An apparatus and method for enhancing discharge power based on DBD

Abstract

The present invention discloses a device and method for enhancing discharge power based on DBD, mainly including an excitation source, a hot air gun, a gas input port, a dielectric, an inner electrode, an outer electrode, etc. The dielectric is an insulating dielectric tube, and the gas input port is used to supply working gas. It is characterized in that the gas input port is located on the side of the dielectric tube, the gas output port is located at the lower end of the dielectric tube, the inner electrode is tubular and grounded through a wire, and the outer electrode is annular and completely wraps around the dielectric as a high-voltage electrode. The inner electrode is fixed in the center of the dielectric tube by high-temperature resistant silica gel, leaving a certain discharge gap between it and the inner wall. By using the hot air gun to convey hot air to heat the inner electrode to increase the temperature of the electrode, under the condition that other conditions remain unchanged, the breakdown voltage can be effectively reduced, the discharge power of dielectric barrier discharge can be greatly enhanced, the number of discharge channels can be increased, and the discharge becomes stronger.

Description

Technical Field

[0001] The present invention relates to the technical field of plasma, and particularly to a plasma generator based on Dielectric Barrier Discharge (DBD) technology. Specifically, it relates to a coaxial DBD plasma generator. Background Art

[0002] Dielectric Barrier Discharge (DBD) refers to a non-equilibrium gas discharge in which an insulating medium is inserted into the discharge space and a plasma is generated by applying a sufficient alternating voltage. In the discharge region of DBD, a large number of active substances are generated, such as high-energy electrons, free radicals, ions, and excited state molecules, etc., enabling it to achieve higher efficiency in applications such as environmental deodorization, purification of industrial three wastes, surface treatment and modification of materials, and ozone generation. In addition, generating plasma at atmospheric pressure eliminates the need for a vacuum chamber device, reducing the cost of the equipment and having broad application prospects in the industrial field.

[0003] In existing DBD systems, when the voltage is small, the discharge power is small and the power is low, often failing to meet customer requirements in applications. Therefore, there is an urgent need for a DBD device and method that can generate a large discharge power at a lower voltage. Summary of the Invention

[0004] The main object of the present invention is to provide a DBD-based device and method for enhancing discharge power to solve the problems of discharge breakdown and small power of DBD at a lower voltage, thereby enhancing the discharge intensity of DBD.

[0005] To achieve the above object, according to an embodiment of the specific implementation manner of the present invention, a coaxial DBD plasma generator is provided, mainly including a quartz dielectric tube with a gas input port, a copper tube, and a copper ring. The gas input port on the side of the quartz dielectric tube is used to supply the working gas, and the gas flows into the discharge space between the quartz dielectric tube and the copper tube, and the generated plasma flows out from the lower end of the quartz dielectric tube along with the gas.

[0006] Further, the dielectric tube is a quartz dielectric tube or can also be a ceramic dielectric tube. The dielectric tube is fixed between the inner electrode and the outer electrode, and the outer electrode can just wrap the dielectric tube.

[0007] Further, the copper tube and the copper ring can also be replaced with conductive materials such as stainless steel and aluminum.

[0008] Further, the distance between the inner electrode and the inner wall of the dielectric tube can be changed by changing its diameter.

[0009] Further, the hot air gun can be replaced with a heating device such as a heating wire.

[0010] Furthermore, the coaxial DBD plasma generator can be replaced by a needle-plate DBD plasma generator. Advantageous Effects

[0011] When using a hot air gun to heat the copper tube, as the temperature of the copper tube rises, the volume of the gas in the discharge space increases, the mean free path of the discharge particles increases, and the energy obtained by the particles is enhanced. Thus, (1) the breakdown voltage of the DBD plasma generator can be effectively reduced; (2) without changing the voltage and frequency, the discharge power of the coaxial DBD plasma generator can be enhanced by increasing the electrode temperature. Description of the Drawings

[0012] In order to more clearly illustrate the technical solutions in the new embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only one embodiment of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0013] Figure 1 Schematic diagram of the experimental process of the embodiment of the present invention;

[0014] Figure 2 Cross-sectional view of the structure of the coaxial DBD plasma generator according to the embodiment of the present invention;

[0015] Figure 3 Top view of the coaxial DBD plasma generator according to the embodiment of the present invention;

[0016] Figure 4 Graph of the change in breakdown voltage of the coaxial DBD plasma generator according to the embodiment of the present invention when the electrode temperature changes;

[0017] Figure 5 Graph of the change in Lissajous figure of the coaxial DBD plasma generator according to the embodiment of the present invention when the electrode temperature changes.

[0018] In the figure: 1 - hot air gun control console; 2 - hot air gun air outlet; 3 - copper tube; 4 - high-temperature resistant silica gel; 5 - quartz dielectric tube; 6 - copper ring; 7 - gas input port; 8 - non-contact infrared thermometer scanning port; 9 - temperature control console; 10 - excitation source; 11 - capacitor; 12 - current probe; 13 - high-voltage probe; 14 - low-voltage probe; 15 - digital oscilloscope. Detailed Embodiments

[0019] To enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solutions in the specific embodiments and the accompanying drawings of the present invention. Obviously, the described embodiments are only one embodiment of the present invention patent, rather than all embodiments. Based on the specific embodiments and examples of the present invention patent, all other embodiments and examples obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention patent.

[0020] Embodiment

[0021] As Figure 1 shown, the devices and equipment required in this example include a hot air gun 1, 2, a non-contact infrared thermometer 8, 9, a copper tube 3, a quartz dielectric tube 5, a copper ring 6, an excitation source 10, a high-voltage probe 13, a low-voltage probe 14, a current probe 12, a digital oscilloscope 15, etc.

[0022] In this example, the excitation source 10 uses a high-voltage AC power supply, the high-voltage end of which is connected to the copper ring 6 through a wire, the copper tube 3 is connected to the grounding end of the excitation source through a wire, there is a quartz dielectric tube 5 between the copper tube 3 and the copper ring 6, and the copper ring 6 can just completely wrap the quartz dielectric tube 5.

[0023] Figure 1 The gas input port 7 in is connected to a gas source through a pipeline to supply working gas to the coaxial DBD plasma generator.

[0024] Under the action of the excitation source 10, a certain working voltage can be established between the copper tube 3 and the copper ring 6.

[0025] In this example, the quartz dielectric tube 5 is located between the copper tube 3 and the copper ring 6, which can effectively limit the infinite growth of the discharge current, avoid arc discharge or spark discharge under high pressure, play a current-limiting role, and improve the discharge stability and operation efficiency.

[0026] Figure 2 is the front view of the coaxial DBD plasma generator, Figure 3It is a top view. a is the inner diameter of the copper tube, which is fixed at the center of the quartz dielectric tube 5 through the high-temperature resistant silica gel 4. By changing the inner diameter a of the copper tube, the discharge gap d can be changed. b is the diameter of the gas input port, and c is the distance from the gas input port to the copper ring. Generally, it is required that c > 2b, which can reduce the influence on discharge caused by uneven gas input. e is the width of the copper ring. In this example, the three channels of the digital oscilloscope 15 are respectively connected to the current probe 12, the high-voltage probe 13, and the low-voltage probe 14. The current probe 12 is used to measure the current in the circuit, the high-voltage probe 13 is used to measure the applied voltage of the excitation source 10, and the low-voltage probe 14 is used to measure the voltage on the capacitor 11 to obtain the transported charge. The electrical signals collected by the three channels will be displayed on the digital oscilloscope 15. By processing the electrical signals collected by the high-voltage probe 13 and the low-voltage probe 14 and using them as the output x-axis and y-axis respectively, a Lissajous figure can be obtained. By comparing the area of the Lissajous figure, the corresponding discharge power can be calculated.

[0027] For the embodiment, Figure 4 It shows the variation law of the breakdown voltage of the coaxial DBD plasma generator when the discharge gap d = 1.5 mm, the diameter b of the gas input port 7 = 1 cm, the width e of the copper ring = 1 cm, and dry air is introduced, by changing the temperature of the copper tube electrode. It is found that as the electrode temperature continuously increases, the breakdown voltage of the coaxial DBD plasma generator continuously decreases.

[0028] For the embodiment, Figure 5 It shows the variation law of the Lissajous figure when the discharge gap d = 1.5 mm, the diameter b of the gas input port 7 = 1 cm, the width e of the copper ring = 1 cm, and dry air is introduced, by changing the temperature of the copper tube electrode. It is found that after effectively increasing the electrode temperature, the area of the Lissajous figure continuously becomes larger, and the corresponding discharge power of the coaxial DBD plasma generator also continuously increases.

[0029] The coaxial DBD plasma generator of the embodiment of the present invention reduces the breakdown voltage and enhances the discharge power by changing the temperature of the copper tube, and both the system efficiency and stability are improved. Further, by adopting the method of adjusting the temperatures of the copper tube and the copper ring, it can very conveniently adapt to various different working environments, greatly improving the applicable range of the system.

[0030] The remaining structures and beneficial effects are basically the same as those of this embodiment, and will not be elaborated here.

[0031] The above are only the preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention are all included within the protection scope of the present invention.

Claims

1. A coaxial DBD plasma generator device heated by electrodes, comprising a gas input port, a quartz dielectric tube, a copper tube, a copper ring, a non-contact infrared thermometer, a hot air gun, an excitation source, and a temperature console, characterized in that: The copper ring completely wraps the quartz dielectric tube, and the quartz dielectric tube is located between the copper tube and the copper ring. The gas input port is located on the side of the quartz dielectric tube. The working gas enters the discharge gap between the quartz dielectric tube and the copper tube through the input port. The hot air gun heats the copper tube by adjusting the temperature through the temperature control console, and the non-contact infrared thermometer collects the temperature of the copper tube through infrared induction.

2. The coaxial DBD plasma generator device with electrode heating as described in claim 1, characterized in that: The materials of the copper tube and the copper ring are replaced with stainless steel or aluminum; the quartz dielectric tube is replaced with a ceramic dielectric tube.

3. The coaxial DBD plasma generator device with electrode heating according to claim 1, characterized in that: The scanning port of the non-contact infrared temperature measurement is perpendicular to the copper tube.

4. The coaxial DBD plasma generator device with electrode heating as claimed in claim 1, wherein: The hot air outlet of the hot air gun conveys hot air directly above the copper tube, so that the electrode is evenly heated, and the temperature of the copper tube is controlled at 25°C, 45°C, 65°C, and 85°C.

5. The coaxial DBD plasma generator device with electrode heating according to claim 1, characterized in that: The copper tube is fixed in the center of the quartz dielectric tube by high-temperature resistant silica gel.

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