Oil-gas cascade ignition combustion-supporting exciter supported by gliding arc plasma

Abstract

The invention relates to an oil-gas cascade ignition combustion-supporting exciter supported by gliding arc plasma, and belongs to the field of plasma ignition combustion supporting. The exciter comprises a first-stage assembly, an air inlet assembly and a second-stage assembly. The primary assembly comprises a shell cathode, an inner cathode arranged in the shell cathode, anodes located in the inner cathode at intervals and an insulator located between the anodes and the inner cathode, the shell cathode is provided with an air entraining pipe, the air entraining pipe is communicated between the shell cathode and the inner cathode, and a gap communicated with the interval is formed between the anodes and the inner cathode; the air inlet assembly comprises a sliding arc pre-combustion cavity, the sliding arc pre-combustion cavity is sleeved with a fuel oil atomization cavity, a fuel oil atomization cavity is formed between the sliding arc pre-combustion cavity and the fuel oil atomization cavity, the shell cathode extends into the sliding arc pre-combustion cavity, and the sliding arc pre-combustion cavity is communicated with the gap; the second-stage assembly comprises a second-stage cavity, and the fuel oil atomization cavity is located in one end of the second-stage cavity. The actuator has the advantages that the fuel flow in oil gas is adjusted, so that the actuator can be switched among different working modes, and the actuator can normally work in a wider equivalence ratio range.

Description

Technical Field

[0001] The invention belongs to the field of plasma ignition and combustion-supporting and plasma activation and cracking, and particularly relates to an oil and gas cascade ignition and combustion-supporting exciter supported by a sliding arc plasma. Background Art

[0002] Reliable and repeatable scramjet combustion chamber ignition at low Mach numbers is a prerequisite for expanding the operational range of hypersonic vehicles. Currently, the most commonly used ignition method is the pyrotechnic igniter, which offers high energy and reliable ignition, but is limited to single, short-duration operation and cannot be repeatedly ignited. Electric spark or pure plasma arc torch ignition is a commonly used repeatable ignition method with rapid response, highly reactive chemical production, and a simple mechanical structure. However, the energy released is linearly proportional to the power source volume, making it unable to meet the requirements for reliable and repeatable ignition of practical scramjet plasmas at higher flow rates.

[0003] Air hot jet igniters are reusable, but they are bulky and have a relatively narrow stable operating equivalence ratio range, making them difficult to meet onboard requirements during flight. The igniter proposed in the invention patent application "Concave Flame Holder Self-Entrained Gliding Arc Plasma Jet Ignitor and Ignition Method," published under the publication number CN113217196B, combines the advantages of both sliding arc plasma igniters and air hot jet igniters. However, due to its limited flow rate, it struggles to meet the ignition energy requirements of higher-flow combustion chambers. Further optimization and refinement are needed to combine the advantages of both sliding arc ignition devices and air hot jets, leading to the design of a new ignition device. Summary of the Invention

[0004] We hope that by adjusting the fuel flow in the oil and gas, the actuator can quickly switch between different operating modes, allowing the actuator to operate normally in a wider equivalence ratio range, realizing cascade energy amplification from electrical energy to the chemical energy of reducing cracking components and high-temperature fuel gas, promoting the evaporation and cracking of kerosene fuel, and improving the ignition and combustion performance of the engine.

[0005] The present application provides a gliding arc plasma-supported oil and gas cascade ignition and combustion-supporting exciter, which adopts the following technical solutions: A gliding arc plasma supported oil and gas cascade ignition and combustion-supporting exciter, comprising a first-stage component, an air intake component and a second-stage component; The first-stage assembly includes a hollow outer shell cathode, an inner cathode spaced apart in the outer shell cathode, an anode located within the inner cathode, and an insulator located between one end of the anode and one end of the inner cathode, one end of the outer shell cathode being connected to one end of the inner cathode, an air bleed pipe being provided on the outer shell cathode, the air bleed pipe being connected to the space between the outer shell cathode and the inner cathode, a gap being provided between a side wall of the anode and an inner side wall of the inner cathode, the gap being connected to the gap; The air intake assembly includes a sliding arc pre-combustion cavity, a fuel atomization cavity is provided on the outside of the sliding arc pre-combustion cavity, and a fuel atomization cavity is formed between the two. A first slit is formed between an end of the sliding arc pre-combustion cavity away from the cathode of the shell and an end of the fuel atomization cavity away from the cathode of the shell. The cathode of the shell extends into the sliding arc pre-combustion cavity, and the sliding arc pre-combustion cavity is connected to the gap. The secondary component includes a secondary cavity, the fuel atomization cavity is located in one end of the secondary cavity, an air intake pipe connected to the fuel atomization cavity is provided on the outer wall of the secondary cavity, and a secondary fuel nozzle connected to the fuel atomization cavity is provided on the fuel atomization cavity.

[0006] By adopting the above technical solution, an inlet pipe on the outer wall of the secondary cavity is used to introduce pure oxidizer or air. A portion of kerosene enters through the secondary fuel nozzle. Both the oxidizer or air and this portion of fuel enter the fuel atomization chamber, where the oxidizer or air promotes atomization of the fuel. The fuel is then sprayed into the secondary cavity through the first slit, which also acts as a flashback preventer. A primary assembly (primary igniter) is positioned at the center of the secondary assembly (secondary igniter) of the ignition and combustion-supporting exciter, creating a primary igniter-centered design. A small portion of the fuel and gas passes through the primary assembly, forming a plasma and a low-flow heat jet. The majority of the fuel and gas enter the cavity enclosed by the secondary assembly. Supported by the gliding arc plasma and low-flow heat jet generated by the primary assembly, the secondary fuel and gas entering the secondary cavity come into contact with the gliding arc plasma and low-flow primary heat jet flame ejected from the primary assembly and are continuously ignited. This forms a swirl flame generated by the cascaded operation of the primary and secondary assemblies. This achieves a more stable swirl flame within the secondary cavity and allows for proper operation over a wider equivalence ratio range.

[0007] When the oil-gas equivalence ratio entering the secondary component is close to one, the exciter operates in a high-temperature ignition mode. The swirling flame in the secondary cavity reaches its highest temperature, forming a high-flow, high-temperature hot jet at the exciter outlet, achieving the high-temperature ignition function of the combustion chamber. When the oil-gas equivalence ratio entering the secondary component is greater than one, the exciter operates in a high-activity combustion-supporting mode. The fuel that has not been completely burned passes through the swirling flame in the secondary cavity and is cracked into a large number of reducing small molecular components in the oxygen-free, high-temperature environment. These small molecular components and the hot jet, after being sprayed into the combustion chamber, can significantly promote the atomization and evaporation of the fuel in the combustion chamber, shortening the ignition delay time in the combustion chamber, thereby producing a combustion-supporting effect. Because the sliding arc plasma and low-flow hot jet generated in the first-stage component are always stable, the exciter can be quickly switched between different operating modes by adjusting the fuel flow in the secondary oil and gas.

[0008] Optionally, one end of the outer shell cathode is threadedly connected to one end of the inner cathode, and the end surface of the other end of the inner cathode is pressed against the inner bottom wall of the other end of the outer shell cathode, or there is a gap between the end surface of the other end of the inner cathode and the inner bottom wall of the other end of the outer shell cathode; A secondary oil and air supply pipe communicating with the interior of the sliding arc pre-combustion cavity is provided on the outer wall of the sliding arc pre-combustion cavity.

[0009] By adopting the above-mentioned technical solution, the exposed threaded end of the inner cathode is rotated so that the end face of the other end of the inner cathode presses against the inner bottom wall of the other end of the outer cathode. The first-stage igniter operates in pure gaseous mode, and the air bleed pipe introduces pure gaseous oxidant (air or pure oxygen). The inner cathode and outer cathode are connected at both ends to form an integral structure. Air or pure oxygen enters the gap and then enters the gap. The sliding arc plasma generated by the air breakdown at the two cathodes and the anode is blown out of the outer cathode into the sliding arc pre-combustion chamber. Kerosene enters the sliding arc pre-combustion chamber through the secondary oil and air supply pipe, where it ignites upon contact with the plasma and oxidant, forming a diffusion service flame that enters the secondary chamber. The air inlet pipe is used to introduce pure oxidant or air. A portion of kerosene enters through the secondary fuel nozzle. The oxidant or air and this portion of fuel enter the fuel atomization chamber to promote atomization of this portion of fuel. The atomized oil-gas mixture is sprayed into the secondary chamber through the first slit, where it contacts the diffusion service flame to form a rich flame, which continues to burn in the secondary chamber. When there is a gap between the end face of the other end of the inner cathode and the inner bottom wall of the other end of the outer cathode, the first-stage igniter operates in an oil-gas mixture mode. A mixture of air and kerosene is introduced into the bleed pipe. The sliding arc plasma generated by the breakdown of the oil-gas mixture by the inner cathode and the anode directly ignites the remaining oil-gas mixture, causing a flame to eject from the gap. When another portion of the oil-gas mixture flows from the gap between the inner cathode and the outer cathode toward the outlet of the outer cathode, it encounters the flame ejected from the gap of the inner cathode and is also ignited. Together, they eject the first-stage component from the outlet and enter the sliding arc pre-combustion cavity to form a rich premixed flame. The rich premixed flame encounters the air injected from the second-stage oil and air supply pipe, and the incompletely burned fuel continues to burn, forming a premixed duty flame. The air inlet pipe is used to introduce pure oxidant or air, and a part of kerosene enters through the secondary fuel nozzle. The oxidant or air and this part of the fuel all enter the fuel atomization chamber to promote the atomization of this part of the fuel. The atomized oil-gas mixture is sprayed into the secondary cavity through the first slit, contacts with the premixed service flame to form a rich flame, and continues to burn in the secondary cavity.

[0010] Optionally, an annular cavity is formed between the fuel atomization cavity and the secondary cavity, and a plurality of small holes are opened on the fuel atomization cavity.

[0011] By adopting the above technical solution, pure oxidant or air enters the annular cavity through the air inlet pipe, then enters the fuel atomization cavity through the small holes and is evenly distributed, coming into contact with the kerosene entering the fuel atomization cavity, so that the kerosene is atomized more evenly and thoroughly.

[0012] Optionally, two fuel supply pipes for supplying cracking fuel are sequentially opened in the middle of the secondary cavity along its length direction.

[0013] By adopting this technical solution, a fuel feeder pipe is installed in the secondary chamber. The high-temperature combustion gas in the secondary chamber cracks the additional fuel, producing more small-molecule fuel products, enhancing the combustion chamber's combustion effect and reducing thermal ablation of the pipe wall. Fuel is injected into the upstream and downstream fuel feeders of the secondary chamber to adjust the degree of fuel cracking. When injected upstream, the fuel remains in the exciter for a longer time, resulting in a deeper degree of cracking. When injected downstream, the degree of cracking is less.

[0014] Optionally, the sliding arc pre-combustion cavity is in a gradually contracting shape or gradually contracting and expanding shape away from the cavity wall of the shell cathode.

[0015] By adopting the above technical solution, when the airflow pressure is low, the sliding arc pre-combustion chamber can use a tapered conduit to ensure a stable flow rate at the sliding arc pre-combustion chamber outlet. When the airflow pressure is high, the sliding arc pre-combustion chamber can use a tapered converging and diverging conduit to improve the airflow mixing ability and combustion volume in the secondary cavity.

[0016] Optionally, the end of the secondary cavity away from the cathode of the shell is in a tapered shape or a decreasingly tapering and gradually expanding shape.

[0017] By adopting this technical solution, when the secondary cavity outlet adopts a tapered pipe, the jet temperature at the exciter outlet is higher, making it suitable for use in ignition scenarios. When the secondary cavity outlet adopts a tapered pipe, the jet velocity at the exciter outlet is higher, penetrating deeper into the mainstream, making it suitable for long-term combustion support operations.

[0018] Optionally, a second slit is formed at one end of the secondary cavity and the fuel atomization cavity away from the cathode of the shell.

[0019] By adopting the above technical solution, the pure oxidant or air introduced into the air inlet pipe flows into the secondary cavity through the second slit, forming an air film on the wall of the secondary cavity, reducing the ablation of the wall of the secondary cavity, and further providing oxygen for the rich flame entering the secondary cavity.

[0020] Optionally, the inner diameter of the secondary cavity is larger than the outer diameter of the cathode of the outer shell.

[0021] In summary, this application includes at least one of the following beneficial technical effects: 1. The exciter involved in the present invention has two working modes. When the oil-gas equivalence ratio of the secondary component is close to 1, the exciter operates in the high-temperature ignition mode. The swirl flame temperature in the secondary cavity is the highest, and a large-flow high-temperature hot jet is formed at the exciter outlet. It is ejected from the exciter outlet, completing the cascade energy amplification of the discharge electrical energy of the first-stage component to the thermal energy of the high-temperature combustion gas, thereby realizing the high-temperature ignition function of the combustion chamber.

[0022] When the fuel-gas equivalence ratio entering the secondary assembly is greater than one, the exciter operates in a high-activity combustion-supporting mode. Unburned fuel passes through the swirling flame within the secondary chamber, where it is cracked into a large number of reducing small molecules in the oxygen-free, high-temperature environment. By adjusting the length of the secondary assembly and the fuel-gas equivalence ratio entering the secondary chamber, the residence time of the secondary fuel gas in the cascade flame, the concentration and ratio of the cracked components, and the cascade flame temperature can be adjusted. These small gaseous components, along with the relatively high-temperature cascade flame gas jet, injected into the combustion chamber significantly promote the evaporation of the fuel atomized material, bypassing some of the fuel cracking process and shortening the ignition delay within the combustion chamber. This produces a combustion-supporting effect, completing the cascade energy amplification from the electrical energy discharged by the primary assembly to the chemical energy of the high-temperature gas of the highly reducing cracked components, thus achieving the high-activity combustion-supporting function of the combustion chamber. Because the gliding arc plasma and low-flow hot jet generated in the primary assembly are always present, the exciter can be rapidly switched between different operating modes by adjusting the fuel flow rate in the secondary assembly without causing flameout.

[0023] 2. This application takes advantage of the high activity of plasma and the high chemical energy of fuel, and through the combined action of the sliding arc plasma generated by discharge and the swirl flame supported by the plasma, realizes cascade energy amplification from electrical energy to the chemical energy of reducing cracking components and high-temperature combustion gas, promotes the evaporation and cracking of kerosene fuel, and improves the ignition and combustion performance of the engine.

[0024] 3. The two-stage structure has a larger gas and fuel flow rate, and the generated thermal power and active component concentration are higher, which can achieve a good ignition and combustion-supporting effect in a combustion chamber with a larger flow rate. Under the condition of outputting 100kW thermal power, the 100kW arc igniter and power supply are huge in size. When powered by 380V, the current load is 263A, and the cooling system is complex. However, the ignition and combustion-supporting exciter proposed in this application outputs 100kW thermal power. Since the high-voltage power supply only needs to connect to the first-stage component with a smaller flow rate to work, the smaller electrode gap can significantly reduce the power supply voltage and power. It can work normally under the condition of 1kW or even lower power input power, reducing the requirements for parameters such as insulation level, volume and weight, which is conducive to engineering realization.

[0025] 4. In traditional air hot jet igniters, due to the heat absorption of the fuel and the heat dissipation of the wall, when deviating from the designed operating conditions, the hot jet flame may become unstable or on the verge of extinction, and the normal operating equivalence ratio range is relatively narrow. However, the sliding arc plasma and low-flow hot jet produced by the first-stage component of the present invention can continuously support and stabilize the swirl flame in the second-stage component, maintaining the normal operation of the igniter and the rapid switching between different modes. At the same time, the ignition and combustion-supporting exciter can use a variety of fuels, including kerosene, gasoline, kerosene, ammonia, etc., and the fuel applicability is wide. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is an overall cross-sectional view of the oil-gas cascade ignition and combustion-supporting exciter supported by the sliding arc plasma of the present application; Figure 2 It is a schematic diagram showing the spacing between the outlet end face of the inner cathode and the outlet end face of the outer shell cathode in the first-stage assembly of the present application; Figure 3 It is a schematic diagram showing that the sliding arc pre-combustion cavity in the secondary assembly of the present application is a straight cylinder; Figure 4 It is a schematic diagram showing that the outlet end face of the inner cathode and the outlet end face of the outer shell cathode in the first-stage assembly of the present application are tightly pressed against each other; Figure 5 It is a schematic diagram showing that the sliding arc pre-combustion cavity in the secondary assembly of the present application is tapered; Figure 6 It is a schematic diagram showing that the sliding arc pre-combustion cavity in the secondary component of the present application is gradually contracting and expanding.

[0027] Description of reference numerals: 1. Air bleed pipe; 2. Air intake pipe; 3. Secondary fuel injection pipe; 4. Secondary fuel and air supply pipe; 5. Fuel supply pipe; 10. Primary component; 11. Outer cathode; 12. Inner cathode; 13. Anode; 14. Insulator; 20. Air intake assembly; 21. Sliding arc pre-combustion chamber; 22. Fuel atomization chamber; 221. Fuel atomization chamber; 211. First slit; 222. Small hole; 30. Secondary assembly; 31. Secondary cavity; 311. Annular cavity; 312. Second slit. DETAILED DESCRIPTION

[0028] The following is a combination of the appended examples of the present application Figures 1-6 , describes the technical solutions in the embodiments of this application.

[0029] The embodiment of the present application discloses a sliding arc plasma-supported oil and gas cascade ignition and combustion-supporting exciter. The arrows in the figure indicate the direction of the airflow, heat jet, and flame.

[0030] See also Figure 1 、 Figure 2 and Figure 3 A sliding arc plasma supported oil and gas cascade ignition and combustion-supporting exciter comprises a first-stage component 10, an air inlet component 20 and a second-stage component 30 which are sequentially arranged along the length direction.

[0031] The first-stage assembly 10 includes a hollow outer shell cathode 11 , an inner cathode 12 located within the outer shell cathode 11 , an anode 13 located within the inner cathode 12 , and an insulator 14 located between the anode 13 and the inner cathode 12 .

[0032] One end of the outer cathode 11 is threadedly connected to one end of the inner cathode 12. An air bleed pipe 1 is provided on this end of the outer cathode 11. The other end of the outer cathode 11 has an end cap with a circular opening in the center. A gap is formed between the outer wall of the inner cathode 12 and the inner wall of the outer cathode 11. The air bleed pipe 1 connects the gap between the outer cathode 11 and the inner cathode 12.

[0033] Insulator 14 is located on the side of anode 13 near air duct 1. A gap is provided between the other sidewall of anode 13 and the inner wall of inner cathode 12. Multiple through-holes are evenly distributed throughout inner cathode 12, connecting the gap and the gap. There is a certain distance between the end of anode 13 away from insulator 14 and the end cap of inner cathode 12 near outer cathode 11. An opening is also provided on inner cathode 12 directly opposite the circular opening of the end cap.

[0034] The air intake assembly 20 includes a hollow sliding arc pre-combustion cavity 21, and a fuel atomization cavity 22 is provided on the outside of the sliding arc pre-combustion cavity, and a fuel atomization cavity 221 is formed between the two. A first slit 211 is formed between the end of the sliding arc pre-combustion cavity 21 away from the outer shell cathode 11 and the end of the fuel atomization cavity 22 away from the outer shell cathode 11. The outer shell cathode 11 extends into the sliding arc pre-combustion cavity 21, and one end of the sliding arc pre-combustion cavity 21 is connected to the circular opening on the end cover and the opening on the inner cathode 12.

[0035] The secondary assembly 30 includes a secondary cavity 31, the inner diameter of which is significantly larger than the outer diameter of the outer shell cathode 11. The fuel atomization cavity 22 is located within one end of the secondary cavity 31. A secondary oil and air supply pipe 4 is provided on the outer wall of the sliding arc pre-combustion cavity 21, communicating with the interior of the cavity. A circular chamber may also be formed outside the sliding arc pre-combustion cavity 21. The secondary oil and air supply pipe 4 connects to this chamber and, through multiple evenly distributed holes formed in this chamber, connects to the interior of the sliding arc pre-combustion cavity 21, thereby evenly supplying air and oil to the sliding arc pre-combustion cavity 21.

[0036] An air intake pipe 2 is installed on the outer wall of the secondary chamber 31, connecting to the fuel atomization chamber 221. A secondary fuel nozzle 3 is installed on the fuel atomization chamber 22, also connecting to the fuel atomization chamber 221. An annular cavity 311 is formed between the fuel atomization chamber 22 and the secondary chamber 31. The fuel atomization chamber 22 is provided with a plurality of small holes 222 extending therethrough. Oxidant or air entering through the air intake pipe 2 enters the fuel atomization chamber 221 through the small holes 222. A portion of kerosene enters through the secondary fuel nozzle 3. The oxidant or air promotes atomization of this portion of fuel, which is then sprayed into the secondary chamber 31 through the first slit 211.

[0037] A second slit 312 is formed on the inner wall of the secondary cavity 31 and the end of the fuel atomization cavity 22 away from the cathode 11 of the outer shell, so that the pure oxidant or air introduced from the air intake pipe 2 flows into the secondary cavity 31 through the second slit 312, forming an air film on the wall of the secondary cavity 31, reducing the ablation of the inner wall of the secondary cavity 31, and further providing oxygen for the rich flame entering the secondary cavity 31.

[0038] The small holes 222 are not perpendicular to the inner surface of the fuel atomization chamber 22, but rather form a certain angle with the outlet normal direction, forming a swirl of air-fuel mixture under the constraints of the inner surface. When air enters the fuel atomization chamber 221 from the intake pipe, its velocity increases, which can shear the fuel injected by the secondary fuel nozzle 3, thereby enhancing the atomization and evaporation of the fuel and accelerating the combustion and cracking process of the fuel in the cavity of the secondary assembly 30. The tangential inlet swirl number is high, and the swirl flame formed by the sliding arc plasma has good stability and high outlet temperature. It may also contain a higher content of small molecule fuel after cracking, and the ignition delay time is shortened.

[0039] The inner cathode 12 is rotated to extend out of the threaded end of the outer shell cathode 11 so that there is a distance between the end of the inner cathode 12 facing the end cover and the end cover, that is, the outlet end face of the inner cathode 12 and the outlet end face of the outer shell cathode 11 are not tightly pressed together. The first-stage igniter (first-stage component 10) works in the oil-gas mixing mode, and the second-stage oil and air supply pipe 4 is used to supply air.

[0040] The air bleed pipe 1 introduces a mixture of air and kerosene. The sliding arc plasma generated by the breakdown of the oil-gas mixture by the inner cathode 12 and anode 13 directly ignites the remaining oil-gas mixture, which then emits a flame from the gap. Another portion of the oil-gas mixture flows from the gap between the inner cathode 12 and the outer shell cathode 11 toward the central circular opening of the end cap of the outer shell cathode 11. It encounters the flame emitted from the gap of the inner cathode 12 and is also ignited. Together, they are ejected from the outer shell cathode 11 and enter the sliding arc pre-combustion chamber 21, forming a rich premixed flame. The rich premixed flame meets the air injected from the secondary oil and air supply pipe 4, and the incompletely burned fuel continues to burn, forming a premixed service flame. The air inlet pipe 2 is used to introduce pure oxidant or air, and a portion of kerosene enters through the secondary fuel nozzle 3. The oxidant or air and this portion of fuel all enter the fuel atomization chamber 221 to promote the atomization of this portion of fuel. The atomized oil-gas mixture is sprayed into the secondary cavity 31 through the first slit 211, contacts the premixed service flame to form a rich flame, and continues to burn in the secondary cavity 31.

[0041] Two fuel replenishment pipes 5 are located along the middle of the secondary chamber 31, each for replenishing the cracked fuel. Fuel injection through these pipes, located upstream and downstream of the secondary chamber 31, adjusts the degree of fuel cracking. When injected upstream, the fuel remains in the exciter longer, resulting in a deeper degree of fuel cracking. When injected downstream, the degree of fuel cracking is less.

[0042] Please also refer to Figure 4 , rotate the inner cathode 12 to extend the threaded end of the outer shell cathode 11, so that the inner cathode 12 is facing one end of the end cover and is tightly pressed against the end cover, that is, the outlet end face of the inner cathode 12 is tightly pressed against the outlet end face of the outer shell cathode 11, and the first-stage igniter (first-stage component 10) works in pure gaseous mode, and the air bleed pipe 1 introduces pure gaseous oxidant (air or pure oxygen), and the second-stage oil and air supply pipe 4 is used to add kerosene.

[0043] The inner cathode 12 and the outer shell cathode 11 are connected at both ends to form an integral structure. Air or pure oxygen enters the gap through the air bleed pipe 1 and then enters the gap through the gap. The sliding arc plasma generated by the air breakdown at the two cathodes and the anode is blown out of the outer shell cathode 11 into the sliding arc pre-combustion chamber 21. Kerosene enters the sliding arc pre-combustion chamber 21 through the secondary oil and air supply pipe 4, where it comes into contact with the plasma and oxidant and is ignited, forming a diffusion service flame that enters the secondary chamber 31. The air inlet pipe 2 is used to introduce pure oxidant or air. A portion of kerosene enters through the secondary fuel nozzle 3. The oxidant or air and this portion of fuel enter the fuel atomization chamber to promote the atomization of this portion of fuel. The atomized oil-gas mixture is sprayed into the secondary chamber 31 through the first slit 211, where it comes into contact with the diffusion service flame to form a rich flame, which continues to burn in the secondary chamber 31.

[0044] Please also refer to Figure 5 and Figure 6The wall of the sliding arc pre-combustion chamber 21 away from the outer shell cathode 11 is tapered or gradually divergent. When the airflow pressure is low, the sliding arc pre-combustion chamber 21 can use a tapered conduit to ensure a stable flow rate at the outlet of the sliding arc pre-combustion chamber 21. When the airflow pressure is high, the sliding arc pre-combustion chamber 21 can use a convergent-divergent conduit to improve the airflow mixing ability and combustion efficiency within the secondary chamber 31.

[0045] The end of the secondary cavity 31, facing away from the cathode 11, features a tapered or gradually diverging shape. When a tapered conduit is used at the outlet of the secondary cavity 31, the jet temperature at the exciter outlet is higher, making it suitable for ignition applications. When a tapered, gradually diverging conduit is used at the outlet of the secondary cavity 31, the jet velocity at the exciter outlet is higher, allowing deeper penetration into the mainstream, making it suitable for long-term combustion support operations.

[0046] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A sliding arc plasma supported oil and gas cascade ignition and combustion-supporting exciter, characterized in that: It comprises a primary component (10), an air intake component (20) and a secondary component (30); The first-stage component (10) comprises a hollow outer shell cathode (11), an inner cathode (12) spaced in the outer shell cathode (11), an anode (13) located in the inner cathode (12), and an insulator (14) located between one end of the anode (13) and one end of the inner cathode (12); one end of the outer shell cathode (11) is connected to one end of the inner cathode (12); an air duct (1) is provided on the outer shell cathode (11); the air duct (1) is connected to the space between the outer shell cathode (11) and the inner cathode (12); a gap is provided between the side wall of the anode (13) and the inner side wall of the inner cathode (12); the gap is connected to the gap; The air intake assembly (20) comprises a sliding arc pre-ignition cavity (21), the sliding arc pre-ignition cavity (21) is provided with a fuel atomization cavity (22) outside, and a fuel atomization cavity (221) is formed between the two, and a first slit (211) is formed between an end of the sliding arc pre-ignition cavity (21) away from the outer shell cathode (11) and an end of the fuel atomization cavity (22) away from the outer shell cathode (11), and the outer shell cathode (11) extends into the sliding arc pre-ignition cavity (21), and the sliding arc pre-ignition cavity (21) is connected to the gap; The secondary component (30) comprises a secondary cavity (31), the fuel atomization cavity (22) being located in one end of the secondary cavity (31), an air intake pipe (2) communicating with the fuel atomization cavity (221) being provided on an outer wall of the secondary cavity (31), and a secondary fuel nozzle (3) communicating with the fuel atomization cavity (221) being provided on the fuel atomization cavity (22).

2. The oil-gas cascade ignition and combustion-supporting exciter supported by sliding arc plasma according to claim 1, characterized in that: One end of the outer shell cathode (11) is threadedly connected to one end of the inner cathode (12), and the end surface of the other end of the inner cathode (12) is pressed against the inner bottom wall of the other end of the outer shell cathode (11), or there is a gap between the end surface of the other end of the inner cathode (12) and the inner bottom wall of the other end of the outer shell cathode (11); A secondary oil and air supply pipe (4) communicating with the interior of the sliding arc pre-ignition cavity (21) is provided on the outer wall of the sliding arc pre-ignition cavity (21).

3. The oil-gas cascade ignition and combustion-supporting exciter supported by sliding arc plasma according to claim 2, characterized in that: An annular cavity (311) is formed between the fuel atomization cavity (22) and the secondary cavity (31), and a plurality of small holes (222) are provided on the fuel atomization cavity (22).

4. The oil-gas cascade ignition and combustion-supporting exciter supported by sliding arc plasma according to claim 3, characterized in that: The secondary chamber (31) is provided with two fuel supply pipes (5) in sequence along the middle of its length direction for supplying cracking fuel.

5. The oil-gas cascade ignition and combustion-supporting exciter supported by sliding arc plasma according to claim 1, characterized in that: The cavity wall of the sliding arc pre-ignition cavity (21) away from the shell cathode (11) is in a gradually contracting shape or a gradually contracting and expanding shape.

6. The oil-gas cascade ignition and combustion-supporting exciter supported by sliding arc plasma according to claim 1, characterized in that: One end of the secondary cavity (31) away from the outer shell cathode (11) is in a gradually contracting shape or a decreasingly contracting and gradually expanding shape.

7. The oil-gas cascade ignition and combustion-supporting exciter supported by sliding arc plasma according to claim 1, characterized in that: The secondary cavity (31) and the fuel atomization cavity (22) form a second slit (312) at one end away from the shell cathode (11).

8. The oil-gas cascade ignition and combustion-supporting exciter supported by sliding arc plasma according to claim 1, characterized in that: The inner diameter of the secondary cavity (31) is greater than the outer diameter of the outer shell cathode (11).

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