An explosion-proof oil-immersed transformer and a method for using the same

Abstract

The present application relates to the technical field of transformer, in particular to an explosion-proof oil-immersed transformer, which comprises a transformer main body, a top plate is installed on the top of the transformer main body, a pressure relief bin is assembled on one side of the top plate, the pressure relief bin is equipped with a pressure relief valve, a sleeve and a piston linkage plate structure, a cavity A is arranged in the pressure relief bin, a third pressure relief port which can be blocked by a pressure block and a first sealing gasket is arranged at the bottom of the cavity, a connecting rod, a sliding block and a first compression spring sealing assembly are assembled at the fourth pressure relief port of the bin side, the scheme utilizes the pressure relief bin and the cavity A to centrally store the oil gas generated by failure, relies on two groups of springs with different elastic forces to realize graded pressure relief, slowly releases the low-pressure gas through the fifth pressure relief port, synchronously discharges the gas in multiple channels under the linkage of short-circuit high-pressure working conditions, collects the insulating oil formed by the condensation of the oil gas in the liquid storage tank and sends it back to the equipment for reuse by a pump, improves the problem that the traditional device only sets a single pressure relief channel and adapts to fewer working conditions, and improves the overall explosion-proof effect of the transformer.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and more specifically, to an explosion-proof oil-immersed transformer and its usage method. Background Technology

[0002] During the operation of oil-immersed transformers, short circuits and localized overheating faults can cause the insulating oil to decompose, continuously generating flammable and explosive oil gases such as hydrogen and acetylene. These oil gases accumulate in the gas phase space at the top of the transformer tank. Existing protection structures mostly use a single pressure relief valve to release pressure, which can only passively spray oil to release gas when the pressure inside the tank exceeds the limit. There is a lack of a dedicated flammable gas collection structure. Some devices that add gas collection chambers rely on a single spring sealing plug to achieve on / off switching. The spring force is fixed and cannot address the two conditions of slight gas generation and instantaneous high-voltage short circuits in stages. A large amount of high-temperature oil gas that surges out during a fault is directly discharged. The oil gas carries a large amount of insulating oil mist. Without a matching oil collection and recovery structure, the oil mist easily adheres to the springs and linkage rods, forming sludge, causing the sealing components to jam and fail, and posing a risk of blockage in the pressure relief channel.

[0003] The existing protective device lacks a graded mechanical linkage structure. The spring force of the exhaust sealing spring in the gas collecting chamber is less than the spring force of the spring separating the tank from the gas collecting chamber. When a sudden short circuit causes a rapid increase in pressure inside the tank, multiple pressure relief channels cannot be opened simultaneously. Relying solely on a single pressure relief port results in insufficient instantaneous gas discharge efficiency, making the tank highly susceptible to pressure buildup and cracking. The vast majority of explosions occur only in oil-immersed power transformers. Because the interior is filled with insulating oil, the explosion is essentially caused by an internal fault generating a large amount of high-temperature oil vapor. This, combined with the external pressure buildup in the sealed oil tank, leads to tank rupture, and the oil vapor ignites upon contact with an open flame.

[0004] In view of this, we propose an explosion-proof oil-immersed transformer and its usage method. Summary of the Invention

[0005] The purpose of this invention is to provide an explosion-proof oil-immersed transformer and its usage method, in order to solve the problem mentioned in the background art that the traditional transformer has a simple pressure relief function and that the flammable gas accumulated on the upper part of the interior is not easy to be discharged.

[0006] To achieve the above objectives, the present invention provides an explosion-proof oil-immersed transformer, including a transformer body, a top plate being provided on the top of the transformer body, and a pressure relief assembly being provided on one side of the top of the top plate;

[0007] The pressure relief assembly includes a pressure relief chamber located on one side of the top of the top plate. A first exhaust port communicating with the inner cavity of the transformer body is opened at one bottom end of the pressure relief chamber. A pressure relief valve communicating with the first exhaust port is installed at one top end of the pressure relief chamber. A sleeve is provided at the output end of the pressure relief valve. A first piston is slidably arranged inside the sleeve. A first crossbar that movably passes through the end of the sleeve is fixedly connected to one end of the first piston. A connecting plate is fixedly connected to one end of the first crossbar. A second pressure relief port is opened above one end of the sleeve.

[0008] The pressure relief chamber has an internal cavity A. At the bottom of cavity A, there are third pressure relief ports that communicate with the inner cavity of the transformer body. The pressure relief chamber is symmetrically arranged with limit posts at the bottom. Two limit posts are movably connected to pressure blocks. The top of the pressure blocks is fixedly connected to insert posts at equal intervals. The bottom of multiple insert posts is fixedly connected to a first sealing gasket for sealing the third pressure relief port.

[0009] A fourth pressure relief port is provided on one side of the upper part of the pressure relief chamber. A connecting rod is movably inserted through the fourth pressure relief port. One end of the connecting rod is provided with a slider that is slidably connected to the inner wall of the pressure relief chamber. The other end of the connecting rod is fixedly connected to a first cover. A second sealing gasket for sealing the fourth pressure relief port is movably inserted through the connecting rod. A first compression spring is sleeved on the outer periphery of the connecting rod. One end of the first compression spring abuts against one side of the second sealing gasket, and the other end of the first compression spring abuts against one side of the first cover. One side of the first cover is fixedly connected to the other end of the connecting plate.

[0010] As a preferred embodiment of the present invention, the top of the pressure relief chamber is provided with a fifth pressure relief port, a vertical rod is slidably passed through the fifth pressure relief port, a third sealing gasket for sealing the fifth pressure relief port is movably passed through the vertical rod, a second cover fixedly connected to the top of the pressure relief chamber is movably passed through the vertical rod, an exhaust hole is provided on the side of the second cover, a second compression spring is sleeved on the outer periphery of the vertical rod, one end of the second compression spring abuts against the top surface of the third sealing gasket, and the other end of the second compression spring abuts against one side of the second cover.

[0011] As a preferred embodiment of the present invention, a liquid storage tank is provided below one end of the pressure relief chamber.

[0012] Preferably, the preload of the first compression spring is greater than that of the second compression spring.

[0013] As a preferred embodiment of the present invention, a support frame is fixedly installed at the top center of the top plate, a gas cylinder is engaged at the top of the support frame, an electric valve is fixedly installed at the input end of the gas cylinder, and a first diversion box is fixedly connected to the output end of the electric valve. The bottom of the first diversion box is fixedly connected to the top of the top plate.

[0014] As a preferred embodiment of the present invention, a first one-way valve and a second one-way valve are fixedly installed on one side of the first shunt box, respectively, and the output end of the first one-way valve is connected to the air inlet on the lower side of the transformer body through a pipe.

[0015] As a preferred embodiment of the present invention, the output end of the second one-way valve is connected to the lower part of the cavity A through a pipe.

[0016] As a preferred embodiment of the present invention, a micro pump is fixedly installed on the top of the top plate near the first distribution box. The input end of the micro pump is connected to the bottom of the liquid storage tank through a pipe. The output end of the micro pump is connected to the second distribution box through a pipe. The bottom of the second distribution box is fixedly connected to the top of the top plate. A one-way valve is provided on one side of the second distribution box, and one end of the valve is connected to the inner cavity of the transformer body.

[0017] As a preferred embodiment of the present invention, a first vertical plate is symmetrically arranged on one side of the top of the top plate, and a cover plate for forming a shield is hinged to the top of the first vertical plate. A second vertical plate is symmetrically arranged on the other side of the top of the top plate, and the top of the second vertical plate abuts against one end of the cover plate. A controller is arranged in the middle of the bottom of the cover plate, and the controller is electrically connected to a micro pump and an electric valve.

[0018] A method for using an explosion-proof oil-immersed transformer:

[0019] S1: The equipment is normally sealed and in standby mode. During normal operation of the transformer body, the pressure block relies on its own weight to press down and drive the first sealing gasket to seal the third pressure relief port, so that the transformer body and the cavity A of the pressure relief chamber are kept isolated. Then the first compression spring and the second compression spring respectively press the second sealing gasket and the third sealing gasket. Then the pressure relief valve, the second pressure relief port, the fourth pressure relief port and the fifth pressure relief port are all kept closed, thereby maintaining the sealed environment inside the transformer body and preventing the intrusion of external air and the leakage of normal oil and gas.

[0020] S2: Low-pressure fault graded slow release pressure relief and periodic gas replacement. When a fault inside the transformer body slowly generates flammable gas, the pressure inside the tank gradually increases and pushes open the pressure block and the first sealing gasket. Then, the flammable gas enters the cavity A through the third pressure relief port and accumulates inside. As the gas pressure inside cavity A continues to rise, based on the fact that the pre-tightening force of the first compression spring is greater than that of the second compression spring, the fifth pressure relief port opens first under low-pressure conditions, so as to slowly release the flammable gas accumulated inside cavity A, and achieve stable pressure release and exhaust. At the same time, the controller opens the electric valve according to the preset cycle. Then, the inert gas inside the gas tank is divided into two paths through the first diversion box. One path is sent to the bottom of the transformer body through the first one-way valve to replace the residual gas upward. The other path is sent into the cavity A through the second one-way valve to dilute the accumulated mixed gas, thereby reducing the risk of flammable and explosive gas accumulation.

[0021] S3: Extreme high-voltage linkage pressure relief and oil recovery and reuse. When a short-circuit fault occurs in the transformer body, causing the internal pressure to rise sharply, the high-pressure airflow enters the pressure relief valve through the first exhaust port, and then pushes the first piston and the first crossbar to drive the connecting rod to move in conjunction with the connecting plate. Then, the second pressure relief port and the fourth pressure relief port are opened. At the same time, the high-pressure airflow opens the fifth pressure relief port to complete multi-channel synchronous rapid pressure relief, reducing the risk of pressure buildup in the tank. The insulating oil mist that is released during the oil and gas flow settles and collects in the liquid storage tank. Then, the controller starts the micro pump at regular intervals. The oil accumulated in the liquid storage tank is returned to the transformer body through the second diversion box, thereby completing the recovery and reuse of insulating oil.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. By adding a pressure relief chamber and cavity A as an independent gas collection space, and then relying on the pressure block and the first sealing gasket to isolate the transformer body from cavity A under normal conditions, a graded pressure relief path is constructed by using a first compression spring and a second compression spring with a difference in pre-tightening elasticity. This allows for the slow release of gas through the fifth pressure relief port when low pressure slowly generates gas, and the simultaneous release of gas through multiple pressure relief channels when short-circuit high pressure occurs. Therefore, it can adapt to the pressure discharge requirements of different fault levels. Next, a liquid storage tank is set below cavity A to collect the insulating oil condensed from the oil and gas. Furthermore, a micro pump can transport the collected oil back to the transformer body for recycling. When a short-circuit fault generates instantaneous high-pressure airflow, the piston linkage structure inside the pipeline can simultaneously open the second, fourth, and fifth pressure relief ports. Therefore, multiple channels work together to relieve internal high pressure and reduce the accumulation of pressure inside the tank. Based on this, the shortcomings of traditional single-channel pressure relief equipment with a narrow range of operating conditions are alleviated, and the explosion-proof strength of the transformer is improved.

[0024] 2. By configuring gas tanks and a first diversion box to form a dual-path inert gas delivery structure, one path of inert gas is delivered to the bottom of the transformer body, and the other path is delivered to the cavity A. This can then dilute the combustible gas mixture remaining in the two spaces, thereby reducing the risk of gas combustion during maintenance or power restoration. The controller can then automatically complete the gas replacement and oil recovery process according to a set cycle, reducing the frequency of manual operation. Furthermore, the cover plate above the top plate can shield external rainwater and dust, slowing down the corrosion rate of moving parts such as springs and connecting rods. Based on this, it makes up for the shortcomings of traditional devices, such as the lack of a gas replacement structure, insufficient number of pressure relief channels under high-pressure conditions, and susceptibility of exposed mechanical parts to environmental corrosion. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall bottom view of the present invention;

[0026] Figure 2This is a top view of the overall structure of the present invention;

[0027] Figure 3 This is a schematic diagram of the overall side view structure of the present invention;

[0028] Figure 4 This is a bottom view of the top plate and pressure relief assembly of the present invention.

[0029] Figure 5 This is a schematic diagram of the top plate of the present invention;

[0030] Figure 6 This is a cross-sectional view of the top plate and pressure relief assembly of the present invention.

[0031] Figure 7 This is a schematic diagram of the pressure relief assembly of the present invention;

[0032] Figure 8 This is a partially enlarged cross-sectional view of the pressure relief component of the present invention;

[0033] Figure 9 This is a partial structural schematic diagram of the pressure relief component of the present invention;

[0034] Figure 10 This is a partially enlarged cross-sectional view of the pressure relief component of the present invention.

[0035] The meanings of the labels in the diagram are as follows:

[0036] 1. Transformer body; 2. Top plate; 3. First vertical plate; 301. Cover plate; 4. Controller; 5. Second vertical plate; 6. Pressure relief assembly; 601. First vent; 602. Pressure relief valve; 603. Bushing; 604. First piston; 605. First crossbar; 606. Connecting plate; 607. Second pressure relief port; 608. Pressure relief chamber; 6080. Liquid storage tank; 6081. Third pressure relief port; 6082. Fourth pressure relief port; 6083. Fifth pressure relief port; 609. Limiting post; 6 10. Pressure block; 611. Insert post; 612. First sealing gasket; 613. Sliding block; 614. Connecting rod; 615. Second sealing gasket; 616. First compression spring; 617. First cover; 618. Vertical rod; 619. Third sealing gasket; 620. Second cover; 621. Second compression spring; 7. Support frame; 8. Gas tank; 9. Electric valve; 10. First diversion box; 11. First check valve; 12. Second check valve; 13. Second diversion box; 14. Miniature pump. Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] Please see Figure 1-10 As shown, this embodiment provides an explosion-proof oil-immersed transformer. The present invention provides an explosion-proof oil-immersed transformer, which includes a transformer body 1. The transformer body 1 can carry insulating oil and internal electrical working devices. Then, a top plate 2 is provided on the top of the transformer body 1. The top plate 2 can seal and shield the upper end of the transformer body 1. Then, a pressure relief component 6 is provided on one side of the top of the top plate 2. The pressure relief component 6 can perform staged pressure relief treatment on the high-pressure oil and gas generated by internal faults of the transformer.

[0040] The pressure relief assembly 6 includes a pressure relief chamber 608 located on one side of the top of the top plate 2. The pressure relief chamber 608 provides an independent gas collection and buffer space. A first exhaust port 601, communicating with the inner cavity of the transformer body 1, is located at the bottom end of the pressure relief chamber 608. The first exhaust port 601 connects the transformer body 1 to the air passage of the pressure relief valve 602. A pressure relief valve 602, communicating with the first exhaust port 601, is installed at the top end of the pressure relief chamber 608. The pressure relief valve 602 senses instantaneous high-pressure airflow and performs initial gas guiding. A sleeve 603 is provided at the output end of the pressure relief valve 602, providing gas flow to the internal sliding components. With a regular motion guide, a first piston 604 is slidably installed inside the sleeve 603. The first piston 604 can generate linear displacement under the thrust of airflow. Then, a first crossbar 605 is fixedly connected to one end of the first piston 604 and moves through the end of the sleeve 603. The first crossbar 605 can synchronously transmit the mechanical power of the first piston 604. Then, a connecting plate 606 is fixedly connected to one end of the first crossbar 605. The connecting plate 606 can realize power transfer linkage. Then, a second pressure relief port 607 is opened above one end of the sleeve 603. The second pressure relief port 607 can release the high-pressure gas accumulated inside the pipeline after the linkage is triggered.

[0041] The pressure relief chamber 608 has an internal cavity A, which can temporarily store the combustible oil gas discharged from the transformer. Then, at the bottom of the cavity A, there are third pressure relief ports 6081 that communicate with the inner cavity of the transformer body 1. The third pressure relief port 6081 can serve as the main ventilation channel between the transformer body 1 and the cavity A. Next, symmetrical limit posts 609 are arranged at the bottom of the interior of the pressure relief chamber 608. The limit posts 609 can restrict the vertical movement trajectory of the pressure block 610. Then, the pressure block 610 is movably inserted through the two limit posts 609. The pressure block 610 can achieve normal sealing and compression by its own weight. Next, the top of the pressure block 610 is fixedly inserted through the equidistant insertion post 611. The insertion post 611 can transmit the compression force of the pressure block 610. Then, the bottom of the multiple insertion posts 611 is fixedly connected to the first sealing gasket 612 for sealing the third pressure relief port 6081. The first sealing gasket 612 can fit the third pressure relief port 6081 to achieve normal airtight isolation.

[0042] A fourth pressure relief port 6082 is provided on one side of the upper part of the pressure relief chamber 608. The fourth pressure relief port 6082 can serve as an auxiliary pressure relief channel under high-pressure linkage conditions. A connecting rod 614 is movably inserted through the fourth pressure relief port 6082. The connecting rod 614 can drive the sealing component to complete the opening and closing action. Then, one end of the connecting rod 614 is provided with a slider 613 that is slidably connected to the inner wall of the pressure relief chamber 608. The slider 613 can ensure the smoothness of the sliding process of the connecting rod 614. Then, the other end of the connecting rod 614 is fixedly connected to a first cover 617. The first cover 617 can provide an end support point for the first compression spring 616. Then, the connecting rod 61... 4. A second sealing gasket 615 is used to seal the fourth pressure relief port 6082. The second sealing gasket 615 can normally seal and block the fourth pressure relief port 6082. Then, a first compression spring 616 is sleeved on the outer periphery of the connecting rod 614. The first compression spring 616 can continuously provide sealing pre-tightening force to the second sealing gasket 615. Then, one end of the first compression spring 616 abuts against one side of the second sealing gasket 615, and the other end of the first compression spring 616 abuts against one side of the first cover 617. Then, one side of the first cover 617 is fixedly connected to the other end of the connecting plate 606. Based on this, the linkage power can be received and the pressure relief channel can be opened.

[0043] The pressure relief chamber 608 has a fifth pressure relief port 6083 at its top, which serves as the main channel for slow-release pressure relief. A vertical rod 618 slides through the fifth pressure relief port 6083, and can drive the sealing component to move vertically to achieve on / off switching. A third sealing gasket 619 for sealing the fifth pressure relief port 6083 then moves through the vertical rod 618, maintaining the port's normal sealing state. A second cover 620, fixedly connected to the top of the pressure relief chamber 608, then moves through the vertical rod 618, providing support for the sliding movement of the vertical rod 618. An exhaust port is located on the side of the second cover 620 to allow the released gas to pass through. A second compression spring 621 is fitted around the outer periphery of the 8. The second compression spring 621 can provide basic sealing elasticity for the third sealing gasket 619. Then, one end of the second compression spring 621 abuts against the top surface of the third sealing gasket 619, and the other end of the second compression spring 621 abuts against one side of the second cover 620. Furthermore, it can adapt to the pressure relief opening requirements of low pressure slow release. A liquid storage tank 6080 is opened below one end of the pressure relief chamber 608. The liquid storage tank 6080 can collect the insulating oil liquid condensed from the oil and gas, so that the waste oil liquid can be centrally collected. The pre-tightening elasticity of the first compression spring 616 is greater than that of the second compression spring 621, so that the opening pressure of the fourth pressure relief port 6082 is higher than that of the fifth pressure relief port 6083. In summary, the working effect of high and low pressure staged pressure relief is achieved.

[0044] A support frame 7 is fixedly installed at the top center of the top plate 2. The support frame 7 can stably support the installation load of the gas tank 8. The gas tank 8 is then snapped onto the top of the support frame 7. The gas tank 8 can store inert gas for gas replacement. Next, an electric valve 9 is fixedly installed at the input end of the gas tank 8. The electric valve 9 can control the output of the inert gas. Then, a first diversion box 10 is fixedly connected to the output end of the electric valve 9. The first diversion box 10 can realize the diversion and delivery of inert gas. Next, the bottom of the first diversion box 10 is fixedly connected to the top of the top plate 2, thereby ensuring the installation stability of the gas circuit structure.

[0045] A first one-way valve 11 and a second one-way valve 12 are fixedly installed on the upper and lower sides of one side of the first diversion box 10, respectively. The first one-way valve 11 can prevent the backflow of gas inside the transformer. The output end of the first one-way valve 11 is connected to the air inlet on the lower side of the transformer body 1 through a pipe, so that inert gas can be sent into the bottom of the transformer to achieve upward displacement. Then, the second one-way valve 12 can prevent the backflow of oil and gas inside cavity A. The output end of the second one-way valve 12 is connected to the lower part of cavity A through a pipe, so that the mixed gas inside cavity A can be diluted and replaced. A micro pump 14 is fixedly installed on the top of the top plate 2 near the first diversion box 10. The micro pump 14 can provide power for the recovery and transportation of insulating oil. The input end of the micro pump 14 is connected to the bottom of the liquid storage tank 6080 through a pipe, and the pipe can smoothly draw the oil accumulated inside the liquid storage tank 6080. Next, the output end of the micro pump 14 is connected to the second diversion box 13 through a pipeline. The second diversion box 13 can transfer and transport the recovered insulating oil. Then, the bottom of the second diversion box 13 is fixedly connected to the top of the top plate 2. A one-way valve is provided on one side of the second diversion box 13. The one-way valve can prevent the backflow of oil and gas inside the transformer from contaminating the pump body pipeline. One end of the valve is connected to the inner cavity of the transformer body 1, so that the recovered insulating oil can be sent back to the equipment for reuse.

[0046] A first vertical plate 3 is symmetrically arranged on one side of the top of the top plate 2. The first vertical plate 3 can provide a hinge support point for the cover plate 301. The top of the first vertical plate 3 is hinged to the cover plate 301 to form a shield. The cover plate 301 can shield the top equipment structure and reduce external environmental interference. Then, a second vertical plate 5 is symmetrically arranged on the other side of the top of the top plate 2. The second vertical plate 5 can support and limit the closed end of the cover plate 301. Then, the top of the second vertical plate 5 abuts against one end of the cover plate 301. A controller 4 is arranged in the middle of the bottom of the cover plate 301. The controller 4 can control the operation sequence of the electrical components of the equipment. The controller 4 is electrically connected to the micro pump 14 and the electric valve 9, so that the gas replacement and oil recovery processes can be completed automatically.

[0047] It should be noted that the controller 4, the micro pump 14, and the electric valve 9 all use commercially available and mature equipment. The power supply logic, signal acquisition logic, and data transmission logic between the entire set of electrical components are all existing mature control technologies. This application does not make any improvements to the circuit control program and electrical connection method. Therefore, the relevant control principles and circuit layout logic will not be described in detail here.

[0048] A method for using an explosion-proof oil-immersed transformer:

[0049] S1: First, the equipment is in a normally sealed standby state. During the normal operation of the transformer body 1, the pressure block 610 relies on its own weight to press down and drive the first sealing gasket 612 to block the third pressure relief port 6081, so that the transformer body 1 and the cavity A of the pressure relief chamber 608 are kept isolated. The first compression spring 616 and the second compression spring 621 respectively press the second sealing gasket 615 and the third sealing gasket 619. Then, the pressure relief valve 602, the second pressure relief port 607, the fourth pressure relief port 6082 and the fifth pressure relief port 6083 are all kept closed, thereby maintaining the sealed environment inside the transformer body 1, preventing the intrusion of external air and the leakage of normal oil and gas, thus ensuring the cleanliness of the oil for a long time.

[0050] S2: Low-pressure fault graded slow release pressure relief and periodic gas replacement. When a fault inside the transformer body 1 slowly generates flammable gas, the pressure inside the tank gradually increases and pushes open the pressure block 610 and the first sealing gasket 612. Then, the flammable gas enters the cavity A through the third pressure relief port 6081 and accumulates inside. As the gas pressure inside the cavity A continues to rise, since the pre-tightening force of the first compression spring 616 is greater than the pre-tightening force of the second compression spring 621, the fifth pressure relief port 6083 opens first under low-pressure conditions, so as to slowly release the flammable gas accumulated inside the cavity A, and achieve stable pressure release and exhaust. At the same time, the controller 4 opens the electric valve 9 according to the preset cycle. Then, the inert gas inside the gas tank 8 is divided into two paths through the first diversion box 10. One path is sent to the bottom of the transformer body 1 through the first one-way valve 11 to replace the residual gas upward. The other path is sent into the cavity A through the second one-way valve 12 to dilute the accumulated mixed gas, thereby reducing the risk of flammable and explosive gas accumulation and thus reducing the probability of explosion.

[0051] S3: Extreme high-voltage linkage pressure relief and oil recovery and reuse. When a short-circuit fault occurs in the transformer body 1, causing a sharp rise in internal pressure, the high-pressure airflow enters the pressure relief valve 602 through the first exhaust port 601. Then, it pushes the first piston 604 and the first crossbar 605, which, together with the connecting plate 606, drive the connecting rod 614 to move. Immediately afterwards, the second pressure relief port 607 and the fourth pressure relief port 6082 are opened. At the same time, the high-pressure airflow opens the fifth pressure relief port 6083 to complete multi-channel synchronous rapid pressure relief, reducing the risk of pressure buildup in the tank. The insulating oil mist that is released during the oil and gas flow settles and collects inside the liquid storage tank 6080. The controller 4 starts the micro pump 14 at regular intervals. The oil accumulated inside the liquid storage tank 6080 is returned to the transformer body 1 through the second diversion box 13, thereby completing the recovery and reuse of insulating oil and achieving the effect of oil saving.

[0052] Working principle: Under normal operating conditions, the transformer body 1 remains sealed, the pressure relief assembly 6 is in a closed standby state, the pressure relief valve 602 and the second pressure relief port 607 remain closed, and the first compression spring 616 and the second compression spring 621 respectively press the second sealing gasket 615 and the third sealing gasket 619. The fourth pressure relief port 6082 and the fifth pressure relief port 6083 remain closed under normal conditions. The pressure block 610 presses down by its own weight, causing the first sealing gasket 612 to press and seal the third pressure relief port 6081. Then, the transformer body 1 and the cavity A inside the pressure relief chamber 608 are mutually isolated, thereby preventing outside air from entering the equipment and preventing oil and gas leakage during normal operation.

[0053] When a fault occurs inside the transformer body 1 and flammable gas is slowly generated, the internal pressure of the tank will gradually increase slightly. Then, the internal gas pressure pushes the pressure block 610 and the first sealing gasket 612 upwards. Immediately afterwards, the third pressure relief port 6081 is opened smoothly, and the explosive gas generated inside the transformer body 1 can smoothly enter the cavity A and collect. As the gas pressure inside the cavity A gradually accumulates and increases, the internal gas pressure will continue to act on the fifth pressure relief port 6083. Since the pre-tightening force of the first compression spring 616 is greater than that of the second compression spring 621, the opening pressure of the fifth pressure relief port 6083 is lower. Then, the gas inside the cavity A pushes open the third sealing gasket 619, thereby slowly and smoothly releasing the explosive gas accumulated inside the cavity A, thus achieving the working effect of low-pressure slow pressure relief and avoiding the situation of rapid pressure accumulation.

[0054] During normal operation, the controller 4 will automatically start working according to the preset cycle. Then, the controller 4 controls the opening of the electric valve 9, and the inert gas stored in the gas tank 8 can stably enter the first diversion box 10. Then, the first diversion box 10 divides the inert gas into two independent gas paths. One inert gas is sent into the lower part of the transformer body 1 through the first one-way valve 11, slowly replacing the trace amount of combustible gas remaining in the tank from bottom to top. The other inert gas is introduced into the cavity A through the second one-way valve 12, which can squeeze and dilute the mixed gas accumulated in the cavity A, thereby completing the gas replacement operation of the entire transformer and reducing the safety hazards caused by the long-term accumulation of combustible gas.

[0055] During the process of oil and gas gathering and depressurizing inside cavity A, the insulating oil mist carried by the oil and gas will gradually condense and settle. Then, the oil will naturally gather and flow into the storage tank 6080 at the bottom of the pressure relief chamber 608 for temporary storage. Then, the controller 4 will start the micro pump 14 at regular intervals. The micro pump 14 will draw out the insulating oil accumulated inside the storage tank 6080 and then transport the oil back to the transformer body 1 through the second diversion box 13 in conjunction with the one-way valve. This can realize the recycling and reuse of insulating oil and reduce oil consumption.

[0056] When a short circuit fault occurs in the transformer body 1, causing a sharp increase in internal pressure, the instantaneous high-pressure airflow in the tank will act on the inside of the pressure relief valve 602 through the first exhaust port 601, and then push the first piston 604 inside the bushing 603 to move. Immediately afterwards, the first piston 604 drives the connecting rod 614 to move in linkage through the first crossbar 605 and the connecting plate 606, thereby opening the second sealing gasket 615 and opening the fourth pressure relief port 6082. The high-pressure airflow simultaneously opens the second pressure relief port 607 and the fifth pressure relief port 6083. In summary, multiple pressure relief channels are simultaneously connected, thereby achieving instantaneous large-flow pressure relief, which is suitable for the extreme high-pressure fault conditions of the transformer.

[0057] 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 preferred examples and are not intended to limit 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 the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An explosion-proof oil-immersed transformer, comprising a transformer body (1), characterized in that: The transformer body (1) is provided with a top plate (2) on the top, and a pressure relief assembly (6) is provided on one side of the top of the top plate (2). The pressure relief assembly (6) includes a pressure relief chamber (608) disposed on one side of the top of the top plate (2). The bottom end of the pressure relief chamber (608) is provided with a first exhaust port (601) communicating with the inner cavity of the transformer body (1). The top end of the pressure relief chamber (608) is provided with a pressure relief valve (602) communicating with the first exhaust port (601). The output end of the pressure relief valve (602) is provided with a sleeve (603). A first piston (604) is slidably disposed inside the sleeve (603). One end of the first piston (604) is fixedly connected to a first crossbar (605) that movably passes through the end of the sleeve (603). One end of the first crossbar (605) is fixedly connected to a connecting plate (606). A second pressure relief port (607) is provided above one end of the sleeve (603). The pressure relief chamber (608) has an internal cavity A. The bottom of the cavity A has a third pressure relief port (6081) that communicates with the inner cavity of the transformer body (1) at equal intervals. The pressure relief chamber (608) has symmetrically arranged limit posts (609) at the bottom. The two limit posts (609) are movably connected to the pressure block (610). The top of the pressure block (610) is fixedly connected to the insert post (611) at equal intervals. The bottom of the multiple insert posts (611) is fixedly connected to a first sealing gasket (612) for sealing the third pressure relief port (6081). A fourth pressure relief port (6082) is provided on one side above the pressure relief chamber (608). A connecting rod (614) is movably inserted through the fourth pressure relief port (6082). One end of the connecting rod (614) is provided with a slider (613) that is slidably connected to the inner wall of the pressure relief chamber (608). The other end of the connecting rod (614) is fixedly connected to a first cover (617). A second sealing gasket (615) for sealing the fourth pressure relief port (6082) is movably inserted through the connecting rod (614). A first compression spring (616) is sleeved on the outer periphery of the connecting rod (614). One end of the first compression spring (616) abuts against one side of the second sealing gasket (615), and the other end of the first compression spring (616) abuts against one side of the first cover (617). One side of the first cover (617) is fixedly connected to the other end of the connecting plate (606).

2. The explosion-proof oil-immersed transformer according to claim 1, characterized in that: The pressure relief chamber (608) has a fifth pressure relief port (6083) at its top. A vertical rod (618) slides through the fifth pressure relief port (6083). A third sealing gasket (619) for sealing the fifth pressure relief port (6083) is movably passed through the vertical rod (618). A second cover (620) is fixedly connected to the top of the pressure relief chamber (608) through the vertical rod (618). An exhaust hole is provided on the side of the second cover (620). A second compression spring (621) is sleeved on the outer periphery of the vertical rod (618). One end of the second compression spring (621) abuts against the top surface of the third sealing gasket (619), and the other end of the second compression spring (621) abuts against one side of the second cover (620).

3. The explosion-proof oil-immersed transformer according to claim 2, characterized in that: A liquid storage tank (6080) is provided below one end of the pressure relief chamber (608).

4. The explosion-proof oil-immersed transformer according to claim 3, characterized in that: The preload force of the first compression spring (616) is greater than that of the second compression spring (621).

5. The explosion-proof oil-immersed transformer according to claim 4, characterized in that: A support frame (7) is fixedly installed at the top center of the top plate (2). A gas tank (8) is fitted onto the top of the support frame (7). An electric valve (9) is fixedly installed at the input end of the gas tank (8). A first diversion box (10) is fixedly connected to the output end of the electric valve (9). The bottom of the first diversion box (10) is fixedly connected to the top of the top plate (2).

6. The explosion-proof oil-immersed transformer according to claim 5, characterized in that: The first one-way valve (11) and the second one-way valve (12) are fixedly installed on one side of the first shunt box (10) at the top and bottom respectively. The output end of the first one-way valve (11) is connected to the air inlet on the lower side of the transformer body (1) through a pipe.

7. The explosion-proof oil-immersed transformer according to claim 6, characterized in that: The output end of the second one-way valve (12) is connected to the lower part of the cavity A through a pipe.

8. The explosion-proof oil-immersed transformer according to claim 7, characterized in that: A micro pump (14) is fixedly installed on the top of the top plate (2) near the first diversion box (10). The input end of the micro pump (14) is connected to the bottom of the liquid storage tank (6080) through a pipe. The output end of the micro pump (14) is connected to the second diversion box (13) through a pipe. The bottom of the second diversion box (13) is fixedly connected to the top of the top plate (2). A one-way valve is provided on one side of the second diversion box (13), and one end of the valve is connected to the inner cavity of the transformer body (1).

9. An explosion-proof oil-immersed transformer according to claim 8, characterized in that: A first vertical plate (3) is symmetrically arranged on one side of the top of the top plate (2). A cover plate (301) for forming a shield is hinged to the top of the first vertical plate (3). A second vertical plate (5) is symmetrically arranged at the other end of the top of the top plate (2). The top of the second vertical plate (5) abuts against one end of the cover plate (301). A controller (4) is arranged in the middle of the bottom of the cover plate (301). The controller (4) is electrically connected to the micro pump (14) and the electric valve (9).

10. A method of using an explosion-proof oil-immersed transformer according to any one of claims 1-9, characterized in that: Includes the following steps: S1: The equipment is normally sealed and in standby mode. During normal operation of the transformer body (1), the pressure block (610) presses down by its own weight to drive the first sealing gasket (612) to block the third pressure relief port (6081), so that the transformer body (1) and the cavity A of the pressure relief chamber (608) are kept isolated. Then the first compression spring (616) and the second compression spring (621) respectively press the second sealing gasket (615) and the third sealing gasket (619). Then the pressure relief valve (602), the second pressure relief port (607), the fourth pressure relief port (6082) and the fifth pressure relief port (6083) are all kept closed, so as to maintain the sealed environment inside the transformer body (1) and prevent the intrusion of external air and the leakage of normal oil and gas. S2: Low-pressure fault graded slow release and periodic gas replacement. When the internal fault of the transformer body (1) slowly generates flammable gas, the pressure inside the tank gradually increases and pushes open the pressure block (610) and the first sealing gasket (612). Then, the flammable gas enters the cavity A through the third pressure relief port (6081) and accumulates. As the gas pressure inside the cavity A continues to rise, based on the fact that the pre-tightening force of the first compression spring (616) is greater than that of the second compression spring (621), the fifth pressure relief port (6083) is opened first under low pressure, so that the flammable gas accumulated inside the cavity A can be slowly released, and the pressure is stabilized and the gas is slowly released. At the same time, the controller (4) opens the electric valve (9) according to the preset cycle. Then, the inert gas inside the gas tank (8) is divided into two paths through the first diversion box (10). One path is sent to the bottom of the transformer body (1) through the first one-way valve (11) to replace the residual gas upward. The other path is sent into the cavity A through the second one-way valve (12) to dilute the accumulated mixed gas, thereby reducing the risk of flammable and explosive gas accumulation. S3: Extreme high-voltage linkage pressure relief and oil recovery and reuse. When the transformer body (1) experiences a short circuit fault, causing the internal pressure to surge rapidly, the high-pressure airflow enters the pressure relief valve (602) through the first exhaust port (601), and then pushes the first piston (604), the first crossbar (605) and the connecting plate (606) to drive the connecting rod (614) to move. Then, the second pressure relief port (607) and the fourth pressure relief port (6082) are opened. At the same time, the high-pressure airflow pushes open the fifth pressure relief port (6083) to complete multi-channel synchronous rapid pressure relief, reducing the risk of pressure buildup in the tank. The insulating oil mist precipitated during the oil and gas flow process settles and collects inside the storage tank (6080). Then, the controller (4) starts the micro pump (14) at regular intervals. The oil accumulated inside the storage tank (6080) is returned to the transformer body (1) through the second diversion box (13), thereby completing the recovery and reuse of insulating oil.

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