Anti-explosion oil tank of oil-immersed transformer

Abstract

The utility model provides an anti-explosion oil tank of an oil-immersed transformer. The oil tank comprises an oil tank body, the cross section of the tank edge is of an inverted-L-shaped structure, and the bottom end of a web of the tank edge is connected with the top end of the tank wall of the oil tank body through a butt weld; and the box cover is arranged above the wing plate of the box edge, and the wing plate of the box edge is connected with the box cover. According to the utility model, the box edge of which the cross section is of the inverted L-shaped structure is adopted at the box edge part to replace the original box edge structure formed by connecting two fillet welds, and a plurality of fillet welds on the original box edge are converted into butt welds, so that the number of the fillet welds is reduced, the fillet welds are transferred from the part where stress concentration is easy to generate, and the production efficiency is improved. According to the anti-explosion oil tank, the welding joint mode between the tank edge and the tank wall is changed, meanwhile, the butt joint welding seam with better performance is adopted for connection, various mechanical properties of the butt joint welding seam are superior to those of a corner joint welding seam, and the anti-explosion capacity of the tank edge part and the oil tank is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of transformer technology, and more specifically, to an explosion-proof oil tank for an oil-immersed transformer. Background Technology

[0002] Oil-immersed electrical equipment relies on insulating oil to achieve its insulation requirements. However, as the insulating properties of the oil gradually decrease, low-resistance faults can induce arcing. During this process, the insulating oil vaporizes and decomposes, rapidly generating a large amount of high-temperature, high-pressure oil gas, which in turn generates pressure waves. As these pressure waves propagate and reflect within the tank, the pressure inside rises sharply, ultimately damaging both the electrical equipment and the tank. If the tank ruptures, the high-temperature, high-pressure oil gas will leak uncontrollably, posing a significant risk of combustion and explosion, and causing severe damage to the environment and personnel.

[0003] The existing tank edge structure consists of one or two steel plates of different thicknesses than the tank wall, connected to the tank wall at corner joints on the top and bottom edges, forming two corner welds. The relatively large number of welds makes this area a weak point in the entire tank during an arc fault, requiring it to withstand the enormous impact force of an arc explosion. Therefore, optimizing the design of this structure is essential. From a stress distribution perspective, the abrupt change in structural geometry at the corner welds easily leads to stress concentration, particularly at the weld toe, where cracks are prone to form, ultimately causing structural failure. Utility Model Content

[0004] In view of this, this utility model proposes an explosion-proof oil tank for oil-immersed transformers, which aims to solve the problem that the existing explosion-proof oil tanks have a large number of welds due to the fact that the tank edge structure is connected to the tank wall by one or two steel plates in a corner joint manner, which easily leads to stress concentration and cracks at the weld toe, resulting in structural failure.

[0005] This utility model proposes an explosion-proof oil tank for an oil-immersed transformer, which includes: an oil tank body; a tank edge with an inverted L-shaped cross-section, wherein the bottom end of the web plate of the tank edge is connected to the top end of the tank wall of the oil tank body by a butt weld; and a tank cover, which is disposed above the wing plate of the tank edge, and the wing plate of the tank edge is connected to the tank cover.

[0006] Furthermore, in the aforementioned oil-immersed transformer explosion-proof tank, both the bottom end of the tank web and the top end of the tank body wall are provided with double-sided X-bevels.

[0007] Furthermore, in the aforementioned oil-immersed transformer explosion-proof tank, the angles of the two bevels on the double-sided X-groove are different.

[0008] Furthermore, in the aforementioned oil-immersed transformer explosion-proof tank, the thickness of the web plate along the tank edge is greater than the thickness of the tank wall of the tank body.

[0009] Furthermore, in the aforementioned oil-immersed transformer explosion-proof tank, a notch is provided at the bottom of the web plate along the tank edge.

[0010] Furthermore, in the aforementioned oil-immersed transformer explosion-proof tank, the thickness of the bottom of the web plate of the tank edge gradually decreases from the position near the wing plate of the tank edge to the end of the wing plate away from the tank edge.

[0011] Furthermore, in the aforementioned oil-immersed transformer explosion-proof tank, a sealing element is also provided between the wing plate of the tank edge and the tank cover for sealing the wing plate of the tank edge and the tank cover.

[0012] Furthermore, in the aforementioned oil-immersed transformer explosion-proof tank, the sealing element is made of copper wire.

[0013] Furthermore, in the aforementioned oil-immersed transformer explosion-proof tank, the tank edge is provided with reinforcing ribs, which are arranged obliquely on the tank edge, and both ends are respectively connected to the wing plate and web plate of the tank edge.

[0014] Furthermore, in the aforementioned oil-immersed transformer explosion-proof tank, the flange of the tank edge is connected to the tank cover by an lap weld, and the end of the tank cover is provided with a single-sided bevel.

[0015] The explosion-proof oil tank for oil-immersed transformers provided by this utility model adopts an inverted L-shaped cross-section for the tank edge, replacing the original edge structure connected by two fillet welds. This transforms the multiple fillet welds on the original edge into butt welds, reducing the number of fillet welds. The bottom end of the web plate of the edge is connected to the top end of the tank wall of the main body via a butt weld, transferring the stress concentration from the fillet welds to the butt weld between the web plate and the tank wall. The stress distribution at the joint between the web plate and the tank wall is relatively uniform. This not only changes the welding joint form between the edge and the tank wall but also uses a higher-performance butt weld connection. The mechanical properties of the butt weld are superior to those of the fillet weld, significantly improving the explosion-proof capability of the edge and the tank itself. In the event of an arc fault explosion, this explosion-proof oil tank for oil-immersed transformers can withstand a greater explosive impact load, greatly improving the explosion-proof performance of the original edge area and enhancing the overall explosion-proof performance of the tank.

[0016] Furthermore, the reinforcing ribs further improve the explosion-proof performance of the tank edge, which can greatly enhance the explosion-proof performance of the fuel tank and provide better explosion protection when subjected to huge arc fault energy. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0018] Figure 1 A schematic diagram of the top structure of the explosion-proof oil tank of an oil-immersed transformer provided in this embodiment of the utility model;

[0019] Figure 2 A top view of the inner edge of the explosion-proof oil tank of an oil-immersed transformer provided in an embodiment of this utility model;

[0020] Figure 3 Cross-sectional view of the box edge provided for an embodiment of this utility model

[0021] Figure 4 This is a schematic diagram of the T-shaped structure provided in an embodiment of the present utility model;

[0022] Figure 5 A schematic diagram of the T-shaped structure cutting process provided in this embodiment of the utility model;

[0023] Explanation of reference numerals in the attached drawings: 1-Tank body, 2-Tank edge, 201-Straight tank edge, 202-Arched tank edge, 21-Body plate, 22-Flange plate, 23-Notch, 3-Tank cover, 4-Butt weld, 5-Lap weld, 6-Seal, 7-Reinforcing rib, 8-Connecting weld, 9-T-shaped steel, 91-Excess flange plate, 92-Excess thickness portion. Detailed Implementation

[0024] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] See Figures 1 to 2 The figure illustrates a preferred structure of the explosion-proof oil tank for an oil-immersed transformer provided by an embodiment of the present invention. As shown in the figure, the explosion-proof oil tank for the oil-immersed transformer includes: a tank body 1, a tank edge 2, and a tank cover 3.

[0026] The cross-section of the tank edge 2 is an inverted L-shaped structure. The bottom end of the web plate 21 of the tank edge 2 is connected to the top end of the tank wall 1 of the tank body by a butt weld 4 to form a butt joint. This connection greatly improves the strength and reliability of the tank edge structure.

[0027] Specifically, the tank body 1 may have multiple tank edges 2 along its circumference, that is, multiple tank edges 2 can be spliced ​​together to form a shape such as... Figure 2 The diagram shows a closed structure that adapts to the circumferential wall of the fuel tank body 1. Multiple tank edges 2 may include straight tank edges 201 arranged in a straight line and curved tank edges 202 with an arc. The curved tank edges 202 can be located at the corners of the fuel tank body 1 wall. There can be four straight tank edges 201 and four curved tank edges 202, forming a rectangular structure with rounded corners that adapts to the fuel tank body 1 wall. The curved tank edges 202 can be formed by bending the straight tank edges using tooling to reduce stress concentration at the fuel tank corners and create a rounded transition structure. In this embodiment, the cross-section of the tank edge 2 is an inverted L-shaped structure, including a vertically arranged web 21 and a wing plate 22 connected to the top of the web 21. The wing plate 22 and the web 21 form an inverted L-shaped structure, which can be an integral structure to ensure the stability of the tank edge 2 and avoid stress concentration. The bottom end of the web plate 21 of the tank edge 2 is connected to the top end of the tank wall of the tank body 1 by a butt weld 4. The butt weld 4 is flush with the wood, i.e., the web plate 21 and the tank wall of the tank body 1, allowing stress to be evenly transmitted along the axial direction, resulting in significantly superior performance. Furthermore, butt welding offers a significant advantage in sealing, making it particularly suitable for transformer tanks used as pressure vessels. Simultaneously, the mechanical properties of the butt weld 4 are superior to those of fillet welds, greatly improving the explosion-proof capability of the tank.

[0028] The lid 3 is positioned above the wing plate 22 of the box edge 2, and the wing plate 22 of the box edge 2 is connected to the lid 3.

[0029] Specifically, the cover 3 can be placed on top of the wing plate 22 of the tank edge 2, and the cover 3 and the wing plate 22 can be connected by a lap weld 5, that is, a lap connection is adopted. In this embodiment, the end of the cover 3 is provided with a single-sided bevel, for example, a single-sided bevel is provided facing the lower side of the oil tank 1, which can improve the welding quality of the lap weld and thus improve the strength of the explosion-proof oil tank structure.

[0030] In this embodiment, the tank cover 3 is welded to the wing plate 22 via a lap weld 5, and there is a gap between the tank cover 3 and the wing plate 22. To ensure the sealing of the top of the tank, preferably, a sealing element 6 is also provided between the wing plate 22 of the tank edge 2 and the tank cover 3 to seal the gap between the wing plate 22 of the tank edge 2 and the tank cover 3, ensuring the sealing of the top of the tank. To further improve the sealing of the tank, the sealing element 6 is made of copper wire, which can be replaced by a finer copper wire to reduce the gap between the wing plate 22 of the tank edge 2 and the tank cover 3. The inverted L-shaped cross-section of the tank edge 2, compared to the T-shaped structure, facilitates the installation of the sealing element 6 for the top cover of the tank.

[0031] See also Figure 1 The box edge 2 is provided with reinforcing ribs 7, which are obliquely arranged on the box edge 2, and their two ends are respectively connected to the wing plate 22 and the web plate 21 of the box edge 2. Specifically, reinforcing ribs 7 can be welded to the outer wing plate of the box edge 2, and the two ends of the reinforcing ribs 7 are respectively connected to the wing plate 22 and the web plate 21 of the box edge 2 by welding. In particular, the wing plate 22 and the web plate 21 of the box edge 2 can be connected by connecting welds 8, which further improves the strength of the box edge 2.

[0032] See Figure 3 This is a cross-sectional view of the tank edge provided in an embodiment of the present invention. As shown in the figure, the thickness of the web plate 21 of the tank edge 2 is greater than the thickness of the tank wall of the tank body 1, and the bottom of the web plate 21 of the tank edge 2 is provided with a notch 23 so that the web plate 21 is away from the end of the wing plate 22 of the tank edge 2 (e.g., Figure 3 The thickness of the bottom end (as shown) is matched to the wall thickness of the tank body 1, thus facilitating welding between the bottom end of the web 21 and the top end of the tank body 1, which are of the same thickness, and thus facilitating the construction of the butt weld 4. The notch 23 can be formed by variable thickness machining. In this embodiment, from the position near the wing plate 22 of the tank edge 2 to the end of the wing plate 22 away from the tank edge 2, that is, from top to bottom, the thickness of the bottom of the web 21 of the tank edge 2 gradually decreases. In other words, the depth of the notch 23 (as shown) is... Figure 3 The width in the horizontal direction shown gradually increases so that the bottom of the web 21 gradually decreases from top to bottom until it matches the thickness of the tank wall of the tank body 1. In this embodiment, the notch 23 is a chamfered notch. Of course, the notch 23 can also be a rounded corner or other structural notch. This embodiment does not limit it in any way.

[0033] In this embodiment, to improve the welding strength between the bottom end of the web plate 21 of the tank edge 2 and the top end of the tank wall 1 of the tank body, preferably, both the bottom end of the web plate 21 of the tank edge 2 and the top end of the tank wall of the tank body 1 are provided with double-sided X-grooves, and the bevel angles on both sides of the double-sided X-grooves are different. Specifically, both the bottom end of the web plate 21 of the tank edge 2 and the top end of the tank wall of the tank body 1 are provided with double-sided X-grooves, forming a V-shaped structure, and the bevel angles on both sides of the double-sided X-grooves are different. That is, during welding, asymmetrical double-sided X-grooves can be opened between the web plate 21 of the tank edge 2 and the tank wall of the tank body 1, with one large and one small double-sided X-grooves. When welding the bottom end of the web plate 21 of the tank edge 2 and the top end of the tank wall of the tank body 1, the side with the smaller bevel angle is welded first, followed by the side with the larger bevel angle, i.e., the smaller bevel area is welded first, followed by the larger bevel area, to reduce the influence of welding deformation and form a smooth welded joint.

[0034] In this embodiment, the processing of the box edge 2 includes the following steps: raw material selection step, selecting such as... Figure 4 The T-shaped steel 9 shown is used as the processing raw material for the tank edge 2. Based on the thickness of the tank body 1 wall and the actual thickness of the original tank edge in the prior art, a T-shaped steel 9 with a flange plate thickness t2 greater than or equal to the actual thickness of the tank edge and a vertical web plate thickness t1 greater than or equal to the thickness of the tank body 1 wall is selected as the processing raw material for the tank edge 2. In the processing steps, the selected T-shaped steel 9 is processed by removing excess flange plate 91 from one side of the flange plate of the T-shaped steel 9 according to the actual requirements of the tank edge. This can be done along... Figure 5 The upper dashed line shown cuts off the excess portion of the flange, i.e., the excess flange plate 91; when the thickness of the vertical web of the selected T-beam 9 is greater than the thickness of the box wall, the end of the vertical web (such as...) Figure 4 The bottom end (as shown) undergoes variable thickness chip processing to make its bottom end thickness match the box wall thickness, which can be done along... Figure 5 The lower dashed line shown cuts off the excess thickness 92 that exceeds the box wall thickness, making the thickness of the T-shaped steel 9 transition smoothly towards the box wall thickness in the vertical web direction to ensure welding quality, resulting in... Figure 3 The shown box edge 2 is ultimately processed from T-shaped steel 9 into a box edge 2 suitable for use in the explosion-proof oil tank of a sealed transformer. The original actual thickness of the box edge can be the thickness of the actual oil tank produced for a 1000kV UHV transformer. The thickness varies depending on the specific production requirements of different oil tank models, and is determined based on the transformer oil tank production process. Alternatively, in the raw material selection step, H-shaped steel can be selected, cut into suitable T-shaped steel parts, and then processed according to the above steps.

[0035] When an arc fault occurs inside the fuel tank, a huge arc shock wave acts on the tank edge, subjecting the edge to a massive dynamic impact load. The overall performance of the butt joint of the tank edge 2 is superior to that of the original fillet weld, and the sealing effect is better; at the same time, the reinforcing rib 7 can further improve the explosion-proof performance of the tank edge, which can greatly improve the explosion-proof performance of the fuel tank.

[0036] In summary, the explosion-proof oil tank of the oil-immersed transformer provided in this embodiment replaces the original edge structure, which was connected by two fillet welds, with an inverted L-shaped cross-section. This transforms the multiple fillet welds on the original edge into butt welds, reducing the number of fillet welds. The bottom end of the web of the edge is connected to the top end of the tank wall via a butt weld, transferring the stress concentration from the fillet welds to the butt weld between the web 21 and the tank wall. The stress distribution at the joint between the web 21 and the tank wall is relatively uniform. This not only changes the welding joint form between the edge and the tank wall but also utilizes a higher-performance butt weld connection. The mechanical properties of the butt weld are superior to those of the fillet weld, significantly improving the explosion-proof capability of the edge and the tank itself. When an arc fault occurs and the tank explodes, this explosion-proof oil tank of the oil-immersed transformer can withstand a larger explosive impact load, greatly improving the explosion-proof performance of the original edge and enhancing the overall explosion-proof performance of the tank.

[0037] Furthermore, the reinforcing rib 7 further improves the explosion-proof performance of the tank edge 2, which can greatly enhance the explosion-proof performance of the oil tank and provide better explosion-proof performance when subjected to huge arc fault energy.

[0038] It should be noted that in the description of this utility model, the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.

[0039] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0040] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. An explosion-proof oil tank for an oil-immersed transformer, characterized in that, include: Fuel tank body; The tank rim has an inverted L-shaped cross-section, and the bottom end of the web of the tank rim is connected to the top end of the tank wall of the tank body by a butt weld. A lid is disposed above the wing plate of the box edge, and the wing plate of the box edge is connected to the lid.

2. The explosion-proof oil tank of the oil-immersed transformer according to claim 1, characterized in that, The bottom end of the web of the tank and the top end of the tank body wall are both provided with double-sided X-bevels.

3. The explosion-proof oil tank of the oil-immersed transformer according to claim 2, characterized in that, The two sides of the double-sided X-groove have different bevel angles.

4. The explosion-proof oil tank of the oil-immersed transformer according to any one of claims 1 to 3, characterized in that, The thickness of the web plate along the tank edge is greater than the thickness of the tank wall of the tank body.

5. The explosion-proof oil tank of the oil-immersed transformer according to claim 4, characterized in that, The bottom of the web plate along the edge of the box has a notch.

6. The explosion-proof oil tank of the oil-immersed transformer according to claim 5, characterized in that, The thickness of the bottom of the web of the box edge gradually decreases from the position of the wing plate near the box edge to the end of the wing plate away from the box edge.

7. The explosion-proof oil tank of the oil-immersed transformer according to any one of claims 1 to 3, characterized in that, A sealing element is also provided between the wing plate of the box edge and the box cover to seal the gap between the wing plate of the box edge and the box cover.

8. The explosion-proof oil tank of the oil-immersed transformer according to claim 7, characterized in that, The seal is made of copper wire.

9. The explosion-proof oil tank of the oil-immersed transformer according to any one of claims 1 to 3, characterized in that, The box edge is provided with reinforcing ribs, which are arranged obliquely on the box edge, and both ends are connected to the wing plate and the web plate of the box edge, respectively.

10. The explosion-proof oil tank of the oil-immersed transformer according to any one of claims 1 to 3, characterized in that, The wing plate along the edge of the box is connected to the box cover by a lap weld, and the end of the box cover is provided with a single-sided bevel.

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