Device and method for synchronously observing multiple parameters of a sliding arc discharge

Abstract

The application discloses a device and method for synchronously observing multiple parameters of sliding arc discharge. The device comprises a trigger time synchronous sliding arc discharge reactor, an electrical measurement system, an optical measurement system and a schlieren system. The discharge electrode of the sliding arc discharge reactor is connected to a direct current high-voltage power supply, and an arc is generated by gas breakdown between the two discharge electrodes. The high-voltage probe and the current probe of the electrical measurement system obtain time-varying data of voltage and current during the sliding arc discharge process. The horizontal angle α between the high-speed optical camera of the optical measurement system and the position of the sliding arc discharge reactor is less than 5 degrees, the arc light emission form during the discharge process is captured, and the optical spectrum analyzer obtains the active particle composition and concentration. The schlieren camera of the schlieren system realizes image visualization of the gas heating area and the gas heating intensity. The sliding arc discharge evolution process is observed in time and space and the plasma multiple parameter in-situ diagnosis is realized from the perspectives of electricity, optics and heat.

Description

Technical Field

[0001] This invention belongs to the field of plasma technology, and more specifically, relates to a device and method for synchronously observing multiple parameters of a sliding arc discharge. Background Technology

[0002] Plasma is the fourth state of matter after solid, liquid, and gas. It is composed of a mixture of charged particles such as electrons and ions, as well as neutral particles, and is macroscopically electrically neutral. Sliding arc plasma generated by sliding arc discharge is a periodic, non-equilibrium plasma. As a warm plasma, it combines the characteristics of both thermal and low-temperature plasmas and is currently mainly used in multiple fields such as assisted combustion, fuel reforming, decomposition of inorganic pollutants, material surface modification, and wastewater treatment.

[0003] During a sliding arc discharge, the arc exhibits a periodic process of "breakdown—elongation—extinction—re-breakdown." In this periodic process, the sliding arc discharge not only involves ionization and luminescence caused by electron collisions, but also significant gas heating due to energy loss. Furthermore, the discharge voltage and discharge current, representing electrical characteristics, continuously change with arc elongation over a microsecond timescale. There is a strong coupling relationship between the two different effects of electron collision ionization and gas heating during the sliding arc discharge process. To decouple the influence of these two effects on the sliding arc discharge, the observation platform needs to possess the ability to observe thermal, optical, and electrical phenomena simultaneously and to achieve in-situ, time-synchronous diagnosis of these physical parameters.

[0004] Current single diagnostic platforms (electrical or optical) can only observe one physical parameter of the sliding arc discharge, and the measured physical quantities are relatively independent and not combined for synchronous analysis. They have not achieved synchronous in-situ diagnosis of plasma during the sliding arc discharge process from multiple physical perspectives. Summary of the Invention

[0005] In view of the shortcomings of related technologies, the purpose of this invention is to provide a device and method for simultaneously observing multiple parameters of sliding arc discharge, aiming to solve the problem that it is impossible to observe multiple physical quantities of plasma at the same time, thus making it impossible to perform in-situ diagnosis of sliding arc discharge from multiple physical perspectives.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a device for synchronously observing multiple parameters of a sliding arc discharge, comprising: a sliding arc discharge reactor with synchronized triggering time, an electrical measurement system, an optical measurement system, and a schlieren system;

[0007] The sliding arc discharge reactor includes two electrodes and a glass cover. The glass cover is connected to a gas cylinder to deliver gas into the sliding arc discharge reactor. One discharge electrode is connected to a DC high-voltage power supply, and the other discharge electrode is grounded. Under the action of high voltage, the gas medium between the two discharge electrodes is broken down to generate an electric arc. As the electric arc slides along the discharge electrode, it continuously elongates until it is extinguished.

[0008] The electrical measurement system includes a multi-channel data acquisition instrument, a high-voltage probe, and a current probe. The high-voltage probe and the current probe are respectively connected to the high-voltage end and the low-voltage end of the discharge electrode to acquire time-varying data of voltage and current during the sliding arc discharge process and display them on the multi-channel data acquisition instrument.

[0009] The optical measurement system includes a high-speed optical camera and a spectrometer. The horizontal angle α between the high-speed optical camera and the sliding arc discharge reactor is less than 5 degrees, and the spectrometer is positioned directly opposite the sliding arc discharge reactor. The high-speed optical camera is used to capture the arc emission pattern during the discharge process. The spectrometer acquires the composition and concentration of active particles generated after the gas is ionized by the discharge electrode.

[0010] The schlieren system includes an LED light source, two concave mirrors, a blade, and a schlieren camera. The LED light source is located at the focal point of concave mirror M1. The two concave mirrors are positioned on both sides of the sliding arc discharge reactor, and the light path passes through the gap between the two discharge electrodes. The schlieren camera acquires the light beam that passes sequentially through concave mirror M1, the sliding arc discharge reactor, concave mirror M2, and the blade, and generates a schlieren image. The grayscale value variation area and magnitude of the schlieren image respectively reflect the area where the gas is heated and the temperature gradient change of the gas in the sliding arc discharge reactor.

[0011] Optionally, the device further includes a synchronization control trigger that adjusts the delays of the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera, and spectrometer to make them all trigger at the same zero point.

[0012] Optionally, the ratio of the focal length to the diameter of the concave mirror in the schlieren system is greater than 8.

[0013] Optionally, the voltage amplitude output by the DC high-voltage power supply is not less than 30kV / cm*d, and the bandwidth of the high-voltage probe and the current probe is 50MHz; the spatial resolution of the schlieren camera is not less than 100 micrometers and the temporal resolution is not less than 20 microseconds, and the spatial resolution of the high-speed optical camera is not less than 1 millimeter and the temporal resolution is not less than 20 microseconds.

[0014] Optionally, the discharge electrode structure adopts a blade-shaped retractable electrode structure.

[0015] Optionally, the device further includes a mass flow meter, which is installed on the gas pipe and is used to display the gas flow rate input from the gas cylinder to the sliding arc discharge reactor in real time, with a resolution of 0.01 L / min.

[0016] In a second aspect, the present invention also provides a method for synchronously observing multiple parameters of a sliding arc discharge, applied to the apparatus as described in any one of the first aspects, comprising:

[0017] The electrical measurement system, optical measurement system, and schlieren system are synchronized in terms of trigger time so that all systems are at the trigger time zero point.

[0018] When the sliding arc discharge reactor is energized, the discharge electrodes break down the gas medium between the two electrodes under high voltage to generate an electric arc. As the electric arc slides along the discharge electrodes, it is continuously generated and elongated until it is extinguished.

[0019] The high-voltage probe and current probe in the electrical measurement system record the changes in voltage and current during the sliding arc discharge process, and display the time-varying waveforms of voltage and current in the multi-channel data acquisition instrument.

[0020] The high-speed optical camera in the optical measurement system captures the arc emission pattern during the sliding arc discharge process, and the spectrometer obtains the active particle composition and concentration generated after the gas is ionized by the discharge electrode.

[0021] The schlieren camera in the schlieren system acquires the light beam passing through the sliding arc discharge reactor and generates a schlieren image. Based on the grayscale value variation area and magnitude of the schlieren image, it generates images of the gas heating area and the gas heating intensity.

[0022] Optionally, synchronizing the trigger times of the electrical measurement system, optical measurement system, and schlieren system so that all systems are at the trigger time zero point includes:

[0023] The inherent trigger delays of the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera, and spectrometer are obtained respectively.

[0024] Adjusting the delay setting of the synchronization control trigger will delay the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera and spectrometer with different inherent delays to the same trigger time, so that the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera and spectrometer are at the same trigger time zero point.

[0025] Compared with the prior art, the above-described technical solutions conceived in this invention can achieve the following beneficial effects:

[0026] 1. The present invention provides a device and method for synchronously observing multiple parameters of sliding arc discharge. It employs an electrical measurement system, an optical measurement system, and a schlieren system to observe multiple physical parameters of the sliding arc discharge reaction, including electrical, optical, and thermal parameters. Since each measuring device has a fixed delay time during signal transmission and signal conversion, the delays of four devices—a multi-channel data acquisition instrument for recording voltage and current waveforms, an optical camera for direct optical imaging, a schlieren camera for thermal visualization, and a spectrometer for measuring active particles—are adjusted to have the same trigger time zero point. This ensures that the signals and data observed for each physical parameter are at the same time zero point, facilitating comparative analysis between different data and achieving synchronous observation of multiple physical parameters in situ.

[0027] 2. The present invention provides a device and method for synchronously observing multiple parameters of sliding arc discharge. Since there is a coupling effect of gas heating and ionization luminescence during the sliding arc discharge process, there will be changes in thermal properties and optical properties. The present invention keeps the camera exposure time of the two observation devices consistent, ensuring that the start and end times of the exposure signal of the captured thermodynamic and optical properties are consistent, thereby eliminating the phase difference of the exposure signal and obtaining the synchronous physical characteristics of thermodynamics and optics within the exposure time period.

[0028] 3. The present invention provides a device and method for synchronously observing multiple parameters of sliding arc discharge. The electrode structure of the sliding arc discharge adopts a blade-like structure with the spacing between the electrodes shrinking from top to bottom, so that the arc can be generated at the shortest point between the two electrodes. During the sliding process, the arc is continuously lengthened until it is extinguished, exhibiting good periodicity, which facilitates the observation of its thermal, electrical and optical characteristics.

[0029] 4. The present invention provides a device and method for synchronously observing multiple parameters of sliding arc discharge. It comprehensively considers parameters such as the time scale of arc movement, current and voltage fluctuations, and maximum and minimum values ​​of voltage and current during the periodic discharge of the sliding arc. It selects high-voltage probes and current probes with bandwidth, accuracy, and range suitable for the electrical parameter requirements during the periodic discharge of the sliding arc, and records the discharge voltage and current waveforms during the sliding arc discharge process completely and clearly. The selected schlieren camera has microsecond-level time resolution and micrometer-level spatial resolution, which can effectively capture and distinguish the movement of the sliding arc. The selected optical camera has a spatial resolution of more than 1 millimeter, which can observe the millimeter-level movement of the arc root and the middle arc column at the electrode, and realizes the fine observation of the two effects of gas heating and ionization luminescence during the sliding arc discharge process. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a device for synchronously observing multiple parameters of sliding arc discharge provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the optical measurement system and schlieren system provided in the embodiments of the present invention;

[0032] Figure 3 This is a schematic diagram of the synchronization control triggering device provided in an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the synchronization time principle provided in an embodiment of the present invention.

[0034] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, including: 1, sliding arc discharge reactor; 2, gas cylinder; 3, gas pipe; 4, DC high-voltage power supply; 5, multi-channel data acquisition instrument; 6, high-voltage probe; 7, current probe; 8, high-speed optical camera; 9, spectrometer; 10, LED light source; 11, concave mirror; 12, knife edge; 13, schlieren camera; 14, current-limiting resistor; 15, high-voltage lead; 16, valve; 17, mass flow meter; 18, ground wire; 19, radio frequency coaxial signal line; 20, collimating lens; 21, gas chromatograph; 101, discharge electrode; 102, glass cover. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0036] The following description, in conjunction with a preferred embodiment, illustrates the content involved in the above embodiments.

[0037] like Figure 1 and Figure 2 As shown, a device for synchronously observing multiple parameters of a sliding arc discharge includes: a sliding arc discharge reactor with synchronized triggering time, an electrical measurement system, an optical measurement system, and a schlieren system;

[0038] The sliding arc discharge reactor 1 includes two discharge electrodes 101 and a glass cover 102. The glass cover 102 is connected to the gas cylinder 2 through a gas pipe 3 to transport gas into the sliding arc discharge reactor 1. One discharge electrode is connected to a DC high-voltage power supply 4, and the other discharge electrode is grounded. Under the action of high voltage, the gas medium between the two discharge electrodes is broken down to generate an electric arc. As the electric arc slides along the discharge electrode 101, the electric arc is continuously lengthened until it is extinguished.

[0039] The electrical measurement system includes a high-voltage probe 6 and a current probe 7 connected to a multi-channel data acquisition instrument 5. The high-voltage probe 6 and the current probe 7 are respectively connected to the high-voltage end and the low-voltage end of the discharge electrode 101, and are used to acquire time-varying data of voltage and current during the sliding arc discharge process and display them on the multi-channel data acquisition instrument 5.

[0040] The optical measurement system includes a high-speed optical camera 8 and a spectrometer 9. The horizontal angle α between the high-speed optical camera 8 and the sliding arc discharge reactor 1 is less than 5 degrees. The spectrometer 9 is positioned directly opposite the sliding arc discharge reactor 1. The high-speed optical camera 8 is used to capture the arc emission pattern during the discharge process. The spectrometer 9 acquires the composition and concentration of active particles generated after the gas is ionized at the discharge electrode 101.

[0041] The schlieren system includes an LED light source 10, two concave mirrors 11, a blade 12, and a schlieren camera 13. The LED light source 10 is located at the focal point of the concave mirror M1. The two concave mirrors 11 are arranged on both sides of the sliding arc discharge reactor 1, and the light path passes through the gap between the two discharge electrodes 101. The schlieren camera 13 acquires the light beam that passes sequentially through the concave mirror M1, the sliding arc discharge reactor 1, the concave mirror M2, and the blade 12, and generates a schlieren image. The grayscale value variation area and the magnitude of the variation of the schlieren image respectively reflect the area where the gas is heated in the sliding arc discharge reactor 1 and the temperature gradient change of the gas.

[0042] Optionally, the device further includes a synchronization control trigger (not shown) that adjusts the delays of the multi-channel data acquisition instrument 5, the high-speed optical camera 8, the schlieren camera 13, and the spectrometer 9 to make them all trigger at the same zero point.

[0043] like Figure 3 As shown, before the experiment began, the inherent trigger delays of the electrical measurement system, optical measurement system, and schlieren system were recorded separately. The inherent trigger delays of the multi-channel data acquisition instrument 5, high-speed optical camera 8, schlieren camera 13, and spectrometer 9 were also recorded separately. The delays were adjusted using a synchronization control trigger to synchronize the trigger times of the multi-channel data acquisition instrument 5, high-speed optical camera 8, schlieren camera 13, and spectrometer 9 to the same zero-point trigger time. Specifically, the falling edge signal of the DC high-voltage power supply 4 was used as the trigger signal. After receiving the trigger signal from the DC high-voltage power supply 4, the synchronization control trigger simultaneously triggered the multi-channel data acquisition instrument 5 to acquire signals. The multi-channel data acquisition instrument 5 then issued a trigger signal to trigger the optical camera, schlieren camera 13, and spectrometer 9 to acquire signals, ensuring the trigger times of the electrical measurement system, optical measurement system, and schlieren system were synchronized. The synchronization principle is as follows: Figure 4 As shown, in the experimental platform, each measuring device has a fixed delay time t during signal transmission and signal conversion.i The delays of four devices—a multi-channel data acquisition instrument for recording voltage and current waveforms, an optical camera for direct optical imaging, a schlieren camera for thermal visualization, and a spectrometer for measuring active particles—are adjusted to align with the same trigger time zero point t0. In this embodiment, the multi-channel data acquisition instrument 5 is preferably an oscilloscope.

[0044] The discharge electrode 101 of the sliding arc discharge reactor 1 is connected to a DC high-voltage power supply 4 via a high-voltage lead 15. A current-limiting resistor 14 is installed between the sliding arc discharge reactor 1 and the DC high-voltage power supply 4 to conduct the high voltage generated by the DC high-voltage power supply 4 to the end of the discharge electrode 101 of the sliding arc discharge reactor 1, resulting in discharge. The lower end of the glass outer casing 102 of the sliding arc discharge reactor 1 is connected to a gas cylinder 2 via a gas pipe 3, and a valve 16 is installed on the gas pipe 3 to control the rate at which the gas cylinder 2 delivers gas into the sliding arc discharge reactor 1. Furthermore, the device also includes a mass flow meter 17, which is installed on the gas pipe 3 to monitor and display the input gas flow rate in real time. Since the elongation process of a sliding arc discharge after breakdown initiation is mainly driven by airflow, causing the arc to tend to move towards the gas outlet, the gas flow rate is closely related to the movement of the arc root and arc column. Even small airflow fluctuations can affect the arc's operating state and morphological structure. To accurately control the influence of gas flow rate on the arc's movement along the electrode, a mass flow meter with a resolution of 0.01 L / min is used, which allows for precise calculation of the gas residence time during the sliding arc discharge process. In this embodiment, the glass cover 102 is preferably a quartz glass cover.

[0045] In the electrical measurement system, high-voltage probe 6 is connected to the high-voltage end of discharge electrode 101 via high-voltage lead 15, and current probe 7 is connected to the low-voltage end of discharge electrode 101 via high-voltage lead 15. Current probe 7 is also connected to the ground via ground wire 18, which has good contact with the grounding grid to ensure unobstructed current discharge path. High-voltage probe 6 and current probe 7 are connected to an oscilloscope via radio frequency coaxial signal line 19. Time-varying data of voltage and current during the sliding arc discharge process are acquired through high-voltage probe 6 and current probe 7, and the time-varying waveforms of voltage and current are displayed on the oscilloscope.

[0046] Because high-voltage discharge experiments are somewhat destructive, all equipment must maintain a certain safe insulation distance to prevent discharge behavior between high-voltage equipment. Under this condition, the length of the high-voltage lead 15 should be shortened as much as possible, the inductance of the generating circuit should be reduced, and the voltage measured by the oscilloscope should be kept as equal as possible to the voltage at the end of the sliding arc discharge reactor 1. The length of its high-voltage lead 15 should be less than 1 meter.

[0047] In the optical measurement system, the high-speed optical camera 8 and the sliding arc discharge reactor 1 are located on the same plane, and the horizontal angle α between their positions is less than 5 degrees. This allows for direct observation of the arc morphology of the ionized light emission, enabling precise parallel observation of the optical characteristics of the sliding arc discharge process. Since the periodic movement of the sliding arc occurs on a microsecond timescale, the high-speed optical camera 8, used for direct optical imaging, has a spatial resolution of no less than 1 mm and a temporal resolution of no less than 20 microseconds. The spectrometer 9 is positioned directly opposite the sliding arc discharge reactor 1, with a collimating mirror 20 positioned between them. This collimates the light generated during the sliding arc discharge process before it enters the spectrometer 9, which measures the composition and concentration of active particles generated after gas ionization during the discharge process.

[0048] In the schlieren system, the gas is heated during the sliding arc discharge. The microsecond-level temporal resolution of the thermally visualized schlieren camera 13 is sufficient to effectively capture and distinguish the movement of the sliding arc. Its spatial resolution is no less than 100 micrometers, and its temporal resolution is no less than 20 microseconds. Due to field emission near the cathode and anode, a metal sputtering layer on the scale of hundreds of micrometers will appear, requiring a thermally visualized schlieren system of hundreds of micrometers. Furthermore, to observe the millimeter-level movement of the arc at the arc root and intermediate arc column at the electrodes, the focal length to diameter ratio of the concave mirror 11 in the schlieren system is greater than 8. Because the gas heating is uneven in different areas of the reactor during the sliding arc discharge, and some areas are not fully heated, a schlieren system with a focal length to diameter ratio greater than 8 is needed to sensitively capture temperature gradient changes with a temperature difference exceeding 20 degrees Celsius, which are then converted into grayscale changes in the schlieren image. Therefore, a concave mirror 11 with a focal length to diameter ratio greater than 8 is used to ensure that the schlieren system can sensitively capture the grayscale changes in the schlieren image caused by the heating effect of the arc on the gas. The region where the gas is heated in the sliding arc discharge reactor 1 can be calculated based on the gray value change region of the schlieren image. The temperature gradient change of the gas in the sliding arc discharge reactor 1 can be calculated based on the magnitude of the gray value change of the schlieren image, thereby realizing the image visualization of the gas heating region and gas heating intensity caused by the sliding arc.

[0049] All other observation devices in the system maintain a safe insulating distance from the sliding arc discharge reactor; when observing the sliding arc discharge process, the exposure time of the optical camera and the schlieren camera is consistent, and the high-speed camera (high-speed optical camera and schlieren camera) captures the optical and thermal morphology at the same moment when triggered to take pictures, so as to realize the synchronous and refined observation of the sliding arc discharge process.

[0050] Based on the above embodiments, the output voltage amplitude of the DC high voltage power supply is not less than 30kV / cm*d.

[0051] To ensure that the gas medium at the shortest point between the two electrodes can be broken down during the sliding arc discharge process, forming an initial arc channel, the DC high-voltage power supply used in this embodiment has an output voltage amplitude of no less than 30 kV / cm*d. Since the initial breakdown field strength of the gas medium between the two electrodes during the sliding arc discharge process is approximately 30 kV / cm, according to the formula U = E*d, an output voltage amplitude greater than 30 kV / cm*d from the DC high-voltage power supply can break down the gas medium and form an initial arc channel.

[0052] Furthermore, the voltage amplitude output by the DC high-voltage power supply is not less than 30kV / cm*d, and the bandwidth of the high-voltage probe and the current probe is 50MHz.

[0053] The high-voltage probe used in this embodiment has a bandwidth of 50MHz, a maximum measurement value of not less than 30kV / cm*d, and a voltage measurement accuracy of not less than 10V; the current probe has a bandwidth of 50MHz, a maximum measurement value of not less than 1A, and a current measurement accuracy of not less than 1mA.

[0054] To accurately measure the voltage and current signals changing on a microsecond timescale during the sliding arc discharge process, this invention preferably uses a high-voltage probe and a current probe with the parameters described above. Since the timescale of arc movement during the sliding arc discharge cycle is on the order of microseconds, the resulting voltage and current fluctuations, representing the relevant electrical characteristics, are also on the order of microseconds. Therefore, the bandwidth of both the high-voltage and current probes must be greater than 35MHz to capture the voltage and current signals changing on a microsecond timescale. The maximum voltage during the sliding arc discharge process is 30kV / cm*d. This value must be lower than the maximum voltage measurement value of the high-voltage probe, and the voltage measurement accuracy must be no less than 10V to ensure that the discharge voltage waveform is recorded completely and clearly. The maximum current during the sliding arc discharge process is on the order of hundreds of mA. This value must be lower than the maximum current measurement value of the current probe, and the current measurement accuracy must be no less than 1mA to ensure that the discharge current waveform is recorded completely and clearly.

[0055] Furthermore, the inlet flow rate of the sliding arc discharge reactor is greater than 1 L / min.

[0056] Since the elongation process of a sliding arc discharge after breakdown is mainly driven by the airflow, causing the arc to tend to move towards the gas outlet, if the gas flow rate is less than 1 L / min, the arc will remain stable at the shortest point between the two electrodes and will not be able to slide along the electrodes, resulting in a continuous high-current short circuit and damaging the motor. To ensure that the arc can stably elongate along the electrodes under the action of the airflow during the sliding arc discharge process and avoid damaging the electrodes, it is preferable that the inlet gas flow rate of the sliding arc discharge reactor is greater than 1 L / min.

[0057] Furthermore, the device provided in this embodiment also includes a gas chromatograph 21, and the upper opening of the sliding arc discharge reactor 1 is connected to a gas pipe 3, which is connected to the gas chromatograph 21.

[0058] The plasma generated after the discharge electrode 101 breaks down the gas mixes with the gas in the sliding arc discharge reactor 1 to produce a mixed gas. As the gas is discharged through the gas tube 3, the gas chromatograph 21 performs qualitative and quantitative analysis on the complex mixture of multiple components.

[0059] This invention employs four devices—an oscilloscope for recording voltage and current waveforms, an optical camera for direct optical imaging, a schlieren camera for thermal visualization, and a spectrometer for measuring active particles—to simultaneously observe multiple physical parameters, including electrical, optical, and thermal aspects. Furthermore, the delays of these four devices are adjusted to ensure they all reach the same trigger time zero point, eliminating errors caused by time delays between the electrical, optical, and thermal physical parameters. This ensures that the observed signals and data for each physical parameter are at the same time zero point, facilitating comparative analysis between different data. This invention addresses the technical problem of not being able to simultaneously observe multiple physical quantities of plasma, thus hindering in-situ diagnosis of sliding arc discharge from multiple physical perspectives. It achieves refined spatiotemporal observation of the sliding arc discharge evolution process from multiple electrical, optical, and thermal perspectives, enabling beneficial in-situ diagnosis of multiple plasma parameters during the sliding arc discharge process.

[0060] Based on the above embodiments, the present invention further provides a method for synchronously observing multiple parameters of a sliding arc discharge, applied to the apparatus as described in any one of the first aspects, comprising:

[0061] The electrical measurement system, optical measurement system, and schlieren system are synchronized in terms of trigger time so that all systems are at the trigger time zero point.

[0062] When the sliding arc discharge reactor is energized, the discharge electrodes break down the gas medium between the two electrodes under high voltage to generate an electric arc. As the electric arc slides along the discharge electrodes, it is continuously generated and elongated until it is extinguished.

[0063] The high-voltage probe and current probe in the electrical measurement system record the changes in voltage and current during the sliding arc discharge process, and display the time-varying waveforms of voltage and current in the multi-channel data acquisition instrument.

[0064] The high-speed optical camera in the optical measurement system captures the arc emission pattern during the sliding arc discharge process, and the spectrometer obtains the active particle composition and concentration generated after the gas is ionized by the discharge electrode.

[0065] The schlieren camera in the schlieren system acquires the light beam passing through the sliding arc discharge reactor and generates a schlieren image. Based on the grayscale value variation area and magnitude of the schlieren image, it generates images of the gas heating area and the gas heating intensity.

[0066] Optionally, synchronizing the trigger times of the electrical measurement system, optical measurement system, and schlieren system so that all measurement systems are at the trigger time zero point includes:

[0067] The inherent trigger delays of the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera, and spectrometer are obtained respectively.

[0068] Adjusting the delay setting of the synchronization control trigger will delay the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera and spectrometer with different inherent delays to the same trigger time, so that the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera and spectrometer are at the same trigger time zero point.

[0069] The method for synchronously observing multiple parameters of sliding arc discharge provided in this embodiment of the invention is applied to a device for synchronously observing multiple parameters of sliding arc discharge provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the execution device.

[0070] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for synchronously observing multiple parameters of a sliding arc discharge, characterized in that, include: The system comprises a sliding arc discharge reactor, an electrical measurement system, an optical measurement system, and a schlieren system; the triggering times of the sliding arc discharge reactor, the electrical measurement system, the optical measurement system, and the schlieren system are synchronized. The sliding arc discharge reactor includes two discharge electrodes and a glass cover. The glass cover is connected to a gas cylinder to deliver gas into the sliding arc discharge reactor. One discharge electrode is connected to a DC high-voltage power supply, and the other discharge electrode is grounded. Under the action of high voltage, the gas medium between the two discharge electrodes is broken down to generate an electric arc. As the electric arc slides along the discharge electrode, it continuously elongates until it is extinguished. The electrical measurement system includes a multi-channel data acquisition instrument, a high-voltage probe, and a current probe. The high-voltage probe and the current probe are respectively connected to the high-voltage end and the low-voltage end of the discharge electrode to acquire time-varying data of voltage and current during the sliding arc discharge process and display them on the multi-channel data acquisition instrument. The optical measurement system includes a high-speed optical camera and a spectrometer. The horizontal angle α between the high-speed optical camera and the sliding arc discharge reactor is less than 5 degrees, and the spectrometer is positioned directly opposite the sliding arc discharge reactor. The high-speed optical camera is used to capture the arc emission pattern during the discharge process. The spectrometer acquires the composition and concentration of active particles generated after the gas is ionized by the discharge electrode. The schlieren system includes an LED light source, two concave mirrors, a blade, and a schlieren camera. The LED light source is located at the focal point of concave mirror M1. The two concave mirrors are arranged on both sides of the sliding arc discharge reactor, and the light path passes through the gap between the two discharge electrodes. The schlieren camera acquires the light beam that passes sequentially through concave mirror M1, the sliding arc discharge reactor, concave mirror M2, and the blade, and generates a schlieren image. The grayscale value variation area and magnitude of the schlieren image reflect the area where the gas is heated and the temperature gradient change of the gas in the sliding arc discharge reactor, respectively. The device further includes a synchronization control trigger, which adjusts the delays of the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera, and spectrometer to make them all trigger at the same zero point.

2. The apparatus as claimed in claim 1, characterized in that, The ratio of the focal length to the diameter of the concave mirror in the schlieren system is greater than 8.

3. The apparatus as described in claim 1, characterized in that, The spatial resolution of the schlieren camera is not less than 100 micrometers, and the spatial resolution of the high-speed optical camera is not less than 1 millimeter, and the temporal resolution is not less than 20 microseconds.

4. The apparatus as claimed in claim 1, characterized in that, The discharge electrode structure adopts a blade-shaped inward-retracting electrode structure.

5. The apparatus as claimed in claim 1, characterized in that, The device also includes a mass flow meter, which is installed on the gas pipe and is used to display the gas flow rate input from the gas cylinder to the sliding arc discharge reactor in real time, with a resolution of 0.01 L / min.

6. A method for synchronously observing multiple parameters of a sliding arc discharge, applied to the apparatus as described in any one of claims 1-5, characterized in that, include: The electrical measurement system, optical measurement system, and schlieren system are synchronized in terms of trigger time so that all systems are at the trigger time zero point. When the sliding arc discharge reactor is energized, the discharge electrodes break down the gas medium between the two electrodes under high voltage to generate an electric arc. As the electric arc slides along the discharge electrodes, it is continuously generated and elongated until it is extinguished. The high-voltage probe and current probe in the electrical measurement system record the changes in voltage and current during the sliding arc discharge process, and display the time-varying waveforms of voltage and current in the multi-channel data acquisition instrument. The high-speed optical camera in the optical measurement system captures the arc emission pattern during the sliding arc discharge process, and the spectrometer obtains the active particle composition and concentration generated after the gas is ionized by the discharge electrode. The schlieren camera in the schlieren system acquires the light beam passing through the sliding arc discharge reactor and generates a schlieren image. Based on the grayscale value variation area and the magnitude of the variation in the schlieren image, an image of the gas heating area and an image of the gas heating intensity are generated. The delays of the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera, and spectrometer are adjusted by a synchronous control trigger to make them all trigger at the same zero point.

7. The method as described in claim 6, characterized in that, The step of synchronizing the trigger times of the electrical measurement system, optical measurement system, and schlieren system so that all systems are at the trigger time zero point includes: The inherent trigger delays of the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera, and spectrometer are obtained respectively. Adjusting the delay setting of the synchronization control trigger will delay the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera and spectrometer with different inherent delays to the same trigger time, so that the multi-channel data acquisition instrument, high-speed optical camera, schlieren camera and spectrometer are at the same trigger time zero point.

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