CN111991906A - System and method for repairing performance of electric insulating oil - Google Patents
System and method for repairing performance of electric insulating oil Download PDFInfo
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- CN111991906A CN111991906A CN202010870942.0A CN202010870942A CN111991906A CN 111991906 A CN111991906 A CN 111991906A CN 202010870942 A CN202010870942 A CN 202010870942A CN 111991906 A CN111991906 A CN 111991906A
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- oil
- adsorption
- backflushing
- insulating oil
- adsorption tank
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D36/00—Filter circuits or combinations of filters with other separating devices
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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
- C10M175/00—Working-up used lubricants to recover useful products ; Cleaning
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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
- C10M175/00—Working-up used lubricants to recover useful products ; Cleaning
- C10M175/0008—Working-up used lubricants to recover useful products ; Cleaning with the use of adsorbentia
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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
- C10M175/00—Working-up used lubricants to recover useful products ; Cleaning
- C10M175/0058—Working-up used lubricants to recover useful products ; Cleaning by filtration and centrifugation processes; apparatus therefor
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- 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
- H01F27/14—Expansion chambers; Oil conservators; Gas cushions; Arrangements for purifying, drying, or filling
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Combustion & Propulsion (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Chemistry (AREA)
- Power Engineering (AREA)
- Transformer Cooling (AREA)
Abstract
The invention relates to a system and a method for repairing the performance of electric insulating oil, which improve an adsorption tank in the original CN103594231A device based on an airspeed theory, improve the adsorption capacity while reducing the adsorbance of an adsorbent in the tank, save more energy, protect the environment, have lower cost and have better application and popularization prospects.
Description
Technical Field
The invention relates to the technical field of electric power, in particular to a system and a method for repairing the performance of electric power insulating oil.
Background
Insulating oils are used in many electrical equipment, such as transformers, and deteriorate over time. If the insulation oil is not properly disposed of, the deteriorated insulation oil may become "dangerous waste", which not only causes great resource waste and economic loss, but also causes serious harm to human life safety and ecological environment. The existing method for repairing the performance of the degraded insulating oil proposed at home and abroad has the problems of oil composition change, short service life after repair, great side effect, low repair speed, complex process, low efficiency and the like, and the current situations of single repair method, poor impurity filtering and desulfurizing effects, environmental pollution and the like also need to be improved.
The company has devoted to the regeneration and performance repair of the power insulating oil for a long time, and has achieved great results, such as CN204364941U (an adsorption device for the regeneration of transformer oil and capable of regenerating an adsorbent on site), CN104232285A (a treatment method and a device for reducing the acid value of a degraded fuel-resistant oil), CN103594231A (a treatment method for reducing dielectric loss of the degraded transformer oil), and the like. Wherein CN103594231A discloses a deteriorated transformer oil treatment device (as shown in fig. 1), which comprises a transformer, an oil treatment machine or an oil regeneration machine (XFJ-02 type), and a vacuum oil filter, wherein the deteriorated oil is treated by the oil treatment machine and the vacuum oil filter to complete performance restoration, and then returns to the transformer for continuous service. The oil processor mainly plays a role in oil discharge, mechanical impurity filtering, deacidification adsorption, decoloration, dielectric loss reduction and the like, and the vacuum oil filter mainly plays a role in water removal, oil granularity grade improvement and the like. In actual use, whether the oil processor and the vacuum oil filter are connected in series or in parallel, and whether the oil processor and the vacuum oil filter are used independently or simultaneously can be determined according to the quality condition of oil.
The structure of the oil treatment machine is shown in fig. 2, and comprises an adsorption tank, a buffer tank, a plate oil filter, a plurality of pipelines and valves. The key part of the whole set of equipment is an adsorption tank filled with an XDK efficient adsorbent, which is formed by combining 1-3 XFG-200 type adsorption tanks in parallel, wherein about 200-600Kg of adsorbent is filled once, about 10-30 tons of degraded transformer oil can be treated without changing oil once, and the medium and small sized transformer degraded oil can be treated without stopping the machine on site. Practice shows that the equipment is not only expensive in cost, but also high in use cost due to the fact that the adsorbent cannot be regenerated, and is not suitable for large-scale use of power companies for a long time. Therefore, the adsorption tank of the equipment is improved based on the airspeed theory, the backwashing function is added, the adsorption quality is further reduced, the adsorption capacity is improved, and a better effect is achieved.
Disclosure of Invention
The invention aims to provide an electric insulating oil performance repairing system, which comprises an oil processor and a vacuum oil filter which are connected in series, wherein the oil processor comprises a flat oil filter, a buffer tank, an adsorption tank and a backflushing device; an inlet and an outlet of the adsorption tank are respectively communicated with the deteriorated insulating oil inlet pipe and an inlet of the buffer tank, an outlet of the buffer tank is communicated with an inlet of the flat oil filter, and an outlet of the flat oil filter is communicated with an inlet of the vacuum oil filter; the backflushing device comprises a backflushing medium liquid inlet pipe, a liquid inlet pump, a heating device and a backflushing medium liquid outlet pipe, wherein the backflushing medium liquid inlet pipe is communicated with an outlet of the adsorption tank after being connected with the heating device and the liquid inlet pump in series, and the backflushing medium liquid outlet pipe is communicated with an inlet of the adsorption tank.
Furthermore, a buffer tank is connected in parallel between the outlet of the flat oil filter and the inlet of the vacuum oil filter.
Furthermore, an internal circulation pipeline and an internal circulation valve are arranged between the outlet of the flat oil filter and the inlet of the adsorption tank.
The using method of the electric insulating oil performance repairing system comprises the following steps: (a) degraded insulating oil in the power equipment is conveyed to an oil processor through a degraded insulating oil inlet pipe, enters a vacuum oil filter after being processed by an adsorption tank, a buffer tank and a flat oil filter, and returns to the power equipment again through insulating oil output from the vacuum oil filter; (b) closing a pipeline connecting the adsorption tank and the buffer tank and an oil inlet pipe of the degraded insulating oil, opening a backflushing device connected with the adsorption tank, heating a backflushing medium to a preset temperature by a heating device, reversely entering the adsorption tank along a backflushing medium liquid inlet pipe under the driving of a liquid inlet pump, and outputting the backflushing medium along a backflushing medium liquid outlet pipe after leaving the adsorption tank; (c) and closing a pipeline valve of the backflushing device, and continuously carrying out restoration and regeneration treatment on the degraded insulating oil.
Further, the mass ratio of the XDK adsorbent filled in the adsorption tank to the deteriorated insulating oil to be treated is more than 2%.
Furthermore, the adsorption temperature of the adsorption tank during operation is 50 ℃, the adsorption pressure is below 0.2MPa, and the adsorption flow is about 100L/min.
Furthermore, the backflushing medium is fresh insulating oil or light distillate oil produced by the same manufacturer with the same brand.
Further, the mass airspeed S during the back flushing of the adsorption tankvControlling the time to be between 1.33 and 2.9 hours-1. The mass space velocity is defined as the inverse of the time it takes to pass a unit of fluid per unit volume of adsorbent.
Further, the heating device is specifically an electric heating wire, the power of the electric heating wire is about 36kW, and the backflushing medium is heated to 50-55 ℃.
The invention correspondingly improves the adsorption tank by utilizing an airspeed theory, and utilizes the heated light distillate oil or fresh insulating oil of the same brand and same manufacturer as a backwashing medium to backwash the adsorption tank which is treated with the degraded oil, thereby reducing the adsorbant of the adsorbent in the tank, improving the adsorption capacity, saving more energy, protecting the environment and lowering the cost. In addition, on the basis of the invention, a deteriorated insulating oil performance repairing adsorption mass transfer method and a physical filtering, degassing, dewatering and flow automatic matching method are provided, an adsorption tank complete set of equipment for performance repairing and life prolonging of the deteriorated insulating oil is developed, an industrial standard for selecting the special insulating oil for the power transformer is formulated, the insulating performance of the deteriorated insulating oil is repaired, the performance repairing and life prolonging of the deteriorated insulating oil are realized, the reutilization rate of the deteriorated insulating oil is more than 95 percent, and the life is generally prolonged by 10 to 20 years. The method of the invention is used in a certain power station, obtains better economic and social benefits and is well received by users.
Drawings
FIG. 1 is a deteriorated insulating oil reprocessing apparatus;
FIG. 2 is a schematic diagram of the oil regenerator of FIG. 1;
FIG. 3 is a schematic view of a modified adsorbent canister;
FIG. 4 is a schematic diagram of the adsorption mass transfer process and the aluminum electron holes inside the adsorbent.
Detailed Description
In order to make those skilled in the art fully understand the technical solutions and advantages of the present invention, the following description is further provided with reference to the specific embodiments and the accompanying drawings.
The invention is an improvement on the basis of patent result CN103594231B earlier published by the applicant, and the key point is to improve an adsorption tank filled with an XDK adsorbent, and additionally increase a set of backwashing device, thereby further improving the performance repair and regeneration effects of the deteriorated insulating oil.
Aiming at the problem that the adsorption mass transfer mechanism of the deteriorated insulating oil is uncertain, the method for repairing the adsorption mass transfer of the deteriorated insulating oil by using the performance is provided by the inventor, and the performance repairing macromolecular oil adsorption mass transfer behavior and the adsorption tank empty speed adsorption mechanism are disclosed (as shown in a figure 4). Through research, the adsorbent adsorbs impurities in the deteriorated insulating oil at a solid-liquid two-phase interface, and the impurities are diffused to the surface of the adsorbent by virtue of concentration difference. Ideally, the concentration C of impurities in the bulk of the degraded insulating oilbWith concentration C at the surface of the adsorbentsIs uniform, so that impurities can be directly diffused to the surface of the adsorbent; however, in practice, the adsorbent surface has a static oil film, and even if the impurities are stirred, the impurities do not reach the adsorbent surface, but rather a concentration gradient is formed in the oil film, and the impurities are diffused to the adsorbent surface by means of the concentration difference. The diffusion rate of the impurities was: (dni/dt) ═ DS (C)b-Cs)/(1). Considering that physical adsorption is mainly adopted and the adsorption speed is high, the total speed of the adsorption treatment process is controlled by the diffusion speed, namely: (-dc/dt) ═ DSCbV (2). As can be seen from the formula (2), C is found in a plurality of cycles after the start of adsorption filtrationbThe adsorption process is fast, and the oil dielectric loss reduction gradient is large; after a number of cycles, CbBecoming small, the adsorption process is slow, which is manifested by a slow decrease in oil dielectric loss. According to the formula (2), the stirring accelerates the thickness of the oil film on the surface of the adsorbent to be thinner, so that the speed of the adsorption process is increased, and the waste oil treatment time is shortened. The thickness of the oil film on the surface of the adsorbent becomes thinner (namely, smaller), the speed of the adsorption process is increased, and the repair and regeneration treatment time of the corresponding deteriorated insulating oil is shortened, which is the reason why the deteriorated insulating oil regenerated by the percolation method or the contact method must be forced to circulate oil or mechanically stirred by an oil pump.
Based on the above principles and notions, my party has introduced a mass space velocity (denoted as S)V) The concept of (1 m) is defined as3Passing 1m in the adsorbent3Reciprocal of time (h) spent by fluid-1) The relationship is as follows: flow rate Q ═ SV*VXFJ. For example, an adsorption tank containing 600g of XDK adsorbent having a specific gravity of 0.4kg/m3Calculating the volume V of the obtained adsorbentXFJIs 1.5m3The total flow rate of the deteriorated insulating oil is 6000L/h, and the average flow rate to 3 adsorption tanks is 2000L/h (namely 2.0 m)3H) into formula SV＝Q/VXFJ＝2/1.5＝1.33h-1。
The cooling mode of a transformer of a certain power station is strong oil air cooling, and the volume of each phase of insulating oil is 92m3Left and right, conservator oil 7m3And open operation. The insulating oil is naphthenic base mineral insulating oil (trade name is Transol) and does not contain antioxidant additives. The transformer substation basically runs at full load since the transformer substation is constructed and operated, the heating is found to be serious after the transformer substation runs for a period of time, the oil temperature of an oil tank body is detected to be about 86 ℃ during the period, and the chromatographic analysis criterion is 020, which indicates that the transformer substation has low-temperature overheating fault, the gas production rate is 75 ppm/month, and the transformer substation is slightly watery and has good pressure resistance. And then, further detection shows that dielectric loss of the insulating oil reaches more than 10 percent, the dielectric loss is seriously exceeded according to the BS-148-1984 standard, and because the transformer operates at low temperature for a long time, organic acid and alcohol in the oil generate polymerization reaction to form organic ester substances, so that oil sludge is separated out and attached to the bottom of a coil, a clamping piece and an oil tank of the transformer, and particularly, a mud layer on a low-voltage busbar which generates heat seriously is thicker. The dielectric loss after a certain unit of treatment of the deteriorated insulating oil is reduced to 4%, but quickly increased to about 7%.
The equipment and the system in the figures 1-2 are adopted by the company to carry out adsorption regeneration treatment on the deteriorated insulating oil of the transformer substation. The transformer substation is maintained after stable operation for more than one year, and further experiments are carried out. In the process of carrying out cyclic regeneration adsorption treatment on the deteriorated insulating oil, in order to control the adsorption treatment effect and decide whether to switch an adsorption tank (whether a recoil device is arranged or not), oil samples are taken from different point positions every 20 hours or so in the cyclic treatment process for analysis test, tg and breakdown voltage of the oil are tested to examine the oil treatment effect, and the results are shown in the following table:
TABLE 1 insulating oil Performance Table for different time periods
Description of the drawings: the dielectric loss instrument is produced by double corporation of America, the breakdown voltage is tested by adopting an IEC method, and the electrode oil cup is hemispherical.
Degraded insulating oil was circulated from day N16: 00, two days later from day N +2 15: and (5) stopping the machine at 00-21:00 to switch the adsorption tanks (during which the adsorption tanks are back flushed by a back flushing device), and stopping the machine for replacing the vacuum pump oil in the (N + 2) th day. After finding that the dielectric loss is reduced slowly in the (N + 2) th day, carrying out corresponding treatment on the adsorption tank; the dielectric loss of the insulating oil can be seen to continue to be obviously reduced after the N +2 days, and the method has the characteristics of short time, quick response, high efficiency and the like.
Claims (9)
1. The electric insulating oil performance repairing system is characterized in that the system comprises an oil treatment machine and a vacuum oil filter which are connected in series, wherein the oil treatment machine comprises a flat oil filter, a buffer tank, an adsorption tank and a backflushing device; an inlet and an outlet of the adsorption tank are respectively communicated with the deteriorated insulating oil inlet pipe and an inlet of the buffer tank, an outlet of the buffer tank is communicated with an inlet of the flat oil filter, and an outlet of the flat oil filter is communicated with an inlet of the vacuum oil filter; the backflushing device comprises a backflushing medium liquid inlet pipe, a liquid inlet pump, a heating device and a backflushing medium liquid outlet pipe, wherein the backflushing medium liquid inlet pipe is communicated with an outlet of the adsorption tank after being connected with the heating device and the liquid inlet pump in series, and the backflushing medium liquid outlet pipe is communicated with an inlet of the adsorption tank.
2. The system of claim 1, wherein: a buffer tank is connected in parallel between the outlet of the flat oil filter and the inlet of the vacuum oil filter.
3. The system of claim 1, wherein: an internal circulation pipeline and an internal circulation valve are also arranged between the outlet of the flat oil filter and the inlet of the adsorption tank.
4. Method for using the electrical insulating oil performance restoration system according to claim 1, characterized by comprising the steps of: (a) degraded insulating oil in the power equipment is conveyed to an oil processor through a degraded insulating oil inlet pipe, enters a vacuum oil filter after being processed by an adsorption tank, a buffer tank and a flat oil filter, and returns to the power equipment again through insulating oil output from the vacuum oil filter; (b) closing a pipeline connecting the adsorption tank and the buffer tank and an oil inlet pipe of the degraded insulating oil, opening a backflushing device connected with the adsorption tank, heating a backflushing medium to a preset temperature by a heating device, reversely entering the adsorption tank along a backflushing medium liquid inlet pipe under the driving of a liquid inlet pump, and outputting the backflushing medium along a backflushing medium liquid outlet pipe after leaving the adsorption tank; (c) and closing a pipeline valve of the backflushing device, and continuously carrying out restoration and regeneration treatment on the degraded insulating oil.
5. The method of claim 4, wherein: the mass ratio of the XDK adsorbent filled in the adsorption tank to the degraded insulating oil to be treated is more than 2%.
6. The method of claim 4, wherein: the adsorption temperature of the adsorption tank during operation is 50 ℃, the adsorption pressure is below 0.2MPa, and the adsorption flow is about 100L/min.
7. The method of claim 4, wherein: the backflushing medium is fresh insulating oil or light distillate oil produced by the same manufacturer with the same brand.
8. The method of claim 4, wherein: mass airspeed S during backwashing of adsorption tanksvControlling the time to be between 1.33 and 2.9 hours-1。
9. The method of claim 4, wherein: the heating device is specifically an electric heating wire, the power of the electric heating wire is about 36kW, and the backflushing medium is heated to 50-55 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202010870942.0A CN111991906A (en) | 2020-08-26 | 2020-08-26 | System and method for repairing performance of electric insulating oil |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010870942.0A CN111991906A (en) | 2020-08-26 | 2020-08-26 | System and method for repairing performance of electric insulating oil |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005023031A (en) * | 2003-07-03 | 2005-01-27 | Tm T & D Kk | Method for cleaning up polychlorinated biphenyl |
| CN103474206A (en) * | 2013-08-26 | 2013-12-25 | 中国广核集团有限公司 | Nuclear power station transformer oil treatment system and method |
| CN103594231A (en) * | 2012-08-14 | 2014-02-19 | 国家电网公司 | Handing method for reducing dielectric loss of deteriorated transformer oil |
| CN104436751A (en) * | 2014-11-19 | 2015-03-25 | 国家电网公司 | Adsorption device capable of regenerating adsorbent on site and used for transformer oil regeneration |
| CN104575965A (en) * | 2015-02-11 | 2015-04-29 | 国家电网公司 | Oil processor for transformer |
| CN105296110A (en) * | 2015-10-29 | 2016-02-03 | 上海中孚特种油品有限公司 | Environment-friendly plant transformer oil and preparation method thereof |
| CN110903887A (en) * | 2019-12-23 | 2020-03-24 | 国网湖北省电力有限公司孝感供电公司 | Replacement system and replacement method for electric power oil |
-
2020
- 2020-08-26 CN CN202010870942.0A patent/CN111991906A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005023031A (en) * | 2003-07-03 | 2005-01-27 | Tm T & D Kk | Method for cleaning up polychlorinated biphenyl |
| CN103594231A (en) * | 2012-08-14 | 2014-02-19 | 国家电网公司 | Handing method for reducing dielectric loss of deteriorated transformer oil |
| CN103474206A (en) * | 2013-08-26 | 2013-12-25 | 中国广核集团有限公司 | Nuclear power station transformer oil treatment system and method |
| CN104436751A (en) * | 2014-11-19 | 2015-03-25 | 国家电网公司 | Adsorption device capable of regenerating adsorbent on site and used for transformer oil regeneration |
| CN104575965A (en) * | 2015-02-11 | 2015-04-29 | 国家电网公司 | Oil processor for transformer |
| CN105296110A (en) * | 2015-10-29 | 2016-02-03 | 上海中孚特种油品有限公司 | Environment-friendly plant transformer oil and preparation method thereof |
| CN110903887A (en) * | 2019-12-23 | 2020-03-24 | 国网湖北省电力有限公司孝感供电公司 | Replacement system and replacement method for electric power oil |
Non-Patent Citations (2)
| Title |
|---|
| 上海试剂五厂: "《分子筛制备与应用》", 30 June 1976, 上海人民出版社 * |
| 杜巧云: "《表面活性剂基础及应用》", 31 August 1996, 中国石化出版社 * |
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Application publication date: 20201127 |