A cryogenic liquefied gas membrane storage tank and its installation method

Abstract

This invention relates to the field of cryogenic liquefied gas (LPG) storage equipment. The invention discloses a cryogenic LPG membrane storage tank and its installation method. The cryogenic LPG membrane storage tank includes an outer tank and multiple insulating box structures installed on the outer tank. Each insulating box structure includes a secondary insulating box, a secondary shielding layer, a main plywood, and a main shielding layer arranged sequentially, with the corrugated positions of the main shielding layer corresponding to the corrugated positions of the corrugated plates in the secondary shielding layer. There are gaps between adjacent insulating box structures. Adjacent secondary shielding layers are connected by secondary connecting plates, and adjacent main shielding layers are connected by main connecting plates. Both the secondary connecting plates and the main connecting plates are located above the gaps. This invention effectively handles the gaps between adjacent insulating box structures, improving the integrity and sealing of the shielding layer.

Description

Technical Field

[0001] This invention relates to the field of cryogenic liquefied gas storage equipment, and in particular to a cryogenic liquefied gas membrane storage tank and its installation method. Background Technology

[0002] Cryogenic liquefied gas membrane storage tanks are important equipment used to store cryogenic liquefied gases such as liquefied natural gas (LNG). They typically employ membrane-type enclosure systems to achieve sealing and cold insulation of the liquefied cargo. A membrane-type enclosure system generally includes an outer tank, an insulation layer, and a shielding layer, with the shielding layer directly contacting the liquefied cargo and withstanding the low-temperature environment.

[0003] In existing cryogenic liquefied gas membrane storage tanks, the insulation box structure is typically constructed on-site, with each component, including the insulation box, corrugated plate, and steel plate, installed layer by layer to form the primary and secondary shielding layers. Membrane tank assembly requires starting from the inner wall of the outer tank and proceeding inwards, following the aforementioned layer-by-layer construction process. The entire assembly process is completed on-site, and this layered construction results in a lengthy on-site construction period.

[0004] Therefore, there is an urgent need to propose a cryogenic liquefied gas membrane storage tank and its installation method to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a cryogenic liquefied gas membrane storage tank and its installation method, which can effectively handle the gap between adjacent insulating box structures and improve the integrity and sealing of the shielding layer.

[0006] To solve the above-mentioned technical problems, the present invention provides a cryogenic liquefied gas membrane storage tank, including an outer tank and a plurality of insulating box structures installed on the outer tank;

[0007] The insulation box structure includes a secondary insulation box, a secondary shielding layer, a main plywood and a main shielding layer arranged in sequence, and the corrugated position of the main shielding layer corresponds to the corrugated position of the corrugated plate in the secondary shielding layer.

[0008] There is a gap between adjacent insulating box structures, a secondary connecting plate is connected between adjacent secondary shielding layers, and a primary connecting plate is connected between adjacent primary shielding layers. Both the secondary connecting plate and the primary connecting plate are located above the gap.

[0009] The length and width dimensions of a single insulating box structure are both greater than 600 mm;

[0010] The secondary shielding layer includes multiple secondary steel plates, multiple secondary corrugated plates, and multiple secondary knots; the multiple secondary corrugated plates are arranged in a crisscross pattern to form a first grid structure, the first grid structure having multiple first intersections and multiple first grid sections; the secondary knots are located at the first intersections; the secondary steel plates are located in the first grid sections, and the secondary steel plates are connected to the sides of the secondary corrugated plates; the secondary insulation box has a gap, the gap is located below the secondary corrugated plates, and the opening faces the secondary corrugated plates.

[0011] Furthermore, the width of the secondary connecting plate is greater than the distance between the secondary corrugated plates in the adjacent insulation box structure.

[0012] Furthermore, the main shielding layer includes multiple main steel plates, multiple main corrugated plates, and multiple main knots; the multiple main corrugated plates are arranged in a crisscross pattern to form a second grid structure, the second grid structure having multiple second intersections and multiple second grid sections; the main knots are located at the second intersections, and the ends of the main knots are connected to the ends of the main corrugated plates, and the sides of the main knots are connected to the main steel plates; the main steel plates are located in the second grid sections, and the main steel plates are connected to the sides of the main corrugated plates.

[0013] Furthermore, the width of the main layer connecting plate is greater than the distance between the main layer corrugated plates in the adjacent insulation box structure.

[0014] Furthermore, the width of the main layer connecting plate is greater than the width of the secondary layer connecting plate.

[0015] Furthermore, a bridging block is provided between adjacent insulating box structures; the bridging block is located between the secondary connecting plate and the primary connecting plate.

[0016] Furthermore, the corrugations of both the primary shielding layer and the secondary shielding layer are oriented towards the liquid cargo space.

[0017] Alternatively, the corrugations of the main shielding layer face the direction of the liquid cargo space, and the corrugations of the secondary shielding layer face the direction of the outer tank, with the corrugations of the main shielding layer and the secondary shielding layer arranged symmetrically.

[0018] Furthermore, this invention also proposes an installation method for a cryogenic liquefied gas membrane storage tank, wherein the installation of the cryogenic liquefied gas membrane storage tank as described above specifically includes the following:

[0019] Multiple insulating box structures are installed on the outer tank;

[0020] The secondary connecting plate is connected to the secondary shielding layer in the adjacent insulation box structure to form a complete secondary shielding layer structure;

[0021] Then, the main layer connecting plate is connected to the main shielding layer in the adjacent insulation box structure to form a complete main shielding layer structure.

[0022] Furthermore, the corrugated installation of the secondary shielding layer and the primary shielding layer specifically includes: cutting a slit in the secondary insulation box according to the predetermined installation position of the corrugated plate in the secondary shielding layer; then, aligning the corrugations of both the primary shielding layer and the secondary corrugated plate towards the liquid cargo space; or, aligning the corrugations of the primary shielding layer towards the liquid cargo space; aligning the corrugations of the secondary corrugated plate towards the outer tank, and pre-pressing the secondary corrugated plate to cause compression deformation of the corrugations; so that the secondary shielding layer can undergo tensile deformation due to low-temperature contraction, thereby offsetting the compression deformation generated during installation.

[0023] Furthermore, after the secondary shielding layer is formed and before the primary shielding layer is formed, the process includes: mounting the bridging block on the secondary connecting plate.

[0024] Through the above technical solution, the present invention has the following beneficial effects:

[0025] This invention reduces on-site installation work and optimizes the traditional layered construction process by prefabricating the secondary insulation box, secondary steel plate, and main plywood in the factory, thereby improving construction efficiency and shortening the construction period.

[0026] By connecting secondary layer connecting plates between adjacent secondary shielding layers and connecting primary layer connecting plates between adjacent primary shielding layers, the gaps between adjacent insulation box structures can be effectively covered.

[0027] Furthermore, by pre-compressing the secondary corrugated plate during installation, the corrugations undergo compressive deformation. This allows the tensile deformation caused by low-temperature shrinkage after the tank is put into use to offset the compressive deformation during installation, preventing excessive stress on the shielding layer during use and thus extending its service life. Simultaneously, by setting the width of the main layer connecting plate to be greater than that of the secondary layer connecting plate, the design is specifically tailored to the greater low-temperature stress the main shielding layer withstands. This improves the reliability of the main shielding layer connections and enhances the overall safety performance of the tank. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of a cryogenic liquefied gas membrane storage tank in one embodiment of the present invention;

[0029] Figure 2 This is an exploded view of a cryogenic liquefied gas membrane storage tank according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the insulation box structure in a cryogenic liquefied gas membrane storage tank according to one embodiment of the present invention;

[0031] Figure 4 This is an exploded view of the insulation box structure in a cryogenic liquefied gas membrane storage tank according to an embodiment of the present invention;

[0032] Figure 5 This is a cross-sectional view of the insulation box structure in a cryogenic liquefied gas membrane storage tank according to an embodiment of the present invention;

[0033] Figure 6 This is a cross-sectional view of the insulation box structure in a cryogenic liquefied gas membrane storage tank according to another embodiment of the present invention;

[0034] Figure 7 This is a flowchart of an installation method for a cryogenic liquefied gas membrane storage tank according to an embodiment of the present invention.

[0035] In the diagram, 1. Outer tank; 2. Secondary insulation box; 3. Secondary shielding layer; 31. Secondary steel plate; 32. Secondary corrugated plate; 33. Secondary knot; 4. Main plywood; 5. Main shielding layer; 51. Main steel plate; 52. Main corrugated plate; 53. Main knot; 6. Secondary connecting plate; 7. Main connecting plate; 8. Gap; 9. Seam; 10. Bridging block. Detailed Implementation

[0036] Based on the teachings of this specification, those skilled in the art can form new technical solutions through cross-combination of different implementation methods without creating technical contradictions. Such variations should all be considered to fall within the protection scope of this invention.

[0037] The following description, in conjunction with the accompanying drawings, provides a more detailed account of a cryogenic liquefied gas membrane storage tank and its installation method, which illustrates preferred embodiments of the invention. It should be understood that those skilled in the art can modify the invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the invention.

[0038] The invention is described more specifically by way of example in the following paragraphs with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0039] like Figures 1-4 As shown, an embodiment of the present invention proposes a cryogenic liquefied gas membrane storage tank, including an outer tank 1 and multiple insulating box structures installed on the outer tank 1.

[0040] Specifically, the insulation box structure includes a secondary insulation box 2, a secondary shielding layer 3, a main plywood 4, and a main shielding layer 5 arranged sequentially, with the corrugated positions of the main shielding layer 5 corresponding to the corrugated positions of the corrugated plates in the secondary shielding layer 3. A gap 8 exists between adjacent insulation box structures. A secondary connecting plate 6 connects adjacent secondary shielding layers 3, and a main connecting plate 7 connects adjacent main shielding layers 5. Both the secondary connecting plate 6 and the main connecting plate 7 are located above the gap 8. This embodiment, by connecting the secondary connecting plate 6 between adjacent secondary shielding layers 3 and the main connecting plate 7 between adjacent main shielding layers 5, effectively covers the gap 8 between adjacent insulation box structures, improving the integrity and sealing of the shielding layer. Simultaneously, the connecting plate arrangement can accommodate the shrinkage and deformation of the shielding layer under low-temperature conditions and reduce stress concentration at the gap 8, thereby improving the safety and reliability of the storage tank.

[0041] In this embodiment, the multiple insulating box structures can be arranged in a matrix, and the specific arrangement can be set according to the actual situation.

[0042] In this embodiment, the length and width dimensions of a single insulating box structure are both greater than 600mm; that is, the insulating box structure contains multiple corrugated spacings in both the length and width directions, and the length and width dimensions are greater than 600mm×600mm.

[0043] Preferably, the secondary shielding layer 3 includes multiple secondary steel plates 31, multiple secondary corrugated plates 32, and multiple secondary knots 33. Specifically, the multiple secondary corrugated plates 32 are arranged in a crisscross pattern to form a first grid structure, which has multiple first intersections and multiple first grid sections. The secondary knots 33 are located at the first intersections, and the ends of the secondary knots 33 are connected to the ends of the secondary corrugated plates 32, while the sides of the secondary knots 33 are connected to the secondary steel plates 31. The secondary steel plates 31 are located in the first grid sections, and the secondary steel plates 31 are connected to the sides of the secondary corrugated plates 32. The crisscross arrangement of the secondary corrugated plates 32 to form a grid structure enhances the overall strength of the secondary shielding layer 3, while the corrugated structure can adapt to deformation caused by low-temperature shrinkage. The secondary knots 33 are located at the intersections of the corrugated plates, effectively connecting the intersecting corrugated plates and improving the reliability of the connection. Secondly, individual insulation box structures can be completed in the factory, and on site, different insulation box structures can be connected by bridging blocks 10, secondary connecting plates 6 and main connecting plates 7, thereby reducing on-site construction.

[0044] Preferably, the secondary insulation box 2 has a gap 9 located below the secondary corrugated plate 32, with its opening facing the secondary corrugated plate 32. The gap 9 on the secondary insulation box 2 provides deformation space for the secondary corrugated plate 32, facilitating its contraction and expansion in low-temperature environments. Simultaneously, it ensures that deformation stress is evenly distributed on the corrugated plate, avoiding stress concentration and improving the deformation uniformity and structural stability of the secondary corrugated plate 32.

[0045] In one embodiment, the width of the secondary connecting plate 6 is greater than the distance between the adjacent secondary corrugated plates 32 in the insulating box structure, facilitating the lap welding of the secondary connecting plate 6 with two adjacent secondary corrugated plates 32. Those skilled in the art will understand that the width of the secondary connecting plate 6 can be set according to the actual gap 8 size and shrinkage amount. The width of the secondary connecting plate 6, being greater than the distance between the secondary corrugated plates 32, can fully cover the gap 8 area, effectively connecting adjacent secondary corrugated plates 32 even after low-temperature shrinkage, thereby improving the sealing and integrity of the secondary shielding layer 3.

[0046] In this embodiment, the main shielding layer 5 includes multiple main steel plates 51, multiple main corrugated plates 52, and multiple main knots 53. Specifically, the multiple main corrugated plates 52 are arranged in a crisscross pattern to form a second grid structure, which has multiple second intersections and multiple second grid sections. The main knots 53 are located at the second intersections, and the ends of the main knots 53 are connected to the ends of the main corrugated plates 52, while the sides of the main knots 53 are connected to the main steel plates 51. The main steel plates 51 are located in the second grid sections, and the main steel plates 51 are connected to the sides of the main corrugated plates 52. The width of the main connecting plate 7 is greater than the distance between the main corrugated plates 52 in adjacent insulation box structures. The crisscross pattern of the main corrugated plates 52 forming a grid structure, similar to the arrangement of the secondary corrugated plates 32, enhances the overall strength of the main shielding layer 5. The main layer knot 53 is located at the intersection of the corrugated plates, which can effectively connect the intersecting corrugated plates and improve the structural stability of the main shielding layer 5. In addition, the width of the main layer connecting plate 7 is greater than the distance between the main layer corrugated plates 52, which facilitates the lap welding of the main layer connecting plate 7 with two adjacent main layer corrugated plates 52, and can also fully cover the gap 8 area, thereby improving the sealing performance of the main shielding layer 5.

[0047] exist Figure 2 In the diagram, only a single main layer knot 53 is shown in the single insulation box structure (the other main layer knots 53 are not shown), and the main layer connecting plate 7 between the left and right secondary insulation boxes 2 and the main layer connecting plate 7 between the front and rear secondary insulation boxes 2 are both shown.

[0048] Preferably, the width of the main connecting plate 7 is greater than the width of the secondary connecting plate 6. Those skilled in the art will understand that the width ratio of the main connecting plate 7 to the secondary connecting plate 6 can be set according to the actual stress distribution and shrinkage characteristics. Since the main shielding layer 5 directly contacts the cryogenic liquefied gas and bears significant cryogenic stress, setting the width of the main connecting plate 7 to be greater than the width of the secondary connecting plate 6 allows for a targeted design to address the greater cryogenic stress borne by the main shielding layer 5, thereby improving the reliability of the connection points of the main shielding layer 5 and enhancing the overall safety performance of the storage tank.

[0049] In one embodiment, a bridging block 10 is provided between adjacent insulating box structures. Specifically, the bridging block 10 is located between the secondary connecting plate 6 and the primary connecting plate 7. The bridging block 10 provides support for the primary connecting plate 7, preventing it from deforming due to external forces. Simultaneously, the bridging block 10 can transfer and disperse the stress of the primary shielding layer 5, helping to improve the stability of the connection.

[0050] Preferably, the bridging block 10 is made of the same material as the main plywood 4, which can maintain similar thermal expansion and contraction characteristics in low-temperature environments, avoiding stress mismatch caused by material differences, thereby improving the overall structure's coordination and reliability.

[0051] In a specific example, such as Figure 5 As shown, the corrugations of both the main shielding layer 5 and the secondary shielding layer 3 face the direction of the liquid cargo space. In this arrangement, the corrugations of the main shielding layer 5 and the secondary shielding layer 3 are aligned, which allows the double shielding layers to deform in the same direction when they shrink at low temperatures, facilitating coordinated deformation and reducing stress differences between the layers.

[0052] In another specific example, such as Figure 6 As shown, the corrugations of the main shielding layer 5 face the direction of the liquid cargo space, and the corrugations of the secondary shielding layer 3 face the direction of the outer tank 1. The corrugations of the main shielding layer 5 and the secondary shielding layer 3 are symmetrically arranged. This symmetrical arrangement allows the main shielding layer 5 and the secondary shielding layer 3 to deform in opposite directions during low-temperature contraction. The symmetrical structure balances each other, helping to reduce the overall deformation and improve the stability of the shielding system.

[0053] In addition, such as Figure 7 As shown in the figure, this embodiment also proposes an installation method for a cryogenic liquefied gas membrane storage tank. The installation of the cryogenic liquefied gas membrane storage tank as described above specifically includes the following steps:

[0054] S1. Install multiple insulating box structures on the outer tank 1;

[0055] S2. Connect the secondary connecting plate 6 to the secondary shielding layer 3 in the adjacent insulation box structure to form a complete secondary shielding layer 3 structure.

[0056] S3. Then connect the main layer connecting plate 7 to the main shielding layer 5 in the adjacent insulation box structure to form a complete main shielding layer 5 structure.

[0057] In this embodiment, by connecting the secondary connecting plate 6 and the main connecting plate 7, the shielding layers in the dispersed insulation box structure can be connected into a complete shielding layer structure, eliminating the gaps 8 between the insulation box structures, avoiding the risk of cryogenic liquefied gas leakage, improving the sealing performance and safety of the storage tank, and at the same time, the complete shielding layer structure can withstand the low-temperature stress as a whole, enhancing the structural stability and durability of the shielding system.

[0058] In this embodiment, the corrugated installation of the secondary shielding layer 3 and the primary shielding layer 5 specifically includes: cutting a slit 9 on the secondary insulation box 2 according to the predetermined installation position of the corrugated plate in the secondary shielding layer 3; and then aligning the corrugations of the primary shielding layer 5 and the secondary corrugated plate 32 towards the liquid cargo space.

[0059] Alternatively, the corrugations of the main shielding layer 5 can be oriented towards the liquid cargo space; the corrugations of the secondary corrugated plate 32 can be oriented towards the outer tank 1, and the secondary corrugated plate 32 can be pre-pressed during installation to induce compression deformation. This allows the secondary shielding layer 3 to undergo tensile deformation due to low-temperature shrinkage, which can then offset the compression deformation generated during installation. Those skilled in the art will understand that the pre-pressing amount can be set according to the actual low-temperature shrinkage. By pre-pressing the secondary corrugated plate 32 to induce compression deformation, the tensile deformation generated by low-temperature shrinkage can offset the compression deformation generated during installation after the storage tank is put into use, avoiding excessive stress on the shielding layer during use, extending the service life of the shielding layer, and improving the reliability of the storage tank.

[0060] In one embodiment, after the formation of the secondary shielding layer 3 and before the formation of the primary shielding layer 5, the process includes: installing a bridging block 10 on the secondary connecting plate 6. The bridging block 10 fills the missing area of ​​the primary plywood 4 at the connection point of adjacent insulation box structures, because the insulation box structure requires space at its edges for installing the secondary connecting plate 6, so the primary plywood 4 is not continuous at this point. By installing the bridging block 10 immediately after the formation of the secondary shielding layer 3, a stable supporting foundation can be provided for the subsequent installation of the primary shielding layer 5, thereby preventing displacement or deformation of the primary connecting plate 7 due to lack of support during installation, and improving the installation accuracy and flatness of the primary shielding layer 5.

[0061] In this embodiment, a positioning axis is first drawn on the inner wall of the concrete outer tank 1 or the inner wall of the ship's cabin using a positioning system. The inner wall is then leveled using a leveling device to provide a precise reference for the subsequent installation of the insulation box structure. Next, resin putty is applied to the back of the insulation box structure, i.e., the side facing the outer tank 1, and then the insulation box structure is fixed to the outer wall according to the positioning axis. After multiple insulation box structures are installed according to a predetermined arrangement, a gap 8 is formed between adjacent insulation box structures.

[0062] During the installation of the insulation box structure, since each insulation box structure prefabricates the secondary insulation box 2, secondary corrugated plate 32, main plywood, and main corrugated plate 52 into a single unit, the workload of on-site layered construction can be significantly reduced, improving installation efficiency. Specifically, the secondary insulation box 2 in the insulation box structure has slits below each corrugation. Because each insulation box structure contains multiple corrugated plate units, without slits, the entire secondary insulation box 2 would shrink around its center, resulting in significant overall shrinkage and stress concentration. By slits below each corrugation, the area below each corrugated unit of the secondary insulation box 2 can deform relatively independently, with the corresponding area below each corrugated unit shrinking around its own center, rather than shrinking around the center of the entire secondary insulation box 2. In this way, when cryogenic liquefied gas is injected into the storage tank, the shrinkage stress is distributed to the independent areas below each corrugated unit. Each area absorbs a portion of the deformation, which avoids stress concentration caused by overall shrinkage. This makes the deformation of the secondary insulation box 2 more uniform, thereby reducing the amount of deformation borne by the secondary corrugated plate 32 and improving the structural stability of the secondary insulation box 2 and the secondary corrugated plate 32.

[0063] After the insulation box structure is installed, the secondary connecting plate 6 is welded to the secondary corrugated plate 32 in the adjacent insulation box structure. Since the width of the secondary connecting plate 6 is greater than the distance between the edges of the secondary corrugated plates 32 in the two adjacent insulation box structures, the secondary connecting plate 6 can fully cover the gap 8 area and overlap with the secondary corrugated plates 32 on both sides. After the secondary connecting plate 6 is placed on the secondary corrugated plate 32, sealing welding is performed along the edge of the secondary connecting plate 6 and the secondary corrugated plate 32. After welding, a secondary shielding layer 3 structure with complete sealing performance is formed. Through the connection of the secondary connecting plate 6, the dispersed secondary corrugated plates 32 in the insulation box structure can be connected into a complete secondary shielding layer 3, eliminating the gap 8 between the insulation box structures, avoiding the risk of cryogenic liquefied gas leakage, and improving the sealing performance and safety of the storage tank.

[0064] After the secondary shielding layer 3 is installed and passes inspection, the bridging blocks 10 are installed and fixed onto the secondary connecting plate 6. Specifically, the bridging blocks 10 are spaced apart along the length of the secondary connecting plate 6, forming multiple support points. The bridging blocks 10 are made of the same material as the main plywood 4, which can maintain similar thermal expansion and contraction characteristics in low-temperature environments, avoiding stress mismatch problems caused by material differences, thereby improving the overall structural coordination and reliability.

[0065] After the bridging block 10 is installed, the main layer connecting plate 7 is welded to the main layer corrugated plate 52 in the adjacent insulation box structure. Since the width of the main layer connecting plate 7 is greater than the distance between the edges of the main layer corrugated plates 52 in the two adjacent insulation box structures, and the width of the main layer connecting plate 7 is greater than the width of the secondary connecting plate 6, the main layer connecting plate 7 can fully cover the gap 8 area and form a reliable overlap with the main layer corrugated plates 52 on both sides. The bridging block 10 provides support below the main layer connecting plate 7, preventing deformation of the main layer connecting plate 7 due to external forces. After the main layer connecting plate 7 is placed on the main layer corrugated plate 52, sealing welding is performed along the edges of the main layer connecting plate 7 and the main layer corrugated plate 52. After welding, a main shielding layer 5 structure with complete sealing performance is formed. The width of the main layer connecting plate 7 is greater than the width of the secondary connecting plate 6, which is specifically designed to address the greater low-temperature stress that the main shielding layer 5 withstands, improving the reliability of the connection points of the main shielding layer 5 and enhancing the overall safety performance of the storage tank.

[0066] When the primary and secondary shielding layers 3 are arranged with their corrugations facing the liquid cargo space, the corrugation directions of the primary shielding layer 5 and the secondary shielding layer 3 are consistent. This ensures that the double-layer shielding layers deform in the same direction during low-temperature contraction, facilitating coordinated deformation and reducing stress differences between layers. When the primary shielding layer 5 is arranged with its corrugations facing the liquid cargo space and the secondary shielding layer 3 is arranged with its corrugations facing the outer tank 1, a certain pressure can be applied to the corrugations during the installation of the secondary corrugated plate 32, causing compression deformation. When the storage tank contains cryogenic liquefied gas, the shielding layers undergo tensile deformation due to low-temperature contraction. This tensile deformation cancels out the compression deformation generated during installation, significantly reducing the stress on the shielding layers and plywood, thus improving structural safety.

[0067] After the main shielding layer 5 is installed, a tightness test is required. Once the test is passed, the entire thermal insulation system is complete. When cryogenic liquefied gas is injected into the storage tank, the liquefied gas directly contacts the main shielding layer 5. The corrugated positions of the main shielding layer 5 and the corrugated plates in the secondary shielding layer 3 correspond, enabling the two shielding layers to work in coordination and jointly withstand cryogenic stress. The main layer connecting plate 7 and the secondary layer connecting plate 6 can adapt to the shrinkage and deformation of the shielding layers in a cryogenic environment, reducing stress concentration at the gap 8. The bridging block 10, located between the main layer connecting plate 7 and the secondary layer connecting plate 6, can transfer and disperse the stress of the main shielding layer 5, helping to improve the stability of the connection. Through the overall installation of the insulation box structure and the connection of the main and secondary connecting plates, a complete and reliable thermal insulation system can be formed, improving the safety and reliability of the cryogenic liquefied gas membrane storage tank.

[0068] In summary, the cryogenic liquefied gas membrane storage tank and its installation method proposed in this invention have the following advantages:

[0069] By connecting secondary layer connecting plates between adjacent secondary shielding layers and primary layer connecting plates between adjacent primary shielding layers, the gaps between adjacent insulation box structures can be effectively covered, reducing complex processes such as on-site welding and improving the integrity and sealing of the shielding layers. Simultaneously, the connecting plates can accommodate the shrinkage and deformation of the shielding layers in low-temperature environments, reducing stress concentration in the gaps and improving the safety and reliability of the storage tank.

[0070] Furthermore, by pre-compressing the secondary corrugated plate during installation, the corrugations undergo compressive deformation. This allows the tensile deformation caused by low-temperature shrinkage after the tank is put into use to offset the compressive deformation during installation, preventing excessive stress on the shielding layer during use and thus extending its service life. Simultaneously, by setting the width of the main layer connecting plate to be greater than that of the secondary layer connecting plate, the design is specifically tailored to the greater low-temperature stress the main shielding layer withstands. This improves the reliability of the main shielding layer connections and enhances the overall safety performance of the tank.

[0071] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A cryogenic liquefied gas membrane storage tank, characterized in that, Includes an outer tank and multiple insulating box structures mounted on the outer tank; The insulation box structure includes a secondary insulation box, a secondary shielding layer, a main plywood and a main shielding layer arranged in sequence, and the corrugated position of the main shielding layer corresponds to the corrugated position of the corrugated plate in the secondary shielding layer. There is a gap between adjacent insulating box structures, and a secondary layer connecting plate is connected between adjacent secondary shielding layers to cover the gap and connect adjacent secondary shielding layers; a primary layer connecting plate is connected between adjacent primary shielding layers to cover the gap and connect adjacent primary shielding layers, and both the secondary layer connecting plate and the primary layer connecting plate are located above the gap; The length and width dimensions of a single insulating box structure are both greater than 600 mm; The secondary shielding layer includes multiple secondary steel plates, multiple secondary corrugated plates, and multiple secondary knots; Multiple secondary corrugated plates are arranged in a crisscross pattern to form a first grid structure, the first grid structure having multiple first intersections and multiple first grid sections; the secondary knot is located at the first intersection; The secondary steel plate is located in the first grid section, and the secondary steel plate is connected to the side of the secondary corrugated plate; The secondary insulation box has a gap located below the secondary corrugated plate and with its opening facing the secondary corrugated plate. The gap in the secondary insulation box provides deformation space for the secondary corrugated plate.

2. The cryogenic liquefied gas membrane storage tank as described in claim 1, characterized in that, The width of the secondary connecting plate is greater than the distance between the secondary corrugated plates in the adjacent insulation box structure.

3. The cryogenic liquefied gas membrane storage tank as described in claim 1, characterized in that, The main shielding layer includes multiple main steel plates, multiple main corrugated plates, and multiple main knots; Multiple main corrugated plates are arranged in a crisscross pattern to form a second grid structure. The second grid structure has multiple second intersections and multiple second grid sections. The main corrugated plate is located at the second intersection, the main steel plate is located in the second grid section, and the main steel plate is connected to the side of the main corrugated plate.

4. The cryogenic liquefied gas membrane storage tank as described in claim 3, characterized in that, The width of the main layer connecting plate is greater than the distance between the main layer corrugated plates in the adjacent insulation box structure.

5. The cryogenic liquefied gas membrane storage tank as described in claim 1, 2, or 3, characterized in that, The width of the main layer connecting plate is greater than the width of the secondary layer connecting plate.

6. The cryogenic liquefied gas membrane storage tank as described in claim 1, characterized in that, A bridging block is provided between adjacent insulating box structures; the bridging block is located between the secondary connecting plate and the primary connecting plate.

7. The cryogenic liquefied gas membrane storage tank as described in claim 1, characterized in that, The corrugations of both the main shielding layer and the secondary shielding layer are oriented towards the liquid cargo space. or, The corrugations of the main shielding layer face the direction of the liquid cargo space, and the corrugations of the secondary shielding layer face the direction of the outer tank. The corrugations of the main shielding layer and the secondary shielding layer are symmetrically arranged.

8. A method for installing a cryogenic liquefied gas membrane storage tank, comprising installing a cryogenic liquefied gas membrane storage tank as described in any one of claims 1-7, characterized in that, Specifically, it includes the following: Multiple insulating box structures are installed on the outer tank; The secondary connecting plate is connected to the secondary shielding layer in the adjacent insulating box structure to form a complete secondary shielding layer structure; and Then, the main layer connecting plate is connected to the main shielding layer in the adjacent insulation box structure to form a complete main shielding layer structure.

9. The installation method of the cryogenic liquefied gas membrane storage tank as described in claim 8, characterized in that, The corrugated installation of the secondary shielding layer and the primary shielding layer specifically includes: cutting a slit in the secondary insulation box according to the predetermined installation position of the corrugated plate in the secondary shielding layer; then, aligning the corrugations of the primary shielding layer and the secondary corrugated plate with the direction of the liquid cargo space. Alternatively, the corrugations of the main shielding layer are oriented towards the liquid cargo space; the corrugations of the secondary corrugated plate are oriented towards the outer tank, and the secondary corrugated plate is pre-pressed during installation to cause compression deformation of the corrugations; this allows the secondary shielding layer to undergo tensile deformation due to low-temperature contraction, thereby offsetting the compression deformation generated during installation.

10. The installation method of the cryogenic liquefied gas membrane storage tank as described in claim 8, characterized in that, After the secondary shielding layer is formed and before the primary shielding layer is formed, the process includes: mounting a bridging block on the secondary connecting plate.

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