Shell thermal stress relief device

Abstract

This application relates to a thermal stress relief device for a casing, comprising a casing, a first tube, a second tube, a cover plate, and a partition plate. One end of the first tube is connected to the casing, and the other end is movably disposed along the axial direction of the first tube. At least a portion of the first tube is capable of deforming and expanding along the axial direction of the first tube. The axial direction of the second tube is the same as that of the first tube. The second tube has a second cavity communicating with the outside. One end of the second tube is connected to the casing, and the other end is movably disposed along the axial direction of the second tube. The end of the second tube facing away from the casing moves synchronously with the end of the first tube facing away from the casing. At least a portion of the second tube is capable of deforming and expanding along the axial direction of the second tube. This device can compensate for the axial length changes of adjacent expansion elements of the GIS casing caused by thermal expansion and contraction, releasing the thermal stress on the casing caused by the thermal expansion and contraction of longer GIS elements.

Description

Technical Field

[0001] This invention relates to the field of power equipment technology, and in particular to a device for relieving thermal stress on the casing. Background Technology

[0002] In modern power systems, SF6 gas-insulated metal-enclosed switchgear (GIS) plays a crucial role as a core device ensuring stable and safe power transmission and distribution. With the continuous growth of electricity demand, GIS equipment at voltage levels of 550kV and above is widely used in ultra-high voltage and extra-high voltage power transmission and transformation projects due to its high voltage level and large transmission capacity. These devices are large in size, reaching hundreds of meters in length, and require various complex electrical main wiring configurations, such as single busbars and double busbars. This results in a wide variety of physical arrangements of components, and the market demands increasingly stringent requirements for their performance reliability and structural stability.

[0003] In terms of shell material selection, aluminum and other metals have become the mainstream choice in the industry due to their good thermal conductivity, mechanical strength, and processing performance. Meanwhile, to ensure the internal insulation performance of the equipment, it is filled with a certain pressure of SF6 insulating gas to achieve efficient electrical insulation and arc extinguishing functions.

[0004] However, due to the inherent thermal expansion and contraction properties of metallic materials, existing designs face severe challenges in coping with environmental temperature variations. Since GIS equipment at voltage levels of 550kV and above is mostly installed outdoors, it is exposed to the natural environment for extended periods, experiencing significant seasonal temperature changes. In the high temperatures of summer, the GIS casing expands and lengthens due to heat, while in the low temperatures of winter, it contracts and shortens. When the casing is entirely rigid, this expansion and contraction caused by temperature changes is restricted by fixed points, generating significant thermal stress at these points. Long-term accumulated thermal stress can not only lead to casing deformation and air leakage, thus affecting the insulation performance of the equipment, but also potentially cause abnormal temperature rises, cracking of the supporting structure, and in more severe cases, even melting of internal conductors, directly threatening the safe and stable operation of the power system and posing significant risks and economic losses to power supply and equipment maintenance. Summary of the Invention

[0005] Therefore, it is necessary to provide a device for relieving thermal stress in existing GIS housings, which is caused by the elongation or shortening due to seasonal temperature changes.

[0006] A shell thermal stress relief device includes a shell, a first tube, a second tube, a cover plate, and a partition plate. The shell has an internal air chamber. The first tube is connected to one side of the shell and has a first cavity communicating with the air chamber. One end of the first tube is fixedly connected to the shell, and the other end is movably disposed along the axial direction of the first tube. At least a portion of the first tube is deformable along its axial direction for expansion and contraction. The second tube is connected to the side of the shell away from the first tube, and its axial direction is aligned with that of the first tube. The second tube has a second cavity communicating with the outside. One end of the second tube is fixedly connected to the housing, and the other end is movable along the axial direction of the second tube. The end of the second tube away from the housing moves synchronously with the end of the first tube away from the housing. The second tube is at least partially deformable along the axial direction of the second tube to extend and retract. The cover plate is connected to the side of the first tube away from the housing and covers the opening of the first cavity away from the air chamber. The partition is connected to the side of the second tube close to the housing and separates the air chamber and the second cavity along the axial direction of the second tube.

[0007] In one embodiment, the first tube includes a first flexible portion, a first outer connection, and a first inner connection. The first flexible portion has a first cavity inside and can deform along its own axis to extend and retract. The first flexible portion is connected between the first outer connection and the first inner connection, and the first inner connection is fixedly connected to the shell.

[0008] In one embodiment, the first flexible part is a bellows.

[0009] In one embodiment, the second tube includes a second flexible portion, a second outer connection and a second inner connection. The second flexible portion has a second cavity inside and can deform along its own axis to extend and retract. The second flexible portion is connected between the second outer connection and the second inner connection, and the second inner connection is fixedly connected to the housing.

[0010] In one embodiment, the second flexible part is a bellows.

[0011] In one embodiment, the outer shell thermal stress relief device further includes a conductive strip, which is made of a conductive material and has its two ends connected to the second external connection and the second internal connection, respectively. The conductive strip is a flexible structure and its length is not less than the maximum distance between the second internal connection and the second external connection.

[0012] In one embodiment, there are multiple conductive strips, and all of the conductive strips are evenly distributed around the outer periphery of the second flexible portion.

[0013] In one embodiment, the housing thermal stress relief device further includes a pull rod assembly, which includes a plurality of parallel pull rods. The first tube has a first connecting hole at one end near the housing, and the first connecting hole is sleeved on the outer periphery of the pull rod.

[0014] And / or, the second tube body is provided with a second connecting hole at one end near the housing, and the second connecting hole is sleeved on the outer periphery of the pull rod.

[0015] In one embodiment, the end of the first tube away from the housing is fixedly connected to the pull rod; and / or, the end of the second tube away from the housing is fixedly connected to the pull rod.

[0016] In one embodiment, when the gas pressure P in the first cavity and the gas chamber is equal to the gas pressure p in the second cavity, the diameter R of the first cavity is equal to the diameter r of the second cavity; and / or, when the gas pressure P in the first cavity and the gas chamber is greater than the gas pressure p in the second cavity, the diameter R of the first cavity is less than the diameter r of the second cavity; and / or, when the gas pressure P in the first cavity and the gas chamber is less than the gas pressure p in the second cavity, the diameter R of the first cavity is greater than the diameter r of the second cavity.

[0017] The shell thermal stress relief device provided in the above solution connects a first tube and a second tube, which can deform and expand in their own axial direction, to the two sides of the shell. By using the synchronous movement of the opposite ends of the first and second tubes, when the length of the second tube is affected by the thermal expansion and contraction of the extension element connected to the second tube, the length of the first tube can change in the opposite direction. In this way, the expansion and contraction of the first and second tubes absorb the thermal stress that would originally act on the shell, thereby compensating for the axial length change of adjacent long-sized extension elements of the GIS shell caused by thermal expansion and contraction. This releases the thermal stress on the shell caused by the thermal expansion and contraction of long GIS elements, and improves the safe and reliable operation of the GIS. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the shell thermal stress relief device in one embodiment of this application.

[0019] Figure 2 for Figure 1 A partial cross-sectional schematic diagram of the first tube body.

[0020] Figure 3 for Figure 1A schematic diagram of the conductive band in the middle.

[0021] Figure 4 for Figure 1 Side view of the conductive band in the middle.

[0022] Figure 5 for Figure 1 A schematic diagram of the structure of the first or second tube.

[0023] Figure 6 This is a schematic diagram of the structure of the shell thermal stress relief device in another embodiment of this application.

[0024] 100. Thermal stress relief device for outer casing; 110. Casing; 111. Air chamber; 120. First tube; 121. First cavity; 122. First flexible part; 123. First external connection; 124. First internal connection; 125. First connecting hole; 130. Second tube; 131. Second cavity; 132. Second flexible part; 133. Second external connection; 134. Second internal connection; 135. Second connecting hole; 140. Cover plate; 150. Partition plate; 160. Conductive strip; 170. Pull rod assembly; 171. Pull rod; 180. Fastening assembly; 181. Spherical washer; 182. Conical washer; 183. Thick nut; 184. Thin nut; 190. Fastening bolt. Detailed Implementation

[0025] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0026] It should be noted that when a component is referred to as being "fixed to," "set on," or "properly placed on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application's specification are for illustrative purposes only and do not represent the only possible implementation.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0030] See Figure 1 , Figure 1 A schematic diagram of the structure of a housing thermal stress relief device 100 in one embodiment of this application is shown. The housing thermal stress relief device 100 provided in one embodiment of this application can be applied to SF6 gas-insulated metal-enclosed switchgear (GIS), but is not intended to limit it.

[0031] like Figure 1 As shown, the outer shell thermal stress relief device 100 includes a shell 110, a first tube 120, a second tube 130, a cover plate 140, and a partition plate 150.

[0032] like Figure 1 As shown, the housing 110 has an air chamber 111 inside. In this embodiment, the housing 110 is made of aluminum alloy. Figure 1 From the perspective of an example, the housing 110 includes a lower flange, a left flange, and a right flange. The left flange connects to the first pipe body 120, the right flange connects to the partition 150 and the second pipe body 130, and the lower flange is used for extended connection with external components (protected components, not described), and its position is approximately fixed. Figure 1As shown, the housing 110 itself, the partition 150 connected to the right flange, and the external components connected to the lower flange together enclose and form an air chamber 111 that opens toward the first tube 120.

[0033] like Figure 1 As shown, the first tube 120 is connected to one side of the housing 110. The first tube 120 has a first cavity 121 that communicates with the air chamber 111. One end of the first tube 120 is fixedly connected to the housing 110, and the other end is movably arranged along the axial direction of the first tube 120. The first tube 120 is at least partially deformable along its axial direction to extend or retract. When the first tube 120 deforms along its own axial direction, the length of the first tube 120 in the axial direction increases or decreases.

[0034] like Figure 1 As shown, the cover plate 140 is connected to the side of the first tube 120 away from the housing 110 and covers the opening of the first cavity 121 away from the air chamber 111, so that the first cavity 121 is connected to the air chamber 111, but not to the outside. In this embodiment, the cover plate 140 is made of aluminum alloy, and the shape of the cover plate 140 is not limited, for example, in... Figure 1 In the illustrated embodiment, the cover plate 140 has a round pot-shaped structure; in such a way... Figure 6 In the embodiment shown, the cover plate 140 has a straight plate structure.

[0035] like Figure 1 As shown, the second tube 130 is connected to the side of the housing 110 away from the first tube 120, and the axial direction of the second tube 130 is the same as that of the first tube 120. Their axial directions can be parallel or... Figure 1 The coaxial configuration shown is not limited.

[0036] like Figure 1 As shown, the second tube 130 has a second cavity 131 inside that communicates with an external expansion element. One end of the second tube 130 is fixedly connected to the housing 110, and the other end is movably disposed along the axial direction of the second tube 130. The end of the second tube 130 away from the housing 110 moves synchronously with the end of the first tube 120 away from the housing 110. The second tube 130 is at least partially deformable along its axial direction to extend or retract. When the second tube 130 deforms along its own axial direction, its axial length increases or decreases. The end of the second tube 130 away from the housing 110 is extended and connected to an external expansion element (long expansion element, not described).

[0037] like Figure 1As shown, the partition 150 is connected to the side of the second tube 130 near the housing 110 and separates the gas chamber 111 and the second cavity 131 in the axial direction of the second tube 130, so that the gas in the second cavity 131 is not in communication with the gas in the gas chamber 111.

[0038] In this embodiment, the partition 150 is made of insulating material. In this embodiment, the partition 150 is made of epoxy resin material and is formed by vacuum casting process, but this is not a limitation and the partition 150 can also be made of other materials.

[0039] like Figure 1 As shown, in this embodiment, the partition 150 is connected between the second inner connection 134 and the housing 110 of the second tube 130 by fastening bolts 190. However, this is not a limitation. In other embodiments, the partition 150 may also be connected to the second inner connection 134 and the housing 110 by welding or other connection methods.

[0040] Combination Figure 2 As shown, Figure 2 A schematic diagram of the structure of the first tube 120 in one embodiment of this application is shown. In one embodiment, the first tube 120 includes a first flexible part 122, a first external connection 123 and a first internal connection 124. The first flexible part 122 has a first cavity 121 inside, and the first flexible part 122 can deform along its own axis to extend and retract. The first flexible part 122 is connected between the first external connection 123 and the first internal connection 124. The first internal connection 124 is fixedly connected to the housing 110. In actual use, the position of the housing 110 is almost fixed. When the first external connection 123 moves, it drives the first flexible part 122 to deform along its own axis to extend and retract.

[0041] like Figure 1 and Figure 2 As shown, in one embodiment, the first flexible part 122 is a bellows, which can deform and expand along its own axis under external force or other internal forces. Exemplarily, the first flexible part 122 is formed by stacking and welding 4-5 layers of 0.8mm thick, highly elastic 06Cr19Ni10 stainless steel sheets. Exemplarily, in this embodiment, each layer of bellows is welded with a longitudinal weld seam using non-consumable cone automatic argon arc welding. Exemplarily, in this embodiment, the bellows has 5-6 alternating convex and concave crests and troughs, with a crest spacing of 50-60mm.

[0042] In this embodiment, the first external connection 123 and the first internal connection 124 are metal flanges, which, for example, can be made of stainless steel sheet (e.g., 06Cr19Ni10) with a thickness of 35mm-40mm.

[0043] In one embodiment, the second tube 130 includes a second flexible part 132, a second outer connection 133, and a second inner connection 134. The second flexible part 132 has a second cavity 131 inside and can deform along its own axis to extend and retract. The second flexible part 132 is connected between the second outer connection 133 and the second inner connection 134. The second inner connection 134 is fixedly connected to the housing 110. Since the position of the housing 110 is almost fixed, when the position of the second outer connection 133 moves, the second flexible part 132 deforms along its own axis to extend and retract.

[0044] In one embodiment, the second flexible portion 132 itself can also be bent, so that when the end of the second tube 130 away from the housing 110 is connected to an external long extension element, if there are manufacturing and installation errors, especially radial errors caused by coaxiality accuracy, the second flexible portion 132 of the second tube 130 can also be used to compensate for radial errors.

[0045] In one embodiment, the second flexible portion 132 is a bellows, which, exemplarily, has the same structure as the first flexible portion 122, but is not intended to limit it.

[0046] In this embodiment, the second external connection 133 and the second internal connection 134 are metal flanges, which, for example, can be made of stainless steel sheet (e.g., 06Cr19Ni10) with a thickness of 35mm-40mm.

[0047] like Figure 1 As shown, the cover plate 140, the first tube 120, the shell 110, the partition 150, and the external components connected to the shell 110 together enclose a sealed space consisting of the first cavity 121 and the gas chamber 111. The partition 150, the second tube 130, and the extension elements connected to the second tube 130 together enclose a sealed space consisting of the second cavity 131. An insulating gas is provided in both the sealed space formed by the first cavity 121 and the gas chamber 111 and in the second cavity 131. For example, this gas can be SF6 (sulfur hexafluoride). The pressure of the insulating gas in both the sealed space formed by the first cavity 121 and the gas chamber 111 and in the second cavity 131 is not limited; in this embodiment, SF6 gas with a pressure of 0.5 MPa is used as an example.

[0048] like Figure 1As shown, in one embodiment, the outer casing thermal stress relief device 100 further includes a conductive strip 160. The conductive strip 160 is made of a conductive material. In this embodiment, the conductive strip 160 is made of copper, which has good current flow, but this is not a limitation. In other embodiments, the conductive strip 160 can also be made of other conductive materials. The two ends of the conductive strip 160 are respectively connected to the second external connection 133 and the second internal connection 134, so that the second external connection 133 and the second internal connection 134 can be well electrically connected. The conductive strip 160 is a flexible structure, and the length of the conductive strip 160 is not less than the maximum distance between the second internal connection 134 and the second external connection 133, so as to avoid the conductive strip 160 affecting the deformation of the second tube body 130 in its own axial direction. Exemplarily, in this embodiment, the conductive strip 160 is fixedly connected to the second external connection 133 and the second internal connection 134 by connecting bolts.

[0049] Combination Figure 3 and Figure 4 As shown, Figure 3 This is a schematic diagram of the conductive strip 160 in one embodiment of this application. Figure 4 This is a side view of the conductive strip 160. In this embodiment, the conductive strip 160 has a wavy structure, but this is not a limitation. In other embodiments, the conductive strip 160 can have any structure that is bent or folded.

[0050] In one embodiment, there are multiple conductive strips 160, and all conductive strips 160 are evenly distributed around the outer periphery of the second flexible portion 132. The number of conductive strips 160 can be set according to the current conditions. In this embodiment, there are eight conductive strips 160, and the eight conductive strips 160 are evenly distributed around the outer periphery of the second flexible portion 132, but this is not a limitation.

[0051] like Figure 1 As shown, in one embodiment, the housing thermal stress relief device 100 further includes a pull rod assembly 170, which includes a plurality of parallel pull rods 171. In this embodiment, the number of pull rods 171 can be 4 to 12, not fully illustrated in the figures. Figure 1 From the perspective shown, only two levers 171 are visible.

[0052] like Figure 1 As shown, in one embodiment, the end of the first tube 120 away from the housing 110 is fixedly connected to the pull rod 171 so that the position of the end of the first tube 120 away from the housing 110 (i.e., the first external connection 123) is fixed relative to the pull rod 171, so that the first tube 120 can extend and retract in the axial direction as the pull rod 171 moves.

[0053] like Figure 1As shown, in one embodiment, the end of the second tube 130 away from the housing 110 is fixedly connected to the pull rod 171, so that the position of the end of the second tube 130 away from the housing 110 (i.e., the second external connection 133) is fixed relative to the pull rod 171, thereby enabling the pull rod 171 to move when the second tube 130 extends or retracts in the axial direction.

[0054] The first external connection 123 of the first tube 120 and the second external connection 133 of the second tube 130 are respectively fixedly connected to different positions of the pull rod 171, so that when the second tube 130 is affected by the external expansion element and the second external connection 133 moves, the first external connection 123 can be driven to move synchronously.

[0055] Combination Figure 5 As shown, Figure 5 The illustration shows a side view of a first tube 120 or a second tube 130 according to one embodiment of this application. The first tube 120 has a first connecting hole 125 at one end near the housing 110. The first connecting hole 125 is fitted onto the outer periphery of the pull rod 171, allowing the end of the first tube 120 near the housing 110, i.e., the first inner connection 124, to slide relative to the pull rod 171. Exemplarily, the diameter of the first connecting hole 125 is 2mm to 4mm larger than the diameter of the corresponding pull rod 171, so that the first inner connection 124 of the first tube 120 can slide smoothly along the outer periphery of the pull rod 171.

[0056] like Figure 5 As shown, in one embodiment, the second tube 130 has a second connecting hole 135 at one end near the housing 110. The second connecting hole 135 is sleeved on the outer periphery of the pull rod 171, so that the end of the second tube 130 near the housing 110, i.e., the second inner connection 134, and the pull rod 171 can slide relative to each other. Exemplarily, the diameter of the second connecting hole 135 is 2mm to 4mm larger than the diameter of the corresponding pull rod 171, so that the second inner connection 134 of the second tube 130 and the pull rod 171 can slide smoothly relative to each other.

[0057] like Figure 1As shown, the outer casing thermal stress relief device 100 also includes a fastening assembly 180, which is used to fix the second external connection 133 of the second tube 130 to the pull rod 171. Fastening assemblies 180 are respectively provided on both sides of the second external connection 133 in the axial direction of the pull rod 171 to fix the relative positions of the second external connection 133 and the pull rod 171. In this embodiment, the fastening assembly 180 includes a spherical washer 181, a conical washer 182, a thin nut 184, and a thick nut 183 arranged sequentially in the direction away from the second external connection 133, which is not limited. In other embodiments, the fastening assembly 180 may also adopt other structures. Similarly, the connection method between the first external connection 123 and the pull rod 171 can also be set according to actual conditions, and it can be the same as or different from the connection method between the second external connection 133 and the pull rod 171, which is not limited.

[0058] Understandably, when the expansion element elongates due to thermal expansion or shortens due to cold contraction, since the second outer connection 133 of the second tube 130 is fixedly connected to the expansion element, it can drive the second outer connection 133 to move synchronously when the expansion element elongates or shortens. At this time, since the second outer connection 133 and the first outer connection 123 are connected by the pull rod 171 to move synchronously, and since the first outer connection 123 of the first tube 120 and the second outer connection 133 of the second tube 130 move synchronously, while the positions of the first inner connection 124 and the second inner connection 134 are nearly fixed, the deformation lengths of the first tube 120 and the second tube 130 in their respective axial directions are the same.

[0059] like Figure 1 As shown, in one embodiment, when the gas pressure P in the first cavity 121 and the gas chamber 111 is equal to the gas pressure p in the second cavity 131, the diameter R of the first cavity 121 is equal to the diameter r of the second cavity 131. At this time, the gas pressure change in the first cavity 121 caused by the deformation length of the first flexible part 122 of the first tube 120 in its axial direction is consistent with the gas pressure change in the second cavity 131 caused by the deformation length of the second flexible part 132 of the second tube 130 in its axial direction. The forces on both ends of the shell 110 are consistent, thereby achieving force balance and avoiding uneven force on the shell 110.

[0060] Combination Figure 6 As shown, Figure 6A schematic diagram of the structure of the shell thermal stress relief device 100 in another embodiment of this application is shown. In one embodiment, when the gas pressure P in the first cavity 121 and the air chamber 111 is greater than the gas pressure p in the second cavity 131, the diameter R of the first cavity 121 is smaller than the diameter r of the second cavity 131. Then, the gas pressure in the first cavity 121 and the air chamber 111 and the force-bearing area of ​​the shell 110 are smaller than the force-bearing area of ​​the shell 110 caused by the gas pressure in the second cavity 131, so as to compensate for the difference in gas pressure between the two, thereby enabling the forces at both ends of the shell 110 to achieve force balance.

[0061] In one embodiment, when the gas pressure P in the first cavity 121 and the air chamber 111 is less than the gas pressure p in the second cavity 131, the diameter R of the first cavity 121 is greater than the diameter r of the second cavity 131. Then, the gas pressure in the first cavity 121 and the air chamber 111 and the force-bearing area of ​​the shell 110 are greater than the force-bearing area of ​​the shell 110 caused by the gas pressure in the second cavity 131, so as to compensate for the difference in gas pressure between the two, thereby enabling the forces at both ends of the shell 110 to achieve force balance.

[0062] Since the position of the housing 110 is nearly fixed, the positions of the first inner connection 124 of the first tube 120 and the second inner connection 134 of the second tube 130 connected to the housing 110 are nearly fixed during use, and the first outer connection 123 of the first tube 120 and the second outer connection 133 of the second tube 130 move synchronously. Therefore, when the housing thermal stress relief device 100 is in use:

[0063] 1. When the extension element connected to the second tube 130 is longer and its operating temperature is higher than its installation temperature, the extension element expands due to thermal expansion, causing the second external connection 133 of the second tube 130 to move towards the housing 110. At this time, the position of the second internal connection 134 of the second tube 130 remains unchanged, causing the extension element to compress the second tube 130, thus shortening the second flexible part 132. Since the first external connection 123 and the second external connection 133 move synchronously, the first external connection 123 moves away from the housing 110, causing the first flexible part 122 of the first tube 120 to extend, thereby eliminating thermal stress. The thermal stress generated by the thermal expansion of the extension element is absorbed by the expansion and contraction of the first tube 120 and the second tube 130, resulting in less stress on the housing 110 located between them, thus ensuring the safe operation of the housing 110 and the extension element connected to it.

[0064] 2. Similarly, when the operating temperature of the expansion element connected to the second tube 130 decreases compared to the installation temperature, the expansion element will shorten due to thermal contraction. At this time, the second flexible portion 132 of the second tube 130 will stretch, and the first external connection 123 and the second external connection 133 will move synchronously. The first external connection 123 will move towards the housing 110, and the first flexible portion 122 of the first tube 120 will shorten, thereby eliminating thermal stress. The thermal stress generated by the expansion element due to thermal contraction is absorbed by the expansion and contraction of the first tube 120 and the second tube 130. The housing 110, located between the two, experiences less stress, thus ensuring the safe operation of the housing 110 and the expansion element connected to the housing 110.

[0065] Meanwhile, when the end of the second tube 130 away from the housing 110 is connected to an external long extension element, if there are manufacturing and installation errors, the axial extensibility of the second tube 130 can be used to compensate for the errors, such as axial dimension errors.

[0066] The shell thermal stress relief device 100 provided in the above solution connects a first tube 120 and a second tube 130, which can deform and expand in their own axial direction, to the two sides of the shell 110 respectively. By using the synchronous movement of the opposite ends of the first tube 120 and the second tube 130, when the length of the second tube 130 is affected by the thermal expansion and contraction of the expansion element connected to the second tube 130, the length of the first tube 120 can change in the opposite direction. Thus, the expansion and contraction of the first tube 120 and the second tube 130 absorb the thermal stress that would originally act on the shell 110, thereby compensating for the axial length change of the adjacent long-sized expansion element of the GIS shell 110 caused by thermal expansion and contraction. This releases the thermal stress on the shell 110 caused by the thermal expansion and contraction of the long GIS element, and improves the safe and reliable operation of the GIS.

[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A device for relieving thermal stress in a housing, characterized in that, The thermal stress relief device for the outer casing includes: The shell has an internal air chamber; A first tube is connected to one side of the housing. The first tube has a first cavity inside that communicates with the air chamber. One end of the first tube is fixedly connected to the housing, and the other end is movably disposed along the axial direction of the first tube. At least part of the first tube is movably deformable along the axial direction of the first tube to extend and retract. The second tube is connected to the side of the housing away from the first tube, and the axial direction of the second tube is the same as that of the first tube. The second tube has a second cavity inside that communicates with the outside. One end of the second tube is fixedly connected to the housing, and the other end is movable along the axial direction of the second tube. The end of the second tube away from the housing moves synchronously with the end of the first tube away from the housing. The second tube is at least partially deformable along the axial direction of the second tube to extend and retract. A cover plate, connected to the side of the first tube away from the housing and covering the opening of the first cavity opposite to the air chamber; and A partition is connected to the side of the second tube near the housing and separates the air chamber and the second cavity in the axial direction of the second tube.

2. The shell thermal stress relief device according to claim 1, characterized in that, The first tube includes a first flexible part, a first external connection and a first internal connection. The first flexible part has a first cavity inside and can deform along its own axis to expand and contract. The first flexible part is connected between the first external connection and the first internal connection, and the first internal connection is fixedly connected to the shell.

3. The shell thermal stress relief device according to claim 2, characterized in that, The first flexible part is a corrugated pipe.

4. The shell thermal stress relief device according to claim 1 or 2, characterized in that, The second tube includes a second flexible part, a second outer connection and a second inner connection. The second flexible part has a second cavity inside and can deform along its own axis to expand and contract. The second flexible part is connected between the second outer connection and the second inner connection, and the second inner connection is fixedly connected to the shell.

5. The shell thermal stress relief device according to claim 4, characterized in that, The second flexible part is a corrugated pipe.

6. The shell thermal stress relief device according to claim 4, characterized in that, The outer shell thermal stress relief device also includes a conductive strip, which is made of a conductive material and has its two ends connected to the second external connection and the second internal connection, respectively. The conductive strip is a flexible structure and its length is not less than the maximum distance between the second internal connection and the second external connection.

7. The outer casing thermal stress relief device according to claim 6, characterized in that, The number of conductive strips is multiple, and all of the conductive strips are evenly distributed around the outer periphery of the second flexible part.

8. The shell thermal stress relief device according to claim 1, characterized in that, The thermal stress relief device for the outer shell further includes a pull rod assembly, which includes a plurality of parallel pull rods, with the end of the first tube away from the shell fixedly connected to the pull rod; and / or, the end of the second tube away from the shell fixedly connected to the pull rod.

9. The shell thermal stress relief device according to claim 8, characterized in that, The first tube body has a first connecting hole at one end near the housing, and the first connecting hole is sleeved on the outer periphery of the pull rod; And / or, the second tube body is provided with a second connecting hole at one end near the housing, and the second connecting hole is sleeved on the outer periphery of the pull rod.

10. The shell thermal stress relief device according to claim 1, characterized in that, When the gas pressure P in the first cavity and the gas chamber is equal to the gas pressure p in the second cavity, the diameter R of the first cavity is equal to the diameter r of the second cavity; And / or, when the gas pressure P in the first cavity and the gas chamber is greater than the gas pressure p in the second cavity, the diameter R of the first cavity is smaller than the diameter r of the second cavity; And / or, when the gas pressure P in the first cavity and the gas chamber is less than the gas pressure p in the second cavity, the diameter R of the first cavity is greater than the diameter r of the second cavity.

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