Corrugated plate and liquefied gas storage vessel having same
By designing an intersection structure at the intersection of the corrugated plates, the problems of insufficient material uniformity and strength are solved, the thickness consistency and structural strength of the corrugated plates are achieved, and the sealing and service life are improved.
Patent Information
- Application Number
- PCT/CN2025/097328
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-28
- Filing Date
- 2025-05-27
- Publication Date
- 2025-10-23
AI Technical Summary
The existing corrugated plates lack material uniformity, smoothness and strength at the intersection of the horizontal and vertical corrugations, which affects the sealing and stability.
A corrugated plate structure is designed, in which an intersection structure is formed at the intersection of a first corrugation and a second corrugation, including a top, a ridge and a pit portion, and the ridges and the pit portions are arranged alternately to ensure uniform distribution of material at the intersection position, avoid excessive thickening or thinning, and enhance structural strength and fatigue resistance.
It achieves uniform distribution of materials at the intersection, ensures the thickness consistency and structural strength of the corrugated plate, improves the sealing and service life, reduces the strain under extreme working conditions, and ensures the safety of the storage container.
Smart Images
Figure CN2025097328_23102025_PF_FP_ABST
Abstract
Description
Corrugated plate and liquefied gas storage container with same
[0001] This application claims priority to Chinese patent application CN202510228284.8 filed on February 28, 2025, the contents of which are incorporated herein by reference. TECHNICAL FIELD
[0002] The present application relates to the field of liquefied gas storage containers of marine engineering equipment, in particular marine equipment such as ships, and more particularly to a corrugated plate and a liquefied gas storage container for marine equipment, in particular marine equipment such as ships, with the corrugated plate. The storage container is particularly a liquefied gas storage tank of marine equipment, in particular marine equipment such as ships, wherein the liquefied gas is, for example, liquefied natural gas, liquid nitrogen, liquid oxygen, liquid hydrogen, and liquid helium, etc. BACKGROUND
[0003] Liquefied natural gas (LNG) has always been the preferred energy source for oil replacement due to its green, environmentally friendly, and efficient advantages, and has become one of the fastest growing energy industries in the world. With the rapid development of China's economy and the increasing demand for environmental governance, the application and development of LNG have attracted more and more attention, especially in the case of frequent haze weather, the importance of LNG is increasingly prominent, thus triggering the rapid growth of social demand for clean energy. One of the key directions of China's clean energy development in the future is LNG.
[0004] LNG usually needs to rely on transportation equipment, such as marine equipment such as ships, to achieve transportation. The main components in the LNG receiving station are wharf unloading, LNG storage, process treatment, and external transmission, and among them, the LNG storage tank that undertakes the storage task has the longest construction period, the most advanced technology, and the most difficulties in the engineering construction process, and has always been managed as the key path of the entire project. Moreover, the construction form and technology of LNG storage tank are also the focus of attention of domestic and international industry professionals.
[0005] In the LNG storage tank, the corrugated plate used to constitute the sealing layer needs to be able to maintain good sealing and stability under various use conditions, so the configuration and quality of the corrugated plate are particularly important, and thus the requirements for the process of producing and manufacturing the corrugated plate are also relatively high. The uniformity, smoothness, and strength of the existing corrugated plate at the corrugated part, especially at the intersection of the horizontal and vertical corrugations, need to be strengthened.
[0006] Therefore, it is necessary to provide a corrugated plate and a storage container with the corrugated plate to at least partially solve the above problems. SUMMARY
[0007] To at least partially achieve the above object, the present application provides a corrugated plate for a liquefied gas storage container, the corrugated plate comprising a plate body, a first corrugation and a second corrugation, wherein the first corrugation projects a first height relative to the plate body along a height direction perpendicular to the plate body and extends along a first direction parallel to the plate body, the second corrugation projects a second height relative to the plate body along the height direction and extends along a second direction parallel to the plate body, the first height is greater than the second height, a maximum width of the first corrugation perpendicular to the first direction is greater than a maximum width of the second corrugation perpendicular to the second direction, the first corrugation and the second corrugation are orthogonal and form an intersection structure at an intersection position, the intersection structure comprises:
[0008] a top portion, the top portion is located at a center of the intersection position, a projection height of the top portion relative to the plate body along the height direction is greater than the first height,
[0009] four ridges, each of the ridges is located in one of four quadrants formed by a first wave crest of the first corrugation and a second wave crest of the second corrugation being orthogonal, extends from the top portion towards the plate body, and a general extension direction of the ridges is respectively intersected with the first direction, the second direction and the height direction; and
[0010] four pit portions, each of the pit portions is located in one of the four quadrants, is formed on an outer side surface of the first corrugation and is sandwiched between the first wave crest of the first corrugation and the ridges, and the pit portion is recessed inwardly relative to the outer side surface of the first corrugation.
[0011] In some embodiments, the ridges terminate at the outer side surface of the first corrugation.
[0012] In some embodiments, the ridges are smoothly connected and transitioned with the outer side surface of the first corrugation.
[0013] In some embodiments, the pit portions have pit edges, the pit edges are defined by a transition part of the outer side surface of the first corrugation from outwardly projecting or flush to inwardly recessed, and the pit edges are smoothly connected and transitioned with the ridges.
[0014] In some embodiments, the pit edges extend from the ridges to the first wave crest of the first corrugation, so that the pit portions are enclosed by the ridges, the pit edges and the first wave crest of the first corrugation.
[0015] In some embodiments, in a plane perpendicular to the height direction, a projection of the pit rim is a convex curve, an angle of a projection of the ridge with respect to the first direction is larger than an angle of a tangent of the projection of the pit rim with respect to the first direction, and a length component of the projection of the ridge in the first direction is smaller than a length component of the projection of the pit rim in the first direction.
[0016] In some embodiments, as the pit rim extends from the ridge, an angle of a tangent of a projection of the pit rim in a plane perpendicular to the height direction gradually increases with respect to the first direction.
[0017] In some embodiments, a depth of the pit portion with respect to the outer side of the first corrugation gradually increases along a direction from an edge of the pit portion to a center of the pit portion.
[0018] In some embodiments, as viewed along the height direction, the ridge and the pit portion are symmetrical with respect to a first peak of the first corrugation and / or a second peak of the second corrugation.
[0019] In some embodiments, a height of the first peak of the first corrugation at a location where the pit portion is formed is flush with a height of the first peak of the first corrugation at other locations.
[0020] In some embodiments, a groove portion is formed above the second corrugation between two ridges located on the same side of the first corrugation, and a groove bottom of the groove portion extends perpendicularly to the plate body.
[0021] According to another aspect of the present application, there is also provided a storage container for liquefied gas, a wall of the storage container comprising a base layer and a sealing layer located on an inner side of the base layer, wherein the sealing layer comprises a corrugated plate according to any of the preceding aspects.
[0022] According to the aspect of the present application, the intersection structure can make the upper and lower surfaces of the corrugated plate at the intersection location have a uniform line length when the second corrugation is formed, thus being able to achieve a uniform thickness, avoid excessive thickening or thinning, and achieve better structural strength and fatigue resistance. BRIEF DESCRIPTION OF DRAWINGS
[0023] For a better understanding of the above and other objects, features, advantages and functions of the present application, reference should be made to the preferred embodiments thereof illustrated in the accompanying drawings. Like numerals refer to like elements throughout the specification. It is to be understood that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the application, and in which:
[0024] Fig. 1 is a perspective view of a corrugated sheet according to a preferred embodiment of the present application;
[0025] Fig. 2 is a plan view of the corrugated sheet shown in Fig. 1 as viewed in the height direction;
[0026] Fig. 3 is a side view of the corrugated sheet shown in Fig. 1 as viewed in the second direction;
[0027] Fig. 4 is a side view of the corrugated sheet shown in Fig. 1 as viewed in the first direction;
[0028] Fig. 5 is a sectional view taken along the line A-A in Fig. 3;
[0029] Fig. 6 is a schematic view of a processing apparatus for processing a corrugated sheet according to the present application.
[0030] Explanation of Reference Numerals:
[0031] 1 corrugated sheet
[0032] 11 sheet body
[0033] 12 first corrugation
[0034] 121 first crest
[0035] 13 second corrugation
[0036] 131 second crest
[0037] 14 intersection structure
[0038] 141 top
[0039] 142 ridge
[0040] 143 pit portion
[0041] 144 pit rim
[0042] 145 groove portion
[0043] 146 groove bottom
[0044] 2 processing apparatus
[0045] 21 first mold
[0046] 211 avoidance groove
[0047] 212 shaping groove
[0048] 22 pressure pad
[0049] 23 second mold
[0050] 231 shaping protrusion
[0051] 24, an auxiliary shaping member;
[0052] 241, an auxiliary shaping protrusion;
[0053] 242, a notch portion;
[0054] D1, a height direction;
[0055] D2, a first direction;
[0056] D3, a second direction. DETAILED DESCRIPTION
[0057] Reference will now be made in detail to the preferred embodiments of the present application, which are illustrated in the accompanying drawings. The preferred embodiments described herein are merely exemplary and not limiting, as persons skilled in the art will think of other ways to implement the present application based on the preferred embodiments described herein, which are also within the scope of the present application.
[0058] The present application provides a corrugated plate, which is preferably made of a metal material (e.g. steel) and is suitable for manufacturing a storage container, especially a storage container for storing liquefied gas such as liquefied natural gas (LNG), liquid nitrogen, liquid oxygen, liquid hydrogen and liquid helium, which can be used for marine engineering equipment or land engineering equipment. Preferred embodiments of the corrugated plate will be described below with reference to Figs. 1 to 5.
[0059] As shown in Fig. 1, the corrugated plate 1 is processed from a flat metal plate and includes a plate body 11, a first corrugation 12 and a second corrugation 13. The first corrugation 12 and the second corrugation 13 both protrude outwardly relative to the plate body 11 in a direction substantially perpendicular to the plane in which the plate body 11 lies. The protruding direction can be referred to as a height direction D1. The protruding height (first height) of the first corrugation 12 relative to the plate body 11 is greater than the protruding height (second height) of the second corrugation 13 relative to the plate body 11. The protruding height here refers to the maximum distance by which the first corrugation 12 and the second corrugation 13 respectively protrude outwardly relative to the plate body 11, i.e. the height of the wave crest. In addition, the first corrugation 12 extends in a first direction D2 on the plate body 11. The second corrugation 13 extends in a second direction D3 on the plate body 11. The first direction D2 and the second direction D3 are substantially perpendicular. That is, the first corrugation 12 and the second corrugation 13 are both substantially orthogonal.
[0060] In some embodiments, the first corrugation 12 and the second corrugation 13 can both be configured as circular-arc corrugations. For example, referring to FIG. 3 and FIG. 4, the first corrugation 12 and the second corrugation 13, when viewed along their respective extending directions, have a projected profile in the shape of a circular arc, and each has a rounded top end without an edge. Of course, it can be appreciated that in other embodiments, at least one of the first corrugation and the second corrugation can be configured as a triangular corrugation, for example, having a projected profile in the shape of a substantially triangle when viewed along its extending direction, and having an edge at its top end. In this case, the first corrugation 12 has a maximum width perpendicular to its extending direction (the first direction D2) that is greater than the maximum width of the second corrugation 13 perpendicular to its extending direction (the second direction D3). The first corrugation 12 can also be referred to as a large corrugation, and the second corrugation 13 can also be referred to as a small corrugation, with reference to the height and width features.
[0061] The first corrugation 12 and the second corrugation 13 both extend and intersect, and the intersection structure 14 is formed at the intersection position. The intersection structure 14 can enhance the structural strength of the corrugated plate 1 at the intersection position, and is beneficial to prolong the service life.
[0062] The intersection structure 14 includes a top portion 141 that protrudes outward from the center of the intersection position relative to the plate body 11 in the height direction D1. The protruding height of the top portion 141 is greater than the protruding height of the first corrugation 12. As can be seen from FIG. 2, the first corrugation 12 is orthogonal to the second corrugation 13, and thus the first wave crest 121 of the first corrugation 12 and the second wave crest 131 of the second corrugation 13 can be regarded as two orthogonal coordinate axes that divide the surrounding plate body 11 into four quadrants. The top portion 141 can be regarded as the origin of the coordinate axes. Four ridges 142 extend from the top portion 141 towards the plate body 11. There is one ridge 142 in each quadrant. As can be seen from FIG. 2, the extending direction of each ridge 142 intersects the first direction D2 and the second direction D3. As can be seen from FIG. 3, the extending direction of the ridge 142 also intersects the height direction D1. The ridge is formed by bending and protruding outward of the plate material of the corrugated plate during the formation of the intersection structure 14.
[0063] According to the present application, the intersection structure 14 is further formed with a concave portion 143. Similar to the ridge 142, the concave portion 143 comprises four and is located in each quadrant respectively. In particular, the concave portion 143 is arranged on the outer side of the first corrugation 12, between the ridge 142 and the first crest 121 of the first corrugation 12. The concave portion 143 is configured to be concave inwardly relative to the outer side of the first corrugation 12. That is, for the first corrugation 12, the concave portion 143 is arranged on both sides of the first crest 121 respectively. The structure of the first crest 121 remains unchanged and always maintains an outward convex shape. That is, the height of the first crest 121 of the first corrugation 12 in the intersection structure 14 is flush with the height of the first crest 121 of the first corrugation 12 at other locations, so that the structural strength of the first corrugation 12 can be maintained unaffected. Preferably, the concave depth of the concave portion 143 gradually increases from the outer edge thereof to the inner portion thereof.
[0064] It can be understood that, in the process of forming corrugations, material accumulation occurs at some locations and material stretching occurs at some locations, so that the thickness of the plate material is not uniform, which has an adverse effect on the strength of the plate material. By arranging the top portion 141, the ridge 142 and the concave portion 143, the intersection structure 14 can absorb the accumulation of material at the intersection location when forming corrugations, and preferentially distribute the accumulated material to the location where the plate material is stretched, in this way, the upper and lower surfaces of the corrugated plate at the intersection location can have a uniform linear length, so that a uniform thickness can be achieved, avoiding excessive thickening or thinning. Through metallographic analysis detection, the intersection structure can achieve a maximum thinning rate of less than 5%, ensuring the thickness consistency of the material and the stability of the product performance. In addition, compared with the conventional corrugated plate with grooves formed at the wave crest, the scheme according to the present application can also achieve better structural strength and fatigue resistance. Through finite element analysis, the maximum strain of the intersection structure under extreme working conditions is 2%, which is far lower than the limit strain that causes structural damage to most metal materials (for example, the single tensile limit strain that causes structural damage to stainless steel usually exceeds 40%), ensuring the safety of the intersection structure and the overall corrugated plate during use.
[0065] The ridge 142 extends from the top portion 141 towards the plate body 11, and is preferably extended to the outer side of the first corrugation 12, i.e. terminated, without extending to the plate body 11. This is beneficial to maintain the integrity of the plate body 11. At the same time, the smooth connection between the ridge 142 and the first corrugation 12 can avoid stress concentration while increasing the structural strength.
[0066] It can be understood that the concave portion 143 is formed on the outer side of the first corrugation 12, which is the position where the outer convex or flush changes to concave, which defines the concave edge 144 of the concave portion 143. In essence, it is a small and less obvious ridge formed on the outer side of the first corrugation 12. Through such an alternating change of the outer convex and inner concave, the structural strength of the corrugated plate 1 at the intersection structure 14 can be further increased.
[0067] Preferably, the concave edge 144 and the ridge 142 are connected and transitioned in a smooth manner on the outer side of the first corrugation 12. That is, there is actually no obvious connection position between the concave edge 144 and the ridge 142, so there is no sharp change in shape, which is beneficial to avoid stress concentration. For the purpose of illustration, the concave edge 144 is symbolically shown as a curved dotted line and the ridge 142 is symbolically shown as a substantially straight dotted line in FIGS. 2 and 3. It can be understood that these dotted lines are only used to represent the general trend of the concave edge 144 and the ridge 142, and are not used to represent their actual shape. As can be seen from FIGS. 2 and 3, the concave edge 144 extends toward the first crest 121 of the first corrugation 12 at one end, except that it is smoothly connected with the ridge 142 at the other end. Whether observed from FIG. 2 along the height direction D1 or from FIG. 3 along the second direction D3, the projection of the concave edge 144 in the corresponding plane is configured as a convex curve.
[0068] Preferably, as shown in FIG. 2, in some embodiments, for the projection curve segment of the concave edge 144 in the plane perpendicular to the height direction D1, the angle of the tangent line thereof relative to the first direction D2 is smaller than the angle of the projection of the ridge 142 relative to the first direction D2. Moreover, as the concave edge 144 extends toward the first crest 121 of the first corrugation 12, the angle of the tangent line of the projection curve segment thereof relative to the first direction D2 gradually increases. In addition, the size along the first direction D2 between the two ends of the projection curve segment of the concave edge 144 is greater than the size along the first direction D2 between the two ends of the projection of the ridge 142 (corresponding to the distance along the first direction D2 between the connection of the concave edge 144 and the ridge 142 and the top 141).
[0069] In this way, for the continuous convex structure formed by the ridge 142 and the pit edge 144, the distance between the ridge 142 and the first wave crest 121 of the first wave 12 along the second direction D3 gradually increases as the ridge 142 extends, and reaches the maximum distance at the connection of the pit edge 144 and the ridge 142. Further, as the pit edge 144 extends towards the first wave crest 121, the distance between the continuous convex structure and the first wave crest 121 along the second direction D3 gradually converges and decreases, and converges to the minimum at the end of the pit edge 144 away from the ridge 142. Wherein, the extension component of the ridge 142 along the first direction D2 is less than the extension component of the pit edge 144 along the first direction D2. Therefore, on the same side of the first wave 12, the ridge 142 and the corresponding pit edge 144 located on both sides of the first wave 12 form a structure of a substantially heart-shaped pattern when viewed along the height direction D1. Preferably, the intersection structure 14 can have substantially the same shape in each quadrant, so that it forms a structure symmetrical with respect to the first wave crest 121 of the first wave 12 and / or the second wave crest 131 of the second wave 13. Preferably, the pit edge 144 extends to the first wave crest 121 of the first wave 12, so that each pit 143 is surrounded by the corresponding ridge 142, pit edge 144 and first wave crest 121 of the first wave 12.
[0070] Referring to FIG. 3, between the two ridges 142 located on both sides of the second wave 13 on the same side of the first wave 12, a groove 145 is formed above the second wave 13. Further, as can be seen from FIG. 4 and FIG. 5, the groove bottom 146 of the groove 145 extends substantially along the height direction D1 (i.e. substantially perpendicular to the plate body 11). This configuration is advantageous for the ridges 142 and the top 141 to have better strength, improving their ability to resist load impact perpendicular to the plate body 11.
[0071] FIG. 6 shows a machining device 2 for machining the corrugated plate according to the present application, especially for machining the intersection structure thereof, which comprises a first die 21, a pressure plate 22, a second die 23 and an auxiliary shaping member 24. It can be understood that the first wave 12 and the second wave 13 can be respectively machined by two independent processes. The machining device 2 is used for further machining the plate material which has been pre-machined with the first wave 12. For this purpose, the first die 21 is provided with a relief groove 211. During machining, the pre-machined first wave 12 can be placed in the relief groove 211, so that the plate body 11 is attached to the upper surface of the first die 21. Then the pressure plate 22 is attached to the first die 21. Preferably, the pressure plate 22 is provided with a pressure protrusion which extends into the first wave 12 to press it tightly in the relief groove 211.
[0072] The first die 21 is further provided with a shaping groove 212 for forming the second corrugation 13. Correspondingly, the second die 23 is provided with a shaping protrusion 231. When the plate is pressed on the first die 21, the second die 23 moves towards the first die 21, and the shaping protrusion 231 presses the plate into the shaping groove 212 to form the second corrugation 13. In the middle of the shaping protrusion 231, a latch (not shown) is further provided, which protrudes outward under the action of an elastic force (e.g. applied by a spring), and has a greater protruding distance relative to the protruding distance of the shaping protrusion 231. The latch extrudes the intersection position of the first corrugation 12 and the second corrugation 13, and under the cooperation of the corresponding shape in the shaping groove 212, the top 141, the ridge 142 and the groove part 145 of the intersection structure 14 are formed.
[0073] In addition, an auxiliary shaping member 24 is arranged on the side of the first die 21 opposite to the second die 23, which has two auxiliary shaping protrusions 241 respectively located on both sides of the shaping protrusion 231 of the second die 23. Each auxiliary shaping protrusion 241 has a notch part 242 at a position corresponding to the peak of the first corrugation 12. The auxiliary shaping member 24 extrudes the plate synchronously with the second die 23. Among them, the notch part 242 avoids the first peak 121 of the first corrugation 12, and the two endpoints of the notch part 242 extrude the outer side of the first corrugation 12 on both sides of the first peak 121, so that two pit parts 143 and corresponding pit edges 144 are formed on both sides of the first peak 121 of the first corrugation 12. In this way, the corrugated plate processing is completed.
[0074] The corrugated plate according to the present application can be used to constitute part of the wall of a storage container. In some embodiments, the wall of the storage container comprises, from the outside to the inside, a secondary insulation layer, a secondary sealing layer, a primary insulation layer and a primary sealing layer. That is, the primary sealing layer is located at the innermost side of the container wall and contacts the content (e.g. LNG) in the storage container, and the secondary insulation layer is located at the outermost side. Among them, the secondary sealing layer and the primary sealing layer can both be constituted by the corrugated plate according to the present application. While the secondary insulation layer and the primary insulation layer are both composed of an insulation plate (e.g. plywood) made of heat insulation material. The secondary insulation layer and the primary insulation layer can also be referred to as base layers.
[0075] The above description of various embodiments of the present application is provided to one of ordinary skill in the relevant art for a descriptive purpose. It is not intended to exclude or limit the present application to a single disclosed embodiment. As such, one of ordinary skill in the art will appreciate or be reasonably capable of determining that various alternatives and modifications to the present application can be used. Therefore, although some alternative embodiments have been specifically described above, one of ordinary skill in the art will appreciate or be reasonably capable of determining other embodiments without undue experimentation. The present application is intended to include all such alternatives, modifications and variations that fall within the spirit and scope of the present application as described above.
Claims
1. A corrugated sheet for a liquefied gas storage vessel, the corrugated sheet comprising a sheet body (11), a first corrugation (12) and a second corrugation (13), wherein, The first corrugation (12) protrudes a first height relative to the plate body (11) along a height direction (D1) perpendicular to the plate body (11) and extends along a first direction (D2) parallel to the plate body (11), the second corrugation (13) protrudes a second height relative to the plate body (11) along the height direction (D1) and extends along a second direction (D3) parallel to the plate body (11), the first height is greater than the second height, a maximum width of the first corrugation (12) perpendicular to the first direction (D2) is greater than a maximum width of the second corrugation (13) perpendicular to the second direction (D3), the first corrugation (12) and the second corrugation (13) are orthogonal and form an intersection structure (14) at an intersection position, characterized in that the intersection structure (14) comprises: a top portion (141) located at the center of the intersection position, the top portion (141) protrudes a height relative to the plate body (11) along the height direction (D1) which is greater than the first height, four ridges (142), each of the ridges (142) is located in one of four quadrants formed by the first wave crest (121) of the first corrugation (12) and the second wave crest (131) of the second corrugation (13) being orthogonal, extends from the top portion (141) towards the plate body (11), and the overall extension direction of the ridges (142) respectively intersects the first direction (D2), the second direction (D3) and the height direction (D1); and four recessed portions (143), each of the recessed portions (143) is located in one of the four quadrants, is formed on the outer side surface of the first corrugation (12) and is clamped between the first wave crest (121) of the first corrugation (12) and the ridges (142), and the recessed portions (143) are recessed inwardly relative to the outer side surface of the first corrugation (12).
2. The corrugated sheet according to claim 1, characterized in that The ridges (142) terminate at the outer side surface of the first corrugation (12).
3. The corrugated sheet according to claim 2, characterized in that The ridges (142) are smoothly connected and transitioned to the outer side surface of the first corrugation (12).
4. The corrugated sheet according to claim 3, characterized in that The recessed portions (143) have recessed edges (144) which are defined by the transition part of the outer side surface of the first corrugation (12) from outward protrusion or flush to inward recess, the recessed edges (144) are smoothly connected and transitioned to the ridges (142).
5. The corrugated sheet according to claim 4, characterized in that The recessed edges (144) extend from the ridges (142) to the first wave crest (121) of the first corrugation (12), so that the recessed portions (143) are enclosed by the ridges (142), the recessed edges (144) and the first wave crest (121) of the first corrugation (12).
6. The corrugated sheet according to claim 4, wherein In a plane perpendicular to the height direction (D1), a projection of the pit rim (144) is a convex curve, an included angle of a projection of the ridge (142) with respect to the first direction (D2) is larger than an included angle of a tangent of the projection of the pit rim (144) with respect to the first direction (D2), and a length component of the projection of the ridge (142) in the first direction (D2) is smaller than a length component of the projection of the pit rim (144) in the first direction (D2).
7. The corrugated sheet according to claim 6, characterized in that From the ridge (142) along the extension of the pit rim (144), an included angle of a tangent of a projection of the pit rim (144) in a plane perpendicular to the height direction (D1) with respect to the first direction (D2) gradually increases.
8. The corrugated sheet of claim 1, wherein A concave depth of the pit portion (143) with respect to an outer side surface of the first corrugation (12) gradually increases along a direction from a rim of the pit portion (143) to a center of the pit portion (143).
9. The corrugated sheet of claim 1, wherein The ridge (142) and the pit portion (143) are symmetrical with respect to a first wave crest (121) of the first corrugation (12) and / or a second wave crest (131) of the second corrugation (13) as viewed along the height direction (D1).
10. The corrugated sheet of claim 1, wherein A height of the first wave crest (121) of the first corrugation (12) at a position where the pit portion (143) is formed is flush with a height of the first wave crest (121) at other positions of the first corrugation (12).
11. The corrugated sheet according to claim 1, wherein A groove portion (145) is formed above the second corrugation (13) between two ridges (142) located on the same side of the first corrugation (12), and a groove bottom (146) of the groove portion (145) extends perpendicularly to the plate body (11).
12. A storage vessel for liquefied gas, the walls of the storage vessel comprising a base layer and a sealing layer on the inside of the base layer, characterised in that, The sealing layer includes the corrugated plate according to any one of claims 1-11.