A method for preventing and treating ablation of a buffer layer based on an electrochemical anticorrosion coating

Abstract

The application discloses a kind of based on electrochemical anticorrosion coating buffer layer ablation prevention and control method, belong to high-voltage power cable processing field, the method includes the following steps: semi-conductive water-resisting buffer layer is wound around insulated core;Electrically conductive anticorrosive paint is sprayed on the inner surface of corrugated aluminum sheath to form electrochemical anticorrosion coating;The outer layer of corrugated aluminum sheath forming electrochemical anticorrosion coating is coated with preservative to obtain anticorrosive corrugated aluminum sheath;Based on the semi-conductive water-resisting buffer layer and anticorrosive corrugated aluminum sheath, high-voltage cable buffer layer ablation is prevented.The application effectively prevents electrochemical corrosion of aluminum sheath and buffer layer, thereby effectively avoiding the occurrence of high-voltage cable buffer layer ablation failure, and can effectively avoid the serious loss caused by ablation failure during cable operation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high-voltage power cable processing, and particularly relates to a buffer layer ablation prevention and treatment method based on an electrochemical corrosion-resistant coating. BACKGROUND

[0002] The high-voltage cable buffer layer ablation defect is a frequent cable failure type in recent years, which has caused great losses to the power transmission system. The main manifestations of the ablation defect are that a large amount of white powder appears on the cable aluminum sheath, the buffer layer and the insulation shielding layer, there are ablation holes in the buffer layer, and corrosion occurs in the aluminum sheath. The water-blocking buffer layer has a three-layer composite structure, and the two sides are respectively fluffy cotton and non-woven fabric, and the middle layer is semi-conductive water-blocking powder, which is obtained by impregnating semi-conductive water-based glue with high water-absorbent resin sodium polyacrylate. A large number of studies on the buffer layer ablation defect show that the high-voltage cable will be locally damp due to the damage of the outer sheath, and the water-blocking powder will absorb water. After the buffer layer is damp, electrochemical corrosion occurs, generating Na2CO3, Na2HCO3 and Al2O3 and other white powder-shaped high-resistance substances. The water-blocking powder shows high resistance characteristics after absorbing water, and expands and separates between the buffer layer and the aluminum sheath and between the buffer layer and the insulation shielding layer. The generated high-resistance substances and the water-blocking powder will cause the local resistance of the buffer layer to increase significantly, and then cause the local pressure of the buffer layer to be too high, which will cause local heat concentration of the buffer layer. The heat causes the overheat melting of the conductive fiber network of the fluffy cotton and non-woven fabric of the buffer layer, continuously damages the buffer layer and even the insulation outer shielding, causes pits or protrusions, and after a long time of accumulation, finally expands to the main insulation, causes irreversible damage to the main insulation, and further causes the breakdown failure of the main insulation. It can be seen that the buffer layer ablation defect seriously endangers the safe and stable operation of the high-voltage cable line.

[0003] The high-voltage cable buffer layer ablation defect belongs to a latent defect of the cable, and at the present stage, the only way to eliminate the water-blocking buffer layer ablation defect hidden danger is to replace the entire cable line by stopping power supply, which is time-consuming and high in cost. At present, the stock of high-voltage cables with water-blocking buffer layer structure is large, therefore, a method for preventing the ablation failure of the buffer layer is urgently needed. SUMMARY

[0004] To solve the above technical problems, the present application provides a buffer layer ablation prevention and treatment method based on an electrochemical corrosion-resistant coating to solve the problems existing in the prior art.

[0005] To achieve the above purpose, the present application provides a buffer layer ablation prevention and treatment method based on an electrochemical corrosion-resistant coating, which comprises:

[0006] The semi-conductive water-blocking buffer layer is wrapped around the insulated core;

[0007] The conductive corrosion-resistant coating is sprayed on the inner surface of the corrugated aluminum sheath to form an electrochemical corrosion-resistant coating;

[0008] The outer layer of the corrugated aluminum sheath is coated with an anticorrosive agent to form an anticorrosive corrugated aluminum sheath.

[0009] The semi-conductive water-resistant buffer layer and the anticorrosive corrugated aluminum sheath are used to prevent and treat the ablation of the buffer layer of the high-voltage cable.

[0010] Optionally, the components of the electrochemical anticorrosive coating include, in terms of mass fraction, 0-15 parts of conductive material, 0-10 parts of aniline, 0-10 parts of eucommia rubber, 0-20 parts of an additive, 0-30 parts of mica powder, 0-50 parts of epoxy resin, 0-50 parts of a solvent, and 0-15 parts of a film-forming resin.

[0011] Optionally, the graphene is thin-layer graphene, the flake diameter of the thin-layer graphene is 1-10 microns, and the thickness is 2-3 nanometers.

[0012] Optionally, the additive includes a dispersant and a curing agent.

[0013] Optionally, the dispersant is polyacrylate or sodium dodecyl benzene sulfonate.

[0014] The curing agent is isocyanate or silane.

[0015] Optionally, the solvent is toluene or xylene or a mixture of toluene and xylene.

[0016] Optionally, the film-forming resin is nitrocellulose or polystyrene or polyvinyl chloride or a mixture of nitrocellulose, polystyrene, and polyvinyl chloride.

[0017] Compared with the prior art, the present application has the following advantages and technical effects:

[0018] The present application provides an electrochemical anticorrosive coating buffer layer ablation prevention method, which effectively solves the problem of ablation of the buffer layer of a high-voltage cable. The semi-conductive water-resistant buffer layer is wrapped around the insulated core, which enhances the insulation performance and water resistance of the cable. The electrochemical anticorrosive coating is formed by spraying conductive anticorrosive paint, which improves the anticorrosive ability of the cable. The outer layer is coated with an anticorrosive agent, which further enhances the anticorrosive effect. The method significantly improves the service life and safety of the high-voltage cable by comprehensively using electrochemical anticorrosion and physical barrier means, and reduces the maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the present application illustrated in the drawings and their descriptions are used to explain the present application and do not limit the present application. In the drawings:

[0020] Figure 1 The present application provides an electrochemical anticorrosive coating buffer layer ablation prevention method, which effectively solves the problem of ablation of the buffer layer of a high-voltage cable. The semi-conductive water-resistant buffer layer is wrapped around the insulated core, which enhances the insulation performance and water resistance of the cable. The electrochemical anticorrosive coating is formed by spraying conductive anticorrosive paint, which improves the anticorrosive ability of the cable. The outer layer is coated with an anticorrosive agent, which further enhances the anticorrosive effect. The method significantly improves the service life and safety of the high-voltage cable by comprehensively using electrochemical anticorrosion and physical barrier means, and reduces the maintenance cost.

[0021] Figure 2 A schematic diagram of a simulation ablation experiment platform for the embodiment of the present application is shown in FIG. 1.

[0022] Figure 3 The morphologies of each layer after the simulation ablation experiment of the embodiment of the present application are shown in FIG. 2, wherein FIG. 2(a) shows the ablation morphology of the sample without the conductive anticorrosive coating, and FIG. 2(b) shows the ablation morphology of the sample with the conductive anticorrosive coating. DETAILED DESCRIPTION

[0023] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a group of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0025] Embodiment One

[0026] The conductive anticorrosive coating provided in the embodiment includes, in terms of mass fraction, 5 parts of conductive carbon black, 10 parts of an additive, 40 parts of an epoxy resin, and 10 parts of a film-forming resin.

[0027] After the above components are weighed according to the proportions, they are placed in a vacuum degassing stirrer for stirring at a speed of 1000 r / min for 8 minutes, and then vacuum degassing is performed for 2 minutes to prepare the conductive anticorrosive coating.

[0028] The conductive anticorrosive coating prepared in this embodiment has relatively low conductive and anticorrosive properties and poor coating effect.

[0029] Embodiment Two

[0030] The conductive anticorrosive coating provided in the embodiment includes, in terms of mass fraction, 15 parts of graphite, 10 parts of an additive, 40 parts of an epoxy resin, 5 parts of aniline, and 10 parts of a solvent.

[0031] After the above components are weighed according to the proportions, they are placed in a vacuum degassing stirrer for stirring at a speed of 1000 r / min for 20 minutes, and then vacuum degassing is performed for 4 minutes to prepare the conductive anticorrosive coating.

[0032] The conductive anticorrosive coating prepared in this embodiment has relatively good conductive and anticorrosive properties and poor coating effect.

[0033] Embodiment Three

[0034] The conductive anticorrosive paint provided by the embodiment includes, in mass parts, 10 parts of graphene, 15 parts of an additive, 40 parts of an epoxy resin, 20 parts of a film-forming resin and 20 parts of a solvent.

[0035] After the components are weighed in proportion, they are placed in a vacuum defoaming stirrer and stirred for 25 minutes at a speed of 1000 r / min, and then vacuum degassed for 5 minutes to obtain the conductive anticorrosive paint.

[0036] The conductive anticorrosive paint prepared in this embodiment has good conductive and anticorrosive properties and good coating effect.

[0037] Embodiment Four

[0038] The conductive anticorrosive paint provided by the embodiment includes, in mass parts, 10 parts of carbon nanotubes, 5 parts of eucommia rubber, 15 parts of an additive, 40 parts of an epoxy resin and 20 parts of a film-forming resin.

[0039] After the components are weighed in proportion, they are placed in a vacuum defoaming stirrer and stirred for 40 minutes at a speed of 1000 r / min, and then vacuum degassed for 5 minutes to obtain the conductive anticorrosive paint.

[0040] The conductive anticorrosive paint prepared in this embodiment has good conductive and anticorrosive properties and poor coating effect.

[0041] Embodiment Five

[0042] The ablation of the buffer layer is caused by the electrochemical corrosion between the buffer layer and the aluminum sheath after the buffer layer absorbs water, and the accumulation of high-resistance powder, which leads to uneven current density and uneven electrical contact, resulting in the concentration of radial current. The local temperature of the buffer layer rises at the current concentration, and the situation is more serious in the case of moisture. The ablation of the buffer layer is caused by the heat effect of the current, and the ablation expands to the aluminum sheath and the semiconductive insulation shielding layer, and further expands to the main insulation, eventually leading to irreversible main insulation breakdown accidents. Therefore, if the occurrence of electrochemical corrosion can be blocked before the ablation defect occurs, the hidden danger of the water-blocking buffer layer ablation defect can be quickly and effectively eliminated at low cost. Currently, there is no method for preventing the ablation of the buffer layer based on the mechanism of electrochemical corrosion of the high-voltage cable buffer layer.

[0043] The method for preventing and treating the ablation of the buffer layer based on the electrochemical anticorrosive coating includes the following steps: winding a semiconductive water-blocking buffer layer around an insulated core; spraying a conductive anticorrosive paint on the inner surface of a corrugated aluminum sheath to form an electrochemical anticorrosive coating; coating an anticorrosive agent on the outer layer of the corrugated aluminum sheath with the electrochemical anticorrosive coating to obtain a corrosion-resistant corrugated aluminum sheath; and preventing and treating the ablation of the buffer layer of the high-voltage cable based on the semiconductive water-blocking buffer layer and the corrosion-resistant corrugated aluminum sheath.

[0044] Step S1: winding a semiconductive water-blocking buffer layer around an insulated core;

[0045] Step S2: the conductive anticorrosive paint to be coated is sprayed on the inner surface of the corrugated aluminum sheath through a transmission pipe to form an electrochemical anticorrosive coating; wherein the components of the conductive anticorrosive paint include, in terms of mass fraction: carbon black 0-15 parts; graphite 0-15 parts; carbon nanotubes 0-15 parts; graphene 0-15 parts; aniline 0-20 parts; eucommia ulmoides gum 0-10 parts; additives 0-5 parts; mica powder 0-30 parts; epoxy resin 0-50 parts; solvent 0-30 parts; film-forming resin 0-5 parts.

[0046] The conductive material is one or more of carbon black, thin-layer graphene, carbon nanotubes or graphite, the graphene is thin-layer graphene with a flake diameter of 1-10 μm and a thickness of 2-3 nm;

[0047] The additives include a dispersant and a curing agent; the dispersant includes polyacrylate or sodium dodecyl benzene sulfonate; and the curing agent includes isocyanate or silane;

[0048] The solvent is specifically one of toluene, xylene or a mixture thereof;

[0049] The film-forming resin is specifically one of nitrocellulose, polystyrene, polyvinyl chloride or a mixture thereof;

[0050] Step S3: the corrugated aluminum sheath is welded, and the outer surface of the corrugated aluminum sheath is coated with an anticorrosive layer: asphalt;

[0051] Step S4: the outer sheath is installed, and the cable is inspected and shipped.

[0052] As a specific embodiment of the present embodiment, the conductive anticorrosive paint in Example Three is selected in the present embodiment, which has good conductivity, anticorrosion and performance, and good coating effect; the conductive anticorrosive paint is uniformly sprayed on the inner surface of the corrugated aluminum sheath through a transmission pipe; after the semi-conductive water-blocking buffer layer is wrapped around the insulated core, the corrugated aluminum sheath after processing of the inner surface is welded, the outer layer of the corrugated aluminum sheath is coated with an anticorrosive layer (asphalt), and the outer sheath is installed for inspection and shipment, and the specific process is as shown in Figure 1 .

[0053] The method for preventing buffer layer ablation discloses in the application improves the cable structure during cable manufacturing, and sprays conductive anticorrosive paint inside the corrugated aluminum sheath. The conductive anticorrosive paint is used, the physical anticorrosion of graphene is based on the impermeability and good chemical inertness of graphene to all atoms and molecules, and the hydrophobicity can increase the contact angle of the coating, so that the physical anticorrosion effect is good; the electrochemical anticorrosion of graphene is based on the excellent conductive performance of graphene. When the metal base material is contacted, the self-corrosion potential is high, and the electrochemical corrosion can be delayed. When the method is used, the cable anticorrosion spraying technology is mature, the operation is simple, the conductive anticorrosive paint has excellent performance in all aspects, the electrochemical corrosion of the aluminum sheath and the buffer layer can be effectively prevented by the method, the ablation failure of the high-voltage cable buffer layer can be effectively avoided, and the serious loss caused by the ablation failure during the operation of the cable can be effectively avoided.

[0054] Example six

[0055] In this embodiment, the ablation in the cable is simulated by building a platform, and the simulated ablation scheme is as shown in Figure 2 , specifically, the three-layer structure of the aluminum sheet-buffer layer-shielding layer is 2cm*2cm, 200g weight is applied, the constant current source is 200mA, 1ml deionized water is injected into the buffer layer, and the ablation is performed for 20min. The aluminum sheet of the control group is not sprayed with the conductive anticorrosive coating, and the aluminum sheet of the experimental group is sprayed with the conductive anticorrosive coating in Example three.

[0056] The morphology of the three layers after ablation of the two groups is as shown in Figure 3 . In which, Fig. (a) is the control group, no conductive anticorrosive coating is sprayed, a large number of corrosion traces and pits can be observed on the surface of the aluminum sheet, a large number of white products are attached to the buffer layer, and the shielding layer is burned, and the ablation phenomenon caused by electrochemical corrosion is obvious; Fig. (b) is the experimental group, the coating on the surface of the aluminum sheet is well attached, no electrochemical corrosion trace is observed, no white powder caused by ablation is observed on the buffer layer, and the shielding layer is not burned. After spraying the conductive anticorrosive coating, the occurrence of electrochemical corrosion of the aluminum sheet is effectively prevented.

[0057] The above is only a preferred specific embodiment of the application, but the protection scope of the application is not limited thereto, any skilled person in the art can easily think of changes or replacements within the technical range disclosed in the application, which should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A method for the ablation control of a buffer layer based on an electrochemical anticorrosion coating, characterized in that, The method comprises the following steps: The insulating core is wrapped with a semi-conductive water-resistant buffer layer; An electrochemical anticorrosive coating is formed by spraying a conductive anticorrosive paint on the inner surface of the corrugated aluminum sheath; The components of the electrochemical anticorrosive coating include, in terms of mass fraction, 0-15 parts of carbon black, 0-15 parts of graphite, 0-15 parts of carbon nanotubes, 0-15 parts of graphene, 0-20 parts of aniline, 0-10 parts of eucommia ulmoides gum, 0-5 parts of an additive, 0-30 parts of mica powder, 0-50 parts of epoxy resin, 0-30 parts of a solvent, 0-5 parts of a film-forming resin, the graphene is thin-layer graphene with a flake diameter of 1-10 μm and a thickness of 2-3 nm, and the additive includes a dispersant and a curing agent; An outer layer of the corrugated aluminum sheath forming the electrochemical anticorrosive coating is coated with an anticorrosive agent to obtain an anticorrosive corrugated aluminum sheath; The semi-conductive water-resistant buffer layer and the anticorrosive corrugated aluminum sheath are used to prevent and treat the ablation of the buffer layer of a high-voltage cable.

2. The method of claim 1, wherein, The dispersant is polyacrylate or sodium dodecyl benzene sulfonate; The curing agent is isocyanate or silane.

3. The method of claim 1, wherein, The solvent is toluene or xylene or a mixture of toluene and xylene.

4. The method of claim 1, wherein, The film-forming resin is nitrocellulose or polystyrene or polyvinyl chloride or a mixture of nitrocellulose, polystyrene and polyvinyl chloride.

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