Improved fuel circuit for fuel injectors

Abstract

The present invention is entitled "Improved fuel circuit for a fuel injector". A fuel injector (200) includes a front end wall (206) and a rear end wall (208). The fuel injector (200) also includes a side wall (204) extending between the front end wall (206) and the rear end wall (208). The front end wall (206), the rear end wall (208) and the side wall (204) together define an opening (210) for air to pass through. At least one fuel injection member (212) is disposed in the opening (210) and extends between the end walls (206, 208). A fuel circuit (250) is defined in the fuel injector (200). The fuel circuit (250) includes an inlet chamber (252) defined in the front end wall (206) of the fuel injector (200). The fuel circuit (250) also includes a fuel passage (254) extending from the inlet chamber (252) and in fluid communication with the inlet chamber. The fuel passage (254) is defined within the at least one fuel injection member (212). The fuel passage (254) has a cross-sectional area that varies along the length of the fuel injection member (212).

Description

Technical Field

[0001] The present disclosure relates generally to fuel injectors for gas turbine combustors, and more particularly, to fuel injectors for use with axial fuel staging (AFS) systems associated with such combustors. Background Art

[0002] Turbines are used in various industries and applications for energy transfer purposes. For example, a gas turbine engine typically includes a compressor section, a combustion section, a turbine section, and an exhaust section. The compressor section gradually increases the pressure of the working fluid entering the gas turbine engine, and supplies the compressed working fluid to the combustion section. The compressed working fluid and fuel (e.g., natural gas) are mixed in the combustion section and burned in the combustion chamber to generate high-pressure and high-temperature combustion gases. The combustion gases flow from the combustion section into the turbine section, where the combustion gases expand to do work. For example, the expansion of the combustion gases in the turbine section can rotate a rotor shaft connected to, for example, a generator to generate electricity. The combustion gases then leave the gas turbine via the exhaust section.

[0003] In some burners, the generation of combustion gases occurs in two spaced-apart stages. Such burners are referred to herein as including an "axial fuel staging" (AFS) system, which delivers fuel and oxidant to one or more fuel injectors downstream of the head end of the burner. In a burner with an AFS system, the main fuel nozzle at the upstream end of the burner injects fuel and air (or a fuel / air mixture) into the main combustion zone in an axial direction, and the AFS fuel injector located at the downstream position of the main fuel nozzle injects fuel and air (or a second fuel / air mixture) as a cross flow into the auxiliary combustion zone downstream of the main combustion zone. The cross flow is roughly transverse to the flow of the combustion products from the main combustion zone. In some cases, it is desirable to introduce fuel and air as a mixture into the auxiliary combustion zone. Therefore, the mixing capacity of the AFS injector affects the overall operating efficiency and / or emissions of the gas turbine.

[0004] Typically, an AFS injector includes a hollow injection member having a plurality of fuel outlets that inject fuel to be mixed with air prior to combustion in the auxiliary combustion zone. However, the use of hollow fuel injection members is problematic. For example, recirculation of fuel within the hollow injection member and uneven pressure drop of the fuel across each of the plurality of fuel outlets may result in uneven distribution of the fuel within the fuel injector. Both the recirculation within the fuel injection member and the uneven pressure drop may result in uneven mixing of fuel and air within the fuel injector, which results in a loss of overall operating efficiency of the gas turbine.

[0005] Therefore, an improved fuel injector is desired in the art that can distribute fuel evenly along its entire length. Specifically, a fuel injector is desired that advantageously minimizes recirculation vortices and flow vortices and balances pressure drop along its entire length, thereby reducing overall emissions of a gas turbine. Summary of the invention

[0006] Various aspects and advantages of fuel injectors and combustors according to the present disclosure will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the technology.

[0007] According to one embodiment, a fuel injector is provided. The fuel injector includes a front end wall and a rear end wall disposed opposite to the front end wall. The fuel injector also includes a side wall extending between the front end wall and the rear end wall. The front end wall, the rear end wall and the side wall together define an opening for air to pass through. At least one fuel injection component is disposed in the opening and extends between the end walls. A fuel circuit is defined in the fuel injector. The fuel circuit includes an inlet chamber defined in the front end wall of the fuel injector. The fuel circuit also includes a fuel channel extending from the inlet chamber and in fluid communication with the inlet chamber. The fuel channel is defined in the at least one fuel injection component. The fuel channel has a cross-sectional area that varies along the length of the fuel injection component.

[0008] According to another embodiment, a burner is provided. The burner includes a head end portion having an end cover and at least one fuel nozzle extending from the end cover. A combustion liner extends between the head end portion and the rear frame and defines a combustion chamber. The burner also includes a fuel injector, which is disposed downstream of the at least one fuel nozzle and is in fluid communication with the combustion chamber. The fuel injector includes a front end wall and a rear end wall disposed opposite to the front end wall. The fuel injector also includes a side wall extending between the front end wall and the rear end wall. The front end wall, the rear end wall and the side wall together define an opening for air to pass through. At least one fuel injection member is disposed in the opening and extends between the end walls. A fuel circuit is defined in the fuel injector. The fuel circuit includes an inlet chamber defined in the front end wall of the fuel injector. The fuel circuit also includes a fuel channel extending from the inlet chamber and in fluid communication with the inlet chamber. The fuel channel is defined in the at least one fuel injection member. The fuel channel has a cross-sectional area that varies along the length of the fuel injection member.

[0009] These and other features, aspects and advantages of the present fuel injector and combustor will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present technology and, together with the description, serve to explain the principles of the present technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A complete and enabling disclosure of the present fuel injector and combustor, including the best mode of making and using the present system and method, is set forth in this specification with reference to the accompanying drawings, in which:

[0011] Figure 1 is a schematic diagram of a turbine according to an embodiment of the present disclosure;

[0012] Figure 2 is a schematic cross-sectional illustration of a burner according to an embodiment of the present disclosure;

[0013] Figure 3 shows a perspective view of a fuel injection assembly separated from a combustor according to an embodiment of the present disclosure;

[0014] Figure 4 shows a cross-sectional plan view of a fuel injection assembly attached to a combustor according to an embodiment of the present disclosure;

[0015] Figure 5 shows a partial cross-sectional plan view of a fuel injection assembly according to an embodiment of the present disclosure;

[0016] Figure 6 shows a cross-sectional side view of a fuel injector according to an embodiment of the present disclosure;

[0017] Figure 7 shows a cross-sectional side view of a fuel injector according to an embodiment of the present disclosure;

[0018] Figure 8 shows a cross-sectional side view of a fuel injector according to an embodiment of the present disclosure;

[0019] Fig. 9 shows a cross-sectional plan view of a fuel injector according to an embodiment of the present disclosure;

[0020] Fig.10 shows a cross-sectional plan view of a fuel injector according to an embodiment of the present disclosure;

[0021] Fig.11 shows a cross-sectional plan view of a fuel injector according to an embodiment of the present disclosure; and

[0022] Fig.12 A cross-sectional plan view of a fuel injector according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0023] Reference will now be made in detail to embodiments of the present fuel injector and burner, one or more examples of which are shown in the accompanying drawings. Each example is provided by way of explanation of the present technology, rather than limitation of the present technology. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present technology without departing from the scope or essence of the present technology as protected by the claims. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, the present disclosure is intended to cover such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0024] The detailed description uses numbers and letter names to refer to the features in the drawings. Similar or similar names in the drawings and the specification have been used to refer to similar or similar parts of the present invention. 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 the various components.

[0025] As used herein, the terms "upstream" (or "upward") and "downstream" (or "downward") refer to relative directions relative to the flow of a fluid in a fluid passage. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction toward which the fluid is flowing. The term "radially" refers to a relative direction that is substantially perpendicular to an axial centerline of a particular component, the term "axially" refers to a relative direction that is substantially parallel and / or coaxially aligned with an axial centerline of a particular component, and the term "circumferentially" refers to a relative direction that extends around the axial centerline of a particular component.

[0026] Approximate terms, such as "substantially" or "about" include values ​​within ten percent greater or less than the specified value. When used in the context of an angle or direction, such terms include values ​​within ten degrees greater or less than the angle or direction. For example, "substantially vertical" includes directions within ten degrees of vertical in any direction (e.g., clockwise or counterclockwise).

[0027] Now refer to the accompanying drawings, Figure 1 A schematic diagram of one embodiment of a turbine is shown, which in the illustrated embodiment is a gas turbine 10. Although an industrial or land-based gas turbine is shown and described herein, the present disclosure is not limited to industrial and / or land-based gas turbines unless otherwise indicated in the claims. For example, the present invention as described herein can be used for any type of turbine, including but not limited to a steam turbine, an aircraft gas turbine, or a marine gas turbine.

[0028] As shown in the figure, the gas turbine 10 generally includes an inlet section 12, a compressor section 14 disposed downstream of the inlet section 12, and a plurality of combustors 17 ( Figure 2 ), a turbine section 18 disposed downstream of the combustor section 16, and an exhaust section 20 disposed downstream of the turbine section 18. In addition, the gas turbine 10 may include one or more shafts 22 coupled between the compressor section 14 and the turbine section 18.

[0029] The compressor section 14 may generally include a plurality of rotor disks 24 (one of which is shown) and a plurality of rotor blades 26 extending radially outward from and connected to each rotor disk 24. Each rotor disk 24, in turn, may be coupled to or form part of a shaft 22 extending through the compressor section 14.

[0030] The turbine section 18 may generally include a plurality of rotor disks 28 (one of which is shown) and a plurality of rotor blades 30 extending radially outward from and interconnected to each rotor disk 28. Each rotor disk 28, in turn, may be coupled to or form a portion of a shaft 22 extending through the turbine section 18. The turbine section 18 also includes an outer casing 31 that circumferentially surrounds a portion of the shaft 22 and the rotor blades 30, thereby at least partially defining a hot gas path 32 through the turbine section 18.

[0031] During operation, a working fluid, such as air 15, flows through the inlet section 12 and into the compressor section 14, where the air 15 is gradually compressed, thereby providing pressurized or compressed air 19 to the combustors of the compressor section 16. The pressurized air is mixed with fuel and combusted within each combustor to produce combustion gases 34. From the combustor section 16, the combustion gases 34 flow through a hot gas path 32 and into the turbine section 18, where energy (kinetic and / or thermal energy) is transferred from the combustion gases 34 to the rotor blades 30, causing the shaft 22 to rotate. The mechanical rotational energy can then be used to power the compressor section 14 and / or generate electricity. The combustion gases 34 leaving the turbine section 18 can then be discharged from the gas turbine 10 via the exhaust section 20.

[0032] Figure 2 1 is a schematic representation of a combustor 17 that may be included in a can annular combustion system for a heavy-duty gas turbine. In a can annular combustion system, a plurality of combustors 17 (e.g., 8, 10, 12, 14, 16, or more) are positioned in an annular array about a shaft 22 that connects the compressor section 14 to the turbine section 18. The turbine section 18 may be operably connected (e.g., via the shaft 22) to a generator (not shown) to generate electrical power.

[0033] like Figure 2As shown in FIG. 1 , the combustor 17 may define an axial direction A and a circumferential direction C extending around the axial direction A. The combustor 17 may also define a radial direction R perpendicular to the axial direction A.

[0034] exist Figure 2 In the embodiment of the present invention, the combustor 17 includes a combustion liner 42, which contains the combustion gases 34 and transmits the combustion gases to the turbine. The combustion liner 42 may have a cylindrical liner portion and a conical transition portion separated from the cylindrical liner portion, as in many conventional combustion systems. Alternatively, the combustion liner 42 may have a monolithic body (or "monolith") structure, in which the cylindrical portion and the conical portion are integral with each other. Therefore, any discussion of the combustion liner 42 herein is intended to cover both conventional combustion systems with separate liners and transition pieces and those combustion systems with monolithic liners. In addition, the present disclosure is also applicable to those combustion systems in which the transition piece of the turbine and the nozzle of the first stage are integrated into a single unit (sometimes referred to as a "transition nozzle" or "integrated outlet piece").

[0035] The combustion liner 42 is surrounded by an outer sleeve 44 that is spaced radially outward of the combustion liner 42 to define a cooling flow ring 132 between the combustion liner 42 and the outer sleeve 44. The outer sleeve 44 may include a flow sleeve portion at a forward end and an impingement sleeve portion at a rearward end, as in many conventional combustion systems. Alternatively, the outer sleeve 44 may have a unitary body (or "single sleeve") construction, wherein the flow sleeve portion and the impingement sleeve portion are integrated with each other in the axial direction A. As previously mentioned, any discussion of the outer sleeve 44 herein is intended to cover both conventional combustion systems having separate flow sleeves and impingement sleeves and combustion systems having a single sleeve outer sleeve.

[0036] The head end portion 120 of the combustor 17 includes one or more fuel nozzles 122 extending from an end cover 126 at the front end of the combustor 17. The fuel nozzle 122 has a fuel inlet 124 at an upstream (or inlet) end. The fuel inlet 124 may be formed by the end cover 126. The downstream (or outlet) end of the fuel nozzle 122 extends through a combustor cap 128.

[0037] The head end portion 120 of the combustor 17 is at least partially surrounded by a forward casing 130 that is physically coupled and fluidly connected to a compressor discharge casing 140. The compressor discharge casing 140 is fluidly connected to the compressor section 14 (e.g., Figure 114 and 15. The compressed air 19 flows from the compressor discharge casing 140 into the cooling flow annulus 132 through holes in the outer casing 44 near the aft end 118 of the combustor 17. Because the cooling flow annulus 132 is fluidly coupled to the head end section 120, the compressed air 19 travels upstream from near the aft end 118 of the combustor 17 to the head end section 120, where the compressed air 19 reverses direction and enters the fuel nozzles 122.

[0038] The fuel nozzle 122 introduces fuel and air as a main fuel / air mixture 46 into the main combustion zone 50 at the front end of the combustion liner 42, where the fuel and air are burned. In one embodiment, the fuel and air are mixed within the fuel nozzle 122 (e.g., in a premixing fuel nozzle). In other embodiments, the fuel and air may be introduced separately into the main combustion zone 50 and mixed within the main combustion zone 50 (e.g., as may occur through a diffusion nozzle). Reference herein to a "first fuel / air mixture" should be interpreted as describing both a premixed fuel / air mixture and a diffusion-type fuel / air mixture, either of which may be produced by the fuel nozzle 122.

[0039] The combustion gases from the primary combustion zone 50 travel downstream toward the rear end 118 of the combustor 17. One or more fuel injectors 100 introduce fuel and air as a secondary fuel / air mixture 56 into the secondary combustion zone 60, where the fuel and air are ignited by the primary combustion zone combustion gases to form a combined combustion gas product stream 34. Such a combustion system having axially separated combustion zones within a single combustor 17 is described as an "axial fuel staging" (AFS) system, and the injector assembly 100 may be referred to herein as an "AFS injector."

[0040] In the illustrated embodiment, fuel for each injector assembly 100 is supplied from the head end of the combustor 17 via a fuel inlet 154. Each fuel inlet 154 is coupled to a fuel supply line 104, which is coupled to a respective injector assembly 100. It should be appreciated that other methods of delivering fuel to the injector assemblies 100 may be employed, including supplying fuel from an annular manifold or from a radially oriented fuel supply line extending through the compressor discharge casing 140.

[0041] Figure 2It is further shown that the injector assembly 100 can be oriented at an angle θ (theta) relative to the centerline 70 of the combustor 17. In the illustrated embodiment, the leading edge portion of the injector 100 (i.e., the portion of the injector 100 located closest to the head end) is oriented away from the centerline 70 of the combustor 17, while the trailing edge portion of the injector 100 is oriented toward the centerline 70 of the combustor 10. The angle θ defined between the longitudinal axis 75 of the injector 100 and the centerline 70 can be between 0 degrees and ±90 degrees, between 0 degrees and ±80 degrees, between 0 degrees and ±70 degrees, between 0 degrees and ±60 degrees, between 0 degrees and ±50 degrees, between 0 degrees and ±40 degrees, between 0 degrees and ±30 degrees, between 0 degrees and ±20 degrees, or between 0 degrees and ±10 degrees, or any intermediate value therebetween.

[0042] Figure 2 The injector assembly 100 is shown oriented at a positive angle relative to the centerline 70 of the combustor. In other embodiments (not separately shown), it may be desirable to orient the injector 100 at a negative angle relative to the centerline 70, such that the leading edge portion is closer to the centerline 70 and the trailing edge portion is farther from the centerline 70. In one embodiment, if set at a non-zero angle, all of the injector assemblies 100 for the combustor 17 are oriented at the same angle (i.e., all are oriented at the same positive angle, or all are oriented at the same negative angle).

[0043] The injector assembly 100 injects the secondary fuel / air mixture 56 into the combustion liner 42 in a direction transverse to the centerline 70 and / or the flow of combustion products from the primary combustion zone, thereby forming the secondary combustion zone 60. The combined combustion gases 34 from the primary and secondary combustion zones travel downstream through the aft end 118 of the combustor can 17 and into the turbine section 18 ( Figure 1 ), wherein combustion gases 34 expand to drive turbine section 18 .

[0044] It is noteworthy that in order to enhance the operating efficiency of the gas turbine 10 and reduce emissions, it is desirable that the injector 100 thoroughly mix the fuel and the compressed gas to form the second fuel / air mixture 56. Therefore, the injector embodiments described below are advantageous for improving mixing. In addition, because the fuel injector 100 includes a large number of fuel injection ports, as further described below, the ability to introduce fuels having a wide range of heat release values ​​is increased, providing greater fuel flexibility for gas turbine operators.

[0045] Figure 3 An exemplary fuel injector assembly 100 according to an embodiment of the present disclosure is shown. As shown, the injector assembly 100 may include a fuel injector 200 and a boss 300. Although the fuel injector 200 and the boss 300 are Figure 3Although shown as two separate components coupled together, in many embodiments, the fuel injector 200 and the boss 300 may be a single integrally formed component.

[0046] As shown, the fuel injector 200 includes end walls 202 spaced apart from each other and side walls 204 extending between the end walls 202. In many embodiments, when installed in the combustor 17, the side walls 204 of the fuel injector 200 may extend parallel to the axial direction A ( Figure 5 The end wall 202 of the fuel injector 200 includes a front end wall 206 and a rear end wall 208 disposed opposite to each other. The side walls 204 may be spaced apart from each other and may extend between the front end wall 206 and the rear end wall 208.

[0047] In many embodiments, both the front end wall 206 and the rear end wall 208 are arcuate and have a generally rounded cross-sectional shape, and the sidewalls may extend generally straight between the end walls 202, such that the end wall 202 and the sidewalls 204 together define a first opening 210 having a cross-section shaped as a geometric stadium. In various embodiments, the sidewalls 204 may be longer than the end walls 204, such that the opening 210 is longest in the axial direction A when attached to the combustor 17. In some embodiments, as shown, the end wall 202 and the sidewalls 204 may together define a geometric stadium-shaped area, i.e., a rectangle with rounded ends, which outlines and defines the perimeter of the first opening 210. In other embodiments (such as Fig. 9 and Fig.10 ), the end wall 202 may be linear such that the end wall 202 and the side wall 204 together define a rectangular shaped region.

[0048] In many embodiments, the first opening 210 may be used to provide a path for the compressed air 19 from the compressed air chamber 142 to travel through and mix with the fuel before reaching the auxiliary combustion zone 60. Figure 3 As shown, the fuel injector 200 may also include at least one fuel injection member 212 that may be disposed within the first opening 210 and extend between the end walls 202. In an exemplary embodiment, the fuel injection member 212 may extend axially between the end walls 202. The fuel injection member 212 may be a substantially hollow body for providing fuel to the first opening 210 via a plurality of fuel ports 214 defined by the fuel injection member 212. Each fuel injection member 212 may extend from a first end located at the front end wall 206 to a second end located at the rear end wall 208. In many embodiments, the fuel injection member 212 may extend in a straight line (i.e., without an abrupt change in direction) from the front end wall 206 to the rear end wall 208 along the axial direction A.

[0049] exist Figure 3In the illustrated embodiment, the fuel injector is shown having two fuel injection members 212 spaced apart from each other within the opening 210. However, the fuel injector 200 may have any number of fuel injection members 212 (e.g., 1, 3, 4, 5, 6, or more) disposed within the first opening 210, and the present disclosure is not limited to any particular number of fuel injection members 212 unless specifically recited in the claims.

[0050] like Figure 3 As shown, the fuel injector 200 also includes a conduit fitting 220 formed integrally with the front end wall 206. The conduit fitting 220 can be fluidly coupled to the fuel supply line 104 so that it is used to receive a flow of fuel from the fuel supply line 104. The conduit fitting 220 can then distribute the fuel to the fuel injection member 212 and / or the sidewall fuel injection members 222, 224 ( Figure 4 ) to be injected into the first opening 210 and mixed with the compressed air 19. The conduit fitting 220 may have any suitable size and shape and may be integrally formed with or coupled to any suitable portion of the fuel injector 200 that enables the conduit fitting 220 to function as described herein.

[0051] In many embodiments, the entire fuel injector 200 can be integrally formed as a single component. That is, each subcomponent (e.g., end wall 202, side wall 204, fuel injection member 212, and any other subcomponent of fuel injector 200) can be manufactured together as a single body. In an exemplary embodiment, a single body of fuel injector 200 can be produced by utilizing an additive manufacturing method (such as 3D printing). In this regard, utilizing an additive manufacturing method, fuel injector 200 can be integrally formed as a single piece of continuous metal, and therefore can include fewer subcomponents and / or joints than existing designs. Forming fuel injector 200 as a whole by additive manufacturing can advantageously improve the entire assembly process. For example, integral formation reduces the number of separate parts that must be assembled, thereby reducing the associated time and total assembly cost. In addition, existing problems such as leakage, joint quality between separate parts, and overall performance can be advantageously reduced. In other embodiments, manufacturing techniques such as casting or other suitable techniques can be used.

[0052] like Figure 3 As shown, the fuel injector assembly 100 may further include a boss 300. Figure 4 and Figure 5As shown, the boss 300 may be fixedly coupled to the combustion liner 42 at a first end 302 and may extend radially through the cooling flow ring 132 to a flange portion 306 disposed at a second end 304. The flange portion 306 may be substantially flat and planar such that it provides a smooth surface for the fuel injector 200 to sealingly couple to the flange portion, which minimizes the possibility of fuel / air leakage during operation of the gas turbine 10. In many embodiments, the boss 300 may include a jacket portion 308 extending between the first end 302 and the flange portion 306.

[0053] The boss 300 may define a second opening 310 that is aligned with the first opening 210 and forms a path for fuel and air to be introduced into the auxiliary combustion zone 60 ( Figure 4 ). For example, in some embodiments, the second opening 310 and the first opening 210 may share a common central axis ( Figure 4 and Figure 5 ). In this arrangement, the boss 300 provides fluid communication between the fuel injector 200 and the auxiliary combustion zone 60. More specifically, the second opening 310 may be defined by the flange portion 306 and the jacket portion 308 of the boss 300, and may be shaped as a stadium geometry, i.e., a rectangle with semicircular ends.

[0054] In many embodiments, the size of the second opening 310 may vary between the fuel injection assemblies 100 on the combustor 17. For example, because the second opening 310 is used at least in part to meter the flow of air and fuel introduced into the auxiliary combustion zone 60, in some embodiments, it may be advantageous to introduce more / less air and fuel through one or more of the fuel injection assemblies 100 on the combustor 17. This differential metering may be achieved by varying the size of the second opening 310 of at least one fuel injector assembly 100 relative to at least one other fuel injector assembly 100, depending on the desired volume of air and fuel to be introduced into the auxiliary combustion zone 60 at a given circumferential location.

[0055] Figure 4 A cross-sectional view of a fuel injection assembly 100 coupled to a combustor 17 is shown. Figure 4 As shown, the jacket portion 308 extends from the flange 306 through the cooling flow ring 132 to the combustion liner 42. In many embodiments, the jacket portion 308 creates an obstruction to the flow of compressed air 19 through the cooling flow ring 132 ( Figure 4 ). However, if Figure 3As shown, the jacket portion 306 is shaped like a stadium with its major axis parallel or substantially parallel to the direction of the flow of compressed air 19. This advantageously creates less obstruction of the compressed air 19 in the cooling flow annulus 132 than, for example, a jacket portion having a circular shape, while still providing sufficient area for fuel and air to be introduced through the second openings 310 and entrained into the auxiliary combustion zone 60.

[0056] In many embodiments, as shown, the sidewall 204 may include a first fuel injection member 222 and a second fuel injection member 224. For example, the first fuel injection member 222 and the second fuel injection member 224 may be integrally formed within the sidewall 204 such that they serve to partially define the first opening 210 and to inject fuel through the plurality of fuel ports 210 for mixing within the fuel injector 200. In various embodiments, as shown, the fuel injection member 212 may include a third fuel injection member 226 and a fourth fuel injection member 228 positioned between the first fuel injection member 222 and the second fuel injection member 224 defined in the sidewall 204.

[0057] In an embodiment with four fuel injection members, there may be six injection planes within the fuel injector 200. For example, a single row of fuel ports 214 may be defined on each of the sidewall fuel injection members 222, 224, which provides two of the fuel injection planes. The other four fuel injection planes may be disposed on the centrally located fuel injection members 226, 228. For example, each fuel injection member 226, 228 may have a single row of fuel ports 214 disposed on either side of the fuel injection members 226, 228, which provides four fuel injection planes. In some embodiments, the first fuel injection member 222 and the second fuel injection member 224 may converge toward each other as they extend radially inward. In this way, the overall geometric stadium area defined by the end wall 202 and the side wall 204 gradually decreases from the radially outer surface to the radially inner surface of the fuel injector 200.

[0058] like Figure 4 As shown, the fuel injection members 226, 228 may each have an outer cross-sectional profile 240 defining a teardrop shape. As shown, the teardrop shape is characterized by having a leading edge 234, a trailing edge 236 opposite the leading edge 234, and a wall 238. The wall 238 may extend between the leading edge 234 and the trailing edge 236. In many embodiments, the wall 238 of each fuel injection member 226, 228 defines a plurality of fuel injection ports 214. In at least one embodiment, the fuel injection ports 214 may be arranged in a single row ( Figure 6 ). Although the fuel injection components 226, 228 are Figure 42 as having an outer cross-sectional profile 240 defining a teardrop shape, but the fuel injection members 226, 228 may each have an outer cross-sectional profile defining any of a circular shape, a triangular shape, a diamond shape, a rectangular shape, or any other suitable cross-sectional shape.

[0059] like Figures 3 to 5 As shown, the outer cross-sectional profile 240 of the fuel injection members 226, 228 can be uniform in the axial direction A so that there are no abrupt changes in shape or orientation as they extend from the front end wall 206 to the rear end wall 208 in the axial direction A. In this way, although the inner profile can vary along the axial direction A, such as Figures 6 to 8 As shown, however, the outer cross-sectional profile 240 may be uniform in the axial direction A.

[0060] Figure 5 A partial cross-sectional plan view of the fuel injection assembly 100 is shown. As shown, the fuel injector 200 may also include a fuel circuit 250 defined therein. As shown, the fuel circuit 250 may be fluidly coupled to the fuel supply line 104 via the conduit fitting 220. In many embodiments, the fuel circuit 250 includes an inlet chamber 252 defined within the front end wall 206 of the fuel injector 200. The inlet chamber 252 may receive fuel from the fuel supply line 104 and distribute it to one or more fuel passages 254 defined within the sidewall fuel injection members 222, 224 and / or the fuel injection members 226, 228. In some embodiments, as shown in FIG. Figure 5 As shown, each fuel passage 254 may extend directly from the inlet fuel chamber 252 to the rear end wall 208 along the axial direction A. In many embodiments, each fuel passage 254 may be parallel to one another.

[0061] like Figure 5 As shown, a plurality of fuel ports 214 may be defined on the sidewall fuel injection members 222, 224 and / or the fuel injection members 226, 228 and may be in fluid communication with corresponding fuel passages 254 to provide fuel to the first opening 210 to mix with the compressed air 19 prior to entering the auxiliary combustion zone 60. For example, in many embodiments, each fuel port 214 of the plurality of fuel ports 214 may extend between a corresponding fuel passage 254 and the opening 210.

[0062] Figures 6 to 8 A cross-sectional side view of a fuel injector 200 is shown showing a fuel injection member 260 according to an embodiment of the present disclosure. Figures 6 to 8The illustrated fuel injection member 260 may represent any or both of the sidewall fuel injection members 222 , 224 and / or fuel injection members 226 , 228 discussed herein. As shown, the injection member 260 is disposed within the first opening 210 and extends axially between the end walls 202 .

[0063] As discussed herein, the fuel injector 200 may further define a fuel circuit 250 having an inlet chamber 252 and a fuel passage 254. In many embodiments, the inlet chamber 252 may be defined within the front end wall 206 of the fuel injector 200. The fuel passage 254 may extend directly from the inlet chamber 252 within the fuel injection member 260 and terminate near the rear end wall 208. In many embodiments, fuel from the inlet fuel chamber 252 may flow into the fuel passage 254 and be injected into the opening 210 via a plurality of fuel ports 214 disposed along the fuel injection member 260. In some embodiments, the fuel passage 254 may terminate within the rear end wall 208. In other embodiments, the fuel passage 254 may terminate in front of the rear end wall 208.

[0064] In many embodiments, the fuel passage 254 can have a cross-sectional area that varies along the axial length 256 of the fuel injection member 260. Specifically, as shown, the radial height 258 (i.e., the width of the fuel passage 254 measured in the radial direction) can vary as the passage extends along the length in the axial direction A, which thereby reduces the total cross-sectional area of ​​the fuel passage 254. In some embodiments, the fuel passage 260 can include a radially inner edge 262 and a radially outer edge 264 that define a radially inner flow boundary and a radially outer flow boundary of the fuel passage 254, respectively.

[0065] exist Figure 6 In the illustrated embodiment, the radially outer edge 264 may be a straight line that is generally parallel to the leading edge 234 of the fuel injection member 260 along the axial direction A. The radially inner edge 262 of the flow channel 254 may taper toward the radially outer edge 264 as the channel extends in the axial direction A. In other words, the radially inner edge 262 is a straight edge (without a curve) that is inclined toward the radially outer edge 264, such that it gradually and continuously converges toward the radially outer edge 264 as it extends in the axial direction A. In this arrangement, the radial height 258 may decrease at a constant rate as the flow channel 254 extends from the leading end wall 206 to the trailing end wall 208 in the axial direction A.

[0066] exist Figure 6In the illustrated embodiment, radially inner edge 262 is shown as including a taper, and radially outer edge 264 is shown as being parallel to leading edge 234. In other embodiments (not shown), radially outer edge 264 may include a taper, and radially inner edge 262 may be parallel to leading edge 234.

[0067] like Figure 7 As shown, the fuel passage 254 may include a straight portion 265, a first convergent portion 266 along a radial direction R, a divergent portion 268, and a second convergent portion 270. The straight portion 265 of the fuel passage 254 may extend from the inlet chamber 252 to the first convergent portion 266, and the divergent portion 268 may extend from the first convergent portion 266 to the second convergent portion 270. Figure 7 As shown, the straight portion may be a section of the fuel passage 252 in which the cross-sectional area is uniform, i.e., constant or unchanged, as the fuel passage 254 extends in the radial direction A. The convergent portions 266, 270 of the fuel passage 254 may be a section of the fuel passage 254 in which the cross-sectional area decreases as the fuel passage 254 extends along the axial direction A. Conversely, the divergent portion 268 may be a section of the fuel passage in which the cross-sectional area increases as the fuel passage 254 extends along the axial direction A.

[0068] like Figure 7 As shown, the radially outer edge 264 can be a straight line that is generally parallel to the leading edge 234 of the fuel injection member 260 along the entire axial length 256 of the fuel injection member 260. As shown, in the straight portion 265, the radially outer edge 264 and the radially inner edge 262 can be parallel to each other so that the radial height 258 is constant along the entire straight portion 265. In the convergent portions 266, 270 of the fuel passage 254, the radially inner edge 262 can be arcuate and can converge toward the radially outer edge 264 as the fuel passage extends in the axial direction A, thereby causing the radial height 258 and the total cross-sectional area of ​​the fuel passage 254 to decrease along the axial direction A. Conversely, in the divergent portion 268 of the fuel passage 254, the radially inner edge 262 can be arcuate and can diverge away from the radially outer edge 264, thereby causing the radial height 258 and the total cross-sectional area of ​​the fuel passage 254 to increase along the axial direction A.

[0069] like Figure 8As shown, the radial outer edge 264 may include a curved portion 272. As shown, the curved portion 272 of the radial outer edge 264 may be arcuate and, as the fuel passage 254 extends in the axial direction A, may converge toward the radial inner edge 262 and then diverge away from the radial inner edge, thereby varying the radial height 258 and the total cross-sectional area of ​​the fuel passage 254 along the axial direction A. In many embodiments, as shown, the curved portion 272 may have a generally parabolic or "U" shape. The curved portion may be used to advantageously reduce flow separation, recirculation, and flow vortices that may occur if the fuel passage 254 is completely straight.

[0070] exist Figures 6 to 8 In the illustrated embodiment, the radially inner edge 262 is shown as tapered and / or curved in the axial direction A, while the radially outer edge is generally straight or has a major portion that is generally straight. However, in other embodiments (not shown), the edge profiles may be switched so that the radially inner edge 262 may be straight or mostly straight, while the radially outer edge 264 is curved in the axial direction A.

[0071] like Figures 6 to 8 As shown, and as discussed herein, the fuel passage 254 can be defined within the fuel injection member 260 and can have a cross-section that varies in the axial direction A. However, as the fuel injector 260 extends in the axial direction, the outer cross-sectional profile 240 (which in some embodiments can be shaped as a teardrop) can be constant, uniform, and / or unchanging. Advances in manufacturing methods (such as the additive manufacturing methods discussed herein) allow for complex and varying fuel passages 254 within the fuel injection member 260 while maintaining a constant outer cross-sectional profile 240 that is important for uniform airflow between the fuel injection members 260.

[0072] Figures 9 to 12 2 shows a plan view of a fuel injector 200 according to an embodiment of the present disclosure, viewed from the radial outside of the fuel injector 200 along the radial direction R. As shown, the fuel injector 200 includes only a single fuel injection member 260. It will be appreciated that Figures 9 to 12 The features of the illustrated fuel injection member 260 may be incorporated into any of the fuel injection members described herein, such as the sidewall fuel injection members 222, 224 and / or the fuel injection members 226, 228. Figures 9 to 12 As shown, the fuel injector 200 may include a transverse direction T that is tangential to a circumferential direction C of the combustor and perpendicular to both the radial direction R and the axial direction A.

[0073] exist Fig. 9In the illustrated embodiment, the fuel passage 254 may also include a converging portion 274 and a diverging portion 276 along the transverse direction T. As shown, the oppositely disposed walls 238 of the fuel injection member 260 may include oppositely disposed inner surfaces 278, 280 that form flow boundaries for fuel traveling through the fuel passage 254 in the transverse direction T. In the converging portion 274 of the fuel passage 254, the inner surfaces 278, 280 may be arcuate and may converge toward each other as the fuel passage 254 extends in the axial direction A, thereby causing the transverse length 282 and the total cross-sectional area of ​​the fuel passage 254 to decrease along the axial direction A.

[0074] In contrast, in the diverging portion 276, the inner surfaces 278, 280 may be arcuate and may diverge away from each other as the fuel passage 254 extends in the axial direction A, thereby causing the transverse length 282 and the total cross-sectional area of ​​the fuel passage 254 to increase along the axial direction A. Varying the transverse length 282 in the fuel passage 254 may advantageously reduce flow separation, recirculation, and flow vortices of the fuel within the fuel passage.

[0075] In other embodiments, such as Fig.11 and Fig.12 In the illustrated embodiment, the first inner surface 278 and the second inner surface 280 may be linear so that the transverse length 282 is uniform in the axial direction. In this way, in certain embodiments, the fuel passage 254 may vary only in radial length, only in transverse length, or both in radial length and transverse length.

[0076] exist Fig.10 In the illustrated embodiment, the fuel passage 254 may converge or taper as it extends axially from the inlet chamber 252 such that the transverse length 282 decreases at a constant rate in the axial direction. As shown, the oppositely disposed walls 238 of the fuel injection member 260 may include oppositely disposed inner surfaces 278, 280 that form flow boundaries in the transverse direction T for fuel traveling through the fuel passage 254. Fig.10 In the illustrated embodiment, the interior surfaces 278, 280 may taper toward each other at a constant rate, thereby causing the transverse length 282 and the total cross-sectional area of ​​the fuel passage 254 to decrease along the axial direction A. Gradually decreasing the transverse length 282 in the fuel passage 254 may advantageously reduce flow separation, recirculation, and flow vortices of the fuel within the fuel passage.

[0077] like Fig. 9 and Fig.10As shown, each of the plurality of fuel ports 214 may be defined within the wall 238 of the fuel injection member 260. More specifically, each of the plurality of fuel ports 214 may extend between a respective inner surface 278, 280 of the wall 238 and a respective outer surface 288, 290 of the wall 238.

[0078] like Fig.11 As shown, each of the plurality of fuel ports 214 may include a chamfered inlet 286. The chamfered inlet 286 may be conical such that the fuel port 214 tapers from a first diameter 292 at the inlet to a second diameter 294 at a transition point 296 disposed between the inlet and the outlet of the fuel port 214. Fig.11 As shown, the first diameter 292 may be greater than the second diameter 294. At the transition point 296, each of the fuel ports 214 may transition from a conical shape to a cylindrical shape such that the second diameter is constant from the transition point 296 to the exit of the fuel port 214. Utilizing the fuel ports 214 with the chamfered inlet 286 may advantageously provide a more uniform fuel distribution within the first opening 210, which allows for a more uniform mixture of fuel and air entering the auxiliary combustion zone 60. As discussed herein, a uniformly mixed fuel / air mixture may improve the overall performance of the gas turbine 10.

[0079] like Fig.12 As shown, each of the plurality of fuel ports 214 may include a rounded inlet 287. For example, the rounded inlet 287 of each fuel port 214 may be generally convex or may be otherwise rounded such that the fuel port 214 tapers from a first diameter 293 at the inlet to a second diameter 295 disposed at a transition point 297 between the inlet and the outlet of the fuel port 214. Fig.11 As shown, the first diameter 293 may be greater than the second diameter 295. At the transition point 297, each fuel port 214 may transition from a rounded shape to a cylindrical shape such that the second diameter 295 is constant from the transition point 297 to the exit of the fuel port 214. Utilizing the fuel ports 214 with the rounded inlet 287 may advantageously provide a more uniform fuel distribution within the first opening 210, which allows for a more uniform mixture of fuel and air entering the auxiliary combustion zone 60. As discussed herein, a uniformly mixed fuel / air mixture may improve the overall performance of the gas turbine 10.

[0080] As disclosed herein, changing the cross-sectional area of ​​the fuel passage 254 along the length of the fuel injection member 260 (rather than, for example, making the fuel passage have a uniform cross-sectional area) advantageously minimizes recirculation, flow separation, and flow vortex of the fuel traveling through the fuel passage 254. This cross-sectional variation makes the fuel distribution through the fuel port 214 equal. With equal fuel distribution, the mixing of fuel and air within the fuel injector 200 is increased, thereby improving the overall operating efficiency of the gas turbine 10. In addition, reducing the cross-sectional area of ​​the fuel passage 254 in certain sections allows the fuel to have a much more uniform pressure along the entire length of the fuel injection member 260. For example, there is a pressure loss on each fuel port 214, but the reduction in the cross-sectional area of ​​the fuel passage 254 increases the fuel pressure, which balances the drop caused by the fuel port 214.

[0081] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any device or system and performing any combined method. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. If these other examples include 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, these other examples are intended to be within the scope of the claims.

Claims

1. A fuel injector (200), comprising: A front end wall (206) and a rear end wall (208) disposed opposite to the front end wall (206); a side wall (204) extending between the front end wall (206) and the rear end wall (208), wherein the front end wall (206), the rear end wall (208) and the side wall (204) together define an opening (210) for passage of air; at least one fuel injection member (212) disposed within the opening (210) and extending between the end walls (206, 208); and A fuel circuit (250) is defined within the fuel injector (200), the fuel circuit (250) comprising: an inlet chamber (252) defined within the front end wall (206) of the fuel injector (200); and A fuel passage (254) extending from the inlet chamber (252) and in fluid communication with the inlet chamber, the fuel passage (254) being defined within the at least one fuel injection member (212), wherein the fuel passage (254) has a cross-sectional area that varies along the length of the fuel injection member (212) relative to an outer cross-sectional area that is uniform along the entire length of the fuel injection member such that the fuel passage includes an inner shape having at least one curvature that is different from the outer shape of the fuel injection member.

2. The fuel injector (200) of claim 1, further comprising a plurality of fuel ports (214) defined on the fuel injection member (212), the plurality of fuel ports (214) providing fluid communication between the fuel passage (254) and the opening (210).

3. The fuel injector (200) of claim 2, wherein each fuel port of the plurality of fuel ports (214) includes one of a chamfered inlet (286) or a radiused inlet (287).

4. The fuel injector (200) according to claim 1, wherein the cross-sectional area of ​​the fuel passage (254) gradually converges from the inlet chamber (252) to the rear end wall of the fuel injector (200).

5. The fuel injector (200) of claim 1, wherein the fuel passage (254) includes a first converging portion (266), a diverging portion (268), and a second converging portion (270).

6. A fuel injector (200) according to claim 1, wherein the at least one fuel injection component (212) includes a pair of fuel injection components (212) arranged between the side walls (204), and the fuel channel (254) includes a first fuel channel and a second fuel channel, wherein the first fuel channel (254) is defined in a first fuel injection component (212) of the pair of fuel injection components (212), and the second fuel channel (254) is defined in a second fuel injection component (212) of the pair of fuel injection components (212).

7. The fuel injector (200) of claim 6, wherein the first fuel passage (254) and the second fuel passage (254) each have a respective cross-sectional area that varies from the inlet chamber (252) to the rear end wall (208).

8. A fuel injector (200) according to claim 6, wherein the side wall (204) includes a first side wall fuel injection member (222) and a second side wall fuel injection member (224), wherein a first side wall fuel passage (254) is defined within the first side wall fuel injection member (222) and a second side wall fuel passage (254) is defined within the second side wall fuel injection member (224), and wherein the first side wall fuel passage (254) and the second side wall fuel passage (254) extend from the inlet chamber (252) and are in fluid communication with the inlet chamber.

9. The fuel injector (200) of claim 8, wherein the first sidewall fuel passage (254) and the second sidewall fuel passage (254) each have a respective cross-sectional area that varies from the inlet chamber (252) to the rear end wall (208).

10. A burner (17), comprising: End cap (126); at least one fuel nozzle (122) extending between the end cover (126) and a combustion liner (42), wherein the combustion liner (42) extends between the at least one fuel nozzle (122) and an aft frame and defines a combustion chamber; A fuel injector (200) disposed downstream of the at least one fuel nozzle (122) and in fluid communication with the combustion chamber, the fuel injector (200) comprising: A front end wall (206) and a rear end wall (208) disposed opposite to the front end wall (206); a side wall (204) extending between the front end wall (206) and the rear end wall (208), wherein the front end wall (206), the rear end wall (208) and the side wall (204) together define an opening (210) for passage of air; at least one fuel injection member (212) disposed within the opening (210) and extending between the end walls (206, 208); and A fuel circuit (250) is defined within the fuel injector (200), the fuel circuit (250) comprising: an inlet chamber (252) defined within the front end wall (206) of the fuel injector (200); and A fuel passage (254) extending from the inlet chamber (252) and in fluid communication with the inlet chamber, the fuel passage (254) being defined within the at least one fuel injection member (212), wherein the fuel passage (254) has a cross-sectional area that varies along the length of the fuel injection member (212) relative to an outer cross-sectional area that is uniform along the entire length of the fuel injection member such that the fuel passage includes an inner shape having at least one curvature that is different from the outer shape of the fuel injection member.

11. The burner (17) of claim 10, further comprising a plurality of fuel ports (214) defined on the fuel injection member (212), the plurality of fuel ports (214) providing fluid communication between the fuel passage (254) and the opening (210).

12. The burner (17) of claim 11, wherein each fuel port of the plurality of fuel ports (214) comprises one of a chamfered inlet (286) or a radiused inlet (287).

13. The burner (17) of claim 10, wherein the cross-sectional area of ​​the fuel passage (254) tapers from the inlet chamber (252) to the rear end wall of the fuel injector (200).

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