A direct plasma jet atomizing double-layer fuel spray boom with an air-cooling structure

Abstract

The present invention discloses a direct-injection plasma jet atomizing double-layer fuel spray rod with an air-cooling structure, comprising a ceramic spray rod, a ground electrode, a ceramic air-cooling housing, and a high-voltage electrode. The ceramic spray rod is provided with a fuel inlet channel; the inner wall and top of the ground electrode are covered with a ceramic air-cooling housing, which extends through the top of the ground electrode and is connected to the ceramic spray rod; the ceramic spray rod extends into the hollow structure of the high-voltage electrode, which is placed in the ceramic air-cooling housing; an air-cooling inlet and an atomizing fuel-air mixture nozzle are provided on one side of the ground electrode and the ceramic air-cooling housing. The present invention adopts a plasma jet method, utilizing air cooling to generate arc-free plasma that contacts aviation kerosene, thereby destroying the surface tension of the fuel; the plasma jet structure, in conjunction with the fuel spray rod, ensures that the fuel enters the combustion chamber through the plasma jet area.

Description

Technical Field

[0001] The present invention relates to the technical field of aviation engines, and in particular to a direct-injection plasma jet atomization double-layer fuel spray bar with an air-cooling structure. Background Art

[0002] Currently, fuel atomization methods primarily focus on medium atomization and mechanical atomization. The following are common fuel atomization methods, along with their advantages and disadvantages: ① Bubble atomization: Advantages include the ability to use a larger outlet orifice, lower atomization pressure, and reduced atomizing gas consumption. Disadvantages include high energy consumption and uneven droplet formation. ② Pneumatic atomization: Advantages include achieving good atomization at lower fuel supply pressures, high atomization quality even with high-viscosity fuels, and wide adjustment range for flexibility. Disadvantages include high energy consumption and uneven droplet formation. ③ Direct atomization: Advantages include high efficiency, speed, and controllability. Disadvantages include high water pressure requirements, limited orifice size, and a narrow flow rate adjustment range. ④ Rotary centrifugal atomization: Advantages include good atomization, adjustable particle size, low energy consumption, and simple operation. Disadvantages include frequent maintenance requirements and poor atomization performance for high-viscosity liquids. Therefore, an improved technology is urgently needed to address the aforementioned issues with existing technologies.

[0003] The Chinese invention patent application, application number CN201720040003.7, titled "A Double-Layer Afterburner Spray Rod," features an air cooling sleeve integrated with the spray rod. The advantage is that it prevents fuel from coking or spontaneous combustion within the spray rod. The disadvantage is that the fuel atomization is poor.

[0004] The Chinese invention patent application, application number CN202210520795.3, titled "Afterburner Fuel Lever Structure," features multiple fuel lines and the integration of the fuel lever with the ignition nozzle. This advantage reduces the space required for the fuel lever within the afterburner. However, the disadvantage is that the combination of the fuel and ignition nozzle causes direct ignition without adequate atomization, reducing afterburner combustion efficiency.

[0005] The Chinese invention patent application, application number CN202010534167.1, is titled "A Plasma Jet-Curve Discharge Dual-Mode Fuel Atomizing Nozzle." Its characteristics are that the spiral copper electrode's rotational direction is the same as that of the cyclone. Adjacent spiral copper electrode coils form a surface discharge area to atomize the fuel, providing secondary fuel excitation. This has the advantage of enhancing fuel atomization and combustion stability. However, its disadvantage is the lack of an air-cooling structure, which can easily lead to fuel coking. Summary of the Invention

[0006] The purpose of the present invention is to provide a direct-injection plasma jet atomization double-layer fuel spray bar with an air-cooling structure, which improves the combustion efficiency of existing aircraft engine afterburners and ramjet engines from the perspective of utilizing low-temperature plasma jets to destroy the surface tension of droplets.

[0007] To achieve the above-mentioned purpose, the technical solution of the present application is: a direct plasma jet atomizing double-layer fuel spray rod with an air-cooling structure, comprising a ceramic spray rod, a grounding electrode, a ceramic air-cooling shell and a high-voltage electrode, wherein a fuel inlet channel is provided in the ceramic spray rod; the inner wall and top of the grounding electrode are covered with a ceramic air-cooling shell, which passes through the top of the grounding electrode and is connected to the ceramic spray rod, the ceramic spray rod extends into the hollow structure of the high-voltage electrode, and the high-voltage electrode is placed in the ceramic air-cooling shell; an air-cooling inlet and an atomizing fuel-air mixture spray hole are provided on one side of the grounding electrode and the ceramic air-cooling shell.

[0008] In a preferred embodiment, the upper portion of the high-voltage electrode is tightly fitted with the ceramic air-cooling shell, and a dielectric barrier discharge region is provided between the lower portion of the high-voltage electrode and the ceramic air-cooling shell, and the dielectric barrier discharge region is connected to the air-cooling inlet.

[0009] In a preferred embodiment, a direct-injection fuel spray hole is provided at the bottom of the ceramic spray rod, and a high-voltage electrode passes through the bottom, and a plasma jet area is formed between the passing part and the ceramic air-cooled shell, and the plasma jet area is connected to the atomized fuel-air mixture spray hole.

[0010] In a preferred embodiment, a drainage hollow cylindrical platform is provided in the middle of the ceramic air-cooling housing, and the drainage hollow cylindrical platform is located above the dielectric barrier discharge area and at the air-cooling inlet.

[0011] In a preferred embodiment, the ceramic air-cooled housing, the ceramic oil spray rod and the high-voltage electrode are fixed by a flange, and a high-voltage electrode power supply terminal is provided on the flange.

[0012] In a preferred embodiment, the ceramic fuel injection rod is connected to the engine oil pipe, and the fuel flows through the fuel inlet channel, passes through the high-voltage electrode, and enters the plasma jet area from the direct fuel injection hole.

[0013] In a preferred embodiment, air enters from the air cooling air inlet. At this time, the high-voltage electrode generates plasma through dielectric barrier discharge under the action of the high-voltage electrode power supply terminal. The plasma flows through the dielectric barrier discharge area with the air to generate a plasma jet that contacts the fuel coming out of the direct fuel nozzle. The plasma destroys the surface tension of the fuel droplets to form an atomized fuel-air mixture, which finally enters the aircraft engine through the atomized fuel-air mixture nozzle.

[0014] In the preferred embodiment, the air is introduced into the air cooling air inlet through the compressor and enters the dielectric barrier discharge area. A large number of arcs are formed between the high-voltage electrode and the ground electrode, filling the entire gap between the ceramic air cooling air shell and the high-voltage electrode, and the gas dynamics of the air are used to form a plasma jet.

[0015] In a preferred embodiment, after high-pressure and low-temperature air is introduced into the air cooling air inlet, the air cooling air passes through the dielectric barrier discharge area and cools the ceramic spray rod by convection heat transfer.

[0016] By adopting the above technical solution, the present invention can achieve the following technical effects: the present invention uses a plasma jet method to utilize air-cooled gas to generate arc-free plasma in contact with aviation kerosene, thereby destroying the surface tension of the fuel; the use of a plasma jet structure, in conjunction with a fuel spray boom, can ensure that the fuel enters the combustion chamber through the plasma jet area, and the air plasma jet contains fuel, ensuring sufficient contact between the plasma and the fuel droplets, thereby improving the atomization effect and increasing the combustion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Shown is a front cross-sectional view of a direct plasma jet atomizing double-layer fuel spray boom with an air-cooling structure;

[0018] Figure 2 Shown is a three-dimensional structural view of a direct plasma jet atomization double-layer fuel spray boom with an air-cooling structure;

[0019] Figure 3 Shown is a three-dimensional top view of a direct plasma jet atomizing double-layer fuel spray boom with an air-cooling structure;

[0020] Figure 4 The figure shows the fluid flow direction in a direct plasma jet atomization double-layer fuel spray boom with an air-cooling structure;

[0021] Figure 5 The figure shows the working state of plasma in a double-layer fuel spray boom with a direct plasma jet atomization and air-cooling structure;

[0022] Figure 6 Shown is a schematic diagram of the fuel atomization effect in a double-layer fuel spray boom with a direct plasma jet atomization structure with an air-cooling structure. The left figure does not have a plasma jet, while the right figure does have a plasma jet.

[0023] Explanation of the numbers in the figure: 1 ceramic fuel injection rod; 2 air cooling air inlet; 3 ground electrode; 4 ceramic air cooling air shell; 5 atomized fuel-air mixture spray hole; 6 direct fuel spray hole; 7 fuel inlet channel; 8 high-voltage electrode; 21 dielectric barrier discharge area; 22 plasma jet area; 41 drainage hollow cylindrical platform. DETAILED DESCRIPTION

[0024] In order to help those skilled in the art better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0025] Example 1

[0026] like Figure 1-6 As shown, this embodiment provides a direct-type plasma jet atomization double-layer fuel spray rod with an air-cooling structure, including a ceramic spray rod, a ground electrode, a ceramic air-cooling housing, and a high-voltage electrode; the high-voltage electrode and the ground electrode are coaxially matched, and the ground electrode is coaxially matched and tightly connected to the ceramic air-cooling housing, thereby saving space to the maximum extent and preventing direct breakdown between the positive and negative electrodes and the generation of an arc. In addition, the air introduced into the ceramic air-cooling housing (dielectric barrier layer) 4 has a cooling function. The air entering the fuel spray rod can not only be used to generate plasma, but also be used for air cooling. After the air-cooling inlet 2 introduces high-pressure and low-temperature air, the air-cooling air cools the ceramic spray rod 1 through convection heat transfer through the dielectric barrier discharge area 21, preventing the fuel in the ceramic spray rod 1 from coking. In addition, a drainage hollow cylindrical platform 41 is provided to reduce the upward backflow caused by the sealing problem of the air-cooling inlet 2.

[0027] The ceramic fuel injector rod 1 is connected to the aircraft engine fuel line. Fuel flows through the fuel inlet channel, past the high-voltage electrode 8, and into the plasma jet zone from the direct-injection fuel nozzle 6. Simultaneously, air enters the fuel injector rod from the air cooling inlet 2. The high-voltage electrode 8, under the action of the high-voltage electrode power supply terminal 81, generates plasma through dielectric barrier discharge. This plasma flows along with the air through the dielectric barrier discharge zone 21, producing a plasma jet that contacts the fuel exiting the direct-injection fuel nozzle 6. This plasma disrupts the surface tension of the fuel droplets, forming an atomized fuel-air mixture that ultimately enters the aircraft engine through the atomized fuel-air nozzle. Furthermore, mixing with air expands the distribution range of the spray, facilitating the refinement of the fuel into droplet particles.

[0028] The process of plasma generation in the fuel boom is as follows: Air is introduced into the air cooler inlet 2 via a compressor, creating a dielectric barrier discharge zone. A large number of arcs form between the high-voltage electrode 8 and the ground electrode 3, filling the entire gap between the ceramic air cooler housing and the high-voltage electrode. The gas dynamics of the air form a plasma jet, which combines with fuel from the direct-injection fuel nozzles 6 and enters the combustion chamber through the atomizing fuel-air mixture nozzles 5. Liquid droplets within a unit area experience multiple exposures to the plasma, achieving atomization. Under the action of the plasma jet, the fuel within the electric field is atomized into fine droplets.

[0029] The atomized fuel-air mixture spray hole can be single or multi-hole; the fuel spray rod can be a single one or multiple ones used together, and can also be made into other structures such as a ring.

[0030] The working process of the direct plasma jet atomizing double-layer fuel spray boom with an air-cooling structure includes the following steps:

[0031] First, after the compressor is turned on, the gas enters the dielectric barrier discharge area through the air cooling air inlet 2, and then the high-voltage electrode power supply terminal starts to be energized, forming plasma in the dielectric barrier discharge area 21 and generating a plasma jet in the plasma jet area 22;

[0032] When the air passes through the dielectric barrier discharge area 21 , the low-temperature plasma air undergoes convection heat exchange with the ceramic air cooling shell 4 and the high-voltage electrode 8 to reduce the temperature of the ceramic spray rod 1 .

[0033] The fuel in the fuel tank is connected to the ceramic fuel injection rod 1 through the fuel pipe. The fuel flows through the high-voltage electrode through the fuel inlet channel 7, enters the plasma jet area from the direct fuel nozzle 6, and enters the combustion chamber through the atomized fuel-air mixture nozzle 5 after being pneumatically atomized by the plasma air.

[0034] The present invention generates an air plasma jet that fills the fuel nozzle outlet range, greatly increases the contact area between the air plasma jet and aviation kerosene, and improves atomization efficiency; and utilizes air cooling gas to generate the plasma jet to assist atomization.

[0035] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A direct plasma jet atomizing double-layer fuel spray boom with an air-cooling structure, characterized in that: It includes a ceramic fuel injection rod, a ground electrode, a ceramic air-cooling housing, and a high-voltage electrode. The ceramic fuel injection rod is provided with a fuel inlet channel. The inner wall and top of the ground electrode are covered with a ceramic air-cooling housing, which passes through the top of the ground electrode and is connected to the ceramic fuel injection rod. The ceramic fuel injection rod extends into the hollow structure of the high-voltage electrode, and the high-voltage electrode is placed in the ceramic air-cooling housing. An air-cooling inlet and an atomized fuel-air mixture spray hole are provided on one side of the ground electrode and the ceramic air-cooling housing. The upper part of the high-voltage electrode is tightly fitted with the ceramic air-cooling housing, and a dielectric barrier discharge area is provided between the lower part of the high-voltage electrode and the ceramic air-cooling housing, and the dielectric barrier discharge area is connected to the air-cooling inlet; The bottom of the ceramic fuel injection rod is provided with a direct fuel injection hole, and the bottom passes through the high-voltage electrode, and a plasma jet area is formed between the passing part and the ceramic air cooling shell, and the plasma jet area is connected to the atomized fuel-air mixture injection hole; A drainage hollow cylindrical platform is provided in the middle of the ceramic air cooling housing, and the drainage hollow cylindrical platform is located above the dielectric barrier discharge area and at the air cooling inlet; The ceramic air cooling housing, the ceramic spray rod and the high-voltage electrode are fixed by a flange, and a high-voltage electrode power supply terminal is provided on the flange; The air cooler inlet introduces air through the compressor and enters the dielectric barrier discharge area. A large number of arcs are formed between the high-voltage electrode and the ground electrode, filling the entire gap between the ceramic air cooler shell and the high-voltage electrode, and using the gas dynamics of the air to form a plasma jet; After high-pressure and low-temperature air is introduced into the air cooling air inlet, the air cooling air passes through the dielectric barrier discharge area and cools the ceramic spray rod through convection heat transfer.

2. The direct plasma jet atomizing double-layer fuel spray boom with an air-cooling structure according to claim 1, characterized in that: The ceramic fuel injection rod is connected to the engine oil pipe, and the fuel flows through the fuel inlet channel, passes through the high-voltage electrode, and enters the plasma jet area from the direct fuel injection hole.

3. The direct-injection plasma jet atomizing double-layer fuel spray boom with an air-cooling structure according to claim 1, characterized in that: Air enters from the air cooling inlet. At this time, the high-voltage electrode generates plasma through dielectric barrier discharge under the action of the high-voltage electrode power supply terminal. The plasma flows through the dielectric barrier discharge area with the air to produce a plasma jet that contacts the fuel coming out of the direct fuel nozzle. The plasma destroys the surface tension of the fuel droplets, forming an atomized fuel-air mixture, which eventually enters the aircraft engine through the atomized fuel-air mixture nozzle.

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