CN118085925A - Production process of extra-high voltage transformer oil - Google Patents
Production process of extra-high voltage transformer oil Download PDFInfo
- Publication number
- CN118085925A CN118085925A CN202410291792.6A CN202410291792A CN118085925A CN 118085925 A CN118085925 A CN 118085925A CN 202410291792 A CN202410291792 A CN 202410291792A CN 118085925 A CN118085925 A CN 118085925A
- Authority
- CN
- China
- Prior art keywords
- oil
- extra
- high voltage
- transformer oil
- voltage transformer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 15
- 238000005984 hydrogenation reaction Methods 0.000 claims abstract description 19
- 238000000034 method Methods 0.000 claims abstract description 7
- 238000007872 degassing Methods 0.000 claims abstract description 6
- 239000000203 mixture Substances 0.000 claims abstract description 3
- 239000003921 oil Substances 0.000 claims description 94
- 239000000047 product Substances 0.000 claims description 23
- 238000006243 chemical reaction Methods 0.000 claims description 21
- 239000002199 base oil Substances 0.000 claims description 17
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 16
- 229910052739 hydrogen Inorganic materials 0.000 claims description 16
- 239000001257 hydrogen Substances 0.000 claims description 16
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 12
- 238000004821 distillation Methods 0.000 claims description 10
- 238000007670 refining Methods 0.000 claims description 8
- 239000007789 gas Substances 0.000 claims description 7
- 239000003963 antioxidant agent Substances 0.000 claims description 6
- 230000003078 antioxidant effect Effects 0.000 claims description 6
- 239000003054 catalyst Substances 0.000 claims description 6
- 239000010779 crude oil Substances 0.000 claims description 6
- 238000005516 engineering process Methods 0.000 claims description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims description 6
- 238000005194 fractionation Methods 0.000 claims description 5
- 239000007795 chemical reaction product Substances 0.000 claims description 4
- 239000000945 filler Substances 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 239000004215 Carbon black (E152) Substances 0.000 claims description 3
- UFWIBTONFRDIAS-UHFFFAOYSA-N Naphthalene Chemical compound C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 claims description 3
- 229930195733 hydrocarbon Natural products 0.000 claims description 3
- 150000002430 hydrocarbons Chemical class 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 2
- 238000006317 isomerization reaction Methods 0.000 claims description 2
- 238000012856 packing Methods 0.000 claims description 2
- 238000009849 vacuum degassing Methods 0.000 claims description 2
- 239000000654 additive Substances 0.000 claims 1
- 230000000996 additive effect Effects 0.000 claims 1
- 239000012530 fluid Substances 0.000 abstract description 5
- 229910052500 inorganic mineral Inorganic materials 0.000 abstract description 5
- 239000011707 mineral Substances 0.000 abstract description 5
- 230000018044 dehydration Effects 0.000 abstract description 2
- 238000006297 dehydration reaction Methods 0.000 abstract description 2
- 238000011161 development Methods 0.000 abstract description 2
- 238000001514 detection method Methods 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 3
- 125000000753 cycloalkyl group Chemical group 0.000 description 3
- 230000015556 catabolic process Effects 0.000 description 2
- 239000004927 clay Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000003208 petroleum Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000001335 aliphatic alkanes Chemical class 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- -1 alkane Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 239000002956 ash Substances 0.000 description 1
- 230000008033 biological extinction Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000002920 hazardous waste Substances 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 125000005575 polycyclic aromatic hydrocarbon group Chemical group 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 229930195734 saturated hydrocarbon Natural products 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229930195735 unsaturated hydrocarbon Natural products 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G67/00—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only
- C10G67/02—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only plural serial stages only
Landscapes
- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Insulating Materials (AREA)
- Lubricants (AREA)
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
Abstract
The invention discloses a production process of extra-high voltage transformer oil, which ensures that the composition of refined oil products meets the characteristic requirement of naphthenic oil through 3 sections of hydrogenation devices with different pressures, has indexes superior to the standard of unused mineral insulating oil (special) for electrical fluid transformers and switches in GB2536-2011, can be customized according to the special requirements of users on some indexes, and meets the operation and use of extra-high voltage transformers above 750 KV. According to the development trend of clean and environment-friendly products, the invention adopts high-pressure hydrofining and is matched with the treatment process of precise cutting and online dehydration and degassing, and has the advantages of flexible product adjustment, excellent stability, clean and environment-friendly production, and the like.
Description
Technical Field
The invention relates to the technical field of transformer oil application, in particular to a production process of extra-high voltage transformer oil.
Background
The transformer oil is a fractionation product of petroleum, and the main components of the transformer oil are compounds such as alkane, naphthenic saturated hydrocarbon, aromatic unsaturated hydrocarbon and the like; mainly installed in transformers, capacitors and varistors, and used as insulating medium, arc extinction and heat conduction. According to the working characteristics of transformer oil, the transformer oil is required to have good electrical performance, strong oxidation stability, excellent low-temperature fluidity, high-temperature safety performance and low contents of acid, alkali, sulfur, ash and other impurities, so the transformer oil is required to be a product of deeply refining petroleum fractions.
The extra-high voltage transformer oil has more severe technical indexes than the common transformer oil, and is characterized in higher flash point, breakdown voltage, oxidation stability and the like, the traditional processing technology adopts a medium-pressure hydrofining technology, and the product generally adopts a common distillation technology, and the disadvantages include: (1) The distillation range of the product is wider, and the regulation means is lacked in the aspects of meeting the flash point requirement and keeping good low-temperature fluidity; (2) The impurity content, especially the aromatic hydrocarbon content, is relatively high, a clay post-refining process is often needed in a refining link, the environment is not friendly, and waste clay needs to be treated as hazardous waste.
According to the development trend of clean and environment-friendly products, the invention adopts high-pressure hydrofining and is matched with the treatment process of precise cutting and online dehydration and degassing, and has the advantages of flexible product adjustment, excellent stability, clean and environment-friendly production, and the like.
Disclosure of Invention
The invention aims at providing a production process of extra-high voltage transformer oil aiming at the traditional production process. Refining by 3 sections of hydrogenation devices with different pressures, and optimally controlling the carbon chain structure of refined oil according to the cycloalkyl characteristic requirement, so that the naphthene content of the base oil is more than 60%, and the cycloalkyl characteristic of the extra-high voltage transformer oil is realized.
The production process of the extra-high voltage transformer oil comprises the following steps:
s1, carrying out hydrogenation deacidification treatment on raw oil of spring wind crude oil, and carrying out hydrogenation deacidification reaction on the raw oil of the spring wind crude oil in a reactor at a reaction temperature of 320-360 ℃ under a hydrogen pressure of 6.0-6.5 mpa to obtain No. 1 refined oil;
S2, feeding the 1# refined oil obtained in the S1 into a high-pressure hydrogenation treatment, and carrying out deep hydrogenation reaction in a reactor under the hydrogen pressure of 17.5-20.0Mpa and the reaction temperature of 300-350 ℃ to obtain 2# refined oil;
S3, feeding the 2# refined oil obtained in the S2 into a medium-pressure hydroisomerization treatment, carrying out hydroisomerization reaction in a reactor at the hydrogen pressure of 10-12 mpa and the reaction temperature of 300-350 ℃, feeding the refined oil into a post-refining reactor, and carrying out hydrofining on an isomerization reaction product at the temperature of 250-290 ℃ to obtain the 3# refined oil;
S4, adding the 3# refined oil obtained in the S3 into a fractionation cutting device, and obtaining the 4# refined oil by cutting off the head light component and the tail heavy component;
s5, adding the No. 4 refined oil obtained in the S4 into a vacuum filler degassing tower, and stripping water and dissolved gas by adopting nitrogen to obtain transformer oil base oil;
and S6, adding an antioxidant into the transformer oil base oil obtained in the S5 to uniformly blend the transformer oil base oil in a tank area, and obtaining an extra-high voltage transformer oil product.
Preferably, S1 adopts an RS-2000 catalyst, and the hydrogen partial pressure is 6.0-6.5 MPa; s2 adopts a RL-2+RLF-2 catalyst, and the hydrogen partial pressure is 17.5-20 MPa; s3, adopting an RLF-20 catalyst, and having a hydrogen partial pressure of 10-12 mpa.
Preferably, the naphthene content CN value of the extra-high voltage transformer oil product is not lower than 60%, the pour point is lower than-50 ℃, and the lowest cold state operation temperature reaches-40 ℃.
Preferably, S4 adopts a two-tower distillation technology, light components and heavy components are removed accurately, flexible control of the distillation range of the base oil of the transformer oil is realized, and the flash point of the base oil is more than 140 ℃.
Preferably, structured packing is adopted in S5, the operation temperature of the drying tower is 50-55 ℃, the vacuum degree is 70kpa, and the stripping nitrogen is controlled according to the proportion of 10Nm 3/t of oil.
Preferably, S5 is controlled by an in-line vacuum degassing technique to have a base oil moisture content of less than 20mg/kg and a total hydrocarbon content in the dissolved gas of less than 5. Mu.L/L.
Preferably, in the S6, a circulating dosing mode is adopted, and the adding content of the antioxidant is controlled within the range of 0.08-0.4% by mass.
The invention has the advantages that the whole quality of the extra-high voltage transformer oil is superior to the standard requirement of GB2536-2011 virgin mineral insulating oil for electrical fluid transformers and switches, the flash point is higher than 140 ℃, the pour point is lower than-50 ℃, the breakdown voltage (2.5 mm) is higher than 60KV, the dielectric loss factor (90 ℃) is lower than 0.0003, the moisture content is lower than 20mg/kg, and the total hydrocarbon content in dissolved gas is less than 5 mu L/L. The CN value of the product is more than 60%, the product has good cycloalkyl characteristic, meanwhile, the aromatic hydrocarbon content of the product is low, and the production process and the service performance of the product are clean and friendly.
Detailed Description
S1, carrying out hydrogenation deacidification treatment on raw oil of spring wind crude oil (taken from a spring wind oil field of Xinjiang). The reactor carries out hydrogenation deacidification reaction under the pressure of 6.3Mpa and the reaction temperature of 335 ℃ to obtain No. 1 refined oil;
S2, feeding the 1# refined oil obtained in the S1 into a high-pressure hydrogenation treatment, and carrying out deep hydrogenation reaction on the 1# refined oil in a reactor at the hydrogen pressure of 18.0Mpa and the reaction temperature of 340 ℃ to obtain 2# refined oil;
S3, adding the 2# refined oil obtained in the S2 into a medium-pressure hydroisomerization treatment, carrying out hydroisomerization reaction in a reactor at the hydrogen pressure of 10.5Mpa and the reaction temperature of 342 ℃, then entering a post-refining reactor, carrying out hydrofining on the isomerism reaction product at the reaction temperature of 294 ℃ to obtain the 3# refined oil.
S4, adding the 3# refined oil obtained in the S3 into a fractionation cutting device, wherein the temperature of the top of the head pulling tower is 240 ℃, the temperature of the top of the tail removing tower is 265 ℃, and the 4# refined oil is obtained by cutting off the head light component and the tail heavy component, and the distillation range of the 4# refined oil is 266-329 ℃.
And S5, adding the 4# refined oil obtained in the S4 into a vacuum filler degassing tower, controlling the feeding temperature to be 50-55 ℃, and removing water and dissolved gas by adopting nitrogen stripping to obtain the transformer oil base oil.
And S6, adding a trace amount of antioxidant into the transformer oil base oil obtained in the S5 to regulate and average the price, and obtaining the extra-high voltage transformer oil product.
Example 2
S1, carrying out hydrogenation deacidification treatment on the spring wind crude oil raw oil. The reactor carries out hydrogenation deacidification reaction under the pressure of 6.3Mpa and the reaction temperature of 336 ℃ to obtain No. 1 refined oil;
S2, feeding the 1# refined oil obtained in the S1 into a high-pressure hydrogenation treatment, and carrying out deep hydrogenation reaction on the 1# refined oil in a reactor at the hydrogen pressure of 18.5Mpa and the reaction temperature of 335 ℃ to obtain 2# refined oil;
S3, adding the 2# refined oil obtained in the S2 into a medium-pressure hydroisomerization treatment, carrying out hydroisomerization reaction in a reactor at the hydrogen pressure of 10.5Mpa and the reaction temperature of 334 ℃, then entering a post-refining reactor, and carrying out hydrofining on an isomerism reaction product at 290 ℃ to obtain the 3# refined oil.
S4, adding the 3# refined oil obtained in the S3 into a fractionation cutting device, wherein the temperature of the top of the head pulling tower is 255 ℃, the temperature of the top of the tail removing tower is 260 ℃, and obtaining the 4# refined oil with a narrower distillation range (the distillation range is 292-309 ℃) by cutting off the head light component and the tail heavy component.
And (5) adding the No. 4 refined oil obtained in the step (S5) and the step (S4) into a vacuum filler degassing tower, and stripping water and dissolved gas by adopting nitrogen to obtain the transformer oil base oil.
And S6, adding a trace amount of antioxidant into the transformer oil base oil obtained in the S5 to regulate and average the price, and obtaining the extra-high voltage transformer oil product.
< Test data >
The product of example 1 was commissioned to the western security thermal institute for testing. The whole quality is superior to the standard requirement of unused mineral insulating oil (special) for electrical fluid transformers and switches in GB2536-2011, the use requirement of the extra-high voltage transformer oil is met, and the detection result is as in accessory 1.
The product in the embodiment 2 is entrusted to lubricating oil Huadong division company for detection, the overall quality is superior to the standard requirement of unused mineral insulating oil (special) for electrical fluid transformers and switches in GB2536-2011, the viscosity at the low temperature of minus 30 ℃ is further reduced, the use requirement of extra-high voltage transformer oil is met, and the detection results are shown in tables-1 and-2.
Table 1 detection of conventional Performance of Extra-high voltage Transformer oil
TABLE 2 analysis of Transformer oil oxidation stability
The product meets the standard requirements of GB2536-2011 (unused mineral insulating oil (special) for electrical fluid transformers and switches), can be customized by further referring to the related safety standards of the electrical industry, and achieves the effect that the internal indexes of the product such as flash point, viscosity, low-temperature viscosity, pour point and the like meet the customization requirements through flexible and accurate distillation range control. The product has stable production process, stable quality, low aromatic hydrocarbon content, no harmful substances of polycyclic aromatic hydrocarbon, and good oxidation resistance. The quality of the product reaches or is superior to the level of imported similar products.
The above embodiments are only for illustrating the technical solution and features of the present invention, and are intended to be better implemented by those skilled in the art, but not to limit the scope of the present invention, and all equivalent changes or modifications made according to the spirit of the present invention are within the scope of the present invention, wherein the prior art is not specifically illustrated.
Claims (7)
1. The production process of the extra-high voltage transformer oil is characterized by comprising the following steps of:
S1, carrying out hydrogenation deacidification treatment on raw oil of spring wind crude oil, and carrying out hydrogenation deacidification reaction on the raw oil of the spring wind crude oil in a hydrogenation deacidification reactor at a reaction temperature of 320-360 ℃ under a hydrogen pressure of 6.0-6.5 mpa to obtain No. 1 refined oil;
S2, feeding the 1# refined oil obtained in the S1 into a high-pressure hydrogenation reactor for deep hydrogenation reaction under the hydrogen pressure of 17.5-20.0Mpa and the reaction temperature of 300-350 ℃ to obtain 2# refined oil;
S3, feeding the 2# refined oil obtained in the S2 into a medium-pressure hydroisomerization treatment, carrying out hydroisomerization reaction in a medium-pressure hydroisomerization reactor under the hydrogen pressure of 10-12 mpa and the reaction temperature of 300-350 ℃, feeding the refined oil into a post-refining reactor, and carrying out hydrofining on an isomerization reaction product at the temperature of 250-290 ℃ to obtain the 3# refined oil;
S4, adding the 3# refined oil obtained in the S3 into a fractionation cutting device, and obtaining the 4# refined oil by cutting off the head light component and the tail heavy component;
s5, adding the No. 4 refined oil obtained in the S4 into a vacuum filler degassing tower, and stripping water and dissolved gas by adopting nitrogen to obtain transformer oil base oil;
and S6, adding an antioxidant into the transformer oil base oil obtained in the S5 to uniformly blend the transformer oil base oil in a tank area, and obtaining an extra-high voltage transformer oil product.
2. The production process of extra-high voltage transformer oil according to claim 1, wherein S1 adopts an RS-2000 catalyst, and the hydrogen partial pressure is 6.0-6.5 MPa; s2 adopts a RL-2+RLF-2 catalyst, and the hydrogen partial pressure is 17.5-20 MPa; s3, adopting an RLF-20 catalyst, and having a hydrogen partial pressure of 10-12 mpa.
3. The process for producing the extra-high voltage transformer oil according to claim 1, wherein the product of the extra-high voltage transformer oil has a naphthene content CN value not lower than 60%, a pour point lower than-50 ℃ and a lowest cold running temperature reaching-40 ℃.
4. The production process of the extra-high voltage transformer oil according to claim 1, wherein the S4 adopts a two-tower distillation technology, light components and heavy components are precisely removed, flexible control of the distillation range of the base oil of the transformer oil is realized, and the flash point of the base oil is more than 140 ℃.
5. The process for producing extra-high voltage transformer oil according to claim 1, wherein the structured packing is adopted in the step S5, the operation temperature of a drying tower is 50-55 ℃, the vacuum degree is 70kpa, and the stripping nitrogen is controlled according to the proportion of 10Nm 3/t oil.
6. The process for producing extra-high voltage transformer oil according to claim 1, wherein S5 is characterized in that the moisture content of the base oil is controlled to be lower than 20mg/kg and the total hydrocarbon content in the dissolved gas is controlled to be lower than 5 mu L/L by an on-line vacuum degassing technology.
7. The production process of the extra-high voltage transformer oil according to claim 1 is characterized in that a circulating additive mode is adopted in S6, and the antioxidant addition content is controlled within a range of 0.08% -0.4% by mass.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410291792.6A CN118085925A (en) | 2024-03-14 | 2024-03-14 | Production process of extra-high voltage transformer oil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410291792.6A CN118085925A (en) | 2024-03-14 | 2024-03-14 | Production process of extra-high voltage transformer oil |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118085925A true CN118085925A (en) | 2024-05-28 |
Family
ID=91151447
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410291792.6A Pending CN118085925A (en) | 2024-03-14 | 2024-03-14 | Production process of extra-high voltage transformer oil |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118085925A (en) |
-
2024
- 2024-03-14 CN CN202410291792.6A patent/CN118085925A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1984927B1 (en) | Electrical insulation oil composition | |
| CN105051831A (en) | Electrical insulating oil composition | |
| CN102485846B (en) | Preparation method of transformer oil base oil | |
| RU2373265C1 (en) | Transformer oil | |
| CN106833740B (en) | Preparation method of transformer oil base oil | |
| CN113122324B (en) | Method for producing special oil product by catalyzing slurry oil hydrogenation | |
| CN114410347B (en) | Method for preparing low-aromatic transformer oil by medium-pressure hydrogenation of naphthenic base distillate oil | |
| CN105462614A (en) | Transformer oil base oil with low freezing point and high naphthenic carbon content and preparation method of transformer oil base oil | |
| CN108977224B (en) | Transformer oil base oil and preparation method thereof | |
| CN104862006A (en) | Transformer oil gassing-resistant additive and preparation method thereof | |
| CN103789019B (en) | Method for hydrogenation of medium-low temperature coal tar to produce transformer oil base oil | |
| CN104694219A (en) | Production method of high-grade naphthenic transformer oil | |
| CN104910959B (en) | A kind of anti-evolving-gas additive of transformer oil and preparation method thereof | |
| CN118085925A (en) | Production process of extra-high voltage transformer oil | |
| CN113234483A (en) | Preparation method of aromatic hydrocarbon-containing transformer oil base oil | |
| CN1254523C (en) | Method for producing anti-evolving-gas additive of transformer oil and its using method | |
| CN102676215B (en) | Method for improving gassing resistance of transformer oil and equipment for producing transformer oil | |
| CN115851359B (en) | Environment-friendly metal cutting fluid and preparation method and application thereof | |
| GB2059433A (en) | Mineral oils | |
| CN101747934B (en) | Preparation method of transformer oil anti-gassing additive | |
| CN108165339B (en) | Cycloalkyl transformer oil composition | |
| CN108587723B (en) | Mineral insulating oil and preparation method thereof | |
| CN108165348A (en) | Cycloalkyl transformer oil composition | |
| CN113930276A (en) | Naphthenic transformer oil composition and application | |
| US4760212A (en) | Electrical insulating oils |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |