CN111223643B

CN111223643B - Vacuum oil injection system and method for transformer

Info

Publication number: CN111223643B
Application number: CN202010029593.XA
Authority: CN
Inventors: 胡硕
Original assignee: Xiangtan Huaxia Special Type Transformer Co ltd
Current assignee: Hunan Huaxia Tebian Co.,Ltd.
Priority date: 2020-01-13
Filing date: 2020-01-13
Publication date: 2022-02-01
Anticipated expiration: 2040-01-13
Also published as: CN111223643A

Abstract

The invention discloses a vacuum oil injection system of a transformer and an oil injection method thereof, belonging to the technical field of vacuum oil injection of transformers. Can realize simple structure, the flow is retrencied, convenient operation, the oiling is efficient, and is provided with the prefiltration device, has reduced the operating pressure of oil filter, has improved oil strain efficiency, and is convenient for take out prefiltration impurity in the device.

Description

Vacuum oil injection system and method for transformer

Technical Field

The invention relates to the technical field of transformer vacuum oil injection, in particular to a transformer vacuum oil injection system and an oil injection method thereof.

Background

The transformer is a device for changing alternating voltage by using the principle of electromagnetic induction, and main components are a primary coil, a secondary coil and an iron core. The main functions are as follows: voltage transformation, current transformation, impedance transformation, isolation, voltage stabilization, and the like. According to the application, the method can be divided into: the transformer comprises a power transformer and a special transformer, wherein the special transformer comprises a furnace transformer, a rectification transformer, a power frequency test transformer, a voltage regulator, a mining transformer, an audio transformer, a medium-frequency transformer, a high-frequency transformer, an impact transformer, an instrument transformer, an electronic transformer, a reactor, a mutual inductor and the like.

The transformer oil is widely used as an insulating medium and a cooling medium of the oil-immersed transformer, and the operation of injecting the transformer oil is required after the oil-immersed transformer is assembled and sealed. The traditional oil injection method of the oil-immersed transformer is to directly inject transformer oil into an oil tank from an oil injection pipe on a tank cover, and the oil injection method has the advantages of simple operation, no need of complex equipment, pipelines and the like, and has the defects that some moisture and a large amount of air are mixed in during the oil injection process, and the oil needs to be statically placed for a long time after being injected so as to facilitate the discharge of internal air, influence the discharge of moisture in the oil tank in addition, and reduce the insulation strength of the transformer oil.

Along with the development of science and technology, traditional direct oiling has been replaced to vacuum oiling, but current vacuum oiling system structure is complicated, and the flow is loaded down with trivial details, trouble very during the oiling, efficiency is lower, and current vacuum oiling system, the oil storage tank generally not be connected with vacuum oil filter directly through prefiltering for vacuum oil filter operating pressure is great, has reduced oil strain efficiency. Therefore, a vacuum oil injection system and an oil injection method of the transformer are provided.

Disclosure of Invention

1. Technical problem to be solved

Aiming at the problems in the prior art, the invention aims to provide a vacuum oil injection system of a transformer and an oil injection method thereof, which have the advantages of simple structure, simple flow, convenient operation and high oil injection efficiency, are provided with a primary filtering device, reduce the working pressure of an oil filter, improve the oil filtering efficiency and facilitate the extraction of filtered impurities in the primary filtering device.

2. Technical scheme

In order to solve the above problems, the present invention adopts the following technical solutions.

A vacuum oil injection system of a transformer comprises an oil storage tank, a vacuum oil filter, a transformer, a vacuum pump and a primary filter device, an oil delivery pipe is communicated with the outer wall of the top of the oil storage tank, a first valve is arranged on the outer wall of the oil delivery pipe, the input end of the vacuum oil filter is communicated with an oil inlet pipe, the output end of the vacuum oil filter is communicated with an oil outlet pipe, the outer wall of the oil outlet pipe is provided with a second valve, an oil filling port of the transformer is communicated with an oil filling pipe, an oil pipe connecting piece is arranged between the oil filling pipe and the oil outlet pipe, the oil filling pipe and the oil outlet pipe are hermetically connected through the oil pipe connecting piece, the top end of the transformer is communicated with a vacuum tube, the output end of the vacuum pump is communicated with an exhaust tube, the vacuum pump is characterized in that a third valve is arranged on the outer wall of the exhaust tube, an air tube connecting piece is arranged between the exhaust tube and the vacuum tube, and the exhaust tube and the vacuum tube are connected in a sealing mode through the air tube connecting piece.

The primary filtering device comprises a filtering box, the filtering box is positioned between an oil conveying pipe and an oil inlet pipe, the outer wall of the left side of the filtering box is provided with an oil inlet end, the outer wall of the right side of the filtering box is provided with an oil outlet end, the inner wall of the filtering box is fixedly provided with a cylindrical filtering net, one side of the filtering net close to the oil inlet end is provided with a vertical rod fixedly arranged on the inner wall of the bottom of the filtering box, the top end of the vertical rod is fixedly provided with a bearing, the inside of the bearing is rotatably connected with a rotating shaft, one end of the rotating shaft close to the filtering net is fixedly connected with a cleaning brush, a linkage block fixedly connected on the cleaning brush is arranged above the rotating shaft, the bottom end of the filtering box is fixedly connected with a hanging rod, one end of the hanging rod far away from the filtering box is fixedly connected with an annular slide rail, the outer wall of the annular slide rail is slidably connected with a magnet, and the top end of the magnet is fixedly connected with a handle rod, the material discharging device is characterized in that the inner wall and the outer wall of the bottom end of the filter box are communicated with a material discharging pipe, a communicating groove formed in the outer wall of the filter box is formed above the material discharging pipe, and a sealing cover is connected to the outer wall of the material discharging pipe in a threaded mode.

Further, on the top outer wall of oil storage tank and be located defeated oil pipe's left side intercommunication and have added oil pipe, the top threaded connection who adds oil pipe has the tube cap to unscrew the tube cap, can add transformer oil in through adding oil pipe case oil storage tank.

Furthermore, the top end of the transformer is provided with a wheat type vacuum gauge, the left side of the wheat type vacuum gauge is provided with an oil gauge pipe arranged at the top end of the transformer, the vacuum degree can be read through the wheat type vacuum gauge, and the oil level can be observed through the oil gauge pipe.

Further, fixed mounting has the bracing piece on the right side outer wall of oil storage tank, the bracing piece sets up to the L style of calligraphy, and the one end and the rose box fixed connection that the oil storage tank was kept away from to the bracing piece, and through the setting of bracing piece, the bracing piece can play the effect of fixed stay to the rose box.

Further, defeated oil pipe keeps away from the one end and the oil feed end of oil storage tank and is linked together, the oil feed pipe is kept away from the one end and the oil outlet end of vacuum oil filter and is linked together for transformer oil in the oil storage tank is earlier through the primary filter device before getting into vacuum filter, makes the filter screen in the primary filter device carry out preliminary filtration to transformer oil, has reduced the operating pressure of oil filter, has improved oil strain efficiency.

Furthermore, the cleaning brush is attached to one surface, close to the oil inlet end, of the filter screen, so that the filter screen can be brushed when the cleaning brush swings, and impurities filtered on the filter screen can be brushed off.

Further, the material of linkage piece is iron, magnet is neodymium iron boron strong magnet, and magnet is located the linkage piece directly over, through the setting of bearing, pivot, clean brush, linkage piece, jib, annular slide rail, magnet, handle bar, uses the handle bar to drive magnet and slides along annular slide rail, and accessible magnet drives the linkage piece swing to the suction of iron linkage piece, and then drives clean brush swing.

Further, arrange the material pipe and be located between montant and the filter screen, the intercommunication groove sets up to the toper, and the right-hand member in intercommunication groove flushes with the left end of filter screen bottom, through the intercommunication groove, arrange the setting of material pipe, sealed lid, rotatory sealed lid of unscrewing, can make the impurity that is brushed and falls by clean brush pass the intercommunication groove in proper order, arrange the material pipe and discharge to be convenient for take out by filterable impurity.

Further, be provided with the stopcock on the top inner wall of sealed lid, the setting of stopcock can block up row material pipe, prevents to persist transformer oil in the row material pipe, and then avoids opening sealed lid occasionally oil leakage.

An oil injection method of a vacuum oil injection system of a transformer is characterized in that: the method comprises the following steps:

s1, opening a third valve and starting a vacuum pump, and uniformly increasing the vacuum degree within one hour to enable the vacuum degree to reach 1.3.Kpa, wherein the vacuum degree can be read by a wheat type vacuum gauge and maintained for 30 minutes;

s2, after observing that each part of the transformer is not abnormal, continuously vacuumizing to maintain the vacuum degree at 45-50 Kpa for 6 hours;

s3, continuing vacuumizing, simultaneously opening the first valve and the second valve, starting the vacuum oil filter, properly controlling the second valve, slowly injecting oil in the oil storage tank into the transformer at a speed of 4-6 tons per hour, strictly monitoring the oil level through an oil gauge pipe in the process, stopping injecting oil when the oil level is 100-150 mm away from the top of the tank, and closing the first valve, the second valve and the vacuum oil filter;

and S4, continuously vacuumizing, maintaining the vacuum degree at 45-50 Kpa, and continuing for 8 hours to finish vacuum oiling.

3. Advantageous effects

Compared with the prior art, the invention has the advantages that:

(1) this scheme is through adding oil pipe's setting for twist off the tube cap, can add transformer oil in through adding oil pipe case oil storage tank.

(2) The transformer is provided with a vacuum gauge and an oil level indicator pipe, the vacuum degree can be read through the vacuum gauge, and the oil level can be observed through the oil level indicator pipe.

(3) Through the setting of bracing piece, the bracing piece can play the effect of fixed stay to the rose box.

(4) Through the setting of prefiltering device, make the filter screen in the prefiltering device carry out preliminary filtration to transformer oil, reduced the operating pressure of oil filter, improved oil strain efficiency.

(5) Through the setting of bearing, pivot, clean brush, linkage piece, jib, annular slide rail, magnet, handle bar, use the handle bar to drive magnet and slide along annular slide rail, accessible magnet drives the linkage piece swing to the suction of iron linkage piece, and then drives clean brush swing, when clean brush swing, can brush the filter screen to the filterable impurity on the brush falls the filter screen.

(6) Through the setting of intercommunication groove, row material pipe, sealed lid, rotatory unscrewing sealed lid can make the impurity that is brushed down by cleaning brush pass the intercommunication groove in proper order, arrange the material pipe and discharge to be convenient for take out by filterable impurity.

(7) The setting of stopcock can block up row material pipe, prevents to persist transformer oil in the row material pipe, and then avoids opening sealed lid occasionally oil leakage.

(8) The oil injection method of the vacuum oil injection system has the advantages of simple process, convenience in operation and higher efficiency.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is an enlarged view taken at A of FIG. 1 in accordance with the present invention;

FIG. 3 is a cross-sectional view of the inside of a filtration tank of the present invention;

FIG. 4 is an enlarged view taken at B of FIG. 3 in accordance with the present invention;

FIG. 5 is a side view of the filter screen of the present invention;

FIG. 6 is a test chart of the present invention at the position of the annular slide rail;

fig. 7 is a cross-sectional view of the inside of a discharge tube of the present invention.

The reference numbers in the figures illustrate:

1. an oil storage tank; 2. a vacuum oil filter; 3. a vacuum pump; 4. a transformer; 5. adding an oil pipe; 6. an oil delivery pipe; 7. a first valve; 8. an oil inlet pipe; 9. an oil outlet pipe; 10. a second valve; 11. an oil filling pipe; 12. an oil pipe connecting piece; 13. an oil gauge pipe; 14. a wheat vacuum gauge; 15. a vacuum tube; 16. an air exhaust pipe; 17. a third valve; 18. a trachea connector; 19. a filter box; 20. an oil inlet end; 21. an oil outlet end; 22. a filter screen; 23. a vertical rod; 24. a bearing; 25. a rotating shaft; 26. cleaning the brush; 27. a linkage block; 28. a boom; 29. an annular slide rail; 30. a magnet; 31. a handle bar; 32. a discharge pipe; 33. a communicating groove; 34. a sealing cover; 35. a pipe plug; 36. a support rod.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention; it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art without any inventive work are within the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "sleeved/connected," "connected," and the like are to be construed broadly, e.g., "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1:

referring to fig. 1, a transformer vacuum oil injection system comprises an oil storage tank 1, a vacuum oil filter 2, a transformer 3, a vacuum pump 4 and a primary filter device, wherein an oil delivery pipe 6 is communicated with the outer wall of the top of the oil storage tank 1, an oil adding pipe 5 is communicated with the outer wall of the top of the oil storage tank 1 and positioned on the left side of the oil delivery pipe 6, a pipe cover is connected to the top end of the oil adding pipe 5 in a threaded manner, so that transformer oil can be added into the oil storage tank 1 through the oil adding pipe 5 by unscrewing the pipe cover, a first valve 7 is arranged on the outer wall of the oil delivery pipe 6, an oil inlet pipe 8 is communicated with the input end of the vacuum oil filter 2, an oil outlet pipe 9 is communicated with the output end of the vacuum oil filter 2, a second valve 10 is arranged on the outer wall of the oil outlet pipe 9, an oil injection port of the transformer 4 is communicated with an oil injection pipe 11, an oil pipe connecting piece 12 is arranged between the oil injection pipe 11 and the oil outlet pipe 9, the oil injection pipe 11 and the oil outlet pipe 9 are hermetically connected through the oil pipe connecting piece 12, the top end of the transformer 4 is communicated with a vacuum tube 15, the top end of the transformer 4 is provided with a vacuum gauge 14, the left side of the vacuum gauge 14 is provided with an oil mark tube 13 arranged at the top end of the transformer 4, the vacuum degree can be read through the vacuum gauge 14, the oil level can be observed through the oil mark tube 13, the output end of the vacuum pump 3 is communicated with an exhaust tube 16, the outer wall of the exhaust tube 16 is provided with a third valve 17, a gas tube connecting piece 18 is arranged between the exhaust tube 16 and the vacuum tube 15, and the exhaust tube 16 and the vacuum tube 15 are hermetically connected through the gas tube connecting piece 18.

Referring to fig. 1-7, the primary filtering device includes a filtering tank 19, a supporting rod 36 is fixedly installed on the right outer wall of the oil storage tank 1, the supporting rod 36 is L-shaped, and one end of the supporting rod 36 away from the oil storage tank 1 is fixedly connected to the filtering tank 19, the supporting rod 36 can play a role of fixedly supporting the filtering tank 19 by the arrangement of the supporting rod 36, the filtering tank 19 is located between the oil delivery pipe 6 and the oil inlet pipe 8, the left outer wall of the filtering tank 19 is provided with an oil inlet end 20, the right outer wall of the filtering tank 19 is provided with an oil outlet end 21, one end of the oil delivery pipe 6 away from the oil storage tank 1 is communicated with the oil inlet end 20, one end of the oil inlet pipe 8 away from the vacuum oil filter 2 is communicated with the oil outlet end 21, so that the transformer oil in the oil storage tank 1 passes through the primary filtering device before entering the vacuum filter 2, so that the filter screen in the primary filtering device primarily filters the transformer oil, the working pressure of the oil filter is reduced, the oil filtering efficiency is improved, a filter screen 22 which is arranged to be cylindrical is fixedly installed on the inner wall of a filter box 19, a vertical rod 23 which is fixedly installed on the inner wall of the bottom of the filter box 19 is arranged on one side, close to an oil inlet end 20, of the filter screen 22, a bearing 24 is fixedly installed at the top end of the vertical rod 23, a rotating shaft 25 is rotatably connected to the inside of the bearing 24, a cleaning hairbrush 26 is fixedly connected to one end, close to the filter screen 22, of the rotating shaft 25, the cleaning hairbrush 26 is attached to one side, close to the oil inlet end 20, of the filter screen 22, the filter screen 22 can be brushed when the cleaning hairbrush 26 swings, so that filtered impurities on the filter screen 22 are brushed off, a linkage block 27 fixedly connected to the cleaning hairbrush 26 is arranged above the rotating shaft 25, a suspender 28 is fixedly connected to the bottom end of the filter box 19, an annular slide rail 29 is fixedly connected to one end, and a magnet 30 is slidably connected to the outer wall of the annular slide rail 29, the linkage block 27 is made of iron, the magnet 30 is made of neodymium iron boron strong magnet, the magnet 30 is located right above the linkage block 27, the magnet 30 is arranged above the linkage block 27 through the bearing 24, the rotating shaft 25, the cleaning hairbrush 26, the linkage block 27, the hanging rod 28, the annular sliding rail 29, the magnet 30 and the handle rod 31, the handle rod 31 is used for driving the magnet 30 to slide along the annular sliding rail 29, the linkage block 27 can be driven to swing through the suction force of the magnet 30 to the iron linkage block 27, the cleaning hairbrush 26 is further driven to swing, the handle rod 31 is fixedly connected to the top end of the magnet 30, the inner wall and the outer wall of the bottom end of the filter box 19 are communicated with the discharge pipe 32, a communicating groove 33 formed in the outer wall of the filter box 19 is formed above the discharge pipe 32, a sealing cover 34 is connected to the outer wall of the discharge pipe 32 in a threaded mode, the discharge pipe 32 is located between the vertical rod 23 and the filter screen 22, the communicating groove 33 is conical, and the right end of the communicating groove 33 is flush with the left end of the bottom of the filter screen 22, through the intercommunication groove 33, arrange the material pipe 32, the setting of sealed lid 34, rotatory sealed lid 34 of unscrewing, can make the impurity that is brushed down by clean brush 26 pass intercommunication groove 33 in proper order, arrange material pipe 32 and discharge, thereby be convenient for take out by filterable impurity, be provided with stopcock 35 on the top inner wall of sealed lid 34, the setting of stopcock 35 can block up row material pipe 32, prevent to arrange the material pipe 32 in and keep transformer oil, and then there is oil leakage when avoiding opening sealed lid 34, take out and just filter the concrete operation by filtering impurity in the device and be: closing the first valve 7 and the second valve 10, starting the vacuum oil filter 2, exhausting transformer oil in the filter tank 19, closing the vacuum oil filter 2, rotating and unscrewing the sealing cover 34, sliding the magnet 30 through the handle rod 31, turning the sliding direction after sliding to the suspender 28, repeating the steps repeatedly for a plurality of times, so that the cleaning hairbrush 26 brushes the filter screen 22 back and forth, brushing off the filtered impurities on the filter screen 22, discharging the filtered impurities through the communicating groove 33 and the discharging pipe 32, and finally screwing the sealing cover 34.

s1, opening the third valve 17 and starting the vacuum pump 4, and uniformly increasing the vacuum degree within one hour to make the vacuum degree reach 1.3Kpa, wherein the vacuum degree can be read by the wheat vacuum gauge 14 and maintained for 30 minutes;

s2, after observing that each part of the transformer 3 is not abnormal, continuously vacuumizing to maintain the vacuum degree at 45-50 Kpa for 6 hours;

s3, continuing vacuumizing, simultaneously opening the first valve 7 and the second valve 10, starting the vacuum oil filter 2, properly controlling the second valve 10, slowly injecting oil in the oil storage tank 1 into the transformer 3 at a speed of 4-6 tons per hour, strictly monitoring the oil level through an oil gauge pipe 13 in the process, stopping injecting oil when the oil level is 100-150 mm away from the top of the tank, and closing the first valve 7, the second valve 10 and the vacuum oil filter 2;

According to the invention, through the arrangement of the oil adding pipe 5, the pipe cover is unscrewed, and then the transformer oil can be added into the oil storage tank 1 through the oil adding pipe 5; the transformer 3 is provided with a vacuum gauge 14 and an oil level indicator pipe 13, the vacuum degree can be read through the vacuum gauge 14, and the oil level can be observed through the oil level indicator pipe 13; through the arrangement of the supporting rod 36, the supporting rod 36 can play a role of fixing and supporting the filter box 19; through the arrangement of the primary filtering device, the filter screen in the primary filtering device can carry out primary filtering on the transformer oil, the working pressure of the oil filter is reduced, and the oil filtering efficiency is improved; through the arrangement of the bearing 24, the rotating shaft 25, the cleaning hairbrush 26, the linkage block 27, the hanging rod 28, the annular sliding rail 29, the magnet 30 and the handle rod 31, the handle rod 31 is used for driving the magnet 30 to slide along the annular sliding rail 29, the linkage block 27 can be driven to swing through the attraction of the magnet 30 to the iron linkage block 27, the cleaning hairbrush 26 is further driven to swing, and when the cleaning hairbrush 26 swings, the filter screen 22 can be brushed, so that impurities filtered on the filter screen 22 can be brushed; through the arrangement of the communicating groove 33, the discharging pipe 32 and the sealing cover 34, the sealing cover 34 is screwed off in a rotating way, so that impurities brushed off by the cleaning hairbrush 26 sequentially pass through the communicating groove 33 and the discharging pipe 32 to be discharged, and the filtered impurities can be taken out conveniently; the pipe plug 35 is arranged to block the discharge pipe 32, so that transformer oil is prevented from being stored in the discharge pipe 32, and oil leakage is avoided when the sealing cover 34 is opened; the oil injection method of the vacuum oil injection system is simple in process, convenient to operate and high in efficiency; compared with the prior art, the oil injection device has the advantages that the structure is simple, the flow is simplified, the operation is convenient, the oil injection efficiency is high, the primary filter device is arranged, the working pressure of the oil filter is reduced, the oil filter efficiency is improved, and filtered impurities in the primary filter device can be taken out conveniently.

The foregoing is only a preferred embodiment of the present invention; the scope of the invention is not limited thereto. Any person skilled in the art should be able to cover the technical scope of the present invention by equivalent or modified solutions and modifications within the technical scope of the present invention.

Claims

1. The utility model provides a transformer vacuum oil injection system, includes oil storage tank (1), vacuum oil filter (2), transformer (3), vacuum pump (4) and just strains the device, its characterized in that: an oil delivery pipe (6) is communicated with the outer wall of the top of the oil storage tank (1), an oil adding pipe (5) is communicated with the outer wall of the top of the oil storage tank (1) and is positioned on the left side of the oil delivery pipe (6), a pipe cover is connected with the top end of the oil adding pipe (5) in a threaded manner, a first valve (7) is arranged on the outer wall of the oil delivery pipe (6), an oil inlet pipe (8) is communicated with the input end of the vacuum oil filter (2), an oil outlet pipe (9) is communicated with the output end of the vacuum oil filter (2), a second valve (10) is arranged on the outer wall of the oil outlet pipe (9), an oil filling opening of the transformer (4) is communicated with an oil filling pipe (11), an oil pipe connecting piece (12) is arranged between the oil filling pipe (11) and the oil outlet pipe (9), the oil filling pipe (11) and the oil outlet pipe (9) are hermetically connected through the oil pipe connecting piece (12), and a wheat type vacuum gauge (14) is arranged on the top end of the transformer (4), an oil mark pipe (13) arranged at the top end of the transformer (4) is arranged on the left side of the wheat type vacuum gauge (14), a vacuum pipe (15) is communicated with the top end of the transformer (4), an exhaust pipe (16) is communicated with the output end of the vacuum pump (3), a third valve (17) is arranged on the outer wall of the exhaust pipe (16), an air pipe connecting piece (18) is arranged between the exhaust pipe (16) and the vacuum pipe (15), and the exhaust pipe (16) and the vacuum pipe (15) are hermetically connected through the air pipe connecting piece (18);

the primary filtering device comprises a filtering box (19), wherein the filtering box (19) is positioned between an oil delivery pipe (6) and an oil inlet pipe (8), an oil inlet end (20) is arranged on the outer wall of the left side of the filtering box (19), an oil outlet end (21) is arranged on the outer wall of the right side of the filtering box (19), one end, away from the oil storage tank (1), of the oil delivery pipe (6) is communicated with the oil inlet end (20), one end, away from the vacuum oil filter (2), of the oil inlet pipe (8) is communicated with the oil outlet end (21), a cylindrical filtering net (22) is fixedly arranged on the inner wall of the filtering box (19), a vertical rod (23) fixedly arranged on the inner wall of the bottom of the filtering box (19) is arranged on one side, close to the oil inlet end (20), of the filtering net (22), a bearing (24) is fixedly arranged on the top end of the vertical rod (23), and a rotating shaft (25) is connected to the inside of the bearing (24), the utility model discloses a filter box, including pivot (25), clean brush (26) of one end fixedly connected with that is close to filter screen (22), clean brush (26) paste mutually with one side that filter screen (22) are close to oil feed end (20), the top of pivot (25) is equipped with linkage piece (27) of fixed connection on clean brush (26), the bottom fixedly connected with jib (28) of rose box (19), the one end fixedly connected with annular slide rail (29) of rose box (19) are kept away from in jib (28), sliding connection has magnet (30) on the outer wall of annular slide rail (29), the material of linkage piece (27) is iron, magnet (30) are neodymium iron boron strong magnet, and magnet (30) are located directly over linkage piece (27), the top fixedly connected with handle bar (31) of magnet (30), the intercommunication has row material pipe (32) on the bottom inside and outside wall of rose box (19), arrange the top of material pipe (32) and be equipped with intercommunication groove (33) of seting up on rose box (19) outer wall, it is located between montant (23) and filter screen (22) to arrange material pipe (32), intercommunication groove (33) set up to the toper, and the right-hand member of intercommunication groove (33) flushes with the left end of filter screen (22) bottom, threaded connection has sealed lid (34) on arranging the outer wall of material pipe (32), be provided with stopcock (35) on the top inner wall of sealed lid (34), fixed mounting has bracing piece (36) on the right side outer wall of oil storage tank (1), bracing piece (36) set up to the L style of calligraphy, and bracing piece (36) keep away from the one end and the rose box (19) fixed connection of oil storage tank (1).

2. The oil injection method of the vacuum oil injection system of the transformer according to claim 1, wherein: the method comprises the following steps:

s1, opening a third valve (17) and starting a vacuum pump (4), uniformly increasing the vacuum degree within one hour to enable the vacuum degree to reach 1.3Kpa, reading the vacuum degree by a wheat type vacuum gauge (14), and maintaining the vacuum degree for 30 minutes;

s2, after observing that all parts of the transformer (3) are not abnormal, continuously vacuumizing to maintain the vacuum degree at 45-50 Kpa for 6 hours;

s3, continuing vacuumizing, simultaneously opening the first valve (7) and the second valve (10), starting the vacuum oil filter (2), properly controlling the second valve (10), slowly injecting oil in the oil storage tank (1) into the transformer (3) at a speed of 4-6 tons per hour, strictly monitoring the oil level through an oil gauge pipe (13) in the process, stopping injecting the oil when the oil is injected to a position where the oil level is 100-150 mm away from the top of the tank, and closing the first valve (7), the second valve (10) and the vacuum oil filter (2);