CN111117744A - Glycerol-magnetic nanoparticle insulating oil and application thereof in pulse power technology - Google Patents

Glycerol-magnetic nanoparticle insulating oil and application thereof in pulse power technology Download PDF

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Publication number
CN111117744A
CN111117744A CN201911393041.0A CN201911393041A CN111117744A CN 111117744 A CN111117744 A CN 111117744A CN 201911393041 A CN201911393041 A CN 201911393041A CN 111117744 A CN111117744 A CN 111117744A
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China
Prior art keywords
glycerol
magnetic
insulating oil
magnetic nanoparticle
nanoparticle
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Pending
Application number
CN201911393041.0A
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Chinese (zh)
Inventor
樊旭亮
巴涛
刘胜
孙旭
潘亚峰
王利民
王俊杰
范红艳
王刚
郭旭
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Northwest Institute of Nuclear Technology
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Northwest Institute of Nuclear Technology
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Priority to CN201911393041.0A priority Critical patent/CN111117744A/en
Publication of CN111117744A publication Critical patent/CN111117744A/en
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    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M169/00—Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
    • C10M169/04—Mixtures of base-materials and additives
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
    • H01B3/20—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances liquids, e.g. oils
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/08—Cooling; Ventilating
    • H01F27/10—Liquid cooling
    • H01F27/12—Oil cooling
    • H01F27/125—Cooling by synthetic insulating and incombustible liquid
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
    • C10M2201/06—Metal compounds
    • C10M2201/062—Oxides; Hydroxides; Carbonates or bicarbonates
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
    • C10M2207/02—Hydroxy compounds
    • C10M2207/021—Hydroxy compounds having hydroxy groups bound to acyclic or cycloaliphatic carbon atoms
    • C10M2207/022—Hydroxy compounds having hydroxy groups bound to acyclic or cycloaliphatic carbon atoms containing at least two hydroxy groups
    • C10M2207/0225—Hydroxy compounds having hydroxy groups bound to acyclic or cycloaliphatic carbon atoms containing at least two hydroxy groups used as base material

Abstract

The invention belongs to the technical field of pulse power, and discloses glycerol-magnetic nanoparticle insulating oil and application thereof in a pulse power technology, which solve the problem of poor liquidity when glycerol is applied to insulating oil, wherein the volume ratio of the mass of magnetic nanoparticles in the glycerol-magnetic nanoparticle insulating oil to the volume of pure glycerol is 0.02 g/L-0.07 g/L. When in use, the main flow comprises heating pure glycerol, mixing the pure glycerol and the magnetic nanoparticles, filling the mixture into a using container, heating the glycerol by the magnetic particles, reaching the specified temperature, stopping irradiation/not reaching the specified temperature, and continuing irradiation; the process conditions include ultrasonic irradiation, vacuum and magnetic field irradiation. The heating mode is a non-contact heating mode by doping the magnetic nanoparticles and adding magnetic field irradiation, heating equipment is not required to be added in an actual device, the heating mode is safe and reliable, reasonable temperature can be kept for a long time, and meanwhile, after the magnetic nanoparticles are doped, the heating mode also has an effect of improving the insulating capacity of glycerin.

Description

Glycerol-magnetic nanoparticle insulating oil and application thereof in pulse power technology
Technical Field
The invention belongs to the technical field of pulse power, and relates to insulating oil, a preparation method thereof and application of the insulating oil in a pulse power technology.
Background
The glycerin is an insulating oil which is widely applied in the field of pulse power technology or high voltage technology in recent years, and is characterized by strong insulating capability and high energy storage density. In particular, in the field of pulse formation, glycerin is widely preferred because of its high relative dielectric constant (approximately 18 times that of transformer oil).
In the actual use process, because the glycerin is extremely viscous at normal temperature, a special container is firstly adopted to heat the glycerin and then the glycerin is filled. Then, after filling into a container for use (such as a transformer, a pulse forming line), the temperature thereof is lowered again, and the fluidity is restored to a poor state at normal temperature. In the field of pulse power technology or high voltage technology, glycerin is used for energy storage or insulation, breakdown or partial discharge is inevitable in a system, the flow performance of the glycerin is limited, and after one breakdown occurs, a discharge channel cannot flow and is evacuated, so that the discharge channel always exists. Experiments also show that the insulation and voltage resistance of glycerol is sharply reduced or even can not be used continuously once the glycerol breaks down, which is unacceptable in engineering practice.
Disclosure of Invention
In order to solve the problem of poor liquidity when glycerin is applied to insulating oil, the invention provides glycerin-magnetic nanoparticle insulating oil and application thereof in a pulse power technology.
The invention is realized by the following technical scheme:
the glycerol-magnetic nanoparticle insulating oil is characterized in that: comprises pure glycerol and magnetic nanoparticles, wherein the volume ratio of the mass of the magnetic nanoparticles to the volume of the pure glycerol is 0.02 g/L-0.07 g/L.
Further, in order to improve the insulating property, the volume ratio of the mass of the magnetic nanoparticles to the pure glycerol is 0.06 g/L.
Further, the magnetic nanoparticles are Fe2O3(ii) a The diameter of the magnetic nano-particles is less than or equal to 50 nm.
The invention also provides a preparation method of the glycerol-magnetic nanoparticle insulating oil, which is characterized in that the magnetic nanoparticles are added into the pure glycerol, wherein the volume ratio of the mass of the magnetic nanoparticles to the volume of the pure glycerol is 0.02 g/L-0.07 g/L; namely, 0.03-0.07 g of magnetic nanoparticles are added into 1L of glycerol and are uniformly mixed in a mixing container to obtain the glycerol-magnetic nanoparticle insulating oil.
Further, the volume ratio of the mass of the magnetic nanoparticles to the pure glycerol is 0.06 g/L.
Further, when pure glycerin and magnetic nanoparticles are mixed in a mixing vessel, the mixing vessel is heated and irradiated with ultrasonic waves.
The invention also provides an application of the glycerol-magnetic nanoparticle insulating oil in a pulse power technology, which comprises the following steps:
filling glycerol-magnetic nanoparticle insulating oil into a using container, and irradiating the using container by using an alternating magnetic field in the working process;
and step two, collecting the temperature of the glycerol-magnetic nanoparticle insulating oil, stopping irradiation if the temperature of the glycerol-magnetic nanoparticle insulating oil reaches a preset temperature, and continuing irradiation or increasing the intensity of an irradiation magnetic field until the temperature of the glycerol-magnetic nanoparticle insulating oil reaches the preset temperature if the temperature of the glycerol-magnetic nanoparticle insulating oil does not reach the specified temperature.
Further, in the step one, the glycerol-magnetic nanoparticle insulating oil is filled in the use container by a vacuum filling method.
Further, in the step one, the frequency of the alternating magnetic field is 2MHz, and the magnetic field intensity is 0.04T.
The invention has the beneficial effects that:
1. according to the invention, the magnetic nanoparticles are doped in the glycerol, and the fluidity of the glycerol is improved by external magnetic field irradiation, so that when the glycerol is used for energy storage or insulation, after the system is subjected to primary breakdown, the discharge channel is evacuated in the glycerol with good fluidity, and the recovery capability of insulation and voltage resistance when the glycerol is used as insulating oil is improved.
2. The heating is realized by external magnetic field irradiation, the heating mode is a non-contact type heating mode, heating equipment does not need to be added in an actual device, and the heating device is safe and reliable and can keep reasonable temperature for a long time.
3. After the glycerol is doped with the magnetic nanoparticles, the glycerol insulation capacity can be improved.
Drawings
FIG. 1 is a flow chart of the preparation and use of the present invention;
Detailed Description
The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.
The invention provides glycerol-magnetic nanoparticle insulating oil and application thereof. Meanwhile, the doped magnetic nanoparticles also have an important effect on improving the insulating capability of the glycerol, and the method achieves the effect of killing two birds with one stone.
When the glycerol-magnetic nanoparticle insulating oil is prepared, the magnetic nanoparticles are mixed in a pure glycerol solution according to a certain proportion, and the mixing method is heating in a special container and assisting ultrasonic irradiation; and (4) observing whether precipitates are generated or not after the mixing is finished for a certain time, and testing the insulation improvement capability of the insulating oil by a direct current withstand voltage tester. The ratio of the magnetic nanoparticles to the glycerol selected in the present invention and the test results are shown in table 1.
Table 1 ratio of magnetic nanoparticles to glycerol and test results
Ratio (g/L) Standing time With or without precipitation (agglomeration) Insulation improvement
0.02 1 month Is free of Is basically free of
0.04 1 month Is free of Is preferably used
0.06 1 month Is free of Optimization of
0.07 1 month Is free of Is preferably used
0.08 1 month Slight agglomeration Variation of
0.1 1 month Agglomeration Variation of
As can be seen from Table 1, the ratio of the magnetic nanoparticles to the glycerin gives consideration to the heating performance after mixing and the electrical performance when in use, and the effect is better when 0.04-0.06 g/L; when the ratio of the magnetic nanoparticles to the glycerol is 0.06g/L, the insulation improvement effect is best, and no agglomeration phenomenon exists even standing for 1 month.
The invention is further described below in conjunction with fig. 1.
FIG. 1 mainly includes two parts of a main process and process conditions, wherein the main process includes 1-heating pure glycerol, 2-pure glycerol + magnetic nano particle mixing, 3-filling into a using container, 4-heating glycerol by magnetic particles, 5.1-reaching a specified temperature, 5.2-not reaching the specified temperature and 6-stopping irradiation; the process conditions include a-ultrasonic irradiation, b-vacuum and c-magnetic field irradiation.
The working time sequence is as follows: firstly, because the glycerin is viscous and approximately in a solidification state at normal temperature, pure glycerin needs to be placed in a special heating container for heating at the beginning, and the glycerin is heated to about 60 ℃, and the fluidity of the glycerin is better at the moment; secondly, putting the magnetic nanoparticles into heated glycerol according to the proportion, and adding ultrasonic waves to irradiate the heating container while stirring so as to uniformly mix the magnetic core nanoparticles with the glycerol; and step three, filling the mixed solution into a using container. The use of a container refers to the actual use of glycerol, such as a transformer or a pulse forming line, and is usually a closed container. The filling method comprises the steps of vacuumizing a using container, opening a valve of a pipeline inserted into the glycerol mixed liquid after a certain vacuum degree is reached, and enabling the mixed liquid to enter the using container; and fourthly, the step is a normalizing step in the actual use process, the container to be used is irradiated by an alternating magnetic field, and the container to be used needs to be allowed to penetrate through the magnetic field. Under the action of an alternating magnetic field, the magnetic nano particles are repeatedly magnetized, and due to the hysteresis characteristic of the particles, the particles generate heat in the repeated process so as to heat the glycerol; and fifthly, gradually increasing the temperature of the glycerol along with the increase of the irradiation time of the magnetic field, stopping irradiation of the magnetic field if the temperature of the glycerol reaches a preset temperature, and continuing the irradiation of the magnetic field or increasing the intensity of the irradiation magnetic field if the temperature of the glycerol does not reach a specified temperature.
The method of use of the invention applied to a pulse transformer is described below. The outer cylinder of the transformer is made of nylon material, and glycerin is filled in the outer cylinder to be used as insulating oil. The magnetic nanoparticles adopt Fe2O3In order to avoid the skin effect at high frequencies, the particle diameter should be controlled below 50nm, with a mass to volume ratio of about 0.03 to the glycerol matrix. The frequency of the external alternating magnetic field is 2MHz, the magnetic field intensity is 0.04T, and the heating is faster when the magnetic field intensity is larger. According to the working sequence. After the magnetic core nano particles are doped, the glycerol insulation field strength can be improved by about 20 percent on average.

Claims (9)

1. A glycerin-magnetic nanoparticle insulating oil, characterized in that: the magnetic glycerol nanoparticle comprises pure glycerol and magnetic nanoparticles, wherein the volume ratio of the mass of the magnetic nanoparticles to the pure glycerol is 0.02 g/L-0.07 g/L.
2. The glycerol-magnetic nanoparticle insulating oil according to claim 2, wherein: the volume ratio of the mass of the magnetic nanoparticles to the pure glycerol is 0.06 g/L.
3. The glycerol-magnetic nanoparticle insulating oil according to claim 1 or 2, characterized in that: the magnetic nano particles are Fe2O3(ii) a The diameter of the magnetic nano-particles is less than or equal to 50 nm.
4. A method for preparing the glycerol-magnetic nanoparticle insulating oil of claim 1, wherein the method comprises the following steps: adding magnetic nanoparticles into pure glycerol, wherein the volume ratio of the mass of the magnetic nanoparticles to the pure glycerol is 0.02 g/L-0.07 g/L; and uniformly mixing in a mixing container to obtain the glycerol-magnetic nanoparticle insulating oil.
5. The method of preparing glycerol-magnetic nanoparticle insulating oil according to claim 4, wherein: wherein the volume ratio of the mass of the magnetic nanoparticles to the pure glycerol is 0.06 g/L.
6. The method of preparing glycerol-magnetic nanoparticle insulating oil according to claim 4, wherein: when pure glycerin and magnetic nanoparticles are mixed in a mixing vessel, the mixing vessel is heated and irradiated with ultrasonic waves.
7. Use of a glycerol-magnetic nanoparticle insulating oil according to any one of claims 1 to 3 in pulsed power technology, characterized in that it comprises the following steps:
filling glycerol-magnetic nanoparticle insulating oil into a using container, and irradiating the using container by using an alternating magnetic field in the working process;
and step two, collecting the temperature of the glycerol-magnetic nanoparticle insulating oil, stopping irradiation if the temperature of the glycerol-magnetic nanoparticle insulating oil reaches a preset temperature, and continuing irradiation or increasing the intensity of an irradiation magnetic field until the temperature of the glycerol-magnetic nanoparticle insulating oil reaches the preset temperature if the temperature of the glycerol-magnetic nanoparticle insulating oil does not reach the specified temperature.
8. Use of the glycerol-magnetic nanoparticle insulating oil according to claim 7 in pulsed power technology, characterized in that: in the first step, the glycerol-magnetic nanoparticle insulating oil is filled in a using container by a vacuum filling method.
9. Use of the glycerol-magnetic nanoparticle insulating oil according to claim 8 in pulsed power technology, characterized in that: in the first step, the frequency of the alternating magnetic field is 2MHz, and the magnetic field intensity is 0.04T.
CN201911393041.0A 2019-12-30 2019-12-30 Glycerol-magnetic nanoparticle insulating oil and application thereof in pulse power technology Pending CN111117744A (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1979699A (en) * 2006-11-09 2007-06-13 上海交通大学 Method for preparing iron-oxide particle suspension
CN101901637A (en) * 2010-07-29 2010-12-01 重庆大学 Composite of vegetable insulating oil and modified nano powder and application and preparation method thereof
CN101950601A (en) * 2010-07-29 2011-01-19 重庆大学 Composite of mineral insulating oil and modified nanoparticle powder as well as application and preparation method thereof
CN102533403A (en) * 2011-12-22 2012-07-04 云南云天化股份有限公司 Nanometer Fe2O3 material for electro-rheological fluid, preparation method of the nanometer Fe2O3 material for electro-rheological fluid and electro-rheological fluid
JP2014094838A (en) * 2012-11-07 2014-05-22 Univ Of Tsukuba Method of manufacturing strong magnetic iron oxide particles
CN105169560A (en) * 2015-06-12 2015-12-23 郑州轻工业学院 Device and method used for controlling magnetic nano particle heating area
CN108587743A (en) * 2018-04-17 2018-09-28 中国人民解放军陆军勤务学院 A kind of magnetorheological glue and preparation method thereof

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1979699A (en) * 2006-11-09 2007-06-13 上海交通大学 Method for preparing iron-oxide particle suspension
CN101901637A (en) * 2010-07-29 2010-12-01 重庆大学 Composite of vegetable insulating oil and modified nano powder and application and preparation method thereof
CN101950601A (en) * 2010-07-29 2011-01-19 重庆大学 Composite of mineral insulating oil and modified nanoparticle powder as well as application and preparation method thereof
CN102533403A (en) * 2011-12-22 2012-07-04 云南云天化股份有限公司 Nanometer Fe2O3 material for electro-rheological fluid, preparation method of the nanometer Fe2O3 material for electro-rheological fluid and electro-rheological fluid
JP2014094838A (en) * 2012-11-07 2014-05-22 Univ Of Tsukuba Method of manufacturing strong magnetic iron oxide particles
CN105169560A (en) * 2015-06-12 2015-12-23 郑州轻工业学院 Device and method used for controlling magnetic nano particle heating area
CN108587743A (en) * 2018-04-17 2018-09-28 中国人民解放军陆军勤务学院 A kind of magnetorheological glue and preparation method thereof

Non-Patent Citations (9)

* Cited by examiner, † Cited by third party
Title
B. X. DU ETAL: "Thermal Conductivity and Dielectric Characteristics of Transformer Oil Filled with BN and Fe3O4 Nanoparticles", 《IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION》 *
BIN DU, ETAL: "Influence of Monodisperse Fe3O4 Nanoparticle Size on Electrical Properties of Vegetable Oil-Based Nanofluids", 《 JOURNAL OF NANOMATERIALS》 *
MARYAM ABARESHI ETAL: "Fabrication, characterization, and measurement of viscosity of α-Fe2O3-glycerol nanofluids", 《FABRICATION, CHARACTERIZATION, AND MEASUREMENT OF VISCOSITY OF Α-FE2O3-GLYCEROL NANOFLUIDS》 *
SMOLKOVA, ILONA S ET AL: "Alternating magnetic field energy absorption in the dispersion of iron oxide nanoparticles in a viscous medium", 《JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS》 *
T.S.RAMU ETAL: "Application of a Class of Nano fluids to improve the Loadability of Power Transformers", 《2012 IEEE 10TH INTERNATIONAL CONFERENCE ON THE PROPERTIES AND APPLICATIONS OF DIELECTRIC MATERIALS》 *
VASILIOS P ETAL: "Dielectric Insulation Characteristics of Natural Ester Fluid Modified by Colloidal Iron Oxide Ions and Silica Nanoparticles", 《ENERGIES》 *
YUZHEN LV ETAL: "tudy of Dielectric Breakdown Performance of Transformer Oil Based Magnetic Nanofluids", 《ENERGIES》 *
吴广宁: "《电气化铁道高电压工程》", 31 May 2011, 中国铁道出版社 *
杨霄等: "甘油介质在同轴形成线中的击穿特性研究", 《强激光与粒子束》 *

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Application publication date: 20200508