Burner assembly, gas turbine combustor, and gas turbine

Abstract

In a burner assembly according to at least one embodiment of the present disclosure, each of a plurality of burners is provided with a flow passage through which air can flow. The flow passage includes a first region, in which a fuel injection hole is formed, and a second region, which is located downstream of the first region and in which the fuel injected through the injection hole and air are mixed. The first region extends from an upstream-side end part of the flow passage to a connection position with the second region, and the injection hole is formed at a position closer to the connection position than the upstream-side end part. The first region has at least one protrusion, which protrudes radially inward of the flow passage and in which the injection hole is formed, and at least one peripheral wall, which is adjacent to the at least one protrusion in the circumferential direction of the flow passage and in which the protrusion is not provided. The cross-sectional area of the flow passage is such that a second cross-sectional area within the second region is less than a first cross-sectional area within the first region.

Description

[Technical Field]

[0001] The present disclosure relates to a burner assembly, a gas turbine combustor, and a gas turbine. This application claims priority based on Japanese Patent Application No. 2023-053155 filed with the Japan Patent Office on March 29, 2023, and incorporates the content thereof herein. [Background Art]

[0002] As a technique for achieving low NOx emissions while having flashback resistance for fuels with a high risk of flashback (such as hydrogen), there is a technique of forming a large number of independent small flames by a burner assembly (cluster burner). In this technique, by arranging a plurality of mixing channels for mixing fuel and air and reducing the scale of fuel mixing, high mixing performance can be obtained without actively utilizing a swirling flow for mixing fuel and air.

[0003] Patent Document 1 discloses a burner assembly for suppressing flashback while achieving low NOx emissions. Each burner of this burner assembly includes a fuel nozzle and a mixing channel into which fuel and air flow, and the fuel nozzle includes a protruding portion that protrudes upstream in the air flow direction from an inlet of the mixing channel. Further, a fuel injection hole is formed on a side surface of the protruding portion, and the fuel injected from the fuel injection hole flows into the inlet of the mixing channel together with air, so that the fuel and air are mixed. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2019-168198 [Summary of the Invention] [Problems to be Solved by the Invention]

[0005] The burner assembly described in Patent Document 1 has room for further improvement in terms of suppressing flashback.

[0006] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a burner assembly, a gas turbine combustor, and a gas turbine capable of suppressing flashback. [Means for solving the problem]

[0007] (1) A burner assembly according to at least one embodiment of the present disclosure is A burner assembly comprising multiple burners for mixing fuel and air, Each of the plurality of burners is provided with a passage through which the air can flow, The aforementioned flow path is A first region is formed in the upstream region of the airflow, and the fuel injection holes are formed in the first region. The region includes a second region downstream of the first region where the fuel injected from the injection hole and the air are mixed, The first region is, It extends from the upstream end of the flow channel to the connection point with the second region, The injection holes are formed at a position closer to the connection position than the upstream end, At least one projection that protrudes radially inward from the flow path and in which the injection hole is formed, In the circumferential direction of the flow path, there is at least one circumferential wall portion adjacent to the at least one protrusion and not having the protrusion, It has, When viewed from the direction of extension of the flow path, the cross-sectional area of ​​the flow path is smaller in the second cross-sectional area in the second region than in the first cross-sectional area in the first region.

[0008] (2) A gas turbine combustor according to at least one embodiment of the present disclosure is A burner assembly with the above configuration (1), A combustion cylinder forming a space for flame formation downstream of the burner assembly, comprising.

[0009] (3) A gas turbine according to at least one embodiment of the present disclosure includes: a compressor; a gas turbine combustor supplied with air compressed by the compressor and fuel, configured to combust the fuel and generate combustion gas; a turbine driven by the combustion gas generated in the gas turbine combustor; comprising, the gas turbine combustor is the gas turbine combustor having the configuration described in (2) above. Effects of the Invention

[0010] According to at least one embodiment of the present disclosure, there can be provided a burner assembly, a gas turbine combustor, and a gas turbine that are capable of suppressing flashback. Brief Description of the Drawings

[0011] [Figure 1] Figure 1 is a schematic configuration diagram of a gas turbine according to an embodiment. [Figure 2] Figure 2 is a cross-sectional view showing the vicinity of a combustor. [Figure 3] Figure 3 is a perspective view for explaining the structure of a combustor. [Figure 4] Figure 4 is a partial schematic perspective view showing a part of a burner assembly according to an embodiment. [Figure 5] Figure 5 is a view corresponding to a cross-sectional view taken along line V-V in Figure 4 for a part of the burner assembly according to an embodiment. [Figure 6] Figure 6 is a schematic view showing a part of a cross-section taken along line VI-VI in Figure 5. [Figure 7] Figure 7 is a partial schematic perspective view showing a part of a burner assembly according to an embodiment, showing a state where an introduction flow path wall is removed for explanation. [Figure 8] Figure 8 is a schematic view, as viewed from an upstream side in an air flow direction along a central axis, of a part of the burner assembly in a state where the introduction flow path wall is removed for explanation. [Figure 9]It is a schematic diagram showing a part of the cross-section taken along line IX-IX in FIG. 8. [Figure 10] It is a schematic diagram showing a part of the cross-section taken along line X-X in FIG. 8. [Figure 11] It is a diagram corresponding to the cross-sectional view taken along line V-V in FIG. 4 for a part of a burner assembly according to another embodiment. [Figure 12] It is a schematic diagram showing a part of the cross-section taken along line XII-XII in FIG. 11. [Figure 13] It is a cross-sectional view of section XIII enclosed by a broken line in FIG. 6 as viewed from the upstream side in the air flow direction. [Figure 14] It is a diagram corresponding to the cross-sectional view of section XIII enclosed by a broken line in FIG. 6 as viewed from the upstream side in the air flow direction, and shows another example of the protrusion. [Figure 15] It is a diagram for explaining the dimensions of each part of the burner assembly according to some embodiments. [Figure 16] It is a diagram for explaining the dimensions of each part of the burner assembly according to some embodiments. [Figure 17] It is a diagram for explaining variations in the shape of the protruding portion. [Figure 18] It is a cross-sectional view of section XVIII enclosed by a broken line in FIG. 17 as viewed from the upstream side in the air flow direction. [Figure 19] It is a diagram corresponding to the cross-sectional view of section XVIII enclosed by a broken line in FIG. 17 as viewed from the upstream side in the air flow direction, and shows another example. [Figure 20] It is a diagram for explaining variations in the shape of the protruding portion. [Figure 21] It is a cross-sectional view of section XXI enclosed by a broken line in FIG. 20 as viewed from the upstream side in the air flow direction. [Figure 22] It is a diagram for explaining modified examples of the introduction flow path wall and the flow path wall. [Figure 23] It is a schematic diagram for explaining the extending direction of the fuel injection hole, and shows a cross-section orthogonal to the central axis. [Figure 24]This is a schematic diagram illustrating the direction of extension of the fuel injection port, showing a cross-section perpendicular to the central axis. [Figure 25] This figure shows another example of the fuel nozzle projection and corresponds to the cross-sectional view taken along the XXV-XXV arrow in Figure 5. [Figure 26] This is a schematic diagram showing a portion of a burner assembly related to a modification of the first region, viewed from the upstream side in the direction of airflow along the central axis L. [Figure 27] This is a schematic cross-sectional view of the first region, which appears in the cross-section including the central axis of the flow path. [Figure 28] This is a schematic cross-sectional view of the first region, which appears in the cross-section including the central axis of the flow path. [Figure 29] This is a schematic cross-sectional view of the first region, which appears in the cross-section including the central axis of the flow path. [Figure 30A] This is a schematic cross-sectional view showing section AA in Figure 26. [Figure 30B] This is a schematic cross-sectional view showing the BB section in Figure 26. [Figure 31A] This is a schematic cross-sectional view showing section AA in Figure 26. [Figure 31B] This is a schematic cross-sectional view showing the BB section in Figure 26. [Figure 32A] This is a schematic cross-sectional view showing section AA in Figure 26. [Figure 32B] This is a schematic cross-sectional view showing the BB section in Figure 26. [Figure 33A] This is a schematic cross-sectional view showing section AA in Figure 26. [Figure 33B] This is a schematic cross-sectional view showing the BB section in Figure 26. [Figure 34A] This is a schematic cross-sectional view showing section AA in Figure 26. [Figure 34B] This is a schematic cross-sectional view showing the BB section in Figure 26. [Figure 35A] This is a schematic cross-sectional view showing section AA in Figure 26. [Figure 35B] This is a schematic cross-sectional view showing the BB section in Figure 26. [Modes for carrying out the invention]

[0012] Hereinafter, several embodiments of this disclosure will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative arrangements, etc., of the components described or shown in the drawings as embodiments are not intended to limit the scope of this disclosure, but are merely illustrative examples. For example, expressions describing relative or absolute arrangements such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" should not only strictly describe such arrangements, but also describe states of relative displacement with tolerances or angles or distances that allow for the same function to be achieved. For example, expressions such as "identical," "equal," and "homogeneous" that describe things being in an equal state not only describe a state of being strictly equal, but also describe a state in which there is a tolerance or a difference that is sufficient to achieve the same function. For example, expressions describing shapes such as squares or cylinders shall not only represent geometrically precise shapes such as squares or cylinders, but also shapes that include protrusions, chamfers, etc., to the extent that the same effect can be achieved. On the other hand, expressions such as "to possess," "to be equipped with," "to have," "to include," or "to have" a single component are not exclusive expressions that exclude the existence of other components.

[0013] First, a gas turbine, which is an example of an application for burners and combustors according to several embodiments, will be described with reference to Figure 1. Figure 1 is a schematic configuration diagram of a gas turbine according to one embodiment. As shown in Figure 1, the gas turbine 1 comprises a compressor 2 for generating compressed air, a combustor 4 for generating combustion gas using compressed air and fuel, and a turbine 6 configured to be rotationally driven by the combustion gas. In the case of a gas turbine 1 for power generation, a generator (not shown) is connected to the turbine 6.

[0014] The compressor 2 includes a plurality of stationary blades 16 fixed to the compressor casing 10 side, and a plurality of rotor blades 18 mounted on the rotor 8 so as to be arranged alternately with respect to the stationary blades 16. Air taken in from the air intake 12 is supplied to the compressor 2, and this air is compressed by passing through multiple stationary blades 16 and multiple rotor blades 18 to become high-temperature, high-pressure compressed air.

[0015] The combustor 4 is supplied with fuel and compressed air generated by the compressor 2. In the combustor 4, the fuel is burned, and combustion gas, which is the working fluid for the turbine 6, is generated. As shown in Figure 1, the gas turbine 1 has multiple combustors 4 arranged circumferentially around the rotor 8 within the casing 20.

[0016] The turbine 6 includes a plurality of stator blades 24 and rotor blades 26 provided in the combustion gas passage formed by the turbine casing 22. The stator blades 24 and rotor blades 26 of the turbine 6 are located downstream of the combustor 4 with respect to the flow of combustion gases. The stator blades 24 are fixed to the turbine casing 22, and multiple stator blades 24 arranged along the circumferential direction of the rotor 8 constitute a stator blade row. The rotor blades 26 are mounted on the rotor 8, and multiple rotor blades 26 arranged along the circumferential direction of the rotor 8 constitute a rotor blade row. The stator blade row and the rotor blade row are arranged alternately in the axial direction of the rotor 8. In the turbine 6, combustion gases from the combustor 4 flow into the combustion gas passage and pass through multiple stationary blades 24 and multiple rotor blades 26, thereby driving the rotor 8 to rotate. This drives a generator connected to the rotor 8, generating electricity. After driving the turbine 6, the combustion gases are discharged to the outside through the exhaust chamber 30.

[0017] Figure 2 is a cross-sectional view showing the vicinity of the combustor 4. Figure 3 is a perspective view illustrating the structure of the combustor 4. The combustor 4 includes a burner assembly 32, a bottomed cylindrical casing 20 housing the burner assembly 32, and a combustion chamber 25 downstream of the burner assembly 32 that forms a space for flame formation. In Figure 2, the dashed line is the central axis L common to the casing 20, the burner assembly 32, and the combustion chamber 25. The burner assembly 32 is located inside the casing 20 of the combustor 4. In the illustrated exemplary embodiment, the burner assembly 32 is held inside a cylindrical member 34 located inside the casing 20, and the cylindrical member 34 is supported by the casing 20 via a plurality of support parts 35 spaced apart around the central axis L. An air passage 36 is formed between the casing 20 and the outer surface of the cylindrical member 34 (between the casing 20 and the outer surface of the burner assembly 32) through which compressed air flowing in from the vehicle chamber 40 flows.

[0018] Compressed air flowing from the cabin 40 into the air passage 36 passes through the axial gap 23 between the burner assembly 32 and the bottom surface 21 of the casing 20 and flows together with fuel into the multiple mixing passages 46 provided in the burner assembly 32 (described later). The fuel and air mixed in the burner assembly 32 are ignited by an ignition device (not shown), forming a flame in the combustion cylinder 25 and generating combustion gases.

[0019] In some embodiments, the burner assembly 32 includes a plurality of burners 42 for mixing fuel and air, as will be described later. Each burner 42 is equipped with a flow path 100 through which fuel and air flow, as will be described later. In some embodiments, as shown in Figure 3, for example, when viewed from the downstream side along the central axis L, the burner assembly 32 has a pentagonal region drawn by a dashed line centered on the central axis L, and five regions outside this pentagon that are arranged circumferentially to correspond to each side of the pentagon, each containing a plurality of flow paths 100. Note that the arrangement pattern of each channel 100 shown in Figure 3 is just one example, and the arrangement pattern of each channel 100 is not necessarily as shown in Figure 3.

[0020] Figure 4 is a partial schematic perspective view showing a part of a burner assembly 32 according to one embodiment. Figure 5 is a diagram corresponding to the cross-sectional view taken along the VV arrow in Figure 4, showing a part of the burner assembly 32 according to one embodiment. Figure 6 is a schematic diagram showing a part of the cross-section taken along the VI-VI arrow in Figure 5. Figure 7 is a partial schematic perspective view showing a part of a burner assembly 32 according to one embodiment, showing the state with the introduction channel wall 115, which will be described later, removed for explanatory purposes. Figure 8 is a schematic diagram of a part of the burner assembly 32 with the introduction channel wall 115 removed for explanatory purposes, viewed from the upstream side in the direction of airflow along the central axis L. Figure 9 is a schematic diagram showing a part of the cross-section taken along the IX-IX arrow in Figure 8. Figure 10 is a schematic diagram showing a part of the cross-section taken along the XX arrow in Figure 8.

[0021] Figure 11 is a diagram corresponding to a cross-sectional view taken along the VV arrow in Figure 4 of a part of the burner assembly 32 according to another embodiment. Figure 12 is a schematic diagram showing a part of the cross-section taken along the XII-XII arrow in Figure 11. Figure 13 is a cross-sectional view of part XIII enclosed by the dashed line in Figure 6, viewed from the upstream side in the direction of airflow. Figure 14 is a diagram corresponding to a cross-sectional view of part XIII enclosed by the dashed line in Figure 6, viewed from the upstream side in the direction of airflow, and shows another example of the protrusion 51, which will be described later.

[0022] For example, as shown in Figures 4 to 9, 11 and 12, the burner assembly 32 includes a plurality of burners 42 for mixing fuel and air.

[0023] Each of the burners 42 according to several embodiments includes an introduction channel 110 for introducing compressed air for combustion from the vehicle chamber 40 (see Figures 1 and 2) to each of the burners 42, a plurality of fuel nozzles 43 for injecting fuel, and a mixing channel 46 into which the fuel injected from the plurality of fuel nozzles 43 and the compressed air supplied from the introduction channel 110 flow. In the illustrated exemplary embodiment, each of the burners 42, as in the first burner 42a (see Figure 8) described later, includes one introduction channel 110, one mixing channel 46, and four fuel nozzles 43 arranged around the one mixing channel 46, with fuel being injected into the one mixing channel 46 from the surrounding four fuel nozzles 43. In other words, four mixing channels 46 are arranged around one fuel nozzle 43, and one fuel nozzle 43 injects fuel into the four mixing channels 46.

[0024] In each of the several embodiments of the burner 42, the flow path 100 through which fuel and air flow has an introduction flow path 110 and a mixing flow path 46 connected to the downstream side of the introduction flow path 110. The introduction flow path 110 and the mixing flow path 46 are connected at the inlet 48 of the mixing flow path 46 (see, for example, Figures 6 and 12), which will be described later as the connection point between the introduction flow path 110 and the mixing flow path 46. The introduction channel 110 is the first region 101 in the channel 100, and the mixing channel 46 is the second region 102 in the channel 100.

[0025] Each of the flow channels 100 is configured as a through-hole extending parallel to each other, and the central axis O of each flow channel 100 extends in a direction along the central axis L of the casing 20. In the illustrated exemplary embodiment, the central axis O of each flow channel 100 and the central axis L of the casing 20 are parallel. In the following description, the radial and circumferential directions centered on the central axis O may be simply referred to as the radial direction and circumferential direction, respectively, when describing the various parts of the flow path 100. The direction of extension of the flow path 100 coincides with the direction of extension of the central axis O.

[0026] (Inlet channel wall 115) For example, the introduction channel wall 115 that forms the introduction channel 110, as shown in Figures 4 to 6, is configured in a cylindrical shape so as to define the introduction channel 110, which has a circular cross-section, on its inside, and functions as a flow straightening section for straightening the air flowing into the mixing channel 46. Furthermore, for example, the introduction channel wall 115 that forms the introduction channel 110, as shown in Figures 11 and 12, is configured in a rectangular tubular shape so as to define the introduction channel 110 with a rectangular cross-section on its inside, and functions as a flow straightening section for straightening the air flowing into the mixing channel 46.

[0027] In the following, for example as shown in Figure 6, any two burners 42 whose mixing channels 46 are closest to each other will be referred to as the first burner 42a and the second burner 42b for convenience. Similarly, the channel 100 of the first burner 42a may be referred to as the first channel 100a, and the channel 100 of the second burner 42b may be referred to as the second channel 100b. The second channel 100b is the channel 100 closest to the first channel 100a. As shown in Figures 4 to 6, 11 and 12, the introduction channel wall 115 forming the introduction channel 110 (110a) of the first burner 42a and the introduction channel wall 115 forming the introduction channel 110 (110b) of the second burner 42b share a partition wall portion 118 (118ab) that separates the introduction channel 110a of the first burner 42a and the introduction channel 110b of the second burner 42b. In the exemplary embodiment shown in Figures 4 to 6, 11 and 12, the introduction channel wall 115 of the introduction channel 110 shares a partition wall portion 118 with each of the introduction channel walls 115 of the multiple introduction channels 110 (four introduction channels 110 in the illustrated embodiment) surrounding the introduction channel 110.

[0028] Furthermore, as shown in Figures 6 and 12, the thickness t1 of the partition wall portion 118 (118ab) in the VI-VI and XII-XII sections of the burner assembly 32 is constant in the direction along the central axis O of the first burner 42a.

[0029] (Fuel nozzle 43) For example, as shown in Figure 9, each fuel nozzle 43 includes a projection 50 that protrudes upstream in the airflow direction from the downstream region of the introduction passage 110, i.e., the inlet 48 of the mixing passage 46 (see, for example, Figure 6). Each fuel nozzle 43 also includes a plurality of fuel injection holes 53 formed on the side surface 44 of the projection 50. In the exemplary embodiment shown in Figure 8, four fuel injection holes 53 are formed on the side surface 44 of the projection 50 at positions corresponding to the four passages 100 (mixing passages 46) around the projection 50. Each fuel injection hole 53 may extend in a direction perpendicular to the central axis O to inject fuel toward the central axis O of the passage 100, as will be described later, or it may extend obliquely to the direction perpendicular to the central axis O.

[0030] As shown in Figure 9, each fuel nozzle 43 includes a base portion 431 having the above-mentioned side surface 44 formed parallel to the central axis O, and a tip portion 432 formed upstream from the base portion 431 in the direction of airflow.

[0031] As shown in Figures 4 to 6, 11 and 12, each of the protruding portions 50 has a base portion 431 and a portion of the tip portion 432 that protrude radially inward into the introduction channel 110 in the downstream region of the introduction channel 110. Each of the protruding portions 50 shown in Figures 4 to 6, 11 and 12 has the same shape as a rotating body with an axis parallel to the central axis O. In the examples shown in Figures 4 to 6, 11 and 12, when viewed along the central axis O, the base end 431 and part of the tip end 432 of each of the four protrusions 50 arranged to surround one inlet channel 110 protrude radially inward from circumferential positions at 90-degree intervals around the central axis O. Focusing on each of the protruding portions 50, in the examples shown in Figures 4 to 6, 11 and 12, each of the protruding portions 50 protrudes into the inside of each of the four introduction channels 110 that are arranged to surround one of the protruding portions 50.

[0032] In the examples shown in Figures 4 to 6, 11 and 12, of the four protrusions 50 arranged to surround one inlet channel 110, the projections 51 that protrude inward into the inlet channel 110 of two adjacent protrusions 50 in the circumferential direction around the central axis O are spaced apart in the circumferential direction. Between the two adjacent projections 51 in the circumferential direction, there is a circumferential wall portion 116 where no projection 51 is provided. That is, in the examples shown in Figures 4 to 6, 11 and 12, at the axial position where the projection 51 is provided, the projection 51 and the circumferential wall portion 116 are arranged alternately in the circumferential direction.

[0033] For example, as shown in Figure 9, the top surface 54 of the projection 50 (the end face of the projection 50 in the direction of axis O, i.e., the tip of the projection 50) includes a convex curved surface 56. In the illustrated exemplary form, the entire top surface 54 of the projection 50 is composed of a smoothly curved convex curved surface 56. The top surface 54 of the projection 50 may be formed in a streamlined shape, for example. Variations in the shape of the projection 50 will be described later.

[0034] In some embodiments of the burner assembly 32, the projection 51 includes a base portion 431 that extends linearly along the direction of extension of the central axis O in a cross-section along the direction of extension of the central axis O, and a tip portion 432 formed upstream of the base portion 431 such that the amount of radial inward projection gradually increases toward the base portion 431. This suppresses the separation of the airflow from the tip 432 to the base 431. Therefore, it becomes less likely for a region with low flow velocity and high fuel concentration to form near the fuel injection hole 53 (near the fuel jet). As a result, the risk of flashback, which is a backfire from the outlet 47 of the mixing channel 46, can be suppressed.

[0035] (Flow channel wall 55) For example, as shown in Figure 8, the channel wall 55 forming the mixing channel 46 is configured in a tubular shape so as to define the mixing channel 46, which has a circular cross-section, on its inside, and functions as a mixing tube for mixing fuel and air. As shown in Figure 8, the channel wall 55 forming the mixing channel 46 (46a) of the first burner 42a and the channel wall 55 forming the mixing channel 46 (46b) of the second burner 42b share a partition wall 58 (58ab) that separates the mixing channel 46a of the first burner 42a from the mixing channel 46b of the second burner 42b. In the exemplary embodiment shown in Figure 8, the channel wall 55 of the mixing channel 46 shares a partition wall 58 with each of the channel walls 55 of the multiple mixing channels 46 (four mixing channels 46 in the illustrated embodiment) surrounding the mixing channel 46.

[0036] Furthermore, as shown in Figures 6 and 12, the thickness t2 of the partition wall portion 58ab in the VI-VI and XII-XII sections of the burner assembly 32 is constant downstream of the airflow direction of the partition wall portion 58ab from the upstream end 61 in the airflow direction, along the central axis O of the first burner 42a. Also, as shown in Figures 8 and 11, the thickness t2 of the partition wall portion 58ab increases as it moves away from the VI-IV section in Figure 5, the CC section in Figure 8, and the XII-XII section in Figure 11. Note that, as shown in Figure 8, the CC section is a cross-section that passes through the center C1 of the inlet 48 of the mixing channel 46a of the first burner 42a and the center C2 of the inlet 48 of the mixing channel 46b of the second burner 42b, and is along the central axis O of the mixing channel 46 of the first burner 42a. The VI-IV section in Figure 5 and the XII-XII section in Figure 11 are cross-sections at the same location as the CC section.

[0037] For example, as shown in Figure 7, in the burner assembly 32, the end face 59 (the upstream end face in the direction of airflow) of the partition wall 58 that separates the two closest mixing channels 46 has a saddle shape. Furthermore, the inlet 48 of the mixing channel 46 (see, for example, Figures 6 and 12), which is the connection point between the introduction channel 110 and the mixing channel 46, is the boundary position between the introduction channel wall 115 and the upstream end 61 in the airflow direction of the partition wall 58ab. Also, when explaining the distance in the direction of the central axis O with respect to the inlet 48 of the mixing channel 46, the position of the inlet 48 of the mixing channel 46 in the direction of the central axis O is the downstream position among the boundary positions, as shown in Figures 6 and 12.

[0038] As shown in Figures 6 and 12, the thickness t2 of the partition wall portion 58ab in the VI-VI and XII-XII sections of the burner assembly 32 decreases towards the upstream side in the airflow direction at the upstream end 61 of the partition wall portion 58ab. Also, in the VI-IV section of Figure 5, the CC section of Figure 8, and the XII-XII section of Figure 11, the upstream end face 59 of the partition wall portion 58ab in the airflow direction includes a convex curve 60. In the illustrated exemplary embodiment, in the VI-IV section of Figure 5, the CC section of Figure 8, and the XII-XII section of Figure 11, the entire end face 59 of the partition wall portion 58ab is composed of a smoothly curved convex curve 60. In the VI-IV section of Figure 5, the CC section of Figure 8, and the XII-XII section of Figure 11, the end face 59 of the partition wall portion 58ab may be formed in a streamlined shape, for example.

[0039] Here, as shown in Figures 8 and 10, the projection 50 of the second fuel nozzle 43b is located on the opposite side from the projection 50 of the first fuel nozzle 43a, across the plane V (see Figure 10) which includes the CC cross-section.

[0040] As shown in Figure 10, the height H of the partition wall 58ab increases as it approaches the protrusion 50 of the first fuel nozzle 43a from the position V in the plane (the position of the CC cross section above), and increases as it approaches the protrusion 50 of the second fuel nozzle 43b from the position V in the plane. Also, in the cross section of the burner assembly 32B shown in Figure 10, the upstream end face 59 of the partition wall 58ab in the direction of airflow includes a concave curve 62 that connects the side surface 44 of the protrusion 50 of the first fuel nozzle 43a and the side surface 44 of the protrusion 50 of the second fuel nozzle 43b. Furthermore, as shown in Figure 11, the XX cross section is a cross section perpendicular to the straight line U (see Figure 8) that connects the center C1 of the inlet 48 (see Figure 6) of the mixing channel 46a of the first burner 42a and the center C2 of the inlet 48 of the mixing channel 46b of the second burner 42b.

[0041] (Regarding the diameter of the flow path 100) In the burner assembly 32 shown in Figures 4 to 6, the first cross-sectional area S1 of the introduction channel 110, viewed along the extension direction of the flow path 100, i.e., along the central axis O, is larger than the second cross-sectional area S2 of the mixing channel 46, viewed along the central axis O. Specifically, in the burner assembly 32 shown in Figures 4 to 6, in the region upstream in the airflow direction from the position where the protrusion 51 appears in the introduction channel 110, the inner diameter Du of the introduction channel 110 is larger than the inner diameter Dm of the mixing channel 46a. Also, as shown in Figure 13, the inner diameter of the introduction channel 110 in the peripheral wall portion 116 is equal to the inner diameter Du of the introduction channel 110 in the region upstream in the airflow direction from the position where the protrusion 51 appears in the introduction channel 110.

[0042] In the burner assembly 32 shown in Figures 11 and 12, the first cross-sectional area S1 of the introduction channel 110, viewed along the central axis O, is larger than the second cross-sectional area S2 of the mixing channel 46, viewed along the central axis O. Specifically, in the burner assembly 32 shown in Figures 11 and 12, in the region upstream in the airflow direction from the position where the protrusion 51 appears in the introduction channel 110, the equivalent diameter Due of the introduction channel 110 is larger than the inner diameter Dm of the mixing channel 46a. The equivalent diameter Due of the introduction channel 110 is the diameter of a circle having a cross-sectional area equal to the cross-sectional area of ​​the introduction channel 110, viewed along the central axis O. In the following description, the equivalent diameter in a given cross-section is the diameter of a circle having a cross-sectional area equal to the cross-sectional area of ​​that cross-section.

[0043] In the burner assembly 32 shown in Figures 4 to 6, 11 and 12, the diameter Dic of the virtual inscribed circle (see Figures 5 and 13) that is inscribed in the base end 431 of the multiple protrusions 51 projecting into a single inlet channel 110 when viewed along the central axis O, that is, the distance between two base end 431s facing each other across the central axis O in the burner assembly 32 shown in Figures 4 to 6, 11 and 12, should be greater than or equal to the inner diameter Dm of the mixing channel 46a, as shown in Figures 13, 14 and Figure 25 described later. For example, as shown in Figure 25 later, the protrusion 50 may be attached to the flow path wall 55 by inserting the protrusion 50, which is made of a separate component from the components constituting the flow path wall 55, into the fuel plenum 55PL, a space formed within the flow path wall 55 that can store fuel, and fixing it to the flow path wall 55. In this case, the diameter Dic of the inscribed circle may be larger than the inner diameter Dm of the mixing flow path 46a, or it may be made equal to the inner diameter Dm of the mixing flow path 46a by making the diameter of the protrusion 50 upstream of the portion inserted into the flow path wall 55 larger. Furthermore, in the exemplary configurations shown in Figures 4 to 6, 11 and 12, when the protrusion 50 and the flow channel wall 55 are formed integrally, the diameter Dic of the inscribed circle may be equal to the inner diameter Dm of the mixing channel 46a, or it may be larger than the inner diameter Dm of the mixing channel 46a, as shown in Figures 5 and 13.

[0044] In the burner assembly 32 shown in Figures 4 to 6, 11 and 12, the upstream end 61 of the partition wall 58 separating adjacent mixing channels 46 is located downstream in the direction of airflow from the circumferential wall 116, which is located between two adjacent protrusions 51 in the circumferential direction.

[0045] (Regarding the effects of the burner assembly 32) In the burner assembly 32 configured in this way, compressed air flowing from the vehicle compartment 40 into the air passage 36 flows through the axial gap 23 between the burner assembly 32 and the bottom surface 21 of the casing 20, and into each of the introduction passages 110 provided for each of the multiple burners 42 of the burner assembly 32. The compressed air flowing into each intake channel 110 is straightened as it flows downstream in the direction of airflow from the upstream end 111 (see Figure 4), which is the upstream end of the intake channel 110 (the upstream end of the channel 100).

[0046] Because the second cross-sectional area S2 of the mixing channel 46 is smaller than the first cross-sectional area S1 of the introduction channel 110, the air flowing in the radially outer region of the introduction channel 110 flows downstream along the upstream end 61 of the partition wall 58 as it flows into the mixing channel 46, while moving radially inward. Fuel is injected into the flow path 100 from fuel injection holes 53 formed on the side surface 44 of the protruding portion 50 that protrudes radially inward. As shown in Figures 6 and 12, the air flowing along the upstream end 61 of the partition wall 58 flows into the mixing channel 46 so as to enter between the fuel injected from the fuel injection hole 53 and the wall surface 55s of the channel wall 55 of the mixing channel 46. As a result, it becomes difficult for a region of high fuel concentration to form near the wall surface 55s of the channel wall 55. Consequently, the risk of flashback, which is a backfire from the outlet 47 of the mixing channel 46, can be suppressed.

[0047] Furthermore, in the burner assembly 32 configured in this way, the fuel injection holes 53 are formed in the introduction channel 110 at a position closer to the inlet 48 than to the upstream end 111. As a result, even if turbulent air flows into the introduction channel 110, it is straightened as it reaches the vicinity of the fuel injection holes 53 (the vicinity of the fuel jet) in the introduction channel 110. Therefore, the effect of turbulence in the airflow before it flows into the introduction channel 110 is suppressed, making it difficult for a region with low flow velocity and high fuel concentration to form near the fuel injection holes 53 (the vicinity of the fuel jet). As a result, the risk of flashback can be suppressed.

[0048] In one embodiment of the combustor 4, since it is equipped with the burner assembly 32 described above, the risk of flashback can be suppressed. Therefore, the combustor 4 can be used stably.

[0049] In one embodiment of the gas turbine 1, the combustor 4 is provided, thereby suppressing the risk of flashback and enabling stable operation of the gas turbine.

[0050] Figure 15 is a diagram illustrating the dimensions of various parts of the burner assembly 32 according to several embodiments. Figure 16 is a diagram illustrating the dimensions of various parts of the burner assembly 32 according to several embodiments. Figure 17 is a diagram illustrating variations in the shape of the protruding portion 50. Figure 18 is a cross-sectional view of portion XVIII enclosed by the dashed line in Figure 17, viewed from the upstream side in the direction of airflow. Figure 19 is a diagram corresponding to a cross-sectional view of portion XVIII enclosed by the dashed line in Figure 17, viewed from the upstream side in the direction of airflow, and shows another example. Figure 20 is a diagram illustrating variations in the shape of the protruding portion 50. Figure 21 is a cross-sectional view of portion XXI enclosed by the dashed line in Figure 20, viewed from the upstream side in the direction of airflow.

[0051] Figure 22 is a diagram illustrating modified examples of the introduction channel wall 115 and the channel wall 55. Figure 23 is a schematic diagram illustrating the extension direction of the fuel injection hole 53, showing a cross-section perpendicular to the central axis O. Figure 24 is a schematic diagram illustrating the extension direction of the fuel injection hole 53, showing a cross-section perpendicular to the central axis O. Figure 25 is a diagram showing another example of the projection 50 of the fuel nozzle 43, corresponding to the cross-sectional view taken along the XXV-XXV arrow in Figure 5.

[0052] (Regarding the dimensions of each part of the burner assembly 32) In some embodiments of the burner assembly 32, as shown in Figure 15, the first distance L1 in the direction of extension of the central axis O between the upstream end 111 of the flow path 100 and the center position of the opening 53ap in the projection 51 of the fuel injection hole 53 is preferably 1 or more times, more than 5 times, the inner diameter Dm of the mixing flow path 46 when viewed from the direction of extension of the central axis O. This allows for effective rectification of the airflow in the introduction channel 110, thereby effectively suppressing the risk of flashback. Furthermore, if the cross-sectional shape of the mixing channel 46, when viewed from the direction of extension of the central axis O, is other than a circle, the inner diameter Dm shall be the equivalent diameter of the mixing channel 46.

[0053] In some embodiments of the burner assembly 32, the second distance L2 in the extending direction between the inlet 48 of the mixing channel 46 and the upstream end 44u on the side surface 44 of the projection 50 is preferably 1 times or less the inner diameter Dm of the mixing channel 46 when viewed from the extending direction of the central axis O. This suppresses the length of the protrusion 51 along the extension direction of the central axis O, thereby preventing the generation of a low-speed region near the wall surface of the flow path 100. Furthermore, if the cross-sectional shape of the mixing channel 46, when viewed from the direction of extension of the central axis O, is other than a circle, the inner diameter Dm shall be the equivalent diameter of the mixing channel 46.

[0054] In some embodiments of the burner assembly 32, the third distance L3 in the direction of extension of the central axis O between the inlet 48 of the mixing channel 46 and the center position of the opening 53ap at the projection 51 of the fuel injection hole 53 is preferably greater than the opening diameter dap of the opening 53ap and smaller than the second distance L2.

[0055] As described above, when air flows from the introduction channel 110 into the mixing channel 46, the cross-sectional area of ​​the channel 100, when viewed from the direction of extension of the channel 100, becomes smaller. As a result, the air flowing from the introduction channel 110 into the mixing channel 46 creates a radially inward flow near the inlet 48 of the mixing channel 46. This makes it difficult for a region of high fuel concentration to form near the wall surface 55s of the mixing channel 46 when fuel is ejected from the fuel injection hole 53. Consequently, the risk of flashback can be suppressed. However, if the third distance L3 is less than or equal to the opening diameter dap of the opening 53ap, the fuel injection hole 53 will be too close to the mixing passage 46, making it difficult for air to enter between the fuel injected from the fuel injection hole 53 and the wall surface 55s of the passage wall 55 of the mixing passage 46. This may reduce the effect of this disclosure, which is that it is difficult for a region of high fuel concentration to form near the wall surface 55s of the mixing passage 46. Furthermore, if the third distance L3 is greater than or equal to the second distance L2, the fuel injection hole 53 will be too far upstream from the vicinity of the inlet 48 of the mixing channel 46, where airflow radially inward occurs. This may make it easier for a region of high fuel concentration to form near the inner wall of the introduction channel 110. According to the burner assembly 32 of several embodiments, the fuel ejected from the fuel injection hole 53 makes it difficult for regions of high fuel concentration to form near the inner walls of the introduction passage 110 and the mixing passage 46, thereby suppressing the risk of flashback.

[0056] In some embodiments of the burner assembly 32, the fourth distance L4 in the direction of extension of the central axis O from the upstream end 111 of the introduction channel 110 to the upstream end 51t of the projection 51 (see Figure 15) should be 0 or greater. This ensures the rectification effect of the air in the introduction channel 110 while suppressing the risk of flashback.

[0057] As shown in Figure 16, in several embodiments of the burner assembly 32, when the upstream end 51t of the projection 51 is located downstream of the upstream end 111 of the introduction channel 110, the inner diameter Du of at least a portion of the introduction channel 110 upstream of the said end 432t, when viewed from the direction of extension of the central axis O, may be equal to the value obtained by subtracting twice the thickness t1 of the partition wall portion 118 (118ab) separating the introduction channel 110 (110a) in the first channel 100a and the introduction channel 110 (110b) in the second channel 100b from the distance P between the central axis O of the introduction channel 110 (110a) in the first channel 100a and the central axis O of the introduction channel 110 (110b) in the second channel 100b (Du = P - 2 × t1). This allows the inner diameter Du of the introduction channel 110 to be adjusted by appropriately adjusting the thickness t1 of the partition wall 118 (118ab) separating the introduction channel 110 (110a) in the first channel 100a and the introduction channel 110 (110b) in the second channel 100b.

[0058] In some embodiments of the burner assembly 32, for example, as shown in Figure 7, the top surface 54 of the tip portion 432 may have an arc shape in a cross-section along the extending direction of the central axis O. That is, in some embodiments of the burner assembly 32, the convex curved surface 56 may be spherical. This makes it possible to suppress the distance from the upstream end 111 to the base end 431 of the introduction channel 110 while making it difficult to disturb the airflow from the tip end 432 to the base end 431, thus making it easier to ensure the effect of this disclosure, which is that it is difficult for a region of high fuel concentration to form near the wall surface 55s of the mixing channel 46.

[0059] In some embodiments of the burner assembly 32, the convex surface 56 may be a cone or a pyramidal surface, rather than a sphere. If the convex surface 56 is a cone or a pyramidal surface, it is preferable that the surface shape changes smoothly from the base end 431 to the cone or pyramidal surface. Furthermore, in some embodiments of the burner assembly 32, the convex surface 56 may be ogive-shaped, like the nose cone at the tip of a rocket, or it may be a surface of revolution of a quadratic curve such as a parabola.

[0060] In some embodiments of the burner assembly 32, for example, as shown in Figure 17, the top surface 54 of the tip portion 432 may have an elliptical arc shape in a cross-section along the extending direction of the central axis O. As a result, for example, if the major axis of the elliptical arc is aligned with the extension direction of the central axis O as shown in Figure 17, the airflow from the tip portion 432 to the base portion 431 can be made less disturbed compared to the case where the top surface 54 of the tip portion 432 has a circular arc shape in a cross-section along the extension direction as shown in Figure 7. Therefore, the effect of this disclosure, which is that a region of high fuel concentration is less likely to form near the wall surface 55s of the mixing channel 46, can be more easily ensured. Furthermore, if, for example, the minor axis of the elliptical arc is aligned with the extending direction of the central axis O, the distance from the upstream end 111 to the base end 431 of the introduction channel 110 can be suppressed compared to the case where the top surface 54 of the tip portion 432 has an arc shape in a cross-section along the extending direction as shown in Figure 7, thereby suppressing an increase in the overall length of the channel 100.

[0061] Furthermore, the shape of the projection 51 that protrudes into the introduction channel 110 of the tip portion 432 may be, for example, a circular shape when the cross-section appears in a plane perpendicular to the central axis O, as shown in Figure 18, or it may be a elliptical shape when the cross-section appears in a plane perpendicular to the central axis O, as shown in Figure 19. In the example shown in Figure 19, the vertex located on the major axis of the ellipse protrudes into the introduction channel 110, but the vertex located on the minor axis of the ellipse may also protrude into the introduction channel 110.

[0062] In some embodiments of the burner assembly 32, the projection 51 may have a shape other than a circle or ellipse in the cross-section that appears in the plane perpendicular to the central axis O where the base end portion 431 is perpendicular (Figure 21), as shown in Figures 20 and 21. For example, it may have a rectangular shape with rounded corners.

[0063] In some embodiments of the burner assembly 32, the protruding portion 50 may be hollow, having a space 50a inside which fuel can be stored, as shown in Figures 20, 21, and 23 to 25. Although not shown in Figures 9 and 10, as shown in Figure 25, a fuel plenum 55PL capable of storing fuel may be formed within the flow path wall 55 downstream of the protrusion 50 in the direction of airflow, communicating with the space 50a.

[0064] (Modifications for the introduction channel wall 115 and channel wall 55) As shown in Figure 22, a gap may be provided between the introduction channel wall 115 that forms the introduction channel 110 (110a) of the first burner 42a and the introduction channel wall 115 that forms the introduction channel 110 (110b) of the second burner 42b, and this gap may be used as a compressed air channel 119. Furthermore, a channel 55fp may be provided that connects the opening 55ap that opens into the wall surface 55s of the channel wall 55 that forms the mixing channel 46 to the channel 119, so that compressed air from the channel 119 can be ejected from the opening 55ap to cool the wall surface 55s of the channel wall 55. The position of the opening 55ap in the direction of the central axis O is preferably near the outlet 47 of the mixing channel 46 (see Figure 4).

[0065] (Regarding the extension direction of the fuel injection port 53) Each of the fuel injection holes 53 may extend in a direction perpendicular to the central axis O so as to inject fuel toward the central axis O of the flow path 100, for example, as shown in Figure 23. Furthermore, each of the fuel injection holes 53 may extend diagonally with respect to the direction perpendicular to the central axis O, as shown in Figure 24, for example. In the examples shown in Figures 23 and 24, each of the fuel injection holes 53 may extend along a plane perpendicular to the central axis O, or it may be inclined toward the downstream side in the direction of airflow, as shown in Figure 25.

[0066] (Other embodiments of the first region 101) For example, as shown in Figure 4, in the burner assembly 32 according to some of the embodiments described above, at the upstream end 111, which is the upstream end of the introduction channel 110 (the upstream end of the channel 100), the introduction channel wall 115 that forms the introduction channel 110 has a flat surface that extends in a direction perpendicular to the central axis O of the channel 100. The presence of such a flat surface carries the risk that air flowing from the outside along the direction of extension of the central axis O will collide with the flat surface, causing turbulence in the flow and leading to separation from the inner circumferential surface near the inlet of the introduction channel 110. However, even if some turbulence in the airflow occurs, in the burner assembly 32 according to some of the embodiments described above, the air is straightened as it flows through the introduction channel 110, reducing the risk of flashback.

[0067] In the burner assembly 32 of the other embodiment described below, an inlet region 112 is provided in the introduction channel 110, which is configured as described later, so that the airflow is smooth when air flows into the introduction channel 110. Figure 26 is a schematic diagram showing a portion of the burner assembly 32 relating to a modified example of the first region 101, viewed from the upstream side in the direction of airflow along the central axis L. Figure 27 is a schematic cross-sectional view of the first region 101 (inlet channel 110) that appears in the cross-section containing the central axis O of the channel 100, and shows either the AA or BB cross-section of Figure 26. Figure 28 is a schematic cross-sectional view of the first region 101 (inlet channel 110) that appears in the cross-section containing the central axis O of the channel 100, and shows either the AA or BB cross-section of Figure 26. Figure 29 is a schematic cross-sectional view of the first region 101 (inlet channel 110) that appears in the cross-section containing the central axis O of the channel 100, and shows either the AA or BB cross-section of Figure 26. Note that the radius of curvature R, which will be discussed later, differs between Figures 27, 28, and 29.

[0068] In the burner assembly 32 of another embodiment, the introduction channels 110 are arranged at equal intervals along, for example, a first direction Dr1 perpendicular to the extending direction of the channel 100 (the extending direction of the central axis O), and a second direction Dr2 perpendicular to the extending direction of the central axis O and the first direction Dr1. As shown in Figure 26, in the burner assembly 32 according to another embodiment, the introduction channel 110 is such that the inner circumferential surfaces (inner wall surfaces 115Is) of adjacent introduction regions 113, which will be described later, are separated by a distance La in the first direction Dr1. For the sake of explanation, in the burner assembly 32 of the other embodiment, the introduction channel 110 is assumed to have the inner wall surfaces 115Is of adjacent introduction regions 113 separated by a distance La or more in the second direction Dr2. In the burner assembly 32 according to other embodiments, the third direction Dr3 is defined as a direction that extends in a direction different from the first and second directions and is perpendicular to the direction of extension of the central axis O. In the burner assembly 32 according to another embodiment, the introduction channel 110 is configured such that the inner wall surfaces 115Is of adjacent introduction regions 113 in the third direction Dr3 are separated by a distance Lb. In this case, the angle difference between the first direction Dr1 and the third direction Dr3 is between 45 degrees and less than 90 degrees, because the inner wall surfaces 115Is of adjacent introduction regions 113 in the second direction Dr2 are separated by a distance La or more.

[0069] In another embodiment, the introduction channel 110 includes an inlet region 112 including an upstream end 111, and an introduction region 113 downstream of the inlet region 112 and connected to the inlet region 112. The inlet region 112 is defined, for example, by an inner wall surface 112Is formed in a curved shape that is convex toward the inside of the first region 101 in a cross-section along the extension direction of the flow path 100 (the extension direction of the central axis O), as shown in Figures 27 to 29 and the figures described later, and is formed so that the cross-sectional area of ​​the flow path 100 gradually decreases toward the downstream side. In the introduction channel 110 according to another embodiment, the inlet region 112 is configured such that, for example, in a cross section along the extending direction of the central axis O, the position of the center of curvature (center of curvature) Ca of the inner wall surface 112Is is set such that the inner wall surface 112Is is convex toward the inside of the first region 101.

[0070] The introduction region 113 is defined in a cross-section along the extension direction of the central axis O (axis O direction) by an inner wall surface formed in a straight line parallel to the extension direction of the central axis O, i.e., the inner wall surface 115Is of the introduction channel wall 115. In other words, the inner circumferential surface of the introduction region 113 is the inner wall surface 115Is of the introduction channel wall 115. The introduction region 113 has a configuration similar to that of the introduction channel 110 in some of the embodiments described above. The downstream side of the introduction region 113 is connected to the mixing channel 46 and the inlet 48 of the mixing channel 46 (see, for example, Figures 6 and 12), similar to some of the embodiments described above. In other words, the introduction channel 110 in other embodiments is configured such that an inlet region 112 is added to the upstream side of the introduction channel 110 in some of the embodiments described above.

[0071] In another embodiment, the entrance region 112 and the introduction region 113 are connected at their connection point 114. At the connection point 114, the inner wall surface 112Is defining the entrance region 112 and the inner wall surface 115Is defining the introduction region 113 are smoothly connected without any steps around the entire circumference of the connection point 114. In other embodiments of the introduction channel 110, in a cross section along the extending direction of the central axis O (axis O direction), the position of the curvature center Ca in the axis O direction for at least the inner wall surface 112Is near the connection position 114 among the inner wall surfaces 112Is that define the inlet region 112 is set to coincide with the position of the connection position 114 in the axis O direction. By setting the position of the curvature center Ca in the direction of axis O in this way, the tangential direction of the inner wall surface 112Is at connection position 114 coincides with the direction of axis O in a cross section along the extension direction of the central axis O (axis O direction). As a result, the inner wall surface 112Is defining the entrance region 112 and the inner wall surface 115Is defining the introduction region 113 can be smoothly connected around the entire circumference of connection position 114.

[0072] (Regarding the size of the radius of curvature R and the shape of the inner wall surface 112Is) For example, Figure 27 shows the case where the radius of curvature R in the cross-section shown in Figure 27 is 0.5 times the distance L (e.g., distance La, distance Lb) between adjacent inner wall surfaces 115Is of the introduction region 113 in the cross-section (R = 0.5 × L). In this case, the inner wall surface 112Is defining the entrance region 112 has a semi-circular shape and is smoothly connected at the connection position 114 to the inner wall surfaces 115Is of the two adjacent introduction regions 113 in the cross-section.

[0073] For example, Figure 28 shows the case where the radius of curvature R in the cross-section shown in Figure 28 is less than 0.5 times the distance L between adjacent inner wall surfaces 115Is of the introduction regions 113 in that cross-section (R < 0.5 × L). In this case, the inner wall surface 112Is of the entrance area 112, which is connected to the inner wall surface 115Is of the left-hand introduction area 113 in the cross-section shown above, is smoothly connected at the connection position 114. Similarly, the inner wall surface 115Is of the entrance area 112, which is connected to the inner wall surface 115Is of the right-hand introduction area 113 in the cross-section shown above, is smoothly connected at the connection position 114.

[0074] In this case, the inner wall surface 112Is of the entrance region 112 on the left side of the figure and the inner wall surface 112Is of the entrance region 112 on the right side of the figure cannot be connected while maintaining their radius of curvature, or even if they can be connected, the connection portion will have a shape that appears to drop downstream. Therefore, if the radius of curvature R is less than 0.5 times the distance L (R < 0.5 × L), the upstream end 111 is constructed with a flat surface 112p, and the inner wall surface 112Is of the entrance region 112 on the left side of the diagram and the inner wall surface 112Is of the entrance region 112 on the right side of the diagram are smoothly connected to the flat surface 112p. In this case, the distance in the direction of axis O between the flat surface 112p and the connection position 114 is equal to the radius of curvature R.

[0075] For example, Figure 29 shows the case where the radius of curvature R in the cross-section shown in Figure 29 exceeds 0.5 times the distance L between adjacent inner wall surfaces 115Is of the introduction region 113 in that cross-section (R > 0.5 × L). In this case, the inner wall surface 112Is of the entrance area 112, which is connected to the inner wall surface 115Is of the left-hand introduction area 113 in the cross-section shown above, is smoothly connected at the connection position 114. Similarly, the inner wall surface 115Is of the entrance area 112, which is connected to the inner wall surface 115Is of the right-hand introduction area 113 in the cross-section shown above, is smoothly connected at the connection position 114. Then, the inner wall surface 112Is of the entrance area 112 on the left side of the diagram is connected to the inner wall surface 112Is of the entrance area 112 on the right side of the diagram. In this case, the connection portion 112c between the inner wall surface 112Is of the entrance region 112 on the left side of the figure and the inner wall surface 112Is of the entrance region 112 on the right side of the figure has a pointed shape in the cross-section shown in Figure 29.

[0076] In Figure 29, the dashed arcs extending from the connection portion 112c are hypothetical lines representing the extension of the inner wall surface 112Is of the entrance region 112 on the left side of the figure to the right side, and hypothetical lines representing the extension of the inner wall surface 112Is of the entrance region 112 on the right side of the figure to the left side, both of which are arcs with a radius of curvature R. The same applies to Figures 32A, 33A, and 33B, which will be described later.

[0077] Regarding the entrance region 112 configured in this way, we will now describe several examples in which the relationship between the distances La and Lb and the radius of curvature R is changed. Note that distance Lb is greater than distance La.

[0078] (When R < 0.5 × La) We will now explain the case where the radius of curvature R is constant over the entire circumference of the entrance region 112 and is less than 0.5 times the distance La (R < 0.5 × La). Figure 30A is a schematic cross-sectional view showing section AA in Figure 26, where the radius of curvature R is less than 0.5 times the distance La (R < 0.5 × La). Figure 30B is a schematic cross-sectional view showing the BB section in Figure 26 when the radius of curvature R is less than 0.5 times the distance La (R < 0.5 × La).

[0079] When the radius of curvature R is less than 0.5 times the distance La (R < 0.5 × La), the shape of the inlet region 112 in both the AA section and the BB section in Figure 26 will be the same as the shape shown in Figure 28. That is, when the radius of curvature R is less than 0.5 times the distance La (R < 0.5 × La), the upstream end 111 in both the AA section and the BB section in Figure 26 will be composed of a flat surface 112p. In other words, when the radius of curvature R is less than 0.5 times the distance La (R < 0.5 × La), the inlet region 112 will be surrounded by a flat surface 112p around its entire circumference.

[0080] However, when the radius of curvature R is less than 0.5 times the distance La (R < 0.5 × La), except for the flat surface 112p, the inlet region 112 is formed by an inner wall surface 112Is having a curve with radius of curvature R in a cross section along the axis O direction. Therefore, when air flows into the inlet region 112, it is easier for the air to be guided into the inlet region 112, making it less likely for air to separate from the inner circumferential surfaces (inner wall surface 112Is, inner wall surface 115Is) of the inlet region 112 and introduction region 113. This reduces pressure loss in the first region 101 (introduction channel 110) and also reduces flow deviation in the first region 101 (introduction channel 110). Thus, the risk of flashback can be suppressed even more effectively.

[0081] (When R = 0.5 × La) We will now explain the case where the radius of curvature R is constant over the entire circumference of the entrance region 112 and is 0.5 times the distance La (R = 0.5 × La). Figure 31A is a schematic cross-sectional view showing section AA in Figure 26, where the radius of curvature R is 0.5 times the distance La (R = 0.5 × La). Figure 31B is a schematic cross-sectional view showing the BB section in Figure 26 when the radius of curvature R is 0.5 times the distance La (R = 0.5 × La).

[0082] In other words, in the burner assembly 32 according to other embodiments, in each of the inlet regions 112, the inner circumferential surface (inner wall surface 112Is) of the inlet region 112 that appears in the cross-section of the inlet region 112 along the axis O direction may be formed in a curved shape having a radius of curvature R that is 0.5 times the distance La between the inner circumferential surfaces (inner wall surfaces 115Is) of adjacent introduction regions 113 in the first direction Dr1.

[0083] When the radius of curvature R is 0.5 times the distance La (R = 0.5 × La), the shape of the entrance region 112 in the AA section in Figure 26 is the same as the shape shown in Figure 27. That is, when the radius of curvature R is 0.5 times the distance La (R = 0.5 × La), in the AA section in Figure 26, the inner wall surface 112Is defining the entrance region 112 has a semi-circular shape, and is smoothly connected to the inner wall surfaces 115Is of the two adjacent introduction regions 113 in the above section at the connection position 114.

[0084] When the radius of curvature R is 0.5 times the distance La (R = 0.5 × La), the shape of the inlet region 112 in the BB cross-section in Figure 26 is the same as the shape shown in Figure 28. That is, when the radius of curvature R is 0.5 times the distance La (R = 0.5 × La), the upstream end 111 in the BB cross-section in Figure 26 is composed of a flat surface 112p.

[0085] When the radius of curvature R is 0.5 times the distance La (R = 0.5 × La), the shape of the inlet region 112 in the AA cross-section in Figure 26 is the same as the shape shown in Figure 27, and except for the flat surface 112p, the inlet region 112 is formed by an inner wall surface 112Is having a curve with a radius of curvature R in a cross-section along the axis O direction. Therefore, when air flows into the inlet region 112, it is easier for the air to be guided into the inlet region 112, making it less likely for air to separate from the inner circumferential surfaces (inner wall surface 112Is, inner wall surface 115Is) of the inlet region 112 and introduction region 113. As a result, pressure loss in the first region 101 (introduction channel 110) can be reduced, and flow deviation in the first region 101 (introduction channel 110) can be reduced. Thus, the risk of flashback can be suppressed even more effectively.

[0086] (When R = 0.5 × Lb) We will now explain the case where the radius of curvature R is constant over the entire circumference of the entrance region 112 and is 0.5 times the distance Lb (R = 0.5 × Lb). Figure 32A is a schematic cross-sectional view showing section AA in Figure 26, where the radius of curvature R is 0.5 times the distance Lb (R = 0.5 × Lb). Figure 32B is a schematic cross-sectional view showing the BB section in Figure 26 when the radius of curvature R is 0.5 times the distance Lb (R = 0.5 × Lb).

[0087] In other words, in the burner assembly 32 according to the other embodiment, in each of the inlet regions 112, the inner circumferential surface (inner wall surface 112Is) of the inlet region 112 that appears in the cross-section of the inlet region 112 along the axis O direction may be formed in a curved shape having a radius of curvature R that is 0.5 times the distance Lb between the inner circumferential surfaces (inner wall surfaces 115Is) of adjacent introduction regions 113 in the third direction Dr3 perpendicular to the axis O direction.

[0088] When the radius of curvature R is 0.5 times the distance Lb (R = 0.5 × Lb), the shape of the entrance region 112 in the AA section in Figure 26 is the same as the shape shown in Figure 29. That is, when the radius of curvature R is 0.5 times the distance Lb (R = 0.5 × Lb), the connection portion 112c has a pointed shape in the AA section in Figure 26.

[0089] When the radius of curvature R is 0.5 times the distance Lb (R = 0.5 × Lb), the shape of the entrance region 112 in the BB cross section in Figure 26 is the same as the shape shown in Figure 27. That is, when the radius of curvature R is 0.5 times the distance Lb (R = 0.5 × Lb), in the BB cross section in Figure 26, the inner wall surface 112Is defining the entrance region 112 has a semi-circular shape, and is smoothly connected to the inner wall surfaces 115Is of the two adjacent introduction regions 113 in the above cross section at connection position 114.

[0090] When the radius of curvature R is 0.5 times the distance Lb (R = 0.5 × Lb), the shape of the inlet region 112 in the BB cross section in Figure 26 becomes the same as the shape shown in Figure 27, and a flat surface 112p is not formed around the entire circumference of the inlet region 112. Therefore, when air flows into the inlet region 112, it is easier for the air to be guided into the inlet region 112, making it less likely for air to separate from the inner circumferential surfaces (inner wall surfaces 112Is, inner wall surfaces 115Is) of the inlet region 112 and the introduction region 113. In particular, in the BB cross section shown in Figure 26, where the distance L between the inner wall surfaces 115Is of two adjacent inlet regions 113 is largest, the shape of the inlet region 112 becomes similar to the shape shown in Figure 27. As a result, when air flows into the inlet region 112, it is easier for the air to be guided into the inlet region 112. This reduces the pressure loss in the first region 101 (inlet channel 110) and also reduces the flow deviation in the first region 101 (inlet channel 110). Therefore, the risk of flashback can be suppressed even more effectively.

[0091] (When R > 0.5 × Lb) We will now describe the case where the radius of curvature R is constant over the entire circumference of the entrance region 112 and exceeds 0.5 times the distance Lb (R > 0.5 × Lb). Figure 33A is a schematic cross-sectional view showing section AA in Figure 26 when the radius of curvature R exceeds 0.5 times the distance Lb (R > 0.5 × Lb). Figure 33B is a schematic cross-sectional view showing the BB section in Figure 26 when the radius of curvature R exceeds 0.5 times the distance Lb (R > 0.5 × Lb).

[0092] In other words, in the burner assembly 32 according to other embodiments, in each of the inlet regions 112, the inner circumferential surface (inner wall surface 112Is) of the inlet region 112 that appears in the cross-section of the inlet region 112 along the axis O direction may be formed in a curved shape having a radius of curvature R that exceeds 0.5 times the distance Lb between the inner circumferential surfaces (inner wall surfaces 115Is) of adjacent introduction regions 113 in the third direction Dr3 perpendicular to the axis O direction.

[0093] When the radius of curvature R exceeds 0.5 times the distance Lb (R > 0.5 × Lb), the shape of the inlet region 112 in both the AA section and the BB section in Figure 26 will be the same as the shape shown in Figure 29. That is, when the radius of curvature R exceeds 0.5 times the distance Lb (R > 0.5 × Lb), the connecting portion 112c has a pointed shape in both the AA section and the BB section in Figure 26. In other words, when the radius of curvature R exceeds 0.5 times the distance Lb (R > 0.5 × Lb), the inlet region 112 will be surrounded by a connecting portion 112c with a pointed shape around its entire circumference. Therefore, when the radius of curvature R exceeds 0.5 times the distance Lb (R > 0.5 × Lb), a flat surface 112p is not formed.

[0094] When the radius of curvature R exceeds 0.5 times the distance Lb (R > 0.5 × Lb), a flat surface 112p is not formed around the entire circumference of the inlet region 112. As a result, when air flows into the inlet region 112, it is easier for the air to be guided into the inlet region 112, making it less likely for air to separate from the inner surfaces (inner wall surfaces 112Is, inner wall surfaces 115Is) of the inlet region 112 and the introduction region 113.

[0095] (When the formation of a flat surface 112p and a connecting portion 112c having a pointed shape is avoided around the entire circumference of the entrance region 112) This section describes a case where the formation of a flat surface 112p and a connecting portion 112c having a pointed shape is avoided around the entire circumference of the inlet region 112, that is, the shape of the inlet region 112 is the same as the shape shown in Figure 27 around the entire circumference of the inlet region 112. Figure 34A is a schematic cross-sectional view showing section AA in Figure 26, in which the formation of a flat surface 112p and a connecting portion 112c having a pointed shape is avoided around the entire circumference of the inlet region 112. Figure 35B is a schematic cross-sectional view showing the BB section in Figure 26, in a case where the formation of a flat surface 112p and a connecting portion 112c having a pointed shape is avoided around the entire circumference of the inlet region 112.

[0096] In order to avoid the formation of a flat surface 112p and a pointed connecting portion 112c around the entire circumference of the entrance region 112, the radius of curvature R should be set such that in any cross section including the central axis O, the radius of curvature R is 0.5 times the distance L between adjacent inner wall surfaces 115Is of the introduction region 113 in that cross section (R = 0.5 × L), that is, the relationship R = 0.5 × L should be held around the entire circumference.

[0097] In each embodiment described using Figures 30A to 34B, the inner wall surface 112Is of the entrance region 112, as shown in the cross-section including the central axis O, had a constant radius of curvature R from the connection position 141 to the upstream end 111. However, the radius of curvature R may be made to change from the connection position 141 to the upstream end 111.

[0098] Figure 35A is a schematic cross-sectional view showing section AA in Figure 26, where the shape of the inner wall surface 112Is of the entrance region 112, as seen in the cross-section including the central axis O around the entire circumference of the entrance region 112, is an elliptical shape with a major axis parallel to the direction of axis O. Figure 35B is a schematic cross-sectional view showing the BB section in Figure 26, where the shape of the inner wall surface 112Is of the entrance region 112, as seen in the cross-section including the central axis O around the entire circumference of the entrance region 112, is an elliptical shape with a major axis parallel to the direction of axis O. As shown in Figures 35A and 35B, the shape of the inner wall surface 112Is of the entrance region 112, as seen in the cross-section including the central axis O over the entire circumference of the entrance region 112, may be, for example, an elliptical shape having a major axis parallel to the direction of axis O. Furthermore, as shown in Figures 35A and 35B, if the shape of the inner wall surface 112Is of the entrance region 112, as shown in the cross-section including the central axis O, is to be an ellipse with a major axis parallel to the direction of axis O, then it is preferable that the radius of the major axis be at least three times the distance L.

[0099] In the embodiments described using Figures 26 to 34B, the first direction Dr1 and the second direction were orthogonal, but they do not necessarily have to be orthogonal.

[0100] This disclosure is not limited to the embodiments described above, but also includes modified forms of the embodiments described above, as well as forms that combine these forms as appropriate. For example, in the embodiment described above, each burner 42 includes one intake channel 110, one mixing channel 46, and four fuel nozzles 43 arranged around the one mixing channel 46, and fuel is injected into the one mixing channel 46 from the surrounding four fuel nozzles 43. However, each burner 42 may have only one fuel nozzle 43, or at least one fuel nozzle 43.

[0101] The contents described in each of the above embodiments can be understood, for example, as follows: (1) A burner assembly 32 according to at least one embodiment of the present disclosure is a burner assembly 32 comprising a plurality of burners 42 for mixing fuel and air. Each of the plurality of burners 42 is provided with a flow path 100 through which air can flow. The flow path 100 includes a first region 101 (inlet flow path 110) which is an upstream region of the airflow and in which fuel injection holes (fuel injection holes 53) are formed, and a second region 102 (mixing flow path 46) which is a region downstream of the first region 101 (inlet flow path 110) in which the fuel injected from the injection holes (fuel injection holes 53) and air are mixed. The first region 101 (inlet flow path 110) extends from the upstream end 111 of the flow path 100 to the connection point (inlet 48) with the second region 102 (mixing flow path 46). In the first region 101 (inlet channel 110), an injection hole (fuel injection hole 53) is formed at a position closer to the connection position (inlet 48) than to the upstream end 111. The first region 101 (inlet channel 110) has at least one projection 51 that protrudes radially inward from the channel 100 and has an injection hole (fuel injection hole 53) formed thereon, and at least one circumferential wall portion 116 adjacent to at least one projection 51 in the circumferential direction of the channel 100, and where no projection 51 is provided. When viewed from the extending direction of the channel 100, the cross-sectional area of ​​the channel 100 is smaller in the second cross-sectional area S2 in the second region 102 (mixing channel 46) than in the first cross-sectional area S1 in the first region 101 (inlet channel 110).

[0102] According to the configuration described in (1) above, when air flows from the first region 101 (inlet channel 110) to the second region 102 (mixing channel 46), the cross-sectional area of ​​the channel 100, as viewed from the direction of extension of the channel 100, becomes smaller. As a result, the air flowing from the first region 101 (inlet channel 110) to the second region 102 (mixing channel 46) generates a radially inward flow near the connection point (inlet 48). This makes it difficult for a region with a high fuel concentration to form near the inner wall (wall surface 55s) of the second region 102 (mixing channel 46). Consequently, the risk of flashback, which is a backfire from the outlet 47 of the second region 102 (mixing channel 46), can be suppressed. Furthermore, according to the configuration of (1) above, the fuel injection port (fuel injection port 53) is formed in the first region 101 (inlet channel 110) at a position closer to the connection position (inlet 48) than to the upstream end 111. As a result, even if turbulent air flows into the first region 101 (inlet channel 110), it is rectified in the process of reaching the vicinity of the injection port (fuel injection port 53) (near the fuel jet) in the first region 101 (inlet channel 110). Therefore, the effect of turbulence in the airflow before it flows into the first region 101 (inlet channel 110) is suppressed, making it difficult for a region with low flow velocity and high fuel concentration to form near the injection port (fuel injection port 53) (near the fuel jet). As a result, the risk of flashback can be suppressed.

[0103] (2) In some embodiments, in the configuration of (1) above, the first distance L1 in the extending direction between the upstream end 111 of the flow path 100 and the center position of the opening 53ap in the projection 51 of the injection hole (fuel injection hole 53) is preferably 1 or more times the equivalent diameter (inner diameter Dm) of the second region 102 (mixing flow path 46) when viewed from the extending direction.

[0104] According to the configuration described in (2) above, the air can be effectively rectified in the first region 101 (introduction channel 110), thereby effectively suppressing the risk of flashback.

[0105] (3) In some embodiments, in the configuration of (2) above, the first distance L1 is preferably 5 times or more the equivalent diameter (inner diameter Dm).

[0106] According to the configuration described in (3) above, the air can be more effectively rectified in the first region 101 (introduction channel 110), thereby more effectively suppressing the risk of flashback.

[0107] (4) In some embodiments, in any of the configurations (1) to (3) above, the projection 51 may include, in a cross section along the extending direction, a straight portion (base end portion 431) that extends linearly along the extending direction, and a tip portion 432 formed upstream of the straight portion (base end portion 431) such that the amount of projection radially inward gradually increases toward the straight portion (base end portion 431).

[0108] According to the configuration of (4) above, the tip portion 432 is formed such that the amount of radial inward protrusion gradually increases as it approaches the straight portion (base portion 431) upstream of the straight portion (base portion 431), so that separation of the airflow from the tip portion 432 toward the straight portion (base portion 431) can be suppressed. Therefore, it is less likely that a region with low flow velocity and high fuel concentration will form near the injection hole (fuel injection hole 53) (near the fuel jet). As a result, the risk of flashback can be suppressed.

[0109] (5) In some embodiments, in the configuration of (4) above, the second distance L2 in the extending direction between the connection position (inlet 48) and the upstream end 44u of the straight section (base end 431) is preferably 1 or less of the equivalent diameter (inner diameter Dm) of the second region 102 (mixing channel 46) when viewed from the extending direction.

[0110] According to the configuration in (5) above, it is possible to suppress the length of the protrusion 51 along the extending direction and to suppress the occurrence of a low-speed region near the wall surface of the flow path 100.

[0111] (6) In some embodiments, in the configuration of (4) or (5) above, the third distance L3 in the extending direction between the connection position (inlet 48) and the center position of the opening 53ap at the projection 51 of the injection hole (fuel injection hole 53) is preferably greater than the opening diameter dap of the opening 53ap and smaller than the second distance L2 in the extending direction between the connection position (inlet 48) and the upstream end 44u at the straight section (base end 431).

[0112] According to the configuration described in (6) above, the fuel ejected from the injection port (fuel injection port 53) makes it difficult for regions with high fuel concentration to form near the inner walls of the first region 101 (inlet passage 110) and the second region 102 (mixing passage 46), thereby suppressing the risk of flashback.

[0113] (7) In some embodiments, in any of the configurations (4) to (6) above, the surface (top surface 54) of the tip portion 432 may have an arc shape in a cross section along the extending direction.

[0114] According to the configuration of (7) above, the distance from the upstream end 111 of the flow path 100 to the straight section (base end 431) can be suppressed, and the airflow from the tip 432 to the straight section (base end 431) can be made less disturbed, making it easier to ensure the effect of this disclosure, which is that a region with a high fuel concentration is less likely to form near the inner wall (wall surface 55s) of the second region 102 (mixing flow path 46).

[0115] (8) In some embodiments, in any of the configurations (4) to (6) above, the surface (top surface 54) of the tip portion 432 may have an elliptical arc shape in a cross section along the extending direction.

[0116] According to the configuration of (8) above, for example, if the major axis of the elliptical arc is aligned with the extension direction of the flow path 100, the airflow from the tip portion 432 to the straight portion (base portion 431) can be made less disturbed compared to the case where the surface (top surface 54) of the tip portion 432 has an arc shape in a cross-section along the extension direction. This makes it easier to ensure the effect of this disclosure, which is that a region with a high fuel concentration is less likely to form near the inner wall (wall surface 55s) of the second region 102 (mixing flow path 46). Furthermore, if, for example, the minor axis of the elliptical arc is aligned with the extension direction of the flow channel 100, the distance from the upstream end 111 to the straight section (base end 431) of the flow channel 100 can be suppressed compared to the case where the surface (top surface 54) of the tip 432 has an arc shape in a cross-section along the extension direction, thereby suppressing an increase in the overall length of the flow channel 100.

[0117] (9) In some embodiments, in any of the configurations (4) to (8) above, the fourth distance L4 in the extending direction from the upstream end 111 of the flow path 100 to the upstream end 51t of the projection 51 should be 0 or greater.

[0118] According to the configuration described in (9) above, the risk of flashback can be suppressed while ensuring the rectification effect of the air in the first region 101 (introduction channel 110).

[0119] (10) In some embodiments, in any of the configurations (1) to (9) above, the first region 101 (inlet channel 110) may include an inlet region 112 including an upstream end 111, and an inlet region 113 connected to the inlet region 112 downstream of the inlet region 112. The inlet region 112 may be defined by an inner wall surface (inner wall surface 112Is) formed in a curved shape that is convex toward the inside of the first region 101 (inlet channel 110) in a cross section along the extending direction (axis O direction), and may be formed such that the cross-sectional area of ​​the channel 100 gradually decreases toward the downstream side. The inlet region 113 may be defined by an inner wall surface (inner wall surface 115Is) formed in a straight line parallel to the extending direction (axis O direction) in a cross section along the extending direction (axis O direction).

[0120] According to the configuration of (10) above, when air flows into the inlet region 112, the air is more easily guided into the inlet region 112, making it less likely for air to separate from the inner circumferential surfaces (inner wall surface 112Is, inner wall surface 115Is) of the inlet region 112 and introduction region 113. As a result, pressure loss in the first region 101 (introduction channel 110) can be reduced, and flow deviation in the first region 101 (introduction channel 110) can be reduced. Therefore, the risk of flashback can be suppressed even more effectively.

[0121] (11) In some embodiments, in the configuration of (10) above, the flow channels 100 may be arranged in multiple equal intervals along a first direction Dr1 perpendicular to the extending direction (axis O direction) and a second direction Dr2 perpendicular to the extending direction (axis O direction) and the first direction Dr1. In each of the inlet regions 112, the inner circumferential surface (inner wall surface 112Is) of the inlet region 112 that appears in the cross-section of the inlet region 112 along the extending direction (axis O direction) may be formed in a curved shape having a radius of curvature R that is 0.5 times the distance La between the inner circumferential surfaces (inner wall surfaces 115Is) of adjacent introduction regions 113 in the first direction Dr1.

[0122] According to the configuration described in (11) above, when air flows into the inlet region 112, the air is more easily guided into the inlet region 112, making it less likely for air to separate from the inner circumferential surfaces (inner wall surface 112Is, inner wall surface 115Is) of the inlet region 112 and introduction region 113. As a result, pressure loss in the first region 101 (introduction channel 110) can be reduced, and flow deviation in the first region 101 (introduction channel 110) can be reduced. Therefore, the risk of flashback can be suppressed even more effectively.

[0123] (12) In some embodiments, in the configuration of (10) above, the flow channels 100 may be arranged in multiple equal intervals along a first direction Dr1 perpendicular to the extending direction (axis O direction) and a second direction Dr2 perpendicular to the extending direction (axis O direction) and the first direction Dr1. In each of the inlet regions 112, the inner circumferential surface (inner wall surface 112Is) of the inlet region 112 that appears in the cross-section of the inlet region 112 along the extending direction (axis O direction) may be formed in a curved shape having a radius of curvature R that is 0.5 times the distance Lb between the inner circumferential surfaces (inner wall surfaces 115Is) of adjacent introduction regions 113 in a third direction Dr3 perpendicular to the extending direction (axis O direction).

[0124] According to the configuration described in (12) above, when air flows into the inlet region 112, the air is more easily guided into the inlet region 112, making it less likely for air to separate from the inner circumferential surfaces (inner wall surface 112Is, inner wall surface 115Is) of the inlet region 112 and introduction region 113. As a result, pressure loss in the first region 101 (introduction channel 110) can be reduced, and flow deviation in the first region 101 (introduction channel 110) can be reduced. Therefore, the risk of flashback can be suppressed even more effectively.

[0125] (13) In some embodiments, in the configuration of (10) above, the flow channels 100 may be arranged in multiple equal intervals along a first direction Dr1 perpendicular to the extending direction (axis O direction) and a second direction Dr2 perpendicular to the extending direction (axis O direction) and the first direction Dr1. In each of the inlet regions 112, the inner circumferential surface (inner wall surface 112Is) of the inlet region 112 that appears in the cross-section of the inlet region 112 along the extending direction (axis O direction) may be formed in a curved shape having a radius of curvature R that exceeds 0.5 times the distance Lb between the inner circumferential surfaces (inner wall surfaces 115Is) of adjacent introduction regions 113 in a third direction Dr3 perpendicular to the extending direction (axis O direction).

[0126] According to the configuration described in (13) above, when air flows into the inlet region 112, the air is more easily guided into the inlet region 112, making it less likely for air to separate from the inner circumferential surfaces (inner wall surface 112Is, inner wall surface 115Is) of the inlet region 112 and introduction region 113. As a result, pressure loss in the first region 101 (introduction channel 110) can be reduced, and flow deviation in the first region 101 (introduction channel 110) can be reduced. Therefore, the risk of flashback can be suppressed even more effectively.

[0127] (14) In some embodiments, in any of the configurations (1) to (9) above, the flow path 100 may include a first flow path 100a and a second flow path 100b that is closest to the first flow path 100a. The upstream end 51t of the projection 51 is preferably located downstream of the upstream end 111 of the flow path 100. The diameter (inner diameter Du) of at least a portion of the first region 101 (introduction channel 110) upstream of the upstream end 51t of the protrusion 51, when viewed from the extension direction, may be equal to the value obtained by subtracting twice the thickness t1 of the partition wall (partition wall portion 118 (118ab)) separating the first region 101 (introduction channel 110 (110a)) in the first channel 100a from the distance P between the central axis (central axis O) along the extension direction of the first region 101 (introduction channel 110 (110b)) in the second channel 100b (Du = P - 2 × t1).

[0128] According to the configuration of (14) above, the inner diameter Du of the introduction channel 110 can be adjusted by appropriately adjusting the thickness t1 of the partition wall (partition wall portion 118 (118ab)) separating the introduction channel 110 (110a) in the first channel 100a and the introduction channel 110 (110b) in the second channel 100b.

[0129] (15) A gas turbine combustor (combustor 4) according to at least one embodiment of the present disclosure comprises a burner assembly 32 having any of the configurations described in (1) to (14) above, and a combustion cylinder 25 that forms a space for flame formation downstream of the burner assembly 32.

[0130] According to the configuration of (15) above, the burner assembly 32 is provided with any of the configurations of (1) to (14) above, thus suppressing the risk of flashback. Therefore, the gas turbine combustor (combustor 4) can be used stably.

[0131] (16) A gas turbine 1 according to at least one embodiment of the present disclosure comprises a compressor 2, a gas turbine combustor (combustor 4) to which compressed air and fuel are supplied by the compressor 2 and configured to burn the fuel to generate combustion gas, and a turbine 6 driven by the combustion gas generated in the gas turbine combustor (combustor 4). The gas turbine combustor (combustor 4) is the gas turbine combustor (combustor 4) configured as described in (15) above.

[0132] According to the configuration of (16) above, since the gas turbine combustor (combustor 4) is provided as configured in (15) above, the risk of flashback is suppressed and the gas turbine 1 can be operated stably. [Explanation of symbols]

[0133] 1 Gas Turbine 2 Compressor 4. Combustor (Gas Turbine Combustor) 6 Turbines 25 Combustion chamber 32 burner assemblies 42 burners 42a First Burner 42b Second Burner 43 Fuel nozzle 44 Side view 44u end 46 Mixing channel 47 Exit 48 Entrance 50 Protrusion 51 Protrusion 51t end 53 Fuel injection hole 53ap aperture 54 Top surface 55 Flow channel wall 55s Wall 58 Bulkhead 61 End 100 channels 100a First channel 100b Second channel 101 First area 102 Second area 110 Inlet channel 111 Upstream end 112 Entrance area 113 Introduction area 115 Inlet channel wall 116 Peripheral wall section 118 Bulkhead 431 Proximal end 432 Tip

Claims

1. A burner assembly comprising multiple burners for mixing fuel and air, Each of the plurality of burners is provided with a passage through which the air can flow, The aforementioned flow path is A first region is formed in the upstream region of the airflow, and the fuel injection holes are formed in the first region. The region includes a second region downstream of the first region where the fuel injected from the injection hole and the air are mixed, The first region is, It extends from the upstream end of the flow channel to the connection point with the second region, The injection holes are formed at a position closer to the connection position than the upstream end, At least one projection that protrudes radially inward from the flow path and in which the injection hole is formed, In the circumferential direction of the flow path, there is at least one circumferential wall portion adjacent to the at least one protrusion and not having the protrusion, It has, When viewed from the direction of extension of the flow path, the cross-sectional area of ​​the flow path is smaller in the second cross-sectional area in the second region than in the first cross-sectional area in the first region. A burner assembly.

2. The first distance in the extending direction between the upstream end of the flow path and the center position of the opening in the projection of the injection hole is at least one times the equivalent diameter of the second region when viewed from the extending direction. The burner assembly according to claim 1.

3. The first distance is five times or more the equivalent diameter. The burner assembly according to claim 2.

4. The aforementioned protrusion is, In the cross-section along the extension direction, a straight portion extends linearly along the extension direction, A tip portion formed upstream of the straight portion such that the amount of protrusion radially inward gradually increases as it approaches the straight portion, including, The burner assembly according to claim 1 or 2.

5. The second distance in the extending direction between the connection point and the upstream end of the straight section is less than or equal to one times the equivalent diameter of the second region when viewed from the extending direction. The burner assembly according to claim 4.

6. The third distance in the extending direction between the connection position and the center position of the opening in the projection of the injection hole is greater than the opening diameter of the opening and less than the second distance in the extending direction between the connection position and the upstream end of the straight section. The burner assembly according to claim 4.

7. The surface of the tip portion has an arc shape in a cross-section along the extending direction. The burner assembly according to claim 4.

8. The surface of the tip portion has an elliptical arc shape in a cross-section along the extending direction. The burner assembly according to claim 4.

9. The fourth distance in the extending direction from the upstream end of the flow path to the upstream end of the projection is 0 or greater. The burner assembly according to claim 4.

10. The first region is, The inlet region including the upstream end, An introduction area connected to the inlet area on the downstream side of the inlet area, Includes, The inlet region is defined by an inner wall surface formed in a curved shape that is convex toward the inside of the first region in a cross-section along the extending direction, and is formed such that the cross-sectional area of ​​the flow path gradually decreases toward the downstream side. The introduction region is defined in a cross-section along the extending direction by an inner wall surface formed in a straight line parallel to the extending direction. The burner assembly according to claim 1 or 2.

11. Multiple flow channels are arranged at equal intervals along a first direction perpendicular to the extending direction and a second direction perpendicular to both the extending direction and the first direction. In each of the aforementioned inlet regions, the inner circumferential surface of the inlet region as seen in the cross-section of the inlet region along the extending direction is formed in a curved shape having a radius of curvature equal to 0.5 times the distance between the inner circumferential surfaces of adjacent introduction regions in the first direction. The burner assembly according to claim 10.

12. Multiple flow channels are arranged at equal intervals along a first direction perpendicular to the extending direction and a second direction perpendicular to both the extending direction and the first direction. In each of the aforementioned inlet regions, the inner circumferential surface of the inlet region, as seen in the cross-section of the inlet region along the extending direction, extends in a direction different from the first and second directions, and is formed in a curved shape having a radius of curvature equal to 0.5 times the distance between adjacent inner circumferential surfaces of the introduction regions in a third direction perpendicular to the extending direction. The burner assembly according to claim 10.

13. Multiple flow channels are arranged at equal intervals along a first direction perpendicular to the extending direction and a second direction perpendicular to both the extending direction and the first direction. In each of the aforementioned inlet regions, the inner circumferential surface of the inlet region as seen in the cross-section of the inlet region along the extending direction extends in a direction different from the first and second directions, and is formed in a curved shape having a radius of curvature greater than 0.5 times the distance between adjacent inner circumferential surfaces of the introduction regions in a third direction perpendicular to the extending direction. The burner assembly according to claim 10.

14. The flow path includes a first flow path and a second flow path that is closest to the first flow path. The upstream end of the projection is located downstream of the upstream end of the flow path. The diameter of at least a portion of the first region, located upstream of the upstream end of the protrusion, as viewed from the extending direction, is equal to the distance between the central axis of the first region in the first channel along the extending direction and the central axis of the first region in the second channel along the extending direction, minus twice the thickness of the partition wall separating the first region in the first channel and the first region in the second channel. The burner assembly according to claim 1 or 2.

15. A burner assembly according to claim 1 or 2, A combustion cylinder forming a space for flame formation downstream of the burner assembly, Equipped with, Gas turbine combustor.

16. Compressor and, A gas turbine combustor is configured to receive compressed air and fuel from the aforementioned compressor, and to burn the fuel to generate combustion gases, A turbine driven by the combustion gas generated in the gas turbine combustor, Equipped with, The gas turbine combustor is the gas turbine combustor described in claim 15. Gas turbine.

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