CN113340073B - On-site drying method and drying system for epoxy impregnated paper transformer - Google Patents
On-site drying method and drying system for epoxy impregnated paper transformer Download PDFInfo
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- CN113340073B CN113340073B CN202110659677.6A CN202110659677A CN113340073B CN 113340073 B CN113340073 B CN 113340073B CN 202110659677 A CN202110659677 A CN 202110659677A CN 113340073 B CN113340073 B CN 113340073B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B9/00—Machines or apparatus for drying solid materials or objects at rest or with only local agitation; Domestic airing cupboards
- F26B9/06—Machines or apparatus for drying solid materials or objects at rest or with only local agitation; Domestic airing cupboards in stationary drums or chambers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B23/00—Heating arrangements
- F26B23/10—Heating arrangements using tubes or passages containing heated fluids, e.g. acting as radiative elements; Closed-loop systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B25/00—Details of general application not covered by group F26B21/00 or F26B23/00
- F26B25/001—Handling, e.g. loading or unloading arrangements
- F26B25/003—Handling, e.g. loading or unloading arrangements for articles
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Abstract
The invention relates to an on-site drying method and a drying system for an epoxy impregnated paper transformer. In the method, the epoxy impregnated transformer comprises an oil tank and an epoxy glue impregnated sleeve, wherein transformer oil is filled in the oil tank, and one end of the epoxy glue impregnated sleeve is immersed in the transformer oil; heating the transformer oil in the oil tank to be not lower than 90 ℃ so as to heat and dry the epoxy glue impregnated paper sleeve; in the process of heating and drying the epoxy glue impregnated paper sleeve, extracting gas in the epoxy glue impregnated paper sleeve, and filling protective gas into the epoxy glue impregnated paper sleeve; and after the step of filling the protective gas into the epoxy glue impregnated paper sleeve, detecting the gas moisture content in the epoxy glue impregnated paper sleeve and the insulation performance parameters of the epoxy glue impregnated paper sleeve. The method can effectively dry the epoxy impregnated transformer on site.
Description
Technical Field
The invention relates to the technical field of electrical equipment, in particular to an on-site drying method and a drying system for an epoxy impregnated paper transformer.
Background
The epoxy impregnated paper sleeve which takes the cured epoxy resin impregnated insulating paper as main insulation is also called a dry sleeve, has excellent electrical performance and explosion-proof flame retardance, has small volume and light weight, is widely applied to power grid construction, and is commonly used as a sleeve of a transformer, such as a valve side sleeve or a direct-current wall bushing of a converter transformer. In a common epoxy impregnated paper bushing, an epoxy impregnated paper capacitor core is connected with a hollow composite insulator through a flange, insulating gas with certain pressure is filled in an air cavity between the epoxy impregnated paper capacitor core and the hollow composite insulator to serve as auxiliary insulation of the bushing, and one end of the epoxy impregnated paper bushing is immersed in transformer oil filled in a transformer oil tank.
Because the insulating paper and the epoxy resin have certain water absorption, the epoxy glue impregnated paper sleeve can easily absorb moisture in the manufacturing, transportation and use and operation processes of the transformer. Meanwhile, due to poor sealing between the hollow composite insulator in the epoxy impregnated paper bushing and the epoxy impregnated paper capacitor core, moisture can invade into the epoxy impregnated paper bushing, the damp can cause the insulating property of the bushing to change, the normal operation of the bushing is affected, and even the bushing discharge fault is caused, so that the transformer is poor in operation. Moreover, once the epoxy impregnated paper sleeve is wetted, the moisture in the epoxy impregnated paper sleeve is difficult to naturally remove. In the conventional technology, the method for treating the damp epoxy adhesive paper bushing is to disassemble the bushing from the transformer and return the bushing to the factory to enter an oven for drying. However, this method requires a series of processes such as casing removal, factory return transportation, casing hollow composite insulator disassembly, core drying, reassembly, re-delivery, field installation, etc., and has the problems of high cost, long time consumption, high risk, etc.
Therefore, the prior art still remains to be developed.
Disclosure of Invention
Based on the method, the epoxy impregnated transformer can be effectively dried on site, a series of processes of removing a damped sleeve arranged on the transformer, returning to a factory for transportation, disassembling a sleeve body, drying a core body, reassembling, re-delivering, re-installing on site and the like are not needed, the method is efficient and convenient, and the drying efficiency of the epoxy impregnated transformer is improved.
The technical scheme of the invention is as follows.
One aspect of the invention provides an on-site drying method for an epoxy impregnated paper transformer, wherein the epoxy impregnated paper transformer comprises an oil tank and an epoxy glue impregnated paper sleeve, transformer oil is filled in the oil tank, one end of the epoxy glue impregnated paper sleeve is immersed in the transformer oil, and the on-site drying method comprises the following steps:
heating the transformer oil in the oil tank to be not lower than 90 ℃ so as to heat and dry the epoxy glue impregnated paper sleeve; in the process that the epoxy glue impregnated paper sleeve is heated and dried, gas in the epoxy glue impregnated paper sleeve is pumped out, and protective gas is filled into the epoxy glue impregnated paper sleeve; and
and after the step of filling the protective gas into the epoxy glue impregnated paper sleeve, detecting the gas moisture content in the epoxy glue impregnated paper sleeve and the insulation performance parameter of the epoxy glue impregnated paper sleeve.
In some of these embodiments, in the step of heating, the transformer oil is heated to 90 ℃ to 100 ℃.
In some embodiments, in the step of pumping out the gas in the epoxy glue impregnated paper sleeve, the gas in the epoxy glue impregnated paper sleeve is pumped out until the vacuum degree in the epoxy glue impregnated paper sleeve is 10pa to 20 pa.
In some embodiments, the step of heating the transformer oil in the oil tank to not lower than 90 ℃ comprises the following steps:
and a heating circulating device is connected with the oil tank so as to enable the transformer oil to circulate between the heating circulating device and the oil tank.
In some embodiments, after the step of filling the protective gas into the epoxy glue impregnated paper sleeve, the step of heating is continued, and the moisture content of the gas in the epoxy glue impregnated paper sleeve is detected every 8-24 hours until the moisture content of the gas in the epoxy glue impregnated paper sleeve reaches a moisture saturation value; and when the moisture content of the gas in the epoxy glue impregnated paper sleeve reaches a moisture saturation value, detecting the insulation performance parameters of the epoxy glue impregnated paper sleeve to obtain the insulation performance parameters after drying.
In some embodiments, when the moisture saturation value of the gas in the epoxy glue impregnated paper bushing is higher than the moisture operation allowable value of the epoxy glue impregnated paper bushing or the insulation performance parameter of the epoxy glue impregnated paper bushing after drying is higher than the insulation performance parameter operation allowable value of the epoxy glue impregnated paper bushing, the method further comprises the following steps:
and continuously heating, pumping out the gas in the epoxy glue impregnated paper sleeve, and continuously filling the protective gas and detecting.
In some embodiments, when the moisture saturation value of the gas in the epoxy glue impregnated paper bushing is lower than or equal to the moisture operation allowable value of the epoxy glue impregnated paper bushing, and the insulation performance parameter of the epoxy glue impregnated paper bushing after drying is lower than or equal to the insulation performance parameter operation allowable value of the epoxy glue impregnated paper bushing, the method further comprises the following steps:
stopping heating; and pumping out the gas in the epoxy glue impregnated paper sleeve, and then filling insulating gas into the epoxy glue impregnated paper sleeve.
In some embodiments, the epoxy glue impregnated paper sleeve contains an insulating gas, and the insulating gas is SF6(ii) a And/or
The protective gas is at least one of nitrogen and an inert gas.
In another aspect of the present invention, an in-situ drying system for an epoxy impregnated transformer is provided, comprising:
the epoxy impregnated paper transformer comprises an oil tank and an epoxy adhesive impregnated paper sleeve, wherein transformer oil is filled in the oil tank, and one end of the epoxy adhesive impregnated paper sleeve is immersed in the transformer oil;
the heating device is used for heating the transformer oil in the oil tank to be not lower than 90 ℃ so as to heat and dry the epoxy glue impregnated paper sleeve;
the air exhaust device is used for exhausting the air in the epoxy glue impregnated paper sleeve in the process of heating and drying the epoxy glue impregnated paper sleeve;
the inflation device is used for inflating protective gas into the epoxy glue impregnated paper sleeve in the process that the epoxy glue impregnated paper sleeve is heated and dried and after the air in the epoxy glue impregnated paper sleeve is pumped out by the air exhaust device;
the gas detection device is used for detecting the gas moisture content in the epoxy glue impregnated paper sleeve after the protective gas is filled; and
and the insulating property detection device is used for detecting the insulating property parameters of the epoxy glue impregnated paper sleeve after the step of filling the protective gas.
In some embodiments, the heating device is a heating cycle device, and the heating cycle device is connected with the oil tank so as to circulate the transformer oil between the heating cycle device and the oil tank.
Advantageous effects
According to the on-site drying method for the epoxy impregnated transformer, the epoxy impregnated transformer can be effectively dried on site without being disassembled. Heating the transformer oil in the oil tank to be not lower than 90 ℃ so as to heat and dry the epoxy glue impregnated paper sleeve; and in the process of heating and drying the epoxy glue impregnated paper sleeve, pumping out the gas in the epoxy glue impregnated paper sleeve, and filling protective gas into the epoxy glue impregnated paper sleeve. And after the step of filling the protective gas, detecting the gas moisture content in the epoxy glue impregnated paper sleeve and the insulation performance parameters of the epoxy glue impregnated paper sleeve. In the process of heating the transformer oil in the oil tank, on one hand, the transformer oil can be degassed and dewatered; on the other hand, the heat of the transformer oil is transferred to the epoxy impregnated paper sleeve, so that the temperature of the sleeve is raised, the moisture in the sleeve is separated out under the promotion of the protective gas and is mixed with the filled protective gas, and the separated moisture is taken out through the protective gas, so that the epoxy impregnated paper sleeve is dried after being heated. And then, detecting the moisture content of the gas in the epoxy glue impregnated paper sleeve and the insulation performance parameters of the epoxy glue impregnated paper sleeve so as to judge the drying degree of the transformer and the sleeve. The whole process is efficient and convenient, and a series of processes of removing the damped sleeve installed on the transformer, returning to a factory for transportation, disassembling the sleeve body, drying the core body, reassembling, re-delivering goods, re-installing on site and the like are not needed.
Drawings
Fig. 1 is a schematic diagram of an in-situ drying system for an epoxy impregnated transformer of example 1.
Detailed Description
In order that the invention may be more fully understood, a more particular description of the invention will now be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
In the conventional technology, the method for treating the damp epoxy adhesive paper bushing is to disassemble the bushing from the transformer and return the bushing to the factory to enter an oven for drying. However, this method requires a series of processes such as casing removal, factory return transportation, casing hollow composite insulator disassembly, core drying, reassembly, re-delivery, field installation, etc., and has the problems of high cost, long time consumption, high risk, etc.
Some technicians attempt to perform impurity removal and degassing treatment on transformer oil in a transformer in a hot oil circulation manner so as to achieve the purpose of circulating the transformer oil, however, the technologies only relate to how to perform impurity removal and degassing treatment on the transformer oil in the transformer. The person skilled in the art creatively proposes to dry the transformer in situ by means of hot oil circulation, but in the experimental process, it is found that: due to the characteristics of large volume, thick insulating layer, long length, slow heat transfer and the like of the epoxy impregnated paper sleeve, the moisture of the epoxy impregnated paper sleeve is difficult to remove by the transferred heat in the hot oil circulation process.
Based on the above, after a great deal of experimental research, technicians of the invention obtain the method for effectively drying the epoxy impregnated transformer on site, so that a series of processes of removing the damped sleeve installed on the transformer, returning to a factory for transportation, disassembling the sleeve body, drying the core body, reassembling, re-delivering goods, re-installing on site and the like are avoided, and the method is efficient and convenient.
The invention provides an on-site drying method of an epoxy impregnated transformer, the epoxy impregnated transformer comprises an oil tank and an epoxy glue impregnated sleeve, transformer oil is filled in the oil tank, and one end of the epoxy glue impregnated sleeve is immersed in the transformer oil, the on-site drying method comprises the following steps of S10-S20.
Step S10, heating the transformer oil in the oil tank to be not lower than 90 ℃ so as to heat and dry the epoxy glue impregnated paper sleeve; and in the process of heating and drying the epoxy glue impregnated paper sleeve, extracting the gas in the epoxy glue impregnated paper sleeve, and filling protective gas into the epoxy glue impregnated paper sleeve.
And step S20, after the step of filling protective gas into the epoxy glue impregnated paper sleeve, detecting the gas moisture content in the epoxy glue impregnated paper sleeve and the insulation performance parameters of the epoxy glue impregnated paper sleeve.
According to the on-site drying method for the epoxy impregnated transformer, the epoxy impregnated transformer can be effectively dried on site without being disassembled. Heating the transformer oil in the oil tank to be not lower than 90 ℃ so as to heat and dry the epoxy glue impregnated paper sleeve; and in the process of heating and drying the epoxy glue impregnated paper sleeve, pumping out the gas in the epoxy glue impregnated paper sleeve, and filling protective gas into the epoxy glue impregnated paper sleeve. And after the step of filling the protective gas, detecting the gas moisture content in the epoxy glue impregnated paper sleeve and the insulation performance parameters of the epoxy glue impregnated paper sleeve. In the process of heating the transformer oil of the oil tank, on one hand, the transformer oil can be degassed and dewatered, on the other hand, the heat of the transformer oil can be transferred to the epoxy impregnated paper sleeve, so that the temperature of the sleeve rises, the moisture in the sleeve is separated out under the promotion of protective gas and is mixed with the filled protective gas, and the separated moisture is taken out through the protective gas, so that the epoxy impregnated paper sleeve is dried after being heated. And then, detecting the gas moisture content in the epoxy glue impregnated paper sleeve and the insulation performance parameters of the epoxy glue impregnated paper sleeve so as to judge the drying degree of the epoxy glue impregnated paper transformer. The whole process is efficient and convenient, and a series of processes of removing the damped sleeve installed on the transformer, transporting the damped sleeve to a factory, disassembling the sleeve body, drying the core body, reassembling, re-delivering, re-installing on site and the like are not needed.
Referring to fig. 1, an embodiment of the present invention further provides an on-site drying system for an epoxy impregnated transformer, and the on-site drying method for an epoxy impregnated transformer can be performed by using the on-site drying system for an epoxy impregnated transformer.
The on-site drying system of the epoxy impregnated transformer comprises:
epoxy soaks paper transformer 10, including oil tank 11 and epoxy glue soaks paper sleeve pipe 12, the oil tank 11 intussuseption is filled with transformer oil, and transformer oil is soaked in the one end of epoxy glue soaks paper sleeve pipe 12.
And the heating device 20 is used for heating the transformer oil in the oil tank 11 to be not lower than 90 ℃ so as to heat and dry the epoxy glue impregnated paper sleeve 12.
And the air exhaust device 30 is used for exhausting air in the epoxy glue impregnated paper sleeve 12 in the process that the epoxy glue impregnated paper sleeve 12 is heated and dried.
And the inflating device 40 is used for inflating protective gas into the epoxy glue impregnated paper sleeve 12 in the process that the epoxy glue impregnated paper sleeve 12 is heated and dried and after the gas in the epoxy glue impregnated paper sleeve 12 is pumped out by the air pumping device 30.
And the gas detection device 50 is used for detecting the gas moisture content in the epoxy glue impregnated paper sleeve 12 after the protective gas filling step.
And the insulating property detection device 60 is used for detecting the insulating property parameter of the epoxy glue impregnated paper sleeve 12 after the protective gas filling step.
Referring to fig. 1, in some embodiments, the heating device 20 is a heating cycle device, and the heating cycle device is connected to the oil tank 11 to circulate the transformer oil between the heating cycle device and the oil tank 11.
Specifically, the heating circulation device is an oil filter, and the oil filter is connected to the oil outlet and the oil inlet of the oil tank 11 through pipes, so that the transformer oil circulates between the oil filter and the oil tank 11. The transformer oil is heated, degassed and impurity-removed by the oil filter, on one hand, the transformer oil in the oil tank is heated to be not lower than 90 ℃ so as to heat and dry the epoxy glue impregnated paper sleeve, and on the other hand, the quality of the transformer oil in the transformer is also improved.
In some of these embodiments, the epoxy impregnated paper bushing 12 includes an epoxy impregnated paper capacitor core 121, a hollow composite insulator 122, an extension guide rod 123, a grading ring 124, and a flange 125.
The epoxy glue impregnated paper capacitor core 121 is connected with the hollow composite insulator 122 through a flange 125, and insulating gas with certain pressure is filled in an air cavity between the epoxy glue impregnated paper capacitor core 121 and the hollow composite insulator 122 to serve as auxiliary insulating substances.
Specifically, the epoxy resin impregnated paper capacitor core 121 has a current-carrying guide rod therein, one end of the current-carrying guide rod is connected to one end of the extension guide rod 123, and the other end of the extension guide rod 123 is connected to the grading ring 124 through a connection terminal.
Further, the epoxy impregnated paper transformer 10 further comprises a transformer winding 13, the transformer winding 13 is located in the oil tank 11, and the transformer oil is filled in a cavity formed by the oil tank 11 and the transformer winding 13.
In some of these embodiments, the other end of the current carrying rod of the epoxy impregnated paper capacitor core 121 is immersed in transformer oil and connected to the transformer winding 13 via terminals at the end of the current carrying rod.
During heating, transformer oil circulates between the oil filter and the tank 11, while also drying the windings 13.
In some embodiments, the hollow composite insulator 122 is provided with a through hole.
Further, the air extractor 30 is communicated with the through hole through a pipeline to extract air in the epoxy glue impregnated paper sleeve 12 in the process that the epoxy glue impregnated paper sleeve 12 is heated and dried.
Further, the air charging device 40 is connected with the through hole through a pipeline, so as to charge protective gas into the epoxy glue impregnated paper sleeve 12 during the process that the epoxy glue impregnated paper sleeve 12 is heated and dried and after the air in the epoxy glue impregnated paper sleeve 12 is pumped out by the air pumping device 30.
Further, a gas detection device 50 is connected to the through hole through a pipe to detect the gas moisture content in the epoxy-impregnated paper sleeve 12 after the step of filling the protective gas.
It should be noted that the pipes of the air extracting device 30, the air charging device 40 and the gas detecting device 50 connected to the ports may be the same pipe or different pipes.
The detection interface of the insulation performance detection device 60 is connected with the detected part of the epoxy glue impregnated paper sleeve 12 through a through hole, and is used for detecting the insulation performance parameters of the epoxy glue impregnated paper sleeve 12 after the step of filling the protective gas. In some embodiments, in step S10, after the step of filling the protective gas into the epoxy glue impregnated paper sleeve, the step of heating is continued, and the moisture content of the gas in the epoxy glue impregnated paper sleeve is detected every 8 to 24 hours until the moisture content of the gas in the epoxy glue impregnated paper sleeve reaches a moisture saturation value; and when the moisture content of the gas in the epoxy glue impregnated paper sleeve reaches a moisture saturation value, detecting the insulation performance parameters of the epoxy glue impregnated paper sleeve to obtain the insulation performance parameters after drying.
It should be noted that, in the process of heating the transformer oil to heat and dry the epoxy glue impregnated paper sleeve, under the atmosphere of the protective gas filled into the epoxy glue impregnated paper sleeve, the precipitation of moisture in the epoxy glue impregnated paper sleeve reaches a limit equilibrium point, and at this time, the moisture content of the gas in the epoxy glue impregnated paper sleeve is the moisture saturation value. Specifically, whether the moisture content of the gas in the epoxy glue impregnated paper sleeve reaches the moisture saturation value or not is judged according to the moisture content value obtained by detecting the moisture content of the gas in the epoxy glue impregnated paper sleeve twice, if the moisture content value obtained by detecting the moisture content of the gas in the epoxy glue impregnated paper sleeve twice is the same, the moisture content of the gas in the epoxy glue impregnated paper sleeve is the moisture saturation value, and if not, the moisture content is not reached.
In the operation of the voltage transformer, the drying degree of the epoxy impregnated paper transformer has specific standards, which are reflected in the requirements on the moisture content of the gas in the epoxy impregnated paper bushing and the insulation parameters of the epoxy impregnated paper bushing.
In some embodiments, when the moisture saturation value of the gas in the epoxy glue impregnated paper sleeve is higher than the moisture operation allowable value of the epoxy glue impregnated paper sleeve or the insulation parameter of the epoxy glue impregnated paper sleeve is higher than the insulation performance parameter operation allowable value of the epoxy glue impregnated paper sleeve, the method further comprises the following steps:
and continuously heating, extracting the gas in the epoxy glue impregnated paper sleeve, and continuously filling the protective gas and detecting.
When the moisture content of the gas in the epoxy glue impregnated paper sleeve or the insulation parameters of the epoxy glue impregnated paper sleeve do not reach the operation standard, the drying degree of the oxygen impregnated paper transformer does not reach the operation standard, the gas in the epoxy glue impregnated paper sleeve is extracted, protective gas is continuously filled, heating circulation is continuously carried out, and the epoxy glue impregnated paper sleeve is continuously heated and dried.
In some embodiments, when the moisture saturation value of the gas in the epoxy glue impregnated paper sleeve is lower than or equal to the moisture operation allowable value of the epoxy glue impregnated paper sleeve, and the insulation parameter of the epoxy glue impregnated paper sleeve is lower than or equal to the insulation performance parameter operation allowable value of the epoxy glue impregnated paper sleeve, the method further comprises the following steps:
stopping heating; and pumping out the gas in the epoxy glue impregnated paper sleeve, and then filling insulating gas into the epoxy glue impregnated paper sleeve.
It can be understood that when the moisture saturation value of the gas in the epoxy glue impregnated paper sleeve and the dielectric loss factor of the epoxy glue impregnated paper sleeve both meet the requirements of the operation standard, at the moment, the drying degree of the transformer meets the operation standard, so that the gas in the epoxy glue impregnated paper sleeve is extracted, the heating is stopped, then the epoxy glue impregnated paper sleeve is filled with the insulating gas, and at the moment, the drying is finished. The dried transformer can be put into operation again.
It should be noted that the step of stopping heating and the step of extracting the gas in the epoxy glue impregnated paper sleeve are not specifically described in sequence.
Specifically, the moisture run tolerance of the epoxy impregnated paper sleeve is less than 250 ppm.
In some of these embodiments, the insulation performance parameters include, but are not limited to: insulation resistance, dielectric loss factor, and frequency domain dielectric spectrum. These parameters reflect the insulating properties of epoxy impregnated paper bushings from different layers.
In a specific example, the insulation performance parameter of the epoxy glue impregnated paper bushing is a dielectric loss factor, and further, the insulation performance parameter of the epoxy glue impregnated paper bushing is a dielectric loss factor, and the operation allowable value is 0.7%.
In some embodiments, in step S10, the heating step is to heat the transformer oil to 90-100 ℃.
The drying efficiency of the epoxy glue impregnated paper sleeve is improved by controlling the temperature of the transformer oil.
In some embodiments, in the step of pumping out the gas in the epoxy glue impregnated paper sleeve, the gas in the epoxy glue impregnated paper sleeve is pumped out until the vacuum degree in the epoxy glue impregnated paper sleeve is 10pa to 20 pa.
It is understood that the protective gas is a gas having stable chemical properties, does not participate in the reaction even during the chemical reaction at high temperature and high pressure, and can serve to isolate active gases in the atmosphere, such as oxygen.
The protective gas includes at least one of an inert gas and nitrogen. Specifically, including but not limited to: helium (He), neon (Ne), argon (Ar), krypton (Kr), and nitrogen (N)2)。
In some of these embodiments, the protective gas is nitrogen.
In some embodiments, the insulating gas is selected from the group consisting of air, nitrogen, sulfur dioxide, and sulfur hexafluoride (SF)6) At least one of (1).
Further, the insulating gas is sulfur hexafluoride (SF)6)。
While the present invention will be described with respect to particular embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover by the appended claims the scope of the invention, and that certain changes in the embodiments of the invention will be suggested to those skilled in the art and are intended to be covered by the appended claims.
DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION
Example 1
1) Referring to fig. 1, a transformer 10 with moisture impregnated epoxy resin in a transformer substation includes an oil tank 11, an epoxy resin impregnated paper sleeve 12 and a transformer winding 13; the oil tank 11 is filled with transformer oil, one end of the epoxy glue paper-impregnated sleeve 12 is immersed in the transformer oil, the transformer winding 13 is positioned in the oil tank 11, and a cavity formed by the oil tank 11 and the transformer winding 13 is filled with the transformer oil. The epoxy glue impregnated paper bushing 12 includes an epoxy glue impregnated paper capacitor core 121, a hollow composite insulator 122, a guide rod 123, and a grading ring 124. The epoxy glue impregnated paper capacitor core 121 is connected with the hollow composite insulator 122 through a flange 125, and the inside of an air cavity between the epoxy glue impregnated paper capacitor core 121 and the hollow composite insulator 122 is filled with insulating gas SF6. One end of an internal current-carrying guide rod of the epoxy glue impregnated paper capacitor core 121 is connected with one end of the guide rod 123, the other end of the guide rod 123 is connected with the grading ring 124 through a wiring terminal, and the other end of the internal current-carrying guide rod of the epoxy glue impregnated paper capacitor core 121 is immersed in transformer oil and is connected with the transformer winding 13 through the wiring terminal at the end part of the internal current-carrying guide rod. The hollow composite insulator 122 is provided with a connection hole.
2) Continuing with fig. 1, the wet epoxy impregnated transformer is dried in the field: the oil filter is respectively connected with an oil outlet and an oil inlet of the oil tank 11 through pipelines so that the transformer oil is heated and circulated between the oil filter and the oil tank 11, and the temperature of the transformer oil is kept at 90-95 ℃; meanwhile, the air extractor 30 is connected with the connection hole through a pipeline, so that in the process that the epoxy glue impregnated paper sleeve 12 is heated and dried, air in the epoxy glue impregnated paper sleeve 12 is extracted until the vacuum degree in the epoxy glue impregnated paper sleeve is 10Pa, the air extractor 40 is connected with the connection hole through a pipeline, and nitrogen is filled into the epoxy glue impregnated paper sleeve 12.
(3) Continuously heating, connecting a gas detection device 50 with the connection hole through a pipeline, and detecting the moisture content of the gas in the epoxy glue impregnated paper sleeve by adopting the gas detection device every 12 hours until the moisture content of the gas in the epoxy glue impregnated paper sleeve reaches a moisture saturation value; recording the moisture saturation value of the gas in the epoxy glue impregnated paper sleeve, then judging whether the moisture saturation value of the gas in the epoxy glue impregnated paper sleeve is higher than an operation allowable value of 250ppm, if so, continuing to pump the gas in the epoxy glue impregnated paper sleeve 12 by using the air pumping device 30 until the vacuum degree in the epoxy glue impregnated paper sleeve is 10Pa, then connecting the epoxy glue impregnated paper sleeve 12 with a connecting hole by using the inflating device 40 through a pipeline, filling nitrogen into the epoxy glue impregnated paper sleeve 12, and circularly performing the detection step until the moisture saturation value of the gas in the epoxy glue impregnated paper sleeve is smaller than the operation allowable value of 250 ppm.
(4) And continuously heating, connecting the insulation performance detection device 60 with the connection hole through a wiring, testing the dielectric loss factor of the epoxy glue impregnated paper capacitor core 121, if the dielectric loss factor is higher than 0.7%, continuously pumping the gas in the epoxy glue impregnated paper sleeve 12 by using the air pumping device 30 until the vacuum degree in the epoxy glue impregnated paper sleeve is 10Pa, then connecting the epoxy glue impregnated paper sleeve 12 with the connection hole through a pipeline by using the air charging device 40, charging nitrogen into the epoxy glue impregnated paper sleeve 12, and circularly performing the detection step until the moisture saturation value of the gas in the epoxy glue impregnated paper sleeve is smaller than the operation allowable value of 250ppm and the dielectric loss factor of the epoxy glue impregnated paper sleeve is smaller than 0.7%. At this time, the hot oil circulating device is closed, the air in the epoxy glue impregnated paper sleeve is pumped out by the air pumping device 30, and the insulating gas SF is filled into the epoxy glue impregnated paper sleeve 12 by the air charging device 406And (5) finishing drying. The dried transformer can be put into operation again.
The drying process is carried out for 72h from the beginning of the heating cycle to the closing of the hot oil circulating device.
Comparative example 1
Comparative example 1 an epoxy impregnated transformer, which was wetted at the same site and to the same extent, was subjected to a drying treatment substantially the same as in example 1. The difference is only that: in the steps (2) - (4), the transformer oil is heated and circulated, and the temperature is kept at 70-80 ℃; the results show that: from the beginning of the heating cycle to the closing of the hot oil circulating device, the moisture saturation value of the gas in the epoxy glue impregnated paper sleeve is still higher than the operation allowable value of 250ppm for more than 72 hours, and the dielectric loss factor of the epoxy glue impregnated paper sleeve is higher than 0.7%.
The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (5)
1. The field drying method of the epoxy impregnated paper transformer is characterized in that the epoxy impregnated paper transformer comprises an oil tank and an epoxy adhesive impregnated paper sleeve, transformer oil is filled in the oil tank, one end of the epoxy adhesive impregnated paper sleeve is immersed in the transformer oil, and the field drying method comprises the following steps:
heating the transformer oil in the oil tank to be not lower than 90 ℃ so as to heat and dry the epoxy glue impregnated paper sleeve; in the process that the epoxy glue impregnated paper sleeve is heated and dried, gas in the epoxy glue impregnated paper sleeve is pumped out, and protective gas is filled into the epoxy glue impregnated paper sleeve; and
after the step of filling the protective gas into the epoxy glue impregnated paper sleeve, detecting the gas moisture content in the epoxy glue impregnated paper sleeve and the insulation performance parameter of the epoxy glue impregnated paper sleeve;
the step of heating the transformer oil in the oil tank to a temperature of not less than 90 ℃ comprises the following steps:
a heating circulating device is connected with the oil tank so as to enable the transformer oil to circulate between the heating circulating device and the oil tank;
after the step of filling the protective gas into the epoxy glue impregnated paper sleeve, continuously heating, and detecting the moisture content of the gas in the epoxy glue impregnated paper sleeve every 8-24 hours until the moisture content of the gas in the epoxy glue impregnated paper sleeve reaches a moisture saturation value; when the moisture content of the gas in the epoxy glue impregnated paper sleeve reaches a moisture saturation value, detecting the insulation performance parameters of the epoxy glue impregnated paper sleeve to obtain the insulation performance parameters after drying;
when the moisture saturation value of the gas in the epoxy glue impregnated paper sleeve is lower than or equal to the moisture operation allowable value of the epoxy glue impregnated paper sleeve, and the insulation performance parameter of the dried epoxy glue impregnated paper sleeve is lower than or equal to the insulation performance parameter operation allowable value of the epoxy glue impregnated paper sleeve, the method further comprises the following steps:
stopping heating; extracting gas in the epoxy glue impregnated paper sleeve, and then filling insulating gas into the epoxy glue impregnated paper sleeve;
when the moisture saturation value of the gas in the epoxy glue impregnated paper sleeve is higher than the moisture operation allowable value of the epoxy glue impregnated paper sleeve or the insulation performance parameter of the dried epoxy glue impregnated paper sleeve is higher than the insulation performance parameter operation allowable value of the epoxy glue impregnated paper sleeve, the method further comprises the following steps:
and continuously heating, pumping out the gas in the epoxy glue impregnated paper sleeve, and continuously filling the protective gas and detecting.
2. The method for drying the epoxy impregnated transformer in situ according to claim 1, wherein in the step of heating, the transformer oil is heated to 90 ℃ to 100 ℃.
3. The in-situ drying method for the epoxy impregnated transformer according to claim 1, wherein in the step of extracting the gas in the epoxy impregnated transformer, the gas in the epoxy impregnated transformer is extracted until the vacuum degree in the epoxy impregnated transformer is 10pa to 20 pa.
4. Epoxy impregnated paper according to any one of claims 1 to 3The on-site drying method of the transformer is characterized in that the epoxy glue impregnated paper sleeve contains insulating gas, and the insulating gas is SF6(ii) a And/or
The protective gas is at least one of nitrogen and an inert gas.
5. An on-site drying system of an epoxy impregnated transformer, wherein the on-site drying system of the epoxy impregnated transformer is used for carrying out an on-site drying method of the epoxy impregnated transformer according to any one of claims 1 to 4, and comprises the following steps:
the epoxy impregnated paper transformer comprises an oil tank and an epoxy adhesive impregnated paper sleeve, wherein transformer oil is filled in the oil tank, and one end of the epoxy adhesive impregnated paper sleeve is immersed in the transformer oil;
the heating device is used for heating the transformer oil in the oil tank to be not lower than 90 ℃ so as to heat and dry the epoxy glue impregnated paper sleeve;
the air exhaust device is used for exhausting the air in the epoxy glue impregnated paper sleeve in the process of heating and drying the epoxy glue impregnated paper sleeve;
the inflation device is used for inflating protective gas into the epoxy glue impregnated paper sleeve in the process that the epoxy glue impregnated paper sleeve is heated and dried and after the air in the epoxy glue impregnated paper sleeve is pumped out by the air exhaust device;
the gas detection device is used for detecting the gas moisture content in the epoxy glue impregnated paper sleeve after the protective gas is filled; and
the insulating property detection device is used for detecting the insulating property parameter of the epoxy glue impregnated paper sleeve after the step of filling the protective gas; the heating device is a heating circulating device, and the heating circulating device is connected with the oil tank so that the transformer oil circulates between the heating circulating device and the oil tank.
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| CN202110659677.6A CN113340073B (en) | 2021-06-15 | 2021-06-15 | On-site drying method and drying system for epoxy impregnated paper transformer |
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| EP1313112B1 (en) * | 2001-11-13 | 2004-03-17 | Messko Albert Hauser GmbH & Co. KG | Air dehumidifier for oil insulated transformers, choke coils as well as tap changers |
| JP2005183857A (en) * | 2003-12-24 | 2005-07-07 | Aichi Electric Co Ltd | Transformer drying method |
| CN202189628U (en) * | 2011-06-30 | 2012-04-11 | 南京智达电气有限公司 | Dry type sleeve |
| EA024057B1 (en) * | 2013-01-03 | 2016-08-31 | Сергей Валерьевич Котов | Device for adding oil to bushings of high-voltage apparatus and transformers |
| CN104103409B (en) * | 2014-06-20 | 2016-08-17 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | The field drying processing method of converter power transformer |
| CN109036823A (en) * | 2018-08-03 | 2018-12-18 | 合肥鑫伟电力设备有限公司 | A kind of transformer vacuum transformation method drying means |
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