Plasma igniter electrode device and plasma igniter

Abstract

The application relates to the field of coal-fired boiler ignition technology and discloses a plasma ignition electrode device and a plasma igniter, which comprise a cathode assembly and an anode assembly. The cathode assembly comprises a rotational flow guide structure and an electric arc self-rotation driving assembly. The rotational flow guide structure guides gas to form a wall-attached rotating gas film, and the electric arc self-rotation driving assembly generates a magnetic field for driving the rotation of the electric arc. The rotational flow direction of the wall-attached rotating gas film is coupled with the rotation direction of the electric arc to balance the thermal load. The anode assembly comprises a conductive base body and a nested ablation-resistant inner lining, and a thermal stress buffering structure for absorbing thermal expansion stress is arranged between the conductive base body and the ablation-resistant inner lining. The end of the cathode assembly is provided with a detachable bullet. The application stabilizes the electric arc through flow-magnetic cooperation and buffers the thermal stress, so that the device can still maintain the basic ignition function when local failure occurs, and the system reliability and service life are improved.

Description

Technical Field

[0001] This application relates to the field of coal-fired boiler ignition technology, specifically to a plasma ignition electrode device and a plasma igniter. Background Technology

[0002] Currently, in plasma ignition systems for power plant boilers, electrode devices typically rely on an external strong magnetic field to drive the arc rotation to prevent localized ablation, and rigid connections are used to fix ablation-resistant components. However, under long-term high-temperature conditions, permanent magnets are prone to demagnetization, leading to arc instability; the gas channel structure is prone to carbon buildup and blockage, causing the gas film protection to fail; and the difference in thermal expansion coefficients between the ablation-resistant components and the conductive substrate generates significant thermal stress, causing cracking or detachment. Once any of these subsystems fails, the electrode loses its basic ignition capability, resulting in frequent system downtime for maintenance, short lifespan, and low reliability. Therefore, there is an urgent need for a plasma ignition electrode device that can maintain basic operational capability even in the event of localized failure. Summary of the Invention

[0003] To address the problem that existing technologies cannot maintain basic ignition capability when electrodes fail locally, this application achieves a stable arc through the coordinated flow field and magnetic field by using a plasma ignition electrode device and a plasma igniter, and achieves thermal stress buffering and physical degradation bearing through a multi-composite structure.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A plasma ignition electrode device includes a cathode assembly and an anode assembly; The cathode assembly includes a swirling flow guiding structure and an arc spin drive assembly. The swirling flow guiding structure is configured to guide gas to form a wall-attached rotating gas film, and the arc spin drive assembly is configured to generate a magnetic field that drives the arc to rotate. The swirling direction of the wall-mounted rotating air film is coupled with the rotation direction of the electric arc to balance the arc's heat load. The anode assembly includes a conductive substrate and an ablation-resistant liner nested within the conductive substrate. A thermal stress buffer structure is provided between the conductive substrate and the ablation-resistant liner, and the thermal stress buffer structure is configured to absorb thermal expansion stress. The cathode assembly is equipped with a detachable warhead at its end.

[0005] Furthermore, the angle between the swirling direction of the wall-mounted rotating air film and the rotation direction of the electric arc is an acute angle; The swirling flow guiding structure includes a swirling gas channel with a non-smooth flow guiding wall, the non-smooth flow guiding wall being configured to guide the gas to form the wall-attached rotating gas film.

[0006] Furthermore, the non-smooth flow guide wall has a serrated open airway structure; The serrated open air passage structure is disposed in the upstream region of the cathode assembly, including a plurality of serrated grooves continuously distributed along the direction of gas flow toward the anode assembly, and the openings of the serrated grooves face the center region of the airflow. The serrated open air passage structure is provided with an open air groove above it, and the open air groove is configured to prevent the deposition of particles in the airflow. After the gas is guided through the serrated open air passage structure, multiple curved streamlines are formed below the serrated groove and in the lower part of the channel, so as to form the wall-attached rotating gas film attached to the non-smooth flow guide wall upstream of the detachable warhead. The outline of the serrated open airway structure is continuously serrated, and the depth and spacing of the serrated grooves are configured to maintain the uniformity of the thickness of the wall-mounted rotating air film when the gas flow rate is within a preset range.

[0007] Furthermore, the arc spin drive assembly includes at least one of a current-coupled magnetic field generating structure and a bias magnet; The current-coupled magnetic field generating structure is configured to generate an induced magnetic field using the arc current itself. The bias magnet is configured to provide a basic guiding magnetic field; When the current-coupled magnetic field generating structure and the bias magnet are installed simultaneously, they are coaxially nested inside the cathode assembly.

[0008] Furthermore, the thermal stress buffer structure includes a mechanical interlocking structure and a metallurgical bonding layer; The mechanical interlocking structure is disposed in at least a portion of the contact area between the conductive substrate and the ablation-resistant liner, and is configured to provide radial and axial mechanical locking; The metallurgical bonding layer is disposed on at least a portion of the contact surface of the mechanical interlocking structure, configured to achieve a metallurgical bond between the conductive substrate and the ablation-resistant liner. The thermal stress buffer structure further includes an elastic buffer layer disposed in at least a portion of the area between the conductive substrate and the ablation-resistant liner, the elastic buffer layer being configured to absorb the stress generated when the ablation-resistant liner is thermally expanded.

[0009] Furthermore, the mechanical interlocking structure is a dovetail groove structure, which includes a groove disposed on the inner wall of the conductive substrate and a protrusion disposed on the outer wall of the ablation-resistant liner, wherein the groove and the protrusion are interlocked. The metallurgical bonding layer is an interface diffusion weld layer, which is formed between the contact surfaces of the groove and the protrusion through a high-temperature diffusion process. The elastic buffer layer is a corrugated elastic buffer layer, which is disposed in at least a portion of the area between the conductive substrate and the ablation-resistant liner and adheres to the inner wall of the conductive substrate. In the region where the elastic buffer layer is provided, an FGM gradient transition layer is also provided between the ablation-resistant liner and the elastic buffer layer. The material composition of the FGM gradient transition layer changes in a gradient from the side closer to the ablation-resistant liner to the side closer to the elastic buffer layer.

[0010] Furthermore, the detachable projectile is connected to the cathode assembly via a bayonet-type quick-connect locking structure; the bayonet-type quick-connect locking structure includes a plug portion disposed at the rear of the detachable projectile and a locking groove disposed at the front of the cathode assembly, the plug portion being configured to be inserted into the locking groove and rotated to lock; The cathode assembly is further provided with an elastic pre-tightening contact piece, which elastically abuts against the conductive connection portion of the detachable projectile and is configured to apply an axial pre-tightening force to the detachable projectile to reduce the axial gap between the insertion portion and the locking groove, and maintain the conductive contact between the detachable projectile and the cathode assembly.

[0011] Furthermore, it also includes an air path system, which includes a mechanical delay valve and a damping air chamber; The mechanical delay valve is located in the air intake channel of the gas system and is configured to remain open for a preset time after the plasma ignition electrode device is shut down and powered off. The damping gas chamber is connected to the gas path of the mechanical delay valve and is configured to maintain the gas purging of the swirling flow guide structure with the internally stored compressed gas within the preset time to prevent electrode carbon buildup and heat backflow.

[0012] Furthermore, the cathode assembly has a cathode cooling water channel inside, and the anode assembly has an anode cooling water channel inside. The cathode cooling water channel and the anode cooling water channel are respectively configured to be circulated with a cooling medium to cool the cathode assembly and the anode assembly. It also includes a housing, on which a status monitoring interface is provided. The status monitoring interface includes a sensor mounting position for collecting at least one parameter among voltage, current, water temperature and air pressure, and a dry contact or current output interface for outputting monitoring signals.

[0013] A plasma igniter includes a power interface and a plasma ignition electrode device as described in claim 9. The power interface is located on the housing of the plasma ignition electrode device and is electrically connected to the plasma ignition electrode device. The housing is provided with an air inlet that communicates with the swirling flow guiding structure and a flame outlet that corresponds to the flame outlet end of the plasma ignition electrode device.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: The plasma ignition electrode device provided in this application, through the synergistic coupling of the swirling flow guiding structure and the arc spin drive component, ensures that the wall-mounted rotating gas film and the arc rotation direction are highly aligned, forming a stable hydromagnetic co-directional driving field. This promotes uniform drift of the arc root on the electrode surface, significantly reducing local heat load concentration and slowing down the electrode ablation rate. The thermal stress buffer structure set between the conductive substrate and the ablation-resistant liner in the anode assembly effectively absorbs thermal expansion stress and prevents interface failure through multiple mechanisms of mechanical interlocking, metallurgical bonding, and elastic buffering. The conductive substrate is allowed to bear load for a short period after wear, and the detachable cathode head structure enables the device to maintain basic ignition function even under partial failure conditions such as weakened gas film, decreased magnetic field, or local structural damage, achieving degradable operation capability; the serrated open gas channel structure avoids carbon buildup and blockage, ensuring long-term gas film stability; the mechanical delayed purging mechanism automatically maintains airflow protection after shutdown to prevent heat backflow and carbon buildup; the overall structure can be installed in situ without modifying the original system, with short maintenance time, significantly improving the reliability, lifespan, and operation and maintenance efficiency of the plasma ignition system. Attached Figure Description

[0015] The accompanying drawings are provided to further understand the invention and constitute a part of this invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0016] Figure 1 This is a schematic diagram of the overall axial cross-sectional structure of the plasma ignition electrode device according to an embodiment of this application; Figure 2 This is a schematic diagram of the internal cross-sectional structure of the cathode assembly according to an embodiment of this application; Figure 3 This is a schematic diagram of the serrated open airway and the formation principle of the wall-adhering air film according to an embodiment of this application; Figure 4 This is a cross-sectional schematic diagram of the composite thermal stress buffer structure of the anode component according to an embodiment of this application; Figure 5 This is a schematic diagram of the principle of fluid-magnetic synergistic coupling and arc distribution in an embodiment of this application.

[0017] Among them, 100-plasma ignition electrode device; 10-cathode assembly; 111-serrated open gas channel structure; 112-open gas slot; 121-current coupling magnetic field generating structure; 122-bias magnet; 13-detachable warhead; 131-plug-in part; 14-elastic pre-tightening contact piece; 20-anode assembly; 21-conductive substrate; 22-ablation resistant liner; 231-mechanical interlocking structure; 232-metallurgical bonding layer; 233-elastic buffer layer; 234-FGM gradient transition layer; 41-cathode cooling water channel; 42-anode cooling water channel; 60-power interface. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0020] Example 1 like Figures 1 to 5 As shown, this embodiment provides a plasma ignition electrode device 100, which is a core component of a power plant boiler plasma ignition system and is used to generate a high-temperature plasma jet to ignite pulverized coal gas flow. The plasma ignition electrode device 100 includes a cathode assembly 10 and an anode assembly 20. In terms of spatial arrangement, the cathode assembly 10 and the anode assembly 20 are coaxially nested, with the front end of the cathode assembly 10 extending into the internal cavity of the anode assembly 20, forming a discharge gap between them. The working gas enters this gap through the internal channel of the cathode assembly 10 and is ionized to form a plasma arc, which is finally ejected from the nozzle of the anode assembly 20.

[0021] The cathode assembly 10 includes a swirling flow guiding structure and an arc spin drive assembly. The swirling flow guiding structure is configured to guide gas to form a wall-attached rotating gas film. Located within the internal flow channels of the cathode assembly 10, the swirling flow guiding structure applies a tangential velocity component to the incoming working gas through a specific flow channel geometry. This causes the gas to spiral along the cathode surface, adhering closely to the wall, thereby forming a continuous cold gas film layer with a certain thickness and rigidity on the cathode surface. This wall-attached rotating gas film not only effectively isolates the cathode body from direct thermal radiation and convective heat transfer by the high-temperature arc, but also removes particulate deposits near the wall, preventing carbon buildup and coking.

[0022] The arc spin drive assembly is configured to generate a magnetic field that drives the arc to rotate. Specifically, the arc spin drive assembly is integrated inside the cathode assembly 10. The magnetic field it generates interacts with the arc current to produce a Lorentz force. This Lorentz force acts as a driving force on the arc root, forcing the arc root to move continuously circumferentially on the electrode surface. This controlled arc root movement prevents the arc from remaining at a single point on the electrode surface for an extended period, thereby dispersing the concentrated heat load across the entire circumference of the electrode, significantly reducing the local ablation rate and extending the electrode's lifespan.

[0023] In this embodiment, the swirling direction of the wall-mounted rotating air film is coupled with the rotation direction of the electric arc to balance the arc's thermal load. For example... Figure 5 As shown, when the airflow swirls in the same direction as the arc rotation, the drag force of the airflow on the arc and the Lorentz force of the magnetic field on the arc combine to maintain the stable rotation of the arc. Simultaneously, the co-directional airflow conforms to the arc's trajectory, reducing lateral shear disturbances between the airflow and the arc, and preventing film tearing or arc jitter caused by airflow scouring. This fluid-magnetic co-coupling mechanism constructs an adaptive stable protective field. Even when the film strength weakens due to operating condition fluctuations, the magnetic field drive can still maintain a uniform distribution at the arc root, preventing instantaneous burn-through due to film failure. This physically endows the device with robustness, allowing it to maintain basic ignition capability even when the performance of some subsystems deteriorates.

[0024] The anode assembly 20 includes a conductive substrate 21 and an ablation-resistant liner 22 nested within the conductive substrate 21. A thermal stress buffer structure is provided between the conductive substrate 21 and the ablation-resistant liner 22, configured to absorb thermal expansion stress. Specifically, the ablation-resistant liner 22 is typically made of high-melting-point materials such as tungsten-hafnium alloy, directly bearing the high-temperature ablation of the electric arc; the conductive substrate 21 is typically made of high thermal conductivity materials such as copper, responsible for conducting current and dissipating heat. Due to the significant difference in their coefficients of thermal expansion, interfacial stress concentration is easily generated during high-temperature start-stop cycles. The thermal stress buffer structure, as a composite transition structure between the two, absorbs and releases this thermal mismatch stress through its own elastic deformation or a special connection mechanism, preventing the ablation-resistant liner 22 from cracking or detaching from the conductive substrate 21. This buffer structure ensures that even if the ablation-resistant liner 22 is gradually consumed and thinned after long-term operation, the conductive substrate 21 can still maintain close contact with the remaining liner, so that the conductive substrate 21 can continue to work as an emergency support for a short period of time, buying time for planned shutdown and replacement, rather than causing catastrophic failure when the liner is exhausted.

[0025] The cathode assembly 10 has a detachable projectile 13 at its end. For example... Figure 1 and Figure 2 As shown, the detachable warhead 13 is located at the very front of the cathode assembly 10 and is the core vulnerable component that directly contacts the electric arc. Its detachable design allows for on-site maintenance without replacing the entire cathode assembly 10; only the warhead needs to be replaced to restore device performance, significantly reducing spare parts costs and maintenance time. The connection between the detachable warhead 13 and the cathode body can employ various mechanical mating methods, as long as the reliability of the connection and ease of assembly and disassembly are ensured.

[0026] In summary, this embodiment transforms the fragile model relying on the integrity of a single system in traditional designs into a robust model based on physical structural redundancy by organically combining a fluid-magnetic synergistic coupling structure with a multi-composite thermal stress buffer structure. The synergistic effect of the swirling flow guiding structure and the arc spin drive component ensures the dynamic balance of the arc heat load and the continuity of the gas film protection; the thermal stress buffer structure solves the thermal fatigue problem of heterogeneous material connections from the perspective of material mechanics and provides structural support for degraded operation under extreme conditions. The synergistic effect of these physical characteristics enables the plasma ignition electrode device 100 to maintain basic ignition function by relying on the compensation effect of the remaining subsystems when facing non-fatal failures such as gas film weakening, magnetic field attenuation, or liner wear, thus achieving highly reliable long-life operation.

[0027] Example 2 Based on Example 1, the angle between the swirling direction of the wall-attached rotating gas film and the rotation direction of the electric arc is acute. The swirling guiding structure includes a swirling gas channel with a non-smooth guiding wall, which is configured to guide the gas to form a wall-attached rotating gas film. Unlike traditional smooth inner wall channels, the non-smooth guiding wall, through its surface geometric discontinuities, induces a stable secondary vortex structure within the boundary layer, effectively suppressing the tendency of high-speed rotating airflow to detach from the wall due to centrifugal effect, thereby ensuring the continuity and stiffness of the wall-attached gas film.

[0028] As a specific implementation method, such as Figure 3 As shown, the non-smooth flow guide wall is a sawtooth-shaped open air passage structure 111. The sawtooth-shaped open air passage structure 111 is located upstream of the cathode assembly and includes multiple sawtooth grooves continuously distributed along the gas flow direction towards the anode assembly, with the openings of the sawtooth grooves facing the center of the airflow. This continuous sawtooth profile causes local acceleration and expansion of the airflow as it passes through each tooth tip, thereby forming a controlled recirculation zone within the groove. These recirculation zones act as buffer zones for momentum exchange, continuously replenishing low-velocity, high-energy gas near the wall, further enhancing the adhesion performance of the gas film. Simultaneously, the design of the sawtooth groove openings facing the center of the airflow allows the mainstream gas to be periodically entrained near the wall, forming an active wall cooling mechanism, rather than relying solely on passive diffusion.

[0029] An open air duct structure 111 with serrated open air passages 112 is provided above it. The open air duct 112 is configured to prevent particle deposition in the airflow. During plasma ignition, the working medium often contains unburned coal powder particles or ash. Traditional closed spiral air passages are prone to forming dead zones at the inertial impact points of these particles, leading to carbon buildup and coking, and eventually clogging the air passage. In this embodiment, the open air duct 112 breaks the limitations of the closed cavity. Utilizing the self-cleaning effect of the main airflow, it removes particles that may be deposited in the duct in real time, fundamentally eliminating the risk of carbon buildup and ensuring the aerodynamic performance stability of the swirling flow guide structure during long-term operation.

[0030] After the gas is guided through the serrated open air passage structure 111, multiple curved streamlines are formed below the serrated grooves and in the lower region of the passage, so as to form a wall-attached rotating gas film attached to the non-smooth flow guide wall upstream of the detachable warhead 13. Figure 3 As shown in the schematic diagram, these curved streamlines are not chaotic, but rather exhibit a highly ordered spiral band distribution, tightly wrapping around the cathode tip and the downstream transition section surface. This streamline morphology ensures that the cooling gas film can completely cover the arc initiation area and all hot spots on the arc root drift path, avoiding protection blind spots.

[0031] Example 3 Based on Embodiment 1, this embodiment further specifies the internal structure and magnetic field generation mechanism of the arc spin drive assembly. The arc spin drive assembly includes at least one of a current-coupled magnetic field generating structure 121 and a bias magnet 122. Figure 2 As shown, in this embodiment, both the current-coupled magnetic field generating structure 121 and the bias magnet 122 are used; when both are arranged simultaneously, they are coaxially nested inside the cathode assembly 10. Specifically, the current-coupled magnetic field generating structure 121 can be a conductive coil arranged around the central axis of the cathode, while the bias magnet 122 can be a ring-shaped permanent magnet. In terms of assembly, the bias magnet 122 can be sleeved on the outer periphery of the current-coupled magnetic field generating structure 121, or embedded in the inner core of the current-coupled magnetic field generating structure 121, as long as the magnetic circuit centers of both are coincident with the geometric axis of the cathode assembly 10. This coaxial nesting design not only makes full use of the limited radial space inside the cathode, but also makes the two magnetic field sources highly overlapping in spatial distribution, which facilitates the vector superposition and functional complementarity of the magnetic fields.

[0032] The current-coupled magnetic field generating structure 121 is configured to generate an induced magnetic field using the arc current itself. When the plasma arc is ignited and current flows through it, according to Ampere's circuital law, this current will excite an axial or radial magnetic field component around the current-coupled magnetic field generating structure 121 that is proportional to the current intensity. As the arc enters the stable combustion stage, the operating current typically reaches the level of hundreds of amperes. At this point, the magnetic field intensity generated by the current-coupled magnetic field generating structure 121 is sufficient to become the dominant force driving the high-speed rotation of the arc. This self-generated magnetic field mechanism has a natural adaptive characteristic: the larger the arc current, the higher the heat load, and the faster the required rotational cooling rate, while the induced magnetic field is enhanced accordingly, thus automatically matching the heat dissipation requirements.

[0033] The bias magnet 122 is configured to provide a basic guiding magnetic field. Unlike the current-coupled magnetic field generating structure 121, the magnetic field provided by the bias magnet 122 is constant and does not change with the arc current. In the early stage of arc ignition, when the arc current has not yet been established or is extremely low, the current-coupled magnetic field generating structure 121 can hardly generate an effective driving force. At this time, without external magnetic field guidance, the arc is very likely to remain stationary at the cathode tip, leading to local instantaneous melting or even arc ignition failure. Although the basic guiding magnetic field provided by the bias magnet 122 is relatively weak, it is sufficient to apply a tangential force to the initial arc root within a microsecond timescale, causing it to deviate from the center and begin to move, thereby ensuring the reliability of the ignition process.

[0034] This design offers significant technical advantages: Firstly, since steady-state operation relies primarily on induced magnetic field drive, the bias magnet 122 does not require rare-earth permanent magnet materials with extremely high magnetic energy product but poor temperature resistance. Even if a high-performance magnet is used, the risk of thermal demagnetization is significantly reduced because it does not bear the main driving load, solving the problem of strong permanent magnets easily failing under high-temperature conditions in traditional designs. Secondly, the system eliminates the dependence on complex external excitation control units, reducing overall cost and the number of failure points. More importantly, from the perspective of degradable operation, even if the current-coupled magnetic field generating structure 121 completely fails due to faults such as coil open circuit, the bias magnet 122 can still provide a minimum magnetic field guidance, causing the device to degrade to a weak magnetic drive mode. Although the rotational speed decreases, it can still avoid catastrophic burn-through caused by complete arc cessation, providing a valuable safety window for emergency shutdown or derating operation. It should be understood that in other embodiments, only the current-coupled magnetic field generating structure 121 or only the bias magnet 122 may be provided, as long as the arc driving requirements under specific working conditions can be met. However, the dual-source nested scheme adopted in this embodiment is superior in terms of overall performance and reliability.

[0035] Example 4 Based on Example 1, this example further defines the specific microstructure of the thermal stress buffer structure in the anode assembly 20. The thermal stress buffer structure includes a mechanical interlocking structure 231 and a metallurgical bonding layer 232. For example... Figure 4 As shown, a mechanical interlocking structure 231 is disposed in at least a portion of the contact area between the conductive substrate 21 and the ablation-resistant liner 22, configured to provide radial and axial mechanical locking. Specifically, this mechanical locking is not a simple interference fit or threaded connection, but rather, through a specific geometric interlocking configuration, macroscopically restricts the degrees of freedom of the ablation-resistant liner 22 relative to the conductive substrate 21. During plasma ignition, the high-speed rotation of the electric arc generates a continuous tangential shear force on the inner wall of the anode, while the high-speed airflow also exerts an axial scouring force. The mechanical interlocking structure 231 directly bears these external loads through physical interlocking, preventing circumferential slippage or axial displacement of the ablation-resistant liner 22 under long-term thermo-mechanical coupling, thus ensuring the overall stability of the structure.

[0036] A metallurgical bonding layer 232 is disposed on at least a portion of the contact surface of the mechanical interlocking structure 231, configured to achieve atomic-level bonding between the conductive substrate 21 and the ablation-resistant liner 22. Unlike macroscopic mechanical locking, the metallurgical bonding layer 232 operates at the microscopic scale. Since the ablation-resistant liner 22 is typically made of high-melting-point refractory metals such as tungsten-hafnium alloys, while the conductive substrate 21 is typically made of oxygen-free copper, their physical properties differ significantly, making it difficult to achieve a high-strength and low-thermal-resistance connection using conventional welding. In this embodiment, the metallurgical bonding layer 232 forms a continuous metallic bonding region by allowing atoms on the contact surface to diffuse into each other under specific temperature and pressure conditions. This atomic-level bonding not only provides extremely high interfacial bonding strength but, more importantly, eliminates the micro-gaps present in traditional mechanical connections, significantly reducing interfacial thermal resistance. This allows the arc heat absorbed by the ablation-resistant liner 22 to be efficiently conducted to the conductive substrate 21 and carried away by cooling water, preventing localized overheating and melting of the liner due to deteriorated interfacial heat transfer.

[0037] The thermal stress buffer structure also includes an elastic buffer layer 233 disposed in at least a portion of the area between the conductive substrate 21 and the ablation-resistant liner 22. The elastic buffer layer 233 is configured to absorb the stress generated when the ablation-resistant liner 22 expands due to thermal expansion. During repeated start-stop cycles, the ablation-resistant liner 22 and the conductive substrate 21 will generate huge alternating thermal stress due to the mismatch in their coefficients of thermal expansion. If a rigid connection is used, this stress can easily lead to cracking of the brittle liner or interface fatigue failure. The elastic buffer layer 233, as an intermediate flexible medium, uses its own elastic deformation capability to compensate for the difference in thermal expansion between the two, transforming the destructive rigid strain into recoverable elastic strain, thereby effectively protecting the interface integrity and significantly extending the thermal fatigue life of the anode assembly.

[0038] As a preferred implementation, the mechanical interlocking structure 231 is a dovetail groove structure. The dovetail groove structure includes a groove on the inner wall of the conductive substrate 21 and a protrusion on the outer wall of the ablation-resistant liner 22, with the groove and protrusion interlocking. The trapezoidal cross-section design of the dovetail groove provides self-locking characteristics, decomposing radial centrifugal force and tangential shear force into normal pressure perpendicular to the inclined plane, thus avoiding root fracture caused by stress concentration. Simultaneously, the continuous or segmented arrangement of the dovetail grooves along the circumference provides precise circumferential positioning, ensuring the coaxiality of the liner during installation. It should be understood that although this embodiment uses a dovetail groove, in other embodiments, T-grooves, serrated grooves, or other interlocking geometries with shear resistance can also be used, as long as the mechanical locking function is satisfied.

[0039] The metallurgical bonding layer 232 is an interfacial diffusion weld layer, formed between the contact surfaces of the groove and the protrusion through a high-temperature diffusion process. During manufacturing, the ablation-resistant liner 22 and the conductive substrate 21 are first assembled, and then subjected to hot-press diffusion treatment under vacuum or a protective atmosphere. During this process, atomic interdiffusion occurs at the tightly fitted surfaces of the groove and the protrusion, forming a metallurgical transition zone with controllable thickness. This transition zone retains the high thermal conductivity of copper while possessing high-temperature strength approaching that of hafnium alloys, achieving a perfect balance between mechanical and thermal properties. Even if microcracks appear in the metallurgical layer under extreme conditions, the dovetail groove can still maintain its structure without detachment; conversely, if the mechanical structure loosens due to wear, the remaining metallurgical bond can still ensure basic thermal and electrical conductivity pathways.

[0040] The elastic buffer layer 233 is a corrugated elastic buffer layer 233, which is disposed in at least a portion of the area between the conductive substrate 21 and the ablation-resistant liner 22 and adheres to the inner wall of the conductive substrate 21. The corrugated structure provides axial and radial compliance through periodic undulating waveforms. When the ablation-resistant liner 22 is thermally expanded, the corrugations undergo compression or bending deformation, absorbing excess thermal elongation; when cooled and contracted, the corrugations spring back to their original position, always maintaining close contact with the liner. Compared to flat gaskets, the corrugated structure has a larger deformation stroke and a more uniform stress distribution at the same thickness, and is less prone to plastic creep failure. In addition, the tiny gaps formed by the corrugations can also serve as reserved space for thermal expansion, further reducing the peak interfacial stress.

[0041] In the region where the elastic buffer layer 233 is located, an FGM gradient transition layer 234 is also provided between the ablation-resistant liner 22 and the elastic buffer layer 233. The material composition of the FGM gradient transition layer 234 changes in a gradient from the side closer to the ablation-resistant liner 22 to the side closer to the elastic buffer layer 233. This continuously varying composition design completely eliminates the abrupt performance steps at the interface of heterogeneous materials, allowing thermal stress to be transmitted smoothly rather than concentrated. The presence of the FGM gradient transition layer 234 enables the entire anode composite structure to withstand up to thousands of thermal shock cycles without delamination.

[0042] In summary, the multi-composite thermal stress buffer structure constructed in this embodiment, consisting of dovetail groove mechanical interlocking, interface diffusion welding, corrugated elastic buffering, and FGM gradient transition, not only ensures the high reliability and long lifespan of the anode assembly under normal operating conditions, but also provides a solid physical basis for "degradable operation." When the ablation-resistant liner 22 is gradually consumed after ultra-long-term operation, the remaining liner or even the exposed conductive substrate 21 can still safely bear the arc current for a short time without instantaneous cracking or melting through, because the conductive substrate 21 and the liner always maintain a high-strength mechanical interlock and good thermal contact.

[0043] Example 5 Based on Embodiment 1, this embodiment further specifies the connection structure of the detachable projectile 13 in the cathode assembly 10. The detachable projectile 13 is connected to the cathode assembly 10 via a bayonet-type quick-connect locking structure. For example... Figure 2 As shown, the bayonet-type quick-connect locking structure includes a connector 131 located at the rear of the detachable projectile 13 and a locking groove located at the front of the cathode assembly 10. The connector 131 is configured to be inserted into the locking groove and rotated to lock. Specifically, the outer circumferential surface of the connector 131 has a radially protruding limiting pin or lug, and the locking groove has an L-shaped or J-shaped path, including an axial guide section and a circumferential locking section. During installation, the operator aligns the connector 131 with the axial entrance of the locking groove and pushes it in completely, then rotates it circumferentially by a certain angle (e.g., 30° to 90°) to allow the limiting pin to slide into the end groove of the locking section, thus completing the mechanical interlock. This connection method eliminates the cumbersome process of traditional multi-turn thread engagement, greatly improving on-site maintenance efficiency.

[0044] The cathode assembly 10 also includes an elastic pre-tightening contact piece 14. This contact piece 14 elastically abuts against the conductive connection portion of the detachable projectile 13 to apply an axial pre-tightening force to the detachable projectile 13 and maintain conductive contact between the detachable projectile 13 and the cathode assembly 10. This elastic pre-tightening effect compensates for axial gaps between the insertion portion 131 and the locking groove caused by machining tolerances, wear, and temperature changes. This ensures stable contact between the conductive end face of the insertion portion 131 and the corresponding conductive portion inside the cathode assembly 10, thereby reducing contact resistance fluctuations and the risk of localized overheating due to poor contact. The elastic pre-tightening contact piece 14 can be made of a high-temperature resistant, elastic conductive material, and its contact surface can be coated with a TiN coating to reduce the risk of contact interface seizing under high-temperature conditions.

[0045] Compared to traditional threaded connections, this embodiment employs a bayonet-type quick-connect locking structure in conjunction with an elastic pre-tightening contact piece 14. The bayonet-type quick-connect locking structure enables rapid axial positioning and circumferential locking of the detachable projectile 13, while the elastic pre-tightening contact piece 14 provides continuous axial pre-tightening and conductive contact. Thus, under conditions of repeated high-temperature start-stop and vibration, the connection stability and conductive reliability between the detachable projectile 13 and the cathode assembly 10 can be maintained while facilitating easy assembly and disassembly.

[0046] Example 6 Based on Embodiment 1, this embodiment further specifies the gas path system of the plasma ignition electrode device 100. The gas path system includes a mechanical delay valve and a damping gas chamber, which are not shown separately in the accompanying drawings. This design aims to solve the problems of high-temperature heat recirculation and electrode carbon buildup caused by the immediate cutoff of gas flow at the moment of shutdown in traditional plasma igniters. Unlike the purge logic that relies on solenoid valves or program control in the prior art, this embodiment uses a purely mechanical structure to achieve the time-delay protection function, ensuring the integrity and inherent safety of the device as an independent hardware entity.

[0047] The mechanical delay valve is installed in the air intake channel of the gas circuit system and is configured to remain open for a preset time after the plasma ignition electrode device is shut down and powered off. Specifically, the mechanical delay valve is installed in series on the main air supply line leading to the vortex guide structure. Internally, it employs a purely mechanical triggering mechanism combining spring return and fluid damping, rather than electromagnetic drive. When the device is operating normally, the intake pressure overcomes the spring force, keeping the valve fully open. When the device is shut down and powered off, and the external air supply stops, the valve does not close instantly like a normal one-way valve. Instead, it relies on its built-in damping mechanism to delay the spring's return stroke, thus physically forcing the gas circuit to remain open for a preset time. This design completely eliminates the dependence on electrical control signals. Even in extreme conditions such as complete control system failure or unexpected power outage, the mechanical delay valve can still automatically perform a delayed shutdown action using its own mechanical potential energy, fundamentally eliminating the risk of protection failure due to electrical control malfunctions.

[0048] The damping chamber is connected to the mechanical delay valve's gas path and is configured to maintain gas purging of the swirling guide structure using internally stored compressed gas within a preset time to prevent electrode carbon buildup and heat backflow. Specifically, the damping chamber acts as a local gas storage container, connected in parallel or series downstream of the mechanical delay valve. During device operation, high-pressure working gas continuously fills the damping chamber to achieve a pressure balance with the main gas path. When a shutdown signal is triggered, the main gas supply is cut off, and the mechanical delay valve begins to slowly close, the compressed gas stored in the damping chamber becomes a temporary emergency gas source, continuing to supply gas to the swirling guide structure. This process ensures that the wall-mounted rotating gas film does not disappear instantly during the critical cooling window after the arc is extinguished, but rather gradually decays. The preset time is typically set between 5 and 15 seconds. This time range is a safety threshold calculated based on the thermal inertia of the electrodes: if it is less than 5 seconds, the residual heat on the anode assembly 20 and the cathode warhead surface is sufficient to ignite coal dust residue, forming carbon deposits, or cause high-temperature flue gas backflow that burns the seals; if it is more than 15 seconds, it will cause unnecessary waste of compressed air and prolong the system standby time. Through the cooperation of the mechanical delay valve and the damping chamber, the device achieves automation and passivity of shutdown protection, without the need for additional sensor detection or algorithm judgment, significantly improving the robustness and reliability of the system in complex industrial environments.

[0049] Example 7 Based on Embodiment 1, this embodiment further specifies the physical channel for thermal management and the hardware interface for state sensing of the plasma ignition electrode device 100. The cathode assembly 10 has a cathode cooling channel 41 inside, and the anode assembly 20 has an anode cooling channel 42 inside. The cathode cooling channel 41 and anode cooling channel 42 are respectively configured to carry cooling media to cool the cathode assembly 10 and the anode assembly 20 respectively. Specifically, the cathode cooling channel 41 and anode cooling channel 42 are not simple external jackets, but rather flow channel structures respectively disposed inside the corresponding electrode bodies. In the anode assembly 20, the anode cooling channel 42 is typically arranged in a spiral or annular labyrinth shape around the inner or outer wall interlayer of the conductive substrate 21, adjacent to the interface between the ablation-resistant liner 22 and the conductive substrate 21, to shorten the heat conduction path. In the cathode assembly 10, the cathode cooling channel 41 extends axially to the area near the detachable warhead 13 and then turns back, forming a forced convection circulation to cool the high-heat-load area at the cathode tip. The flow direction of the cooling medium can be set according to actual heat exchange requirements to improve heat exchange efficiency and reduce the risk of local overheating. The specific cross-sectional shape of the cathode cooling channel 41 and the anode cooling channel 42 can be circular, rectangular, or irregularly shaped, as long as it can provide a flow cross-section that meets the heat exchange requirements within a limited electrode volume. The above-mentioned built-in cooling structure helps to keep the cathode assembly 10 and the anode assembly 20 within the allowable operating temperature range, providing thermal management assurance for the long-term operation of the device.

[0050] The plasma ignition electrode device 100 also includes a housing, on which a status monitoring interface is provided. Figure 1 Not shown separately. The housing serves as the mechanical support and protective barrier for the entire electrode device, and its surface has reserved standardized physical interface areas for integrating various sensing and signal transmission components. The status monitoring interface includes sensor mounting positions for acquiring at least one parameter among voltage, current, water temperature, and air pressure, as well as dry contact or current output interfaces for outputting monitoring signals.

[0051] In this embodiment, the status monitoring interface serves only as a physical channel for data acquisition and signal output. The plasma ignition electrode device 100 itself does not contain any data processing unit, microcontroller, or control algorithm module. All raw signals acquired through this interface are received, parsed, and logically judged by an external independent control system (such as a PLC, DCS, or dedicated ignition control cabinet). This purely hardware-based interface design has multiple technical advantages: First, it completely avoids the reliability risks associated with integrating fragile electronic components inside the electrode body, which is subject to high temperatures and strong electromagnetic interference, ensuring the inherent safety of the device under harsh operating conditions. Second, the standardized physical interface allows the device to seamlessly connect to boiler control systems of different brands and generations, enabling the upgrade of status sensing functions without modifying the original control logic, greatly improving product compatibility and in-situ replacement capabilities. Finally, by physically decoupling the sensing layer from the decision layer, when the external control strategy needs to be adjusted or optimized, only the external software needs to be updated without replacing the electrode hardware, significantly reducing the overall lifecycle maintenance costs. It should be understood that although this embodiment lists four typical parameters, namely voltage, current, water temperature and air pressure, in other embodiments, sensor mounting positions for other parameters such as vibration, flow rate and arc intensity can be added according to actual needs, or a wireless transmission module can be used to replace the wired interface, as long as it can provide a physical signal interface that reflects the operating status of the device to the external system.

[0052] Example 8 like Figure 1 As shown, this embodiment provides a plasma igniter, which is a complete functional unit for end-use scenarios such as power plant boilers and industrial kilns. It is used to provide a stable high-temperature plasma jet for reliable ignition during the initial fuel commissioning phase. The plasma igniter includes a power interface and a plasma ignition electrode device 100 as described in the previous embodiment. The plasma ignition electrode device 100 includes a housing, which serves as the mechanical support and protective barrier for the entire device, and as the interface carrier for mechanical, electrical, and fluid interaction with the external boiler environment.

[0053] The cathode assembly 10 and anode assembly 20 of the plasma ignition electrode device 100 are installed and supported within the housing. Specifically, the internal cavity of the housing has positioning steps or mounting flanges that match the outer contours of the cathode assembly 10 and anode assembly 20 to ensure coaxiality after assembly. For installation, mechanical connections such as bolt fastening, clamp locking, or interference fits can be used, as long as they ensure that the cathode assembly 10 and anode assembly 20 do not experience unexpected displacement or loosening under high-temperature vibration conditions. The housing can fully cover the non-working sections of the components, or the nozzle section of the anode assembly 20 can be exposed to facilitate heat dissipation or docking with the burner.

[0054] The power interface is electrically connected to the plasma ignition electrode device 100. Specifically, the power interface is located on the outer surface of the housing or the tail end cap, serving as an electrical connection channel between the external DC power supply and the internal electrodes. Internally, it is reliably connected to the cathode or anode conductive parts of the plasma ignition electrode device 100 via high-temperature insulated wires or rigid conductive rods. Considering that the plasma igniter draws hundreds of amperes and experiences high-frequency electromagnetic interference during operation, the power interface typically uses shielded aviation plugs, high-voltage terminals, or dedicated copper busbar terminals, and is equipped with an insulating sealing kit to prevent dust intrusion or short circuits. Furthermore, the power interface's location is carefully designed for ease of maintenance, typically positioned within easy reach of operators and away from the high-temperature flame zone. This standardized electrical interface design allows plasma ignition electrode devices 100 of different power ratings or models to share the same set of external power cables and connectors, simplifying spare parts management and system integration complexity.

[0055] The outer casing is equipped with an air inlet connected to the swirling flow guiding structure of the plasma ignition electrode device 100 and a flame outlet corresponding to the ignition end of the plasma ignition electrode device 100. Specifically, the air inlet is located on the side wall or rear end of the casing, and precisely connects with the inlet of the swirling flow guiding structure through an internal air passage to ensure that compressed air or other working gases can enter the electrode interior without leakage and with low resistance to form a wall-mounted rotating gas film. The air inlet typically uses a standard pipe thread or quick-connect fitting for easy direct connection to the existing instrument air pipelines in the power plant. The flame outlet is located at the front end of the casing, and its aperture and shape match the anode nozzle of the plasma ignition electrode device 100 and are compatible with the ignition gun mounting sleeve of the boiler burner. The design of the flame outlet not only ensures the smooth ejection of the plasma jet but also provides heat insulation and guidance, preventing the high-temperature flame from burning back onto the casing body. More importantly, the relative position, spacing, and interface specifications of the air inlet and flame outlet all comply with industry-standard practices or the installation specifications of mainstream boiler manufacturers. This means that the plasma igniter provided in this application can directly replace the existing old igniters without requiring any destructive modifications such as cutting, welding, or re-drilling of the boiler body, air duct, or mounting bracket.

[0056] In summary, this embodiment constructs an independent, complete, and highly compatible plasma igniter product based on a plasma ignition electrode device 100 with high reliability and degradable operation capability, and by configuring a universal power interface, air inlet, and flame outlet.

[0057] Example 9 This embodiment aims to further verify, through dynamic simulation of typical application scenarios, how the dispersed structural features in the aforementioned embodiments work synergistically in actual operation to achieve degradable operation capability. This degradable operation does not rely on logical judgments or manual intervention from an external control system, but is automatically triggered by the inherent multiple redundancy mechanisms within the physical structure of the plasma ignition electrode device 100. In specific applications, the device can maintain basic ignition function through the compensation effect of the remaining subsystems under non-fatal failure conditions such as weakened gas film, decreased magnetic field, or lining wear, thereby significantly improving the system's robustness and operational continuity.

[0058] In the first typical degradation scenario, when the strength of the rotating gas film attached to the wall weakens due to pressure fluctuations or partial blockage in the gas supply pipeline, the magnetic field generated by the arc spin drive component can still independently maintain the continuous rotation of the arc root. Specifically, even if the fluid drag force of the airflow on the arc decreases, the current-coupled magnetic field generating structure 121 can still drive the arc root to move circumferentially along the electrode surface using the Lorentz force generated by the arc current itself, preventing the arc from remaining at a certain point for a long time and causing local melting and breakdown. At this time, although the device loses the dual synergistic protection of the gas film and the magnetic field, it can still operate in a derating state thanks to the single redundancy mechanism driven by the magnetic field. That is, it can continue to complete the ignition task under the premise of appropriately reducing the operating current, thus buying valuable time for maintenance personnel to adjust the operating conditions or arrange planned maintenance.

[0059] In the second typical degradation scenario, when the magnetic field driving force of the arc spin drive component weakens or even fails due to coil aging or permanent magnet demagnetization, the wall-mounted rotating gas film can still effectively play a protective role, preventing the electrode from burning through instantly. Specifically, the cold gas film layer formed by the swirling flow guiding structure acts as a physical barrier, continuously isolating the high-temperature arc from direct thermal radiation to the electrode body and removing a large amount of heat through forced convection. Even if the arc root rotation speed slows down or tends to stop, this stable gas film can significantly delay the rate of temperature rise on the electrode surface, preventing it from reaching the material's melting point in a short time. This passive protection mechanism based on fluid dynamics constitutes the last line of defense for the device in the event of failure of the magnetic field subsystem, ensuring that the system will not experience catastrophic structural collapse under extreme abnormal conditions.

[0060] In the third typical degradation scenario, when the ablation-resistant liner 22 in the anode assembly 20 is gradually worn away after long-term operation, the thermal stress buffer structure can ensure that the conductive substrate 21 can safely bear the arc current for a short period of time until the anode assembly 20 is shut down for maintenance. Specifically, due to the multiple composite connection structures between the conductive substrate 21 and the ablation-resistant liner 22, such as dovetail mechanical interlocking, interface diffusion welding, and corrugated elastic buffer layer, even if the liner material is completely worn, the remaining liner and the conductive substrate 21 still maintain a tight mechanical interlock and a good thermal contact path. This allows the highly thermally conductive copper conductive substrate 21 to temporarily replace the liner to withstand arc erosion and quickly conduct heat to the anode cooling channel 42 for removal. Although the ablation resistance of the copper substrate is much lower than that of the hafnium alloy liner, it is sufficient to support the device to complete the current ignition cycle or safe shutdown procedure within an emergency window of several minutes to tens of minutes. After the current ignition cycle is completed or a safe shutdown is achieved, the anode assembly 20 can be inspected or replaced, thereby reducing the impact of sudden shutdown on the boiler's production rhythm.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation of the invention, but these changes, modifications or equivalent substitutions are all within the scope of protection of the pending claims of the invention.

Claims

1. A plasma ignition electrode device, characterized in that, Includes a cathode assembly (10) and an anode assembly (20); The cathode assembly (10) includes a swirling flow guiding structure and an arc spin drive assembly. The swirling flow guiding structure is configured to guide gas to form a wall-attached rotating gas film, and the arc spin drive assembly is configured to generate a magnetic field that drives the arc to rotate. The swirling direction of the wall-mounted rotating air film is coupled with the rotation direction of the electric arc to balance the arc's heat load. The anode assembly (20) includes a conductive substrate (21) and an ablation-resistant liner (22) nested within the conductive substrate (21). A thermal stress buffer structure is provided between the conductive substrate (21) and the ablation-resistant liner (22), and the thermal stress buffer structure is configured to absorb thermal expansion stress. The cathode assembly (10) is provided with a detachable warhead (13) at its end.

2. The plasma ignition electrode device according to claim 1, characterized in that, The angle between the swirling direction of the wall-mounted rotating air film and the rotation direction of the electric arc is an acute angle. The swirling flow guiding structure includes a swirling gas channel with a non-smooth flow guiding wall, the non-smooth flow guiding wall being configured to guide the gas to form the wall-attached rotating gas film.

3. The plasma ignition electrode device according to claim 2, characterized in that, The non-smooth flow guide wall is a sawtooth open airway structure (111). The serrated open air passage structure (111) is disposed in the upstream region of the cathode assembly (10), including a plurality of serrated grooves continuously distributed along the direction of gas flow toward the anode assembly (20), and the opening of the serrated grooves faces the center region of the airflow. An open air groove (112) is provided above the serrated open air passage structure (111), and the open air groove (112) is configured to prevent the deposition of particles in the airflow. After the gas is guided through the sawtooth open air passage structure (111), multiple curved flow lines are formed below the sawtooth groove and in the lower part of the channel to form the wall-attached rotating gas film attached to the non-smooth flow guide wall upstream of the detachable warhead (13). The serrated open airway structure (111) has a continuous serrated outline, and the depth and spacing of the serrated grooves are configured to maintain the uniformity of the thickness of the wall-mounted rotating air film when the gas flow rate is within a preset range.

4. The plasma ignition electrode device according to claim 1, characterized in that, The arc spin drive assembly includes at least one of a current-coupled magnetic field generating structure (121) and a bias magnet (122); The current-coupled magnetic field generating structure (121) is configured to generate an induced magnetic field using the arc current itself; The bias magnet (122) is configured to provide a basic guiding magnetic field; When the current-coupled magnetic field generating structure (121) and the bias magnet (122) are simultaneously arranged, they are coaxially nested inside the cathode assembly (10).

5. The plasma ignition electrode device according to claim 1, characterized in that, The thermal stress buffer structure includes a mechanical interlocking structure (231) and a metallurgical bonding layer (232). The mechanical interlocking structure (231) is disposed in at least a portion of the contact area between the conductive substrate (21) and the ablation-resistant liner (22), and is configured to provide radial and axial mechanical locking; The metallurgical bonding layer (232) is disposed on at least a portion of the contact surface of the mechanical interlocking structure (231) and configured to achieve a metallurgical bond between the conductive substrate (21) and the ablation-resistant liner (22). The thermal stress buffer structure further includes an elastic buffer layer (233) disposed in at least a portion of the area between the conductive substrate (21) and the ablation-resistant liner (22), the elastic buffer layer (233) being configured to absorb the stress generated when the ablation-resistant liner (22) is heated.

6. The plasma ignition electrode device according to claim 5, characterized in that, The mechanical interlocking structure (231) is a dovetail groove structure, which includes a groove on the inner wall of the conductive substrate (21) and a protrusion on the outer wall of the ablation-resistant liner (22), wherein the groove and the protrusion are interlocked. The metallurgical bonding layer (232) is an interface diffusion weld layer, which is formed between the contact surfaces of the groove and the protrusion by a high-temperature diffusion process. The elastic buffer layer (233) is a corrugated elastic buffer layer, which is disposed in at least a portion of the area between the conductive substrate (21) and the ablation-resistant liner (22) and adheres to the inner wall of the conductive substrate (21). In the region where the elastic buffer layer (233) is provided, an FGM gradient transition layer (234) is also provided between the ablation-resistant liner (22) and the elastic buffer layer (233). The material composition of the FGM gradient transition layer (234) changes in a gradient from the side near the ablation-resistant liner (22) to the side near the elastic buffer layer (233).

7. The plasma ignition electrode device according to claim 1, characterized in that, The detachable projectile (13) is connected to the cathode assembly (10) via a bayonet-type quick-connect locking structure; the bayonet-type quick-connect locking structure includes a plug-in portion (131) disposed at the rear of the detachable projectile and a locking groove disposed at the front of the cathode assembly (10), the plug-in portion (131) being configured to be inserted into the locking groove and rotated to lock; The cathode assembly (10) is further provided with an elastic pre-tightening contact piece (14), which elastically abuts against the conductive connection portion of the detachable projectile (13) and is configured to apply an axial pre-tightening force to the detachable projectile (13) to reduce the axial gap between the insertion portion (131) and the locking groove, and to maintain the conductive contact between the detachable projectile (13) and the cathode assembly (10).

8. The plasma ignition electrode device according to claim 1, characterized in that, It also includes a pneumatic system, which includes a mechanical delay valve and a damping air chamber; The mechanical delay valve is located in the air intake channel of the gas system and is configured to remain open for a preset time after the plasma ignition electrode device is shut down and powered off. The damping gas chamber is connected to the gas path of the mechanical delay valve and is configured to maintain the gas purging of the swirling flow guide structure with the internally stored compressed gas within the preset time to prevent electrode carbon buildup and heat backflow.

9. The plasma ignition electrode device according to claim 1, characterized in that, The cathode assembly (10) is provided with a cathode cooling water channel (41) inside, and the anode assembly (20) is provided with an anode cooling water channel (42) inside. The cathode cooling water channel (41) and the anode cooling water channel (42) are respectively configured to be circulated with cooling medium to cool the cathode assembly (10) and the anode assembly (20). It also includes a housing, on which a status monitoring interface is provided. The status monitoring interface includes a sensor mounting position for collecting at least one parameter among voltage, current, water temperature and air pressure, and a dry contact or current output interface for outputting monitoring signals.

10. A plasma igniter, characterized in that, Includes a power interface (60) and a plasma ignition electrode device as described in claim 9; The power interface (60) is disposed on the housing of the plasma ignition electrode device and is electrically connected to the plasma ignition electrode device. The housing is provided with an air inlet that communicates with the swirling flow guiding structure and a flame outlet that corresponds to the flame outlet end of the plasma ignition electrode device.

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