Vegetable oil additive for power transformer and preparation method of vegetable oil additive

Abstract

The invention relates to a vegetable oil additive for a power transformer and a preparation method thereof, and belongs to the technical field of power transformers. The invention discloses a high-temperature-resistant oil which comprises the following components in parts by weight: 1.5-3.5 parts of maleic anhydride-styrene copolymer used for reducing the freezing point of the oil and improving the low-temperature fluidity; 0.1 to 0.3 part of nano silicon dioxide hollow spheres; the octylphenol polyoxyethylene ether is used for improving the compatibility with the vegetable oil; 0.5-1.5 parts of butylated hydroxytoluene, which is used for ensuring the oxidation stability of the oil while ensuring the fluidity improvement; the titanate coupling agent is used for improving the dispersity and enhancing the stability and functionality of the vegetable oil. The vegetable oil additive disclosed by the invention can remarkably reduce the viscosity of vegetable oil and improve the fluidity, so that the vegetable oil can transfer heat and current more efficiently in a power transformer, meanwhile, the insulating property and the thermal stability are kept, and the using effect is greatly improved.

Description

Technical Field

[0001] The invention relates to a vegetable oil additive for a power transformer and a preparation method thereof, belonging to the technical field of power transformers. Background Art

[0002] A power transformer is a device that uses the principle of electromagnetic induction to change AC voltage. There are two types of transformers: oil-dry type and oil-immersed type. Oil-immersed transformers use transformer oil. Traditional ones mostly use mineral oil, but mineral oil has a relatively low ignition point and leakage will pollute the environment. Vegetable oil is more environmentally friendly and renewable.

[0003] With growing environmental awareness and the promotion of sustainable development concepts, vegetable oils are gaining increasing attention as alternatives to insulating oil in power transformers. However, vegetable oils suffer from high viscosity and poor fluidity, which to some extent limits their widespread use in power transformers. Based on this, the present invention provides a vegetable oil additive for power transformers and a method for preparing the same. Summary of the Invention

[0004] In view of this, the present invention provides a vegetable oil additive for power transformers and a preparation method thereof, which can significantly reduce the viscosity of vegetable oil, improve fluidity, and maintain insulation performance and thermal stability.

[0005] The invention provides a vegetable oil additive for a power transformer. The additive comprises the following components, measured in parts by weight: 1.5-3.5 parts of a maleic anhydride-styrene copolymer for lowering the freezing point of the oil and improving low-temperature fluidity; 0.1-0.3 parts of hollow nano-silica spheres; 0.05-0.15 parts of octylphenol polyoxyethylene ether for improving compatibility with the vegetable oil; 0.5-1.5 parts of butylated hydroxytoluene for ensuring the oxidative stability of the oil while improving fluidity; and 0.01-0.03 parts of a titanate coupling agent for improving dispersibility and enhancing the stability and functionality of the vegetable oil.

[0006] A method for preparing a vegetable oil additive for a power transformer comprises the following steps:

[0007] S1: Weigh maleic anhydride-styrene copolymer, nano-silica hollow spheres, octylphenol polyoxyethylene ether, butylated hydroxytoluene, and titanate coupling agent according to the proportion;

[0008] S2: Transesterification pretreatment: Vegetable oil and lower monohydric alcohol are stirred in a stirrer at a certain volume ratio. Sulfuric acid catalyst is added during the stirring process. The mixture is then placed in a microwave extraction reactor for transesterification. After the reaction is completed, the mixture is allowed to stand and separate to obtain the upper layer of pretreated oil.

[0009] S3: Composite modification: Heat the pretreated oil, then add maleic anhydride copolymer and stir and mix evenly, then add nano-silica hollow spheres and titanate coupling agent and stir and mix evenly, then add octylphenol polyoxyethylene ether and stir and mix evenly, then add butylated hydroxytoluene and stir and mix evenly, then perform ultrasonic dispersion treatment to obtain a mixed solution;

[0010] S4: Vacuum dehydration: Dehydrate under vacuum conditions for 2-3 hours.

[0011] S5: Filtration: The solution is filtered to remove impurities and undissolved particles to obtain the final vegetable oil additive product.

[0012] Furthermore, the lower monohydric alcohol in step S2 is isopropyl alcohol, and the vegetable oil is one or a mixture of two or more of rapeseed oil, peanut oil, camellia seed oil, sunflower oil, and corn oil.

[0013] Furthermore, in step S2, the concentration of sulfuric acid is 0.02-0.05 mol / L, and the volume ratio of the vegetable oil to the lower monohydric alcohol is 1:3-5.

[0014] Furthermore, the transesterification reaction is carried out under microwave irradiation at 60-70° C. for 10-15 minutes.

[0015] Furthermore, the pre-treated oil is heated at a temperature of 80-90°C in step S3.

[0016] Furthermore, the ultrasonic dispersion treatment in step S3 is carried out in a 40 kHz ultrasonic field, and the temperature is controlled to be ≤50°C.

[0017] Furthermore, the vacuum conditions in step S4 are pressure of -0.09 MPa and temperature of 100-110°C.

[0018] Beneficial effects of the present invention:

[0019] The present invention provides a vegetable oil additive for power transformers and a preparation method thereof, which can significantly reduce the viscosity of the vegetable oil and improve its fluidity, so that the vegetable oil can more efficiently transfer heat and current in the power transformer while maintaining insulation performance and thermal stability, thereby greatly improving the use effect. DETAILED DESCRIPTION

[0020] The terms "up", "down", "left", "right", "front", "back", "front", "back", "top", "bottom" and other directional terms mentioned or possibly mentioned in this specification are defined relative to the structure of the device and are relative concepts. Therefore, they may vary depending on the location and usage of the device; therefore, these or other directional terms should not be interpreted as restrictive.

[0021] As used in this specification, the singular forms "a," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the following further describes this application in detail in conjunction with the implementation methods. It should be understood that the implementation methods described herein are only used to explain this application and are not used to limit this application.

[0023] The preferred embodiments of the present invention will be described in detail below.

[0024] The invention provides a vegetable oil additive for a power transformer. The vegetable oil additive comprises the following components, measured in parts by weight: 1.5-3.5 parts of a maleic anhydride-styrene copolymer, which is used for lowering the freezing point of the oil and improving low-temperature fluidity; 0.1-0.3 parts of hollow nano-silica spheres; 0.05-0.15 parts of octylphenol polyoxyethylene ether, which is used for improving the compatibility between the additive and the vegetable oil and ensuring that the additive can be uniformly dispersed in the vegetable oil; 0.5-1.5 parts of butylated hydroxytoluene, which is used for ensuring the oxidative stability of the oil while improving the fluidity, maintaining the performance of the additive stable during long-term storage and use, and preventing performance degradation due to oxidation, corrosion, and the like; and 0.01-0.03 parts of a titanate coupling agent, which is used for improving dispersibility, enhancing the stability and functionality of the vegetable oil, reducing the viscosity of the system, and improving the fluidity.

[0025] A method for preparing a vegetable oil additive for a power transformer comprises the following steps:

[0026] S1: Weigh maleic anhydride-styrene copolymer, nano-silica hollow spheres, octylphenol polyoxyethylene ether, butylated hydroxytoluene, and titanate coupling agent according to the proportion;

[0027] S2: Transesterification pretreatment: Vegetable oil and lower monohydric alcohol are stirred and mixed in a stirrer at a volume ratio of 1:3-5, wherein the lower monohydric alcohol is isopropyl alcohol, and the vegetable oil is one or a mixture of two or more selected from rapeseed oil, peanut oil, camellia oil, sunflower oil, and corn oil. During the stirring process, sulfuric acid catalyst with a concentration of 0.02-0.05 mol / L is added, and then the mixture is placed in a microwave extraction reactor for transesterification reaction, and microwave irradiation is performed at 60-70°C for 10-15 minutes. After the reaction, the mixture is allowed to stand and separate to obtain an upper layer of pretreated oil, which helps improve the fluidity of the vegetable oil because esters generally have low viscosity.

[0028] S3: Composite modification: Heat the pretreated oil to 80-90°C, then add the maleic anhydride copolymer and stir and mix evenly, then add the nano-silica hollow spheres and titanate coupling agent and stir and mix evenly, then add octylphenol polyoxyethylene ether and stir and mix evenly, then add butylated hydroxytoluene and stir and mix evenly, then perform ultrasonic dispersion treatment in a 40kHz ultrasonic field at a temperature of ≤50°C to obtain a mixed solution;

[0029] S4: Vacuum dehydration: Dehydrate under vacuum conditions for 2-3 hours, with a vacuum pressure of -0.09 MPa and a temperature of 100-110°C.

[0030] S5: Filtration: Filter the solution to remove impurities and undissolved particles to obtain the final vegetable oil additive product.

[0031] As an optional embodiment, 100 kg of rapeseed oil is mixed with isopropyl alcohol at a ratio of 1:4, 0.03 mol / L sulfuric acid solution is added, and microwave treatment is performed at 65°C for 12 minutes. 2 kg of maleic anhydride copolymer, 0.2 kg of nano-silica treated with a titanate coupling agent, 0.1 kg of octylphenol polyoxyethylene ether, and 0.2 kg of butylated hydroxytoluene are added, ultrasonically dispersed for 25 minutes, and then vacuum-dehydrated to obtain the final vegetable oil additive product. The kinematic viscosity at 40°C can be reduced to 12-15 mm. 2 / s, the pour point dropped from -15℃ to below -35℃, and the oxidation stability increased by 3 times (acid value ≤ 0.03mgKOH / g).

[0032] The vegetable oil additive can significantly reduce the viscosity of the vegetable oil and improve its fluidity, so that the vegetable oil can transfer heat and current more efficiently in the power transformer while maintaining insulation performance and thermal stability, thereby greatly improving the use effect.

[0033] The above description of the present invention and its embodiments is non-limiting, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by the above description and, without departing from the purpose of the present invention, designs a structure and embodiment similar to the technical solution without creatively designing, they shall fall within the scope of protection of the present invention.

Claims

1. A vegetable oil additive for power transformers, characterized in that: The composition includes the following components by weight: 1.5-3.5 parts of maleic anhydride-styrene copolymer, which is used to lower the freezing point of the oil and improve low-temperature fluidity; 0.1-0.3 parts of nano-silica hollow spheres; Octylphenol polyoxyethylene ether 0.05-0.15 parts is used to improve the compatibility with vegetable oil; butylated hydroxytoluene 0.5-1.5 parts is used to ensure the oxidative stability of the oil while improving the fluidity; titanate coupling agent 0.01-0.03 parts is used to improve the dispersibility and strengthen the stability and functionality of the vegetable oil.

2. The method for preparing a vegetable oil additive for power transformer according to claim 1, wherein: The following steps are involved: S1: Weigh maleic anhydride-styrene copolymer, nano-silica hollow spheres, octylphenol polyoxyethylene ether, butylated hydroxytoluene, and titanate coupling agent according to the proportion; S2: Transesterification pretreatment: Vegetable oil and lower monohydric alcohol are stirred in a stirrer at a certain volume ratio. Sulfuric acid catalyst is added during the stirring process. The mixture is then placed in a microwave extraction reactor for transesterification. After the reaction is completed, the mixture is allowed to stand and separate to obtain the upper layer of pretreated oil. S3: Composite modification: Heat the pretreated oil, then add maleic anhydride copolymer and stir and mix evenly, then add nano-silica hollow spheres and titanate coupling agent and stir and mix evenly, then add octylphenol polyoxyethylene ether and stir and mix evenly, then add butylated hydroxytoluene and stir and mix evenly, then perform ultrasonic dispersion treatment to obtain a mixed solution; S4: Vacuum dehydration: dehydrate under vacuum conditions for 2-3 hours; S5: Filtration: Filter the solution to remove impurities and undissolved particles to obtain the final vegetable oil additive product.

3. The vegetable oil additive for power transformer and the preparation method thereof according to claim 2, characterized in that: The lower monohydric alcohol in step S2 is isopropyl alcohol, and the vegetable oil is one or a mixture of two or more of rapeseed oil, peanut oil, camellia seed oil, sunflower oil, and corn oil.

4. The vegetable oil additive for power transformer and the preparation method thereof according to claim 2, characterized in that: In step S2, the concentration of sulfuric acid is 0.02-0.05 mol / L, and the volume ratio of the vegetable oil to the lower monohydric alcohol is 1:3-5.

5. The vegetable oil additive for power transformer and the preparation method thereof according to claim 2, characterized in that: The transesterification reaction was carried out under microwave irradiation at 60-70° C. for 10-15 min.

6. The vegetable oil additive for power transformer and the preparation method thereof according to claim 2, characterized in that: The pre-treated oil is heated at a temperature of 80-90°C in step S3.

7. The vegetable oil additive for power transformer and the preparation method thereof according to claim 2, characterized in that: The ultrasonic dispersion treatment in step S3 is carried out in a 40 kHz ultrasonic field, and the temperature is controlled to be ≤50°C.

8. The vegetable oil additive for power transformer and the preparation method thereof according to claim 2, characterized in that: The vacuum conditions in step S4 are a pressure of -0.09 MPa and a temperature of 100-110°C.