Fuel nozzle device for gas turbine

Abstract

To reduce pressure loss of compressed air supplied into a fuel nozzle device for a gas turbine.SOLUTION: A fuel nozzle device for injecting a fuel into a combustion chamber of a gas turbine engine, includes: an outer cylinder extending in a prescribed axial direction and projecting into a combustion chamber; a rear end wall closing a base end of the outer cylinder; a tapered conical cylinder body coaxially extending from an inner periphery of an intermediate portion of the outer cylinder toward a free end portion of the outer cylinder, defining a first jetting port at its free end portion, and defining an annular second jetting port coaxially externally surrounding the first jetting port in cooperation with the free end portion of the outer cylinder; a fuel passage penetrating through the rear end wall, and reaching a fuel jetting port open toward an inner peripheral face of a base end portion of the conical cylinder body; a first air introduction passage formed through a part between the base end portion of the conical cylinder body and a part adjacent to the fuel jetting port, of the outer cylinder in a manner of including a component in a tangential direction; and a second air introduction passage formed through a part between the base end portion of the conical cylinder body and the free end portion, of the outer cylinder in a manner of including a component in the tangential direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a fuel nozzle apparatus for a gas turbine. [Background technology]

[0002] In a gas turbine, a fuel such as kerosene is injected into compressed air in a combustor to form an air-fuel mixture, which is then combusted to produce combustion gas for driving the turbine. In order to achieve efficient combustion, it is desirable to atomize or vaporize the fuel well, i.e., to mix the fuel with the air well.

[0003] Patent Document 1 discloses a nozzle device having a central tube for supplying liquid, a conical cylinder having a base end coaxially surrounding the central tube and a tapered free end extending coaxially forward, and an outer cylinder coaxially surrounding the outer periphery of the conical cylinder. A first annular air passage is defined between the central tube and the inner periphery of the conical cylinder, and a second air passage is defined between the outer periphery of the conical cylinder and the inner periphery of the outer cylinder. Both air passages include narrowed portions, and a high-speed flow of pressurized air supplied to the nozzle is formed in these narrowed portions. As a result, negative pressure is formed in these regions, and the liquid is ejected from the central tube in the form of a jet flow, and is mixed with the pressurized air introduced into the first air passage. The flow of this mixed flow is further accelerated by the pressurized air introduced into the second air passage. In addition, since a swirler is provided in these air passages, the high-speed flow of pressurized air forms a swirling flow, and as a result, the liquid can be highly atomized. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-297589 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the nozzle device described in Patent Document 1 atomizes liquid by generating a high-speed pressurized air flow. On the other hand, in a gas turbine, the pressure difference between the compressed air chamber and the combustion chamber is relatively small, so a high-speed pressurized air flow cannot be obtained. Therefore, this nozzle device cannot be directly applied to a fuel nozzle for a gas turbine.

[0006] SUMMARY OF THE PRESENT EMBODIMENT In view of the above problems, an object of the present invention is to provide a fuel nozzle device for a gas turbine that can combust fuel efficiently. [Means for solving the problem]

[0007] In order to solve this problem, one aspect of the present invention is a fuel nozzle device (100) that injects fuel into a combustion chamber (52) of a gas turbine engine (10), comprising: an outer cylinder (101) extending in a predetermined axial direction and projecting into the combustion chamber; a rear end wall (102) that closes a base end of the outer cylinder; and a tapered cone extending coaxially from an inner periphery of a middle part of the outer cylinder toward a free end of the outer cylinder, defining a first ejection port (118) at the free end, and defining an annular second ejection port (119) that coaxially surrounds the first ejection port in cooperation with the free end of the outer cylinder. The present invention provides a fuel nozzle device including a cylindrical body (104), a fuel passage (108) penetrating the rear end wall in the axial direction and leading to a fuel ejection port (109) opened toward the inner circumferential surface of the base end of the conical cylinder, a first air introduction passage (111) formed through a portion of the outer cylinder between the base end of the conical cylinder and a portion adjacent to the fuel ejection port so as to include a tangential component, and a second air introduction passage (113) formed through a portion of the outer cylinder between the base end and the free end of the conical cylinder so as to include a tangential component.

[0008] According to this aspect, the fuel and the compressed air can be mixed well, and the combustion efficiency in the combustion chamber can be improved.

[0009] In the above configuration, it is preferable that a front surface of the rear end wall is flat, and a rear edge of the first air introduction passage is substantially aligned with the front surface of the rear end wall.

[0010] According to this configuration, air can be efficiently introduced from the first air introduction passage toward the high-speed fuel jet injected from the fuel ejection port without encountering resistance.

[0011] In the above configuration, the inlet of the first air introduction passage and the inlet of the second air introduction passage may be disposed adjacent to each other in the axial direction.

[0012] According to this configuration, the axial length of the nozzle device can be minimized, and with a given axial length, the flows introduced from both air introduction passages can be made into better swirling flows.

[0013] In the above configuration, the fuel passage may be inclined at a predetermined angle in the circumferential direction.

[0014] With this configuration, the fuel injected into the conical cylinder from the fuel injection port can be swirled in the circumferential direction in the same direction as the swirling direction of the compressed air introduced from the first air introduction passage, which makes it possible to form a liquid film of fuel adhering to the inner surface of the conical cylinder with a more uniform thickness, thereby enabling the fuel to be atomized well.

[0015] In the above configuration, the fuel passage may be configured so that the fuel is injected in a direction in which the fuel impinges on an inner surface of the conical cylinder.

[0016] With this configuration, the liquid film of fuel that is ejected from the fuel ejection port into the conical cylinder and adheres to the inner surface of the conical cylinder can be formed to a more uniform thickness, enabling the fuel to be atomized satisfactorily.

[0017] In addition, in the above configuration, it is preferable that the outer cylinder includes a front cylinder (105) and a rear cylinder (106) which are coaxial with each other, and a flange (107) facing radially outward is formed at the rear end of the conical cylinder, and the flange is sandwiched between the rear end of the front cylinder and the front end of the rear cylinder.

[0018] This configuration facilitates assembly of the fuel nozzle device.

[0019] In the above configuration, the inlet of the first air introduction passage and the inlet of the second air introduction passage may have a rectangular or oval shape that is long in the axial direction.

[0020] According to this configuration, the area of ​​the inlet of the first air introduction passage and the area of ​​the inlet of the second air introduction passage can be made large, so that the pressure loss in the first air flow path and the second air flow path can be reduced.

[0021] In the above configuration, the outer cylinder may have a tapered inner circumferential surface that extends forward of the second ejection port.

[0022] According to this configuration, the flows ejected from the first ejection port and the second ejection port are improved.

[0023] In the above configuration, it is preferable that a portion of the outer cylinder surrounding the front portion of the conical cylinder has a tapered inner circumferential surface tapering toward the second ejection port.

[0024] According to this configuration, the space defined by the inner peripheral surface of the outer cylinder and the outer peripheral surface of the conical cylinder tapers forward, thereby enhancing the swirling flow passing through this space.

[0025] In the above configuration, it is preferable that an inner circumferential portion of the outer cylinder that defines the first air introduction passage has a shoulder surface facing forward, and the fuel ejection port opens at the shoulder surface.

[0026] According to this configuration, the structure of the nozzle device is simplified, and the nozzle device is easily formed. Effect of the Invention

[0027] According to the present invention, there is provided a fuel nozzle device for a gas turbine that can satisfactorily mix fuel and compressed air and improve the combustion efficiency in a combustion chamber. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a cross-sectional view showing a gas turbine provided with a fuel nozzle device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view showing the fuel nozzle device; [Diagram 3] FIG. 3 is a cross-sectional view showing the fuel nozzle device; [Figure 4] FIG. 4 is a cross-sectional view of the fuel nozzle device taken along line IV-IV in FIG. [Diagram 5] FIG. 4 is a cross-sectional view of the fuel nozzle device taken along line VV in FIG. [Figure 6] FIG. 2 is a cross-sectional view of a fuel nozzle assembly showing fuel passages in an alternative embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, an embodiment in which a fuel nozzle device 100 according to the present invention is used in a gas turbine engine 10 for an aircraft will be described with reference to the drawings. First, an overview of the gas turbine engine 10 in which the fuel nozzle device 100 of the present embodiment is used will be described with reference to FIG.

[0030] The gas turbine engine 10 has a substantially cylindrical outer casing 12 and an inner casing 14 that are coaxially arranged with respect to a central axis X. Inside the inner casing 14, a low-pressure system rotating shaft 20 is rotatably supported by a front first bearing 16 and a rear first bearing 18. The high-pressure system rotating shaft 26 is a hollow shaft that coaxially surrounds the low-pressure system rotating shaft 20 with respect to the central axis X, and is rotatably supported by the inner casing 14 and the low-pressure system rotating shaft 20 by a front second bearing 22 and a rear second bearing 24.

[0031] The low-pressure system rotating shaft 20 includes a generally conical tip portion 20A that protrudes forward from the inner casing 14. A plurality of front fans 28 are provided around the tip portion 20A in the circumferential direction. A plurality of stator vanes 30 are provided at predetermined intervals in the circumferential direction in the outer casing 12 downstream of the front fans 28. A bypass duct 32 having an annular cross-sectional shape formed between the outer casing 12 and the inner casing 14 and an air compression duct 34 having an annular cross-sectional shape formed coaxially with the inner casing 14, i.e., coaxially with the central axis X, are provided in parallel on the downstream side of the stator vanes 30.

[0032] An axial compressor 36 is provided at the inlet of the air compression duct 34. The axial compressor 36 has two rows of rotor blades 38 provided on the outer periphery of the low-pressure system rotating shaft 20 and two rows of stator blades 40 provided in the inner casing 14, which are alternately arranged adjacent to each other in the axial direction.

[0033] A centrifugal compressor 42 is provided at the outlet of the air compression duct 34. The centrifugal compressor 42 has an impeller 44 provided on the outer periphery of the high-pressure system rotating shaft 26. A strut 46 that crosses the air compression duct 34 is provided in the inner casing 14 at the outlet of the air compression duct 34, i.e., immediately upstream of the impeller 44. A diffuser 50 fixed to the inner casing 14 is provided at the outlet of the centrifugal compressor 42.

[0034] A gas turbine combustor 54 is provided downstream of the diffuser 50. The gas turbine combustor 54 defines an annular combustion chamber 52 centered on a central axis line X. Compressed air is supplied from the diffuser 50 toward the combustion chamber 52 via a compressed air chamber 56.

[0035] A plurality of fuel injection nozzles 70 that inject fuel into the combustion chamber 52 are attached to the inner casing 14 at predetermined intervals in the circumferential direction about the central axis X. Each fuel injection nozzle 70 injects fuel toward the combustion chamber 52. In the combustion chamber 52, a mixture of fuel injected from the fuel injection nozzles 70 and compressed air supplied from the compressed air chamber 56 is combusted to generate high-temperature combustion gas.

[0036] A high-pressure turbine 60 and a low-pressure turbine 62 are provided downstream of the combustion chamber 52. The high-pressure turbine 60 includes a stator vane row 58 fixed to the outlet of the combustion chamber 52, and a rotor blade row 64 fixed to the outer periphery of the high-pressure system rotating shaft 26. The low-pressure turbine 62 is located downstream of the high-pressure turbine 60, and has a plurality of stator vane rows 66 fixed to the inner casing 14 and a plurality of rotor blade rows 68 provided on the outer periphery of the low-pressure system rotating shaft 20, which are alternately arranged adjacent to each other in the axial direction.

[0037] The gas turbine engine 10 is started by driving the high-pressure system rotating shaft 26 to rotate by a starter motor (not shown). When the high-pressure system rotating shaft 26 is driven to rotate, compressed air compressed by the centrifugal compressor 42 is supplied to the combustion chamber 52, and the air-fuel mixture is combusted in the combustion chamber 52 to generate fuel gas. The fuel gas is sprayed to the rotor blade rows 64, 68, and rotates the high-pressure system rotating shaft 26 and the low-pressure system rotating shaft 20. As a result, the front fan 28 rotates, and the axial compressor 36 and the centrifugal compressor 42 are operated, so that compressed air is supplied to the combustion chamber 52. As a result, the gas turbine engine 10 continues to operate even after the starter motor is stopped.

[0038] Furthermore, a portion of the air sucked in by the front fan 28 during operation of the gas turbine engine 10 passes through the bypass duct 32 and is ejected rearward to generate thrust. The remaining portion of the air sucked in by the front fan 28 is supplied to the combustion chamber 52 and combusted as a mixture with fuel to generate fuel gas. The combustion gas contributes to the rotational drive of the low-pressure system rotating shaft 20 and the high-pressure system rotating shaft 26, and is then ejected rearward to generate thrust.

[0039] Next, the fuel nozzle device 100 according to this embodiment will be described in detail. Fig. 2 and Fig. 3 show the fuel nozzle device 100 in detail. The fuel nozzle device 100 includes an external cylinder 101 that protrudes from the rear end of the combustion chamber 52 toward the inside of the combustion chamber 52. The external cylinder 101 is a cylindrical body that extends in the axial direction centered on a central axis A different from the central axis X of the gas turbine engine 10. A rear end wall 102 is provided slightly forward of the rear end of the external cylinder 101, and a fuel chamber 103 is defined by the rear surface of the rear end wall 102 and the inner peripheral surface of the external cylinder 101. The fuel chamber 103 is a cylindrical body that is arranged coaxially with the external cylinder 101, and is connected to a fuel pipe (not shown) to receive a supply of fuel.

[0040] A base end (large diameter end) of a conical cylinder 104, which is a tapered cylinder arranged coaxially with the outer cylinder 101 and extends in the axial direction, is joined to the inner peripheral surface of the axially intermediate portion of the outer cylinder 101, and a free end (small diameter end) of the conical cylinder 104 reaches the front end of the outer cylinder 101. In this embodiment, the outer cylinder 101 is composed of a front cylinder 105 and a rear cylinder 106 which are coaxial with each other. A flange 107 extending radially outward is provided at the base end of the conical cylinder 104. The flange 107 is sandwiched between the front cylinder 105 and the rear cylinder 106, and the front cylinder 105, the rear cylinder 106, and the flange 107 are joined by welding or brazing.

[0041] The front cylinder 105 is a cylinder having a constant outer diameter, and the front end of the rear cylinder 106 has approximately the same outer diameter as the front cylinder 105. The outer diameter of the rear end of the rear cylinder 106, which defines the fuel chamber 103, is larger than that of the front end. The front surface of the rear end wall 102 is approximately flat, and corresponds to a region where the outer periphery of the rear cylinder 106 begins to expand in diameter toward the rear. The inner circumferential surface near the front end of the rear cylinder 106 is located radially inward of the inner circumferential surface of the fuel chamber 103.

[0042] Six fuel passages 108 are formed in the rear end wall 102 corresponding to the outer periphery of the fuel chamber 103 at a predetermined interval in the circumferential direction and penetrating in the axial direction. In this embodiment, the inner circumference of the front end of the rear cylinder 106 is slightly smaller in diameter than the inner circumference of the base end of the conical cylinder 104, so that, as shown in FIG. 4, an annular shoulder surface 110 extending in the axial direction and facing forward is formed on the inner circumference of the front end of the rear cylinder 106. In addition, the front end of the fuel passages 108 forms a fuel ejection port 109 and opens in front of the annular shoulder surface 110. These fuel ejection ports 109 are arranged near the boundary between the rear end surface of the conical cylinder 104 facing rearward and the inner circumferential surface forming the conical surface of the conical cylinder 104. In particular, it is preferable that the extension of the fuel ejection port 109 abuts against a curved surface area connected to the conical surface or rear end surface of the conical cylinder 104.

[0043] A plurality of first air introduction passages 111 arranged in the circumferential direction are formed through the side wall of the rear cylinder 106 in a region between the rear end wall 102 and the base end of the conical cylinder 104. The first air introduction passages 111 have an elliptical or rectangular shape that is long in the front-rear direction and extend at an incline tangentially to the radial direction. The rear edge of the first air introduction passage 111 is approximately aligned with the flat front surface of the rear end wall 102. In this embodiment, the rear edge of the first air introduction passage 111 is defined by the flat front surface of the rear end wall 102. As shown in FIG. 4, the fuel passage 108 is located near the inner circumferential surface of the side wall of the rear cylinder 106 between the adjacent first air introduction passages 111. The first air introduction passage 111 communicates with a first air flow passage 112 defined by the inner circumferential surface of the conical cylinder 104. That is, the first air introduction passage 111 is directly connected to an upstream portion of a first air flow passage 112 that forms a cylindrical passage defined in front of the rear end wall 102 .

[0044] A plurality of second air introduction passages 113 arranged in the circumferential direction are formed penetrating the side wall of the front cylinder 105 in a region immediately before the base end of the conical cylinder 104. The second air introduction passages 113 have a substantially square cross section and extend inclined in the same tangential direction as the first air introduction passage 111 with respect to the radial direction. As shown in FIG. 5, the second air introduction passage 113 communicates with a second air flow path 114 defined by the outer peripheral surface of the conical cylinder 104 and the inner peripheral surface of the front cylinder 105. The inlet of the first air introduction passage 111 and the inlet of the second air introduction passage 113 are disposed close to each other in the axial direction.

[0045] The front end of the front cylinder 105 is located slightly forward of the front end of the conical cylinder 104. The inner peripheral surface of the front cylinder 105 includes a tapered portion 115 located rearward of the front end of the conical cylinder 104, a widened portion 116 located forward of the front end of the conical cylinder 104, and a narrowed portion 117 located between the tapered portion 115 and the widened portion 116 and provided at a position approximately corresponding to the front end of the conical cylinder 104. In this way, the inner peripheral surface of the front cylinder 105 coaxially faces the outer peripheral surface of the conical cylinder 104. Therefore, the front end of the conical cylinder 104 forms a first outlet 118 of the first air flow passage 112, which is circular, and the portion between the front end of the front cylinder 105 and the narrowed portion 117 forms a second outlet 119 of the second air flow passage 114.

[0046] Next, the operation of the fuel nozzle device 100 will be described. Pressurized fuel is introduced into the fuel chamber 103, passes through the fuel passage 108, and is then ejected as a high-speed jet flow into the first air passage 112 through the fuel ejection port 109. At this time, negative pressure is created around the fuel flow, and compressed air introduced from the compressed air chamber 56 is sucked into the first air passage 112 through the first air introduction passage 111. Since the first air introduction passage 111 is inclined in the tangential direction with respect to the radial direction, the compressed air sucked into the first air passage 112 forms a swirling flow, and the fuel is atomized or vaporized well. Since the first air passage 112 has a tapered cone shape, the swirling flow increases in swirl speed as it moves forward, and is ejected from the first ejection port 118 toward the combustion chamber 52. At this time, the jet flow ejected from the first jet port 118 sucks the compressed air introduced into the second air flow passage 114 via the second air introduction passage 113 from the second jet port 119. In particular, since the second jet port 119 is narrower than its upstream and downstream sides in the second air flow passage 114, a good flow of compressed air is realized at the second jet port 119. In addition, since the second air introduction passage 113 is inclined, the compressed air sucked out from the second air flow passage 114 forms a swirling flow and is well mixed with the mixture gas ejected from the first jet port 118.

[0047] Here, the front surface of the rear end wall 102 is flat, and the rear edge of the first air introduction passage 111 is approximately aligned with the front surface of the rear end wall 102. This allows air to be efficiently introduced from the first air introduction passage 111 toward the high-speed fuel jet injected from the fuel ejection port 109 without resistance.

[0048] In addition, a considerable amount of the fuel ejected from the fuel ejection port 109 collides with the inner surface of the conical cylinder 104. As a result, the fuel adheres to the inner surface or flows along the inner surface, accelerating atomization or vaporization of the fuel.

[0049] Furthermore, the first air introduction passage 111 and the second air introduction passage 113 have a rectangular or elliptical shape that is long in the axial direction. This allows the areas of the first air introduction passage 111 and the second air introduction passage 113 to be large, making it possible to increase the amount of compressed air supplied from the compressed air chamber 56. Furthermore, the first air introduction passage 111 and the second air introduction passage 113 are disposed close to each other in the axial direction. This allows the axial length of the fuel nozzle device 100 to be minimized, and with a given axial length, the flow of compressed air introduced from the first air introduction passage 111 and the second air introduction passage 113 can be made into a better swirling flow.

[0050] 6, in a modified embodiment of the present invention, the fuel passages 108 are inclined at a predetermined angle in the circumferential direction. This causes the fuel ejected from the fuel ejection port 109 to become a swirling flow having a velocity of an axial component and a circumferential component, thereby enabling the fuel to be atomized or vaporized more effectively.

[0051] Although the specific embodiment has been described above, the present invention is not limited to the above embodiment and can be modified in a wide range of ways. For example, the front cylinder 105, the rear cylinder 106, and the flange 107 can be integrally assembled by providing threaded portions at the opposing ends of the front cylinder 105 and the rear cylinder 106 and screwing the two cylinders together so that the flange 107 is sandwiched between the two cylinders. [Explanation of symbols]

[0052] 10: Gas turbine engine 52: Combustion chamber 100: Fuel nozzle device 101: Outer cylinder 102: Rear end wall 103:Fuel chamber 104: Conical cylinder 105: Front barrel 106: Rear barrel 108:Fuel passage 109: Fuel injection port 110: Shoulder surface 111: First air inlet 112: First air flow path 113: Second air inlet 114: second air flow path 115: Taper 116: Thick tip 117: Stenosis 118: 1st spout 119:Second spout A: Central axis of the fuel nozzle device X: Central axis of the gas turbine

Claims

1. 1. A fuel nozzle device for injecting fuel into a combustion chamber of a gas turbine engine, comprising: an outer cylinder extending in a predetermined axial direction and projecting into the combustion chamber; a rear end wall that closes the base end of the outer cylinder; a tapered conical cylinder extending coaxially from an inner periphery of a middle portion of the outer cylinder toward a free end portion of the outer cylinder, defining a first jet outlet at the free end portion, and defining an annular second jet outlet coaxially surrounding the first jet outlet in cooperation with the free end portion of the outer cylinder; a fuel passage penetrating the rear end wall in the axial direction and leading to a fuel ejection port that is open toward an inner circumferential surface of a base end of the conical cylinder; a first air introduction passage formed through a portion of the outer cylinder between the base end of the conical cylinder and a portion adjacent to the fuel ejection port so as to include a tangential component; a second air introduction passage formed through the outer cylinder in a portion between the base end and the free end of the conical cylinder so as to include a tangential component; The fuel passage is inclined at a predetermined angle in a circumferential direction.

2. 1. A fuel nozzle device for injecting fuel into a combustion chamber of a gas turbine engine, comprising: an outer cylinder extending in a predetermined axial direction and projecting into the combustion chamber; a rear end wall that closes the base end of the outer cylinder; a tapered conical cylinder extending coaxially from an inner periphery of a middle portion of the outer cylinder toward a free end portion of the outer cylinder, defining a first jet outlet at the free end portion, and defining an annular second jet outlet coaxially surrounding the first jet outlet in cooperation with the free end portion of the outer cylinder; a fuel passage penetrating the rear end wall in the axial direction and leading to a fuel ejection port that is open toward an inner circumferential surface of a base end of the conical cylinder; a first air introduction passage formed through a portion of the outer cylinder between the base end of the conical cylinder and a portion adjacent to the fuel ejection port so as to include a tangential component; a second air introduction passage formed through the outer cylinder in a portion between the base end and the free end of the conical cylinder so as to include a tangential component; the outer cylinder includes a front cylinder body and a rear cylinder body that are coaxial with each other; A flange is formed on the rear end of the conical cylinder, the flange facing radially outward; the flange is sandwiched between an aft end of the front barrel and a forward end of the rear barrel.

3. 3. The fuel nozzle device according to claim 1, The fuel nozzle apparatus further includes a fuel chamber defined by a rear surface of the rear end wall and an inner circumferential surface of the outer casing.

4. A fuel nozzle apparatus according to any one of claims 1 to 3, a front surface of the rear end wall being flat, and a trailing edge of the first air introduction passage being generally aligned with the front surface of the rear end wall.

5. A fuel nozzle apparatus according to any one of claims 1 to 4, a first air introduction passage inlet and a second air introduction passage inlet disposed adjacent to each other in the axial direction;

6. A fuel nozzle apparatus according to any one of claims 1 to 5, 13. A fuel nozzle apparatus comprising: a fuel passage configured to inject fuel into a cone such that the fuel impinges on an inner surface of the cone.

7. A fuel nozzle apparatus according to any one of claims 1 to 6, a first air introduction passage inlet and a second air introduction passage inlet each having a rectangular or elliptical shape that is elongated in the axial direction;

8. A fuel nozzle apparatus according to any one of claims 1 to 7, a second nozzle hole formed in the second nozzle hole and having a first end and a second end, the second nozzle hole being formed in the first nozzle hole and a second end, the second end being formed in the second nozzle hole.

9. A fuel nozzle apparatus according to any one of claims 1 to 8, a portion of the outer cylinder surrounding the front portion of the conical cylinder has an inner circumferential surface that tapers toward the second nozzle port.

10. 10. A fuel nozzle apparatus according to any one of claims 1 to 9, an inner circumferential portion of the outer cylinder that defines the first air introduction passage has a shoulder surface facing forward; The fuel nozzle device according to claim 1, wherein the fuel ejection port opens at the shoulder surface.

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