Anti-backfire staged combustion hydrogen nozzle and combustion control method

Abstract

This invention relates to the field of aero-engine technology and discloses a staged combustion hydrogen nozzle with backfire prevention and combustion control method. The invention features a mixing orifice with a hydrogen fuel injection spiral structure on the nozzle combustion head disk, enhancing the mixing of hydrogen fuel and air, improving the uniformity of hydrogen fuel-air mixing, enabling more complete combustion of hydrogen fuel, reducing flame dwell time, and thus reducing NOx emissions. Simultaneously, an air orifice is provided near the mixing orifice, through which high-speed airflow is ejected, increasing the airflow velocity, shortening the flame dwell time, reducing NOx emissions, preventing backfire, and the high-speed airflow also cools the nozzle head, reducing the nozzle operating temperature and extending nozzle lifespan.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology and discloses a backfire-preventing staged combustion hydrogen nozzle and combustion control method. Background Technology

[0002] Compared to traditional aviation kerosene, hydrogen fuel possesses unique physical properties, including high compressibility, high combustion limits, high calorific value, high heat sink rate, and rapid diffusion. The design of fuel nozzles in traditional aero-engine combustors is unsuitable for the rapid combustion characteristics of hydrogen fuel, easily leading to flame backflow to the nozzle and causing backfire. Traditional fuel nozzles rely on the atomization of liquid fuel for air mixing, while hydrogen fuel exists in a gaseous state. Due to its extremely low density, low injection momentum, and weak jet penetration, direct injection of hydrogen fuel by traditional nozzles makes mixing with air difficult, hindering the formation of a homogeneous mixture and resulting in incomplete combustion. Furthermore, hydrogen fuel's high compressibility, compared to the incompressible liquid aviation kerosene, can lead to uneven flow rates during actual supply. Therefore, based on the characteristics of hydrogen fuel—low density, high volumetric flow rate, rapid diffusion, and high calorific value—the traditional fuel nozzle structure in aero-engine combustors is unsuitable for hydrogen fuel. Summary of the Invention

[0003] The purpose of this invention is to provide a backfire-preventing staged combustion hydrogen nozzle and combustion control method, which can enhance the mixing effect of hydrogen fuel and air, improve the mixing uniformity, reduce NOx emissions, and prevent backfire.

[0004] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows:

[0005] A backfire-preventing staged combustion hydrogen nozzle, comprising:

[0006] The nozzle combustion head disk includes an air orifice, a shift combustion unit, and a main combustion stage combustion unit. The main combustion stage combustion unit is arranged around the shift combustion unit. Both the shift combustion unit and the main combustion stage combustion unit include a plurality of mixing orifices. A hydrogen fuel injection spiral structure is provided in the mixing orifice. The hydrogen fuel injection spiral structure is used to guide the air flowing through the mixing orifice to form a swirling flow and inject hydrogen fuel into the swirling flow to mix the hydrogen fuel with the air.

[0007] The hydrogen supply pipeline includes a duty hydrogen supply pipeline and a main combustion stage hydrogen supply pipeline, both of which are connected to the nozzle combustion head disk. The duty hydrogen supply pipeline is used to supply hydrogen fuel to the mixing orifice of the duty combustion unit; the main combustion stage hydrogen supply pipeline is used to supply hydrogen fuel to the mixing orifice of the main combustion stage combustion unit.

[0008] Furthermore, the hydrogen fuel injection spiral structure is a hollow spiral, and the cross-section of the hollow spiral includes at least two hollow branches that are radially distributed and interconnected with each other around the axis of the mixing hole. The spacing between the hollow branches is equal, and the hollow branches are provided with hydrogen fuel injection holes.

[0009] Furthermore, the duty combustion unit includes a central mixing hole and at least one first mixing hole surrounding the central mixing hole; the hydrogen fuel injection spiral structure of the central mixing hole is connected to the hydrogen fuel injection spiral structure of the first mixing hole.

[0010] Furthermore, the main combustion stage combustion unit includes at least one ring of second mixing holes surrounding the duty combustion unit, and the hydrogen fuel injection spiral structures of all the second mixing holes are interconnected.

[0011] Furthermore, the nozzle combustion head disk includes a first disk body and a partition ring; the first disk body is a hollow structure; the partition ring divides the internal space of the first disk body into a duty combustion unit cavity located inside the partition ring and a main combustion stage combustion unit cavity located outside the partition ring;

[0012] The duty combustion unit is provided with a central mixing tube having the central mixing hole and a first mixing tube having the first mixing hole. The hydrogen fuel injection spiral structure in the central mixing tube and the first mixing tube are both connected to the cavity of the duty combustion unit. The cavity of the main combustion stage is provided with a second mixing tube having the second mixing hole. The hydrogen fuel injection spiral structure in the second mixing tube is connected to the cavity of the main combustion stage.

[0013] The air vent is located on the separator ring.

[0014] Furthermore, the hydrogen supply pipeline for the duty shift is connected to the cavity of the duty shift combustion unit, and the hydrogen supply pipeline for the main combustion stage is connected to the cavity of the main combustion stage combustion unit.

[0015] Furthermore, the nozzle combustion head disk includes a second disk body and an inner core block, and an annular hydrogen supply channel is provided between the inner wall of the second disk body and the outer peripheral wall of the inner core block;

[0016] The air vent, the central mixing vent and the first mixing vent of the duty combustion unit, and the second mixing vent of the main combustion stage combustion unit are all located on the inner core block of the disk. The hydrogen fuel injection spiral structure of the central mixing vent and the first mixing vent is connected through the first hydrogen supply channel, and the hydrogen fuel injection spiral structure of the second mixing vent is connected through the second hydrogen supply channel. Furthermore, the hydrogen fuel injection spiral structure of the second mixing vent near the outer peripheral wall of the inner core block is connected to the annular hydrogen supply channel.

[0017] Furthermore, the on-duty hydrogen supply pipeline is connected to the first hydrogen supply channel, and the main combustion stage hydrogen supply pipeline is connected to the annular hydrogen supply channel or the second hydrogen supply channel.

[0018] A method for controlling the combustion of a backfire-preventing staged combustion hydrogen nozzle is provided, which controls the backfire-preventing staged combustion hydrogen nozzle to start the duty combustion unit and the main combustion stage combustion unit in stages according to the load requirements of the aero-engine.

[0019] Compared with the prior art, the beneficial effects of this invention are:

[0020] This invention features a mixing orifice with a hydrogen fuel injection spiral structure on the nozzle combustion head disk. This enhances the mixing of hydrogen fuel and air, improves the uniformity of hydrogen fuel-air mixing, and allows for more complete combustion of hydrogen fuel, reducing flame dwell time and thus lowering NOx emissions. Simultaneously, an air hole is provided near the mixing orifice, through which high-speed airflow is ejected, increasing the airflow velocity, shortening the flame dwell time, reducing NOx emissions, preventing backfire, and the high-speed airflow also cools the nozzle head, lowering the nozzle operating temperature and extending the nozzle's service life. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the first structure of the anti-backfire staged combustion hydrogen nozzle in the embodiment;

[0022] Figure 2 for Figure 1 Schematic diagram of the exhaust side of the staged combustion hydrogen nozzle with anti-backfire capability;

[0023] Figure 3 for Figure 2 A partially enlarged schematic diagram of the second mixing hole and the hydrogen fuel injection spiral structure inside the hole;

[0024] Figure 4 for Figure 1 Cross-sectional view of a staged combustion hydrogen nozzle with anti-backfire capability;

[0025] Figure 5 for Figure 4 Axonometric view;

[0026] Figure 6 This is a schematic diagram of the second structure of the anti-backfire staged combustion hydrogen nozzle in the embodiment;

[0027] Figure 7 for Figure 6 Cross-sectional view of a staged combustion hydrogen nozzle with anti-backfire capability;

[0028] Figure 8 for Figure 7 Axonometric view;

[0029] Among them, 1-nozzle combustion head disk, 11-first disk body, 12-air hole, 13-on-call combustion unit, 131-central mixing hole, 132-first mixing hole, 14-main combustion stage combustion unit, 141-second mixing hole, 151-on-call combustion unit cavity, 152-main combustion stage combustion unit cavity, 16-separation ring, 17-disk inner core block, 181-annular hydrogen supply channel, 182-first hydrogen supply channel, 183-second hydrogen supply channel, 19-second disk body, 2-hydrogen supply pipeline, 21-on-call hydrogen supply pipeline, 22-main combustion stage hydrogen supply pipeline, 3-hydrogen fuel injection spiral structure, 31-hydrogen fuel injection hole, 32-hollow branch, 4-central mixing pipe, 5-first mixing pipe, 6-second mixing pipe. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0031] See Figures 1 to 8 The present invention provides a backfire-proof staged combustion hydrogen nozzle, comprising:

[0032] The nozzle combustion head disk 1 includes an air hole 12, a duty combustion unit 13, and a main combustion stage combustion unit 14. The main combustion stage combustion unit 14 is arranged around the duty combustion unit 13. Both the duty combustion unit 13 and the main combustion stage combustion unit 14 include a plurality of mixing holes. A hydrogen fuel injection spiral structure 3 is provided in the mixing holes. The hydrogen fuel injection spiral structure 3 is used to guide the air flowing through the mixing holes to form a swirling flow and inject hydrogen fuel into the swirling flow so that the hydrogen fuel is mixed with the air.

[0033] The hydrogen supply line 2 includes a duty hydrogen supply line 21 and a main combustion stage hydrogen supply line 22, both connected to the nozzle combustion head disk 1. The duty hydrogen supply line 21 supplies hydrogen fuel to the mixing orifice of the duty combustion unit 13; the main combustion stage hydrogen supply line 22 supplies hydrogen fuel to the mixing orifice of the main combustion stage combustion unit 14. The hydrogen fuel is hydrogen gas.

[0034] This invention provides a mixing hole with a hydrogen fuel injection spiral structure 3 on the nozzle combustion head disk 1, which enhances the mixing of hydrogen fuel and air, improves the uniformity of hydrogen fuel and air mixing, enables more complete combustion of hydrogen fuel, reduces flame dwell time, and reduces NOx emissions. At the same time, an air hole 12 is provided near the mixing hole. The high-speed airflow ejected from the air hole 12 increases the airflow velocity, shortens the combustion flame dwell time, reduces NOx emissions, prevents backfire, and the high-speed airflow can also cool the nozzle head, reduce the nozzle operating temperature, and improve the nozzle service life.

[0035] In some embodiments, see Figures 1 to 3 The hydrogen fuel injection spiral structure 3 is a hollow spiral. The cross-section of the hollow spiral includes at least two hollow branches 32 that are radially distributed and interconnected with each other around the axis of the mixing hole. The spacing between the hollow branches 32 is equal. The hollow branches 32 are provided with hydrogen fuel injection holes 31. For example, the hollow branches 32 can form radial structures such as a straight line, a Y shape, or an X shape. Correspondingly, the hydrogen fuel injection spiral structure 3 can be a hollow spiral with a cross-section of a straight line, a Y shape, or an X shape. In this embodiment, the hydrogen fuel injection spiral structure 3 adopts a hollow spiral with a Y-shaped cross-section. This invention employs a hollow spiral to create a swirling effect in the airflow channel of the mixing orifice. This swirling airflow generates strong rotational motion, forming a rotating airflow with high tangential velocity. Hydrogen fuel is injected into the mixing orifice through hydrogen fuel injection hole 31, and is entrained in the rotating airflow. This intensifies the relative motion between hydrogen fuel and air, increasing the contact area and probability between them, thus significantly accelerating the mixing of hydrogen fuel and air. This results in more uniform mixing, ensuring even combustion, eliminating localized hot spots, and achieving complete combustion. Furthermore, the air swirling effect creates a three-dimensional mixing pattern between hydrogen fuel and air within the nozzle, preventing localized enrichment or depletion. Compared to simple mixing without swirling, the air swirling effect allows for more uniform mixing of hydrogen fuel and air throughout the combustion zone, forming a homogeneous combustible mixture. This is particularly important for hydrogen fuel, which has a fast combustion rate and high flame propagation speed; uniform mixing ensures a more stable and efficient combustion process. Uniform and thorough mixing allows for more complete combustion of hydrogen fuel. During combustion, each hydrogen fuel molecule reacts promptly with oxygen molecules, releasing more energy. Compared to incomplete mixing, this reduces the emission of unburned hydrogen fuel, improves energy utilization efficiency, and thus enhances the overall efficiency of the combustion process, while simultaneously lowering peak combustion temperature and nitrogen oxide (NOx) formation. The rotating airflow generated by the air swirl creates a stable recirculation zone at the nozzle exit. This recirculation zone guides the high-temperature combustion gases back to the flame root, providing a continuous heating and ignition source for the hydrogen-air mixture, making the flame root more stable and less prone to extinguishing. It also enhances resistance to external disturbances. In actual operation, the combustion system may be affected by various external factors, such as airflow fluctuations and pressure changes. The stable flow field formed by the air swirl enhances the flame's resistance to these external disturbances, maintaining stable combustion and ensuring the stability of the combustion process.

[0036] In some embodiments, see Figures 1 to 4The duty combustion unit 13 includes a central mixing hole 131 and at least one ring of first mixing holes 132 surrounding the central mixing hole 131. In this embodiment, the first mixing hole 132 has one ring. The hydrogen fuel injection spiral structure 3 of the central mixing hole 131 is connected to the hydrogen fuel injection spiral structure 3 of the first mixing hole 132. When the duty hydrogen supply pipeline 21 supplies hydrogen fuel to the duty combustion unit 13, the hydrogen fuel is injected into the central mixing hole 131 through the hydrogen fuel injection spiral structure 3 and mixes with air. At the same time, the hydrogen fuel is injected into the first mixing hole 132 through the hydrogen fuel injection spiral structure 3 and mixes with air. It should be noted that the first mixing holes 132 in each ring are axially symmetrically distributed to ensure that the hydrogen fuel pressure of the first mixing holes 132 in the same ring is the same.

[0037] In some embodiments, see Figures 1 to 4 The main combustion stage unit 14 includes at least one ring of second mixing holes 141 surrounding the main combustion stage unit 13, and the hydrogen fuel injection spiral structures 3 of all the second mixing holes 141 are interconnected. It should be noted that one ring of second mixing holes 141 can be regarded as a first-stage main combustion stage unit 14, or two rings of second mixing holes 141 can be regarded as a first-stage main combustion stage unit 14, and the main combustion stage unit 14 can be set with several stages as needed.

[0038] In some embodiments, see Figures 1 to 5 The nozzle combustion head disk 1 includes a first disk body 11 and a partition ring 16; the first disk body 11 is a hollow structure; the partition ring 16 divides the internal space of the first disk body 11 into a duty combustion unit cavity 151 located inside the partition ring 16 and a main combustion stage combustion unit cavity 152 located outside the partition ring 16; the duty combustion unit cavity 151 is provided with a central mixing tube 4 having the central mixing hole 131 and a first mixing tube 5 having the first mixing hole 132, and the hydrogen fuel injection spiral structure 3 in the central mixing tube 4 and the first mixing tube 5 are both connected to the duty combustion unit cavity 151; the main combustion stage combustion unit cavity 152 is provided with a second mixing tube 6 having the second mixing hole 141, and the hydrogen fuel injection spiral structure 3 in the second mixing tube 6 is connected to the main combustion stage combustion unit cavity 152; the air hole 12 is provided on the partition ring 16.

[0039] Furthermore, the duty-shift hydrogen supply pipeline 21 is connected to the duty-shift combustion unit cavity 151, enabling the supply of hydrogen fuel to the central mixing hole 131 and the first mixing hole 132 within the duty-shift combustion unit 13. The main combustion stage hydrogen supply pipeline 22 is connected to the main combustion stage combustion unit cavity 152, enabling the supply of hydrogen fuel to the second mixing hole 141 within the main combustion stage combustion unit 14. Since the partition ring 16 divides the internal space of the first disc 11 into two isolated parts, the hydrogen fuel supply to the central duty-shift combustion unit 13 and the outer ring main combustion stage combustion unit 14 is independent of each other, so as to achieve staged combustion control of the central duty-shift combustion unit 13 and the outer ring main combustion stage combustion unit 14, that is, to open the central duty-shift combustion unit 13 alone or to open the outer ring main combustion stage combustion unit 14 alone, or to open the central duty-shift combustion unit 13 and the outer ring main combustion stage combustion unit 14 simultaneously, to adapt to the usage requirements of different operating conditions.

[0040] In some embodiments, see Figures 6 to 8 The nozzle combustion head disk 1 can also be a structure including a second disk body 19 and an inner disk core block 17. An annular hydrogen supply channel 181 is provided between the inner wall of the second disk body 19 and the outer peripheral wall of the inner disk core block 17. The air hole 12, the central mixing hole 131 and the first mixing hole 132 of the duty combustion unit 13, and the second mixing hole 141 of the main combustion stage combustion unit 14 are all provided on the inner disk core block 17; the hydrogen fuel injection spiral of the central mixing hole 131 and the first mixing hole 132 Structure 3 is connected through the first hydrogen supply channel 182, and the first hydrogen supply channel 182 is connected to the duty hydrogen supply pipeline 21; the hydrogen fuel injection spiral structure 3 of the second mixing hole 141 is connected through the second hydrogen supply channel 183, and the hydrogen fuel injection spiral structure 3 of the second mixing hole 141 near the outer peripheral wall of the inner core block 17 is connected to the annular hydrogen supply channel 181, and the annular hydrogen supply channel 181 or the second hydrogen supply channel 183 is connected to the main combustion stage hydrogen supply pipeline 22. Hydrogen fuel flows through the shift hydrogen supply pipeline 21 into the first hydrogen supply channel 182, and then flows evenly to the hydrogen fuel injection spiral structure 3 of the central mixing hole 131 and the first mixing hole 132, and is finally injected into the central mixing hole 131 and the first mixing hole 132. At the same time, hydrogen fuel flows through the main combustion stage hydrogen supply pipeline 22 into the annular hydrogen supply channel 181 or the second hydrogen supply channel 183, and then flows evenly to the hydrogen fuel injection spiral structure 3 of the second mixing hole 141, and is finally injected into the second mixing hole 141.

[0041] It should be noted that the shape of the inlet and outlet of the air hole 12 is not limited, and the size and shape of the air hole 12 along the axial direction can be changed in a continuous and smooth manner. In this embodiment, the aperture of the air hole 12 gradually decreases along the air flow direction to accelerate the air ejection speed from the air hole 12. The high-speed air ejected from the air hole 12 can carry the combustion flame away from the nozzle combustion head disk 1, preventing backfire, while reducing the local combustion temperature peak, avoiding local high temperature and oxygen-rich zones, significantly reducing NOx emissions. Moreover, the high-speed airflow can carry away some of the heat from the nozzle combustion head disk 1, cooling the nozzle head, extending the nozzle life, and preventing nozzle deformation or failure due to high temperature.

[0042] It should be noted that the first mixing hole 132 and the second mixing hole 141 in each ring are axially symmetrically distributed to ensure that the hydrogen fuel injection pressure of each mixing hole in the same combustion unit is the same, the hydrogen fuel injection flow is uniform, and the local hot spots of the combustion flame are prevented from causing NOx emissions to increase. At the same time, the combustion stability of the nozzle head is improved.

[0043] Based on the same inventive concept, this embodiment also provides a method for controlling the combustion of a backfire-preventing staged combustion hydrogen nozzle. This method controls the aforementioned backfire-preventing staged combustion hydrogen nozzle by connecting a programmable logic controller (PIC) and a solenoid valve to the duty hydrogen supply line 21 and the main combustion stage hydrogen supply line 22, respectively. This allows for independent on / off control of the hydrogen fuel supply to each combustion unit, controlling the fuel distribution of each combustion stage. Specifically, the backfire-preventing staged combustion hydrogen nozzle control method includes: when the aero-engine is under low load conditions, only the intermediate duty combustion unit 13 is activated; when the aero-engine is under medium or high load conditions, the method autonomously selects to activate each stage of the main combustion stage 14 and the duty combustion unit 13 as needed.

[0044] This embodiment also provides an optimization method for a staged combustion hydrogen nozzle to prevent backfire, comprising the following steps:

[0045] Step 1: Determine the structural parameters of the hydrogen injection spiral structure as optimization variables, with the equivalence ratio at the mixing orifice outlet of the nozzle and the NOx emission concentration of the nozzle as optimization targets. The optimization variables are the torsion angle of the hydrogen injection spiral structure and the axial distance from the center of the hydrogen injection orifice to the mixing orifice outlet. The torsion angle of the hydrogen injection spiral structure refers to the relative rotation angle between the upper and lower end faces of the hydrogen injection spiral structure when one end face is fixed and the other end face is twisted, so that pure torsional deformation occurs while keeping the position of the central axis of the column unchanged, forming a spiral structure.

[0046] Step 2: Perform finite element analysis on the nozzle under design conditions to obtain the equivalence ratio at the outlet of the mixing hole for different torsion angles of the hydrogen injection spiral structure under cold conditions, and the NOx emission concentration after combustion under hot conditions; based on the finite element analysis results, select the torsion angle with the smallest equivalence ratio at the outlet of the mixing hole and the smallest NOx emission concentration after combustion as the target torsion angle.

[0047] Specifically, this embodiment analyzes the flow and combustion performance of the combustion chamber under three structural configurations with torsion angles of 0°, 180°, and 360°. Under cold conditions, when the torsion angle is 0°, the equivalence ratio distribution at the outlet of the micro-mixing unit is concentrated at around 1.0; while when the torsion angle increases to 360°, the outlet equivalence ratio decreases to approximately 0.6, with the result for the 180° structure falling between the two. This shows that as the torsion angle increases, the mixing effect of fuel and air is significantly enhanced, and the mixing uniformity within the flow field is significantly improved.

[0048] Under thermal conditions, the NO corresponding to the 0° structure x The emission concentration was 21.26 ppm; the 180° structure falls between the two; while the 360° structure... x Emissions were reduced to 6.67 ppm, demonstrating excellent low-emission characteristics.

[0049] Therefore, this embodiment selects a hydrogen jet spiral structure with a torsion angle of 360° as the basis for subsequent structural optimization and performance improvement research.

[0050] Step 3: Set the torsion angle of the hydrogen injection spiral structure in the nozzle as the target torsion angle, and perform finite element analysis on the nozzle under the design conditions to obtain the equivalence ratio of the hydrogen injection orifice of the hydrogen injection spiral structure at different axial distances under cold conditions, and the NOx emission concentration after combustion under hot conditions; based on the finite element analysis results, select the axial distance with the smallest equivalence ratio and the smallest NOx emission concentration after combustion at the outlet of the mixing orifice as the target axial distance.

[0051] Specifically, this embodiment investigated three structures with axial distances of 6.5 mm, 9.5 mm, and 12.5 mm for the hydrogen injection orifices. Under cold conditions, the mixing results showed that the mixing uniformity of hydrogen fuel and air gradually improved with increasing axial distance of the hydrogen fuel orifice. When the orifice position was 12.5 mm, the local maximum equivalence ratio at the outlet plane of the mixing orifice was the smallest, and the fuel and air were almost completely mixed at the outlet section of the micro-mixing unit. This indicates that a larger axial distance helps to extend the mixing path, enhance shear and turbulent diffusion effects, and thus significantly improve the mixing quality.

[0052] Under hot conditions, the NOx emission concentration is approximately 15 ppm when the axial distance of the hydrogen fuel orifice is 6.5 mm, 11.25 ppm when the axial distance is 9.5 mm, and the lowest NOx emission concentration is observed when the axial distance is 12.5 mm. In summary, NOx emissions from the three-pronged combustion chamber show a significant decreasing trend with increasing axial distance of the fuel orifice. This indicates that appropriately extending the premixing distance between fuel and air helps improve mixing uniformity and reduce local high-temperature zones, thereby effectively suppressing the formation of thermal NOx. Therefore, a hydrogen injection spiral structure with an axial distance of 12.5 mm for the hydrogen fuel orifice is adopted.

[0053] Step 4: Based on the selected torsion angle of the hydrogen injection spiral structure and the axial distance from the center of the hydrogen injection hole to the outlet of the mixing hole, determine the optimal structural parameters of the hydrogen injection spiral structure, that is, determine the torsion angle of the hydrogen injection spiral structure to be 360° and the axial distance from the center of the hydrogen injection hole to the outlet of the mixing hole to be 12.5 mm.

[0054] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A staged combustion hydrogen nozzle with backfire prevention, characterized in that, include: The nozzle combustion head disk (1) is provided with an air hole (12), a duty combustion unit (13) and a main combustion stage combustion unit (14); the main combustion stage combustion unit (14) is arranged around the duty combustion unit (13); both the duty combustion unit (13) and the main combustion stage combustion unit (14) include a plurality of mixing holes, and a hydrogen fuel injection spiral structure (3) is provided in the mixing holes. The hydrogen fuel injection spiral structure (3) is used to guide the air flowing through the mixing holes to form a swirling flow and inject hydrogen fuel into the swirling flow so that the hydrogen fuel is mixed with the air. The hydrogen supply line (2) includes a duty hydrogen supply line (21) and a main combustion stage hydrogen supply line (22). The duty hydrogen supply line (21) is used to supply hydrogen fuel to the mixing hole of the duty combustion unit (13); the main combustion stage hydrogen supply line (22) is used to supply hydrogen fuel to the mixing hole of the main combustion stage combustion unit (14). The hydrogen fuel injection spiral structure (3) is a hollow spiral body. The cross-section of the hollow spiral body includes at least two hollow branches (32) that are radially distributed and interconnected with each other around the axis of the mixing hole. The spacing between the hollow branches (32) is equal, and the hollow branches (32) are provided with hydrogen fuel injection holes (31). The duty combustion unit (13) includes a central mixing hole (131) and at least one first mixing hole (132) surrounding the central mixing hole (131); the hydrogen fuel injection spiral structure (3) of the central mixing hole (131) is connected to the hydrogen fuel injection spiral structure (3) of the first mixing hole (132); The main combustion stage combustion unit (14) includes at least one ring of second mixing holes (141) surrounding the duty combustion unit (13), and the hydrogen fuel injection spiral structures (3) of all the second mixing holes (141) are interconnected.

2. The backfire-preventing staged combustion hydrogen nozzle according to claim 1, characterized in that, The nozzle combustion head disk (1) includes a first disk body (11) and a partition ring (16); the first disk body (11) is a hollow structure; the partition ring (16) divides the internal space of the first disk body (11) into a duty combustion unit cavity (151) located inside the partition ring (16) and a main combustion stage combustion unit cavity (152) located outside the partition ring (16); The duty combustion unit cavity (151) is provided with a central mixing tube (4) having the central mixing hole (131) and a first mixing tube (5) having the first mixing hole (132). The hydrogen fuel injection spiral structure (3) in the central mixing tube (4) and the first mixing tube (5) are both connected to the duty combustion unit cavity (151). The main combustion stage combustion unit cavity (152) is provided with a second mixing tube (6) having the second mixing hole (141). The hydrogen fuel injection spiral structure (3) of the second mixing tube (6) is connected to the main combustion stage combustion unit cavity (152). The air hole (12) is provided on the partition ring (16).

3. The backfire-preventing staged combustion hydrogen nozzle according to claim 2, characterized in that, The hydrogen supply pipeline (21) for the duty class is connected to the cavity (151) of the duty class combustion unit, and the hydrogen supply pipeline (22) for the main combustion stage is connected to the cavity (152) of the main combustion stage combustion unit.

4. The backfire-preventing staged combustion hydrogen nozzle according to claim 3, characterized in that, The nozzle combustion head disk (1) includes a second disk body (19) and an inner core block (17). An annular hydrogen supply channel (181) is provided between the inner wall of the second disk body (19) and the outer peripheral wall of the inner core block (17). The air hole (12), the central mixing hole (131) and the first mixing hole (132) of the duty combustion unit (13), and the second mixing hole (141) of the main combustion stage unit (14) are all located on the inner core block (17). The hydrogen fuel injection spiral structure (3) of the central mixing hole (131) and the first mixing hole (132) are connected through the first hydrogen supply channel (182). The hydrogen fuel injection spiral structure (3) of the second mixing hole (141) is connected through the second hydrogen supply channel (183). The hydrogen fuel injection spiral structure (3) of the second mixing hole (141) near the outer peripheral wall of the inner core block (17) is connected to the annular hydrogen supply channel (181).

5. The anti-backfire staged combustion hydrogen nozzle according to claim 4, characterized in that, The on-duty hydrogen supply pipeline (21) is connected to the first hydrogen supply channel (182), and the main combustion stage hydrogen supply pipeline (22) is connected to the annular hydrogen supply channel (181) or the second hydrogen supply channel (183).

6. A method for controlling the combustion of a flashback-proof staged combustion hydrogen nozzle, used to control the flashback-proof staged combustion hydrogen nozzle according to any one of claims 1-5, characterized in that, According to the load requirements of the aircraft engine, the duty combustion unit (13) and the main combustion stage combustion unit (14) are started in stages.

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