A low-temperature envelope system corner structure that blocks convection

Abstract

The application discloses a kind of low temperature enclosure system corner area structures of blocking convection, including secondary insulation layer, secondary shielding layer, main insulation layer and main shielding layer in turn from outside to inside.Secondary insulation layer includes first secondary insulation layer and second secondary insulation layer respectively installed in two wall surfaces of corner area, each secondary insulation layer is composed of secondary insulation box, and each secondary insulation box includes polyurethane block and inner and outer plywood.Secondary shielding layer includes secondary metal plate and secondary corner folding piece, and the secondary corrugation on secondary corner folding piece includes first corrugation protruding towards secondary insulation layer and second corrugation protruding towards the inside of enclosure system.Main insulation layer and main shielding layer are respectively covered on the inside of secondary shielding layer.The secondary corrugation is set as corrugation in two directions of positive and negative in the application, the convection path of protective gas is blocked, and the liquid cargo evaporation rate is effectively reduced;Meanwhile, the avoidance groove on main insulation layer is eliminated, the structural integrity and heat insulation performance of main insulation layer are guaranteed, and welding and fixing with plane area are facilitated.

Description

Technical Field

[0001] This invention relates to the field of cryogenic liquid cargo storage and transportation equipment technology, specifically to a corner structure of a cryogenic enclosure system that blocks convection. Background Technology

[0002] Cryogenic containment systems are widely used in liquefied natural gas (LNG) carriers and onshore cryogenic storage tanks for the safe storage and transport of liquefied gases in extremely low-temperature environments. Membrane-type containment systems typically include an insulation layer and a metallic shielding layer installed inside the bulkhead. The insulation layer prevents external heat transfer, while the shielding layer prevents leakage of the liquefied cargo. The containment system is also filled with nitrogen protective gas to test the shielding layer's seal and to provide an inert protective environment.

[0003] In the corner area of ​​the enclosure system, that is, the boundary area between two adjacent walls, a special corner structure is required to achieve a continuous transition between the insulation layer and the shielding layer at the turning point. The corner structure typically includes, from the outside in, a secondary insulation layer, a secondary shielding layer, a primary insulation layer, and a primary shielding layer. Among them, the shielding layer has a corrugated structure to absorb the thermal shrinkage deformation of the metal shielding layer under low-temperature conditions.

[0004] In existing technologies, the secondary corrugations on the corner secondary shielding layer all protrude towards the interior of the enclosure system. This design has the following problems: First, because the secondary corrugations protrude towards the interior of the enclosure system, corresponding clearance grooves need to be set on the main insulation layer to accommodate the protruding secondary corrugations. The opening of clearance grooves disrupts the structural integrity of the main insulation layer, weakening its mechanical strength and making it more susceptible to damage under swaying impact loads. Furthermore, it creates weak points in the insulation in the clearance groove area, reducing the insulation performance of that area. Second, the secondary corrugations all protrude in the same direction, allowing unobstructed convection of protective gas between the main and secondary shielding layers, and between the secondary shielding layer and the wall surface, in the corner area. This convection heat transfer significantly increases the efficiency of heat transfer from the outside to the liquid cargo side, leading to an increased evaporation rate and increased load on the evaporative gas treatment system. Third, the processing of clearance grooves increases manufacturing steps and costs, and the fitting precision requirements between the clearance grooves and the secondary corrugations are high, making assembly difficult.

[0005] Therefore, there is an urgent need for a low-temperature enclosure system corner structure that can effectively block the convection of protective gas in the corner area while avoiding the need to create clearance grooves on the main insulation layer. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a corner structure of a low-temperature enclosure system that blocks convection, which addresses the problems caused by the corrugation of the secondary shielding layer in the corner area protruding towards the inside of the enclosure system in the prior art.

[0007] To address the aforementioned technical problems, this invention provides a corner structure for a cryogenic enclosure system that blocks convection, comprising, from the outside in: The secondary insulation layer includes a first insulation layer installed on the first wall surface of the corner area and a second insulation layer installed on the second wall surface of the corner area. The first insulation layer and the second insulation layer are connected at the junction of the first wall surface and the second wall surface. The first insulation layer includes a plurality of first insulation boxes arranged along the length direction of the corner area. The second insulation layer includes a plurality of second insulation boxes corresponding to the first insulation boxes. Both the first insulation box and the second insulation box include a secondary polyurethane block and a secondary outer plywood and a secondary inner plywood that clamp the secondary polyurethane block. The secondary shielding layer includes a secondary metal plate that fixes the first insulation box and the second insulation box at the angle between the first wall surface and the second wall surface, and a secondary corner piece that connects the secondary metal plate. Each secondary corner piece is provided with at least one secondary corrugation, and there is a first corrugation spacing between adjacent secondary corrugations. The secondary corrugation includes a first corrugation that protrudes towards the secondary insulation layer at the junction of the first wall surface and the second wall surface, and a second corrugation that protrudes towards the interior of the enclosure system at the edge of the secondary insulation layer. The main insulation layer includes a first main insulation layer and a second main insulation layer respectively connected to the two sides of the secondary shielding layer. The first main insulation layer includes a plurality of first main insulation boxes arranged along the length direction of the corner area, and the second main insulation layer includes a plurality of second main insulation boxes arranged along the length direction of the corner area. The main shielding layer includes a main metal plate that fixes the first main insulation box and the second main insulation box at the included angle of the first wall surface and the second wall surface, and a main corner piece that connects the main metal plate. Each main corner piece is provided with at least one main corrugation, and there is a second wave spacing between adjacent main corrugations. The main corrugations protrude toward the interior of the enclosure system.

[0008] Furthermore, the lengths of the first insulation box and the second insulation box are the same as the first wave spacing, the secondary wave is provided at the joints of adjacent first insulation boxes and adjacent second insulation boxes, and the edges of the first insulation box and the second insulation box are provided with receiving notches corresponding to the secondary wave.

[0009] Furthermore, the ratio of the first wave spacing to the second wave spacing is 3:2, the main corner piece is provided with 3 main corrugations, the secondary corner piece is continuously welded and fixed to the secondary metal plate only on both sides, and the main corner piece is continuously welded and fixed to the main metal plate only on both sides.

[0010] Furthermore, the width of the outer side of the first main insulation box on the line perpendicular to the intersection of the first wall and the second wall is less than the width of the inner side of the first insulation box, the width of the outer side of the second main insulation box is less than the width of the inner side of the second insulation box, and the length of the second corrugation is less than the width difference between the outer side of the first main insulation box and the inner side of the first insulation box, as well as the width difference between the outer side of the second main insulation box and the inner side of the second insulation box.

[0011] Furthermore, both the first main insulation box and the second main insulation box include a main polyurethane block, an outer plywood and an inner plywood that hold the main polyurethane block within them.

[0012] Furthermore, the secondary metal plate is provided with a first stud corresponding to the top corner of the main layer outer plywood, and the main layer polyurethane block is provided with a clearance notch corresponding to the first stud. The first stud passes through the main layer outer plywood and is locked to it.

[0013] Furthermore, the first main insulation box and the second main insulation box are respectively composed of a first main plywood and a second main plywood.

[0014] Furthermore, a second stud is provided on the secondary metal plate, and the cross-sections of the first main plywood and the second main plywood are T-shaped, with both sides of the first main plywood and the second main plywood being locked to the second stud.

[0015] Furthermore, the peaks of the main ripples do not coincide with the peaks of the secondary ripples.

[0016] Furthermore, the offset between the crests of the main wave and the secondary wave in the direction perpendicular to the wave extension is equal to half the greatest common factor of the first wave spacing and the second wave spacing.

[0017] Furthermore, at least one of the main corrugations on the main corner piece has its peak aligned with the peak of the secondary corrugation.

[0018] Furthermore, the sum of the thicknesses of the secondary insulating layer and the primary insulating layer is greater than or equal to 400 mm.

[0019] The beneficial effects of this invention are: (1) The first corrugation of the secondary corrugation protrudes towards the secondary insulation layer, rather than towards the interior of the enclosure system. Therefore, there is no need to open the clearance groove on the main insulation layer, which ensures the structural integrity and thermal insulation performance of the main insulation layer, avoids the mechanical and thermal weak points in the clearance groove area, and reduces the processing steps, thereby reducing the manufacturing cost and assembly difficulty of the main insulation layer.

[0020] (2) The secondary corrugations have corrugations that bulge in both directions, which creates a barrier between the main shielding layer and the secondary shielding layer, and between the secondary shielding layer and the wall. The protective gas cannot form a continuous convection channel in this gap, which effectively blocks the convective heat transfer in the corner area and reduces the liquid evaporation rate.

[0021] (3) The second corrugation at the end of the second corrugation protrudes towards the interior of the enclosure system and is used to weld and fix it to the secondary shielding layer in the planar area. This ensures structural continuity and eliminates the need to set up an avoidance structure on the main insulation layer.

[0022] (4) The main corrugations bulge towards the interior of the enclosure system to avoid opening receiving grooves on the main insulation layer and improve the strength and thermal insulation performance of the main insulation layer. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the secondary structure of the present invention; Figure 3 This is a schematic diagram of the main layer structure in Embodiment 1 of the present invention; Figure 4 This is a cross-sectional view of Embodiment 1 of the present invention; Figure 5 This is a cross-sectional view of Embodiment 2 of the present invention; Figure 6 This is a front view of Embodiment 3 of the present invention.

[0024] Explanation of the labels in the diagram: 10. Secondary insulation layer; 11. First insulation box; 111. Secondary polyurethane block; 112. Secondary outer plywood; 113. Secondary inner plywood; 114. Accommodation notch; 12. Secondary insulation box; 20. Secondary shielding layer; 21. Secondary metal plate; 211. First stud; 212. Secondary stud; 22. Secondary corner piece; 23. Secondary corrugation; 231. First corrugation; 232. Secondary corrugation; 30. Main insulation layer; 31. First main insulation box; 311. Main layer polyurethane block; 312. Main layer outer plywood; 313. Main layer inner plywood; 314. Clearance notch; 315. First main plywood; 316. Second main plywood; 32. Second main insulation box; 40. Main shielding layer; 41. Main metal plate; 42. Main corner piece; 43. Main corrugation. Detailed Implementation

[0025] 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.

[0026] like Figure 1 The diagram shows an overall structural schematic of a corner section structure of a cryogenic enclosure system for blocking convection, as described in Embodiment 1 of the present invention. This structure is used for the transition connection at the junction of two adjacent walls in cryogenic liquid storage and transportation equipment. The corner section structure, from the outside in, includes a secondary insulation layer 10, a secondary shielding layer 20, a primary insulation layer 30, and a primary shielding layer 40. "Outer" refers to the side closer to the load-bearing tank wall, and "inner" refers to the side closer to the liquid cargo. The corner section structure extends along its length, covering the junction area of ​​the first and second walls. The first and second walls are two adjacent load-bearing tank walls, forming an angle at their junction. This angle is typically a right angle, but can also be applied to corner section structures with other angles. The corner section structure connects to the planar section structure of the enclosure system at both ends along its length, achieving a continuous transition between the insulation layer and the shielding layer from the planar section to the corner section. In the planar area, the enclosure system also includes a secondary insulation layer 10, a secondary shielding layer 20, a primary insulation layer 30, and a primary shielding layer 40. The secondary shielding layer 20 of the corner structure achieves orientation conversion and welding connection with the planar area secondary shielding layer 20 at the edge through a second corrugation 232.

[0027] like Figure 2 As shown, the secondary insulation layer 10 includes a first insulation layer installed on the first wall surface of the corner area and a second insulation layer installed on the second wall surface of the corner area. The first insulation layer and the second insulation layer are connected at the junction of the first wall surface and the second wall surface to form a continuous secondary insulation layer 10 covering the area. The first insulation layer includes a plurality of first insulation boxes 11 arranged along the length direction of the corner area, and each first insulation box 11 is arranged sequentially and attached to the inner side of the first wall surface. The second insulation layer includes a plurality of second insulation boxes 12 corresponding to the first insulation boxes 11, and each second insulation box 12 is arranged sequentially and attached to the inner side of the second wall surface.

[0028] Both the primary insulation box 11 and the secondary insulation box 12 include a secondary polyurethane block 111, and a secondary outer plywood 112 and a secondary inner plywood 113 that hold the secondary polyurethane block 111 within it. The secondary outer plywood 112 is located on the side closest to the wall, and the secondary inner plywood 113 is located on the side closest to the interior of the enclosure system. The polyurethane block provides the primary thermal insulation function, while the plywood provides structural support and protection. The plywood is bonded to the polyurethane block with an adhesive, resulting in a sandwich structure that combines good thermal insulation performance with mechanical strength.

[0029] Because the secondary corrugations 23 protrude towards the secondary insulating layer 10, and the primary insulating box 11 and secondary insulating box 12 corresponding to the two walls of the secondary insulating layer 10 are separately arranged and then connected by a secondary metal plate to form an integral unit that matches the corner area, the lengths of the primary insulating box 11 and secondary insulating box 12 are the same as the first wave spacing of the secondary corrugations 23 in order to ensure the fit between the secondary shielding layer 20 and the secondary insulating layer 10. Thus, the secondary corrugations 23 can be positioned at the joints of adjacent primary insulating boxes 11 and adjacent secondary insulating boxes 12, that is, the position of each secondary corrugation 23 is aligned with the joint position between adjacent insulating boxes, reducing the processing difficulty of the secondary insulating boxes. To accommodate the secondary corrugations 23, the edges of both the primary insulating box 11 and the secondary insulating box 12 are provided with receiving notches 114 corresponding to the secondary corrugations 23, allowing the secondary corrugations 23 to be embedded in the receiving notches 114, achieving the fit between the secondary shielding layer 20 and the secondary insulating layer 10. This arrangement creates a regular correspondence between the arrangement of the insulating boxes and the corrugation spacing, facilitating standardized production and assembly.

[0030] Reference Figure 2 As shown, the secondary shielding layer 20 includes a secondary metal plate 21 that fixes the first insulation box 11 and the second insulation box 12 at the included angle of the first wall surface and the second wall surface, and a secondary corner piece 22 connecting the secondary metal plate 21. The secondary metal plate 21 is a thin-film stainless steel plate that is respectively attached to the inner surfaces of the first insulation box 11 and the second insulation box 12, fixing the first insulation box 11 and the second insulation box 12 at a specific mating angle. The secondary corner piece 22 is used to provide corrugations for the secondary shielding layer 20. Each secondary corner piece 22 is provided with at least one secondary corrugation 23, and there is a first corrugation gap between adjacent secondary corrugations 23. The presence of the secondary corner piece 22 provides elastic deformation for the ultra-low temperature thermal expansion and contraction of the enclosure system, releasing thermal stress; at the same time, the secondary corner piece 22 can also cover the gap between the secondary metal plates 21, so that the secondary shielding layer 20 forms a continuous sealing surface in the corner area.

[0031] In this embodiment, the secondary corrugation 23 includes a first corrugation 231 and a second corrugation 232. The first corrugation 231 is disposed at the junction of the first wall surface and the second wall surface, and protrudes toward the secondary insulating layer 10, that is, toward the wall surface outside the enclosure system. The second corrugation 232 is disposed at the edge of the secondary insulating layer 10, that is, the end of the secondary corrugation 23, and protrudes toward the interior of the enclosure system, that is, toward the liquid cargo direction, so that a single secondary corrugation 23 has protrusions in both positive and negative directions.

[0032] In this embodiment, the first corrugation 231 is configured to occupy a large proportion of the length of the second corrugation 23 and protrude towards the second insulating layer 10, so that it is embedded in the receiving notch 114 of the second insulating box, rather than protruding towards the main insulating layer 30. In this way, the main insulating layer 30 does not need to have a relief groove, ensuring its structural integrity and thermal insulation performance. At the same time, the first corrugation 231 protruding towards the second insulating layer 10 is set to correspond to the gap between two adjacent first insulating boxes 11 and the gap between the second insulating boxes 12. On the one hand, there is no need to make additional cuts to the secondary metal plate to avoid the first corrugation 231. On the other hand, it is only necessary to cut the corners of the first insulating box 11 and the second insulating box 12 to accommodate the first corrugation 231, which simplifies the processing.

[0033] Meanwhile, only the end of the second corrugation 232, i.e., the secondary corrugation 23, protrudes towards the interior of the enclosure system. On one hand, because the welding equipment welds from the inside of the corner piece, when the corrugation protrudes towards the secondary insulation layer 10, the welding surface is not planar and the operating space is small, making it inconvenient for the welding equipment to operate. However, when the corrugation protrudes towards the interior of the enclosure system, the welding equipment can easily directly butt-weld the end of the corner secondary corner piece 22 to the planar secondary metal plate 21, forming a smooth waveform transition. On the other hand, the length of the second corrugation 232 is relatively small, precisely avoiding the location where the main insulation layer 30 is set, thus eliminating the need to set an avoidance groove on the main insulation layer 30. Furthermore, when the secondary corrugation 23 has a first corrugation 231 and a second corrugation 232 protruding in both directions, the originally completely connected corrugated space becomes uneven, hindering the flow of protective gas. Specifically, when all the secondary corrugations 23 protrude towards the interior of the enclosure system, the space formed by the protruding corrugations is completely connected, forming a continuous gas channel. Due to temperature differences throughout the enclosure system, the protective gas undergoes natural convection driven by these temperature differences, exchanging heat unimpeded within the corrugated space. However, the reverse second corrugation 232 divides the continuous gas channel into several discontinuous sections. Gas within each section cannot exchange with gas in other sections, thus eliminating the driving force for convective heat transfer and significantly reducing heat transfer along this path.

[0034] The secondary corner piece 22 is continuously welded to the secondary metal plate 21 only on both sides. That is, the two side edges of the secondary corner piece 22 are welded to the secondary metal plates 21 on both sides, while the middle area of ​​the secondary corner piece 22 is not fixed to the secondary metal plate 21. This welding method allows the secondary corner piece 22 to be unrestrained between the welding areas, integrating the dispersed expansion and contraction differences generated by the multiple primary insulation boxes 11 and secondary insulation boxes 12 covered by the secondary corner piece 22. This makes the deformation evenly distributed on the multiple secondary corrugations 23 on the entire secondary corner piece 22, so that the plate can expand and contract evenly. This effectively reduces the risk of corrugation fatigue damage caused by local stress concentration and improves the overall service life and sealing reliability of the membrane enclosure system.

[0035] Reference Figure 3 As shown, the main insulation layer 30 includes a first main insulation layer and a second main insulation layer respectively connected to the two sides of the secondary shielding layer 20. The first main insulation layer is installed on the secondary shielding layer 20 on the first wall side, and the second main insulation layer is installed on the secondary shielding layer 20 on the second wall side. The first main insulation layer includes a plurality of first main insulation boxes 31 arranged along the length direction of the corner area, and the second main insulation layer includes a plurality of second main insulation boxes 32 arranged along the length direction of the corner area. The arrangement of the main insulation boxes is similar to that of the secondary insulation boxes, arranged sequentially along the length direction of the corner area.

[0036] The width D1 of the outer side of the first main insulation box 31 in the direction perpendicular to the intersection of the first and second wall surfaces is smaller than the width D2 of the inner side of the first insulation box 11, and the width D3 of the outer side of the second main insulation box 32 is smaller than the width D4 of the inner side of the second insulation box 12. That is, the size of the main insulation box in the corner area is smaller than that of the secondary insulation box, which facilitates the installation of the main insulation layer 30 inside the secondary shielding layer 20. The length of the second corrugation 232 is smaller than the width difference between the outer side of the first main insulation box 31 and the inner side of the first insulation box 11, and the width difference between the outer side of the second main insulation box 32 and the inner side of the second insulation box 12, thus avoiding interference between the main insulation box and the second corrugation 232 and ensuring that the second corrugation 232 is completely within the range formed by the width difference.

[0037] In Embodiment 1 of the present invention, the main insulation box adopts a composite structure of plywood-polyurethane-plywood. For example... Figure 3 and Figure 4As shown, both the first main insulation box 31 and the second main insulation box 32 include a main layer polyurethane block 311 and a main layer outer plywood 312 and a main layer inner plywood 313 that hold the main layer polyurethane block 311 within it. The main layer outer plywood 312 is located on the side closer to the secondary shielding layer 20, and the main layer inner plywood 313 is located on the side closer to the main shielding layer 40. In this embodiment, to fix the main insulation layer 30, the secondary metal plate 21 is provided with a first stud 211 corresponding to the apex corner of the main layer outer plywood 312. The main layer polyurethane block 311 is provided with a clearance notch 314 corresponding to the first stud 211, providing space for the first stud 211 to pass through, and the first stud 211 passes through and is locked to the main layer outer plywood 312. The first stud 211 is welded or otherwise fixed to the secondary metal plate 21 and extends toward the main insulation layer 30. This connection method firmly fixes the main insulation box to the secondary shielding layer 20, while avoiding the reduction in thermal insulation performance caused by studs penetrating the entire polyurethane block. The first studs 211 are positioned at the corners of the outer plywood 312 of the main layer, and each main insulation box is connected to the secondary metal plate 21 through multiple first studs 211. The stud connection method creates a reliable mechanical transmission path between the main insulation box and the secondary shielding layer 20. When the ship is subjected to swaying impact loads during navigation, the load is transferred from the main insulation box to the secondary metal plate 21 and the secondary insulation layer 10 through the studs, and is ultimately borne by the load-bearing bulkhead. The design of the clearance notch 314 provides operating space for the studs to be locked, facilitating installation.

[0038] In Embodiment 2 of the present invention, the main insulating layer 30 is a pure plywood structure. For example... Figure 5 As shown, the first main insulation box 31 and the second main insulation box 32 are respectively composed of a first main plywood 315 and a second main plywood 316, that is, the main insulation box only uses plywood material and does not have polyurethane blocks. In this structure, the thickness of the secondary polyurethane block 111 in the secondary insulation layer 10 is relatively large. Without reducing the total thickness of the enclosure system, the insulation performance of the enclosure system will not be affected even if the main insulation layer 30 does not have polyurethane blocks. In this embodiment, a second stud 212 is provided on the secondary metal plate 21. The cross-section of the first main plywood 315 and the second main plywood 316 is T-shaped. The two side flanges of the T-shaped first and second main plywood are locked with the second stud 212. The second stud 212 passes through the through holes on the two side flanges of the first and second main plywood and is locked by a nut, realizing a reliable connection between the main insulation box and the secondary shielding layer 20.

[0039] like Figure 3As shown, the main shielding layer 40 includes a main metal plate 41 that fixes the first main insulation box 31 and the second main insulation box 32 at the included angle of the first wall surface and the second wall surface, and main corner pieces 42 that connect the main metal plate 41. The main metal plate 41 is a thin-film stainless steel plate, which is respectively attached to the inner side of the first main insulation box 31 and the second main insulation box 32. The main corner pieces 42 connect the main metal plates 41 on both sides, and each main corner piece 42 is provided with at least one main corrugation 43, with a second corrugation spacing between adjacent main corrugations 43. The main corrugations 43 protrude towards the interior of the enclosure system, i.e., the liquid cargo side, so that the main insulation layer 30 does not need to be cut to avoid the main corrugations 43, thus ensuring the structural integrity and thermal insulation performance of the main insulation layer 30.

[0040] Furthermore, in this embodiment, the ratio of the first wave spacing to the second wave spacing is set to 3:2. The lengths of the first main insulation box 31 and the second main insulation box 32 are the same as the lengths of the first insulation box 11 and the second insulation box 12, all being the first wave spacing. Since the second wave spacing of the main corrugation 43 is different from the lengths of the first main insulation box 31 and the second main insulation box 32, if only one main corrugation 43 is provided on each main corner piece 42, then the installation positions of each main corner piece 42 on the first main insulation box 31 and the second main insulation box 32 will be different. Given that the degree of shrinkage of each part of the insulation box under extremely cold conditions is slightly different, the degree of expansion and contraction of the main corrugation 43 on each main corner piece 42 will be different, resulting in differences in the fatigue life of each main corrugation 43, affecting the total life of the enclosure system. Therefore, in this case, three main corrugations 43 are provided on the main corner piece 42. The three main corrugations 43 are evenly distributed. The main corner piece 42 is only continuously welded and fixed to the main metal plate 41 on both sides. The unwelded part in the middle area allows the main corrugations 43 to deform freely. This integrates the dispersed expansion and contraction differences generated by the multiple first main insulation boxes 31 and second main insulation boxes 32 within the coverage area of ​​the main corner piece 42, so that the deformation is evenly distributed on the three main corrugations 43 on the whole main corner piece 42, thereby making the force on each main corrugation 43 balanced and maintaining a consistent service life.

[0041] Reference Figure 1 and Figure 5 As shown, in Embodiments 1 and 2 of the present invention, the crests of the main corrugation 43 and the secondary corrugation 23 do not coincide; that is, the main corrugation 43 and the secondary corrugation 23 are staggered in the direction perpendicular to the corrugation extension. The staggered amount is equal to half of the greatest common factor of the first and second corrugation spacing. Since the ratio of the first to the second corrugation spacing is 3:2, let the first corrugation spacing be 3k and the second corrugation spacing be 2k, then the greatest common factor of the two is k, and the staggered amount is k / 2. This staggered arrangement makes the main corrugation 43 and the secondary corrugation 23 uniformly intersect in space, avoiding stress superposition caused by the alignment of the crests of the two corrugations, and effectively reducing local stress peaks.

[0042] Reference Figure 6 As shown, in Embodiment 3 of the present invention, at least one main corrugation 43 on the main corner member 42 has its crest aligned with the crest of the secondary corrugation 23. That is, at certain specific locations, the crests of the main corrugation 43 and the secondary corrugation 23 coincide in a direction perpendicular to the plane of the enclosure system. This alignment arrangement facilitates the positioning of the main corrugation 43 and makes installation convenient.

[0043] Furthermore, the sum of the thicknesses of the secondary insulation layer 10 and the primary insulation layer 30 is not less than 400 mm. Specifically, because the polyurethane block bears the main thermal insulation function, its thermal insulation capacity is poor when the primary insulation layer 30 is a pure plywood structure. Therefore, the thickness of the secondary insulation layer 10 is set to be not less than 300 mm. By increasing the thickness of the secondary insulation layer 10, sufficient thermal insulation capacity is ensured for the corner structure, controlling the heat flow from the outside to the liquid cargo side within the allowable range. When the primary insulation layer 30 is a three-layer composite structure, its thickness is 150 mm. In this case, the primary layer bears part of the thermal insulation function, so the thickness of the secondary layer can be set to 250 mm, thus ensuring that the sum of the thicknesses of the secondary insulation layer 10 and the primary insulation layer 30 is not less than 400 mm. This thickness design ensures thermal insulation performance while controlling the overall volume of the enclosure system, maximizing the effective volume of the liquid cargo tank. If the total thickness is less than 400 mm, the thermal insulation performance of the corner structure may not meet the requirements of cryogenic storage and transportation, resulting in excessively high liquid cargo evaporation rates.

[0044] In the manufacturing process of this invention, the first insulation box 11 and the second insulation box 12 are first fixed together as a whole using a secondary metal plate 21 at the factory, so that the first insulation box 11 and the second insulation box 12 are fixed together at the included angle of their corresponding two walls to form a secondary layer prefabricated component. Regardless of whether the main insulation layer 30 adopts a composite structure or a pure plywood structure, the first main insulation box 31 and the second main insulation box 32 are fixed together as a whole using a main metal plate 41, so that the first main insulation box 31 and the second main insulation box 32 are fixed together at the included angle of their corresponding two walls to form a main layer prefabricated component.

[0045] During installation, resin putty is first applied to the outer sides of the first insulation box 11 and the second insulation box 12. Then, the secondary prefabricated components are installed sequentially along the extension direction of the boundary line between the first and second wall surfaces, so that the outer sides of the first insulation box 11 and the second insulation box 12 are respectively attached to the first and second wall surfaces. The secondary insulation boxes and the wall surfaces are then locked together by mechanical fasteners such as bolts. Through the combined effect of the adhesive force of the putty and the mechanical fasteners, it is ensured that the first insulation box 11 and the second insulation box 12 will not shift during subsequent construction. At the same time, the resin putty can also fill the tiny gaps between the first insulation box 11 and the second insulation box 12 and the wall surfaces, improving the fit and enhancing the heat insulation effect.

[0046] After the positions of the first insulation box 11, the second insulation box 12, and the secondary metal plate 21 are determined, the secondary corner pieces 22 can be installed according to the correspondence between the secondary corrugations 23 and the secondary insulation boxes. The two sides of the secondary corner pieces 22 are then continuously welded and fixed to the secondary metal plate 21. In this embodiment, the lengths of the first insulation box 11 and the second insulation box 12 are equal to the first corrugation pitch. The secondary corner pieces 22 are placed above the gaps between adjacent secondary metal plates 21, so that the two sides of the secondary corner pieces 22 overlap the two secondary metal plates 21 respectively, and are continuously welded. It should be noted that "equal to" here does not mean that the length of the secondary insulation box is exactly the same as the first corrugation pitch, but rather that one secondary insulation box corresponds exactly to one corrugation pitch within a certain range. There may be installation gaps between the secondary insulation boxes.

[0047] Continue placing the main layer prefabricated component inside the secondary shielding layer 20 according to the design position, and secure the main layer prefabricated component to the secondary metal plate 21 using the studs fixed on the secondary metal plate 21. Finally, according to the correspondence between the main corrugations 43 and the secondary corrugations 23, after setting the main corner component 42 in the predetermined position, continuously weld and fix both sides of the main corner component 42 to the main metal plate 41. The installation of the corner structure is completed.

[0048] The corner structure of the present invention achieves the following technical effects by setting the first corrugation 231 of the secondary corrugation 23 to protrude toward the secondary insulating layer 10: First, since the first corrugation 231 protrudes towards the secondary insulation layer 10 and is embedded in the receiving notch 114 of the secondary insulation box, it will not protrude towards the main insulation layer 30. Furthermore, the second corrugation 232 avoids the position of the main insulation layer 30. Therefore, the main insulation layer 30 does not need to have a clearance groove. This ensures the structural integrity and thermal insulation uniformity of the main insulation layer 30, avoids mechanical and thermal weaknesses in the clearance groove area, and improves the main insulation layer 30's resistance to damage under swaying impact loads.

[0049] Secondly, the secondary corrugation 23 is provided with corrugations raised in both positive and negative directions, which avoids the continuous convection channel formed by corrugations with uniform direction, blocks the convection and heat exchange of the protective gas, and reduces the evaporation loss of the liquid cargo.

[0050] Third, the second corrugation 232 protrudes towards the interior of the enclosure system, which facilitates the welding connection between the corner area and the plane area, ensuring the continuity and sealing of the secondary shielding layer 20 throughout the enclosure system.

[0051] 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 corner structure for a cryogenic enclosure system that blocks convection, characterized in that, From the outside in, the following are included: The secondary insulation layer includes a first insulation layer installed on the first wall surface of the corner area and a second insulation layer installed on the second wall surface of the corner area. The first insulation layer and the second insulation layer are connected at the junction of the first wall surface and the second wall surface. The first insulation layer includes a plurality of first insulation boxes arranged along the length direction of the corner area. The second insulation layer includes a plurality of second insulation boxes corresponding to the first insulation boxes. Both the first insulation box and the second insulation box include a secondary polyurethane block and a secondary outer plywood and a secondary inner plywood that clamp the secondary polyurethane block. The secondary shielding layer includes a secondary metal plate that fixes the first insulation box and the second insulation box at the angle between the first wall surface and the second wall surface, and a secondary corner piece that connects the secondary metal plate. Each secondary corner piece is provided with at least one secondary corrugation, and there is a first corrugation spacing between adjacent secondary corrugations. The secondary corrugation includes a first corrugation that protrudes towards the secondary insulation layer at the junction of the first wall surface and the second wall surface, and a second corrugation that protrudes towards the interior of the enclosure system at the edge of the secondary insulation layer. The main insulation layer includes a first main insulation layer and a second main insulation layer respectively connected to the two sides of the secondary shielding layer. The first main insulation layer includes a plurality of first main insulation boxes arranged along the length direction of the corner area, and the second main insulation layer includes a plurality of second main insulation boxes arranged along the length direction of the corner area. The main shielding layer includes a main metal plate that fixes the first main insulation box and the second main insulation box at the included angle of the first wall surface and the second wall surface, and a main corner piece that connects the main metal plate. Each main corner piece is provided with at least one main corrugation, and there is a second wave spacing between adjacent main corrugations. The main corrugations protrude toward the interior of the enclosure system.

2. The corner structure of a low-temperature enclosure system for blocking convection as described in claim 1, characterized in that, The lengths of the first insulation box and the second insulation box are the same as the first wave spacing. The secondary wave is provided at the joints of adjacent first insulation boxes and adjacent second insulation boxes. The edges of the first insulation box and the second insulation box are provided with receiving notches corresponding to the secondary wave.

3. The corner structure of a low-temperature enclosure system for blocking convection as described in claim 2, characterized in that, The ratio of the first wave spacing to the second wave spacing is 3:

2. The main corner piece is provided with 3 main corrugations. The secondary corner piece is continuously welded and fixed to the secondary metal plate only on both sides. The main corner piece is continuously welded and fixed to the main metal plate only on both sides.

4. The corner structure of a low-temperature enclosure system for blocking convection as described in claim 1, characterized in that, The width of the outer side of the first main insulation box on the line perpendicular to the intersection of the first wall and the second wall is less than the width of the inner side of the first insulation box, the width of the outer side of the second main insulation box is less than the width of the inner side of the second insulation box, and the length of the second corrugation is less than the width difference between the outer side of the first main insulation box and the inner side of the first insulation box, and the width difference between the outer side of the second main insulation box and the inner side of the second insulation box.

5. The corner structure of a low-temperature enclosure system for blocking convection as described in claim 1, characterized in that, Both the first and second main insulation boxes include a main polyurethane block, an outer plywood and an inner plywood that hold the main polyurethane block within them.

6. The corner structure of a low-temperature enclosure system for blocking convection as described in claim 5, characterized in that, The secondary metal plate is provided with a first stud corresponding to the top corner of the main outer plywood, and the main polyurethane block is provided with a clearance notch corresponding to the first stud. The first stud passes through the main outer plywood and is locked to it.

7. The corner structure of a low-temperature enclosure system for blocking convection as described in claim 1, characterized in that, The first main insulation box and the second main insulation box are respectively composed of a first main plywood and a second main plywood.

8. The corner structure of a low-temperature enclosure system for blocking convection as described in claim 7, characterized in that, The secondary metal plate is provided with a second stud, and the cross-sections of the first main plywood and the second main plywood are T-shaped. The two sides of the first main plywood and the second main plywood are locked with the second stud.

9. The corner structure of a low-temperature enclosure system for blocking convection as described in claim 1, characterized in that, The crests of the main ripples do not coincide with the crests of the secondary ripples.

10. The corner structure of a cryogenic enclosure system for blocking convection as described in claim 9, characterized in that, The offset between the crests of the main wave and the secondary wave in the direction perpendicular to the wave extension is equal to 1 / 2 of the greatest common factor of the first wave spacing and the second wave spacing.

11. The corner structure of a cryogenic enclosure system for blocking convection as described in claim 1, characterized in that, At least one of the main corrugations on the main corner piece has its peak aligned with the peak of the secondary corrugation.

12. The corner structure of a cryogenic enclosure system for blocking convection as described in claim 1, characterized in that, The sum of the thicknesses of the secondary insulation layer and the primary insulation layer is greater than or equal to 400 mm.

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