Sealing structure of voltage transformer and gas insulated combined voltage transformer

Abstract

The application discloses a sealing structure of a voltage transformer and a gas-insulated composite voltage transformer, and comprises a sealing element, wherein the sealing element is an annular structure made of a non-rigid material, a tank opening accommodating groove is arranged at a tank opening of a tank, an inner side wall of a cover is provided with a cover accommodating groove, the sealing element is arranged between the tank opening accommodating groove and the cover accommodating groove, and the tank opening accommodating groove and the cover accommodating groove axially extrude the sealing element. The conventional sealing structure is usually arranged between the tank opening and the cover, axial extrusion is adopted to realize radial sealing, and the conventional sealing mode only adopts one-way sealing, so that once the sealing structure is damaged or reaches the service life, the gas leakage will occur. The application also adopts axial extrusion of the sealing element, but because the tank opening accommodating groove and the cover accommodating groove are arranged, when the sealing element is axially extruded, axial sealing and radial sealing can be realized, and the risk of gas leakage is greatly reduced through bidirectional sealing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transformers, and more particularly to a sealing structure of a voltage transformer and a gas-insulated composite voltage transformer. BACKGROUND

[0002] At present, the voltage transformers used in high-voltage power grids are still mainly oil-immersed voltage transformers, which account for more than 50% of the total number of high-voltage transformers in power grids. The oil-immersed transformers have been in use for a long time, and users are very familiar with their use methods and maintenance points. Moreover, the oil-immersed transformers are low in price and are still used in large quantities in power grids used earlier. However, the oil-immersed transformers are large in size and heavy in maintenance workload, and are prone to fire and explosion. Therefore, the oil-immersed transformers are rarely used in newly-built power grids, and are replaced by high-voltage SF6 gas-insulated voltage transformers. In order to meet the intelligent development trend of power plants, the applicant has developed a series of multifunctional voltage transformers using SF6 gas as the insulating medium based on the design concept of combined electrical apparatus. The series of products are pot-shaped closed metal shells, and SF6 gas is used to realize insulation and arc extinguishing. The series of products have the advantages of small size, low dielectric loss, maintenance-free, low temperature rise, large capacity, high safety and reliability and the like. Although the SF6 gas has excellent performance, the greenhouse effect of the SF6 gas is 23500 times that of CO2. Therefore, the emission, sealing and recovery of the gas are required to be very strict, and the use of the SF6 gas has been legislated by the European Union. Therefore, how to ensure the sealing property of the voltage transformer and prevent the SF6 gas from leaking is an important research topic and direction in the industry, and is also a technical problem to be solved by the present application. SUMMARY

[0003] A series of simplified concepts are introduced in the summary section, which will be further described in detail in the specific embodiment section. The summary section of the present application does not mean to attempt to limit the key features and necessary technical features of the claimed technical solution, and does not mean to attempt to determine the protection scope of the claimed technical solution.

[0004] To at least partially solve the above problems, the present application provides a sealing structure of a voltage transformer, which comprises a sealing member made of a non-rigid material in an annular structure. A tank opening of a tank is provided with a tank opening accommodating groove, and an inner side wall of a cover is provided with a cover accommodating groove. The sealing member is arranged between the tank opening accommodating groove and the cover accommodating groove, and the tank opening accommodating groove and the cover accommodating groove axially extrude the sealing member.

[0005] Preferably, the tank mouth setting groove is a first tank mouth setting groove, the cover setting groove is a first cover setting groove, the sealing element is a first sealing element, the first tank mouth setting groove is an annular groove provided on the inner wall of the tank mouth, the first cover setting groove is an annular groove provided on the inner wall of the cover, the first tank mouth setting groove and the first cover setting groove are in communication to form an annular containing groove when the cover is connected to the tank mouth, and the first sealing element is arranged in the containing groove, the inner top surface of the first cover setting groove abuts against the top surface of the first sealing element, and the inner bottom surface of the first tank mouth setting groove abuts against the bottom surface of the first sealing element.

[0006] Preferably, the first sealing element has an arc-shaped inner annular surface and an arc-shaped outer annular surface, the top surface and the bottom surface of the first sealing element are both flat surfaces, and the outer annular surface is provided with a first annular groove in the circumferential direction, and the joint between the tank mouth and the cover is opposite to the opening of the first annular groove when the tank mouth is connected to the cover.

[0007] Preferably, the top surface of the first sealing element is provided with a first abutting ring which extends away from the top surface of the first sealing element.

[0008] Preferably, the bottom surface of the first sealing element is provided with a second abutting ring which extends away from the bottom surface of the first sealing element.

[0009] Preferably, the tank mouth setting groove is a second tank mouth setting groove, the cover setting groove is a second cover setting groove, and the sealing element is a second sealing element, the second tank mouth setting groove is an annular groove provided on the outer wall of the tank mouth, the second cover setting groove is an annular groove provided on the inner wall of the cover, the inner bottom surface of the second tank mouth setting groove is opposite to the inner top surface of the second cover setting groove when the cover is connected to the tank mouth, and the second sealing element is located between the inner bottom surface of the second tank mouth setting groove and the inner top surface of the second cover setting groove.

[0010] Preferably, the top portion of the second sealing element is provided with a second annular groove, the inner top surface of the second cover setting groove is provided with a limiting ring, and the limiting ring is located in the second annular groove.

[0011] Preferably, the outer wall of the second tank mouth setting groove abuts against the inner wall of the second sealing element and extends into the cover to abut against the inner wall of the cover, and the inner wall of the second cover setting groove abuts against the outer wall of the second sealing element and extends in the direction of the containing tank to abut against the outer wall of the tank mouth.

[0012] A gas-insulated composite voltage transformer includes a containing tank and a cover, and further includes a sealing structure of the voltage transformer, the inner wall of the tank mouth of the containing tank is provided with a first tank mouth setting groove, the inner wall of the cover is provided with a first cover setting groove, and the first sealing element is arranged between the first tank mouth setting groove and the first cover setting groove.

[0013] The gas-insulated composite voltage transformer comprises a containing tank and a cover, and further comprises a sealing structure of the voltage transformer, an outer wall of a tank opening is provided with a second tank opening accommodating groove, an inner wall of the cover is provided with a second cover accommodating groove, and the second sealing element is arranged between the second tank opening accommodating groove and the second cover accommodating groove, and an annular third sealing element is arranged between the cover and the containing tank.

[0014] Compared with the prior art, the present application at least has the following beneficial effects:

[0015] The conventional sealing structure is usually arranged between the tank opening and the cover, and realizes radial sealing through axial extrusion, and because only one-way sealing is adopted, once the sealing structure is damaged or reaches the service life, the gas leakage will occur. The axial extrusion sealing element is also adopted in the present application, but because the tank opening accommodating groove and the cover accommodating groove are arranged, the sealing element can realize axial sealing and radial sealing when being axially extruded, and the risk of gas leakage is greatly reduced through the two-way sealing.

[0016] The sealing structure of the voltage transformer and the gas-insulated composite voltage transformer, other advantages, objects and features of the present application will be embodied in part through the following description, and will be understood by those skilled in the art through research and practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, and are used to explain the present application together with embodiments of the present application, and do not constitute a limitation on the present application. In the drawings:

[0018] Figure 1 When the sealing structure of the voltage transformer adopts the first embodiment, a schematic diagram of the gas-insulated composite voltage transformer.

[0019] Figure 2 A structural schematic diagram of the first embodiment of the sealing structure of the voltage transformer.

[0020] Figure 3 A partial sectional view of the first embodiment of the sealing structure of the voltage transformer.

[0021] Figure 4 When the sealing structure of the voltage transformer adopts the first embodiment, a schematic diagram of the sealing.

[0022] Figure 5 When the sealing structure of the voltage transformer adopts the second embodiment, a schematic diagram of the gas-insulated composite voltage transformer.

[0023] Figure 6The schematic diagram of the gas insulation composite voltage transformer when the sealing structure of the voltage transformer adopts the second embodiment.

[0024] Figure 7 The exploded view of the gas insulation composite voltage transformer when the sealing structure of the voltage transformer adopts the second embodiment.

[0025] Figure 8 The partial schematic diagram of the sealing structure of the voltage transformer. Figure 7

[0026] Figure 9 The schematic diagram of the sealing when the sealing structure of the voltage transformer adopts the second embodiment.

[0027] In the figure: 100, the containing tank; 101, the tank mouth; 200, the cover; 1, the first tank mouth setting groove; 2, the first cover setting groove; 3, the first sealing element; 31, the first ring groove; 32, the first abutting ring; 33, the second abutting ring; 4, the second tank mouth setting groove; 5, the second cover setting groove; 51, the limiting ring; 6, the second sealing element; 61, the second ring groove; 7, the third sealing element. DETAILED DESCRIPTION

[0028] The application will be further described in detail below with reference to the accompanying drawings and examples, so that those skilled in the art can implement the application according to the description.

[0029] It should be understood that the terms such as "have", "contain" and "include" used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0030] As shown in the drawings, the application provides a sealing structure of a voltage transformer, which comprises a sealing element, the sealing element is an annular structure made of a non-rigid material, a tank mouth setting groove is arranged at the tank mouth 101 of the containing tank 100, and an inner side wall of the cover 200 is provided with a cover setting groove, the sealing element is arranged between the tank mouth setting groove and the cover setting groove, and the tank mouth setting groove and the cover setting groove axially extrude the sealing element. Figures 1-9 The conventional sealing structure is usually arranged between the tank mouth 101 and the cover 200, and the radial sealing is realized through axial extrusion, as shown in the third sealing element 7 in the drawings. Figure 2 Figure 9 The conventional sealing mode will cause gas leakage once the sealing structure is damaged or reaches the service life because only one-way sealing is adopted. The application also adopts axial extrusion of the sealing element, but because the tank mouth setting groove and the cover setting groove are arranged, the sealing element can realize axial sealing and radial sealing when being axially extruded, and the risk of gas leakage is greatly reduced through two-way sealing. As one of the many embodiments, the application provides two different embodiments for realizing two-way radial and axial sealing. ​​

[0031] In the first embodiment, the jar mouth accommodating groove is a first jar mouth accommodating groove 1, the cover accommodating groove is a first cover accommodating groove 2, and the sealing member is a first sealing member 3. The first jar mouth accommodating groove 1 is an annular groove provided on the inner wall of the jar mouth 101. The first cover accommodating groove 2 is an annular groove provided on the inner wall of the cover 200. As shown in Figure 4 When the cover 200 is connected to the jar mouth 101, the first jar mouth accommodating groove 1 and the first cover accommodating groove 2 are in communication to form an annular accommodating groove. The height of the accommodating groove (i.e., the distance between the inner top surface and the inner bottom surface) is d. The first sealing member 3 is arranged in the accommodating groove. The thickness of the first sealing member 3 (i.e., the distance between the top surface and the bottom surface) is D, and D > d. The inner diameter of the first sealing member 3 is adapted to the inner diameter of the jar mouth 101. The inner top surface of the first cover accommodating groove 2 abuts against the top surface of the first sealing member 3, and the inner bottom surface of the first jar mouth accommodating groove 1 abuts against the bottom surface of the first sealing member 3. Thus, when the cover 200 is connected to the jar mouth 101, the first sealing member 3 can be deformed by extrusion.

[0032] Further, the first sealing member 3 has an arc-shaped inner annular surface and an arc-shaped outer annular surface. The top surface and the bottom surface of the first sealing member 3 are both flat surfaces. When the first sealing member 3 is extruded in the axial direction, the first sealing member 3 can have a larger contact area, and the area with large deformation is concentrated on the inner annular surface and the outer annular surface. The outer annular surface is provided with a first annular groove 31 in the circumferential direction. The cross section of the first annular groove 31 is arc-shaped, and the opening of the first annular groove 31 faces the joint between the jar mouth 101 and the cover 200. When the jar mouth 101 is connected to the cover 200, the joint between the jar mouth 101 and the cover 200 is opposite to the opening of the first annular groove 31.

[0033] Further, the top surface of the first sealing member 3 is provided with a first abutting ring 32. The first abutting ring 32 extends away from the top surface of the first sealing member 3, and the cross section of the first abutting ring 32 is triangular. The bottom surface of the first sealing member 3 is provided with a second abutting ring 33. The second abutting ring 33 extends away from the bottom surface of the first sealing member 3, and the cross section of the second abutting ring 33 is triangular. As shown in Figure 2 and Figure 3 .

[0034] The application also provides a gas-insulated composite voltage transformer. The voltage transformer comprises a housing jar 100, a cover 200, a winding, and other necessary existing structures. The voltage transformer further comprises the sealing structure of the voltage transformer. The inner wall of the jar mouth 101 of the housing jar 100 is provided with a first jar mouth accommodating groove 1. The inner wall of the cover 200 is provided with a first cover accommodating groove 2. The first sealing member 3 is arranged between the first jar mouth accommodating groove 1 and the first cover accommodating groove 2. As shown in Figure 1 .

[0035] When installing the sealing structure, first place the first sealing member 3 on the first tank mouth installation groove 1, then buckle the cover 200 on the tank mouth 101, at this time the top of the first abutting ring 32 abuts against the inner top surface of the first cover installation groove 2, and the bottom of the second abutting ring 33 abuts against the inner bottom surface of the first tank mouth installation groove 1, as shown in Figure 4 A.

[0036] Then tighten the screws and nuts on the cover 200 and the tank mouth 101, during the tightening process, the first cover installation groove 2 and the first tank mouth installation groove 1 will axially extrude the first sealing member 3, because the inner and outer annular surfaces of the first sealing member 3 are both arc surfaces, so when the two abutting rings drive the first sealing member 3 to deform, the inner annular surface will expand and extend to the inside of the transformer, and the outer annular surface will be extruded on the inner sidewall of the accommodating groove, at the same time, the first annular groove 31 is extruded and deformed to shrink to the inside of the first sealing member 3, as shown in Figure 4 B.

[0037] After the screws and nuts on the cover 200 and the tank mouth 101 are tightened, pour insulating gas into the accommodating tank 100 (the processes of air extraction and high-pressure gas injection in the pouring process are prior art), because the first sealing member 3 has been extruded and fixed, even when the accommodating tank 100 is subjected to vacuumizing operation, the first sealing member 3 will not be separated from the accommodating groove.

[0038] When pouring high-pressure insulating gas, as the pressure in the accommodating tank 100 increases, the first sealing member 3 will be extruded and deformed, and finally the opening of the first annular groove 31 will be closed to form an "air bag" inside the first sealing member 3. As shown in Figure 4 C, the air pressure in the "air bag" cooperates with the two abutting rings to always maintain the first sealing member 3 in contact with the inner top surface and the inner bottom surface of the accommodating groove in the axial direction, so that even when the first sealing member 3 reaches the service life or is damaged, it can still be firmly fixed in the accommodating groove, thereby preventing the insulating gas from leaking.

[0039] In the first embodiment, we use the form of built-in first sealing member 3 to avoid the influence of the external environment on the sealing structure, because the first tank mouth installation groove 1 and the first cover installation groove 2 are both arranged on the inner wall, and it is relatively simple to process the first cover installation groove 2 on the cover 200 because the cover 200 is small in size. However, the first tank mouth installation groove 1 is arranged on the tank mouth 101, and the accommodating tank 100 itself is large and heavy in size, and it is more troublesome to perform boring than to directly process the outer wall of the tank mouth 101, therefore, on the basis of the prior art, we provide a second embodiment.

[0040] In this embodiment, the can opening placement groove is a second can opening placement groove 4, the cap placement groove is a second cap placement groove 5, and the sealing element is a second sealing element 6. The second can opening placement groove 4 is an annular groove provided on the outer wall of the can opening 101, and the second cap placement groove 5 is an annular groove provided on the inner wall of the cap 200. When the cap 200 is connected to the can opening 101, the inner bottom surface of the second can opening placement groove 4 is opposite to the inner top surface of the second cap placement groove 5. The outer wall of the second can opening placement groove 4 abuts against the inner wall of the second sealing element 6 and extends into the cap 200, abutting against the inner wall of the cap 200. The inner wall of the second cap placement groove 5 abuts against the outer wall of the second sealing element 6 and extends toward the direction of receiving the can 100, abutting against the outer wall of the can opening 101. This creates a rectangular accommodating space between the can opening 101 and the cap 200. The second sealing element 6 is located between the inner bottom surface of the second can opening mounting groove 4 and the inner top surface of the second cap mounting groove 5. As the cap 200 is connected and pressed against the can opening 101, the top of the second sealing element 6 abuts against the inner top surface of the second cap mounting groove 5, the bottom of the second sealing element 6 abuts against the inner bottom surface of the second can opening mounting groove 4, the inner sidewall of the second sealing element 6 abuts against the inner wall surface of the second can opening mounting groove 4, and the outer sidewall of the second sealing element 6 abuts against the inner wall surface of the second cap mounting groove 5. Figure 9 As shown, by sealing the four surfaces of the second sealing element 6 (upper, lower, inner, and outer), a two-way seal in both the radial and axial directions is achieved.

[0041] Furthermore, the top of the second sealing member 6 is provided with a second annular groove 61, and the inner top surface of the second cover mounting groove 5 is provided with a limiting ring 51, the limiting ring 51 being located within the second annular groove 61, such as... Figure 8 and Figure 9 As shown, the second annular groove 61 and the limiting ring 51 cooperate with each other to not only have basic limiting capabilities, but also increase the number of sealing surfaces on the top surface of the second sealing element 6, thereby further improving the sealing performance.

[0042] The application also provides a gas-insulated composite voltage transformer, which comprises a necessary existing structure such as a containing tank 100, a cover 200 and a winding, and further comprises the sealing structure of the voltage transformer, an outer wall of a tank opening 101 is provided with a second tank opening accommodating groove 4, an inner wall of the cover 200 is provided with a second cover accommodating groove 5, and the second sealing element 6 is arranged between the second tank opening accommodating groove 4 and the second cover accommodating groove 5. Through the design of the above structure, the second sealing element 6 can still not be in contact with the external environment, and the existing containing tank 100 can be directly transformed according to the embodiment. Different from the first embodiment, the contact area of the second sealing element 6 with the insulating gas in the containing tank 100 is extremely small, so that the material selection of the second sealing element 6 can be more diversified, and the erosion of the insulating gas on the second sealing element 6 does not need to be worried about. Meanwhile, an annular third sealing element 7 can be further arranged between the cover 200 and the containing tank 100, as shown in Figures 5-9 the sealing property can be further increased, because the third sealing element 7 is added, so that the second sealing element 6 is completely isolated from the external environment, and then the service life of the second sealing element 6 can be greatly improved while the sealing property is ensured.

[0043] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0044] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected or can communicate with each other; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] While embodiments of the application have been disclosed in connection with the above specification and drawings this description is not intended to limit the scope of the application and many modifications, enhancements, alternatives, and variations will become apparent to those skilled in the art from this disclosure. Accordingly, it is intended that the application not be limited to the described embodiments, but that it include all variations falling within the scope of the claims, and their equivalents.

Claims

1. A sealed structure of a voltage transformer, characterized by comprising: The utility model relates to a sealing structure of voltage transformer, and a sealing structure of voltage transformer is provided. The utility model relates to a sealing structure of voltage transformer, and a sealing structure of voltage transformer is provided. The utility model relates to a sealing structure of voltage transformer, and a sealing structure of voltage transformer is provided. The utility model relates to a sealing structure of voltage transformer, and a sealing structure of voltage transformer is provided. The utility model relates to a sealing structure of voltage transformer, and a sealing structure of voltage transformer is provided. ​ 2. A gas-insulated composite voltage transformer comprising a housing tank (100) and a cover (200), characterized in that, ​ 3. A sealed structure of a voltage transformer, characterized by ​ ​ The can mouth setting groove is a second can mouth setting groove (4), the cover setting groove is a second cover setting groove (5), the sealing element is a second sealing element (6), the second can mouth setting groove (4) is an annular groove arranged on the outer wall of the can mouth (101), the second cover setting groove (5) is an annular groove arranged on the inner wall of the cover (200), and the inner bottom surface of the second can mouth setting groove (4) is opposite to the inner top surface of the second cover setting groove (5) after the cover (200) is connected with the can mouth (101), and the second sealing element (6) is located between the inner bottom surface of the second can mouth setting groove (4) and the inner top surface of the second cover setting groove (5). The top of the second sealing element (6) is provided with a second ring groove (61), and the inner top surface of the second cover setting groove (5) is provided with a limiting ring (51), and the limiting ring (51) is located in the second ring groove (61).

4. The sealing structure of a voltage transformer according to claim 3, characterized by The outer wall of the second can mouth setting groove (4) abuts against the inner wall of the second sealing element (6) and extends into the cover (200) to abut against the inner wall of the cover (200), and the inner wall of the second cover setting groove (5) abuts against the outer wall of the second sealing element (6) and extends in the direction of the containing tank (100) to abut against the outer wall of the can mouth (101).

5. A gas-insulated composite voltage transformer comprising a housing tank (100) and a cover (200), characterized in that The sealing structure of the voltage transformer also comprises the sealing structure of the voltage transformer according to any one of claims 3 or 4, the outer wall of the can mouth (101) is provided with the second can mouth setting groove (4), the inner wall of the cover (200) is provided with the second cover setting groove (5), the second sealing element (6) is arranged between the second can mouth setting groove (4) and the second cover setting groove (5), and the cover (200) and the containing tank (100) are provided with an annular third sealing element (7).

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