Intelligent torch ignition device based on high-frequency induction heating

Abstract

The present invention belongs to the field of automatic control technology, and specifically relates to an intelligent torch ignition device based on high-frequency induction heating. The device includes: an eddy current heating unit for arranging a high-frequency coil in the ignition area, generating an alternating magnetic field through the high-frequency coil, inducing eddy currents in the metal chip or metal catalyst inside the torch, performing induction heating, and thus forming a high-density heat source; a critical temperature rise determination unit for determining whether the temperature of the mixed gas exceeds the critical temperature when the mixed gas is heated by radiation and heat conduction from the metal chip or metal catalyst; a high-frequency ionization unit for performing electric field excitation to maximize plasma formation efficiency; and a fire core self-sustaining control unit for calculating the fire core radius in real time. If the fire core radius does not reach the self-sustaining threshold, induction heating and electric field excitation are continued. The present invention significantly improves the response speed, ignition success rate, and environmental adaptability of the ignition system.

Description

Technical Field

[0001] The invention belongs to the technical field of automatic control, and in particular relates to an intelligent torch ignition device based on high-frequency induction heating. Background Art

[0002] In current industrial and civil gas systems, torch ignition is a common ignition method and is widely used in gas boilers, chemical exhaust incineration, gas thermal energy devices, and environmentally friendly combustion systems. Traditional torch ignition methods can be roughly divided into mechanical ignition, spark ignition, piezoelectric ignition, and high-energy electronic ignition. Spark ignition and piezoelectric ignition are widely used due to their simple structure and low cost. However, these conventional methods show obvious shortcomings under complex working conditions. For example, in scenarios with high humidity, low temperature, severe wind disturbance, or large fluctuations in gas concentration, problems such as low ignition success rate, slow response speed, and short equipment life frequently occur, resulting in reduced operating efficiency of the entire combustion system and even safety hazards.

[0003] In addition to the limitations of the hardware structure, existing technologies also have significant shortcomings in the ignition process control strategy. On the one hand, most ignition systems are based on only a single physical quantity such as temperature, voltage or current as the ignition criterion, and lack a comprehensive judgment mechanism for gas composition, ionization degree and thermal field state, resulting in excitation execution in non-optimal ignition windows, high energy consumption and low success rate. On the other hand, most existing systems are open-loop control modes, lacking the ability to adaptively adjust after ignition failure, and are unable to dynamically adjust heating parameters, ionization time or excitation amplitude to cope with environmental disturbances and gas fluctuations. This defect in the control strategy makes it difficult for existing technologies to meet the comprehensive requirements of modern gas applications for intelligence, high reliability and multi-adaptability. Summary of the Invention

[0004] In view of this, the main purpose of the present invention is to provide an intelligent torch ignition device based on high-frequency induction heating. By introducing a non-contact induction heat source and a plasma control mechanism, the response speed, ignition success rate and environmental adaptability of the ignition system are significantly improved.

[0005] The technical solution adopted in the present invention is as follows:

[0006] An intelligent torch ignition device based on high-frequency induction heating comprises: an eddy current heating portion for arranging a high-frequency coil in the ignition area, generating an alternating magnetic field through the high-frequency coil, inducing eddy currents in a metal chip or metal catalyst inside the torch, performing induction heating, and thereby forming a high-density heat source; a critical temperature rise determination portion for determining whether the temperature of the mixed gas exceeds a critical temperature when the mixed gas is heated by radiation and heat conduction from the metal chip or metal catalyst; a high-frequency ionization portion for estimating the electron density in the mixed gas when the temperature of the mixed gas exceeds the critical temperature, comparing the electron density with an ionization threshold, and executing electric field excitation if the electron density exceeds the ionization threshold to maximize plasma formation efficiency; and a fire core self-sustaining control portion for calculating the fire core radius in real time by constructing a fire core radius expansion function. If the fire core radius reaches the self-sustaining threshold, it is determined that the fire core can achieve self-sustaining, and induction heating and electric field excitation are stopped in sequence. If the fire core radius does not reach the self-sustaining threshold, induction heating and electric field excitation are continued.

[0007] Furthermore, the metal chip or metal catalyst is located at the geometric center of the high-frequency coil, and the axial spacing between the heating surface or center point of the metal chip or metal catalyst and the cross-sectional plane of the high-frequency coil is in the range of one-quarter to one-half of the radius of the high-frequency coil to maximize magnetic flux coupling.

[0008] Furthermore, the ignition area is a spherical area formed with a radius 2 to 3 times the radius of the metal chip or the metal catalyst body; and the flow rate of the mixed gas is less than 0.5 m / s.

[0009] Furthermore, at the moment The temperature of the mixed gas at for:

[0010] ;

[0011] in, is the initial ambient temperature, in K; is the efficiency of heat radiation and conduction, ranging from 0.2 to 0.6; is the instantaneous power of induction heating, in W; The effective area of ​​the metal chip or metal catalyst in direct contact with the mixed gas, in m²; is the density of the mixed gas, in kg / m³; is the constant pressure specific heat capacity of the mixed gas, in J / (kg·K); is the volume of the ignition area; The time constant of heat conduction controls the temperature rise rate and its value range is 5ms to 100ms.

[0012] Furthermore, the instantaneous power of induction heating for:

[0013] ;

[0014] in, The electrical conductivity of the metal chip or metal catalyst is expressed in S / m. is the angular frequency of the alternating magnetic field, in rad / s; is the peak magnetic induction intensity of the high-frequency coil, in T; is the radius of the metal chip or metal catalyst, in meters; is the eddy current penetration depth, in m; ,in, The magnetic permeability of the metal chip or metal catalyst material, in H / m; The electrical conductivity of the metal chip or metal catalyst, measured in S / m.

[0015] Furthermore, the heat conduction time constant for:

[0016] ;

[0017] in, It is the heat transfer coefficient between the metal chip or metal catalyst and the gas, ranging from 50 to 200, and the unit is W / (m²·K).

[0018] Furthermore, at the moment The electron density in the mixed gas at for:

[0019] ;

[0020] in, is the vacuum dielectric constant, which is 8.854×10 -12 , unit is F / m; is the electric field strength of the high-frequency coil, in V / m; is the density of neutral gas molecules, in m -3 ; is the average collision frequency; is the electron mobility, in m² / (V·s); is Planck's constant; is the equivalent plasma frequency induced by the high-frequency coil, in Hz; is the nonlinear ionization damping coefficient of the gas medium, in Pa -1 ; is the static pressure of the mixed gas; is the ionization cross section, with units of m², which represents the probability of a unit electron ionizing a neutral particle per unit time.

[0021] Furthermore, at the moment The radius of the fire core for:

[0022] ;

[0023] in, is the initial fire core radius, ranging from 1 to 3, in mm; is the flame propagation enhancement coefficient, which represents the increase in the rate of fire core expansion caused by eddy current or heat diffusion; is the thermal conductivity of the mixed gas, in W / (m·K); is the auto-ignition temperature of the mixed gas; The heat released by combustion of unit mass of mixed gas.

[0024] Furthermore, the critical temperature is the auto-ignition temperature of the mixed gas ; Assume the ionization threshold is ;when and When the mixed gas is a mixture of methane and air, The value range is ; When the mixed gas is a mixture of propane and air, The value range is ; When the mixed gas is a mixture of oxygen and hydrogen, The value range is .

[0025] By adopting the above technical solution, the present invention produces the following beneficial effects: by introducing a non-contact induction heat source and plasma control mechanism, the response speed, ignition success rate and environmental adaptability of the ignition system are significantly improved. Compared with traditional spark discharge or mechanical ignition methods, the device does not require electrode contact, which not only eliminates the problems of short life such as electrode wear and corrosion, but also effectively avoids the occurrence of electrical misfires or uneven ignition. By quickly forming a concentrated heat source in the metal chip or catalyst body through high-frequency induction, the gas in the ignition zone can be heated to above the auto-ignition threshold in a very short time, ensuring the immediacy and controllability of the ignition process. In addition, the system integrates a dual-criteria model based on electron density and gas temperature, so that the ionization excitation action is triggered only at the optimal time, avoiding energy waste and enhancing discharge efficiency. After the ignition is completed, the system further determines whether the fire core has the ability to sustain itself based on the flame front expansion model. If the requirements are not met, secondary ignition compensation is automatically performed to achieve closed-loop intelligent control of the entire process. The present invention supports adaptive ignition strategies for multiple gas types, can automatically adjust the judgment threshold according to the type of gas, has high versatility and reliability, and is suitable for scenarios such as industrial gas ignition, chemical exhaust incineration, and distributed thermal energy control under complex working conditions. It has significant engineering application value and promotion prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of an intelligent torch ignition device based on high-frequency induction heating provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] All features disclosed in this specification, or all steps in the disclosed methods or processes, except mutually exclusive features and / or steps, can be combined in any manner.

[0028] Any feature disclosed in this specification (including any appended claims and abstract), unless otherwise stated, may be replaced by other equivalent or similar features. In other words, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0029] Example 1, reference Figure 1: An intelligent torch ignition device based on high-frequency induction heating, the device includes: an eddy current heating part, which is used to arrange a high-frequency coil in the ignition area, generate an alternating magnetic field through the high-frequency coil, induce eddy currents in the metal chip or metal catalyst inside the torch, perform induction heating, and thus form a high-density heat source; a critical temperature rise judgment part, which is used to judge whether the temperature of the mixed gas exceeds the critical temperature when the mixed gas is heated due to the radiation and heat conduction of the metal chip or metal catalyst; a high-frequency ionization part, which is used to estimate the electron density in the mixed gas when the temperature of the mixed gas exceeds the critical temperature, and compare the electron density with the ionization threshold. If the electron density exceeds the ionization threshold, electric field excitation is performed to maximize the plasma formation efficiency; a fire core self-sustaining control part, which is used to calculate the fire core radius in real time by constructing a fire core radius expansion function. If the fire core radius reaches the self-sustaining threshold, it is judged that the fire core can achieve self-sustaining, and the induction heating and electric field excitation are stopped in sequence. If the fire core radius does not reach the self-sustaining threshold, induction heating and electric field excitation are continued.

[0030] The eddy current heating part is based on high-frequency electromagnetic induction technology. By configuring a high-frequency excitation coil in the ignition area, the coil generates an alternating magnetic field after a high-frequency alternating current is passed through it. This magnetic field penetrates the conductive metal body or metal catalytic chip at its center, and then induces a circular induced current inside the chip, which is also called eddy current. When the induced current flows inside the chip, the resistance properties of the chip itself will produce a Joule heating effect, causing the inside of the chip to heat up rapidly, forming a high-temperature local heat source area. This high-density heat source has both instantaneous heating capabilities and can achieve efficient radiation and conduction of heat to the surrounding space, providing a physical basis for subsequent gas temperature rise and ionization reactions. The entire eddy current heating process has three major characteristics: non-contact, fast response, and high local energy concentration. It is suitable for torch ignition scenarios with limited space, complex environment, and high ignition accuracy requirements.

[0031] The eddy current heating system consists of three main components: the first is a high-frequency inverter power module, which generates a stable and adjustable high-frequency electrical signal and inputs it into the coil system. The second is the induction coil structure, which adopts a spiral or flat disc coil layout. The size and number of turns are optimized according to the chip geometry and the torch cavity size, thereby achieving precise control of the magnetic flux density and spatial magnetic field distribution. The third is a metal chip or metal catalyst located at the geometric center or focal area of ​​the coil. The material is typically a high-conductivity, high-heat-resistant metal such as copper, nickel, or their alloys to enhance the eddy current response and prevent structural damage at high temperatures. When the eddy current heating system is in operation, the high-frequency current generates a spatial magnetic flux in the excitation coil. The magnetic flux penetrates the chip volume and induces a closed-loop eddy current path. The current distribution exhibits a surface skin effect, concentrating heat on the chip surface and shallow areas. In a very short time, the chip surface temperature can rise to over 1,000 degrees Celsius, thus forming an effective ignition heat source.

[0032] To ensure the stable operation of the system under actual working conditions, the eddy current heating part is also embedded with a number of engineering protection and regulation mechanisms. In terms of structure, a high-temperature resistant ceramic insulation support is provided between the coil and the chip to avoid thermal degradation of the coil insulation layer due to heat diffusion or thermal radiation; in terms of electrical control, the inverter power supply system has a power adjustable function, which can adapt the output frequency and voltage according to variables such as ambient temperature and gas concentration, thereby realizing closed-loop control of the induced power; in terms of safety protection, a temperature sensor and a timing logic unit are also provided. If the chip temperature continues to rise but no ignition occurs, the system will automatically determine it as a thermal failure state and execute a power reduction or shutdown command to prevent overheating damage to the device. In addition, the layout of the eddy current heating structure also takes into account the gas flow characteristics of the torch cavity, ensuring that the heating area and the gas mainstream area have a good heat exchange contact surface, thereby maximizing the thermal coupling efficiency of the chip heat energy to the mixed gas.

[0033] The critical temperature rise determination component serves as the intermediate logic link between heat source excitation and plasma formation, serving as a key control node for determining whether the gas mixture has reached a critical flammable state. Its operating principle is based on fundamental knowledge of the autoignition limit in gas combustion science. By real-time monitoring, evaluation, and comparison of the gas mixture's temperature, it determines whether it exceeds a certain physical threshold, thereby deciding whether to initiate the subsequent high-frequency ionization module. In its actual design, this component integrates a temperature sensing unit, a threshold determination unit, and a logic control unit. It is physically and signal-coupled with the preceding eddy current heating unit, forming a complete thermal determination and execution chain. Within the flare chamber, the gas mixture is in close contact with a metal chip or metal catalyst. When the chip surface is excited to a high temperature by high-frequency induction, heat is transferred to the surrounding gas-air mixture through both radiation and conduction, rapidly increasing its temperature. During this process, the temperature sensing unit captures transient temperature changes in the gas mixture at a fixed sampling frequency and transmits this data in real time to the threshold determination module, which then compares the data against a preset critical temperature value.

[0034] The critical temperature setting is not arbitrary, but is determined by the type of gas used in the torch. Different gases have different auto-ignition points. For example, the auto-ignition temperatures of methane, propane, and hydrogen are different. Therefore, the system needs to select the corresponding critical parameters based on the gas composition and solidify them in the control module when it leaves the factory. If the system is a programmable platform, dynamic assignment of critical temperatures corresponding to different gas switches can be achieved, further improving the versatility and adaptability of the device. When the discrimination module receives the real-time temperature value from the sensor, it will make a logical judgment based on the deviation between this value and the critical temperature. If the current temperature has not reached the gas auto-ignition limit, the system remains in a waiting state while maintaining the continuous action of induction heating, prompting the chip to further heat and enhance the thermal excitation ability of the gas. When it is determined that the temperature reaches or exceeds the critical threshold, the system automatically sends a signal to start the high-frequency ionization part, preparing for the next stage of electron density assessment and plasma generation. During this process, the temperature discrimination module not only acts as a logic controller but also undertakes a safety guarantee function. That is, when the temperature cannot reach the critical point for a long time or the temperature rise rate is significantly lower than the expected value, the system can trigger the fault diagnosis function through the temperature discrimination module to determine whether there are abnormal conditions such as insufficient gas concentration, decreased chip sensing efficiency or obstructed heating path, and take corresponding protective measures.

[0035] Because flare ignition typically occurs within a very short timeframe and the temperature gradient is steep, the selected sensor must possess high sensitivity, high-frequency response, and high-temperature resistance. Commonly used devices include micro-thermocouples, infrared non-contact thermometers, or thermistor arrays. Furthermore, the sensor must be located close to the primary gas heating zone and away from direct exposure to the chip's high-temperature radiation center to avoid damage or distorted readings. Therefore, an isothermal stable point 2 to 5 mm from the chip is typically used as the sampling reference. After acquisition, temperature data undergoes a filtering and digital smoothing process to eliminate spike noise caused by transient airflow disturbances or electromagnetic interference, ensuring input stability for the discrimination logic. Furthermore, the threshold discrimination logic must incorporate a certain tolerance mechanism to allow for transient temperature fluctuations within a reasonable range without triggering false positives. This prevents minor fluctuations from frequently activating or deactivating subsequent ionization modules when the temperature approaches the critical point. The overall system response time is typically controlled between tens and hundreds of milliseconds to meet the dual requirements of speed and reliability for industrial flare ignition.

[0036] The high-frequency ionization component constitutes the key physical module for achieving ignition conversion. Its core function is to induce the stripping of outer-shell electrons from molecules or atoms within the gas after the gas mixture is heated to a critical temperature. This process generates a certain density of free electrons, forming a plasma seed, which provides the fundamental electron density support for the formation of a flame core. This process relies on the collision mechanism and energy transfer between electrons and neutral molecules at the microscopic scale. The principle can be summarized as a balance between the high-frequency field's ability to excite gas molecules and the critical free electron density required for plasma formation. When the temperature of the gas mixture reaches the critical point for autoignition but has not yet spontaneously combusted, the introduction of a high-frequency electric field effectively raises the energy state of the free electrons, giving them sufficient ionization kinetic energy upon collision with neutral particles. This, in turn, breaks the molecular bonds and releases new electrons, thus triggering a multi-stage electron cascade reaction, ultimately establishing a stable ionized core region in space. This region serves as the seed region for the flame core. If the electron density and spatial size are sufficient, the entire combustion reaction chain can be further stimulated, leading to the self-sustaining combustion stage.

[0037] The physical structure of the high-frequency ionization section includes an electric field excitation device, an ionization parameter calculation unit, and ionization discrimination control logic. Its operating sequence is determined by a pre-installed critical temperature rise discrimination module. Once the mixed gas temperature exceeds the set auto-ignition point, the system triggers the ionization module to activate. The high-frequency power supply module applies a voltage signal of tens of megahertz to an electrode group or secondary induction coil within the torch chamber, generating a spatially uniformly distributed high-frequency alternating electric field. This electric field is superimposed on the existing induction heating coil field, forming a composite electromagnetic excitation system that enhances the electron acceleration effect. Under the action of this electric field, some electrons in the gas gain kinetic energy, triggering the release of secondary electrons through multiple collisions, gradually increasing the free electron density within the gas region. To monitor the ionization state of the gas in real time, the ionization parameter calculation unit estimates the electron density. This estimate is based on pre-set physical conditions such as the ionization characteristics of the gas medium, the current gas temperature, the local pressure, and the electric field strength. It determines whether the electron density generated by the current system has exceeded the preset ionization threshold. If the estimation results show that the electron density is still insufficient, the system will continue to maintain the excitation state of the high-frequency electric field; if the density reaches or exceeds the threshold, it is considered that the plasma seed has been successfully generated, and the ionization process can enter the maintenance or release stage, providing an electron field basis for subsequent flame core expansion and self-sustaining control.

[0038] To ensure high efficiency and precision, the system design fully considers the impact of different gas types on the ionization process. For example, hydrogen has significantly different ionization energies than methane or propane, necessitating different ionization thresholds and electric field strength parameters. Furthermore, because the gas flow rate and mixed concentration within the torch chamber can interfere with the spatial stability of the ionization region, the system must monitor fluctuations in the mixed gas concentration in real time and adjust the excitation frequency and amplitude through dynamic electric field modulation technology to ensure that the plasma seed is generated at the appropriate location and time and maintained for a sufficient length of time. Furthermore, to prevent electrode overheating or energy waste due to excessive ionization, the high-frequency ionization module has a built-in timing limiting mechanism. When the electron density remains high for an extended period and does not trigger core expansion, the system automatically reduces the excitation amplitude or shuts down the electric field output to prevent device aging or thermal damage caused by the continuous operation of the high-frequency power supply.

[0039] The high-frequency ionization section also coordinates with the flame core self-sustaining control section. When the system detects that the flame core radius has reached the self-sustaining propagation condition, the module automatically exits operation to save energy and reduce interference. If the flame core fails to form or becomes unstable after formation, the high-frequency ionization section restarts, reassesses the electron density based on temperature and pressure conditions, and implements the ionization excitation process. This reentrant operating mechanism gives the system strong fault tolerance and robustness. Even under the influence of external gas flow disturbances, temperature fluctuations, or changes in gas concentration, the system can maintain the dynamic regulation of electron density through a feedback mechanism, ensuring that the system can continuously maintain the basic physical environment required for ignition seeds.

[0040] The fire core self-sustaining control component plays a crucial role in determining whether a flame has been successfully established and whether it can stably propagate. Its primary function is to dynamically calculate the actual expansion of the flame core based on changes in the system's internal temperature distribution, ionization state, and flame core structure, and to determine whether critical conditions for sustainable combustion have been met. Once the fire core is confirmed to be formed and self-sustaining, the system sequentially shuts down the preceding induction heating module and high-frequency ionization module to achieve convergence control of the ignition process. Conversely, if the fire core fails to expand or propagate, the system restarts the induction heating and ionization modules to continue providing excitation energy and ensure successful ignition. The core of the fire core self-sustaining control component is the real-time perception and analysis of the spatial size and structural evolution of the flame core. This process does not rely directly on the measurement results of a single sensor, but rather builds a fire core radius evolution model, combining the system's existing temperature, gas physical parameters, thermal conductivity, and reaction exothermic characteristics to comprehensively infer and determine the process.

[0041] In its implementation, the system first deploys multiple temperature sensors or infrared-based flame detection elements near the ignition zone. These sensors do not directly measure the boundaries of the flame core, but instead capture the thermal field distribution variations of the gas mixture at different locations. After collecting this thermal field data, the system indirectly estimates the effective radius of the current flame core and the flame front's expansion rate by spatially extrapolating the temperature gradient. This calculated result is then compared with a pre-set self-sustaining threshold. This threshold is typically predetermined based on factors such as gas type, flow rate, and ambient pressure. It represents the minimum spatial extent a flame must reach under specific conditions to maintain a continuous combustion reaction chain. If the current flame core radius exceeds the self-sustaining threshold, the system determines that the flame possesses sufficient heat transfer capacity and chemical reactivity to propagate continuously throughout the flare's combustion zone without relying on external energy input. At this point, the system immediately shuts down the induction heating module and ionization module, switching to normal gas supply and maintaining the flare in a self-sustaining combustion state, thereby reducing power consumption and extending component life.

[0042] On the other hand, if the fire core's expansion slows significantly after initial formation, or its spatial radius remains below the self-sustaining threshold for an extended period, this indicates that the current ignition process has failed to trigger a self-sustaining combustion reaction. This situation could be caused by a variety of factors, including excessive gas flow, insufficient gas concentration, insufficient chip heating power, or low ionized electron density. In this case, the fire core self-sustaining control module uses logic to restart the induction heating module. Based on the specific timing and parameter characteristics of the previous ignition failure, it appropriately adjusts the heating power, ionization duration, or gas mixture ratio to improve the success rate of the next ignition attempt. This control module not only automatically determines the self-sustaining conditions and implements closed-loop control through repeated attempts, but also establishes an adaptive flame stability optimization mechanism by recording historical system data and dynamically adjusting strategies. This feature is particularly important for flare ignition tasks in complex environments, particularly in outdoor scenarios with wind disturbances, fluctuating gas concentrations, or frequent ignition starts. It effectively avoids energy waste and equipment damage caused by repeated ignition failures.

[0043] Furthermore, the metal chip or metal catalyst is located at the geometric center of the high-frequency coil, and the axial spacing between the heating surface or center point of the metal chip or metal catalyst and the cross-sectional plane of the high-frequency coil is in the range of one-quarter to one-half of the radius of the high-frequency coil to maximize magnetic flux coupling.

[0044] When energized, a high-frequency coil generates a relatively uniform alternating magnetic field with the highest magnetic flux density in its center. The thermal output of induction heating is proportional to the square of the magnetic flux density at this location. When the metal chip is located within this optimal axial magnetic flux density zone, induced currents (i.e., eddy currents) form a high-intensity circular current path within the metal chip, rapidly generating a skin effect and inducing Joule heating. If the chip is too close to the coil plane, it may fall into a blind spot for magnetic field interference; if it is too far away, the magnetic flux density will be severely attenuated, resulting in a significant decrease in induction power. Therefore, this technical structure precisely targets the strong coupling band of the alternating magnetic field in the axial direction by limiting its placement to between one-quarter and one-half of the radius. This ensures concentrated, efficient, and uniform heating, providing a reliable and rapid heat input foundation for subsequent temperature rise determination, ionization induction, and flame core self-sustaining control during the torch ignition process.

[0045] Furthermore, the ignition area is a spherical area formed with a radius 2 to 3 times the radius of the metal chip or the metal catalyst body; and the flow rate of the mixed gas is less than 0.5 m / s.

[0046] The ignition zone is defined as a spherical spatial area with a radius two to three times the radius of the metal chip or metal catalyst. This is based on the typical spatial attenuation of heat radiation and conduction in a gas during induction heating. Under the influence of a high-frequency alternating magnetic field, the metal chip rapidly heats up, reaching surface temperatures exceeding 800°C. This heat diffuses into the surrounding gas through radiation and conduction, while the actual heated area of ​​the gas often exhibits a nearly spherical symmetry. Setting the ignition zone to two to three times the chip radius ensures that the mixed gas within this area reaches or approaches the auto-ignition temperature within a short period of time, meeting the spatial coverage requirements for the temperature rise discrimination module's triggering conditions. If this zone is too small, uneven heating will result, reducing the probability of fire nucleation. If it is too large, the heat density will decrease, affecting the concentration of ignition energy. Therefore, selecting this ratio range achieves an optimal structural scale balance between heating power, gas heat capacity, and spatial response speed.

[0047] In addition, the flow rate of the mixed gas is limited to less than 0.5m / s. The reason is that the gas flow rate has a direct impact on heat accumulation, energy loss and plasma maintenance time during the torch ignition process. Too fast an airflow will quickly carry away the heat generated on the chip surface, causing a lag in gas temperature rise and the inability to trigger the critical temperature judgment in time; at the same time, it will also disturb the initially formed seed plasma cluster, making it difficult to maintain the free electron density above the threshold, directly leading to ionization failure. Furthermore, if the flow rate is too high after the fire core is formed, it will also destroy the expansion path of the flame front, making it impossible for the flame to propagate stably. Therefore, by controlling the gas flow rate to below 0.5m / s, the heating efficiency of the local gas by the chip heat can be significantly improved, the residence time of the ionized particles can be extended, and the entire ignition chain can be guaranteed to complete self-sustaining transformation within the physical time window.

[0048] Furthermore, at the moment The temperature of the mixed gas at for:

[0049] ;

[0050] in, is the initial ambient temperature, in K; is the efficiency of heat radiation and conduction, ranging from 0.2 to 0.6; is the instantaneous power of induction heating, in W; The effective area of ​​the metal chip or metal catalyst in direct contact with the mixed gas, in m²; is the density of the mixed gas, in kg / m³; is the constant pressure specific heat capacity of the mixed gas, in J / (kg·K); is the volume of the ignition area; The time constant of heat conduction controls the temperature rise rate and its value range is 5ms to 100ms.

[0051] Specifically, the first term on the right side of the formula It reflects the thermal equilibrium background of the gas in the initial state, usually ranging from 293K to 298K under normal temperature conditions; the second term is the response term of the gas temperature over time, which is determined by the ratio between the heat transfer input intensity and the gas heat capacity impedance, and the exponential decay function term It reflects the time characteristics of the heating process and characterizes the thermal inertia and conduction response speed of the system. The effective thermal coupling efficiency between the metal chip or metal catalyst and the mixed gas takes into account various factors such as radiation heat transfer, contact heat conduction, and gas parcel uniformity. In actual systems, the value is usually between 0.2 and 0.6. For example, when the chip layout is compact, the gas flow rate is low, and the thermal isolation is good, The upper limit value can be 0.6; if there is strong convection or the contact area between the chip and the gas is limited, It may drop to 0.2. The instantaneous power generated by high-frequency induction heating, measured in watts, is a direct indicator of heating intensity. This power comes from the high-frequency coil exciting eddy currents within the chip through an alternating magnetic field. The eddy currents flow within the metal and generate Joule heating due to their inherent resistance. In actual devices, the induction power can be controlled by adjusting the frequency, current amplitude, or coil structure, with typical values ​​ranging from 50 to 200 watts. Parameters This represents the actual heat exchange area between the chip and the gas, measured in square meters. This area is typically determined by the chip's geometry. For example, if the chip is a disk with an 8 mm diameter, the effective contact area is approximately 5.0 × 10^{-5} m².

[0052] At the same time, the density of the gas and specific heat capacity at constant pressure Determines the amount of heat energy required per unit volume. At normal temperature and pressure, the density of air or methane-air mixture is about 1.1 kg / m³, and the specific heat capacity is about 1000 J / (kg·K), which means that about 1.1 J of heat is required to increase the temperature of each liter of gas by 1 K. is the volume of the ignition area, which depends on the chip radius and the flame seed envelope. If the chip radius is 4 mm, the ignition area is a spherical structure 2.5 times the chip radius, then .at last, The heat conduction time constant is used to control the system response rate after heat input. Its typical value ranges from 5ms to 100ms. The specific value depends on the thermal diffusion characteristics of the gas and the thermal conductivity of the chip surface. This means that the gas heats up faster, which is more conducive to rapid ignition.

[0053] Assume that the following parameters are set for an actual ignition process: initial temperature , thermal coupling efficiency , induction heating power , heat exchange area , gas density , gas specific heat capacity , ignition area volume , heat conduction time constant Substituting the above parameters into the temperature rise formula, we can get the expression of temperature change over time:

[0054] ;

[0055] Calculating the ratio term, the thermal power term is 2.16 J / K, the specific heat term is about 4.7 J / K, and the temperature rise coefficient is about 460 K, which means that theoretically the gas temperature can eventually rise by 460 K, that is, to 758 K. Continue to calculate the time response: when When , the exponential term is , the corresponding temperature rise is about 290K, and the gas temperature rises to 588K; when When the temperature rises to 395 K, the exponential term is approximately 0.86, the temperature rise is 395 K, and the gas temperature is 693 K. If the heating is continued to 0.1 s, the exponential term approaches 0.98, and the final temperature approaches the target value of 758 K. This shows that in less than 0.1 seconds, the gas in the ignition area can be heated from room temperature to above 700 K, which is close to the lower limit of the autoignition temperature of gases such as methane, providing sufficient heat preparation for subsequent ionization excitation and flame core expansion.

[0056] Furthermore, the instantaneous power of induction heating for:

[0057] ;

[0058] in, The electrical conductivity of the metal chip or metal catalyst is expressed in S / m. is the angular frequency of the alternating magnetic field, in rad / s; is the peak magnetic induction intensity of the high-frequency coil, in T; is the radius of the metal chip or metal catalyst, in meters; is the eddy current penetration depth, in m; ,in, The magnetic permeability of the metal chip or metal catalyst material, in H / m; The electrical conductivity of the metal chip or metal catalyst, measured in S / m.

[0059] In the intelligent torch ignition device based on high-frequency induction heating of the present invention, achieving a fast, stable, and efficient ignition process requires first establishing a reliable and controllable heat source. This heat source is generated by a metal chip or metal catalyst located at the center of the high-frequency coil, heated by high-frequency induction. Its essence is the Joule heating effect generated by eddy currents excite the metal material in an alternating magnetic field. Therefore, the instantaneous thermal power model of induction heating is the primary basis for modeling the ignition process. Its expression is: .in, Indicates the electrical conductivity of a metal chip or metal catalyst, with the unit being S / m, and describes the metal material's ability to conduct current. The higher the electrical conductivity, the greater the Joule heat generated per unit current per unit volume, and therefore has a direct impact on the efficiency of eddy current heating. Common materials such as copper, nickel, and molybdenum usually have a conductivity range of to S / m, when selecting materials, both conductivity and high temperature stability must be considered. It represents the angular frequency of the alternating magnetic field of the excitation coil in rad / s and is defined as ,in is the excitation frequency, in Hz. In this system, the operating frequency of the high-frequency power supply is generally set to tens to hundreds of kilohertz, corresponding to exist to In the rad / s range, the higher the angular frequency, the more dramatic the magnetic field change, the greater the induced electromotive force, and the stronger the eddy current. The peak magnetic induction intensity of the alternating magnetic field generated by the coil, measured in Tesla (T), typically ranges from 0.01 to 0.1 T. It is determined by the excitation current, the number of coil turns, and the coil geometry. The magnetic field strength directly determines the magnetic flux per unit area, thereby controlling the magnitude of the induced potential and the intensity of the excitation current.

[0060] The chip's geometric parameters also have an important influence on the induced power. The radius of the metal chip or catalyst, measured in meters, is proportional to the square of the induction power. A larger chip provides a wider induction path and a larger heating volume, but also brings greater thermal inertia and higher energy consumption. Therefore, the design should take into account the thermal power required for ignition and the volume limit. The last key parameter is the eddy current penetration depth in meters, defined as: . This item describes the penetration distance at which the alternating magnetic field can effectively induce eddy currents in a conductor, and is a quantitative parameter of the skin effect. The higher the frequency of the magnetic field, the greater the electrical conductivity or the stronger the magnetic permeability, the shallower the penetration depth, that is, the eddy currents are mainly concentrated near the metal surface, generating surface-concentrated Joule heat. This characteristic enables the chip to achieve high surface temperatures in a very short time, thereby quickly transferring heat to the surrounding combustible gas in the form of radiation and heat conduction, achieving temperature rise preparation before ignition. The penetration depth not only controls the spatial distribution of eddy currents, but also affects the equivalent heating volume and actual power density. It is an important basis for designing chip thickness and material selection.

[0061] Assume that the material selected is electrolytic copper, whose conductivity is S / m, the magnetic permeability is taken as H / m (approximate vacuum magnetic permeability of non-ferromagnetic materials), the high-frequency excitation frequency is 100kHz, and the corresponding angular frequency is rad / s. Substituting the above values ​​into the eddy current penetration depth formula, we get:

[0062] ;

[0063] This shows that under this excitation condition, the induction heating is mainly concentrated in the 66 μm area on the chip surface. m (i.e. 8 mm in diameter), the peak value of magnetic induction intensity is T, then the instantaneous induced power is:

[0064] ;

[0065] To perform the operation, first calculate each term: ; ; ;

[0066] Substituting in:

[0067] ;

[0068] ;

[0069] Results show that the induction power is approximately 62 watts, capable of raising the chip surface temperature to over 600°C in a very short time, rapidly forming a thermal excitation zone in the surrounding gas and achieving the critical heat input required for ignition. Because the heated area on the chip surface is thin and concentrated, it has low thermal inertia and fast response, making it ideal for applications such as high-frequency startup and high-speed ignition.

[0070] Furthermore, the heat conduction time constant for:

[0071] ;

[0072] in, It is the heat transfer coefficient between the metal chip or metal catalyst and the gas, ranging from 50 to 200, and the unit is W / (m²·K).

[0073] in, is the density of the mixed gas in units of , which determines the mass of gas per unit volume; is the constant pressure specific heat capacity of the gas, in units of , which reflects the energy required to raise the temperature of the unit mass of gas by 1K; the product of the two is the heat required to raise the temperature of the unit volume of gas, which is further compared with the volume of the ignition area. Multiplying them together expresses the total heat capacity of the mixed gas in the entire ignition space. represents the heat power released by the metal chip to the gas under unit temperature difference, where is the heat transfer coefficient, in units of , is an empirical constant that describes the comprehensive heat transfer process such as heat conduction and convection, reflecting the heat transfer rate per unit area and unit temperature difference; is the effective heat exchange area between the chip and the gas, in units of Therefore, the entire The expression reflects the basic characteristics of "total heat capacity / heat power". The larger the value, the slower the heat conduction reaction; the smaller the value, the faster the thermal response and the faster the gas heating process. From the perspective of engineering implementation, The control of is crucial to the stability and sensitivity of the entire ignition device. If the value is too large, the induction heating is strong, but the heat diffusion efficiency in the gas is low, and it is difficult to quickly form a critical temperature zone that meets the ignition requirements, resulting in ignition failure or increased energy consumption; if If the value is too small, it will be conducive to rapid temperature rise, but it may cause local overheating or flame instability, affecting system reliability. Therefore, in the design, it is necessary to reasonably match the gas type, chip geometry parameters, material selection and environmental flow field to control the Falls within the ideal range of 5ms to 100ms.

[0074] Set the ignition area volume The mixed gas is methane-air, and its density at normal pressure and temperature is , specific heat capacity at constant pressure The effective heat transfer area of ​​the metal chip is , assume that the heat transfer coefficient is taken in the control system design , we can calculate:

[0075] ;

[0076] This value is obviously too large, indicating that if only the above parameter combination is used, the gas temperature rise rate is too slow to meet the rapid ignition requirements. or increase , such as selecting materials with better thermal conductivity (such as nickel-based catalysts) or optimizing the chip surface structure to enhance turbulent heat transfer. When it is increased to 200W / (m²·K), Reduced to about 0.52 seconds, if further reduced to , then you can The system response speed is significantly improved by controlling the time to less than 0.3 seconds. In addition, if the induction power is increased and dynamic feedback is adjusted, the overall ignition time of the system can be shortened to between 0.1 and 0.2 seconds, fully meeting the dual requirements of industrial-grade torch systems for response time and reliability.

[0077] The numerical adjustment of is also closely related to the time window for judging the formation of fire cores. In the ionization and flame core propagation module, if the gas temperature rises too slowly and fails to reach the auto-ignition temperature in time, the seed ionization will dissipate quickly, causing ignition failure. Therefore, a real-time estimation model can be set in the control logic to calculate the induction power. , heat capacity and heat transfer coefficient Substitute jointly to estimate , dynamically predict the evolution of gas temperature and determine in advance whether ionization excitation can be triggered. At the same time, this model can also be used as an indirect indicator for monitoring chip material aging and airflow interference status. If it is significantly larger, it may indicate that there is a problem with the heat exchange path and maintenance or parameter readjustment is required.

[0078] Furthermore, at the moment The electron density in the mixed gas at for:

[0079] ;

[0080] in, is the vacuum dielectric constant, which is 8.854×10 -12 , unit is F / m; is the electric field strength of the high-frequency coil, in V / m; is the density of neutral gas molecules, in m -3 ; is the average collision frequency; is the electron mobility, in m² / (V·s); is Planck's constant; is the equivalent plasma frequency induced by the high-frequency coil, in Hz; is the nonlinear ionization damping coefficient of the gas medium, in Pa -1 ; is the static pressure of the mixed gas; is the ionization cross section, with units of m², which represents the probability of a unit electron ionizing a neutral particle per unit time.

[0081] When a gas mixture is excited by a high-frequency electric field, the valence electrons in some neutral molecules or atoms gain external energy and escape from their atomic orbits, forming free electrons. These free electrons are further accelerated in the electric field and, through collisions with other neutral molecules, induce the release of even more electrons, thereby forming a cascade ionization process. In the system, the rate of change of electron density is limited by physical properties such as the gas's molecular density, collision frequency, and the mobility of free electrons. It is also suppressed by the nonlinear dissipative effects of the gas's pressure. Therefore, this expression not only describes the ionization growth behavior of the gas under the action of a high-frequency electric field, but also incorporates gas pressure and nonlinear losses into the model to dynamically determine the effectiveness of ignition under different operating conditions.

[0082] Furthermore, at the moment The radius of the fire core for:

[0083] ;

[0084] in, is the initial fire core radius, ranging from 1 to 3, in mm; is the flame propagation enhancement coefficient, which represents the increase in the rate of fire core expansion caused by eddy current or heat diffusion; is the thermal conductivity of the mixed gas, in W / (m·K); is the auto-ignition temperature of the mixed gas; The heat released by combustion of unit mass of mixed gas.

[0085] The flame speed is determined by the heat diffusion term and the combustion reaction excitation term. Under constant pressure conditions, the propagation speed of the combustion wave is It can be simplified as follows:

[0086] ;

[0087] This expression is derived from thermal flame theory, which states that the speed of the flame front is related to the thermal conductivity of the medium, the difference between its temperature and the ignition temperature, and the ratio of the gas heat capacity to the heat of combustion. It is the thermal conductivity of the gas mixture, which determines the ability of heat diffusion and propagation; It characterizes the temperature gradient between the fire core and the autoignition limit and is the thermal driving force for flame propagation. is the gas density, It is the heat released by combustion per unit mass of gas. Its ratio is a measure of the heat energy that can be released per unit volume, which determines whether heat propagation can be maintained under a certain temperature rise. Since the flame propagation in this system is not a pure heat diffusion process, it is also enhanced by multiple factors such as residual induction excitation, ionization channel guidance, and gas flow field disturbance. Therefore, a correction factor is introduced. , called the flame propagation enhancement coefficient. This coefficient is usually greater than 1, and its value is obtained based on experimental calibration or simulation parameters, indicating the flame speed gain caused by turbulence, plasma excitation, gas self-convection and other mechanisms. Under ideal static conditions, ; In a combustion-enhanced environment, It can reach 1.5–3.0. Therefore, the fire core propagation speed is expressed as:

[0088] ;

[0089] Integrating this expression over the time dimension yields the complete formula for the change in the radius of the fire core over time:

[0090] ;

[0091] In this expression, the temperature function It is the real-time temperature distribution function of the gas estimated by the induction heating model in the previous stage and has the following form:

[0092] ;

[0093] Substituting this temperature function into the fire core propagation expression, the fire core expansion can be further directly coupled with the previous stage heat source input, so that the system has the ability to continuously model the entire process of temperature rise-ionization-diffusion-self-sustaining.

[0094] For example, if the chip is inductively heated, the gas temperature rises to The auto-ignition temperature of the mixed gas is , the thermal conductivity of gas is , the density is The heat released by combustion per unit mass is , take the enhancement coefficient , initial fire core radius , then the propagation speed is:

[0095] ;

[0096] If the system enters the ionization expansion stage after induction heating and lasts for 0.1 seconds, the fire core expansion length is approximately , the total fire core radius is If the temperature is further increased to , the propagation speed increases rapidly and can reach This means the fire core will expand to a range of 3–5 mm within a few hundred milliseconds, sufficient to enter the self-sustaining phase. This radius growth directly determines whether the system triggers the "fire core self-sustaining" logic and is a key input condition for the "self-judgment, self-control, and self-retreat" process in this invention.

[0097] Furthermore, the critical temperature is the auto-ignition temperature of the mixed gas ; Assume the ionization threshold is ;when and When the mixed gas is a mixture of methane and air, The value range is ; When the mixed gas is a mixture of propane and air, The value range is ; When the mixed gas is a mixture of oxygen and hydrogen, The value range is .

[0098] Taking the mixture of methane and air as an example, the auto-ignition temperature of methane is about , in the ignition control logic, when the gas temperature function after induction heating When this temperature is reached and the electron density function Exceed When , the system starts electric field excitation. Assume that the peak electric field strength of the high frequency coil at this time is , the gas density is , the electron mobility is , the plasma frequency is , Planck constant and vacuum dielectric constant are respectively and , it is calculated that the electron density at this moment is approximately , satisfying the excitation conditions. The system immediately drives the release of high-frequency electric field, further increasing the rate of ionization cascade reaction, so that the free electrons generated by the initial ionization produce secondary ionization through collision, thus quickly forming a high-density plasma channel. In contrast, if the mixed gas is propane-air, its autoignition temperature is , but the required electron density is higher, about The reason is that propane has a complex molecular structure, high ionization energy, and a high dependence on high-energy electrons. Therefore, under the same heating conditions, the system requires a stronger induction power or a longer preheating time to ensure that the ionization criterion is met. If a hydrogen-oxygen mixed gas is used, the auto-ignition temperature is , the electron threshold density only needs to reach The system can complete temperature rise and ionization preheating in a very short time, and the overall response time is controlled within 0.05 seconds, which is suitable for high-speed start-up of the torch system.

[0099] Chip material: copper (conductivity S / m, magnetic permeability H / m); Chip radius: m; High frequency coil operating frequency: kHz, rad / s; Peak magnetic induction intensity: T; effective sensing area: m²; thermal radiation and thermal conductivity efficiency: ; Ignition ball radius: m, volume m³; density of mixed gas: kg / m³; Specific heat capacity at constant pressure: J / (kg·K); thermal conductivity: W / (m·K); Combustion heat release: J / kg; Autoignition temperature: K; initial temperature: K; ionization threshold: m -3 ; Electric field strength: V / m; gas molecule density: m-3 ; Collision frequency: Hz; Electron mobility: m² / (V·s); plasma frequency: Hz; ionization cross section: m²; nonlinear damping factor: Pa -1 ;Gas static pressure: Pa; , .

[0100] ;

[0101] Induction power:

[0102] ;

[0103] ;

[0104] Gas temperature evolution (take ):

[0105] ;

[0106] At this time, the temperature has not yet reached the critical point and the heating time needs to be extended.

[0107] like , we can get:

[0108] ;

[0109] Continue to extend to , which can be achieved:

[0110] ;

[0111] Still below the autoignition temperature, so by increasing To 0.07T:

[0112] ;

[0113] Calculate the new temperature, , satisfied ;

[0114]

[0115] satisfy , electric field excitation can be performed.

[0116] set up , mm, substitute:

[0117] ;

[0118] If it lasts until , mm, meeting the self-sustaining propagation threshold.

[0119] Calculations in this example show that, using a copper chip, a methane-air mixture, and a high-frequency power of 120W, after an excitation time of 2.5 seconds, both the gas temperature and electron density meet the triggering conditions for ignition. After 0.5 seconds of electric field excitation, the fire core radius expands to 3.0 mm, meeting the criteria for self-sustaining combustion and achieving a complete intelligent torch ignition process.

[0120] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these specific embodiments are merely illustrative, and that those skilled in the art may omit, substitute, and modify the details of the methods and systems described above without departing from the principles and spirit of the present invention. For example, combining the above method steps to perform substantially the same functions in substantially the same manner to achieve substantially the same results falls within the scope of the present invention. Accordingly, the scope of the present invention is limited solely by the appended claims.

Claims

1. Intelligent torch ignition device based on high frequency induction heating, characterized in that: The device includes: an eddy current heating part, which is used to arrange a high-frequency coil in the ignition area, generate an alternating magnetic field through the high-frequency coil, induce eddy currents in the metal chip or metal catalyst inside the torch, perform induction heating, and thus form a high-density heat source; a critical temperature rise judgment part, which is used to judge whether the temperature of the mixed gas exceeds the critical temperature when the mixed gas is heated by the radiation and heat conduction of the metal chip or the metal catalyst; a high-frequency ionization part, which is used to estimate the electron density in the mixed gas when the temperature of the mixed gas exceeds the critical temperature, compare the electron density with the ionization threshold, and perform electric field excitation if the electron density exceeds the ionization threshold to maximize the plasma formation efficiency; a fire core self-sustaining control part, which is used to By constructing a fire core radius expansion function, the fire core radius is calculated in real time. If the fire core radius reaches the self-sustaining threshold, it is determined that the fire core can achieve self-sustaining, and the induction heating and electric field excitation are stopped in sequence. If the fire core radius does not reach the self-sustaining threshold, the induction heating and electric field excitation are continued; the metal chip or metal catalyst is located at the geometric center of the high-frequency coil, and the axial spacing between the heating surface or center point of the metal chip or metal catalyst and the cross-sectional plane of the high-frequency coil is in the range of one-quarter to one-half of the radius of the high-frequency coil to maximize magnetic flux coupling; the ignition area is a spherical area formed with a radius of 2 to 3 times the radius of the metal chip or metal catalyst; the flow rate of the mixed gas is less than 0.5 m / s.

2. The intelligent torch ignition device based on high-frequency induction heating according to claim 1, characterized in that: At the moment The temperature of the mixed gas at for: ； in, is the initial ambient temperature, in K; is the efficiency of heat radiation and conduction, ranging from 0.2 to 0.6; is the instantaneous power of induction heating, in W; The effective area of ​​the metal chip or metal catalyst in direct contact with the mixed gas, in m²; is the density of the mixed gas, in kg / m³; is the constant pressure specific heat capacity of the mixed gas, in J / (kg·K); is the volume of the ignition area; The time constant of heat conduction controls the temperature rise rate and its value range is 5ms to 100ms.

3. The intelligent torch ignition device based on high-frequency induction heating according to claim 2, characterized in that: Instantaneous power of induction heating for: ； in, The electrical conductivity of the metal chip or metal catalyst is expressed in S / m. is the angular frequency of the alternating magnetic field, in rad / s; is the peak magnetic induction intensity of the high-frequency coil, in T; is the radius of the metal chip or metal catalyst, in meters; is the eddy current penetration depth, in m; ,in, The magnetic permeability of the metal chip or metal catalyst material, in H / m; The electrical conductivity of the metal chip or metal catalyst, measured in S / m.

4. The intelligent torch ignition device based on high-frequency induction heating according to claim 3, characterized in that: Heat conduction time constant for: ； in, It is the heat transfer coefficient between the metal chip or metal catalyst and the gas, ranging from 50 to 200, and the unit is W / (m²·K).

5. The intelligent torch ignition device based on high-frequency induction heating according to claim 4, characterized in that: At the moment The electron density in the mixed gas at for: ； in, is the vacuum dielectric constant, which is 8.854×10 -12 , unit is F / m; is the electric field strength of the high-frequency coil, in V / m; is the density of neutral gas molecules, in m -3 ; is the average collision frequency; is the electron mobility, in m² / (V·s); is Planck's constant; is the equivalent plasma frequency induced by the high-frequency coil, in Hz; is the nonlinear ionization damping coefficient of the gas medium, in Pa -1 ; is the static pressure of the mixed gas; is the ionization cross section, with units of m², which represents the probability of a unit electron ionizing a neutral particle per unit time.

6. The intelligent torch ignition device based on high-frequency induction heating according to claim 5, characterized in that: At the moment The radius of the fire core for: ； in, is the initial fire core radius, ranging from 1 to 3, in mm; is the flame propagation enhancement coefficient, which represents the increase in the rate of fire core expansion caused by eddy current or heat diffusion; is the thermal conductivity of the mixed gas, in W / (m·K); is the auto-ignition temperature of the mixed gas; The heat released by combustion of unit mass of mixed gas.

7. The intelligent torch ignition device based on high-frequency induction heating according to claim 6, characterized in that: The critical temperature is the auto-ignition temperature of the mixed gas ; Assume the ionization threshold is ;when and When the mixed gas is a mixture of methane and air, The value range is ; When the mixed gas is a mixture of propane and air, The value range is ; When the mixed gas is a mixture of oxygen and hydrogen, The value range is .

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