A plasma discharge electrode structure capable of producing glow discharge effect

Abstract

The present invention discloses a plasma discharge electrode structure capable of producing a glow discharge effect, comprising a high-voltage electrode in the middle that is in the shape of a column as a whole, the high-voltage electrode is wrapped with an insulating material, and a grounding electrode is spirally wound outside the insulating material, characterized in that the grounding electrodes are two and form a double-helix winding arrangement structure that is staggered with each other. The present invention has the advantages of good ionization effect, high exhaust gas treatment efficiency, and long service life, and is particularly suitable for ship exhaust gas treatment applications.

Description

[0001] This application is a divisional application of the patent "A method for treating ship exhaust gas" with application number 202110583629.3 and application date 2021-5-27. Technical Field

[0002] The invention relates to the field of ship exhaust gas treatment, and in particular to a plasma discharge electrode structure capable of producing a glow discharge effect. Background Art

[0003] In recent years, with the rapid development of international maritime trade, more and more people have begun to care about the impact of air pollutants on the world. Since ship exhaust emissions can easily be transmitted over long distances in the atmosphere, from the ocean to the land, or even from one continent to another, ship exhaust emissions can have a significant impact on local and regional air quality. In addition, some ship emissions occur in coastal areas, and exhaust pollutants can spread directly to the mainland, causing environmental problems that affect human health and the ecosystem. According to statistics from the European Environment Agency (EEA), global ships emit about 25 million tons of nitrogen oxides (NOX), about 15 million tons of sulfur oxides (SOX), and about 1.3 million tons of particulate matter (PM) into the atmosphere each year.

[0004] At present, the ship exhaust SOX control technology mainly includes low-sulfur fuel technology, dry desulfurization technology and wet scrubbing technology. The ship exhaust NOX control technology mainly includes exhaust gas recirculation technology (EGR system) and selective catalytic reduction technology (SCR system).

[0005] Among the traditional desulfurization and denitrification technologies, the seawater desulfurization process has a simple workflow, is reliable, environmentally friendly, and highly economical. However, the current seawater desulfurization method is not very effective in treating exhaust gas emitted when high-sulfur fuel oil is burned. In addition, the overall equipment occupies a large space and has low desulfurization efficiency in low-salinity sea areas. In addition, the entire desulfurization process requires the renewal of a large amount of seawater, which requires additional fuel to provide these powers, increasing costs. The biggest limiting factor of the dry desulfurization system is the replenishment of the desulfurizer and the accumulation of reaction by-products after exhaust gas treatment. The dry desulfurization system has high requirements for the absorbent, the desulfurizer has poor stability, and there are many by-products after the reaction. It is also troublesome to handle and utilize them, and additional configuration devices need to be added. The EGR system can reduce the temperature of the circulating exhaust gas, which greatly reduces the NOX (nitrogen oxides) emissions of the ship's main engine. However, the exhaust gas reflux ratio needs to be strictly controlled during EGR operation, and the optimal reflux volume needs to be continuously adjusted according to the change in load to balance economic benefits and NOX emission reduction. The investment and operation costs of EGR technology are relatively high, with unit investment costs generally being $60-80 / kW, and operating costs generally being 4%-6% of the fuel costs of ships sailing in emission control areas. Similarly, SCR technology also has the problems of large floor space, high investment and operating costs. The SCR system is relatively complex, and installation costs account for about 5%-8% of the total cost of the ship. The deactivation of the catalyst at low temperatures, the leakage of the reducing agent, and the need to consume a large amount of reducing agent urea during operation, etc., have increased operating costs to a certain extent.

[0006] Therefore, it is necessary for technical personnel in this field to find new low-cost and highly reliable ship exhaust gas treatment methods.

[0007] In the field of waste gas treatment, the use of plasma discharge technology to purify exhaust gas (mainly engine exhaust gas) is a relatively efficient waste gas treatment method in recent years. Plasma, also known as plasma, is an ionized gaseous substance with a large number of positive and negative ions produced by the ionization of atoms and atomic groups after some electrons are deprived. At the same time, the plasma also includes electrons, various excited atoms, atoms and free radicals, so it has a higher energy level and activity. The principle of plasma discharge treatment is to rely on the plasma generated by ionization to decompose the pollutants in the exhaust gas, thereby achieving the purpose of degrading pollutants. For example, CN204051409U once disclosed a toothed plate uniform flow cold plasma exhaust treatment device, and CN104941400B once disclosed a discharge plasma automobile exhaust treatment device with a rotating spiral electrode and a treatment method thereof, both of which use plasma to achieve exhaust treatment technology.

[0008] Plasma can be divided into plasmas generated by arc discharge, corona discharge, dielectric barrier discharge and glow discharge according to the generation form. Among them, the first three discharge methods are more common plasma treatment methods in the field of exhaust gas treatment. However, the main mechanism of arc discharge is high temperature, which is more used for air purification and sterilization, and is not suitable for exhaust gas treatment. The energy level of the plasma generated by corona discharge treatment is low, and the sterilization effect is not as good as that of glow discharge plasma, and the decomposition efficiency of harmful substances such as formaldehyde is not high. Dielectric barrier discharge requires a dielectric layer for breakdown between the electrodes, and its ionization structure is inconvenient to set and is not conducive to the passage of exhaust gas. Glow discharge plasma has a higher energy level and activity, and mainly degrades pollutants through high-energy particles inside the plasma. It is usually a more ideal exhaust gas treatment method; however, the conventional glow discharge method has a small discharge area and needs to be formed in a low-pressure environment, which is difficult to be actually applied in the field of exhaust gas purification. At the same time, most of the existing exhaust gas treatment devices are for automobile exhaust treatment, and their treatment efficiency is difficult to meet the needs of ship exhaust treatment.

[0009] Patent CN102548177B, which the inventor's research group has applied for, discloses a discharge electrode structure of a plasma air purification device, which adopts positive and negative electrodes arranged in a cross-shaped mesh structure, and discharges by direct contact after the positive and negative electrodes are wrapped with insulating materials. This patented technology is different from the conventional ionization treatment, which adopts the discharge mode of two electrodes not in contact and relying on the action of electric field to discharge. It can generate discharge at the electrode contact point based on the surface discharge principle to generate low-temperature plasma and diffuse outward. The low-temperature plasma generated in this way has the properties similar to glow discharge plasma, with high sterilization rate, good degradation effect of pollutants, short time consumption and low power consumption; but the structure only generates ionization discharge at the cross contact point of the electrode, and the efficiency is relatively low. Therefore, based on this patent, the inventor's research group also applied for a plasma disinfection and sterilization device with a flexible discharge electrode structure of CN105848397B. In this patented device, the ground electrode is spirally wound on the high-voltage electrode after wrapping the insulating medium to achieve ionization discharge. Its discharge principle has the properties of dielectric barrier discharge and surface discharge at the same time, and can generate low-temperature plasma with a glow discharge effect on the surface of the electrode contact junction, which is more suitable for treating tail gas.

[0010] However, the device of CN105848397B still has defects such as material limitations, short life and limited treatment effect. It is not suitable for direct use in ship exhaust gas treatment and needs further improvement to improve its treatment efficiency and effect. Summary of the invention

[0011] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is: how to provide a ship exhaust gas treatment method with good exhaust gas treatment effect, high treatment efficiency, convenient implementation and low cost, and a plasma discharge electrode structure that can produce a glow discharge effect.

[0012] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0013] A method for treating ship exhaust gas, which uses ionization discharge to the ship exhaust gas, and relies on plasma ionization particles generated by the ionization discharge to achieve degradation of harmful components in the ship exhaust gas. It is characterized in that the ionization discharge is generated between the surface of a high-voltage electrode wrapped with an insulating material and a wound ground electrode, and the ionization discharge is a glow discharge effect.

[0014] In this way, conventional tail gas treatment is all plasma in the form of arc discharge or corona discharge, and the plasma energy level and activity obtained by ionization are low. In the present application, an ionization discharge phenomenon is generated between the surface of a high-voltage electrode wrapped with an insulating material and a wound ground electrode, which can generate an ionized plasma with a glow discharge effect, which can have a higher energy level and activity, can better meet the treatment needs of ship tail gas, and improve the treatment effect and efficiency.

[0015] Furthermore, two grounding electrodes are alternately wound on the surface of the high voltage electrode.

[0016] In this way, the energy level of the ionized plasma can be better improved, the energy level types of the ionized particles can be enriched, and the treatment effect can be greatly improved.

[0017] Furthermore, the method is implemented by connecting a ship exhaust treatment device based on plasma ionization in the ship exhaust channel. The ship exhaust treatment device includes a shell, one end of the shell is an air inlet end, and the other end is an air outlet end. An air passage is formed in the middle of the shell, and a plasma discharge electrode is arranged in the air passage. The plasma discharge electrode includes a high-voltage electrode that is located in the middle and is in a columnar shape as a whole. The high-voltage electrode is wrapped with an insulating material, and a grounding electrode is spirally wound outside the insulating material. The plasma discharge electrode is arranged in layers along the cross-section of the air passage and has multiple layers arranged at intervals along the air passage direction. Each layer of plasma discharge electrodes includes multiple electrodes arranged in parallel and at intervals.

[0018] When the device is used, the air inlet and outlet of the shell are connected to the exhaust gas discharge channel (of ships) to be treated, and the two ends of all high-voltage electrodes and grounding electrodes are respectively connected to the high-voltage end and grounding end of the power supply. Specifically, a plasma AC power supply system with a high-frequency and high-voltage output circuit can be used to achieve control (the specific structure of the control part is a conventional existing technology and is not described in detail here). After the device is powered on to reach the discharge voltage, a discharge circuit is formed between the high-voltage electrode and the grounding electrode of the plasma discharge electrode. Based on the principles of dielectric barrier discharge and surface discharge, a low-temperature plasma similar to the glow discharge effect (that is, the discharge phenomenon is a uniformly diffused light blue discharge, the discharge current is at the milliampere level, and there are a small amount of current pulses) can be generated on the surface of the electrode contact junction to achieve ionization purification of the exhaust gas. In this device, multiple layers of electrodes are arranged at intervals along the direction of exhaust gas passing, and multiple electrodes are arranged in parallel and at intervals along the cross section of the gas passage on each layer of electrodes, which greatly increases the number of ionization areas in the three-dimensional space of the gas passage, realizes three-dimensional ionization purification treatment of the intake air, and greatly improves the exhaust gas treatment effect, which is especially suitable for the treatment needs of large amounts of ship exhaust gas.

[0019] Furthermore, each two adjacent layers of plasma discharge electrodes are arranged in a crisscross pattern with a mutual offset of 90 degrees.

[0020] In this way, the staggered arrangement of two adjacent layers of electrodes can better form a three-dimensional grid-like ionization area space, and better achieve ionization and purification treatment of the passing airflow.

[0021] Furthermore, the plasma discharge electrodes of different layers but arranged in the same direction are staggered in the arrangement spacing direction, so that there is no gap in the projection of all the plasma discharge electrodes on the cross section along the exhaust gas flow direction.

[0022] In this way, the projections of all horizontal and vertical rows of electrodes on the air duct section can cover 100% of the entire channel section. This arrangement can ensure that all exhaust pollutant gases can fully contact the electrode surface to ensure the treatment effect.

[0023] Furthermore, the high voltage electrode is a cylindrical structure made of copper material.

[0024] This has the advantages of low cost, easy installation and good power generation effect. Of course, other metal materials with good electrical conductivity can also be used during implementation.

[0025] Furthermore, the insulating material is ceramic or glass fiber material.

[0026] Ceramic or glass fiber high temperature resistant material is a good inorganic electret material. Compared with the organic electret material such as polytetrafluoroethylene used in the patent described in the background technology, it can better withstand the high temperature of 300-500°C in ship exhaust gas, making it particularly suitable for the treatment of high-temperature ship exhaust gas; and more importantly, its surface is rougher than the smooth polytetrafluoroethylene, and has a better ability to retain charge. After one discharge, the charged particles generated in the previous discharge process can enter the shallow layer of the material surface under the action of the electric field and be preserved, greatly improving the ionization treatment effect.

[0027] Furthermore, the ground electrode is made of carbon fiber material, which is low in cost, easy to implement, has good conductivity, and can better control the ionization discharge effect.

[0028] Furthermore, in the plasma discharge electrode, there are two ground electrodes forming a double helical winding arrangement structure that is staggered with each other.

[0029] Thus, compared with the structure of the single-spiral grounding electrode in the background patent, the double-spiral arrangement of two grounding electrodes can increase the ionization area of ​​the high-voltage electrode surface and reduce the ionization dark area. More importantly, the two grounding electrodes are arranged in a cross-arrangement manner, so that at the cross position of the two grounding electrodes, the grounding electrodes are pressed to the surface of the high-voltage electrode to a different degree than the other positions, and the current passing through this position is also different from the other grounding electrodes due to the contact between the two grounding electrodes. The contact point position will produce an instantaneous increase in the current passing through due to the reduction in resistance, which will cause the ionization discharge effect generated at the contact point to be different from the contact position between the other grounding electrodes and the high-voltage electrode surface, and can produce ionized particles with higher energy levels (or from the perspective of electric field superposition, compared with the grounding electrodes arranged in the same direction and parallel spirals, the grounding electrodes arranged in the cross-double-spiral arrangement have different electric field superposition effects formed between different positions on the high-voltage electrode surface and the two grounding electrodes, which leads to different ionization energy levels at various positions, and thus can produce a richer variety of ionized particles). In this way, the entire high-voltage electrode surface can generate more ionized particles of different energy levels, greatly enriching the types and quantities of ionized particles generated, so that it can better cope with the various harmful components in (ship) exhaust gas, resulting in slightly different treatment requirements. This greatly improves the overall treatment effect of (ship) exhaust gas.

[0030] Furthermore, the ground electrode is formed by weaving a plurality of carbon fiber threads.

[0031] In this way, the ground electrode is woven from a plurality of carbon fiber threads, so that it can have a certain elasticity and flexible deformation ability. Therefore, the ground electrode located at the bottom at the intersection of the two ground electrodes can be deformed and flattened, so that there is as little gap as possible between the electrode located above and the surface of the high-voltage electrode, so as to avoid the gap causing filamentary discharge and burning the electrode. In addition, the ground electrode is woven from a plurality of carbon fiber threads, which can be regarded as forming a plurality of micro-shaped carbon fiber thread electrodes woven and wound with each other. From a microscopic perspective, it can be regarded as being able to generate local currents of different instantaneous sizes at different cross-sectional positions of the ground electrode, thereby forming ionization discharge effects of different energy levels at different positions, thereby greatly enriching the types and quantities of ionized particles generated. At the same time, a number of tiny areas for the generation and retention of ionized particles are woven between the carbon fiber threads, so that the generated ionized particles can slowly diffuse outward along the surface of the ground electrode. Therefore, compared with the structure of the whole-root ground electrode, this structural method can greatly improve the ionization treatment effect of exhaust gas from multiple angles.

[0032] Furthermore, in the plasma discharge electrode, two ground electrodes are wound in an alternating manner up and down in sequence, or the same ground electrode is wound in a manner that it is always kept below the alternating position.

[0033] Among them, the first winding method is that the first ground electrode presses the second ground electrode at the first contact point, and the second ground electrode presses the first ground electrode at the second contact point. This method can improve the contact performance between the ground electrode and the insulating layer, and try to avoid the generation of gaps that cause filamentary discharge to burn the electrode, which is relatively safer. The second method always keeps a ground electrode at the bottom, which can be more convenient for production.

[0034] Furthermore, in the plasma discharge electrode, two high temperature resistant insulating wires are reversely wound outside the two grounding electrodes.

[0035] This is because after the two ground electrodes are interlaced, they are compressed at the intersection, so that the part of each ground electrode between two adjacent intersections will produce a reverse outward expansion force. Although this force is very small, because the ground electrode is composed of multiple carbon fiber threads woven together and is in a very harsh high-temperature ionization environment for a long time. Therefore, this force will cause the ground electrode to bulge easily in the middle between two adjacent intersections, so that the inner surface is not in tight contact and a gap is generated, and the carbon fiber threads on the outer surface are broken. The inner gap will produce a filamentary power generation and burn the electrode; the broken carbon fiber threads on the outside bulge outward to form burrs, causing the glow discharge effect to deteriorate. Therefore, after the two high-temperature resistant insulating wires are reversely wound, the high-temperature resistant insulating wire can pass through and press the middle position of the ground electrode between the two adjacent intersections, thereby offsetting the outward tension here, avoiding the formation of gaps on the inner side of the ground electrode and better avoiding the formation of burrs on the outside, and avoiding the formation of tip discharge. In addition, after adding two reversely wound high temperature resistant insulated wires, the high temperature resistant insulated wires and the grounding electrode can form a closed grid-shaped convex area on the surface of the high voltage electrode. The closed grid-shaped area forms a reaction pool, which is conducive to the ionized particles and harmful gases to stay in contact and react therein to complete the treatment. Therefore, the improved structure can ensure the glow discharge effect of the electrode, greatly improve its ionization treatment effect, and better extend its service life. Furthermore, the high temperature resistant insulated wire is a nylon wire.

[0036] It has the advantages of good insulation effect and low cost.

[0037] In summary, the above scheme also substantially discloses a plasma discharge electrode structure capable of producing a glow discharge effect, that is, two ground electrodes are wound around a high voltage electrode wrapped with an insulating material to form a staggered double helical winding arrangement structure. At the same time, the above schemes for further optimizing and improving the electrode structure and their advantages and effects are applicable to a single plasma discharge electrode.

[0038] During implementation, the plasma discharge electrode structure can be prepared by the following preparation method, first obtain a high-voltage electrode wrapped with an insulating material, obtain a grounding electrode woven from multiple carbon fiber threads, and then when winding, pull one end of the grounding electrode obliquely to the surface of one side of the high-voltage electrode end and bond it, pull the high-voltage electrode axially and keep the high-voltage electrode and the grounding electrode rotating relative to each other, wind a single spiral of the grounding electrode to the other end of the high-voltage electrode and then bond it to the side surface of the high-voltage electrode at that end, and then fix the second grounding electrode to be wound with the side surface of the high-voltage electrode at the other end as the starting point, push or pull the high-voltage electrode in the opposite direction to move and reset at the same speed along the axial direction and keep rotating relative to the grounding electrode in the same direction, so that the second grounding electrode is wound around the high-voltage electrode and forms a cross arrangement with the first grounding electrode, and after the second grounding electrode is wound to the starting end of the high-voltage electrode, it is cut off and bonded to the starting end of the side surface of the high-voltage electrode.

[0039] In this way, the cross winding of the two grounding electrodes can be realized by driving the high-voltage electrode back and forth along the axis and keeping it rotating in the same direction, which is very convenient, fast, efficient and reliable. Then the winding of the two high-temperature resistant insulated wires can be realized in the same way.

[0040] During implementation, the plasma discharge electrode structure can be prepared using the following electrode winding equipment, which includes a base, with a fixed bracket vertically upwardly arranged on the left and right sides of the base, and a sliding sleeve for the high-voltage electrode to pass through is relatively fixedly arranged in the middle of the upper end of the fixed bracket. A rotating frame with an overall rectangular frame structure is rotatably installed outside the two sliding sleeves by bearings, and the opposite inner ends of the two sliding sleeves are installed and pass through the inner surface of the middle position of the rotating frame. The side of the rotating frame is also provided with a pulley steering mechanism that is staggered with the position of the sliding sleeve, and a wire roller installation mechanism is also provided at the end of the rotating frame.

[0041] In this way, when the electrode winding equipment is in use, the high-voltage electrode (wrapped with insulating material) passes through the two sleeves, the grounding electrode or the high-temperature resistant insulating wire is installed on the wire roller installation mechanism in the form of a wire roller, and then the grounding electrode or the high-temperature resistant insulating wire to be wound is led out from the wire roller, made to bypass the pulley steering mechanism and then bonded and fixed to the starting end of the high-voltage electrode inside the rotating frame. Then, it is only necessary to pull the high-voltage electrode. Since the pulley steering mechanism and the sleeve are staggered, the rotating frame can be driven to rotate under the action of the reverse force, thereby completing the winding.

[0042] Furthermore, a passive gear coaxial with the slide cylinder is fixed on the rotating frame, and the passive gear is transmission-connected to a driving motor fixed on the rotating frame through a gear mechanism.

[0043] In this way, when the rotating frame is too heavy to realize self-rotation by relying on reaction force, it can be driven by the motor to realize rotation, so as to facilitate winding.

[0044] Furthermore, a pulley steering mechanism is provided at the front and rear positions of the left and right sides of the rotating frame. In this way, the four pulley steering structures can facilitate the simultaneous arrangement and sequential winding of two grounding electrodes and two high temperature resistant insulated wires. Furthermore, a wire roller installation mechanism capable of installing two wire rollers is provided at each end of the rotating frame. This facilitates the simultaneous arrangement of four wire rollers of two grounding electrodes and two high temperature resistant insulated wires.

[0045] Furthermore, the pulley steering mechanism includes a horizontally arranged pulley positioning bolt, the head of the pulley positioning bolt can be vertically slidably clamped in a dovetail groove vertically arranged on the inner side of the rotating frame, a self-fixing nut is screwed on the pulley positioning bolt to fix the pulley positioning bolt; a steering pulley is also movably sleeved on the pulley positioning bolt.

[0046] In this way, the up and down height positions of the steering pulley can be changed and adjusted, thereby adjusting the winding angle.

[0047] Furthermore, a pulley positioning nut is screwed onto the pulley positioning bolts on both sides of the deflection pulley respectively.

[0048] Like this, can rely on two pulley locating bolts to adjust the position of the deflection pulley on the pulley locating bolts as needed.

[0049] Furthermore, a position adjustment coil spring is connected between one side of the deflection pulley and the corresponding pulley positioning nut.

[0050] In this way, during the winding of the ground electrode through the steering pulley, an initial force can be applied to the spiral spring, and the steering pulley can be driven to move back and forth on the bolt during the winding process by relying on this force, thereby repeatedly changing the tension angle and tension force of the steering pulley. In addition, the resistance of the spiral spring during repeated expansion and contraction will gradually reduce the elastic force until the steering pulley gradually stops moving, so the tension applied at each moment during the winding process can be different. In this way, the degree of compression of the ground electrode at each position on the high-voltage electrode is different, so that the ionization effect generated at each position of the ground electrode is rich in variation, and more abundant types of ionized particles can be generated, thereby improving the ionization treatment effect of the exhaust gas. In particular, combined with the structural characteristics of the ground electrode itself being woven from multiple carbon fiber threads, when the degree of compression changes, the mixed compression and deformation conditions of each carbon fiber thread are different, resulting in a richer variety of ionized particles, which greatly improves the exhaust gas treatment effect.

[0051] In summary, the present invention has the advantages of good ionization effect, high exhaust gas treatment efficiency and long service life, and is particularly suitable for ship exhaust gas treatment applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a schematic structural diagram of a ship exhaust gas treatment device based on plasma ionization when implementing the present invention.

[0053] Figure 2 for Figure 1 Left view of .

[0054] Figure 3 for Figure 1 Schematic diagram of the structure of a single plasma discharge electrode in the device.

[0055] Figure 4 for Figure 1 Schematic diagram of the structure of the end face of a separate grounding electrode in the device.

[0056] Figure 5 This is a schematic diagram of the structure of the electrode winding equipment.

[0057] Figure 6 for Figure 5 Schematic diagram of the structure of the separate pulley steering mechanism. DETAILED DESCRIPTION

[0058] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0059] Optimal implementation: A method for treating ship exhaust gas, which uses ionization discharge to treat ship exhaust gas, and relies on plasma ionization particles generated by ionization discharge to achieve degradation of harmful components in the ship exhaust gas. The improvement is that the ionization discharge is generated between the surface of a high-voltage electrode wrapped with insulating material and a wound ground electrode, and the ionization discharge is a glow discharge effect.

[0060] In this way, conventional tail gas treatment is all plasma in the form of arc discharge or corona discharge, and the plasma energy level and activity obtained by ionization are low. In the present application, an ionization discharge phenomenon is generated between the surface of a high-voltage electrode wrapped with an insulating material and a wound ground electrode, which can generate an ionized plasma with a glow discharge effect, which can have a higher energy level and activity, can better meet the treatment needs of ship tail gas, and improve the treatment effect and efficiency.

[0061] Among them, two grounding electrodes are alternately wound on the surface of the high-voltage electrode.

[0062] In this way, the energy level of the ionized plasma can be better improved, the energy level types of the ionized particles can be enriched, and the treatment effect can be greatly improved.

[0063] Specifically, the method is implemented by connecting a ship exhaust gas treatment device based on plasma ionization in the ship exhaust gas channel. Figures 1 to 4As shown, it includes a shell 1, one end of the shell 1 is an air inlet end, and the other end is an air outlet end. A gas passage is formed in the middle of the shell 1, and a plasma discharge electrode is arranged in the gas passage. The plasma discharge electrode includes a high-voltage electrode 2 which is located in the middle and is in a columnar shape as a whole. The high-voltage electrode 2 is wrapped with an insulating material 3, and a grounding electrode 4 is spirally wound outside the insulating material 3. The plasma discharge electrode is arranged in layers along the cross-section of the gas passage and has multiple layers arranged at intervals along the gas direction, and each layer of plasma discharge electrodes includes multiple electrodes arranged in parallel and at intervals.

[0064] When the above device is used, the air inlet and outlet of the shell are connected to the exhaust gas discharge channel (of ships) to be treated, and the two ends of all high-voltage electrodes and ground electrodes are respectively connected to the high-voltage end and ground end of the power supply (a high-frequency high-voltage AC power supply is used in implementation, and the output waveform is a standard sine wave, which can maintain stable operation when powering the electrodes). Specifically, a plasma AC power supply system with a high-frequency high-voltage output circuit can be used to achieve control (the specific structure of the control part is conventional existing technology and is not described in detail here). After the device is powered on to reach the discharge voltage, a discharge circuit is formed between the high-voltage electrode and the ground electrode of the plasma discharge electrode. Based on the principles of dielectric barrier discharge and surface discharge, a low-temperature plasma similar to the glow discharge effect (i.e., the discharge phenomenon is a uniformly diffused light blue discharge, the discharge current is at the milliampere level, there are a small amount of current pulses, and the discharge is uniform, stable and filamentous) can be generated on the surface of the electrode contact junction to achieve ionization purification of the exhaust gas. This device adopts a method of arranging multiple layers of electrodes at intervals along the direction of exhaust gas passing, and arranging multiple electrodes in parallel and at intervals along the cross-section of the air passage in each layer, which greatly increases the number of ionization areas in the three-dimensional space of the air passage, realizes three-dimensional ionization purification treatment of the intake air, greatly improves the exhaust gas treatment effect, and is particularly suitable for the treatment needs of large amounts of ship exhaust gas.

[0065] During implementation, the specific number of layers can be selected according to actual needs. The interval between two adjacent layers of electrodes can be 1 cm, and the interval between a single electrode in the same layer can be 5 mm.

[0066] During implementation, the shell 1 can be a rectangular parallelepiped structure, and the specific size can be selected according to the actual ship exhaust emission pipeline. The left and right sides are channels, and the upper, lower, front and rear four sides can be made of stainless steel. Holes are staggered on these four sides to install plasma generating electrodes. Then, the high-voltage ends and ground ends of all electrodes are respectively led out, and they are connected in parallel to the high-voltage end and ground end of a high-frequency high-voltage AC power supply to achieve control.

[0067] Among them, each two adjacent layers of plasma discharge electrodes are arranged in a criss-cross direction with a mutual offset of 90 degrees.

[0068] In this way, the staggered arrangement of two adjacent layers of electrodes can better form a three-dimensional grid-like ionization area space, and better achieve ionization and purification treatment of the passing airflow.

[0069] The plasma discharge electrodes of different layers but arranged in the same direction are staggered in the arrangement spacing direction, so that there is no gap in the projection of all the plasma discharge electrodes on the cross section along the exhaust gas flow direction.

[0070] In this way, the projections of all horizontal and vertical rows of electrodes on the air duct section can cover 100% of the entire channel section. This arrangement can ensure that all exhaust pollutant gases can fully contact the electrode surface to ensure the treatment effect.

[0071] The high voltage electrode 2 is a cylindrical structure made of copper material, and the diameter can be 0.6 mm.

[0072] This has the advantages of low cost, easy installation and good power generation effect. Of course, other metal materials with good electrical conductivity can also be used during implementation.

[0073] The insulating material 3 is ceramic or glass fiber material. The thickness can be 0.2 mm, which is conducive to the generation of surface discharge.

[0074] Ceramic or glass fiber high temperature resistant material is a good inorganic electret material. Compared with the organic electret material such as polytetrafluoroethylene used in the patent described in the background technology, it can better withstand the high temperature of 300-500°C in ship exhaust gas, making it particularly suitable for the treatment of high-temperature ship exhaust gas; and more importantly, its surface is rougher than the smooth polytetrafluoroethylene, and has a better ability to retain charge. After one discharge, the charged particles generated in the previous discharge process can enter the shallow layer of the material surface under the action of the electric field and be preserved, greatly improving the ionization treatment effect.

[0075] Wherein, the ground electrode 4 is made of carbon fiber material. This material has low cost, is easy to implement, has good conductivity, and can better control the generation of ionization discharge effect.

[0076] Among them, in the plasma discharge electrode, the number of the grounding electrodes 4 is two and they form a double helical winding arrangement structure that is staggered with each other.

[0077] Thus, compared with the structure of the single-spiral grounding electrode in the background patent, the double-spiral arrangement of two grounding electrodes can increase the ionization area of ​​the high-voltage electrode surface and reduce the ionization dark area. More importantly, the two grounding electrodes are arranged in a cross-arrangement manner, so that at the cross position of the two grounding electrodes, the grounding electrodes are pressed to the surface of the high-voltage electrode to a different degree than the other positions, and the current passing through this position is also different from the other grounding electrodes due to the contact between the two grounding electrodes. The contact point position will produce an instantaneous increase in the current passing through due to the reduction in resistance, which will cause the ionization discharge effect generated at the contact point to be different from the contact position between the other grounding electrodes and the high-voltage electrode surface, and can produce ionized particles with higher energy levels (or from the perspective of electric field superposition, compared with the grounding electrodes arranged in the same direction and parallel spirals, the grounding electrodes arranged in the cross-double-spiral arrangement have different electric field superposition effects formed between different positions on the high-voltage electrode surface and the two grounding electrodes, which leads to different ionization energy levels at various positions, and thus can produce a richer variety of ionized particles). In this way, the entire high-voltage electrode surface can generate more ionized particles of different energy levels, greatly enriching the types and quantities of ionized particles generated, so that it can better cope with the various harmful components in (ship) exhaust gas, resulting in slightly different treatment requirements. This greatly improves the overall treatment effect of (ship) exhaust gas.

[0078] The ground electrode 4 is formed by weaving a plurality of carbon fiber threads 6. Specifically, the ground electrode may be formed by a cluster of carbon fibers with a diameter of 0.2 mm and composed of 1k carbon fiber filaments with a diameter of 7 um.

[0079] In this way, the ground electrode is woven from a plurality of carbon fiber threads, so that it can have a certain elasticity and flexible deformation ability. Therefore, the ground electrode located at the bottom at the intersection of the two ground electrodes can be deformed and flattened, so that there is as little gap as possible between the electrode located above and the surface of the high-voltage electrode, so as to avoid the gap causing filamentary discharge and burning the electrode. In addition, the ground electrode is woven from a plurality of carbon fiber threads, which can be regarded as forming a plurality of micro-shaped carbon fiber thread electrodes woven and wound with each other. From a microscopic perspective, it can be regarded as being able to generate local currents of different instantaneous sizes at different cross-sectional positions of the ground electrode, thereby forming ionization discharge effects of different energy levels at different positions, thereby greatly enriching the types and quantities of ionized particles generated. At the same time, a number of tiny areas for the generation and retention of ionized particles are woven between the carbon fiber threads, so that the generated ionized particles can slowly diffuse outward along the surface of the ground electrode. Therefore, compared with the structure of the whole-root ground electrode, this structural method can greatly improve the ionization treatment effect of exhaust gas from multiple angles.

[0080] Among them, in the plasma discharge electrode, two ground electrodes 4 are wound in an alternating manner up and down in sequence, or the same ground electrode is always wound in a manner of being kept below the alternating position.

[0081] Among them, the first winding method is that the first ground electrode presses the second ground electrode at the first contact point, and the second ground electrode presses the first ground electrode at the second contact point. This method can improve the contact performance between the ground electrode and the insulating layer, and try to avoid the generation of gaps that cause filamentary discharge to burn the electrode, which is relatively safer. The second method always keeps a ground electrode at the bottom, which can be more convenient for production.

[0082] Among them, in the plasma discharge electrode, two high temperature resistant insulating wires 5 are reversely wound outside the two grounding electrodes.

[0083] This is because after the two ground electrodes are interlaced, they are compressed at the intersection, so that the part of each ground electrode between two adjacent intersections will produce a reverse outward expansion force. Although this force is very small, because the ground electrode is composed of multiple carbon fiber threads woven together and is in a very harsh high-temperature ionization environment for a long time. Therefore, this force will cause the ground electrode to bulge easily in the middle between two adjacent intersections, so that the inner surface is not in tight contact and a gap is generated, and the carbon fiber threads on the outer surface are broken. The inner gap will produce a filamentary power generation and burn the electrode; the broken carbon fiber threads on the outside bulge outward to form burrs, causing the glow discharge effect to deteriorate. Therefore, after the two high-temperature resistant insulating wires are reversely wound, the high-temperature resistant insulating wire can pass through and press the middle position of the ground electrode between the two adjacent intersections, thereby offsetting the outward tension here, avoiding the formation of gaps on the inner side of the ground electrode and better avoiding the formation of burrs on the outside, and avoiding the formation of tip discharge. In addition, after adding two reversely wound high-temperature resistant insulating wires, the high-temperature resistant insulating wires and the grounding electrode can together form a convex area in the shape of a closed grid on the surface of the high-voltage electrode. The closed grid-shaped area forms a reaction pool, which is conducive to the ionized particles and harmful gases to stay in contact and react therein to complete the treatment. Therefore, the improved structure can ensure the glow discharge effect of the electrode, greatly improve its ionization treatment effect, and better extend its service life. During implementation, the two high-temperature resistant insulating wires can be set 180° apart from the two grounding electrodes so that they can just pass through and press the grounding electrode in the middle position between two adjacent staggered points, thereby improving the above effects. The high temperature resistance refers to the ability to withstand 300-400 degrees Celsius of exhaust gas high temperature.

[0084] The high temperature resistant insulating wire 5 is a nylon wire, and the diameter can be 0.1 mm.

[0085] It has the advantages of good insulation effect and low cost.

[0086] In summary, the above scheme also substantially discloses a plasma discharge electrode structure capable of producing a glow discharge effect, that is, two ground electrodes are wound around a high voltage electrode wrapped with an insulating material to form a staggered double helical winding arrangement structure. At the same time, the above schemes for further optimizing and improving the electrode structure and their advantages and effects are applicable to a single plasma discharge electrode.

[0087] During implementation, the plasma discharge electrode structure can be prepared by the following preparation method, first obtain a high-voltage electrode wrapped with an insulating material, obtain a grounding electrode woven from multiple carbon fiber threads, and then when winding, pull one end of the grounding electrode obliquely to the surface of one side of the high-voltage electrode end and bond it, pull the high-voltage electrode axially and keep the high-voltage electrode and the grounding electrode rotating relative to each other, wind a single spiral of the grounding electrode to the other end of the high-voltage electrode and then bond it to the side surface of the high-voltage electrode at that end, and then fix the second grounding electrode to be wound with the side surface of the high-voltage electrode at the other end as the starting point, push or pull the high-voltage electrode in the opposite direction to move and reset at the same speed along the axial direction and keep rotating relative to the grounding electrode in the same direction, so that the second grounding electrode is wound around the high-voltage electrode and forms a cross arrangement with the first grounding electrode, and after the second grounding electrode is wound to the starting end of the high-voltage electrode, it is cut off and bonded to the starting end of the side surface of the high-voltage electrode.

[0088] In this way, the cross winding of the two grounding electrodes can be realized by driving the high-voltage electrode back and forth along the axis and keeping it rotating in the same direction, which is very convenient, fast, efficient and reliable. Then the winding of the two high-temperature resistant insulated wires can be realized in the same way.

[0089] During implementation, the plasma discharge electrode structure may be Figure 5-6 The electrode winding device shown in the figure is prepared, and the electrode winding device includes a base 7, and a fixed bracket 8 is vertically arranged on the left and right sides of the base 7, and a sliding sleeve 9 for the high-voltage electrode to pass through is relatively fixedly arranged in the middle of the upper end of the fixed bracket 8. A rotating frame 10 with an overall rectangular frame structure is rotatably installed on the outside of the two sliding sleeves 9 by bearings. The opposite inner ends of the two sliding sleeves 9 are installed and pass through the inner surface of the middle position of the rotating frame. The side of the rotating frame is also provided with a pulley steering mechanism 11 that is staggered with the position of the sliding sleeve, and a wire roller installation mechanism 12 is also provided at the end of the rotating frame.

[0090] In this way, when the electrode winding equipment is in use, the high-voltage electrode (wrapped with insulating material) passes through the two sleeves, the grounding electrode or the high-temperature resistant insulating wire is installed on the wire roller installation mechanism in the form of a wire roller, and then the grounding electrode or the high-temperature resistant insulating wire to be wound is led out from the wire roller, made to bypass the pulley steering mechanism and then bonded and fixed to the starting end of the high-voltage electrode inside the rotating frame. Then, it is only necessary to pull the high-voltage electrode. Since the pulley steering mechanism and the sleeve are staggered, the rotating frame can be driven to rotate under the action of the reverse force, thereby completing the winding.

[0091] A driven gear coaxial with the slide cylinder is fixed on the rotating frame 10, and the driven gear is connected to a driving motor fixed on the rotating frame through a gear mechanism, which is not shown in the figure.

[0092] In this way, when the rotating frame is too heavy to realize self-rotation by relying on reaction force, it can be driven by the motor to realize rotation, so as to facilitate winding.

[0093] Among them, a pulley steering mechanism 11 is respectively provided at the front and rear positions on the left and right sides of the rotating frame. In this way, the four pulley steering structures can facilitate the simultaneous arrangement and sequential winding of two grounding electrodes and two high temperature resistant insulated wires. A wire roller installation mechanism 12 capable of installing two wire rollers is respectively provided at both ends of the rotating frame. This facilitates the simultaneous arrangement of four wire rollers of two grounding electrodes and two high temperature resistant insulated wires.

[0094] Among them, the pulley steering mechanism 11 includes a horizontally arranged pulley positioning bolt 13, the head of the pulley positioning bolt 13 can be vertically slidably clamped in a dovetail groove vertically arranged on the inner side of the rotating frame, and a self-fixing nut 14 is screwed on the pulley positioning bolt to fix the pulley positioning bolt; a steering pulley 15 is also movably sleeved on the pulley positioning bolt.

[0095] In this way, the up and down height positions of the steering pulley can be changed and adjusted, thereby adjusting the winding angle.

[0096] The pulley positioning bolts 13 on both sides of the deflection pulley 15 are respectively screwed with a pulley positioning nut 16 .

[0097] Like this, can rely on two pulley locating bolts to adjust the position of the deflection pulley on the pulley locating bolts as needed.

[0098] A position adjustment coil spring 17 is also connected between one side of the deflection pulley and the corresponding pulley positioning nut.

[0099] In this way, during the winding of the ground electrode through the steering pulley, an initial force can be applied to the spiral spring, and the steering pulley can be driven to move back and forth on the bolt during the winding process by relying on this force, thereby repeatedly changing the tension angle and tension force of the steering pulley. In addition, the resistance of the spiral spring during repeated expansion and contraction will gradually reduce the elastic force until the steering pulley gradually stops moving, so the tension applied at each moment during the winding process can be different. In this way, the degree of compression of the ground electrode at each position on the high-voltage electrode is different, so that the ionization effect generated at each position of the ground electrode is rich in variation, and more abundant types of ionized particles can be generated, thereby improving the ionization treatment effect of the exhaust gas. In particular, combined with the structural characteristics of the ground electrode itself being woven from multiple carbon fiber threads, when the degree of compression changes, the mixed compression and deformation conditions of each carbon fiber thread are different, resulting in a richer variety of ionized particles, which greatly improves the exhaust gas treatment effect.

[0100] In summary, the device of the present invention can be placed in the exhaust pipe of a ship, and the generated high-temperature gas can be directly treated through the hierarchical mesh electrode structure, which can effectively improve the pollutant treatment efficiency. In addition, the device is simple, occupies a small area, has low energy consumption, is energy-saving and environmentally friendly, and significantly reduces operating costs.

Claims

1. A plasma discharge electrode structure capable of producing a glow discharge effect, comprising a high-voltage electrode in the middle that is in the shape of a column as a whole, the high-voltage electrode is wrapped with an insulating material, and a grounding electrode is spirally wound around the insulating material, characterized in that: There are two grounding electrodes that form a double-helix winding arrangement structure that is staggered with each other. At the intersection position where the two grounding electrodes are wound, the grounding electrodes are pressed to the surface of the high-voltage electrode to a different degree than at other positions.

2. The plasma discharge electrode structure capable of producing a glow discharge effect as claimed in claim 1, characterized in that: The high voltage electrode is a cylindrical structure made of copper material.

3. The plasma discharge electrode structure capable of producing a glow discharge effect as claimed in claim 1, characterized in that: The insulating material is ceramic or glass fiber material.

4. The plasma discharge electrode structure capable of producing a glow discharge effect as claimed in claim 1, characterized in that: The ground electrode is made of carbon fiber material.

5. The plasma discharge electrode structure capable of producing a glow discharge effect as claimed in claim 4, characterized in that: The ground electrode is formed by weaving a plurality of carbon fiber threads.

6. The plasma discharge electrode structure capable of producing a glow discharge effect as claimed in claim 1, characterized in that: In the plasma discharge electrode, two ground electrodes are wound in an alternating manner up and down in sequence, or the same ground electrode is wound in a manner that is always kept below the alternating position.

7. The plasma discharge electrode structure capable of producing a glow discharge effect as claimed in claim 1, characterized in that: In the plasma discharge electrode, two high temperature resistant insulating wires are reversely wound outside the two grounding electrodes.

8. The plasma discharge electrode structure capable of producing a glow discharge effect as claimed in claim 7, characterized in that: The high temperature resistant insulating wire is a nylon wire.

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