Fuel injector and fuel nozzle for a gas turbine and gas turbine engine comprising the nozzle

Abstract

This disclosure provides a fuel injector (19) including a fuel feed chamber (21) and a central body (31) extending along a longitudinal axis from the fuel feed chamber (21) to a distal end (37) of the central body. An outer sleeve (35) surrounds the central body and forms an annular premixing chamber (43) between the outer sleeve and the central body. The central body includes a distal tip that protrudes beyond the annular premixing chamber and extends beyond the distal end of the outer sleeve.

Description

Technical Field

[0001] The subject matter disclosed herein relates generally to gas turbine engines. More specifically, this disclosure relates to premixed fuel nozzles for gas turbine engine combustors, and gas turbine engine combustors. Background Technology

[0002] Gas turbine engines for both aircraft and industrial applications include at least one combustor in which fuel, in gaseous or liquid form, is mixed with and burned with a stream of compressed air to produce a hot, pressurized stream of combustion gases. The combustion gases expand within a turbine comprising one or more turbine stages to generate mechanical power. A portion of the mechanical power generated by the turbine is used to drive the gas turbine engine's compressor and to support the continuous supply of combustion air to the combustor. The remaining available power is used to drive loads such as generators or compressors, or to generate thrust for aircraft propulsion.

[0003] The combustor includes a combustion chamber and multiple fuel nozzles that introduce liquid or gaseous fuel into a compressed air stream from an air compressor to obtain a mixture of combustion air and fuel. Upon startup, the mixture is ignited to burn the fuel. The combustion process is maintained by continuously supplying compressed air and fuel to the combustor to produce a continuous flow of compressed, hot combustion gases, thereby driving the turbine.

[0004] Flame control in the burner is one of the key aspects of fuel nozzle design. One of the goals of nozzle design is to reduce harmful emissions such as nitrogen oxides (NOx), carbon monoxide, and unburned hydrocarbons. Other concerns include reducing flame instability, reducing sound pressure fluctuations or oscillations (i.e., combustion noise), reducing the risk of lean flameout, and reducing hot spots in the combustion chamber, such as those caused by asymmetrical temperature distribution.

[0005] In this context, an important aspect is the stability of the flame shape and spatial position. Changes in flame shape and position during burner operation can adversely affect the harmful emissions of gas turbine engines and increase sound pressure fluctuations and oscillations.

[0006] Therefore, improved fuel nozzle designs aimed at reducing the instability of flame shape and position will be welcomed in this field. Summary of the Invention

[0007] In the embodiments disclosed herein, the fuel injector includes a fuel feed chamber having end walls and a central body extending along a longitudinal axis from the end walls to a distal end of the central body. An outer sleeve surrounds the central body and extends along the axis of the central body from the end walls to a distal end of the outer sleeve opposite the fuel feed chamber. Thus, an annular premixing chamber is defined between the outer sleeve and the central body.

[0008] The premixing chamber has an annular outlet at the distal end of the outer casing. The center body includes a distal tip that terminates at the distal end of the center body and protrudes into the combustion chamber beyond the distal end of the outer casing.

[0009] According to another embodiment disclosed herein, the central body has an additional fluid conduit extending along the central body and fluidly connected to at least one outlet port at the distal tip of the central body. In use, fuel, air, or an air / fuel mixture can be delivered toward the distal tip of the central body via the additional fluid conduit, depending on the operating conditions of the gas turbine in which the fuel injector is located.

[0010] The outlet port can be located on the axis of the central body or off-axis. In some implementations, more than one outlet port may be provided.

[0011] According to another aspect, this document discloses a fuel nozzle for a gas turbine engine, which includes one or more fuel injectors as described above.

[0012] This disclosure also relates to a combustor assembly for a gas turbine engine. In one embodiment, the combustor assembly has a combustion chamber extending from an upstream end to a downstream end. The downstream end is adapted to be fluidly coupled to a turbine of the gas turbine engine, and the upstream end is further adapted to be fluidly coupled to an air compressor of the gas turbine engine. The combustor assembly also has at least one fuel nozzle as described above.

[0013] This article also discloses a gas turbine engine that includes a burner assembly.

[0014] In this specification and the appended claims, unless otherwise stated, the terms "upstream" and "downstream" refer to the direction of air, fuel, or an air-fuel mixture. Attached Figure Description

[0015] Now, please briefly refer to the attached diagram, in which:

[0016] Figure 1 This is a schematic diagram of a gas turbine engine suitable for a variety of useful applications (including industrial applications);

[0017] Figure 2 It is a schematic cross-sectional view of a combustor for a gas turbine engine, which has multiple fuel nozzles and an annular combustion chamber;

[0018] Figure 3 It is an isometric view of the fuel nozzle;

[0019] Figure 4 yes Figure 3A cross-sectional view of the fuel nozzle;

[0020] Figure 5 This is a front view of the fuel nozzle in another embodiment;

[0021] Figure 6 It is based on Figure 5 A sectional view of line VI-VI;

[0022] Figure 7 This is a front view of the fuel nozzle in another embodiment;

[0023] Figure 8 It is similar to another implementation scheme. Figure 6 A sectional view;

[0024] Figure 9 This is an enlarged detail view of the distal end of the central body in another embodiment;

[0025] Figure 10 and Figure 11 This is a cross-sectional view of the fuel nozzle in some of the implementation schemes;

[0026] Figure 12 This is a front view of the fuel nozzle in yet another embodiment; and

[0027] Figure 13 It is based on Figure 12 A sectional view of line XIII-XIII. Detailed Implementation

[0028] To improve flame shape and flame position stability in the combustor of a gas turbine engine, a novel fuel injector is provided, having a fuel feed chamber and a central body extending along a longitudinal axis from a proximal end of the central body adjacent to the fuel feed chamber to a distal end of the central body. The distal end is positioned downstream of the proximal end relative to the flow direction of the fuel-air mixture. An outer sleeve extends around the central body. The outer sleeve extends from the fuel feed chamber toward the combustion chamber and terminates at an annular edge opposite the fuel feed chamber. The outer sleeve includes side holes for supplying air into an annular premixing chamber (also referred to as a premixer) formed between the central body and the outer sleeve. The central body includes ports for supplying fuel into the annular premixing chamber.

[0029] In operation, air and fuel are premixed in an annular premixing chamber or premixer, and the fuel-air mixture exiting the annular premixing chamber is combusted, thereby forming a flame extending toward the interior of the combustion chamber. To improve flame stability (involving flame shape and flame position, i.e., the point where the flame is positioned relative to the fuel nozzle (which includes one or more of these new fuel injectors), the center body includes a distal tip protruding beyond the annular premixing chamber and beyond the distal end of the outer sleeve. The distal tip protruding beyond the premixing chamber or premixer may have a raised outer surface. In embodiments, the distal tip has a rotational surface coaxial with the center body. For example, the distal tip may have a dome shape, a spherical cup shape, a hemispherical shape, an oval shape, etc. Typically, the distal tip has an aerodynamic shape. Advantageously, the distal tip protruding beyond the premixing chamber is connected to a portion of the center body within the premixing chamber that has a curved surface.

[0030] Embodiments of the present invention are applicable to all types of gas turbine engines, regardless of the end-use application. The fuel injectors disclosed herein can be used in aero-derivative gas turbines as well as heavy-duty industrial gas turbines. In the following description, reference will be made to gas turbines for mechanical drives; however, those skilled in the art will understand that the fuel injectors disclosed herein can also be used in gas turbines for power generation and for air propulsion.

[0031] Although references are specifically made to burners including annular combustion chambers in the following description, it should be understood that fuel injectors and fuel nozzles incorporating features of this specification may also be used in other types of burners, such as those including canister combustion chambers or tubular annular combustion chambers.

[0032] Now turn to the attached image. Figure 1 A schematic diagram of a gas turbine engine 1 is shown, configured for various applications, including (by way of example) but not limited to industrial or power generation applications, such as driving a load 3. The load 3 may include a compressor or compressor unit, for example, in one example, a refrigerant compressor of the type used in a liquefied natural gas production plant, or in another example, a gas compressor in a gas pipeline. In other embodiments, when the gas turbine engine is used for power generation purposes, the load may be a generator.

[0033] The gas turbine engine 1 includes an air compressor 5, a combustor 7, and a turbine section 9. (This is just an example.) Figure 1 In this embodiment, the turbine section 9 includes a high-pressure turbine 9A and a low-pressure turbine 9B. In one implementation, the high-pressure turbine 9A is mechanically coupled to the air compressor 5 to drive its rotation. The low-pressure turbine 9B is drivably coupled to the load 3 and provides power to drive the load 3.

[0034] therefore, Figure 1An exemplary gas turbine engine is a dual-shaft turbine. However, for example, the fuel injector disclosed herein can also be advantageously used in other types of gas turbines, such as single-shaft gas turbines or gas turbines with three shafts.

[0035] According to some implementation schemes, the burner 7 includes an annular combustion chamber 11, such as Figure 2 The combustion chamber 11 is schematically shown. It includes an outer bushing 13 and an inner bushing 15. The outer bushing 13 and the inner bushing 15 are coaxial with each other and with the rotational axis AA of the gas turbine engine 3. The combustion chamber 11 extends from the air compressor 5 to the turbine section 9 in an upstream-downstream direction. A plurality of fuel nozzles 17 are arranged in the upstream region of the combustor 7. One of the fuel nozzles 17... Figure 3 It is shown in perspective view, and in Figure 4 The cross-sectional view is shown in the diagram based on the radial plane containing the axis of rotation AA.

[0036] Each fuel nozzle 17 typically includes multiple fuel injectors 19, such as in Figure 3 and Figure 4 The best illustration is shown below and disclosed in more detail. Specifically, in the illustrated embodiment, each fuel nozzle comprises four fuel injectors. Figure 4 The cross-sectional view shows two fuel injectors. The number of fuel injectors 19 for each fuel nozzle 17 is merely exemplary. Furthermore, the same burner may include different fuel nozzles, for example, with different shapes and sizes, and may have a variable number of fuel injectors.

[0037] Each fuel injector 19 includes a fuel feed chamber 21, which includes an end wall 23 facing the combustion chamber 11 (i.e., oriented toward the combustion chamber 11 and the turbine section 9). The fuel feed chambers 21 of the fuel injectors 19 belonging to the fuel nozzle 17 can be combined to form a fuel feed booster chamber 25. In other embodiments, each fuel feed chamber 21 may form a separate fuel feed booster chamber 25 fluidly connected to a single fuel injector 19.

[0038] Fuel feed pressurization chamber 25 and included in fuel injector structure 27 ( Figure 3 The fuel supply conduit in the fuel supply conduit is in fluid communication with the fuel feed pressurization chamber 25, from which liquid or gaseous fuel is transported to the fuel feed pressurization chamber 25 and from the fuel feed pressurization chamber to the fuel injector 19.

[0039] Each fuel injector 19 also includes a center body 31 that extends along a longitudinal axis BB from a proximal or upstream end of the end wall 23 toward a distal or downstream end 33 of the center body 31, the distal or downstream end facing the interior of the combustion chamber 11 and the turbine section 9.

[0040] Each fuel injector 19 also includes an outer sleeve 35. The outer sleeve 35 may be coaxial with the corresponding central body 31. In other embodiments, the central body 31 and the outer sleeve 35 may be non-coaxial with each other.

[0041] Each outer sleeve 35 extends from the proximal end of the fuel feed chamber 21 at the end wall 23 to the distal end 37. Outer sleeves 35 belonging to the same fuel nozzle 17 are connected to a common front wall 36.

[0042] exist Figure 4 In the embodiment shown, the center body 31 and the outer sleeve 35 of the fuel nozzle 17 are parallel to each other.

[0043] Each outer sleeve 35 includes a plurality of air inlet ports 41 extending through the outer sleeve and in fluid communication with an annular premixing chamber 43 or premixer formed between the central body 31 and the outer sleeve 35. The annular premixing chamber 43 has a bottom at the end wall 23 of the fuel feed chamber 21 and an annular outlet 45 surrounded by the distal end 37 of the outer sleeve 35.

[0044] If the outer sleeve 35 and the central body 31 are coaxial, such as Figure 4 As shown, the annular premixing chamber 43 and its outlet 45 have a constant radial dimension, as illustrated in the exemplary embodiment. However, as stated above, this is not restrictive. In some of the embodiments shown, the central body 31 and the outer sleeve 35 may be non-coaxial. In extreme cases, the central body 31 and the outer sleeve 35 may contact each other. In this case, the annular premixing chamber 43 and the annular outlet 45 will have non-constant radial dimensions, and if the central body 31 and the outer sleeve 35 are in contact with each other, there may even be a break along the cross-section, because in the contact area, the radial dimension of the annular premixing chamber and / or the annular outlet 45 will become zero. In this specification and the appended claims, the term "annular" also includes a configuration in which the annular premixing chamber 43 and / or the annular outlet 45 have a radial dimension that varies about the axis of the central body, and this radial dimension may become zero at one or more locations about the axis BB.

[0045] Compressed air supplied by air compressor 5 (see Figure 2 Arrow A) enters each annular premixing chamber 43 through the air inlet port 41 and is premixed with fuel delivered through the fuel injection port (described later) provided in the central body 31 to produce an air-fuel mixture.

[0046] Each central body 31 has a distal end 33 with a distal tip 47 that protrudes beyond the annular outlet 45 of the annular premixing chamber 43 in the combustion chamber 11. In some embodiments, the distal tip 47 has a raised outer surface, such as approximately hemispherical, dome-shaped, cup-shaped, or oval.

[0047] More generally, the distal tip 47 of each central body 31 protrudes beyond the annular outlet 45 of the premixing chamber 43, a portion of which is shaped to prevent the air / fuel mixture from forming a recirculation zone (negative or low axial velocity).

[0048] In some embodiments, the distal tip 47 of the center body 31 tapers from the annular outlet 45 of the annular premixing chamber 43 toward the combustion chamber 11 and may terminate with a pointed, rounded, or flattened apex. The tapered surface of the distal tip 47 protruding from the annular outlet 45 of the annular premixing chamber 43 in the combustion chamber 11 is shaped to prevent gas separation from the wall and gas recirculation, thereby preventing flame anchoring or adhesion to the center body 31.

[0049] In some embodiments, the distal tip 47 may have an externally projecting surface, which may be defined as a surface of revolution generated by a generatrix rotating about the axis BB of the central body 31. As used herein, a generatrix is ​​a curve that produces the surface when moved along a given path. The path guiding the movement of the generatrix is ​​called a guideline. More specifically, in the embodiments disclosed herein where the externally projecting surface is a surface of revolution, the guideline is a circumferential line. In other embodiments, the guideline may be an elliptical line.

[0050] In some embodiments, each center body 31 includes a body portion housed within a premixing chamber 43, the body portion being connected to a distal tip 37 of the center body projecting out of the premixing chamber 43, wherein the body may have a constant or variable cross-section. In some embodiments, as shown in the figures, each center body 31 includes a body portion consisting of a first proximal portion 31A and a second distal portion 31B. The first portion 31A is located near the end wall 23 of the fuel feed chamber 21 and extends toward the distal end 33 of the center body 31. The second portion 31B is located between the first portion 31A and the distal tip 47. The first portion 31A may have a generally cylindrical shape with a circular or elliptical cross-section. The second portion 31B may have a tapered shape, i.e., a generally truncated conical shape, having a circular or elliptical cross-section, and its lateral dimension (the diameter in the case of a circular cross-section) increases from the first portion 31A toward the distal tip 47 of the center body 31. Therefore, the annular premixing chamber 43 has a constant annular cross-section along the first part and a tapering annular cross-section, i.e., a converging cross-section, whose cross-sectional area gradually decreases toward the annular outlet 45.

[0051] from Figure 4 As can be understood from the cross-sectional view, for example, the generatrix defining the distal tip 47 of the central body 31 forms a smooth transition zone from the main body portions 31A, 31B of the central body located within the premixing chamber 43 to the distal tip 47 of the central body protruding outside the premixing chamber 43. Sharp edges in the transition zone are avoided, and an aerodynamic shape of the distal tip 47 of the central body 31 is achieved. This improves the smoothness of the air / fuel mixture flow without recirculation.

[0052] As understood in this paper, a smooth transition region can be a region without sharp edges or corners. Therefore, in the region defining the transition region, the generatrix forming the outer surface of the central body is a curve with a continuous derivative.

[0053] The transition zone may extend to the distal end 33 of the central body, that is, to the most downstream end of the central body. As mentioned above, the distal tip of the central body may terminate at a pointed tip, or at a plane or flat surface. At the pointed tip or the plane or flat surface of the end, the derivative of the curve representing the profile may be discontinuous.

[0054] Typically, the smooth transition region also includes at least a portion of the tapered distal tip 47, and preferably includes the entire tapered portion of the distal tip 47.

[0055] Typically, the annular premixing chamber 43 has a distal portion terminating at its outlet 45, which has a converging shape, i.e., a cross-sectional area decreasing toward the distal tip 47 of the central body 31 in the proximal-to-distal direction (i.e., in the flow direction of the air / fuel mixture). In the embodiment shown in the figures, the converging shape of the premixing chamber is achieved by a tapered surface of the central body 31 adjacent to its downstream end 33. As the air-fuel mixture moves along the annular premixing chamber 43 in the proximal-to-distal direction, the air-fuel mixture accelerates until it reaches the annular outlet.

[0056] As the tightly premixed air / fuel mixture formed in the annular premixing chamber 43 flows through the annular outlet 45, the velocity of the air / fuel mixture is suddenly reduced, and the aerodynamic shape of the distal tip 47 ensures the correct flame shape and flame position in the combustion chamber.

[0057] In other embodiments, the converging distal portion of the premixing chamber can be obtained by combining the cylindrical shape of the outer surface of the central body 31 with the tapered inner surface of the distal portion of the outer sleeve 35. In this case, the distal portion of the inner surface of the outer sleeve 35 will have an inner diameter that gradually decreases in the proximal to distal direction.

[0058] The tapered (i.e. converging) end portion of the premixing chamber 43 can also be obtained by combining the conical distal portion of the central body and the conical distal portion of the inner surface of the outer sleeve 35.

[0059] To supply fuel to the annular premixing chamber 43, a fuel conduit is provided inside the central body 31. In some embodiments, the central body 31 includes an axially extending outer tubular wall 51 and an axially extending inner tubular wall 53. The axially extending outer tubular wall 51 and the axially extending inner tubular wall 53 form an annular gap 52 therebetween. More specifically, the axially extending outer tubular wall 51 and the axially extending inner tubular wall 53 extend from the end wall 23 of the fuel feed chamber 21 toward the distal tip 47 of the respective central body 31. The outer tubular wall 51 is integral with the distal tip 47, and the outer surface of the outer tubular wall merges with the raised surface of the distal tip 47 of the central body 31. The inner tubular wall 53 terminates at a distance from the inner surface of the distal tip 47 of the central body 31.

[0060] A fuel conduit is thus formed within the central body 31, extending in a first direction along the axial cavity 56 of the inner tubular wall 53 from the fuel feed chamber 21 toward the distal end 33 of the central body 31, and in the opposite second direction along the annular gap 52 formed between the inner and outer tubular walls 53 from the distal end 33 of the central body 31 toward the fuel feed chamber 21. At least one, and preferably multiple, fuel injection ports 57 extend through the outer tubular wall 51, adjacent to the end of the annular gap 52 opposite to the distal end 33 of the central body 31. Thus, fuel is delivered from the fuel feed chamber 21 through the axial cavity 56, the annular gap 52, and the fuel injection ports 57 into the annular premixing chamber 43.

[0061] In the annular premixing chamber 43, fuel is mixed with compressed air supplied by the air compressor 5 of the gas turbine engine 1 and flowing through the air inlet port 41. The tightly premixed fuel-air mixture formed in the annular premixing chamber 43 flows through the annular outlet 45. Once the mixture is ignited, a flame forms downstream of the distal end 33 of each fuel injector 19 and is sustained by the premixed air and fuel continuously supplied through the annular premixing chamber 43.

[0062] It has been found that, through the aforementioned enhanced shape and geometry of the distal tip 47 of the central body 31, the flame remains stable in its shape and position even under variable operating conditions of the combustor and gas turbine engine 1. This results in a reduction of harmful emissions, a more regular heat load, reduced combustion noise and vibration, and overall more effective control of combustion conditions.

[0063] Specifically, the enhanced shape of the center body 31, particularly the enhanced shape of its distal tip 47, has a smooth transition zone from the main body portion inside the premixing chamber 43 to the distal tip 47 outside the premixing chamber, resulting in an aerodynamic shape of the center body. This improved aerodynamic shape provides a more uniform flow of the air / fuel mixture, higher velocity, and no flow recirculation, thus avoiding the risk of flame anchoring to the distal end 37 of the center body or outer sleeve 35. Flame stability is improved, and the risk of thermal damage to the fuel nozzle due to flame anchoring to the metal parts of the fuel nozzle is greatly reduced.

[0064] Figure 5 and Figure 6 Another embodiment of the fuel nozzle 17 according to this disclosure is shown. The same reference numerals are used to indicate that... Figure 4 The parts, components and parts shown in the diagram. Figure 4 Implementation plan and Figure 5 and Figure 6 The main differences between the implementation schemes involve the interior of the central body 31 and the fuel delivery path. Figure 5 and Figure 6 In one embodiment, each center body 31 includes a plurality of fuel injection ports 57 arranged near the proximal end of the center body 31, preferably in the region where the air inlet port 41 is located. The fuel injection ports 57 provide fluid connection between the interior of the center body 31 and the annular premixing chamber 43. The interior of the center body 31 does not have an inner tubular wall 53 and simply forms an extension of the fuel feed chamber 21.

[0065] Although Figure 5 and Figure 6 In one implementation, each central body 31 is coaxial with the corresponding outer sleeve 35, but as previously mentioned, different non-coaxial arrangements may be provided in other configurations. Figure 7 Another implementation scheme similar to this is shown. Figure 5 The front view shows that each central body 31 is non-coaxial with respect to the corresponding outer sleeve 35. Due to the non-coaxial arrangement, the annular premixing chamber 43 has a variable radial dimension about the axis BB of the central body 31.

[0066] exist Figure 7 In one embodiment, each central body 31 contacts the inner surface of the outer sleeve 35 at 32, and thus the annular premixing chamber 43 has a minimum radial dimension at 32, which is equal to zero. However, in other embodiments, a non-coaxial arrangement allows the central body 31 to not contact the inner surface of the outer sleeve 35.

[0067] In the embodiments disclosed so far, the fuel injectors 19 are parallel to each other, that is, the axis BB of the central body 31 and the axis of the outer sleeve 35 are both parallel to each other. In other embodiments, at least two fuel injectors 19 may not be parallel to each other. Figure 8 The diagram shows a fuel nozzle 17 similar to the fuel injector 19. Figure 7 The cross-sectional view shows that these fuel injectors are arranged in a converging configuration such that their axes BB converge toward a point located in the combustion chamber 11. All four fuel injectors 19 may converge toward the central axis CC of the fuel nozzle 17. Alternatively, the axes BB of two pairs of fuel injectors 19 may be arranged in a converging configuration on two parallel planes.

[0068] Figure 7 Non-coaxial arrangement and Figure 8 Non-parallel arrangements can be combined with each other.

[0069] In the embodiments described so far, the distal tip 47 has a fully convex shape with a tapered shape, i.e., a cross-section that decreases from proximal to distal. In other embodiments, the outer surface of the distal tip 47 may not be fully convex. For example, the distal tip 47 may have a convex outer surface in which a groove extends along a plane containing the axis BB of the central body 31, thereby defining a flow guide channel extending toward the apex (i.e., the downstream point) of the distal tip 47 toward the central body 31.

[0070] Figure 9 An exemplary embodiment with a distal tip having a grooved outer surface is shown. Figure 9 The central body 31 can be used in any of the foregoing embodiments. A groove or channel along the outer surface of the distal tip of the central body 31 is designated 61. Figure 9 In one exemplary embodiment, the groove 61 extends from a first end 61A positioned along the maximum circumference of the distal tip 47 to a second end 61B positioned at the apex V of the distal tip 47. Other embodiments may include shorter grooves.

[0071] exist Figure 9 In one embodiment, the distal tip 47 remains generally convex and tapers from a larger portion of the proximal end facing the central body 31 to a narrower portion at the apex V of the distal tip 47.

[0072] Figure 10 Another embodiment of the fuel injector and fuel nozzle according to this disclosure is shown. Figures 1 to 9 The same reference numerals used in the drawings indicate the same or similar parts or components, and will not be described again.

[0073] To further enhance flame control, according to Figure 10In one embodiment, in addition to the fuel conduit terminating at the fuel injection port 57, the central body 31 also has an additional fluid conduit extending along the central body 31 and terminating at one or more outlet ports at the distal tip or downstream end 33 of the central body 31. Figure 10 In the implementation scheme, the additional fluid conduit is labeled 71, and the outlet port is labeled 73.

[0074] exist Figure 10 In one embodiment, the additional fluid conduit 71 has a single outlet port 73 located at the top of the distal tip 47 of the dome. In another embodiment (not shown), the additional fluid conduit 71 may be fluidly connected to multiple outlet ports 73, which are preferably arranged in axially symmetrical positions about the axis BB of the central body 31. In still other embodiments (not shown), more than one additional fluid conduit 71 may be provided within the central body 31, each conduit fluidly connected to one or more outlet ports.

[0075] The outlet port 73 may be circular. In other embodiments, for example, if the port is arranged about the axis BB of the central body 31, the outlet port 73 may have an elongated shape, for example, in the tangential direction about the axis BB of the central body 31, or they may be elongated in the longitudinal direction.

[0076] In some embodiments, the additional fluid conduit 71 is connected to a fluid source, schematically shown as 75, or to two fluid sources shown as 75 and 77. In some currently preferred embodiments, fluid source 75 may be a combustion air source. In other embodiments, fluid source 75 may be a fuel source. If two fluid sources 75 and 77 are provided, one fluid source may be an air fluid source, and the other may be a fuel source.

[0077] Control valves 79 and 81 may be provided to control the flow of fluid toward and through one or more additional fluid conduits 71. For example, a valve 79 may be provided to control the flow of additional combustion air from source 75 toward one or more outlet ports 73. A valve 81 may be provided to control the flow of additional fuel from source 77 toward one or more outlet ports 73.

[0078] In some embodiments, if two or more additional fluid conduits 71 are provided in the central body 31, at least one of them may be fluidly connected to the combustion air source, and the other additional fluid conduits may be fluidly connected to the fuel source.

[0079] Additional combustion air, additional fuel, or a mixture of air and fuel can be delivered to the distal tip of the central body 31 via additional fluid conduits to provide additional means of controlling the flame shape. Depending on the operating conditions of the burner 7, additional combustion air and / or fuel can be delivered to the distal tip of the central body 31 to provide optimal control over the combustion process, enhance the shape and positional stability of the flame, and prevent the flame from adhering to the distal tip of the central body 31, i.e., to the burner.

[0080] Furthermore, the additional fluid conduit prevents flame ignition in low-speed zones and reduces the risk of acoustic interactions. This results in enhanced thermoacoustic response and reduced emissions, as well as better control over burner tip temperature and durability.

[0081] Figure 11 Another embodiment of a fuel nozzle including multiple fuel injectors is shown. Figure 11 The same reference numerals in the figures indicate that they have been combined with the preceding ones. Figures 1 to 10 Components that are identical or equivalent to those described will not be described in detail again. Figure 11 In one embodiment, each central body 31 has an internal partition wall 101 that divides the hollow space within the central body 31 into a first internal volume 32A and a second internal volume 32B. The first internal volume is formed by an extension of a corresponding fuel feed chamber 21, and the second internal volume extends from the partition wall 101 to a distal tip. One or more fuel injection ports 57 extend from the first internal volume 32A to an annular premixing chamber 43 to deliver a fuel flow from the fuel feed chamber 21 toward the annular premixing chamber 43, in which fuel is mixed with air flowing through air inlet ports 41 disposed in the approximately cylindrical walls of the outer sleeve 35.

[0082] Although Figure 11 Only one fuel injection port 57 is shown, but it should be understood that two or more fuel injection ports 57 may be provided, preferably arranged circumferentially around the axis BB of the central body 31.

[0083] The second internal volume 32B is in fluid communication with at least one additional fluid conduit 71. An outlet port 73 at the outermost end of the distal tip 47 provides fluid communication between the second internal volume 32B and the combustion chamber 11.

[0084] As mentioned above Figure 10 The additional fluid conduit 71 may be directed toward the distal tip 47 and deliver an additional air flow, or an additional fuel flow, or an additional fuel and air combination flow through the outlet port 73 of the central body 31.

[0085] Figure 12 and Figure 13Another embodiment of a fuel nozzle comprising multiple fuel injectors is shown. The same reference numerals are used to denote the same elements shown in the previously described figures and will not be described again. Figure 12 and Figure 13 Implementation plan and Figure 11 The main difference in the implementation scheme lies in the arrangement of multiple outlet ports 73 within the distal tip 47 of the central body 31. More specifically, the central outlet port 73A is located at the center of the distal tip 47, which lies on the axis of the central body 31. A first set of additional outlet ports 73B is distributed along a first circumference centered on the axis of the central body 31. A second set of additional outlet ports 73C is distributed along a second circumference centered on the axis of the central body 31. Ports 73A, 73B, and 73C may have the same cross-section and may be, for example, circular. In other implementations, the ports may have cross-sections of varying size and / or shape. The location of the ports and the number of circular arrangements of the ports may also vary depending on design options.

[0086] Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. Those skilled in the art will understand that various changes, omissions, and additions may be made to the specific disclosure herein without departing from the scope of the invention as defined in the following claims.

Claims

1. A fuel injector for a gas turbine engine, the fuel injector comprising: A fuel feed chamber, the fuel feed chamber including an end wall; A central body extending along a longitudinal axis from the end wall to a distal end of the central body, the central body forming a distal tip and having a fuel injection port; An outer sleeve surrounds the central body and extends from the end wall along the longitudinal axis of the central body to the distal end of the outer sleeve opposite the fuel feed chamber; An annular premixing chamber is disposed between the outer sleeve and the central body; the annular premixing chamber includes an annular outlet at the distal end of the outer sleeve. An air inlet port extending through the outer sleeve and in fluid communication with the annular premixing chamber; and A fuel conduit located within the central body and in fluid communication with the fuel feed chamber and the annular premixing chamber; The distal tip protrudes beyond the annular premixing chamber, extending beyond the distal end of the outer sleeve; The distal tip has a tapered, raised outer surface, and The fuel injection port allows fuel flow from the fuel conduit to the annular premixing chamber.

2. The fuel injector according to claim 1, wherein the protruding outer surface of the distal tip is a rotating surface coaxial with the central body.

3. The fuel injector according to claim 1, wherein the distal tip has one of the following shapes: dome shape, spherical cup shape, hemispherical shape, and oval shape.

4. The fuel injector of claim 1, wherein the premixing chamber has a converging distal portion, the cross-sectional area of ​​which tapers in a proximal-to-distal direction until the annular outlet of the premixing chamber.

5. The fuel injector of claim 1, wherein the central body has a distal portion terminating at the distal tip and having a tapered shape having a cross-section that increases toward the distal tip.

6. The fuel injector of claim 1, wherein the central body has a main body portion located in the premixing chamber, and wherein the main body portion and the distal tip are connected by a smooth transition region tapering toward the distal end of the central body.

7. The fuel injector of claim 1, wherein the central body has a main body portion located in the premixing chamber, wherein the main body portion is connected to the distal tip along a transition region tapering toward the distal end of the central body, and wherein the transition region is formed by a surface generated by a generatrix having a continuous derivative.

8. The fuel injector of claim 1, wherein the central body comprises: The first part extends close to the end wall of the fuel feed chamber and toward the distal tip of the central body; The second part is located between the first part and the distal tip; The first part has a cylindrical shape, and the cylindrical shape has a circular cross-section; and The second portion has a tapered shape, the tapered shape having a circular cross-section and a diameter that increases from the first portion to the distal tip.

9. The fuel injector according to claim 1, wherein the central body and the outer sleeve are coaxial.

10. The fuel injector of claim 1, wherein the central body and the outer sleeve are non-coaxial, and the annular premixing chamber has a radial dimension that varies about the longitudinal axis of the central body.

11. The fuel injector of claim 1, wherein the central body includes an additional fluid conduit, at least one of the additional fluid conduits extending along the central body and fluidly connected to an outlet port at the distal tip of the central body.

12. The fuel injector of claim 11, wherein the additional fluid conduit is adapted to deliver at least one of the following to the at least one outlet port: combustion air; fuel; or an air / fuel mixture.

13. The fuel injector of claim 11, wherein the outlet port is located on the longitudinal axis of the central body.

14. The fuel injector of claim 11, further comprising: Multiple outlet ports, which are fluidly connected to the additional fluid conduit, are distributed in a circular arrangement around the axis of the central body.

15. The fuel injector of claim 11, further comprising: Another additional fluid conduit extends along the central body and is fluidly connected to another outlet port at the distal end of the central body; The additional fluid conduit is adapted to deliver fuel to the other outlet port.

16. A fuel nozzle for a gas turbine engine, the fuel nozzle comprising the fuel injector according to claim 1.

17. The fuel nozzle of claim 16, wherein the fuel nozzle comprises a plurality of fuel injectors of claim 1.

18. The fuel nozzle of claim 17, further comprising: Front wall, wherein the outer sleeve of the fuel injector is connected to the front wall.

19. The fuel nozzle of claim 17, wherein the fuel injectors are parallel to each other.

20. The fuel nozzle of claim 17, wherein at least two of the fuel injectors have a converging axis.

21. A combustor assembly for a gas turbine engine, the combustor assembly comprising: A combustion chamber extending from an upstream end to a downstream end, wherein the downstream end is adapted to be fluidly connected to a turbine section of the gas turbine engine, and the upstream end is adapted to be fluidly connected to an air compressor of the gas turbine engine; At least one fuel nozzle according to claim 16; and A fuel delivery conduit, which is fluidly connected to the fuel injector of the fuel nozzle.

22. A gas turbine engine comprising the combustor assembly according to claim 21.

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