CN101949550B - Stable supersonic combustion method based on jetting plasma activation - Google Patents

Abstract

The supersonic stable combustion method based on jet plasma activation relates to a supersonic stable combustion method to solve the problem of large support plate thickness in the existing stable flame combustion method, resulting in large flow loss and low supersonic combustion performance. Method: 1. The first L-shaped through-hole and the third L-shaped through-hole are coated with ceramic film; 2. The input end of the second L-shaped through-hole is connected to the fuel pipe, and the first L-shaped through-hole and the third L-shaped through-hole The input ends of the shaped through-holes are respectively connected with the corresponding plasma generators; 3. The fuel is injected into the main combustion zone through the second L-shaped through-hole to form a diffusion flame; the plasma generated by the plasma generator is fed by the first L-shaped through-hole The hole and the third L-shaped through hole are injected into the main combustion area and ejected to generate jet-type plasma; 4. The plasma promotes the combustion of the diffusion flame and forms a continuous combustion flame to achieve supersonic stable combustion. The invention is used for ignition, mixing and combustion of fuel in a supersonic combustion chamber.

Description

Supersonic stable combustion method based on jet plasma activation

technical field

The invention relates to a supersonic stable combustion method.

Background technique

In supersonic combustion technology, the incoming flow flows at supersonic speed in the combustion chamber, and the stagnation time is only a few milliseconds. It is very difficult to achieve fuel ignition and combustion in such a short time. Measures to stabilize the flame are necessary for supersonic combustion. The support plate combustion method is a commonly used stable flame method at present. The fuel is introduced into the combustion chamber through the pipe embedded in the support plate, and the combustion in the high-speed airflow is realized by the self-diffusion of the fuel. In order to stabilize the flame, the support plate is required to be thicker (10mm-15mm) to build a large-scale low-speed vortex area at the end, so that the combustible gas can stay in this area for a sufficient time to form a stable high-temperature flame. The flow loss caused by the thick strut plate in the supersonic combustion chamber is often large, which reduces the performance of supersonic combustion.

Contents of the invention

The purpose of the present invention is to provide a supersonic stable combustion method based on jet plasma activation to solve the problems of large thickness of the support plate in the existing support plate combustion method, resulting in large flow loss and low supersonic combustion performance.

The method of the present invention is realized through the following steps: step 1, process three L-shaped through holes sequentially from the main combustion zone of the engine combustion chamber to the combustion chamber entrance on the wall thickness of the support plate in the engine combustion chamber, respectively the first One L-shaped through hole, the second L-shaped through-hole and the third L-shaped through-hole, the first L-shaped through-hole, the second L-shaped through-hole and the third L-shaped through-hole all pass through the casing and the outside of the engine combustion chamber In the same way, the inner surfaces of the first L-shaped through hole and the third L-shaped through hole are coated with a ceramic film, and the thickness of the support plate is 5 mm to 8 mm; step 2, the input end of the second L-shaped through hole is connected to the fuel pipe, The input ends of the first L-shaped through hole and the third L-shaped through hole are respectively connected to the outlets on the corresponding plasma generating device, and the first L-shaped through hole, the second L-shaped through hole and the third L-shaped through hole output Both ends are facing the main combustion area of the engine combustion chamber; step 3, the fuel is injected into the main combustion area of the engine combustion chamber through the second L-shaped through hole to form a diffusion flame; the plasma generator is powered by a high-voltage and high-frequency plasma power supply The plasma generated under the excitation is injected into the main combustion area of the engine combustion chamber through the first L-shaped through hole and the third L-shaped through hole, and is injected at the main combustion area to generate jet-type plasma. The voltage is 5000V-10000V, the frequency is 30000Hz-50000Hz, and the working medium for generating plasma is argon; step 4, the activated groups in the plasma promote the combustion of the diffusion flame, forming a continuous combustion flame, and the flame It can exist stably in the combustion chamber of the engine, so as to realize supersonic stable combustion.

The advantages of the present invention are: the present invention adds a channel coated with a ceramic film in the support plate, and introduces the plasma generated outside the combustion chamber into the combustion chamber; the activation of the plasma is used to induce the chain combustion reaction of the fuel, forming A continuous combustion flame; the stability of the flame mainly depends on the existence of plasma, and does not require a large-scale low-speed vortex area at the end of the support plate, thereby reducing the design requirements for the thickness of the support plate and reducing the flow loss of the support plate.

Description of drawings

Fig. 1 is a schematic structural view of the first embodiment of the present invention, and Fig. 2 is a schematic structural view of the plasma generator 3 in Step 2 of the first specific embodiment of the present invention (mark 6 in the figure is a high-voltage high-frequency plasma Body power supply, mark 5-2 is a high-strength quartz tube, mark 5-3 is a blockage, mark 5-4 is a stainless steel tube).

Detailed ways

Specific embodiment one: this embodiment is described in conjunction with Fig. 1 and Fig. 2, and present embodiment is realized through the following steps: Step 1, on the wall thickness of support plate 1 in engine combustion chamber 2, by the main combustion of engine combustion chamber 2 Three L-shaped through holes are sequentially processed from zone 2-1 to the entrance of the combustion chamber, which are respectively the first L-shaped through hole 1-1, the second L-shaped through hole 1-2 and the third L-shaped through hole 1-3, The first L-shaped through hole 1-1, the second L-shaped through hole 1-2 and the third L-shaped through hole 1-3 all communicate with the outside through the shell of the engine combustion chamber 2, and the first L-shaped through hole 1- 1 and the inner surfaces of the third L-shaped through hole 1-3 are coated with a ceramic film, and the thickness of the support plate 1 is 5 mm to 8 mm; step 2, the input end of the second L-shaped through hole 1-2 is connected to the fuel pipe, The input ends of the first L-shaped through hole 1-1 and the third L-shaped through hole 1-3 are respectively connected to the outlet 3-1 on the corresponding plasma generating device 3, the first L-shaped through hole 1-1, the second L-shaped through hole 1-3 Two L-shaped through-holes 1-2 and the third L-shaped through-hole 1-3 output ends are all towards the main combustion zone 2-1 of engine combustion chamber 2; Step 3, fuel oil is injected into by the second L-shaped through-hole 1-2 At the main combustion zone 2-1 of the engine combustion chamber 2, a diffusion flame 4 is formed; the plasma generated by the plasma generator 3 under the excitation of a high-voltage and high-frequency plasma power supply is formed by the first L-shaped through hole 1-1 and the first L-shaped through hole 1-1. The third L-shaped through hole 1-3 is injected into the main combustion zone 2-1 of the engine combustion chamber 2, and jet plasma 5 is generated by injection at the main combustion zone 2-1, and the voltage of the plasma power supply is 5000V～ 10000V, the frequency is 30000Hz ~ 50000Hz, the working medium for generating plasma is argon; step 4, the activated group in the plasma 5 promotes the combustion of the diffusion flame 4, forming a continuous combustion flame, and the flame can be stable Existing in the engine combustion chamber 2, the high-energy particles in the plasma 5 will cause dissociation, excitation and even ionization of fuel molecules through collisions, forming a large number of active groups and strong oxidizing particles. The "stimulant" will sharply accelerate the combustion process and form a combustion chain reaction; thus, the plasma 5 strengthens the combustion reaction of the fuel in the main combustion zone 2-1, forming a combustion flame that depends on the activation of the plasma, and realizes Stable combustion of fuel, that is, stable combustion at supersonic speed. The plasma generator 3 is a prior art.

Specific Embodiment 2: This embodiment is described with reference to FIG. 1 . In Step 1 of this embodiment, the thickness of the support plate 1 is 6 mm. The thickness of the support plate in the prior art is greater than 10 mm, and the greater the thickness of the support plate, the greater the loss of supersonic combustion; the thickness of the support plate 1 in the present invention is 6 mm, which can reduce the loss of the support plate 1 in the supersonic combustion chamber . Other steps are the same as in the first embodiment.

Specific Embodiment Three: This embodiment is described in conjunction with FIG. 1 . The thickness of the ceramic film on the inner surface of the first L-shaped through hole 1-1 and the third L-shaped through hole 1-3 in Step 1 of this embodiment is 0.1 mm. ~02mm. The ceramic film realizes the insulating effect between the plasma and the support plate, and the ceramic film can generate secondary electron emission under the collision of the plasma, which is beneficial to the stable propagation of the plasma in the through hole. Other steps are the same as those in Embodiment 1 or 2.

Embodiment 4: The voltage of the plasma power source in step 3 of this embodiment is 6500V. Other steps are the same as in the third embodiment.

Embodiment 5: The frequency of the plasma power supply in Step 3 of Step 3 of this embodiment is 40000 Hz. Other steps are the same as those in Embodiment 1 or Embodiment 4.

Claims (5)

1. a supersonic stable combustion method based on jet plasma activation, it is characterized in that: described method is realized by following steps: step 1, on the wall thickness of strut plate (1) in engine combustion chamber (2) by Three L-shaped through holes are sequentially processed from the main combustion zone (2-1) of the engine combustion chamber (2) to the combustion chamber entrance, which are respectively the first L-shaped through-hole (1-1), the second L-shaped through-hole ( 1-2) and the third L-shaped through hole (1-3), the first L-shaped through hole (1-1), the second L-shaped through hole (1-2) and the third L-shaped through hole (1- 3) Both communicate with the outside through the shell of the engine combustion chamber (2), and the inner surfaces of the first L-shaped through hole (1-1) and the third L-shaped through hole (1-3) are coated with a ceramic film, and the support The thickness of the plate (1) is 5 mm to 8 mm; step 2, the input end of the second L-shaped through hole (1-2) is connected to the fuel pipe, the first L-shaped through hole (1-1) and the third L-shaped through hole The input ends of the holes (1-3) are respectively connected to the outlets (3-1) on the corresponding plasma generator (3), the first L-shaped through hole (1-1), the second L-shaped through hole (1 -2) and the output end of the third L-shaped through hole (1-3) are all towards the main combustion zone (2-1) of the engine combustion chamber (2); ) into the main combustion zone (2-1) of the engine combustion chamber (2) to form a diffusion flame (4); the plasma generated by the plasma generator (3) under the excitation of a high-voltage, high-frequency plasma It is injected into the main combustion zone (2-1) of the engine combustion chamber (2) through the first L-shaped through hole (1-1) and the third L-shaped through hole (1-3), and in the main combustion zone (2-1) -1) is sprayed to generate jet-type plasma (5), the voltage of the plasma power supply is 5000V～10000V, the frequency is 30000Hz～50000Hz, and the working medium for generating plasma is argon; step 4, in the plasma (5) The activating group promotes the combustion of the diffusion flame (4), forming a continuous combustion flame, and the flame can stably exist in the engine combustion chamber (2), realizing supersonic stable combustion. 2. The supersonic stable combustion method based on jet plasma activation according to claim 1, characterized in that: in step 1, the thickness of the support plate (1) is 6mm. 3. according to claim 1 or 2 described based on the supersonic stable combustion method of jet plasma activation, it is characterized in that: the first L-shaped through hole (1-1) and the 3rd L-shaped through hole (1-1) in the step 1 3) The thickness of the ceramic film on the inner surface is 0.1 mm to 0.2 mm. 4. The supersonic stable combustion method based on jet plasma activation according to claim 1, characterized in that: the voltage of the plasma power supply in step 3 is 6500V. 5. The supersonic stable combustion method based on jet plasma activation according to claim 1 or 4, characterized in that: the frequency of the plasma power supply in step 3 is 40000 Hz.

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