Protection device with oil discharge pressure control and explosion-proof nitrogen injection fire extinguishing structure for transformer

Abstract

The invention discloses a transformer protection device with an oil discharge pressure control and anti-explosion nitrogen injection fire extinguishing structure, and relates to the technical field of transformer protection, the transformer protection device comprises a box body, a transformer oil tank mounted on the left side of the box body and an oil discharge pipe fixedly connected in the box body, and the head of the oil discharge pipe is located on the left side of the box body and detachably connected with a first pipe; the rear side of the first pipe is fixedly connected with an air cylinder on the left side surface of the box body. According to the protection device with the oil discharge pressure control and anti-explosion nitrogen injection fire extinguishing structure for the transformer, through the arrangement of the moving ring, the nitrogen injection branch pipe, the branch pipe assembly and the backflow mechanism, nitrogen is evenly distributed, the circulation amount is the same, the fire extinguishing and cooling effects of the protection device on transformer oil are improved, the moving ring circularly pushes pressure relief oil to flow in a pipeline, and the safety of the transformer is improved. The pressure relief operation of the protection device is accelerated, the nitrogen injection waiting time is shortened, the protection effect of the protection device on the transformer is facilitated, the use safety of the transformer is improved, and meanwhile the operation and maintenance cost of the transformer can be reduced through the backflow mechanism.

Description

Technical Field

[0001] The present invention relates to the technical field of transformer protection, and particularly relates to a protection device for a transformer with an oil drainage and pressure control and explosion-proof nitrogen injection fire extinguishing structure. Background Technique

[0002] A transformer is a device that uses the principle of electromagnetic induction to change the AC voltage. Transformers can be classified into various types according to their uses, including oil-immersed transformers. During the operation of an oil-immersed transformer, if internal insulation damage or short circuit and other fault conditions occur in the transformer, the oil temperature exceeds the ignition point and generates various combustible gases, the internal pressure of the fuel tank increases, which is likely to damage the tank shell of the transformer. Moreover, when the combustible gas, high-temperature oil comes into contact with oxygen, it is easy to cause a fire and there is an explosion hazard.

[0003] Most existing enterprises set up protection devices near oil-immersed transformers. The protection devices achieve the effects of explosion-proof, fire-proof and fire extinguishing for the transformer through the methods of oil drainage and pressure relief, and nitrogen filling and cooling. However, the nitrogen injection in the existing protection devices is unevenly distributed, which affects the cooling effect of the transformer oil, resulting in an increased risk of fire spread. At the same time, the oil drainage depends on the self-flow rate of the oil to relieve pressure, which is likely to prolong the waiting time for nitrogen injection, affecting the protection effect of the protection device on the transformer. And there is no oil return action for the transformer oil, which is likely to cause waste of the transformer oil, thus affecting the safety of transformer use and the operation and maintenance cost. In order to solve the deficiencies of the existing technology, we propose a protection device for a transformer with an oil drainage and pressure control and explosion-proof nitrogen injection fire extinguishing structure. Summary of the Invention

[0004] The main purpose of the present invention is to provide a protection device for a transformer with an oil drainage and pressure control and explosion-proof nitrogen injection fire extinguishing structure, which can effectively solve the problems in the background technique.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A protection device for a transformer with an oil drainage and pressure control and explosion-proof nitrogen injection fire extinguishing structure, including a box body, a transformer oil tank installed on the left side of the box body, and an oil discharge pipe fixedly connected inside the box body. The head of the oil discharge pipe is detachably connected to a first pipe on the left side of the box body. An air pressure mechanism for pushing the pressure-relieving oil to move is arranged inside the first pipe. A reflux mechanism for refluxing the pressure-relieving oil is arranged behind the first pipe. A connecting pipe is detachably connected to the surface of the bottom of the first pipe on the left side of the box body. A nitrogen injection branch pipe is fixedly connected inside the tail of the connecting pipe. One end of the nitrogen injection branch pipe penetrates through the bent part of the connecting pipe and extends into the box body. The other end of the nitrogen injection branch pipe extends into the transformer oil tank along the axis of the connecting pipe and is provided with a sub-pipe assembly that is distributed around the bottom of the transformer oil tank and can uniformly inject nitrogen.

[0007] Preferably, the branch pipe assembly includes mounting rings fixedly connected to the ends of the nitrogen injection branch pipes. There are multiple mounting rings, and a connecting pipe is detachably connected between adjacent mounting rings. An air outlet is formed at the top of the mounting ring, a conical block is fixedly connected to the bottom port of the air outlet, and a ventilation hole is formed at the center of the conical block.

[0008] Preferably, the diameter of the ventilation hole gradually increases along the extension line of the nitrogen injection branch pipe towards the transformer oil tank.

[0009] Preferably, the shape of the branch pipe assembly is rectangular, an arc-shaped elastic plate is provided at the corner of the branch pipe assembly, the connecting pipe is a flexible pipe, a nozzle is detachably connected to the outer side surface of the mounting ring at the top port of the air outlet, a valve flap group is fixedly connected to the inner wall of the bottom of the nozzle, and a ball is rotatably connected to the bottom of the mounting ring.

[0010] Preferably, the air compression mechanism includes a cylinder fixedly connected to the left surface of the box body, a connecting plate is detachably connected to the piston rod of the cylinder, a grasping rod is detachably connected to the bottom surface of the front side of the connecting plate, a moving ring is provided at the bottom of the grasping rod, a fixed ring is fixedly connected to the inner wall at the tail of the first pipe, and a first circular plate and a second circular plate are respectively rotatably connected to the upper surfaces of the moving ring and the fixed ring.

[0011] Preferably, the grasping rod includes a first rod provided at the end of the connecting plate, a plurality of arc-shaped brackets are fixedly connected to the bottom of the first rod, there are three arc-shaped brackets, and a support plate is fixedly connected to the bottom of the arc-shaped brackets.

[0012] Preferably, a guide rod is detachably connected to the top surface of the first pipe, and the connecting plate is slidably connected to the surface of the guide rod.

[0013] Preferably, the reflux mechanism includes a reflux chamber fixedly connected to the tail of the drain pipe, a reflux pipe is detachably connected between the reflux chamber and the first pipe, a driving rod is rotatably connected to the top of the first rod and the bottom surface of the connecting plate at the rotating part, a fixing mechanism for fixing the positions of the first circular plate and the second circular plate is provided inside the support plate, and an extrusion valve device is installed on the upper surface of the second circular plate.

[0014] Preferably, the bottom surface of the reflux chamber is arc-shaped, a reflux pipe is detachably connected to the lowest point of the bottom surface of the reflux chamber, the port at the tail of the reflux pipe is detachably connected to the outer side surface of the first pipe, and the head of the driving rod is fitted with the outer side surface of the top of the first rod.

[0015] Preferably, the fixing mechanism includes a toothed plate fixedly connected to the upper surface of the moving ring. The inner side of the bottom of the support plate is rotatably connected to a rotating shaft. The top of the rotating shaft is fixedly connected to a shielding plate. The rotating shaft is engaged with the toothed plate. The bottom of the support plate slides on the upper surface of the moving ring. A groove is formed in the bottom surface of the moving ring. Magnetic sheets are fixedly connected to the bottom surface of the support plate on the moving ring and the top surface of the support plate on the fixed ring, and the magnetic poles are opposite.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. In the present invention, through the arranged nitrogen injection branch pipes and the sub-pipe assembly, the nitrogen injection branch pipes and the sub-pipe assembly make nitrogen flow from the periphery of the bottom of the transformer oil tank to the top of the transformer oil tank, and the nitrogen flow rate is the same, so as to facilitate the uniform distribution of nitrogen, improve the fire extinguishing and cooling effect of the protection device on the transformer oil and the safety of transformer use.

[0018] 2. In the present invention, through the arranged moving ring and the reflux mechanism, the moving ring circulates to push the pressure-relief oil to flow in the pipeline, which is convenient to increase the flow rate of the pressure-relief oil and accelerate the pressure-relief operation of the protection device, so as to reduce the nitrogen injection waiting time and the risk of fire spread, thereby improving the protection effect of the protection device on the transformer. At the same time, the reflux mechanism reflows the pressure-relief oil back into the transformer oil tank to recycle the pressure-relief oil and reduce the operation and maintenance cost of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the overall structural schematic diagram of the oil-draining and nitrogen-injecting fire extinguishing device of the present invention;

[0020] Figure 2 is the structural schematic diagram of the nitrogen injection branch pipe related to the present invention;

[0021] Figure 3 is the structural schematic diagram of the valve group related to the present invention;

[0022] Figure 4 is the structural schematic diagram of the conical block related to the present invention;

[0023] Figure 5 is the internal structural schematic diagram of the No. 1 pipe of the present invention;

[0024] Figure 6 is the structural schematic diagram of the moving ring related to the present invention;

[0025] Figure 7 is the structural schematic diagram of the fixed ring related to the present invention;

[0026] Figure 8 is the structural schematic diagram of the support plate related to the present invention;

[0027] Figure 9 is the structural schematic diagram of the reflux chamber related to the present invention.

[0028] In the figure:

[0029] 1. Box body; 11. Drain pipe; 12. Connecting pipe; 2. Transformer oil tank; 21. First pipe; 22. Cylinder; 23. Connecting plate; 24. Grabbing rod; 25. Arc-shaped bracket; 26. First rod; 3. Support plate; 31. Moving ring; 32. First circular plate; 33. Fixed ring; 34. Second circular plate; 35. Guide rod; 4. Pneumatic mechanism; 41. Nitrogen injection branch pipe; 5. Sub-pipe assembly; 51. Installation ring; 52. Connecting pipe; 53. Valve group; 54. Nozzle; 55. Ball; 56. Elastic plate; 57. Air outlet; 58. Conical block; 59. Vent hole; 6. Return mechanism; 61. Return chamber; 62. Return pipe; 63. Driving rod; 7. Fixing mechanism; 71. Toothed plate; 72. Rotating shaft; 73. Baffle plate; 74. Groove; 75. Extrusion valve device. Specific embodiments

[0030] In order to make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0031] A protection device for a transformer with an oil drainage and pressure control and explosion-proof nitrogen injection fire extinguishing structure includes a box body 1, a transformer oil tank 2 installed on the left side of the box body 1, and a drain pipe 11 fixedly connected inside the box body 1. The first end of the drain pipe 11 is detachably connected to a first pipe 21 on the left side of the box body 1. An air pressure mechanism 4 for pushing the pressure-relieving oil to move is arranged inside the first pipe 21. A return mechanism 6 for returning the pressure-relieving oil is arranged at the rear side of the first pipe 21. A connecting pipe 12 is detachably connected to the bottom surface of the first pipe 21 on the left side of the box body 1. A nitrogen injection branch pipe 41 is fixedly connected inside the tail end of the connecting pipe 12. One end of the nitrogen injection branch pipe 41 penetrates through the bent part of the connecting pipe 12 and extends into the box body 1. The other end of the nitrogen injection branch pipe 41 extends along the axis of the connecting pipe 12 into the transformer oil tank 2 and is provided with a sub-pipe assembly 5 distributed around the bottom of the transformer oil tank 2 and capable of evenly injecting nitrogen.

[0032] As Figures 1-4 shown, one end of the nitrogen injection branch pipe 41 penetrates through the bent part of the connecting pipe 12 and extends into the box body 1. This end is detachably connected to the tail end of the nitrogen channel inside the box body 1, so that the nitrogen injection branch pipe 41 is connected and communicated with the nitrogen channel. The other end of the nitrogen injection branch pipe 41 extends along the axis of the connecting pipe 12 into the transformer oil tank 2 and is provided with a sub-pipe assembly 5 distributed around the bottom of the transformer oil tank 2. Nitrogen flows into the sub-pipe assembly 5 through the nitrogen injection branch pipe 41, so that nitrogen evenly surges from the bottom of the transformer oil tank 2 to the top of the transformer oil tank 2;

[0033] Among them, the nitrogen injection and oil drainage share the same auxiliary port on the side of the bottom of the transformer oil tank 2, which can reduce the number of auxiliary ports opened on the surface of the transformer oil tank 2 and lighten the labor burden of the installation workers.

[0034] As Figures 2-4 shown, the branch pipe assembly 5 includes a mounting ring 51 fixedly connected to the end of the nitrogen injection branch pipe. A connecting pipe 52 is detachably connected between adjacent mounting rings 51. An air outlet 57 is opened at the top of the mounting ring 51. A conical block 58 is fixedly connected to the bottom port of the air outlet 57 inside the mounting ring 51. A ventilation hole 59 is opened at the center of the conical block 58. The air outlet 57 is communicated with the mounting ring through the ventilation hole 59. Nitrogen flows into the mounting ring 51 and the connecting pipe 52 through the nitrogen injection branch pipe 41. Multiple mounting rings 51 are evenly distributed at the bottom of the transformer oil tank 2. Nitrogen flows inside the connecting pipe 52 and flows to the bottom of the transformer oil tank 2 through the air outlet 57 and the ventilation hole 59.

[0035] The outer side surface of the conical block 58 can guide nitrogen to move around inside the connecting pipe 52, which helps nitrogen to flow inside the connecting pipe 52.

[0036] As Figure 4 shown, on the extension line of the nitrogen injection branch pipe 41 towards the transformer oil tank 2, the diameter of the ventilation hole 59 gradually increases, so that the nitrogen flow rate of each air outlet 57 and the ventilation hole 59 is the same, which helps nitrogen to surge evenly upwards from the bottom of the transformer oil tank 2 and improves the cooling efficiency of the transformer oil.

[0037] As Figure 2 shown, the connecting pipe 52 is a flexible pipe, and its length can be changed, so the distance between adjacent mounting rings 51 can also be changed. The connecting pipe 52 can be made of silicone rubber or polytetrafluoroethylene material to maintain the stability of the connecting pipe 52. During installation, adjacent mounting rings 51 are close to each other, so that the branch pipe assembly 5 extends into the transformer oil tank 2 through the auxiliary port on the transformer oil tank 2 in a contracted form.

[0038] A nozzle 54 is detachably connected to the top port of the air outlet 57 on the outer side surface of the mounting ring 51. A valve group 53 is fixedly connected to the inner wall of the bottom of the nozzle 54. The valve group 53 is composed of multiple valve groups 53 and a cross groove is provided at the center. When static, the cross groove is closed and the valve group 53 closes the air outlet 57.

[0039] After the branch pipe assembly 5 is to be placed, nitrogen can be pre-injected into the connecting pipe 52 and the inside of the mounting ring 51 through the nitrogen injection branch pipe 41, so that the connecting pipe 52 is unfolded at the bottom of the transformer oil tank 2, so that multiple mounting rings 51 are spaced apart on the bottom surface of the transformer oil tank 2. At this time, the valve flap group 53 is not opened; during operation, nitrogen is continuously filled into the branch pipe assembly 5, and the nitrogen will push the valve flap group 53 to open outward, so that the air outlet 57 is opened, and then the nitrogen is sprayed above the transformer oil tank 2 through the nozzle 54;

[0040] As Figure 3 shown, the mounting ring 51 is made of stainless steel. Relying on the weight of the mounting ring 51 itself, the entire branch pipe assembly 5 can sink to the bottom of the transformer oil tank 2. At the same time, a ball 55 is rotatably connected to the bottom of the mounting ring 51, which is convenient for reducing the friction between the mounting ring 51 and the bottom of the transformer oil tank 2, improving the smoothness of the movement of the mounting ring 51, and facilitating the unfolding of multiple mounting rings 51 at the bottom of the transformer oil tank 2.

[0041] As Figure 2 shown, the shape of the unfolded branch pipe assembly 5 is rectangular, so that multiple mounting rings 51 are distributed on the X-axis and Y-axis at the bottom of the transformer oil tank 2, increasing the distribution range of the mounting rings 51, facilitating the nitrogen to rush from multiple directions at the bottom of the transformer oil tank 2 to the top of the transformer oil tank 2, and being beneficial to the working efficiency of quickly isolating oxygen by nitrogen and reducing the oil temperature; at the same time, an elastic plate 56 is provided at the corner of the branch pipe assembly 5. The middle of the elastic plate is fixedly connected to the mounting ring 51 at the corner. The two ends of the elastic plate 56 are respectively detachably connected to the adjacent connecting pipes 52. The elastic plate 56 is set to be arc-shaped. The elastic plate 56 assists the branch pipe assembly 5 to form a rectangle, reducing the occurrence of folding at the corner of the branch pipe assembly 5 and affecting the flow of nitrogen in the branch pipe assembly 5.

[0042] As Figure 1 shown, a main valve and a controllable valve are provided on the drain pipe 11. The main valve is installed at the top of the drain pipe 11 inside the box body 1. Usually, the main valve is open during equipment operation, and the main valve is closed when the equipment needs to be repaired; the controllable valve is installed in the middle of the drain pipe 11 inside the box body 1. The controllable valve has a matching control device. Multiple sensors are arranged inside and outside the transformer oil tank 2. If the sensors detect an abnormal situation, they will feedback to the control device. The control device will control the solenoid valve inside the controllable valve to start, so that the heavy column drives the valve rod to rotate, so that the controllable valve is opened. At the same time, the rotation of the valve rod will also unlock the mechanical valve inside the controllable valve to be opened. The mechanical valve is installed on the nitrogen pipeline. The transformer oil tank 2 will drain oil and relieve pressure. After the pressure relief is over, the control device can also control the solenoid valve at the top of the nitrogen tank to open, so that the nitrogen in the nitrogen tank is injected into the transformer oil tank 2 to isolate oxygen and reduce the oil temperature in the transformer oil tank 2.

[0043] As Figure 1 and as Figures 5-7As shown, it should be noted that at the head of the drain pipe 11, a first pipe 21 is detachably connected to the left side of the box body 1. The tail of the first pipe 21 is detachably connected to the head of the connecting pipe 12, and the tail of the connecting pipe 12 is detachably connected to the bottom side of the transformer oil tank 2.

[0044] Sealing mechanisms are provided at various pipe connections, such as sealing gaskets, sealants, mechanical seals, or ferrule connection seals, etc.

[0045] A moving ring 31 and a fixed ring 33 are arranged inside the first pipe 21. The moving ring 31 can slide up and down inside the first pipe 21. The fixed ring 33 is fixedly connected to the inner side of the bottom of the first pipe 21. The axles of the moving ring 31 and the fixed ring 33 are both hollow grooves. The outer edge of the first circular plate 32 is fixedly connected with a protruding plate. The protruding plate can rotate around the edge of the moving ring 31, and a torsion spring is installed at the rotating part. The first circular plate 32 can open or close the hollow groove on the moving ring 31. At the same time, the second circular plate 34 is also arranged on the top surface of the fixed ring 33, and the second circular plate 34 can open or close the hollow groove on the fixed ring 33.

[0046] As Figure 5 shown, three support plates 3 are arranged on the upper surface of the moving ring 31. The bottoms of the three arc-shaped brackets 25 are respectively fixedly connected to the top surfaces of the three support plates 3. The arc-shaped brackets 25 are connected to the upper surface of the moving ring 31 through the support plates 3. The tops of the three arc-shaped brackets 25 converge at the tail of the first rod 26 and are fixedly connected to the tail of the first rod 26. The space inside the three arc-shaped brackets 25 can enable the first circular plate 32 or the second circular plate 34 to rotate.

[0047] The head of the first rod 26 penetrates through the top surface of the first pipe 21 and is detachably connected to the front side of the connecting plate 23. The air cylinder 22 is fixedly connected to the left side of the box body 1 and is located behind the grabbing rod 24. The piston rod of the air cylinder 22 is detachably connected to the rear side of the connecting plate 23. When the air cylinder 22 is started, the air cylinder 22 can drive the grabbing rod 24 to move up and down through the connecting plate 23, so that the grabbing rod 24 drives the moving ring 31 to move inside the first pipe 21. When the moving ring 31 moves upward, the first circular plate 32 is closed and the second circular plate 34 is open. The pressure-relief oil at the bottom of the connecting pipe 12 flows into the space between the moving ring 31 and the fixed ring 33 through the hollow groove of the fixed ring 33. At the same time, the moving ring 31 pushes the upper pressure-relief oil to flow into the drain pipe 11 along the first pipe 21. On the contrary, when the moving ring 31 moves downward, the first circular plate 32 is open and the second circular plate 34 is closed. The pressure-relief oil between the moving ring 31 and the fixed ring 33 flows into the upper part of the moving ring 31 through the hollow groove of the moving ring 31. The moving ring 31 moves back and forth, improving the efficiency of pressure-relief oil flow rate and pressure relief.

[0048] As Figure 5As shown in the figure, a guide rod 35 is detachably connected to the top surface of the first pipe 21. The top of the guide rod 35 penetrates through the connecting plate 23. The connecting plate 23 can move up and down along the guide rod 35. By sliding the connecting plate 23 on the guide rod 35, the stability of the grasping rod 24 moving up and down in the first pipe 21 is improved.

[0049] As Figure 1 、 Figures 5-8 shown and as Figure 9 shown, the reflux mechanism 6 includes a reflux chamber 61 fixedly connected to the tail of the drain pipe 11. The reflux chamber 61 is generally buried below the ground near the box body 1. The bottom surface of the reflux chamber 61 is set to be arc-shaped. A reflux pipe 62 is provided between the bottom surface of the reflux chamber 61 and the rear side of the first pipe 21. One end of the reflux pipe 62 is located at the lowest point of the bottom surface of the reflux chamber 61, and the other end is detachably connected to the outer side surface of the first pipe 21, and the port is located between the moving ring 31 and the fixed ring 33. At the same time, a solenoid valve is provided at this port, and the solenoid valve is also controlled by the above control device;

[0050] The top of the first rod 26 and the bottom surface of the front side of the connecting plate 23 are set to be rotatable. Tooth marks are provided on the outer side surface of the top of the first rod 26. A driving rod 63 is provided on the rear side of the first rod 26 at the top of the first pipe 21. The driving rod 63 is a telescopic rod and a protruding block engaged with the tooth marks is provided at the front end. The driving rod 63 is provided with a corresponding motor, and the rear end of the driving rod 63 is fixedly connected to the left side surface of the box body 1 through the motor housing. When the driving rod 63 is started, the front end of the driving rod 63 can push the first rod 26 to rotate on the bottom surface of the front side of the connecting plate 23, realizing the rotation of the grasping rod 24. The rotation of the grasping rod 24 can control the opening or closing of the fixing mechanism 7;

[0051] When the fixing mechanism 7 is started, the first circular plate 32 and the second circular plate 34 are always closed. Then the air cylinder 22 drives the moving ring 31 to move in the first pipe 21 through the grasping rod 24. At this time, the control device controls the solenoid valve at the port of the reflux pipe 62 to open. As the moving ring 31 moves up and down, under the action of pressure, the pressure relief oil in the reflux chamber 61 is pumped into the first pipe 21 through the reflux pipe 62, and under the extrusion of the moving ring 31, the pressure relief oil returns to the connecting pipe 12 through the extrusion valve device 75 until it returns to the transformer oil tank 2 again, so as to achieve the effect of reflux of the pressure relief oil and reduce resource waste.

[0052] As Figures 5-8 shown, the fixing mechanism 7 includes a toothed plate 71 fixedly connected to the upper surface of the moving ring 31. The toothed plate 71 is arc-shaped and is arranged along the outer edge of the upper surface of the moving ring 31. A plurality of tooth blocks are fixedly connected to the outside of the toothed plate 71. The bottom of the support plate 3 can slide on the upper surface of the moving ring 31. A rotating shaft 72 is rotatably connected to the inside of the support plate 3. A shielding plate 73 is fixedly connected to the top of the rotating shaft 72. Tooth grooves are provided on the bottom surface of the rotating shaft 72, and the tooth grooves are engaged with the tooth blocks;

[0053] When the grab bar 24 rotates, the grab bar 24 drives the support plate 3 to slide on the upper surface of the moving ring 31, so that the toothed plate 71 pushes the rotating shaft 72 to rotate through the tooth groove, so that the rotating shaft 72 drives the shielding plate 73 to move to the upper surface of the first circular plate 32, so as to achieve the effect of restricting the position of the first fixed ring 33. At the same time, the upper surface of the fixed ring 33 is also provided with a toothed plate 71, a tooth block, a support plate 3, a rotating shaft 72, a shielding plate 73 and a tooth groove; wherein a groove 74 is formed in the bottom surface of the moving ring 31, the top surface material of the groove 74 is made of transparent plastic material, a magnetic sheet is fixedly connected to the bottom surface of the support plate 3 on the moving ring 31, and a magnetic sheet is also fixedly connected to the top surface of the support plate 3 on the fixed ring 33. When the oil drainage and pressure relief and nitrogen injection fire extinguishing are over and there is no fire, the grab bar 24 drives the moving ring 31 to approach the fixed ring 33. The support plate 3 on the fixed ring 33 extends into the groove 74 and is opposite to the bottom surface of the support plate 3 on the moving ring 31. The opposite surfaces of the two magnetic sheets have opposite magnetic properties and attract each other. Therefore, the support plate 3 on the fixed ring 33 moves synchronously with the support plate 3 on the moving ring 31. Therefore, when the position of the first circular plate 32 is fixed, the fixing mechanism 7 on the fixed ring 33 also fixes the position of the second circular plate 34.

[0054] It should be noted that the present invention is a protection device for a transformer with an oil drainage and pressure control and explosion-proof nitrogen injection fire extinguishing structure. When in use, as Figure 1 - As Figure 9 shown, during the process of oil drainage and pressure relief, the oil in the transformer oil tank 2 flows into the first pipe 21 through the connecting pipe 12, and then flows from the first pipe 21 to the return bin 61 through the drain pipe 11. Among them, the air cylinder 22 drives the grab bar 24 to move through the connecting plate 23, so that the grab bar 24 drives the moving ring 31 to move cyclically. Under the cooperation of the first circular plate 32 and the second circular plate 34, the pressure relief oil continuously flows into the drain pipe 11, improving the efficiency of the pressure relief oil flow rate and pressure relief, and facilitating the timely start of the nitrogen injection work; after the pressure relief is over, the nitrogen in the nitrogen tank flows into the branch pipe assembly 5 through the nitrogen injection branch pipe 41, and the branch pipe assembly 5 makes the nitrogen evenly rush to the top of the transformer oil tank 2, so as to evenly reduce the oil temperature in the transformer oil tank 2; if a return operation is required, the fixing mechanism 7 is started. As the moving ring 31 moves cyclically, under the action of pressure, the pressure relief oil in the return bin 61 is pumped into the first pipe 21 through the return pipe 62, and then the pressure relief oil returns to the transformer oil tank 2 again through the extrusion valve device 75 and the connecting pipe 12, realizing the effect of the pressure relief oil return and reducing resource waste.

[0055] 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 by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A protection device for a transformer with an oil drainage and pressure control and explosion-proof nitrogen injection fire extinguishing structure, comprising a box body (1), a transformer oil tank (2) installed on the left side of the box body (1), and an oil discharge pipe (11) fixedly connected inside the box body (1), characterized in that: At the head of the drain pipe (11), a first pipe (21) is detachably connected to the left side of the box body (1). An air pressure mechanism (4) for pushing the pressure-relieving oil to move is arranged inside the first pipe (21). A reflux mechanism (6) for refluxing the pressure-relieving oil is arranged at the rear side of the first pipe (21). A connecting pipe (12) is detachably connected to the bottom surface of the left side of the box body (1) at the bottom of the first pipe (21). A nitrogen injection branch pipe (41) is fixedly connected inside the tail of the connecting pipe (12). One end of the nitrogen injection branch pipe (41) penetrates through the bent part of the connecting pipe (12) and extends into the box body (1). The other end of the nitrogen injection branch pipe (41) extends along the axis of the connecting pipe (12) into the transformer oil tank (2), and a branch pipe assembly (5) is arranged around the bottom of the transformer oil tank (2) and can uniformly inject nitrogen.

2. The protection device with an oil-draining pressure control and explosion-proof nitrogen injection fire extinguishing structure for a transformer according to claim 1, characterized in that: The branch pipe assembly (5) includes mounting rings (51) fixedly connected to the end of the nitrogen injection branch pipe. A plurality of the mounting rings (51) are provided. A communicating pipe (52) is detachably connected between adjacent mounting rings (51). An air outlet (57) is formed at the top of the mounting ring (51). A conical block (58) is fixedly connected to the bottom port of the air outlet (57). A vent hole (59) is formed at the axis of the conical block (58).

3. The protection device for a transformer with an oil-draining pressure control and explosion-proof nitrogen injection fire extinguishing structure according to claim 2, characterized in that: The diameter of the vent hole (59) gradually increases along the extension line of the nitrogen injection branch pipe (41) towards the transformer oil tank (2).

4. The protection device with an oil-draining pressure control and explosion-proof nitrogen injection fire extinguishing structure for a transformer according to claim 3, characterized in that: The shape of the branch pipe assembly (5) is set as a rectangle. An arc-shaped elastic plate (56) is arranged at the corner of the branch pipe assembly (5). The communicating pipe (52) is set as a flexible pipe. A nozzle (54) is detachably connected to the outer side surface of the mounting ring (51) at the top port of the air outlet (57). A valve flap group (53) is fixedly connected to the inner wall of the bottom of the nozzle (54). A ball (55) is rotatably connected to the bottom of the mounting ring (51).

5. The protection device with an oil-draining pressure control and explosion-proof nitrogen injection fire extinguishing structure for a transformer according to claim 1, characterized in that: The air pressure mechanism (4) includes a cylinder (22) fixedly connected to the left side surface of the box body. The piston rod of the cylinder (22) is detachably connected to a connecting plate (23). A grasping rod (24) is detachably connected to the bottom surface of the front side of the connecting plate (23). A moving ring (31) is arranged at the bottom of the grasping rod (24). A fixed ring (33) is fixedly connected to the inner wall at the tail of the first pipe at the bottom of the moving ring (31). A first circular plate (32) and a second circular plate (34) are respectively rotatably connected to the upper surfaces of the moving ring (31) and the fixed ring (33).

6. The protection device with an oil-draining pressure control and explosion-proof nitrogen injection fire extinguishing structure for a transformer according to claim 5, characterized in that: The grasping rod (24) includes a first rod (26) arranged at the end of the connecting plate (23). A plurality of arc-shaped brackets (25) are fixedly connected to the bottom of the first rod (26). Three arc-shaped brackets (25) are provided. A support plate (3) is fixedly connected to the bottom of the arc-shaped brackets (25).

7. The protection device with an oil-draining pressure control and explosion-proof nitrogen injection fire extinguishing structure for a transformer according to claim 6, characterized in that: A guide rod (35) is detachably connected to the top surface of the first pipe (21). The connecting plate (23) is slidably connected to the surface of the guide rod (35).

8. The protection device for a transformer with an oil-draining pressure-control and explosion-proof nitrogen-injection fire-extinguishing structure according to claim 6, characterized in that: The reflux mechanism (6) includes a reflux chamber (61) fixedly connected to the tail of the drain pipe (11). A reflux pipe (62) is detachably connected between the reflux chamber (61) and the first pipe (21). At the top of the first rod (26), a driving rod (63) is rotatably arranged at the bottom surface of the connecting plate (23). Inside the support plate (3), a fixing mechanism (7) is provided for fixing the positions of the first circular plate (32) and the second circular plate (34). On the upper surface of the second circular plate (34), a squeezing valve device (75) is installed.

9. The protection device for a transformer with an oil-draining pressure control and explosion-proof nitrogen injection fire extinguishing structure according to claim 8, characterized in that: The bottom surface of the reflux chamber (61) is set to be arc-shaped. At the lowest point of the bottom surface of the reflux chamber (61), a reflux pipe (62) is detachably connected. The tail end port of the reflux pipe (62) is detachably connected to the outer side surface of the first pipe (21). The head end of the driving rod (63) is fitted with the outer side surface of the top of the first rod (26).

10. The protection device for a transformer with an oil-draining pressure control and explosion-proof nitrogen injection fire extinguishing structure according to claim 9, characterized in that: The fixing mechanism (7) includes a toothed plate (71) fixedly connected to the upper surface of the moving ring (31). Inside the bottom of the support plate (3), a rotating shaft (72) is rotatably connected. At the top of the rotating shaft (72), a shielding plate (73) is fixedly connected. The rotating shaft (72) is fitted with the toothed plate (71). The bottom of the support plate (3) is slidably connected to the upper surface of the moving ring (31). A groove (74) is formed in the bottom surface of the moving ring (31). On the bottom surface of the support plate (3) on the moving ring (31) and the top surface of the support plate (3) on the fixed ring (33), magnetic sheets are fixedly connected and have opposite magnetic polarities.

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