duty nozzles, combustion nozzles and gas turbines

Abstract

This invention discloses a standby nozzle, a combustion nozzle, and a gas turbine. The standby nozzle includes a first housing, a second housing, and a cover plate. The first housing is fitted onto the second housing, defining a standby air passage between the first and second housings. The second housing defines a standby fuel passage. The cover plate is located at the same end of the first and second housings and has a standby fuel injection hole. The inlet end of the standby fuel injection hole communicates with the standby fuel passage, and the flow area of ​​the standby fuel injection hole gradually increases in the direction away from the standby fuel passage. The cover plate also has multiple standby air injection holes, which are arranged at intervals around the standby fuel injection hole. The inlet end of the standby air injection hole communicates with the standby air passage, and the standby air injection holes extend from the inner end to the outer end of the cover plate and are inclined towards the standby fuel injection hole. The standby nozzle of this invention can adapt to various operating conditions of the gas turbine and has good environmental performance.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, specifically to a duty nozzle, a combustion nozzle, and a gas turbine. Background Technology

[0002] A gas turbine is a rotary thermal engine that uses combustion to drive a continuously flowing gas impeller to rotate at high speed, converting thermal energy into mechanical work. Its main components include a compressor, a combustion chamber, and a gas turbine.

[0003] To meet relevant environmental regulations, most mainstream gas turbines currently employ lean premixed combustion technology. This involves premixing air and fuel at a ratio lower than the stoichiometric ratio before introducing the mixture into the combustion chamber through a combustion nozzle. This improves the combustion efficiency of the gas turbine while reducing nitrogen oxide emissions. However, under partial load conditions, such as when the airflow velocity in the premixing channel is too high or the stoichiometric ratio is too low, the flame stability formed by the combustion nozzle is poor. This leads to a decrease in combustion temperature, causing thermoacoustic oscillations and severely damaging the service life of related components in the combustion chamber.

[0004] In related technologies, to solve the above problems, a standby nozzle is usually installed downstream of the combustion nozzle. The gas ejected from the standby nozzle forms a diffuse flame during combustion, thereby improving the combustion stability of the combustion nozzle. However, the diffuse flame generated by the standby nozzle in related technologies has a high combustion temperature and a more concentrated heat release. When the gas turbine is under low load conditions, the emissions of carbon monoxide and unburned hydrocarbons are high. When the gas turbine is under basic load or high load conditions, the emissions of nitrogen oxides are high. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a duty nozzle that generates a diffusion flame with strong stability, which can adapt to various operating conditions of gas turbines, thereby reducing the emissions of nitrogen oxides, carbon monoxide and unburned hydrocarbons.

[0006] Embodiments of the present invention also provide a combustion nozzle.

[0007] Embodiments of the present invention also propose a gas turbine.

[0008] The duty nozzle of this invention includes: a first housing and a second housing, the first housing and the second housing extending along a first direction, the first housing being sleeved on the second housing, a duty air passage defined between the inner circumferential surface of the first housing and the outer circumferential surface of the second housing, and a duty fuel passage defined between the inner circumferential surface of the second housing; a cover plate disposed at one end of the first housing in the first direction and one end of the second housing in the first direction to cover the duty air passage and the duty fuel passage, the cover plate having a duty fuel injection hole, the inlet end of the duty fuel injection hole being connected to the... The duty fuel channel is connected, and the flow area of ​​the duty fuel nozzle gradually increases in the direction away from the duty fuel channel. The cover plate also has a plurality of duty air nozzles, which are arranged at intervals around the duty fuel nozzle. The inlet end of the duty air nozzle is connected to the duty air channel. The duty air nozzle extends from the inner end of the cover plate to the outer end of the cover plate and is inclined toward the duty fuel nozzle so that the air ejected from the outlet end of the duty air nozzle and the fuel ejected from the outlet end of the duty fuel nozzle are premixed at the outer end of the cover plate.

[0009] According to an embodiment of the present invention, in the duty nozzle, the duty air passage between the first housing and the second housing is used for duty air circulation. After the duty air flows to the front end of the duty air passage, the duty air continues to flow out from the outer end face of the duty fuel injection hole. Meanwhile, the duty fuel passage within the second housing is used for duty fuel circulation. After the duty fuel flows to the front end of the duty fuel passage, the duty air continues to flow out from a plurality of duty air nozzles spaced around the duty fuel injection hole toward the outer end face of the cover plate. Due to the limitation of the extension direction of the duty air nozzles and the duty fuel injection hole, the ejected duty fuel airflow and duty airflow... The airflow will be mixed by counter-current mixing at the outer end face of the cover plate to form a mixed airflow, thereby improving the combustion efficiency of the duty nozzle and thus enhancing the stability of the diffused flame formed by the duty nozzle to adapt to various operating conditions of the gas turbine, reducing the emissions of nitrogen oxides, carbon monoxide and unburned hydrocarbons. In the duty nozzle of this application, the inventors directly use the extension direction of the pipeline to guide the duty air and duty fuel to be mixed by counter-current mixing at the outer end face of the cover plate, avoiding unnecessary complex pipeline design at the front end of the duty nozzle, thereby reducing the space occupied by the duty nozzle and simplifying the production process of the duty nozzle.

[0010] In some embodiments, the duty fuel injection unit further includes a booster branch, which is disposed on the second housing and / or the cover plate. The booster branch connects the duty fuel passage and the duty fuel injection hole. The flow area of ​​the duty fuel passage is S1, and the flow area of ​​the booster branch is S2, then S1 > S2.

[0011] In some embodiments, the inlet end of the booster branch is connected to the outlet end of the second housing by a rounded corner, and the outlet end of the booster branch is smoothly connected to the inlet end of the duty fuel injection hole.

[0012] In some embodiments, the outer end face of the cover plate has a mixing groove, and the outlet end of the duty fuel injection hole and the outlet ends of the plurality of duty air injection holes are connected to the mixing groove.

[0013] In some embodiments, a portion of the inner circumferential surface of the duty air nozzle is connected to the inner circumferential surface of the mixing tank, and another portion of the inner circumferential surface of the duty air nozzle is connected to the bottom surface of the mixing tank.

[0014] In some embodiments, in the first direction, the depth of the mixing tank is H1 and the thickness of the cover plate is H2, then 0.4H2≤H1≤0.6H2.

[0015] In some embodiments, the cover plate further has a plurality of cooling nozzles arranged at intervals around the mixing tank, and the inlet end of the cooling nozzles is connected to the duty air channel.

[0016] In some embodiments, the flow area of ​​the duty air nozzle is S3, and the flow area of ​​the cooling nozzle is S4, then S3 > S4.

[0017] In some embodiments, the central axis of the duty air nozzle has an inclination angle relative to the first direction, the inclination angle being α, where 30° < α < 80°; the duty fuel nozzle is a conical nozzle, the cone angle of the conical nozzle being β, where 40° < β < 60°.

[0018] In some embodiments, on the outer end face of the cover plate, the interval between the duty fuel injection hole and the duty air injection hole is L1, then 3mm < L1 < 5mm, and the interval between adjacent duty air injection holes is L2, then L2 > 2mm.

[0019] The fuel nozzle of this embodiment includes: a standby nozzle, wherein the standby nozzle is the standby nozzle according to the above embodiment; a fuel input pipe, wherein the fuel input pipe defines a fuel input channel, and the fuel input channel is connected to the standby fuel channel of the standby nozzle; an air input pipe, wherein the air input pipe is sleeved on the fuel input pipe, and an air input channel is defined between the inner circumferential surface of the air input pipe and the outer circumferential surface of the fuel input pipe, and the air input channel is connected to the standby air channel of the standby nozzle; and a premixed fuel input pipe, wherein the premixed fuel input pipe is sleeved on the air input pipe, and a premixed fuel channel is defined between the inner circumferential surface of the premixed fuel input pipe and the outer circumferential surface of the air input pipe, wherein the premixed fuel input pipe has a plurality of premixed fuel nozzles at one end facing the standby nozzle, and the plurality of premixed fuel nozzles are spaced apart circumferentially along the premixed fuel input pipe.

[0020] According to the embodiments of the present invention, the fuel nozzle can supply standby fuel to the standby nozzle of the above embodiment through the fuel input channel and supply standby air to the standby nozzle of the above embodiment through the air input channel to ensure the normal operation of the micro-mixed standby nozzle. The premixed fuel in the premixed fuel channel is sprayed out by the premixed fuel nozzle and comes into contact with the diffusion flame formed by the standby nozzle for combustion to ensure stable combustion of the combustion nozzle and reduce the emission of polluting gases from the combustion nozzle.

[0021] The gas turbine of this invention includes a fuel nozzle as described in the above embodiments.

[0022] The gas turbine according to the embodiments of the present invention, by employing the combustion nozzle described in the above embodiments, exhibits strong operational stability and good environmental performance. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the duty nozzle according to an embodiment of the present invention.

[0024] Figure 2 This is an isometric view of the duty nozzle according to an embodiment of the present invention.

[0025] Figure 3 yes Figure 2 AA cross-section view.

[0026] Figure 4 yes Figure 2 BB cross-section.

[0027] Figure 5 This is a schematic diagram of the structure of a combustion nozzle according to an embodiment of the present invention.

[0028] Figure label:

[0029] 1. First housing; 11. Boosting branch; 2. Second housing; 3. Cover plate; 31. Shift fuel nozzle; 32. Shift air nozzle; 33. Cooling nozzle; 34. Blending tank; 4. Shift air passage; 5. Shift fuel passage; 6. Fuel input pipe; 7. Air input pipe; 8. Premixed fuel input pipe; 81. Premixed fuel nozzle; Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] like Figures 1-4 As shown, the duty nozzle of this embodiment of the invention includes a first housing 1, a second housing 2, and a cover plate 3.

[0032] Specifically, the first housing 1 and the second housing 2 are along a first direction (e.g., Figure 2 Extending in the front-to-back direction (as shown), the first housing 1 is fitted onto the second housing 2. A duty air passage 4 is defined between the inner circumferential surface of the first housing 1 and the outer circumferential surface of the second housing 2. A duty fuel passage 5 is defined by the inner circumferential surface of the second housing 2. A cover plate 3 is located at one end of the first housing 1 in the first direction and one end of the second housing 2 in the first direction to cover the duty air passage 4 and the duty fuel passage 5. The cover plate 3 has a duty fuel injection hole 31, the inlet end of which communicates with the duty fuel passage 5, and the flow of the duty fuel injection hole 31... The area gradually increases in the direction away from the duty fuel channel 5. The cover plate 3 also has multiple duty air nozzles 32. The multiple duty air nozzles 32 are arranged at intervals around the duty fuel nozzle 31. The inlet end of the duty air nozzle 32 is connected to the duty air channel 4. The duty air nozzles 32 extend from the inner end of the cover plate 3 to the outer end of the cover plate 3 and are arranged obliquely toward the duty fuel nozzle 31 so that the air ejected from the outlet end of the duty air nozzle 32 and the fuel ejected from the outlet end of the duty fuel nozzle 31 are premixed at the outer end of the cover plate 3.

[0033] It is understandable that the first housing 1 and the second housing 2 form a dual-channel sleeve structure. The space between the first housing 1 and the second housing 2 is used for the circulation of duty air. After the duty air flows to the front end of the first housing 1, it continues to flow out from the duty fuel injection hole 31 to the outer end face of the cover plate 3. After the duty fuel flows to the front end of the second housing 2, the duty air continues to flow out from multiple duty air injection holes 32 arranged at intervals around the duty fuel injection hole 31 to the outer end face of the cover plate 3. Since the flow area of ​​the duty fuel injection hole 31 gradually expands forward, the ejected duty fuel airflow... The airflow is a cone shape that gradually diffuses outward. At the same time, since the duty air nozzle 32 gradually extends at an angle close to the duty fuel nozzle 31, the ejected duty airflow will flow towards the duty fuel flow under the limitation of the extension direction of the duty air nozzle 32. Thus, the duty fuel flow and the duty air flow will mix against each other at the outer end face of the cover plate 3 to form a mixed flow, thereby improving the combustion efficiency of the duty nozzle and improving the stability of the diffused flame formed by the duty nozzle, so as to adapt to various operating conditions of the gas turbine and reduce the emissions of nitrogen oxides, carbon monoxide and unburned hydrocarbons.

[0034] Understandably, under different gas turbine operating conditions, the mixing ratio of duty air and duty fuel can be changed by adjusting the air supply in duty air nozzle 32 or the fuel supply in duty fuel nozzle 31, thereby obtaining better diffusion flame stability and less pollutant gas emissions.

[0035] It should be noted that in related technologies, the front end of the duty nozzle is usually equipped with complex pipelines to mix the duty fuel and duty air before it is ejected. This not only increases the space occupied by the duty nozzle, but also increases the difficulty of its production. In the duty nozzle of this application, the inventors directly use the extension direction of the pipeline to guide the duty air and duty fuel to mix against each other on the outer end face of the cover plate 3, thereby avoiding unnecessary pipeline design of the duty nozzle, reducing the space occupied by the duty nozzle, and simplifying the production process of the duty nozzle.

[0036] Furthermore, such as Figures 1-4 As shown, the central axis of the duty air nozzle 32 has an inclined angle relative to the first direction, and the inclined angle is α, then 30° < α < 80°. The duty fuel nozzle 31 is a conical nozzle, and the cone angle of the conical nozzle is β, then 80° < β < 100°. Therefore, under the above angle limitation, the duty fuel and duty air can achieve a better mixing effect.

[0037] Preferably, such as Figures 1-4As shown, multiple duty air nozzles 32 are arranged in a circular pattern around the outer periphery of the duty fuel nozzle 31, and the spacing between two adjacent duty air nozzles 32 is equal. This improves the rationality of the nozzle structure while ensuring that the mixing amount of duty air and duty fuel remains consistent in all directions, thus ensuring the stability of the diffusion flame formed by the duty nozzle.

[0038] Optionally, the first housing 1, the second housing 2, and the cover plate 3 are integrally formed, or the first housing 1, the second housing 2, and the cover plate 3 are separately set. The specific choice can be made according to the process requirements of the gas turbine. In some embodiments, the first housing 1 and the second housing 2 are circular tubes with different diameters, and the central axes of the two circular tubes are coaxial, which simplifies the production process of the micro-mixing duty nozzle while improving the uniformity of gas flow.

[0039] According to an embodiment of the present invention, in the duty nozzle, the duty air passage between the first housing and the second housing is used for duty air circulation. After the duty air flows to the front end of the duty air passage, the duty air continues to flow out from the outer end face of the duty fuel injection hole. Meanwhile, the duty fuel passage within the second housing is used for duty fuel circulation. After the duty fuel flows to the front end of the duty fuel passage, the duty air continues to flow out from a plurality of duty air nozzles spaced around the duty fuel injection hole toward the outer end face of the cover plate. Due to the limitation of the extension direction of the duty air nozzles and the duty fuel injection hole, the ejected duty fuel airflow and duty airflow... The airflow will be mixed by counter-current mixing at the outer end face of the cover plate to form a mixed airflow, thereby improving the combustion efficiency of the duty nozzle and thus enhancing the stability of the diffused flame formed by the duty nozzle to adapt to various operating conditions of the gas turbine, reducing the emissions of nitrogen oxides, carbon monoxide and unburned hydrocarbons. In the duty nozzle of this application, the inventors directly use the extension direction of the pipeline to guide the duty air and duty fuel to be mixed by counter-current mixing at the outer end face of the cover plate, avoiding unnecessary complex pipeline design at the front end of the duty nozzle, thereby reducing the space occupied by the duty nozzle and simplifying the production process of the duty nozzle.

[0040] Furthermore, such as Figure 4 As shown, the duty fuel injection unit also includes a booster branch 11, which is located on the second housing 2 and / or cover plate 3. The booster branch 11 connects the duty fuel passage 5 and the duty fuel injection hole 31. The flow area of ​​the duty fuel passage 5 is S1, and the flow area of ​​the booster branch 11 is S2. Then S1 > S2.

[0041] It is understandable that when the standby fuel flows into the pressurization branch 11 from the standby fuel channel 5, the reduction in the flow area will have a throttling and pressurizing effect on the standby fuel, thereby increasing the jet rigidity of the standby fuel airflow so that the standby fuel airflow has sufficient momentum at the outer end of the cover plate 3 to mix with the standby airflow and improve the mixing effect of the two.

[0042] It should be noted that the flow area of ​​the booster branch 11 is selected mainly based on two factors. One is the minimum pressure ratio between the standby fuel in the standby fuel passage 5 and the standby fuel in the booster branch 11, and the other is the maximum flow rate of the standby fuel. This ensures that the standby fuel can be injected into the combustion chamber normally, and at the same time ensures that the booster branch 11 will not be blocked when the standby fuel reaches the maximum flow rate. In some embodiments, the standby fuel passage 5 and the booster branch 11 are coaxial circular pipes with different orifice diameters.

[0043] Optionally, in some embodiments, the booster branch 11 may be located at the front end of the second housing 2 as an integral structure; in other embodiments, the booster branch 11 may be located at the rear end of the cover plate 3 as an integral structure; in other embodiments, the second housing 2, the booster branch 11 and the cover plate 3 are integrally formed.

[0044] Furthermore, such as Figures 2-4 As shown, the inlet end of the booster branch 11 is connected to the outlet end of the second housing 2 by a rounded corner, and the outlet end of the booster branch 11 is smoothly connected to the inlet end of the duty fuel injection port 31.

[0045] It is understandable that when the standby fuel enters the booster branch 11 from the standby fuel channel 5, the rounded corner design at the connection between the two will cause the standby fuel airflow to form a certain angle as it flows into the booster branch 11, thus accelerating the flow speed of the standby fuel airflow in the booster branch 11. When the standby fuel flows from the booster branch 11 into the standby fuel nozzle 31, the smooth transition connection between the two will cause the standby fuel airflow to flow into the standby fuel nozzle 31 with low loss.

[0046] Furthermore, such as Figures 1-4 As shown, the outer end face of the cover plate 3 has a mixing groove, and the outlet end of the duty fuel injection hole 31 and the outlet ends of multiple duty air injection holes 32 are connected to the mixing groove.

[0047] Understandably, when the duty fuel and duty air are mixed on the outer end face of the cover plate 3, the mixing tank can limit the mixing space of the two within the mixing tank, prevent the loss of duty fuel or duty air, improve the utilization rate of duty fuel and duty air, and further optimize the mixing effect of the two.

[0048] It should be noted that, in the mixing tank, the duty fuel nozzle 31 is generally located in the center of the mixing tank, while multiple duty air nozzles 32 are arranged in a circular pattern around the duty fuel nozzle 31. In some embodiments, the outlet ends of the duty air nozzles 32 are all located on the bottom wall of the mixing tank, while in other embodiments, the outlet ends of the duty air nozzles 32 are all located on the inner peripheral wall of the mixing tank.

[0049] Preferably, such as Figures 1-4As shown, a portion of the inner circumferential surface of the duty air nozzle 32 is connected to the inner circumferential surface of the mixing tank, and another portion of the inner circumferential surface of the duty air nozzle 32 is connected to the bottom surface of the mixing tank. That is, a portion of the outlet end of the duty air nozzle 32 is located on the bottom wall of the mixing tank, and the other portion is on the inner circumferential wall of the mixing tank. At this time, the duty air injected by the duty air nozzle 32 can fill the internal space of the mixing tank to the maximum extent, prevent the spread flame from backfire, and improve the safety of the duty nozzle operation.

[0050] Furthermore, such as Figure 3 As shown, in the first direction, the depth of the mixing tank is H1, and the thickness of the cover plate 3 is H2, then 0.4H2≤H1≤0.6H2.

[0051] In other words, the depth of the mixing tank is between 40% and 60% of the thickness of the cover plate 3, so as to avoid affecting the structural strength of the cover plate 3 due to the mixing tank being too large. In some embodiments, the mixing tank is an annular tank.

[0052] Furthermore, such as Figures 1-4 As shown, the cover plate 3 also has multiple cooling nozzles 33, which are arranged at intervals around the mixing tank, and the inlet end of the cooling nozzles 33 is connected to the duty air channel 4.

[0053] It should be noted that the duty air in the duty air channel 4 can be mixed with duty fuel to form a premixed gas, and can also be used as cooling gas for the duty nozzle. Specifically, in the duty nozzle of this application, multiple cooling nozzles 33 are arranged at intervals around the mixing tank. Thus, when the duty air flows into the cooling nozzles 33 from the duty air channel 4, the low-temperature airflow can directly exchange heat with the high-temperature airflow generated by combustion in the mixing tank, thereby reducing the temperature of the cover plate 3 and improving the durability of the duty nozzle.

[0054] It is understandable that there is a gap between adjacent duty air nozzles 32, and cooling nozzles 33 can also be arranged in this gap to specifically cool down the parts of the cover plate 3 where heat is concentrated.

[0055] Furthermore, such as Figures 1-4 As shown, the flow area of ​​the duty air nozzle 32 is S3, and the flow area of ​​the cooling nozzle 33 is S4, then S3 > S4.

[0056] It is understandable that the flow rate of the duty air is the same in the duty air channel 4. After the duty air is diverted to the duty air nozzle 32 and the cooling nozzle 33, the flow rate of the duty air will change because the flow areas of the duty air nozzle 32 and the cooling nozzle 33 are different. When S3 > S4, the flow rate of the duty air in the cooling nozzle 33 will be greater than that in the duty air nozzle 32, thereby ensuring that there is always fresh low temperature gas to exchange heat with the high temperature airflow in the mixing tank, so as to achieve rapid cooling of the duty nozzle.

[0057] Furthermore, such as Figures 1-3 As shown, on the outer end face of the cover plate 3, the interval between the duty fuel injection hole 31 and the duty air injection hole 32 is L1, then 3mm < L1 < 5mm, and the interval between adjacent duty air injection holes 32 is L2, then L2 > 2mm. Thus, the duty fuel injection hole 31 and multiple duty air injection holes 32 are reasonably arranged to avoid affecting the structural strength of the cover plate 3 due to the excessive number of injection holes, and to improve the durability of the cover plate 3.

[0058] like Figure 5 As shown, the fuel nozzle in this embodiment of the invention includes a duty nozzle, an air input pipe 7, a fuel input pipe 6, and a premixed fuel input pipe 86.

[0059] Specifically, the duty nozzle is the duty nozzle of the above embodiment. The fuel input pipe 6 defines a fuel input channel, which is connected to the duty fuel channel 5 of the duty nozzle. The air input pipe 7 is sleeved on the fuel input pipe 6, and the inner circumferential surface of the air input pipe 7 and the outer circumferential surface of the fuel input pipe 6 define an air input channel, which is connected to the duty air channel 4 of the duty nozzle. The premixed fuel input pipe 86 is sleeved on the air input pipe 7, and the inner circumferential surface of the premixed fuel input pipe 86 and the outer circumferential surface of the air input pipe 7 define a premixed fuel channel. The end of the premixed fuel input pipe 86 facing the duty nozzle is provided with a plurality of premixed fuel nozzles 81, which are spaced apart along the circumference of the premixed fuel input pipe 86.

[0060] Understandably, the standby fuel can flow into the standby fuel passage 5 through the fuel input passage to supply standby fuel to the standby nozzle, and the standby air can flow into the standby air fuel passage through the air input passage to supply standby air to the standby nozzle, thereby ensuring the normal operation of the standby nozzle. The premixed fuel in the premixed fuel passage is sprayed out through the premixed fuel nozzle 81 and comes into contact with the diffusion flame formed by the standby nozzle for combustion to ensure the normal operation of the gas turbine.

[0061] According to the embodiments of the present invention, the fuel nozzle can supply standby fuel to the standby nozzle of the above embodiment through the fuel input channel and supply standby air to the standby nozzle of the above embodiment through the air input channel to ensure the normal operation of the micro-mixed standby nozzle. The premixed fuel in the premixed fuel channel is sprayed out by the premixed fuel nozzle 81 and comes into contact with the diffusion flame formed by the standby nozzle for combustion to ensure stable combustion of the combustion nozzle and reduce the emission of polluting gases from the combustion nozzle.

[0062] The gas turbine of this invention includes a fuel nozzle according to the above embodiment.

[0063] The gas turbine according to the embodiments of the present invention, by employing the combustion nozzle described in the above embodiments, exhibits strong operational stability and good environmental performance.

[0064] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0065] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0066] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0067] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0068] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A duty nozzle, characterized in that, include: A first housing and a second housing, the first housing and the second housing extending along a first direction, the first housing being fitted onto the second housing, a duty air passage being defined between the inner peripheral surface of the first housing and the outer peripheral surface of the second housing, and a duty fuel passage being defined between the inner peripheral surface of the second housing. A cover plate is disposed at one end of the first housing in the first direction and one end of the second housing in the first direction to cover the duty air passage and the duty fuel passage. The cover plate has a duty fuel injection hole, the inlet end of which is connected to the duty fuel passage, and the flow area of ​​the duty fuel injection hole gradually increases in the direction away from the duty fuel passage. The cover plate also has a plurality of duty air injection holes, which are arranged at intervals around the duty fuel injection hole. The inlet end of the duty air injection hole is connected to the duty air passage. The duty air injection holes extend in the direction from the inner end of the cover plate to the outer end of the cover plate and are inclined toward the duty fuel injection hole so that the air ejected from the outlet end of the duty air injection hole and the fuel ejected from the outlet end of the duty fuel injection hole are premixed at the outer end of the cover plate. A booster branch is provided on the second housing and / or the cover plate. The booster branch connects the duty fuel channel and the duty fuel injection port. The flow area of ​​the duty fuel channel is S1, and the flow area of ​​the booster branch is S2, where S1 > S2. The inlet end of the booster branch is connected to the outlet end of the second housing by a rounded corner, and the outlet end of the booster branch is smoothly connected to the inlet end of the duty fuel injection port. The outer end face of the cover plate has a mixing groove, and the outlet end of the duty fuel injection hole and the outlet ends of the plurality of duty air injection holes are connected to the mixing groove; a portion of the inner circumferential surface of the duty air injection hole is connected to the inner circumferential surface of the mixing groove, and another portion of the inner circumferential surface of the duty air injection hole is connected to the bottom surface of the mixing groove; in the first direction, the depth of the mixing groove is H1, and the thickness of the cover plate is H2, then 0.4H2≤H1≤0.6H2.

2. The duty nozzle according to claim 1, characterized in that, The cover plate also has multiple cooling nozzles, which are arranged at intervals around the mixing tank, and the inlet end of each cooling nozzle is connected to the duty air channel.

3. The duty nozzle according to claim 2, characterized in that, The flow area of ​​the duty air nozzle is S3, and the flow area of ​​the cooling nozzle is S4, then S3 > S4.

4. The duty nozzle according to claim 1, characterized in that, The central axis of the duty air nozzle has an inclination angle relative to the first direction, and the inclination angle is α, then 30° < α < 80°. The duty fuel nozzle is a conical nozzle, and the cone angle of the conical nozzle is β, then 40° < β < 60°.

5. The duty nozzle according to claim 4, characterized in that, On the outer end face of the cover plate, the interval between the duty fuel injection hole and the duty air injection hole is L1, then 3mm < L1 < 5mm, and the interval between adjacent duty air injection holes is L2, then L2 > 2mm.

6. A fuel nozzle, characterized in that, include: A duty nozzle, wherein the duty nozzle is the duty nozzle according to any one of claims 1-5; A fuel input pipe defines a fuel input channel, which is connected to the duty fuel channel of the duty nozzle; An air input pipe is sleeved on the fuel input pipe, and an air input channel is defined between the inner circumferential surface of the air input pipe and the outer circumferential surface of the fuel input pipe. The air input channel is connected to the duty air channel of the duty nozzle. A premixed fuel input pipe is sleeved on the air input pipe, and a premixed fuel channel is defined between the inner circumferential surface of the premixed fuel input pipe and the outer circumferential surface of the air input pipe. The end of the premixed fuel input pipe facing the duty nozzle is provided with a plurality of premixed fuel injection holes, and the plurality of premixed fuel injection holes are arranged at intervals along the circumference of the premixed fuel input pipe.

7. A gas turbine, characterized in that, Includes the fuel nozzle according to claim 6.

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