner 34 includes a miniature dome assembly 80, which includes a miniature dome wall 82 and houses a miniature fuel injector 84. The miniature fuel injector 84 may be fluidly coupled to a secondary fuel passage 86, which may be adapted to receive a secondary fuel flow (referred to herein as "F2"). The miniature fuel injector 84 terminates at a secondary fuel outlet (also referred to herein as a miniature dome inlet 88 leading to a secondary combustion chamber 54). In some embodiments, the miniature fuel injector 84 may include a low-swirling-number swirler 89 arranged circumferentially around the miniature dome inlet 88, i.e., having a number less than 1 and a low tangential velocity. Further contemplation is that the group of secondary burners may not include swirlers but may have non-swirling air passages.

[0036] The dome inlet 66 defines the primary centerline (denoted as "CL1"). The primary burner length (denoted 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. A smaller dome inlet 88 may define a secondary centerline CL2 extending toward the secondary burner outlet 58. The secondary burner outlet 58 intersects the secondary centerline CL2 to define the geometric center 90 of the secondary burner outlet 58. The main combustion zone 94 is defined as the volume between the dome inlet 66 and the geometric center 90. The main combustion length (denoted as "L1")... M The length of the main combustion chamber L is measured parallel to the primary centerline CL1 from the dome wall 44 to the geometric center 90. M It is 5% to 90% of the primary burner length L1. Combustion length L M The combustion residence time of the primary burner 94 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 endpoints. The combustion residence time of the secondary combustion chamber can be in the range of 0.1 ms to 8 ms, including the endpoints. The total combustion residence time of combustion section 14 can be in the range of 1.1 ms to 20 ms, including the endpoints.

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

[0038] refer to Figure 4 During operation, compressed air C can be fed into the primary fuel injector 30 and mixed with the primary fuel stream F1 to define a primary fuel / air mixture (denoted as "FA1"). The primary fuel injector 30, together with the primary igniter 76, defines a primary combustion system with a primary flame. The primary fuel injector 30 can dispense a premixed or partially premixed primary fuel / air mixture FA1. Furthermore, the fuel stream F1 can be diffusion fuel without an air mixture before entering the primary combustion chamber 46. The primary combustion system can be a rich or lean system. A rich combustion system includes a fuel / air ratio higher than the stoichiometric fuel / air ratio, while a lean combustion system includes a fuel / air ratio lower than the stoichiometric fuel / air ratio. The rich system used for the primary burner 32 will generate higher temperatures within the primary combustion chamber 46, thereby providing flame stability for the entire combustion system. When combined with a lean system used for the secondary burners 50, NO is reduced from the secondary combustion chamber 54. x Similarly, the primary burner 32 can be used to reduce NO from the primary combustion chamber 46. x The system is a lean-burn system, wherein the group of secondary burners 50 has a rich-burn system for providing flame stability to the primary burner 32 and the entire combustion system. Furthermore, both the primary burner 32 and the group of secondary burners 50 can be either rich-burn or lean-burn systems. Since both have lean-burn systems, NO... xEmissions are significantly reduced. However, at least one or more of the primary fuel injector 30 or the miniature fuel injector 84 will need to be fuel-rich to provide flame stability. Similarly, both the primary burner 32 and the group of secondary burners 50 can have a fuel-rich system, where NO in the system is reduced. x Lower NO production is achieved by using staged fuels and by reducing O2 levels in the primary burner 32 through the release of products from the secondary burners 50. x This is achieved through [the means].

[0039] Compressed air C can be fed into a small fuel injector 84 and mixed with a secondary fuel stream F2 to define a secondary fuel / air mixture (denoted as "FA2"). The small fuel injector 84, together with a 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 or lean system. The fuel supplied to the primary fuel injector 30 and the small fuel injector 84 can include injectable natural gas or more reactive fuels such as H2 and H2 mixtures. In some embodiments, the turbine engine 10 can be started on conventional fuel using this set of secondary combustors 50, wherein secondary exhaust gas G2 propagates toward a primary combustion chamber 46, which can be fueled using conventional fuel or H2 fuel.

[0040] When the secondary exhaust gas G2 is directed into the primary combustion chamber 46, the primary exhaust gas G1 and the secondary exhaust gas G2 mix, which reduces the O2 level in the primary combustion chamber 46, thereby reducing NO. x Emissions. Fuel staging between the primary combustion chamber 46 and the secondary combustion chamber 54 reduces the fuel / air ratio in these stages of combustion section 14, which helps to further reduce temperature and NO. x Emissions. In contrast, single-stage combustors will have a relatively high fuel / air ratio and higher temperature, which leads to higher NOx emissions. x Emissions. The process of guiding secondary exhaust gas G2 from the miniature combustor 34 into the primary combustion chamber 46 at the primary combustor angle α increases the turbulence level. Turbulence helps to thoroughly mix primary exhaust gas G1 and secondary exhaust gas G2, which improves the uniformity of temperature distribution and again leads to NO emissions. x The reduction.

[0041] Furthermore, the arrangement described herein improves the outlet temperature distribution and mode factor of the primary combustor 32. Due to the increased turbulence generated by the products of mutual collisions, mixing the combustion products from this group of secondary combustors 50 with those from the primary combustor 32 helps improve the temperature distribution within the primary combustion chamber 46. The amount of secondary exhaust gas G2 recirculated in the primary or main combustor chamber 94 can range from 0.1% to 100% to reduce NO. x emission.

[0042] Figure 5 A combustion section 114, having a set of secondary burners 150 circumferentially oriented around a primary burner 132, is shown according to another aspect disclosed herein. The combustion section 114 is similar to... Figure 2-4 Combustion section 14; therefore, similar portions will be identified by similar numbers incremented by 100, and it should be understood that, unless otherwise stated, the description of similar portions of combustion section 14 applies to combustion section 114. Furthermore, although four miniature burners 134 are shown as the group of secondary burners 150, it should be understood that any number of miniature burners 134 can be contemplated. Similarly, any number of associated primary fuel injectors 130 and miniature fuel injectors (not shown) can be contemplated, including whether they are the same or different quantities, and the figures depicted herein are non-limiting examples.

[0043] Combustion section 114 includes an annular arrangement of primary fuel injectors 130 disposed around 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 bushing 138, which includes an outer bushing 140 and an inner bushing 142 that are concentric with each other and annularly surrounding engine centerline 120. A dome wall 144, together with the primary combustor bushing 138, defines an annular primary combustion chamber 146 surrounding engine centerline 120.

[0044] Combustion section 114 also includes a circumferential arrangement of miniature burners 134 defining the set of secondary burners 150. Each miniature burner 134 in the set of secondary burners 150 is defined by a secondary burner bushing 152 extending substantially perpendicularly from the primary burner bushing 138. The secondary burner bushing 152 defines at least a portion of a secondary combustion chamber 154 circumferentially spaced around the engine centerline 120. The set of secondary burners 150 is fluidly connected to the primary burner 132 via at least one opening 157 extending through the liner 140. More specifically, the secondary combustion chamber 154 terminates at 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, a first orientation angle θ1 with the secondary centerline CL2 in the transverse plane TP. The first orientation angle θ1 is measured clockwise (denoted as "CW") from the secondary centerline CL2 to the radial line R.

[0046] Primary burner 132 produces primary exhaust gas G1 in primary combustion chamber 146, which recirculates in a first direction (by way of a non-limiting example, clockwise, denoted as "CW") produced by swirl converter 68. Secondary burners 50 produce secondary exhaust gas G2 in secondary combustion chamber 54, which flows into primary combustion chamber 146 and recirculates in the same direction as the first direction (clockwise CW). The circulation of secondary exhaust gas G2 in primary combustion chamber 146 results in insufficient O2 levels and lowers the temperature within primary combustion chamber 146. This leads to NO... x Emissions reduction. In another embodiment, it is further envisioned that the primary exhaust gas G1 can be 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 burners 250 circumferentially oriented around a primary burner 232, is shown according to another aspect disclosed herein. The combustion section 214 is similar to... Figure 2-4 Combustion section 14; therefore, similar portions will be identified by similar numbers incremented by 200, and it should be understood that, unless otherwise stated, the description of similar portions of combustion section 14 applies to combustion section 214. Furthermore, although four miniature burners 234 are shown as the group of secondary burners 250, it should be understood that any number of miniature burners 234 can be contemplated. Similarly, any number of associated primary fuel injectors 230 and miniature fuel injectors (not shown) can be contemplated, including whether they are the same or different quantities, and the figures depicted herein are non-limiting examples.

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

[0049] Combustion section 214 also includes a circumferential arrangement of miniature burners 234 defining the set of secondary burners 250. Each miniature burner 234 in the set of secondary burners 250 is defined by a secondary burner bushing 252 extending substantially perpendicularly from the primary burner bushing 238. The secondary burner bushing 252 defines at least a portion of a secondary combustion chamber 254 circumferentially spaced around the engine centerline 220. The set of secondary burners 250 is fluidly connected to the primary burner 232 via at least one opening 257 extending through the 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 centerline CL2 at the geometric center 290 of the secondary burner outlet 258. The radial line R and the secondary centerline CL2 form a second orientation angle θ2 in the transverse plane TP. The first orientation angle θ1 ( Figure 5 The second orientation angle θ2 can be the same value or a different value. The second orientation angle θ2 is measured in the counterclockwise direction CW from the secondary centerline CL2 to the radial line R.

[0051] Primary burner 232 produces primary exhaust gas G1 in primary combustion chamber 246, which recirculates in a first direction (clockwise CW, as a non-limiting example). Secondary burner 250 produces secondary exhaust gas G2 in secondary combustion chamber 254, which flows into primary combustion chamber 246 and recirculates in a direction opposite to the first direction (counterclockwise CCW, as a non-limiting example). The circulation of secondary exhaust gas G2 in primary combustion chamber 246 results in insufficient O2 levels and lowers the temperature within primary combustion chamber 246. This leads to NO... x Emissions reduction.

[0052] Figure 7 A combustion section 314, having a set of secondary burners 350 circumferentially oriented around a primary burner 332, is shown according to another aspect disclosed herein. The combustion section 314 is... Figure 2-4 Combustion section 14 and Figure 5 The combination of combustion sections 114. Similar portions will be identified by similar numbers increasing by 300 relative to combustion section 14. It should be understood that, unless otherwise stated, the description of similar portions of combustion section 14 applies to combustion section 314. Furthermore, although four miniature burners 334 are shown as the group of secondary burners 350, it should be understood that any number of miniature burners 334 can be contemplated.

[0053] Combustion section 314 includes an annular arrangement of primary fuel injectors 330 disposed around 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 bushing 338, which includes an outer bushing 340 and an inner bushing 342 that are concentric with each other and annularly surrounding engine centerline 320. A dome wall 344, together with the primary combustor bushing 338, defines an annular primary combustion chamber 346 surrounding engine centerline 320.

[0054] Combustion section 314 also includes a plurality of miniature burners 334, and more specifically, a circumferential arrangement of miniature burners 335 with different orientations. The miniature burners 335 with different orientations may define the group of secondary burners 350. As a non-limiting example, the miniature burners 335 with different orientations may include those... Figure 2 The miniature burners 34 are similarly angled to the first plurality of miniature burners 334a, wherein the radial line R extends from the center line 320 and is aligned with the secondary center line CL2 in the transverse plane TP. Miniature burners 335 with different orientations may further include those... Figure 5 The miniature burner 134 is similarly angled to a second plurality of miniature burners 334b, wherein the radial line and the secondary centerline CL2 form a fifth burner angle θ5 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 burner 34 and Figure 5 The combination of miniature burners 134, but it should be understood that miniature burners 34, 134, and 234 ( Figure 6 ), 334 Figure 7 Any combination of these can define small burners 335 with different orientations.

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

[0056] Used for control Figure 2-7The method for addressing nitrogen oxides present in combustion zones 14, 114, 214, and 314 includes generating primary exhaust gas G1 in primary combustion chambers 46, 146, 246, and 346, and generating secondary exhaust gas G2 in the group of secondary burners 50, 150, 250, and 350, including secondary combustion chambers 54, 154, 254, and 354. The method also includes injecting the secondary exhaust gas G2 into a main combustion zone 94 of the primary combustion chambers 46, 146, 246, and 346. By omitting dilution orifices in the main combustion zone 94, the method further includes ensuring O2 deficiency in the main combustion zone 94.

[0057] The method may further include allowing compressed air C to flow into primary combustion chambers 46, 146, 246, 346 and secondary combustion chambers 54, 154, 254, 354. Flowing compressed air C includes receiving 60% to 90% of the compressed air C in the primary combustion chambers 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 group of secondary combustors 50, 150, 250, 350.

[0058] The benefits associated with the combination of the secondary burners and primary burners described herein, and the associated methods, are that NO reduction is achieved even in demanding cycles with higher operating air pressures, higher temperatures, higher fuel / air ratios, and heated fuels. x Emissions. Typically, a higher fuel / air ratio within the combustion system leads to higher flame temperatures, which in turn result in higher NOx levels. x By having two combustion chambers within the combustion system, fuel can be split between these chambers, thereby reducing the fuel / air ratio in each chamber, resulting in lower temperatures and thus lower NO emissions. x Emissions. By directing combustion products from secondary combustion to the primary combustion chamber, the O2 level in the primary combustion chamber can be reduced, thereby further reducing NO. x Emissions. The combustion section described in this article can be operated using 100% H2 fuel.

[0059] Although described in the context of a turbocharged engine, it should be understood that the combustor described herein can be used for engines with NO emissions. x Any engine with a combustor. It should be understood that the applications of the disclosed aspects discussed herein can also be applied to engines with propeller sections or fan and supercharger sections, as well as turbojet engines and turbine engines.

[0060] Within the scope not described herein, different features and structures of various embodiments may be combined or substituted for each other as needed. The fact that a feature is not shown in all embodiments does not mean that it cannot be shown so, but rather that it is done for the sake of brevity. Therefore, various features of different embodiments may be mixed and matched as needed to form new embodiments, regardless of whether the new embodiments are explicitly described. All combinations or permutations of the features described herein are covered by this disclosure.

[0061] This written description uses examples to illustrate aspects of the disclosure described herein, including best practices, and also enables any person skilled in the art to practice aspects of this disclosure, including making and using any apparatus or system and methods of making any combinations. The patentable scope of aspects of this disclosure is defined by the claims, and may include other examples that would occur to a person skilled in the art. Such other examples are intended to fall within the scope of the claims if they have structural elements that are not indistinguishable from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

[0062] Further details are provided by the following topics:

[0063] A combustion section for a turbine engine, the combustion section comprising: a primary combustor bushing including an inner liner and an outer liner; a dome wall extending between the inner liner and the outer liner; a dome inlet located within the dome wall; at least one opening located within the outer liner downstream of the dome inlet; a primary combustor having a primary combustion chamber defined at least partially by the inner liner, the outer liner, and the dome wall; and a set of secondary combustors including at least one secondary combustion chamber fluidly connected 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 zone according to any of the foregoing clauses further includes a set of dilution openings located in the liner, downstream of the at least one opening.

[0065] According to any of the preceding clauses, the combustion section wherein the at least one secondary combustion chamber is directed toward the dome inlet.

[0066] The combustion section according to any of the foregoing clauses further includes a small dome wall and a small dome inlet, the small dome wall being radially spaced from the outer liner and further defining the at least one secondary combustion chamber, the small dome inlet being located in the small dome wall and fluidly connected to the at least one secondary combustion chamber.

[0067] The combustion section according to any of the foregoing clauses further includes a primary fuel injector and a secondary fuel injector, the primary fuel injector being fluidly connected to the dome inlet and the secondary fuel injector being fluidly connected to the secondary dome inlet.

[0068] According to any of the preceding clauses, the combustion section wherein the dome inlet defines a primary centerline and the smaller dome inlet defines a secondary centerline, the secondary centerline intersecting the primary centerline to define a primary burner angle α.

[0069] According to any of the preceding clauses, the combustion zone wherein the primary burner angle is in the range of 25 degrees to 90 degrees.

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

[0071] According to any of the preceding clauses, the combustion section wherein 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.

[0072] According to any of the preceding clauses, the orientation angle is a first orientation angle measured in a clockwise direction from the secondary centerline to the radial line.

[0073] According to any of the preceding clauses, the combustion zone, wherein the orientation angle is a second orientation angle measured in a counterclockwise direction from the secondary centerline to the radial line.

[0074] According to any of the preceding clauses, the combustion section wherein the primary combustion chamber produces primary exhaust gas that is recirculated in a first direction.

[0075] According to any of the preceding clauses, the combustion section wherein the at least one secondary combustion chamber produces secondary exhaust gas that flows into the primary combustion chamber in a second direction different from the first direction.

[0076] According to any of the preceding clauses, the combustion section wherein the at least one secondary combustion chamber produces secondary exhaust gas that flows into the primary combustion chamber in the same direction as the first direction.

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

[0078] The combustion zone according to any of the foregoing clauses further includes a main combustion zone that extends the main combustion length between the geometric center of the dome inlet and the at least one opening.

[0079] According to any of the preceding clauses, the primary burner extends the primary burner length between the dome inlet and the primary burner outlet, and the main combustion length is 5% to 90% of the primary burner length, including the endpoints.

[0080] According to any of the preceding clauses, the combustion residence time of the main combustion zone is in the range of 1.0 ms to 12 ms, including the endpoints.

[0081] According to any of the preceding clauses, the combustion residence time of the at least one secondary combustion chamber is in the range of 1.1 ms to 20 ms, including the endpoints.

[0082] According to any of the preceding clauses, the combustion section wherein the at least one opening is radially aligned with the primary fuel injector.

[0083] The combustion section according to any of the foregoing clauses further includes a secondary burner bushing extending from the at least one opening to define a secondary burner outlet, the secondary burner bushing defining at least a portion of the secondary combustion chamber.

[0084] According to any of the preceding clauses, the combustion zone, wherein the at least one opening is a plurality of openings circumferentially spaced around the outer liner.

[0085] According to any of the preceding clauses, the combustion section wherein the set of secondary burners includes a plurality of miniature burners fluidly connected to the primary combustion chamber at corresponding multiple openings.

[0086] The combustion section according to any of the foregoing clauses further includes a primary fuel injector fluidly connected to the dome inlet.

[0087] A turbine engine includes a compressor section, a combustion section, and a turbine section arranged in series along an engine centerline. The combustion section includes: an inner liner arranged circumferentially around the engine centerline; an outer liner radially spaced outward from and concentric with the inner liner; a dome wall extending between the inner and outer liners; a dome inlet located within the dome wall; at least one opening located within the outer liner downstream of the dome inlet; and a primary combustor outlet located axially downstream of the dome inlet. The burner extends along its length and is defined by the inner liner and the outer liner; a primary burner having a primary combustion chamber defined at least partially 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 connected to the primary combustion chamber at 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] The turbine engine according to any of the foregoing clauses further includes a set of dilution openings located in the liner, downstream of the secondary burner outlet.

[0089] A method for controlling nitrogen oxides present in a combustor of a turbine engine, the method comprising: generating primary exhaust gas in a primary combustion chamber; generating 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 depleting the main combustion zone of O2.

[0090] The method according to any of the foregoing clauses further includes allowing compressed air to flow into the primary combustion chamber and the at least one secondary combustion chamber.

[0091] According to any of the foregoing provisions of the method, wherein the compressed air flow 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] The method according to any of the foregoing clauses further includes starting the turbine engine using the set of secondary combustors.

Claims

1. A combustion section for a turbine engine, characterized in that, The combustion zone includes: A primary burner bushing, the primary burner bushing comprising an inner bushing and an outer bushing; A dome wall extending between the inner liner and the outer liner; A dome-shaped inlet, located within the dome wall, defining a primary centerline; At least one opening, said at least one opening being located in the outer liner, downstream of the dome entrance; A primary burner having a primary fuel injector and a primary combustion chamber, the primary combustion chamber being at least partially defined by the inner liner, the outer liner, and the dome wall, wherein the primary burner extends between the dome wall and the primary burner outlet, and wherein an upstream direction is defined from the primary burner outlet to the dome inlet; and A set of secondary burners, the set of secondary burners including at least one secondary combustion chamber fluidly connected to the primary combustion chamber at at least one opening, wherein the liner has no dilution opening upstream of the at least one opening, the set of secondary burners including a miniature burner and a miniature fuel injector fluidly connected to a secondary fuel passage, wherein the miniature fuel injector terminates at a miniature dome defining a secondary centerline pointing toward the dome inlet; The secondary exhaust gas G2 from the at least one secondary combustion chamber is directed toward the primary combustion chamber, and at least a portion of the secondary exhaust gas G2 is mixed with the primary exhaust gas G1 upstream of the at least one opening.

2. The combustion zone according to claim 1, characterized in that, It further includes a set of dilution openings located in the outer liner, downstream of the at least one opening.

3. The combustion zone according to claim 1, characterized in that, The miniature burner includes a miniature dome wall and a miniature dome inlet, the miniature dome wall being radially spaced from the outer liner, and the miniature dome inlet being located in the miniature dome wall and fluidly connected to the at least one secondary combustion chamber.

4. The combustion zone according to claim 3, characterized in that, It further includes a primary fuel injector and a secondary fuel injector, the primary fuel injector being fluidly connected to the dome inlet and the secondary fuel injector being fluidly connected to the secondary dome inlet.

5. The combustion zone according to claim 3, characterized in that, in, The small dome-shaped inlet defines the secondary centerline, which intersects the primary centerline to define the primary burner angle α.

6. The combustion zone according to claim 5, characterized in that, in, The primary burner angle α is within the range of 25 degrees or greater and less than 90 degrees.

7. The combustion zone according to claim 6, characterized in that, in, A radial line extending from the engine centerline of the turbine engine intersects the geometric center of the at least one opening and forms a second burner angle β in the radial plane with the secondary centerline, the secondary burner angle β being complementary to the primary burner angle α.

8. The combustion zone according to claim 6, 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.

9. The combustion zone according to claim 8, 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.

10. The combustion zone according to claim 8, characterized in that, in, The orientation angle is a second orientation angle measured in the counterclockwise direction from the secondary centerline to the radial line.

11. The combustion zone according to claim 1, characterized in that, in, The primary combustion chamber produces the primary exhaust gas G1 that is recirculated in the first direction.

12. The combustion zone according to claim 11, characterized in that, in, The at least one secondary combustion chamber generates the secondary exhaust gas G2, which flows into the primary combustion chamber in a second direction different from the first direction.

13. The combustion zone according to claim 1, characterized in that, in, The at least one opening is a plurality of openings circumferentially spaced around the outer liner, and wherein the set of secondary burners includes a plurality of miniature burners fluidly connected to the primary combustion chamber at corresponding openings of the plurality of openings.

14. The combustion zone according to claim 1, characterized in that, It further includes a main combustion zone that extends the main combustion length between the geometric center of the dome inlet and the at least one opening.

15. The combustion zone according to claim 14, characterized in that, in, The primary burner extends the primary burner length between the dome inlet and the primary burner outlet, and the main combustion length is 5% to 90% of the primary burner length, including the endpoints.

16. The combustion zone according to claim 15, characterized in that, in, The combustion residence time in the main combustion zone is in the range of 1.0 ms to 12 ms, including the endpoints.

17. The combustion zone according to claim 16, characterized in that, in, The combustion residence time of the at least one secondary combustion chamber is in the range of 1.1 ms to 20 ms, including the endpoints.

18. The combustion zone according to claim 1, characterized in that, It further includes a primary igniter, which is fluidly connected to the primary combustion chamber.

19. The combustion zone according to claim 1, characterized in that, At least one of the primary fuel injector or the miniature fuel injector is coupled to a fuel system configured to supply hydrogen (H2) fuel or a mixture of hydrogen (H2) fuel to the primary fuel injector or the miniature fuel injector.

20. A turbine engine, characterized in that, include: A compressor section, a combustion section, and a turbine section are arranged in a series flow along the engine centerline, wherein the combustion section includes: A liner, the liner being arranged circumferentially around the centerline of the engine; An outer liner, which is radially outwardly spaced from and concentric with the inner liner; A dome wall extending between the inner liner and the outer liner; A dome-shaped entrance, located within the dome wall; A primary burner having a primary combustion chamber defined at least partially by the inner liner, the outer liner, and the dome wall, and extending between the dome inlet and the primary burner outlet, wherein the primary burner outlet is located at a distance of one primary burner length from the dome inlet, and wherein an upstream direction is defined from the primary burner outlet to the dome inlet, and a downstream direction is defined from the dome inlet to the primary burner outlet; At least one opening, said at least one opening being located in the outer liner and downstream of the dome inlet, wherein said outer liner has no dilution opening upstream of said at least one opening; and A set of secondary burners, the set of secondary burners including at least one secondary combustion chamber, the at least one secondary combustion chamber being fluidly connected to the primary combustion chamber at at least one opening to define a secondary burner outlet, the set of secondary burners including a miniature burner and a miniature fuel injector, the miniature fuel injector being fluidly connected to a secondary fuel passage, wherein the miniature fuel injector terminates at a miniature dome inlet, the miniature dome inlet defining a secondary centerline pointing toward the dome inlet; The secondary exhaust gas G2 from the miniature burner is directed toward the primary combustion chamber, and at least a portion of the secondary exhaust gas G2 is mixed with the primary exhaust gas G1 upstream of the at least one opening.

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