Multifunctional additive of insulating oil, efficient antioxidant heat-conducting insulating oil and preparation method of efficient antioxidant heat-conducting insulating oil
By grafting antioxidants in situ on the surface of mesoporous nanoparticles and adding them to the insulating oil, the complexity and impurities of existing insulating oil performance improvement methods are solved, and multiple performance improvements and cost-effective maintenance of insulating oil are achieved.
Patent Information
- Application Number
- CN202510208914.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-25
- Publication Date
- 2025-05-30
AI Technical Summary
Existing methods for improving performance of insulating oils are usually limited to a particular performance, requiring the introduction of multiple additives, increasing production complexity and possible impurities, affecting costs and performance.
Mesoporous nanoparticles are used as multifunctional additives, and antioxidants are grafted onto the surface of nanoparticles through initiators to enhance the compatibility of nanoparticles with insulating oil, and prevent the free migration of antioxidant, insulating and thermal conductivity of insulating oil.
The comprehensive performance improvement of insulating oil has been achieved, including improvements in oxidation resistance, insulation and thermal conductivity, while maintaining high cost-effectiveness and long-term stability, which is suitable for large-scale industrial production.
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of insulating oils, and particularly to a multifunctional additive for insulating oils, a highly efficient antioxidant and heat-conducting insulating oil, and a preparation method thereof. Background Art
[0002] As a key insulating medium in the power system, the performance of insulating oil directly affects the operation safety and service life of electrical equipment. With the development of the power industry, the requirements for insulating oil are increasing day by day, especially in terms of antioxidant performance and heat conduction performance. At present, there are mainly two ways to improve the performance of insulating oil in the market: one is to develop new high-performance insulating oil substrates, which has high technical difficulty and R & D cost; the other is to improve the performance of existing insulating oil through additives, which is currently the simplest, economical and effective method.
[0003] Among them, the most common method to improve the antioxidant performance of insulating oil is to add antioxidants to the insulating oil. These antioxidants are mostly phenolic, amine or mercaptan compounds, which inhibit the oxidation process of the oil by reacting with free radicals in the oil, decomposing peroxides or terminating the free radical chain reaction. In addition, in terms of improving the heat conduction performance, the current technology mainly adds heat conduction enhancers, such as metal oxides or nanomaterials.
[0004] It can be seen that the current methods for improving the performance of insulating oil are usually limited to selecting additives for a specific performance. When improving the antioxidant and heat conduction performance of insulating oil, it is necessary to introduce a variety of additives with different functions, which not only increases the complexity of the production process, but also may introduce too many impurities, affecting the production cost and product performance of insulating oil. Summary of the Invention
[0005] The present invention provides a multifunctional additive for insulating oils, a highly efficient antioxidant and heat-conducting insulating oil, and a preparation method thereof, so as to provide a multifunctional additive with both antioxidant and heat conduction performance, realize multiple improvements in the antioxidant performance, insulating performance, heat conduction performance and stability of insulating oil, maintain high cost-effectiveness and long-term stability, and improve the comprehensive quality of insulating oil products.
[0006] In order to solve the above technical problems, one of the objectives of the present invention is to provide a preparation method for a multifunctional additive for insulating oils, comprising the following steps:
[0007] Disperse mesoporous nanoparticles in a solvent, add an initiator, and the mass ratio of the mesoporous nanoparticles to the initiator is (10 - 20) : 3. Heat and stir, and at the same time add an antioxidant while stirring. The mass ratio of the antioxidant to the mesoporous nanoparticles is (2 - 5) : 10. Continue to stir evenly, filter and dry to obtain mesoporous nanoparticles grafted with an antioxidant; the particle size of the mesoporous nanoparticles is 1 - 100 nm.
[0008] By adopting the above scheme, the chemical bonds in the added initiator molecules will decompose to generate free radicals in a high-temperature environment. These free radicals have high activity and will attack the active sites on the surface of the mesoporous nanoparticles and the antioxidant molecules, causing the nanoparticles and the antioxidant molecules to form reactive intermediates. As a result, the antioxidant is in-situ grafted onto the surface of the mesoporous nanoparticles in a chemical bonding manner, which can not only enhance the compatibility between the mesoporous nanoparticles and the organic body of the insulating oil, but also effectively prevent the free migration of the antioxidant in the insulating oil, control the release duration of the antioxidant, extend the action time of the antioxidant, and the mesoporous nanoparticles can also improve the insulation performance and thermal conductivity of the insulating oil. Compared with the traditional method, it improves the cost-effectiveness and product performance stability, and the process is simple, suitable for large-scale industrial production.
[0009] As a preferred scheme, the initiator is at least one of benzoyl peroxide, 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis(isobutyrate), dicarbonate peroxide, acyl peroxide, dialkyl peroxide.
[0010] As a preferred scheme, the antioxidant is at least one of hindered phenol antioxidants, amine antioxidants, sulfur antioxidants.
[0011] As a preferred scheme, the mesoporous nanoparticles are at least one of nano-silica, nano-zinc oxide, nano-aluminum oxide, boron nitride, nano-titanium dioxide.
[0012] As a preferred scheme, the heating and stirring temperature is 50-80 °C, the stirring rate is 300-600 rpm, and the stirring time after adding the antioxidant is 30-60 min.
[0013] As a preferred scheme, the solvent is at least one of water, ethanol, methanol, n-hexane, acetone, tetrahydrofuran, cyclohexane, pentane, octane, dichlorobenzene, dichloromethane.
[0014] As a preferred scheme, 100-200 mL of solvent is added per 0.1 moL of mesoporous nanoparticles.
[0015] As a preferred scheme, the solvent is an ethanol aqueous solution with a mass fraction of 20 wt%-50 wt%.
[0016] As a preferred scheme, the particle size of the mesoporous nanoparticles is 30-80 nm, and the specific surface area is 20-600 m 2 / g.
[0017] As a preferred scheme, the mesoporous nanoparticles are nano-silica, and the specific surface area is 200-600 m 2 / g.
[0018] As a preferred embodiment, the mesoporous nanoparticles are nano-titanium dioxide with a specific surface area of 5 - 120 m 2 / g.
[0019] As a preferred embodiment, the mesoporous nanoparticles are nano-zinc oxide with a specific surface area of 30 - 70 m 2 / g.
[0020] As a preferred embodiment, the mesoporous nanoparticles are nano-aluminum oxide with a specific surface area of 100 - 500 m 2 / g.
[0021] As a preferred embodiment, the mesoporous nanoparticles are boron nitride with a specific surface area of 5 - 20 m 2 / g.
[0022] By adopting the above scheme, the nanoparticles in this application have a relatively small particle size, relatively high specific surface area and surface energy, can be in full contact with and interact with insulating oil molecules, significantly improve the heat dissipation performance of the insulating oil, have good dispersibility and stability, are not easy to agglomerate, and can maintain good performance for a long time. If the specific surface area of the nanoparticles decreases, the surface energy decreases, the interaction force with the insulating oil molecules weakens, and agglomeration is likely to occur, resulting in uneven dispersion in the insulating oil, affecting the stability of the insulating oil performance. Moreover, larger particle size nanoparticles will significantly increase the viscosity of the insulating oil, affecting the fluidity of the insulating oil, which is not conducive to heat dissipation and oil circulation during equipment operation, may cause local overheating of the equipment, and reduce the operation efficiency and lifespan of the equipment. At the same time, when the particle size of the nanoparticles is relatively large, polarization is likely to occur under the action of an electric field, resulting in local electric field distortion, thereby reducing the insulation performance of the insulating oil and increasing the risk of insulation failure of the equipment. Larger nanoparticles will also face the problem of precipitation caused by weakened Brownian motion, which is more likely to affect operation safety.
[0023] To solve the above technical problems, the second object of the present invention provides a multifunctional additive for insulating oil prepared by a preparation method of a multifunctional additive for insulating oil.
[0024] To solve the above technical problems, the third object of the present invention provides a highly efficient antioxidant and heat-conducting insulating oil containing 0.1 wt% - 1 wt% of the multifunctional additive.
[0025] As a preferred embodiment, it includes 0.1 wt% - 1 wt% of the multifunctional additive, 90 - 99.9 wt% of the insulating oil matrix, and 0 wt% - 9 wt% of the functional auxiliary agent.
[0026] As a preferred embodiment, the insulating oil matrix is a synthetic ester insulating oil, a mineral insulating oil, or a natural ester insulating oil.
[0027] As a preferred embodiment, the functional auxiliary agent is at least one of a preservative, an antifoaming agent, and an anti-emulsifying agent.
[0028] Compared with the prior art, the present invention has the following beneficial effects:
[0029] In this application, an antioxidant is in-situ grafted onto the surface of mesoporous nanoparticles in a chemically bonded manner by using an initiator, which enhances the compatibility between the mesoporous nanoparticles and the organic body of the insulating oil. At the same time, it can effectively prevent the free migration of the antioxidant in the insulating oil, improve the antioxidant strength, extend the action time of the antioxidant, and the mesoporous nanoparticles can also improve the insulation performance and thermal conductivity of the insulating oil. While achieving the improvement of comprehensive performance, it also maintains a high cost-effectiveness and is suitable for large-scale industrial production. Specific Embodiments
[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.
[0031] It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention. In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded within the range.
[0032] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation 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 related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.
[0033] As used herein, the terms:
[0034] "Prepared from" is synonymous with "comprising". As used herein, the terms "comprising", "including", "having", "containing" or any other variation thereof are intended to cover non-exclusive inclusion. For example, a composition, step, method, article or apparatus that comprises the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article or apparatus.
[0035] The conjunctive "consisting of" excludes any unrecited element, step or component. If used in a claim, this phrase renders the claim closed, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the claim body rather than immediately following the subject, it only limits the elements described in that clause; other elements are not excluded from the claim as a whole.
[0036] In these examples, unless otherwise specified, the parts and percentages are by mass.
[0037] "Parts by mass" refers to the basic measurement unit representing the proportional relationship of the masses of multiple components. One part can represent any unit mass. It should not be misunderstood that, different from the number of parts by mass, the sum of the parts by mass of all components is not limited to 100 parts.
[0038] "And / or" is used to indicate that either or both of the stated circumstances may occur. For example, A and / or B includes (A and B) and (A or B).
[0039] To further illustrate the present invention, the present invention will be described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention. Unless otherwise specified, the raw materials used in the following examples and comparative examples of the present application are commercially available, and the same raw materials are used in parallel experiments.
[0040] Preparation Example 1
[0041] A multifunctional composite additive for insulating oil, the preparation method of which comprises the following steps:
[0042] Select particles with a particle size of 50 nm and a specific surface area of 40 - 70 m 2 / g of mesoporous nanoparticles are dispersed in an ethanol aqueous solution, wherein the mesoporous nanoparticles are nano-titanium dioxide, and 150mL of a 33wt% ethanol aqueous solution is added to every 1g of the mesoporous nanoparticles. At the same time, a toluoyl peroxide initiator is added, and the mass ratio of the mesoporous nanoparticles to the initiator is 5:1. The mixture is fully stirred at a temperature of 60°C and a stirring speed of 500rpm, and 2,6-di-tert-butyl-4-methylphenol antioxidant is added while stirring, and the mass ratio of the antioxidant to the mesoporous nanoparticles is 3:10. The stirring is continued for 30 minutes, and then the mixture is filtered and dried to obtain mesoporous nanoparticles grafted with an antioxidant.
[0043] Preparation Example 2
[0044] A multifunctional composite additive for insulating oil, the preparation method of which comprises the following steps:
[0045] Select particle size 80nm, specific surface area 20-50m 2 / g of mesoporous nanoparticles are dispersed in an ethanol aqueous solution, wherein the mesoporous nanoparticles are nano-titanium dioxide. 100mL of a 20wt% ethanol aqueous solution is added to every 1g of the mesoporous nanoparticles. At the same time, azobisisoheptanenitrile initiator is added, and the mass ratio of the mesoporous nanoparticles to the initiator is 10:3. The mixture is fully stirred at a temperature of 50°C and a stirring speed of 300rpm. While stirring, butylated hydroxytoluene antioxidant is added, and the mass ratio of the antioxidant to the mesoporous nanoparticles is 2:10. The stirring is continued for 40 minutes, and then the mixture is filtered and dried to obtain mesoporous nanoparticles grafted with an antioxidant.
[0046] Preparation Example 3
[0047] A multifunctional composite additive for insulating oil, the preparation method of which comprises the following steps:
[0048] Select particle size 30nm, specific surface area 60-120m 2 / g of mesoporous nanoparticles are dispersed in an ethanol aqueous solution, wherein the mesoporous nanoparticles are nano-titanium dioxide, and 200mL of a 40wt% ethanol aqueous solution is added to every 1g of the mesoporous nanoparticles. At the same time, a dimethyl azobisisobutyrate initiator is added, and the mass ratio of the mesoporous nanoparticles to the initiator is 20:3. The mixture is fully stirred at a temperature of 80°C and a stirring speed of 600rpm, and tert-butylhydroquinone antioxidant is added while stirring, and the mass ratio of the antioxidant to the mesoporous nanoparticles is 5:10. The stirring is continued for 60 minutes, and then the mixture is filtered and dried to obtain mesoporous nanoparticles grafted with an antioxidant.
[0049] Comparative Preparation Example 1
[0050] A multifunctional composite additive for insulating oil, the preparation method of which comprises the following steps:
[0051] Select mesoporous nanoparticles with a particle size of 50 nm and a specific surface area of 40 - 70 m 2 / g. Disperse them in an ethanol aqueous solution. The mesoporous nanoparticles are nano-titanium dioxide. For every 1 g of mesoporous nanoparticles, add 150 mL of an ethanol aqueous solution with a concentration of 33 wt%. Stir well at a temperature of 60 °C and a stirring speed of 500 rpm. While stirring, add 2,6-di-tert-butyl-4-methylphenol antioxidant. The mass ratio of the antioxidant to the mesoporous nanoparticles is 3:10. Continue stirring for 30 min, and then filter and dry to obtain mesoporous nanoparticles loaded with the antioxidant.
[0052] Comparative Preparation Example 2
[0053] A multifunctional composite additive for insulating oil, and its preparation method includes the following steps:
[0054] Select mesoporous nanoparticles with a particle size of 80 nm and a specific surface area of 20 - 50 m 2 / g. Disperse them in an ethanol aqueous solution. The mesoporous nanoparticles are nano-titanium dioxide. For every 1 g of mesoporous nanoparticles, add 100 mL of an ethanol aqueous solution with a concentration of 20 wt%. Stir well at a temperature of 50 °C and a stirring speed of 300 rpm. While stirring, add dibutylhydroxytoluene antioxidant. The mass ratio of the antioxidant to the mesoporous nanoparticles is 2:10. Continue stirring for 40 min, and then filter and dry to obtain mesoporous nanoparticles loaded with the antioxidant.
[0055] Comparative Preparation Example 3
[0056] A multifunctional composite additive for insulating oil, and its preparation method includes the following steps:
[0057] Select mesoporous nanoparticles with a particle size of 30 nm and a specific surface area of 60 - 120 m 2 / g. Disperse them in an ethanol aqueous solution. The mesoporous nanoparticles are nano-titanium dioxide. For every 1 g of mesoporous nanoparticles, add 200 mL of an ethanol aqueous solution with a concentration of 40 wt%. Stir well at a temperature of 80 °C and a stirring speed of 600 rpm. While stirring, add tert-butylhydroquinone antioxidant. The mass ratio of the antioxidant to the mesoporous nanoparticles is 5:10. Continue stirring for 60 min, and then filter and dry to obtain mesoporous nanoparticles loaded with the antioxidant.
[0058] Comparative Preparation Example 4
[0059] A multifunctional composite additive for insulating oil, and its preparation method includes the following steps:
[0060] Select mesoporous nanoparticles with a particle size of 200 nm and a specific surface area of 5 - 15 m 2 / g of mesoporous nanoparticles are dispersed in an ethanol aqueous solution, wherein the mesoporous nanoparticles are nano-titanium dioxide, and 150mL of a 33wt% ethanol aqueous solution is added to every 1g of the mesoporous nanoparticles. At the same time, a toluoyl peroxide initiator is added, and the mass ratio of the mesoporous nanoparticles to the initiator is 5:1. The mixture is fully stirred at a temperature of 60°C and a stirring speed of 500rpm, and 2,6-di-tert-butyl-4-methylphenol antioxidant is added while stirring, and the mass ratio of the antioxidant to the mesoporous nanoparticles is 3:10. The stirring is continued for 30 minutes, and then the mixture is filtered and dried to obtain mesoporous nanoparticles grafted with an antioxidant.
[0061] Example 1
[0062] A high-efficiency anti-oxidation heat-conducting insulating oil comprises 0.1wt% of the multifunctional composite additive of Preparation Example 1 and the remainder of TMP triester insulating oil, and the preparation method thereof comprises the following steps:
[0063] Add a multifunctional composite additive to TMP triester insulating oil, place the oil sample on a magnetic stirrer and stir it for 10 hours at room temperature using a small or medium-sized elliptical stirring bar to ensure that the composite additive is fully dissolved in the oil sample. After the dissolution is completed, the oil sample is clear without suspension and the color is slightly deepened to obtain a synthetic ester insulating oil.
[0064] Example 2
[0065] A high-efficiency anti-oxidation heat-conducting insulating oil comprises 0.3wt% of the multifunctional composite additive of Preparation Example 2 and the remainder of Karamay #25 mineral insulating oil, and the preparation method thereof comprises the following steps:
[0066] Add a multifunctional composite additive to Karamay #25 mineral insulating oil, place the oil sample on a magnetic stirrer and stir it for 10 hours at room temperature using a small or medium-sized elliptical stirring bar to ensure that the composite additive is fully dissolved in the oil sample. After the dissolution is complete, the oil sample is clear without suspension and the color is slightly deepened to obtain mineral insulating oil.
[0067] Example 3
[0068] A high-efficiency anti-oxidation thermally conductive insulating oil, comprising 0.5 wt% of the multifunctional composite additive of Preparation Example 3 and the remainder of Cargill The natural ester, the preparation method of which comprises the following steps:
[0069] Cargill A multifunctional composite additive is added to the natural ester, and the oil sample is placed on a magnetic stirrer and fully stirred for 10 hours using a small or medium-sized elliptical stirring bar at room temperature to ensure that the composite additive is fully dissolved in the oil sample. After the dissolution is completed, the oil sample is clear without suspension and the color is slightly deepened to obtain natural ester insulating oil.
[0070] Comparative Example 1
[0071] An efficient antioxidant and thermally conductive insulating oil, comprising 0.1 wt% of the multifunctional composite additive of Comparative Preparation Example 1 and the balance of TMP triester insulating oil, and its preparation method comprises the following steps:
[0072] Add the multifunctional composite additive to the TMP triester insulating oil, and place the oil sample on a magnetic stirrer with a medium-sized or small-sized oval stir bar at room temperature and stir thoroughly for 10 h to ensure that the composite additive is fully dissolved in the oil sample. After dissolution is completed, the oil sample is clear without suspension and the color is slightly darkened to obtain a synthetic ester insulating oil.
[0073] Comparative Example 2
[0074] An efficient antioxidant and thermally conductive insulating oil, comprising 0.3 wt% of the multifunctional composite additive of Comparative Preparation Example 2 and the balance of Karamay #25 mineral insulating oil, and its preparation method comprises the following steps:
[0075] Add the multifunctional composite additive to the Karamay #25 mineral insulating oil, and place the oil sample on a magnetic stirrer with a medium-sized or small-sized oval stir bar at room temperature and stir thoroughly for 10 h to ensure that the composite additive is fully dissolved in the oil sample. After dissolution is completed, the oil sample is clear without suspension and the color is slightly darkened to obtain a mineral insulating oil.
[0076] Comparative Example 3
[0077] An efficient antioxidant and thermally conductive insulating oil, comprising 0.5 wt% of the multifunctional composite additive of Comparative Preparation Example 3 and the balance of Cargill natural ester, and its preparation method comprises the following steps:
[0078] Add the multifunctional composite additive to Cargill natural ester, and place the oil sample on a magnetic stirrer with a medium-sized or small-sized oval stir bar at room temperature and stir thoroughly for 10 h to ensure that the composite additive is fully dissolved in the oil sample. After dissolution is completed, the oil sample is clear without suspension and the color is slightly darkened to obtain a natural ester insulating oil.
[0079] Comparative Example 4
[0080] An efficient antioxidant and thermally conductive insulating oil, comprising 0.1 wt% of mesoporous nanoparticles and the balance of TMP triester insulating oil, wherein the mesoporous nanoparticles are nano-titanium dioxide with a particle size of 80 nm and a specific surface area of 20 - 50 m 2 / g, and its preparation method comprises the following steps:
[0081] Mesoporous nanoparticles were added to the TMP triester insulating oil, and the oil sample was placed on a magnetic stirrer with a medium - sized oval stir bar at room temperature and stirred thoroughly for 10 h to ensure that the composite additive was fully dissolved in the oil sample. After dissolution, the oil sample was clear without suspension and its color was slightly darkened, obtaining the synthetic ester insulating oil.
[0082] Comparative Example 5
[0083] A highly efficient antioxidant and heat - conducting insulating oil comprises 0.1 wt% of 2,6 - di - tert - butyl - 4 - methylphenol antioxidant and the balance of TMP triester insulating oil. Its preparation method includes the following steps:
[0084] 2,6 - Di - tert - butyl - 4 - methylphenol was added to the TMP triester insulating oil, and the oil sample was placed on a magnetic stirrer with a medium - sized oval stir bar at room temperature and stirred thoroughly for 10 h to ensure that the composite additive was fully dissolved in the oil sample. After dissolution, the oil sample was clear without suspension and its color was slightly darkened, obtaining the synthetic ester insulating oil.
[0085] Comparative Example 6
[0086] A highly efficient antioxidant and heat - conducting insulating oil comprises 0.1 wt% of mesoporous nanoparticles and the balance of Karamay #25 mineral insulating oil. The mesoporous nanoparticles are nano - titanium dioxide with a particle size of 80 nm and a specific surface area of 20 - 50 m 2 / g. Its preparation method includes the following steps:
[0087] Mesoporous nanoparticles were added to the Karamay #25 mineral insulating oil, and the oil sample was placed on a magnetic stirrer with a medium - sized oval stir bar at room temperature and stirred thoroughly for 10 h to ensure that the composite additive was fully dissolved in the oil sample. After dissolution, the oil sample was clear without suspension and its color was slightly darkened, obtaining the mineral insulating oil.
[0088] Comparative Example 7
[0089] A highly efficient antioxidant and heat - conducting insulating oil comprises 0.1 wt% of 2,6 - di - tert - butyl - 4 - methylphenol antioxidant and the balance of Karamay #25 mineral insulating oil. Its preparation method includes the following steps:
[0090] 2,6 - Di - tert - butyl - 4 - methylphenol was added to the Karamay #25 mineral insulating oil, and the oil sample was placed on a magnetic stirrer with a medium - sized oval stir bar at room temperature and stirred thoroughly for 10 h to ensure that the composite additive was fully dissolved in the oil sample. After dissolution, the oil sample was clear without suspension and its color was slightly darkened, obtaining the mineral insulating oil.
[0091] Comparative Example 8
[0092] A highly efficient antioxidant and heat - conducting insulating oil comprises 0.1 wt% of mesoporous nanoparticles and the balance of Cargill Natural ester, mesoporous nanoparticles are titanium dioxide nanoparticles with a particle size of 80 nm and a specific surface area of 20 - 50 m 2 / g, and its preparation method includes the following steps:
[0093] Add mesoporous nanoparticles to Cargill natural ester, place the oil sample on a magnetic stirrer with a small and medium-sized oval stir bar at room temperature and stir well for 10 h to ensure that the composite additive is fully dissolved in the oil sample. After dissolution, the oil sample is clear without suspension and the color is slightly darkened to obtain natural ester insulating oil.
[0094] Comparative Example 9
[0095] An efficient antioxidant and heat-conducting insulating oil, including 0.1 wt% of 2,6-di-tert-butyl-4-methylphenol antioxidant and the balance of Cargill natural ester, and its preparation method includes the following steps:
[0096] Add 2,6-di-tert-butyl-4-methylphenol to Cargill natural ester, place the oil sample on a magnetic stirrer with a small and medium-sized oval stir bar at room temperature and stir well for 10 h to ensure that the composite additive is fully dissolved in the oil sample. After dissolution, the oil sample is clear without suspension and the color is slightly darkened to obtain natural ester insulating oil.
[0097] Comparative Example 10
[0098] An efficient antioxidant and heat-conducting insulating oil, including 0.1 wt% of the multifunctional composite additive of Comparative Preparation Example 4 and the balance of TMP triester insulating oil, and its preparation method includes the following steps:
[0099] Add the multifunctional composite additive to TMP triester insulating oil, place the oil sample on a magnetic stirrer with a small and medium-sized oval stir bar at room temperature and stir well for 10 h to ensure that the composite additive is fully dissolved in the oil sample. After dissolution, the oil sample is clear without suspension and the color is slightly darkened to obtain synthetic ester insulating oil.
[0100] Comparative Example 11
[0101] An efficient antioxidant and heat-conducting insulating oil, including 0.3 wt% of the multifunctional composite additive of Comparative Preparation Example 4 and the balance of Karamay #25 mineral insulating oil, and its preparation method includes the following steps:
[0102] Add the multifunctional composite additive to Karamay #25 mineral insulating oil, place the oil sample on a magnetic stirrer with a small and medium-sized oval stir bar at room temperature and stir well for 10 h to ensure that the composite additive is fully dissolved in the oil sample. After dissolution, the oil sample is clear without suspension and the color is slightly darkened to obtain mineral insulating oil.
[0103] Comparative Example 12
[0104] A high-efficiency anti-oxidation thermal conductive insulating oil, comprising 0.5wt% of the multifunctional composite additive of comparative preparation example 4 and the remainder of Cargill The natural ester, the preparation method of which comprises the following steps:
[0105] Cargill A multifunctional composite additive is added to the natural ester, and the oil sample is placed on a magnetic stirrer and fully stirred for 10 hours using a small or medium-sized elliptical stirring bar at room temperature to ensure that the composite additive is fully dissolved in the oil sample. After the dissolution is completed, the oil sample is clear without suspension and the color is slightly deepened to obtain natural ester insulating oil.
[0106] Performance testing
[0107] 1. Insulation performance: The power frequency breakdown voltage and the dielectric loss factor at 90° C. of the insulating oil samples prepared in the embodiment and the comparative example were measured using an insulating oil dielectric strength tester and a dielectric loss tester, respectively. The power frequency breakdown voltage test was performed according to the IEC60156-2018 standard, and the dielectric loss factor was performed according to the IEC 60247 standard. The test results are shown in Table 1 below.
[0108] 2. Antioxidant stability: The acid value and AOM value of the insulating oil samples of the embodiment and the comparative example were measured using a fat oxidation tester. The acid value was tested according to GB / T 7599-2014 standard, and the AOM value was tested according to AOM AOCSCd12-57 standard. The test results are shown in Table 1 below.
[0109] 3. Kinematic viscosity: The kinematic viscosity of the insulating oil samples of the embodiment and the comparative example at 40° C. was measured using a capillary viscometer in accordance with GB / T 265-1988. The test results are shown in Table 1 below.
[0110] 4. Thermal conductivity: The thermal conductivity of the insulating oil samples of the embodiment and the comparative example was measured using a heat flow meter and a thermal conductivity meter according to ASTM D5470-17. The test results are shown in Table 1 below.
[0111] Table 1 - Performance test results of insulating oil in examples and comparative examples
[0112]
[0113]
[0114] As shown in Table 1, in Examples 1-3, a multifunctional additive was added to the insulating oil. Compared with the insulating oil without the additive, the power frequency breakdown voltage was higher and the dielectric loss factor was lower, indicating an improvement in insulation performance. The total acid ester content and kinematic viscosity decreased, and the AOM value increased, indicating an improvement in antioxidant stability. The increase in thermal conductivity indicated an improvement in heat conduction performance. The antioxidant in the multifunctional additive of the present application is chemically bonded to the surface of nano-silica by an initiator, which can prevent the antioxidant from free migration in the insulating oil, improve the ability to capture free radicals in the insulating oil, extend the release duration of the antioxidant, and nano-zirconia can also improve the insulation and heat conduction performance of the insulating oil, thereby improving the overall comprehensive performance.
[0115] As shown in Table 1, compared with Examples 1-3, in Comparative Examples 4, 6, and 8, mesoporous nanoparticles were added to the insulating oil, and no antioxidant component was loaded on their surfaces. The total acid ester content of the prepared insulating oil was not much different from that of the base insulating oil, and the AOM value was significantly lower than that of Examples 1-3, indicating a significant decrease in antioxidant ability; although the thermal conductivity had a certain improvement effect compared with the base oil, it was still not as good as that of Examples 1-3, indicating a decrease in heat conductivity. In addition, compared with Examples 1-3, in Comparative Examples 5, 7, and 9, only antioxidant components were added to the insulating oil. The total acid ester content of the prepared insulating oil was lower than that of the base insulating oil, and the AOM value was higher, but the antioxidant, insulation, and heat conduction performances were all not as good as those of Examples 1-3. This is because the antioxidant in Examples 1-3 is chemically bonded to the surface of the mesoporous nanoparticles, which can prevent the antioxidant from free migration in the insulating oil, thereby improving the antioxidant ability. Moreover, the mesoporous nanoparticles have a relatively high specific surface area and surface energy, can fully contact and interact with the insulating oil molecules, significantly improve the heat dissipation performance of the insulating oil, and comprehensively improve the insulation and heat conduction performances of the insulating oil.
[0116] As shown in Table 1, compared with Examples 1-3, the particle size of the mesoporous nanoparticles in the insulating oil of Comparative Examples 10-12 was relatively large, 200 nm. The specific surface area and surface energy of the mesoporous nanoparticles were relatively low, the interaction force with the insulating oil molecules was weakened, and agglomeration was likely to occur, resulting in uneven dispersion in the insulating oil, affecting the stability of the insulating oil performance. Moreover, the relatively large particle size of the nanoparticles would significantly increase the kinematic viscosity of the insulating oil, affecting the fluidity of the insulating oil, which was not conducive to heat dissipation and oil circulation during the operation of the equipment, and the thermal conductivity was significantly reduced. At the same time, the relatively large particle size of the nanoparticles was prone to polarization under the action of an electric field, resulting in local electric field distortion, thereby causing a decrease in the insulation performance of the insulating oil.
[0117] The specific embodiments described above have further elaborated on the object, technical solution and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not intended to limit the protection scope of the present invention. In particular, it is pointed out that for those skilled in the art, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A method for preparing a multifunctional additive for insulating oil, characterized in that: The following steps are involved: Dispersing mesoporous nanoparticles in a solvent, adding an initiator, the mass ratio of the mesoporous nanoparticles to the initiator being (10-20):3, heating and stirring, adding an antioxidant while stirring, the mass ratio of the antioxidant to the mesoporous nanoparticles being (2-5):10, continuing to stir evenly, filtering, and drying to obtain mesoporous nanoparticles grafted with an antioxidant; The particle size of the mesoporous nanoparticles is 1-100 nm.
2. The method for preparing a multifunctional additive for insulating oil according to claim 1, characterized in that: The initiator is at least one of toluoyl peroxide, azobisisoheptonitrile, dimethyl azobisisobutyrate, dicarbonate peroxide, acyl peroxide, and dialkyl peroxide.
3. The method for preparing a multifunctional additive for insulating oil according to claim 1, characterized in that: The antioxidant is at least one of a hindered phenol antioxidant, an amine antioxidant, and a sulfur antioxidant; And / or, the mesoporous nanoparticles are at least one of nano-silicon dioxide, nano-zinc oxide, nano-aluminum oxide, boron nitride, and nano-titanium dioxide.
4. The method for preparing a multifunctional additive for insulating oil according to claim 1, characterized in that: The heating and stirring temperature is 40-80° C., the stirring rate is 300-600 rpm, and the stirring time after the antioxidant is added is 30-60 min.
5. The method for preparing a multifunctional additive for insulating oil according to claim 1, characterized in that: The solvent is at least one of water, ethanol, methanol, n-hexane, acetone, tetrahydrofuran, cyclohexane, pentane, octane, dichlorobenzene and dichloromethane; And / or, 100-200 mL of solvent is added for every 0.1 mol of mesoporous nanoparticles.
6. The method for preparing a multifunctional additive for insulating oil according to claim 1, characterized in that: The solvent is an ethanol aqueous solution with a mass fraction of 20wt%-50wt%.
7. The method for preparing a multifunctional additive for insulating oil according to claim 1, characterized in that: The particle size of the mesoporous nanoparticles is 30-80 nm, and the specific surface area is 20-600 m 2 / g.
8. A multifunctional additive for insulating oil prepared by the method for preparing a multifunctional additive for insulating oil according to any one of claims 1 to 7.
9. A high-efficiency anti-oxidation thermally conductive insulating oil, characterized in that: The multifunctional additive for insulating oil according to claim 8 contains 0.1wt%-1wt% by mass.
10. The high-efficiency anti-oxidation thermally conductive insulating oil according to claim 9, characterized in that: The invention comprises 0.1wt%-1wt% of a multifunctional additive, 90-99.9wt% of an insulating oil matrix and 0wt%-9wt% of a functional additive, wherein the insulating oil matrix is a synthetic ester insulating oil, a mineral insulating oil or a natural ester insulating oil, and the functional additive is at least one of a preservative, an antifoaming agent and an anti-emulsifier.