Oil injection system and method of transformer

Abstract

The invention relates to the technical field of transformer oil injection, in particular to an oil injection system and method of a transformer, comprising an oil injection pipe and a connecting pipe, the connecting pipe is fixedly connected with the lower end of the oil injection pipe, the middle lower end of the oil injection pipe is provided with an oil level monitoring assembly, the upper end of the oil injection pipe is internally provided with a defoaming assembly, and the lower end of the oil injection pipe is provided with an oil-gas separation assembly; bubbles in insulating oil are eliminated through the defoaming assembly, along with rising of the oil level in the connecting pipe, the bubbles in the oil move upwards, floating balls on a second filter screen float along with the oil level, and when the floating balls collide with one another, puncture needles on the floating balls extrude and puncture the residual bubbles in the oil; when the insulating oil in the connecting pipe is accumulated to a certain weight, the spring in the elastic telescopic rod is stretched, the fixing plate moves downwards accordingly, the insulating oil enters the transformer oil tank, in the process, the second filter screen intercepts bubbles which are not punctured by the puncture needle in the oil, the insulating oil with the bubbles is prevented from entering the transformer oil tank, and the safety of the transformer oil tank is guaranteed. The transformer work is influenced.

Description

Technical Field

[0001] This invention relates to the field of transformer oil filling technology, specifically to a transformer oil filling system and method. Background Technology

[0002] In transformers, oil filling refers to the process of injecting insulating oil (also known as insulating oil) into the insulating oil tank. Insulating oil is a special liquid insulating medium used in transformer oil filling systems and methods to provide electrical insulation and cooling functions inside the transformer.

[0003] During the process of filling transformer oil, air bubbles or gas traps may exist in the insulating oil inside the transformer. In order to ensure the quality and insulation performance of the oil inside the transformer, the gas in the insulating oil needs to be discharged. If the gas is not discharged, it may affect the normal operation of the transformer. Furthermore, it is necessary to grasp the timing of closing the oil filling when filling the transformer. Closing it too early may result in the transformer oil tank not being full, while closing it too late may result in the insulating oil overflowing.

[0004] Chinese patent CN114420415A discloses a transformer auxiliary oil filling device, belonging to the field of transformers. The device includes an oil filling funnel and a connecting pipe. The connecting pipe has an oil filling inlet matching the output end of the oil filling funnel. A guide post is fixed to the bottom of the oil filling inlet, and a float is slidably connected to the guide post. A tension spring is clamped between the float and the guide post. An N-shaped gas collecting chamber is provided outside the oil filling inlet. One end of the N-shaped gas collecting chamber has an oil filling outlet, and the other end of the N-shaped gas collecting chamber is connected to the oil filling inlet through a connecting hole. A sedimentation tank is provided between the connecting hole and the N-shaped gas collecting chamber, filled with gas-capturing particles. An oil-gas separation device is provided at the top of the sedimentation tank. This invention provides an auxiliary oil filling device that can provide oil level warning and discharge gas from the oil. However, this patent may still have the following problems:

[0005] After adsorbing air bubbles, the gas-capturing particles move upward under the action of buoyancy, while the insulating oil flows out through the overflow port on the side. Therefore, the gas-capturing particles may be deflected at an angle under the action of the insulating oil flow direction, which will prevent them from aligning with the conical groove and will not be conducive to defoaming.

[0006] The oil filling funnel has a small storage space. When the insulating oil overflows, the oil level in the funnel rises significantly. If the funnel is closed even slightly late, the oil may overflow. Therefore, staff need to pay close attention and close the funnel quickly without any delay.

[0007] Therefore, the present invention provides an oil injection system and method for a transformer. Summary of the Invention

[0008] This invention addresses the problems of incomplete defoaming and insufficient time for oil level warning by designing an oil injection system and method for transformers.

[0009] The technical solution adopted by this invention to solve its technical problem is: an oil injection system and method for a transformer, comprising an oil injection pipe and a connecting pipe, wherein the connecting pipe is fixedly connected to the lower end of the oil injection pipe, an oil level monitoring component is provided at the lower end of the oil injection pipe, an anti-foaming component is provided inside the upper end of the oil injection pipe, and an oil-gas separation component is provided at the lower end of the oil injection pipe. The oil-gas separation component is configured to eliminate residual air bubbles in the insulating oil through the cooperation of a second guide plate, a second filter screen, and a float ball disposed within the connecting pipe; the float ball is disposed on top of the second filter screen. The bubbles are punctured by a puncture needle fixed to the float, in conjunction with a second guide plate and an elastic telescopic rod. The elastic telescopic rod allows the fixed plate to slide against the connecting pipe through gravity and a tension spring. The defoaming component is driven by a motor to rotate the rotating basket, causing the insulating oil to impact the inner wall of the oil injection pipe and break the bubbles, thus achieving defoaming. The first filter screen fixed on the rotating basket also facilitates bubble breaking. The oil level monitoring component is designed to allow the oil inlet to be exposed by the upward movement of the annular float when the oil level in the oil injection pipe rises, thereby allowing the insulating oil to enter the oil storage tank.

[0010] Preferably, the oil injection pipe has an overall hourglass-shaped hollow interior, a cover plate is fixedly connected to the upper end of the oil injection pipe, a first vent is provided on the cover plate, a support base is fixedly connected to the bottom of the oil injection pipe, a first through groove is provided on the lower side wall of the oil injection pipe, and a first guide plate is fixedly connected to the middle section inside the oil injection pipe.

[0011] Preferably, the defoaming component includes a rotating basket, which is rotatably connected to the cover plate. A support frame is fixedly installed inside the oil injection pipe. A motor is installed above the support frame. The motor drive shaft is fixedly connected to the bottom of the rotating basket. A second through groove is opened on the lower side wall of the rotating basket. A set of first filter screens is fixedly installed in the second through groove.

[0012] Preferably, the oil-gas separation assembly includes a second guide plate, a second filter screen, a float ball, and an elastic telescopic rod. The second filter screen is fixedly connected to the inner wall of the connecting pipe. The second guide plate is located above the second filter screen and is fixedly connected to the inner wall of the connecting pipe. A fixed plate is provided below the second filter screen. An elastic telescopic rod is fixedly installed at the bottom of the support base. A tension spring is provided inside the elastic telescopic rod. The telescopic end of the elastic telescopic rod is fixedly connected to the fixed plate.

[0013] Preferably, the outer surfaces of the float and the fixed end of the elastic telescopic rod are provided with puncture needles, a float plate is fixedly connected below the fixed plate, a second vent is opened at the top of the connecting pipe, the second guide plate is hourglass shaped, the second filter screen is located below the second guide plate, the fixed plate is slidably connected to the connecting pipe, the elastic telescopic rod passes through the second filter screen and is slidably connected to it, and the distance between the elastic telescopic rod and the narrowest point of the second guide plate is less than the diameter of the float.

[0014] Preferably, both the first and second exhaust ports are equipped with one-way valves and connected to a vacuum pump.

[0015] Preferably, the oil level monitoring component includes an oil inlet and an oil outlet on the side wall of the oil injection pipe. A limiting ring is provided below the oil inlet. The limiting ring is fixedly connected to the inner wall of the oil injection pipe. An annular float is movably arranged on the limiting ring. A float plug is provided below the annular float. An oil storage tank is fixedly installed in the middle section of the outer wall of the oil injection pipe. A liquid level sensor is fixedly installed on the top of the inner wall of the oil storage tank.

[0016] Preferably, the annular float is located below the first guide plate, the oil outlet is located below the oil inlet, the lowest point of the bottom of the oil storage tank is adapted to the oil outlet, and the float, annular float and float plug are all made of lightweight corrosion-resistant material with a density less than that of insulating oil.

[0017] Preferably, a fixing rod is fixedly connected to the top of the support base, a limiting block is fixedly connected to the top of the fixing rod, the fixing rod is slidably connected to the float, and a sliding groove is provided at the bottom of the float, the sliding groove being slidably connected to the limiting block.

[0018] A preferred method for using a transformer oil filling system includes the following steps:

[0019] S1: First connect the oil inlet to the upper end of the oil inlet pipe. The oil inlet only injects oil into the rotating basket. Turn on the motor to make the rotating basket rotate. Under the action of centrifugal force, the transformer oil passes through the first filter screen and is discharged from the second channel, causing the transformer oil to hit the inner wall of the oil inlet pipe. The gas is discharged from the first exhaust port.

[0020] S2: Transformer oil flows into the connecting pipe through the first channel, and the float moves upward. The collision of the piercing needles between the floats punctures the residual air bubbles, and the gas is discharged from the second exhaust port. When the oil volume reaches a certain level, the tension spring is stretched, causing the fixed plate to move downward. The second filter screen intercepts air bubbles in the oil. When the fixed plate separates from the connecting pipe, the oil enters the transformer oil tank.

[0021] S3: When the transformer oil tank is full, the float plate moves up, causing the fixed plate to seal the bottom of the connecting pipe. The oil level in the oil injection pipe rises, causing the float plug to move up and seal the oil injection pipe. After the oil level at the top of the float plug rises, the annular float moves up, the oil inlet is exposed, and the oil enters the oil storage tank. When the liquid level sensor in the oil storage tank sends a signal, the oil injection can be shut off.

[0022] S4: After the oil level in the transformer oil tank drops, the fixing plate moves down again to replenish the oil tank. After the float moves down, the oil outlet is exposed, and the oil in the storage tank flows out through the oil outlet to continue replenishing.

[0023] The beneficial effects of this invention are:

[0024] (1) The oil filling system and method for a transformer described in this invention eliminates air bubbles in the insulating oil through a defoaming component. After one round of defoaming, the insulating oil flows into the connecting pipe. As the oil level in the connecting pipe rises, the air bubbles in the oil move upward. The float on the second filter screen floats with the oil level. When the floats collide with each other, the piercing needle on the float punctures the residual air bubbles in the oil. When the insulating oil in the connecting pipe accumulates to a certain weight, the tension spring in the elastic telescopic rod is stretched, and the fixing plate moves downward. When the fixing plate separates from the connecting pipe, the insulating oil enters the transformer oil tank. During this process, the second filter screen intercepts the air bubbles in the oil that have not been punctured by the piercing needle, preventing the insulating oil with air bubbles from entering the transformer oil tank and affecting the operation of the transformer.

[0025] (2) The oil injection system and method for a transformer described in this invention drive the rotating basket to rotate. When the insulating oil enters the rotating basket, it is discharged from the basket through the second channel under the action of centrifugal force. The insulating oil hits the inner wall of the oil injection pipe, which breaks up the air bubbles, thereby achieving the defoaming effect. The double-layer first filter screen in the second channel is conducive to breaking the bubbles.

[0026] (3) In the oil filling system and method of the transformer described in this invention, when the float comes into contact with the inner wall of the oil filling pipe as the oil level rises, it indicates that the insulating oil tank has been filled. At this time, if the oil is continued to be filled to a certain amount, the annular float will move upward, so that the oil inlet is exposed. The insulating oil enters the oil storage tank through the oil inlet. The oil storage tank plays a buffering role. When the liquid level sensor in the oil storage tank sends a signal, whether the oil filling is closed in time or the closure is delayed, the transformer oil tank is in a full state. When the oil level in the transformer oil tank drops, the float moves down and separates from the inner wall of the oil filling pipe. The insulating oil in the oil storage tank can be replenished to the transformer oil tank through the oil outlet. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Figure 1This is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 A cross-sectional view of the overall structure provided for this invention;

[0030] Figure 3 This is a schematic diagram of the connection between the oil injection pipe and the connecting pipe provided by the present invention;

[0031] Figure 4 This is a cross-sectional view of the oil injection pipe provided by the present invention;

[0032] Figure 5 This is a schematic diagram of the oil-gas separation component structure provided by the present invention;

[0033] Figure 6 for Figure 5 Enlarged view of point A;

[0034] Figure 7 This is a schematic diagram showing the connection between the fixing plate and the second filter screen provided by the present invention;

[0035] Figure 8 This is a schematic diagram of the defoaming component structure provided by the present invention;

[0036] Figure 9 A schematic diagram of the internal structure of the elastic telescopic rod provided by the present invention.

[0037] In the diagram: 1. Oil injection pipe; 11. Cover plate; 12. Support base; 13. First guide plate; 14. First vent; 15. First channel; 2. Defoaming component; 21. Support frame; 22. Rotating basket; 23. Second channel; 24. First filter screen; 25. Motor; 3. Oil level monitoring component; 31. Oil storage tank; 32. Oil inlet; 33. Oil outlet; 34. Liquid level sensor; 35. Limiting ring; 36. Annular float; 37. Float plug; 38. Slide groove; 39. Fixing rod; 310. Limiting block; 4. Oil-gas separation component; 41. Connecting pipe; 42. Second guide plate; 43. Second filter screen; 44. Elastic telescopic rod; 441. Tension spring; 45. Float ball; 46. Puncture needle; 47. Fixing plate; 48. Float plate; 49. Second vent. Detailed Implementation

[0038] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0039] Example:

[0040] like Figures 1-9As shown, the present invention discloses an oil injection system and method for a transformer, comprising an oil injection pipe 1 and a connecting pipe 41. The connecting pipe 41 is fixedly connected to the lower end of the oil injection pipe 1. An oil level monitoring component 3 is provided at the lower end of the oil injection pipe 1. An anti-foaming component 2 is provided inside the upper end of the oil injection pipe 1. An oil-gas separation component 4 is provided at the lower end of the oil injection pipe 1. The oil-gas separation component 4 is configured to eliminate residual air bubbles in the insulating oil through the cooperation of a second guide plate 42, a second filter screen 43, and a float 45 disposed within the connecting pipe 41. The float 45 is disposed on top of the second filter screen 43 and is fixedly connected to the float 45. The puncture needle 46, in conjunction with the second guide plate 42 and the elastic telescopic rod 44, punctures the air bubbles; the elastic telescopic rod 44, through gravity and the tension spring 441, allows the fixed plate 47 to slide against the connecting pipe 41; the defoaming component 2, through the power of the motor 25, drives the rotating basket 22 to rotate, causing the insulating oil to impact the inner wall of the oil injection pipe 1 and break the air bubbles to achieve defoaming, and the first filter screen 24 fixedly installed on the rotating basket 22 is conducive to breaking the bubbles; the oil level monitoring component 3, is set to allow the oil inlet 32 ​​to be exposed by the upward movement of the annular float 36 when the oil level in the oil injection pipe 1 rises, thereby allowing the insulating oil to enter the oil storage tank 31.

[0041] In this embodiment, the motor 25 of the defoaming component 2 drives the rotating basket 22 to rotate. Under the action of centrifugal force, the insulating oil is thrown out from the rotating basket 22. After being thrown out, the insulating oil hits the inner wall of the oil injection pipe 1, breaking the air bubbles in the oil, thereby achieving the purpose of defoaming. The defoamed insulating oil flows into the connecting pipe 41 through the gap between the float 37 and the inner wall of the oil injection pipe 1. However, there may be air bubbles in the oil that have not been eliminated. As the oil level in the connecting pipe 41 rises, the float 45 moves upward accordingly. When the air bubbles in the oil move upward, when the floats 45 collide with each other, the piercing needles 46 on their surfaces puncture each other and break the air bubbles. When the oil volume in the connecting pipe 41 reaches a certain level, the tension spring 441 is stretched under the action of gravity, causing the fixing plate 47 to move downward. When the fixing plate 47 moves downward, the oil level line in the connecting pipe 41 also moves downward. When the fixing plate 47 separates from the connecting pipe 41, the oil level line in the connecting pipe 41 is also lowered. The insulating oil, after two rounds of defoaming, flows from the connecting pipe 41 to the transformer oil tank. Since the float plate 48 is made of a lightweight, corrosion-resistant material with a density lower than that of the insulating oil, when the oil tank is full, even if the connecting pipe 41 is filled with insulating oil, the fixing plate 47 can remain inside the connecting pipe 41 under the support of the float plate 48, that is, the fixing plate 47 keeps the connecting pipe 41 closed. As the oil level in the oil injection pipe 1 rises, the float plug 37 moves upward and engages with the inner wall of the oil injection pipe 1. At this time, continuing to inject oil will cause the annular float 36 to move upward and expose the oil inlet 32, so the insulating oil enters the oil storage tank 31. At this time, the oil outlet 33 is in a closed state. When the liquid level sensor 34 sends a signal, the oil injection can be stopped. The oil storage tank 31 has a certain storage space, and delaying the oil injection for a certain period of time will not cause the insulating oil to overflow. After the insulating oil enters the oil storage tank 31, it can be used to replenish the transformer oil tank later.

[0042] like Figure 4 and Figure 8 As shown, the defoaming component 2 includes a rotating basket 22, which is rotatably connected to the cover plate 11. A support frame 21 is fixedly installed inside the oil injection pipe 1. A motor 25 is installed above the support frame 21. The drive shaft of the motor 25 is fixedly connected to the bottom of the rotating basket 22. A second through groove 23 is opened on the lower side wall of the rotating basket 22. A set of first filter screens 24 is fixedly installed in the second through groove 23.

[0043] In this embodiment, the motor 25 drives the rotating basket 22 to rotate, causing the insulating oil to be thrown out of the rotating basket 22. During this process, the insulating oil passes through the first filter screen 24. Both layers of the first filter screen 24 are set with high density, which is conducive to breaking bubbles. The insulating oil hits the inner wall of the oil injection pipe 1 under high-speed rotation, and the bubbles in the oil are broken, thereby achieving the defoaming effect. The gas is discharged from the first exhaust port 14.

[0044] like Figures 5-7As shown, the oil-gas separation assembly 4 includes a second guide plate 42, a second filter screen 43, a float ball 45, and an elastic telescopic rod 44. The second filter screen 43 is fixedly connected to the inner wall of the connecting pipe 41. The second guide plate 42 is located above the second filter screen 43 and is fixedly connected to the inner wall of the connecting pipe 41. A fixing plate 47 is provided below the second filter screen 43. An elastic telescopic rod 44 is fixedly installed at the bottom of the support base 12. A tension spring 441 is provided inside the elastic telescopic rod 44. The telescopic end of the elastic telescopic rod 44 is fixed to the fixing plate 47. Connection; both the outer surfaces of the fixed ends of the float 45 and the elastic telescopic rod 44 are provided with piercing needles 46; a float 48 is fixedly connected below the fixed plate 47; a second exhaust port 49 is opened at the top of the connecting pipe 41; the second guide plate 42 is hourglass-shaped; the second filter screen 43 is located below the second guide plate 42; the fixed plate 47 is slidably connected to the connecting pipe 41; the elastic telescopic rod 44 passes through the second filter screen 43 and is slidably connected to it; the distance between the elastic telescopic rod 44 and the narrowest point of the second guide plate 42 is less than the diameter of the float 45.

[0045] In this embodiment, after a round of defoaming, the insulating oil flows into the connecting pipe 41 through the first channel 15. At this time, the fixing plate 47 is in contact with the second filter screen 43. As the oil level in the connecting pipe 41 rises, the float 45 moves upward. Under the action of the hourglass-shaped second guide plate 42, the floats 45 gradually gather together around the elastic telescopic rod 44. The floats 45 collide with each other, and the piercing needles 46 on their surfaces puncture each other. Combined with the piercing needles 46 on the elastic telescopic rod 44, the residual air bubbles in the oil are punctured. Since the distance between the elastic telescopic rod 44 and the narrowest point of the second guide plate 42 is less than the diameter of the float 45, the float 45 is always in position. In the lower half of the second guide plate 42, when there is too much oil in the connecting pipe 41, the tension spring 441 is stretched under the action of gravity, and the elastic telescopic rod 44 extends, thereby causing the fixing plate 47 to move down. When the fixing plate 47 separates from the connecting pipe 41, the insulating oil in the connecting pipe 41 enters the transformer oil tank. At this time, the air bubbles in the connecting pipe 41 may move towards the bottom of the connecting pipe 41 under the action of the flow of the insulating oil. The second filter screen 43 can intercept the air bubbles in the oil and prevent them from entering the transformer oil tank. When the transformer oil tank is full, the float plate 48 moves up, causing the fixing plate 47 to seal the bottom of the connecting pipe 41.

[0046] like Figures 2-5As shown, the oil injection pipe 1 has an overall hourglass-shaped hollow structure. A cover plate 11 is fixedly connected to the upper end of the oil injection pipe 1, and a first vent 14 is provided on the cover plate 11. A support base 12 is fixedly connected to the bottom of the oil injection pipe 1. A first through groove 15 is provided on the lower side wall of the oil injection pipe 1. A first guide plate 13 is fixedly connected to the middle section inside the oil injection pipe 1. The oil level monitoring component 3 includes an oil inlet 32 ​​and an oil outlet 33 provided on the side wall of the oil injection pipe 1. A limit ring 35 is provided below the oil inlet 32. The limit ring 35 is fixedly connected to the inner wall of the oil injection pipe 1. An annular float 36 is movably provided on the limit ring 35. A float plug 37 is provided below the annular float 36. An oil storage tank 31 is fixedly installed in the middle section of the outer wall of the oil injection pipe 1. A liquid level sensor 34 is fixedly installed on the top of the inner wall of the oil storage tank 31; an annular float 36 is located below the first guide plate 13, and the oil outlet 33 is located below the oil inlet 32. The lowest point of the bottom of the oil storage tank 31 is adapted to the oil outlet 33. The float ball 45, the annular float 36, and the float plug 37 are all made of lightweight corrosion-resistant materials with a density less than that of insulating oil; a fixed rod 39 is fixedly connected to the top of the support base 12, and a limit block 310 is fixedly connected to the top of the fixed rod 39. The fixed rod 39 is slidably connected to the float plug 37, and a sliding groove 38 is opened at the bottom of the float plug 37. The sliding groove 38 is slidably connected to the limit block 310; a one-way valve is provided on the first exhaust port 14 and the second exhaust port 49 and connected to a vacuum pump.

[0047] In this embodiment, the insulating oil flows downwards after being defoamed by the defoaming component 2. At this time, the annular float 36 is in contact with the limiting ring 35, and the oil inlet 32 ​​is closed. When the oil level in the oil injection pipe 1 rises, the float 37 moves upwards until it engages with the inner wall of the oil injection pipe 1. Continuing to inject oil will cause the oil level at the top of the float 37 to gradually rise, causing the annular float 36 to move upwards. The first guide plate 13 prevents the insulating oil flowing down from above from contacting the annular float 36. After the annular float 36 moves upwards, the oil inlet 32 ​​is exposed, and the insulating oil thus enters the oil storage tank 31 through the oil inlet 32. The oil storage tank 31 has a certain storage space. When the liquid level sensor 34 sends a signal, there is a certain time... Used to shut off the oil filling without close monitoring, avoiding the situation where insulating oil overflows due to failure to shut off the oil filling in time. In addition to extending the reserve time after the warning, the oil storage tank 31 also serves a storage function, which can reduce the frequency of oil filling to a certain extent. When the float plug 37 closes the oil filling pipe 1, the oil outlet 33 is also closed at the same time. When the insulating oil passes through the gap between the float plug 37 and the inner wall of the oil filling pipe 1, even if a small amount of insulating oil enters the oil outlet 33, it will flow back to the bottom of the oil filling pipe 1 through the inclined oil outlet 33. The gas from the bubbles broken by the defoaming component 2 is discharged through the first exhaust port 14, and the gas from the bubbles punctured by the piercing needle 46 is discharged through the second exhaust port 49.

[0048] Working principle: When in use, connect the oil inlet to the upper end of the oil inlet pipe 1, turn on the vacuum pump and the one-way valve to discharge the gas in the oil inlet pipe 1 and the connecting pipe 41 through the first exhaust port 14 and the second exhaust port 49, turn on the motor 25 to make the rotating basket 22 rotate, and the insulating oil is discharged from the rotating basket 22 through the second channel 23 under the action of centrifugal force. The high-density first filter screen 24 set in the second channel 23 is conducive to breaking bubbles. When the insulating oil hits the inner wall of the oil inlet pipe 1, the bubbles in the oil are broken under the action of impact force, thereby achieving the purpose of defoaming. The gas is then discharged through the first exhaust port 14.

[0049] The defoamed insulating oil flows through the gap between the inner wall of the oil injection pipe 1 and the float 37 to the bottom of the oil injection pipe 1, and then flows through the first channel 15 into the connecting pipe 41. In the initial state, the tension spring 441 in the elastic telescopic rod 44 is in a compressed state. At this time, the fixing plate 47 is in contact with the second filter screen 43, and the bottom of the connecting pipe 41 is in a closed state. When the oil level in the connecting pipe 41 rises, the float 45 on the second filter screen 43 moves upward and slowly gathers at the narrowest point of the second guide plate 42. Since the gas is lighter, the air bubbles in the oil move upward. When the float 45 collides with the float 45, the puncture needle 46 on its surface, together with the puncture needle 46 on the elastic telescopic rod 44, punctures the residual air bubbles. The gas is discharged from the second exhaust port 49. When the oil in the connecting pipe 41 reaches a certain weight, the tension spring 441 is stretched under the action of gravity. The fixing plate 47 moves down and separates from the connecting pipe 41, so the oil flows into the transformer oil tank. The second filter screen 43 can intercept air bubbles in the oil and prevent unpunctured air bubbles from flowing into the oil tank. When the oil tank is full, the fixing plate 47, supported by the float plate 48, keeps the connecting pipe 41 closed. After the bottom of the connecting pipe 41 is closed, the oil level in the oil injection pipe 1 continues to rise, which causes the float 37 to move up until the float 37 is engaged with the inner wall of the oil injection pipe 1. At this time, the oil injection continues to cause the annular float 36 to move up and expose the oil inlet 32. The oil then flows into the oil storage tank 31. When the liquid level sensor 34 in the oil storage tank 31 sends a signal, it means that the oil injection can be closed. The oil storage tank 31 has a certain storage space and can play a buffer role. It will not have any impact if the oil injection is closed after receiving the signal for a period of time. There is no need to pay close attention to it.

[0050] When the oil level in the transformer oil tank drops, the float plate 48 loses its buoyancy support, and the fixed plate 47 moves down again to separate from the connecting pipe 41. The oil in the connecting pipe 41 replenishes the oil tank. When the oil level in the oil injection pipe 1 drops, the float plug 37 moves down and the oil outlet 33 is exposed. The oil in the oil storage tank 31 flows out through the oil outlet 33 to continue replenishing the oil tank, which can reduce the oil injection frequency to a certain extent.

[0051] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An oil injection system of a transformer, comprising an oil injection pipe (1) and a connecting pipe (41), the connecting pipe (41) being fixedly connected with the lower end of the oil injection pipe (1), an oil level monitoring assembly (3) being arranged at the lower end of the oil injection pipe (1), and a defoaming assembly (2) being arranged inside the upper end of the oil injection pipe (1), characterized in that: An oil-gas separation assembly (4) is provided at the lower end of the oil injection pipe (1); The oil-gas separation assembly (4) is configured to eliminate residual air bubbles in the insulating oil through the cooperation between the second guide plate (42), the second filter screen (43) and the float (45) disposed in the connecting pipe (41); A float (45) is placed on top of the second filter screen (43). A puncture needle (46) fixedly connected to the float (45) works with the second guide plate (42) and the elastic telescopic rod (44) to puncture the air bubbles. The elastic telescopic rod (44) allows the fixed plate (47) and the connecting pipe (41) to slide under the action of gravity and the tension spring (441); The defoaming component (2) can drive the rotating basket (22) to rotate through the power of the motor (25), so that the insulating oil hits the inner wall of the oil injection pipe (1) to break the bubbles and achieve defoaming. The first filter screen (24) fixedly installed on the rotating basket (22) is conducive to breaking the bubbles. The oil level monitoring component (3) is configured such that when the oil level in the oil injection pipe (1) rises, the annular float (36) can float up with the rise of the insulating oil surface, so that the oil inlet (32) is exposed, thereby allowing the insulating oil to enter the oil storage tank (31).

2. The oil injection system for a transformer according to claim 1, characterized in that: The oil injection pipe (1) is hollow in the shape of an hourglass. A cover plate (11) is fixedly connected to the upper end of the oil injection pipe (1). A first vent (14) is opened on the cover plate (11). A support base (12) is fixedly connected to the bottom of the oil injection pipe (1). A first through groove (15) is opened on the lower side wall of the oil injection pipe (1). A first guide plate (13) is fixedly connected to the middle section inside the oil injection pipe (1).

3. The oil injection system for a transformer according to claim 2, characterized in that: The defoaming component (2) includes a rotating basket (22), which is rotatably connected to the cover plate (11). A support frame (21) is fixedly installed inside the oil injection pipe (1). A motor (25) is installed above the support frame (21). The drive shaft of the motor (25) is fixedly connected to the bottom of the rotating basket (22). A second through groove (23) is opened on the lower side wall of the rotating basket (22). A set of first filter screens (24) is fixedly installed in the second through groove (23).

4. The oil injection system for a transformer according to claim 3, characterized in that: The oil-gas separation assembly (4) includes a second guide plate (42), a second filter screen (43), a float (45), and an elastic telescopic rod (44). The second filter screen (43) is fixedly connected to the inner wall of the connecting pipe (41). The second guide plate (42) is located above the second filter screen (43) and is fixedly connected to the inner wall of the connecting pipe (41). A fixing plate (47) is provided below the second filter screen (43). An elastic telescopic rod (44) is fixedly installed at the bottom of the support base (12). A tension spring (441) is provided inside the elastic telescopic rod (44). The telescopic end of the elastic telescopic rod (44) is fixedly connected to the fixing plate (47).

5. The oil injection system for a transformer according to claim 4, characterized in that: The outer surfaces of the float (45) and the fixed end of the elastic telescopic rod (44) are provided with puncture needles (46). A float plate (48) is fixedly connected below the fixed plate (47). A second exhaust port (49) is opened at the top of the connecting pipe (41). The second guide plate (42) is hourglass-shaped. The second filter screen (43) is located below the second guide plate (42). The fixed plate (47) is slidably connected to the connecting pipe (41). The elastic telescopic rod (44) passes through the second filter screen (43) and is slidably connected to it. The distance between the elastic telescopic rod (44) and the narrowest point of the second guide plate (42) is less than the diameter of the float (45).

6. The oil injection system for a transformer according to claim 5, characterized in that: Both the first exhaust port (14) and the second exhaust port (49) are equipped with one-way valves and connected to a vacuum pump.

7. The oil injection system for a transformer according to claim 1, characterized in that: The oil level monitoring component (3) includes an oil inlet (32) and an oil outlet (33) on the side wall of the oil injection pipe (1). A limiting ring (35) is provided below the oil inlet (32). The limiting ring (35) is fixedly connected to the inner wall of the oil injection pipe (1). An annular float (36) is movably provided on the limiting ring (35). A float plug (37) is provided below the annular float (36). An oil storage tank (31) is fixedly installed in the middle section of the outer wall of the oil injection pipe (1). A liquid level sensor (34) is fixedly installed on the top of the inner wall of the oil storage tank (31).

8. The oil injection system for a transformer according to claim 7, characterized in that: The annular float (36) is located below the first guide plate (13), the oil outlet (33) is located below the oil inlet (32), the lowest point of the bottom of the oil storage tank (31) is adapted to the oil outlet (33), and the float (45), the annular float (36) and the float plug (37) are all made of lightweight corrosion-resistant materials with a density less than that of insulating oil.

9. The oil injection system for a transformer according to claim 2, characterized in that: The top of the support base (12) is fixedly connected to a fixing rod (39), and the top of the fixing rod (39) is fixedly connected to a limiting block (310). The fixing rod (39) is slidably connected to the float (37), and the bottom of the float (37) is provided with a sliding groove (38). The sliding groove (38) is slidably connected to the limiting block (310).

10. A method of using a transformer oil injection system, characterized in that, The steps are as follows: S1: First connect the oil inlet to the upper end of the oil inlet pipe (1). The oil inlet only injects oil into the rotating basket (22). Turn on the motor (25) to make the rotating basket (22) rotate. Under the action of centrifugal force, the insulating oil passes through the first filter screen (24) and is discharged from the second channel (23), so that the insulating oil hits the inner wall of the oil inlet pipe (1), and the gas is discharged from the first exhaust port (14). S2: Insulating oil flows through the first channel (15) into the connecting pipe (41), and the float (45) moves upward. The collision of the piercing needles (46) between the floats (45) punctures the residual air bubbles, and the gas is discharged from the second exhaust port (49). When the oil volume reaches a certain level, the tension spring (441) is stretched, causing the fixing plate (47) to move downward. The second filter screen (43) intercepts the air bubbles in the oil. When the fixing plate (47) separates from the connecting pipe (41), the oil enters the transformer oil tank. S3: When the transformer oil tank is full, the float plate (48) moves up, causing the fixed plate (47) to seal the bottom of the connecting pipe (41). The oil level in the oil injection pipe (1) rises, causing the float plug (37) to move up and seal the oil injection pipe (1). After the oil level at the top of the float plug (37) rises, the annular float (36) moves up, the oil inlet (32) is exposed, and the oil enters the oil storage tank (31). When the liquid level sensor (34) in the oil storage tank (31) sends a signal, the oil injection can be closed. S4: After the oil level in the transformer oil tank drops, the fixing plate (47) moves down again to replenish the oil tank. After the float (37) moves down, the oil outlet (33) is exposed, and the oil in the storage tank (31) flows out through the oil outlet (33) to continue replenishing.

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