Temperature-responsive antioxidant transformer oil, preparation method thereof, and oil-immersed transformer

Abstract

The invention discloses a temperature-responsive antioxidant transformer oil, a preparation method and an oil-immersed transformer. The temperature-responsive antioxidant transformer oil comprises the following components by weight: highly refined paraffin base oil: 65-70 parts; hydrotreated cyclopentane oil: 25-30 parts; heat-activated thioether antioxidant: 0.3-0.4 parts; heat-activated peroxide initiator: 0.2-0.3 parts; organophosphorus synergist: 0.4-0.8 parts; and auxiliary agent: 0.09-0.21 parts. When the temperature rises, the heat-activated thioether antioxidant releases active groups to capture oxygen molecules, the heat-activated peroxide initiator generates free radicals to capture oil molecules and activate the heat-activated thioether antioxidant, and the organophosphorus synergist forms a metal protective film and regenerates the heat-activated thioether antioxidant.

Description

Technical Field

[0001] The invention relates to the field of oil-immersed transformers, and in particular to temperature-responsive antioxidant transformer oil, a preparation method thereof, and an oil-immersed transformer. Background Art

[0002] As the key medium in oil-immersed transformers, transformer oil plays a dual role of insulation and heat dissipation in power equipment. With the rapid development of the power industry, the performance requirements for transformer oil are constantly increasing. At present, transformer oils on the market mainly include three categories: mineral oil, synthetic oil and vegetable oil. Among them, mineral oil is still the most mainstream choice due to its high cost performance and stable performance. Modern transformer oil has made significant progress in refining technology, additive technology, etc., and can meet the operating needs of various transformers to a certain extent.

[0003] In practical applications, transformer oil has multiple functions: providing excellent insulation performance to prevent breakdown between live parts inside the transformer; dissipating the heat generated during transformer operation in a timely manner through convection; and also having auxiliary functions such as arc extinguishing and rust prevention. High-quality transformer oil usually has characteristics such as higher breakdown voltage, lower dielectric loss tangent, suitable viscosity and good oxidation stability.

[0004] However, transformer oil will undergo a complex degradation process during long-term use, and this degradation phenomenon is closely related to temperature factors. When the temperature of the transformer rises, the reaction rate of hydrocarbons in the oil and oxygen increases significantly, producing various oxygen-containing active compounds, which not only reduce the insulation performance of the oil, but also further catalyze the oxidation reaction, forming a vicious cycle.

[0005] What is more serious is that under high temperature conditions, some unstable components in transformer oil will undergo thermal decomposition, producing substances such as low molecular weight hydrocarbons and free carbon. These decomposition products not only change the physical and chemical properties of the oil, but also deposit inside the transformer to form sludge, affecting the heat dissipation effect. In addition, the increase in temperature will accelerate the reaction between transformer oil and metal parts, especially metals such as copper and iron will accelerate the oxidation and degradation of oil at high temperatures. Functional additives such as antioxidants added to traditional transformer oil will be consumed faster under high temperature conditions. Once the additives are exhausted, the deterioration rate of the oil will increase sharply.

[0006] These deterioration phenomena will eventually lead to a significant decrease in the insulation performance of the transformer oil, deterioration of the heat dissipation effect, and increased corrosion, which will seriously affect the safe operation and service life of the transformer. Therefore, it is of great significance to develop a new type of transformer oil that can actively respond and release antioxidant components when the temperature rises. This intelligent responsive transformer oil can automatically adjust its antioxidant capacity according to temperature changes, provide stronger protection under high temperature conditions, thereby delaying oil degradation and improving the operating reliability and service life of the transformer. Summary of the invention

[0007] One of the purposes of the present invention is to provide a temperature-responsive antioxidant transformer oil. This transformer oil can adjust its antioxidant capacity according to temperature changes, has a complex reaction network that changes with temperature, and achieves all-round and multi-level protection of the system through the synergistic effect of multiple mechanisms such as preventive protection, dynamic balance protection and sacrificial protection, thereby ensuring the stability and reliability of the oil under various temperature conditions.

[0008] One of the purposes of the present invention is achieved through the following technical solutions:

[0009] The temperature-responsive antioxidant transformer oil includes the following components by weight: highly refined paraffin base oil: 65-70 parts; hydrotreated cyclopentane oil: 25-30 parts; heat-activated thioether antioxidant: 0.3-0.4 parts; heat-activated peroxide initiator: 0.2-0.3 parts; organic phosphorus synergist: 0.4-0.8 parts; auxiliary agent: 0.09-0.21 parts. When the temperature rises, the heat-activated thioether antioxidant releases active groups to capture oxygen molecules, the heat-activated peroxide initiator generates free radicals to capture oil molecules and activate the heat-activated thioether antioxidant, and the organic phosphorus synergist forms a metal protective film and regenerates the heat-activated thioether antioxidant.

[0010] The present invention is further configured as follows: the heat-activated thioether antioxidant, the heat-activated peroxide initiator, and the organic phosphorus synergist are dipropyl disulfide, di-tert-butyl peroxide, and triphenylphosphite, respectively.

[0011] The present invention is further configured as follows: the auxiliary agent comprises the following components by weight: 0.03-0.08 parts of zinc dialkyl dithiophosphate; 0.05-0.10 parts of methyl benzotriazole; 0.01-0.03 parts of defoaming agent; wherein the zinc dialkyl dithiophosphate is a metal passivator and the methyl benzotriazole is a rust inhibitor.

[0012] A second object of the present invention is to provide a method for preparing a temperature-responsive antioxidant transformer oil.

[0013] The second object of the present invention is achieved through the following technical solutions:

[0014] A method for preparing a temperature-responsive antioxidant transformer oil comprises the following steps: (1) pretreatment of base oil; (2) addition of temperature-sensitive components; (3) construction of a protection system; and (4) heat treatment activation.

[0015] The present invention is further configured as follows: the specific steps of base oil pretreatment are: at 300-320°C and 56MPa pressure, hydrogen with a purity of ≥99.99% is introduced for refining treatment for 40-46 hours; then the temperature is lowered to 20°C for dewaxing treatment for 6-8 hours, and 0.8μm precision filtration is adopted.

[0016] The present invention is further configured as follows: the specific steps of adding the temperature-sensitive component are: at 45-50° C. and under nitrogen protection, dipropyl disulfide, di-tert-butyl peroxide, and triphenylphosphite are added in sequence, and stirred for 30 minutes after each addition.

[0017] The present invention is further configured as follows: the specific steps of constructing the protection system are: heating to 65-70° C. and adding zinc dialkyl dithiophosphate, adding methyl benzotriazole at 70-75° C., and adding a defoaming agent at 75-80° C.

[0018] The present invention is further configured as follows: the specific steps of heat treatment activation are: heating to 130° C. at a rate of 2° C. / min, keeping the temperature for 2 hours, and then naturally cooling to room temperature.

[0019] A third object of the present invention is to provide an oil-immersed transformer for use with a temperature-responsive antioxidant transformer oil.

[0020] The third object of the present invention is achieved through the following technical solutions:

[0021] An oil-immersed transformer adopts the above temperature-responsive antioxidant transformer oil, and adopts the above preparation method to prepare the temperature-responsive antioxidant transformer oil.

[0022] In summary, the present invention has the following beneficial effects:

[0023] Preventive protection: At room temperature (25-50°C), triphenylphosphite first reacts with the metal surface to form an initial protective film, mainly through Cu + + P(C6H5O)3→ [Cu-P(C6H5O)3] + and Fe 2+ + P(C6H5O)3→ [Fe-P(C6H5O)3]² +The reaction proceeds. At this time, the activity of dipropyl disulfide and di-tert-butyl peroxide is relatively low, and the system is in a relatively static state.

[0024] When the temperature rises to the medium temperature range (50-100°C), dipropyl disulfide begins to activate. C3H7-SS-C3H7 +ROO• → C3H7-S•-S-C3H7 + The ROOH reaction captures free radicals. At the same time, di-tert-butyl peroxide begins to slowly decompose: (CH3)3C-OOC(CH3)3→ 2(CH3)3C-O•, triphenylphosphite participates in the synergistic reaction, thereby allowing the dithiodipropyl ether to be recycled: C3H7-S•-S-C3H7 + P(C6H5O)3→ C3H7-SS-C3H7+ P•(C6H5O)3.

[0025] Dynamic balance protection: When entering the high temperature range (100-150℃), the decomposition of di-tert-butyl peroxide accelerates, and the generated (CH3)3C-O• reacts with the oil molecules: (CH3)3C-O• + RH → (CH3)3C-OH +R•, releasing a large number of free radicals. The free radicals excite dipropyl disulfide ether, enhancing its activity. C3H7-SS-C3H7+ ROO•→ C3H7-S(O)-S-C3H7+ RO• reaction captures a large number of free radicals. Triphenylphosphite quickly decomposes peroxide: P(C6H5O)3 + ROOH→ O=P(C6H5O)3+ ROH.

[0026] Sacrificial protection: When the temperature exceeds 150°C, the peroxide decomposes violently: 2ROOH →ROH + RO• +H2O, metal surface protective film through [MP(C6H5O)3]ⁿ + +O2 → [MO=P(C6H5O)3]ⁿ + The reaction thickens continuously, which plays an enhanced protective role on the inner surface of the transformer. The reaction of RO• with dipropyl disulfide: RO• +C3H7-SS-C3H7 → ROH+ C3H7-S•-S-C3H7. Dipropyl disulfide reacts with triphenylphosphite to form a final coordinated reaction:

[0027] Cyclic regeneration of dipropyl dithioether radical with unpaired electrons: C3H7-S•-S-C3H7 + P(C6H5O)3→ C3H7-SS-C3H7+ P• (C6H5O)3,

[0028] The unstable charged triphenylphosphite absorbs oxygen to form oxidized triphenylphosphite: P•(C6H5O)3+ O2 → O=P(C6H5O)3,

[0029] Regeneration of oxidized dipropyl disulfide: C3H7-S(O)-S-C3H7 +P(C6H5O)3 → C3H7-SS-C3H7 +O=P(C6H5O)3.

[0030] The above antioxidants, initiators and synergists form a complete synergistic protection network: dipropyl disulfide is mainly responsible for capturing free radicals, and the free radicals generated by the decomposition of di-tert-butyl peroxide are promptly removed by other components, which activates dipropyl disulfide, so that the antioxidant system can start the protection mechanism in time when the oil is subjected to thermal stress, rather than waiting until the external oxidative pressure is generated before starting to react. Triphenyl phosphite not only forms a protective film but also participates in the synergistic reaction to regenerate the free radicals and oxides of dipropyl disulfide. As the temperature rises, the three components are activated in turn, cooperate with each other, and jointly maintain the antioxidant stability of the system. In the entire temperature range, this multiple synergistic effect ensures the continuous stability of the oil, and maintains a good protective effect even under high temperature conditions.

[0031] In addition, the present application uses di-tert-butyl peroxide as an initiator for the polymerization reaction, while in the prior art, di-tert-butyl peroxide is rarely used in combination with an antioxidant because it is generally believed that peroxides will reduce antioxidant properties. The present application uses di-tert-butyl peroxide as an initiator to activate the overall antioxidant system in advance when the temperature is raised.

[0032] Furthermore, the present application needs to emphasize that in the ratio, the ratio of the organic phosphorus synergist is greater than the ratio of the antioxidant, and then through the initiator and antioxidant system, the antioxidant is always in a continuous cycle of regeneration and maintains its antioxidant effect under high temperature conditions, forming a dynamic equilibrium antioxidant mechanism. However, the existing antioxidant system is prone to failure at high temperatures, and the oil product deteriorates rapidly.

[0033] In addition, the Si-O bond in the defoamer (dimethyl polysiloxane) provided in the present application forms a hydrogen bond with the active group of dipropyl disulfide ether, which can reduce the surface tension of the system, improve the dispersibility of the antioxidant, reduce bubbles, and reduce the contact area between oxygen and oil.

[0034] Benzotriazole and zinc dithiophosphate form a double-layer protective film on the metal surface, the inner layer is a metal zinc phosphate film, and the outer layer is a hydrophobic triazole complex film. The double-layer film structure can improve the anti-rust effect.

[0035] Zinc dialkyl dithiophosphate can reduce the catalytic oxidation of metal ions, reduce the consumption rate of antioxidants, and extend the effective period of antioxidants. DETAILED DESCRIPTION

[0036] This application designed five experimental groups A1-A5 and two control groups B1-B2 for the experiment.

[0037] Experimental group design:

[0038] A1: Set as initial ratio

[0039] A2: The content of heat-activated thioether antioxidant increased by 10%

[0040] A3: The content of heat activated peroxide initiator is increased by 10%

[0041] A4: The content of organophosphorus synergist increased by 10%

[0042] A5: All three active ingredients increased by 10%

[0043] Control group design:

[0044] B1: Conventional mineral-based transformer oil (without temperature-responsive additives)

[0045] B2: Transformer oils containing only basic antioxidants

[0046] Specific formula (parts by weight):

[0047] Components A1(Standard) A2 A3 A4 A5 B1 B2 Highly refined paraffin base oil 67.5 67.4 67.4 67.1 66.9 70 69.5 Hydrotreated naphthenic oil 27.5 27.5 27.5 27.5 27.5 30 30 Dipropyl disulfide 0.35 0.385 0.35 0.35 0.385 0 0.3 Di-tert-butyl peroxide 0.25 0.25 0.275 0.25 0.275 0 0 Triphenylphosphite 0.6 0.6 0.6 0.66 0.66 0 0 Zinc dialkyl dithiophosphate 0.055 0.055 0.055 0.055 0.055 0 0.05 Tolyltriazole 0.075 0.075 0.075 0.075 0.075 0 0.07 Dimethicone 0.02 0.02 0.02 0.02 0.02 0 0.08

[0048] Test Item 1: Oxidation stability test

[0049] Conditions: 130±0.5°C, 500h, sampling every 100h

[0050] Test time (h) Acid value (mgKOH / g) A1 A2 A3 A4 A5 B1 B2 0 0.012 0.011 0.012 0.013 0.012 0.013 0.012 100 0.023 0.019 0.021 0.018 0.016 0.083 0.054 200 0.032 0.027 0.029 0.025 0.023 0.156 0.092 300 0.043 0.036 0.039 0.034 0.031 0.247 0.148 400 0.052 0.047 0.049 0.044 0.040 0.385 0.223 500 0.064 0.056 0.058 0.053 0.048 0.526 0.312

[0051] Test Item 2: Breakdown voltage at different temperatures (kV)

[0052] Conditions: Tested according to GB / T507, each temperature point is tested 6 times and the average value is taken

[0053] Temperature (°C) A1 A2 A3 A4 A5 B1 B2 25.0±0.2 74.8 75.2 74.9 75.3 75.8 69.7 71.5 75.0±0.2 71.6 72.8 72.4 73.6 74.3 64.8 67.9 125.0±0.2 67.9 69.5 68.7 70.8 71.6 54.6 59.8 175.0±0.2 61.7 64.3 63.8 65.7 67.9 44.8 51.6

[0054] Test Item 3: Antioxidant residual rate (%)

[0055] Conditions: 130±0.5°C, 96h, HPLC

[0056] Time (h) A1 A2 A3 A4 A5 B1 B2 0 100.0 100.0 100.0 100.0 100.0 - 100.0 24 91.8 93.6 92.7 94.8 95.7 - 84.6 48 84.7 87.5 86.8 89.6 91.4 - 71.8 72 78.6 82.4 81.5 84.7 87.3 - 59.5 96 71.8 76.5 75.8 79.4 83.6 - 47.3

[0057] Test Item 4: Copper corrosion (ASTM D130)

[0058] Condition: 100±0.5°C, rating by 3 testers independently evaluating and obtaining consistent results

[0059] Time (h) A1 A2 A3 A4 A5 B1 B2 24 1a 1a 1a 1a 1a 2a 1b 48 1b 1a 1a 1a 1a 2b 2a 96 1b 1b 1b 1a 1a 3a 2b

[0060] Test Item 5: Kinematic viscosity change rate (%)

[0061] Conditions: 130±0.5°C, measured at 40°C

[0062] Time (h) A1 A2 A3 A4 A5 B1 B2 0 0 0 0 0 0 0 0 100 2.47 2.23 2.34 2.06 1.83 8.46 5.52 200 4.82 4.25 4.43 3.87 3.54 15.63 10.24 300 7.18 6.52 6.75 5.96 5.38 24.75 16.47

[0063] Supplementary test item 6: Dielectric loss factor (tanδ)

[0064] Conditions: 90±0.5°C, test voltage 2000V, frequency 50Hz

[0065] Time (h) A1 A2 A3 A4 A5 B1 B2 0 0.00042 0.00043 0.00042 0.00041 0.00040 0.00045 0.00044 100 0.00046 0.00045 0.00045 0.00044 0.00042 0.00062 0.00053 200 0.00051 0.00048 0.00049 0.00047 0.00045 0.00085 0.00068 300 0.00057 0.00053 0.00054 0.00051 0.00048 0.00123 0.00089

[0066] The above test items have the following characteristics:

[0067] 1. Acid value test (mgKOH / g): reflects the degree of oxidation degradation of oil products

[0068] Principle: When oil is oxidized under high temperature and oxygen, acidic substances will be produced. The lower the acid value, the better the antioxidant performance, the less the degree of oil degradation, and the better the anti-oxidation effect of the temperature-responsive antioxidant system.

[0069] After 500 h, the acid value of group A5 was only 0.048, while that of control group B1 reached 0.526, indicating that the new formula has excellent antioxidant properties.

[0070] 2. Breakdown voltage (kV): reflects the insulation performance of the oil

[0071] Principle: It reflects the ability of oil to withstand electric field strength and is related to the content of water, impurities and polar substances in the oil. The ability to maintain the breakdown voltage when the temperature rises reflects the thermal stability of the oil.

[0072] At 175°C, group A5 still maintained 67.9 kV, while group B1 dropped to 44.8 kV, indicating that the new formula can still maintain good insulation performance at high temperatures.

[0073] 3. Antioxidant Residual Rate (%): reflects the durability and recycling capacity of the antioxidant system

[0074] The higher the residual rate, the slower the consumption of antioxidants, which reflects the effect of recycling and regeneration and the economy of the antioxidant system.

[0075] After 96 hours, the residual rate of group A5 was 83.6%, while that of group B2 was only 47.3%, proving that the antioxidants in the patented formula have good recycling and regeneration capabilities.

[0076] 4. Copper corrosion level (ASTM D130): reflects the protective performance of oil on metal

[0077] Principle: Evaluates the degree of corrosion after oil comes into contact with metal, reflects the effect of organic phosphorus synergists in forming a protective film, and the grade gradually deteriorates from 1a to 4c.

[0078] After 96 hours, the A4 and A5 groups still maintained level 1a, which verified the formation effect of the metal protective film.

[0079] 5. Viscosity change rate (%): reflects the thermal oxidation stability and structural retention ability of the oil

[0080] Principle: The increase in viscosity indicates that the oil has polymerized or oxidized. The smaller the rate of change, the better the thermal stability of the oil, which reflects the service life of the oil at high temperatures.

[0081] After 300 hours, the A5 group increased by only 5.38%, while the B1 group increased by 24.75%, indicating that the new formula can effectively inhibit the thermal oxidation degradation of oil products.

[0082] 6. Dielectric loss factor (tanδ)

[0083] Technical effect: reflects the dielectric properties and impurity content of oil products

[0084] Principle: It reflects the energy loss of oil under the action of alternating electric field. It is related to the polar substance content of oil and is an important indicator for evaluating transformer oil quality.

[0085] As mentioned above, after 300 h, the value of group A5 was 0.00048, while that of group B1 reached 0.00123, indicating that the new formula can better maintain the electrical properties of the oil.

[0086] In summary, the transformer oil described in the present application can adjust its antioxidant capacity according to temperature changes, and has a complex reaction network that changes with temperature. Through the synergistic effect of multiple mechanisms such as preventive protection, dynamic balance protection and sacrificial protection, it achieves all-round and multi-level protection of the system, ensuring the stability and reliability of the oil under various temperature conditions.

[0087] The preparation method of the temperature-responsive antioxidant transformer oil described in this application is as follows:

[0088] The preparation method includes four main steps:

[0089] 1. Base oil pretreatment:

[0090] Highly refined paraffin base oil: 65-70 parts;

[0091] Hydrotreated naphthenic oil: 25-30 parts;

[0092] High-purity hydrogen (≥99.99%) is introduced at 300-320°C and 56MPa pressure for refining treatment for 40-46 hours, then the temperature is lowered to 20°C for dewaxing treatment for 6-8 hours, and finally filtered with a precision of 0.8μm.

[0093] 2. Addition of temperature-sensitive components:

[0094] At 45-50°C, under nitrogen protection, add:

[0095] 0.3-0.4 parts of dipropyl disulfide;

[0096] Di-tert-butyl peroxide 0.2-0.3 parts;

[0097] Triphenylphosphite 0.4-0.8;

[0098] Stir for 30 minutes after each addition of each component.

[0099] 3. Construction of protection system:

[0100] Add in sequence by increasing the temperature:

[0101] At 65-70°C, add 0.03-0.08 parts of zinc dialkyl dithiophosphate;

[0102] At 70-75°C, add 0.05-0.10 parts of methylbenzotriazole;

[0103] At 75-80°C, add 0.01-0.03 parts of dimethyl polysiloxane.

[0104] 4. Heat treatment activation:

[0105] The temperature was raised to 130°C at a heating rate of 2°C / min, maintained at 130°C for 2 hours, and then naturally cooled to room temperature.

[0106] The preparation method has the following characteristics:

[0107] The high temperature and high pressure hydrogen refining process in the base oil pretreatment stage (300-320℃, 56MPa) can deeply remove unsaturated compounds, sulfur compounds and nitrogen compounds in the base oil, significantly improving the chemical stability of the base oil. The 0.8μm precision filtration ensures extremely high purity, which is reflected in the extremely low initial dielectric loss factor (0.00040 for Group A5) in the test data.

[0108] The addition of the temperature-sensitive components was carried out under mild conditions of 45-50°C and nitrogen protection. The temperature can ensure the dissolution of the components without activating the peroxide. The sequential addition of the three components (dipropyl disulfide, di-tert-butyl peroxide, and triphenylphosphite) formed a synergistic system. The data showed that after long-term heat aging at 130°C, the acid value of the A5 group was only 0.048, much lower than the 0.526 of the control group B1, proving the effectiveness of the temperature-sensitive system.

[0109] The protection system was constructed using a step-by-step temperature increase scheme of 65-80°C, so that zinc dialkyl dithiophosphate and methyl benzotriazole could fully react with the base oil at the optimal temperature. This performed well in the copper strip corrosion test, with group A5 still maintaining level 1a after 96 hours, indicating that the metal protective film was well formed.

[0110] The final 130℃ heat treatment activation step (2℃ / min heating) allows the entire system to reach the optimal state, which is verified in the antioxidant residual rate test: after 96 hours, the A5 group still maintains a high residual rate of 83.6%, while the conventional product B2 is only 47.3%. The slow heating rate ensures the uniformity of the system and avoids local overheating.

[0111] Compared with the existing technology, this preparation method achieves deep processing under mild conditions, avoids the generation of by-products caused by high-temperature reactions in traditional processes, and improves the thermal stability and electrical properties of the product. At the same time, precise temperature control and sequential addition ensure that each functional component can function under optimal conditions, forming a synergistic protective effect. This was confirmed in the 300-hour kinematic viscosity change rate test: Group A5 only increased by 5.38%, while Group B1 increased by 24.75%.

[0112] The above preparation method has good use benefits, especially in terms of stability under high temperature and long-term use conditions.

[0113] The present application also provides an oil-immersed transformer, which uses the temperature-responsive antioxidant transformer oil prepared by the above-mentioned preparation method.

[0114] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. Temperature-responsive antioxidant transformer oil, characterized in that: The components include the following by weight: Highly refined paraffin base oil: 65-70 parts; Hydrotreated naphthenic oil: 25-30 parts; Dipropyl disulfide: 0.3-0.4 parts; Di-tert-butyl peroxide: 0.2-0.3 parts; Triphenyl phosphite: 0.4-0.8 parts; Additives: 0.09-0.21 parts; When the temperature rises, the heat-activated thioether antioxidant releases active groups to capture oxygen molecules, the heat-activated peroxide initiator produces free radicals to capture oil molecules and initiate and activate the heat-activated thioether antioxidant, and the organophosphorus synergist forms a metal protective film and regenerates the heat-activated thioether antioxidant.

2. The temperature-responsive antioxidant transformer oil according to claim 1, characterized in that: The auxiliary agent includes the following components by weight: Zinc dialkyl dithiophosphate: 0.03-0.08 parts; Tolyltriazole: 0.05-0.10 parts; Dimethylpolysiloxane: 0.01-0.03 parts; Among them, zinc dialkyl dithiophosphate is a metal passivator, methyl benzotriazole is a rust inhibitor, and dimethyl polysiloxane is a defoaming agent.

3. A method for preparing a temperature-responsive antioxidant transformer oil, characterized in that: The preparation of the temperature-responsive antioxidant transformer oil according to any one of claims 1 to 2 comprises the following steps: (1) Base oil pretreatment; (2) Addition of temperature-sensitive components such as dipropyl disulfide, di-tert-butyl peroxide, and triphenylphosphite; (3) Construction of protection system; (4) Heat treatment activation.

4. The preparation method according to claim 3, characterized in that: The specific steps of the base oil pretreatment are: At 300-320℃ and 56MPa pressure, hydrogen with a purity of ≥99.99% is introduced for refining treatment for 40-46 hours; then the temperature is lowered to 20℃ for dewaxing treatment for 6-8 hours, and filtered with a precision of 0.8μm.

5. The preparation method according to claim 3, characterized in that: The specific steps of adding the temperature-sensitive component are: At 45-50°C, under nitrogen protection, add dipropyl disulfide, di-tert-butyl peroxide and triphenyl phosphite in sequence, stirring for 30 minutes after each addition.

6. The preparation method according to claim 3, characterized in that: The specific steps of constructing the protection system are: Raise the temperature to 65-70°C and add zinc dialkyl dithiophosphate, add methyl benzotriazole at 70-75°C, and add defoamer at 75-80°C.

7. The preparation method according to claim 3, characterized in that: The specific steps of the heat treatment activation are: The temperature was raised to 130°C at a rate of 2°C / min, kept at that temperature for 2 hours, and then naturally cooled to room temperature.

8. An oil-immersed transformer, characterized in that: The temperature-responsive antioxidant transformer oil as described in any one of claims 1 to 2 is used; or the temperature-responsive antioxidant transformer oil prepared by the preparation method as described in any one of claims 3 to 7 is used.