An airflow self-driven rotating sliding arc plasma ammonia-hydrogen burner

Abstract

The present invention relates to an airflow self-driven rotating sliding arc plasma ammonia-hydrogen burner, comprising a grounding tube and a high-voltage conductive rod. A flow-equalizing nozzle and a one-way anti-backfire valve are provided at the upper and lower ends of the grounding tube. The high-voltage conductive rod is coaxially arranged in the grounding tube and is located between the flow-equalizing nozzle and the one-way anti-backfire valve. A plurality of rotating electrodes are rotatably provided on the high-voltage conductive rod, and the rotating electrodes include a plurality of metal blades, with gaps between the metal blades and the inner wall of the grounding tube. A plurality of arc-starting metal strips are axially provided on the inner wall of the grounding tube, and an insulating layer is filled between adjacent arc-starting metal strips. An isolated grounding section made of high-strength insulating material is provided at the bottom of the grounding tube. The present invention combines the flow-equalizing nozzle and the anti-backfire one-way airflow valve system to achieve efficient hydrogen production from ammonia cracking by rotating sliding arc plasma, avoids the use of motor-driven electrodes, and solves the problems of high power supply cost, high energy consumption, and severe electrode corrosion in V-shaped electrode systems.

Description

Technical Field

[0001] The invention belongs to the field of plasma technology, and in particular relates to an airflow self-driven rotating sliding arc plasma ammonia-hydrogen burner. Background Art

[0002] Ammonia (NH3) has high hydrogen storage density (mass fraction of hydrogen is 17.6%), high energy density (maximum cracking specific energy is 5.59kWh / kg), low price, easy liquefaction (can be liquefied at room temperature under 0.8Mpa pressure), good safety (narrow ignition range, pungent odor, easy to identify leaks, and no hydrogen embrittlement during hydrogen storage and transportation), low storage and transportation costs, and the only products of complete cracking are the target product H2 (volume concentration can reach 75%) and the by-product N2, with zero carbon emissions. It is considered to be the most promising and safest hydrogen alternative energy carrier. The ammonia decomposition reaction to produce hydrogen is: The hydrogen production process is endothermic and requires a lot of energy. The commonly used catalytic thermal decomposition of ammonia to hydrogen technology has a good conversion effect, but due to the high operating temperature, the effective cracking temperature of the reaction depends on the catalyst used. The ammonia cracking activity of different metals is ranked as follows: Ru>Rh>Ni>Co>Ir>Fe>>Pt>Cr>Pd>Cu>Te, Se, Pb. The more active K-Ru / MgO-CNTs catalyst can produce H2 at a rate of 585 mL / (min·g at 350°C. cat ), when the ammonia feed space velocity is 60000 mL / (h·g cat ), the ammonia conversion rate can reach about 80% at 400°C and more than 99% at 450°C. However, precious metal ammonia cracking catalysts are expensive and have poor economic efficiency. Although non-precious metal catalysts are cheap, their activity is relatively low. To completely crack ammonia, a very high reaction temperature must be used. For example, the operating temperature of nickel-based catalysts needs to exceed 1000°C, and other catalysts require a temperature of at least 650°C to 700°C to achieve a more reasonable conversion level. At the same time, this technical equipment also faces problems such as long preheating time and bulky insulation system. Therefore, the development of new technologies that can meet the requirements of ammonia decomposition and hydrogen production at lower temperatures or alternative processes has become an important exploration direction.

[0003] Discharge plasma is rich in high-energy electrons, and the electron energy distribution range is wide, which can easily meet the energy threshold of ammonia decomposition reaction to produce hydrogen and activate the active sites of the catalyst, breaking through the thermodynamic reaction limitations. It shows unique advantages in the activation and cracking of highly chemically inert molecules (NH3, CO2, benzene, etc.), and has become a potential stock and research hotspot for non-thermal decomposition of ammonia to produce hydrogen in recent years. It is expected to break through the high reaction temperature limitations of catalytic thermal decomposition of ammonia to produce hydrogen technology.

[0004] As a typical local thermal equilibrium plasma discharge method, sliding arc discharge technology has been introduced into the research on ammonia cracking and hydrogen production due to its advantages such as high reaction rate, normal pressure operation, fast start-up and low dependence on catalysts.

[0005] Existing sliding arc discharge devices use either a fixed V-shaped electrode structure or a motor-driven rotating electrode structure to generate arc plasma. Fixed-electrode structures often maintain arcs for extended periods, and the high current creates challenges for the driver power supply, increasing the cost of the plasma equipment. In motor-driven rotating electrode structures, the high-voltage discharge introduces high reverse bias and high current injection into the motor system, severely challenging the stable and reliable operation of the motor and creating a bottleneck for these types of sliding arc devices. For example, patent CN112483243A discloses an ammonia engine based on online plasma cracking, ignition, and combustion support. This technology utilizes a sliding arc plasma to rapidly reform ammonia fuel and regulate the ammonia / hydrogen ratio, while simultaneously utilizing plasma ignition and combustion support to significantly improve combustion stability and efficiency. However, the sliding arc plasma generator in this device utilizes a coaxial V-shaped electrode structure, with the high-voltage electrode being a rod and the ground electrode being a reduced-contraction cylinder. This structure relies on generating the arc at the minimum gap between the electrodes. Under the influence of temperature rise, the arc drifts axially to form a sliding arc, resulting in a poorly controlled process and severe electrode corrosion. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention proposes an airflow self-driven rotating sliding arc plasma ammonia-hydrogen burner, which is a sliding arc discharge plasma generation technology and equipment in which airflow self-drives the rotation of high-voltage electrodes. Combined with a uniform flow nozzle and an anti-backfire one-way airflow valve system, it realizes the efficient cracking of ammonia to produce hydrogen by rotating sliding arc plasma, avoids the use of motor-driven electrodes, and solves the problems of high power cost, high energy consumption and severe electrode corrosion of the V-shaped structure electrode system.

[0007] The technical solution of the present invention to solve the above problems is: an airflow self-driven rotating sliding arc plasma ammonia hydrogen burner, which is special in that:

[0008] It includes a grounding tube and a high-voltage conductive rod. The upper and lower ends of the grounding tube are provided with a flow-equalizing nozzle and a one-way anti-backfire valve. The high-voltage conductive rod is coaxially arranged in the grounding tube, and the high-voltage conductive rod is located between the flow-equalizing nozzle and the one-way anti-backfire valve. A plurality of rotating electrodes are rotatably provided on the high-voltage conductive rod. The rotating electrodes include a plurality of metal blades, and a gap is left between the metal blades and the inner wall of the grounding tube; a plurality of arc-starting metal strips are axially provided on the inner wall of the grounding tube, and an insulating layer is filled between two adjacent arc-starting metal strips; an isolation grounding section made of high-strength insulating material is provided at the bottom of the grounding tube.

[0009] Furthermore, an air guide shell is coaxially provided on the outer side of the grounding cylinder, and the annular space between the air guide shell and the grounding cylinder is used for introducing oxygen.

[0010] Furthermore, the flow-uniform nozzle includes a ceramic body, a plurality of through holes are evenly arranged in the ceramic body, and metal sheets are provided on the upper and lower end surfaces of the ceramic body, and holes corresponding to the through holes of the ceramic body are provided on the metal sheets.

[0011] Furthermore, the surface of the metal sheet at the upper end of the ceramic body is covered with a proton exchange membrane, the material of which is a metal proton membrane such as a palladium-copper alloy membrane.

[0012] Furthermore, the rotating electrode is mounted on the high-voltage conductive rod via a non-damping bearing.

[0013] Furthermore, a spring top ball is provided on the high-voltage conductive rod for limiting the non-damping bearing, which is easy to repair, disassemble and install.

[0014] Furthermore, the rotating electrode includes three blades, and the angle between each blade and the horizontal plane is 15°-45°.

[0015] Furthermore, the angle between two adjacent blades is 120°, and the distance between the blade tips and the inner wall of the grounding tube is 5-15 mm.

[0016] Furthermore, the plurality of rotating electrodes are arranged at equal intervals on the high-voltage conductive rod, and the distance between two adjacent rotating electrodes is 5 mm to 20 mm.

[0017] Furthermore, an arc-starting metal strip is provided on the inner wall of the grounding tube every 120 degrees, and the arc-starting metal strip and the insulating layer are arranged alternately.

[0018] Advantages of the present invention:

[0019] Compared with traditional DC arc, dielectric barrier discharge, hot nozzle or microwave plasma hydrogen production devices, this device has the following significant benefits:

[0020] (1) The present invention proposes a gas flow self-driven rotating sliding arc plasma ammonia hydrogen burner, which adopts a coaxial structure design, combines rotating electrodes with sliding arc discharge, and can achieve dynamic and high-energy plasma excitation during the flow of mixed gases (such as ammonia and inert gases);

[0021] (2) The device combines a rotating electrode with a sliding arc, and the arc dynamically expands on the electrode surface to form a rotating sliding arc, which effectively expands the plasma action area, improves the ammonia conversion efficiency, and slows down electrode ablation, thereby improving the system stability and service life;

[0022] (3) The gas enters the reaction chamber from bottom to top, is cracked in the discharge zone, and is discharged from the top uniform flow nozzle, which can quickly take away the reaction products, prevent the occurrence of side reactions and backfire, and improve the purity of hydrogen production and the safety of system operation;

[0023] (4) The present invention achieves effective electrical isolation and flame blocking between the high-voltage area and the air intake system by providing a one-way anti-backfire valve and a grounded isolation section, thereby ensuring the safety of operators and equipment;

[0024] (5) This device has a compact structure and distinct modules, and can be used in laboratory research, small hydrogen energy devices, or distributed plasma application systems. It has good practical prospects and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the internal structure diagram of the airflow self-driven rotating sliding arc plasma ammonia hydrogen burner;

[0026] Figure 2 It is a top view of the flow-uniform nozzle;

[0027] Figure 3 is the structural diagram of the rotating electrode;

[0028] Figure 4 A top view of the grounding tube.

[0029] In the figure, 1-flow-uniform nozzle, 2-rotating electrode, 3-high-voltage conductive rod, 4-grounding tube, 5-air guide shell, 6-one-way anti-backfire valve, 7-isolation grounding section, 8-through hole, 9-metal blade, 10-insulating layer, 11-arcing metal strip. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention for which protection is claimed, but merely represents selected embodiments of the present invention.

[0031] This invention proposes a self-propelled rotating sliding arc plasma ammonia-hydrogen burner. This device utilizes the synergistic effect of a high-voltage electric field and rotating electrodes, combined with dynamic airflow control and multiple safety features, to achieve stable arc generation, controlled sliding, and efficient arc utilization. Electrode rotation extends the arc path and prevents localized electrode ablation. A flow-sharing structure optimizes airflow distribution, improving energy conversion efficiency.

[0032] See attached Figure 1-Figure 4 The airflow self-driven rotating sliding arc plasma ammonia hydrogen burner includes a grounding tube 4 and a high-voltage conductive rod 3. The upper and lower ends of the grounding tube 4 are provided with a flow-equalizing nozzle 1 and a one-way anti-backfire valve 6. The high-voltage conductive rod 3 is coaxially fixed in the grounding tube 4, and the high-voltage conductive rod 3 is located between the flow-equalizing nozzle 1 and the one-way anti-backfire valve 6. A plurality of rotating electrodes 2 are rotatably provided on the high-voltage conductive rod 3, and the rotating electrodes 2 include a plurality of metal blades 9, with gaps being left between the metal blades 9 and the inner wall of the grounding tube 4. A plurality of arc-starting metal strips 11 are axially provided on the inner wall of the grounding tube 4, and an insulating layer 10 is filled between two adjacent arc-starting metal strips 11; the bottom of the grounding tube 4 is provided with an isolation grounding section 7 made of high-strength insulating material.

[0033] Specifically, the isolated grounding section 7 is made of a high-strength insulating material (such as PTFE or ceramic) and has a height of 1-5 cm. The arc-starting metal strip 11 can be embedded in the grounding tube 4, and the insulating layer 10 (approximately 1 mm thick) is fixed in the grounding tube 4 by coating or embedding.

[0034] As a preferred embodiment of the present invention, see Figure 1 An air guide shell 5 is coaxially provided on the outside of the grounding tube 4. The annular space between the air guide shell 5 and the grounding tube 4 is used to let in air, and the air flow also ensures the directionality of the flame.

[0035] Specifically, the outer diameter of the air guide shell is 20-50 mm, and the wall thickness is 0.5-1 mm; the outer diameter of the grounding tube is adjustable from 16-46 mm, and the wall thickness is 1 mm.

[0036] As a preferred embodiment of the present invention, see Figure 2 The flow-distributing nozzle 1 comprises a ceramic body with a plurality of through-holes 8 uniformly disposed therein. Metal sheets are fixed to the upper and lower end surfaces of the ceramic body by adhesive bonding or countersunk screws. The metal sheets are provided with holes corresponding to the through-holes 8 in the ceramic body. A high-voltage conductive rod 3 is embedded in the center of the ceramic body to a depth of 5 mm.

[0037] Specifically, the flow averaging nozzle has a diameter of 10-30 mm and a height of 10-50 mm, and the diameter of the hole on the metal sheet is 0.1-1 mm.

[0038] As a preferred embodiment of the present invention, the metal sheet on the upper end of the ceramic body is covered with a proton exchange membrane to separate and purify hydrogen. The proton exchange membrane is made of a metal proton membrane such as a palladium-copper alloy membrane, and the metal proton membrane has a thickness of 1 mm.

[0039] As a preferred embodiment of the present invention, the rotating electrode 2 is mounted on the high-voltage conductive rod 3 via a non-damping bearing. The high-voltage conductive rod 3 is provided with a spring top ball for limiting the non-damping bearing, which is easy to maintain, disassemble and install.

[0040] As a preferred embodiment of the present invention, see Figure 3 The rotating electrode 2 includes three blades, each blade has an angle of 15°-45° with the horizontal plane, the angle between two adjacent blades is 120°, and the distance between the blade tip and the inner wall of the grounding tube is 5-15 mm.

[0041] As a preferred embodiment of the present invention, see Figure 1 The above-mentioned multiple rotating electrodes 2 are arranged at equal intervals on the high-voltage conductive rod 3, and the distance between two adjacent rotating electrodes is 5mm-20mm.

[0042] As a preferred embodiment of the present invention, see Figure 4 An arc-starting metal strip 11 is provided on the inner wall of the grounding tube 4 at intervals of 120°, and the arc-starting metal strip 11 and the insulating layer 10 are alternately provided.

[0043] The working principle of the airflow self-driven rotating sliding arc plasma ammonia hydrogen burner provided by the present invention is:

[0044] Gas flows from bottom to top. Ammonia (NH3) enters the burner from the bottom and first passes through an isolated grounding section 7 located at the bottom, effectively electrically isolating the entire discharge chamber from the external grounding system and preventing unintended leakage of power to ground. After entering the device, the gas continues upward, passing through a one-way flashback valve 6. This component, a mechanical or thermally sensitive structure, effectively prevents flames or high-temperature gases generated during the discharge process from flowing back into the gas supply pipeline, ensuring system safety. The gas then rises into the discharge zone, which consists of an internal high-voltage conductive rod 3. The rotating electrode 2, which is rotatably connected to the high-voltage conductive rod 3, and an external grounding tube 4 form a discharge electrode pair. The metal blades 9 on the rotating electrode 2 rotate under the impact of the airflow, causing an arc to form between the rotating electrode 2 and the grounding tube 4. This arc is then driven along the arc-starting metal strip 11 on the inner wall of the grounding tube 4. The insulating layer 10 suppresses arc prolongation, stabilizing and pulsing the arc, thereby increasing the plasma's range and energy efficiency. Finally, the gas generated by the reaction cracking is discharged from the uniform flow nozzle 1 at the top, which improves the uniformity and speed of the ejected gas and provides a good basis for subsequent gas sampling or analysis.

[0045] In summary, the present invention provides a self-propelled, rotating, sliding arc plasma ammonia-hydrogen burner with a coaxial design. The burner primarily comprises seven functional modules: a flow-uniform nozzle, a rotating electrode, a high-voltage conductive rod, a grounding tube, an air guide housing, a one-way anti-flashback valve, and an isolated grounding section. These modules combine to form a compact reactor with a stable flow field and excellent electrical isolation. This device achieves ammonia cracking through bottom-up airflow guidance and a high-voltage rotating sliding arc discharge, combined with a nozzle to control gas discharge. This device boasts high energy efficiency, a compact structure, and safety and reliability, making it suitable for energy conversion applications such as hydrogen production from ammonia plasma cracking.

[0046] The above descriptions are merely embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied to other related system fields, are also included in the scope of protection of the present invention.

Claims

1. An airflow self-driven rotating sliding arc plasma ammonia hydrogen burner, characterized by: The invention comprises a grounding tube (4) and a high-voltage conductive rod (3), wherein a flow-averaging nozzle (1) and a one-way anti-backfire valve (6) are respectively provided at the upper and lower ends of the grounding tube (4), and the high-voltage conductive rod (3) is coaxially arranged in the grounding tube (4), and the high-voltage conductive rod (3) is located between the flow-averaging nozzle (1) and the one-way anti-backfire valve (6), and a plurality of airflow-self-driven rotating electrodes (2) are rotatably provided on the high-voltage conductive rod (3), and the rotating electrodes (2) include a plurality of metal blades (9), and a gap is left between the metal blades (9) and the inner wall of the grounding tube (4); The inner wall of the grounding tube (4) is provided with a plurality of arc-starting metal strips (11), wherein each arc-starting metal strip (11) is arranged along the axial direction of the grounding tube (4), and an insulating layer (10) is filled between two adjacent arc-starting metal strips (11); the bottom of the grounding tube (4) is provided with an isolated grounding section (7) made of high-strength insulating material; An air guide housing (5) is coaxially provided on the outside of the grounding cylinder (4), and an annular space between the air guide housing (5) and the grounding cylinder (4) is used for introducing air; The uniform flow nozzle (1) comprises a ceramic body, a plurality of through holes (8) are evenly arranged in the ceramic body, and metal sheets are provided on the upper and lower end surfaces of the ceramic body, and holes corresponding to the through holes (8) of the ceramic body are provided on the metal sheets.

2. The airflow self-driven rotating sliding arc plasma ammonia hydrogen burner according to claim 1, characterized in that: The surface of the metal sheet at the upper end of the ceramic body is covered with a proton exchange membrane.

3. The airflow self-driven rotating sliding arc plasma ammonia hydrogen burner according to claim 1, characterized in that: The rotating electrode (2) is mounted on a high-voltage conductive rod (3) via a non-damping bearing.

4. The airflow self-driven rotating sliding arc plasma ammonia hydrogen burner according to claim 3, characterized in that: The high-voltage conductive rod (3) is provided with a spring top ball for limiting the non-damping bearing.

5. The airflow self-driven rotating sliding arc plasma ammonia hydrogen burner according to claim 1, characterized in that: The rotating electrode (2) comprises three metal blades (9), and the angle between each metal blade (9) and the horizontal plane is 15°-45°.

6. The airflow self-driven rotating sliding arc plasma ammonia hydrogen burner according to claim 5, characterized in that: The angle between two adjacent metal blades (9) is 120°, and the distance between the ends of the metal blades (9) and the inner wall of the grounding tube is 5-15 mm.

7. The airflow self-driven rotating sliding arc plasma ammonia hydrogen burner according to any one of claims 1 to 6, characterized in that: A plurality of rotating electrodes (2) are arranged at equal intervals on the high-voltage conductive rod (3).

8. The airflow self-driven rotating sliding arc plasma ammonia hydrogen burner according to claim 7, characterized in that: An arc-starting metal strip (11) is provided on the inner wall of the grounding tube (4) at intervals of 120°, and the arc-starting metal strip (11) and the insulating layer (10) are arranged in an alternating manner.

Images