Modified transformer oil and preparation method thereof

Abstract

The invention discloses modified transformer oil and a preparation method thereof, the transformer oil is composed of insulating oil and fluoride, and the volume of the fluoride accounts for 1-5% of the volume of the modified transformer oil; the fluoride is one or a mixture of two of perfluorooctane and perfluorooctane. According to the invention, 1%-5% by volume of fluoride is added into the mineral insulating oil, so that the flash point and the ignition point can be remarkably improved, high breakdown voltage and excellent insulating property can be maintained, and the anti-explosion safety of the transformer oil is greatly enhanced; the method is simple in process and low in cost, existing transformer equipment does not need to be transformed, the defect that traditional mineral oil is inflammable and explosive is overcome, and an efficient and reliable solution is provided for safe operation of power equipment.

Description

Technical Field

[0001] This invention relates to the field of insulating oil treatment technology, specifically to a modified transformer oil and its preparation method. Background Technology

[0002] In the vast and complex operation of modern power systems, mineral insulating oil, with its advantages of wide availability and economic cost, has become the most widely used insulating medium in key electrical equipment such as transformers and reactors. It not only undertakes the core functions of insulation, cooling, and arc extinguishing, but its performance directly affects the operational safety and lifespan of power equipment. However, with the rapid development of power facilities towards higher voltage and larger capacity, phenomena such as localized overheating and arc discharge during the operation of electrical equipment are becoming increasingly frequent, posing a serious challenge to the combustion and explosion risks of mineral insulating oil.

[0003] In recent years, improving the flame-retardant properties of insulating oil and reducing the risk of combustion and explosion has become a key technical challenge that the power industry urgently needs to overcome. Research has reported on improving the flame-retardant properties of insulating oil by adding additives. For example, Chinese patent application CN111286396A reports a method to increase the flash point of transformer oil by adding nanomaterials. However, due to the high amount of nanomaterials added (>5%), viscosity increases, sedimentation risk increases, and the preparation process of nanomaterials is complex. Chinese patent application CN113308290A discloses a method to improve the flame-retardant properties of insulating oil by adding flame retardants and polyhalogenated hydrocarbons, but this requires the addition of multiple types of solubilizers, which affects the oxidation stability and other properties of the insulating oil. Chinese patent application CN112175699A discloses a fluorinated liquid composition, but it suffers from drawbacks such as high cost and difficulty in widespread application. Summary of the Invention

[0004] The technical problem to be solved by this invention is how to simply improve the flammability and explosiveness of insulating oil.

[0005] The present invention solves the above-mentioned technical problems through the following technical means: A modified transformer oil is composed of insulating oil and fluoride, wherein the volume of fluoride accounts for 1-5% of the volume of the modified transformer oil; the fluoride is one or a mixture of two of perfluoronaphthene and perfluorooctane.

[0006] Preferably, the volume ratio of insulating oil to fluoride is 95-99:1-5; more preferably, it is one of 99:1, 98:2, or 95:5.

[0007] Preferably, the volume of fluoride accounts for 2-5% of the volume of the modified transformer oil.

[0008] Preferably, the volume of fluoride accounts for 3-5% of the volume of the modified transformer oil.

[0009] Preferably, the volume of the fluoride accounts for 5% of the volume of the modified transformer oil.

[0010] Preferably, when the fluoride is perfluoronaphthene, the volume of the fluoride accounts for 1-5% of the volume of the modified transformer oil; when the fluoride is perfluorooctane, the volume of the fluoride accounts for 2-5% of the volume of the modified transformer oil; preferably 2%.

[0011] Preferably, the fluoride is perfluoronaphthalene.

[0012] Preferably, the modified transformer oil is composed of insulating oil and fluoride, and the volume of fluoride accounts for 5% of the volume of the modified transformer oil; the fluoride is perfluoronaphthalene.

[0013] Preferably, the insulating oil is No. 25 mineral insulating oil.

[0014] The present invention also proposes a method for preparing the modified transformer oil, comprising the following steps: mixing insulating oil and fluoride and stirring evenly to obtain the modified transformer oil.

[0015] Preferably, the stirring temperature is 45-55℃ and the stirring time is 25-35 minutes.

[0016] Preferably, the stirring temperature is 50°C and the stirring time is 30 minutes.

[0017] Preferably, the modified transformer oil is obtained by stirring until homogeneous and then cooling to room temperature.

[0018] The advantages of this invention are: This invention addresses the shortcomings of complex nano-composite modification processes, deterioration of insulation performance of solubilized systems, high cost and poor compatibility of fluorinated liquid replacements. It provides a mineral insulating oil modification method with low addition amount, high compatibility and simple process, which significantly improves the flash point while maintaining high breakdown voltage and long-term stability. This invention involves adding 1%-5% (preferably 5%) by volume of perfluoronaphthene and perfluorooctane to mineral insulating oil and mixing them uniformly at 45-55°C (preferably 50°C). This significantly improves the flash point and ignition point while maintaining high breakdown voltage and excellent insulation performance, greatly enhancing the fire and explosion resistance of transformer oil. This method is simple, low-cost, and requires no modification to existing transformer equipment. It solves the problem of the flammability and explosion of traditional mineral oil, providing an efficient and reliable solution for the safe operation of power equipment.

[0019] This invention achieves uniform dispersion by adding perfluoronaphthalene and / or perfluorooctane to mineral oil at a low ratio (1%-5%) and mixing at 45-55℃, which significantly enhances safety while maintaining high breakdown voltage, and requires no modification to transformer equipment. Attached Figure Description

[0020] Figure 1 The mineral insulating oil of Example 3 of the present invention has 5% perfluoronaphthalene added. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available.

[0023] Unless otherwise specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product manual may be followed.

[0024] The basic insulating oil described below is No. 25 mineral insulating oil.

[0025] Example 1 Preparation and testing of oil modified with 1% perfluoronaphthalene Accurately measure 99 mL of basic insulating oil and 1 mL of perfluoronaphthalene to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, test its flash point and ignition point according to the standard method (GB / T3536), and test its breakdown voltage according to the standard method (GB / T 507).

[0026] Example 2 Preparation and testing of oil modified with 2% perfluoronaphthalene. Accurately measure 98 mL of basic insulating oil and 2 mL of perfluoronaphthalene to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, test its flash point and ignition point according to the standard method (GB / T3536), and test its breakdown voltage according to the standard method (GB / T 507).

[0027] Example 3 Preparation and testing of oil modified with 5% perfluoronaphthalene. Accurately measure 95 mL of basic insulating oil and 5 mL of perfluoronaphthalene to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, test its flash point and ignition point according to the standard method (GB / T3536), and test its breakdown voltage according to the standard method (GB / T 507); the resulting modified oil is shown in the photograph. Figure 1 As shown.

[0028] Example 4 Preparation and testing of oil modified with 1% perfluorooctane Accurately measure 99 mL of basic insulating oil and 1 mL of perfluorooctane to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, test its flash point and ignition point according to the standard method (GB / T3536), and test its breakdown voltage according to the standard method (GB / T 507).

[0029] Example 5 Preparation and testing of oil modified with 2% perfluorooctane Accurately measure 98 mL of basic insulating oil and 2 mL of perfluorooctane to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, test its flash point and ignition point according to the standard method (GB / T3536), and test its breakdown voltage according to the standard method (GB / T 507).

[0030] Example 6 Preparation and testing of oil modified with 5% perfluorooctane Accurately measure 95 mL of basic insulating oil and 5 mL of perfluorooctane to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, test its flash point and ignition point according to the standard method (GB / T3536), and test its breakdown voltage according to the standard method (GB / T 507).

[0031] Comparative Example 1 Preparation and testing of oil modified with 10% perfluoronaphthalene. Accurately measure 90 mL of basic insulating oil and 10 mL of perfluoronaphthalene to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, it was found that some perfluoronaphthalene precipitated at the bottom of the oil mixture, making it impossible to perform effective tests on flash point, ignition point, and breakdown voltage.

[0032] Comparative Example 2 Preparation and testing of oil modified with 10% perfluorooctane Accurately measure 90 mL of basic insulating oil and 10 mL of perfluorooctane to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, it was found that some perfluorooctane precipitated at the bottom of the oil mixture, making it impossible to perform effective tests on flash point, ignition point, and breakdown voltage.

[0033] Comparative Example 3 Preparation and testing of modified oil with 5% heptadecyltrimethoxysilane Accurately measure 95 mL of basic insulating oil and 5 mL of heptadecafluorodecyltrimethoxysilane to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, test its flash point and ignition point according to the standard method (GB / T 3536), and test its breakdown voltage according to the standard method (GB / T 507).

[0034] Comparative Example 4 Preparation and testing of modified oil with 10% heptadecyltrimethoxysilane Accurately measure 90 mL of basic insulating oil and 10 mL of heptadecafluorodecyltrimethoxysilane to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, it was found that some heptadecafluorodecyltrimethoxysilane precipitated at the bottom of the oil mixture, resulting in large fluctuations in the data for effective testing of flash point, ignition point, and breakdown voltage.

[0035] Comparative Example 5 Basic insulating oil performance test Accurately measure 100 mL of basic insulating oil (No. 25 mineral insulating oil) sample. Test its flash point and ignition point according to the standard method (GB / T 3536), and test its breakdown voltage according to the standard method (GB / T 507).

[0036] Comparative Example 6 Preparation and testing of modified oil with 1% perfluorooctyl ethyl acrylate Accurately measure 99 mL of basic insulating oil and 1 mL of perfluorooctyl ethyl acrylate to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, test its flash point and ignition point according to the standard method (GB / T 3536), and test its breakdown voltage according to the standard method (GB / T 507).

[0037] Comparative Example 7 Preparation and testing of modified oil with 2% perfluorooctyl ethyl acrylate Accurately measure 98 mL of basic insulating oil and 2 mL of perfluorooctyl ethyl acrylate to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, test its flash point and ignition point according to the standard method (GB / T 3536), and test its breakdown voltage according to the standard method (GB / T 507).

[0038] Comparative Example 8 Preparation and testing of modified oil with 5% perfluorooctyl ethyl acrylate Accurately measure 95 mL of basic insulating oil and 5 mL of perfluorooctyl ethyl acrylate to prepare a 100 mL mixture. Heat the mixture to 50°C and stir continuously at this temperature for 30 minutes to ensure homogeneity. After cooling to room temperature, test its flash point and ignition point according to the standard method (GB / T 3536), and test its breakdown voltage according to the standard method (GB / T 507).

[0039] Table 1. Test results of flash point, ignition point and breakdown voltage of insulating oils with different types and proportions of fluorides added.

[0040] In the table, " / " indicates that there is no valid test data.

[0041] Therefore, the modified insulating oil with 5% perfluoronaphthalene exhibited a higher breakdown voltage (55.9 kV), significantly better than the base oil (38.7 kV) and the sample with 5% perfluorooctane (37.4 kV). This indicates that adding 5% perfluoronaphthalene significantly increases the flash point while maintaining good insulating strength (high breakdown voltage) in the insulating oil.

[0042] In summary, the preferred embodiment determined by this invention is: adding 5% by volume of perfluoronaphthalene to the insulating oil and mixing it uniformly at 50°C. This method can significantly increase the flash point of the insulating oil (up to 210°C) while maintaining good breakdown voltage performance, thereby effectively enhancing its anti-flammability and explosion resistance.

[0043] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified transformer oil, characterized in that: It is composed of insulating oil and fluoride, and the volume of fluoride accounts for 1-5% of the volume of modified transformer oil; the fluoride is one or a mixture of two of perfluoronaphthene and perfluorooctane.

2. The modified transformer oil according to claim 1, characterized in that: The volume of fluoride accounts for 2-5% of the volume of modified transformer oil.

3. The modified transformer oil according to claim 1, characterized in that: Fluorides account for 3-5% of the volume of modified transformer oil.

4. The modified transformer oil according to claim 1, characterized in that: The volume of fluoride accounts for 5% of the volume of modified transformer oil.

5. The modified transformer oil according to claim 1, characterized in that: The fluoride is a perfluoronaphthalene.

6. The modified transformer oil according to claim 1, characterized in that: It consists of insulating oil and fluoride, with the volume of fluoride accounting for 5% of the volume of modified transformer oil; the fluoride is perfluoronaphthalene.

7. The modified transformer oil according to any one of claims 1-6, characterized in that: The insulating oil is No. 25 mineral insulating oil.

8. A method for preparing modified transformer oil according to any one of claims 1-7, characterized in that: Includes the following steps: The modified transformer oil is obtained by mixing insulating oil and fluoride and stirring evenly.

9. The method for preparing modified transformer oil according to claim 8, characterized in that: The stirring temperature is 45-55℃, and the stirring time is 25-35 minutes.

10. The method for preparing modified transformer oil according to claim 9, characterized in that: After stirring evenly, the mixture is cooled to room temperature to obtain the modified transformer oil.

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