Control device and method for generating nitric oxide through sliding arc

Abstract

The invention discloses a control device and method for generating nitrogen oxide by sliding arc, and aims to solve the problems of unstable arc, insufficient control precision of discharge parameters and low efficiency of generating nitrogen oxide in the discharge process of the sliding arc. The control device comprises a power supply module, a nitrogen oxide generation module, a measurement module and a monitoring control module; the nitrogen oxide generation module comprises an adjustable air pump unit and a sliding arc unit, the adjustable air pump unit is connected with the sliding arc unit in series, and after the adjustable air pump unit sucks air, active gas of nitrogen oxide is generated through discharging of the sliding arc unit. The electric parameters of the sliding arc are monitored in real time, and the working parameters of the nitrogen oxide generation module are controlled, so that the relationship between the electric discharge data of the sliding arc and the working parameters of the nitrogen oxide generation module is established, the device is ensured to be in the optimal operation state, and the stability of the sliding arc and the energy utilization rate are ensured. Meanwhile, the generation efficiency of nitrogen oxides is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing nitrogen oxides, and in particular to a control device and method for generating nitrogen oxides by a sliding arc. Background Art

[0002] Nitrogen oxides (NO X , mainly nitric oxide NO and nitrogen dioxide NO2) are key basic substances in fertilizer production, chemical synthesis and medical applications (such as respiratory NO gas therapy, preparation of anti-infection plasma-activated water). Traditional industrial-grade nitrogen oxide production mainly relies on the Haber-Bosch process, which needs to operate under high temperature (>400°C) and high pressure (20-40 MPa) conditions, and relies on large reaction devices. There are problems such as high energy consumption (>3 MJ / mol) and large carbon emissions, making it difficult to adapt to distributed nitrogen fixation scenarios and the requirements of biomedical devices for miniaturized and low-power nitrogen oxide generators.

[0003] As a new alternative, plasma technology realizes catalyst-free nitrogen oxide synthesis driven by electric energy through the Zeldovich chain reaction mechanism. Among them, sliding arc discharge can construct a weakly ionized field (electric field strength <100 Td), preferentially excite the vibration energy level of N2 molecules rather than directly ionize the gas, and can achieve high-efficiency (2.1 MJ / mol) nitrogen oxide generation. Although the existing rotary sliding arc system can achieve a nitrogen oxide yield of 5.9% under catalyst-free and atmospheric pressure conditions, its system volume (>10 L) and power consumption (>1 kW) still severely limit its application in portable scenarios (such as in-vehicle medical devices, on-site first aid). Therefore, developing a compact and efficient sliding arc nitrogen oxide generation system to break through the bottlenecks such as poor power supply adaptability, lack of parameter collaborative optimization and blank energy efficiency model in the existing technology has important engineering value for the integration of biomedical devices and the construction of distributed energy systems.

[0004] Currently, there is a lack of parameter collaborative optimization in the arc nitrogen oxide generation system. Non-electrical parameters such as electrode spacing and gas flow rate have a significant impact on arc stability (periodic fluctuation ±30%) and energy coupling efficiency (fluctuation ±22%). However, the existing optimization methods rely on manual trial-and-error experiments and lack intelligent control means based on electrical characteristic parameters (such as voltage ripple coefficient, current harmonic distortion rate). In addition, the research on the energy efficiency model is blank. Although the physical mechanisms of the arc voltage-current (V-I) characteristics and discharge mode (glow-arc transition state) have been clarified, the quantitative correlation model between electrical parameters (such as voltage peak value, sliding period) and nitrogen oxide yield is still blank. The instability of the arc, low energy utilization efficiency, insufficient control accuracy of discharge parameters and high system power loss during the sliding arc discharge process limit the nitrogen oxide generation efficiency. Summary of the Invention

[0005] The object of the present invention is to provide a control device and method for generating nitrogen oxides by a sliding arc, aiming to solve the problems of unstable arc, insufficient control accuracy of discharge parameters and low efficiency of generating nitrogen oxides during the sliding arc discharge process, so as to achieve efficient control of nitrogen oxide generation.

[0006] To solve the above problems, a first aspect of the present invention provides a control device for generating nitrogen oxides by a sliding arc, including a power supply module, a nitrogen oxide generation module, a measurement module and a monitoring and control module;

[0007] The nitrogen oxide generation module includes an adjustable air pump unit and a sliding arc unit. The adjustable air pump unit is connected in series with the sliding arc unit. After the adjustable air pump unit inhales air, it discharges through the sliding arc unit to generate active gases of nitrogen oxides.

[0008] The measurement module is connected to the sliding arc unit and is used to collect the discharge data of the sliding arc unit.

[0009] The monitoring and control module is respectively connected to the measurement module, the nitrogen oxide generation module and the power supply module, and is used to monitor and analyze the data collected by the measurement module, and control the working parameters of the nitrogen oxide generation module according to the analysis results.

[0010] The power supply module is connected to the sliding arc unit and is used to provide a discharge voltage.

[0011] Preferably, the discharge data includes voltage data and current data during the discharge process, the working parameters include the air flow rate of the adjustable air pump unit and the input power of the sliding arc unit, and the monitoring and control module includes a data processing unit and a feedback adjustment unit;

[0012] The data processing unit is used to analyze the frequencies of the current and voltage and the waveform patterns of the current and voltage, and calculate the first electrical parameter during the discharge process of the sliding arc unit based on the analysis results;

[0013] The feedback adjustment unit receives the first electrical parameter and is used to adjust the air flow rate of the adjustable air pump unit and the input power of the sliding arc unit when the first electrical parameter exceeds the preset range of the second electrical parameter.

[0014] Preferably, the first electrical parameter includes the average sliding period, the average effective current value and the average voltage peak value, and the second electrical parameter includes the optimal sliding period, the optimal effective current value and the optimal voltage peak value;

[0015] When the average sliding period exceeds the preset range of the optimal moving period, or the effective value of the average current exceeds the preset range of the optimal current effective value, or the peak value of the average voltage exceeds the preset range of the optimal voltage peak value, the feedback adjustment unit fixes the input power of the sliding arc unit and gradually increases the air flow rate of the adjustable air pump unit;

[0016] When the current air flow rate when the average sliding period is at a minimum value is the optimal air flow rate, the feedback adjustment unit fixes the adjustable air pump unit at the optimal air flow rate and gradually increases the input power of the sliding arc unit;

[0017] When the current input power when the effective value of the average current is at a maximum value is the optimal input power, the feedback adjustment unit finely adjusts the air flow rate and the input power;

[0018] When the peak value of the average voltage is at a maximum value, the feedback adjustment unit controls the adjustable air pump unit to maintain the current air flow rate and the sliding arc unit to maintain the current input power.

[0019] Preferably, the power supply module includes a DC power supply unit, a resonance unit, and a transformer unit. The output end of the DC power supply unit is connected to the input end of the resonance unit. The output end of the resonance unit is connected to the input end of the transformer unit. The output end of the transformer unit is connected to the input end of the sliding arc unit. The transformer unit provides a sinusoidal high voltage for the sliding arc unit;

[0020] The DC power supply unit includes an adjustable AC power supply, a rectifier, and an inverter. The output end of the adjustable AC power supply is connected to the input end of the rectifier. The output end of the rectifier is connected to the input end of the inverter. The output end of the inverter is connected to the input end of the resonance unit.

[0021] Preferably, the resonance unit includes a series resonance capacitor, a series resonance inductor, a parallel resonance capacitor, and a parallel resonance inductor;

[0022] The series resonance capacitor is connected in series with the series resonance inductor to form a series resonance path. The parallel resonance inductor uses a transformer excitation inductor. The parallel resonance capacitor and the parallel resonance inductor are connected in parallel to form a parallel resonance path. The series resonance path and the parallel resonance path are connected in series. The inductance values of the series resonance inductor and the parallel resonance inductor are approximately equal. The capacitance value of the series resonance capacitor is much larger than the capacitance value of the parallel resonance capacitor.

[0023] Another aspect of the present invention provides a control method for generating nitrogen oxides by using a control device, including:

[0024] Collect voltage and current data during the sliding arc discharge process;

[0025] Calculate the first electrical parameter during the sliding arc discharge process based on the voltage and current data;

[0026] Control the gas flow rate through the sliding arc and the input power of the sliding arc according to the first electrical parameter.

[0027] Preferably, the controlling the gas flow rate through the sliding arc and the input power of the sliding arc according to the first electrical parameter includes: based on the second electrical parameter, determining whether the first electrical parameter deviates from the preset range of the second electrical parameter, and if the first electrical parameter deviates from the preset range of the second electrical parameter, adjusting the gas flow rate through the sliding arc and the input power of the sliding arc.

[0028] Preferably, the second electrical parameter is determined according to the following steps:

[0029] Fix the input power, adjust the gas flow rate, and determine the optimal gas flow rate based on the voltage and current data during the sliding arc discharge process;

[0030] Fix the optimal gas flow rate, adjust the input power, and determine the optimal input power based on the voltage and current data during the sliding arc discharge process;

[0031] Fine-tune the optimal gas flow rate and the optimal input power, and calculate the second electrical parameter for the optimal state of the electrical parameter during the sliding arc discharge process at the current gas flow rate and input power based on the voltage and current data during the sliding arc discharge process.

[0032] Preferably, the preset range of the second electrical parameter includes:

[0033] Average sliding period Deviation from the optimal sliding period The range does not exceed ±2%:

[0034]

[0035] Average effective current Deviation from the optimal effective current The range does not exceed ±5%:

[0036]

[0037] Average voltage peak Deviation from the optimal voltage peak The range does not exceed ±5%:

[0038]

[0039] Preferably, if the first electrical parameter deviates from the preset range of the second electrical parameter, adjusting the gas flow rate passing through the sliding arc and the input power of the sliding arc includes:

[0040] Fix the input power, adjust the gas flow rate, obtain the average sliding period at each gas flow rate, and record the optimal gas flow rate when the average sliding period is at a minimum value;

[0041] Fix the gas flow rate at the optimal gas flow rate, adjust the input power, obtain the average sliding period and the average effective current value, and record the optimal input power when both the average sliding period and the average effective current value are at maximum values;

[0042] At the optimal gas flow rate and the optimal input power, finely adjust the gas flow rate and the input power, obtain the average sliding period, the average effective current value, and the average peak voltage value, and keep the current gas flow rate and input power running when both the average sliding period, the average effective current value, and the average peak voltage value are at maximum values.

[0043] By setting a measurement module and a detection and control module in the control device, the present invention realizes real-time monitoring of the electrical parameters of the sliding arc, controls the working parameters of the nitrogen oxide generation module, thereby establishing the relationship between the discharge data of the sliding arc electricity and the working parameters of the nitrogen oxide generation module, and further ensuring that the device is in the best operating state, ensuring the stability of the sliding arc and the energy utilization rate, while improving the generation efficiency of nitrogen oxides and ensuring the stable output of the device under complex working conditions. In addition, according to the voltage and current data of the sliding arc during the discharge process, the first electrical parameter of the sliding arc is calculated, and the gas flow rate and the input power of the sliding arc are controlled according to the first electrical parameter, ensuring the high efficiency and stability of nitrogen oxide generation, and improving the control effect of nitrogen oxide generation and the consistency of product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is the overall structural block diagram of a control device for generating nitrogen oxides by a sliding arc according to the present invention;

[0045] Figure 2 is the simulation result diagram of the capacitance-inductance resonant power supply in an embodiment of the present invention;

[0046] Figure 3 is the voltage-current waveform diagram at the moment when the air between the sliding arc electrodes is broken down in an embodiment of the present invention;

[0047] Figure 4 is the circuit schematic diagram of the resonant unit in the power supply module of the control device provided by the present invention;

[0048] Figure 5It is a flowchart of a control method for generating nitrogen oxides using a control device provided according to the present invention. Detailed implementation manners

[0049] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific implementation manners and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following descriptions, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0050] A schematic diagram of a layer structure according to an embodiment of the present invention is shown in the accompanying drawings. These figures are not drawn to scale, where for the purpose of clarity, some details are enlarged and some details may be omitted. The various regions, shapes of the layers, and their relative sizes and positional relationships shown in the figures are merely exemplary, and in practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0051] The first aspect of the present invention provides a control device for generating nitrogen oxides by a sliding arc, including a power supply module, a nitrogen oxide generation module, a measurement module, and a monitoring and control module; the nitrogen oxide generation module includes an adjustable air pump unit and a sliding arc unit, the adjustable air pump unit is connected in series with the sliding arc unit, and the adjustable air pump unit inhales air and then generates active gases of nitrogen oxides through the discharge of the sliding arc unit; the measurement module is connected to the sliding arc unit and is used to collect discharge data of the sliding arc unit; the monitoring and control module is respectively connected to the measurement module, the nitrogen oxide generation module, and the power supply module, and is used to monitor and analyze the data collected by the measurement module and control the working parameters of the nitrogen oxide generation module according to the analysis results; the power supply module is connected to the sliding arc unit and is used to provide a discharge voltage. Specifically, as Figure 1As shown, when the control device is running, air enters the sliding arc unit from the adjustable air pump unit. The adjustable air pump unit is used to adjust the change of air flow rate. The sliding arc unit breaks down the passing air, thereby generating nitrogen oxide gas. During the generation of nitrogen oxides, data during the sliding arc discharge process, such as voltage and current data, is collected by the measurement module. At the same time, the monitoring and control module analyzes the collected data, constantly obtains the current sliding arc discharge situation, and controls the working parameters of the nitrogen oxide generation module. For example, it controls the adjustable air pump unit to achieve air flow control, adjusts the input power of the sliding arc unit, etc. Here, the way to adjust the input power of the sliding arc unit can be that the monitoring and control module controls the power of the power supply module, thereby realizing the adjustment of the input power of the sliding arc unit. By setting a measurement module and a detection and control module in the control device, the electrical parameters of the sliding arc are monitored in real time, and the working parameters of the nitrogen oxide generation module are controlled, thereby establishing the relationship between the discharge data of the sliding arc and the working parameters of the nitrogen oxide generation module. Furthermore, it ensures that the device is in the best operating state, ensures the stability of the sliding arc and the utilization rate of energy, while improving the generation efficiency of nitrogen oxides and ensuring the stable output of the device under complex working conditions.

[0052] It should be noted that the specific parameters during the sliding arc discharge process are not restricted here, nor are the specific contents of the operating parameters of the nitrogen oxide generation module. The monitoring and control module can judge the operating status of the current device based on the data during the sliding arc discharge process, and control the nitrogen oxide generation module according to the data of the current sliding arc discharge, ensuring that the sliding arc unit is in the best working state and the generation efficiency of nitrogen oxides is the highest. In a preferred scenario, the discharge data includes voltage data and current data during the discharge process, and the operating parameters include the air flow rate of the adjustable air pump unit and the input power of the sliding arc unit; the monitoring and control module includes a data processing unit and a feedback adjustment unit; the data processing unit is used to analyze the frequency of the current and voltage and the waveform patterns of the current and voltage, and calculate the first electrical parameter during the discharge process of the sliding arc unit based on the analysis results; the feedback adjustment unit receives the first electrical parameter and is used to adjust the air flow rate of the adjustable air pump unit and the input power of the sliding arc unit when the first electrical parameter exceeds the preset range of the second electrical parameter. Through such a setting, the relationship between the first electrical parameter during the discharge process of the sliding arc unit and the air flow rate and input power is established. On the one hand, it is possible to compare the first electrical parameter during the discharge process of the sliding arc unit with the preset second electrical parameter to judge whether the current sliding arc unit is in the best working state; on the other hand, by adjusting the air flow rate and input power, the sliding arc unit is always in the best state, thereby ensuring the generation efficiency and quality of nitrogen oxides. At the same time, through such a control method, compared with the traditional method of adjusting the air flow rate and input power multiple times according to the concentration or real-time efficiency of the generated nitrogen oxides, the control device of the present invention can adjust the working state of the sliding arc unit more quickly and accurately, ensure the continuous and stable operation of the device, and ensure the stable output of nitrogen oxides under complex working conditions.

[0053] It should be noted that generally, the electrical parameters during the arc discharge process mainly include voltage, current, power, resistance, duration, and energy, etc. The specific contents of the first parameter and the second parameter are not restricted here, and it is possible to reflect the state of the current sliding arc discharge process based on the first electrical parameter and the second electrical parameter, and adjust the nitrogen oxide generation module in a timely manner. Nor is the specific adjustment sequence of the air flow rate and input power restricted. It can be to adjust the input power first, or to adjust the air flow rate first. In a preferred scenario, the first electrical parameter includes the average sliding period the root mean square value of the average current and the average peak voltage The second electrical parameter includes the optimal sliding period the optimal root mean square value of the current and the optimal peak voltage When the average sliding period exceeds the preset range of the optimal sliding period or the root mean square value of the average current Exceed the effective value of the optimal current of the preset range, or the peak value of the average voltage Exceed the peak value of the optimal voltage When the preset range is exceeded, the feedback regulation unit fixes the input power of the sliding arc unit and gradually increases the air flow rate of the adjustable air pump unit; when the current air flow rate at the minimum value of the average sliding period is the optimal air flow rate, the feedback regulation unit fixes the adjustable air pump unit at the optimal air flow rate and gradually increases the input power of the sliding arc unit; when the current input power at the maximum value of the average current effective value is the optimal input power, the feedback regulation unit finely tunes the air flow rate and the input power; when the peak value of the average voltage is at the maximum value, the feedback regulation unit controls the adjustable air pump unit to maintain the current air flow rate and the sliding arc unit to maintain the current input power.

[0054] Specifically, the average sliding period The calculation formula is:

[0055]

[0056] where T arc,i is the sliding period of the i-th cycle, T arc,i = t i - t i-1 t i is the starting time of the i-th pulse, is the starting time of the (i - 1)-th pulse, and n is the number of measured cycles;

[0057] The effective value of the current I rms is defined as the square root of the average value of the square of the instantaneous current value i(t) within a discharge cycle T, and the calculation formula is:

[0058]

[0059] The average effective value of the current The calculation formula is:

[0060]

[0061] where I rms,i is the effective value of the current in the i-th cycle;

[0062] The peak value of the voltage V pp is defined as the maximum value of the absolute value of the positive or negative peak value V(t) of the voltage waveform within each sliding cycle as the peak value of the voltage in this cycle, and the calculation formula is: V pp = max(|V(t)|);

[0063] The average peak value of the voltage The calculation formula is:

[0064]

[0065] Among them, V pp,i is the peak voltage of the i-th cycle.

[0066] There is no limitation on the specific range of the preset of the second parameter here. It can be that when the first parameter is not equal to the second parameter, the feedback regulation unit triggers the air flow rate and input power regulation actions, or it can be that the first parameter deviates from the preset range of the second parameter. Within this preset range, the current discharge parameters of the sliding arc unit can satisfy the efficient generation of nitrogen oxide gas and ensure the generation quality of nitrogen oxides. In a preferred case, the preset range of the second electrical parameter includes:

[0067] Average sliding period Deviating from the optimal sliding period by a range not exceeding ±2%:

[0068]

[0069] Average effective current Deviating from the optimal average effective current by a range not exceeding ±5%:

[0070]

[0071] Average peak voltage Deviating from the optimal peak voltage by a range not exceeding ±5%:

[0072]

[0073] Through such a setting, on the one hand, it can ensure that the first electrical parameter during the discharge process of the sliding arc unit always remains near the second electrical parameter, thereby ensuring that the sliding arc unit is in the best working state, ensuring the continuous and stable operation of the device, and ensuring the stable output of nitrogen oxides under complex working conditions; on the other hand, setting the allowable deviation range of the first electrical parameter also avoids the device always being in an adjustment state, reduces the working load of each module in the device, and prolongs the service life of the device.

[0074] It should be noted that the specific structure of the power supply module is not limited here, and it is only necessary to be able to control the power supply module to supply power to the sliding arc unit and adjust the input power through the monitoring and control module. In a preferred case, the power supply module includes a DC power supply unit, a resonance unit, and a transformer unit. The output end of the DC power supply unit is connected to the input end of the resonance unit, the output end of the resonance unit is connected to the input end of the transformer unit, and the output end of the transformer unit is connected to the input end of the sliding arc unit. The transformer unit provides a sinusoidal high voltage for the sliding arc unit; the DC power supply unit includes an adjustable AC power supply, a rectifier, and an inverter. The output end of the adjustable AC power supply is connected to the input end of the rectifier, and the output end of the rectifier is connected to the input end of the inverter; the output end of the inverter is connected to the input end of the resonance unit. Further, the switching tubes of the inverter are precisely controlled by a single-chip microcomputer, and zero-voltage turn-on within a wide output voltage range can be achieved; the transformer unit is not only used for boosting, but also by opening an air gap in the central part of the magnetic core, the excitation inductance value of the transformer reaches the microhenry level. The transformer adopts a skeleton structure with separate primary and secondary sides and is potted to prevent inter-turn short circuit faults caused by current pulses in the microsecond level.

[0075] Through such a setting, based on the full-condition zero-voltage switching (ZVS) technology (the switching loss is reduced by 80%) and the high-frequency transformer integrated design (UY20 magnetic core, 1:40 turns ratio, epoxy layered potting), the energy efficiency leap and miniaturization breakthrough are synchronously achieved, saving the space occupied by the DC power supply unit, and being able to provide a reliable power supply with high energy efficiency. As Figure 2 shown, when the switching tube of the inverter conducts instantaneously, the gate voltage V gs rises precisely synchronously with the reverse zero-crossing point of the current I gs so that the voltage across the switching tube has dropped to zero before conduction, avoiding the energy and device losses caused by the overlap of current and voltage in traditional hard switching.

[0076] It should be noted that the specific structures of the adjustable air pump unit and the sliding arc unit are not limited here. In an optional case, the adjustable air pump unit adopts a vortex air pump, a diaphragm air pump, or a turbine air pump, and the air flow rate can be adjusted by changing the duty cycle of the PWM wave (pulse width modulation wave) or the supply voltage. The sliding arc unit includes two discharge electrodes and a glass outer cover. The glass outer cover is connected to the adjustable air pump unit for introducing gas into the discharge reactor inside the sliding arc unit; the two discharge electrodes of the sliding arc discharge reactor are respectively connected to the two output ends of the transformer unit in the power supply module; the structure of the discharge electrodes can be a blade-retracted electrode structure, a rotary electrode structure (including air-blowing or magnetic-blowing type rotary electrodes), an electrode-rotary structure, or a parallel-plate electrode structure, etc.

[0077] The specific structure of the measurement module is not limited. In a preferred case, the measurement module includes a high-voltage probe, a current probe and a data acquisition circuit. The bandwidth of the high-voltage probe and the current probe is not less than 50MHz. The data acquisition circuit uses a single-chip microcomputer with a simple sampling circuit to extract the current peak and voltage peak through a peak hold algorithm. Furthermore, the monitoring and control module also includes a signal conditioning module, which amplifies and filters the collected signal to ensure the stability and accuracy of the signal. The data processing unit has a built-in algorithm, including a peak detection and identification module, which uses a fast Fourier transform (FFT) to analyze the frequency and waveform of the current and voltage, and calculates the average sliding period. Average current effective value and average voltage peak The feedback adjustment unit receives the analysis result of the data processing unit and cooperates with the monitoring and control module to realize adaptive control of the sliding arc discharge state by adjusting system parameters such as airflow and power output.

[0078] In a preferred case, the resonant unit includes a series resonant capacitor, a series resonant inductor, a parallel resonant capacitor and a parallel resonant inductor; the series resonant capacitor and the series resonant inductor are connected in series to form a series resonant path, the parallel resonant inductor adopts the transformer excitation inductance, the parallel resonant capacitor and the parallel resonant inductor are connected in parallel to form a parallel resonant path, the series resonant path and the parallel resonant path are connected in series, the inductance values of the series resonant inductor and the parallel resonant inductor are approximately equal, and the capacitance value of the series resonant capacitor is much larger than the capacitance value of the parallel resonant capacitor.

[0079] Specifically, Figure 4As shown, in one embodiment of the present invention, the power supply module adopts an inductor-capacitor resonant high-voltage power supply module (LCLC), which includes an adjustable AC power supply, a rectifier, an inverter, a resonant unit, and a transformer unit. The input of the adjustable AC power supply is 220V mains electricity, and after passing through the rectifier, a direct current of approximately 310V is obtained. Two power field-effect transistors (MOSFETs) S1 and S2, and capacitors C1 and C2 form a switching network unit. S1 and S2 work complementarily with a duty cycle of approximately 50%. This unit chops the DC voltage into a high-frequency square wave, whose peak-to-peak value is approximately 313V and the frequency is approximately 43kHz. In the resonant unit, Cs is the series resonant capacitor, Cp is the parallel resonant capacitor, Ls is the series resonant inductor, and Lp is the parallel resonant inductor. Since the leakage inductance in the transformer unit is usually used as the series resonant inductor and the magnetizing inductance is used as the parallel resonant inductor, Lp is also called the magnetizing inductance. The input square wave passes through the resonant unit to obtain a high-frequency sine wave, whose peak-to-peak value is approximately 200V and the frequency is approximately 43kHz. The function of the transformer unit is to electrically isolate the primary side and the secondary side. The secondary side of the transformer unit usually adopts a double-winding structure with a center tap, and is boosted to the required voltage through the transformer unit. Usually, the parameter design of the LCLC circuit plays a decisive role in the performance of the LCLC. When designing these parameters, the following contents are included:

[0080] First, normalize the voltage gain of the LCLC. Set the ratio of the parallel inductor to the series inductor as the inductance ratio n, and the ratio of the parallel capacitor to the series capacitor as the capacitance ratio m; set the normalized angular frequency ω n as the ratio of the switching angular frequency to the series-parallel resonant angular frequency; set the quality factor Q of the LCLC resonant network as the ratio of the characteristic impedance of the half-bridge LCLC resonant network to the equivalent resistance of the sliding arc load. Set G as the voltage gain, and the specific formula is as follows:

[0081]

[0082] Secondly, design the resonant parameters of the LCLC. The sliding arc load can be equivalent to a resistor R GAD , which has a negative impedance characteristic. Before the gas in the sliding arc electrode gap is broken down, the sliding arc load behaves as a very large resistance, similar to an open circuit state. After the electrode is broken down, the sliding arc load is equivalent to a finite resistor R GAD. Ignoring the electrode resistance, in the non-breakdown state, the series inductor Ls resonates with the series capacitor Cs and the parallel capacitor Cp together. At this time, Cs and Cp are in series. Since the breakdown of the sliding arc requires high voltage, a high-voltage resonant circuit must be formed before breakdown. After the sliding arc breaks down, the equivalent resistance RL is about dozens to hundreds of ohms. At this time, Cp plays the main resonant role. Therefore, based on the above analysis, for ignition startup and steady-state operation, it is required that Cs >> Cp, and the value of m is taken as 0.056. The smaller n is, the stronger the inductance of the parallel resonant branch, but the larger the excitation current of the transformer and the greater the loss, which reduces the efficiency of the converter. The value of n is taken as 1.1. Set the switching frequency to 8KHz, then the series switching frequency is set to 8KHz, set the value of Ls to 330μF, and calculate the series capacitance value according to the following formula:

[0083]

[0084] In order to enable the main circuit switch tube to achieve ZVS, set the switching frequency to 43KHz, set the value of LP to 300μF, and calculate the parallel capacitance value according to the following formula:

[0085]

[0086] Design the transformer parameters of LCLC. The design of this high-frequency high-voltage transformer takes the manganese-zinc ferrite UY20 magnetic core as the core, uses the area product method (Ap method) to determine the magnetic core specifications, and realizes a 10kV high-voltage output through a turns ratio of 1:40 (25 turns on the primary side / 1000 turns on the secondary side). When designing, comprehensively consider the skin effect (wire diameter ≤ 0.5mm for the primary / 0.25mm for the secondary), window filling factor (0.0425), and magnetic flux density (0.2T). Use three-layer insulated wire to wind in layers and cooperate with the epoxy potting process, and arrange the primary / secondary windings at both ends of the toroidal magnetic core respectively.

[0087] Finally, select components for LCLC. In the optional cases, select the JCS12N50C field effect transistor (500V / 13A) to meet the 2-fold voltage margin (311V bus) and 5-fold current margin (2.4A demand). The control circuit uses the high-performance half-bridge drive integrated circuit IR2153, and its output complementary PWM signals are respectively connected to the upper-bridge MOSFET (gate of terminal A1) and lower-bridge MOSFET (gate of terminal A2) of the half-bridge circuit, and the two signals have a built-in fixed dead time of 1.2μs. In the resonant network, select the 106125 series for the series inductor, the MKP63 series for the parallel capacitor, and the KP105 series for the series capacitor.

[0088] Through the parameter optimization of the LCLC resonant network, zero-voltage switching of the MOSFET is successfully achieved in the circuit simulation, as shown in Figure 2。When the switching transistor is turned on instantaneously, the rising edge of the gate voltage Vgs is precisely synchronized with the reverse zero-crossing point of the drain-source current Igs, causing the voltage across the switching transistor to drop to zero before conduction and avoiding the losses caused by the overlap of current and voltage in traditional hard switching. Figure 3 As shown, when the air between the sliding arc electrodes is broken down instantaneously, there will be voltage and current spikes with a duration of μs level, a voltage peak of 20 kV, and nearly 17 A. When the gas of the sliding arc blade electrode is broken down, its impedance decreases rapidly, and arc discharge occurs during this process, and the voltage amplitude decreases rapidly to 2 - 3 kV. Through the optimization of the capacitance-inductance resonance network parameters (Cs = 1 μF, Cp = 56 nF), dynamic impedance matching is achieved within the full operating range (50 - 5000 Ω) of the sliding arc load. When the air between the sliding arc electrodes is broken down instantaneously, the series resonance path dominates the resonance, generating a μs-level high-voltage pulse of 20 kV / 17 A. After the gas of the sliding arc blade electrode is broken down, it automatically switches to the low-voltage constant-current mode through the parallel resonance path, outputting a stable sine wave of 5 kV / 40 mA, effectively solving the problem of arc failure caused by electrode corrosion or power supply aging, and at the same time avoiding the voltage collapse and efficiency decline defects of the traditional scheme during load mutation.

[0089] Combined with Figure 5 , another aspect of the present invention provides a control method for generating nitrogen oxides using a control device, including:

[0090] Collecting voltage and current data during the sliding arc discharge process;

[0091] Calculating the first electrical parameter during the sliding arc discharge process based on the voltage and current data;

[0092] Controlling the gas flow rate passing through the sliding arc and the input power of the sliding arc according to the first electrical parameter.

[0093] Through such a control method, the correlation between the first electrical parameter during the sliding arc discharge process and the gas flow rate and input power is realized. By adjusting the gas flow rate passing through the sliding arc and the input power of the sliding arc, precise control of the arc discharge state is achieved. This method effectively suppresses the periodic shift caused by load fluctuations or environmental interference in the traditional sliding arc, significantly improves the consistency between the continuity of the sliding arc and the nitrogen oxide generation efficiency, and ensures the stable output of the device under complex working conditions.

[0094] In a preferred case, controlling the gas flow rate passing through the sliding arc and the input power of the sliding arc according to the first electrical parameter includes: based on the second electrical parameter, determining whether the first electrical parameter deviates from the preset range of the second electrical parameter. If the first electrical parameter deviates from the preset range of the second electrical parameter, then adjusting the gas flow rate passing through the sliding arc and the input power of the sliding arc.

[0095] It should be noted that the second electrical parameter can be set in advance according to the models of each module in the device, or can be determined in real time by the monitoring control module and the measurement module before the device is used. In a preferred scenario, the second electrical parameter is determined according to the following steps:

[0096] Fix the input power, adjust the gas flow rate, and determine the optimal gas flow rate based on the voltage and current data during the sliding arc discharge process;

[0097] Fix the optimal gas flow rate, adjust the input power, and determine the optimal input power based on the voltage and current data during the sliding arc discharge process;

[0098] Fine-tune the optimal gas flow rate and the optimal input power, and calculate the second electrical parameter when the electrical parameters of the sliding arc discharge process at the current gas flow rate and input power are in the optimal state based on the voltage and current data during the sliding arc discharge process.

[0099] It should be noted that during the long-term operation of the device, changes in equipment parameters often occur, such as parameter changes in the sliding arc unit caused by equipment aging. The initially set second electrical parameter is not the electrical parameter for reference in the optimal state during the current sliding arc unit discharge process. At this time, the second electrical parameter can also be reset by the above method, that is, the second electrical parameter is updated to ensure the accuracy of the judgment of the device operation state. Through such a control method, dynamic monitoring and correction of the device are realized, and further ensure the stable operation of the device under complex working conditions.

[0100] In a preferred scenario, when the first electrical parameter deviates from the preset range of the second electrical parameter, the adjustment steps of the gas flow rate of the sliding arc and the input power of the sliding arc include:

[0101] Fix the input power, adjust the gas flow rate, obtain the average sliding period at each gas flow rate, and record the optimal gas flow rate when the average sliding period is at the minimum value;

[0102] Fix the gas flow rate at the optimal gas flow rate, adjust the input power, obtain the average sliding period and the average effective current value, and record the optimal input power when both the average sliding period and the average effective current value are at the maximum value;

[0103] At the optimal gas flow rate and the optimal input power, fine-tune the gas flow rate and the input power, obtain the average sliding period, the average effective current value, and the average voltage peak value, and maintain the current gas flow rate and input power operation when the average sliding period, the average effective current value, and the average voltage peak value are all at the maximum value.

[0104] It should be understood that the above specific embodiments of the present invention are only for illustrative or explanatory purposes of the principles of the present invention, and do not constitute a limitation to the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all variations and modifications that fall within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A control device for generating nitrogen oxides by a sliding arc, characterized in that, The control device includes a power supply module, a nitrogen oxide generation module, a measurement module, and a monitoring and control module; The nitrogen oxide generation module includes an adjustable air pump unit and a sliding arc unit. The adjustable air pump unit is connected in series with the sliding arc unit. After the adjustable air pump unit inhales air, active gas of nitrogen oxides is generated through the discharge of the sliding arc unit; The measurement module is connected to the sliding arc unit and is used for collecting the discharge data of the sliding arc unit; The monitoring and control module is respectively connected to the measurement module, the nitrogen oxide generation module, and the power supply module, and is used for monitoring and analyzing the data collected by the measurement module, and controlling the working parameters of the nitrogen oxide generation module according to the analysis results; The power supply module is connected to the sliding arc unit and is used for providing a discharge voltage.

2. The control device according to claim 1, characterized in that, The discharge data includes voltage data and current data during the discharge process. The working parameters include the air flow rate of the adjustable air pump unit and the input power of the sliding arc unit. The monitoring and control module includes a data processing unit and a feedback adjustment unit; The data processing unit is used for analyzing the frequencies of the current and voltage and the waveform patterns of the current and voltage, and calculating a first electrical parameter during the discharge process of the sliding arc unit based on the analysis results; The feedback adjustment unit receives the first electrical parameter and is used for adjusting the air flow rate of the adjustable air pump unit and the input power of the sliding arc unit when the first electrical parameter exceeds the preset range of the second electrical parameter; 3. The control device according to claim 2, wherein The first electrical parameter includes an average sliding period, an average effective current value, and an average voltage peak value. The second electrical parameter includes an optimal sliding period, an optimal effective current value, and an optimal voltage peak value; When the average sliding period exceeds the preset range of the optimized sliding period, or the average effective current value exceeds the preset range of the optimal effective current value, or the average voltage peak value exceeds the preset range of the optimal voltage peak value, the feedback adjustment unit fixes the input power of the sliding arc unit and gradually increases the air flow rate of the adjustable air pump unit; When the current air flow rate when the average sliding period is at a minimum value is the optimal air flow rate, the feedback adjustment unit fixes the adjustable air pump unit at the optimal air flow rate and gradually increases the input power of the sliding arc unit; When the current input power when the average effective current value is at a maximum value is the optimal input power, the feedback adjustment unit finely adjusts the air flow rate and the input power; When the average voltage peak value is at a maximum value, the feedback adjustment unit controls the adjustable air pump unit to maintain the current air flow rate and the sliding arc unit to maintain the current input power.

4. The control device according to claim 3, characterized in that, The power supply module includes a DC power supply unit, a resonance unit, and a transformer unit. The output end of the DC power supply unit is connected to the input end of the resonance unit. The output end of the resonance unit is connected to the input end of the transformer unit. The output end of the transformer unit is connected to the input end of the sliding arc unit. The transformer unit provides a sinusoidal high voltage for the sliding arc unit; The DC power supply unit includes an adjustable AC power supply, a rectifier, and an inverter. The output end of the adjustable AC power supply is connected to the input end of the rectifier, and the output end of the rectifier is connected to the input end of the inverter. The output end of the inverter is connected to the input end of the resonant unit.

5. The control device according to claim 3, characterized in that, The resonant unit includes a series resonant capacitor, a series resonant inductor, a parallel resonant capacitor, and a parallel resonant inductor. The series resonant capacitor and the series resonant inductor are connected in series to form a series resonant path. The parallel resonant inductor uses a transformer exciting inductor. The parallel resonant capacitor and the parallel resonant inductor are connected in parallel to form a parallel resonant path. The series resonant path and the parallel resonant path are connected in series. The inductance values of the series resonant inductor and the parallel resonant inductor are approximately equal, and the capacitance value of the series resonant capacitor is much larger than the capacitance value of the parallel resonant capacitor.

6. A control method for generating nitrogen oxides by using the control device according to any one of claims 1-5, characterized in that, The control method includes: Collecting voltage and current data during the sliding arc discharge process. Calculating a first electrical parameter during the sliding arc discharge process based on the voltage and current data. Controlling the gas flow rate passing through the sliding arc and the input power of the sliding arc according to the first electrical parameter.

7. The control method according to claim 6, wherein The controlling the gas flow rate passing through the sliding arc and the input power of the sliding arc according to the first electrical parameter includes: Based on a second electrical parameter, determining whether the first electrical parameter deviates from a preset range of the second electrical parameter. If the first electrical parameter deviates from the preset range of the second electrical parameter, then adjusting the gas flow rate passing through the sliding arc and the input power of the sliding arc.

8. The control method according to claim 7, wherein The second electrical parameter is determined according to the following steps: Fixing the input power, adjusting the gas flow rate, and determining the optimal gas flow rate based on the voltage and current data during the sliding arc discharge process. Fixing the optimal gas flow rate, adjusting the input power, and determining the optimal input power based on the voltage and current data during the sliding arc discharge process. Fine-tuning the optimal gas flow rate and the optimal input power, and calculating a second electrical parameter for which the electrical parameters during the sliding arc discharge process are in an optimal state at the current gas flow rate and input power based on the voltage and current data during the sliding arc discharge process.

9. The control method according to claim 8, wherein The preset range of the second electrical parameter includes: Average sliding period Deviation from the optimal sliding period shall not exceed ±2%: RMS average current Deviation from the RMS optimal current shall not exceed ±5%: Average voltage peak value Deviation from the optimal voltage peak value shall not exceed ±5%:

10. The control method according to claim 9, wherein The adjusting the gas flow rate passing through the sliding arc and the input power of the sliding arc if the first electrical parameter deviates from the preset range of the second electrical parameter includes: Fixing the input power, adjusting the gas flow rate, obtaining the average sliding period at each gas flow rate, and recording the optimal gas flow rate when the average sliding period is at a minimum value. Fixing the gas flow rate at the optimal gas flow rate, adjusting the input power, obtaining the average sliding period and the average effective current value, and recording the optimal input power when both the average sliding period and the average effective current value are at maximum values. At the optimal gas flow rate and the optimal input power, fine-tuning the gas flow rate and the input power, obtaining the average sliding period, the average effective current value, and the average voltage peak value, and maintaining the current gas flow rate and input power operation when the average sliding period, the average effective current value, and the average voltage peak value are all at maximum values.

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