A transformer and its explosion-proof structure

Abstract

This invention discloses a transformer and its explosion-proof structure. The explosion-proof structure includes an explosion-proof shell, an explosion-proof membrane, and an explosion-proof plate. One end of the explosion-proof shell can be connected to a transformer riser, and the inner cavities of the explosion-proof shell and the transformer riser are in communication. The explosion-proof plate is installed at the other end of the explosion-proof shell. The explosion-proof membrane is installed in the inner cavity of the explosion-proof shell, dividing the inner cavity into a buffer chamber and a vacuum chamber. The space between the explosion-proof membrane and the explosion-proof plate is the vacuum chamber, and the space between the explosion-proof membrane and the transformer riser is the buffer chamber. This transformer explosion-proof structure enables rapid pressure reduction when the internal pressure of the transformer tank exceeds a set value, thereby effectively reducing the explosion hazard when an internal transformer fault occurs, improving the safety performance and reliability of the equipment, and ensuring the normal operation of the power system and the safety of personnel and property. This invention has broad application prospects in the field of transformer explosion-proof protection.

Description

Technical Field

[0001] This invention belongs to the field of power equipment, specifically relating to a transformer and its explosion-proof structure. Background Technology

[0002] Power transformers are crucial equipment in power systems, playing a vital role in the transmission and use of electrical energy. Large oil-immersed transformers, in particular, bear the burden of large-scale power transmission and transformation, making their safety and normal operation paramount. Power transformers operate at high voltages. When the insulation materials deteriorate due to electrical, thermal, or mechanical factors, their performance may decline, leading to breakdown and arcing. Arcing causes the oil to crack and vaporize. The gas absorbs some of the arc energy, causing its temperature to rise and its volume to expand, while the transformer oil blocks this expansion. The pressure difference between these gases generates pressure waves. Continuous fluctuations in dynamic pressure will cause the internal pressure of the transformer to rise. When the pressure rise exceeds the maximum mechanical strength that the transformer tank or connecting components such as bolts can withstand, it can lead to major safety accidents such as tank rupture, explosion, or transformer bushing "launch." These transformer safety issues not only directly affect the normal operation of the power system but also threaten the safety of surrounding buildings, equipment, and personnel. Therefore, it is necessary to install explosion-proof protection devices for oil-immersed power transformers.

[0003] Currently, pressure relief valves are commonly used for explosion-proof protection of power transformers. However, these devices have inherent limitations, such as the opening speed being greatly affected by the pressure increase, the small effective pressure relief area, and the complex pressure relief channels of traditional pressure relief valves. These limitations result in slow response speed and untimely pressure reduction in traditional explosion-proof pressure relief devices for transformers. For large-capacity oil-immersed power transformers, when a high-energy arc fault occurs inside, the dynamic pressure inside the transformer rises sharply. At this time, the pressure relief valve cannot provide effective protection due to its inherent limitations, and local cracking and explosion of the oil tank may occur. Therefore, it is necessary to propose a new type of explosion-proof transformer structure and its design method to overcome the limitations of traditional explosion-proof pressure reduction devices. Summary of the Invention

[0004] To address the problems existing in the prior art, the purpose of this invention is to provide a transformer and its explosion-proof structure. This invention can effectively overcome the limitations of the aforementioned traditional explosion-proof pressure reducing devices.

[0005] The technical solution adopted in this invention is as follows: An explosion-proof structure for a transformer includes an explosion-proof shell, an explosion-proof membrane, and an explosion-proof plate. One end of the explosion-proof shell can be connected to a transformer riser base, and the inner cavities of the explosion-proof shell and the transformer riser base are in communication. The explosion-proof plate is installed at the other end of the explosion-proof shell. The explosion-proof membrane is installed in the inner cavity of the explosion-proof shell and divides the inner cavity of the explosion-proof shell into a buffer chamber and a vacuum chamber, wherein the space between the explosion-proof membrane and the explosion-proof plate is the vacuum chamber, and the space between the explosion-proof membrane and the transformer riser base is the buffer chamber.

[0006] Preferably, the explosion-proof housing adopts a tubular channel structure with the same diameter as the transformer riser.

[0007] Preferably, the pressure inside the vacuum chamber is lower than atmospheric pressure.

[0008] Preferably, the explosion-proof membrane adopts a plate-like structure, and the outer edge of the explosion-proof membrane is sealed to the inner wall of the explosion-proof shell.

[0009] Preferably, the surface of the explosion-proof film near the vacuum chamber has grooves.

[0010] Preferably, the depth of the grooves varies in a gradient.

[0011] Preferably, the connection strength between the explosion-proof plate and the explosion-proof shell is less than the connection strength between the transformer riser and the transformer bushing.

[0012] Preferably, the explosion-proof housing is provided with a flange structure that connects to the explosion-proof plate. The explosion-proof plate and the flange structure are connected by bolts. These bolts are the same as those between the transformer riser and the transformer bushing. The number of bolts connecting the explosion-proof plate and the flange structure is less than the number of bolts connecting the transformer riser and the transformer bushing.

[0013] The present invention also provides a transformer, including a transformer bushing, a transformer riser base, and the transformer explosion-proof structure described above. The transformer bushing is connected to the transformer riser base, and the side wall of the transformer riser base is provided with an explosion-proof port and a flange is provided at the explosion-proof port. The explosion-proof shell is connected to the flange by bolts.

[0014] The present invention has the following specific beneficial effects: In the transformer explosion-proof structure of this invention, a buffer chamber is set in the explosion-proof shell. This ensures the normal operation of the transformer riser and, when the pressure inside the riser increases, guides the surge to the explosion-proof membrane, preventing direct damage to the riser. Furthermore, the explosion-proof membrane is not directly connected to the riser, preventing deformation of the riser due to membrane deformation upon rupture, thus ensuring the riser's reusability. A vacuum chamber is also set in the explosion-proof shell, providing space for transformer oil after the explosion-proof membrane ruptures, preventing direct entry into the environment and further preventing fire hazards. Since there is no gas in the vacuum chamber, it will not expand under high temperatures, ensuring safety. The vacuum also helps guide the surge in pressure inside the riser to the explosion-proof membrane, thus protecting the riser. The explosion-proof shell and the inner cavity of the riser are directly connected. Compared to a pressure relief valve, this invention can quickly drain the transformer oil from the riser into the explosion-proof shell when the pressure inside increases, thus effectively protecting the transformer structure. In summary, the transformer explosion-proof structure of this invention enables rapid pressure reduction when the internal pressure of the transformer tank exceeds a set value, thereby effectively reducing the explosion hazard in the event of an internal transformer fault, improving the safety and reliability of the equipment, and ensuring the normal operation of the power system and the safety of personnel and property. This invention has broad application prospects in the field of transformer explosion-proof protection. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the transformer structure of the present invention.

[0016] Figure 2 This is a schematic diagram of the overall structure of the explosion-proof film of the present invention.

[0017] Figure 3 This is a simulation analysis method used in the design process of this invention.

[0018] In the diagram: 1-1 is the transformer bushing, 1-2 is the transformer riser, 1-3 is the explosion-proof enclosure, 1-4 is the vacuum chamber, 1-5 is the explosion-proof baffle, 1-6 is the explosion-proof membrane, 1-6-1 is the notch, and 1-7 is the buffer chamber. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] See Figure 1The present invention relates to a transformer, comprising a transformer bushing 1-1, a transformer riser 1-2, and an explosion-proof structure. The transformer bushing 1-1 is connected to the transformer riser 1-2. The side wall of the transformer riser 1-2 has an explosion-proof opening and a flange at the explosion-proof opening. The explosion-proof structure includes an explosion-proof shell 1-3, an explosion-proof membrane 1-6, and an explosion-proof plate 1-5. The explosion-proof shell 1-3 adopts a tubular channel structure with the same diameter as the transformer riser 1-2, and the channel diameter is approximately equal to the diameter of the transformer riser. One end of the explosion-proof shell 1-3 can be bolted to the flange on the transformer riser 1-2. The explosion-proof shell 1-3 communicates with the inner cavity of the transformer riser 1-2. The diameter of the explosion-proof opening on the transformer riser 1-2 is approximately equal to the inner diameter of the explosion-proof shell 1-3. Compared to a pressure relief valve, this explosion-proof structure has a larger oil outlet and oil inlet to increase the cross-sectional area of ​​the oil flow channel. The explosion-proof enclosure 1-3 is located on the side of the transformer riser 1-2 and is connected to the inside of the oil tank so that the explosion-proof structure can function promptly when pressure is generated inside the oil tank. The explosion-proof plate 1-5 is installed at the other end of the explosion-proof enclosure 1-3. The connection strength between the explosion-proof plate 1-5 and the explosion-proof enclosure 1-3 is less than the connection strength between the transformer riser 1-2 and the transformer bushing 1-1. The explosion-proof membrane 1-6 is installed in the inner cavity of the explosion-proof enclosure 1-3 and divides the inner cavity of the explosion-proof enclosure 1-3 into a buffer chamber 1-7 and a vacuum chamber 1-4. The space between the explosion-proof membrane 1-6 and the explosion-proof plate 1-5 is the vacuum chamber 1-4. The pressure in the vacuum chamber 1-4 is lower than the atmospheric pressure. Under normal operating conditions, this area is evacuated to form a vacuum chamber, which plays a buffering role. The space between the explosion-proof membrane 1-6 and the transformer riser 1-2 is the buffer chamber 1-7.

[0021] In a preferred embodiment of the present invention, the explosion-proof membrane 1-6 adopts a plate-like structure, and the outer edge of the explosion-proof membrane 1-6 is sealed to the inner wall of the explosion-proof housing 1-3. The surface of the explosion-proof membrane 1-6 near the vacuum chamber 1-4 is provided with a notch 1-6-1, which creates a certain stress concentration, allowing the explosion-proof membrane 1-6 to rupture promptly at the notch 1-6-1 when the tank pressure increases, thus protecting the entire transformer. Furthermore, the depth of the notch 1-6-1 varies in a gradient, which can accommodate fluctuations in the fracture strength of the explosion-proof membrane 1-6 due to variations in its material tensile strength and dimensional deviations in the notch 1-6-1, ensuring that the rupture strength of the processed explosion-proof membrane 1-6 is within a certain range, guaranteeing that the explosion-proof membrane 1-6 can be ruptured when the pressure inside the tank of the transformer riser 1-2 increases.

[0022] As an optional embodiment of the present invention, the explosion-proof housing 1-3 is provided with a flange structure connected to the explosion-proof plate 1-5. The explosion-proof plate 1-5 and the flange structure are connected by bolts, which are the same bolts used between the transformer riser seat 1-2 and the transformer bushing 1-1. The number of bolts connecting the explosion-proof plate 1-5 and the flange structure is less than the number of bolts connecting the transformer riser seat 1-2 and the transformer bushing 1-1. Therefore, the constraint force between the explosion-proof baffle 1-5 and the flange is less than the constraint force between the transformer bushing 1-1 and the riser seat flange. When the internal pressure of the transformer reaches the warning value, the explosion-proof structure will take effect first, releasing pressure in time and protecting the transformer tank and the riser seat bushing.

[0023] The transformer of the present invention can achieve rapid pressure reduction when the internal pressure of the transformer tank exceeds a set value, effectively protecting the safe operation of the transformer and improving the stability and reliability of the power system.

[0024] The design method of the explosion-proof transformer structure of the present invention includes the following steps: Step 1: Determine the rated capacity and operating pressure of the transformer.

[0025] Before designing an explosion-proof structure, it is necessary to first determine the rated capacity of the transformer and the internal pressure of the tank under normal operating conditions and fault conditions.

[0026] Step 2: Design the structure of the explosion-proof device, including a larger cross-sectional area of ​​the oil flow channel, the length of the explosion-proof device and the volume of the vacuum chamber, and select appropriate materials according to working conditions and requirements.

[0027] Step 3: Design reasonable dimensions for the serrations on the explosion-proof film, including the width and depth of the serrations.

[0028] Step 4: Conduct simulation and verification analysis to verify whether the design of the new explosion-proof structure meets the working conditions and requirements of the transformer.

[0029] For the designed explosion-proof structure, simulation and analysis are required to verify its performance and safety under different operating conditions. Through these analyses, the design scheme can be further optimized to ensure the reliability and stability of the transformer in actual operation.

[0030] Step 5: Manufacture samples and conduct experiments to verify them, and optimize the design based on the experimental results.

[0031] After completing the design scheme, samples were manufactured for experimental verification. Analysis of the experimental results allowed for further refinement and optimization of the design, ensuring that the performance and safety of the new explosion-proof structure met design requirements.

[0032] See Figure 3 The simulation analysis method in the design process of this invention includes the following steps: Step 1: Establish the geometric model: Use simulation software to create a 3D model of the transformer's explosion-proof structure. The model should include key components such as the explosion-proof shell, the internal vacuum chamber, and the explosion-proof membrane. Based on the design and parameter settings, accurately define the model's geometry, material properties, and boundary conditions.

[0033] Step 2: Determine boundary conditions and loading conditions: Based on the actual working environment and conditions, define the boundary conditions and loading conditions of the explosion-proof structure simulation model. Boundary conditions include the fixed boundaries and free boundaries of the model, and loading conditions include simulating the working state of the explosion-proof structure under rated load and overload conditions.

[0034] Step 3: Define material properties: Define appropriate physical properties for each material used in the model, such as density and Young's modulus. Obtain these property values ​​based on the actual material properties or through experimental data to ensure the accuracy of the simulation results.

[0035] Step 4: Mesh Generation: Set the size of the finite element mesh according to the accuracy requirements of the calculation results. The choice of mesh size directly affects the simulation efficiency and the accuracy of the results.

[0036] Step 5: Run the simulation: Based on the set parameters, run the simulation program to simulate and calculate the response of the transformer explosion-proof structure under different operating conditions. The simulation time depends on the complexity of the simulation and the performance of the computing resources.

[0037] Step 6: Analyze the simulation results: Analyze the simulation results, including key parameters such as temperature distribution, stress distribution, and magnetic field distribution. Through analysis of the results, evaluate the performance and safety of the explosion-proof structure and compare it with design requirements.

[0038] Step 7: Optimize the Design: Based on the simulation results, optimize the design of the transformer's explosion-proof structure. This may require adjustments to material selection, internal winding layout, and cooling system design. Continuously optimize the design to meet the transformer's operational and explosion-proof requirements.

[0039] Step 8: Verify the optimization results: Perform simulation verification on the optimized design again to ensure that the performance and safety of the explosion-proof transformer meet the design requirements.

Claims

1. A transformer explosion-proof structure, characterized in that, The device includes an explosion-proof housing (1-3), an explosion-proof membrane (1-6), and an explosion-proof plate (1-5). One end of the explosion-proof housing (1-3) can be connected to a transformer riser (1-2), and the inner cavities of the explosion-proof housing (1-3) and the transformer riser (1-2) are connected. The explosion-proof plate (1-5) is installed at the other end of the explosion-proof housing (1-3). The explosion-proof membrane (1-6) is installed in the inner cavity of the explosion-proof housing (1-3) and divides the inner cavity of the explosion-proof housing (1-3) into a buffer chamber (1-7) and a vacuum chamber (1-4). The space between the explosion-proof membrane (1-6) and the explosion-proof plate (1-5) is the vacuum chamber (1-4), and the space between the explosion-proof membrane (1-6) and the transformer riser (1-2) is the buffer chamber (1-7). The pressure inside the vacuum chamber (1-4) is lower than atmospheric pressure; The explosion-proof membrane (1-6) adopts a plate-like structure, and the outer edge of the explosion-proof membrane (1-6) is sealed to the inner wall of the explosion-proof shell (1-3); The surface of the explosion-proof membrane (1-6) near the vacuum chamber (1-4) is provided with grooves (1-6-1); the depth of the grooves (1-6-1) varies in a gradient. The connection strength between the explosion-proof plate (1-5) and the explosion-proof enclosure (1-3) is less than the connection strength between the transformer riser (1-2) and the transformer bushing (1-1); the explosion-proof enclosure (1-3) is provided with a flange structure that connects to the explosion-proof plate (1-5), and the explosion-proof plate (1-5) and the flange structure are connected by bolts. The bolts are the same as the bolts between the transformer riser (1-2) and the transformer bushing (1-1). The number of bolts connecting the explosion-proof plate (1-5) and the flange structure is less than the number of bolts connecting the transformer riser (1-2) and the transformer bushing (1-1).

2. The explosion-proof structure for a transformer according to claim 1, characterized in that, The explosion-proof enclosure (1-3) adopts a tubular channel structure with the same diameter as the transformer riser (1-2).

3. A transformer, characterized in that, The transformer includes a transformer bushing (1-1), a transformer riser (1-2), and the explosion-proof structure of the transformer as described in any one of claims 1-2. The transformer bushing (1-1) is connected to the transformer riser (1-2). The side wall of the transformer riser (1-2) is provided with an explosion-proof port and a flange is provided at the explosion-proof port. The explosion-proof housing (1-3) is connected to the flange by bolts.

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