Low-temperature liquid cargo containment tank

Abstract

The application discloses a low-temperature liquid cargo closed storage tank, which comprises a secondary insulation module, a main insulation module and a fastening assembly. The main insulation module is arranged on the opposite inner side of the secondary insulation module. The secondary insulation module comprises an inner structural plate, an outer structural plate and a main insulation layer arranged between the inner structural plate and the outer structural plate. The end of the main insulation layer is provided with a relief cut corner along the thickness direction of the main insulation layer, and the main insulation layer has a connecting side wall at the relief cut corner. The inner structural plate is fixed with the inner side wall of the main insulation layer, and the outer structural plate is fixed with the outer side wall and the connecting side wall of the main insulation layer and wraps the corner of the main insulation layer. The fastening assembly is connected between the secondary insulation module and the outer structural plate to fix the main insulation module on the secondary insulation module. The structure disperses the stress at the corner through the double fixed interfaces of the outer structural plate and the outer side wall and the connecting side wall of the main insulation layer, and improves the fixing reliability of the main insulation module.

Description

Technical Field

[0001] This invention relates to the field of cryogenic liquid cargo storage and transportation technology, and in particular to a cryogenic liquid cargo sealed storage tank. Background Technology

[0002] Cryogenic sealed storage tanks are the core storage units of cryogenic liquid cargo storage and transportation equipment such as liquefied natural gas (LNG) and liquefied ethylene. Their insulation performance directly affects the tank's evaporation rate control, structural safety, and operational economy. Therefore, the rational design and reliable fixing of the tank's insulation structure are crucial for ensuring storage and transportation safety and reducing evaporation losses. In existing technologies, cryogenic sealed storage tanks typically include a secondary insulation module and a primary insulation module located relatively inside the secondary insulation module. The primary insulation module is fixed to the secondary insulation module by fastening components. However, during ship navigation or tank operation, stress concentration easily occurs at the connection points between the primary and secondary insulation modules due to the effects of cryogenic alternating loads and mechanical vibrations. Especially at the corners of the primary insulation layer, the interface between the outer structural plate and the primary insulation layer is prone to peeling or loosening, leading to a decrease in the fixing reliability of the primary insulation module and thus affecting the overall insulation performance of the tank, indicating room for improvement. Summary of the Invention

[0003] The main objective of this application is to provide a cryogenic liquid cargo sealed storage tank to solve the technical problem in the prior art where stress concentration easily occurs at the connection between the main insulation module and the secondary insulation module, especially at the corner of the main insulation layer where the interface between the outer structural plate and the main insulation layer is prone to peeling or loosening, leading to a decrease in the fixing reliability of the main insulation module.

[0004] According to the present invention, a cryogenic liquid cargo sealed storage tank is provided, comprising a secondary insulation module; a primary insulation module disposed on the inner side of the secondary insulation module, the primary insulation module comprising: an inner structural plate, an outer structural plate, and a primary insulation layer disposed between the inner structural plate and the outer structural plate, the end of the primary insulation layer having a clearance chamfer along its thickness direction, the primary insulation layer having a connecting sidewall at the clearance chamfer, the inner structural plate being fixed to the inner sidewall of the primary insulation layer, the outer structural plate being fixed to the outer sidewall of the primary insulation layer and the connecting sidewall respectively, and wrapping around the corner of the primary insulation layer; and a fastening assembly connected between the secondary insulation module and the outer structural plate to fix the primary insulation module to the secondary insulation module. The fastening assembly includes: a pressure plate, a screw assembly, and a pressure spring assembly; The screw assembly includes a stud, a nut, and a fixing plate. The fixing plate is fixed to the secondary insulation module. One end of the stud is fixed to the fixing plate, and the other end of the stud is adapted to pass through the pressure plate and the pressure spring assembly to connect with the nut. The pressure spring assembly is clamped between the nut and the pressure plate. The pressing spring assembly includes: a first spring protruding towards the nut in the middle and a second spring protruding away from the nut in the middle, the second spring being sandwiched between the two first springs; Each of the fastening components is disposed between the four main insulation modules. The pressure plate simultaneously presses against the four outer structural plates of the four main insulation modules. The pressure plate is provided with a limiting protrusion, which limits and supports the outer structural plates between two adjacent ones.

[0005] Furthermore, the outer structural panel includes: a large surface fixing plate and a corner fixing block. The large surface fixing plate is fixed to the outer side wall of the main insulation layer and extends to below the avoidance chamfer. The corner fixing block is fixed to the large surface fixing plate and embedded in the avoidance chamfer to be fixed to the connecting side wall.

[0006] Furthermore, the outer structural plate is constructed as an integrally formed structural component, and the outer structural plate includes: a thin fixing part and a thick fixing part. The thickness of the thick fixing part is greater than the thickness of the thin fixing part. The thin fixing part is fixed to the outer side wall of the main insulation layer, and the thick fixing part is adapted to extend into the avoidance chamfer to be fixed to the connecting side wall.

[0007] Furthermore, the outer structural panel includes: a large-face fixing plate and two side fixing plates. The large-face fixing plate is fixed to the outer wall of the main insulation layer and extends to below the avoidance chamfer. The two side fixing plates are connected at an angle and are fixed to the large-face fixing plate and respectively fixed to the two connecting side walls at the avoidance chamfer.

[0008] Furthermore, the pressure plate presses against the corner fixing block and is locked by the screw assembly.

[0009] Furthermore, the pressure plate presses against the thick fixing part and is locked by the screw assembly.

[0010] Furthermore, the main insulation layer is recessed into the interior of the main insulation layer at the connecting side wall to form a mounting groove, the side fixing plate is embedded and fixed in the mounting groove, the portion of the large surface fixing plate extending to the lower part of the avoidance chamfer is formed as a limiting part, the pressure plate presses against the limiting part and is locked by the screw assembly.

[0011] In the cryogenic liquid cargo sealed storage tank of the present invention, the chamfered end of the main insulation layer forms a connecting sidewall. The outer structural plate is simultaneously fixed to both the outer sidewall and the connecting sidewall of the main insulation layer, and wraps around the corner of the main insulation layer. This creates two mutually perpendicular fixed interfaces between the outer structural plate and the main insulation layer, thereby dispersing the tensile stress at the corner, which was originally concentrated on a single interface, into two directions. Specifically, when cryogenic alternating loads or mechanical vibrations act on the main insulation module, the shear or peeling stress generated between the main insulation layer and the secondary insulation module is no longer borne solely by the fixed interface on the outer sidewall, but is shared by both the fixed interface on the outer sidewall and the fixed interface on the connecting sidewall. Combined with fastening components, the outer structural plate is pressed and fixed onto the secondary insulation module, significantly enhancing the bonding force between the outer structural plate and the main insulation layer. This effectively prevents peeling or loosening of the bonding interface at the corner, thereby improving the fixing reliability of the main insulation module on the secondary insulation module and ensuring the overall insulation performance and operational safety of the storage tank. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 A partial structural schematic diagram of a cryogenic liquid cargo sealed storage tank provided for an embodiment of this application; Figure 2 for Figure 1 Exploded view; Figure 3 for Figure 1 A sectional view; Figure 4 for Figure 1 A schematic diagram of a partial structure; Figure 5 A partial structural schematic diagram of a cryogenic liquid cargo sealed storage tank provided for another embodiment of this application; Figure 6 A partial structural schematic diagram of a cryogenic liquid cargo sealed storage tank provided in another embodiment of this application; Figure 7 for Figure 6 Exploded view.

[0014] Explanation of reference numerals in the attached figures: 10. Secondary insulation module; 20. Main insulation module; 21. Inner structural plate; 22. Outer structural plate; 221. Large surface fixing plate; 222. Corner fixing block; 223. Thin fixing part; 224. Thick fixing part; 225. Side fixing plate; 23. Main insulation layer; 231. Avoidance chamfer; 232. Connecting side wall; 235. Limiting part; 236. Mounting groove; 30. Fastening assembly; 31. Pressure plate; 311. Limiting protrusion; 32. Screw assembly; 321. Stud; 322. Nut; 323. Fixing plate; 33. Pressing spring assembly; 331. First spring; 332. Second spring. Detailed Implementation

[0015] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0016] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. In this application, unless otherwise stated, directional terms such as "inner" and "outer" generally refer to the inner and outer contours of the corresponding structures.

[0017] like Figures 1-4 As shown in the figure, this application embodiment provides a cryogenic liquid cargo sealed storage tank, which includes a secondary insulation module 10, a main insulation module 20, and a fastening assembly 30. The main insulation module 20 is disposed on the inner side of the secondary insulation module 10. The main insulation module 20 includes an inner structural plate 21, an outer structural plate 22, and a main insulation layer 23 disposed between the inner structural plate 21 and the outer structural plate 22. The end of the main insulation layer 23 is provided with an avoidance chamfer 231 along its thickness direction, which causes the main insulation layer 23 to form two connecting sidewalls 232 at its end. The inner structural plate 21 is fixed to the inner sidewall of the main insulation layer 23, and the outer structural plate 22 is fixed to the outer sidewall and the connecting sidewall 232 of the main insulation layer 23, respectively, and the outer structural plate 22 covers the corner of the main insulation layer 23. The fastening assembly 30 is connected between the secondary insulation module 10 and the outer structural plate 22 to fix the main insulation module 20 as a whole onto the secondary insulation module 10.

[0018] According to this embodiment, by providing an avoidance chamfer 231 at the end of the main insulation layer 23, a connecting sidewall 232 at an angle to the outer wall is formed. When the outer structural plate 22 wraps around the corner of the main insulation layer 23, it is simultaneously fixedly connected to both the outer wall and the connecting sidewall 232. This "L"-shaped or similar angled wrapping and fixing method transforms the original single planar connection between the outer structural plate 22 and the main insulation layer 23 into a multi-faceted spatial connection. When the storage tank experiences thermal shrinkage due to loading cryogenic liquid cargo, or mechanical vibration due to ship navigation, the peeling stress or shear stress acting at the corner will be decomposed onto the mutually angled outer wall and connecting sidewall 232. The clamping force applied by the fastening assembly 30 to the outer structural plate 22 is transmitted to the interior of the main insulation layer 23 through these two fixed surfaces, forming a stable mechanical constraint system. This greatly enhances the anti-peeling and anti-shear capabilities of the corner area, solves the problem of loosening of the bonding interface caused by stress concentration, and thus effectively ensures the fixing reliability of the main insulation module 20 and the long-term insulation performance of the storage tank.

[0019] In practical applications, the overall fixing process and force mechanism of the main insulation module 20 of the storage tank are as follows: First, the ends of the main insulation layer 23 are pre-machined with avoidance chamfers 231. Then, the outer structural plate 22 is precisely attached and fixed to the outer side wall and connecting side wall 232 of the main insulation layer 23, forming a tight wrap around the corner. Finally, the outer structural plate 22 is fastened to the secondary insulation module 10 by the fastening assembly 30. During operation, any force attempting to lift the main insulation module 20 from the secondary insulation module 10 will be offset by the clamping force of the fastening assembly 30. This clamping force is evenly distributed to the two different side walls of the main insulation layer 23 through the outer structural plate 22, avoiding excessive stress concentration at a single point or on a surface.

[0020] In some embodiments, specifically, such as Figures 1-4As shown, the outer structural panel 22 adopts a split structure, which includes a large-area fixing plate 221 and corner fixing blocks 222. The large-area fixing plate 221 is fixed to the outer wall of the main insulation layer 23 by adhesive or similar means, and the main body of the large-area fixing plate 221 extends below the avoidance chamfer 231. The corner fixing blocks 222 are fixed to the large-area fixing plate 221 by adhesive or other means, and are precisely embedded in the avoidance chamfer 231, thereby fitting and fixing to the connecting side wall 232. This design, which splits the outer structural panel 22 into the large-area fixing plate 221 and the corner fixing blocks 222, adapts to the two different functional requirements of large-area fitting and corner filling of the main insulation layer 23, reducing the processing difficulty of complex shapes. Furthermore, based on the above principles, the beneficial effects of this structure are: the split design allows for the selection of different materials or thicknesses for each component, optimizing cost and performance; and the independent corner fixing block 222 can be more precisely embedded into the avoidance corner 231, ensuring the fit with the connecting side wall 232, thereby forming a reliable embedded fixation at the corner, enhancing the structural rigidity and assembly processability at the corner.

[0021] Therefore, by setting the outer structural plate 22 as a combination of a large-area fixing plate 221 and a corner fixing block 222, with the corner fixing block 222 embedded in the avoidance chamfer 231 and fixed to the connecting sidewall 232, the outer structural plate 22 and the main insulation layer 23 form an embedded fixed fit at the corner. When the pressure plate 31 presses against the corner fixing block 222 and is locked by the screw assembly 32, the fastening force is directly transmitted to the connecting sidewall 232 through the corner fixing block 222, so that a tight surface contact is formed between the connecting sidewall 232 and the corner fixing block 222, which further enhances the wrapping and fixing strength of the outer structural plate 22 to the corner of the main insulation layer 23 and improves the peel resistance of the main insulation module 20.

[0022] In some embodiments, as an alternative implementation, such as Figure 5As shown, the outer structural panel 22 is constructed as a one-piece molded structural component. This one-piece molded outer structural panel 22 includes a thin fixing portion 223 and a thick fixing portion 224, the thickness of which is designed to be greater than the thickness of the thin fixing portion 223. The thinner fixing portion 223 is used to fix to the outer wall of the main insulation layer 23, while the thicker fixing portion 224 is precisely adapted to extend into the avoidance chamfer 231 to fix to the connecting sidewall 232. The one-piece molded structure eliminates potential weak points caused by welding or bonding at the source, significantly improving the integrity and rigidity of the outer structural panel 22. Furthermore, the beneficial effects of the same technical solution as this embodiment are as follows: the integrated structure has higher structural integrity. The thick fixing part 224 not only provides a high-strength connection base, but its larger thickness also significantly enhances the bending section modulus at the corner, which can more effectively resist bending deformation. The clamping force of the fastening component 30 is transferred from the thick fixing part 224 to the connecting side wall 232 and the thin fixing part 223 without damage and evenly, which greatly reduces the stress concentration in the corner area and improves the structural stability and reliability under extreme working conditions.

[0023] Therefore, by constructing the outer structural plate 22 as an integrally molded structural component including a thin fixing part 223 and a thick fixing part 224, with the thin fixing part 223 fixed to the outer wall of the main insulation layer 23 and the thick fixing part 224 extending into the avoidance chamfer 231 and fixed to the connecting side wall 232, the integrally molded structure avoids the connection gaps that may exist between separate components. This allows the clamping force applied by the fastening assembly 30 to be evenly transmitted to the connecting side wall 232 and the outer wall through the thick fixing part 224, thereby improving the rigidity and stress transmission efficiency of the overall structure of the outer structural plate 22. At the same time, the thicker cross-section of the thick fixing part 224 enhances the bending stiffness at the corner and reduces the stress concentration near the fastening area, further ensuring the fixing stability of the main insulation module 20.

[0024] In other embodiments, such as Figure 6 and Figure 7As shown, the outer structural panel 22 includes a large fixed plate 221 and two side fixed plates 225. The large fixed plate 221 is fixed to the outer wall of the main insulation layer 23 and extends below the avoidance chamfer 231. The two side fixed plates 225 are connected at an angle and are fixed to the large fixed plate 221, respectively, and are fixed to the two connecting side walls 232 at the avoidance chamfer 231. As a more specific implementation, the main insulation layer 23 is recessed inward at the connecting side walls 232 to form a mounting groove 236. The side fixed plates 225 are designed to be embedded and fixed in the mounting groove 236. At the same time, the portion of the large fixed plate 221 extending below the avoidance chamfer 231 forms a limiting part 235. This structural design provides a new force point for the pressing of the pressure plate 31. Furthermore, the fastening assembly 30 includes a pressure plate 31 and a screw assembly 32. The pressure plate 31 presses against the limiting part 235 and is locked by the screw assembly 32. The beneficial effect of this solution is that the two side fixing plates 225 respectively fix the two connecting side walls 232, achieving more comprehensive coverage of the corner. The design of the side fixing plates 225 embedded in the mounting groove 236 forms a clever limiting structure, so that the side fixing plates 225 are constrained by the groove wall of the mounting groove 236 when subjected to lateral force, making them less prone to displacement.

[0025] Therefore, by setting two side fixing plates 225 to be fixed to the two connecting side walls 232 at the avoidance chamfer, the two mutually perpendicular connecting side walls 232 at the corner of the main insulation layer 23 are reliably fixed and supported. Furthermore, by forming an installation groove 236 by recessing inward at the connecting side wall 232, the side fixing plate 225 is embedded in the installation groove 236. At the same time, the installation groove 236 forms a limiting constraint on the side fixing plate 225, restricting the displacement of the side fixing plate 225 during the fastening process, avoiding local crushing or deformation of the main insulation layer 23 due to stress concentration, thereby enhancing the fixing reliability of the main insulation module 20 under vibration and low temperature alternating conditions.

[0026] Correspondingly, under different configurations of the outer structural plate 22, the specific pressing positions of the fastening assembly 30 vary, but all include the core pressure plate 31 and screw assembly 32. For Figure 4 In the embodiment shown with corner fixing block 222, the pressure plate 31 of the fastening assembly 30 presses directly against the corner fixing block 222 and is locked by the screw assembly 32. For Figure 5 In the embodiment of the integrated outer structural panel 22 shown, the pressure plate 31 of the fastening assembly 30 presses against the thick fixing portion 224 and is locked by the screw assembly 32. For Figure 6In the embodiment shown with the limiting portion 235, as described above, the pressure plate 31 presses against the limiting portion 235 and is locked by the screw assembly 32. By specifically selecting the pressing position of the pressure plate 31 on the structural feature that best exerts the fastening effect, efficient transmission of the locking force is ensured.

[0027] In some more preferred embodiments, reference is made to Figures 2-4 To compensate for material shrinkage under low-temperature conditions and the potential decrease in preload caused by vibration, the fastening assembly 30 further includes a pressure spring assembly 33. The screw assembly 32 includes a stud 321, a nut 322, and a fixing plate 323. The fixing plate 323 is pre-fixed to the structure of the secondary insulation module 10. One end of the stud 321 is fixedly connected to the fixing plate 323, and the other end passes through the pressure plate 31 and the pressure spring assembly 33, and the pressure plate 31 is pressed down by tightening the nut 322. The pressure spring assembly 33 is clamped between the nut 322 and the pressure plate 31. This design provides the fastening system with elastic compensation capabilities. Furthermore, the beneficial effect of this is that under low-temperature operating conditions, the components shrink to varying degrees due to differences in the thermal expansion coefficients of the materials, or undergo slight plastic deformation under long-term vibration, all of which lead to a decrease in the preload of the fasteners. At this time, the pre-compressed pressure spring assembly 33 releases its elastic potential energy, automatically compensates for the gap caused by contraction or deformation, and continuously provides a stable clamping force to ensure that the constraint of the pressure plate 31 on the external structural plate 22 is always effective, prevents loosening of the fastener, thereby significantly extending the maintenance-free period of the storage tank and improving the reliability of long-term operation.

[0028] Therefore, by setting a pressure spring assembly 33 in the fastening assembly 30 and clamping the pressure spring assembly 33 between the nut 322 and the fixing plate 323, the elastic deformation capability of the pressure spring assembly 33 provides a continuous elastic compensation force when the fasteners tend to loosen due to low temperature shrinkage or mechanical vibration. This keeps the pressure of the pressure plate 31 on the external structural plate 22 stable, prevents the fasteners from loosening due to temperature cycling, extends the maintenance cycle of the fastening assembly 30, and further improves the structural stability of the storage tank during long-term operation.

[0029] As a specific configuration of elastic elements, such as Figures 2-4As shown, the compression spring assembly 33 includes a first spring 331 protruding towards the nut 322 in the middle and a second spring 332 protruding away from the nut 322 in the middle, with the second spring 332 sandwiched between the two first springs 331. This combination of multiple disc-shaped springs or similar elastomers with different orientations constitutes a precise elastic system. Therefore, the stiffness, compression stroke, and restoring force characteristics of a spring assembly formed by stacking multiple springs in the same or opposite directions can be flexibly adjusted by changing the number, thickness, and combination of the springs. The "concave-convex" combination in this design allows each spring in the compression spring assembly 33 to undergo elastic deformation sequentially or simultaneously when compressed, providing a relatively stable and continuous elastic restoring force over a wider range of compression, effectively absorbing impact and vibration energy, and exhibiting strong adaptability to complex load conditions caused by temperature cycling and continuous vibration.

[0030] Therefore, by configuring the pressure spring assembly 33 to include a first spring 331 protruding towards the nut 322 and a second spring 332 protruding away from the nut 322, with the second spring 332 sandwiched between the two first springs 331, the first springs 331 and the second springs 332 will generate elastic deformation in opposite directions when the pressure spring assembly 33 is compressed, forming a multi-level elastic compensation mechanism. This provides a stable elastic recovery force over a wider compression stroke range, enhances the adaptability of the fastening assembly 30 under large temperature fluctuations and vibration conditions, and further ensures the fixing reliability of the main insulation module 20.

[0031] In application scenarios where multiple main insulation modules 20 are combined and installed, such as Figures 1-4 As shown, a fastening assembly 30 is positioned at the cross joint of four adjacent main insulation modules 20. The pressure plate 31 of this fastening assembly 30 is designed to have sufficient coverage area to simultaneously press against four outer structural plates 22 from the four different main insulation modules 20. Furthermore, to ensure the stability and uniformity of the pressing, a limiting protrusion 311 is provided on the pressure plate 31, which accurately limits and supports the connection between two adjacent outer structural plates 22. This centralized fastening design achieves simultaneous fixing of the four modules through a single fastening point. Therefore, this structure not only reduces the overall number of fastening assemblies 30, simplifies the installation process, and lowers costs, but also ensures a high degree of consistency in the fixing of adjacent main insulation modules 20 at the boundary by simultaneously locking four main insulation modules 20 with a single pressure plate 31. The limiting protrusions 311 on the pressure plate 31 play a precise positioning and isolation role, preventing the pressure plate 31 from rotating or slipping when under force, and ensuring that each main insulation module 20 is pressed to a basically consistent degree, avoiding local warping or damage caused by uneven force, and improving the flatness and integrity of the entire main insulation module 20 after paving.

[0032] Therefore, by placing each fastening component 30 between the four main insulation modules 20 and simultaneously pressing the pressure plate 31 against the four outer structural plates 22, one fastening component 30 can simultaneously fix the four main insulation modules 20, reducing the number of fastening components 30 required. The limiting protrusion 311 on the pressure plate 31 provides limiting support between two adjacent outer structural plates 22, preventing the pressure plate 31 from shifting its position when subjected to vibration or thermal stress. This ensures that the pressure force of the pressure plate 31 on each outer structural plate 22 is uniform and stable in direction, thereby simplifying the fixing structure while improving the fixing consistency between multiple main insulation modules 20 and reducing the risk of local loosening.

[0033] Furthermore, it should be noted that in some optional embodiments, the main insulation layer 23 can be made of reinforced polyurethane foam or other insulation materials suitable for ultra-low temperature environments. The fixing methods for the inner structural plate 21 and the outer structural plate 22 are not limited to adhesive bonding, but may also include mechanical connections such as bolting and riveting. The pressure spring assembly 33 in the fastening assembly 30 can also be replaced by a single helical spring or a higher stiffness elastic element. The main insulation module 20 and the secondary insulation module 10 can have a multi-layer composite structure to meet different insulation level requirements. All of these optional alternatives do not depart from the technical concept of this application and should be covered within the scope of protection of this application.

[0034] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A cryogenic liquid cargo sealed storage tank, characterized in that, include: Secondary insulation module; A main insulation module is disposed on the inner side of the secondary insulation module. The main insulation module includes an inner structural plate, an outer structural plate, and a main insulation layer disposed between the inner structural plate and the outer structural plate. The end of the main insulation layer is provided with a clearance chamfer along its thickness direction. The main insulation layer has a connecting sidewall at the clearance chamfer. The inner structural plate is fixed to the inner sidewall of the main insulation layer. The outer structural plate is fixed to the outer sidewall of the main insulation layer and the connecting sidewall, respectively, and wraps around the corner of the main insulation layer. A fastening assembly is connected between the secondary insulation module and the outer structural plate to fix the primary insulation module to the secondary insulation module; The fastening assembly includes: a pressure plate, a screw assembly, and a pressure spring assembly; The screw assembly includes a stud, a nut, and a fixing plate. The fixing plate is fixed to the secondary insulation module. One end of the stud is fixed to the fixing plate, and the other end of the stud is adapted to pass through the pressure plate and the pressure spring assembly to connect with the nut. The pressure spring assembly is clamped between the nut and the pressure plate. The pressing spring assembly includes: a first spring protruding towards the nut in the middle and a second spring protruding away from the nut in the middle, the second spring being sandwiched between the two first springs; Each of the fastening components is disposed between the four main insulation modules. The pressure plate simultaneously presses against the four outer structural plates of the four main insulation modules. The pressure plate is provided with a limiting protrusion, which limits and supports the outer structural plates between two adjacent ones.

2. The cryogenic liquid cargo sealed storage tank according to claim 1, characterized in that, The outer structural panel includes a large surface fixing plate and a corner fixing block. The large surface fixing plate is fixed to the outer wall of the main insulation layer and extends to the area below the avoidance chamfer. The corner fixing block is fixed to the large surface fixing plate and embedded in the avoidance chamfer to be fixed to the connecting side wall.

3. The cryogenic liquid cargo sealed storage tank according to claim 1, characterized in that, The outer structural plate is constructed as an integrally formed structural component. The outer structural plate includes a thin fixing part and a thick fixing part. The thickness of the thick fixing part is greater than the thickness of the thin fixing part. The thin fixing part is fixed to the outer side wall of the main insulation layer. The thick fixing part is adapted to extend into the avoidance chamfer to be fixed to the connecting side wall.

4. The cryogenic liquid cargo sealed storage tank according to claim 1, characterized in that, The outer structural panel includes: a large fixed panel and two side fixed panels. The large fixed panel is fixed to the outer wall of the main insulation layer and extends to below the avoidance chamfer. The two side fixed panels are connected at an angle and are fixed to the large fixed panel and respectively fixed to the two connecting side walls at the avoidance chamfer.

5. The cryogenic liquid cargo sealed storage tank according to claim 2, characterized in that, The pressure plate presses against the corner fixing block and is locked by the screw assembly.

6. The cryogenic liquid cargo sealed storage tank according to claim 3, characterized in that, The pressure plate presses against the thick fixing part and is locked by the screw assembly.

7. The cryogenic liquid cargo sealed storage tank according to claim 4, characterized in that, The main insulation layer is recessed into the interior of the main insulation layer at the connecting side wall to form a mounting groove. The side fixing plate is embedded and fixed in the mounting groove. The portion of the large surface fixing plate extending below the avoidance chamfer is formed as a limiting part. The pressure plate presses against the limiting part and is locked by the screw assembly.

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