High-flash-point mineral insulating oil and preparation method thereof

Abstract

The invention discloses high-flash-point mineral insulating oil and a preparation method thereof, and belongs to the technical field of electric insulating oil. The high-flash-point mineral insulating oil comprises the following components in percentage by weight: 94-95% of mineral transformer oil, 2% of cresyl diphenyl phosphate, 1-2% of triphenyl phosphate, 1-2% of triphenyl phosphate and 1-2% of tributyl phosphate. The high-flash-point mineral insulating oil provided by the invention has the beneficial effects that the selected flame retardant is a harmless liquid substance, halogen compounds harmful to the environment are completely avoided, and the final high-flash-point mineral insulating oil can be quickly formed by directly mixing the flame retardant and the mineral oil without the help of any solubilizer and by utilizing a mechanical stirring mode.

Description

Technical Field

[0001] The invention relates to the technical field of electric insulating oil, and in particular to a high flash point insulating oil and a preparation method thereof. Background Art

[0002] Mineral insulating oil is a liquid insulating medium widely used in electrical equipment. It has excellent electrical insulation and cooling properties and is low in cost. However, the flash point and ignition point of mineral insulating oil are low, less than 150 and 180°C respectively. Once the oil-filled electrical equipment fails such as short circuit, overheating, discharge, etc., the insulating oil is easy to catch fire and cause a fire accident, resulting in unnecessary electrical equipment losses and casualties.

[0003] In response to the low flash point and flammability of mineral insulating oil, flame-retardant or non-flammable products such as polychlorinated biphenyls, silicone oil, synthetic ester, high molecular weight hydrocarbon (HMWH oil), α oil, β oil, and natural ester insulating oil have been developed. However, due to various limitations such as cooling and insulation that cannot meet the requirements of electrical equipment or high production costs, the risk of explosion of the current stock of mineral insulating oil transformers cannot be solved. At present, mineral insulating oil is still the preferred liquid insulating medium for oil-filled electrical equipment. Developing a high flash point insulating oil based on mineral insulating oil is a feasible way to solve the risk of explosion of the current huge number of transformers in operation.

[0004] The Chinese patent application document with publication number CN111808667A discloses a high-ignition-point mineral insulating oil and a preparation method thereof, wherein a liquid flame retardant with a mass content of 3.5-7% is added, including halogen-containing flame retardants such as tris(1,3-dichloroisopropyl) phosphate and chlorinated paraffin 42. However, the halogen-containing flame retardant will also produce toxic or corrosive hydrogen halide gas during combustion, causing irreversible damage to human health or the environment. In addition, the introduction of paraffin-based hydrocarbons will reduce the pour point of the insulating oil.

[0005] A Chinese patent application document with publication number CN113308290A discloses a flame retardant transformer oil and a preparation method thereof, which is modified by adding a halogen-containing flame retardant. The flame retardant modifier used and the non-polar mineral insulating oil have poor compatibility, making it difficult to form a uniform and stable mixed solution, and it is necessary to additionally add amphiphilic substances such as polyhalogenated hydrocarbons and polyhalogenated ethers as solubilizers.

[0006] Disadvantages of existing technology: Halogen-containing flame retardants and solubilizers are often required in the preparation process of flame-retardant insulating oil, which has the risk of high preparation cost and easy environmental pollution. In addition, too many additives will also cause loss of electrical performance. Summary of the invention

[0007] The technical problem to be solved by the present invention is how to solve the problems of poor flame retardant effect and easy environmental pollution of the existing flame retardant insulating oil.

[0008] The present invention solves the above technical problems through the following technical means:

[0009] The first aspect of the present invention provides a high flash point mineral insulating oil, comprising the following components in weight percentage: (94-95)% mineral transformer oil, 2% toluene diphenyl phosphate, (1-2)% triphenyl phosphate, (1-2)% triphenyl phosphite and (1-2)% tributyl phosphate.

[0010] Preferably, the following components are included in weight percentage: 94% mineral transformer oil, 2% toluene diphenyl phosphate, 2% triphenyl phosphate, 1% triphenyl phosphite and 1% tributyl phosphate.

[0011] Preferably, the following components are included in weight percentage: 94% mineral transformer oil, 2% toluene diphenyl phosphate, 1% triphenyl phosphate, 2% triphenyl phosphite and 1% tributyl phosphate.

[0012] Preferably, the following components are included in weight percentage: 94% mineral transformer oil, 2% toluene diphenyl phosphate, 1% triphenyl phosphate, 1% triphenyl phosphite and 2% tributyl phosphate.

[0013] Preferably, the following components are included in weight percentage: 95% mineral transformer oil, 2% toluene diphenyl phosphate, 1% triphenyl phosphate, 1% triphenyl phosphite and 1% tributyl phosphate.

[0014] Preferably, the mineral transformer oil is one or more of No. 10, No. 25, and No. 45 mineral transformer oil.

[0015] The second aspect of the present invention provides a method for preparing the above-mentioned high flash point mineral insulating oil, comprising the following steps: mixing the ingredients according to the above-mentioned weight percentage, stirring at room temperature, and standing to obtain the high flash point mineral insulating oil.

[0016] Preferably, the stirring speed is 700-800 r / min, and the stirring time is 50-80 min; more preferably, it is 750 r / min, 60 min.

[0017] Preferably, the standing time is 22-28 hours, more preferably 24 hours.

[0018] The beneficial effects of the present invention are:

[0019] 1. The present invention provides a high flash point mineral insulating oil and a preparation method thereof, which is unique in that the flame retardant selected is a harmless liquid substance, completely avoiding halogen compounds that are harmful to the environment. In the preparation process, the flame retardant is directly mixed with the mineral oil without any solubilizer, and the final high flash point insulating oil can be quickly formed by mechanical stirring, thereby improving the flame retardant effect of the insulating oil.

[0020] 2. The present invention not only simplifies the production steps, but also ensures that the flash point and ignition point of the insulating oil are significantly improved, while maintaining excellent electrical properties, fully meeting the requirements of current standards, and the amount of flame retardant added is small and the cost is low. In addition, the addition of multiple flame retardants can give play to their respective advantages and achieve the purpose of synergistic enhancement. Different phosphorus-containing flame retardants can show different characteristics in terms of carbonization or free radical capture. Mixing can enhance the flame retardant effect at multiple levels and improve the overall flame retardant performance. This compounding strategy can not only improve the flame retardant efficiency, but also help reduce the total amount of flame retardant required, thereby reducing the negative impact on other properties of the insulating oil.

[0021] 3. High flash point insulating oil can be prepared by simple mechanical stirring and mixing without adding solubilizer. The introduction of halogen-free flame retardant significantly improves the flash point and ignition point of mineral insulating oil without changing the physical, chemical and electrical properties of mineral insulating oil. The phosphorus-containing free radicals generated by phosphorus-containing flame retardant during combustion can effectively inhibit the generation of hydroxyl and hydrogen free radicals in the flame, thereby achieving the principle of flame retardant effect. It effectively reduces the preparation cost of insulating oil and the risk of environmental pollution. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0024] If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0025] In order to facilitate the understanding of the present invention, the present invention is further described below in conjunction with preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0026] Embodiment 1:

[0027] A high flash point mineral insulating oil comprises the following components in percentage by weight: 94% of mineral transformer oil, 2% of toluene diphenyl phosphate, 2% of triphenyl phosphate, 1% of triphenyl phosphite and 1% of tributyl phosphate.

[0028] The preparation method of the high flash point insulating oil comprises the following steps: adding 94g of No. 25 mineral transformer oil, 2g of toluene diphenyl phosphate, 2g of triphenyl phosphate, 1g of triphenyl phosphite and 1g of tributyl phosphate according to weight percentage, and mechanically stirring at room temperature for 1h at a stirring speed of 750r / min to obtain a mixed oil. The mixed oil is cooled at room temperature and left to stand for 24h, and no stratification or turbidity occurs, so that the high flash point insulating oil is obtained.

[0029] Embodiment 2:

[0030] The difference between this embodiment and embodiment 1 is that it comprises the following components in weight percentage: 94% mineral transformer oil, 2% toluene diphenyl phosphate, 1% triphenyl phosphate, 2% triphenyl phosphite and 1% tributyl phosphate. The rest is the same as embodiment 1.

[0031] Embodiment 3:

[0032] The difference between this embodiment and embodiment 1 is that it comprises the following components in weight percentage: 94% mineral transformer oil, 2% toluene diphenyl phosphate, 1% triphenyl phosphate, 1% triphenyl phosphite and 2% tributyl phosphate. The rest is the same as embodiment 1.

[0033] Embodiment 4:

[0034] The difference between this embodiment and embodiment 1 is that it comprises the following components in weight percentage: 95% mineral transformer oil, 2% toluene diphenyl phosphate, 1% triphenyl phosphate, 1% triphenyl phosphite and 1% tributyl phosphate. The rest is the same as embodiment 1.

[0035] Comparative Example 1:

[0036] The mineral insulating oil of this comparative example is different from that of Example 1 in that it comprises the following components in weight percentage: 98% mineral transformer oil and 2% toluene diphenyl phosphate. The rest is the same as Example 1.

[0037] Comparative Example 2:

[0038] The mineral insulating oil of this comparative example is different from that of Example 1 in that it comprises the following components in weight percentage: 98% mineral transformer oil and 2% triphenyl phosphate. The rest is the same as Example 1.

[0039] Comparative Example 3:

[0040] The mineral insulating oil of this comparative example is different from that of Example 1 in that it comprises the following components in weight percentage: 98% mineral transformer oil, 1% triphenyl phosphite and 1% tributyl phosphate. The rest is the same as Example 1.

[0041] Comparative Example 4:

[0042] The mineral insulating oil of this comparative example is different from that of Example 1 in that it comprises the following components in weight percentage: 99% mineral transformer oil and 1% triphenyl phosphite. The rest is the same as Example 1.

[0043] Comparative Example 5:

[0044] The mineral insulating oil of this comparative example is different from that of Example 1 in that it comprises the following components in weight percentage: 99% mineral transformer oil and 1% tributyl phosphate. The rest is the same as Example 1.

[0045] Comparative Example 6:

[0046] The mineral insulating oil of this comparative example is different from that of Example 1 in that it comprises the following components in weight percentage: 99% mineral transformer oil and 1% tris(1,3-dichloroisopropyl) phosphate. The rest is the same as Example 1.

[0047] Comparative Example 7:

[0048] The mineral insulating oil of this comparative example is different from that of Example 1 in that it comprises the following components in weight percentage: 95% mineral transformer oil, 2% tris(1,3-dichloroisopropyl) phosphate, 2% triisopropylphenyl phosphate and 1% chlorinated paraffin 42. The rest is the same as Example 1.

[0049] The properties of the mineral insulating oils prepared in Examples 1-4 and Comparative Examples 1-7 were tested using existing methods. The test results are shown in Table 1.

[0050] Table 1 Test results of mineral insulating oil performance in Examples 1-4 and Comparative Examples 1-7

[0051]

[0052]

[0053] It can be seen from Table 1 that the mineral insulating oil of the present invention has a high flash point and a high fire point, and while improving the flash point and the fire point, the power frequency breakdown voltage and the kinematic viscosity thereof are not significantly changed, and can meet the requirements of existing standards.

[0054] Embodiment 5:

[0055] The difference between this embodiment and embodiment 1 is that it comprises the following components in weight percentage: 94.5% mineral transformer oil, 2% toluene diphenyl phosphate, 1.5% triphenyl phosphate, 2% triphenyl phosphite and 1% tributyl phosphate. The rest is the same as embodiment 1.

[0056] Embodiment 6:

[0057] The difference between this embodiment and embodiment 1 is that it comprises the following components in weight percentage: 94% mineral transformer oil, 2% toluene diphenyl phosphate, 1% triphenyl phosphate, 1.5% triphenyl phosphite and 1.5% tributyl phosphate. The rest is the same as embodiment 1.

[0058] Embodiment 7:

[0059] The difference between this embodiment and embodiment 1 is that the stirring speed is 700 r / min, the stirring time is 80 min, and the standing time is 28 h. The rest is the same as embodiment 1.

[0060] Embodiment 8:

[0061] The difference between this embodiment and embodiment 1 is that the stirring speed is 800 r / min, the stirring time is 50 min, and the standing time is 22 h. The rest is the same as embodiment 1.

[0062] The properties of the high flash point mineral insulating oils prepared in Examples 5-8 are similar to those in Example 1.

[0063] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high flash point mineral insulating oil, characterized in that: The invention comprises the following components in weight percentage: (94-95)% mineral transformer oil, 2% toluene diphenyl phosphate, (1-2)% triphenyl phosphate, (1-2)% triphenyl phosphite and (1-2)% tributyl phosphate.

2. The high flash point mineral insulating oil according to claim 1, characterized in that: The invention comprises the following components in weight percentage: 94% of mineral transformer oil, 2% of toluene diphenyl phosphate, 2% of triphenyl phosphate, 1% of triphenyl phosphite and 1% of tributyl phosphate.

3. The high flash point mineral insulating oil according to claim 1, characterized in that: The invention comprises the following components in weight percentage: 94% of mineral transformer oil, 2% of toluene diphenyl phosphate, 1% of triphenyl phosphate, 2% of triphenyl phosphite and 1% of tributyl phosphate.

4. The high flash point mineral insulating oil according to claim 1, characterized in that: The invention comprises the following components in weight percentage: 94% of mineral transformer oil, 2% of toluene diphenyl phosphate, 1% of triphenyl phosphate, 1% of triphenyl phosphite and 2% of tributyl phosphate.

5. The high flash point mineral insulating oil according to claim 1, characterized in that: The invention comprises the following components in weight percentage: 95% of mineral transformer oil, 2% of toluene diphenyl phosphate, 1% of triphenyl phosphate, 1% of triphenyl phosphite and 1% of tributyl phosphate.

6. The high flash point mineral insulating oil according to claim 1, characterized in that: The mineral transformer oil is one or more of No. 10, No. 25, and No. 45 mineral transformer oils.

7. The method for preparing a high flash point mineral insulating oil according to any one of claims 1 to 5, characterized in that: The following steps are involved: The ingredients are prepared according to weight percentage, stirred at room temperature, and allowed to stand to obtain the product.

8. The high flash point mineral insulating oil according to claim 7, characterized in that: The stirring speed is 700-800 r / min, and the stirring time is 50-80 min.

9. The high flash point mineral insulating oil according to claim 8, characterized in that: The stirring speed is 750 r / min, and the stirring time is 60 min.

10. The high flash point mineral insulating oil according to claim 7, characterized in that: The standing time is 22-28 hours.

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