Needle ring electrode parameter optimization method and system
By simulated and analyzed and optimized electrode parameters in the needle ring plasma jet structure, the problems of high excitation voltage and large energy consumption in the existing technology are solved, and the effect of reducing energy consumption is achieved.
Patent Information
- Application Number
- CN202411532792.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-03-18
AI Technical Summary
The existing needle ring plasma jet structure requires a high external excitation voltage and a large energy consumption.
By building the needle ring plasma jet structure under the electrostatic field, the parameter vector to be optimized is determined, the electric field intensity is simulated, and the numerical value of the parameter to be optimized corresponding to the target electric field intensity is determined based on the fitting function to optimize the electrode parameters.
Effectively reduce the applied excitation voltage required for plasma generation, thereby reducing the energy consumption of the excitation source.
Smart Images
Figure CN119647053A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of electrode parameter optimization, and in particular to a needle ring electrode parameter optimization method and system. Background Art
[0002] Atmospheric pressure plasma jet is a new type of high-efficiency plasma generation method. It is generally generated in a cavity filled with air or working gas (mainly inert gas) at a standard atmospheric pressure or close to standard atmospheric pressure. The main forms of plasma discharge under atmospheric pressure are corona, dielectric barrier, arc and spark discharge. Among them, corona discharge is a typical extremely non-uniform electric field discharge, which is generated in places with a large radius of curvature, such as the field strength around the needle electrode is very large, and local breakdown will occur to form a corona.
[0003] Atmospheric pressure plasma jet modification can effectively improve the physical and chemical properties and electrical properties of the material surface. The plasma jet device, as one of the core equipment, determines the feasibility of practical application and the level of energy consumption. However, the existing needle-ring plasma jet structure requires a high external excitation voltage and consumes a lot of energy. Summary of the invention
[0004] In view of the above problems existing in the prior art, the present invention is proposed.
[0005] Therefore, the problem to be solved by the present invention is that the existing needle ring plasma jet structure requires a relatively high external excitation voltage and consumes a relatively large amount of energy.
[0006] To solve the above technical problems, the present invention provides the following technical solutions: a needle ring electrode parameter optimization method, which includes building a needle ring plasma jet structure under an electrostatic field; determining a parameter vector to be optimized of the needle ring plasma jet structure; using the parameter to be optimized as a variable, simulating and analyzing the electric field strength of the needle ring plasma jet structure; repeating the previous step to obtain a fitting function between each parameter to be optimized and the electric field strength; and determining the value of the parameter to be optimized corresponding to the target electric field strength based on the fitting function.
[0007] As a preferred solution of the needle-ring electrode parameter optimization method of the present invention, the needle-ring plasma jet structure includes a dielectric tube, a needle electrode arranged inside the dielectric tube and coaxial therewith, and a ring electrode arranged around the outside of the dielectric tube, and the ring electrode is grounded.
[0008] As a preferred embodiment of the needle-ring electrode parameter optimization method of the present invention, the parameter vector to be optimized includes but is not limited to the diameter of the needle electrode, the radius of curvature of the needle electrode tip, the relative distance between the needle electrode and the ring electrode, and the thickness and diameter of the dielectric tube.
[0009] As a preferred solution of the needle ring electrode parameter optimization method of the present invention, when one of the parameters to be optimized is used as a variable, the other parameters to be optimized are kept as fixed quantities.
[0010] As a preferred scheme of the needle ring electrode parameter optimization method described in the present invention, the step of obtaining the fitting function of each parameter to be optimized and the electric field strength includes: setting the initial value of the parameter to be optimized; recording the electric field strength output by the needle ring plasma jet structure under the initial value of the parameter to be optimized; updating the value of the parameter to be optimized and recording the electric field strength output by the needle ring plasma jet structure under the corresponding value; repeating the previous step to construct a fitting function of the parameter to be optimized and the electric field strength output by the needle ring plasma jet structure.
[0011] As a preferred solution of the needle-ring electrode parameter optimization method of the present invention, the material of the needle electrode and the ring electrode is copper.
[0012] As a preferred solution of the needle ring electrode parameter optimization method of the present invention, the material of the dielectric tube is quartz glass.
[0013] Another object of the present invention is to provide a needle ring electrode parameter optimization system, which is suitable for the above-mentioned needle ring electrode parameter optimization method.
[0014] The beneficial effects of the present invention are as follows: by analyzing the electric field distribution of the plasma jet device and simulating and optimizing the electrode parameters, the present invention can effectively reduce the external excitation voltage required for plasma generation, thereby reducing the energy consumption of the excitation source. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0016] Figure 1 Schematic diagram of the needle-ring plasma jet structure.
[0017] Figure 2 The overall perspective and local magnified perspective of the potential distribution of the needle-ring electrode structure.
[0018] Figure 3 The volume perspective and local magnified perspective of the electric field intensity cloud map of the needle-ring electrode structure.
[0019] Figure 4 is the effect of needle electrode diameter on electric field distribution; Figure 4(a) is the relationship between the electric field intensity and the needle diameter, Figure 4 (b) is a schematic diagram of the change in needle diameter.
[0020] Figure 5 This is the relationship between the tip curvature radius and the electric field strength.
[0021] Figure 6 This is a graph showing the relationship between the relative position of the two electrodes and the electric field strength.
[0022] Figure 7 Schematic diagram of the relative positions of the two electrodes.
[0023] Figure 8 This is a graph showing the relationship between the electric field strength at different ring electrode lengths and thicknesses.
[0024] Fig. 9 This is the relationship diagram between dielectric tube parameters and electric field strength. DETAILED DESCRIPTION
[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.
[0026] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.
[0027] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is mutually exclusive with other embodiments, either individually or selectively.
[0028] Example 1
[0029] This embodiment is the first embodiment of the present invention. This embodiment provides a needle ring electrode parameter optimization method. The needle ring electrode parameter optimization method includes:
[0030] S1: Build a needle-ring plasma jet structure under an electrostatic field.
[0031] Specifically, refer to Figure 1 The needle-ring plasma jet structure includes a dielectric tube 100, a needle electrode 200, and a ring electrode 300. The needle electrode 200 is located inside the dielectric tube 100 and is coaxial with the dielectric tube 100, and the ring electrode 300 surrounds and wraps around the outside of the dielectric tube 100 and is close to the needle electrode 200 and is kept grounded.
[0032] S2: Determine the parameter vector to be optimized for the needle-ring plasma jet structure.
[0033] Specifically, determine the parameter vector to be optimized C = {c1, c2, ... c n}, where c n The parameters to be optimized include but are not limited to the diameter of the needle electrode 200 , the radius of curvature of the needle tip of the needle electrode 200 , the relative distance between the needle electrode 200 and the ring electrode 300 , and the thickness and diameter of the medium tube 100 .
[0034] The diameter range of the needle electrode 200 is [X, Y], the curvature radius of the needle electrode 200 tip is [X, Y], the relative distance between the needle electrode 200 and the ring electrode 300 is in the range of [X, Y], the thickness range of the medium tube 100 is [X, Y], and the diameter range of the medium tube 100 is [X, Y].
[0035] S3: Taking the parameters to be optimized as variables, the electric field intensity of the needle ring plasma jet structure is simulated and analyzed.
[0036] Specifically, the parameter c to be optimized i As a variable, the electric field intensity of the needle ring plasma jet structure is simulated and analyzed to construct the parameter c to be optimized. i The fitting function of the electric field strength. Where i = 1, 2, ..., n.
[0037] Furthermore, the parameter to be optimized c is set i The initial value c i0 ;
[0038] Monitor and record the electric field intensity output by the needle ring plasma jet structure;
[0039] Update optimization parameter c i The value of c ij+1 =c ij +Δc i , and repeatedly monitor the electric field intensity output by the needle-ring plasma jet structure. Δc i is the parameter update step size, and the initial value of j is 0.
[0040] Repeat the previous step several times to construct the parameter c to be optimized i Fitting function of the electric field strength.
[0041] S4: Based on the fitting function, determine the value of the parameter to be optimized corresponding to the target electric field strength.
[0042] This embodiment also provides a needle ring electrode parameter optimization system, which is applicable to the needle ring electrode parameter optimization method described in this embodiment.
[0043] Example 2
[0044] This embodiment is the second embodiment of the present invention, and is based on the previous embodiment. Different from the previous embodiment, the diameter range of the needle electrode 200 of this embodiment is [0.6, 1.4], the radius of curvature of the needle electrode 200 tip is [0.05, 0.25], the relative distance between the needle electrode 200 and the ring electrode 300 is in the range of [-5, 15], the thickness range of the medium tube 100 is [1.2, 2.8], and the diameter range of the medium tube 100 is [0.6, 1.4].
[0045] Example 3
[0046] Reference Figures 1 to 9 , which is the third embodiment of the present invention, and is based on the first two embodiments. This embodiment provides an optimized implementation.
[0047] Specifically, the electric field distribution characteristics are studied through the electrostatic field module, and the geometric model of the needle ring plasma jet structure is as follows: Figure 1 As shown. The high-voltage needle electrode 200 is located on the central axis of the dielectric tube 100, and the ring electrode 300 is a copper foil with a thickness of 0.1 mm and a certain width wrapped around the dielectric tube to maintain grounding. The material of the electrode is all copper. To avoid the occurrence of surface flashover, the lower edge of the ring electrode 300 is 20 mm away from the lower end outlet of the dielectric tube 100. The material of the dielectric tube 100 is quartz glass, the length of the tube is 120 mm, the outer diameter is 4 mm, and the inner diameter is 2 mm.
[0048] In the electrostatic field module, the field intensity distribution simulation under different electrode parameters is carried out to select the electrode structure parameters that are most conducive to discharge, reduce the external applied voltage, and reduce the energy consumption of the excitation source. The condition of zero charge is added to the boundary of the entire air layer, and the boundary properties of the "terminal" are added to the needle electrode and the ring electrode. The influence of each electrode parameter on the electric field strength is studied in detail. Therefore, a DC 5kV excitation voltage is applied to the needle electrode 200, and the ring electrode 300 is kept grounded to observe the spatial distribution of the electric field and potential. The overall distribution trend of the needle-ring structure potential is shown in the figure. Figure 2 shown.
[0049] The electric field strength distribution is Figure 3 As shown in the figure, the area with the largest electric field strength is concentrated near the needle tip. Due to the small curvature radius of the needle tip, it has a great effect on the electric field distortion. The maximum electric field strength here reaches 6.45×10 7 V / m. This extremely uneven electric field distribution causes discharge to occur first at the needle tip, and the particles around the strong electric field area are more easily ionized to generate electrons and thus flow into the plasma, promoting the rapid development of plasma in the early stages of its formation.
[0050] Next, the electrode parameters were simulated and studied using the single factor rotation method. The independent variables include the diameter of the needle electrode 200, the radius of curvature of the needle tip, the relative position of the two electrodes, and the length and thickness of the ring electrode 300. The specific parameter level settings are shown in Table 1. Since the field strength at the needle tip is the largest and has the greatest impact on discharge, the electric field strength at the needle tip is used as the dependent variable to analyze and summarize the influence of the needle ring electrode parameters on the electric field distribution.
[0051] Table 1 Simulation parameter settings
[0052]
[0053] The electric field strength under different needle electrode 200 diameters is as follows Figure 4 As shown in (a) in FIG. 1 , when the diameter of the needle electrode 200 gradually increases, the maximum electric field intensity decreases accordingly.
[0054] The diameter of the needle electrode 200 varies as follows Figure 4 As shown in (b), when the diameter of the needle electrode 200 increases, the inclination angle of the front cone portion increases. The original curvature radius "1" with a larger radius becomes the curvature radius "2" with a smaller radius. When there are two strong field areas in the region, the overall electric field distribution will become more uniform, and the maximum electric field strength will also decrease. That is, when the diameter becomes larger, it is equivalent to introducing a new strong field area "2", so the maximum field strength is reduced. Considering that the maximum field strength is only reduced by 9.4% when the needle diameter increases from 0.6mm to 1.4mm, when designing the needle ring electrode structure, try to choose a small needle electrode 200 diameter while ensuring the overall rigidity of the electrode.
[0055] The influence of the tip curvature radius on the maximum field strength is as follows: Figure 5 As shown in the figure, when the radius of curvature of the needle tip increases, the unevenness of the electric field around the needle tip decreases, the maximum field strength also decays, and the rate of decrease gradually decreases. When the radius of curvature increases from 0.01mm to 0.09mm, the field strength decreases by 82%. Therefore, in order to reduce the starting discharge voltage, a small radius of curvature should be used as much as possible when designing the needle tip. A lower discharge voltage can reduce the energy consumption of the excitation source. However, when the plasma jet device is in long-term operation, multiple discharges will ablate the electrode. At the same time, an extremely small radius of curvature may exceed the processing accuracy, resulting in surface pits and burrs, asymmetric needle tips, and other problems that affect the electric field distribution.
[0056] The relative position diagram of the two electrodes is shown in Figure 7 As shown in the figure, when the needle tip is parallel to the upper edge of the ground electrode, the relative position is recorded as "0"; when the needle tip is located in the center of the ring electrode 300, the relative position is "5" (the height of the ring electrode 300 is 10 mm); when the needle tip is located at the lower edge of the ring electrode 300, the relative position is "10". The relationship between the relative position of the two electrodes and the electric field strength is shown in Figure 6As shown in the figure, the electric field intensity reaches a peak value when the needle tip is close to the center of the ground electrode. When the relative position moves from -5mm to 5mm, the field intensity doubles, but the field intensity does not change much within the range of 2.5mm to 7.5mm. When the needle tip and the ring electrode 300 do not overlap in the horizontal direction, the electric field intensity will drop rapidly. This shows that the relative position of the two electrodes has a great influence on the electric field distribution. When designing the electrode structure, the needle tip should be located in the center of the ring electrode.
[0057] The relationship between the length and thickness of the ring electrode 300 and the field strength is as follows: Figure 8 As shown, the field strength is the largest when the length of the ring electrode 300 is 10 mm and the thickness is 0.5 mm. However, since the ring electrode 300 is grounded as a whole, the length and thickness have little effect on the electric field strength, and the maximum field strength variation range is less than 2%. Therefore, the effect of the geometric dimensions of the ring electrode 300 on the overall electric field distribution can be basically ignored. When optimizing the electrode structure, there is no need to consider the ring electrode 300.
[0058] Finally, the parameters of the quartz medium tube 100 are analyzed, mainly including the inner diameter (air gap) and the wall thickness of the tube. The simulation results are shown in Fig. 9 As shown in the figure, as the air gap and the thickness of the tube wall increase, the radial distance between the two electrodes increases, and the field strength decreases linearly. When the voltage remains unchanged, the increase in distance leads to a decrease in the overall field strength. Therefore, when designing the device, the diameter and thickness of the medium tube should be minimized while meeting the treatment area.
[0059] In summary, the beneficial effects of the present invention are:
[0060] 1. The present invention can effectively reduce the external excitation voltage required for plasma generation by analyzing the electric field distribution of the plasma jet device and simulating and optimizing the electrode parameters, thereby reducing the energy consumption of the excitation source.
[0061] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.
Claims
1. A needle ring electrode parameter optimization method, characterized in that: include, Build a needle-ring plasma jet structure under an electrostatic field; Determining a parameter vector to be optimized for the needle ring plasma jet structure; Taking the parameters to be optimized as variables, a simulation analysis is performed on the electric field intensity of the needle ring plasma jet structure; Repeat the previous step to obtain a fitting function between each parameter to be optimized and the electric field strength; Based on the fitting function, the value of the parameter to be optimized corresponding to the target electric field strength is determined.
2. The needle ring electrode parameter optimization method according to claim 1, characterized in that: The needle-ring plasma jet structure comprises a dielectric tube (100), a needle electrode (200) arranged inside the dielectric tube (100) and coaxial with the dielectric tube (100), and a ring electrode (300) arranged around the outside of the dielectric tube (100), wherein the ring electrode (300) is grounded.
3. The needle ring electrode parameter optimization method according to claim 2, characterized in that: The parameter vector to be optimized includes, but is not limited to, the diameter of the needle electrode (200), the radius of curvature of the needle tip of the needle electrode (200), the relative distance between the needle electrode (200) and the ring electrode (300), and the thickness and diameter of the medium tube (100).
4. The needle ring electrode parameter optimization method according to claim 3, characterized in that: When one of the parameters to be optimized is used as a variable, the other parameters to be optimized are kept as fixed quantities.
5. The needle ring electrode parameter optimization method according to claim 4, characterized in that: The step of obtaining a fitting function between each of the parameters to be optimized and the electric field strength comprises: Setting the initial value of the parameter to be optimized; Recording the electric field intensity output by the needle-ring plasma jet structure when the parameter to be optimized is at the initial value; Updating the value of the parameter to be optimized and recording the electric field intensity output by the needle ring plasma jet structure under the corresponding value; Repeat the previous step to construct a fitting function between the parameter to be optimized and the electric field intensity output by the needle ring plasma jet structure.
6. The needle ring electrode parameter optimization method according to claim 5, characterized in that: The needle electrode (200) and the ring electrode (300) are made of copper.
7. The needle ring electrode parameter optimization method according to claim 6, characterized in that: The material of the medium tube (100) is quartz glass.
8. A needle ring electrode parameter optimization system, characterized in that: The method is applicable to the needle ring electrode parameter optimization method as described in any one of claims 1 to 7.