Combustion system having a combustion axial stage having a combustor body configured

Abstract

A combustion system (100) is provided that includes a combustor assembly (102) in an axial stage downstream of a main combustion stage. The assembly comprises a plurality of burner bodies (104), each burner body being arranged to deliver a mixture of reactants. Each combustor body includes a fuel interconnection structure (110) and an air guide structure (112). The structure (110) comprises fuel conduits (118), each fuel conduit being arranged to interconnect with the structure (112). Each fuel conduit extends along a respective longitudinal axis to deliver a respective fuel jet into the air directing structure. The longitudinal axis of each duct (118) is arranged to define a respective angle with respect to a normal to the air guide structure (112) at the injection point. The angle is configured such that a respective fuel flow jet at least partially opposes an air flow passing along the section of the air directing structure.

Description

Technical Field

[0001] The disclosed embodiments generally relate to combustion turbine engines, such as gas turbine engines, and more specifically, to a combustion system having a combustor assembly disposed in a combustion axial stage downstream of the main combustion stage of the combustion system. Background Technology

[0002] As those skilled in the art will understand, axial staged combustion technology has been applied in modern turbines to further increase turbine combustion temperatures and reduce emissions such as nitrogen oxides (NOx) and carbon monoxide (CO). Axial staged combustion is a combustion technology that divides the combustion process into, or otherwise separates into, independent stages. While emissions levels can be reduced by supplying a portion of the fuel downstream of the main combustion stage for ignition, further improvements are needed, especially with fuels (or fuel mixtures) that have high energy density levels, such as those involving hydrogen fuels or hydrogen-rich fuel mixtures. Several patent examples disclosing axial staged combustion technology for combustion turbine engines are as follows: US8752386, US8113000, and US7886539. Summary of the Invention

[0003] In one aspect, a combustion system is provided. The system includes a burner assembly disposed in a combustion axial stage downstream of a main combustion stage. The burner assembly includes a plurality of burner bodies. Each respective burner body is arranged to deliver a respective reactant mixture to the combustion axial stage via an outlet port of the respective burner body. Each burner body includes a fuel interconnection structure and an air guide structure. The air guide structure allows an airflow constituting one of the reactants to pass through. The fuel interconnection structure includes a plurality of fuel conduits, each arranged to interconnect at a segment of the air guide structure. Each of the plurality of fuel conduits extends along a respective longitudinal axis to deliver a respective fuel jet into the airflow passing along that segment of the air guide structure, wherein the fuel constitutes another reactant. A respective longitudinal axis of a respective fuel conduit is arranged to define a respective angle relative to the normal at a corresponding injection point of the air guide structure at that segment. This respective angle is configured such that the respective fuel jet is at least partially opposite to the airflow passing along that segment of the air guide structure. Attached Figure Description

[0004] Figure 1 This is a partial cross-sectional view of one embodiment of the disclosed combustion system, wherein the combustor assembly includes multiple combustor bodies disposed in the combustion axial stage of a gas turbine engine.

[0005] Figure 2An enlarged view of a respective burner body among multiple burner bodies is shown, wherein the respective burner body includes a fuel interconnection structure and an air guiding structure.

[0006] Figure 3 A schematic diagram for conceptualizing the disclosed arrangement is shown, wherein corresponding fuel jets from fuel conduits in the fuel interconnection structure are at least partially opposed to airflow passing through the air guide structure.

[0007] Figure 4 This is an isometric view of an exemplary embodiment of the corresponding burner body.

[0008] Figure 5 This is a partial isometric view of the burner body.

[0009] Figures 6 to 8 These are partial cross-sectional views of corresponding alternative embodiments of the disclosed combustion system.

[0010] Figure 9 This is a partial cross-sectional view of one embodiment of the disclosed combustion system. Detailed Implementation

[0011] During flashback, the flame can propagate upstream, causing it to "flash back" onto the combustion chamber hardware. This continued upstream propagation can cause severe thermal damage to the combustion chamber hardware and related components. For example, hydrogen and hydrogen-rich fuel mixtures tend to exhibit faster kinetics and higher flame velocities compared to conventional turbine fuels, making them more susceptible to flashback.

[0012] The disclosed embodiments provide a reliable and cost-effective technical solution that effectively, for example, suppresses flame backflash in an axial staged combustion system that utilizes fuels (or fuel mixtures) with high energy density levels, such as hydrogen fuels or hydrogen-rich fuel mixtures.

[0013] Before explaining the disclosed embodiments in detail, it should be understood that the disclosed embodiments are not limited in their application to the construction details and component arrangements set forth in this specification or shown in the following drawings. The disclosed embodiments can be practiced or performed in a variety of ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting.

[0014] Various techniques relating to the disclosed embodiments will now be described with reference to the accompanying drawings, wherein like reference numerals denote like elements throughout. The drawings discussed below and the various embodiments used to describe the principles of this disclosure in this patent document are illustrative only and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged apparatus. It should be understood that functions described as being performed by certain system elements can be performed by multiple elements. Similarly, for example, an element can be configured to perform functions described as being performed by multiple elements. Numerous innovative teachings of this application will be described with reference to exemplary, non-limiting embodiments.

[0015] It should be understood that the words or phrases used herein should be interpreted broadly, unless explicitly limited in certain examples. For example, the terms “comprising,” “having,” and “including,” and their derivatives, mean including but not limited to. The singular forms “a,” “an,” and “the” are intended to also include the plural forms, unless the context explicitly indicates otherwise. Furthermore, the term “and / or” as used herein refers to and covers any and all possible combinations of one or more associated listed items. The term “or” is inclusive, meaning and / or, unless the context explicitly indicates otherwise. The phrases “associated with” and “associated with,” and their derivatives, may mean including, being included, communicating with, containing, being contained within, connected to or connected with, linked to or connected with, able to communicate with, cooperate with, interleaved, juxtaposed, adjacent to, combined to or combined with, having, possessing the nature of, or similar meanings. Moreover, while multiple embodiments or constructions may be described herein, any feature, method, step, component, etc., described with respect to one embodiment is equally applicable to other embodiments unless explicitly stated to the contrary.

[0016] Furthermore, although the terms “first,” “second,” and “third,” etc., may be used herein to refer to various elements, information, functions, or behaviors, these elements, information, functions, or behaviors should not be limited by these terms. Rather, these numerical adjectives are used to distinguish different elements, information, functions, or behaviors. For example, a first element, information, function, or behavior may be referred to as a second element, information, or action; similarly, a second element or action may be referred to as a first element, message, function, or behavior, without departing from the scope of this disclosure.

[0017] Furthermore, the term "proximately" may mean that a component is relatively close to but not in contact with another component, or that the component is in contact with the other component, unless the context clearly indicates otherwise. Additionally, the phrase "based on" is intended to mean "at least partially based on," unless otherwise clearly stated. The terms "approximately," "substantially," or similar terms are intended to cover variations in the value within normal industry manufacturing tolerances. If no industry standard is available, 20% variation will fall within the meaning of these terms, unless otherwise stated.

[0018] Those skilled in the art will understand that the hardware and software described in the disclosed embodiments can vary for specific implementations. The examples depicted are for illustrative purposes only and are not intended to imply any architectural limitation of this disclosure. Furthermore, those skilled in the art will recognize that, for simplicity and clarity, this document does not depict or describe the complete structure and operation of all data processing systems applicable to this disclosure. Rather, only portions of data processing systems unique to or necessary for understanding this disclosure are depicted and described. The remaining construction and operation of the data processing system may conform to any of the various current implementations and practices known in the art.

[0019] Figure 1 This is a partial cross-sectional view of one embodiment of a combustion system 100 in a combustion turbine engine (such as a gas turbine engine). In one exemplary embodiment, a combustor assembly 102 is arranged in a combustion axial stage 103 of the engine. The combustion axial stage 103 is located downstream of the engine's main combustion stage (not shown). In one exemplary embodiment, the combustor assembly 102 includes a plurality of combustor bodies 104 (nozzles) circumferentially distributed at radially outward positions in the combustion axial stage 103. Each corresponding combustor body 104 is arranged to deliver a corresponding reactant mixture to the combustion axial stage 103 through an outlet port 108 of the corresponding combustor body 104.

[0020] Unless otherwise specified, the terms upstream and downstream refer to the direction of airflow and / or working gas flow through the combustion system. Unless otherwise specified, the terms axial, radial, and circumferential are defined with reference to the longitudinal axis 20 of the combustion system 100.

[0021] Each corresponding burner body 104 includes a fuel interconnection structure 110 and an air guiding structure 112 through which airflow is directed (schematically indicated by arrow 116). Figure 2In this example, air constitutes one of the reactants. The fuel interconnection structure 110 defines a plurality of fuel conduits 118, each fuel conduit 118 being arranged to interconnect with a segment of the air guide structure 112. Each of the plurality of fuel conduits 118 extends along a corresponding longitudinal axis 120 to deliver a corresponding fuel jet through a corresponding orifice into the airflow passing along that segment of the air guide structure 112, wherein the fuel constitutes another reactant.

[0022] Figure 3 This is a schematic diagram of an arrangement disclosed for conceptualization, wherein, as described in more detail below, the corresponding fuel conduits 118 from the fuel interconnection structure 110 ( Figure 2 The corresponding fuel jet is at least partially opposite to the airflow passing through the air guide structure 112. In one exemplary embodiment, the corresponding longitudinal axis 120 of a corresponding one of the plurality of fuel conduits 118 is arranged to define a corresponding angle θ relative to the normal 124 at the corresponding injection point of that segment of the air guide structure 112. The normal 124 is perpendicular to the tangent 126 at the injection point. In one exemplary embodiment, the corresponding angle θ is configured such that the corresponding fuel jet is at least partially opposite to the airflow passing through that segment of the air guide structure. In one exemplary embodiment, the corresponding angle θ is in the range of -50 degrees to +110 degrees. To establish an example reference coordinate system, if the value of angle θ is equal to 0 degrees, this would represent a completely perpendicular relationship between the corresponding fuel jet and the tangent 126. And when angle θ rotates counterclockwise from the normal, this would be considered a positive angle. Conversely, when angle θ rotates clockwise from the normal, this would be considered a negative angle.

[0023] It should be understood that in some embodiments, the fuel conduits 118 may be arranged in an interlaced manner relative to each other, and need not be arranged to have any particular alignment relative to each other. For example, fuel flows in a generally radial direction in a fuel interconnection structure (such as...) Figure 2 (As shown schematically by the middle arrow 156) does not necessarily mean that fuel lines 118 need to be aligned with each other.

[0024] The aforementioned features (e.g., configuring a corresponding angle θ such that the corresponding fuel jet is at least partially opposite to the airflow passing through that section of the air guide structure) facilitate rapid mixing of fuel and air over a relatively short distance, thereby helping to suppress nitrogen oxide (NOx) emissions. It should be understood that carbon monoxide (CO) emissions are generally reduced due to the characteristics of the axial stage fuel staging arrangement. For example, in some embodiments, only the main combustion stage and the pilot (or head) stage can be actively operating at a certain load level, while the axial stage can be activated at load values ​​above that load level. Before reaching that load level, the airflow will pass through the corresponding combustor body 104 (e.g., axial stage nozzles), making it feasible for the head to operate with relatively less air and higher fuel, and effectively ensuring substantially complete combustion at partial loads, which helps reduce carbon monoxide (CO) emissions.

[0025] In one exemplary embodiment, the corresponding burner body 104 houses the air guiding structure 112 and the fuel interconnection structure 110. In one exemplary embodiment, as... Figure 4 As can be better understood, the corresponding burner body 104 forms a streamlined body, such as blades, rectangular prisms, trapezoidal prisms, etc. The streamlined body has a streamlined cross-sectional profile extending along a longitudinal direction 130, which is perpendicular or inclined to the flow direction 132 of the portion of air flowing outside between adjacent burner bodies 104.

[0026] In one exemplary embodiment, each of the plurality of burner bodies 104 is formed by a corresponding streamlined body. This feature effectively, for example, suppresses pressure drop in the portion of the air flowing externally between adjacent burner bodies 104. The plurality of streamlined burner bodies 104 or nozzles distributed circumferentially make the air passing between these bodies relatively more streamlined and uniform. This airflow is delivered to the head of the combustion system with lower pressure loss and higher uniformity. Compared to, for example, some prior art embodiments, where, for example, some main nozzles may lack air, this improvement in the uniformity of the airflow into the main stage effectively increases the margin against backflash, for example, by distributing the air delivered to each main nozzle substantially uniformly.

[0027] The aforementioned features (each of the plurality of burner bodies 104 being formed by a corresponding streamlined body) further effectively suppress the circumferential space occupied by the plurality of burner bodies 104. Compared to known arrangements involving burners with blunt bodies, in the disclosed embodiments, the circumferential space occupied by the plurality of burner bodies is sufficiently suppressed or otherwise reduced to allow for an increase in the number of circumferentially distributed plurality of burner bodies at radially outward positions of the combustion axis stage. For example, the number of streamlined burner bodies that can be circumferentially distributed at radially outward positions of the combustion axis stage 103 can range from four to one hundred burner bodies. In another exemplary embodiment, the number of streamlined burner bodies that can be circumferentially distributed at radially outward positions of the combustion axis stage 103 can range from ten to forty burner bodies. That is, the number of streamlined burner bodies can be appropriately customized according to the needs of a given application. Compared to known arrangements involving burners with blunt heads, this feature improves the distribution of fuel and air in any given axial stage because the number of streamlined burners can be easily increased in the disclosed embodiments. This, in turn, helps to suppress the formation of regions with uneven (e.g., higher, lower) volumetric heat generation. It should be understood that the rows arranged in the burner body 104 can be staggered. For example, suppose in an exemplary embodiment, the first row of axial stage nozzles includes ten nozzles, and a downstream second row also includes ten nozzles. In this exemplary embodiment, the ten nozzles in the downstream second row can (but are not required to) be staggered circumferentially relative to the nozzles in the first row.

[0028] like Figure 4 and Figure 5 As shown, each corresponding burner body 104 has an air inlet port 134 to receive air forming an airflow in the air guide structure 112. In one exemplary embodiment, each corresponding air guide structure 112 includes a curved portion configured to redirect the airflow within the air guide structure 122 from an axial direction to a radially inward direction, such that a corresponding mixture of reactants discharged through the outlet port 108 of the corresponding burner body 104 forms a corresponding flame in the combustion axial stage 103, such as... Figure 2 The star-shaped line 138 in the diagram is schematically represented.

[0029] In another embodiment, some burner bodies 104 may be arranged in opposite directions relative to the combustion chamber axis, such that the air inlet port 134 is oriented towards the head. For example, as shown, the air inlet port 134 will be located at the trailing edge of the burner body 104 rather than the leading edge. This arrangement allows air that has already undergone some streamlining to be delivered to each receiving nozzle, thereby making the air more uniform if needed and further improving anti-flash margin.

[0030] like Figure 1 and Figure 2 As shown, the respective burner body 104 also defines a fuel reservoir 140, which is fluidly connected via a fuel interconnection structure 110 to deliver fuel to the air guide structure 112. In some embodiments, for example as shown below... Figure 1 and Figure 6 As shown, the fuel manifold 150 is disposed externally relative to the engine housing 152. The fuel manifold 150 is in fluid communication with a cavity 154 within the engine housing 152, and consequently with a fuel reservoir 140 defined within the corresponding burner body 104. In the above embodiment, the fuel manifold 150 is radially aligned relative to the fuel reservoir 140, as shown... Figure 2 Arrow 156 in the diagram is used to represent the symbol.

[0031] In some alternative embodiments, such as Figure 7 and Figure 8 As shown, the fuel manifold 150 can be axially offset relative to the corresponding burner body 104. Figure 7 An embodiment with a fuel line device 160 is shown, which is wired within the combustion chamber housing 153 and the engine housing 152, while Figure 8 An embodiment of the fuel line assembly 160 being wired inside the housings 152 and 153 is shown.

[0032] At least in Figure 1 and Figure 4 It is understood that, in some exemplary embodiments, the corresponding burner body 104 can be secured to the engine housing 152 via a threaded connection 162. This feature facilitates user-friendly personalization and replaceability, as well as the maintainability of the corresponding burner body.

[0033] In one exemplary embodiment, such as Figure 9 As shown, the combustion chamber bushing 164 and the combustion chamber housing 153 can be configured to define an air passage 166 having a cross-sectional area (schematically indicated by double-headed arrow 168) arranged to allow a portion of the externally flowing air (schematically indicated by arrow 170) between adjacent burner bodies 104 to pass through. Figure 9As shown, in one exemplary embodiment, the cross-sectional area of ​​cross-sectional region 168 gradually decreases as it advances upstream away from the combustion axis stage 103 toward the main combustion stage. This feature improves the uniformity of the airflow 170 ultimately delivered to the main stage (e.g., suppressing wake eddies or other turbulence), which in turn helps to further suppress backflash and higher levels of nitrogen oxide (NOx) and carbon monoxide (CO) emissions. This arrangement also allows for a larger area at the expansion from the main stage burner to the bushing, which contributes to flame stability, particularly at lower loads where fuel flow is lower and partial combustion will be problematic.

[0034] like Figure 5 As shown, in one exemplary embodiment, the combustion chamber liner includes a plurality of slots 170, each slot configured to receive a radially inward edge of a respective burner body 104, such that each outlet port 108 is nearly flush with the combustion chamber liner, for example. A suitable clearance can be provided between the respective slot 170 and the radially inward edge of the respective burner body 104 to allow for appropriate thermal expansion / contraction. This feature allows for user-friendly assembly (e.g., press fit or interference fit), which facilitates the integration of the burner body 104 with the combustion chamber liner and effectively avoids the need to weld the burner body 104 to the combustion chamber liner.

[0035] In operation, the disclosed embodiments provide a reliable and cost-effective technical solution for effectively suppressing flame backflash, for example, in the case of an axially staged combustion system utilizing fuels (or fuel mixtures) with high energy density levels, such as hydrogen fuels or hydrogen-rich fuel mixtures.

[0036] In operation, compared to known arrangements involving burners with blunt heads, the disclosed embodiments allow for an increase in the number of circumferentially distributed burner bodies at radially outward positions in the combustion axial stage. This feature allows for improved fuel and air distribution in any given axial stage, thereby helping to suppress the formation of regions with uneven (e.g., higher, lower) volumetric heat generation.

[0037] In operation, the disclosed embodiments are characterized by improving the aerodynamic uniformity of the airflow delivered to the head of the combustion system (e.g., suppressing wake vortices or other turbulence) while reducing pressure loss. Therefore, it should now be understood that the disclosed embodiments are advantageous for effectively achieving multiple objectives, such as providing one or more of the following technical improvements in the burner body: superior fuel / air mixing, better airflow uniformity to the main stage, and suppression of pressure loss in this airflow.

[0038] In operation, the disclosed embodiments are characterized by facilitating rapid mixing of fuel and air over a relatively short distance, thereby helping to suppress nitrogen oxide (NOx) emissions. Furthermore, the disclosed embodiments are characterized by user-friendly replaceability and maintainability of the corresponding burner body.

Claims

1. A combustion system, comprising: The burner assembly is located in an axial combustion stage downstream of the main combustion stage of the combustion system. The burner assembly includes multiple burner bodies, each of which is arranged to deliver a corresponding reactant mixture to the combustion axis via its outlet port. The corresponding burner body includes a fuel interconnection structure and an air guiding structure. The air guiding structure allows airflow, which constitutes one of the reactants, to pass through. The fuel interconnection structure includes multiple fuel conduits, each arranged to interconnect with a segment of the air guiding structure. Each of the multiple fuel conduits extends along a corresponding longitudinal axis to deliver a corresponding fuel jet into an airflow passing through the segment of the air guiding structure. The fuel constitutes another reactant. The longitudinal axis of a corresponding one of the plurality of fuel lines is arranged to define a corresponding angle relative to the normal at the corresponding injection point at the section of the air guide structure, wherein the corresponding angle is configured such that the corresponding fuel jet is at least partially opposite to the airflow passing along the section of the air guide structure.

2. The combustion system according to claim 1, wherein, The corresponding angle is in the range of -50 degrees to +110 degrees.

3. The combustion system according to any one of the preceding claims, wherein, The corresponding burner body houses the air guiding structure and the fuel interconnection structure.

4. The combustion system according to any one of the preceding claims, wherein, The corresponding burner body includes a streamlined body.

5. The combustion system according to claim 4, wherein, The streamlined body has a streamlined cross-sectional profile that extends along a longitudinal direction, which is perpendicular or inclined to the flow direction of a portion of the air flowing externally between adjacent burner bodies of the plurality of burner bodies.

6. The combustion system according to claim 4 or 5, wherein, Each of the plurality of burner bodies has a corresponding streamlined body, wherein the plurality of burner bodies are circumferentially distributed at the radially outward position of the combustion axis stage.

7. The combustion system according to claim 6, wherein, The respective streamlined body of each of the plurality of burner bodies can effectively suppress the pressure drop in the portion of air flowing externally between adjacent burner bodies of the plurality of burner bodies.

8. The combustion system according to claim 6 or 7, wherein, The streamlined body of each of the plurality of burner bodies can effectively suppress the circumferential space occupied by the plurality of burner bodies.

9. The combustion system according to claim 8, wherein, The circumferential space occupied by the plurality of burner bodies is sufficiently suppressed to increase the number of the plurality of burner bodies circumferentially distributed at the radially outward position of the combustion axis stage.

10. The combustion system according to claim 8 or 9, wherein, The number of burner bodies circumferentially distributed at the radially outward position of the combustion axis stage ranges from 4 to 100 burner bodies.

11. The combustion system according to claim 4 or 5, wherein, The streamlined body includes blades.

12. The combustion system according to claim 4 or 5, wherein, The streamlined body includes a rectangular prism or a trapezoidal prism.

13. The combustion system according to any one of the preceding claims, wherein, The corresponding burner body has an air inlet port to receive air that forms the airflow in the air guiding structure.

14. The combustion system according to any one of the preceding claims, wherein, The air guiding structure has a curved portion configured to redirect the airflow from the axial direction to the radially inward direction.

15. The combustion system according to any one of the preceding claims, wherein, The corresponding burner body also includes a fuel storage chamber, which is fluidly connected to the fuel interconnection structure.

16. The combustion system according to any one of the preceding claims, further comprising a fuel manifold disposed externally relative to the housing, the fuel manifold being in fluid communication with a corresponding fuel storage chamber, wherein, The fuel manifold is radially aligned relative to the corresponding burner body.

17. The combustion system according to any one of the preceding claims, further comprising a fuel manifold disposed externally relative to the housing, the fuel manifold being in fluid communication with a corresponding fuel storage chamber, wherein, The fuel manifold is axially offset relative to the corresponding burner body.

18. The combustion system according to any one of the preceding claims, wherein, The corresponding burner body is fixed to the housing by a threaded connection.

19. The combustion system according to any one of the preceding claims, the combustion system further comprising a combustion chamber bushing and a housing, the combustion chamber bushing and the housing defining a cross-sectional region arranged such that an externally flowing airflow between adjacent burner bodies of the plurality of burner bodies passes through, the area of ​​the cross-sectional region gradually decreasing as it advances in a direction from the combustion axial stage toward the main combustion axial stage.

20. The combustion system according to any one of the preceding claims, the combustion system further comprising a combustion chamber liner having a plurality of slots, each slot being configured to receive a radially inward edge of the respective burner body.

21. The combustion system according to claim 9, wherein, The number of burner bodies circumferentially distributed at the radially outward position of the combustion axis stage ranges from 10 to 40 burner bodies.

22. A combustion turbine engine, comprising: Combustion system, the combustion system comprising: The burner assembly is located in an axial combustion stage downstream of the main combustion stage of the combustion system. The burner assembly includes multiple burner bodies, each of which is arranged to deliver a corresponding reactant mixture to the combustion axis via its outlet port. The corresponding burner body includes a fuel interconnection structure and an air guiding structure. The air guiding structure allows airflow, which constitutes one of the reactants, to pass through. The fuel interconnection structure includes multiple fuel conduits, each arranged to interconnect with a segment of the air guiding structure. Each of the multiple fuel conduits extends along a corresponding longitudinal axis to deliver a corresponding fuel jet into an airflow passing through the segment of the air guiding structure. The fuel constitutes another reactant. The longitudinal axis of a corresponding one of the plurality of fuel lines is arranged to define a corresponding angle relative to the normal at the corresponding injection point at the section of the air guide structure, wherein the corresponding angle is configured such that the corresponding fuel jet is at least partially opposite to the airflow passing along the section of the air guide structure.

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