Fuel injection assembly for combustor and axial fuel staging combustor comprising the fuel injection assembly

Abstract

To provide a fuel injection assembly capable of supplying alternative fuel and air to a secondary combustion area without causing a problem of flame holding or flashback.SOLUTION: A fuel injection assembly (100) for a combustor of a gas turbine engine includes a body (202) including a head (204) defining an air intake chamber (206). A mixing chamber (226) is disposed adjacent to the intake chamber. A deflection member (212) is disposed in the intake chamber. The deflection member includes a deflection surface (214) and a side surface (216) spaced apart from an inner wall surface (210) of the air intake chamber, and an outer peripheral air passage (222) for passing air from the air intake chamber to the mixing chamber is defined. A plurality of ribs (236) are disposed along a longitudinal side wall (230) of the mixing chamber. A fuel plenum (242) is disposed along the longitudinal side wall (230) of the mixing chamber, and a first plurality of fuel injection holes (246) are defined from the fuel plenum through the longitudinal side wall of the mixing chamber and at least some of the ribs.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates generally to a fuel injection assembly for a gas turbine combustor as set forth in the claims, and more particularly to a fuel injection assembly for use in an axial fuel staging (AFS) combustor, as well as an axial fuel staging combustor including such a fuel injection assembly. [Background technology]

[0002] Turbomachines are used in various industries and applications for energy transfer. For example, a gas turbine engine is a turbomachine that generally includes, in order of flow, a compressor section, a combustion section, a turbine section, and an exhaust section. The compressor section gradually increases the pressure of a 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 combusted in a combustion chamber to generate high-pressure, high-temperature combustion gases. The combustion gases flow from the combustion section to the turbine section, where they expand to produce work. For example, the expansion of the combustion gases in the turbine section rotates a rotor shaft connected to, for example, an electrical generator. The combustion gases then exit the gas turbine through the exhaust section.

[0003] In some combustors, combustion gas generation occurs in two axially spaced stages. Such combustors, referred to herein as including an "axial fuel staging" (AFS) system, deliver fuel and oxidizer to one or more fuel injectors downstream from the combustor's head end. In combustors equipped with an AFS system, a primary fuel nozzle at the upstream end of the combustor injects fuel and air (or a fuel / air mixture) axially into a primary combustion zone, and AFS fuel injectors located downstream from the primary fuel nozzle inject a crossflow of fuel and air (or a second fuel / air mixture) into a secondary combustion zone downstream from the primary combustion zone. The crossflow is generally transverse to the flow of combustion products from the primary combustion zone.

[0004] A conventional gas turbine engine includes one or more combustors that burn a mixture of natural gas and air in a combustion chamber to produce high-pressure, high-temperature combustion gases. Nitrogen oxides (NOx) and other pollutants are generated as by-products and are emitted through an exhaust section. Regulatory requirements for low emissions from gas turbines are becoming increasingly stringent, and environmental agencies worldwide are demanding further reductions in the emission rates of NOx and other pollutants from both new and existing gas turbines.

[0005] Burning a mixture of natural gas and significant amounts of hydrogen and / or pure hydrogen in place of natural gas in a combustor significantly reduces or eliminates NOx and other pollutant emissions. However, because the combustion characteristics of hydrogen are different from those of natural gas, conventional combustion systems, including conventional AFS fuel injectors, cannot safely burn concentrated and / or pure hydrogen. For example, burning concentrated and / or pure hydrogen in conventional combustion systems can promote flashback or flame-holding conditions, in which the combustion flame moves toward the fuel delivered by the injector, which can severely damage the injector in a relatively short period of time.

[0006] Therefore, there is a need in the art for a fuel injection assembly that can deliver alternative fuels (such as hydrogen) and air to the secondary combustion zone without causing flame holding or flashback problems. Summary of the Invention

[0007] The present invention is directed to technology as set forth in the claims. Aspects and advantages of the present invention will be set forth in the following detailed description, and in some cases will be obvious from the detailed description, or may be learned by practice of the technology.

[0008] One aspect of the present disclosure provides an embodiment of a fuel injection assembly for a combustor of a gas turbine engine that provides a solution to the above-mentioned problem. The fuel injection assembly includes a body having a head defining an intake chamber. A mixing chamber is disposed adjacent to, and more specifically downstream of, the intake chamber and includes lateral end walls and longitudinal side walls. The lateral end walls and longitudinal side walls generally refer to walls extending in different directions and enclosing the chamber. In another aspect, the fuel injection assembly may be installed in a combustor or combustor can such that the fuel injection assembly extends in the longitudinal or lateral direction of the combustor or combustor can, respectively. A turning member is disposed in the intake chamber and includes a turning surface, particularly an upstream turning surface or a turning surface facing the intake side, and a side surface spaced from the inner wall of the intake chamber, such that an outer circumferential air passage is defined between the turning member and the inner wall of the intake chamber for passing air from the intake chamber to the mixing chamber. A plurality of ribs are disposed along each of the longitudinal side walls of the mixing chamber. The ribs are disposed on and extend from the inner surfaces of the longitudinal sidewalls. The ribs extend along a direction from the intake chamber toward the outlet end of the mixing chamber and are spaced apart along a direction between the lateral endwalls. The ribs extend radially and are spaced apart longitudinally with respect to the combustion can to which the fuel injection assembly is attached. A fuel plenum is disposed along the longitudinal sidewalls of the mixing chamber, and more specifically, along the outer surface of the longitudinal sidewalls of the mixing chamber. A first plurality of fuel injection holes define passages from the fuel plenum through the longitudinal sidewalls and ribs and into the mixing chamber. This unique configuration promotes turbulent mixing of the compressed air / fuel mixture within the mixing chamber, resulting in more efficient and complete ignition of the mixture in the secondary combustion zone and minimizing flashback and flame-holding conditions.

[0009] In one embodiment, the air intake chamber includes lateral end walls and longitudinal side walls, and the lateral sides of the deflecting member are spaced parallel to and from the inner wall surfaces of the longitudinal side walls of the air intake chamber, such that the circumferential air passage is defined as a slot extending along each of the longitudinal side walls of the air intake chamber. In this embodiment, the deflecting member extends between and is attached to the lateral end walls of the air intake chamber.

[0010] In one embodiment, the intake chamber has a cross-sectional area greater than a cross-sectional area of the mixing chamber, defining a throat between the intake chamber and the mixing chamber. The throat may have a tapered cross-sectional profile from the intake chamber to the mixing chamber.

[0011] In some embodiments, the intake chamber may have a rectangular cross-sectional shape and the mixing chamber may have an even smaller rectangular cross-sectional shape. In more specific embodiments, each side of the rectangular cross-sectional shape of the mixing chamber may be shorter than the corresponding side of the rectangular cross-sectional shape of the intake chamber.

[0012] In yet another embodiment, the fuel plenum may include an external fuel duct adjacent an exterior surface of each of the longitudinal sidewalls of the mixing chamber, and a first plurality of fuel injection holes in fluid communication with the fuel duct and defined through the longitudinal sidewalls of the mixing chamber. In this embodiment, the intake chamber may include lateral end walls, longitudinal sidewalls, and a stepped ledge between the longitudinal sidewalls of the intake chamber and the longitudinal sidewalls of the mixing chamber, and although the external fuel duct is shown in the drawings as being located below the stepped ledge, it is generally located adjacent to an exterior surface or face of the stepped ledge in exemplary embodiments.

[0013] The diverting member may have a variety of shapes. For example, in one embodiment, the diverting member may have a sloped or curved lower surface that extends from the side of the diverting member into the throat between the intake chamber and the mixing chamber. Alternatively, the lower diverting surface of the diverting member may be flat.

[0014] Similarly, the turning surface of the turning member may be angled or curved toward the side of the turning member in some embodiments, or may be flat in other embodiments.

[0015] The ribs within the mixing chamber, extending to the outlet end of the mixing chamber, may also be configured in a variety of ways. In one embodiment, the ribs may be sharp-edged with relatively straight edges parallel to the centerline axis of the mixing chamber. In other embodiments, the edges may be scalloped, tapered, or have other non-linear edges.

[0016] The fuel injection holes may be defined through the front face or apex of the rib or through the sidewall of the rib.

[0017] In yet another embodiment, the fuel injection assembly may include a second plurality of fuel injection holes defining passages from the fuel plenum through the ribs and into the mixing chamber, the second plurality of fuel injection holes being spaced apart from the first plurality of fuel injection holes along a centerline axis (254) through the mixing chamber (226).

[0018] The present disclosure also encompasses an axial fuel staging (AFS) combustor for a gas turbine. The AFS combustor includes a head end and one or more fuel nozzles configured in the head end. A combustion liner extends downstream from the one or more fuel nozzles and defines a primary combustion zone at a forward end of the combustion liner and a secondary combustion zone at an aft end of the combustion liner. A fuel injection assembly is disposed through the liner in the secondary combustion zone downstream from the primary combustion zone. The fuel injection assembly may be any or a combination of the injection assemblies described above.

[0019] These and other features, aspects, and advantages of the present fuel injection assembly and combustor will become better understood with reference to the following detailed description and claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various embodiments of the disclosed technology and, together with the description, serve to explain the principles of the technology. [Brief explanation of the drawings]

[0020] The present fuel injection assembly and combustor, including the best mode of making and using the system and method, are fully disclosed in the following detailed description, taken in conjunction with the accompanying drawings, to enable those skilled in the art to practice the invention. [Figure 1] 1 is a schematic diagram of a turbomachine according to an embodiment of the present disclosure; [Figure 2] 2 is a schematic diagram of a combustor that may be used in the turbomachine of FIG. 1, the combustor may be configured with a fuel injection assembly according to an embodiment of the present disclosure. [Figure 3]FIG. 1 is a perspective view of a fuel injection assembly according to an embodiment of the present disclosure. [Figure 4] 4 is a cross-sectional view of the fuel injection assembly of FIG. 3 for use in a combustor according to an embodiment of the present disclosure. [Figure 5] 4 is a longitudinal cross-sectional view of the fuel injection assembly of FIG. 3 for use in a combustor according to an embodiment of the present disclosure. [Figure 6] 3 is a cross-sectional view of another embodiment of a fuel injection assembly for use in a combustor according to an embodiment of the present disclosure. [Figure 7] 3 is a longitudinal cross-sectional view of another embodiment of a fuel injection assembly for use in a combustor according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0021] Various embodiments of the present fuel injection assembly and combustor are described in detail below, one or more examples of which are illustrated in the drawings. Each example is intended to be illustrative, not limiting, of the present technology. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made in the present technology without departing from the scope and spirit of the appended claims. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Accordingly, the present disclosure covers modifications and variations within the scope of the appended claims and their equivalents.

[0022] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Moreover, unless specifically stated otherwise, all embodiments described herein are to be construed as illustrative.

[0023] The detailed description of the invention uses numerical and letter designations to refer to features depicted in the drawings. In the drawings and the detailed description of the invention, like or similar designations indicate like or similar components of the technology. In this specification, the terms "first," "second," and "third" are used interchangeably to distinguish one component from another, and do not denote the location or importance of the individual components.

[0024] The term "fluid" refers to a gas or a liquid. The term "fluid communication" means the ability to flow or transport a fluid between given areas.

[0025] As used herein, the terms "upstream" (or "forward") and "downstream" (or "aft") refer to relative directions with respect to fluid flow in a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction to which the fluid flows. The term "radial" refers to a relative direction that is substantially perpendicular to the axial centerline of a component, the term "axial" refers to a relative direction that is substantially parallel and / or coaxial to the axial centerline of a component, and the term "circumferential" refers to a relative direction about the axial centerline of a component. A first component that is radially inward (i.e., relative to the axial centerline of the combustor) of a second component may be referred to herein as "below" or "below," regardless of the component's mounting location in the combustor. Such components may also be referred to as "vertically spaced apart."

[0026] Approximate terms such as "about," "approximately," and "substantially" are not limited to the exact numerical values stated. In at least some cases, the approximating expression corresponds to the precision of an instrument that measures the value or the precision of a method or machine for constructing or manufacturing the part and / or system. In at least some cases, the approximating expression corresponds to the precision of an instrument that measures the value or the precision of a method or machine for constructing or manufacturing the part and / or system. For example, approximating expressions can refer to an error within 1%, 2%, 4%, 5%, 10%, 15%, or 20% of a particular numerical value, a numerical range, and / or any of the upper and lower limits defining the numerical range. When used in reference to an angle or direction, such terms encompass within ±10 degrees of the stated angle or direction. For example, "approximately perpendicular" encompasses directions within 10 degrees in any direction (e.g., clockwise or counterclockwise) from perpendicular.

[0027] Terms such as "coupled," "secured," or "attached," unless otherwise specified herein, refer to direct coupling, fixing, or attachment, as well as indirect coupling, fixing, or attachment via one or more intermediate components or features. Terms such as "directly coupled," "directly secured," and "directly attached" refer to a first component being joined to a second component without an intervening structure. As used herein, the terms "comprising," "having," and "comprises" are non-exclusive inclusions. For example, a process, method, article, or device that includes recited features is not necessarily limited to those features and may include other features not expressly recited or inherent in such process, method, article, or device. Furthermore, unless otherwise specified, the term "or" refers to an inclusive rather than an exclusive alternative. For example, a condition A or B is true if A is true (or present) and B is false (or absent), or if A is false (or absent) and B is true (or present).

[0028] In this specification and claims, ranges with numerical limitations specify and encompass all subranges within that range, unless otherwise clear from the context, etc. For example, all ranges disclosed herein are inclusive of their limits, and the limits are independently combinable with each other.

[0029] As used herein, the term "premix" may be used to describe a component, passage, or cavity upstream of a respective combustion zone within which mixing occurs. For example, "premix" may be used to describe a component, passage, or cavity in which two fluids (e.g., fuel and air) are mixed together before being discharged from such component, passage, or cavity (e.g., into the combustion zone).

[0030] 1 shows a schematic diagram of one embodiment of a turbomachine, which in the illustrated embodiment is a gas turbine engine 1000. While industrial or land-based gas turbines are described and illustrated herein, the present disclosure is not limited to industrial or land-based gas turbine engines unless otherwise stated in the claims. For example, the techniques described herein may be used with any type of turbomachine, including, but not limited to, a steam turbine, an aircraft gas turbine, or a marine gas turbine.

[0031] As shown in the figure, gas turbine engine 1000 generally includes, in flow order, an intake section 112, a compressor section 114 disposed downstream from intake section 112, a plurality of combustors (shown in FIG. 2 ) in a combustion section 116 disposed downstream from compressor section 114, a turbine section 118 disposed downstream from combustion section 116, and an exhaust section 120 disposed downstream from turbine section 118. Additionally, gas turbine engine 1000 may include one or more shafts 122 coupled between compressor section 114 and turbine section 118.

[0032] Compressor section 114 generally includes a plurality of rotor disks 124 (one shown) and a plurality of rotor blades 126 extending radially outward from and connected to each rotor disk 124. Each rotor disk 124 is coupled to or forms an upstream portion of a shaft 122 that extends through compressor section 114. Compressor section 114 also includes a plurality of stationary vanes (not shown) that are arranged in stages with rotor blades 126 and direct flow to rotor blades 126.

[0033] Turbine section 118 generally includes a plurality of rotor disks 128 (one shown) and a plurality of rotor blades 130 extending radially outward from and connected to each rotor disk 128. Each rotor disk 128 is coupled to or forms a downstream portion of a shaft 122 that extends through turbine section 118. Turbine section 118 also includes an outer casing 131 that circumferentially surrounds the downstream portion of shaft 122 and rotor blades 130, at least partially defining a hot gas path 132 through turbine section 118. Turbine section 118 also includes a plurality of stationary vanes (not shown) that are arranged in stages with rotor blades 130 and direct flow to rotor blades 130.

[0034] During operation, a working fluid, such as air, enters the intake section 112 and enters the compressor section 114, where the air is progressively compressed by multiple compressor stages of rotating blades and stationary vanes to provide compressed air 115 to the combustors 10 ( FIG. 2 ) in the combustor section 116. The compressed air 115 is mixed with fuel and combusted in each combustor 10 to generate combustion gases 134. The combustion gases 134 flow from the combustor section 116 through the hot gas path 132 and into the turbine section 118, where they expand and transfer energy (kinetic and / or thermal) to the rotor blades 130, causing the shaft 122 to rotate. The mechanical rotational energy may then be used to drive the compressor section 114 and / or to generate electricity. After exiting the turbine section 118, the combustion gases 134 may then exit the gas turbine engine 1000 via the exhaust section 120.

[0035] Figure 2 is a schematic diagram of a combustor 10 in the form of a combustion can, which may be included in the combustion system 116 of Figure 1. A plurality (e.g., 8, 10, 12, 14, 16, or more) of combustion cans 10 are arranged in an annular array about a shaft 122.

[0036] As shown in FIG. 2 , the combustion can 10 includes a liner 12 that contains and channels combustion gases 134 to the turbine. The liner 12 may have a cylindrical liner portion and a tapered transition portion separate from the cylindrical liner portion, as in many conventional combustion systems. Alternatively, the liner 12 may have a one-piece (or “unibody”) structure in which the cylindrical and tapered portions are integrated with one another. Thus, all references herein to the liner 12 encompass both conventional combustion systems having separate liners and transition pieces, as well as combustion systems having unibody liners. Furthermore, the present disclosure may equally apply to combustion systems in which the transition piece is integrated with the turbine's first-stage nozzle (also referred to as a “transition nozzle” or “integral outlet piece”).

[0037] The liner 12 is surrounded by an outer sleeve 14, which is spaced radially outward from the liner 12 to define an annulus 32 between the liner 12 and the outer sleeve 14. The outer sleeve 14 may include a flow sleeve portion at its forward end and an impingement sleeve portion at its aft end, as in many conventional combustion systems. Alternatively, the outer sleeve 14 may have a one-piece (or "unisleeve") structure in which the flow sleeve portion and the impingement sleeve portion are axially integrated with one another. As noted above, any reference herein to the outer sleeve 14 is intended to encompass both conventional combustion systems having separate flow sleeves and impingement sleeves as well as combustion systems having a uni-sleeve outer sleeve.

[0038] The head end portion 20 of the combustion can 10 includes one or more fuel nozzles 22. The fuel nozzles 22 have a fuel inlet 24 at their upstream (or inlet) end. The fuel inlet 24 may be formed through an end cover 26 at the forward end of the combustion can 10. The downstream (or outlet) end of the fuel nozzles 22 extends through a combustor cap 28.

[0039] The head-end section 20 of the combustion can 10 is at least partially surrounded by a forward casing 30, which is physically and fluidly coupled to a compressor discharge case 40. The compressor discharge case 40 is fluidly coupled to the outlet of the compressor section (114 in FIG. 1) and defines a compressed air plenum 42 that surrounds at least a portion of the combustion can 10. Air 36 (compressed air 115 in FIG. 1) flows from the compressor discharge case 40 into an annulus 32 at the aft end of the combustion can 10. Because the annulus 32 is fluidly coupled to the head-end section 20, the airflow 36 travels upstream from the aft end of the combustion can 10 to the head-end section 20, where it reverses direction and enters the fuel nozzle 22.

[0040] Fuel and air are introduced by the fuel nozzles 22 into a primary combustion zone 50 at the forward end of the liner 12, where the fuel and air combust to produce combustion gases 46. In one embodiment, the fuel and air are mixed within the fuel nozzles 22 (e.g., in a premix fuel nozzle). In other embodiments, the fuel and air may be introduced separately into the primary combustion zone 50 and mixed within the primary combustion zone 50 (e.g., as occurs in a diffusion nozzle). References herein to a "first fuel / air mixture" are intended to mean both premixed fuel / air mixtures and diffusion-type fuel / air mixtures, either of which may be produced by the fuel nozzles 22.

[0041] The combustion gases 46 travel downstream toward the aft end 18 of the combustion can 10. Additional fuel and air are introduced by one or more fuel injection assemblies 100 (also referred to herein as "fuel injectors" or "injectors") into a secondary combustion zone 60 where they ignite with the combustion gases 46 to produce combustion gases 56. The combustion gases 46 and the combustion gases 56 together form a combined combustion gas product stream 134. A combustion system with multiple axially separated combustion zones in this manner is referred to as an "axial fuel staging" (AFS) system 200, and the downstream fuel injectors 100 are sometimes referred to as "AFS injectors." Embodiments of an AFS according to the present disclosure are described in detail below.

[0042] In the illustrated embodiment, fuel for each AFS injector 100 is supplied from the head end portion 20 of the combustion can 10 via a fuel inlet 54. Each fuel inlet 54 is coupled to a fuel supply line 104, which in turn is coupled to each AFS injector 100. Other methods of supplying fuel to the AFS injectors 100 may be used, including supplying fuel from a ring manifold or from radially oriented fuel supply lines that pass through the compressor discharge case 40.

[0043] Each AFS injector 100 is supplied with high pressure air 36 from a compressed air plenum 42 through the open top end of the fuel injection assembly 100 .

[0044] 2 further illustrates that the AFS injector 100 may have an elongated shape and may be oriented at an angle θ relative to the longitudinal centerline 70 of the combustion can 10. In the illustrated embodiment, the leading edge of the fuel injection assembly 100 (i.e., the portion of the fuel injection assembly 100 closest to the head end) is oriented away from the centerline 70 of the combustion can 10, and the trailing edge of the fuel injection assembly 100 is oriented toward the centerline 70 of the combustion can 10. The angle θ defined between the longitudinal axis 75 of the fuel injection assembly 100 and the centerline 70 may be in the range of 1 degree to 45 degrees, 1 degree to 30 degrees, 1 degree to 20 degrees, or 1 degree to 10 degrees, or any value within these ranges. In other embodiments, it may be desirable to orient the fuel injection assembly 100 so that the leading edge is proximate the centerline 70 and the trailing edge is distal from the centerline 70.

[0045] The fuel injection assembly 100 injects the second fuel / air mixture radially into the combustion liner 12 to form secondary combustion products 56 in the secondary combustion zone 60. The combined hot gases 134 from the primary and secondary combustion zones 50, 60 travel downstream through the aft end 18 of the combustor can 10 and enter the turbine section 118 (FIG. 1) where the combustion gases 134 expand to drive the rotation of blades within the turbine section 118.

[0046] In particular, to improve gas turbine operating efficiency and reduce emissions, it is desirable for the fuel injection assembly 100 to thoroughly mix the fuel and compressed gas to form a second fuel / air mixture before introduction into the secondary combustion zone 60. Thus, embodiments of the injector 100 described below facilitate improved mixing.

[0047] 3 and 4 illustrate an embodiment of a fuel injection assembly 100 in accordance with an aspect of the present invention, which is particularly suited as an AFS injector for use with the combustor 10 described above. The fuel injection assembly 100 includes a body 202, which may be formed as a single piece or may be formed as multiple pieces that are later assembled together. The body 202 includes a head 204 that defines an air intake chamber 206 having an open top end 208. As described with reference to FIG. 2, compressed air 36 from the high-pressure air plenum 42 enters the fuel injection assembly 100 through the open top end 208.

[0048] The body 202 may include a flange 260 with holes 262 for mounting the fuel injection assembly 100 to the outer sleeve 14 of the combustion can 10 (FIG. 2).

[0049] The air intake chamber 206 may be configured in a variety of ways. In the illustrated embodiment, the air intake chamber 206 is generally rectangular and includes side walls 207 and lateral end walls 205 (FIG. 5). The side walls 207 have an inner wall surface 210.

[0050] 4, the fuel injection assembly 100 includes a fuel / air mixing chamber 226 disposed adjacent to (and more specifically downstream from) the intake chamber 206. The mixing chamber 226 may include a sidewall 230 having an outer wall surface 234, a lateral end wall 228, and an open exit end 232.

[0051] The turning member 212 is disposed within the intake chamber 206 and includes a turning surface 214 and a side surface 216, with the side surface 216 spaced from the inner wall surface 210 of the intake chamber sidewall 207. In the specific illustration, the turning surface is an upper turning surface on the upper side of the turning member. Generally, the turning surface can be considered an upstream turning surface or a turning surface facing the intake side of the intake chamber. In this configuration, peripheral air passages 222 are defined between the side surface 216 of the turning member 212 and the sidewall 207. These air passages 222 may take the form of longitudinally extending slots. As shown by the arrows in FIG. 4 , pressurized air enters the top opening of the intake chamber 206 and impacts the top surface 214 of the turning member 212, creating a turbulent air mass within the intake chamber 206. The turbulent air masses separate and travel along the longitudinal sides of the deflecting member 212 through slotted air passages 222 and into the throat 250 within the fuel injection assembly 100 where they recombine into turbulent air masses.

[0052] In the embodiment of FIG. 4, the deflecting member 212 has a relatively flat deflecting surface 214 and a tapered or curved lower surface 220 that extends downwardly to a throat.

[0053] 6, the deflecting member 212 has a curved or tapered deflecting surface 214 and a relatively flat lower surface 220. In yet another embodiment (not shown), the deflecting member 212 may be plate-like with a flat upper surface 214 and a flat lower surface 220.

[0054] 5, the deflecting member 212 may extend longitudinally (with respect to the longitudinal axis 256) between the lateral end walls 205 of the air intake chamber 206. Specifically, the deflecting member 212 may be connected to each of the lateral end walls 205 and extend from one end wall 205 to the opposing end wall 205.

[0055] For a combustion can in which the fuel injection assembly is installed, a plurality of radially extending, longitudinally spaced ribs 236 are disposed within the mixing chamber 226 along the inner surface of the sidewall 230. The ribs 236 extend from the intake chamber 206 toward the outlet end 232 of the mixing chamber 226, or in one aspect, along the centerline axis 254 through the mixing chamber, and are spaced apart between the lateral end walls 205 (i.e., from one lateral end wall to the opposite end wall). The ribs 236 generally extend from the throat 250 toward the open outlet end 232 of the mixing chamber 226. In the illustrated embodiment, the ribs 236 terminate at the open outlet end 232. In other embodiments (not shown), one or more of the ribs 232 may be spaced apart from the outlet end 232. The ribs 236 may be variously configured. In the illustrated embodiment, the ribs 236 have a blade shape with relatively straight edges or leading faces 240 and are aligned generally parallel to a centerline axis 254 through the mixing chamber 226 (i.e., the centerline axis 254 extends in the radial direction R with respect to the combustor 10). The ribs 236 may have tapered leading edges 238, as shown in FIGS. 4 and 6, resulting in a tapered cross-sectional profile of the throat 250 from the intake chamber 206 to the mixing chamber 226. In another embodiment, not shown, the ribs 236 may have scalloped, tapered, or other non-linear edges 240. The ribs 236 may have an angled or helical orientation within the mixing chamber 226.

[0056] In one embodiment, the ribs 236 may have a generally rectangular or square cross-sectional shape. In another embodiment, the ribs 236 may have a generally triangular cross-sectional shape with the apex pointing toward the mixing chamber 226.

[0057] 3-7 generally, a fuel plenum 242 is disposed along the longitudinal sidewall 230 of the mixing chamber 226. In the illustrated embodiment, the fuel plenum 242 is provided by a fuel duct that at least partially wraps around the periphery of the mixing chamber 226. For example, the fuel duct may include a head 243 (FIG. 3) that connects to the fuel supply line 104. The head 243 communicates with a leg 244 that extends along the outer wall surface 234 of the mixing chamber sidewall 230.

[0058] A first plurality of fuel injection holes 246 are in fluid communication with the fuel duct (i.e., with the fuel plenum 242 defined within the legs 244 of the fuel duct) and are defined through at least a portion of the longitudinal sidewalls 230 of the mixing chamber 226 and the ribs 236, as shown in FIGS. 4 and 5. Thus, a plurality of fuel passages are defined from the fuel duct (i.e., from the legs 244) through some or all of the ribs 236 and into the mixing chamber 226. The fuel injection holes 246 may be angled toward the open end 232 of the mixing chamber 226. The fuel injection holes 246 may be defined in the front surface or apex 240 of the rib 236 that faces the mixing chamber 226. Alternatively / in addition, the fuel injection holes 246 may be defined in the sidewalls of the ribs and angled into the mixing chamber, as shown in FIG. 7.

[0059] In the embodiment of Figure 4, the fuel duct leg 244 is formed by a closed piece (e.g., a box section piece), and the fuel injection holes 246 are drilled or otherwise formed through the duct 244, the side wall 230, and the rib 236. In another embodiment, shown in Figure 6, the duct 244 is a C-shaped piece, the open side of which is closed by the outer wall surface 234 of the mixing chamber side wall 230. The fuel injection holes 246 are drilled or otherwise formed through the side wall 230 and communicate with the internal plenum 242 of the fuel duct 244.

[0060] 6 and 7, a second plurality of fuel injection holes 248 are also provided extending from the fuel duct 244 through at least a portion of the rib 236 and into the mixing chamber 226. These fuel injection holes 248 may be at a different angular orientation than the first fuel injection holes 246 and at a different radial location on the rib 236. The second plurality of fuel injection holes may be spaced apart from the first plurality of fuel injection holes along a centerline axis 254 through the mixing chamber 226, and in particular, may be located downstream relative to the flow within the mixing chamber. For example, as shown in FIG. 6, at least a portion of the rib 236 may include the first fuel injection holes 236 and the second fuel injection holes 248, which are spaced apart from each other and oriented at different angles along the centerline axis 254 through the mixing chamber 226. 7, the first fuel injection holes 246 may be alternated with the second fuel injection holes 248 in the ribs 236 (i.e., a set of first ribs 236 with first fuel injection holes 246 may alternate with a set of second ribs 236 with second fuel injection holes 248). The first fuel injection holes 236 may be staggered with the second fuel injection holes 248 along a centerline axis 254 through the mixing chamber 226 or radially relative to the combustion can where the fuel injection assembly is located, and / or may be oriented to introduce fuel at different angles.

[0061] In the illustrated embodiment, the intake chamber 206 includes a stepped shelf 252 between the longitudinal sidewall 207 and the mixing chamber 226. The side legs 244 of the fuel duct are positioned adjacent to this shelf 252 and may extend radially with respect to the combustion can on which the fuel injection assembly is mounted or along a centerline 254 through the mixing chamber to a mounting flange 260, which may be flush with the sidewall 207 as shown in Figures 4 and 6.

[0062] As shown in Figure 4, the stepped shelf 252 is oriented at or about a 90 degree angle relative to the longitudinal sidewall 207 and at or about a 90 degree angle relative to the mixing chamber sidewall 230. Alternatively, as shown in Figure 6, the outer surface of the stepped shelf may be oriented at or about a 90 degree angle relative to the longitudinal sidewall 207 and the mixing chamber sidewall 230. However, the inner surface 253 of the stepped shelf 252 may extend at an angle between the longitudinal sidewall 207 and the mixing chamber sidewall 230, which accelerates the flow of air around the diverting member 212 and into the throat 250.

[0063] In the illustrated embodiment, the intake chamber 206 has a cross-sectional area that is larger than the cross-sectional area of the mixing chamber 226. For example, the intake chamber 206 may have a rectangular cross-sectional shape with a lateral width 272 and a longitudinal length 274 that is larger than the lateral width 272, and the mixing chamber 226 may have a smaller rectangular cross-sectional shape with a lateral width 282 and a longitudinal length 284 that is larger than the lateral width 282. The lateral width 282 of the mixing chamber 226 is the maximum internal dimension in the circumferential direction (e.g., the area between the ribs 236). The lateral width 272 of the intake chamber 206 is larger than the lateral width 282 of the mixing chamber 226.

[0064] In the illustrated exemplary embodiment, fuel injection assembly 100 may further include a debris filter 258 at the open end 208 of intake chamber 206, through which air entering fuel injection assembly 100 from high-pressure plenum 42 (FIG. 2) passes. Debris filter 258 traps dirt, dust, and other particulates that may be entrained in the airflow from compressor section 114 (FIG. 1).

[0065] This specification has used examples to disclose the invention, including the best mode, and to enable any person skilled in the art to practice the invention, including making and using the devices or systems and practicing the methods. Other examples are within the scope of the claims, provided they include elements consistent with the claims.

[0066] Additional aspects of the present invention are presented in the following embodiments section. [Embodiment Item 1] A fuel injection assembly (100) for a combustor (10) of a gas turbine engine (1000), the fuel injection assembly (100) comprising: a body (202) including a head (204) defining an intake chamber (206); a mixing chamber (226) disposed adjacent to, and particularly downstream from, the intake chamber (206), the mixing chamber (226) including a lateral end wall (228) and a longitudinal side wall (230); and a turning member (212) disposed within the intake chamber (206), the turning member (212) including a turning surface (214) and a side surface (216) spaced apart from an inner wall surface (210) of the intake chamber (206), such that the turning member (212) and the intake chamber (206) are in communication with each other. a turning member (212) defining an outer circumferential air passage (222) between itself and an inner wall surface (210) of the turning member (212) for passing air from the intake chamber (206) to the mixing chamber (226); a plurality of radially extending and longitudinally spaced ribs (236) disposed along the inner surface of each of the longitudinal sidewalls (230) of the mixing chamber (226); a fuel plenum (242) disposed along the longitudinal sidewalls (230) of the mixing chamber (226); and a first plurality of fuel injection holes (246) defining a passage from the fuel plenum (242) through at least a portion of the longitudinal sidewalls (230) and the ribs (236) of the mixing chamber (226). [Embodiment 2] A fuel injection assembly (100) as described in embodiment 1, wherein the intake chamber (206) has lateral end walls (205) and longitudinal side walls (207), the side surfaces (216) of the deflecting member (212) are spaced parallel to the longitudinal side walls (207) of the intake chamber (206), and the peripheral air passage (222) includes a slot extending along each of the longitudinal side walls (207) of the intake chamber (206). [Embodiment 3] The fuel injection assembly (100) of embodiment 1 or embodiment 2, wherein the deflecting member (212) extends between the lateral end walls (205) of the intake chamber (206). [Embodiment 4] The fuel injection assembly (100) of any one of embodiments 1 to 3, wherein the intake chamber (206) includes a cross-sectional area greater than a cross-sectional area of the mixing chamber (226), and further includes a throat portion (250) between the intake chamber (206) and the mixing chamber (226). [Embodiment 5] The fuel injection assembly (100) of any one of embodiments 1 through 4, wherein the throat portion (250) includes a tapered cross-sectional profile from the intake chamber (206) to the mixing chamber (226). [Embodiment 6] The fuel injection assembly (100) of any one of embodiments 1 through 5, wherein the intake chamber (206) includes a rectangular cross-sectional shape and the mixing chamber (226) includes an even smaller rectangular cross-sectional shape. [Embodiment 7] The fuel injection assembly (100) of any one of embodiments 1 to 6, wherein the fuel plenum (242) includes an external fuel duct (244) adjacent to an outer wall surface (234) of each of the longitudinal sidewalls (230) of the mixing chamber (226), and a first plurality of fuel injection holes (246) are defined through the longitudinal sidewalls (230) and within the mixing chamber (226). [Embodiment 8] The fuel injection assembly (100) of any one of embodiments 1 to 7, wherein the intake chamber (206) comprises lateral end walls (205), longitudinal side walls (207), and a stepped ledge (252) between the longitudinal side walls (207) of the intake chamber (206) and the mixing chamber (226), and the external fuel duct (244) is positioned adjacent to an outer surface or face of the stepped ledge (252). [Embodiment Item 9] The fuel injection assembly (100) of any one of embodiments 1 to 8, wherein the deflection member (212) includes an inclined or curved lower surface (220) extending from the side surface (216) of the deflection member (212) into the throat portion (250). [Embodiment Item 10] The fuel injection assembly (100) of any one of embodiments 1 through 9, wherein the turning surface (214) of the turning member (212) is flat. [Embodiment Item 11] The fuel injection assembly (100) of any one of embodiments 1 to 10, wherein the turning surface (214) of the turning member (212) is inclined or curved toward the side surface (216) of the turning member (212). [Embodiment Item 12] The fuel injection assembly (100) of any one of embodiments 1 through 11, wherein the ribs (236) extend radially within the mixing chamber (226) to the outlet end (232) of the mixing chamber (226). [Embodiment Item 13] The fuel injection assembly (100) of any one of embodiments 1 to 12, wherein the first plurality of fuel injection holes (246) penetrate the front or apex of the rib (236) or the sidewall of the rib (236). [Embodiment Item 14] The fuel injection assembly (100) of any one of embodiments 1 through 13, wherein the rib (236) includes a linear edge (240) parallel to a centerline axis (254) passing through the mixing chamber (226). [Embodiment Item 15] The fuel injection assembly (100) of any one of embodiment paragraphs 1 to 5, further comprising a second plurality of fuel injection holes (248) defining a passageway from the fuel plenum (242) through one or more ribs (236) and into the mixing chamber (236), the second plurality of fuel injection holes (248) being vertically spaced apart from the first plurality of fuel injection holes (246). [Embodiment 16] An axial fuel staging (AFS) combustor (10) for a gas turbine engine (1000), the AFS combustor (10) comprising: a head end (20); a plurality of fuel nozzles (22) configured in the head end (20); and a combustion liner (12) extending downstream from the plurality of fuel nozzles (22), the combustion liner (12) defining a primary combustion zone (50) at a forward end of the combustion liner (12) and a secondary combustion zone (60) downstream of the primary combustion zone (60). The fuel injection assembly (100) includes a combustion liner (12) and a fuel injection assembly (100) disposed through the liner (12) in the secondary combustion zone (60), the fuel injection assembly (100) including a body (202) including a head (204) defining an intake chamber (206), and a mixing chamber (226) disposed adjacent to, and particularly downstream from, the intake chamber (206), the mixing chamber (226) including a lateral end wall (228) and a longitudinal side wall (230). and a diverting member (212) disposed within the intake chamber (206), the diverting member (212) including a diverting surface (214) and a side surface (216) spaced apart from the inner wall surface (210) of the intake chamber (206), such that an outer peripheral air passage (222) is defined between the diverting member (212) and the inner wall surface (210) of the intake chamber (206) for passing air from the intake chamber (206) to the mixing chamber (226). a plurality of radially extending and longitudinally spaced ribs disposed along each of the longitudinal sidewalls (230) of the mixing chamber (226); a fuel plenum (242) disposed along the longitudinal sidewalls (230) of the mixing chamber (226); and a first plurality of fuel injection holes (246) defining passages from the fuel plenum (242) through at least a portion of the ribs (236) and into the mixing chamber (226). [Embodiment Item 17] An axial fuel staging (AFS) combustor (10) as described in embodiment 16, wherein the intake chamber (206) has lateral end walls (205) and longitudinal side walls (207), the side surfaces (216) of the turning members (212) are equidistantly spaced from the longitudinal side walls (207) of the intake chamber (206), and the peripheral air passage (222) includes slots extending along each of the longitudinal side walls (207) of the intake chamber (206). [Embodiment Item 18] The axial fuel staging (AFS) combustor (10) of embodiment 16 or embodiment 17, wherein the intake chamber (206) includes a cross-sectional area greater than a cross-sectional area of the mixing chamber (226), and further includes a throat portion (250) between the intake chamber (206) and the mixing chamber (226). [Embodiment Item 19] The axial fuel staging (AFS) combustor (10) of any one of embodiments 16 to 18, wherein the intake chamber (206) includes a rectangular cross-sectional shape, the mixing chamber (226) includes an even smaller rectangular cross-sectional shape, the fuel plenum (242) includes an external fuel duct (244) attached to an outer wall surface (234) of each of the longitudinal side walls (230) of the mixing chamber (226), and a first plurality of fuel injection holes (246) are defined in the mixing chamber (226) through the longitudinal side walls (230) and each rib (236). [Embodiment Item 20] The axial fuel staging (AFS) combustor (10) of any one of embodiments 16 to 19, wherein the intake chamber (206) comprises lateral end walls (205), longitudinal side walls (207), and a stepped shelf (252) between the longitudinal side walls (207) of the intake chamber (206) and the mixing chamber (226), and the external fuel duct (244) is positioned adjacent to an outer surface or face of the stepped shelf (252). [Explanation of symbols]

[0067] 10 Combustor 12 Liner 14 Outer sleeve 20 Headend 22 fuel nozzle 24 Fuel inlet 26 End cover 28 Combustor Cap 32 Annulus 50 Primary combustion zone 60 Secondary combustion zone 100 Fuel Injection Assembly 104 Fuel supply line 112 Intake section 114 Compressor Section 116 Combustion Section 118 Turbine Section 120 Exhaust Section 122 Shaft 134 Combustion Gas 202 Main Unit 204 Head 205 Lateral end wall of intake chamber 206 Intake chamber 207 Longitudinal side wall of intake chamber 210 Inner wall surface of intake chamber 212 Turning member 214 Turning surface of turning member 216 Side of turning member 220 Lower surface of turning member 222 Peripheral air passage 226 Mixing room 228 Lateral end walls of mixing chamber 230 Longitudinal sidewall of mixing chamber 232 Open outlet end of mixing chamber 236 Ribs 242 Fuel Plenum 244 External Fuel Duct 246 first plurality of fuel injection holes 248 second plurality of fuel injection holes 250 throat 252 Tiered shelf 1000 Gas Turbine Engine

Claims

1. A fuel injection assembly (100) for a combustor (10) of a gas turbine engine (1000), the fuel injection assembly comprising: a body (202) including a head (204) defining an intake chamber (206); a mixing chamber (226) disposed adjacent to the intake chamber (206), the mixing chamber (226) including lateral end walls (228) and longitudinal side walls (230); a deflecting member (212) disposed within the intake chamber (206), the deflecting member (212) including a deflecting surface (214) and a side surface (216) spaced apart from an inner wall surface (210) of the intake chamber (206), such that an outer peripheral air passage (222) is defined between the deflecting member (212) and the inner wall surface (210) of the intake chamber (206) for passing air from the intake chamber (206) to a mixing chamber (226); a plurality of ribs (236) disposed along the inner surface of each of the longitudinal side walls (230) of the mixing chamber (226), the ribs extending along a direction from the intake chamber (206) toward the outlet end (232) of the mixing chamber (226) and spaced apart along a direction between the lateral end walls (228); a fuel plenum (242) disposed along the longitudinal sidewall (230) of the mixing chamber (226); a first plurality of fuel injection holes (246) defining passages from the fuel plenum (242) through the longitudinal sidewalls (230) of the mixing chamber (226) and at least a portion of the ribs (226); A fuel injection assembly comprising:

2. 2. The fuel injection assembly of claim 1, wherein the intake chamber (206) has lateral end walls (205) and longitudinal side walls (207), the side surfaces (212) of the deflecting members (212) are spaced parallel to and from the inner wall surfaces (210) of the longitudinal side walls (207) of the intake chamber, and the outer circumferential air passage (202) comprises slots extending along each of the longitudinal side walls (207) of the intake chamber (206).

3. The fuel injection assembly of claim 2, wherein the deflecting member (212) extends between lateral end walls (205) of the intake chamber (206).

4. 4. The fuel injection assembly of claim 1, wherein the intake chamber (206) includes a cross-sectional area greater than a cross-sectional area of the mixing chamber (226), and wherein a throat (250) is provided between the intake chamber and the mixing chamber.

5. The fuel injection assembly of claim 4, wherein the throat portion (250) includes a tapered cross-sectional profile from the intake chamber to the mixing chamber.

6. The fuel injection assembly of any one of claims 1 to 5, wherein the intake chamber (206) includes a rectangular cross-sectional shape and the mixing chamber (226) includes a smaller rectangular cross-sectional shape.

7. 7. The fuel injection assembly of claim 1, wherein the fuel plenum includes an external fuel duct adjacent an outer wall surface of each of the longitudinal sidewalls of the mixing chamber, and wherein a first plurality of fuel injection holes are defined in the mixing chamber through the longitudinal sidewalls of the mixing chamber.

8. 8. The fuel injection assembly of claim 7, wherein the intake chamber comprises lateral end walls, longitudinal side walls, and a stepped ledge between the longitudinal side walls of the intake chamber and the longitudinal side walls of the mixing chamber, and the external fuel duct is disposed adjacent an outer surface of the stepped ledge.

9. 9. A fuel injection assembly according to claim 4 or any one of claims 5 to 8 when dependent on claim 4, wherein the deflecting member (212) includes an angled or curved lower surface (220) extending from a side surface (216) of the deflecting member (212) into the throat portion (250).

10. 10. The fuel injection assembly of claim 1, wherein the turning surface (214) of the turning member (212) is flat or is inclined or curved toward a side surface (216) of the turning member (212).

11. The fuel injection assembly of any preceding claim, wherein the ribs (236) extend within the mixing chamber (226) to the outlet end (232) of the mixing chamber.

12. The fuel injection assembly of any one of claims 1 to 11, wherein the first plurality of fuel injection holes (246) extend through a front face or apex of the rib (236) or a sidewall of the rib (236).

13. The fuel injection assembly of any preceding claim, wherein the rib (236) includes a straight edge (240) parallel to a centerline axis (254) passing through the mixing chamber (226).

14. 14. The fuel injection assembly of claim 1, further comprising a second plurality of fuel injection holes (248) defining passages from the fuel plenum (242) through the one or more ribs (236) and into the mixing chamber (236), the second plurality of fuel injection holes (248) being spaced apart from the first plurality of fuel injection holes (246) along a centerline axis (254) through the mixing chamber (226).

15. An axial fuel staging combustor (10) for a gas turbine engine (1000), comprising: a head end (20); one or more fuel nozzles (22) configured in the head end (20); a combustion liner (12) extending downstream from one or more fuel nozzles (22), the combustion liner (12) defining a primary combustion zone (50) at a forward end of the combustion liner (12) and a secondary combustion zone (60) downstream of the primary combustion zone (60); 15. An axial fuel staging combustor comprising: a fuel injection assembly (100) according to any one of claims 1 to 14, the fuel injection assembly (100) being disposed through a liner (12) in a secondary combustion zone (60).

Images