A styrene / atmospheric pressure plasma based cable accessory insulation surface performance enhancement apparatus and method

Abstract

The application provides a styrene / atmospheric pressure plasma-based cable accessory insulation surface performance improvement device, a plastic tee joint divides inert gas bottle output gas into two, one gas path enters a gas mixing box; the other gas path, an anti-backflow bottle and a styrene medium bottle enter the gas mixing box, the gas mixing box mixes the two gas paths and enters a jet reactor, discharge occurs, a plasma plume is generated, the medium of the styrene medium bottle is styrene, the inert gas is Ar, and a mixed styrene polymer polycell is formed in the gas mixing box. The improvement method of the application utilizes plasma jet spraying modification, optimizes the gap problem existing between the cable sheath and the interface insulation interface, improves the electrical performance of the cable system, prolongs the service life of the power transmission and distribution cable and improves various performances, meanwhile, the application can be popularized to other application occasions such as power system external insulation and bushings. And the medium used is determined, the operation process and specific values are specified, and the error caused by manual operation is reduced.

Description

Technical Field

[0001] This invention belongs to the field of cable accessory surface modification, and relates to a device and method for improving the insulation surface performance of cable accessories based on styrene / atmospheric pressure plasma. Background Technology

[0002] Gaps between the insulation surfaces of cable accessories can lead to serious accidents. Therefore, optimizing the compatibility between the insulation interfaces of cable accessories is increasingly important. For the problems of gaps and poor interface contact in composite insulation interfaces of cable accessories, existing technologies include reactive bonding, dissolution and wetting bonding, and mechanical bonding. Plasma treatment for optimizing the insulation interface through plasma spraying can obtain a deposition medium with good compatibility and similar dielectric properties to the accessory insulation interface, and can improve the electrical performance of the cable sheath. Vacuum silicone grease can improve the contact interface between cable accessories and the cable body insulation, but it cannot solve the problem of charge accumulation at the composite interface. Furthermore, the aging of vacuum silicone grease will introduce new defects to the interface, making it difficult to achieve the desired insulation effect. Cable accessories such as cross-linked polyethylene and EPDM rubber are hydrocarbon materials. Selecting media containing other elements will introduce new functional groups, making it impossible to control the depth of traps. Currently, most media used in laboratories contain elements such as fluorine, silicon, and titanium. Although these can improve the electrical performance of the materials, they reduce the compatibility between interfaces, increasing the possibility of poor contact and gaps in the cable body insulation and shielding layer.

[0003] The effectiveness of plasma modification is greatly affected by factors such as operating procedures, processing time, and the relative position of the plasma plume and the treated material. This leads to significant errors between the data parameters obtained in actual applications and the ideal data parameters obtained in the laboratory, greatly reducing the safety and reliability of repaired cables. Currently, most of the media used in laboratories contain elements such as fluorine, silicon, and titanium, which easily introduce new functional groups, thereby reducing the compatibility between the insulation interfaces of cable accessories.

[0004] Regarding material modification devices, relevant solutions have been disclosed in existing patents. One such patent, CN201510228992.8, describes a heat-shrinkable composite stress tube and its production method, which simultaneously uses heat-shrinkable and cold-shrinkable stress tubes, obtaining a composite stress tube through extrusion to achieve a seamless fit with the cable. However, it cannot specifically optimize the internal interface of the cable accessory.

[0005] A surface state improvement method for suppressing interfacial charge in insulation of high-voltage DC cable accessories (CN201710729185.3) involves injecting fluorine-containing gas into a reactor to replace tertiary hydrogen atoms in the molecular chains of the ethylene propylene rubber insulation material of the DC cable accessories with fluorine atoms, forming a fluorinated polymer transition layer several micrometers thick. Interfacial charge suppression is achieved through the fluorinated polymer transition layer. However, the introduction of fluorine increases the water contact angle, raising the possibility of gaps existing between the interfaces.

[0006] High-voltage direct-current cable accessory insulation interface charge suppression material and suppression method CN201710729467.3 selects silicon carbide SiC as a filler, and obtains an ethylene propylene diene rubber EPDM / SiC composite material by physical blending and hot pressing forming, the material can suppress charges, but the introduction of silicon increases the water contact angle, increases the possibility of existing gaps between interfaces, and cannot be applied to other insulation interfaces of cable accessories, and has great limitations. SUMMARY

[0007] 1. The technical problems to be solved are: The prior art increases the internal pressure of the cable by physical means, increases the electrical performance by filling materials, chemical reactions and other means. The proposed method has high cost, high operation difficulty coefficient and great limitations. In some methods using plasma jet, the operation steps and specific parameters are not described in detail, and the medium does not contain only carbon and hydrogen elements. There are few existing methods for optimizing the compatibility of the insulation interface of the cable accessory, which cannot ensure that no new elements are introduced before and after the surface treatment of the cable accessory insulation, the interface compatibility is optimized, and the electrical performance is improved.

[0008] 2. Technical scheme: In order to solve the above problems, the present application provides a kind of based on styrene / atmospheric pressure plasma cable accessory insulation surface performance improvement device, including inert gas bottle and jet reactor, plastic tee joint divides inert gas bottle output gas into two, one gas path passes through flow meter A and enters gas mixing box;Another gas path leads to flow meter B, anti-suck bottle and styrene medium bottle enter gas mixing box, gas mixing box fully mixes two gas paths and enters jet reactor, discharges under the action of plasma nanosecond pulse source, generates plasma plume, the medium of styrene medium bottle is styrene, inert gas is Ar, and mixed styrene polymer multiple body is formed in gas mixing box.

[0009] This invention also provides a method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma. Using the aforementioned improvement device, the method includes the following steps: Step S01: Place the cable accessory insulation surface horizontally upwards and clean the surface; Step S02: Inspect the device, including whether the wind speed at the bottom of the jet reactor is stable, whether there is any blockage, whether the discharge is normal, and whether the plasma plume is clear and stable. If stable, adjust flow meter A to 0 L / min; Step S03: Slowly adjust flow meter B to sequentially introduce inert gas Ar into the anti-backflow bottle and the styrene medium bottle. After the medium has completely eliminated the original air in the gas path, adjust flow meter A and flow meter B until the styrene flow rate reaches a preset value; Step S04: Turn on the plasma nanosecond pulse source. The jet reactor is above the cable accessory insulation surface. Under the action of plasma, polyploid styrene polymers are deposited on the material surface, forming flat and uniform sheet-like particles, increasing the hydrophilicity and surface energy of the material surface, increasing the creepage distance, and improving the electrical performance of the insulation material surface.

[0010] In step S01, the method for cleaning the surface of the accessory is as follows: place the insulation surface of the cable accessory horizontally upward, spray the insulation surface of the cable accessory with 95% or higher industrial alcohol 2-3 times, wipe it repeatedly with lint-free paper 3 to 5 times to ensure that there are no stains left on the surface of the accessory, wipe it clean and then let it stand until the remaining alcohol evaporates completely.

[0011] In step S02, the specific method for checking the device is as follows: Open the pressure reducing valve, slowly adjust the flow meter A to 0.8-1.2 L / min, and let the inert gas Ar directly enter the jet reactor. Wait for 25-35 seconds, and during this period, feel with the back of your hand whether the wind speed at the bottom of the jet reactor is stable. If it is stable, turn on the plasma nanosecond pulse source, adjust the voltage amplitude to 9.5-10.5 kV, adjust the frequency to 4.5-5.5 kHz, and the rise and fall edges to 95-105 ns. Send data and observe whether the discharge is normal and whether the plasma plume is clear and stable. If it is stable, reduce the flow meter A to 0 L / min and turn off the plasma nanosecond pulse source.

[0012] In step S03, after the inert gas Ar is sequentially introduced into the anti-backflow bottle and the styrene medium bottle, bubbles are generated in the styrene medium bottle. Observe whether the bubble generation is stable. If the bubble generation is stable, wait for 4-6 minutes, and the medium will completely remove the original air in the gas path.

[0013] After the medium completely removes the air from the gas path, simultaneously adjust flow meters A4 and B5 at a speed ratio of 18-22:1 until the styrene flow rate reaches the preset value.

[0014] In step S04, once the bubble is in a stable state, turn on the plasma nanosecond pulse source and adjust the voltage amplitude to 9.5-10.5kV, the frequency to 4.5-5.5kHz, and the rise and fall edges to 95-105ns.

[0015] The distance between the insulation surface of the treated cable accessory and the jet reactor is 99-11 mm, and the jet reactor is at an angle of 85-95 degrees to the insulation surface of the cable accessory.

[0016] 3. Beneficial effects: This invention proposes a method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma. Utilizing plasma jet spraying modification technology, it can easily and quickly optimize the gap between the cable sheath and the interface insulation, improving the electrical performance of the cable system, extending the service life of existing power transmission and distribution cables, and enhancing various aspects of performance. Furthermore, this invention can be extended to other applications such as external insulation and bushings in power systems. The invention also specifies the medium used, the operating procedures, and specific values, reducing errors caused by human intervention and improving the safety and reliability of the repaired cable. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a device for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma.

[0018] Figure 2 This is a schematic diagram of the state of the cable accessory insulation surface under a microscope before and after treatment.

[0019] Figure 3 This is a schematic diagram of the state of the cable accessory insulation surface under a microscope after treatment.

[0020] Figure 4 It is the water contact angle of the cable accessory insulation surface before and after treatment.

[0021] Figure 5 It is the front and back water contact angle of the insulation surface of the cable accessory after treatment.

[0022] Explanation of reference numerals in the attached diagram: 1. Inert gas cylinder; 2. Pressure reducing valve; 3. T-connector; 4. Flow meter A; 5. Flow meter B; 6. Anti-backflow bottle; 7. Styrene medium bottle; 8. Mixing box; 9. Jet reactor; 10. Plasma plume; 12. Plasma nanosecond pulse source; 13. Accessory insulating surface. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] like Figure 1As shown, a device for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma includes an inert gas cylinder 1 and a jet reactor 9. After passing through a pressure reducing valve 2, the inert gas cylinder 1 is split into two by a plastic tee connector 3. One gas path passes through a flow meter A4 and enters a mixing chamber 8; the other gas path leads to a flow meter B5, an anti-backflow bottle 6, and a styrene medium bottle 7 before entering the mixing chamber 8. The mixing chamber 8 thoroughly mixes the two gas paths before introducing them into the jet reactor 9. Under the action of a plasma nanosecond pulse source 12, a discharge occurs, generating a plasma plume 10, ensuring that the plasma plume 10 contacts the insulation surface 13 of the cable accessory. The medium in the styrene medium bottle 7 is styrene, and the inert gas is Ar. A polyploid styrene polymer is formed in the mixing chamber 8.

[0025] Under the influence of plasma, excited-state particles Ar* and e* open the vinyl-CH=CH2 double bond in the reaction medium styrene or remove the vinyl-CH=CH2 from the phenyl group in styrene; furthermore, benzenes containing unsaturated vinyl groups can undergo polymerization reactions to form diploid or even polyploid styrene; finally, the above polymers are grafted onto the surface of insulating materials, as shown in Formulas 1-3. Under plasma irradiation, the aforementioned polyploid styrene polymer can be deposited on the material surface, forming flat and uniform sheet-like particles. This alters the contact morphology between the material surface and water droplets. Due to the relatively large spacing between the deposited sheet-like particles, water can become trapped between the polyploid polyethylene particles, causing water droplet diffusion. This significantly reduces the water contact angle and increases the hydrophilicity and surface energy of the material surface. Furthermore, the deposition of polyploid styrene polymer on the surface of insulating materials effectively increases the surface roughness, thereby increasing the creepage distance and improving the electrical properties of the insulating material surface. Example

[0026] This invention also provides a method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma. In step S01, the cable accessory insulation surface is placed horizontally upwards. 95% industrial alcohol is sprayed twice onto the cable accessory insulation surface 13. The surface is then repeatedly wiped three to five times with lint-free paper to ensure no residue remains. After wiping clean, the surface is left to stand for sixty seconds to allow the remaining alcohol to evaporate completely.

[0027] Step S02: Open pressure reducing valve 2 and slowly adjust flow meter A4 to 1 L / min, allowing 99.999% pure Ar to be directly introduced into jet reactor 9. Wait 30 seconds, during which time you can use the back of your hand to feel whether the airflow at the bottom of jet reactor 9 is stable and whether there is any blockage. If everything is in good condition, turn on plasma nanosecond pulse source 12, adjust the voltage amplitude to 10kV, adjust the frequency to 5kHz, and set both the rise and fall edges to 100ns. Send data and observe whether the discharge is normal and whether the plasma plume 10 is clear and stable. If stable, reduce flow meter A4 to 0 L / min and proceed to step three.

[0028] Step S03: First, slowly adjust flow meter B5 to sequentially introduce 99.999% pure inert gas Ar into the anti-backflow bottle 6 and the styrene medium bottle 7. Bubbles will form in the styrene medium bottle 7; observe whether the bubble formation is stable. If the bubble formation is stable, wait 5 minutes until the medium has completely expelled the air from the gas path. Then, adjust flow meters A4 and B5 simultaneously at a 20:1 ratio until the styrene flow rate reaches the preset value. Next, slowly adjust flow meter A4 to the optimal ratio. During the adjustment process, constantly monitor the liquid level in the conduits of the anti-backflow bottle and the medium bottle to prevent backflow.

[0029] In step S04, if the bubble is in a stable state, turn on the plasma nanosecond pulse source 12, adjust the voltage amplitude to 10kV, adjust the frequency to 5kHz, and set both the rise and fall edges to 100ns. Send data and observe whether the discharge is normal and whether the plasma plume 10 is clear and stable. The insulation surface 13 of the cable accessory to be treated is approximately 10mm away from the jet reactor 9 to ensure that the plasma plume 10 can fully react with the insulation surface 13 of the cable accessory. During the treatment, the jet reactor 9 is at a 90-degree angle to the insulation surface 13 of the cable accessory to ensure the uniformity of the formed film, thereby greatly improving the reliability of the optimized cable.

[0030] Using EPDM rubber for cable accessories as the treatment material, the material was treated for at least 2 minutes under the aforementioned experimental setup and treatment conditions. After optimization, it was found that effective modification of the EPDM rubber insulation surface could be achieved at a gas flow rate of 1 L / min controlled by flowmeter A4 and a gas flow rate of 20 mL / min controlled by flowmeter B5. The microstructure of the material surface before and after plasma treatment is shown below. Figure 2 and Figure 3 As shown, after styrene / atmospheric pressure plasma treatment, smooth and uniform flaky particles formed on the surface of the insulating material, increasing the surface roughness. The water contact angle measurement results are as follows... Figure 4 and Figure 5As shown, the water contact angle decreased from 104.21° to 8.87° after treatment, indicating enhanced hydrophilicity and increased surface energy. Furthermore, the flashover voltage of the untreated material surface was 10.5 kV, which increased to 13.3 kV after treatment, demonstrating improved electrical insulation performance. These results prove the feasibility of using styrene / atmospheric pressure plasma to improve the surface insulation properties of cable accessories.

Claims

1. A device for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma, comprising an inert gas cylinder (1) and a jet reactor (9), wherein a plastic tee connector (3) splits the gas output from the inert gas cylinder (1) into two parts, one gas path passing through a flow meter A (4) into a mixing chamber (8); the other gas path passing through a flow meter B (5), an anti-backflow bottle (6), and a styrene medium bottle (7) into the mixing chamber (8), the mixing chamber (8) fully mixes the two gas paths and passes them into the jet reactor (9), where they discharge under the action of a plasma nanosecond pulse source (12) to generate a plasma plume (10), characterized in that: The medium in the styrene medium bottle (7) is styrene, and the inert gas is Ar. They are mixed in the mixing box (8) to form a polyploid styrene polymer.

2. A method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma, using the improvement device as described in claim 1, comprising the following steps: Step S01: Place the cable accessory with the insulation surface facing upwards and clean the surface of the accessory; Step S02: Check the device, including whether the bottom wind speed of the jet reactor (9) is stable, whether there is any blockage, whether the discharge is normal, and whether the plasma plume (10) is clear and stable. If stable, adjust the flow meter A (4) to 0 L / min. Step S03: Slowly adjust the flow meter B (5) to allow the inert gas Ar to be introduced into the anti-backflow bottle (6) and the styrene medium bottle (7) in sequence. After the medium has completely removed the original air in the gas path, adjust the flow meter A (4) and the flow meter B (5) until the styrene flow rate reaches the preset value. Step S04: Turn on the plasma nanosecond pulse source (12). The distance between the treated cable accessory insulation surface (13) and the jet reactor (9) is 9-11 mm. The jet reactor (9) and the cable accessory insulation surface (13) are at an angle of 85-95 degrees. Under the action of plasma, the polyploid styrene polymer is deposited on the material surface, forming flat and uniform sheet-like particles, which increases the hydrophilicity and surface energy of the material surface, and also increases the creepage distance and improves the electrical performance of the insulation material surface.

3. The method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma as described in claim 2, characterized in that: In step S01, the method for cleaning the surface of the accessory is as follows: place the insulation surface of the cable accessory horizontally upward, spray the insulation surface (13) of the cable accessory with 95% or higher industrial alcohol 2-3 times, wipe it repeatedly with lint-free paper three to five times to ensure that there are no stains left on the surface of the accessory, wipe it clean and then let it stand still until the remaining alcohol evaporates completely.

4. The method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma as described in claim 2, characterized in that: In step S02, the specific method for checking the device is as follows: open the pressure reducing valve (2), slowly adjust the flow meter A (4) to 0.8-1.2L / min, so that the inert gas Ar is directly introduced into the jet reactor (9), wait for 25-35 seconds, during which time feel with the back of your hand whether the wind speed at the bottom of the jet reactor (9) is stable. If it is stable, turn on the plasma nanosecond pulse source (12), adjust the voltage amplitude to 9.5-10.5kV, adjust the frequency to 4.5-5.5kHz, and the rising and falling edges are both 95-105ns. Send data and observe whether the discharge is normal and whether the plasma plume (10) is clear and stable. If it is stable, reduce the flow meter A (4) to 0L / min and turn off the plasma nanosecond pulse source (12).

5. The method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma as described in claim 2, characterized in that: In step S03, after the inert gas Ar is sequentially introduced into the anti-backflow bottle (6) and the styrene medium bottle (7), bubbles are generated in the styrene medium bottle (7). Observe whether the bubble generation is stable. If the bubble generation is stable, wait for 4-6 minutes, and the medium will completely remove the original air in the gas path.

6. The method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma as described in claim 5, characterized in that: After the medium removes all the original air from the gas path, while maintaining the flow rate ratio of flow meter A to flow meter B at 18:1 to 22:1, the flow rates of both are adjusted synchronously until the styrene flow rate reaches the preset value.

7. The method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma as described in claim 6, characterized in that: Adjust flow meter A (4) and flow meter B (5) at a speed ratio of 20:

1.

8. The method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma as described in claim 5, characterized in that: In step S04, once the bubble is in a stable state, turn on the plasma nanosecond pulse source (12) and adjust the voltage amplitude to 9.5-10.5kV, the frequency to 4.5-5.5kHz, and the rising and falling edges to 95-105ns.

9. The method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma as described in claim 4 or 8, characterized in that: The voltage amplitude is 10kV, the adjustment frequency is 5kHz, and both the rising and falling edges are 100ns.

10. The method for improving the surface performance of cable accessory insulation based on styrene / atmospheric pressure plasma as described in claim 2, characterized in that: The cable accessory insulation surface (13) is 10 mm away from the jet reactor (9), and the jet reactor (9) is at a 90-degree angle to the cable accessory insulation surface (13).

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