An enclosure structure and enclosure system for the dome corner area of ​​a cryogenic liquefied gas storage tank.

Abstract

This invention belongs to the field of cryogenic liquid cargo storage technology, specifically relating to an enclosure structure and system for the corner area of ​​a cryogenic liquefied gas (LPG) storage tank dome. The enclosure structure is located at the junction of the dome, the top surface of the hold, and the forward / rear bulkhead of the LPG storage tank. It includes: a corner insulation box connected to the corner, with planar insulation boxes extending at both ends and connected to the wall surface; a secondary steel plate in the corner area attached to the inner side of the corner insulation box at the corner; a primary steel plate in the corner area welded to the inner side of the secondary steel plate at the corner area via connecting plates; a secondary shielding layer attached to the surface of the insulation box and welded to the secondary steel plate in the corner area; a primary shielding layer located inside the secondary shielding layer and welded to the primary steel plate in the corner area; and a supporting and fixing plate between the two. Compared with existing technologies, this invention solves the problems of high stress, large deformation, and poor structural stability in existing enclosure systems when applied to domes. This solution ensures the sealing performance and operational reliability of the cryogenic LPG storage tank at the corner area of ​​the dome.

Description

Technical Field

[0001] This invention belongs to the field of cryogenic liquid cargo storage technology, specifically relating to an enclosure structure and enclosure system for the dome corner area of ​​a cryogenic liquefied gas storage tank. Background Technology

[0002] In the membrane protection system of cryogenic liquefied gas carrier membrane tanks, for the 90° (or inferior angle) dihedral corner structure of the inner wall of the tank, since the connection surface between the corner structure and the outer tank is larger than the contact surface between the corner structure and the liquid cargo, the support is stronger than the load, making it a highly stable structure. Therefore, it is not easily deformed and has a strong load-bearing capacity. Thus, by adopting the weak support and weak deformation control structures disclosed in existing technologies such as CN118623202B (an installation structure and method for the corner area of ​​a cryogenic storage tank), CN117585120A (an installation method for a two-sided corner area arrangement structure of a membrane-type enclosure system), CN117585121A (a three-sided corner area arrangement structure of a membrane-type enclosure system), and CN119267778A (an installation structure and method for a cryogenic storage tank and its dihedral corner area), the stress and structural stability problems existing during storage and transportation can be overcome.

[0003] However, for the dome structure of cryogenic liquefied gas ships, since the corner area of ​​the dome structure is 270° (or asymmetric angle), the supporting surface is smaller than the load surface, which is a weakly stable structure. It has problems such as large stress, large deformation and poor structural stability. Therefore, the 90° (or inferior angle) dihedral corner structure designed for strong stable structures cannot be used.

[0004] Although the corner region of the dome structure in the existing GTT Mark-Ⅲ thin film maintenance system adopts a different structure than the 90° (or inferior angle) dihedral corner region structure designed for strong stability structures, other problems still exist, as follows.

[0005] The GTT Mark-Ⅲ membrane protection system consists of a secondary insulation layer, a secondary shielding layer, a primary insulation layer, and a primary shielding layer. The primary shielding layer is a stainless steel corrugated sheet, the secondary shielding layer is a three-layer composite membrane, and the secondary insulation layer is composed of plywood and polyurethane. In the regular planar areas, the primary insulation layer is similar to the secondary insulation layer, also composed of plywood and polyurethane, and the secondary shielding layer is bonded to the primary and secondary insulation layers with adhesive. In the corner areas, the structure of the secondary insulation layer remains unchanged, while the primary insulation layer becomes a rigid corner plate composed of thick steel plate and thick plywood, and the secondary shielding layer is bonded to the secondary insulation layer and the rigid corner plate with adhesive.

[0006] In this scheme, at the corners of the dome structure, the rigid corner plates have a large difference in stiffness and thermal expansion coefficient compared to the secondary insulation layer. Therefore, under temperature and pressure loads, the secondary shielding layer is very easy to be damaged. If the primary shielding layer leaks, the secondary shielding layer loses its function as a second sealing barrier.

[0007] Therefore, for the dome structure of cryogenic liquefied gas carriers, a special structure needs to be designed, which is different from the conventional enclosure system located in the corner area, to ensure that the enclosure system has sufficient structural reliability in the corner area of ​​the cryogenic liquefied gas storage tank dome. Summary of the Invention

[0008] The purpose of this invention is to provide an enclosure structure and system for the corner area of ​​a cryogenic liquefied gas storage tank dome, addressing at least one of the aforementioned problems. This solves the issues of high stress, large deformation, and poor structural stability inherent in existing enclosure systems applied to domes. This solution proposes an enclosure structure and system for dome structures with a prominent angle, exhibiting excellent structural reliability and ensuring the sealing and operational reliability of the cryogenic liquefied gas storage tank at the corner area of ​​the dome.

[0009] The objective of this invention is achieved through the following technical solution:

[0010] The first aspect of the present invention discloses an enclosure structure at the dome corner area of ​​a cryogenic liquefied gas storage tank. The enclosure structure is disposed at the junction of at least two of the dome, the top surface of the hull, and the front / rear bulkhead (front bulkhead or rear bulkhead) in the cryogenic liquefied gas storage tank, wherein the dome and the top surface of the hull form an angle.

[0011] The enclosure structure includes corner insulation boxes, planar insulation boxes, secondary shielding layers, primary shielding layers, secondary steel plates in the corner areas, and primary steel plates in the corner areas;

[0012] The corner insulation box is connected to the wall at the corner of the cryogenic liquefied gas storage tank, and a planar insulation box is respectively provided in the extension direction at both ends of the corner insulation box. The planar insulation box is connected to the wall of the cryogenic liquefied gas storage tank.

[0013] The corner secondary steel plate is attached and fixed to the inside of the corner insulation box, and the corner main steel plate is welded and fixed to the inside of the corner secondary steel plate through a connecting plate.

[0014] The secondary shielding layer is bonded to the surface of the corner insulation box and the planar insulation box, and the secondary shielding layer is welded and fixed to the secondary steel plate in the corner area;

[0015] The main shielding layer is disposed inside the secondary shielding layer, and the main shielding layer is welded and fixed to the corner main layer steel plate; a support fixing plate is provided between the main shielding layer and the secondary shielding layer.

[0016] Preferably, the corner insulation box is composed of a pair of inclined insulation boxes and at least one supporting insulation box;

[0017] A pair of inclined insulating boxes are disposed at the corner of the cryogenic liquefied gas storage tank, and the inclined surfaces of the pair of inclined insulating boxes are arranged to fit together; at least one of the supporting insulating boxes is disposed between the inclined insulating box and the wall of the cryogenic liquefied gas storage tank.

[0018] The pair of inclined insulating boxes are fixedly connected by a limiting mechanism.

[0019] Preferably, the length of the inclined insulating box is greater than the vertical distance from the corner of the corner insulating box to the wall of the cryogenic liquefied gas storage tank;

[0020] The inclined insulation box has a thickened plate on its inner wall, and the thickness of the thickened plate is greater than that of the inner wall of the flat insulation box.

[0021] The corner secondary steel plate is fixedly connected to the thickened plate by fastening bolts.

[0022] Preferably, the limiting mechanism includes a support plate and a fixed connecting plate;

[0023] The support plate is abutted between the inner walls of the pair of inclined insulation boxes, and the thickness of the support plate is equal to or similar to the thickness of the inner walls of the inclined insulation boxes; the fixed connecting plate is fixedly connected between the inclined surfaces of the pair of inclined insulation boxes.

[0024] Preferably, a bridging block is provided between the corner insulation box and the planar insulation box; the bridging block is composed of a plate shell and filled with an elastic heat-insulating material; the bridging block extends from the inside of the corner insulation box to the inside of the planar insulation box.

[0025] Preferably, the corner insulation box and the planar insulation box are filled with heat-insulating material; and / or, the corner insulation box and the planar insulation box are filled with heat-insulating material; and / or, the corner insulation box and the planar insulation box are bonded and fixed to the wall of the cryogenic liquefied gas storage tank by a resin adhesive layer.

[0026] Preferably, both the secondary shielding layer and the primary shielding layer are made of stainless steel corrugated plates; the supporting fixing plate is filled between adjacent corrugations of the secondary shielding layer and the primary shielding layer.

[0027] In a preferred embodiment, the supporting fixing plate is a main layer of plywood.

[0028] Preferably, the thermal insulation material is polyurethane, the heat insulation material is glass wool, and the panels in the enclosure structure are all plywood.

[0029] The second aspect of this invention discloses an enclosure system for the dome corner area of ​​a cryogenic liquefied gas storage tank, which is composed of several enclosure structures as described above connected together.

[0030] The enclosure structure includes an inverse dihedral type, a first trihedral type, and a second trihedral type, wherein:

[0031] The inverted dihedral enclosure structure is used for the connection between one side wall of the dome and the top of the cabin.

[0032] The first trihedral enclosure structure is used for the connection between one side wall of the dome, the top of the cabin, and the front / rear bulkheads.

[0033] The second trihedral enclosure structure is used for the connection between the adjacent side walls of the dome and the roof of the cabin.

[0034] Preferably, adjacent enclosure structures are fixed together by welding with corrugated elbows.

[0035] Preferably, the corrugated elbow includes a secondary corrugated elbow and a primary corrugated elbow;

[0036] The secondary corrugated elbow is welded and fixed to the secondary shielding layer and the corner secondary steel plate of the adjacent enclosure structure to form a corner secondary sealing layer;

[0037] The main corrugated elbow is welded and fixed to the main shielding layer and the corner main steel plate of the adjacent enclosure structure to form the corner main sealing layer.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] This application primarily addresses the stress and structural stability issues in the dome corner area by combining corner insulation boxes and primary and secondary steel plates within the enclosure structure, supplemented by limiting mechanisms, thickened plates, bridging blocks within the corner insulation boxes, and enclosure structures designed based on the contours of the dome corner area, including inverted dihedral, first trihedral, and second trihedral shapes. This is further complemented by corrugated elbows connecting adjacent enclosure structures within the overall enclosure system. Specifically:

[0040] 1) Since the 90° structure of the storage tank corner area in the existing technology is a strong and stable structure, its insulation box itself is relatively firm and stable. Therefore, the plywood used in the insulation box does not need to be lengthened. Its length is the same as that of the secondary steel plate and will not protrude from the end face of the steel plate.

[0041] In this solution, for the 270° structure, to address the issues of high stress, large deformation, and poor structural stability, the length of the corner insulation box has been extended, ensuring that the corner insulation box extends beyond the wall of the cryogenic liquefied gas storage tank, thus allowing for secure fixing. Furthermore, support plates are used at the corner positions of the corner insulation box to connect and support them, evenly transferring the stress of the secondary and primary steel plates in the corner area to the corner insulation box, forming a stable structure that shares the load. At the same time, all parts within the corner insulation box are bonded and fixed as a whole, preventing significant misalignment under load that could cause warping of the primary and secondary shielding layers and thus damage, effectively improving structural stability.

[0042] 2) In order to further improve structural stability, this solution combines the setting of bridging blocks to improve the deformation layer difference between insulation boxes (corner insulation boxes and planar insulation boxes).

[0043] 3) The bridging block adopts an elastic structure rather than a rigid structure. Specifically, it is composed of a plate shell and a flexible insulation material filling, which can further buffer and overcome the deformation layer difference between the corner insulation box and the planar insulation box when the dome corner area is subjected to stress deformation, thus ensuring the overall structural stability.

[0044] 4) Regarding the GTT Mark-Ⅲ scheme, the primary and secondary shielding layers and the primary and secondary steel plates in this scheme are made of the same material and can be fixed by welding. Therefore, there is no problem of easy damage to the secondary shielding layer due to the difference in the thermal expansion coefficients of the materials. At the same time, in this scheme, the corrugated elbows connecting adjacent enclosure structures in the enclosure system can absorb the shrinkage deformation of the primary and secondary steel plates in the corner area due to cooling based on their corrugated shape. This ensures that the enclosure system will not generate structural defects between the enclosure structures during use, further avoiding damage to the secondary shielding layer. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of a typical enclosure system for the corner area of ​​a storage tank in the prior art;

[0046] Figure 1 middle:

[0047] 1'-Hull; 2'-Glass wool; 3'-Plywood; 4'-Polyurethane; 5'-Thickened plywood; 6'-Secondary steel plate; 7'-Connecting plate; 8'-Main steel plate; 9'-Main shielding layer; 10'-Secondary shielding layer;

[0048] Figure 2 This is a structural diagram showing the position of the dome relative to the ship's hold in a cryogenic liquefied gas storage tank.

[0049] Figure 3 A top view schematic diagram of the dome structure in a cryogenic liquefied gas storage tank;

[0050] Figure 4 This is a schematic diagram showing the installation position of the enclosure system of the present invention at the dome corner area of ​​the cryogenic liquefied gas storage tank;

[0051] Figure 5 This is a schematic cross-sectional view of the enclosure structure of the present invention at the dome corner area of ​​the cryogenic liquefied gas storage tank.

[0052] Figure 6 for Figure 5 The diagram shows the dimensions of the corner insulation box.

[0053] Figure 7 for Figure 5 A magnified schematic diagram of the partial structure at point A in the middle;

[0054] Figure 8 for Figure 5 A magnified schematic diagram of the local structure at point B;

[0055] Figure 9 This is a schematic diagram of the enclosure structure of the present invention, which is in the form of an inverse dihedron.

[0056] Figure 10 This is a schematic diagram of the enclosure structure of the present invention, which is in the form of a first trihedral shape;

[0057] Figure 11 This is a schematic diagram of the enclosure structure of the present invention, which is in the form of a second trihedron.

[0058] Figure 12 This is a schematic diagram of the enclosure system of the present invention at the connection between adjacent enclosure structures;

[0059] Figures 2-12 In the middle: 100-Cryogenic liquefied gas storage tank; 110-Dome; 120-Top surface of the ship's hold; 130-Forward / Aft bulkhead; 140-Containment structure;

[0060] 20 - Corner insulation box; 21 - Slanted insulation box; 22 - Support insulation box; 23 - Support plate; 24 - Fixed connection plate; 25 - Thickened plate; 30 - Flat insulation box;

[0061] 1-Secondary shielding layer; 2-Main shielding layer; 3-Bridging block; 4-Resin adhesive layer; 5-Supporting and fixing plate;

[0062] 11-Secondary steel plate in corner area; 12-Main steel plate in corner area; 13-Connecting plate; 14-Fastening bolt;

[0063] 41 - Secondary corrugated elbow; 42 - Primary corrugated elbow. Detailed Implementation

[0064] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0065] Unless otherwise specified, the materials used in the following description may be commercially available products, the methods used may be conventional means in the field, and other matters not covered herein may be referred to as common general knowledge.

[0066] In this scheme description, the side facing the liquid cargo area is called the inner side, and the side facing the hull is called the outer side.

[0067] like Figure 1 The diagram illustrates a typical enclosure structure for the corner area of ​​a cryogenic liquefied gas storage tank. From the inner side (liquid cargo side) to the outer side (hull 1'), it consists of a main steel plate 8' / main shielding layer 9', a connecting plate 7', a secondary steel plate 6' / secondary shielding layer 10', thickened plywood 5', polyurethane 4', and plywood 3'. The thickened plywood 5', polyurethane 4', and plywood 3' form an inclined insulation box, and the gap between the two inclined insulation boxes at the corner is filled with glass wool 2'. This typical structure demonstrates that for a normal 90° dihedral corner structure of a storage tank, the outer hull 1' provides stronger support than the load, exhibiting strong stability and resistance to deformation, thus possessing a high capacity to withstand loads. Therefore, the two inclined insulating boxes that make up the corner area structure are mainly filled with glass wool, and no additional plywood is needed for bonding; moreover, the difference in deformation layer between the corner insulating box and the adjacent planar insulating box in this structure is small, so it will not affect the stress on the shielding layer, and therefore no additional bridging block is needed.

[0068] However, when this structure is applied to the dome corner area of ​​a cryogenic liquefied gas storage tank, taking the 270° inverse dihedral corner area as an example, since the supporting surface is smaller than the load surface, it is a weakly stable structure. The smaller supporting surface leads to greater stress and deformation of the insulation box. At this time, due to the large difference between the rigidity and thermal expansion coefficient of the rigid corner plate and the secondary insulation layer in the existing maintenance system, the secondary shielding layer is easily damaged under temperature and pressure loads.

[0069] Example 1

[0070] An enclosure structure 140 at the corner of the dome 110 of a cryogenic liquefied gas storage tank, such as... Figures 2-12 As shown, the enclosure structure 140 is located at the junction of at least two of the dome 110, the top surface 120 of the cabin, and the front / rear bulkhead 130 (front bulkhead or rear bulkhead) in the cryogenic liquefied gas storage tank 100, wherein the dome 110 and the top surface 120 of the cabin form an angle.

[0071] The enclosure structure 140 includes a corner insulation box 20, a planar insulation box 30, a secondary shielding layer 1, a primary shielding layer 2, a corner secondary steel plate 11, and a corner primary steel plate 12;

[0072] The corner insulation box 20 is connected to the wall at the corner of the cryogenic liquefied gas storage tank 100, and a planar insulation box 30 is respectively provided in the extending direction at both ends of the corner insulation box 20. The planar insulation box 30 is connected to the wall of the cryogenic liquefied gas storage tank 100.

[0073] The corner secondary steel plate 11 is attached and fixed to the inside of the corner of the corner insulation box 20, and the corner main steel plate 12 is welded and fixed to the inside of the corner of the corner secondary steel plate 11 through the connecting plate 13.

[0074] The secondary shielding layer 1 is attached to the surface of the corner insulation box 20 and the planar insulation box 30, and the secondary shielding layer 1 is welded and fixed to the corner secondary steel plate 11.

[0075] The main shielding layer 2 is disposed inside the secondary shielding layer 1, and the main shielding layer 2 is welded and fixed to the corner main layer steel plate 12; a support fixing plate 5 is provided between the main shielding layer 2 and the secondary shielding layer 1.

[0076] More specifically, in this embodiment:

[0077] The enclosure structure 140 is designed specifically for the structural characteristics of the corner area of ​​the dome 110 of the cryogenic liquefied gas storage tank 100, such as... Figure 2 , 3 As shown, the main feature is the enclosure at the junction of the dome 110, the top surface 120 of the hull, and the front / rear bulkhead 130 in the cryogenic liquefied gas storage tank 100.

[0078] The enclosure structure is 140, such as Figures 5-8 Specifically, it includes:

[0079] Corner insulation box 20, planar insulation box 30, secondary shielding layer 1, main shielding layer 2, corner secondary steel plate 11 and corner main steel plate 12.

[0080] The corner insulation box 20 and the planar insulation box 30 are each bonded to the inner wall of the cryogenic liquefied gas storage tank 100 (facing the liquid cargo area / liquid cargo side) by a resin adhesive layer 4 formed of resin putty (taking a 270° corner as an example in this embodiment); wherein, the corner insulation box 20 is located at the corner of the cryogenic liquefied gas storage tank 100, and the planar insulation box 30 is located at the corner of the corner insulation box 20, extending along its two ends. The space between the corner insulation box 20 and the planar insulation box 30 is filled with heat-insulating glass wool, and a bridging block 3 is provided on the inner side of the box wall of the corner insulation box 20 and the planar insulation box 30 (located inside the corner insulation box 20 and the planar insulation box 30).

[0081] The planar insulation box 30 is consistent with the insulation box in the existing structure, and its interior is filled with polyurethane insulation material as a planar secondary insulation layer.

[0082] The corner insulation box 20 is a modular structure, specifically comprising a pair of inclined insulation boxes 21 (in a right-angled trapezoidal shape) and a supporting insulation box 22. The pair of inclined insulation boxes 21 are arranged with their inclined surfaces abutting each other; the supporting insulation box 22 is positioned in the gap between one of the inclined insulation boxes 21 and the wall of the cryogenic liquefied gas storage tank 100. The inner walls (lower bottom edges) of the two inclined insulation boxes 21 are reinforced with thickened plates 25, specifically plywood. The thickness of these thickened plates 25 is greater than that of the inner walls of the planar insulation box 30 to improve overall stability, reduce the layer difference between the corner area and the planar area, and effectively alleviate fatigue stress on the secondary shielding layer 1 and the primary shielding layer 2. Furthermore, the length of the two inclined insulation boxes 21 (the length of their lower bottom edges, D1 / D2) is greater than the vertical distance d1 / d2 from the corner apex of the corner insulation box 20 to the outer wall of the cryogenic liquefied gas storage tank 100 perpendicular to the corresponding thickened plate 25 of the inclined insulation box 21. Figure 6 As shown, this ensures the corner insulation box 20 is firmly fixed. A support plate 23 and a fixing connecting plate 24 are also fixedly bonded between the two inclined insulation boxes 21. The support plate 23 is an L-shaped structure, fixedly installed between the thickened plates 25 of the two inclined insulation boxes 21. The thickness of the support plate 23 is designed to be the same as or approximately the thickness of the thickened plates 25, and it fits against the outer side of the secondary steel plate 11 in the corner area. This L-shaped support plate 23 can directly support the thickened plates 25 at both ends and can transfer the load from the liquid cargo area along its extension direction to the corner insulation boxes 20 on both sides. The fixing connecting plate 24 is plywood, bonded and fixed between the inclined surfaces of the two inclined insulation boxes 21, making the two inclined insulation boxes 21 bonded and fixed as one unit, preventing significant misalignment of the two inclined insulation boxes 21 under load, which would cause the shielding layer to warp and be damaged. Therefore, the corner insulation box 20 constitutes a stable structure to jointly bear the load. Furthermore, the corner insulation box 20 is connected to the planar insulation box 30 near the outer side via a bridging block 3, which can improve the deformation layer difference between the corner insulation box and the planar insulation box. The corner insulation box 20 is also filled with polyurethane insulation material as a secondary insulation layer at the corner.

[0083] The bridging block 3, designed to further reduce and eliminate the generation of deformation layer differences, is constructed from an outer sheet metal shell (plywood) and an inner (low-density) polyurethane filling. Therefore, the bridging block 3 is not a rigid structure but possesses a certain degree of elasticity and load-bearing capacity. The bridging block 3 is positioned between the corner insulation box 20 and the flat insulation box 30 (extending from the interior of the corner insulation box 20 to the interior of the flat insulation box 30) to level the layer difference between them, further mitigating the adverse effects of the potential layer difference between the corner insulation box 20 and the flat insulation box 30 on the main shielding layer 2 and the secondary shielding layer 1. In this embodiment, the thickness of the bridging block 3 is also controlled to be consistent with the thickness of the thickened plate 25.

[0084] The corner secondary steel plate 11 is fixedly assembled at the corner position of the corner insulation box 20 by fastening bolts 14 welded to it. Specifically, bolt holes are provided on the thickened plate 25 of the inclined insulation box 21. The fastening bolts 14 welded to the corner secondary steel plate 11 pass through the bolt holes and are tightened by nuts. The thickened plate 25 ensures a reliable connection between the corner secondary steel plate 11 and the corner insulation box 20, and protects the corner insulation box 20 from damage when the corner secondary steel plate 11 transmits loads. The corner main steel plate 12 is welded to the inner side of the corner secondary steel plate 11 by connecting plate 13.

[0085] Both the secondary shielding layer 1 and the primary shielding layer 2 are made of stainless steel corrugated plates with a corrugated structure. The secondary shielding layer 1 is attached to and covers the surfaces of the corner insulation box 20 and the flat insulation box 30, and is welded and fixed to the corner secondary steel plate 11 at the corner. The primary shielding layer 2 is located inside the secondary shielding layer 1, and is welded and fixed to the corner primary steel plate 12 at the corner. The two are fixedly assembled by a support fixing plate 5 (using plywood as the primary plywood) set between the primary shielding layer 2 and the secondary shielding layer 1, and the support fixing plate 5 is set between the corrugated structures of the secondary shielding layer 1 and the primary shielding layer 2. Thus, the secondary shielding layer 1 and the primary shielding layer 2 located on different wall sides are connected by the corner secondary steel plate 11 and the corner primary steel plate 12.

[0086] When the aforementioned enclosure structure 140 is applied at the corner area of ​​the dome 110 of the actual cryogenic liquefied gas storage tank 100, multiple enclosure structures 140 are jointly constructed to form an enclosure system. For different locations of the enclosure system within the cryogenic liquefied gas storage tank 100, such as the dome 110, the top surface 120 of the hull, and the forward / rear bulkheads 130, the enclosure system may be configured as follows: Figure 4 As shown, the aforementioned enclosure structure 140 is designed in three shapes: inverted dihedral ( Figure 9 ), the first trihedral type ( Figure 10 ) and second trihedral type ( Figure 11These three shapes are used to connect: one side wall of the cabin roof 120 and the dome 110, the front / rear bulkhead 130, one side wall of the cabin roof 120 and the dome 110, and the side walls of two adjacent domes 110 and the cabin roof 120.

[0087] In this enclosure system, to better ensure the connection reliability and overall structural stability of each enclosure structure 140, corrugated elbows are used to connect adjacent enclosure structures 140. These corrugated elbows are further divided into main layer corrugated elbows 42 and secondary layer corrugated elbows 41, such as... Figure 12 As shown, the main corrugated elbow 42 is sealed and welded to the corner main steel plate 12 and the main shielding layer 2, forming the corner main sealing layer; the secondary corrugated elbow 41 is sealed and welded to the corner secondary steel plate 11 and the secondary shielding layer 1, forming the corner secondary sealing layer. In this enclosure system, the corrugated elbow also has a corrugated structure, so it can be used to absorb the shrinkage deformation of the corner steel plate caused by cooling; when the corner steel plate is cooled, the direction of force on the corrugated elbow is... Figure 12 The horizontal direction shown.

[0088] Through the above structural design, it can be ensured that the main shielding layer 2 and the secondary shielding layer 1 are firmly connected. When subjected to external loads, the corner steel plate and the shielding layer deform in a coordinated manner, avoiding damage to the secondary shielding layer 1 due to inconsistent deformation of different components in the corner area.

[0089] In summary, by Figures 2-8 As can be seen, since the supporting surface of the dome 110 corner structure is smaller than the load surface, it is a weakly stable structure. The smaller supporting surface leads to greater stress and deformation of the insulation box. Therefore, it is necessary to bond the two inclined insulation boxes 21 together with the fixed connecting plate 24 to further enhance the stability of the overall structure and resist deformation. In addition, due to its weakly stable characteristics, the deformation layer difference between the dome 110 corner insulation box and the adjacent insulation box is large, which will adversely affect the stress on the main shielding layer 2 and the secondary shielding layer 1. Therefore, a bridging block 3 is also required. Furthermore, the use of the thickened plate 25 in the inclined insulation box 21, the combination of the main steel plate 12 and the secondary steel plate 11 in the corner, and the combination of the contour-designed enclosure structure 140 of the dome 110 corner and the corrugated elbow connecting the adjacent enclosure structures 140 ensure the structural reliability, sealing, and operational reliability of the enclosure system at the dome 110 corner of the cryogenic liquefied gas storage tank 100.

[0090] During construction, the two inclined insulation boxes 21 and the corner steel plates (including the secondary corner steel plate 11, the main corner steel plate 12, the connecting plate 13, and the fastening bolts 14) of the enclosure system were prefabricated as a single unit in the factory and then transported to the site for overall installation. Due to the influence of the ship's hull structure, the dome corner structure needed to be installed in stages: first, the flat insulation box 30 installed on the side wall of the dome was installed and fixed, and then the components consisting of the two inclined insulation boxes 21, the fixed connecting plate 24, the corner steel plates, and other parts prefabricated in the factory were installed and fixed. After the corner structure and its adjacent flat insulation box 30 were installed, the bridging block 3 was finally installed. Then, the secondary shielding layer 1, the main shielding layer 2, and the corrugated elbow located on the inner side were welded and fixed in sequence. The installation of the enclosure system at the corner of the dome 110 of the cryogenic liquefied gas storage tank 100 was completed.

[0091] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. An enclosure structure for the dome corner area of ​​a cryogenic liquefied gas storage tank, characterized in that, The enclosure structure (140) is located at the junction of at least two of the dome (110), the top surface of the cabin (120) and the front / rear bulkhead (130) in the cryogenic liquefied gas storage tank (100), wherein the dome (110) and the top surface of the cabin (120) form an angle. The enclosure structure (140) includes a corner insulation box (20), a planar insulation box (30), a secondary shielding layer (1), a primary shielding layer (2), a corner secondary steel plate (11), and a corner primary steel plate (12). The corner insulation box (20) is connected to the wall at the corner of the cryogenic liquefied gas storage tank (100), and a flat insulation box (30) is provided on both ends of the corner insulation box (20) in the extension direction. The flat insulation box (30) is connected to the wall of the cryogenic liquefied gas storage tank (100). The corner secondary steel plate (11) is attached and fixed to the inside of the corner of the corner insulation box (20), and the corner main steel plate (12) is welded and fixed to the inside of the corner of the corner secondary steel plate (11) through the connecting plate (13). The secondary shielding layer (1) is attached to the surface of the corner insulation box (20) and the planar insulation box (30), and the secondary shielding layer (1) is welded and fixed to the corner secondary steel plate (11); The main shielding layer (2) is located inside the secondary shielding layer (1), and the main shielding layer (2) is welded and fixed to the corner main layer steel plate (12); a support fixing plate (5) is provided between the main shielding layer (2) and the secondary shielding layer (1).

2. The enclosure structure at the dome corner area of ​​a cryogenic liquefied gas storage tank according to claim 1, characterized in that, The corner insulation box (20) is composed of a pair of inclined insulation boxes (21) and at least one supporting insulation box (22); A pair of inclined insulating boxes (21) are provided at the corner of the cryogenic liquefied gas storage tank (100), and the inclined surfaces of the pair of inclined insulating boxes (21) are arranged to fit together; at least one of the supporting insulating boxes (22) is provided between the inclined insulating box (21) and the wall of the cryogenic liquefied gas storage tank (100). The pair of inclined insulating boxes (21) are fixedly connected by a limiting mechanism.

3. The enclosure structure at the dome corner area of ​​a cryogenic liquefied gas storage tank according to claim 2, characterized in that, The length D1 / D2 of the inclined insulation box (21) is greater than the vertical distance d1 / d2 from the corner of the corner insulation box (20) to the wall of the cryogenic liquefied gas storage tank (100); The inclined insulation box (21) uses a thickened plate (25) on the inner side of the box wall, and the thickness of the thickened plate (25) is greater than the thickness of the inner side of the flat insulation box (30). The corner secondary steel plate (11) is fixedly connected to the thickened plate (25) by fastening bolts (14).

4. The enclosure structure at the dome corner area of ​​a cryogenic liquefied gas storage tank according to claim 2, characterized in that, The limiting mechanism includes a support plate (23) and a fixed connecting plate (24); The support plate (23) is abutted between the inner walls of the pair of inclined insulating boxes (21), and the thickness of the support plate (23) is equal to or similar to the thickness of the inner walls of the inclined insulating boxes (21); the fixed connecting plate (24) is fixedly connected between the inclined surfaces of the pair of inclined insulating boxes (21).

5. The enclosure structure at the dome corner area of ​​a cryogenic liquefied gas storage tank according to claim 1, characterized in that, A bridging block (3) is provided between the corner insulation box (20) and the planar insulation box (30); the bridging block (3) is composed of a plate shell and filled with elastic heat-insulating material; the bridging block (3) extends from the inside of the corner insulation box (20) to the inside of the planar insulation box (30).

6. The enclosure structure at the dome corner area of ​​a cryogenic liquefied gas storage tank according to claim 1, characterized in that, The corner insulation box (20) and the planar insulation box (30) are filled with heat-insulating material; and / or, the corner insulation box (20) and the planar insulation box (30) are filled with heat-insulating material; and / or, the corner insulation box (20) and the planar insulation box (30) are bonded and fixed to the wall of the cryogenic liquefied gas storage tank (100) by a resin adhesive layer (4).

7. The enclosure structure at the dome corner area of ​​a cryogenic liquefied gas storage tank according to claim 1, characterized in that, The secondary shielding layer (1) and the main shielding layer (2) are both stainless steel corrugated plates; the supporting fixing plate (5) is filled between the adjacent corrugations of the secondary shielding layer (1) and the main shielding layer (2).

8. An enclosure system for the dome corner area of ​​a cryogenic liquefied gas storage tank, characterized in that, It is composed of several enclosure structures (140) as described in any one of claims 1-7 connected together; The enclosure structure (140) includes an inverse dihedral type, a first trihedral type, and a second trihedral type, wherein: The dihedral enclosure structure (140) is used for the connection between one side wall of the dome (110) and the top surface of the cabin (120); The first trihedral enclosure structure (140) is used for the connection between one side wall of the dome (110), the cabin roof (120) and the front / rear bulkhead (130); The second trihedral enclosure (140) is used for the connection between the adjacent side walls of the dome (110) and the cabin roof (120).

9. The enclosure system for the dome corner area of ​​a cryogenic liquefied gas storage tank according to claim 8, characterized in that, The adjacent enclosure structures (140) are fixed together by welding with corrugated elbows.

10. The enclosure system for the dome corner area of ​​a cryogenic liquefied gas storage tank according to claim 9, characterized in that, The corrugated elbow includes a secondary corrugated elbow (41) and a primary corrugated elbow (42). The secondary corrugated elbow (41) is welded and fixed to the secondary shielding layer (1) and the corner secondary steel plate (11) of the adjacent enclosure structure (140) to form a corner secondary sealing layer; The main corrugated elbow (42) is welded and fixed to the main shielding layer (2) and the corner main steel plate (12) of the adjacent enclosure structure (140) to form the corner main sealing layer.

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