KR20080071454A - Counterflow injection mechanism having coaxial fuel-air passages - Google Patents

Abstract

A counter-flow injection mechanism having coaxial fuel-air passages is provided to easily mix fuel with air in a gas turbine combustor by using a coaxial fuel-air injection mechanism. A counter-flow injection mechanism(50) comprises coaxial fuel-air passages extending to fuel-air injection ports(70,72). The fuel-air injection ports are arranged in an off-axis position relative to a gas turbine combustor(30). The fuel-air injection ports are aligned in a predetermined direction so that fuel-air is prevented from being introduced into a turbine through the gas turbine combustor. The fuel-air injection ports are coaxially arranged and offset from each other along the common shaft of the coaxial fuel-air passages.

Description

COUNTERFLOW INJECTION MECHANISM HAVING COAXIAL FUEL-AIR PASSAGES}

1 is a block diagram of an exemplary system having a gas turbine engine coupled to a rod in accordance with certain embodiments of the present invention;

FIG. 2 is a longitudinal schematic view of an exemplary combustor of a gas turbine engine as shown in FIG. 1, with a plurality of fuel-air injection lobes disposed circumferentially along a solid inner casing of the combustor in accordance with certain embodiments of the present invention; Further showing a countercurrent jetting mechanism comprising:

3 is a cross-sectional schematic view of an embodiment of a combustor as shown in FIG. 2, further showing a plurality of fuel-air injection lobes disposed in multiple radial positions along the circumference of the solid inner casing;

4 is a longitudinal schematic view of a variant embodiment of the combustor as shown in FIGS. 1 and 2, with a backflow with a radial array of coplanar fuel-air injection regions circumferentially disposed along the solid inner casing of the combustor; A drawing further illustrating the spraying mechanism,

5 is a longitudinal schematic of a variant embodiment of the combustor as shown in FIGS. 1 and 2, with a radial array of inwardly cantilevered fuel-air injection members disposed circumferentially along a solid inner casing of the combustor; It further illustrates a countercurrent injection mechanism with an inner cantilevered fuel-air injection member each having a plurality of coaxial fuel-air ports oriented generally longitudinally and countercurrently with respect to the longitudinal flow axis of the combustor. , drawing,

FIG. 6 is a lateral schematic of an embodiment of a combustor as shown in FIG. 5, further showing a radial array of inwardly cantilevered fuel-air injection members disposed in multiple radial positions along the circumference of the solid inner casing drawing,

FIG. 7 is a cross-sectional view of one embodiment of an inwardly cantilevered fuel-air injection member as shown in FIG. 5, further illustrating coaxial flow of fuel and air oriented generally longitudinally and countercurrently with respect to the longitudinal flow axis of the combustor. Drawing to show,

FIG. 8 is a longitudinal schematic view of a variant embodiment of the combustor as shown in FIG. 5, in which each of the inwardly cantilevered fuel-air injection members is oriented generally transversely and countercurrently with respect to the longitudinal flow axis of the combustor. Further comprising a coaxial fuel-air port, drawing

FIG. 9 is a lateral schematic of an embodiment of a combustor as shown in FIG. 8, further showing a radial array of inwardly cantilevered fuel-air injection members disposed in multiple radial positions along the circumference of the solid inner casing. drawing,

FIG. 10 is a cross sectional view of one embodiment of an inwardly cantilevered fuel-air injection member as shown in FIG. 8, with coaxial flow of fuel and air in a direction generally longitudinal and countercurrent with respect to the longitudinal flow axis upon combustion; FIG. Further illustrating the coaxial flow of fuel and air in two opposite directions, generally transverse and countercurrent, with respect to the longitudinal flow axis of the combustor,

FIG. 11 is a longitudinal schematic view of an embodiment of a combustor as shown in FIG. 1, with a backflow having a single inward cantilevered fuel-air injection member disposed on or near the turbine nozzle on the solid inner casing of the combustor; Further illustrating the injection mechanism, the inward cantilevered fuel-air injection member comprises a plurality of coaxial fuel-air ports oriented generally longitudinally and countercurrently with respect to the longitudinal flow axis of the combustor,

12 is a schematic diagram of an exemplary fuel-air injector having coaxial fuel and air flow in the same longitudinal or axial direction, in accordance with certain embodiments of the present invention;

FIG. 13 is a schematic illustration of a variant embodiment of a fuel-air injector with coaxial fuel and air flow, wherein the fuel flow is redirected transversely or outwardly with respect to the air flow;

14 is a schematic illustration of another modified embodiment of a fuel-air injector having a central axial air flow and an external fuel flow oriented transversely or inwardly radially relative to the air flow;

FIG. 15 is a schematic representation of another variant embodiment of a fuel-air injector having air flow and coaxial fuel comprising a vortex mechanism for both fuel air flows.

<Description of the symbols for the main parts of the drawings>

10 system 12 gas turbine engine

18 compressor 24 exhaust section

56: solid inner casing 58: perforated outer casing

64: fuel injection assembly 66: air injection assembly

96: fuel flow 98: air flow

150: injection mechanism 152: fuel-air injection member

154: co-fluid 200: central fuel port

210, 211: coaxial fuel-air port 260: coaxial fuel-air injection mechanism

328: fuel vortex mechanism 332: air vortex mechanism

This section is intended to guide those skilled in the art in various technical forms that may relate to aspects of the invention disclosed and / or claimed below. This description is believed to be helpful to those skilled in the art, together with background information, to facilitate a good understanding of the various forms of the invention. Therefore, these descriptions should be read in this light, not as an introduction of the prior art.

Combustion engines, such as gas turbine engines, produce a variety of pollutant emissions. For example, pollutant emissions generally include carbon oxides (COx), nitrogen oxides (NOx), sulfur oxides (SOx), and particulate matter (PM). These pollutant emissions are strictly regulated in the United States and elsewhere. NOx emissions from gas turbine engines can be reduced by premixing fuel and air. Unfortunately, premixing can cause unstable flames that are difficult to fix, and today the best premixed systems may not reach the NOx emission target. Another approach is selective catalytic reduction (NOC) of NOx via ammonia injection. Unfortunately, the SCR approach is relatively expensive.

Thus, improved techniques need to reduce pollutant emissions, such as NOx emissions from gas turbine combustors.

Specific embodiments corresponding to the scope of the invention as originally claimed are described below. These embodiments are merely intended to provide those skilled in the art with a brief summary of the specific forms the invention may take, and these embodiments are not intended to limit the scope of the invention. In addition, the present invention will include various embodiments that may not be described later.

According to a particular embodiment, the system includes a fuel air injection mechanism that includes coaxial fuel and air passages leading to the fuel and air injection openings. The fuel and air injection openings are configured to be disposed in an off-axis position of the gas turbine combustor, and the fuel and air injection openings are configured to be oriented in an injection direction that is not aligned with the flow direction through the gas turbine combustor to the turbine. It is.

According to another embodiment, the system includes a combustion liner having a generally longitudinal flow axis extending from the stagnation zone to the turbine nozzle. The gas turbine combustor also includes a countercurrent fuel-air injector disposed in the combustion liner at one or more intermediate positions between the stagnation zone and the turbine nozzle. The countercurrent fuel-air injector includes coaxial fuel and air passages extending from the stagnation zone to the turbine nozzle to fuel and air injection openings that are not aligned with the flow direction.

According to another embodiment, the method comprises coaxially flowing fuel and air with a countercurrent fuel-air injector oriented generally in the counterflow direction about the longitudinal flow axis from the stagnation zone of the gas turbine combustor to the turbine nozzle.

Various calibrations of the foregoing features exist with respect to various aspects of the present invention. Other features can also be incorporated into these various forms. These calibrations and additional features can exist individually or in any combination. For example, various features described below in connection with one or more of the illustrated embodiments may be incorporated in any of the foregoing forms of the invention, alone or in any combination. Again, the foregoing brief summary is merely intended to inform one skilled in the art of the specific form and content of the present invention without limiting the claimed subject matter.

These and other features, aspects, and advantages of the present invention will be better understood when the following detailed description is read with reference to the accompanying drawings, wherein like reference numerals indicate like parts throughout the figures.

One or more specific embodiments of the invention are described below. In order to provide a precise description of these embodiments, all features of an actual performance may not be disclosed in the specification. In the development of all these actual practices, for every engineer or design project, numerous performance-specific decisions have been made to flexibly cope with system-related and business-related pressures that can change from one performance to another. It is important to understand that the developer has achieved certain goals, such as: In addition, such development efforts can be complex and time consuming, but those skilled in the art will nevertheless be routine businesses of design, manufacture and manufacture.

1 is a block diagram of an exemplary system 10 that includes a gas turbine engine 12 coupled to an application 14 in accordance with certain embodiments of the present invention. In certain embodiments, system 10 may include an aircraft, a ship, a locomotive, a power generation system, or a combination thereof. Thus, the application 14 may comprise a generator, a propeller or a combination thereof. The gas turbine engine 12 shown includes an air intake section 16, a compressor 18, a combustor section 20, a turbine 22 and an exhaust section 24. The turbine 22 is operatively coupled to the compressor 18 via a shaft 26. As described in more detail below, the disclosed embodiment of the combustor section 20 includes various countercurrent fuel-air injection mechanisms that facilitate the mixing of fuel, air and hot combustion products within the combustor section. More specifically, the disclosed countercurrent fuel-air injection mechanism injects both fuel and air in one or more directions generally resisting or opposing general flow through the gas turbine engine 12, particularly the combustor section 20.

As shown by the arrows, air flows through the suction section 16 into the compressor 18, which compresses the air before entering the combustor section 20. The combustor section 20 shown comprises a combustor housing 28 disposed concentrically or annularly about the shaft 26 between the compressor 18 and the turbine 22. The combustor section 20 inside the combustor housing 28 includes a plurality of combustors 30 arranged in multiple radial positions in a circular or annular configuration about the shaft 26. As described in more detail below, the compressed air from the compressor 18 enters each combustor 30, and then is mixed and combusted with fuel in each combustor 30 to drive the turbine 22. .

In certain embodiments, combustor 30 may be configured as a multi-stage combustor, with fuel injectors located at different stages along the length of each combustor 30. Optionally, the combustor 30 can be configured as a single stage combustor, with the fuel injectors being arranged in a single stage or zone of combustion. In the following description, combustor 30 is disclosed as a single stage combustor, although the disclosed embodiments may utilize a single stage or multi stage combustor within the scope of the present invention.

The disclosed embodiment of the combustor 30 includes various countercurrent fuel-air injection mechanisms that orient air and fuel in one or more directions generally resistant to flow through the combustor 30. For example, the countercurrent fuel-air injection mechanism includes a plurality of longitudinally oriented fuel-air injectors, transversely-oriented fuel-air injectors, or angled fuel-air injectors having both longitudinal and transverse portions. can do. The longitudinally-oriented fuel-air injectors are generally aligned longitudinally along the combustor 30, while the transversely-oriented fuel-air injectors are generally transverse to the longitudinal flow or axis along the combustor 30. It can be aligned in the direction, transverse direction or radial direction. In general, the acute direction generally comprises longitudinal and transverse sections or may be classified into longitudinal and transverse sections. These longitudinal, transverse and acute angles can each be defined as the counterflow direction.

As described in more detail below, the countercurrent fuel-air injection mechanism injects fuel and air away from the turbine 22 in these counterflow directions towards the opposite ends of the combustor 30, resulting in fuel and air stagnation. Are mixed and burned in the zone. The stagnant zone at the opposite end of the combustor 30 generally increases the stability and fixability of the flame within the combustor 30. The hot combustion product then moves back toward the turbine 22 through a countercurrent fuel-air injection mechanism. Again, the countercurrent fuel-air injection mechanism facilitates the mixing of hot combustion products with fuel and air. The hot combustion product then passes through a nozzle 32 leading to the turbine 22. These hot combustion products drive the turbine 22, thereby driving the compressor 18 and the rod 34 of the application 14 via the shaft 26. Next, the hot combustion product is exhausted through the exhaust section 24.

FIG. 2 is a longitudinal schematic view of an exemplary embodiment of the combustor 30 as shown in FIG. 1, in which the combustor 30 differs around the inner circumference of the combustion liner 54 in accordance with certain embodiments of the present invention. It includes a backflow injection mechanism 50 that includes a plurality of fuel-air injection lobes 52 disposed in radial positions. The combustion liner 54 shown includes a solid inner casing 56 surrounded by a perforated outer casing 58. That is, the combustion liner 54 has a hollow wall structure with a generally continuous gap between the inner casing 56 and the outer casing 58. Combustion liner 54 includes a ceramic, summit or other suitable material. In general, the fuel-air injection lobes 52 are formed with the solid inner casing 56 or are coupled with the solid inner casing 56. In the illustrated embodiment, the fuel-air injection lobes 52 are multiple around the solid inner casing 56 at one longitudinal position 60 with respect to the central longitudinal axis 62 along the combustor 30. It is arranged in a radial position. Thus, the combustor 30 shown is configured as a single stage combustor. However, other embodiments of the combustor 30 may have fuel-air injection lobes 52 disposed in multiple longitudinal positions relative to the axis 62.

The countercurrent injection mechanism 50 shown includes a fuel injection assembly 64 disposed adjacent the air injection assembly 66. In certain embodiments, the fuel and air injection assemblies 64, 66 are disposed in close proximity to one another. The fuel injection assembly 64 includes a plurality of fuel injectors 68 with elongated injector tips 70. The air injection assembly 66 includes a number of example air passages 72 disposed at various radial positions about the inner circumference of the solid inner casing 56. In certain embodiments, elongated injector tip 70 may be disposed proximate to air passage 72. For example, in the illustrated embodiment of FIG. 2, the long injector tip 70 is generally coaxial or concentric with the air passage 72. Both the long injector tip 70 and the air passage 72 extend through the lobe structure 74 at multiple radial positions around the inner circumference of the solid inner casing 56. That is, each of the fuel air injection lobes 52 includes one of the elongated injector tips 70 and one of the air passages 72 disposed in one of the lobe structures 74. As shown, lobe structure 74 includes protruding portions 76 and concave portions 78 on opposite longitudinal sides of position 60. In certain embodiments, the lobe structures 74 each have a generally circular or annular configuration (e.g., a toroidal shape), the contour shape of which gradually changes between the protruding portion 76 and the concave portion 78. .

In the illustrated embodiment of FIG. 2, the elongated injector tip 70 and air passageway 72 of each fuel-air injection lobe 52 are routed through a gas turbine engine 12 as described above with reference to FIG. 1. It is oriented generally in the opposite or countercurrent direction with respect to the general flow 80. For example, elongated injector tip 70 and air passageway 72 may be disposed at angles 82 and 84 with respect to shaft 62 of combustor 30. The angles 82, 84 may be substantially the same or may be different from each other. The angles 82 and 84 also depend on the length and other factors of the combustion liner 54 and may vary between 0 degrees and 90 degrees. For example, the angles 82, 84 may be about 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 with respect to the inner surface of the shaft 62 or the solid inner casing 56. It may be 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees or 85 degrees. Moreover, the elongated injector tip 70 and air passageway 72 of the fuel-air injection lobe 52 generally converge toward the stagnation zone 86 in the closed rear portion 88 of the solid inner casing 56. It can be oriented in a way. In general, stagnation zone 86 improves flame stability and fixability near the closed rear portion 88 of combustor 30.

In operation, combustor 30 as shown in FIG. 2 receives compressed air from compressor 18 through opening 90 in perforated outer casing 58 as indicated by arrow 92. . Upon entering the combustion liner 54 through the perforated outer casing 58, the compressed air remains in the annular space between the solid inner casing 56 and the perforated outer casing 58. That is, the combustion liner 54 has a hollow wall, such as a hollow annular or can-shaped wall defined by the inner casing 56 and the outer casing 58. Preferably, the combustion liner 54 allows compressed air to flow along the solid inner casing 56 toward the plurality of fuel-air injection lobes 52, as indicated by arrow 94. In this way, the air flow 94 facilitates cooling of the solid inner casing 56 before being injected into the interior of the combustor 30 via the air passage 72.

In the fuel-air injection lobe 52, the long injector tip 70 injects a fuel flow 96 that is accompanied by an air flow 98 from the air passage 72. In the illustrated embodiment, the fuel and air flows 96, 98 are coaxial or concentric with respect to each other. In particular, the air flow 98 is disposed concentrically about the fuel flow 96 as a result of the concentric or coaxial configuration of the long combustor tip 70 in the air passage 72. Again, the long injector tip 70 and the air passage 72 are disposed at angles 82 and 84, thereby converging toward the axis 62 and stagnation zone 86 in a manner that fuel and air flow 96 , 98 is moved at least initially at angles 82 and 84. Thus, the coaxial or concentric configuration of the fuel-air injection lobes 52 and the resulting flows 96, 98 facilitates fuel-air mixing in the combustor 30 rather than premixing. In addition, the convergence relationship of the fuel-air injection lobes 52 facilitates the mixing of fuel and air in the stagnation zone 86 as indicated by the flow / mix arrow 100. As shown, the flow 100 includes a U-shaped flow that flows inward toward the axis 62 and outward toward the walls of the solid inner casing 56. That is, when the flow 100 moves in the counterflow direction from the fuel-air injection lobe 52 toward the closed rear portion 88, the flow 100 generally has a shaft 62 and a solid inner casing 56. The wall of the backflow is reversed in a U-shaped manner toward both. Similar flow patterns can be made in accordance with other embodiments described below. The fuel-air mixture flow 100 is combusted in the stagnation zone 86 in the vicinity of the closed rear portion 88 to preferably retain or fix the flame to improve flame stability in the combustor 30.

Thus, the hot combustion product moves longitudinally from the stagnation zone 86 toward the nozzle 32 along with the combustor 30, as indicated by arrow 102. Thus, hot combustion product 102 flows in the same general direction 80 of flow through gas turbine engine 12, while fuel and air flows 96, 98 injected from fuel-air injection lobes 52. ) Is generally countercurrent. Again, the backflow is oriented in the longitudinal direction toward stagnant bone 86, transverse to the axis 62 or solid inner casing 56, in an acute angle with longitudinal and transverse portions, or in a combination thereof. Can be. In this way, the countercurrent injection mechanism 50 improves the mixing of fuel and air with the hot combustion products in the combustor 30, thereby improving combustion and exhausting contaminants from the combustor 30 (eg, NOx emissions). The lobe structure 74 also slightly offsets the long injector tip 70 and the air passage 72 relative to the inner circumference of the solid inner casing 56, thereby preventing the injection of fuel and air flows 96, 98. Located slightly away from the inner circumference to improve mixing of fuel, air and hot combustion products.

3 is a cross-sectional schematic view of an embodiment of the combustor 30 as shown in FIG. 2, with multiple radial positions 110, 112, 114, about a solid inner casing 56, in accordance with certain embodiments of the present invention. It is further shown the radial configuration of the fuel-air injection lobes 52 of the countercurrent injection mechanism 50 at 116, 118, 120, 122, 124. As described above with reference to FIG. 2, the fuel and air flows 96, 98 of the plurality of fuel-air injection lobes 52 converge generally toward the axis 62 in the stagnation zone 86. In certain embodiments, the fuel and air flows 96, 98 may converge generally at the center of the axis 62 as indicated by dashed lines 110, 112, 114, 116, 118, 120, 122, 124. .

In another embodiment, the fuel-air injection lobes 52 may be oriented towards the stagnation zone 86 in a manner that converges toward the axis 62, while the axis 62 as indicated by arrow 126. ) Is at least slightly offset from the center. As a result of the convergence direction offset from this center of fuel-air injection lobe 52, fuel and air flows 96, 98 may produce a vortex flow, as indicated by dashed arrow 128. In both configurations, the convergence relationship between the fuel-air injection lobes 52 facilitates fuel and air mixing (and also with hot combustion products) in the stagnation zone 86. However, the addition of vortex flows 128 in stagnation zone 86 may further improve fuel-air mixing and combustion in combustor 30. In some embodiments, the fuel-air injection lobes 52 may all be oriented to produce clockwise vortex flow or counterclockwise vortex flow. Optionally, the fuel-air injection lobes 52 may be staggered to produce both clockwise and counterclockwise vortex flows. For example, the odd fuel-air injection lobes 52 (eg, at radial positions 110, 114, 118, 122) may be oriented to produce a clockwise vortex flow, while the even fuel-air Injection lobes 52 (eg, at radial positions 112, 116, 120, 124) may be oriented to produce counterclockwise vortex flow. Again, a particular embodiment of the combustor 30 shown is a fuel-air injection lobe as shown in FIG. 3 in multiple longitudinal positions along the axis 62 as in the multi-stage combustor 30 as described above. It may also include the annular array of 52.

4 is a longitudinal schematic view of a variant embodiment of the combustor 30 as shown in FIGS. 1-3, where the backflow injection mechanism 50 is coplanar fuel-air injection zone 140 in accordance with certain embodiments of the present invention. A radial array or configuration). As shown, the elongated injector tip 70 and air passageway 72 of the fuel and air injection assemblies 64, 68 extend into a position substantially coplanar with the solid inner casing 56 of the combustion liner 54. It is. That is, the long injector tip 70 and the air passage 72 are generally concave from the inner surface 142 of the solid inner casing 56, while the inner casing 56 is the long injector tip 70 and the air passage 72. It does not protrude near. Thus, in contrast to the fuel-air injection lobe 52 as shown in FIGS. 2 and 3, the radial array of coplanar fuel-air injection regions 140 as shown in FIG. 4 is a solid inner casing 56. Do not protrude into the interior of the combustor 30. However, in certain embodiments, the long injector tip 70 may be oriented to partially protrude from the inner surface 142 of the solid inner casing 56. Optionally, elongated injector tip 70 may be retracted into air passage 72 as shown and described in more detail below with reference to FIG. 12. Again, as shown in FIG. 4, the backflow injection mechanism 50 is fuel and air flow 96 in a manner that generally converges through the gas turbine engine 12 toward stagnation zone 86 against the general flow 80. , 98). Thus, the hot combustion product moves from stagnant zone 96 through the nozzle 32 through the radial array of coplanar fuel-air injection zones 140 to exit combustor 30.

FIG. 5 is a longitudinal schematic view of another variant embodiment of the combustor 30 as shown in FIG. 1, the combustor 30 having an inner side disposed along the interior of the solid inner casing 56 in accordance with certain embodiments of the present invention. And a countercurrent injection mechanism 150 having a radial array of cantilevered fuel-air injection members 152. In the illustrated embodiment, the fuel-air injection member 152 faces the central longitudinal axis 62 of the combustor 30 but does not reach this axis 62. Protrude inward from 56). That is, the fuel-air injection member 152 is cantilevered and offset from the axis 62 at the center.

The illustrated fuel-air injection member 152 has a co-fluid 154 having coaxial fuel-air ports 156, 157 disposed along an edge 158 towards the stagnation zone 86. In the illustrated embodiment, the coaxial fuel-air port 156 includes three ports 156 that are generally parallel to the axis 62, while the coaxial fuel air port 157 defines the stagnation zone 86. And a single port 157 angled inward toward axis 62 (or converging to axis) in the counterflow direction. In alternative embodiments, the fuel-air ports 156 and 157 may include any other number or arrangement of ports disposed along the co-fluid 156 at the required spacing. Coaxial fuel-air port 156 connects to fuel pump or injector 160 and air passage 162 extending into the space between solid inner casing 56 and perforated outer casing 58 of combustion liner 54. do.

Accordingly, the fuel-air injection member 152 is fuel and into the combustor 30 from the coaxial fuel-air port 156, 157 in the longitudinal direction generally toward the stagnation zone 86, as indicated by arrows 164, 165. Both fuel and air are received through a co-fluid 154 that injects a co-flow of air. In the illustrated embodiment, the longitudinal flow 164 of fuel and air is generally parallel to the axis 62 of the combustor 40, while the flow 165 generally converges toward the axis 62. However, in other embodiments, coaxial fuel-air port 156 may be oriented at a generally converging or diverging angle with respect to axis 62. Moreover, the coaxial fuel-air ports 156, 157 can be oriented generally clockwise or counterclockwise about the axis 62, whereby the vortex flow is combusted 30 as described above with reference to FIG. 3. It can also be generated within the.

In operation, similar to the embodiment of FIG. 2, the combustor 30 passes through the outer casing 58 and the solid inner casing perforated toward the countercurrent injection mechanism 150, as shown by arrows 92, 94. Receives compressed air along 56. Upon reaching the countercurrent injection mechanism 150, the compressed air enters the co-fluid 154 through the air passage 162 and fuel is received from the fuel pump or injector 160. The fuel-air injection member 152 then injects co-flow of both fuel and air from the ports 156 and 157 into the interior of the solid inner casing 56 as indicated by arrows 164 and 165. Again, these cavity flows 164, 165 are disposed in multiple peripheral-radial positions offset from the axis 162. In addition, the co-flows 164, 165 are oriented towards the stagnation zone 86 in a generally opposite or countercurrent direction relative to the general flow 80 via the gas turbine engine 12. In this way, the fuel-air co-flows 164, 165 facilitate fuel-air mixing, thereby improving combustion in the combustor 40 and reducing pollutant emissions. In the stagnation zone 86, the fuel-air mixture 100 is combusted, and then the hot combustion product is moved past the countercurrent injection mechanism 150 onto the nozzle 32 as indicated by arrow 102. Again, the fuel air co-flows 164 and 165 generally flow back to the flow 102 of the hot combustion product. Thus, this backflow further improves fuel-air mixing with the hot combustion products in combustor 30 as described above.

FIG. 6 is a cross-sectional schematic view of the combustor 30 as shown in FIG. 5 and in the radial direction of the fuel-air injection member 152 cantilevered into the backflow injection mechanism 150 in accordance with certain embodiments of the present invention. The array is further illustrated. The embodiment of FIG. 6 is slightly different from the embodiment of FIG. 5. Specifically, the number of ports 156 is four rather than three, and the length of the co-fluid 154 is relatively shorter than in the embodiment of FIG. However, the number of ports 156, 157 may be increased or decreased as needed for the particular combustor 30. In addition, the length of the fluid 154 may be increased to extend closer to the axis 62. In addition, the ports 156 and 157 are angled inward toward the axis 62, respectively.

In the illustrated embodiment, the fuel-air injection member 152 extends around the inner circumference or periphery of the solid inner casing 56 as indicated by dashed lines 166, 168, 170, 172, 174, 76, 178, 180. It is arranged in multiple radial positions about its center. In addition, the fuel-air injection member 152 is generally aligned or centered with the axis 62. However, the inner or free end of the inwardly cantilevered fuel-air injection member 152 is generally offset from the axis 62 or off centered, as indicated by arrow 182. In a particular embodiment, the fuel-air injection member 152 is angled with respect to the axis 62, thereby creating a counterclockwise or clockwise vortex flow downstream in the stagnation zone 86. For example, the fuel-air injection member 152 may be acute relative to the inner surface of the solid inner casing 56 rather than substantially vertical. In the illustrated embodiment, the countercurrent injection mechanism 150 includes eight fuel-air injection members 152 in a peripheral-radial configuration as shown in FIGS. 5 and 6. However, other embodiments of backflow injection mechanism 150 may include other suitable numbers of fuel-air injection members 152.

7 is a cross-sectional view of an exemplary embodiment of a fuel-air injection member 152 as shown in FIGS. 5 and 6, with a co-flow passage within the interior of a co-fluid 154 in accordance with certain embodiments of the present invention. To show more. As shown, the co-fluid 154 generally has an aerodynamic appearance or airfoil structure. In addition, the co-fluid 154 may include a plurality of lateral fuel injection passages extending from the longitudinal or common fuel supply passage 186 relative to the longitudinal axis of the co-fluid 154 (eg, vertical in the figure). 184). These passages 184, 186 are generally supported by upper and lower support members 188, 190 and one or more lateral support structures 192 having passages 184. Co-fluid 154 also includes one or more air passages 194, 196, 198. The illustrated fuel injection passage 184 and the air passages 194, 196, 198 are directed along the edge 158 toward the coaxial fuel-air ports 156, 157 as described above. In particular, as shown in FIG. 7, coaxial fuel-air ports 156, 157 are connected to the central fuel port 200 from the lateral fuel injection passage 184 and from the air passages 194, 196, 198. Concentric or annular air port 202. Thus, in operation, fuel flows through the fuel-air injection member 152 as indicated by arrow 204, while air moves fuel-air injection member 152 as indicated by arrow 206. Flow through.

8-10 illustrate a variant embodiment of the combustor 30 as shown in FIGS. 5-7, wherein a radial array of inwardly cantilevered fuel-air injection members 152 is a particular aspect of the present invention. In accordance with an embodiment additional coaxial fuel-air ports 210, 211 along the top and bottom sides of co-fluid 154. Referring first to FIG. 8, this FIG. 8 is a longitudinal schematic of the combustor 30, along the face of the series of coaxial fuel-air ports 156, 157 and the co-fluid 154 along the edge 158. A series of coaxial fuel-air ports 210 and 211 are shown. As described above with reference to FIG. 5, the coaxial fuel-air port 156 is generally longitudinally oriented with respect to the axis 62 of the combustor 30, whereby the fuel and air as indicated by arrow 164 is indicated. Creates a coaxial flow of air. Again, these coaxial flows 164 may be generally aligned to be parallel to, converging about, or diverging about axis 62. However, these coaxial flows 164 are generally oriented generally longitudinally towards the combustor 30 toward the stagnation zone 86. Similarly, coaxial fuel-air port 157 (and flow 165) is oriented along the length of combustor 30 toward stagnation zone 86. However, as discussed above, the coaxial fuel-air port 157 (and flow 165) generally converges toward axis 62 in the counterflow direction toward stagnation zone 86.

In contrast, the coaxial fuel-air port 210 is oriented laterally at a distance relative to the axis 62. In other words, the coaxial fuel-air port 210 is oriented to produce a flow that is generally vertical in the diagram of FIG. 8. In addition, the coaxial fuel-air port 211 is oriented clockwise relative to the axis 62. However, in contrast to the coaxial fuel-air port 210, the coaxial fuel-air port 211 is oriented radially inward in a manner that converges directly toward the axis 62, as indicated by arrow 167. That is, the coaxial fuel-air port 211 is directed toward the axis 62 all in a straight line, similar to the spoke of the wheel or the rays of the sun. In this way, the fuel-air injection member 152 creates both longitudinal and transverse flow, facilitating mixing of fuel and air in the combustor 30.

FIG. 9 is a cross-sectional schematic view of the combustor 30 as shown in FIG. 8, with coaxial fuel-air disposed on opposite surfaces 212, 218 of the co-fluid 154 in accordance with certain embodiments of the present invention. Further depicted is the transverse flow of fuel and air 214, 216 from port 210. Again, the embodiment of FIG. 9 is slightly different from the embodiment of FIG. 8. In particular, the number of ports 156, 210 is four rather than three, and the length of the co-fluid 154 is relatively shorter than in the embodiment of FIG. 8. However, the number of ports 156, 157, 210, 211 may be increased or decreased as needed for the particular combustor 30. In addition, the length of the fluid 154 may be increased to extend closer to the axis 62. In addition, the ports 156, 157, 210, and 211 may each be angled inward toward the axis 62.

As shown in FIG. 9, coaxial flows 214, 216 are generally larger from axis 62 at progressively greater distances from the free end of co-fluid 154 to the solid inner casing 56 of combustion liner 54. Is offset. In addition, the co-flow 214 is oriented generally in a clockwise orientation about the axis 62, while the co-flow 216 is oriented generally counterclockwise around the axis 62. In this way, the co-flows 214, 216 can produce a reverse rotation or vortex flow as indicated by arrows 220, 222, respectively. In addition, coaxial flows 165, 167 generally converge toward axis 62, such that coaxial flows 165, 167 are generally transverse or transverse to coaxial flows 214, 216.

FIG. 10 is a cross sectional view of a fuel-air injection member 152 as shown in FIGS. 8 and 9, and coaxial fuel-air port 210 disposed on faces 212, 218 in accordance with certain embodiments of the present invention. 211, which further illustrates an internal passageway. Again, similar to the embodiment of FIG. 7, the co-fluid 154 generally has an aerodynamic contour or airfoil structure and a longitudinal relative to the longitudinal axis of the co-fluid 154 (eg, perpendicular to the drawing). There are a plurality of transverse fuel injection passages 184 extending from the directional or common fuel supply passage 186. Co-fluid 154 also includes one or more air passages 194, 196, 198. The illustrated fuel injection passage 184 and the air passages 194, 196, 198 are directed along the edge 158 toward the coaxial fuel-air ports 156, 157 as described above. In particular, as shown in FIG. 7, coaxial fuel-air ports 156, 157 are connected to central fuel port 200 from transverse fuel injection passage 184 and from air passages 194, 196, 198. Concentric or annular air port 202.

In addition to the features of the embodiment of FIG. 7, the upper and lower support members 188, 190 of FIG. 10 respectively inject fuel on opposing surfaces 212, 218 from a second one of the longitudinal or common fuel supply passages 186. Upper and lower fuel injection passages 230, 232 leading to ports 234, 236. That is, the illustrated embodiment includes two independent fuel supply passages 186, with ports 156 and 157 being fueled independently of ports 210 and 211. In alternative embodiments, a single fuel supply passage 186 may be used for all ports 156, 157, 210, 211. In other alternative embodiments, independent fuel supply passages 186 may be used for each set of ports 156, 157, 210, 211. Coaxial fuel-air ports 210 and 211 also include air injection ports 238 and 240 disposed concentrically or annularly around fuel injection ports 234 and 236, respectively. Thus, in operation, fuel and air flow through the fuel-air injection member 152 as indicated by arrows 204 and 206.

FIG. 11 is a longitudinal schematic view of another embodiment of the combustor 30 as shown in FIG. 5, wherein the countercurrent injection mechanism 150 is applied to the nozzle 32 or to the nozzle 32 in accordance with certain embodiments of the present invention. In proximity or with a single inward cantilevered fuel-air injection member 152 disposed inside the nozzle 32. As shown, the co-fluid 154 of the single cantilevered fuel-air injection mechanism 152 protrudes from one side of the solid inner casing 56 and traverses a substantial portion of the diameter of the nozzle 32. Extends. Thus, in this embodiment, the co-fluid 154 extends across the central longitudinal axis 62 of the combustor 30 at the nozzle 32. Coaxial fuel-air port 156 is disposed across the side of shaft 62, whereby fuel-air injection member 152 causes coaxial flow of fuel and air in an eccentric or offset position relative to shaft 62. 164). In the illustrated embodiment, one of the coaxial fuel-air ports 156 is generally aligned or centered along the axis 62, whereby one coaxial flow of fuel and air centered on the axis 62 ( 164). In some embodiments, fuel-air injection member 152 may further include a coaxial fuel-air port 210 as shown in the embodiment of FIGS. 8-10. In addition, since the countercurrent injection mechanism 150 is disposed at or near the nozzle 32 rather than at an intermediate position between the closed end 88 and the nozzle 32 of the combustor 30, the combustor ( 30 has a relatively short length when compared to the embodiments of FIGS. 2, 4, 5 and 8.

12-15 illustrate a fuel-air injection lobe 52, a coplanar fuel-air injection region 140, and a cantilevered fuel-air injection member 152 as described above with reference to FIGS. 2 through 11. Is a schematic diagram illustrating various alternative embodiments for a fuel-air injection mechanism, such as: Referring first to the embodiment of FIG. 12, this FIG. 12 illustrates a coaxial fuel-fuel injection mechanism 260 in accordance with certain embodiments of the present invention. As shown, the coaxial fuel-air injection mechanism 260 includes a central fuel passage 262 along the axis 264 and a concentric or outer annular air passage 266 disposed concentrically about the central fuel passage 262. ). In the illustrated embodiment, the end 268 of the central fuel passage 262 is disposed at an offset distance 270 relative to the end 272 of the concentric or outer annular air passage 266. In particular, the end 268 of the central fuel passage 262 is concave with respect to the end 272 of the concentric or outer annular air passage 266. However, in other embodiments of the coaxial fuel-air injection mechanism 260, the ends 268, 272 may be substantially coplanar with one another, or the ends 268 of the central fuel passage 262 may be concentric or outer annular. It may protrude outward from the end 272 of the air passage 266. In operation, the coaxial fuel-air injection mechanism 260 produces a central fuel flow 274 surrounded by an annular air flow 276 that facilitates fuel-air mixing in the combustor 30.

13 is a schematic diagram of an exemplary radial-axial fuel-air injection mechanism 280 with both radial and axial flows colliding with each other to facilitate fuel-air mixing in accordance with certain embodiments of the present invention. . In the illustrated embodiment, the radial-axial fuel-air injection mechanism 280 is concentric or outer annular disposed about the central fuel passage 282 along the axis 284 and the central fuel passage 282. An air passage 286. The central fuel passage 282 also includes one or more radial ports 288 generally perpendicular to the axis 284. The central fuel passage 282 also has a tapered section or end 290 downstream from the radial port 288. In operation, air travels through the concentric or outer annular air passage 286 about the central fuel passage 282 in the axial direction along the axis 284 as indicated by arrow 292. Fuel also flows through the central fuel passage 282 generally in the axial direction along the axis 284 as indicated by arrow 294. Upon reaching the radial port 288, the fuel moves radially outward from the axis 284 into the air flow 292, as indicated by arrow 296. Thus, the air and fuel flows 292 and 296 are generally crossed or orthogonal to each other to facilitate fuel and air mixing in the radial-axial fuel-air injection mechanism 280 just before being injected into the combustor 30. do. In addition, the radial-axial fuel-air injection mechanism 280 facilitates fuel-air mixing in the combustor 30 rather than premixing fuel and air.

14 is a schematic diagram of a modified radial-axial fuel-air injection mechanism 300 in accordance with certain embodiments of the present invention. As shown, the fuel injection mechanism 302 is coupled to the outer wall 304 of the central air passage 306. The illustrated fuel injection mechanism 302 includes a plurality of radial fuel ports 308 extending through the outer wall 304. In operation, air flows through the central air passage 306 generally along the axis 312 in the axial direction 310. In contrast, fuel flows through the radial fuel port 308 in a generally radial or transverse direction 314 relative to the axis 312. In this way, the air and fuel flows 310, 314 collide with each other within the radial-axial fuel-air injection mechanism 300. Impingement of air and fuel flows 310, 314 facilitates fuel-air mixing within the injection mechanism 300. In addition, the radial-axial fuel-air injection mechanism 300 facilitates fuel-air mixing in the combustor 30 rather than premixing fuel and air.

15 is a schematic diagram of another coaxial fuel-air vortex injection mechanism 320 in accordance with certain embodiments of the present invention. As shown, the vortex injection mechanism 320 includes a central fuel passage 322 extending along an axis 324 and a concentric or outer annular air passage 326 disposed about the central fuel passage 322. do. The central fuel passage 322 also includes a fuel vortex mechanism 328 disposed at or near the fuel outlet or port 330. Concentric or outer annular air passages 326 also include one or more air vortex mechanisms 332 disposed upstream from the fuel outlet or port 330. In operation, fuel travels through the central passage 322 in a generally axial direction 334 along the axis 324. Upon reaching the fuel vortex mechanism 328, the fuel flow obtains a clockwise or counterclockwise rotation or vortex as indicated by arrow 336. Similarly, air flows through the concentric or outer annular air passage 326 in a generally axial direction as indicated by arrow 338. Upon reaching the air vortex mechanism 332, the air flow gains rotation in a clockwise or counterclockwise direction as indicated by arrow 340. In this way, the rotating or vortex fuel and air flows 336, 340 facilitate fuel and air mixing within the swirl injection mechanism 320.

In certain embodiments, the rotating or vortex fuel and air flows 336, 340 have a common direction of rotation, such as both clockwise or counterclockwise. However, in other embodiments, the rotating or vortex fuel and air flows 336, 340 have opposite or opposite rotational directions, such as clockwise and counterclockwise. Moreover, some embodiments of the vortex injection mechanism 320 include only the air vortex mechanism 332 without the fuel vortex mechanism 328 or only the fuel vortex mechanism 328 without the air vortex mechanism 332. Other embodiments may include additional fuel and air vortex mechanisms 328 and 332 disposed in series or in parallel with each other. Again, these vortex mechanisms 328 and 332 facilitate fuel and air mixing within the vortex injection mechanism 320. In addition, the coaxial fuel-air vortex injection mechanism 320 facilitates fuel-air mixing in the combustor 30 rather than premixing fuel and air.

The present invention may accommodate various modifications and various forms, and specific embodiments are shown by way of example in the drawings and are described in detail herein. However, it is to be understood that the invention is not limited to the specific forms disclosed. Rather, the invention covers all modifications, equivalents, and variations that fall within the spirit and scope of the invention as defined by the appended claims.

According to the present invention, the coaxial or concentric configuration of the fuel-air injection lobe and the resulting flow has the effect of facilitating fuel-air mixing in the combustor rather than premixing.

Claims (10)

In the system, A fuel air injection mechanism 50, 150 including coaxial fuel and air passages leading to the fuel and air injection openings 70, 72, 156, 157, 210, 211, and The fuel and air injection openings 70, 72, 156, 157, 210, 211 are configured to be disposed in an off-axis position of the gas turbine combustor 30, The fuel and air injection openings 70, 72, 156, 157, 210, 211 are configured to be oriented in an injection direction that is not aligned with the flow direction through the gas turbine combustor 30 to the turbine 22. system. The method of claim 1, The fuel and air injection openings 70, 72, 156, 157, 210, 211 are generally coaxial with each other. system. The method of claim 1, The fuel and air injection openings 70, 72, 156, 157, 210, 211 are offset from each other 262, 272 along the common axis of the coaxial fuel and air passage. system. The method of claim 1, The fuel and air injection openings 70, 72, 156, 157, 210, 211 are oriented in the transverse direction 286, 288, 306, 308 with respect to each other. system. The method of claim 4, wherein The fuel injection opening 308 is disposed in the circumferential wall 304 of the air passage 306 of the coaxial fuel and air passage. system. The method of claim 4, wherein The fuel injection opening 288 is disposed in the circumferential wall of the fuel passage 282 of the coaxial fuel and air passage. system. The method of claim 1, The coaxial fuel and air passages include a fuel vortex mechanism 328, or an air vortex mechanism 332, or an inverse vortex mechanism, or a combination thereof. system. The method of claim 1, A plurality of fuel-air injection mechanisms, including fuel-air injection mechanisms 50 and 150 disposed in multiple radial positions in a circumferential arrangement system. In a system comprising a gas turbine combustor 30, The gas turbine combustor 30 includes a combustion liner 54 having a generally longitudinal flow axis extending from the stagnation zone 86 to the turbine nozzle 22; A countercurrent fuel-air injector (50, 150) disposed in the combustion liner (54) at one or more intermediate positions between the stagnation zone (86) and the turbine nozzle (22), The backflow fuel-air injectors 50, 150 are fuel and air injection openings 70, 72, 156, 157, 210, 211 not aligned with the flow direction from the stagnation zone 86 to the turbine nozzle 22. Comprising a coaxial fuel and an air passage extending into the system. Fuel and air to countercurrent fuel-air injectors 50, 150 oriented generally in the counterflow direction about the longitudinal flow axis 62 from the stagnant zone 86 of the gas turbine combustor 30 to the turbine nozzle 22. Flowing coaxially Way.

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