Dielectric barrier discharge device and method of operation thereof

Abstract

The application provides a dielectric barrier discharge device and a working method thereof, and belongs to the technical field of plasma. The dielectric barrier discharge device comprises a dielectric tube, a high-voltage electrode and a thermal deformation structure. The dielectric tube is sleeved outside the high-voltage electrode, and a gap is formed between the high-voltage electrode and the dielectric tube. The thermal deformation structure is trumpet-shaped, the large end of the thermal deformation structure is connected with one end of the dielectric tube close to the air inlet direction, and the small end of the thermal deformation structure extends into the inside of the dielectric tube. When the temperature in the dielectric tube rises, the small end of the thermal deformation structure is used for bending towards the direction away from the high-voltage electrode. The dielectric barrier discharge device provided by the application can control the flow rate of CO2 gas by using the thermal deformation structure arranged at one end of the dielectric tube, thereby realizing self-regulation of the temperature and improving the conversion efficiency of CO2 gas.

Description

Technical Field

[0001] This invention relates to the field of plasma technology, and more specifically, to a dielectric barrier discharge device and its operating method. Background Technology

[0002] Human survival and development are inseparable from natural resources. Especially since the Industrial Revolution, the application of fossil fuel resources has greatly propelled human societal progress. However, the combustion of fossil fuels results in the emission of large amounts of the greenhouse gas CO2 into the environment, causing serious problems such as global warming and climate change. To address these severe environmental and social issues, efforts are currently underway to reduce CO2 emissions and utilize its resources.

[0003] Traditional CO2 thermal decomposition methods not only require harsh reaction conditions but also have low energy efficiency, necessitating the development of novel technologies to improve CO2 conversion efficiency. In recent years, several conversion methods have been developed, including photocatalysis, electrocatalysis, photoelectric reduction, and plasma conversion, all demonstrating promising application prospects. Among these, plasma conversion, due to its high catalytic efficiency and mild reaction conditions, is considered a strong alternative to pyrolysis.

[0004] Plasma is rich in highly reactive substances such as various ions, electrons, excited-state atoms and molecules, and free radicals. Dielectric barrier discharge (DPD) devices are simple in structure, easy to manufacture, and produce uniform and stable discharges, enabling continuous processing of large quantities of gas and showing promising application prospects. However, because DPD devices release a large amount of heat during the discharge conversion process, the gas temperature within the plasma gap of the DPD device increases, thus limiting the CO2 conversion efficiency to some extent. Summary of the Invention

[0005] The problem solved by this invention is to provide a dielectric barrier discharge device that can self-regulate temperature, thereby enabling real-time control of the gas temperature of the plasma in the gas gap during discharge and maintaining a high CO2 conversion efficiency during the discharge process.

[0006] To address the above problems, the present invention provides a dielectric barrier discharge device, comprising a dielectric tube, a high-voltage electrode, and a thermosensitive deformation structure;

[0007] The dielectric tube is sleeved outside the high-voltage electrode. The length of the high-voltage electrode is greater than the length of the dielectric tube, and the high-voltage electrode and the dielectric tube are coaxially arranged. The outer diameter of the high-voltage electrode is smaller than the inner diameter of the dielectric tube, so as to form a gap between the high-voltage electrode and the dielectric tube.

[0008] The thermosensitive deformation structure is trumpet-shaped, with the outer diameter of the large end of the thermosensitive deformation structure being the same as the inner diameter of the dielectric tube, and the inner diameter of the small end of the thermosensitive deformation structure being larger than the outer diameter of the high-voltage electrode.

[0009] The large end of the thermosensitive deformation structure is connected to the end of the medium tube near the air inlet direction, and the small end of the thermosensitive deformation structure extends into the interior of the medium tube;

[0010] When the temperature inside the dielectric tube rises, the small end of the thermosensitive deformation structure is bent toward the direction away from the high-voltage electrode.

[0011] Preferably, the dielectric barrier discharge device further includes an inlet chamber, an outlet chamber, and a grounding electrode;

[0012] One end of the medium tube extends into the air inlet chamber and the other end extends into the air outlet chamber. The air inlet chamber is provided with an air inlet and the air outlet chamber is provided with an air outlet.

[0013] The high-voltage electrode passes sequentially through the air inlet chamber, the medium pipe, and the air outlet chamber;

[0014] The grounding electrode is covered by the dielectric tube, and the inner diameter of the grounding electrode is the same as the outer diameter of the dielectric tube. The gap at the corresponding position of the grounding electrode coverage area forms a discharge gas gap.

[0015] Preferably, the thermosensitive deformation structure is made of a thermo-bimetallic material.

[0016] Preferably, the linear temperature range of the thermal bimetallic material includes 300-575K.

[0017] Preferably, on the vertical projection plane, the ratio of the wall length of the thermosensitive deformation structure to the width of the discharge gap is 1:1, and the angle between the outer wall of the thermosensitive deformation structure and the adjacent inner wall of the dielectric tube is 30°, wherein the wall length is the distance between the large end and the small end.

[0018] Preferably, the dielectric tube comprises a quartz dielectric tube with an inner diameter of 6 mm and a wall thickness of 1 mm.

[0019] Preferably, the high-voltage electrode comprises a stainless steel rod with a length of 18cm and an outer diameter of 2mm.

[0020] Preferably, the grounding electrode is wrapped around the dielectric tube, the grounding electrode comprises aluminum foil, and the length of the grounding electrode wrapping area is 10 cm.

[0021] This invention achieves self-regulation of the temperature within the dielectric tube by incorporating a thermosensitive deformable structure in the gap between the dielectric tube and the high-voltage electrode near the inlet end. The flow rate of CO2 gas into the dielectric tube is controlled by the shape of this structure at different temperatures, ensuring efficient CO2 gas conversion. Specifically, initially, the thermosensitive deformable structure is not bent by heat, resulting in significant CO2 gas impediment and a low CO2 gas flow rate, thus guaranteeing high conversion efficiency. When the reaction generates a large amount of heat and the temperature inside the dielectric tube increases, the thermosensitive deformable structure bends, reducing its CO2 impediment and increasing the CO2 gas flow rate. The gas carries heat away from the dielectric tube, lowering the temperature. The thermosensitive deformable structure gradually returns to its original shape until the temperature stabilizes. It then regains its pre-deformation shape, further increasing its CO2 impediment and improving CO2 gas conversion efficiency. This cycle repeats continuously, thus achieving self-regulation of the temperature. The dielectric barrier discharge device provided by the present invention can control the flow rate of CO2 gas by using a thermosensitive deformation structure set at one end of the dielectric tube, thereby achieving self-regulation of temperature and improving the conversion efficiency of CO2 gas.

[0022] The present invention also provides a method for operating a dielectric barrier discharge device, based on the dielectric barrier discharge device described above, comprising the following steps:

[0023] Step S1: Introduce CO2 gas into the dielectric barrier discharge device, connect the high-voltage electrode to the power supply, and generate plasma in the gap.

[0024] Step S2: As heat is released during plasma generation, the temperature inside the dielectric tube rises, the thermosensitive deformation structure deforms due to heat, reducing its obstruction effect on the airflow, thereby increasing the flow rate of CO2 gas in the dielectric tube and carrying away the heat in the dielectric tube.

[0025] Step S3: When the temperature inside the medium tube decreases, the thermosensitive deformation structure recovers, thereby reducing the flow rate of the CO2 gas in the medium tube.

[0026] Preferably, in step S1, the flow rate of the CO2 gas in the gap is less than 100 sccm.

[0027] The working method of the dielectric barrier discharge device provided by the present invention has the same beneficial effects as the prior art, and will not be repeated here. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the dielectric barrier discharge device in its initial state according to an embodiment of the present invention;

[0029] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0030] Figure 3 This is a schematic diagram of the dielectric barrier discharge device under thermal deformation in an embodiment of the present invention;

[0031] Figure 4 for Figure 2 Enlarged view of point B in the middle;

[0032] Figure 5 This is a schematic flowchart illustrating the operation of the dielectric barrier discharge device in an embodiment of the present invention.

[0033] Figure 6 A simulation comparison of the cooling effects of different devices.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Inlet chamber; 11. Inlet port; 2. Medium pipe; 3. Outlet chamber; 31. Outlet port; 4. High voltage electrode; 5. Grounding electrode; 6. Thermosensitive deformation structure. Detailed Implementation

[0036] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below.

[0037] It should be noted that, unless otherwise specified, the features in the embodiments of this invention can be combined with each other. The terms "comprising," "including," "containing," and "having" are non-limiting, meaning that other steps and other components that do not affect the results can be added. The above terms cover the terms "composed of" and "substantially composed of." Unless otherwise specified, the materials, equipment, and reagents are commercially available.

[0038] Furthermore, although specific embodiments have been described herein, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways not used in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

[0039] During the operation of a dielectric barrier discharge (DBD) device, the increased temperature of the plasma gas within the discharge gap significantly reduces the forward reaction rate, thus drastically limiting the CO2 gas conversion efficiency. Currently, common temperature control methods for DBD devices involve externally placing condensers or fans in the discharge region to promote reactor heat dissipation and achieve cooling. However, due to the low thermal conductivity of the plasma within the discharge gap, these methods not only offer limited control over the plasma gas temperature but also cause a temperature gradient within the discharge gap, resulting in significant limitations in temperature control effectiveness.

[0040] The conversion efficiency of CO2 gas and the heat absorption and release capacity of plasma in the discharge gap vary under different CO2 gas flow rates in the dielectric barrier discharge device. Specifically, when the CO2 gas flow rate is low, the CO2 gas has a high conversion efficiency, but the reaction releases a large amount of heat. When the CO2 gas flow rate is high, the temperature of the plasma generated in the dielectric barrier discharge device decreases. This is mainly because the heat released by the reaction in the plasma decreases, and the increased flow rate carries away more heat, which to some extent leads to a decrease in the CO2 gas conversion efficiency.

[0041] like Figures 1-4 As shown, an embodiment of the present invention provides a dielectric barrier discharge device, including a dielectric tube 2, a high-voltage electrode 4, and a thermosensitive deformation structure 6;

[0042] The dielectric tube 2 is sleeved outside the high-voltage electrode 4. The length of the high-voltage electrode 4 is greater than the length of the dielectric tube 2, and the high-voltage electrode 4 and the dielectric tube 2 are coaxially arranged. The outer diameter of the high-voltage electrode 4 is smaller than the inner diameter of the dielectric tube 2, so as to form a gap between the high-voltage electrode 4 and the dielectric tube 2.

[0043] The thermosensitive deformation structure 6 is trumpet-shaped. The outer diameter of the large end of the thermosensitive deformation structure 6 is the same as the inner diameter of the dielectric tube 2, and the inner diameter of the small end of the thermosensitive deformation structure is larger than the outer diameter of the high voltage electrode 4.

[0044] The large end of the thermosensitive deformation structure 6 is connected to the end of the medium pipe 2 near the air inlet direction, and the small end of the thermosensitive deformation structure 6 extends into the interior of the medium pipe 2.

[0045] When the temperature inside the dielectric tube 2 rises, the small end of the thermosensitive deformation structure 6 is bent toward the direction away from the high-voltage electrode 4.

[0046] This invention, in its embodiment, incorporates a thermosensitive deformable structure 6 in the gap between the dielectric tube 2 and the high-voltage electrode 4 near the inlet end. The flow rate of CO2 gas flowing into the dielectric tube 2 is controlled by the shape of the thermosensitive deformable structure 6 at different temperatures, thus achieving self-regulation of the temperature within the dielectric tube 2 and ensuring the conversion efficiency of the CO2 gas. Specifically, in the initial state, the thermosensitive deformable structure 6 is not bent by heat, resulting in a significant barrier effect against CO2 gas and a low flow rate of CO2 gas into the dielectric tube 2, ensuring high conversion efficiency. When the reaction generates a large amount of heat and the temperature inside the dielectric tube 2 increases, the thermosensitive deformable structure 6 bends due to heat, reducing its barrier effect against CO2. The flow rate of CO2 gas into the dielectric tube 2 increases, and the gas carries heat away from the dielectric tube 2, lowering the temperature inside the dielectric tube 2. The thermosensitive deformable structure 6 gradually recovers its original shape until the temperature inside the dielectric tube 2 returns to its initial state and stabilizes. At this point, the thermosensitive deformable structure 6 returns to its original shape, further increasing its barrier effect against CO2 and improving the conversion efficiency of the CO2 gas within the dielectric tube 2. This cycle repeats continuously, thereby achieving self-regulation of the temperature. The dielectric barrier discharge device provided in this embodiment of the invention can control the flow rate of CO2 gas by using the thermosensitive deformation structure 6 set at one end of the dielectric tube 2, thereby achieving self-regulation of temperature and improving the conversion efficiency of CO2 gas.

[0047] like Figure 1-4 As shown, in one embodiment, the dielectric barrier discharge device further includes an inlet chamber 1, an outlet chamber 3, and a grounding electrode 5;

[0048] One end of the medium tube 2 extends into the air inlet chamber 1, and the other end extends into the air outlet chamber 3. The air inlet chamber 1 is provided with an air inlet 11, and the air outlet chamber 3 is provided with an air outlet 31.

[0049] The high-voltage electrode 4 passes sequentially through the air inlet chamber 1, the medium pipe 2, and the air outlet chamber 3;

[0050] The grounding electrode 5 covers the outside of the dielectric tube 2. The inner diameter of the grounding electrode 5 is the same as the outer diameter of the dielectric tube 2. The gap at the corresponding position of the area covered by the grounding electrode 5 forms a discharge gas gap.

[0051] like Figure 1 and Figure 3 As shown, the high-voltage electrode 4 passes through the air inlet chamber 1, the medium pipe 2 and the air outlet chamber 3 in sequence, and the two ends of the high-voltage electrode 4 are located outside the air inlet chamber 1 and the air outlet chamber 3, which facilitates the connection of the high-voltage electrode 4 to the power supply.

[0052] Figure 1 and Figure 2 This is a schematic diagram of the dielectric barrier power generation device in its initial state. At this time, the thermosensitive deformation structure 6 has not undergone bending deformation, and its barrier effect on the CO2 gas entering the dielectric pipe 2 is relatively large. Figure 3 and Figure 4 This is a schematic diagram of the dielectric barrier power generation device after thermal deformation. At this time, the thermally sensitive deformation structure 6 is bent and deformed by heat, which reduces its barrier effect on CO2 gas entering the dielectric pipe 2.

[0053] In one embodiment, the thermosensitive deformation structure 6 is made of a thermo-bimetallic material.

[0054] Thermo-bimetallic materials are composed of two or more metals or alloys with different coefficients of thermal expansion, and have the function of deforming with temperature changes.

[0055] Specifically, the linear temperature range of the thermal bimetallic material includes 300-575K.

[0056] It should be noted that K represents Kelvin, and the range of 300-575K corresponds to the range of 26.85-301.5℃. The linear temperature range of the thermal metal material includes 300-575K, indicating that the linear temperature range of the thermistor material is greater than or equal to 300-575K.

[0057] The linear temperature range indicates that the bending of the bimetallic material changes linearly with temperature within this range. When the dielectric tube 2 is a quartz dielectric tube, the typical gas temperature range inside the dielectric tube 2 is 300-473K, while when the dielectric tube 2 is an alumina dielectric tube, the typical gas temperature range inside the dielectric tube 2 is 300-573K. Selecting a bimetallic material with a linear temperature range including 300-573K ensures that the thermosensitive deformation structure 6 can change linearly within the typical gas temperature range.

[0058] For example, the thermal bimetallic material includes 5J1970 material. The linear temperature range of 5J1970 material is -20 to 350°C (253.15-623.15K), which meets the requirements of the embodiments of the present invention.

[0059] It should be noted that the 5J1970 material is only used as an exemplary illustration of the embodiments of the present invention and is not intended to limit the scope of protection of the present invention. For example, the embodiments of the present invention may also use the 5J2370 material (linear temperature range of -20 to 380°C).

[0060] In one embodiment, on the vertical projection plane, the ratio of the wall length of the thermosensitive deformation structure 6 to the width of the discharge gap is 1:1, and the angle between the outer wall of the thermosensitive deformation structure 6 and the adjacent inner wall of the dielectric tube 2 is 30°, wherein the wall length is the distance between the large end and the small end.

[0061] It should be noted that the wall length of the thermosensitive deformable structure 6 refers to the distance between the large end and the small end of the thermosensitive deformable structure 6 when it is not bent.

[0062] By setting the ratio of the wall length of the thermosensitive deformation structure 6 to the width of the discharge gap to 1:1, and the angle between the outer wall of the thermosensitive deformation structure 6 and the adjacent inner wall of the dielectric tube 2 to 30°, the influence of the bending deformation of the thermosensitive deformation structure 6 on the CO2 gas flow rate can be improved, thus achieving better flow rate control.

[0063] The size of the dielectric barrier discharge device can be set as needed, and the materials of each component in the dielectric barrier discharge device can also be selected as needed.

[0064] In one embodiment, the dielectric tube 2 includes a quartz dielectric tube with an inner diameter of 6 mm and a wall thickness of 1 mm.

[0065] Quartz dielectric tubes have advantages such as good pressure resistance, good high-frequency characteristics, and stable thermal performance. Their dimensions can be set as follows: inner diameter of 6mm and wall thickness of 1mm.

[0066] Accordingly, the high-voltage electrode 4 includes a stainless steel rod with a length of 18cm and an outer diameter of 2mm.

[0067] In other words, the high-voltage electrode 4 can be made of stainless steel, and it is rod-shaped with a length of 18cm and an outer diameter of 2mm. In the dielectric barrier discharge device, the high-voltage electrode 4 and the quartz dielectric tube are coaxially arranged, and a gap with a width of 2mm is formed between the high-voltage electrode 4 and the inner wall of the quartz dielectric tube.

[0068] Preferably, the grounding electrode 5 is wrapped around the dielectric tube 2, and the grounding electrode 5 comprises aluminum foil. The length of the wrapped area of ​​the grounding electrode 5 is 10 cm. The gap in the area wrapped by the grounding electrode 5 on the dielectric tube 2 forms a discharge gap. The length of the wrapped area of ​​the grounding electrode 5 determines the length of the discharge gap. When the length of the wrapped area is 10 cm, a high CO2 conversion efficiency can be guaranteed.

[0069] This invention also provides a method for operating a dielectric barrier discharge device, based on the dielectric barrier discharge device described above, such as... Figure 5 As shown, it includes the following steps:

[0070] Step S1: Introduce CO2 gas into the dielectric barrier discharge device, connect the high-voltage electrode 4 to the power supply, and generate plasma in the gap.

[0071] Step S2: As heat is released during plasma generation, the temperature inside the dielectric tube 2 rises, and the heat-sensitive deformation structure 6 deforms due to heat, reducing its obstruction effect on the airflow and increasing the flow rate of the CO2 gas in the dielectric tube 2, thus carrying away the heat in the dielectric tube 2.

[0072] Step S3: When the temperature inside the medium tube 2 decreases, the thermosensitive deformation structure 6 recovers, thereby reducing the flow rate of the CO2 gas in the medium tube 2.

[0073] The working method of the dielectric barrier discharge device provided in this embodiment of the invention has the same beneficial effects on the prior art as the dielectric barrier discharge device, and will not be repeated here.

[0074] In one embodiment, in step S1, the flow rate of the CO2 gas in the gap is less than 100 sccm.

[0075] When the flow rate of CO2 gas in the gap is less than 100 sccm, the CO2 gas in medium tube 2 can maintain a high conversion efficiency.

[0076] like Figure 6 As shown, a two-dimensional finite element model was established for a dielectric barrier discharge device with a thermosensitive deformation structure. Figure 6 (The solid line portion) and dielectric barrier discharge devices without thermal deformation structures ( Figure 6 The simulation results (shown as dashed lines in the image) demonstrate the effect of temperature regulation in the dielectric barrier discharge device without a thermosensitive deformation structure. The temperature rises linearly within the discharge region (0-0.1m) and gradually stabilizes after leaving the discharge region. In contrast, the temperature of the dielectric barrier discharge device with a thermosensitive deformation structure fluctuates within the discharge region. Although the overall trend is still a gradual increase followed by stabilization after leaving the discharge region, the temperature remains relatively low. This indicates that the thermosensitive deformation structure in the dielectric barrier discharge device provided by this embodiment of the invention has a good effect on temperature self-regulation.

[0077] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A dielectric barrier discharge device, characterized in that, It includes a dielectric tube (2), a high-voltage electrode (4), and a thermo-deformable structure (6); The dielectric tube (2) is sleeved outside the high voltage electrode (4). The length of the high voltage electrode (4) is greater than the length of the dielectric tube (2), and the high voltage electrode (4) and the dielectric tube (2) are coaxially arranged. The outer diameter of the high voltage electrode (4) is smaller than the inner diameter of the dielectric tube (2) to form a gap between the high voltage electrode (4) and the dielectric tube (2). The thermosensitive deformation structure (6) is trumpet-shaped. The outer diameter of the large end of the thermosensitive deformation structure (6) is the same as the inner diameter of the dielectric tube (2), and the inner diameter of the small end of the thermosensitive deformation structure (6) is larger than the outer diameter of the high voltage electrode (4). The large end of the thermosensitive deformation structure (6) is connected to the end of the medium tube (2) near the air intake direction, and the small end of the thermosensitive deformation structure (6) extends into the inside of the medium tube (2). When the temperature inside the dielectric tube (2) rises, the small end of the thermosensitive deformation structure (6) is bent toward the direction away from the high voltage electrode (4).

2. The dielectric barrier discharge device according to claim 1, characterized in that, It also includes an air inlet chamber (1), an air outlet chamber (3), and a grounding electrode (5); One end of the medium tube (2) extends into the air inlet chamber (1) and the other end extends into the air outlet chamber (3). The air inlet chamber (1) is provided with an air inlet (11) and the air outlet chamber (3) is provided with an air outlet (31). The high-voltage electrode (4) passes through the air inlet chamber (1), the medium tube (2) and the air outlet chamber (3) in sequence. The grounding electrode (5) covers the outside of the dielectric tube (2), and the inner diameter of the grounding electrode (5) is the same as the outer diameter of the dielectric tube (2). The gap at the corresponding position of the area covered by the grounding electrode (5) forms a discharge gas gap.

3. The dielectric barrier discharge device according to claim 1, characterized in that, The thermosensitive deformation structure (6) is made of thermobimetallic material.

4. The dielectric barrier discharge device according to claim 3, characterized in that, The linear temperature range of the thermal bimetallic material is 300-575K.

5. The dielectric barrier discharge device according to claim 2, characterized in that, On the vertical projection plane, the ratio of the wall length of the thermosensitive deformation structure (6) to the width of the discharge gas gap is 1:1, and the angle between the outer wall of the thermosensitive deformation structure (6) and the adjacent inner wall of the dielectric tube (2) is 30°, wherein the wall length is the distance between the large end and the small end.

6. The dielectric barrier discharge device according to claim 2, characterized in that, The medium tube (2) includes a quartz medium tube with an inner diameter of 6 mm and a wall thickness of 1 mm.

7. The dielectric barrier discharge device according to claim 6, characterized in that, The high-voltage electrode (4) includes a stainless steel rod with a length of 18cm and an outer diameter of 2mm.

8. The dielectric barrier discharge device according to claim 6, characterized in that, The grounding electrode (5) is wrapped around the dielectric tube (2), the grounding electrode (5) includes aluminum foil, and the length of the area covered by the grounding electrode (5) is 10cm.

9. A method for operating a dielectric barrier discharge device, based on the dielectric barrier discharge device as described in any one of claims 1-8, characterized in that, Includes the following steps: Step S1: Pass CO2 gas into the dielectric barrier discharge device, connect the high voltage electrode (4) to the power supply, and generate plasma in the gap; Step S2: As heat is released during plasma generation, the temperature inside the dielectric tube (2) rises, the heat-sensitive deformation structure (6) deforms due to heat, reducing the obstruction effect on the airflow, increasing the flow rate of the CO2 gas in the dielectric tube (2), and carrying away the heat in the dielectric tube (2). Step S3: When the temperature inside the medium tube (2) decreases, the thermosensitive deformation structure (6) recovers, thereby reducing the flow rate of the CO2 gas in the medium tube (2).

10. The operating method of the dielectric barrier discharge device according to claim 9, characterized in that, In step S1, the flow rate of the CO2 gas in the gap is less than 100 sccm.

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