Hydrogen-kerosene dual-fuel integrated strut flame stabilizer, afterburner and aero-engine

Abstract

The application discloses a hydrogen-kerosene dual-fuel integrated strut flame stabilizer, an afterburner and an aero-engine, and belongs to the technical field of afterburners of aero-engines. The strut flame stabilizer comprises a straight strut body, the straight strut body is arranged along a radial direction and is perpendicular to a flow path, a plurality of hydrogen injection holes and kerosene injection holes are longitudinally and uniformly distributed on the side surface of the straight strut body, and a kerosene main pipe and a hydrogen main pipe are arranged in the straight strut body. The hydrogen-kerosene dual-fuel integrated strut flame stabilizer, the afterburner and the aero-engine can coordinate hydrogen-kerosene dual-fuel combustion, improve combustion efficiency, make temperature distribution uniform, and have the advantages of simple structure and light weight.

Description

Technical Field

[0001] This invention relates to the field of afterburner technology for aero-engines, and in particular to an integrated hydrogen-kerosene dual-fuel flame stabilizer, an afterburner, and an aero-engine. Background Technology

[0002] In existing technologies, hydrogen-cooled aero engines, as advanced power plants with high-altitude, wide-speed, and long-range characteristics, demonstrate unique advantages and development potential in the aviation field. However, under high-speed flight conditions, they face a series of performance challenges. When an aircraft is at high speed, the intake ramjet effect causes a sharp increase in the total inlet temperature of the turbine engine, which directly leads to a significant decrease in the compressor's flow capacity and pressure ratio. Moreover, the higher the compressor's design pressure ratio, the more severe this performance degradation becomes. At the same time, under high-speed conditions, the outlet temperature of the high-pressure ratio compressor also increases significantly, resulting in a significant reduction in the heating capacity of the combustion chamber, ultimately causing a significant deterioration in engine performance.

[0003] To address these issues, a solution using hydrogen as a cooling medium to pre-cool the compressor inlet air has emerged. This method maximizes air cooling efficiency, and the gaseous hydrogen produced during cooling can also enter the afterburner to participate in combustion with kerosene, achieving highly efficient utilization of the cooling system. This enhances both cooling performance and fuel efficiency.

[0004] Against the backdrop of rapid advancements in the performance of military fighter jets, engines, as the core power unit of aircraft, are also constantly evolving. The demands for high short-term performance and a wide flight envelope during combat have placed higher standards on aero engines, leading to the development of afterburners. The operation of hydrogen-cooled aero engines exhibits phased characteristics. Once the afterburner is activated, as the throttle is gradually increased, the engine initially transitions from a low afterburner state with only the duty stage engaged to a high afterburner state with both the duty and main working stages fully engaged. As thrust further increases, hydrogen from the main stage replaces the kerosene in the main stage, forming a dual-fuel afterburner (kerosene and hydrogen) to meet the operational requirements under varying thrust demands.

[0005] Despite some progress in design and application, existing technologies still have some shortcomings and deficiencies:

[0006] First, hydrogen and kerosene have a significant density difference, and the flame propagation speed of hydrogen is 6-7 times faster than that of kerosene. This characteristic can easily lead to backfire, and in severe cases, it can even cause the stabilizer to burn out.

[0007] Secondly, hydrogen has a lower density than the high-temperature gas flow, while kerosene has a higher density. This density difference will seriously affect the mixing effect of the dual fuels and the high-temperature gas flow, which is not conducive to the complete combustion of fuel and the stable performance of the engine.

[0008] Finally, kerosene flames spread slowly and require atomization and evaporation to burn. In high-speed, low-oxygen environments, kerosene is difficult to ignite and is prone to extinguishing. Summary of the Invention

[0009] The purpose of this invention is to provide an integrated hydrogen-kerosene dual-fuel flame stabilizer, afterburner, and aero-engine that can coordinate the combustion of hydrogen and kerosene dual fuels, improve combustion efficiency, ensure uniform temperature distribution, and has a simple structure and light weight.

[0010] To achieve the above objectives, the present invention provides an integrated hydrogen-kerosene dual-fuel flame stabilizer, comprising a straight plate support body, wherein the straight plate support body is arranged radially and perpendicular to the flow path, and a plurality of hydrogen injection holes and kerosene injection holes are evenly distributed longitudinally on the side of the straight plate support body, and a kerosene main pipe and a hydrogen main pipe are provided inside the straight plate support body.

[0011] Preferably, the windward side of the straight plate support body is a rounded wall surface, and the leeward side of the straight plate support body is a wall surface with an isosceles triangle cross-section.

[0012] Preferably, the hydrogen nozzle is positioned forward of the kerosene nozzle, and the injection direction of the hydrogen nozzle is radially perpendicular to the mainstream direction.

[0013] Preferably, the hydrogen main pipe is connected to the hydrogen nozzle, and the kerosene main pipe is connected to the kerosene nozzle.

[0014] Preferably, the hydrogen nozzle is a multi-hole nozzle with a diameter of 1.5mm-4.0mm and 4-12 nozzles on one side.

[0015] Preferably, the diameter of the kerosene nozzle is 0.4mm-1.2mm, and the number of nozzles on one side is 4-12.

[0016] Furthermore, hydrogen is produced by diffusion combustion, and the appropriate momentum ratio is achieved by rationally setting the number, diameter, and Mach number of hydrogen nozzles.

[0017] Furthermore, during kerosene injection, the momentum ratio with the mainstream should be reduced as much as possible, and the penetration depth should be minimized to facilitate ignition.

[0018] The present invention also provides an afterburner, including the aforementioned integrated hydrogen-kerosene dual-fuel flame stabilizer.

[0019] The present invention also provides an aircraft engine equipped with the above-described afterburner.

[0020] Therefore, the present invention employs the above-mentioned integrated hydrogen-kerosene dual-fuel flame stabilizer, afterburner, and engine cooling system, and the technical effects are as follows:

[0021] High combustion efficiency: Hydrogen employs a diffusion combustion mechanism. The presence of a blunt body creates a backflow zone, increasing turbulence intensity and facilitating hydrogen / air mixing, thus improving combustion efficiency. Simultaneously, the hydrogen is injected perpendicular to the mainstream direction, increasing penetration depth and promoting mixing with the high-temperature combustion gas flow. Furthermore, the relatively forward positioning of the hydrogen nozzle provides ample space for diffusion, preventing it from being dispersed by the high-speed airflow, further enhancing combustion efficiency.

[0022] Uniform temperature distribution: By reasonably setting the number, diameter and Mach number of hydrogen nozzles, a suitable momentum ratio is achieved, which is conducive to the mixing of hydrogen and air, and also achieves a good flame-coupling effect, resulting in a uniform temperature distribution.

[0023] Coordinated combustion of hydrogen and kerosene dual fuels: The hydrogen nozzle and kerosene nozzle are set separately, with the hydrogen nozzle in front and the kerosene nozzle in the back. This adapts to the different physicochemical properties of the two, ensuring that the kerosene can be ignited and burn stably, while avoiding hydrogen backfire.

[0024] Simple structure and light weight: The stabilizer, support plate and nozzle are integrated into one design, which simplifies the structure of the afterburner, reduces the number of parts, lightens the weight of the afterburner, reduces flow loss, improves the thrust-to-weight ratio of the engine, and facilitates maintenance.

[0025] The innovative use of hydrogen and kerosene as dual fuels in the afterburner improves compressor efficiency and promotes combustion. At the same time, using kerosene as the standby stage and hydrogen as the working stage facilitates hydrogen ignition and enables the afterburner to start stably.

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of an embodiment of the hydrogen-kerosene dual-fuel integrated support plate flame stabilizer of the present invention.

[0028] Figure 2 This is a schematic diagram of an embodiment of the hydrogen-kerosene dual-fuel integrated support plate flame stabilizer of the present invention installed in a rectangular channel;

[0029] Figure 3 This is a schematic diagram of an embodiment of the hydrogen-kerosene dual-fuel integrated support plate flame stabilizer installed in the afterburner chamber according to the present invention;

[0030] Figure 4 This is the result of a thermal numerical simulation of a pure hydrogen operating condition for an embodiment of a hydrogen-kerosene dual-fuel integrated support plate flame stabilizer of the present invention.

[0031] Figure 5 This is the numerical simulation result of a dual-fuel integrated support plate flame stabilizer embodiment of the present invention, which is a hydrogen-kerosene dual-fuel flame stabilizer.

[0032] Figure Labels

[0033] 1. Straight plate support body; 2. Kerosene nozzle; 3. Hydrogen nozzle; 4. Kerosene main pipe; 5. Hydrogen main pipe; 6. Windward side; 7. Leeward side. Detailed Implementation

[0034] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0035] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "comprising" or "including," as used in this invention, mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms "connected" or "linked," etc., are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0036] Example 1

[0037] like Figure 1 As shown, this invention provides an integrated hydrogen-kerosene dual-fuel flame stabilizer with a support plate, comprising a straight support plate body 1, which is arranged radially and perpendicular to the flow path. The height of the body is consistent with the height of the test section of the afterburner, the length is set to 130mm, and the width d is 20mm. The calculated blockage ratio is 0.25, which is within a reasonable range of 0.23 to 0.28, effectively balancing airflow resistance and combustion requirements.

[0038] The windward side 6 adopts a rounded wall design, with a radius of curvature projected in the direction of the flow equal to 0.5d (i.e., 10mm). This design reduces the resistance generated by airflow impact, allowing the airflow to flow more smoothly over the stabilizer. The leeward side 7 is a wall with an isosceles triangular cross-section and a apex angle of 55°. This angle ensures that a suitable recirculation zone is formed at the rear end of the stabilizer to promote combustion, while avoiding flame instability caused by an excessively large recirculation zone.

[0039] The straight plate support body 1 has several hydrogen nozzles 3 and kerosene nozzles 2 evenly distributed longitudinally on its side. The hydrogen nozzles 3 are positioned forward relative to the kerosene nozzles 2 to provide more space for hydrogen diffusion.

[0040] The hydrogen nozzle 3 is a multi-hole jet, with the jet direction radially perpendicular to the main flow direction. There are eight nozzles on each side, each with a diameter of 2.5 mm. The main hydrogen pipe 5 is located inside the straight plate support body 1 and connects to all the hydrogen nozzles 3, used to deliver hydrogen to each nozzle. Through calculation, the Mach number of the hydrogen nozzles 3 is set to achieve a suitable momentum ratio for the hydrogen jet, ensuring both the penetration depth and dispersion diameter of the hydrogen jet, facilitating thorough mixing with air, and achieving a good flame-coupling effect.

[0041] There are 7 kerosene nozzles 2 on each side, each with a diameter of 0.8 mm. The kerosene main pipe 4 is also located inside the straight plate support body 1 and is connected to all the kerosene nozzles 2, responsible for transporting the kerosene. During kerosene injection, a setting that reduces the flow rate to the main flow is adopted to decrease the penetration depth, thereby facilitating kerosene ignition.

[0042] The straight plate support body 1 has a protruding structure at its end. This structure can fill the backflow zone formed by hydrogen under high-speed airflow, effectively improving the aerodynamic structure of the stabilizer and preventing the flame from burning the stabilizer along the backflow zone.

[0043] Example 2

[0044] The afterburner in this embodiment includes the integrated hydrogen-kerosene dual-fuel flame stabilizer from Embodiment 1. A schematic diagram of the installation of one of the stabilizers in the afterburner within a rectangular combustion test specimen is shown below. Figure 2 As shown.

[0045] Install the stabilizer according to the installation diagram ( Figure 3 The stabilizer is assembled into the afterburner and fixed radially to ensure it is perpendicular to the flow path of the afterburner. The afterburner receives airflow from the inner and outer ducts. When the airflow passes through the stabilizer, a recirculation zone is formed on the leeward side of the stabilizer, increasing the turbulence intensity and providing favorable conditions for the combustion of hydrogen and kerosene.

[0046] Hydrogen is delivered to hydrogen nozzle 3 via hydrogen main pipe 5 and ejected perpendicular to the mainstream direction to fully mix with the incoming flow. Kerosene is delivered to kerosene nozzle 2 via kerosene main pipe 4 and injected into the expansion area behind the stabilizer to facilitate droplet breakup and evaporation. Both fuels are burned in the afterburner with kerosene as the standby stage and hydrogen as the working stage, achieving stable operation of the afterburner.

[0047] Example 3

[0048] The aero-engine of this embodiment is equipped with the afterburner as described in Embodiment 2. During engine operation, after the afterburner is activated, as the throttle increases, it first enters a low afterburner state with only the duty stage engaged, where power is primarily provided by kerosene combustion; then it reaches a high afterburner state with both the duty stage and the main working stage fully engaged, where kerosene and hydrogen participate in combustion together; as the thrust further increases, hydrogen from the main stage replaces the kerosene from the main stage, forming a dual-fuel afterburner combustion mode with the duty stage kerosene.

[0049] By using hydrogen as a cooling medium to pre-cool the compressor inlet air, the resulting gaseous hydrogen enters the afterburner and combusts with kerosene, improving cooling efficiency and achieving efficient fuel utilization. Simultaneously, the use of an integrated hydrogen-kerosene dual-fuel flame stabilizer enhances engine combustion efficiency and provides more uniform temperature distribution. Furthermore, the use of a straight-plate stabilizer results in a simple, lightweight structure and effectively improves the thrust-to-weight ratio, meeting performance requirements under high-altitude and high-speed conditions while also facilitating maintenance.

[0050] The results of Fluent numerical simulation of the test specimen are as follows: Figure 4 As shown, this is a cross-sectional temperature distribution cloud map under pure hydrogen conditions. The temperature distribution at the outlet at the end of the computational domain is relatively uniform, indicating good combustion performance. Figure 5 The combustion results are for hydrogen and kerosene dual-fuel combustion. Although some tempering erosion occurred at the rear end of the bluff body, the overall numerical results are good.

[0051] Therefore, the present invention employs the above-mentioned integrated hydrogen-kerosene dual-fuel flame stabilizer, afterburner, and cooling engine, which can coordinate the combustion of hydrogen-kerosene dual fuels, improve combustion efficiency, make the temperature distribution uniform, and has a simple structure and light weight.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A hydrogen-kerosene dual-fuel integrated support plate flame stabilizer, characterized in that: The device includes a straight plate support body, which is arranged radially and perpendicular to the flow path. Several hydrogen injection holes and kerosene injection holes are evenly distributed longitudinally on the side of the straight plate support body. The interior of the straight plate support body is provided with a kerosene main pipe and a hydrogen main pipe. The windward side of the straight plate support body is a rounded wall surface, and the leeward side of the straight plate support body is a wall surface with an isosceles triangle cross-section. The hydrogen nozzle is positioned forward relative to the kerosene nozzle, and the injection direction of the hydrogen nozzle is radially perpendicular to the mainstream direction.

2. The hydrogen-kerosene dual-fuel integrated support plate flame stabilizer according to claim 1, characterized in that: The hydrogen main pipe is connected to the hydrogen nozzle, and the kerosene main pipe is connected to the kerosene nozzle.

3. The hydrogen-kerosene dual-fuel integrated support plate flame stabilizer according to claim 1, characterized in that: The hydrogen nozzle is a multi-hole nozzle with a diameter of 1.5mm-4.0mm and 4-12 nozzles on one side.

4. The hydrogen-kerosene dual-fuel integrated support plate flame stabilizer according to claim 1, characterized in that: The diameter of the kerosene nozzle is 0.4mm-1.2mm, and the number of nozzles on one side is 4-12.

5. An afterburner, characterized in that: It includes the hydrogen-kerosene dual-fuel integrated support plate flame stabilizer as described in any one of claims 1-4.

6. An aircraft engine, characterized in that: It is equipped with the afterburner as described in claim 5.

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