Preparation method of an ultraviolet fluorescent profile - showing coating and its application in detecting oil - leakage areas of heat radiators of wind power transformers

Abstract

The present invention provides a method for preparing an ultraviolet fluorescent outline coating and its application in detecting oil leakage areas on wind power transformer heat sinks, belonging to the technical field of transformers. The ultraviolet fluorescent outline coating of the present invention is prepared by mixing a coumarin derivative with anhydrous ethanol to obtain a diluted fluorescent solution, dissolving ethyl orthosilicate in the mixed solution to obtain a base solution, and then mixing the diluted fluorescent solution with the base solution. The ultraviolet fluorescent outline coating can be further used in detecting oil leakage points on wind power transformer heat sinks. By displaying the outline of the oil leakage area, it assists in repairing oil leakage points on transformer heat sinks. It is not limited by the shape and size of the leakage point, and can help on-site maintenance personnel quickly determine the oil leakage area on the heat sink, improve the efficiency of oil leakage repair work, and reduce the risk of safety accidents.

Description

Technical Field

[0001] The present invention belongs to the technical field of transformers, and in particular relates to a preparation method of an ultraviolet fluorescent outline marking paint and an application thereof in detecting oil leakage areas of a heat sink of a wind power transformer. Background Art

[0002] Transformers in coastal wind turbines often use a fin-type structure to achieve rapid air cooling. The high-temperature, high-humidity, and high-salt marine atmosphere creates favorable conditions for fin corrosion. The heat sink fins are prone to corrosion and perforation, leading to cooling oil leaks and serious safety accidents. The hidden nature of the corrosion process makes it difficult to identify the leaking oil site, increasing the difficulty of repairing heat sink leaks. Current research on detecting heat sink leak sites is mostly conducted in the offline quality inspection phase, which cannot meet the needs of on-site repair work. The cooling oil contained in the heat sink unit of the transformer is colorless and transparent. After flowing on the surface of the heat sink, it drips to the bottom of the heat sink. Promptly discovering and identifying the heat sink oil leak area is of guiding significance for heat sink repair and maintenance work. Therefore, there is an urgent need for a method to efficiently detect heat sink oil leak areas to help on-site maintenance personnel quickly identify the heat sink oil leak area, improve the efficiency of oil leak repair work, and reduce the risk of safety accidents. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention proposes a preparation method of an ultraviolet fluorescent outline marking paint and its application in the detection of oil leakage areas of heat sinks of wind power transformers.

[0004] To achieve the above objectives, the present invention provides the following technical solutions:

[0005] One of the technical solutions of the present invention:

[0006] A method for preparing an ultraviolet fluorescent outline marking paint comprises the following steps: mixing a coumarin derivative with anhydrous ethanol to obtain a diluted fluorescent solution, dissolving ethyl orthosilicate in the mixed solution to obtain a base solution, and then mixing the diluted fluorescent solution with the base solution to obtain the ultraviolet fluorescent outline marking paint;

[0007] The coumarin derivative is a coumarin derivative having fluorescent properties obtained by substitution with an electron-donating group;

[0008] The mixed solution consists of N,N-dimethylformamide, methanol and polyethylene glycol.

[0009] Furthermore, the mass concentration of the coumarin derivative in the diluted fluorescent solution is 10%.

[0010] Furthermore, the volume ratio of the ethyl orthosilicate to the mixed solution is 2:98.

[0011] Furthermore, the volume ratio of the diluted fluorescent solution to the substrate solution is 1:100.

[0012] Furthermore, the volume ratio of N,N-dimethylformamide, methanol and polyethylene glycol in the mixed solution is 40:40:5.

[0013] Furthermore, the coumarin derivative is a coumarin derivative having fluorescent properties obtained by substituting one or both of the 3-position, 4-position and 7-position coumarin (the structural formula of coumarin and the schematic diagram of the substitution position are shown in Figure 2 ).

[0014] Furthermore, the coumarin derivatives include 7-(diethylamino)coumarin, 7-(diethylamino)coumarin-3-carbonitrile, 7-(diethylamino)coumarin-3-carboxylic acid, 7-(diethylamino)coumarin-3-carbohydrazide, 7-(diethylamino)coumarin-3-ethyl formate, coumarin-3-carboxylic acid, coumarin-3-carboxylic acid hexyl ester, and 7-hydroxy-4-methylcoumarin. The coumarin derivatives can be replaced with other substances with ultraviolet fluorescent properties that are compatible with the base solution, but they must not corrode the heat sink substrate.

[0015] The reason why the ultraviolet fluorescent outline marking paint prepared by the present invention can achieve excellent technical effects only after adding ethyl orthosilicate is that:

[0016] Ethyl orthosilicate hydrolyzes in a diluted fluorescent alcohol solution to form silica sol. The hydrophobic and lipophilic properties of silica sol allow it to encapsulate or load fluorescent coumarin derivatives, acting as a carrier for the fluorescent coumarin. Furthermore, the hydrophobic and lipophilic properties of silica sol allow for targeted adsorption near oil leaks, guiding the fluorescent reagent to accumulate near the oil path and providing a "probe" effect within the oil path.

[0017] The second technical solution of the present invention:

[0018] An ultraviolet fluorescent outline marking paint prepared by the above preparation method.

[0019] The third technical solution of the present invention:

[0020] The above-mentioned ultraviolet fluorescent outline paint is used in the detection of oil leakage points on the heat sink of a wind power transformer.

[0021] The fourth technical solution of the present invention:

[0022] A method for detecting oil leakage points of a wind power transformer heat sink using ultraviolet fluorescent marker paint comprises applying the ultraviolet fluorescent marker paint on the surface of the wind power transformer heat sink, irradiating the heat sink surface with ultraviolet light, and observing the fluorescent area.

[0023] Furthermore, the surface density of the ultraviolet fluorescent outline paint applied on the surface of the wind power transformer heat sink is 1mL / cm 2 The coating density is controlled because leaked cooling oil accumulates in cracks at the leak site, absorbing the oil-based fluorescent paint and producing strong fluorescence in the leaked area. However, since the coating is applied to a relatively large area of the entire potential leak area, and considering that a small amount of residual oil-based fluorescent paint in non-crack areas may interfere with the determination of fluorescence intensity at the cracks, the coating density is limited to a minimum.

[0024] Furthermore, before applying the ultraviolet fluorescent marker paint, the wind turbine transformer heat sink needs to be pretreated. The specific steps are: remove the rust and peeling surface coating on the surface of the wind turbine transformer heat sink and polish it smooth, and use a clean cotton ball dipped in deionized water and anhydrous ethanol respectively, and brush the heat sink to be inspected in turn to remove dust and oil stains on the heat sink surface.

[0025] Furthermore, after applying the ultraviolet fluorescent outline paint, let it stand for 5-10 minutes, then use a clean cotton ball dipped in anhydrous ethanol or ether to brush the surface of the heat sink to wipe off the oily reagent.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] The present invention proposes a method for locating the oil leakage area of the heat sink using ultraviolet fluorescent outline paint, and assists in the repair of the oil leakage point of the transformer heat sink by displaying the outline of the oil leakage area. This oil leakage point detection method is not limited by the shape and size of the leakage point, and can help on-site maintenance personnel quickly determine the oil leakage area of the heat sink, improve the efficiency of oil leakage repair work, and reduce the risk of safety accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0029] Figure 1 Schematic diagram of fluorescence display before and after application of the ultraviolet fluorescent outline marking paint prepared by the present invention when the heat sink of a wind power transformer has no defects, crack defects and oil leakage, or hole defects and oil leakage;

[0030] Figure 2 Schematic diagram of the coumarin structural formula and substitution positions. DETAILED DESCRIPTION

[0031] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0032] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0033] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0034] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0035] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0036] An embodiment of the present invention provides a method for preparing an ultraviolet fluorescent outline marking paint, comprising the following steps: mixing a coumarin derivative with anhydrous ethanol to obtain a diluted fluorescent solution, dissolving ethyl orthosilicate in the mixed solution to obtain a base solution, and then mixing the diluted fluorescent solution with the base solution to obtain the ultraviolet fluorescent outline marking paint;

[0037] The coumarin derivative is a coumarin derivative having fluorescent properties obtained by substitution with an electron-donating group;

[0038] The mixed solution consists of N,N-dimethylformamide, methanol and polyethylene glycol.

[0039] The silicon-based base solution serves as a carrier for the fluorescent coumarin. The silica sol formed during the preparation process is hydrophobic and lipophilic, which can help the fluorescent coumarin locate the oil circuit. It is absorbed by the cooling oil leaking from cracks or defects. The fluorescence intensity shows the oil circuit position, thereby determining the leaking oil defect site.

[0040] In a preferred embodiment of the present invention, the mass concentration of the coumarin derivative in the diluted fluorescent solution is 10%. Limiting the concentration of the coumarin derivative to 10% is intended to ensure that the fluorescent coumarin accounts for an appropriate proportion of the final coating composition, thereby preventing excessive fluorescent coumarin concentration from causing residual fluorescence in non-crack areas, which could interfere with the identification of fluorescence intensity at cracks. Furthermore, low concentrations of the fluorescent coumarin derivative may prevent insufficient fluorescence intensity at cracks, which could affect the identification of defect locations.

[0041] In a preferred embodiment of the present invention, the volume ratio of ethyl orthosilicate to the mixed solution is 2:98. Excessively high ethyl orthosilicate concentrations can lead to excessively rapid hydrolysis and cross-linking reactions, forming SiO2 particles that fail to encapsulate and act as a carrier for the fluorescent coumarin, thus failing to achieve the desired effects of the present invention. Furthermore, the solvent itself is highly volatile, and the effect of solvent volatilization on the reaction must be considered. Therefore, the volume ratio of ethyl orthosilicate to the mixed solution is set at 2%.

[0042] In a preferred embodiment of the present invention, the volume ratio of the diluted fluorescent solution to the base solution is 1:100. To ensure sufficient dispersion of the fluorescent coumarin in the formed silica sol, the proportion of coumarin in the silica sol carrier base solution is limited to avoid excessive or insufficient fluorescence intensity, which could affect the determination and identification of the location of the radiator oil leakage defect.

[0043] In a preferred embodiment of the present invention, the volume ratio of N,N-dimethylformamide, methanol, and polyethylene glycol in the mixed solution is 40:40:5. Methanol and N,N-dimethylformamide are mixed to form a mixed solution, which serves as a solvent to regulate the rate of hydrolysis of ethyl orthosilicate to form silica sol, while polyethylene glycol regulates the dispersibility of the silica sol.

[0044] In an embodiment of the present invention, the coumarin derivative is a coumarin derivative with fluorescent properties obtained by substituting any one or both of the 3-position, 4-position and 7-position of coumarin. Preferably, the coumarin derivative includes 7-(diethylamino) coumarin, 7-(diethylamino) coumarin-3-carbonitrile, 7-(diethylamino) coumarin-3-carboxylic acid, 7-(diethylamino) coumarin-3-carbohydrazide, 7-(diethylamino) coumarin-3-ethyl formate, coumarin-3-carboxylic acid, coumarin-3-carboxylic acid hexyl ester, and 7-hydroxy-4-methyl coumarin.

[0045] The specific embodiment of the present invention is prepared using 7-(diethylamino)coumarin (purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.) as an example. The coumarin derivatives used in the present invention can be replaced by other substances with ultraviolet fluorescent properties that are compatible with the base solution, but it is required that they do not cause corrosion damage to the heat sink base material.

[0046] The embodiment of the present invention also provides an ultraviolet fluorescent outline marking paint prepared by the above preparation method.

[0047] The embodiment of the present invention further proposes the application of the above-mentioned ultraviolet fluorescent outline marking paint in the detection of oil leakage points of the heat sink of a wind power transformer.

[0048] The embodiment of the present invention also proposes a method for detecting oil leakage points of wind power transformer heat sinks using ultraviolet fluorescent marker paint. The above-mentioned ultraviolet fluorescent marker paint is applied to the surface of the wind power transformer heat sink, and ultraviolet light is used to illuminate the heat sink surface to observe the fluorescent area.

[0049] In a preferred embodiment of the present invention, the surface density of the ultraviolet fluorescent outline paint applied on the surface of the wind power transformer heat sink is 1mL / cm 2 The reason for limiting the coating density is that leaked cooling oil accumulates in cracks at the leak site, absorbing the oil-based fluorescent paint and producing strong fluorescence in the leaked area. However, since the coating is applied to a relatively large area of the entire potential leak area, and considering that a small amount of residual oil-based fluorescent paint in non-crack areas may interfere with the determination of fluorescence intensity at the cracks, the coating density is limited to a minimum.

[0050] In a preferred embodiment of the present invention, before applying the ultraviolet fluorescent marker paint, the wind power transformer heat sink needs to be pretreated. The specific steps are: remove the rust and peeling surface coating on the surface of the wind power transformer heat sink and polish it smooth, and use a clean cotton ball dipped in deionized water and anhydrous ethanol respectively, and brush the parts of the heat sink to be inspected in turn to remove dust and oil stains on the surface of the heat sink. The above processes are all conventional technical means in this field.

[0051] In a preferred embodiment of the present invention, after applying the ultraviolet fluorescent marker paint, let it stand for 5-10 minutes, then use a clean cotton ball dipped in anhydrous ethanol or ether to brush the surface of the heat sink to wipe off the oily agent.

[0052] Schematic diagram of fluorescence display before and after applying the ultraviolet fluorescent outline paint prepared by the present invention when the heat sink of the wind power transformer has no defects, crack defects and oil leakage, as shown in FIG. Figure 1 .

[0053] All raw materials used in the examples of the present invention are commercially available.

[0054] The technical solution of the present invention is further illustrated by the following examples.

[0055] Example 1

[0056] 7-(diethylamino)coumarin was mixed with anhydrous ethanol to obtain a diluted fluorescent solution with a mass concentration of 10%, 2 mL of ethyl orthosilicate was dissolved in 98 mL of a mixed solution (composed of N,N-dimethylformamide, methanol, and polyethylene glycol in a volume ratio of 40:40:5) to obtain a silicon-based base solution, and then the diluted fluorescent solution prepared above was mixed with the silicon-based base solution in a volume ratio of 1:100 to obtain an ultraviolet fluorescent outline coating;

[0057] Before applying the UV fluorescent marker paint, remove the rust and peeling surface coating on the heat sink and polish it smooth. Then, use a clean cotton ball dipped in deionized water and anhydrous ethanol to apply to the heat sink to be tested, and remove dust and oil stains on the heat sink surface.

[0058] The ultraviolet fluorescent outline coating prepared above was 2 Apply the entire heat sink of the wind power transformer with a surface density of 100 μg / cm2. After standing for 10 minutes, use a clean cotton ball dipped in anhydrous ethanol to apply to the heat sink surface. Wipe off the oily reagent. After drying for 2 minutes, irradiate with ultraviolet light (light intensity: 90uW / cm2). 2 , illumination time: 10s) on the surface of the heat sink and observe the fluorescent area.

[0059] Results: The fluorescence intensity signal is obvious, which can well show the outline of the oil spill area.

[0060] Comparative Example 1

[0061] Same as Example 1, except that the UV fluorescent outline paint was sprayed at 0.5 mL / cm 2 The surface density of the whole wind power transformer heat sink is painted. The specific steps are as follows:

[0062] 7-(diethylamino)coumarin was mixed with anhydrous ethanol to obtain a diluted fluorescent solution with a mass concentration of 10%, 2 mL of ethyl orthosilicate was dissolved in 98 mL of a mixed solution (composed of N,N-dimethylformamide, methanol, and polyethylene glycol in a volume ratio of 40:40:5) to obtain a silicon-based base solution, and then the diluted fluorescent solution prepared above was mixed with the silicon-based base solution in a volume ratio of 1:100 to obtain an ultraviolet fluorescent outline coating;

[0063] Before applying the UV fluorescent marker paint, remove the rust and peeling surface coating on the heat sink and polish it smooth. Then, use a clean cotton ball dipped in deionized water and anhydrous ethanol to apply to the heat sink to be tested, and remove dust and oil stains on the heat sink surface.

[0064] The ultraviolet fluorescent outline coating prepared above was irradiated at 0.5 mL / cm 2Apply the entire heat sink of the wind power transformer with a surface density of 100 μg / cm2. After standing for 10 minutes, use a clean cotton ball dipped in ether to apply to the heat sink surface. Wipe off the oily reagent. After drying for 2 minutes, irradiate with ultraviolet light (light intensity: 90uW / cm2). 2 , illumination time: 10s) on the surface of the heat sink and observe the fluorescent area.

[0065] Results: Fluorescent spots gathered in the oil leakage area, and the fluorescence intensity was weak.

[0066] Comparative Example 2

[0067] Same as Example 1, except that the UV fluorescent outline paint was sprayed at 5 mL / cm 2 The surface density of the whole wind power transformer heat sink is painted. The specific steps are as follows:

[0068] 7-(diethylamino)coumarin was mixed with anhydrous ethanol to obtain a diluted fluorescent solution with a mass concentration of 10%, 2 mL of ethyl orthosilicate was dissolved in 98 mL of a mixed solution (composed of N,N-dimethylformamide, methanol, and polyethylene glycol in a volume ratio of 40:40:5) to obtain a silicon-based base solution, and then the diluted fluorescent solution prepared above was mixed with the silicon-based base solution in a volume ratio of 1:100 to obtain an ultraviolet fluorescent outline coating;

[0069] Before applying the UV fluorescent marker paint, remove the rust and peeling surface coating on the heat sink and polish it smooth. Then, use a clean cotton ball dipped in deionized water and anhydrous ethanol to apply to the heat sink to be tested, and remove dust and oil stains on the heat sink surface.

[0070] The ultraviolet fluorescent outline coating prepared above was sprayed with 5mL / cm 2 Apply the entire heat sink of the wind turbine transformer with a surface density of 100 nm. After standing for 10 minutes, use a clean cotton ball dipped in ether to apply to the surface of the heat sink. Wipe off the oily reagent. After drying for 2 minutes, use ultraviolet light to irradiate the surface of the heat sink and observe the fluorescent area.

[0071] Results: The fluorescent spots were observed to be scattered throughout the entire heat sink area to be tested. The fluorescence intensity signal was obvious and could not clearly show the outline of the oil leakage area.

[0072] Comparative Example 3

[0073] 7-(diethylamino)coumarin was mixed with anhydrous ethanol to obtain a diluted fluorescent solution with a mass concentration of 10%;

[0074] Before applying the UV fluorescent marker paint, remove the rust and peeling surface coating on the heat sink and polish it smooth. Then, use a clean cotton ball dipped in deionized water and anhydrous ethanol to apply to the heat sink to be tested, and remove dust and oil stains on the heat sink surface.

[0075] The diluted fluorescent solution prepared above was added at 1 mL / cm 2 Apply the entire heat sink of the wind turbine transformer with a surface density of 100 nm. After standing for 10 minutes, use a clean cotton ball dipped in anhydrous ethanol to apply to the surface of the heat sink. Wipe off the oily reagent. After drying for 2 minutes, use ultraviolet light to irradiate the surface of the heat sink and observe the fluorescent area.

[0076] Results: The fluorescent spots were observed to be scattered throughout the entire heat sink area to be tested. The fluorescence intensity signal was obvious and could not clearly show the outline of the oil leakage area.

[0077] According to the results of Example 1 and Comparative Examples 1-3, the UV fluorescent marker coating on the heat sink of the wind power transformer requires a suitable surface density to achieve a high fluorescence intensity signal, and the silicon-based base solution is the key to helping the fluorescent particles locate in the oil leakage area.

[0078] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. The application of ultraviolet fluorescent outline paint in the detection of oil leakage points of wind power transformer heat sinks is characterized by: The preparation method of the ultraviolet fluorescent outline marking paint comprises the following steps: mixing a coumarin derivative with anhydrous ethanol to obtain a diluted fluorescent solution, dissolving ethyl orthosilicate in the mixed solution to obtain a base solution, and then mixing the diluted fluorescent solution with the base solution to obtain the ultraviolet fluorescent outline marking paint; The mixed solution consists of N,N-dimethylformamide, methanol and polyethylene glycol; The mass concentration of the coumarin derivative in the diluted fluorescent solution is 10%; The coumarin derivative is selected from the group consisting of 7-(diethylamino)coumarin, 7-(diethylamino)coumarin-3-carbonitrile, 7-(diethylamino)coumarin-3-carbohydrazide, 7-(diethylamino)coumarin-3-ethyl formate, coumarin-3-carboxylic acid, coumarin-3-carboxylic acid hexyl ester, and 7-hydroxy-4-methylcoumarin; The surface density of the ultraviolet fluorescent outline paint applied on the surface of the wind power transformer heat sink is 1mL / cm 2 .

2. The application of the ultraviolet fluorescent outline paint in the detection of oil leakage points of the heat sink of a wind power transformer according to claim 1 is characterized in that: The volume ratio of the ethyl orthosilicate to the mixed solution is 2:

98.

3. The application of the ultraviolet fluorescent outline paint in the detection of oil leakage points of the heat sink of a wind power transformer according to claim 1 is characterized in that: The volume ratio of the diluted fluorescent solution to the substrate solution is 1:

100.

4. The application of the ultraviolet fluorescent outline paint in the detection of oil leakage points of the heat sink of a wind power transformer according to claim 1 is characterized in that: The volume ratio of N,N-dimethylformamide, methanol and polyethylene glycol in the mixed solution is 40:40:

5.

5. A method for detecting oil leaks on a wind power transformer heat sink using ultraviolet fluorescent marker paint, characterized in that: The ultraviolet fluorescent outline paint prepared according to any one of claims 1 to 4 is applied to the surface of a heat sink of a wind power transformer, and the surface of the heat sink is irradiated with ultraviolet light to observe the fluorescent area.

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