A high strength thin film type enclosure system

Abstract

The application discloses a high-strength thin film type enclosure system, which comprises a secondary insulation layer, a secondary shielding layer, a primary insulation layer and a primary shielding layer from the ship body to the cargo hold in sequence. The secondary shielding layer is spliced by multiple block-shaped invar steel flat plates, the edges of the invar steel flat plates are provided with pressing shoulders, the adjacent invar steel flat plates are fixed by upper and lower lap joints of the pressing shoulders, and are welded and connected with first anchoring pieces on the secondary insulation layer; the primary shielding layer is made of a stainless steel thin film plate, and a first corrugation and a second corrugation which are perpendicular to each other are arranged on the plate surface. Compared with the prior art, the secondary shielding layer of the application adopts pressing shoulder lap joint instead of edge folding connection, and it is not necessary to open an edge folding avoiding groove on the secondary insulation layer; the stress concentration hidden danger at the groove of the insulation layer is eliminated, the cracking risk of the insulation layer under low-temperature cyclic load is reduced, the cold leakage is effectively prevented, the structural strength and integrity of the insulation layer are maintained, and the cold preservation reliability of the enclosure system is improved.

Description

Technical Field

[0001] This invention relates to the field of containment systems for liquefied natural gas (LNG) transport vessels, and more specifically to a high-strength membrane protection system. Background Technology

[0002] Liquefied natural gas (LNG) is stored at extremely low temperatures (approximately -163°C), LNG carriers must be equipped with cargo hold containment systems that offer excellent thermal insulation and cryogenic sealing performance. Membrane containment systems are widely used in large LNG carriers due to their advantages such as light weight and high space utilization.

[0003] Existing membrane-type containment systems typically consist of four layers from the hull to the cargo hold: a secondary insulation layer, a secondary shielding layer, a primary insulation layer, and a primary shielding layer. The secondary and primary shielding layers jointly provide a liquid-tight seal, while the secondary and primary insulation layers jointly provide structural support and thermal insulation.

[0004] In existing technologies, the primary shielding layer and / or secondary shielding layer are typically made of Invar steel or stainless steel. For Invar steel, see [link to relevant documentation]. Figure 1 As shown, Invar steel plates 1 are currently typically manufactured as long strips, with both sides of the plate folded upwards. The folded edges 2 on the same side of two adjacent Invar steel plates 1 are welded to both sides of an anchor 3 extending upwards from between adjacent insulation layers. This folded edge connection method requires the creation of receiving grooves 5 in the corresponding insulation layer 4 to accommodate the Invar steel folded edges, which compromises the integrity of the insulation layer 4, reduces its strength, increases the risk of cracking and cold leakage, and is complex and difficult to construct.

[0005] For stainless steel sheets, a corrugated structure is required to prevent deformation caused by thermal expansion and contraction at low temperatures. Since the corrugations protrude from the sheet surface, clearance grooves matching the shape of the corrugations must be created in adjacent insulating layers to accommodate them. However, the presence of these clearance grooves also compromises the integrity of the insulating layers, reduces their structural strength, and introduces additional thermal bridges, increasing the risk of cold leakage.

[0006] In summary, both existing solutions share the following drawbacks: (1) they require clearance grooves to be made in the insulation layer, which compromises the integrity of the insulation layer and reduces its thermal insulation performance; (2) the clearance grooves introduce additional thermal bridges into the insulation layer, increasing cold leakage points and heat leakage channels; and (3) the processing is cumbersome and the cost is high. Therefore, there is an urgent need for a new type of thin-film enclosure system that can maintain the integrity of the insulation layer, has a reliable structure, and is easy to process. Summary of the Invention

[0007] The purpose of this invention is to overcome the defects of existing thin-film enclosure systems, which weaken the structural strength of the insulation layer, increase the risk of insulation layer cracking, and cause cold leakage due to the opening of clearance grooves on the insulation layer, and to provide a high-strength thin-film enclosure system.

[0008] To address the aforementioned technical problems, this invention provides a high-strength membrane-type enclosure system, comprising, from the hull to the cargo hold, the following components: The secondary insulation layer includes a plurality of first insulation blocks, which are spliced ​​and fixed to the hull, and are provided with first anchors on the first insulation blocks. The secondary shielding layer comprises multiple spliced ​​block Invar steel flat plates, which are welded and fixed to the first anchor. At least one edge of the Invar steel flat plate is provided with a shoulder, and adjacent flat plates are fixed by overlapping the shoulders. A main insulating layer, wherein the main insulating layer and the secondary shielding layer are fixed together by a dot matrix, and the main insulating layer includes a plurality of second insulating blocks, wherein second anchors are provided on the second insulating blocks; The main shielding layer comprises multiple stainless steel film plates spliced ​​together. The stainless steel film plates are welded and fixed to the second anchor. The stainless steel film plates are provided with a first corrugation and a second corrugation protruding from the plane of the stainless steel plate. The first corrugation and the second corrugation are perpendicular to each other. Both the first insulating block and the second insulating block include a polyurethane intermediate layer and an upper plywood and a lower plywood that hold the polyurethane intermediate layer in place.

[0009] Preferably, both the first and second corrugations protrude toward the interior of the warehouse.

[0010] Preferably, in the extending direction of the first corrugation and / or the second corrugation, there are protrusions protruding towards the interior of the warehouse and recesses concave towards the interior of the warehouse, respectively, and the protrusions and recesses are connected by extensions.

[0011] Preferably, the protrusion and the recess have the same cross-sectional shape.

[0012] Preferably, the second insulating block is provided with a relief groove to accommodate the recess.

[0013] Preferably, both the first and second anchors are anchor bars, and the upper plywood is provided with a groove. The anchor bar includes a sliding part that cooperates with the groove and a welded part that connects to the main shielding layer or the secondary shielding layer.

[0014] Preferably, the first anchor has a U-shaped cross-section, with one side of the U-shaped anchor embedded in the polyurethane intermediate layer on the side of the first insulating block, and the other side of the U-shaped anchor attached to the upper surface of the plywood of the first insulating block.

[0015] Preferably, a buffer layer is provided between the secondary shielding layer and the primary insulating layer and / or the secondary insulating layer.

[0016] Preferably, the buffer layer is one or a combination of fibers, polypropylene, and aerogel.

[0017] Preferably, the Invar steel flat plate is provided with a corrugated group that protrudes toward the secondary insulation layer, and the height of the corrugated group is less than the thickness of the upper plywood.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) The structural strength and integrity of the insulation layer are maintained. The secondary shielding layer uses block-shaped Invar steel flat plates, which are connected by overlapping shoulders. There is no need to fold the edges or open relief grooves on the corresponding insulation layer to accommodate the folds. The cross section of the insulation layer is intact and the structural strength is not weakened. The stress concentration at the groove position is eliminated, and the risk of cracking of the insulation layer under low temperature cyclic load is reduced. This effectively prevents cold leakage and significantly improves the long-term service reliability of the enclosure system.

[0019] (2) The construction process is simple. There is no need to cut grooves on the insulation layer, which reduces the processing difficulty of the insulation layer. In addition, the edge shoulder design of the Invar steel flat plate allows adjacent plates to be welded by overlapping, which is intuitive and convenient. There is no need to align with the avoidance groove on the insulation layer, which reduces the construction accuracy requirements and improves the installation efficiency. Attached Figure Description

[0020] Figure 1 This is the existing method of connecting Invar steel plates; Figure 2 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention; Figure 3 This is a cross-sectional view of Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the first insulating block in Embodiment 1 of the present invention; Figure 5 This is the present invention. Figure 3 Enlarged view of the structure of area A in the middle; Figure 6 This is a schematic diagram of the primary shielding layer according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the main insulating layer in Embodiment 1 of the present invention; Figure 8 This is a schematic diagram of the main shielding layer in Embodiment 1 of the present invention; Figure 9 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention; Figure 10 This is a cross-sectional view of Embodiment 2 of the present invention; Figure 11 This is the present invention. Figure 10 Enlarged view of the structure in area B; Figure 12 This is a schematic diagram of the structure of Embodiment 3 of the present invention.

[0021] Explanation of the labels in the diagram: 1. Invar steel plate; 2. Folded edge; 3. Anchor; 4. Insulation layer; 5. Receiving groove; 10. Secondary insulation layer; 11. First insulation block; 111. Polyurethane intermediate layer; 112. Upper plywood; 113. Lower plywood; 12. First anchor; 121. Anchor strip; 122. Sliding part; 123. Welded part; 13. Slide groove; 14. Clearance trench; 20. Secondary shielding layer; 21. Invar steel straight plate; 211. Shoulder; 22. Corrugated group; 30. Main insulation layer; 31. Second insulation block; 32. Clearance groove; 40. Main shielding layer; 41. Stainless steel film plate; 42. First corrugation; 43. Second corrugation; 44. Second anchor; 45. Protrusion; 46. Recess; 47. Extension; 50. Buffer layer. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0023] Reference Figure 2 and Figure 3 The diagram shown is a schematic representation of an embodiment of a high-strength membrane-type enclosure system according to the present invention.

[0024] The high-strength membrane enclosure system of this embodiment is installed on the inner wall of the cargo hold of an LNG carrier and includes, in sequence from the hull to the cargo hold, a secondary insulation layer 10, a secondary shielding layer 20, a primary insulation layer 30, and a primary shielding layer 40.

[0025] The secondary insulation layer 10 includes a plurality of first insulating blocks 11. The first insulating blocks 11 are spliced ​​and arranged along the inner wall of the ship and fixed to the inner wall of the ship by mechanical fixing and adhesive bonding.

[0026] Reference Figure 4As shown, the first insulating block 11 includes a polyurethane intermediate layer 111, an upper plywood 112, and a lower plywood 113. The upper plywood 112 and the lower plywood 113 sandwich the polyurethane intermediate layer 111, and the three are bonded together to form a composite panel structure with high thermal insulation performance. The polyurethane intermediate layer 111 is a closed-cell polyurethane foam with low thermal conductivity, and is the main contributor to the system's thermal insulation performance. The upper plywood 112 and the lower plywood 113 are rigid plywoods, providing sufficient structural rigidity for the insulating block and providing a supporting surface for the installation of the shielding layer and anchors.

[0027] A first anchor 12 is provided on the first insulating block 11. In this embodiment, the first anchor 12 is an anchoring strip 121. (Refer to...) Figure 5 As shown, the anchoring strip 121 extends along the length and width of the first insulating block 11, serving both to fix and connect the secondary shielding layer 20. The anchoring strip 121 includes a sliding part 122 and a welding part 123, wherein the sliding part 122 cooperates with the groove 13 opened on the upper plywood 112 of the first insulating block 11, and the welding part 123 is exposed upward for welding and fixing the Invar steel flat plate 21 of the secondary shielding layer 20.

[0028] The cross-sectional shape of the sliding part 122 matches the cross-sectional shape of the groove 13. In this embodiment, the groove 13 is set as a T-shaped cross-section or a dovetail groove cross-section, so that the anchoring strip 121 can be freely inserted along the extension direction of the groove 13, which facilitates the installation of the anchoring strip 121. At the same time, it is limited in the direction perpendicular to the groove 13 to prevent the anchoring strip 121 from falling out of the insulating block.

[0029] When the system is running in a low-temperature environment, the thermal shrinkage of the shielding layer and the thermal shrinkage of the insulation layer may not be synchronized. By sliding the sliding part 122 in the slide groove 13, the relative displacement between the shielding layer and the insulation layer caused by the temperature difference can be effectively released, avoiding weld tearing or insulation block damage caused by rigid connection, and significantly improving the long-term reliability and fatigue resistance of the system.

[0030] Furthermore, since the interior of the hull is not perfectly flat, gaps inevitably exist between adjacent first insulating blocks 11 during installation. In order to ensure the thermal insulation performance of the secondary insulating layer 10, flexible sealing material is filled in the gaps between the first insulating blocks 11. The flexible sealing material can be glass wool, mineral wool, or other materials suitable for low-temperature environments. It not only has thermal insulation and sealing properties, but also has a certain elastic deformation. After filling, it not only blocks the thermal bridge channels between the insulating blocks, but also adapts to the changes in the spacing between the insulating blocks caused by low-temperature shrinkage.

[0031] Reference Figure 6As shown, the secondary shielding layer 20 comprises multiple block-shaped Invar steel flat plates 21 arranged in a spliced ​​manner. Invar steel has an extremely low coefficient of thermal expansion and generates almost no thermal stress at the LNG storage temperature of -163°C, making it an ideal material for cryogenic sealing barriers.

[0032] Reference Figure 5 and Figure 6 As shown, the Invar steel flat plate 21 is a block-shaped flat plate with a flat surface. It is laid on top of the secondary insulation layer 10 and is fixed to the first anchor 12 by welding to the welded part 123 at its edge. Laser welding or TIG welding is preferred to ensure welding quality and low heat input, and to prevent the Invar steel from deteriorating in the heat-affected zone.

[0033] In this embodiment, at least one edge of the Invar steel flat plate 21 is provided with a shoulder 211. The shoulder 211 is a stepped protrusion formed by cold pressing on the edge of the Invar steel flat plate 21, and its height is equal to the thickness of one Invar steel flat plate 21. Adjacent Invar steel flat plates 21 overlap vertically at the shoulder 211 position: the shoulder 211 of the edge of one Invar steel flat plate 21 is located above the edge of another Invar steel flat plate 21 without a shoulder 211, and the two are welded and fixed in the overlapping area to achieve a sealed connection. Furthermore, the overlapping welding position of the Invar steel flat plates 21 is also the position of the first anchor 12. While welding the two Invar steel flat plates 21 together, the two Invar steel flat plates 21 are also welded and fixed to the first anchor 12, realizing the connection between the secondary shielding layer 20 and the secondary insulation layer 10.

[0034] Since the Invar steel flat plate 21 is flat overall and adjacent plates are connected by overlapping shoulders 211, there is no need to fold the edges. The height of the shoulder 211 is only the thickness of one Invar steel flat plate 21. Therefore, there is no need to open any clearance grooves 32 on the secondary insulation layer 10 and the main insulation layer 30 on both sides of the secondary shielding layer 20. The cross-sections of the secondary insulation layer 10 and the main insulation layer 30 remain intact, and the structural strength is not weakened. This eliminates the stress concentration hazards caused by the grooves in the prior art and reduces the risk of cracking of the secondary insulation layer 10 under low temperature cyclic loads and hull vibration, thereby effectively preventing cold leakage.

[0035] The main insulation layer 30 and the secondary shielding layer 20 are fixed by a dot matrix method, that is, by using spaced fasteners instead of full-surface bonding, in order to adapt to the independent thermal deformation of the two at low temperatures and prevent structural cracking caused by rigid connection.

[0036] Reference Figure 7As shown, the main insulating layer 30 includes a plurality of second insulating blocks 31. The structure of the second insulating block 31 is the same as that of the first insulating block 11, also including a polyurethane intermediate layer 111, an upper plywood 112, and a lower plywood 113, which are composited together. In this embodiment, the first insulating block 11 and the second insulating block 31 have the same thickness. In other embodiments of the present invention, the thickness of the first insulating block 11 may be greater than the thickness of the second insulating block 31. A second anchor 44 is provided on the second insulating block 31 for welding connection with the stainless steel film plate 41 of the main shielding layer 40. Flexible sealing material is also filled between adjacent second insulating blocks 31. In this embodiment, the second anchor 44 is also an anchor strip 121. The anchor strip 121 extends along the length and width of the second insulating block 31, and has the function of fixing and connecting the main shielding layer 40. The anchoring strip 121 includes a sliding part 122 and a welding part 123. The sliding part 122 cooperates with the T-shaped or dovetail-shaped groove 13 opened on the upper plywood 112 of the second insulating block 31. The welding part 123 is exposed upward for welding and fixing of the stainless steel film plate 41 of the main shielding layer 40.

[0037] Reference Figure 8 As shown, the main shielding layer 40 includes multiple spliced ​​stainless steel film plates 41. The stainless steel film plates 41 are laid on top of the main insulation layer 30 and are welded and fixed to the welding part 123 of the second anchor 44 through their edges to form a main liquid sealing layer that directly contacts LNG.

[0038] The stainless steel film sheet 41 is provided with a first corrugation 42 and a second corrugation 43 protruding from the surface of the sheet. The first corrugation 42 and the second corrugation 43 are arranged perpendicular to each other and extend along the length and width of the stainless steel film sheet 41, respectively. This gives the film sheet a degree of freedom of deformation in two orthogonal directions, which can effectively absorb the thermal stress caused by low temperature shrinkage and prevent the film sheet from cracking due to stress concentration.

[0039] In this embodiment, both the first corrugation 42 and the second corrugation 43 protrude toward the interior of the warehouse, that is, the protrusion 45 protrudes toward the interior of the warehouse, so that the corrugation is higher than the main plane of the stainless steel film plate 41. The corrugation and the main insulation layer 30 are kept apart, so there is no need to open the relief groove 32 to accommodate the corrugation on the main insulation layer 30, thus maintaining the cross-sectional integrity and structural strength of the main insulation layer 30.

[0040] In this embodiment, by setting the secondary shielding layer 20 as an Invar steel flat plate 21 and using a lap welding method, the upper surface of the secondary insulation layer 10 corresponding to the secondary shielding layer 20 and the lower surface of the main insulation layer 30 do not need to be provided with corresponding clearance grooves 32. At the same time, the corrugations of the main shielding layer 40 face the inside of the cargo hold, so the upper surface of the main insulation layer 30 also does not need to be provided with corrugated clearance grooves 32. This ensures the integrity of the secondary insulation layer 10 and the main insulation layer 30, making its structure strong, reducing the risk of cracking of the insulation layer under low temperature cyclic load, thereby effectively preventing cold leakage and significantly improving the long-term service reliability of the enclosure system.

[0041] Reference Figure 9 , Figure 10 The diagram shown is a schematic representation of Embodiment 2 of the present invention. In this embodiment, the containment system, from the hull to the cargo hold, sequentially includes a secondary insulation layer 10, a secondary shielding layer 20, a buffer layer 50, a primary insulation layer 30, and a primary shielding layer 40.

[0042] The secondary insulation layer 10 is fixed to the hull wall by mechanical fixing and adhesive bonding. First anchors 12 are provided on the plurality of first insulation blocks 11 of the secondary insulation layer 10. (Refer to...) Figure 11 As shown, in this embodiment, the first anchor 12 has a U-shaped cross-section. One side of the U-shaped cross-section is embedded in the polyurethane intermediate layer 111 on the side of the first insulating block 11, and the other side of the U-shaped cross-section is attached to the upper surface of the upper plywood 112 of the first insulating block 11. The U-shaped first anchor 12 is tightly fitted with the polyurethane intermediate layer 111 to prevent the first anchor 12 from coming off upward. The U-shaped first anchor 12 is attached to the surface of the upper plywood 112 to provide a welding base surface for the Invar steel flat plate 21 of the secondary shielding layer 20, so as to weld it to the secondary shielding layer 20. This avoids the gap between the U-shaped first anchor 12 and the upper plywood 112 being too large, which would result in an excessive gap between the secondary shielding layer 20 and the secondary insulating layer 10.

[0043] The secondary shielding layer 20 comprises multiple spliced ​​Invar steel flat plates 21, which are flat overall and laid on top of the secondary insulation layer 10. They are welded and fixed to one side of the upper plywood 112 via their edges using U-shaped first anchors 12. At least one edge of the Invar steel flat plate 21 has a shoulder 211. The shoulder 211 is a stepped protrusion formed by cold pressing along the edge of the Invar steel flat plate 21, and its height is equal to the thickness of one Invar steel flat plate 21. Adjacent Invar steel flat plates 21 overlap vertically at the shoulder 211.

[0044] The main insulation layer 30 includes a plurality of second insulation blocks 31 with the same structure as the first insulation block 11. Second anchors 44 are provided on the second insulation blocks 31. In this embodiment, the second anchors 44 can be configured as a U-shaped structure similar to the first anchor 12, or as an anchoring strip 121 similar to that in Embodiment 1. For ease of configuration, the second anchors 44 on the main insulation layer 30 are preferably of the anchoring strip 121 structure.

[0045] Reference Figure 10 As shown, the main shielding layer 40 includes multiple spliced ​​stainless steel film plates 41. The stainless steel film plates 41 are provided with mutually perpendicular first corrugations 42 and second corrugations 43, with different widths and heights. In this embodiment, the first corrugation 42 has protrusions 45 protruding towards the interior of the cargo hold and recesses 46 recessed towards the interior of the cargo hold along its extension direction. The protrusions 45 and recesses 46 are alternately distributed along the extension direction, and adjacent protrusions 45 and recesses 46 are smoothly connected by extensions 47. The alternating arrangement of the protrusions 45 and recesses 46 periodically interrupts the internal space of the corrugations in the extension direction, preventing the gas from forming a continuous natural convection circulation along the corrugated channels, thereby suppressing the loss of cold energy through the convection path, reducing the evaporation rate of liquefied natural gas, and improving the cold insulation efficiency. Similarly, in the extension direction of the second corrugation 43, there are also protrusions 45 protruding towards the interior of the warehouse and recesses 46 recessed towards the interior of the warehouse. The protrusions 45 and recesses 46 are alternately distributed along the extension direction, and adjacent protrusions 45 and recesses 46 are smoothly connected by extensions 47.

[0046] The protrusions 45 and the recesses 46 have the same cross-sectional shape, only opposite in the direction of protrusion. The uniform cross-sectional shape gives the corrugated structure a uniformly distributed stiffness along the extension direction, which is beneficial for the uniform transfer and dispersion of thermal stress across the entire thin film plate surface.

[0047] A clearance groove 32 is provided on the upper surface of the second insulating block 31 at the position corresponding to the recess 46. The shape of the clearance groove 32 is adapted to the cross-sectional shape of the recess 46 to accommodate the downwardly recessed portion 46 and prevent the recess 46 from directly pressing the surface of the main insulating layer 30. Since the same corrugation only needs to be grooved at the position corresponding to the recess 46, and the recess 46 only occupies a part of the total length of the corrugation, the clearance groove 32 is discontinuously distributed on the main insulating layer 30 rather than continuously. The weakening effect on the cross-sectional strength of the main insulating layer 30 is much smaller than that of the continuous groove in the prior art, thus minimizing the impact on the structural strength of the main insulating layer 30.

[0048] Reference Figure 11As shown, in this embodiment, a buffer layer 50 is further provided between the secondary shielding layer 20 and the primary insulation layer 30. The buffer layer 50 is laid between the upper surface of the Invar steel flat plate 21 and the lower plywood 113 of the second insulation block 31. The buffer layer 50 is made of one or more combinations of fiber felt, polypropylene foam, and / or aerogel felt. The buffer layer 50 has good elasticity and can absorb the relative displacement between the secondary shielding layer 20 and the primary insulation layer 30 caused by temperature changes, preventing the primary insulation layer 30 from being damaged by impact under hull rolling or temperature cycling conditions. The buffer layer 50 fills the gap between the secondary shielding layer 20 and the primary insulation layer 30, reducing the interlayer airflow space and inhibiting the formation of natural convection circulation of gas driven by temperature difference, thereby further reducing cooling loss and reducing the evaporation rate of liquefied natural gas.

[0049] Furthermore, the buffer layer 50 is not only disposed between the secondary shielding layer 20 and the main insulation layer 30, but also between the secondary shielding layer 20 and the secondary insulation layer 10. The two buffer layers 50 work together to further enhance the buffering protection capability of the secondary shielding layer 20 when subjected to mechanical vibration or low-temperature cyclic stress from the hull, thus extending the service life of the secondary shielding layer 20.

[0050] The buffer layer 50 preferably adopts a layered structure of aerogel felt and fiberglass cloth. The aerogel felt provides heat insulation and buffering functions, while the fiberglass cloth provides necessary structural support to prevent the aerogel felt from pulverizing and failing under pressure.

[0051] In this embodiment, a buffer layer 50 is further provided on at least one side of the secondary shielding layer 20, reducing the airflow space between the two layers and effectively suppressing the formation of natural convection circulation of gas in the gap between the two layers. This reduces cold loss, decreases the evaporation rate of liquefied natural gas, and improves the overall insulation performance of the enclosure system. Simultaneously, the corrugations of the main shielding layer 40 are set to alternate in both positive and negative directions, causing the internal space of the corrugations to be periodically interrupted in the extension direction. This prevents the gas from forming continuous natural convection circulation along the corrugated channels, thereby suppressing the loss of cold energy through the convection path and reducing the evaporation rate of liquefied natural gas.

[0052] Reference Figure 12 As shown, this is Embodiment 3 of the present invention. In this embodiment, the Invar steel flat plate 21 is provided with a corrugated group 22 protruding towards the secondary insulation layer 10. The corrugated group 22 can be composed of mutually perpendicular corrugations or other corrugated shapes. The corrugations protrude towards the secondary insulation layer 10, that is, the protruding direction faces away from the cargo compartment. The protrusion height of the corrugated group 22 is less than the thickness of the plywood 112 on the secondary insulation layer 10.

[0053] The corrugated group 22 gives the Invar steel flat plate 21 a certain ability to expand and contract in the in-plane direction, enabling the Invar steel flat plate 21 to better adapt to dimensional changes caused by low temperature shrinkage and thermal cycling loads, and further reduce the risk of weld or plate cracking caused by thermal stress concentration. Since the corrugated group 22 protrudes towards the secondary insulation layer 10 and the protrusion height is less than the thickness of the upper plywood 112, the protrusion 45 of the corrugated group 22 is completely accommodated within the thickness range corresponding to the upper plywood 112 of the secondary insulation layer 10. Therefore, no clearance groove 32 needs to be opened on one side of the main insulation layer 30, and the cross-section of the main insulation layer 30 is intact and the structural strength is not affected. The secondary insulation layer 10 only needs to open clearance grooves 14 on the upper plywood 112 that are adapted to the shape of the corrugated group 22. The depth of the clearance grooves 14 does not exceed the thickness of the upper plywood 112 and does not involve the polyurethane intermediate layer 111. The impact on the overall structural strength of the secondary insulation layer 10 is extremely limited, effectively maintaining the cold insulation integrity and structural reliability of the secondary insulation layer 10.

[0054] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A high-strength membrane-type enclosure system, characterized in that, From the hull to the cargo hold, the following are included: The secondary insulation layer includes a plurality of first insulation blocks, which are spliced ​​and fixed to the hull, and are provided with first anchors on the first insulation blocks. The secondary shielding layer comprises multiple spliced ​​block Invar steel flat plates, which are welded and fixed to the first anchor. At least one edge of the Invar steel flat plate is provided with a shoulder, and adjacent Invar steel flat plates are fixed by overlapping the shoulders. A main insulating layer, wherein the main insulating layer and the secondary shielding layer are fixed together by a dot matrix, and the main insulating layer includes a plurality of second insulating blocks, wherein second anchors are provided on the second insulating blocks; The main shielding layer comprises multiple stainless steel film plates spliced ​​together. The stainless steel film plates are welded and fixed to the second anchor. The stainless steel film plates are provided with a first corrugation and a second corrugation protruding from the plane of the stainless steel film plates. The first corrugation and the second corrugation are perpendicular to each other. Both the first insulating block and the second insulating block include a polyurethane intermediate layer and an upper plywood and a lower plywood that hold the polyurethane intermediate layer in place. The Invar steel flat plate is provided with a corrugated group that protrudes toward the secondary insulation layer, and the height of the corrugated group is less than the thickness of the upper plywood. The first anchor has a U-shaped cross section. One side of the U-shaped first anchor is embedded in the polyurethane intermediate layer on the side of the first insulating block, and the other side of the U-shaped first anchor is attached to the upper surface of the plywood of the first insulating block. The second anchor is an anchoring strip. The upper plywood is provided with a sliding groove. The anchoring strip includes a sliding part that cooperates with the sliding groove and a welded part that connects to the main shielding layer.

2. The high-strength membrane-type enclosure system as described in claim 1, characterized in that, Both the first and second corrugations protrude toward the interior of the warehouse.

3. The high-strength membrane enclosure system as described in claim 1, characterized in that, In the extending direction of the first corrugation and / or the second corrugation, there are respectively a protruding part that protrudes into the interior of the warehouse and a recessed part that is recessed into the interior of the warehouse, and the protruding part and the recessed part are connected by an extension.

4. The high-strength membrane-type enclosure system as described in claim 3, characterized in that, The protrusion and the recess have the same cross-sectional shape.

5. The high-strength membrane-type enclosure system as described in claim 3, characterized in that, The second insulating block is provided with a relief groove to accommodate the recess.

6. The high-strength membrane enclosure system as described in claim 1, characterized in that, A buffer layer is provided between the secondary shielding layer and the primary insulation layer and / or the secondary insulation layer.

7. The high-strength membrane enclosure system as described in claim 6, characterized in that, The buffer layer is one or more of fiber, polypropylene and aerogel.

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