Micro-mixing nozzle for gas turbine

Abstract

The invention discloses a micro-mixing nozzle for a gas turbine, and relates to the technical field of gas turbines. The multi-stage fuel gas inlet pipe specifically comprises a multi-stage fuel gas inlet pipe and a nozzle, the multi-stage fuel gas inlet pipe comprises a flange plate, an igniter and a plurality of fuel gas inlet pipes, the igniter and the fuel gas inlet pipes are installed on the flange plate, and the fuel gas inlet pipes comprise an ignition torch-stage fuel gas inlet pipe and a staged fuel gas inlet pipe; the nozzle comprises a nozzle outer wall and a plurality of micro-pipes arranged and distributed on the inner side of the nozzle outer wall. Wherein the outlet end of the staged fuel gas inlet pipe is connected with the nozzle and extends into the nozzle, a staged fuel cavity is formed in the nozzle, and corresponding staged fuel spraying holes are formed in a micro pipe in the staged fuel cavity. Fuel enters the staged fuel cavity through the staged fuel air inlet pipe, is sprayed into the micro-pipe through the corresponding staged fuel spraying holes and is mixed with air in the micro-pipe, and micro-premixing of the staged fuel is achieved. Safe and stable ignition can be achieved, and the low-pollution emission requirement under different operation working conditions can be met through graded fuel micro-premixing.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbines, and in particular to a micro-mixing nozzle for a gas turbine. Background Art

[0002] In the combustion chamber of a gas turbine, the uniformity of premixing of fuel and air is a key factor in controlling combustion NOx emissions. Since the gas turbine combustion chamber mainly produces thermal NOx, its generation is closely related to the combustion temperature. Therefore, when the average combustion temperature is the same, the different mixing uniformity of fuel and air causes the local combustion temperature in different areas to deviate from the average temperature, with some areas being higher and some areas being lower. In areas with higher temperatures, thermal NOx is generated in large quantities, which ultimately leads to a significant increase in the NOx emissions at the outlet.

[0003] Premixed micro-mixed combustion technology has broad application prospects in the field of gas turbine combustion chambers due to its advantages such as high combustion efficiency, low pollutant emissions, and wide fuel adaptability. Premixed micro-mixed combustion technology combines the characteristics of premixing and micro-mixing, realizes the premixing of fuel and air in the burner, and reduces the premixing scale and improves the premixing uniformity through a small-scale (millimeter-level) nozzle, thereby improving combustion efficiency and reducing pollutant emissions. At present, the premixed micro-mixed burners in the prior art mainly use transverse jet premixing tubes, coaxial jet premixing tubes, etc. to premix, forming combustible premixed gas into the combustion chamber. The premixing area in these micro-mixed burners is mostly a circular pipe, and air and gas enter the circular pipe in the form of transverse jets or coaxial jets for mixing; at the same time, a swirl flow is generated by tilting the premixing tube or adding a swirler, and the mixing degree of air and gas is enhanced by swirl. Among them, the coaxial jet mixing method can achieve a more uniform mixing effect, but the mixing process of air and gas mainly occurs in the interphase boundary layer area, so the mixing efficiency is low and the time is long. The transverse jet mixing method can form local turbulence and vortex structures in the circular pipe flow field, which is beneficial to the rapid mixing of air and fuel. However, the mixing degree of this method is weak in the radial direction, and it is easy to form local uneven mixing areas. The transverse jet hole is generally perpendicular to the additive manufacturing direction, which leads to low manufacturing accuracy of the fuel jet hole and deteriorates the mixing uniformity.

[0004] Existing patent CN110440290A discloses a micro-mixing nozzle for a gas turbine, the micro-mixing nozzle includes a fuel chamber, a pre-swirl assembly and a micro-mixing tube, the pre-swirl assembly is arranged throughout the fuel chamber, the pre-swirl assembly includes an inner tube, an outer tube and a swirl member, an annular channel is formed between the outer tube and the inner tube, the inner tube is provided with a first hole, the outer tube is provided with a second hole, the micro-mixing tube is arranged in the fuel chamber, the micro-mixing tube is provided with a third hole, wherein a part of the fuel in the annular channel enters the inner tube through the first hole to be pre-swirled and mixed with the air in the inner tube, and another part of the fuel discharged from the second hole enters the micro-mixing tube through the third hole to be mixed with the air in the micro-mixing tube. The micro-mixing nozzle for a gas turbine of the present invention combines pre-swirl mixing and micro-mixing of fuel and air to stabilize the ignition source, prevent the flame from being blown out or lifted too high, enhance the flame stability, and suppress combustion oscillation.

[0005] The existing patent CN118729322A discloses a method for manufacturing a nozzle and a micro-mixing tube suitable for a pure hydrogen gas turbine. A specific embodiment of the nozzle includes: a first panel, a second panel, a side panel, at least one fuel pipe and at least one micro-mixing tube, wherein the micro-mixing tube includes a micro-mixing tube body and at least one fuel hole, the diameter of the micro-mixing tube body is 3 to 5 mm, each fuel hole is arranged on the side of the corresponding micro-mixing tube body, the first panel, the second panel and the side panel form a fuel cavity, each fuel pipe is arranged on the first panel, and the outlet end of each fuel pipe is connected to the fuel cavity; the inlet end of each micro-mixing tube is arranged on the first panel, in the fuel cavity, and at least one air inlet hole is arranged on the first panel; at least one mixed fuel outlet hole is arranged on the second panel, and each micro-mixing tube outlet end corresponds to a mixed fuel outlet hole. This embodiment can reduce the risk of flashback and the emission of nitrogen oxides.

[0006] In summary, the above two existing patents fail to completely solve the problem of uniformity of premixing of fuel and air in the burner. Summary of the invention

[0007] Based on the above technical problems, the present invention proposes a micro-mixing nozzle for a gas turbine to solve the problem of uniformity of premixing of fuel and air in the burner in the prior art. The specific technical solution is as follows:

[0008] A micro-mixing nozzle for a gas turbine comprises a multi-stage fuel inlet pipe and a nozzle, wherein the multi-stage fuel inlet pipe comprises a flange and an igniter mounted on the flange, an ignition torch-level fuel inlet pipe and a graded fuel inlet pipe, wherein the nozzle comprises a nozzle outer wall and a plurality of micro-tubes arranged and distributed on the inner side of the nozzle outer wall, wherein the graded fuel inlet pipe is connected to the nozzle and extends to the inside of the nozzle, wherein the fuel cavity of the nozzle is divided into graded fuel cavities, wherein the graded fuel inlet pipe corresponds to the graded fuel cavities one by one, and the micro-tubes in the graded fuel cavity are provided with corresponding graded fuel spray holes.

[0009] Furthermore, a gap between the outer wall of the nozzle and the wall of the micro-tube forms a fuel cavity, and the nozzle further comprises a fuel cavity partition plate, and the fuel cavity partition plate is used to divide the fuel cavity into graded fuel cavities.

[0010] Furthermore, the fuel chamber partition includes a radial partition and a plurality of axial partitions, and the radial partition and the axial partition together divide the fuel chamber into a primary fuel chamber and a secondary fuel chamber.

[0011] Furthermore, the radial partition is vertically arranged at the outlet of the graded fuel inlet pipe, one end of the axial partition is vertically connected to the edge of the radial partition, and the other end is connected to the outer wall of the nozzle at one end of the nozzle outlet, the inner side of the radial partition and the axial partition is the primary fuel chamber, and the outer side is the secondary fuel chamber.

[0012] Furthermore, a primary fuel spray hole is formed on the micro-tube in the primary fuel cavity, and a secondary fuel spray hole is formed on the micro-tube in the secondary fuel cavity.

[0013] Furthermore, the graded fuel intake pipe is installed through the center of the flange, and the graded fuel intake pipe includes a primary fuel intake pipe and a secondary fuel intake pipe.

[0014] Furthermore, the graded fuel intake pipe is cylindrical, the first-level fuel intake pipe is a through hole that passes through both end surfaces of the cylinder and is located at the center of the circle, and the second-level fuel intake pipe is an annular hole or multiple arc holes located outside the first-level fuel intake pipe.

[0015] Furthermore, the inlet of the secondary fuel intake pipe does not penetrate the end surface of the cylinder, and the inlet of the secondary fuel intake pipe is an inclined pipe arranged on the side surface of the cylinder.

[0016] Furthermore, the outlet of the primary fuel intake pipe is not closed by the radial partition, the outlet of the secondary fuel intake pipe is closed by the radial partition, and a fuel outlet is opened on the side wall of the outlet of the secondary fuel intake pipe.

[0017] Furthermore, the primary fuel injection hole is opened at one end of the micro-tube close to the nozzle outlet, and the secondary fuel injection hole is opened at one end of the micro-tube close to the nozzle inlet.

[0018] Furthermore, a bending portion is provided at one end of the micro-tube close to the nozzle inlet, and the secondary fuel spray hole is opened on a side of the protrusion of the bending portion.

[0019] Furthermore, the ignition torch-level fuel inlet is installed vertically through the flange, and the ignition torch-level fuel inlet pipe is located above the graded fuel inlet pipe.

[0020] Furthermore, the igniter is installed obliquely through the flange, the igniter is located above the ignition torch-level fuel inlet pipe, and one end of the igniter close to the nozzle is close to the outlet of the ignition torch-level fuel inlet pipe.

[0021] Furthermore, the microtube outlet diameter of the microtube is 2-10 mm, and the flow cross section gradually decreases.

[0022] Based on the above technical solution, compared with the prior art, the present invention has at least the following beneficial effects:

[0023] 1. The present invention proposes a micro-mixing nozzle for a gas turbine, in which the fuel is divided into multiple levels. An igniter is used to first ignite the torch-level fuel and then ignite the first-level premixed fuel, thereby achieving safe and stable ignition.

[0024] 2. The present invention proposes a micro-mixing nozzle for a gas turbine, in which the fuel is divided into multiple stages, and the first-stage fuel micro-premixing and the second-stage fuel micro-premixing can meet the low pollution emission requirements under different operating conditions.

[0025] 3. The present invention proposes a micro-mixing nozzle for a gas turbine, in which a micro-tube is provided with a micro-tube bending portion and a secondary fuel spray hole is opened thereon, which not only strengthens the micro-premixing of fuel and air, but also the angle between the secondary fuel hole direction and the additive manufacturing direction of the nozzle is less than 30°, thereby improving the processing accuracy and consistency of the secondary fuel spray hole, ensuring that the concentration distribution of the fuel and air premixed gas at the nozzle outlet is uniform, and realizing basic load low NOx operation.

[0026] 4. The present invention proposes a micro-mixing nozzle for a gas turbine, wherein the micro-tube outlet is gradually narrowed and the outlet diameter is in the order of millimeters, so that the outlet flow velocity is uniform and accelerated, and the anti-flashback capability can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 It is a structural schematic diagram of a micro-mixing nozzle for a gas turbine proposed by the present invention;

[0029] Figure 2 is a cross-sectional schematic diagram of a micro-mixing nozzle for a gas turbine proposed by the present invention;

[0030] Figure 3 is a cross-sectional schematic diagram of a micro-mixing nozzle for a gas turbine proposed by the present invention;

[0031] Figure 4 It is a partial schematic diagram of a micro-mixing nozzle for a gas turbine proposed by the present invention.

[0032] Figure markings: 1-flange, 2-igniter, 3-ignition torch level fuel inlet pipe, 4-primary fuel inlet pipe, 5-secondary fuel inlet pipe, 6-nozzle outer wall, 7-fuel chamber partition, 8-primary fuel chamber, 9-secondary fuel chamber, 10-microtube, 11-primary fuel spray hole, 12-secondary fuel spray hole, 13 microtube inlet, 14-microtube outlet, 15-microtube bending part. DETAILED DESCRIPTION

[0033] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0034] The present invention is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed by the present invention.

[0035] In order to solve the problem of uniformity of premixing of fuel and air in a burner in the prior art, the present invention proposes a micro-mixing nozzle for a gas turbine.

[0036] To achieve the above-mentioned purpose, the present invention proposes a micro-mixing nozzle for a gas turbine. Since the geometric dimensions of the premixed micro-mixing burner channel are small and the internal structure is complex, the traditional mechanical processing method can no longer meet its processing requirements. Additive manufacturing technology (3D printing technology) is an advanced manufacturing technology that constructs objects by adding materials layer by layer. The development of this technology has made the manufacture of burners no longer limited to traditional methods, and has brought greater freedom and more innovation opportunities to the design and optimization of premixed micro-mixing burners. Based on additive manufacturing technology, the present invention proposes a micro-mixing nozzle for a gas turbine, in which the micro-tube is bent and the outlet section is gradually reduced, and the fuel hole is in the same direction as the additive manufacturing direction, providing a new idea for the design of advanced burners.

[0037] See also Figure 1-Figure 4As shown, a micro-mixing nozzle for a gas turbine is specifically exemplified. The micro-mixing nozzle includes a multi-stage fuel inlet pipe and a nozzle. The multi-stage fuel inlet pipe includes a flange 1, an igniter 2 installed on the flange 1, and a plurality of fuel inlet pipes. The nozzle includes a nozzle outer wall 6 and a plurality of micro-tubes 11 arranged and distributed on the inner side of the nozzle outer wall 6. Among them, the multiple fuel inlet pipes include an ignition torch-level fuel inlet pipe 3 and a graded fuel inlet pipe. The outlet end of the graded fuel inlet pipe is connected to the nozzle and extends to the inside of the nozzle; a graded fuel cavity is provided inside the nozzle, and corresponding graded fuel spray holes are provided on the micro-tubes 11 in the graded fuel cavity. The present invention can realize graded fuel micro-premixing to meet the low pollution emission requirements under different operating conditions.

[0038] As a specific implementation of the multi-stage fuel intake pipe, refer to Figure 1 and Figure 2 As shown, the flange 1 is a circular disk, on which an igniter 2, an ignition torch-grade fuel inlet pipe 3 and a graded fuel inlet pipe are arranged, and the graded fuel inlet pipe includes a primary fuel inlet pipe 4 and a secondary fuel inlet pipe 5. The graded fuel inlet pipe is vertically arranged at the center of the circular disk, and the shape of the graded fuel inlet pipe is a cylinder, and a through hole is provided on the cylinder that penetrates the two end faces of the cylinder and is located at the center of the circle, and the through hole is the primary fuel inlet pipe 4, and an annular through hole or a plurality of arc-shaped through holes with equal spacing from the through hole are provided on the outside of the through hole, and the annular through hole or the arc-shaped through hole is the secondary fuel inlet pipe 5, and the outlet of the secondary fuel inlet pipe 5 penetrates the end face of the cylinder, and the inlet of the secondary fuel inlet pipe 5 does not penetrate the end face of the cylinder, but is connected to a fuel inlet arranged obliquely to the side of the cylinder. The ignition torch-grade fuel inlet pipe 3 is arranged above the graded fuel inlet pipe and is parallel to the graded fuel inlet pipe. The igniter 2 is arranged above the ignition torch-grade fuel inlet pipe 3. The igniter 2 is inclined, with one end close to the outlet of the ignition torch-grade fuel inlet pipe 3 and the other end separated from the inlet of the ignition torch-grade fuel inlet pipe 3 by a certain distance.

[0039] As a specific embodiment of the nozzle, see Figure 1 and Figure 3 As shown, the shape of the nozzle is a fan-shaped column, including a nozzle outer wall 6 and a plurality of microtubes 11 arranged and distributed on the inner side of the nozzle outer wall 6. The plurality of microtubes 11 are arranged according to a certain rule to form a microtube cluster, such as staggered arrangement at equal intervals or parallel arrangement, etc. The microtubes 11 are not arranged at the extension of the graded fuel intake pipe. The two ends of the microtube 11 are respectively a microtube inlet and a microtube outlet, and the two ends thereof penetrate the end faces of the axial ends of the nozzle outer wall 6. The gap between the nozzle outer wall 6 and the tube wall of the microtube 11 forms a fuel cavity. A fuel cavity partition 7 is arranged inside the nozzle to separate the fuel cavity into a primary fuel cavity 8 and a secondary fuel cavity 9. The fuel cavity partition 7 only separates the nozzle outer wall 6 and the tube wall of the microtube 11 to form a fuel cavity, and does not divide the interior of the microtube 11.

[0040] See also Figure 2 As shown, the fuel chamber partition 7 includes a radial partition, which is vertically arranged at the outlet end of the graded fuel intake pipe. The area of ​​the radial partition is larger than the cross-sectional area of ​​the graded fuel intake pipe. The radial partition axially divides the fuel chamber in the middle part into two parts. At the same time, the radial partition does not close the outlet of the first-level fuel intake pipe 4, but closes the outlet of the second-level fuel intake pipe 5. A notch is set at the outlet side wall of the second-level fuel intake pipe 5 as the outlet of the second-level fuel intake pipe 5.

[0041] See also Figure 3 As shown, the fuel cavity partition 7 also includes a plurality of axial partitions, one end of each axial partition is vertically connected to the edge of the radial partition, and the other end extends to the nozzle outlet and is connected to the axial end face of the nozzle outer wall 6. The axial partition separates the fuel cavity in the middle part from the surrounding fuel cavities. The inner fuel cavity separated and surrounded by the radial partition and the axial partition is the primary fuel cavity 8, and the outer fuel cavity is the secondary fuel cavity 9. Therefore, the fuel introduced from the primary fuel intake pipe 4 enters the primary fuel cavity 8, and the fuel introduced from the secondary fuel intake pipe 5 enters the secondary fuel cavity 9.

[0042] See also Figure 2 As shown, the front end of the microtube in the primary fuel cavity 8 is provided with a primary fuel spray hole 10, and the fuel in the primary fuel cavity 8 is sprayed into the corresponding microtube 11 through the primary fuel spray hole 10, and is mixed with the air in the microtube 11 to achieve micro-premixing of the primary fuel and the air. The rear end of the microtube in the secondary fuel cavity 9 is provided with a secondary fuel spray hole 12, and the fuel in the secondary fuel cavity 9 is sprayed into the corresponding microtube 11 through the secondary fuel spray hole 12, and is mixed with the air in the microtube to achieve micro-premixing of the secondary fuel and the air.

[0043] Optionally, the shape of the radial partition may also be circular, rectangular, or diamond-shaped.

[0044] Optional, see Figure 4 As shown, the microtube 11 located in the secondary fuel cavity 9 includes a microtube inlet 13, a microtube outlet 14 and a microtube bending portion 15. The secondary fuel nozzle 12 is opened on the side of the protrusion of the microtube bending portion 15. The fuel introduced from the secondary fuel hole 12 is mixed with the air cross jet to form a premixed gas. The microtube bending portion 15 changes the flow direction of the airflow to form a secondary flow, and the disturbance is enhanced, thereby improving the mixing uniformity of the secondary premixed gas at the microtube outlet 15 and reducing NOx emissions.

[0045] Optionally, the diameter of the micro-tube outlet 14 is 2-10 mm, and the flow cross section is gradually reduced. This configuration accelerates the airflow and improves the anti-flashback capability.

[0046] When using the above-mentioned micro-mixing nozzle in a gas turbine, first open the igniter 2 for a certain period of time, then introduce fuel from the ignition torch-level fuel inlet pipe 3, form a torch at the outlet of the ignition torch-level fuel inlet pipe 3, diffuse the burning flame and flue gas into the downstream micro-tube, then introduce the primary fuel from the primary fuel inlet pipe 4, form a primary premixed flame at the outlet of the micro-tube, then close the ignition torch-level fuel inlet pipe 3 and the igniter 2 in turn, so as to achieve safe and stable ignition of the micro-mixing nozzle, especially for hydrogen-rich or pure hydrogen fuels that are prone to deflagration. The primary fuel micro-premixing combustion meets the demand for low NOx emissions during partial load operation, and the secondary fuel micro-premixing combustion meets the demand for low NOx emissions during basic load operation.

[0047] The structure of the above-mentioned micro-mixing nozzle is complex. Compared with the traditional machining and welding process, additive manufacturing has more configuration advantages. However, the diameter of the fuel hole is generally on the order of 0.5 mm. The small-size holes manufactured by additive manufacturing have low precision and poor consistency. However, in this scheme, the angle between the secondary fuel nozzle direction and the additive manufacturing direction (from right to left) is less than 30°, which can not only achieve the mixing effect of fuel and air, but also improve the additive manufacturing accuracy of the fuel small hole, thereby achieving low pollution emission indicators under basic load operating conditions.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0049] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0050] It should be noted that, in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

Claims

1. A micro-mixing nozzle for a gas turbine, characterized in that: It comprises a multi-stage fuel inlet pipe and a nozzle, wherein the multi-stage fuel inlet pipe comprises a flange and an igniter mounted on the flange, an ignition torch-level fuel inlet pipe and a graded fuel inlet pipe, the nozzle comprises a nozzle outer wall and a plurality of micro-tubes arranged and distributed on the inner side of the nozzle outer wall, the graded fuel inlet pipe is connected to the nozzle and extends to the inside of the nozzle, the fuel cavity of the nozzle is divided into graded fuel cavities, the graded fuel inlet pipe corresponds to the graded fuel cavities one by one, and the micro-tubes in the graded fuel cavity are provided with corresponding graded fuel spray holes.

2. The micro-mixing nozzle for a gas turbine according to claim 1, characterized in that: A gap between the outer wall of the nozzle and the wall of the micro-tube forms a fuel cavity. The nozzle further comprises a fuel cavity partition plate, and the fuel cavity partition plate is used to divide the fuel cavity into graded fuel cavities.

3. The micro-mixing nozzle for a gas turbine according to claim 2, characterized in that: The fuel cavity partition includes a radial partition and a plurality of axial partitions, and the radial partition and the axial partition together divide the fuel cavity into a primary fuel cavity and a secondary fuel cavity.

4. The micro-mixing nozzle for a gas turbine according to claim 3, characterized in that: The radial partition is vertically arranged at the outlet position of the graded fuel inlet pipe, one end of the axial partition is vertically connected to the edge of the radial partition, and the other end is connected to the outer wall of the nozzle at one end of the nozzle outlet, the inner side of the radial partition and the axial partition is the primary fuel cavity, and the outer side is the secondary fuel cavity.

5. The micro-mixing nozzle for a gas turbine according to claim 4, characterized in that: A primary fuel spray hole is formed on the micro-tube in the primary fuel cavity, and a secondary fuel spray hole is formed on the micro-tube in the secondary fuel cavity.

6. The micro-mixing nozzle for a gas turbine according to claim 4, characterized in that: The graded fuel intake pipe is vertically penetrated and installed at the center of the flange, and the graded fuel intake pipe includes a primary fuel intake pipe and a secondary fuel intake pipe.

7. The micro-mixing nozzle for a gas turbine according to claim 6, characterized in that: The graded fuel intake pipe is cylindrical, the primary fuel intake pipe is a through hole that penetrates both end surfaces of the cylinder and is located at the center of the circle, and the secondary fuel intake pipe is an annular hole or multiple arc holes located outside the primary fuel intake pipe.

8. The micro-mixing nozzle for a gas turbine according to claim 7, characterized in that: The inlet of the secondary fuel intake pipe does not penetrate the end surface of the cylinder, and the inlet of the secondary fuel intake pipe is an inclined pipe arranged on the side surface of the cylinder.

9. The micro-mixing nozzle for a gas turbine according to claim 7, characterized in that: The outlet of the primary fuel intake pipe is not closed by the radial partition, the outlet of the secondary fuel intake pipe is closed by the radial partition, and the side wall of the outlet end of the secondary fuel intake pipe is provided with a fuel outlet.

10. The micro-mixing nozzle for a gas turbine according to claim 5, characterized in that: The primary fuel injection hole is formed at one end of the micro-tube close to the nozzle outlet, and the secondary fuel injection hole is formed at one end of the micro-tube close to the nozzle inlet.

11. The micro-mixing nozzle for a gas turbine according to claim 10, characterized in that: A bending portion is arranged at one end of the micro-tube close to the nozzle inlet, and the secondary fuel spray hole is opened on one side of the protrusion of the bending portion.

12. The micro-mixing nozzle for a gas turbine according to claim 6, characterized in that: The ignition torch-level fuel inlet pipe is vertically penetrated and installed on the flange plate, and the ignition torch-level fuel inlet pipe is located above the graded fuel inlet pipe.

13. The micro-mixing nozzle for a gas turbine according to claim 12, characterized in that: The igniter is installed obliquely through the flange, and is located above the ignition torch-level fuel inlet pipe. One end of the igniter close to the nozzle is close to the outlet of the ignition torch-level fuel inlet pipe.

14. The micro-mixing nozzle for a gas turbine according to claim 1, characterized in that: The microtube outlet diameter of the microtube is 2-10 mm, and the flow cross section of the microtube gradually decreases.

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