CN105762737B - A kind of the micro-positive pressure system and micro-positive pressure implementation method of isolated-phase enclosed bus - Google Patents
A kind of the micro-positive pressure system and micro-positive pressure implementation method of isolated-phase enclosed bus Download PDFInfo
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- CN105762737B CN105762737B CN201610221739.4A CN201610221739A CN105762737B CN 105762737 B CN105762737 B CN 105762737B CN 201610221739 A CN201610221739 A CN 201610221739A CN 105762737 B CN105762737 B CN 105762737B
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- positive pressure
- micro
- enclosed busbar
- gas
- busbar
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
- H02G5/00—Installations of bus-bars
- H02G5/06—Totally-enclosed installations, e.g. in metal casings
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D16/00—Control of fluid pressure
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- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Installation Of Bus-Bars (AREA)
Abstract
The present invention relates to a kind of micro-positive pressure system of isolated-phase enclosed bus and micro-positive pressure implementation method, micro-positive pressure system includes gas supply device, oil expeller, micro positive pressure device, high pressure cooling tank and three-phase enclosed busbar；The gas outlet of gas supply device and the air inlet of oil expeller connect, the gas outlet of oil expeller and the first air inlet of micro positive pressure device connect, the delivery outlet of micro positive pressure device is connect with the air inlet of high pressure cooling tank, the gas outlet of high pressure cooling tank and the second air inlet of micro positive pressure device connect, the gas outlet of micro positive pressure device is connect with the air inlet of three-phase enclosed busbar, and the air pressure thief hatch of three-phase enclosed busbar and the gas returning port of micro positive pressure device connect.Gas supply device uses power plant's air source or Whole oiless idling press.The present invention can carry out integral sealing to the enclosed busbar in power plant, and enclosed busbar is made really to realize micro-positive pressure ability.
Description
Technical field
The invention belongs to technical field of power generation, and in particular to a kind of the micro-positive pressure system and micro-positive pressure reality of isolated-phase enclosed bus
Existing method.
Background technology
Currently, at home in the generating set in most thermal power plants, generator isolated-phase enclosed bus is because having user
Just, steel construction fever less, high safety and reliability, relatively small and not affected by environment operation and maintenance amount the advantages that and it is wide
General application.Since isolated-phase enclosed bus is relative closure, when ambient temperature decline or load current reduction cause bus temperature
When reduction, the air pressure in enclosed busbar will reduce, and moisture or dust etc. will be sucked from some leakage points with air and be closed
In busbar, to which the operation to enclosed busbar brings security risk.
To prevent extraneous moisture, dust etc. from entering in enclosed busbar, people are using micro-positive pressure air charging system simultaneously to three-phase
It is filled with anhydrous, oil-free dry gas inside enclosed busbar, the air pressure in enclosed busbar is made to be slightly above external atmosphere pressure and be formed
Gas, to avoid inside the intrusion enclosed busbar such as extraneous moisture, dust, haze and industrial waste gas, effective Restraining seal busbar
The generation of internal condensation can also avoid the hydrogen that generator leaks from entering closing while preventing various flashover faults from occurring
Inside busbar.
In recent years, different degrees of flashover fault occurred in succession for domestic many gencos isolated-phase enclosed bus, and
Tend to the situation that takes place frequently, seriously affects the safe and reliable operation of generating set.Currently, enclosed busbar itself is asked there are still many
Topic and hidden danger, this " inferior health " state of enclosed busbar, it is difficult to it is continuous to resist the weathers such as current high humidity, sleet, thick fog, haze
Change adverse effect.Its major accident causes humid air to be invaded the reason is that since enclosed busbar body seal is not tight
Shorted to earth accident is directly contributed after causing internal serious moisture condensation that flashover fault or inner inlet occurs after entering.Although in recent years
Design, manufacture isolated-phase enclosed bus have some dewing-proof measures, such as an enclosed busbar with micro-positive pressure function, but due to
Poorly sealed, internal pressure keeps not living at all, and 80% or more isolated-phase enclosed bus is all unable to normal use, remaining 20%
Isolated-phase enclosed bus may seal slightly better, can maintain the pressure of a few minutes substantially, but charger is needed ceaselessly to work,
It was found that busbar leak point also can only by beat fluid sealant carry out simple process, use after some months sealing performance reduce or lose.
The sealing problem of enclosed busbar has become the important restriction factor of the safe and stable operation of generating set.To find out its cause,
Mainly there is the following：1) disc insulator sealing structure the most key in enclosed busbar and support insulator sealing structure
It designs unreasonable.2) there are quality problems for enclosed busbar.3) there are problems for the transit link of enclosed busbar.4) enclosed busbar shows
Field installation is there are problem, and enclosed busbar is formed by several sections, and during the installation process, the shell between busbar is in the welding process
The problems such as in the presence of weldering, sand holes, stomata is omitted.
Invention content
In order to solve the above problem of the existing technology, the present invention provides a kind of micro-positive pressure systems of isolated-phase enclosed bus
System and micro-positive pressure implementation method.
To achieve the above object, the present invention takes following technical scheme：A kind of micro-positive pressure system packet of isolated-phase enclosed bus
Include gas supply device, oil expeller, micro positive pressure device, high pressure cooling tank and three-phase enclosed busbar；The gas supply device
Gas outlet is connect with the air inlet of the oil expeller, the first air inlet of the gas outlet of the oil expeller and the micro positive pressure device
Connection, the delivery outlet of the micro positive pressure device are connect with the air inlet of the high pressure cooling tank, the outlet of the high pressure cooling tank
Mouth is connect with the second air inlet of the micro positive pressure device, the gas outlet of the micro positive pressure device and the three-phase enclosed busbar
Air inlet connects, and the air pressure thief hatch of the three-phase enclosed busbar is connect with the gas returning port of the micro positive pressure device.
Further, the gas supply device is using one kind in power plant's air source and Whole oiless idling press.
Further, it is respectively provided with safety valve at the air inlet of the oil expeller and at the top of high pressure cooling tank；The oil removing
Pressure gauge is set at the gas outlet of device.
Further, the bottom of the Whole oiless idling press, oil expeller and high pressure cooling tank is both provided with discharging valve.
A kind of micro-positive pressure implementation method of the micro-positive pressure system based on isolated-phase enclosed bus comprising following steps：
Gas supply device inputs output gas in oil expeller；
It is turbid that gas enters oil expeller progress oil removing drop；
Oil removing drop it is turbid after gas by micro positive pressure device enter in high pressure cooling tank into horizontal high voltage cool down；
High pressure cooling gas, which enters in micro positive pressure device, to be filtered, remove water and dries；
Treated that gas is filled in the shell of three-phase enclosed busbar for micro positive pressure device, makes the air in enclosed busbar shell
Pressure remains at slight positive pressure state.
Further, the end of opening of the enclosed busbar is sealed and is separated using disc insulator, and institute is fixedly mounted
The outward flange for stating disc insulator is process using casting aluminium material.
Further, the mounting process of the disc insulator includes：
Cast aluminium outward flange is welded on to the both ends of enclosed busbar, in outer shell barrel wall, using argon arc welding to whole circle cast aluminium outside
Flange and barrel carry out all-position welding；
Luggage is packed into basin to match；First, rubber weather strip is fixed in outer flange seal groove, to seal when fixed
Item is in nature；Secondly, basin is covered and carries out horizontal location；Again, after fixing basin set, the concentricity of conductor is adjusted, until seam
Sealing strip is installed again after gap is uniform, inner flange is installed；Finally, basin set must be between inner flange and conductor, diagonally after all installing
2 grading ring devices are installed.
Further, it after the cast aluminium outward flange is fixed, is welded using diagonal, multipoint mode spot welding mode.
Further, the conductor in the enclosed busbar is supported using adjustment lip block.
Further, the adjustment lip block is made of DMC insulating materials.
The invention adopts the above technical scheme, which has the following advantages：The present invention by using gas supply device,
Oil expeller, micro positive pressure device, high pressure cooling tank and three-phase enclosed busbar can carry out the enclosed busbar in power plant whole close
Envelope, makes enclosed busbar really realize micro-positive pressure ability.The present invention is improved by the structure to enclosed busbar can be further
Improve the overall tightness of enclosed busbar.
Description of the drawings
Fig. 1 is the structural schematic diagram of the micro-positive pressure system of the isolated-phase enclosed bus provided in one embodiment of the invention.
In figure：1, power plant's air source；2, Whole oiless idling press；3, oil expeller；4, micro positive pressure device；5, high pressure cooling tank；6、
Three-phase enclosed busbar；7, safety valve；8, pressure gauge；9, discharging valve.
Specific implementation mode
The present invention is described in detail below with reference to the accompanying drawings and embodiments.
As shown in Figure 1, the present invention provides a kind of micro-positive pressure systems of isolated-phase enclosed bus comprising gas supply dress
It sets, oil expeller 3, micro positive pressure device 4, high pressure cooling tank 5 and three-phase enclosed busbar 6.Wherein, gas supply device uses power plant's gas
Source 1 or Whole oiless idling press 2；When using power plant's air source 1, the gas outlet of power plant's air source 1 is connect with the air inlet of oil expeller 3.
When using Whole oiless idling press 2, the gas outlet of Whole oiless idling press 2 is connect with the air inlet of oil expeller 3.Oil expeller 3 goes out
Gas port is connect with the first air inlet of micro positive pressure device 4, and the delivery outlet of micro positive pressure device 4 connects with the air inlet of high pressure cooling tank 5
It connects, the gas outlet of high pressure cooling tank 5 is connect with the second air inlet of micro positive pressure device 4, the gas outlet of micro positive pressure device 4 and three-phase
The air inlet of enclosed busbar 6 connects, and the air pressure thief hatch of three-phase enclosed busbar 6 is connect with the gas returning port of micro positive pressure device 4.
The course of work of the micro-positive pressure system of isolated-phase enclosed bus of the present invention is：Power plant's air source 1 or Whole oiless idling press 2 are defeated
In the gas input oil expeller 3 gone out, it is turbid that oil expeller 3 carries out oil removing drop to gas.Oil removing drop it is turbid after gas through micro positive pressure device 4
Into in high pressure cooling tank 5, high pressure cooling tank 5 is compressed and is cooled down to gas, obtains high pressure cooling gas.High pressure cooling air
Body enters micro positive pressure device 4, and micro positive pressure device 4 is filled into three-phase envelope after being filtered, remove water and drying to high pressure cooling gas
In the shell of close nut line 6, the air pressure in enclosed busbar shell is made to remain at slight positive pressure state.
In above-described embodiment, at the air inlet of the oil expeller 3 and top of high pressure cooling tank 5 is respectively provided with safety valve 7.
In above-described embodiment, pressure gauge 8 is set at the gas outlet of oil expeller 3.
In above-described embodiment, the bottom of Whole oiless idling press 2, oil expeller 3 and high pressure cooling tank 5 is both provided with discharging valve 9.
Micro-positive pressure system based on isolated-phase enclosed bus provided by the invention, the present invention also provides a kind of realizations of micro-positive pressure
Method comprising following steps：
1) gas supply device inputs output gas in oil expeller 3.
2) it is turbid to enter the progress oil removing drop of oil expeller 3 for gas.
3) oil removing drop it is turbid after gas enter in high pressure cooling tank 5 by micro positive pressure device 4 and cooled down into horizontal high voltage.
4) high pressure cooling gas, which enters in micro positive pressure device 4, is filtered, removes water and dries.
5) treated that gas is filled in the shell of three-phase enclosed busbar 6 for micro positive pressure device 4, makes in enclosed busbar shell
Air pressure remains at slight positive pressure state.
In above-mentioned micro-positive pressure implementation method, to keep the overall tightness of power plant metal isolated-phase enclosed bus good, realize micro-
Positive pressure ability, the present invention also improve the structure of isolated-phase enclosed bus.
Isolated-phase enclosed bus is mainly made of shell and conductor, is propped up by many support insulators between shell and conductor
Support, disc insulator are sealed and are separated to opening end.Support insulator and the structure of disc insulator decide from mutually sealing
The quality of close nut line overall sealing performance, and then influence the micro-positive pressure ability of the micro-positive pressure system of isolated-phase enclosed bus.
The outward flange that disc insulator is fixedly mounted is process using casting aluminium material, and basin is fixedly mounted in the prior art
The outward flange generally use wrought aluminium plate of formula insulator is process.Compared with wrought aluminium plate, casting aluminium material has the following advantages：It is whole
Reprocessing is poured, surface degree is high, small with the shell welding deformation of isolated-phase enclosed bus, and intensity is high, and bolt is twisted tightly, is not easy to take off
Button, to realize that the sealing performance of high quality provides necessary condition.
After running a period of time inside the shell due to the conductor in isolated-phase enclosed bus, conductor will appear sinking, therefore must
Strength need be given to the conductor of sinking to support.The conductor of sinking is supported using adjustment lip block, adjusts supporting pad
Block is made of DMC insulating materials.
The present invention also improves the mounting process of disc insulator, specifically includes：
1) it is welded and fixed the cast aluminium outward flange of basin set；
Cast aluminium outward flange is welded on to the both ends of enclosed busbar, in outer shell barrel wall, using argon arc welding to whole circle cast aluminium outside
Flange and barrel carry out all-position welding.
To ensure to cover the smooth of binding face with disk, cast aluminium outward flange must be horizontal with shell.
After cast aluminium outward flange is fixed, it is necessary to first use diagonal, multipoint mode spot welding mode, whole circle that cannot be less than 8 solder joints, i.e.,
45 degree of solder joints, it is therefore an objective to reduce welding deformation as possible.If cast aluminium outward flange is uneven or deformation is excessive, it is pasted after disk set installation
Conjunction face can imprecision, the rupture of disk set or gradually rupture can be caused after bolt clamp force.
2) assembly of basin set；
First, rubber weather strip is fixed in outer flange seal groove, to make that sealing strip is in nature when fixed, no
It can be too tight or too loose.Purpose is that adhesive tape is easy out slot when mounting pot being avoided to cover, and cannot be observed, and causes poor sealing.
Secondly, it is to the technological requirement of basin set positioning：Basin is sleeved on into whole process in the cylinder of enclosed busbar, it is necessary to
Keep it is whole in level, progressive state, especially need to be more steady when close to fixed outward flange, in order to avoid by slot interior sealing adhesive tape
It squeezes and touches away.
Basin is covered with after outward flange contraposition, is respectively fixed with two fixing bolts in diagonal ten word direction of 180 degree.It is general whole
Enclose the fixing bolt of 24~32 M8~12.
Again, after fixing basin set, whether the gap observed between bus-bars conductor and basin set border is uniform, if uneven, most
Big gap is more than the diameter using sealing strip, it is necessary to adjust the concentricity of conductor, until installing sealing strip after gap is uniform again, pacify
Inner flange is filled, mounting process is identical as assembly outward flange.
Finally, 2 grading ring devices must be diagonally installed, for releasing between inner flange and conductor after basin set all installs
The upper overvoltage of basin set is put, otherwise local temperature can be exceeded, so as to cause rubber seal aging, failure.
The present invention is not limited to above-mentioned preferred forms, and those skilled in the art can obtain under the inspiration of the present invention
Other various forms of products, however, make any variation in its shape or structure, it is every that there is same as the present application or phase
Approximate technical solution, is within the scope of the present invention.
Claims (3)
1. a kind of micro-positive pressure implementation method of isolated-phase enclosed bus comprising following steps：
Gas supply device inputs output gas in oil expeller；
It is turbid that gas enters oil expeller progress oil removing drop；
Oil removing drop it is turbid after gas by micro positive pressure device enter in high pressure cooling tank into horizontal high voltage cool down；
High pressure cooling gas, which enters in micro positive pressure device, to be filtered, remove water and dries；
Treated that gas is filled in the shell of three-phase enclosed busbar for micro positive pressure device, makes the air pressure in enclosed busbar shell
Remain at slight positive pressure state；The end of opening of the enclosed busbar is sealed and is separated using disc insulator, fixed peace
The outward flange for filling the disc insulator is process using casting aluminium material；
The mounting process of the disc insulator includes：
Cast aluminium outward flange is welded on to the both ends of enclosed busbar, in outer shell barrel wall, using argon arc welding to whole circle cast aluminium outward flange
All-position welding is carried out with barrel；Cast aluminium outward flange is horizontal with shell；After the cast aluminium outward flange is fixed, using pair
Angle, multipoint mode spot welding mode are welded, and whole circle is no less than 8 solder joints；
Luggage is packed into basin to match；First, rubber weather strip is fixed in outer flange seal groove, so that sealing strip is in when fixed
Nature；Secondly, basin is covered and carries out horizontal location, basin is sleeved on into whole process in the cylinder of enclosed busbar, to keep whole
Body is in horizontal, progressive state；Again, after fixing basin set, the concentricity of conductor is adjusted, until installing sealing after gap is uniform again
Item installs inner flange；Finally, 2 grading ring devices must be diagonally installed between inner flange and conductor after basin set all installs.
2. a kind of micro-positive pressure implementation method as described in claim 1, it is characterised in that：Conductor in the enclosed busbar uses
Adjustment lip block is supported.
3. a kind of micro-positive pressure implementation method as claimed in claim 2, it is characterised in that：The adjustment lip block uses DMC
Insulating materials is made.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610221739.4A CN105762737B (en) | 2016-04-11 | 2016-04-11 | A kind of the micro-positive pressure system and micro-positive pressure implementation method of isolated-phase enclosed bus |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610221739.4A CN105762737B (en) | 2016-04-11 | 2016-04-11 | A kind of the micro-positive pressure system and micro-positive pressure implementation method of isolated-phase enclosed bus |
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| CN105762737A CN105762737A (en) | 2016-07-13 |
| CN105762737B true CN105762737B (en) | 2018-07-17 |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201717537U (en) * | 2010-04-27 | 2011-01-19 | 中国西电电气股份有限公司 | Integral carrying device of bus in gaseous insulating metal closed switch device |
| CN103457211A (en) * | 2013-07-02 | 2013-12-18 | 大唐黑龙江发电有限公司哈尔滨第一热电厂 | Micro positive pressure device of 30MW generator enclosed busbar and working method of micro positive pressure device |
| CN203442484U (en) * | 2013-07-05 | 2014-02-19 | 大唐华银电力股份有限公司金竹山火力发电分公司 | Novel generator enclosed busbar micro positive pressure device |
| CN104882837A (en) * | 2015-05-25 | 2015-09-02 | 镇江市高等专科学校 | Enclosed busbar micro-positive-pressure hot air maintenance apparatus |
| CN105298433A (en) * | 2015-09-21 | 2016-02-03 | 河南理工大学 | Hydraulic pressing, flushing and pumping integrated hole sealing device and method |
| CN205724757U (en) * | 2016-04-11 | 2016-11-23 | 北京良乡昊融电力设备有限公司 | A kind of pressure-fired system of isolated-phase enclosed bus |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005056735B3 (en) * | 2005-11-29 | 2006-08-10 | Koch, Christian, Dr. | Preparation of diesel oil from hydrocarbon containing residual substances in an oil circulation with solid separation and product distillation, comprises providing heat through main energy carriers by one or more high speed mixing chambers |
| CN202167762U (en) * | 2011-05-23 | 2012-03-14 | 平高集团有限公司 | Bus assembly for super-high voltage engineering GIS |
| CN103178467A (en) * | 2013-03-14 | 2013-06-26 | 河南省电力公司南阳供电公司 | SF6 (sulfur hexafluoride) gas chamber sealing method of combined electric appliance |
-
2016
- 2016-04-11 CN CN201610221739.4A patent/CN105762737B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201717537U (en) * | 2010-04-27 | 2011-01-19 | 中国西电电气股份有限公司 | Integral carrying device of bus in gaseous insulating metal closed switch device |
| CN103457211A (en) * | 2013-07-02 | 2013-12-18 | 大唐黑龙江发电有限公司哈尔滨第一热电厂 | Micro positive pressure device of 30MW generator enclosed busbar and working method of micro positive pressure device |
| CN203442484U (en) * | 2013-07-05 | 2014-02-19 | 大唐华银电力股份有限公司金竹山火力发电分公司 | Novel generator enclosed busbar micro positive pressure device |
| CN104882837A (en) * | 2015-05-25 | 2015-09-02 | 镇江市高等专科学校 | Enclosed busbar micro-positive-pressure hot air maintenance apparatus |
| CN105298433A (en) * | 2015-09-21 | 2016-02-03 | 河南理工大学 | Hydraulic pressing, flushing and pumping integrated hole sealing device and method |
| CN205724757U (en) * | 2016-04-11 | 2016-11-23 | 北京良乡昊融电力设备有限公司 | A kind of pressure-fired system of isolated-phase enclosed bus |
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| CN105762737A (en) | 2016-07-13 |
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