Prefabricated trihedral member of a thin film envelope system and method of manufacture

Abstract

The application discloses a prefabricated trihedral component of a thin film enclosure system and a manufacturing method. The trihedral component is arranged at an angle point region of three surfaces and comprises, from outside to inside, a secondary heat insulation layer, a secondary shielding layer, a main heat insulation layer and a main shielding layer. The secondary heat insulation layer comprises three secondary heat insulation blocks, and an outer plywood top corner is provided with a first locking groove matched with a ship shell connecting piece. The secondary shielding layer is an integrally formed first steel corner piece, the outer surface of which is provided with a first threaded stud locked with the secondary heat insulation layer, and the inner surface of which is provided with a second threaded stud used for positioning the main heat insulation layer. The main heat insulation layer comprises three main heat insulation blocks, and an outer plywood top corner is provided with a second locking groove matched with the second threaded stud. The main shielding layer is an integrally formed second steel corner piece, and the outer surface of which is provided with a third threaded stud locked with the main heat insulation layer. The four-layer structure of the trihedral region is integrally prefabricated as a single component, the field joint is eliminated, and the assembly precision and sealing reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of liquefied natural gas storage and transportation equipment technology, and more specifically, to a prefabricated trihedral component of a membrane enclosure system and its manufacturing method. Background Technology

[0002] Membrane containment systems for liquefied natural gas (LNG) typically employ a double-layer shielding and double-layer insulation design, resulting in geometrically complex areas covered by these systems. In most areas, the containment system is laid along or near-planar surfaces of the ship's hull, termed planar regions. At the intersection of two surfaces within the hull structure, a dihedral region is formed, where two surfaces intersect along an edge. At the intersection of three surfaces, a trihedral region is formed, where three surfaces intersect at a single corner along three edges.

[0003] As the corner where three faces intersect, the trihedral region faces more severe technical challenges in its structural design than the planar and dihedral regions. First, the geometry of the trihedral region is the most complex; second, the space in the trihedral region is the smallest and most enclosed, with extremely limited operating space for construction personnel; third, the trihedral region involves a large number of components and numerous joints, each of which is a potential leakage path and thermal bridge channel.

[0004] In existing technologies, the insulation blocks and shielding panels of each layer in the three-sided region are typically prefabricated separately and installed on-site. This separate installation method has the following prominent problems in the three-sided region: First, the four-layer components on three sides need to be installed and positioned one by one. Each component needs to be adjusted, fixed and sealed in a narrow space, making the on-site assembly process complicated.

[0005] Secondly, the trihedral region involves the intersection of components in three directions. Any deviation in the position of any component will affect the installation of adjacent components, making it difficult to control the assembly accuracy.

[0006] Third, the split installation method creates dozens of joints between components in the three-sided area, and each joint requires on-site sealing, resulting in low sealing reliability.

[0007] Therefore, there is an urgent need for a technical solution for the overall prefabrication of the trihedral region, which can assemble the four-layer structure in the factory to form a single prefabricated trihedral component, thereby reducing on-site processes, eliminating on-site joints, and improving assembly accuracy and quality consistency. Summary of the Invention

[0008] The purpose of this invention is to provide a prefabricated three-sided component for a membrane enclosure system, which prefabricates the four-layer structure of the three-sided region into a single component, solving the problems of complicated procedures, difficulty in controlling precision, numerous seams, and low sealing reliability in the existing three-sided region separate installation method.

[0009] To address the aforementioned technical problems, this invention provides a prefabricated trihedral component for a membrane enclosure system, disposed at the corner region where the three surfaces intersect, comprising, from the outside in: The secondary insulation layer includes secondary insulation blocks corresponding to three sides. Each secondary insulation block includes a first outer plywood, a first inner plywood, and a first polyurethane layer sandwiched between the first outer plywood and the first inner plywood. Each first outer plywood has a first locking groove at its top corner that mates with a connector on the hull. The secondary shielding layer is an integrally formed first steel corner piece. The first steel corner piece has three surfaces that match the corner area. A first stud is fixed on the outer surface of the first steel corner piece. The first stud is locked to a first nut inside the secondary insulation layer. A second stud is also provided on each inner surface of the first steel corner piece. The main insulation layer includes main insulation blocks corresponding to three sides. Each main insulation block includes a second outer plywood, a second inner plywood, and a second polyurethane layer sandwiched between the second outer plywood and the second inner plywood. A second locking groove that mates with the second stud is provided at the top corner of each second outer plywood. The main shielding layer is an integrally formed second steel corner piece. A third stud is provided on the outer surface of the second steel corner piece, and the third stud is locked to a second nut inside the main insulation layer.

[0010] Furthermore, a first assembly strip is provided on the outer side of two adjacent secondary insulation blocks, and the first assembly strip covers the joint of the two adjacent secondary insulation blocks to fix the relative position of the two adjacent secondary insulation blocks; a second assembly strip is provided on the outer side of two adjacent main insulation blocks, and the second assembly strip covers the joint of the two adjacent main insulation blocks to fix the relative position of the two adjacent main insulation blocks.

[0011] Furthermore, both the first assembly tape and the second assembly tape are low-temperature adhesive tapes.

[0012] Furthermore, the first inner plywood and the second inner plywood are respectively provided with mounting holes corresponding to the first stud and the third stud, and the ends of the first stud and the third stud pass through the mounting holes and are locked with the first nut and the second nut respectively.

[0013] Furthermore, gaskets are provided between the first nut and the first inner plywood, and between the second nut and the second inner plywood.

[0014] Furthermore, the inner surfaces of the first polyurethane layer and the second polyurethane layer are respectively provided with receiving grooves corresponding to the first stud and the third stud.

[0015] Furthermore, the thickness of the first inner plywood is greater than the thickness of the first outer plywood, and the thickness of the second inner plywood is greater than the thickness of the second outer plywood.

[0016] Furthermore, there is a first gap between two adjacent secondary insulation blocks and a second gap between two adjacent main insulation blocks. The outer side of the first gap and the second gap is filled with plywood, and the inner side of the first gap and the second gap is filled with glass wool.

[0017] Furthermore, the first locking groove and the second locking groove include a first end with a large aperture and a second end with a small aperture, the second end being close to the apex of the first outer plywood and the second outer plywood, and the first end being close to the junction of the first outer plywood and the junction of the second outer plywood.

[0018] Furthermore, the first polyurethane layer and the second polyurethane layer are respectively provided with notches to avoid the first locking groove and the second locking groove.

[0019] Furthermore, both the first and second steel corner pieces are made of stainless steel. The first and second studs are welded and fixed to the first steel corner piece, and the third stud is welded and fixed to the second steel corner piece.

[0020] The present invention also provides a method for manufacturing a prefabricated trihedral component of a membrane enclosure system, comprising the following steps: S10: Cut out the first outer plywood, first polyurethane layer, and first inner plywood of each secondary insulation block according to the design dimensions, as well as the second outer plywood, second polyurethane layer, and second inner plywood of each main insulation block. S20: Stamp out the first and second steel angle pieces according to the set dimensions and connect the first stud, the second stud and the third stud; S30: Lock the first steel corner piece to the three first inner plywoods and the second steel corner piece to the three second inner plywoods to form the first precast part and the first main precast part; S40: The first precast component is assembled with three first polyurethane layers and three first outer plywood according to the design structure, and then filled with glass wool and plywood before being pressed into a second precast component. The first main precast component is assembled with three second polyurethane layers and three second outer plywood according to the design structure, and then filled with glass wool and plywood before being pressed into a second main precast component. S50: Lock the filled second precast component and the second main precast component to form a precast trihedral component.

[0021] Furthermore, in step S40, a first assembly strip and a second assembly strip are respectively attached to the outer surfaces of the second preform and the second main preform.

[0022] Furthermore, the quality of the completed prefabricated trihedral components is inspected.

[0023] The beneficial effects of this invention are: 1. This invention prefabricates the four-layer structure of the trihedral region into a single component in the factory, reducing the seams formed by on-site splicing between components in the corner area, significantly reducing the number of potential leakage paths and thermal bridges, while improving the assembly accuracy and assembly quality consistency of the trihedral region, and greatly enhancing the overall sealing and thermal insulation performance of the system.

[0024] 2. Both the secondary shielding layer and the primary shielding layer use integrally molded steel corner pieces, eliminating the splicing seams of the shielding layer itself. The connection of the steel corner pieces is firm and reliable, avoiding the risk of stress concentration and sealing failure at the splicing seams, and ensuring the stability of the overall structure of the prefabricated three-sided structure under thermal expansion and contraction.

[0025] 3. The inner plywood is thicker than the outer plywood, giving the inner side of the insulation block higher structural strength and better able to withstand the locking force and low-temperature shrinkage stress from the shielding layer. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the secondary structure of the present invention; Figure 3 This is a bottom view of the secondary structure of the present invention; Figure 4 This is an exploded view of the secondary structure of the present invention; Figure 5 This is a cross-sectional view of the layer structure of the present invention; Figure 6 This is a schematic diagram of the main layer structure of the present invention; Figure 7 This is a bottom view of the main structure of the present invention; Figure 8 This is an exploded view of the main layer structure of the present invention; Figure 9 This is a cross-sectional view of the main layer structure of the present invention.

[0027] Explanation of the labels in the diagram: 10. Secondary insulation layer; 11. Secondary insulation block; 12. First outer plywood; 121. First locking groove; 122. First end; 123. Second end; 13. First inner plywood; 14. First polyurethane layer; 141. Notch; 15. First assembly strip; 16. First gap; 17. Filling plywood; 18. Glass wool; 19. Mounting hole; 20. Secondary shielding layer; 21. First steel angle bracket; 22. First stud; 23. First nut; 24. Second stud; 30. Main insulation layer; 31. Main insulation block; 32. Second outer plywood; 321. Second locking groove; 33. Second inner plywood; 34. Second polyurethane layer; 35. Second assembly strip; 36. Second gap; 40. Main shielding layer; 41. Second steel angle bracket; 42. Third stud; 43. Second nut. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0029] Reference Figure 1 The diagram shown is a schematic representation of the overall structure of the prefabricated trihedral component of this invention. The prefabricated trihedral component of this invention is positioned at the corner region where the three surfaces intersect in the membrane enclosure system. The corner region refers to the transition area in a ship hull structure where the three surfaces meet at a single corner, such as the corner where the bottom of the hull meets the side walls. The prefabricated trihedral component comprises, from the outside in, a secondary insulation layer 10, a secondary shielding layer 20, a primary insulation layer 30, and a primary shielding layer 40, totaling four layers. After being prefabricated and assembled in the factory, it is transported as a complete component to the construction site for overall installation.

[0030] Reference Figure 2 , Figure 3 and Figure 4The diagram shows the overall structure of the secondary layer of the present invention. Here, the secondary layer is an integral structure composed of the secondary insulation layer 10 and the secondary shielding layer 20. The secondary insulation layer 10 includes secondary insulation blocks 11 corresponding to three sides. Each secondary insulation block 11 includes a first outer plywood 12, a first inner plywood 13, and a first polyurethane layer 14 sandwiched between the first outer plywood 12 and the first inner plywood 13. The first outer plywood 12 is located on the outer side of the secondary insulation block 11, that is, the side closer to the hull, and is the side where the secondary insulation block 11 connects to the inner surface of the hull. Specifically, the secondary insulation block 11 is bonded to the hull with resin putty and also secured by connectors. The first inner plywood 13 is located on the inner side of the secondary insulation block 11, that is, the side closer to the liquid cargo, and is the side where the secondary insulation block 11 is adjacent to the secondary shielding layer 20. The first polyurethane layer 14 is filled between the first outer plywood 12 and the first inner plywood 13, forming a "sandwich" structure of plywood-polyurethane-plywood.

[0031] Both the first outer plywood 12 and the first inner plywood 13 are made of low-temperature resistant plywood material, which can maintain structural performance under the extremely low temperature conditions of LNG storage and transportation environment, without low-temperature embrittlement or significant strength reduction. The first polyurethane layer 14 has an extremely low thermal conductivity, providing excellent thermal insulation performance. It is the core material for the secondary insulation layer 10 to achieve its thermal insulation function. A good bonding interface is formed between the polyurethane and the plywood, ensuring the integrity of the sandwich structure.

[0032] To secure the secondary insulation layer 10 to the hull, a first locking groove 121 is provided at the top corner of each first outer plywood 12 to engage with the connecting parts on the hull. One first locking groove 121 is provided at the outermost top corner of each first outer plywood 12, and a total of three first locking grooves 121 are provided for the three secondary insulation blocks 11. The function of the first locking groove 121 is to engage with the pre-set connecting bolts on the hull when the prefabricated three-sided component is installed onto the hull, thereby achieving the positioning and fixation of the prefabricated three-sided component on the hull.

[0033] Because the prefabricated three-sided component is located at the corner of the hull, the connecting bolts on the hull will be recessed inward. To ensure that the prefabricated three-sided component can mate with the connecting bolts, the first locking groove 121 includes a first end 122 with a large diameter and a second end 123 with a small diameter. The second end 123 is close to the apex of the first outer plywood 12, that is, located near the corner of the apex of the first outer plywood 12. The first end 122 is close to the junction of the first outer plywood 12, that is, located at the junction of the first outer plywood 12 and the first outer plywood 12 of the adjacent secondary insulation block 11. During installation, the connecting bolt enters from the first end 122 with a large diameter, is guided by the large diameter to slide in, and finally locks into the second end 123. The secondary insulation layer 10 is locked to the hull by the limiting effect of the gasket and the second end 123. This flared design makes the installation operation simple and reliable, and the connector is effectively guided during insertion, avoiding positional deviation and installation difficulties.

[0034] Since the first locking groove 121 is located at the top corner of the first outer plywood 12, it needs to occupy a certain space, and space needs to be reserved for the locking bolts. Therefore, the first polyurethane layer 14 has a notch 141 at the position corresponding to the first locking groove 121 to avoid the first locking groove 121. The notch 141 can be reserved before polyurethane foaming, or it can be removed by mechanical processing after foaming.

[0035] In this embodiment, since the first inner plywood 13 needs to fix the secondary shielding layer 20, in order to withstand the locking force from the studs of the secondary shielding layer 20 and the shrinkage stress under low-temperature conditions, the thickness of the first inner plywood 13 is greater than the thickness of the first outer plywood 12, so as to provide higher structural strength and load-bearing capacity. The first outer plywood 12 is located on the side of the secondary insulation block 11 closer to the hull, and mainly serves to encapsulate the polyurethane layer and support the first locking groove 121. It experiences relatively less stress, and a thinner plywood is used to reduce the overall weight of the secondary insulation block 11. In this embodiment, the thickness of the first inner plywood 13 is 1.5 to 2 times the thickness of the first outer plywood 12.

[0036] Furthermore, to fix the relative positions of two adjacent secondary insulation blocks 11, a first assembly strip 15 is provided on the outer side of the two adjacent secondary insulation blocks 11 in this embodiment. The first assembly strip 15 covers the joint of the two adjacent secondary insulation blocks 11. The first assembly strip 15 is a low-temperature tape, specifically aluminum foil butyl tape. This type of low-temperature tape is not easy to harden and crack under low-temperature conditions, and maintains its adhesive performance. It is connected to the outer surface of the first outer plywood 12 of the two adjacent secondary insulation blocks 11 by adhesive method, connecting the three secondary insulation blocks 11 into a whole, ensuring that the relative positions of each secondary insulation block 11 are fixed; at the same time, the low-temperature tape allows a small relative displacement between adjacent secondary insulation blocks 11 within a certain range, adapting to the long-term low-temperature expansion and contraction deformation of the membrane enclosure system, and avoiding stress concentration caused by rigid constraints.

[0037] To accommodate the minute displacements caused by thermal expansion and contraction under low-temperature conditions, and to provide assembly tolerances, a first gap 16 exists between two adjacent secondary insulation blocks 11. In this embodiment, a plywood 17 is provided on the outer side of the first gap 16, and glass wool 18 is provided on the inner side.

[0038] At the outer edge of the angle between two adjacent secondary insulation blocks 11, due to irregular geometric shapes at the hull corner, such as casting allowances, welding deformations, and local protrusions, the apex of the secondary insulation block 11 needs to be flattened to better fit the inner surface of the hull. However, this flattening operation weakens the support of the plywood at the angle to the first polyurethane layer 14, reducing structural strength. To compensate for this strength loss, a filler plywood 17 is provided on the outer side of the first gap 16 to reinforce the root of the flattened area. The filler plywood 17 is made of the same material as the plywood of the secondary insulation block 11, and its thickness is similar to that of the first outer plywood 12. It covers the outer part of the first gap 16 along the depth direction, sharing the load with the corresponding polyurethane layer, increasing the structural strength at this point, and ensuring that the secondary insulation block 11 has sufficient load-bearing capacity at the apex of the angle.

[0039] The remaining space in the first gap 16 is filled with glass wool 18. Glass wool 18 is a fibrous insulation material with a lower density than polyurethane, a soft texture, low thermal conductivity, and good insulation performance. Glass wool 18 can adapt to changes in the shape of the first gap 16, allowing slight displacement between adjacent secondary insulation blocks 11 while ensuring insulation performance. It absorbs deformation caused by thermal expansion and contraction, does not impose rigid constraints on adjacent insulation blocks, and avoids stress concentration.

[0040] In this embodiment, the secondary shielding layer 20 is an integrally formed first steel corner piece 21. The first steel corner piece 21 is made of stainless steel, which maintains good mechanical properties and ductility even in the extremely low temperature environment of LNG, without undergoing low-temperature embrittlement, ensuring the sealing reliability of the secondary shielding layer 20 under long-term low-temperature conditions. The first steel corner piece 21 is integrally formed by bending or stamping processes and has three interconnected surfaces, corresponding to the three surfaces of the trihedral region. The included angles between the three surfaces match the included angles between the three surfaces of the trihedral region, ensuring that the first steel corner piece 21 can fit against the inner surface of the secondary insulation layer 10.

[0041] Reference Figure 4 and Figure 5As shown, to secure the first steel angle member 21 to the secondary insulation layer 10, a first stud 22 is fixed to the outer surface of the first steel angle member 21. The first stud 22 is provided on three sides of the first steel angle member 21, with at least one stud 22 on each side, ensuring the connection strength and uniformity between the first steel angle member 21 and the secondary insulation layer 10. The first stud 22 is welded to the first steel angle member 21 and, after passing through the first inner plywood 13, is locked to the first nut 23 inside the secondary insulation layer 10.

[0042] Specifically, the first inner plywood 13 of the secondary insulation block 11 is provided with mounting holes 19 corresponding to the first studs 22. The diameter of the mounting holes 19 is slightly larger than the outer diameter of the first studs 22, facilitating the insertion of the first studs 22. After passing through the mounting holes 19, the first studs 22 engage with the first nut 23 on the other side of the first inner plywood 13 for locking, thus fixing the first steel angle piece 21 to the secondary insulation layer 10. A gasket is provided between the first nut 23 and the first inner plywood 13 to increase the contact area between them, disperse the locking force, and prevent the first nut 23 from directly pressing against the first inner plywood 13, causing local crushing or damage. At the same time, the inner surface of the first polyurethane layer 14 is also provided with receiving grooves corresponding to the first studs 22 to avoid direct contact between the first studs 22 and the first polyurethane layer 14, preventing local damage to the polyurethane layer.

[0043] Each inner surface of the first steel angle member 21 is also provided with a second stud 24. The second stud 24 is perpendicular to the surface of the first steel angle member 21, with one second stud 24 on each surface, for a total of three second studs 24 on the three surfaces. The second studs 24 are welded and fixed to the first steel angle member 21, ensuring a firm and reliable connection. The function of the second studs 24 is to provide a positioning reference when assembling the main insulation layer 30. They cooperate with the second locking groove 321 on the second outer plywood 32 of the main insulation block 31 to achieve precise positioning and connection of the main insulation layer 30 relative to the secondary shielding layer 20.

[0044] Reference Figure 6 , Figure 7 and Figure 8 The diagram shown is a schematic of the main layer structure of the present invention. The main insulation layer 30 includes main insulation blocks 31 corresponding to the three faces of the three-sided region, and also corresponding to the three secondary insulation blocks 11.

[0045] Each main insulation block 31 includes a second outer plywood 32, a second inner plywood 33, and a second polyurethane layer 34 sandwiched between the second outer plywood 32 and the second inner plywood 33. The second outer plywood 32 is located on the outer side of the main insulation block 31, i.e., the side closer to the hull, and is the surface of the main insulation block 31 adjacent to the secondary shielding layer 20. The second inner plywood 33 is located on the inner side of the main insulation block 31, i.e., the side closer to the liquid cargo, and is the surface of the main insulation block 31 adjacent to the main shielding layer 40. The second polyurethane layer 34 fills the space between the second outer plywood 32 and the second inner plywood 33, forming a plywood-polyurethane-plywood "sandwich" core structure, similar to the core structure of the secondary insulation block 11.

[0046] The second outer plywood 32 and the second inner plywood 33 are both made of the same low-temperature resistant plywood material as the plywood of the secondary insulation block 11. A second polyurethane layer 34 fills the space between the second outer plywood 32 and the second inner plywood 33, providing excellent thermal insulation performance. Each second outer plywood 32 has a second locking groove 321 at its apex corner that mates with the second stud 24. One second locking groove 321 is provided at the outermost apex corner of each second outer plywood 32, and a total of three second locking grooves 321 are provided for the three main insulation blocks 31. The second locking groove 321 is used to mate with the second stud 24 on the first steel angle member 21, which serves as the secondary shielding layer 20, to achieve a positioning connection between the main insulation layer 30 and the secondary shielding layer 20.

[0047] The second locking groove 321 is similar to the first locking groove 121, including a first end 122 with a large aperture and a second end 123 with a small aperture. The second end 123 is near the apex corner of the second outer plywood 32, and the first end 122 is near the junction of the second outer plywood 32. When assembling the main insulation layer 30, the second stud 24 on the secondary shielding layer 20 enters from the first end 122 with a large aperture, slides in guided by the large aperture, and finally locks into the second end 123. The main insulation layer 30 and the secondary shielding layer 20 are locked together by the limiting action of the gasket and the second end 123. To facilitate the locking operation, the second polyurethane layer 34 is provided with a notch 141 at the position corresponding to the second locking groove 321 to avoid the second locking groove 321.

[0048] The second inner plywood 33 is located on the side of the main insulation block 31 closest to the main shielding layer 40. It bears the locking force from the studs of the main shielding layer 40 and the shrinkage stress under low-temperature conditions, requiring higher structural strength. Therefore, the thickness of the second inner plywood 33 is greater than the thickness of the second outer plywood 32. The second outer plywood 32 is located on the side of the main insulation block 31 closest to the secondary shielding layer 20. It mainly serves to encapsulate the polyurethane layer and support the second locking groove 321. It experiences relatively less stress, so a thinner plywood is used to reduce the overall weight of the main insulation block 31. In this embodiment, the thickness of the second inner plywood 33 is 1.5 to 2 times the thickness of the second outer plywood 32.

[0049] A second assembly strip 35 is also provided on the outer side of two adjacent main insulation blocks 31. The second assembly strip 35 covers the joint between the two adjacent main insulation blocks 31, fixing the relative position of the two adjacent main insulation blocks 31. The second assembly strip 35 is the same as the first assembly strip 15, both being low-temperature adhesive tape. The second assembly strip 35 is connected to the outer surface of the second outer plywood 32 of the two adjacent main insulation blocks 31 by adhesive bonding, fully or partially covering the joint between the two main insulation blocks 31. The function of the second assembly strip 35 is to connect the three main insulation blocks 31 into a whole during the prefabrication process, ensuring that the relative position between each main insulation block 31 is fixed, while allowing slight relative displacement between adjacent main insulation blocks 31 to accommodate thermal expansion and contraction deformation.

[0050] A second gap 36 exists between two adjacent main insulation blocks 31. A plywood 17 is installed on the outer side of the second gap 36, and glass wool 18 is installed on the inner side. The plywood 17 covers the outer portion of the second gap 36 along its depth direction, providing structural support and strengthening the root. The glass wool 18 fills the remaining space of the second gap 36, serving the same function as the glass wool 18 in the first gap 16 of the secondary insulation layer 10.

[0051] The main shielding layer 40 is a single-piece second steel corner piece 41 made of stainless steel, the same material as the first steel corner piece 21, ensuring the sealing reliability of the main shielding layer 40 in extremely low temperature environments. The second steel corner piece 41 is integrally formed by bending or stamping processes and has three interconnected surfaces, corresponding to the three surfaces of the trihedral region.

[0052] Reference Figure 5As shown, a third stud 42 is provided on the outer surface of the second steel angle member 41. The third stud 42 is provided on three faces of the second steel angle member 41, with at least one third stud 42 on each face. The third stud 42 is welded and fixed to the second steel angle member 41 to ensure a firm and reliable connection. After passing through the main insulation block 31, the third stud 42 is locked with the second nut 43 inside the main insulation layer 30. Specifically, the second inner plywood 33 of the main insulation block 31 is provided with mounting holes 19 corresponding to the third stud 42. The diameter of the mounting holes 19 is slightly larger than the outer diameter of the third stud 42 to facilitate its insertion. After passing through the mounting holes 19, the third stud 42 engages with the second nut 43 on the other side of the second inner plywood 33 to lock it in place, thus fixing the second steel angle member 41 to the main insulation layer 30. A washer is provided between the second nut 43 and the second inner plywood 33 to increase the contact area between them, disperse the locking force, and prevent the second nut 43 from directly pressing against the second inner plywood 33, causing local crushing or damage. The inner surface of the second polyurethane layer 34 also has a corresponding receiving groove for the third stud 42. This prevents direct contact between the third stud 42 and the second polyurethane layer 34, thus avoiding localized damage to the polyurethane layer.

[0053] The assembly process of the prefabricated trihedral component is completed in the factory, and the specific steps of its manufacturing method are as follows: S10: Prefabricated components. Based on the dimensions and angles of the three faces of the trihedral region, the dimensions of each layer of the prefabricated trihedral component are designed. According to the designed dimensions, the first outer plywood 12, the first polyurethane layer 14, and the first inner plywood 13 of the three secondary insulation blocks 11, and the second outer plywood 32, the second polyurethane layer 34, and the second inner plywood 33 of the three main insulation blocks 31 are cut out respectively. A first locking groove 121 is machined at the apex of the first outer plywood 12. Mounting holes 19 corresponding to the first studs 22 are machined on the first inner plywood 13. A second locking groove 321 is machined at the apex of the second outer plywood 32. Mounting holes 19 corresponding to the third studs 42 are machined on the second inner plywood 33.

[0054] S20: Prefabricated secondary shielding layer 20 and primary shielding layer 40. First steel angle piece 21 and second steel angle piece 41 are stamped according to set dimensions and connected to first stud 22, second stud 24, and third stud 42. After the first steel angle piece 21 is integrally formed, the first stud 22 and second stud 24 are welded and fixed at the designed positions on the inner and outer surfaces, respectively; after the second steel angle piece 41 is integrally formed, the third stud 42 is welded and fixed at the designed position on the outer surface.

[0055] S30: Assemble the first prefabricated component and the first main prefabricated component. Attach the three first inner plywood boards 13 to the corresponding outer surfaces of the first steel angle pieces 21, allowing the first studs 22 to pass through the mounting holes 19. Use the first nuts 23 to lock the first steel angle pieces 21 and the three first inner plywood boards 13 to form the first prefabricated component. Attach the three second inner plywood boards 33 to the corresponding outer surfaces of the second steel angle pieces 41, allowing the third studs 42 to pass through the mounting holes 19. Use the second nuts 43 to lock the second steel angle pieces 41 and the three second inner plywood boards 33 to form the first main prefabricated component.

[0056] S40: Assemble the secondary and primary layers separately. Assemble the first prefabricated component with the three first polyurethane layers 14 and the three first outer plywoods 12 according to their corresponding positions. A first gap 16 is reserved between two adjacent first polyurethane layers 14 and the first outer plywoods 12. A filler plywood 17 is placed on the outer side of the first gap 16, and glass wool 18 is filled in the remaining space of the first gap 16. Then, the entire component is pressed together using an airbag and allowed to cure to form an integrated second prefabricated component. Assemble the first primary prefabricated component with the three second polyurethane layers 34 and the three second outer plywoods 32 according to their corresponding positions. A second gap 36 is reserved between two adjacent second polyurethane layers 34 and the second outer plywoods 32. A filler plywood 17 is placed on the outer side of the second gap 36, and glass wool 18 is filled in the remaining space of the second gap 36. Then, the entire component is pressed together using an airbag and allowed to cure to form an integrated second primary prefabricated component. To ensure the stability of the second precast component and the second main precast component, a first assembly strip 15 and a second assembly strip 35 are respectively attached to the outer surfaces of the second precast component and the second main precast component.

[0057] S50: Prefabricated three-sided component: The second main prefabricated component is placed inside the second prefabricated component. The second locking groove 321 on the second outer plywood 32 of each main insulation block 31 is engaged with the corresponding second stud 24 on the first steel corner piece 21 of the secondary shielding layer 20. After the second stud 24 passes through the second locking groove 321, it is locked by a nut. The second main prefabricated component and the second prefabricated component are firmly connected to form a complete prefabricated three-sided component.

[0058] S60: Quality Inspection. A comprehensive quality inspection is conducted on the completed prefabricated three-sided components, including the dimensional accuracy of each structural layer, the tightening torque of locking connections, the fit accuracy of each locking groove and stud, the integrity of gap filling, and the fixing status of the assembly belts. After passing the inspection, the prefabricated three-sided components can be shipped from the factory to the construction site.

[0059] This invention prefabricates the four-layer structure of the trihedral region as a single component, completes all assembly and quality inspection in the factory, and only requires overall hoisting and sealing with adjacent areas on site. This significantly reduces on-site construction procedures and time, eliminates on-site splicing seams in the trihedral region, improves assembly accuracy and quality consistency, and ensures the system's sealing reliability and thermal insulation performance.

[0060] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A prefabricated trihedral component for a membrane enclosure system, characterized in that, The corner region, located at the intersection of three faces, includes, from the outside in, the following: The secondary insulation layer includes secondary insulation blocks corresponding to three sides. Each secondary insulation block includes a first outer plywood, a first inner plywood, and a first polyurethane layer sandwiched between the first outer plywood and the first inner plywood. Each first outer plywood has a first locking groove at its top corner that mates with a connector on the hull. The secondary shielding layer is an integrally formed first steel corner piece. The first steel corner piece has three surfaces that match the corner area. A first stud is fixed on the outer surface of the first steel corner piece. The first stud is locked to a first nut inside the secondary insulation layer. A second stud is also provided on each inner surface of the first steel corner piece. The main insulation layer includes main insulation blocks corresponding to three sides. Each main insulation block includes a second outer plywood, a second inner plywood, and a second polyurethane layer sandwiched between the second outer plywood and the second inner plywood. A second locking groove that mates with the second stud is provided at the top corner of each second outer plywood. The main shielding layer is an integrally formed second steel corner piece, and a third stud is provided on the outer surface of the second steel corner piece. The third stud is locked to a second nut inside the main insulation layer. The first locking groove and the second locking groove include a first end with a large aperture and a second end with a small aperture. The second end is close to the top corner of the first outer plywood and the second outer plywood, and the first end is close to the junction of the first outer plywood and the junction of the second outer plywood.

2. The prefabricated trihedral component of the membrane enclosure system according to claim 1, characterized in that, A first assembly strip is provided on the outer side of two adjacent secondary insulation blocks, and the first assembly strip covers the joint of the two adjacent secondary insulation blocks to fix the relative position of the two adjacent secondary insulation blocks; a second assembly strip is provided on the outer side of two adjacent main insulation blocks, and the second assembly strip covers the joint of the two adjacent main insulation blocks to fix the relative position of the two adjacent main insulation blocks.

3. The prefabricated trihedral component of the membrane enclosure system according to claim 2, characterized in that, Both the first assembly tape and the second assembly tape are low-temperature adhesive tapes.

4. The prefabricated trihedral component of the membrane enclosure system according to claim 1, characterized in that, The first inner plywood and the second inner plywood are respectively provided with mounting holes corresponding to the first stud and the third stud. The ends of the first stud and the third stud pass through the mounting holes and are locked with the first nut and the second nut respectively.

5. The prefabricated trihedral component of the membrane enclosure system according to claim 4, characterized in that, Gaskets are provided between the first nut and the first inner plywood, and between the second nut and the second inner plywood.

6. The prefabricated trihedral component of the membrane enclosure system according to claim 1, characterized in that, The inner surfaces of the first polyurethane layer and the second polyurethane layer are respectively provided with receiving grooves corresponding to the first stud and the third stud.

7. The prefabricated trihedral component of the membrane enclosure system according to claim 1, characterized in that, The thickness of the first inner plywood is greater than the thickness of the first outer plywood, and the thickness of the second inner plywood is greater than the thickness of the second outer plywood.

8. The prefabricated trihedral component of the membrane enclosure system according to claim 1, characterized in that, There is a first gap between two adjacent secondary insulation blocks and a second gap between two adjacent main insulation blocks. The outer side of the first gap and the second gap is filled with plywood, and the inner side of the first gap and the second gap is filled with glass wool.

9. The prefabricated trihedral component of the membrane enclosure system according to claim 1, characterized in that, The first polyurethane layer and the second polyurethane layer are respectively provided with notches to avoid the first locking groove and the second locking groove.

10. The prefabricated trihedral component of the membrane enclosure system according to claim 1, characterized in that, The first and second steel angle pieces are both made of stainless steel. The first and second studs are welded to the first steel angle piece, and the third stud is welded to the second steel angle piece.

11. A method for manufacturing a prefabricated trihedral component of a membrane enclosure system as described in any one of claims 1-10, characterized in that, Includes the following steps: S10: Cut out the first outer plywood, first polyurethane layer, and first inner plywood of each secondary insulation block according to the design dimensions, as well as the second outer plywood, second polyurethane layer, and second inner plywood of each main insulation block. S20: Stamp out the first and second steel angle pieces according to the set dimensions and connect the first stud, the second stud and the third stud; S30: Lock the first steel corner piece to the three first inner plywoods and the second steel corner piece to the three second inner plywoods to form the first precast part and the first main precast part; S40: The first precast component is assembled with three first polyurethane layers and three first outer plywood according to the design structure, and then filled with glass wool and plywood before being pressed into a second precast component. The first main precast component is assembled with three second polyurethane layers and three second outer plywood according to the design structure, and then filled with glass wool and plywood before being pressed into a second main precast component. S50: Lock the filled second precast component and the second main precast component to form a precast trihedral component.

12. The method for manufacturing a prefabricated trihedral component of a membrane enclosure system according to claim 11, characterized in that, In step S40, a first assembly strip and a second assembly strip are respectively attached to the outer surfaces of the second preform and the second main preform.

13. The method for manufacturing a prefabricated trihedral component of a membrane enclosure system according to claim 11, characterized in that, Quality inspection is carried out on the completed prefabricated trihedral components.

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