Thermochromic coating material for positioning short-circuit fault of GIL (Gas Insulated Line) pipe gallery and preparation method of thermochromic coating material
The thermochromic coating material prepared by the invention has a rapid and irreversible color-locking response within the temperature range of the short-circuit fault point in the GIL (Gas Infrared Lever) tunnel, which solves the problems of low fault point location accuracy and unstable color-changing material in the prior art. It achieves accurate identification and trace preservation of the fault point and is suitable for short-circuit fault location in GIL tunnels.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-29
- Publication Date
- 2026-04-07
AI Technical Summary
In existing GIL (Gas Inlet and Outer Space) short-circuit fault location technology, it is difficult to quickly and accurately locate the fault point. Existing thermochromic materials have mismatched response temperatures, poor color change stability, and cannot retain fault traces for a long time. Furthermore, they lack compatibility with the equipment substrate.
A thermochromic coating material composed of 45-55 parts matrix resin, 25-35 parts toughening agent, 11-21 parts composite color-changing filler and 6-10 parts curing agent is used to achieve centimeter-level fault location by rapidly responding and irreversibly locking color in the temperature range of 80-100℃. Combined with the composite color-changing filler of crystal violet and cobalt oxide, it is applied to the surface of the GIL shell.
It achieves centimeter-level precise location of fault points, the coating material has good compatibility with the GIL shell, and the traces can be retained for a long time after discoloration, which is convenient for subsequent analysis. It does not affect the insulation performance of the equipment, and the construction is simple and low-cost.
Smart Images
Figure CN121801419A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of power equipment fault detection materials, and particularly relates to a thermochromic coating material for locating short-circuit faults in GIL (Gas Inlet and Outer Limit) tunnels and its preparation method. Background Technology
[0002] Gas-insulated metal-enclosed transmission lines (GILs) are key equipment in ultra-high voltage (UHV) power transmission projects, offering advantages such as large transmission capacity, small footprint, and high reliability. They are widely used in special scenarios such as crossing rivers and seas and underground in cities. However, GIL tunnels are enclosed structures with multiple circuits and hundreds of gas chambers inside. When a short-circuit fault occurs, the fault point is difficult to locate quickly, seriously affecting repair efficiency and power supply stability.
[0003] Currently, mainstream GIL (Gas Inertial Ingress) fault location methods include ultrasonic detection, grounding current method, and traveling wave method, but all have significant drawbacks: the ultrasonic method is susceptible to environmental noise interference and requires highly skilled operators; the grounding current method is only suitable for low-voltage distribution networks and cannot meet the needs of ultra-high-voltage systems; the traveling wave method is based on software calculations, not direct measurement, and has limited location accuracy. Location technologies developed in recent years based on transient magnetic field or temperature changes, while capable of pinpointing the faulty gas chamber, struggle to achieve precise fault location, and existing thermochromic materials are mostly reversible, failing to retain fault traces long-term, which is detrimental to subsequent analysis.
[0004] The application of existing thermochromic materials in power equipment often suffers from problems such as mismatch between the response temperature and the short-circuit fault temperature of the gas-insulated line-of-sight (GIL), poor color stability, and insufficient compatibility with the equipment substrate. During a GIL short circuit, the outer casing temperature near the fault point can reach approximately 100°C, and the instantaneous temperature inside the gas chamber can reach as high as 140°C. Therefore, there is an urgent need for a thermochromic coating material for locating short-circuit faults in GIL pipe racks and its preparation method to solve the above problems. Summary of the Invention
[0005] To overcome the shortcomings of the prior art, this invention provides a thermochromic coating material for short-circuit fault location in GIL (Gas Inlet Utility) tunnels and its preparation method. The thermochromic coating material of this invention is a thermochromic coating that can respond rapidly in a temperature range of 80-100℃, irreversibly lock in color, and is compatible with the GIL shell material, thereby achieving centimeter-level fault location.
[0006] To achieve one of the above objectives, the present invention adopts the following technical solution: A thermochromic coating material for locating short-circuit faults in GIL (Gas Inlet and Outlet) pipe racks, comprising 45-55 parts of base resin, 25-35 parts of toughening agent, 11-21 parts of composite color-changing filler, and 6-10 parts of curing agent; wherein the base resin is pretreated.
[0007] Preferably, the temperature response range of the material is 80-100℃.
[0008] Preferably, the matrix resin is bisphenol A type epoxy resin (E-51).
[0009] Preferably, the toughening agent is polysulfide rubber; the curing agent is polyamide curing agent.
[0010] Preferably, the composite color-changing filler consists of 10-20 parts crystal violet and 1 part cobalt oxide.
[0011] Preferably, the pretreatment method is to preheat the matrix resin in an oven at 50-80℃ for 20-40 minutes.
[0012] To achieve the second objective mentioned above, this invention provides a method for preparing a thermochromic coating material for short-circuit fault location in GIL (Gas Infrared Lever) tunnels, the specific steps of which are as follows: S1. Pretreatment: Place the matrix resin in an oven at 50-80℃ for 20-40 minutes to remove moisture and set aside. S2, Mixed Matrix: The preheated matrix resin and toughening agent are mixed evenly to form a matrix mixture; S3. Add composite color-changing filler: Add composite color-changing filler to the matrix mixture to form a uniformly dispersed composite color-changing filler mixture system; S4. Curing and molding: Add curing agent to the mixture, stir evenly, apply to the surface of GIL shell, and let it stand at room temperature to cure and mold, thus obtaining a thermochromic coating material.
[0013] Preferably, in step S2, the preheated matrix resin and toughening agent are added to a high-speed mixer and mixed at 1000 r / min for 15-25 minutes to form a uniform matrix mixture.
[0014] Preferably, in step S3, crystal violet and cobalt oxide are added to the matrix mixture, and the rotation speed is adjusted to 1500 r / min, and the mixture is mixed for 25-35 minutes to ensure that the composite color-changing filler is uniformly dispersed.
[0015] Preferably, in step S4, the coating method is spraying or brushing; the coating thickness is 0.3-0.5mm, and the standing time is ≥24 hours.
[0016] The advantages of this invention are: (1) The composite color-changing filler in the thermochromic coating material prepared by the present invention responds rapidly in the 80-100℃ range, which is highly matched with the temperature of the GIL short circuit fault point, and can accurately identify the fault location with precise temperature response.
[0017] (2) After the crystal violet in the thermochromic coating material prepared by the present invention fades, the black color of cobalt oxide is stable and irreversible, which can retain fault traces for a long time, making it convenient for subsequent fault analysis and recording.
[0018] (3) The thermochromic coating material prepared by the present invention adheres firmly to the metal material of the GIL shell, has strong adhesion, and has good flexibility. It can adapt to slight vibrations and temperature fluctuations during the operation of the GIL and has good compatibility.
[0019] (4) The matrix epoxy resin and composite filler in this invention have good insulation properties. The breakdown strength after coating curing is ≥20kV / mm, which will not affect the insulation performance of GIL equipment. The insulation performance is excellent.
[0020] (5) This invention can be applied by spraying or brushing, and it cures at room temperature. No special equipment is required, making it suitable for on-site application. It is also low in cost, easy to apply, and easy to promote on a large scale.
[0021] (6) The coating of the present invention can be directly applied to the surface of the GIL shell. When a fault occurs, the fault point can be directly identified by color change, achieving centimeter-level positioning with high positioning accuracy and greatly improving the repair efficiency.
[0022] (7) This invention uses a composite of crystal violet and cobalt oxide as a composite color-changing filler. Crystal violet undergoes a protonation reaction and fades at 80-100℃ (the characteristic temperature of GIL short-circuit fault), while cobalt oxide presents a stable black color, achieving irreversible color locking and solving the problem that existing materials cannot retain fault traces after color change. The coating composition ratio is optimized, and epoxy resin and polysulfide rubber are compounded as the matrix, taking into account the coating's adhesion and flexibility, ensuring compatibility with the metal material of the GIL shell and long-term operational stability. The coating can be cured and formed at room temperature, making construction simple and requiring no special equipment. It also has good insulation properties and will not affect the operation of the GIL equipment. The color change is intuitive and obvious, enabling centimeter-level location of GIL short-circuit fault points, greatly improving fault location efficiency and repair speed, and solving the problem of insufficient location accuracy in existing technologies.
[0023] (8) The epoxy resin used in this invention is bisphenol A type epoxy resin (E-51), which has good adhesion and insulation properties; the toughening agent polysulfide rubber can improve the flexibility of the coating and prevent the coating from cracking due to slight vibration during GIL operation; in the composite color-changing filler, crystal violet, as a temperature-sensitive component, undergoes a protonation reaction at 80-100℃, and the rearrangement of the conjugated double bond system leads to color change; cobalt oxide, as a color-developing matrix, presents a stable black color after the crystal violet fades, thus achieving the color-locking function; the curing agent polyamide curing agent can cure the coating at room temperature without high-temperature treatment, thus avoiding the impact on the GIL equipment.
[0024] (9) The present invention aims to solve the technical problems in the existing GIL pipe gallery short circuit fault location technology, such as low fault point location accuracy, inaccurate response of existing color-changing materials, inability to lock color after color change, and poor compatibility with equipment substrate. The prepared crystal violet-cobalt oxide composite thermochromic coating can respond quickly in the GIL short circuit fault temperature range (80-100℃) and show obvious irreversible color change, so as to achieve accurate fault point identification. It also has good adhesion, mechanical properties and environmental adaptability, which meets the long-term operation requirements of GIL pipe gallery. Attached Figure Description
[0025] Figure 1 This is the curve showing the relationship between coating color depth and time at 100°C in Example 1 of the present invention.
[0026] Figure 2 The curves show the color change response time test results of Embodiment 1 of the present invention under different ambient temperatures.
[0027] Figure 3 The curves show the response time test results at 100℃ for different crystal violet-cobalt oxide mass ratios in Examples 2, 3, and 4 of this invention.
[0028] Figure 4 The curves show the coating adhesion strength test results at different test temperatures in Example 4 of the present invention. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0030] Example 1
[0031] Composition ratio (parts by weight): 50 parts epoxy resin (E-51), 30 parts polysulfide rubber, 16 parts crystal violet, 1 part cobalt oxide, and 8 parts polyamide curing agent; Preparation process: S1. Pretreatment: Place 50 parts of epoxy resin in a 60℃ oven and preheat for 30 minutes to remove moisture; S2. Mixing matrix: Add the preheated epoxy resin and 30 parts of polysulfide rubber to a high-speed mixer and mix at 1000 r / min for 20 minutes to obtain a uniform matrix mixture; S3. Add composite color-changing filler: Add 16 parts crystal violet and 1 part cobalt oxide to the matrix mixture, mix at 1500 r / min for 30 minutes to ensure that the composite color-changing filler is evenly dispersed and forms a mixed system; S4. Curing and molding: Add 8 parts of polyamide curing agent to the mixing system, stir evenly, and then apply it to the surface of the GIL simulation shell (Q235 steel) by spraying. The coating thickness is 0.4mm. Let it stand at room temperature for 24 hours to cure. A thermochromic coating material 1 is formed on the GIL simulation shell.
[0032] The performance of the thermochromic coating material 1 prepared in Example 1 was tested: (1) Temperature response test (corresponding to) Figure 1-2 ): according to Figure 1 Test: At 100℃, the 0-4h period is the rapid fading stage (color depth increases from 0 to 0.9), and after 4h, it enters the color-locking and stabilizing stage (color depth remains at 1.0). according to Figure 2 Test results: Response time 48 hours at 70℃, 30 hours at 80℃, and 12 hours at 100℃, which meets the requirements. Figure 2 The trend of "increasing temperature and shortening response time"; (2) Adhesion performance test: The cross-cut test was used. The coating adhesion was grade 1, and there was no peeling. (3) Mechanical property test: tensile strength is 18MPa, bending strength is 25MPa, impact strength is 5.2kJ / m², and there is no cracking; (4) Insulation performance test: The breakdown strength is 22kV / mm, which meets the insulation requirements of GIL equipment.
[0033] Example 2
[0034] Composition ratio (parts by weight): 45 parts epoxy resin (E-51), 28 parts polysulfide rubber, 10 parts crystal violet, 1 part cobalt oxide, and 6 parts polyamide curing agent; Preparation process: Following the preparation steps of Example 1, the coating thickness was 0.3 mm, and a thermochromic coating material 2 was formed on the GIL simulation shell.
[0035] The performance of the thermochromic coating material 2 prepared in Example 2 was tested: (1) Temperature response test (corresponding to) Figure 3 ): Color change response time is 25 hours at 100℃ (matching) Figure 3 (Experimental data showing a 10:1 ratio corresponding to a 25-hour response time). (2) Adhesion performance test: Adhesion is grade 1, and the adhesion is firm; (3) Mechanical property tests: tensile strength 16MPa, flexural strength 23MPa, impact strength 4.8kJ / m 2 ; (4) Insulation performance test: breakdown strength 20kV / mm, which meets the requirements for use.
[0036] Example 3
[0037] Composition ratio (parts by weight): 55 parts epoxy resin (E-51), 32 parts polysulfide rubber, 14 parts crystal violet, 1 part cobalt oxide, and 9 parts polyamide curing agent; Preparation process: Following the preparation steps of Example 1, the coating thickness was 0.5 mm, and a thermochromic coating material 3 was formed on the GIL simulation shell.
[0038] The performance of the thermochromic coating material 3 prepared in Example 3 was tested: (1) Temperature response test (corresponding to) Figure 3 ): At 80℃, the color change response time is 14 hours (matching) Figure 3 (Experimental data showing a 14:1 ratio corresponding to a 14-hour response time). (2) Adhesion performance test: Adhesion level 1, no peeling; (3) Mechanical property tests: tensile strength 20MPa, flexural strength 27MPa, impact strength 5.5kJ / m 2 ; (4) Insulation performance test: breakdown strength 23kV / mm, which meets the requirements.
[0039] Example 4
[0040] Composition ratio (parts by weight): 52 parts epoxy resin (E-51), 31 parts polysulfide rubber, 20 parts crystal violet, 1 part cobalt oxide, and 10 parts polyamide curing agent; Preparation process: Following the preparation steps of Example 1, the coating thickness was 0.4 mm, and a thermochromic coating material 4 was formed on the GIL simulation shell.
[0041] The performance of the thermochromic coating material 4 prepared in Example 4 was tested: (1) Temperature response test (corresponding to) Figure 3 ): Color change response time 8 hours at 100℃ (matching) Figure 3 The conclusion that "a 20:1 ratio is optimal, corresponding to an 8-hour response time" is drawn from this. (2) Bond strength test (corresponding to) Figure 4): The bond strength is 17.2 MPa at -20℃, 18.5 MPa at 25℃, and 17.5 MPa at 100℃; (3) Comprehensive performance test: tensile strength 19MPa, bending strength 26MPa, breakdown strength 22.5kV / mm, all indicators meet the requirements of GIL equipment.
[0042] The above embodiments 1-4 show that the thermochromic coating material of the present invention can respond quickly in the temperature range of 80-100℃, exhibiting obvious color change, and the color change is irreversible and locked in. At the same time, it has good adhesion, mechanical properties and insulation properties, which fully meets the application requirements of GIL pipe gallery short circuit fault location.
[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A thermochromic coating material for short-circuit fault location in GIL (Gas Infrared Lever) tunnels, characterized in that: The material consists of 45-55 parts of matrix resin, 25-35 parts of toughening agent, 11-21 parts of composite color-changing filler and 6-10 parts of curing agent; the matrix resin is pretreated.
2. The thermochromic coating material for short-circuit fault location in GIL (Gas Infrared Lever) tunnels according to claim 1, characterized in that: The temperature response range of this material is 80-100℃.
3. The thermochromic coating material for short-circuit fault location in GIL (Gas Infrared Lever) tunnels according to claim 1, characterized in that: The matrix resin is a bisphenol A type epoxy resin.
4. The thermochromic coating material for short-circuit fault location in GIL (Gas Infrared Lever) tunnels according to claim 1, characterized in that: The toughening agent is polysulfide rubber; the curing agent is polyamide curing agent.
5. The thermochromic coating material for short-circuit fault location in GIL (Gas Infrared Lever) tunnels according to claim 1, characterized in that: The composite color-changing filler consists of 10-20 parts crystal violet and 1 part cobalt oxide.
6. A thermochromic coating material for short-circuit fault location in GIL (Gas Inlet and Line of Service) tunnels according to claim 1 or 3, characterized in that, The pretreatment method is as follows: place the matrix resin in an oven at 50-80℃ and preheat for 20-40 minutes.
7. A method for preparing a thermochromic coating material for short-circuit fault location in GIL (Gas Infrared Lever) tunnels as described in any one of claims 1-6, characterized in that, The specific steps are as follows: S1. Pretreatment: Place the matrix resin in an oven at 50-80℃ for 20-40 minutes for later use. S2, Mixed Matrix: The preheated matrix resin and toughening agent are mixed evenly to form a matrix mixture; S3. Add composite color-changing filler: Add composite color-changing filler to the matrix mixture to form a uniformly dispersed composite color-changing filler mixture system; S4. Curing and molding: Add curing agent to the mixture, stir evenly, apply to the surface of GIL shell, and let it stand at room temperature to cure and mold, thus obtaining a thermochromic coating material.
8. The method for preparing a thermochromic coating material for short-circuit fault location in GIL (Gas Infrared Lever) tunnels according to claim 1, characterized in that: In step S2, the preheated matrix resin and toughening agent are added to a mixer and mixed at 1000 r / min for 15-25 minutes to form a uniform matrix mixture.
9. The method for preparing a thermochromic coating material for short-circuit fault location in GIL (Gas Infrared Lever) tunnels according to claim 1, characterized in that: In step S3, crystal violet and cobalt oxide are added to the matrix mixture, and the rotation speed is adjusted to 1500 r / min, and the mixture is mixed for 25-35 minutes.
10. A method for preparing a thermochromic coating material for short-circuit fault location in GIL (Gas Infrared Lever) tunnels according to claim 1, characterized in that: In step S4, the coating method is spraying or brushing; the coating thickness is 0.3-0.5mm, and the standing time is ≥24 hours.