A hydrogen fuel nozzle and its working method

Abstract

The present invention relates to the technical field of gas turbines, and particularly relates to a hydrogen fuel nozzle and its working method. The hydrogen fuel nozzle includes: a fuel housing, the inner wall of which encloses to form a fuel chamber; a primary fuel cylinder; an air cylinder coaxially arranged with the primary fuel cylinder; a secondary fuel structure arranged between the primary fuel cylinder and the air cylinder, the secondary fuel structure including a first cylinder and a second cylinder arranged at intervals; a first air flow path is formed at a radial interval between the first cylinder and the primary fuel cylinder; a secondary fuel passage is formed at a radial interval between the first cylinder and the second cylinder; a second air flow path is formed at a radial interval between the outer peripheral wall of the second cylinder and the inner peripheral wall of the air cylinder; air film holes are formed on the primary fuel cylinder, the first cylinder and the second cylinder. The hydrogen fuel nozzle provided by the present invention can prevent hydrogen embrittlement, hydrogen corrosion and flashback phenomena from occurring, and improve combustion stability.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbines, and particularly to a hydrogen fuel nozzle and its working method. Background Art

[0002] Most of the existing heavy-duty gas turbines for power generation use natural gas as fuel, which produces a large amount of carbon dioxide gas during combustion, significantly increasing carbon emissions. Many thermal power plants at home and abroad have gradually explored the technology of burning natural gas blended with hydrogen, and foreign gas turbine suppliers have also started to develop pure hydrogen gas turbines, hoping to replace traditional hydrocarbon fuels and reduce carbon emissions.

[0003] Hydrogen is regarded as an ideal energy source as a clean and efficient energy source, and it has been widely used in fields such as transportation, chemical industry, and power production. When hydrogen burns, the combustion product is only water, which can significantly reduce carbon emissions, but there are also problems such as hydrogen embrittlement, hydrogen corrosion, and flashback. Hydrogen embrittlement is a phenomenon in which hydrogen in the material polymerizes into hydrogen molecules, causing stress concentration to exceed the strength limit of the material, forming fine cracks inside it, and leading to embrittlement or even cracking of the material; hydrogen corrosion refers to a phenomenon in which the material is exposed to a high-temperature and high-pressure hydrogen environment, and hydrogen atoms react with unstable carbides on its surface or penetrate into the interior to generate methane, causing permanent damage to the mechanical strength; flashback refers to a phenomenon in which the flame propagates reversely along the combustion chamber, causing combustion to occur in the premixed section. The above phenomena will seriously affect the combustion stability and significantly reduce the safety of heavy-duty gas turbines. Therefore, there is an urgent need for a new type of fuel nozzle suitable for gas turbines to solve the above problems. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the existing gas turbines in the prior art are easily affected by hydrogen embrittlement, hydrogen corrosion, and flashback problems during pure hydrogen fuel combustion, seriously affecting the combustion stability, so as to provide a hydrogen fuel nozzle and its working method that can prevent the occurrence of hydrogen embrittlement, hydrogen corrosion, and flashback phenomena and improve the combustion stability.

[0005] To solve the above technical problem, the hydrogen fuel nozzle provided by the present invention includes:

[0006] A fuel housing, the inner wall of which encloses a fuel chamber;

[0007] A primary fuel cylinder, coaxially arranged with the fuel housing, the inner circumferential wall of the primary fuel cylinder encloses a primary fuel passage, and the primary fuel passage is communicated with the fuel chamber;

[0008] An air cylinder, coaxially arranged with the primary fuel cylinder; an annular cavity is formed at a radial interval between the air cylinder and the primary fuel cylinder;

[0009] The secondary fuel structure is disposed in the annular cavity, and the secondary fuel structure includes a first cylinder and a second cylinder which are arranged at intervals in the radial direction;

[0010] A first air flow path is formed at a radial interval between the inner peripheral wall of the first cylinder and the outer peripheral wall of the primary fuel cylinder; a secondary fuel passage is formed at a radial interval between the outer peripheral wall of the first cylinder and the inner peripheral wall of the second cylinder, and the secondary fuel passage communicates with the fuel cavity; a second air flow path is formed at a radial interval between the outer peripheral wall of the second cylinder and the inner peripheral wall of the air cylinder;

[0011] The primary fuel cylinder, the first cylinder and the second cylinder are all provided with film holes.

[0012] Optionally, the inner diameter of the film hole is d, and the value range of d is 0.1mm ≤ d ≤ 0.5mm.

[0013] Optionally, the axial pitch between every two adjacent film holes is P, and P satisfies P < 10·d; the circumferential pitch between every two adjacent film holes is Q, and Q satisfies Q < 3·d.

[0014] Optionally, an arc-shaped plate is provided at one end of the air cylinder away from the fuel housing along the axial direction, and the radial cross-section of the arc-shaped plate gradually contracts along the axial direction away from the fuel housing; the included angle between the arc-shaped plate and the central axis of the hydrogen fuel nozzle is α, and α satisfies 30° ≤ α ≤ 60°.

[0015] Optionally, a plurality of support plates are provided between the air cylinder and the fuel housing, and the support plates are adapted to connect the air cylinder and the fuel housing;

[0016] The support plates are circumferentially and uniformly arranged on the side wall of the fuel housing close to the air cylinder, and an air supply passage is formed at a circumferential interval between any two adjacent support plates.

[0017] Optionally, a swirl vane is provided at one end of the secondary fuel passage away from the fuel housing along the axial direction; the swirl vane is provided with the film hole.

[0018] Optionally, a secondary fuel connecting pipe is provided between the fuel housing and the secondary fuel structure, and the secondary fuel connecting pipe is adapted to communicate the secondary fuel passage with the fuel cavity;

[0019] The secondary fuel connecting pipe is provided with a film hole, and the film hole is adapted to introduce air from the outside of the secondary fuel connecting pipe into the secondary fuel connecting pipe.

[0020] Optionally, an end plate is provided between one end of the primary fuel cylinder body axially away from the fuel housing and the first cylinder body, and the end plate is adapted to enclose the first air flow path;

[0021] The end plate is provided with air film holes, and the air film holes are adapted to introduce the air in the first air flow path to the other side axially of the end plate.

[0022] The working method of the hydrogen fuel nozzle provided by the present invention is applied to the hydrogen fuel nozzle as described above, and the working method of the hydrogen fuel nozzle includes:

[0023] Supply hydrogen from the fuel supply pipeline to the fuel chamber, and distribute the hydrogen to the primary fuel channel and the secondary fuel channel respectively through the fuel chamber;

[0024] Supply air from the air supply channel to the first air flow path and the second air flow path, so that a part of the air enters the primary fuel channel and the secondary fuel channel respectively through the air film holes to be premixed with hydrogen, and the other part of the air directly flows to the end of the nozzle through the second air flow path;

[0025] By continuously flowing air from the air film holes into the hydrogen flow path to form a micro-premix with hydrogen, the premixed gas in the primary fuel channel is directly sprayed into the combustion chamber, and the premixed gas in the secondary fuel channel generates a stable swirl after passing through the swirl vanes and flows into the combustion chamber, and is quickly and uniformly mixed with the air directly flowing to the end of the nozzle and the premixed gas transmitted from the primary fuel channel, and then burns continuously and stably.

[0026] Optionally, the volume ratio of the air entering the primary fuel channel and the secondary fuel channel from the air film holes to the premixed gas is less than 15%.

[0027] The technical solution of the present invention has the following advantages:

[0028] 1. The hydrogen fuel nozzle provided by the present invention, by providing a multi-stage fuel channel, thus sharing the hydrogen flow rate to reduce the hydrogen ratio in each fuel channel, thereby reducing the probability of occurrence of hydrogen embrittlement and hydrogen corrosion; by densely arranging the air film holes on the channel wall surface through which hydrogen flows, on the one hand, the air film formed after introducing air can cover the channel wall surface, thereby isolating hydrogen and preventing the occurrence of hydrogen embrittlement and hydrogen corrosion, ensuring combustion stability; on the other hand, by introducing part of the air into the fuel channel through the air film holes, a micro-premix can be formed in the hydrogen flow path, improving the mixing uniformity, being beneficial to fuel combustion, and the introduced air volume does not reach the concentration required for hydrogen ignition, so center flow backfire can be prevented; moreover, the introduced air can form a continuous wall-attached air film at the wall surface, which can physically isolate the flame and prevent boundary layer backfire during hydrogen combustion, improving combustion stability, and further enabling the gas turbine to operate safely and stably.

[0029] 2. The hydrogen fuel nozzle provided by the present invention, the inner diameter d of the gas film hole has a value range of 0.1 mm ≤ d ≤ 0.5 mm, so as to ensure that the gas film hole jets at high speed and fully, so as to form a gas film on the channel wall surface through which hydrogen flows, which can not only cool the channel wall surface, but also effectively avoid direct contact between hydrogen and the wall surface, and further effectively prevent the occurrence of hydrogen embrittlement and hydrogen corrosion phenomena; the axial distance between every two adjacent gas film holes is P, and P satisfies P < 10·d, and the circumferential distance between every two adjacent gas film holes is Q, and Q satisfies Q < 3·d, where d is the inner diameter of the gas film hole, so as to ensure that the gas film formed when air exits from the gas film hole can completely cover the wall surface, end surface, etc. through which hydrogen flows, and further effectively isolate hydrogen and prevent the occurrence of hydrogen embrittlement and hydrogen corrosion phenomena.

[0030] 3. The hydrogen fuel nozzle provided by the present invention, an arc-shaped plate is arranged at one end of the air cylinder body axially away from the fuel housing, and the arc-shaped plate is adapted to change the flow direction of the air exiting from the second air flow path, so that this part of the air exits from the nozzle outlet; the radial cross-section of the arc-shaped plate gradually contracts axially in the direction away from the fuel housing; the included angle α between the arc-shaped plate and the central axis of the hydrogen fuel nozzle has a value range of 30° ≤ α ≤ 60°, which is beneficial to both the mixing of air and fuel and the fluid flow.

[0031] 4. The working method of the hydrogen fuel nozzle provided by the present invention, after air exits from the gas film hole, a continuous air film can be formed, which adheres to the material surface to isolate hydrogen and prevent direct contact between hydrogen and the material, thereby preventing the occurrence of hydrogen embrittlement and hydrogen corrosion phenomena, extending the service life of the nozzle, and ensuring combustion stability at the same time; at the same time, air continuously flows into the hydrogen flow path from the gas film hole, forms a micro-premix with hydrogen, and the premixed gas in the primary fuel channel is directly sprayed into the flame tube, which can increase the average flow velocity of the premixed gas; the premixed gas in the secondary fuel channel generates a stable swirl after passing through the swirl vane, and flows into the flame tube, and is quickly and uniformly mixed with the air flowing directly to the nozzle end and the premixed gas exiting from the primary fuel channel, and then burns continuously and stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 It is the front view of the hydrogen fuel nozzle of the present invention;

[0034] Figure 2This is the right view of the hydrogen fuel nozzle of the present invention;

[0035] Figure 3 is Figure 2 the sectional view of the A-A section in

[0036] Figure 4 This is the axonometric view of the hydrogen fuel nozzle of the present invention.

[0037] Explanation of reference numerals:

[0038] 10. Fuel housing; 100. Fuel chamber; 11. Flange part; 110. Bolt hole;

[0039] 20. Primary fuel cylinder; 200. Primary fuel passage; 21. End plate;

[0040] 30. Air cylinder; 300. Air film hole; 31. Arc plate;

[0041] 40. Secondary fuel structure; 400. Secondary fuel passage; 41. First cylinder; 410. First air flow path; 42. Second cylinder; 420. Second air flow path; 43. Secondary fuel connecting pipe;

[0042] 50. Support plate; 500. Air supply passage;

[0043] 60. Swirl vane;

[0044] 70. Fuel supply pipe. Detailed implementation manners

[0045] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0046] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0049] Embodiment 1

[0050] Combined with Figures 1-4 As shown, the hydrogen fuel nozzle provided in this embodiment includes:

[0051] A fuel housing 10, the inner wall of which encloses a fuel chamber 100;

[0052] A primary fuel cylinder 20, coaxially arranged with the fuel housing 10, the inner circumferential wall of the primary fuel cylinder 20 encloses a primary fuel passage 200, and the primary fuel passage 200 is in communication with the fuel chamber 100;

[0053] An air cylinder 30, coaxially arranged with the primary fuel cylinder 20; an annular cavity is formed at a radial interval between the air cylinder 30 and the primary fuel cylinder 20;

[0054] A secondary fuel structure 40, arranged in the annular cavity, the secondary fuel structure 40 includes a first cylinder 41 and a second cylinder 42 arranged at a radial interval;

[0055] A first air flow path 410 is formed at a radial interval between the inner circumferential wall of the first cylinder 41 and the outer circumferential wall of the primary fuel cylinder 20; a secondary fuel passage 400 is formed at a radial interval between the outer circumferential wall of the first cylinder 41 and the inner circumferential wall of the second cylinder 42, and the secondary fuel passage 400 is in communication with the fuel chamber 100; a second air flow path 420 is formed at a radial interval between the outer circumferential wall of the second cylinder 42 and the inner circumferential wall of the air cylinder 30;

[0056] The primary fuel cylinder 20, the first cylinder 41, and the second cylinder 42 are all provided with air film holes 300.

[0057] It should be noted that please refer to Figure 3As shown, the inner wall of the fuel housing 10 encloses to form a fuel chamber 100. One axial side of the fuel chamber 100 is adapted to communicate with a fuel supply pipe 70, and the other side is adapted to communicate with a fuel passage. The fuel passages are arranged in stages to allocate the total amount of hydrogen fuel and reduce the proportion of hydrogen in each stage of the fuel passage, thereby reducing the probability of hydrogen embrittlement and hydrogen corrosion. The fuel passage of the present invention can be divided into 2 - 5 stages according to the design conditions of the hydrogen fuel nozzle. Each additional stage can reduce the amount of hydrogen in each fuel passage. Since the total amount of hydrogen remains unchanged, the reduction of the amount of hydrogen in a single fuel pipeline is beneficial to reducing the probability of hydrogen embrittlement and hydrogen corrosion. For the convenience of better explaining and understanding the present invention, in this embodiment, a primary fuel passage 200 and a secondary fuel passage 400 are used for illustration, that is, the number of fuel passage stages in this embodiment is 2. The working principles of the fuel passages with 3, 4, and 5 stages are the same as those of the 2 - stage fuel passage and will not be elaborated in this embodiment.

[0058] Optionally, a flange portion 11 extends radially away from the central axis of the hydrogen fuel nozzle on the outer peripheral wall of the fuel housing 10. The flange portion 11 is adapted to fix the hydrogen fuel nozzle to the flame tube. A bolt hole 110 is axially formed on the flange portion 11, and the flange portion 11 can be bolt - connected to the flame tube through the bolt hole 110.

[0059] It should be noted that still referring to Figure 3As shown, the primary fuel cylinder 20 is coaxially arranged with the fuel housing 10. The central axis of the primary fuel cylinder 20 coincides with the central axis of the hydrogen fuel nozzle. The inner circumferential wall of the primary fuel cylinder 20 encloses a primary fuel passage 200. A hydrogen gas flow is suitable for flowing through the primary fuel passage 200. One axial end of the primary fuel passage 200 is communicated with the fuel chamber 100, and the other end is suitable for injecting fuel into the combustion chamber at a high speed, thereby increasing the average flow velocity of the fuel-air mixture. The air cylinder 30 is coaxially arranged with the primary fuel cylinder 20. An annular cavity is formed at a radial interval between the inner circumferential wall of the air cylinder 30 and the outer circumferential wall of the primary fuel cylinder 20. The secondary fuel structure 40 is arranged in the annular cavity. The secondary fuel structure 40 is of an annular structure, and its opening faces away from the fuel housing 10 along the axis. The secondary fuel structure 40 includes a first cylinder 41 and a second cylinder 42 arranged at a radial interval. Wherein, a first air flow path 410 is formed at a radial interval between the inner circumferential wall of the first cylinder 41 and the outer circumferential wall of the primary fuel cylinder 20. An air flow is suitable for flowing through the first air flow path 410. A secondary fuel passage 400 is formed at a radial interval between the outer circumferential wall of the first cylinder 41 and the inner circumferential wall of the second cylinder 42. A hydrogen gas flow is suitable for flowing through the secondary fuel passage 400. The secondary fuel passage 400 is communicated with the fuel chamber 100. A second air flow path 420 is formed at a radial interval between the outer circumferential wall of the second cylinder 42 and the inner circumferential wall of the air cylinder 30. An air flow is suitable for flowing through the second air flow path 420. The second air flow path 420 is used to provide most of the air required for fuel combustion.

[0060] It should be noted that still referring to Figure 3 As shown, air film holes 300 are formed in the primary fuel cylinder 20, the first cylinder 41 and the second cylinder 42. The air film holes 300 are suitable for transmitting the air in the air flow path to the fuel passage. The air film holes 300 are densely distributed on the wall surfaces of the primary fuel cylinder 20, the first cylinder 41 and the second cylinder 42, so as to ensure that the air film formed when the air exits from the air film holes 300 can completely cover the wall surface of the hydrogen gas flow passage, so as to isolate hydrogen gas, prevent hydrogen embrittlement and hydrogen corrosion, and ensure combustion stability. At the same time, by densely forming the air film holes 300 on the wall surface of the hydrogen gas flow passage to introduce part of the air, firstly, a micro-premix can be formed in the hydrogen gas flow path, improving the mixing uniformity and being beneficial to fuel combustion. Secondly, the introduced air volume does not reach the concentration required for hydrogen ignition, so center flow flashback can be prevented. In addition, a continuous wall-attached air film is formed at the wall surface, which can physically isolate the flame and prevent boundary layer flashback during hydrogen combustion, improving combustion stability, so that the gas turbine can operate safely and stably.

[0061] In this embodiment, a multi-stage fuel channel is provided to distribute the hydrogen flow rate, so as to reduce the proportion of hydrogen in each fuel channel, thereby reducing the probability of hydrogen embrittlement and hydrogen corrosion. By densely opening the air film holes 300 on the wall of the channel through which the hydrogen flows, on the one hand, the air film formed after the air is introduced can cover the wall of the channel, thereby isolating the hydrogen, preventing the occurrence of hydrogen embrittlement and hydrogen corrosion, and ensuring the combustion stability. On the other hand, by introducing part of the air into the fuel channel through the air film holes 300, micro-premixing can be formed in the hydrogen flow path, thereby improving the mixing uniformity, which is beneficial to fuel combustion, and the amount of air introduced does not reach the concentration required for hydrogen ignition, thereby preventing the center flow from flashing back. Moreover, the introduced air can form a continuous wall-attached air film at the wall, which can physically isolate the flame, prevent the boundary layer flashback during hydrogen combustion, improve the combustion stability, and thus enable the gas turbine to operate safely and stably.

[0062] Specifically, the inner diameter of the air film hole 300 is d, and the value range of d is 0.1mm≤d≤0.5mm.

[0063] It should be noted that the inner diameter of the air film hole 300 is d, and the inner diameter of the air film hole 300 cannot be too small, otherwise the flow area of the air film hole 300 is too small, which may easily lead to a relatively low amount of air film formed on the wall of the channel through which the hydrogen flows, which is not conducive to the air film blocking hydrogen, and there is a risk of hydrogen embrittlement and hydrogen corrosion. Therefore, the inner diameter d must satisfy d≥0.1mm; at the same time, the inner diameter of the air film hole 300 cannot be too large, otherwise it may easily lead to the injection of the air film hole 300. The flow velocity is relatively low, and the air flow velocity is relatively low, which is not conducive to the air film blocking hydrogen. Therefore, the inner diameter d must also satisfy d≤0.5mm; in summary, the value range of the inner diameter d of the air film hole 300 is 0.1mm≤d≤0.5mm, thereby ensuring that the air film hole 300 is fully jetted at high speed to form an air film on the wall of the channel through which hydrogen flows, which can not only cool the wall of the channel, but also effectively avoid direct contact between hydrogen and the wall, thereby effectively preventing the occurrence of hydrogen embrittlement and hydrogen corrosion.

[0064] Specifically, the axial distance between each two adjacent air film holes 300 is P, and P satisfies P<10·d; the circumferential distance between each two adjacent air film holes 300 is Q, and Q satisfies Q<3·d.

[0065] It should be noted that the axial spacing and / or circumferential spacing of the air film holes 300 should not be too large, otherwise it is easy to cause the air film holes 300 to be relatively scattered, and it may not be possible to ensure that the air film completely covers the wall surface and end surface through which the hydrogen gas flows, resulting in direct contact between the hydrogen gas and the wall surface in a local area, and there is a risk of hydrogen embrittlement and hydrogen corrosion; in the present invention, the axial spacing between every two adjacent air film holes 300 is P, and P satisfies P < 10·d. The circumferential spacing between every two adjacent air film holes 300 is Q, and Q satisfies Q < 3·d, where d is the inner diameter of the air film hole 300, so as to ensure that the air film formed when the air exits from the air film hole 300 can completely cover the wall surface, end surface, etc. through which the hydrogen gas flows, thereby effectively isolating the hydrogen gas and preventing the occurrence of hydrogen embrittlement and hydrogen corrosion phenomena.

[0066] Specifically, an arc-shaped plate 31 is provided at one end of the air cylinder 30 axially away from the fuel shell 10, and the radial cross-section of the arc-shaped plate 31 gradually contracts axially in a direction away from the fuel shell 10; the included angle between the arc-shaped plate 31 and the central axis of the hydrogen fuel nozzle is α, and α satisfies 30° ≤ α ≤ 60°.

[0067] It should be noted that, please refer to Figure 3 As shown, an arc-shaped plate 31 is provided at one end of the air cylinder 30 axially away from the fuel shell 10. The arc-shaped plate 31 is adapted to change the flow direction of the air exiting from the second air flow path 420, so that this part of the air exits from the nozzle outlet; the radial cross-section of the arc-shaped plate 31 gradually contracts axially in a direction away from the fuel shell 10. The included angle between the arc-shaped plate 31 and the central axis of the hydrogen fuel nozzle is α. The included angle α cannot be too small, otherwise it is easy to cause the angle of change of the air propagation direction to be too small, which is not conducive to mixing with the fuel inside. Therefore, the included angle α needs to satisfy α ≥ 30°; at the same time, the included angle α cannot be too large, otherwise it is easy to cause the axial component velocity of the air to be too small, which is not conducive to fluid flow. Therefore, the included angle α needs to satisfy α ≤ 60°; in the present invention, the value range of the included angle α between the arc-shaped plate 31 and the central axis of the hydrogen fuel nozzle is 30° ≤ α ≤ 60°, so as to be conducive to both the mixing of air and fuel and fluid flow.

[0068] Specifically, a plurality of support plates 50 are provided between the air cylinder 30 and the fuel shell 10, and the support plates 50 are adapted to connect the air cylinder 30 and the fuel shell 10;

[0069] The support plates 50 are circumferentially and uniformly arranged on the side wall surface of the fuel shell 10 close to the air cylinder 30, and an air supply channel 500 is formed at intervals circumferentially between any two adjacent support plates 50.

[0070] Optionally, the number of the support plates 50 is four, and the four support plates 50 are circumferentially and evenly arranged on a side wall surface of the fuel housing 10 close to the air cylinder 30. An air supply channel 500 is formed between every two adjacent support plates 50 at intervals in the circumferential direction, and the air supply channel 500 is adapted to supply air into the first air flow path 410 and the second air flow path 420.

[0071] Specifically, a swirl vane 60 is arranged at one end of the secondary fuel channel 400 axially away from the fuel housing 10; and air film holes 300 are formed in the swirl vane 60.

[0072] In this embodiment, a plurality of swirl vanes 60 are arranged at one end of the secondary fuel channel 400 axially away from the fuel housing 10, and the plurality of swirl vanes 60 are circumferentially and evenly arranged in the secondary fuel channel 400 to form a swirler for swirling the fluid, and the air film holes 300 are formed in each swirl vane 60.

[0073] It should be noted that, as shown in Figure 3 in addition to the primary fuel channel 200, a swirl vane 60 is arranged at one end of the remaining fuel channels axially away from the fuel housing 10, and each stage of the remaining fuel channels is connected to the fuel chamber 100 through a plurality of fuel connecting pipes ( Figure 3 only one fuel connecting pipe is exemplarily shown in the figure to show its structure and connection relationship). For example, in this embodiment, a plurality of swirl vanes 60 are arranged at one end of the secondary fuel channel 400 axially away from the fuel housing 10 ( Figure 2 and Figure 3 only one swirl vane is exemplarily shown in the figure to show its structure and specific setting position), and the plurality of swirl vanes 60 are adapted to form a swirler for swirling the air flow. The secondary fuel channel 400 is connected to the fuel chamber 100 through a secondary fuel connecting pipe 43; the specific setting conditions of the swirl vanes and the fuel connecting pipes in the 3rd-stage, 4th-stage and 5th-stage fuel channel structures are the same as those of the secondary fuel channel 400, and will not be described herein again.

[0074] It should be noted that a plurality of the swirl vanes 60 are provided and are hollow inside. The inner walls of the swirl vanes 60 surround to form a chamber (not shown in the figure). One radial end of the chamber is communicated with the first air flow path 410 through a first supply hole (not shown in the figure), and the other end is communicated with the second air flow path 420 through a second supply hole (not shown in the figure). The swirl vanes 60 are provided with the film holes 300, and the film holes 300 are communicated with the chamber. The film holes 300 are densely distributed on the surface of the swirl vanes 60, so as to ensure that the air film formed when the air exits from the film holes 300 can completely cover the wall surface of the swirl vanes 60 through which the hydrogen gas flows, so as to effectively isolate the hydrogen gas and prevent the occurrence of hydrogen embrittlement and hydrogen corrosion phenomena.

[0075] Specifically, a secondary fuel connecting pipe 43 is provided between the fuel housing 10 and the secondary fuel structure 40. The secondary fuel connecting pipe 43 is adapted to communicate the secondary fuel passage 400 with the fuel chamber 100.

[0076] The secondary fuel connecting pipe 43 is provided with the film holes 300, and the film holes 300 are adapted to introduce air from the outside of the secondary fuel connecting pipe 43 into the secondary fuel connecting pipe 43.

[0077] In this embodiment, a plurality of secondary fuel connecting pipes 43 are provided between the fuel housing 10 and the secondary fuel structure 40. The plurality of secondary fuel connecting pipes 43 are circumferentially and uniformly arranged on a side wall surface of the fuel housing 10 close to the air cylinder 30. Each secondary fuel connecting pipe 43 is provided with the film holes 300.

[0078] It should be noted that the secondary fuel connecting pipe 43 is provided with the film holes 300, and the film holes 300 are densely distributed on the surface of the secondary fuel connecting pipe 43, so as to ensure that the air film formed when the air exits from the film holes 300 can completely cover the wall surface of the secondary fuel connecting pipe 43 through which the hydrogen gas flows, so as to effectively isolate the hydrogen gas and prevent the occurrence of hydrogen embrittlement and hydrogen corrosion phenomena.

[0079] Specifically, a end plate 21 is provided between one end of the primary fuel cylinder 20 axially away from the fuel housing 10 and the first cylinder 41. The end plate 21 is adapted to close the first air flow path 410.

[0080] The end plate 21 is provided with the film holes 300, and the film holes 300 are adapted to introduce the air in the first air flow path 410 to the other side axially of the end plate 21.

[0081] It should be noted that air film holes 300 are formed in the end plate 21, and the air film holes 300 are densely distributed on the surface of the end plate 21, so as to ensure that the air film formed when air exits from the air film holes 300 can completely cover the end face through which the hydrogen gas flows, effectively isolating the hydrogen gas and preventing the occurrence of hydrogen embrittlement and hydrogen corrosion phenomena.

[0082] It should be noted that between the primary fuel cylinder body 20 and the fuel housing 10, between the secondary fuel connection pipe 43 and the fuel housing 10, and between the support plate 50 and the fuel housing 10, non-welding connection methods can be adopted. The non-welding connection methods such as flange, bolt and other connection methods are convenient for maintenance and replacement; if welding connection is adopted, it is also possible, but when a certain component is damaged and needs to be replaced, it needs to be cut off, and it can be separated by methods such as angle grinder and wire cutting, which is more cumbersome than flange, bolt, etc. Therefore, since the fuel housing 10 and its upstream components are in the non-high temperature area inside the gas turbine, when hydrogen embrittlement and hydrogen corrosion phenomena occur in the fuel housing 10 or its upstream components, the non-welding connection method is convenient for disassembly and replacement.

[0083] Embodiment 2

[0084] The working method of the hydrogen fuel nozzle provided in this embodiment is applied to the hydrogen fuel nozzle as described above. The working method of the hydrogen fuel nozzle includes:

[0085] Supply hydrogen from the fuel supply pipe 70 to the fuel chamber 100, and distribute the hydrogen to the primary fuel passage 200 and the secondary fuel passage 400 through the fuel chamber 100;

[0086] Supply air from the air supply passage 500 to the first air flow path 410 and the second air flow path 420, so that a part of the air enters the primary fuel passage 200 and the secondary fuel passage 400 respectively through the air film holes 300 to premix with the hydrogen, and another part of the air directly flows to the end of the nozzle through the second air flow path 420;

[0087] By continuously flowing air from the air film holes 300 into the hydrogen gas flow path to form a micro-premix with the hydrogen, the premixed gas in the primary fuel passage 200 is directly sprayed into the combustion chamber, and the premixed gas in the secondary fuel passage 400 generates a stable swirl after passing through the swirl vane 60 and flows into the combustion chamber, and is quickly and uniformly mixed with the air directly flowing to the end of the nozzle and the premixed gas exiting from the primary fuel passage 200, and then burns continuously and stably.

[0088] Specifically, the volume ratio of the air entering the primary fuel passage 200 and the secondary fuel passage 400 from the air film holes 300 to the mixed gas is less than 15%.

[0089] It should be noted that the volume ratio of the air entering the primary fuel passage 200 and the secondary fuel passage 400 through the air film holes 300 to the fuel-air mixture is less than 15%, so as to avoid the hydrogen ratio falling within the explosive concentration range, which is beneficial to improving the safety of the gas turbine.

[0090] The working method of the hydrogen fuel nozzle of the present invention will be described uniformly as follows:

[0091] Combined with Figure 3 As shown, when the hydrogen fuel nozzle works, hydrogen enters the fuel chamber 100 from the fuel supply pipe 70, and then enters the primary fuel passage 200 and the secondary fuel passage 400 from the fuel chamber 100 respectively. At the same time, air enters the first air flow path 410 and the second air flow path 420 from the air supply passage 500; among them, the air entering the first air flow path 410 can be divided into five parts. The first part enters the air film holes 300 on the secondary fuel connecting pipe 43, the second part enters the air film holes 300 on the primary fuel cylinder body 20, the third part enters the air film holes 300 on the first cylinder body 41, the fourth part is transmitted to the chamber of the swirl vane 60 through the supply holes on the first cylinder body 41, and then exits from the air film holes 300 on the swirl vane 60, and the fifth part enters the air film holes 300 on the end plate 21; the air entering the second air flow path 420 can be divided into three parts. The first part enters the air film holes 300 of the second cylinder body 42, the second part is transmitted to the chamber of the swirl vane 60 through the supply holes on the second cylinder body 42, and then exits from the air film holes 300 on the swirl vane 60, and the third part is used to provide most of the air required for hydrogen combustion. When the third part of the air flows to the arc plate 31, its flow direction is changed by the arc plate 31, and then it exits from the nozzle outlet; after the air exits from the above-mentioned air film holes 300, a continuous air film can be formed, which adheres to the material surface to isolate hydrogen and prevent hydrogen from directly contacting the material, thereby preventing hydrogen embrittlement and hydrogen corrosion phenomena, prolonging the service life of the nozzle, and ensuring combustion stability at the same time; at the same time, air continuously flows into the hydrogen flow path from the air film holes 300 and forms a micro-premix with hydrogen. The premixed gas in the primary fuel passage 200 is directly sprayed into the combustion chamber, which can increase the average flow velocity of the fuel-air mixture; the premixed gas in the secondary fuel passage 400 generates a stable swirl after passing through the swirl vane 60 and flows into the combustion chamber, and quickly mixes evenly with the air flowing directly to the nozzle end and the premixed gas exiting from the primary fuel passage 200, and then burns continuously and stably.

[0092] Obviously, the above-mentioned embodiments are only examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A hydrogen fuel nozzle, characterized in that, Comprising: A fuel housing (10), the inner wall of which encloses a fuel chamber (100); A primary fuel cylinder (20) arranged coaxially with the fuel housing (10), the inner circumferential wall of the primary fuel cylinder (20) enclosing a primary fuel passage (200), and the primary fuel passage (200) being in communication with the fuel chamber (100); An air cylinder (30) arranged coaxially with the primary fuel cylinder (20); an annular cavity is formed at a radial interval between the air cylinder (30) and the primary fuel cylinder (20); A secondary fuel structure (40) arranged in the annular cavity, the secondary fuel structure (40) including a first cylinder (41) and a second cylinder (42) arranged at a radial interval; A first air flow path (410) is formed at a radial interval between the inner circumferential wall of the first cylinder (41) and the outer circumferential wall of the primary fuel cylinder (20); a secondary fuel passage (400) is formed at a radial interval between the outer circumferential wall of the first cylinder (41) and the inner circumferential wall of the second cylinder (42), and the secondary fuel passage (400) is in communication with the fuel chamber (100); a second air flow path (420) is formed at a radial interval between the outer circumferential wall of the second cylinder (42) and the inner circumferential wall of the air cylinder (30); Gas film holes (300) are formed on the primary fuel cylinder (20), the first cylinder (41) and the second cylinder (42); A plurality of support plates (50) are arranged between the air cylinder (30) and the fuel housing (10), the support plates (50) being adapted to connect the air cylinder (30) and the fuel housing (10), the support plates (50) being circumferentially arranged on the side wall of the fuel housing (10) close to the air cylinder (30), and an air supply passage (500) is formed at a circumferential interval between any two adjacent support plates (50); A secondary fuel connecting pipe (43) is arranged between the fuel housing (10) and the secondary fuel structure (40), and the secondary fuel connecting pipe (43) is adapted to communicate the secondary fuel passage (400) with the fuel chamber (100); An end plate (21) is arranged between one end of the primary fuel cylinder (20) axially away from the fuel housing (10) and the first cylinder (41), and the end plate (21) is adapted to close the first air flow path (410); Gas film holes (300) are formed on the end plate (21), and the gas film holes (300) are adapted to introduce the air in the first air flow path (410) to the other side axially of the end plate (21).

2. The hydrogen fuel nozzle according to claim 1, characterized in that, The inner diameter of the gas film hole (300) is d, and the value range of d is 0.1 mm ≤ d ≤ 0.5 mm.

3. The hydrogen fuel nozzle according to claim 2, characterized in that, The axial pitch between every two adjacent gas film holes (300) is P, and P satisfies P < 10·d; the circumferential pitch between every two adjacent gas film holes (300) is Q, and Q satisfies Q < 3·d.

4. The hydrogen fuel nozzle according to claim 1, characterized in that, An arc-shaped plate (31) is provided at one end of the air cylinder body (30) axially away from the fuel housing (10). The radial cross-section of the arc-shaped plate (31) gradually contracts axially in a direction away from the fuel housing (10). The angle between the arc-shaped plate (31) and the central axis of the hydrogen fuel nozzle is α, and α satisfies 30° ≤ α ≤ 60°.

5. The hydrogen fuel nozzle according to claim 1, characterized in that, The support plates (50) are circumferentially and uniformly arranged on the side wall surface of the fuel housing (10) close to the air cylinder body (30). An air supply channel (500) is formed at intervals in the circumferential direction between any two adjacent support plates (50).

6. The hydrogen fuel nozzle according to any one of claims 1-5, characterized in that, A swirl vane (60) is provided at one end of the secondary fuel channel (400) axially away from the fuel housing (10). The air film holes (300) are formed in the swirl vane (60).

7. The hydrogen fuel nozzle according to any one of claims 1-5, characterized in that, The air film holes (300) are formed in the secondary fuel connecting pipe (43). The air film holes (300) are adapted to introduce air from the outside of the secondary fuel connecting pipe (43) into the secondary fuel connecting pipe (43).

8. A working method of a hydrogen fuel nozzle, applied to the hydrogen fuel nozzle according to any one of the above-mentioned claims 1-7, characterized in that, The working method of the hydrogen fuel nozzle includes: Supplying hydrogen from a fuel supply pipeline into the fuel chamber (100), and distributing the hydrogen to the primary fuel channel (200) and the secondary fuel channel (400) respectively through the fuel chamber (100); Supplying air from the air supply channel (500) to the first air flow path (410) and the second air flow path (420), so that a part of the air enters the primary fuel channel (200) and the secondary fuel channel (400) respectively through the air film holes (300) to be premixed with hydrogen, and another part of the air directly flows to the end of the nozzle through the second air flow path (420); By continuously flowing air from the air film holes (300) into the hydrogen gas flow path to form micro-premixing with hydrogen, the premixed gas in the primary fuel channel (200) is directly injected into the combustion chamber. The premixed gas in the secondary fuel channel (400) generates stable swirl after passing through the swirl vane (60), and flows into the combustion chamber, and is quickly and uniformly mixed with the air directly flowing to the end of the nozzle and the premixed gas coming out of the primary fuel channel (200), and then burns continuously and stably.

9. The working method of the hydrogen fuel nozzle according to claim 8, characterized in that, The volume ratio of the air entering the primary fuel channel (200) and the secondary fuel channel (400) from the air film holes (300) to the mixed gas is less than 15%.

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