Buffer layer ablation inhibitor of high-voltage cable as well as preparation method and application of buffer layer ablation inhibitor
By using liquid buffer layer ablation inhibitors prepared with components such as aniline tetramer, diamine-based end capped homopolymer and polyaldehyde functional group crosslinking agent, the problems of blockage and high maintenance complexity of high voltage cable buffer layer ablation inhibitors are solved, and the effect of effectively repairing cable buffer layer ablation and simplifying the maintenance process is achieved.
Patent Information
- Application Number
- CN202411625341.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-14
- Publication Date
- 2025-03-25
AI Technical Summary
The existing high-voltage cable buffer ablation inhibitors have problems with blockage and high maintenance complexity, making it difficult to effectively repair cable buffer ablation.
A liquid low viscosity and high conductivity buffer layer ablation inhibitor is prepared by using components such as aniline tetramer, diamine-based end capped homopolymer and polyaldehyde functional group crosslinking agent. This inhibitor can gel at room temperature, avoid conductor migration and reduce maintenance complexity.
This inhibitor can effectively repair ablation of the cable buffer layer, reduce the risk of blockage, simplify the maintenance process, and improve the stability and reliability of the cable.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of cable repair, and in particular relates to an aniline tetramer-based liquid gelled buffer layer ablation inhibitor for high-voltage cables, and a preparation method and application thereof. Background Art
[0002] The surge in electricity demand has driven the need for cross-regional and even cross-national grid connections, and the expansion of the energy internet is significantly promoting the expansion of the high-voltage transmission system market. In this field, cross-linked polyethylene (XLPE) cables have become core components in high-voltage power transmission systems due to their excellent insulation and mechanical properties. The buffer layer of XLPE cables plays a key role in cable construction. It not only ensures the quality of the electrical connection between the semi-conductive shielding layer and the aluminum sheath, but also has a waterproof effect, which directly affects the electrical performance of the cable. However, the aging and failure of the buffer layer of XLPE cables seriously affect the reliability and stability of the cables, and may even cause safety accidents in the cable system, which has a great impact on the safe and stable operation of national and regional power systems.
[0003] In order to extend the life of cables with buffer layer ablation, avoid frequent replacement of faulty cables, save grid operation costs, avoid waste of non-renewable resources, and ensure stable operation and economic maintenance of the grid, researchers and maintenance personnel have developed buffer layer repair fluids in recent years and gradually established practical repair processes and technologies.
[0004] In the existing scheme, injecting conductive fillers (such as graphite) into the buffer layer and the aluminum sheath can effectively inhibit the ablation of the cable buffer layer (Song Pengxian et al., Insulation Materials, 2023, 56(10), 84-90). However, the filled conductive filler is solid and cannot be dissolved. It can only be suspended in the inhibitory liquid matrix, which brings serious problems such as easy clogging and high filling pressure during injection. At the same time, since the injected liquid needs to be maintained in the corresponding space of the cable, it must be connected to the closed space through a pressurized liquid storage tank to keep the liquid full, which increases the complexity of the system and the difficulty of maintenance. Summary of the invention
[0005] The technical problem to be solved by the present invention is to provide a buffer layer ablation inhibitor for a high-voltage cable which is not prone to clogging and can reduce the complexity of injection and subsequent maintenance, as well as a preparation method and application thereof.
[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: the buffer layer ablation inhibitor of the high-voltage cable includes the following components by weight: 2 to 35 parts of aniline tetramer, 10 to 40 parts of diamine-terminated homopolymer, 5 to 30 parts of multi-aldehyde functional group cross-linking agent, and 30 to 80 parts of organic solvent.
[0007] The preparation method of the above-mentioned buffer layer ablation inhibitor for high-voltage cables includes the following steps: mixing aniline tetramer, diamine-terminated homopolymer and organic solvent evenly, adding a multi-aldehyde functional group cross-linking agent under stirring conditions until the mixture is evenly mixed, and obtaining the buffer layer ablation inhibitor for high-voltage cables.
[0008] The buffer layer ablation inhibitor of the high-voltage cable or the buffer layer ablation inhibitor of the high-voltage cable obtained by the above preparation method is used in cable repair.
[0009] The beneficial effects of the present invention are as follows: the buffer layer ablation inhibitor provided by the present invention is suitable for repairing cables with ablated buffer layers. The present invention mainly reacts with aniline tetramer, diamine-terminated homopolymer and multi-aldehyde functional group cross-linking agent to form a liquid low-viscosity, high-conductivity and gelatinizable repair liquid. Its liquid form is conducive to injection during repair, reducing the difficulty of maintenance. At the same time, since there are no visible particles, it overcomes the problem of easy blockage of cable pipelines caused by injection of traditional carbon-based buffer layer ablation inhibitors. The buffer layer ablation inhibitor of the present invention can be cured (gelled) at room temperature after injection, and the conductor will not migrate. After the cable is repaired using the buffer layer ablation inhibitor provided by the present invention, the cable has high stability, no complex maintenance system is required, and the complexity of later maintenance is greatly reduced. DETAILED DESCRIPTION
[0010] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes.
[0011] The buffer layer ablation inhibitor of a high-voltage cable comprises the following components by weight: 2 to 35 parts of aniline tetramer, 10 to 40 parts of diamine-terminated homopolymer, 5 to 30 parts of multi-aldehyde functional group cross-linking agent, and 30 to 80 parts of organic solvent.
[0012] The conductivity of the buffer layer ablation inhibitor is not less than (greater than or equal to) 2 mS / cm.
[0013] From the above description, it can be seen that the beneficial effects of the present invention are: (1) The buffer layer ablation inhibitor provided by the present invention uses aniline tetramer instead of traditional carbon-based, metal-based particles or powders as conductive materials. Aniline tetramer has good dispersibility in the system, and its dispersibility is greatly improved compared with the carbon or metal fillers used in the prior art. There are no visible particles, and the liquid viscosity is low, which is conducive to the subsequent injection of liquid into the cable pipeline, greatly reducing the probability of pipeline blockage during the injection process. And due to good dispersibility, its conductivity is good, which greatly improves the repair effect.
[0014] (2) The buffer layer ablation inhibitor component provided by the present invention, the aniline tetramer and the polymer solute are both amino-terminated, have a certain affinity, and are conducive to uniform dispersion; and the amine group of the aniline tetramer can participate in the cross-linking reaction of the polymer system and become a part of the cross-linking system after curing.
[0015] (3) The polymer matrix used in the buffer layer ablation inhibitor provided by the present invention is a prepolymer terminated with an amine group and a cross-linking agent with multiple aldehyde functional groups. The cross-linking process is caused by the reaction of aldehyde groups and amine groups to form a Schiff base. The reaction can usually occur at room temperature, and the system forms a cross-link after the reaction. Regardless of whether the solvent is evaporated later, the injected conductor will not move again. In addition, the aniline tetramer conductive matrix used has an amine group and can also react with the cross-linking system to form a whole. The conductive material will not migrate again, so its stability is improved after injection and cross-linking, and no complicated maintenance system is required.
[0016] (4) Due to the above advantages, the probability of pipeline blockage during the injection process is reduced, and the cross-linking reaction can occur automatically after injection without initiation, which greatly reduces the complexity of injection and subsequent maintenance.
[0017] Furthermore, the diamine-terminated homopolymer is diamine-terminated polydimethoxysilane and / or diamine-terminated polyethylene glycol, wherein the diamine-terminated polydimethoxysilane has a CAS number of 99904-16-2 and the diamine-terminated polyethylene glycol has a CAS number of 24991-53-5.
[0018] Furthermore, the multi-aldehyde functional group cross-linking agent is one or more of glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, adipaldehyde, terephthalaldehyde, and trisuccinaldehyde.
[0019] The specific selection of the combination of diamine-terminated homopolymer and multialdehyde functional group cross-linking agent helps to reduce viscosity and improve conductivity. It is not advisable to replace it with other gelling components, which will cause the viscosity and conductivity to fail to meet the standards when using diamine-terminated homopolymer and multialdehyde functional group cross-linking agent.
[0020] Furthermore, the organic solvent is one or more of n-hexane, cyclohexane, petroleum ether, tetrahydrofuran, acetone, ethanol, and ethyl acetate.
[0021] The preparation method of the above-mentioned buffer layer ablation inhibitor for high-voltage cables includes the following steps: mixing aniline tetramer, diamine-terminated homopolymer and organic solvent evenly, adding a multi-aldehyde functional group cross-linking agent under stirring conditions until the mixture is evenly mixed, and obtaining the buffer layer ablation inhibitor for high-voltage cables.
[0022] As can be seen from the above description, in the preparation process, the aniline tetramer, the diamine-terminated homopolymer and the organic solvent are first mixed uniformly to obtain a mixed solution, which can be prepared and stored in advance before use, and then a multi-aldehyde functional group cross-linking agent is added before use and stirred until uniform to obtain a buffer layer ablation inhibitor, which is prepared for use. There is no special requirement for the stirring rate during the stirring process, and it is sufficient to stir and mix thoroughly.
[0023] The above-mentioned application of the buffer layer ablation inhibitor of the high-voltage cable in cable repair.
[0024] The application of the above-mentioned buffer layer ablation inhibitor for high-voltage cables to repair cables includes the following steps: injecting any of the above-mentioned buffer layer ablation inhibitor for high-voltage cables or the buffer layer ablation inhibitor for high-voltage cables prepared by the above-mentioned preparation method into the cavity between the buffer layer and the metal sheath of the cable to be repaired.
[0025] Furthermore, after injecting the buffer layer ablation inhibitor of the high-voltage cable and before sealing the injection hole, the method further includes a step of standing the mixture until the solvent evaporates and is completely dried.
[0026] The gelation time has a crucial influence on the elimination of defects. If the gelation time is too long, the power outage time of the cable line will be extended; if the gelation time is too short, gelation may occur during the inhibitor injection process, making it difficult to carry out the subsequent cable segment perfusion process, thereby failing to achieve the purpose of restoring the electrical connection between the defective cable insulation shielding layer and the aluminum sheath. The gelation process of the buffer layer ablation inhibitor of the present invention is a double bond polymerization reaction, and the gelation reaction can occur at room temperature (25°C). The reaction process takes about 5 hours, and the viscosity rises to more than 10Pa·s. Furthermore, after the injection hole is closed, the step of heating the cable to 40~70°C to accelerate the gelation of the inhibitor is also included.
[0027] It can be seen from the above description that the buffer layer ablation inhibitor of the present invention can achieve gelation at room temperature, and the gelation can also be accelerated by heating the cable to 40-70°C.
[0028] Embodiment 1: The cable buffer layer ablation inhibitor comprises, by weight, 20 parts of aniline tetramer, 10 parts of diamine-terminated silicone oil (diamine-terminated polydimethoxysilane), 15 parts of benzene trialdehyde, and 50 parts of tetrahydrofuran; During the preparation, aniline tetramer, diamine-terminated silicone oil and tetrahydrofuran are mixed and stirred at room temperature, and then benzene trialdehyde is added under stirring and continued to be stirred until uniform, so as to obtain a cable buffer layer ablation inhibitor.
[0029] Embodiment 2: The cable buffer layer ablation inhibitor comprises, by weight, 2 parts of aniline tetramer, 40 parts of diamine-terminated polyethylene glycol, 5 parts of butyric acid trialdehyde, 30 parts of petroleum ether, and 50 parts of ethyl acetate; During the preparation, aniline tetramer, diamine-terminated silicone oil and tetrahydrofuran are mixed and stirred at room temperature to obtain a mixed solution for use. Before use, benzene trialdehyde is added under stirring conditions and continued to be stirred until uniform to obtain a cable buffer layer ablation inhibitor.
[0030] Embodiment 3: The cable buffer layer ablation inhibitor comprises, by weight, 10 parts of aniline tetramer, 15 parts of diamine-terminated polyethylene glycol, 10 parts of diamine-terminated silicone oil, 5 parts of glyoxal, 10 parts of malondialdehyde, 10 parts of n-hexane, 5 parts of cyclohexane, 30 parts of petroleum ether, and 10 parts of ethanol; The preparation method is the same as Example 1.
[0031] Embodiment 4: The cable buffer layer ablation inhibitor comprises, by weight, 30 parts of aniline tetramer, 20 parts of diamine-terminated polyethylene glycol, 5 parts of diamine-terminated silicone oil, 25 parts of glyoxal, 15 parts of cyclohexane, 20 parts of petroleum ether, and 20 parts of ethanol; The preparation method is the same as Example 1.
[0032] Embodiment 5: The cable buffer layer ablation inhibitor comprises, by weight, 35 parts of aniline tetramer, 35 parts of diamine-terminated silicone oil, 30 parts of terephthalaldehyde, 20 parts of petroleum ether, and 30 parts of ethanol; The preparation method is the same as Example 1.
[0033] Embodiment 6: The cable buffer layer ablation inhibitor comprises, by weight, 15 parts of aniline tetramer, 25 parts of diamine-terminated silicone oil, 18 parts of terephthalaldehyde, 20 parts of ethyl acetate, and 10 parts of tetrahydrofuran; The preparation method is the same as Example 1.
[0034] The physical properties of the cable buffer layer ablation inhibitors of Examples 1 to 6 were tested using a conductivity meter and a viscometer. The results are shown in Table 1.
[0035] Table 1
[0036] It can be seen from Table 1 that, compared with the currently used carbon-based powder filler inhibitor, the buffer layer ablation inhibitor provided by the present invention has better conductivity and lower viscosity, and is more conducive to application and injection construction.
[0037] Embodiment 7: The application of the buffer layer ablation inhibitor of the high voltage cable in the cable repair includes the following steps: S1, injecting the buffer layer ablation inhibitor of Example 2 into the cavity between the buffer layer and the metal sheath of the high-voltage cable to be repaired; S2, the step of standing until the solvent evaporates and completely dries; S3, closing the injection hole; S4, waiting for the buffer layer ablation inhibitor to continue to react and gel.
[0038] Embodiment 8: The application of the buffer layer ablation inhibitor of the high voltage cable in the cable repair includes the following steps: S1, injecting the buffer layer ablation inhibitor of Example 2 into the cavity between the buffer layer and the metal sheath of the high-voltage cable to be repaired; S2, the step of standing until the solvent evaporates and completely dries; S3, closing the injection hole; S4. Heat the high voltage cable to 40°C for about 2 hours to gel the buffer layer ablation inhibitor (viscosity > 10 Pa·s).
[0039] Embodiment 9: The application of the buffer layer ablation inhibitor of the high voltage cable in the cable repair includes the following steps: S1, injecting the buffer layer ablation inhibitor of Example 3 into the cavity between the buffer layer and the metal sheath of the high-voltage cable to be repaired; S2, the step of standing until the solvent evaporates and completely dries; S3, closing the injection hole; S4. Heat the high voltage cable to 55°C for about 1 hour to gel the buffer layer ablation inhibitor (viscosity > 10 Pa·s).
[0040] Embodiment 10: The application of the buffer layer ablation inhibitor of the high voltage cable in the cable repair includes the following steps: S1, injecting the buffer layer ablation inhibitor of Example 4 into the cavity between the buffer layer and the metal sheath of the high-voltage cable to be repaired; S2, the step of standing until the solvent evaporates and completely dries; S3, closing the injection hole; S4, waiting for the buffer layer ablation inhibitor to continue to react and gel.
[0041] Embodiment 11: The application of the buffer layer ablation inhibitor of the high voltage cable in the cable repair includes the following steps: S1, injecting the buffer layer ablation inhibitor of Example 5 into the cavity between the buffer layer and the metal sheath of the high-voltage cable to be repaired; S2, the step of standing until the solvent evaporates and completely dries; S3, closing the injection hole; S4, waiting for the buffer layer ablation inhibitor to continue to react and gel.
[0042] Embodiment 12: The application of the buffer layer ablation inhibitor of the high voltage cable in the cable repair includes the following steps: S1, injecting the buffer layer ablation inhibitor of Example 6 into the cavity between the buffer layer and the metal sheath of the high-voltage cable to be repaired; S2, the step of standing until the solvent evaporates and completely dries; S3, closing the injection hole; S4. Heat the high voltage cable to 70°C for about 20 minutes to gel the buffer layer ablation inhibitor (viscosity > 10 Pa·s).
[0043] In summary, the buffer layer ablation inhibitor provided by the present invention does not add conductive carbon black, nano-ATO conductive powder, graphene, conductive copper powder and other carbon-based or metal-based conductive materials. By adopting a specific polymer matrix - an amino-terminated prepolymer and a cross-linking agent with multiple aldehyde functional groups in combination with an aniline tetramer, it can have lower viscosity and good electrical conductivity compared to traditional carbon-based powder filler inhibitors. In addition, since it does not have visible particles of inhibitors made of traditional carbon-based or metal-based particles or powders, it has better dispersibility, which is conducive to the injection of the buffer layer during the repair process, greatly reducing the difficulty of the repair operation and improving the repair effect.
[0044] The cross-linking reaction of the buffer layer ablation inhibitor provided by the present invention can be carried out at room temperature, and during and after the formation of the gel, the conductive substances in the system will not migrate, so that the buffer layer ablation inhibitor has good stability after injection, does not require a complex repair system (maintenance system), reduces the difficulty of operation, and ensures the repair effect.
[0045] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention specification, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A buffer layer ablation inhibitor for a high voltage cable, characterized in that: The invention comprises the following components by weight: 2 to 35 parts of aniline tetramer, 10 to 40 parts of diamine-terminated homopolymer, 5 to 30 parts of multi-aldehyde functional group cross-linking agent and 30 to 80 parts of organic solvent.
2. The buffer layer ablation inhibitor for a high voltage cable according to claim 1, characterized in that: The diamine-terminated homopolymer is diamine-terminated polydimethoxysilane and / or diamine-terminated polyethylene glycol.
3. The buffer layer ablation inhibitor for a high voltage cable according to claim 1, characterized in that: The multi-aldehyde functional group cross-linking agent is one or more of glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, adipaldehyde, terephthalaldehyde, and trisuccinaldehyde.
4. The buffer layer ablation inhibitor for a high voltage cable according to claim 1, characterized in that: The organic solvent is one or more of n-hexane, cyclohexane, petroleum ether, tetrahydrofuran, acetone, ethanol, and ethyl acetate.
5. The method for preparing the buffer layer ablation inhibitor of a high-voltage cable according to any one of claims 1 to 4, characterized in that: The following steps are involved: The aniline tetramer, the diamine-terminated homopolymer and the organic solvent are mixed uniformly, and a multi-aldehyde functional group cross-linking agent is added under stirring until the mixture is uniformly mixed.
6. Use of the buffer layer ablation inhibitor of a high-voltage cable according to any one of claims 1 to 4 in cable repair.
7. The use according to claim 6, characterized in that: The method comprises the following steps: injecting the buffer layer ablation inhibitor of the high-voltage cable according to any one of claims 1 to 4 into the cable to be repaired, and then sealing the injection hole.
8. The use according to claim 7, characterized in that: Inject the buffer layer ablation inhibitor of the high-voltage cable according to any one of claims 1 to 4 into the cavity between the buffer layer and the metal sheath of the cable to be repaired.
9. The use according to claim 7, characterized in that: After injecting the buffer layer ablation inhibitor of the high-voltage cable and before sealing the injection hole, the method further includes standing still until the solvent evaporates and completely dries.
10. The use according to claim 7, characterized in that: After the injection hole is sealed, the method further comprises heating the cable to 40-70° C. to gel the buffer layer ablation inhibitor.