Sealing film for sealed insulated storage tank for low-temperature liquefied gas, tank using same, and manufacturing method therefor

Abstract

A sealing film for a sealed insulated storage tank for storing and transporting low-temperature liquefied gas, a tank using same, and a manufacturing method therefor. Each metal plate included in the sealing film comprises a plurality of welding units (1) which are orthogonally spliced at 90 degrees, connected in a sealed welding manner, and arranged in a rectangular shape. Each welding unit (1) comprises a planar portion (2) and a protruding portion comprising primary protrusions (3) and secondary protrusions (4). The primary protrusions (3) comprise a transverse elongated protrusion (5) and longitudinal elongated protrusions (6) which are arranged in a cross shape and divide an upper surface of the welding unit into four planar sub-portions. The longitudinal elongated protrusions (6) are respectively arranged on two sides of the transverse elongated protrusion. Each planar portion is provided with secondary protrusions (4). Four secondary protrusions (4) are spliced to form a closed regular polygon or circle. A spacing between the secondary protrusion (4) and the closest primary protrusion (3) is at least the width dimension of one transverse elongated protrusion. The height dimension of the secondary protrusion (4) is not greater than the height dimension of the primary protrusion (3).

Description

Sealing film, tank body and manufacturing method of low-temperature liquefied gas sealed insulation storage tank

[0001] Related applications

[0002] This disclosure claims priority to the Chinese invention patent application with application number 202311175861.9 filed on September 12, 2023, and cites the entire contents of the above patent application disclosure as part of this disclosure. Technical Field

[0003] The present disclosure relates to the technical field of sealed insulated storage tanks for storing and transporting cryogenic liquefied gas, and in particular to a sealing film, a tank body, and a method for manufacturing the sealing film of a sealed insulated storage tank for storing and transporting cryogenic liquefied gas. Background Art

[0004] Chinese patent No. CN114144611A discloses a sealed and thermally insulated tank for storing LNG or LPG, which includes an auxiliary thermal insulation shield, an auxiliary sealing membrane resting on the auxiliary thermal insulation shield, a main thermal insulation shield resting on the auxiliary sealing membrane, and a main sealing membrane resting on the main thermal insulation shield and intended to be in contact with the liquefied gas, wherein the main sealing membrane is composed of a single or multiple protrusions in the shape of a sphere, an ellipsoid, and a polyhedron.

[0005] When such a tank is installed on a floating structure, the liquefied gas within the tank will experience sloshing motion when exposed to sea conditions or wind. Sloshing motion is the fluctuation of the free surface of the liquid, causing nonlinear, random movement of the liquid within the tank. This sloshing liquid typically impacts the tank, and this impact stress can adversely affect the sealing membrane and tank wall. Damage to the sealing membrane or tank wall due to impact can cause the sealing membrane to lose its functionality, ultimately leading to leakage of the liquefied gas.

[0006] Therefore, when cryogenic storage tanks are used in liquid cargo tanks of LNG ships, LPG ships, etc., the sealing membrane inside the cargo tank needs to have sufficient displacement margin when exposed to cold or heat, and the sealing membrane should have sufficient bearing capacity to resist sloshing pressure.

[0007] Summary of the Invention

[0008] In view of the above-mentioned problems existing in the prior art, the embodiments of the present disclosure provide a sealing membrane, a tank body and a manufacturing method for a sealed insulated storage tank for storing and transporting low-temperature liquefied gas, wherein the sealed insulated storage tank is used to transport liquefied natural gas at a temperature between -163°C and -80°C or liquefied petroleum gas at a temperature between -50°C and 0°C. These tanks can be placed on land or installed on a water structure (ship or marine engineering structure). When installed on a water structure, the liquefied gas stored and transported by the tank can be used as fuel to propel the operation of the structure itself, which reduces the risk of sloshing impact damaging the tank body sealing membrane and increases the displacement margin of the sealing membrane for expansion and contraction.

[0009] The present disclosure provides a sealing membrane for a cryogenic liquefied gas sealed insulation storage tank. The sealing membrane includes at least one metal plate. Each metal plate includes a plurality of rectangular welding units that are orthogonally spliced ​​at 90 degrees and fixedly connected by sealing welding.

[0010] Each welding unit includes a planar portion and a raised portion, the raised portion includes a main raised portion and a secondary raised portion, the main raised portion includes a transverse long raised portion and a longitudinal long raised portion arranged in a cross shape on the upper surface of the welding unit and dividing the upper surface of the welding unit into four sub-planar portions, the longitudinal long raised portion includes longitudinal sub-long raised portions respectively arranged on both sides of the transverse long raised portion and not intersecting with the transverse long raised portion, each of the four sub-planar portions is provided with a secondary raised portion, and after the welding units corresponding to the four secondary raised portions are orthogonally spliced ​​at 90 degrees, the four secondary raised portions form a closed regular polygon or circle;

[0011] Among them, the spacing between the secondary protrusion and the closest main protrusion is at least the width dimension of a transverse long protrusion, the spacing between the transverse long protrusion and any longitudinal sub-strip protrusion is at least half the width dimension of the transverse long protrusion, and the height dimension of the secondary protrusion is not greater than the height of the main protrusion.

[0012] In some embodiments of the present disclosure, both ends of the transverse long strip protrusion are arranged in an ellipsoidal shape, and both ends of the longitudinal sub-long strip protrusion are arranged in an ellipsoidal shape.

[0013] In some embodiments of the present disclosure, the cross-sectional shape of the main protrusion includes a top arc, a connecting area arc connected to both ends of the top arc, and a transition area arc respectively connected to the connecting area arc, and the connected arcs are all connected in a tangent and smooth manner, wherein:

[0014] The top arc and the connecting area arc are both curves with continuous curvature, and one end of the transition area arc away from the connecting area arc connected to the transition area arc is tangent to the plane portion.

[0015] In some embodiments of the present disclosure, the width dimension of the transverse long protrusion is the dimension between the tangent point of the arc in the transition area of ​​the cross-sectional curve shape of the transverse long protrusion in the width direction and the flat portion.

[0016] In some embodiments of the present disclosure, the height dimension of the cross section of the main protrusion is represented by H, and is 38 mm ≤ H ≤ 78 mm;

[0017] The radius of the top arc is represented by R1, the radius of the connecting area arc is represented by R2, and the radius of the transition area arc is represented by R3, and the following conditions are met:

[0018] 0.8≤R1:R3≤1.2;

[0019] 5≤R2:R3≤6;

[0020] R2:H≤4.

[0021] In some embodiments of the present disclosure, the height dimension of the cross section of the main protrusion is represented by H, and is 40 mm ≤ H ≤ 100 mm;

[0022] The top arc and the connecting area arc of the cross-sectional shape of the main protrusion satisfy the parabola shape expressed by the following formula, specifically,

[0023] The arc of the transition region is tangent to the parabola, and the radius of the arc of the transition region is represented by R3, and satisfies the condition of R3=0.2H.

[0024] In some embodiments of the present disclosure, the height dimension of the cross section of the main protrusion is represented by H, and is 30 mm ≤ H ≤ 80 mm;

[0025] The top arc and the connecting area arc of the cross-sectional shape of the main protrusion satisfy the elliptical shape expressed by the following formula, specifically,

[0026] Among them, 1 / 3≤a / H≤5 / 8;

[0027] The arc of the transition area is tangent to the ellipse of the first and second quadrants and meets the requirement of 0.1≤R3:H≤0.3.

[0028] Wherein, R3 represents the radius of the arc in the transition area.

[0029] In some embodiments of the present disclosure, each metal plate has a length of at least 1.2 m in the longitudinal direction and a length of at least 0.6 m in the transverse direction;

[0030] The plate welding unit has a thickness ranging from 1 mm to 1.8 mm and is made of a metal material with a yield strength ranging from 170 MPa to 500 MPa. The plate welding unit is a welding unit included in the metal plate.

[0031] The present disclosure also provides a tank body using the sealing film of the cryogenic liquefied gas sealed insulation storage tank according to the above embodiment, the tank body comprising:

[0032] The tank wall, which encloses the interior space of the tank and is in contact with the cryogenic liquefied gas;

[0033] An insulating structure is attached to the tank wall, and a sealing film is provided on a surface of the insulating structure away from the tank wall;

[0034] Wherein, low-temperature elastic glue is filled between the secondary convex portion of the sealing film and the insulating structure, and the low-temperature elastic glue after solidification does not adhere to the sealing film and the insulating structure.

[0035] The present disclosure also provides a method for manufacturing a sealing film for a cryogenic liquefied gas sealed insulated storage tank as described above, wherein the method comprises the following steps:

[0036] Step 1: According to the structural design drawing of the sealing membrane corresponding to the sealing membrane of the cryogenic liquefied gas sealed insulation storage tank in the above embodiment, a corresponding stamping die is produced, and the metal plate is cut into rectangular metal plates of the required size;

[0037] Step 2: placing the manufactured stamping die and the cut rectangular metal plate together in a stamping machine for forming to obtain a welding unit having the shape of the flat portion and the convex portion of the sealing film;

[0038] Step 3: Assemble the stamped welding units, specifically arranging adjacent welding units at 90 degrees orthogonally to form the shape of the metal plate required for the sealing film, and then weld and fix the welding units by sealing welding to form a metal plate;

[0039] Step 4: According to the principle of butting the raised parts of adjacent metal plates, the metal plates are welded together by lap welding to form a complete sealing membrane.

[0040] Compared with the prior art, the sealing film, tank body and manufacturing method of the sealed insulated storage tank for storing and transporting cryogenic liquefied gas provided by the embodiment of the present disclosure have the following beneficial effects: by arranging the main protrusions of the welding unit protrusions in a crisscross manner on the plane area, and arranging the secondary protrusions evenly on the plane area, the temperature stress generated in the plane area with low continuity when exposed to cold or heat is greatly reduced. On the other hand, the protrusions also provide a large displacement margin. Furthermore, by setting the height of the main protrusion to be no less than the height of the secondary protrusion, the protrusions of different shapes can more evenly bear the pressure caused by the sloshing of the liquid in the tank through the arrangement of different heights, effectively avoiding damage to the sealing film and preventing the failure of the storage tank function. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG1 is a schematic top view of a first structure of a sealing membrane of a cryogenic liquefied gas sealed insulated storage tank provided by an embodiment of the present disclosure;

[0042] FIG2 is a schematic structural diagram of a welding unit corresponding to a first structure of a sealing membrane of a cryogenic liquefied gas sealed insulated storage tank provided by an embodiment of the present disclosure;

[0043] FIG3 is a schematic top view of a second structure of a sealing membrane of a cryogenic liquefied gas sealed insulated storage tank provided by an embodiment of the present disclosure;

[0044] FIG4 is a schematic structural diagram of a welding unit corresponding to a second structure of a sealing membrane of a cryogenic liquefied gas sealed insulated storage tank provided by an embodiment of the present disclosure;

[0045] FIG5 is a schematic top view of a third structure of a sealing membrane of a cryogenic liquefied gas sealed insulated storage tank provided by an embodiment of the present disclosure;

[0046] FIG6 is a schematic structural diagram of a welding unit corresponding to a third structure of a sealing membrane of a cryogenic liquefied gas sealed insulated storage tank provided by an embodiment of the present disclosure;

[0047] FIG7 is a schematic cross-sectional view of a secondary raised portion of a welding unit corresponding to a third structure of a sealing film of a cryogenic liquefied gas sealed insulated storage tank provided by an embodiment of the present disclosure;

[0048] FIG8 is a schematic cross-sectional view of a planar portion of a sealing membrane of a cryogenic liquefied gas sealed insulated storage tank according to an embodiment of the present disclosure, wherein the sealing membrane is arranged by adding corresponding secondary protrusions as shown in FIG7 ;

[0049] FIG9 is a schematic diagram of the cross-sectional shape of the main protrusion of the welding unit corresponding to the first structure of the sealing film of the cryogenic liquefied gas sealed insulated storage tank provided by an embodiment of the present disclosure;

[0050] FIG10 is a schematic diagram showing a first cross-sectional line shape of a main protrusion portion of a welding unit of a sealing film of a cryogenic liquefied gas sealed insulated storage tank provided by an embodiment of the present disclosure;

[0051] FIG11 is a schematic diagram showing a second cross-sectional shape of a main protrusion of a welding unit of a sealing film of a cryogenic liquefied gas sealed insulated storage tank provided by an embodiment of the present disclosure;

[0052] FIG12 is a schematic diagram showing a third cross-sectional shape of a main protrusion of a welding unit of a sealing film of a cryogenic liquefied gas sealed insulated storage tank provided by an embodiment of the present disclosure;

[0053] FIG13 is a schematic structural diagram of a tank body provided in an embodiment of the present disclosure.

[0054] Figure numerals: 1. welding unit; 2. plane part; 3. main protrusion; 4. secondary protrusion; 5. transverse long protrusion; 6. longitudinal long protrusion; 7. cross section of main protrusion; 8. top arc; 9. connection area arc; 10. transition area arc; 11. insulation structure; 12. low-temperature elastic glue; 13. plywood. DETAILED DESCRIPTION

[0055] In order to enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure is described in detail below with reference to the accompanying drawings and specific implementation methods.

[0056] Various aspects and features of the present disclosure are described herein with reference to the accompanying drawings.

[0057] These and other characteristics of the present disclosure will become apparent from the following description of a preferred form of embodiment given as a non-limiting example with reference to the accompanying drawings.

[0058] It should also be understood that although the present disclosure has been described with reference to certain specific examples, those skilled in the art will be able to realize many other equivalent forms of the present disclosure that have the characteristics recited in the claims and are therefore within the scope of protection defined thereby.

[0059] The above and other aspects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0060] Specific embodiments of the present disclosure will be described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments claimed are merely examples of the present disclosure, which may be implemented in a variety of ways. Familiar and / or repetitive functions and structures are not described in detail to clarify the true intention based on the user's historical operations and to avoid unnecessary or redundant details that obscure the present disclosure. Therefore, the specific structural and functional details claimed in the present disclosure are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use the present disclosure in a variety of ways with substantially any appropriate detailed structure.

[0061] This description may use the phrases "in one embodiment," "in another embodiment," "in a further embodiment," or "in other embodiments," each of which may refer to one or more of the same or different embodiments according to the present disclosure.

[0062] The embodiment of the present disclosure provides a sealing membrane for a cryogenic liquefied gas sealed insulated storage tank, as shown in Figures 1 to 12, the sealing membrane includes at least one metal plate, each of which includes a plurality of welding units 1 that are orthogonally spliced ​​at 90 degrees and fixedly connected by sealing welding and arranged in a rectangular shape, wherein each welding unit 1 includes a plane portion 2 and a raised portion, the raised portion includes a main raised portion 3 and a secondary raised portion 4, the main raised portion 3 includes a transverse long raised portion 5 and a longitudinal long raised portion 6 that are arranged in a cross shape on the upper surface of the welding unit 1 and divide the upper surface of the welding unit 1 into four sub-plane portions, the longitudinal long raised portion 6 includes two sides of the transverse long raised portion 5 and a secondary raised portion 4. The transverse long strip protrusions 5 do not intersect with the longitudinal sub-long strip protrusions, and each of the four sub-plane parts is provided with a secondary protrusion 4. After the welding units 1 corresponding to the four secondary protrusions 4 are orthogonally spliced ​​at 90 degrees, the four secondary protrusions 4 form a closed regular polygon or a circle; wherein, the protrusions in the main protrusion 3 and the secondary protrusion 4 are spaced apart from each other and are not connected to each other, and the spacing between the secondary protrusion 4 and the nearest main protrusion 3 is at least the width dimension of a transverse long strip protrusion 5, and the spacing between the transverse long strip protrusion 5 and any longitudinal sub-strip protrusion is at least half the width dimension of the transverse long strip protrusion 5, and the height dimension of the secondary protrusion 4 is not greater than the height of the main protrusion 3. Furthermore, the secondary protrusions 4 are distributed on the planar portion 2 of the welding unit 1 and are symmetrical about the center point of the welding unit 1. The width dimension of the main protrusion 3 is the dimension between the tangent points of the arc of the cross-sectional curve shape of the main protrusion 3 in the width direction and the planar portion 2. At the same time, after the welding units 1 are spliced, the four welding units 1 can be surrounded by the transverse long protrusions 5 and the longitudinal long protrusions 6 to form a planar area that is approximately an equilateral rectangle, and the secondary protrusions 4 are evenly distributed in the center of the planar area; in addition, each main protrusion 3 and each secondary protrusion 4 has at least one axially symmetrical plane.

[0063] In the above embodiment, as shown in Figures 2, 4, and 6, three embodiments of the welding unit 1 are shown. The welding unit 1 is symmetrical along the mid-longitudinal plane and the mid-transverse cross-section, but not centrally symmetrical. The metal plate is welded by the welding unit 1 in a sealed welding manner. Since the welding unit 1 is not centrally symmetrical, it has two orientations during welding: front and side. During the metal plate production process, multiple rectangular welding units 1 are orthogonally spliced ​​at 90 degrees. Specifically, when two welding units 1 are placed side by side in the same direction, when one welding unit 1 is spliced ​​with another welding unit 1, the welding unit 1 is first rotated 90 degrees with its own center line as the center of the circle, and then the side of the welding unit 1 rotated 90 degrees is spliced ​​with the side of the other welding unit 1. That is, the side edges of the two welding units 1 that are spliced ​​together are perpendicular to each other when the two welding units 1 are placed side by side in the same direction. It should be noted that in the above description, the meaning of asymmetry is that the welding unit 1 does not overlap with itself after being rotated 90 degrees with its own center line as the center of the circle. It should be understood that the above-mentioned welding unit can also be centrally symmetrical. For example, the welding unit 1 can be rotated 180 degrees with the center point of its pattern as the center of the circle and then overlap with itself. At the same time, in this embodiment, the length of each metal plate in the longitudinal direction is at least 1.2m, and the length in the transverse direction is at least 0.6m. As an example, the length of the metal plate in the longitudinal direction can be 2.4m, and the length in the transverse direction can be 1.2m. At the same time, the thickness of the above-mentioned welding unit 1 is between 1mm and 1.8mm, and it is made of a metal material with a yield strength between 170MPa and 500MPa. Specifically, it can be made of stainless steel or high manganese steel.

[0064] Furthermore, in the above embodiment, both ends of the transverse long strip raised portion 5 are ellipsoidally arranged, and both ends of the longitudinal sub-long strip raised portion are ellipsoidally arranged, so that both ends of the transverse long strip raised portion 5 and both ends of the longitudinal sub-long strip raised portion can bear force better.

[0065] At the same time, in the above embodiment, as shown in Figure 9, the cross-sectional shape of the main protrusion 3 includes a top arc 8, a connecting area arc 9 connected to both ends of the top arc 8, and a transition area arc 10 respectively connected to the connecting area arc 9. The connected arcs are all connected in a tangent and smooth manner, so that the top shape of the cross section 7 of the main protrusion is a curve with continuous curvature, wherein the top arc 8 and the connecting area arc 9 are both curves with continuous curvature, and the transition area arc 10 is tangent to the plane part 2 at one end away from the connecting area arc 9 connected thereto.

[0066] In the above embodiment, the width dimension of the horizontal long protrusion 5 is the dimension between the tangent points of the transition region arc 10 of the cross-sectional curve shape of the horizontal long protrusion 5 in the width direction and the plane portion 2. That is, the width dimension of the horizontal long protrusion 5 is the dimension between the tangent points of the transition region arc 10 of the cross-sectional curve shape of the horizontal long protrusion 5 in the width direction and the plane portion 2.

[0067] In this embodiment, as shown in FIG. 10, the height dimension of the shape formed by the cross-section 7 of the main protrusion is represented by H, and 38 mm ≤ H ≤ 78 mm; the top of the shape of the cross-section 7 of the main protrusion is formed by two arcs tangent to each other, specifically including a top arc 8, a connecting region arc 9 connected to both ends of the top arc 8, and a transition region arc 10 respectively connected to the connecting region arc 9. The arcs connected to each other are all connected in a tangent and smooth connection manner. The radius of the top arc 8 is represented by R1, the radius of the connecting region arc 9 is represented by R2, and the radius of the transition region arc 10 is represented by R3. Among them, R1 < R2, and R1, R2, and R3 satisfy the following conditions:

[0068] 0.8 ≤ R1:R3 ≤ 1.2;

[0069] 5 ≤ R2:R3 ≤ 6;

[0070] R2:H ≤ 4;

[0071] As an example, the height dimension H of the shape formed by the cross-section 7 of the main protrusion can be set to 44 mm, the radius R1 of the top arc 8 can be set to 10 mm, the radius R2 of the connecting region arc 9 can be set to 46 mm, and the radius R3 of the transition region arc 10 can be set to 10 mm.

[0072] In some embodiments of the present disclosure, as shown in FIG. 11, the height dimension of the shape formed by the cross-section 7 of the main protrusion is still represented by H, and 40 mm ≤ H ≤ 100 mm;

[0073] The top arc 8 and the connecting region arc 9 of the cross-sectional shape of the main protrusion 3 satisfy the parabolic shape represented by the following formula. Specifically,

[0074] Among them, the top arc 8 and the connecting region arc 9 coincide with a partial curve of the parabola defined by this formula. It should be noted that the above formula is only used to describe the curve shape of the top arc 8 and the connecting region arc 9, and the opening direction of the parabola represented by it is not a limitation on the curve shape of the top arc 8 and the connecting region arc 9. For example, the opening of this parabola can be in the direction of the insulating structure 11. Among them, the curve shapes of the top arc 8 and the connecting region arc 9 can coincide with the shape of a partial curve near the vertex of the parabola.

[0075] The transition area arc 10 of the cross-sectional shape of the main protrusion 3 is tangent to the parabola, and the radius of the transition area arc 10 is represented by R3 and satisfies the condition of R3=0.2H;

[0076] As an example, the height dimension H of the shape formed by the cross section of the main protrusion 3 is 43 mm, and the radius R3 of the transition area arc 10 is 10 mm.

[0077] In addition, in some embodiments of the present disclosure, as shown in FIG12 , the height dimension of the shape formed by the cross section of the main protrusion 3 is still represented by H, and has a range of 30 mm ≤ H ≤ 80 mm;

[0078] The top arc 8 and the connecting area arc 9 of the cross-sectional shape of the main protrusion 3 satisfy the elliptical shape expressed by the following formula, specifically,

[0079] Among them, 1 / 3≤a / H≤5 / 8;

[0080] The top arc 8 and the connecting area arc 9 coincide with the curves of the parts of the ellipse defined by the formula in the first quadrant and the second quadrant.

[0081] The transition area arc 10 of the cross-sectional shape of the main protrusion 3 is tangent to the ellipse of the first quadrant and the second quadrant of the ellipse and meets the requirement of 0.1≤R3:H≤0.3, where R3 represents the radius of the transition area arc 10;

[0082] As an example, as shown in FIG12 , the height dimension H of the shape formed by the cross section of the main protrusion 3 is 40 mm, the minor radius a of the ellipse is 20 mm, and the radius R3 of the transition area arc 10 is 8.4 mm.

[0083] In some embodiments of the present disclosure, specifically referring to Figures 1 and 2, the secondary protrusion 4 can have a similar cross-sectional shape to the main protrusion 3, and the secondary protrusion 4 can be a ring-shaped secondary protrusion 4 obtained by rotating the protrusion cross section 360° with the center of the plane portion 2 as the rotation center. Of course, the secondary protrusion 4 can also be a ring-shaped secondary protrusion 4 obtained by rotating the protrusion cross section 360° with the center of the sub-plane portion in which it is located as the rotation center. There is at least one spacing between the secondary protrusions 4 equal to the width dimension of the secondary protrusion 4, and the width dimension of the secondary protrusion 4 is the dimension between the tangent points of the arc of the cross-sectional curve shape of the secondary protrusion 4 in the width direction and the plane portion 2. In addition, in this embodiment, the secondary protrusion 4 can also be intermittent, that is, the secondary protrusion 4 is arranged in an intermittent structure, and the two ends of each section of the secondary protrusion 4 can be arranged in an ellipsoidal shape.

[0084] In some embodiments of the present disclosure, while the secondary protrusion 4 can have a similar cross-sectional shape to the primary protrusion 3, the secondary protrusion 4 can also be arranged as a single unit located in the center of the sub-plane portion in which it is located. The secondary protrusion 4 has a similar cross-sectional shape to the primary protrusion 3, and the shape curve is used as a slice to sweep and stretch along the shape of an equilateral rectangle to obtain a rectangular secondary protrusion 4, as shown in Figures 3 and 4. In addition, in this embodiment, the secondary protrusion 4 can also be arranged intermittently, that is, the secondary protrusion 4 is arranged in an intermittent structure, and the two ends of each section of the secondary protrusion 4 can be arranged in an ellipsoidal shape.

[0085] In addition, in some embodiments of the present disclosure, as shown in Figures 5 and 6, when the arrangement of the main protrusion 3 is the same as in the previous embodiments, the secondary protrusion 4 can also be a spherical protrusion on the sub-plane portion where it is located. The secondary protrusion 4 has two arrangements, which can be arranged according to the protrusion width. For example, a single secondary protrusion 4 is arranged at the center of the sub-plane portion where it is located, or multiple secondary protrusions are evenly arranged on the sub-plane portion where they are located. In the design process of a cryogenic storage tank, the sealing membrane located at the bottom or top of the cryogenic storage tank is usually designed with a metal plate with multiple protrusions. This measure will be more beneficial to the structural safety of the tank sealing membrane.

[0086] Through the above technical solution, it can be seen that the sealing membrane provided by the above embodiment of the present disclosure arranges the main protrusions 3 of the protruding portion of the welding unit 1 in a crisscross pattern on the plane area, and the secondary protrusions 4 are evenly arranged on the plane area. This greatly reduces the temperature stress generated in the plane area with low continuity when it is exposed to heat and cold. On the other hand, the protrusions also provide a large displacement margin. Furthermore, by setting the height of the main protrusion 3 to be no less than the height of the secondary protrusion 4, the protrusions of different shapes can more evenly bear the pressure caused by the sloshing of the liquid in the tank through the different height arrangements, effectively avoiding damage to the sealing membrane and preventing the failure of the storage tank function.

[0087] The present disclosure also provides a tank body using the sealing membrane of the cryogenic liquefied gas sealed insulated storage tank of the above embodiment. Specifically, as shown in FIG13 , the tank body can be used as a sealed insulated storage tank for storing and transporting LNG. The tank body includes:

[0088] The tank wall, which encloses the interior space of the tank and is in contact with the cryogenic liquefied gas;

[0089] An insulating structure 11 is attached to the tank wall. A sealing film is provided on the surface of the insulating structure 11 away from the tank wall. Specifically, the sealing film includes at least one metal plate, and each metal plate includes a plurality of rectangular welding units 1 that are orthogonally spliced ​​at 90 degrees and fixedly connected by sealing welding. At the same time, the welding unit 1 includes a flat portion 2 and a raised portion.

[0090] The space between the secondary raised portion 4 in the raised part of the sealing film and the insulating structure 11 is filled with low-temperature elastic glue 12 . The solidified low-temperature elastic glue 12 does not adhere to the sealing film and the insulating structure 11 .

[0091] In this embodiment, the tank body comprises, from the inside out, a sealing membrane, a low-temperature elastic adhesive 12 (e.g., a flexible low-temperature adhesive), a primary insulating structure within the insulating structure 11, a secondary insulating structure within the insulating structure 11, and an outer wall, wherein the outer wall is the tank wall. Furthermore, plywood 13 or a plywood-like structure may be provided between the low-temperature elastic adhesive 12 and the primary insulating structure, and between the secondary insulating structure and the outer wall.

[0092] By filling the low-temperature elastic glue 12 between the secondary raised portion 4 of the sealing film and the insulating structure 11, the low-temperature glue after solidification can play a certain supporting and reinforcing role, and can enable the raised portion to maintain a certain displacement margin to prevent structural damage. The low-temperature glue can be in direct contact with the sealing film and the insulating structure 11, but not adhere to each other, thereby preventing additional deformation stress from being applied to the low-temperature glue during low-temperature shrinkage.

[0093] With these features, the height of the primary protrusions 3 and the spacing and dimensions of the secondary protrusions 4 allow the raised portion to withstand sloshing impacts relatively evenly, without experiencing excessive sloshing. Furthermore, the regular distribution of the secondary protrusions 4 and the support provided by the low-temperature adhesive effectively and evenly distribute and withstand sloshing impact loads, thereby effectively preventing damage to the sealing membrane and ensuring the membrane's tightness.

[0094] The tank body using the sealing membrane of the cryogenic liquefied gas sealed insulation storage tank can be used as an onshore storage tank or an offshore structure storage tank, for example, for onshore LNG storage, or installed on an offshore structure, particularly a cryogenic liquefied gas carrier, a deep-water transport vessel, or an above-water or underwater floating (production) storage unit. The tank body can also be used as a fuel storage tank in an above-water or underwater floating structure.

[0095] At the same time, the embodiment of the present disclosure also provides a method for manufacturing a sealing film for the cryogenic liquefied gas sealed insulated storage tank as described in the above embodiment, the method comprising the following steps:

[0096] Step 1: According to the structural design drawing of the sealing membrane corresponding to the sealing membrane of the low-temperature liquefied gas sealed insulating storage tank as described in the above embodiment, a corresponding stamping die is made, and the metal plate is cut into rectangular metal plates of the required size; it should be understood that the metal plate in step 1 is the original metal plate.

[0097] Step 2: Place the prepared stamping die and the cut rectangular metal plate together in a stamping machine for forming to obtain a welding unit 1 in the shape of a flat portion 2 of the sealing film and a convex portion;

[0098] Step 3: Assemble the stamped welding units 1, specifically arranging adjacent welding units 1 at 90 degrees orthogonally to form the shape of the metal plate required for the sealing film, and then weld and fix the welding units 1 by sealing welding to form a metal plate;

[0099] The aspect ratio of the metal plate required for the sealing film may be 2:1.

[0100] Step 4: According to the principle of butting the raised parts of adjacent metal plates, the metal plates are welded together by lap welding to form a complete sealing membrane.

[0101] The above embodiments are merely exemplary embodiments of the present disclosure and are not intended to limit the present disclosure. The scope of protection of the present disclosure is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present disclosure within the essence and scope of protection of the present disclosure, and such modifications or equivalent substitutions shall also be deemed to fall within the scope of protection of the present disclosure.

Claims

1. A sealing film for a cryogenic liquefied gas sealed insulating storage tank, characterized in that: The sealing film comprises at least one metal plate, each of which comprises a plurality of welding units arranged in a rectangular shape and orthogonally spliced ​​at 90 degrees and fixedly connected by sealing welding, wherein: Each of the welding units comprises a plane portion and a raised portion, wherein the raised portion comprises a main raised portion and a secondary raised portion, wherein the main raised portion comprises a transverse long raised portion and a longitudinal long raised portion which are arranged in a cross shape on the upper surface of the welding unit and divide the upper surface of the welding unit into four sub-plane portions, wherein the longitudinal long raised portion comprises longitudinal sub-long raised portions which are respectively arranged on both sides of the transverse long raised portion and do not intersect with the transverse long raised portion, wherein each plane portion of the four sub-plane portions is provided with the secondary raised portion, and after the welding units corresponding to the four secondary raised portions are orthogonally spliced ​​at 90 degrees, the four secondary raised portions form a closed regular polygon or a circle; Among them, the spacing between the secondary protrusion and the closest main protrusion is at least the width dimension of one of the transverse long protrusions, the spacing between the transverse long protrusion and any of the longitudinal sub-long protrusions is at least half the width dimension of the transverse long protrusion, and the height dimension of the secondary protrusion is not greater than the height of the main protrusion.

2. The sealing film of the cryogenic liquefied gas sealed insulation storage tank according to claim 1, characterized in that: Both ends of the transverse long strip protrusion are arranged in an ellipsoid shape, and both ends of the longitudinal sub-long strip protrusion are arranged in an ellipsoid shape.

3. The sealing film of the cryogenic liquefied gas sealed insulation storage tank according to claim 1, characterized in that: The cross-sectional shape of the main protrusion includes a top arc, a connection area arc connected to both ends of the top arc, and a transition area arc respectively connected to the connection area arc, and the connected arcs are connected in a tangent and smooth manner, wherein: The top arc and the connection area arc are both curves with continuous curvature, and one end of the transition area arc away from the connection area arc connected to the transition area arc is tangent to the plane portion.

4. The sealing film of the cryogenic liquefied gas sealed insulation storage tank according to claim 3, characterized in that: The width dimension of the transverse long protrusion is the dimension between the arc of the transition area of ​​the cross-sectional curve shape of the transverse long protrusion in the width direction and the tangent point of the plane part.

5. The sealing film of the cryogenic liquefied gas sealed insulation storage tank according to claim 3, characterized in that: The height dimension of the cross section of the main protrusion is represented by H, and is 38mm≤H≤78mm; The radius of the top arc is represented by R1, the radius of the connection area arc is represented by R2, and the radius of the transition area arc is represented by R3, and the following conditions are met: 0.8≤R1:R3≤1.2; 5≤R2:R3≤6; R2:H≤4.

6. The sealing film of the low-temperature liquefied gas sealed insulation storage tank according to claim 3, characterized in that: The height dimension of the cross section of the main protrusion is represented by H, and is 40mm≤H≤100mm; The top arc and the connecting area arc of the cross-sectional shape of the main protrusion satisfy the parabola shape expressed by the following formula, specifically, The transition area arc is tangent to the parabola, and the radius of the transition area arc is represented by R3, and satisfies the condition of R3=0.2H.

7. The sealing film of the cryogenic liquefied gas sealed insulation storage tank according to claim 3, characterized in that: The height dimension of the cross section of the main protrusion is represented by H, and is 30mm≤H≤80mm; The top arc and the connecting area arc of the cross-sectional shape of the main protrusion satisfy the ellipse represented by the following formula, specifically, Among them, 1 / 3≤a / H≤5 / 8; The transition area arc is tangent to the ellipse of the first quadrant and the second quadrant of the ellipse, and meets the requirement of 0.1≤R3:H≤0.3, Wherein, R3 represents the radius of the arc of the transition area.

8. The sealing film of the cryogenic liquefied gas sealed insulation storage tank according to claim 1, characterized in that: Each metal plate has a length of at least 1.2 m in the longitudinal direction and a length of at least 0.6 m in the transverse direction; The plate welding unit has a thickness between 1 mm and 1.8 mm and is made of a metal material with a yield strength between 170 MPa and 500 MPa.

9. A tank body using the sealing film of a cryogenic liquefied gas sealed insulation storage tank as claimed in any one of claims 1 to 8, characterized in that: The tank body comprises: a tank wall, the tank wall enclosing an inner space of the tank body and in contact with the cryogenic liquefied gas; An insulating structure, wherein the insulating structure is attached to the tank wall, and the sealing film is arranged on the surface of the insulating structure on a side away from the tank wall; Wherein, low-temperature elastic glue is filled between the secondary convex portion of the sealing film and the insulating structure, and the low-temperature elastic glue after solidification does not adhere to the sealing film and the insulating structure.

10. A method for manufacturing a sealing film for a cryogenic liquefied gas sealed insulating storage tank as claimed in any one of claims 1 to 8, characterized in that: The method comprises the following steps: Step 1: According to the structural design drawing of the sealing film corresponding to the sealing film of the low-temperature liquefied gas sealed insulation storage tank as described in any one of claims 1 to 8, a corresponding stamping die is manufactured, and the metal plate is cut into a rectangular metal plate of a required size; Step 2: placing the manufactured stamping die and the cut rectangular metal plate together in a stamping machine for forming to obtain a welding unit having the shape of the planar portion and the convex portion of the sealing film; Step 3: Assemble the stamped welding units, specifically arrange the adjacent welding units at 90 degrees orthogonally to assemble the shape of the metal plate required by the sealing film, and weld and fix the welding units by sealing welding to form a metal plate; Step 4: According to the principle of butting the raised parts of adjacent metal plates, the metal plates are welded together by lap welding to form a complete sealing film.

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