Storage tank, installation, removal, and closure method of temporary installation structure thereof, and ship

Abstract

The application discloses a storage and transportation tank, a temporary installation structure, an installation and removal and sealing method of the temporary installation structure and a ship. The installation method comprises the following steps: installing a secondary temporary insulation module along the periphery of a temporary opening, the supporting surface of the secondary temporary insulation module is flush with the supporting surface of a secondary heat insulation layer, and the secondary temporary insulation module is used for supporting a secondary sealing film; installing a secondary metal apron along the periphery of the temporary opening; installing a primary temporary insulation module along the periphery of the temporary opening, the supporting surface of the primary temporary insulation module is flush with the supporting surface of a primary heat insulation layer, and the primary temporary insulation module is used for supporting the primary sealing film; and installing a primary metal apron along the periphery of the temporary opening. The supporting surface of the temporary insulation module and the supporting surface of the heat insulation layer form a complete plane for supporting the sealing structure, the metal corrugated plate and the metal apron for installing the sealing film, the temporary installation structure realizes sealing of the corrugated plate close to the edge of the temporary opening, ensures the reliability of the airtightness detection, and is simple, convenient, efficient, and the like in installation and removal.

Description

Technical Field

[0001] This invention relates to the field of liquefied natural gas storage tank containment membrane manufacturing technology, specifically to a storage and transportation tank, a method for installing, dismantling, and sealing its temporary installation structure, and a ship thereof. Background Technology

[0002] Cryogenic membrane tanks are large storage tank structures used to store cryogenic media such as liquefied natural gas (LNG), typically for the storage and long-distance transportation of LNG. From the inside out, a cryogenic membrane tank generally consists of a main sealing layer, a main plywood layer, a secondary sealing layer, and an insulation box.

[0003] Temporary doors serve as the main entrances and exits for scaffolding, elevators, materials, and equipment during the construction phase of cryogenic membrane tanks. Once the overall construction of other areas within the cryogenic membrane tank is largely completed, and all large equipment, scaffolding, elevators, etc., have been removed from the tank, the temporary doors will be sealed. Before sealing the temporary doors, a leak test must be performed on all welded areas of the metal plates inside the tank. Current temporary door designs lack solutions for sealing the corrugated plates.

[0004] Therefore, there is a need to provide a temporary installation structure for a liquefied gas storage and transportation tank, a liquefied gas storage and transportation tank, and a ship for transporting liquefied gas, in order to at least partially solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a temporary installation structure for a liquefied gas storage and transportation tank and a ship for transporting liquefied gas, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides an installation method for a temporary installation structure of a liquefied gas storage and transportation tank. The temporary installation structure is installed at the end of the liquefied gas storage and transportation tank near a temporary opening. The liquefied gas storage and transportation tank is arranged in a support structure and includes multiple tank walls. The multiple tank walls are connected to each other and fixed to the support structure. The tank walls, in the thickness direction from the outside to the inside of the liquefied gas storage and transportation tank, include: a secondary insulation layer fixed to the support structure; a secondary sealing membrane supported by the secondary insulation layer; a primary insulation layer supported by the secondary sealing membrane; and a primary sealing membrane supported by the primary insulation layer and for contact with the liquefied gas. The temporary installation structure includes a primary temporary insulation module, a primary metal skirt, a secondary temporary insulation module, and a secondary metal skirt. The installation method includes:

[0008] S1. Install a secondary temporary insulation module around the perimeter of the temporary opening. The secondary temporary insulation module is attached to the secondary insulation layer, and the supporting surface of the secondary temporary insulation module is flush with the supporting surface of the secondary insulation layer to support the secondary sealing film.

[0009] S2. Install a secondary metal skirt plate around the perimeter of the temporary opening. The secondary metal skirt plate is disposed on the support surface of the secondary temporary insulation module. One end of the secondary metal skirt plate is welded to the support structure, and the other end is welded to the secondary sealing membrane.

[0010] S3. Install a primary temporary insulation module around the perimeter of the temporary opening. The primary temporary insulation module is attached to the primary insulation layer, and the supporting surface of the primary temporary insulation module is flush with the supporting surface of the primary insulation layer to support the primary sealing film.

[0011] S4. Install a primary metal skirt plate around the perimeter of the temporary opening. The primary metal skirt plate is disposed on the support surface of the primary temporary insulation module. One end of the primary metal skirt plate is welded to the secondary metal skirt plate, and the other end is welded to the primary sealing membrane.

[0012] Primary / secondary temporary insulation modules are bonded to the conventional insulation modules and support structure of the insulation layer using disc-shaped resin putty. This adhesive bonding method eliminates the need for drilling compared to bolt fixing, preventing damage to the integrity of the insulation structure and avoiding cold bridging and leakage. The adhesive structure is easy to install and remove, leaving no residue and not affecting subsequent permanent sealing of temporary doors. It is reusable, reducing construction costs. The support surface of the temporary insulation module forms a complete plane with the support surface of the insulation layer to support the sealing structure. A corrugated metal plate and metal skirt are used to install the sealing membrane, which is welded to the support structure via the metal skirt. This temporary installation structure achieves a seal near the edge of the corrugated plate opening, ensuring reliable leak detection, and is simple and efficient to install and remove.

[0013] Preferably, the secondary metal skirt is connected to the supporting structure via angle steel; step S2 includes:

[0014] Install the angle steel in the four corner areas and the plane corner area in sequence, and spot weld the angle steel to the angle steel and the angle steel to the supporting structure;

[0015] Install the secondary metal skirting plates in sequence for the four corner areas and the plane corner areas, and spot weld the secondary metal skirting plates to each other and to the angle steel.

[0016] The angle steel in the diagonal area and the angle steel in the planar area are overlapped and welded together.

[0017] The secondary metal skirting plates in the diagonal area are overlapped and unsoldered with the secondary metal skirting plates in the planar area;

[0018] The secondary metal skirt plate and the angle steel are overlapped and unwelded.

[0019] The angle steel and the supporting structure are overlapped and unwelded.

[0020] The secondary metal skirt uses L-shaped angle steel to achieve a transitional connection with the supporting structure. This angle steel can form lap welds with both the secondary metal skirt and the supporting structure, allowing for adaptive adjustment of the installation position and lap size based on on-site assembly errors, effectively improving structural adaptability, welding accuracy, and connection stability. This process first uses lap spot welding to pre-position each component, locking the relative positions of the angle steel and the secondary metal skirt to prevent component misalignment during full welding. Then, a back-welding method is used to complete the full weld, effectively dispersing welding heat input and reducing residual stress and welding deformation. Furthermore, considering the structural characteristics of the supporting structure, which has a much greater thickness and stiffness than the secondary metal skirt and angle steel, a differentiated welding sequence is adopted: first welding the butt welds of thin-walled components, then welding the angle steel and the base support welds. This avoids stress concentration in the thin-walled welds caused by rigid base constraints, significantly improving the welding quality of the secondary metal skirt and the integrity of the sealing structure.

[0021] Preferably, the secondary sealing membrane comprises a plurality of corrugated metal plates, which are juxtaposed in a repeating pattern and welded together in a sealing manner; the temporary installation structure further comprises a corrugated sealing element; the edge of the secondary metal skirt welded to the corrugated metal plates has a mating groove; the corrugated sealing element includes a flat area mating portion; step S2 comprises:

[0022] The corrugated sealing member is welded to the corrugated portion of the corrugated metal plate;

[0023] The flat area is welded to the flat areas on both sides of the corrugation of the corrugated metal plate and the joint groove, respectively.

[0024] The position and size of the groove correspond to the position and size of the corrugations on the corrugated metal plate. The corrugations of the corrugated metal plate extend into the groove, and the flat areas on both sides of the corrugations overlap and weld with the edge areas on both sides of the groove. The groove structure can precisely avoid the corrugated protrusions and accommodate the flat area of ​​the corrugated sealing component, allowing the metal skirt to fit the edge contour of the corrugated plate and the corrugated sealing component, eliminating welding gaps, improving welding sealing performance, preventing air leakage during airtightness testing, and providing high positioning accuracy for the concave-convex fit, thereby improving the efficiency of temporary sealing assembly and welding consistency.

[0025] Preferably, step S4 includes:

[0026] Install the primary metal skirting plates in the four corner areas in sequence, and spot weld the primary metal skirting plates together with the primary metal skirting plates.

[0027] The primary metal skirting plate in the diagonal area overlaps and is unsoldered with the primary metal skirting plate in the planar area;

[0028] The primary metal skirt plate and the secondary metal skirt plate are overlapped and unwelded.

[0029] Preferably, the temporary mounting structure further includes a temporary end cap; step S4 includes:

[0030] The temporary end caps are welded to the corrugated portion of the corrugated metal plate and the primary metal skirt plate, respectively.

[0031] The present invention also provides a method for dismantling a temporary installation structure for a liquefied gas storage and transportation tank, wherein the temporary installation structure is obtained according to the installation method of the temporary installation structure for a liquefied gas storage and transportation tank as described above; the dismantling method includes:

[0032] S5. After confirming the airtightness test and acceptance of the liquefied gas storage and transportation tank, cut the primary metal skirt of the temporary installation structure along the weld of the temporary end cap of the temporary installation structure and the weld between the primary metal skirt and the secondary metal skirt, and remove the primary metal skirt.

[0033] S6. Remove the primary temporary insulation module;

[0034] S7. Cut the secondary metal skirt of the temporary installation structure along the weld seam between the secondary metal skirt and the secondary sealing membrane and angle steel of the liquefied gas storage and transportation tank, and remove the secondary metal skirt.

[0035] S8. Cut the angle steel of the temporary installation structure along the weld between the angle steel and the supporting structure, and remove the angle steel;

[0036] S9. Remove the secondary temporary insulation module.

[0037] After the airtightness test and acceptance, the temporary installation structure was dismantled. The primary metal skirt was cut directly along the weld of the temporary end cap of the temporary installation structure, and the primary metal skirt and the temporary end cap were cut off at the same time. The secondary metal skirt was cut directly along the weld of the secondary sealing membrane, and the secondary metal skirt and the corrugated sealing component were cut off at the same time, which improved the dismantling efficiency.

[0038] Preferably, the demolition method further includes:

[0039] Grind and cut away any remaining weld seams, and replace any damaged thermal protection components under the primary and / or secondary sealing films.

[0040] The present invention also provides a method for sealing a temporary installation structure of a liquefied gas storage and transportation tank, wherein the temporary installation structure is dismantled according to the method for dismantling a temporary installation structure of a liquefied gas storage and transportation tank as described above; the sealing method includes:

[0041] S10. Install the secondary insulation module at the temporary opening and check the integrity of the secondary insulation module.

[0042] S11. Install a secondary sealing membrane on the support surface of the secondary insulation module at the temporary opening and weld it to the secondary sealing membrane of the tank wall.

[0043] S12. Install the primary insulation module at the temporary opening and check the integrity of the primary insulation module;

[0044] S13. Install the primary sealing membrane on the support surface of the primary insulation module at the temporary opening and weld it to the primary sealing membrane of the tank wall.

[0045] After the temporary installation structure is removed, the secondary insulation module, secondary sealing membrane, primary insulation module and primary sealing membrane are installed sequentially at the temporary opening to form a complete tank wall.

[0046] The present invention also provides a liquefied gas storage and transportation tank, the liquefied gas storage and transportation tank including a temporary installation structure obtained according to the installation method of the temporary installation structure of the liquefied gas storage and transportation tank as described above, the temporary installation structure including a primary temporary insulation module, a primary metal skirt, a secondary temporary insulation module, and a secondary metal skirt.

[0047] The present invention also provides a ship for transporting liquefied gas, the ship comprising a hull and a liquefied gas storage and transport tank as described above disposed in the hull.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] 1. Adaptable to corrugated structure, high sealing accuracy: By setting matching grooves for the corrugated plate structure in the secondary metal skirt, and using special corrugated sealing parts, the protruding structure of the corrugated plate can be accurately avoided, eliminating the welding gap at the edge of the corrugated plate. This solves the problem that existing technologies cannot adapt to corrugated sealing plates for sealing and plugging, completely eliminating the problem of air leakage during tightness testing, and greatly improving the accuracy and reliability of tank tightness testing.

[0050] 2. Scientific welding process and strong structural stability: The welding process adopts spot welding for positioning and then layered back welding for full welding. Combined with the L-shaped angle steel transition connection structure, the assembly position and lap size can be precisely adjusted, effectively releasing weld stress and avoiding weld deformation and cracking. At the same time, the welding sequence of "welding small parts first and then welding large parts" is followed, which greatly reduces the weld stress of thin-walled metal skirt and improves the overall strength and sealing performance of the sealing structure.

[0051] 3. Convenient and efficient disassembly and assembly, and reusable: The modular temporary installation structure has a clear disassembly and assembly process and is easy to operate. The adhesive insulation modules can be easily peeled off, and the metal structure can be quickly removed by precisely cutting along the preset weld seam, which greatly improves construction efficiency. Moreover, the temporary insulation modules, metal skirts, angle steel and other components are undamaged after disassembly and can be reused, effectively reducing the construction cost of the tank.

[0052] 4. Complete construction loop and high tank forming quality: This invention forms a complete construction process loop of "temporary installation - tightness test - non-destructive dismantling - permanent sealing". After dismantling, the corresponding weld grinding and heat protection component replacement and repair processes are completed. After sealing, the multi-layer sealing and heat insulation structure of the tank is completely restored, ensuring the core performance of low temperature insulation and sealing pressure of the storage and transportation tank, and meeting the harsh working conditions of ocean-going low temperature transportation. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the structure of the liquefied gas storage and transportation tank in Embodiment 1 of the present invention;

[0054] Figure 2 This is a first side view of the temporary installation structure of the liquefied gas storage and transportation tank in Embodiment 1 of the present invention;

[0055] Figure 3 This is a second side view of the temporary installation structure of the liquefied gas storage and transportation tank in Embodiment 1 of the present invention;

[0056] Figure 4 for Figure 2 Cross-sectional view of detail A in the middle;

[0057] Figure 5 for Figure 2 A schematic diagram of detail B in the middle;

[0058] Figure 6 This is a schematic diagram of the corrugated sealing component of the temporary installation structure of the liquefied gas storage and transportation tank in Embodiment 1 of the present invention;

[0059] Figure 7 This is a third side view of the temporary installation structure of the liquefied gas storage and transportation tank in Embodiment 1 of the present invention;

[0060] Figure 8 for Figure 7 Cross-sectional view of detail C;

[0061] Figure 9 This is a flowchart of the installation method for the temporary installation structure of the liquefied gas storage and transportation tank in Embodiment 1 of the present invention;

[0062] Figure 10 for Figure 2 A schematic diagram of detail D in the middle;

[0063] Figure 11 This is a flowchart of the method for dismantling the temporary installation structure of the liquefied gas storage and transportation tank in Embodiment 1 of the present invention;

[0064] Figure 12 This is a schematic diagram of the removal of the primary metal skirt of the temporary installation structure from the inside of the liquefied gas storage and transportation tank in Embodiment 1 of the present invention.

[0065] Figure 13 This is a schematic diagram of the removal of the secondary metal skirt of the temporary installation structure from the inside of the liquefied gas storage and transportation tank in Embodiment 1 of the present invention.

[0066] Figure 14 This is a flowchart of the sealing method for the temporary installation structure of the liquefied gas storage and transportation tank in Embodiment 1 of the present invention.

[0067] Figure 15 This is a cross-sectional view of the tank of the ship in Embodiment 3 of the present invention.

[0068] Explanation of reference numerals in the attached figures:

[0069] 1: Support structure;

[0070] 2: Temporary opening;

[0071] 3: Corrugated metal sheet;

[0072] 5: Temporary insulation module;

[0073] 51: Secondary temporary insulation module;

[0074] 6: Metal skirting board;

[0075] 61: Secondary metal skirting board;

[0076] 62: Primary metal skirting board;

[0077] 7: Corrugated sealing components;

[0078] 71: The junction of flat areas;

[0079] 8: Combined with the groove;

[0080] 9: Liquefied gas storage and transportation tanks;

[0081] 10: Shell;

[0082] 11: Secondary sealing membrane;

[0083] 12: Primary sealing membrane;

[0084] 13: Temporary cap;

[0085] 14: Angle steel;

[0086] 21: Secondary insulation layer;

[0087] 22: Primary insulation layer;

[0088] 221: Standard plywood;

[0089] 222: Unconventional plywood;

[0090] 223: Temporary plywood;

[0091] 2231: Protruding compensation section;

[0092] 31: First weld;

[0093] 32: Second weld;

[0094] 33: Third weld;

[0095] 34: Fourth weld;

[0096] 41: Fifth weld;

[0097] 42: Sixth weld. Detailed Implementation

[0098] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0099] In the description of this invention, it should be understood that, unless otherwise stated, the terms "center," "perpendicular to the wall thickness direction," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0100] Furthermore, unless otherwise stated, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0101] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0102] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0103] Example 1

[0104] Please see the appendix Figure 1 As shown, this embodiment provides a liquefied gas storage and transportation tank, including at least one top wall, a bottom wall, and a plurality of side walls extending between the top wall and the bottom wall. A temporary opening is provided on one of the side walls, which is the main inlet and outlet for scaffolding, elevators, materials, and equipment during the construction phase of the liquefied gas storage and transportation tank.

[0105] Please see the appendix Figures 2-5 As shown, this embodiment provides a temporary installation structure for a liquefied gas storage and transportation tank. The structure is installed at the end of the liquefied gas storage and transportation tank near the temporary opening 2. The support structure 1 has an opening, and the temporary installation structure is arranged around the opening. The metal skirt 6 of the temporary installation structure defines the temporary opening 2 along the thickness direction of the tank wall. The liquefied gas storage and transportation tank is arranged in the support structure 1 and includes multiple tank walls. The multiple tank walls are connected to each other and fixed to the support structure 1. Each tank wall includes at least one sealing membrane and at least one heat insulation layer. The sealing membrane is disposed on the support surface of the heat insulation layer. The sealing membrane includes multiple corrugated metal plates 3, which are juxtaposed in a repeating pattern and welded together in a sealed manner.

[0106] The temporary installation structure includes a temporary insulation module 5, a metal skirt 6, and a corrugated sealing component 7. One end face of the temporary insulation module 5 is attached to the opposite end face of the conventional insulation module of the insulation layer, and the support surface of the insulation layer is flush with the support surface of the temporary insulation module 5. The metal skirt 6 has an L-shaped cross-section and is set on the support surface of the temporary insulation module 5. One end of the metal skirt 6 is welded to the support structure 1, and the other end is welded to the flat area of ​​the corrugated metal plate 3 near the temporary opening 2. The corrugated sealing component 7 is welded to the corrugated part of the corrugated metal plate 3 and the metal skirt 6.

[0107] The flat areas and corrugations of the corrugated plate are sealed by the metal skirt 6 and the corrugated sealing element 7, respectively. The L-shaped metal skirt 6 seals the corrugated plate to the support structure 1 to form a sealed space. The support surface of the temporary insulation module 5 and the support surface of the insulation layer form a complete plane to support the sealing structure. The temporary installation structure achieves sealing of the edge of the corrugated plate near the temporary opening 2, ensuring the reliability of the tightness test, and is simple and efficient to install and remove.

[0108] In this embodiment, the temporary insulation module 5 is bonded to the conventional insulation module and support structure 1 of the insulation layer. The temporary insulation module 5 is fixed to the conventional insulation module and support structure 1 by bonding, which eliminates the need for drilling compared to bolt fixing, thus avoiding damage to the integrity of the insulation structure and preventing cold bridging and leakage defects. The bonded structure is easy to assemble and disassemble, leaves no residual damage after removal, does not affect the subsequent construction of the temporary door permanent sealing panel, and is reusable, reducing construction costs.

[0109] It should be noted that, Figure 4 for Figure 2 Cross-sectional view of detail A in the middle. Figure 4 The corrugations are the corrugations at the far end of the cross-section where they meet the metal skirt.

[0110] The corrugations on the plate are not present in the metal skirting itself. For example... Figure 5 As shown, in this embodiment, the edge of the metal skirt plate 6 welded to the corrugated metal plate 3 has a mating groove 8; the position of the mating groove 8 corresponds to the position of the corrugations of the corrugated metal plate 3. The corrugations of the corrugated metal plate 3 extend into the mating groove 8, and the flat areas on both sides of the corrugations overlap and weld with the edge areas on both sides of the mating groove 8; the groove structure can precisely avoid the corrugated protrusion structure, so that the metal skirt plate 6 fits the edge contour of the corrugated plate and the corrugated sealing component 7, eliminating welding gaps, improving welding sealing performance, preventing air leakage during airtightness testing, and achieving high positioning accuracy for the concave-convex fit, thereby improving the efficiency of temporary sealing assembly and welding consistency. Figure 6As shown, in actual engineering, the size of the corrugated plug 7 is slightly larger than the size of the corrugation and has a flat area joint 71 to achieve mutual welding. The size of the joint groove 8 matches the flat area joint 71 of the corrugated plug 7 to accommodate the flat area joint 71 of the corrugated plug 7. The interior of the joint groove 8 is welded to the corrugated plug 7, and the edge areas on both sides of the joint groove 8 overlap and weld with the flat areas on both sides of the corrugation.

[0111] Please see the appendix Figures 7-8 As shown, in one optional embodiment, the sealing membrane is a secondary sealing membrane 11, and the insulation layer is a secondary insulation layer 21. The tank wall, in the thickness direction from the outside to the inside of the liquefied gas storage and transportation tank, includes: a secondary insulation layer 21 fixed to the support structure 1; a secondary sealing membrane 11 carried by the secondary insulation layer 21; a primary insulation layer 22 carried by the secondary sealing membrane 11; and a primary sealing membrane 12 carried by the primary insulation layer 22 and used for contact with the liquefied gas. The temporary installation structure, in the thickness direction from the outside to the inside of the liquefied gas storage and transportation tank, includes: a secondary temporary insulation module 51 attached to the secondary insulation layer 21; a secondary metal skirt 61 welded to the secondary sealing membrane 11; a primary temporary insulation module attached to the primary insulation layer 22; and a primary metal skirt 62 welded to the primary sealing membrane 12. The corrugations of the primary sealing membrane 12 near the temporary opening are sealed by end caps to achieve a tight seal.

[0112] Preferably, the primary insulation layer 22 includes a conventional plywood 221 and an unconventional plywood 222 near the temporary opening 2; the conventional plywood 221 supports the corrugated metal plate 3 in the flat area; the unconventional plywood 222 supports the flat area where the corrugated metal plate 3 is welded to the primary metal skirt 62; the size of the unconventional plywood 222 is smaller than the size of the conventional plywood 221. Before setting up the temporary installation structure, the corrugated plate at the temporary opening needs to be cut. In this embodiment, the corrugations perpendicular to the temporary opening 2 are cut off, rather than the corrugations parallel to the temporary opening 2. The unconventional plywood 222 is used to support the cut corrugated plate, and its size is smaller than that of the conventional plywood 221.

[0113] The primary temporary insulation module includes a temporary plywood 223; the temporary plywood 223 includes at least two protruding compensation portions 2231; the protruding compensation portions 2231 are used to fit with the non-conventional plywood 222 to form a supporting plane supporting the primary sealing membrane 12 and the primary metal skirt 62. The protruding compensation portions 2231 of the temporary plywood 223 fit with the non-conventional plywood 222 to form a supporting plane supporting the primary sealing membrane 12 and the primary metal skirt 62, filling the support gap at the edge of the temporary opening 2, eliminating steps and gaps in the insulation layer, ensuring a smooth and continuous supporting surface, increasing the contact area of ​​the plywood, dispersing the welding stress of the metal membrane, avoiding local hard contact that could cause membrane depression or deformation, and protecting the structural integrity of the sealing layer. The corrugations of the secondary sealing membrane 11 extend into the groove 2232 between the two protruding compensation portions 2231. The concave-convex plug-in assembly structure is simple to position, allows for rapid on-site installation, shortens the temporary sealing construction cycle, and improves assembly accuracy.

[0114] It should be noted that, Figure 8 for Figure 7 Cross-sectional view of detail C in the middle. Figure 9 The middle corrugation is the junction with the primary metal skirt at the far end of the cross-section.

[0115] The corrugations in the corrugated sheet are not present in the primary metal skirt itself.

[0116] like Figure 9 As shown, this embodiment provides an installation method for a temporary installation structure of a liquefied gas storage and transportation tank, including:

[0117] S1. Install a secondary temporary insulation module around the perimeter of the temporary opening. The secondary temporary insulation module is attached to the secondary insulation layer, and the supporting surface of the secondary temporary insulation module is flush with the supporting surface of the secondary insulation layer to support the secondary sealing film.

[0118] S2. Install a secondary metal skirt plate around the perimeter of the temporary opening. The secondary metal skirt plate is set on the support surface of the secondary temporary insulation module. One end of the secondary metal skirt plate is welded to the support structure, and the other end is welded to the secondary sealing membrane.

[0119] S3. Install the primary temporary insulation module around the perimeter of the temporary opening. The primary temporary insulation module is attached to the primary insulation layer, and the supporting surface of the primary temporary insulation module is flush with the supporting surface of the primary insulation layer to support the primary sealing film.

[0120] S4. Install the primary metal skirt plate around the perimeter of the temporary opening. The primary metal skirt plate is set on the support surface of the primary temporary insulation module. One end of the primary metal skirt plate is welded to the secondary metal skirt plate, and the other end is welded to the primary sealing membrane.

[0121] Primary / secondary temporary insulation modules are bonded to the conventional insulation modules and support structure of the insulation layer using disc-shaped resin putty. This adhesive bonding method eliminates the need for drilling compared to bolt fixing, preventing damage to the integrity of the insulation structure and avoiding cold bridging and leakage. The adhesive structure is easy to install and remove, leaving no residue and not affecting subsequent permanent sealing of temporary doors. It is reusable, reducing construction costs. The support surface of the temporary insulation module forms a complete plane with the support surface of the insulation layer to support the sealing structure. A corrugated metal plate and a metal skirt are used to install the sealing membrane, which is welded to the support structure via the metal skirt. This temporary installation structure achieves a seal near the edge of the corrugated plate opening, ensuring reliable leak detection, and is simple and efficient to install and remove.

[0122] like Figure 10 As shown, in this embodiment, the secondary metal skirt is connected to the supporting structure via angle steel 14; step S2 includes:

[0123] Install the angle steel in the four corner areas and the plane corner area in sequence, and spot weld the angle steel to the angle steel and the angle steel to the supporting structure;

[0124] Install the secondary metal skirting plates in sequence for the four corner areas and the plane corner areas, and spot weld the secondary metal skirting plates to each other and to the angle steel.

[0125] The angle steel in the diagonal area and the angle steel in the planar area are overlapped and welded back; in Figure 10 In the middle, the angle steel in the corner area can be welded to the angle steel in the planar area along the first weld seam 31.

[0126] The secondary metal skirting plates in the diagonal area overlap and are unsoldered with the secondary metal skirting plates in the planar area; in Figure 10 In the middle, the secondary metal skirt plate in the corner area can be welded to the secondary metal skirt plate in the planar area along the second weld seam 32.

[0127] For the secondary metal skirt panel and angle steel lap joint, the welding is reversed; Figure 10 In the middle, the secondary metal skirt can be welded to the angle steel along the third weld seam 33.

[0128] The angle steel is lapped and welded back to the supporting structure; in Figure 10 In the middle, the angle steel can be welded to the supporting structure along the fourth weld seam 34.

[0129] The secondary metal skirt uses L-shaped angle steel to achieve a transitional connection with the supporting structure. This angle steel can form lap welds with both the secondary metal skirt and the supporting structure, allowing for adaptive adjustment of the installation position and lap size based on on-site assembly errors, effectively improving structural adaptability, welding accuracy, and connection stability. This process first uses lap spot welding to pre-position each component, locking the relative positions of the angle steel and the secondary metal skirt to prevent component misalignment during full welding. Then, a back-welding method is used to complete the full weld, effectively dispersing welding heat input and reducing residual stress and welding deformation. Furthermore, considering the structural characteristics of the supporting structure, which has a much greater thickness and stiffness than the secondary metal skirt and angle steel, a differentiated welding sequence is adopted: first welding the butt welds of thin-walled components, then welding the angle steel and the base support welds. This avoids stress concentration in the thin-walled welds caused by rigid base constraints, significantly improving the welding quality of the secondary metal skirt and the integrity of the sealing structure.

[0130] Step S2 also includes:

[0131] Weld the corrugated sealing component to the corrugated part of the corrugated metal plate;

[0132] The flat areas are welded to the flat areas on both sides of the corrugation of the corrugated metal plate, and then to the grooves.

[0133] The position and size of the groove correspond to the position and size of the corrugations on the corrugated metal plate. The corrugations of the corrugated metal plate extend into the groove, and the flat areas on both sides of the corrugations overlap and weld with the edge areas on both sides of the groove. The groove structure can precisely avoid the corrugated protrusions and accommodate the flat area of ​​the corrugated sealing component, allowing the metal skirt to fit the edge contour of the corrugated plate and the corrugated sealing component, eliminating welding gaps, improving welding sealing performance, preventing air leakage during airtightness testing, and providing high positioning accuracy for the concave-convex fit, thereby improving the efficiency of temporary sealing assembly and welding consistency.

[0134] Furthermore, step S4 specifically includes:

[0135] Install the primary metal skirting plates in the four corner areas in sequence, and spot weld the primary metal skirting plates together with the primary metal skirting plates.

[0136] The primary metal skirting plate in the diagonal area overlaps and is unsoldered with the primary metal skirting plate in the planar area;

[0137] Unsoldering is applied to the overlap between the primary metal skirting plate and the secondary metal skirting plate.

[0138] In this embodiment, the temporary mounting structure further includes a temporary end cap 13; step S4 includes:

[0139] The temporary end caps are welded to the corrugated part of the corrugated metal plate and the primary metal skirt plate, respectively.

[0140] like Figure 11As shown, this embodiment also provides a method for dismantling a temporary installation structure for a liquefied gas storage and transportation tank. The temporary installation structure is obtained according to the installation method for the temporary installation structure of the liquefied gas storage and transportation tank described above. The dismantling method includes:

[0141] S5. After confirming the airtightness test and acceptance of the liquefied gas storage and transportation tank, cut the primary metal skirt of the temporary installation structure along the weld seam of the temporary end cap and the weld seam between the primary and secondary metal skirts, and remove the primary metal skirt; Figure 12 As shown, the primary metal skirt is cut along the fifth weld seam 41.

[0142] S6. Remove the primary temporary insulation module;

[0143] S7. Cut the secondary metal skirt of the temporary installation structure along the weld seams between the secondary metal skirt and the secondary sealing membrane and angle steel of the liquefied gas storage tank, and remove the secondary metal skirt; if Figure 13 As shown, the secondary metal skirt is cut along the sixth weld seam 42.

[0144] S8. Cut the angle steel of the temporary installation structure along the weld between the angle steel and the supporting structure, and remove the angle steel;

[0145] S9. Remove the secondary temporary insulation module.

[0146] After the airtightness test and acceptance, the temporary installation structure was dismantled. The primary metal skirt was cut directly along the weld of the temporary end cap of the temporary installation structure, and the primary metal skirt and the temporary end cap were cut off at the same time. The secondary metal skirt was cut directly along the weld of the secondary sealing membrane, and the secondary metal skirt and the corrugated sealing component were cut off at the same time, which improved the dismantling efficiency.

[0147] Preferably, the demolition method further includes:

[0148] Grind and cut away any remaining weld seams, and replace any damaged thermal protection components under the primary and / or secondary sealing films.

[0149] During the dismantling of the temporary installation structure, grinding and cutting processes are first used to remove residual weld metal from the damaged area; then the damaged main screen wall (primary sealing membrane) and secondary screen wall corrugated plate (secondary sealing membrane) are removed, and the heat protection components arranged at the bottom of the corrugated plate are replaced.

[0150] The thermal protection component installed at the bottom of the corrugated plate is a special heat insulation and protection structure for welding. During the early stage of corrugated plate splicing and welding, it can isolate the high temperature of the electric arc from being conducted downward along the stainless steel corrugated plate, preventing the welding heat from directly burning the insulation box below, preventing the insulation foam from carbonizing due to heat, the adhesive layer from delaminating due to high temperature, and the insulation box from deforming and being damaged. It is a key component for protecting the thermal insulation integrity of the insulation box. When the membrane is damaged and the thermal protection component below is also damaged, it must be replaced at the same time.

[0151] like Figure 14 As shown, the present invention also provides a method for sealing a temporary installation structure of a liquefied gas storage and transportation tank, wherein the temporary installation structure is dismantled according to the above-described method for dismantling the temporary installation structure of a liquefied gas storage and transportation tank; the sealing method includes:

[0152] S10. Install the secondary insulation module at the temporary opening and check the integrity of the secondary insulation module.

[0153] S11. Install a secondary sealing membrane on the support surface of the secondary insulation module at the temporary opening and weld it to the secondary sealing membrane of the tank wall.

[0154] S12. Install the primary insulation module at the temporary opening and check the integrity of the primary insulation module;

[0155] S13. Install the primary sealing membrane on the support surface of the primary insulation module at the temporary opening and weld it to the primary sealing membrane of the tank wall.

[0156] After the temporary installation structure is removed, the secondary insulation module, secondary sealing membrane, primary insulation module and primary sealing membrane are installed sequentially at the temporary opening to form a complete tank wall.

[0157] Example 2

[0158] This embodiment also provides a liquefied gas storage and transportation tank, which includes a temporary installation structure obtained according to the installation method of the temporary installation structure of the liquefied gas storage and transportation tank as described above, the temporary installation structure being removed according to the dismantling method of the temporary installation structure of the liquefied gas storage and transportation tank as described above, and the temporary installation structure being closed according to the sealing method of the temporary installation structure of the liquefied gas storage and transportation tank as described above.

[0159] Example 3

[0160] This embodiment provides a ship, including a hull 10 and a liquefied gas storage and transportation tank 9 disposed in the hull 10 as described above.

[0161] refer to Figure 15A cross-sectional view of a vessel used for transporting liquefied gas shows a liquefied gas storage tank 9, typically prismatic in shape, mounted within the hull 10 of the vessel. The wall of the liquefied gas storage tank 9 may include a primary sealing membrane for contact with the LNG contained within the tank, a secondary sealing membrane disposed between the primary sealing membrane and the hull of the vessel, and two insulating layers disposed between the primary and secondary sealing membranes, respectively, and between the secondary sealing membrane and the hull. Furthermore, a device / unloading pipe located on the upper deck of the vessel can be connected to an offshore or port terminal via suitable connectors to transfer LNG between the cargo ship and the tank.

[0162] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for installing a temporary installation structure for a liquefied gas storage and transportation tank, the temporary installation structure being installed at the end of the liquefied gas storage and transportation tank near a temporary opening (2), the liquefied gas storage and transportation tank being arranged in a support structure (1) and comprising a plurality of tank walls, the plurality of tank walls being connected to each other and fixed to the support structure (1), the tank walls comprising, in the thickness direction from the outside to the inside of the liquefied gas storage and transportation tank: A secondary insulation layer (21) fixed to the support structure (1); a secondary sealing membrane (11) carried by the secondary insulation layer (21); a primary insulation layer (22) carried by the secondary sealing membrane (11); and a primary sealing membrane (12) carried by the primary insulation layer (22) and used for contact with the liquefied gas; the temporary installation structure includes a primary temporary insulation module, a primary metal skirt (62), a secondary temporary insulation module (51), and a secondary metal skirt (61); characterized in that the installation method includes: S1. Install a secondary temporary insulation module around the perimeter of the temporary opening. The secondary temporary insulation module is attached to the secondary insulation layer, and the supporting surface of the secondary temporary insulation module is flush with the supporting surface of the secondary insulation layer to support the secondary sealing film. S2. Install a secondary metal skirt plate around the perimeter of the temporary opening. The secondary metal skirt plate is disposed on the support surface of the secondary temporary insulation module. One end of the secondary metal skirt plate is welded to the support structure, and the other end is welded to the secondary sealing membrane. S3. Install a primary temporary insulation module around the perimeter of the temporary opening. The primary temporary insulation module is attached to the primary insulation layer, and the supporting surface of the primary temporary insulation module is flush with the supporting surface of the primary insulation layer to support the primary sealing film. S4. Install a primary metal skirt plate around the perimeter of the temporary opening. The primary metal skirt plate is set on the support surface of the primary temporary insulation module. One end of the primary metal skirt plate is welded to the secondary metal skirt plate, and the other end is welded to the primary sealing membrane. The secondary sealing membrane comprises multiple corrugated metal plates, which are juxtaposed in a repeating pattern and welded together in a sealing manner; the temporary installation structure further comprises a corrugated sealing element (7); the edge of the secondary metal skirt (61) welded to the corrugated metal plates has a mating groove (8); the corrugated sealing element (7) comprises a flat area mating portion (71); step S2 includes: The corrugated sealing member is welded to the corrugated portion of the corrugated metal plate; The flat area is welded to the flat areas on both sides of the corrugation of the corrugated metal plate and the joint groove, respectively.

2. The installation method of the temporary installation structure for the liquefied gas storage and transportation tank according to claim 1, characterized in that, The secondary metal skirt is connected to the supporting structure via angle steel (14); step S2 includes: Install the angle steel in the four corner areas and the plane corner area in sequence, and spot weld the angle steel to the angle steel and the angle steel to the supporting structure; Install the secondary metal skirting plates in sequence for the four corner areas and the plane corner areas, and spot weld the secondary metal skirting plates to each other and to the angle steel. The angle steel in the diagonal area and the angle steel in the planar area are overlapped and welded together. The secondary metal skirting plates in the diagonal area are overlapped and unsoldered with the secondary metal skirting plates in the planar area; The secondary metal skirt plate and the angle steel are overlapped and unwelded. The angle steel and the supporting structure are overlapped and unwelded.

3. The installation method of the temporary installation structure for the liquefied gas storage and transportation tank according to claim 1, characterized in that, Step S4 includes: Install the primary metal skirting plates in the four corner areas in sequence, and spot weld the primary metal skirting plates together with the primary metal skirting plates. The primary metal skirting plate in the diagonal area overlaps and is unsoldered with the primary metal skirting plate in the planar area; The primary metal skirt plate and the secondary metal skirt plate are overlapped and unwelded.

4. The installation method of the temporary installation structure for the liquefied gas storage and transportation tank according to claim 1, characterized in that, The temporary installation structure also includes a temporary end cap (13); step S4 includes: The temporary end caps are welded to the corrugated portion of the corrugated metal plate and the primary metal skirt plate, respectively.

5. A method for dismantling a temporary installation structure of a liquefied gas storage and transportation tank, characterized in that, The temporary installation structure is obtained by the installation method of the temporary installation structure of the liquefied gas storage and transportation tank according to claim 4; the dismantling method includes: S5. After confirming the airtightness test and acceptance of the liquefied gas storage and transportation tank, cut the primary metal skirt of the temporary installation structure along the weld of the temporary end cap of the temporary installation structure and the weld between the primary metal skirt and the secondary metal skirt, and remove the primary metal skirt. S6. Remove the primary temporary insulation module; S7. Cut the secondary metal skirt of the temporary installation structure along the weld seam between the secondary metal skirt and the secondary sealing membrane and angle steel of the liquefied gas storage and transportation tank, and remove the secondary metal skirt. S8. Cut the angle steel of the temporary installation structure along the weld between the angle steel and the supporting structure, and remove the angle steel; S9. Remove the secondary temporary insulation module.

6. The method for dismantling the temporary installation structure of the liquefied gas storage and transportation tank according to claim 5, characterized in that, The demolition method also includes: Grind and cut away any remaining weld seams, and replace any damaged thermal protection components under the primary and / or secondary sealing films.

7. A method for sealing a temporary installation structure of a liquefied gas storage and transportation tank, characterized in that, The temporary installation structure is dismantled using the method for dismantling the temporary installation structure of the liquefied gas storage and transportation tank according to any one of claims 5-6; the sealing method includes: S10. Install the secondary insulation module at the temporary opening and check the integrity of the secondary insulation module. S11. Install a secondary sealing membrane on the support surface of the secondary insulation module at the temporary opening and weld it to the secondary sealing membrane of the tank wall. S12. Install the primary insulation module at the temporary opening and check the integrity of the primary insulation module; S13. Install the primary sealing membrane on the support surface of the primary insulation module at the temporary opening and weld it to the primary sealing membrane of the tank wall.

8. A liquefied gas storage and transportation tank, characterized in that, The liquefied gas storage and transportation tank includes a temporary installation structure obtained by the installation method of the temporary installation structure of the liquefied gas storage and transportation tank according to any one of claims 1 to 4, wherein the temporary installation structure includes a primary temporary insulation module, a primary metal skirt, a secondary temporary insulation module, and a secondary metal skirt.

9. A ship for transporting liquefied gases, characterized in that, The vessel includes a hull and a liquefied gas storage and transportation tank according to claim 8 disposed within the hull.

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