Low-temperature-resistant sealing film for covering insulating material, storage tank and manufacturing method

Abstract

Embodiments of the present disclosure provide a low-temperature-resistant sealing film for covering an insulating material, a storage tank and a manufacturing method. The sealing film comprises at least one film plate, wherein each film plate comprises a plurality of quadrangular plate units welded and fixed in a sealed welding mode; each plate unit comprises an undulating region and a plane region; the undulating region is provided with main protruding portions which are arranged in a circular arc strip shape and connected to each other in a tangent mode; each plate unit is provided with at least four main protruding portions which are symmetrically arranged about a center line passing through the center of the plate unit and perpendicular to the plate unit, and each arc-shaped main protruding portion takes a corner endpoint of the plate unit corresponding to the inner side of the main protruding portion as a center of a circle; and each main protruding portion is hollow, and the cross section of each main protruding portion comprises a top arc section and a connecting portion arc section, wherein the curvature of the top arc section is continuous, one end of the connecting portion arc section is connected to one end of the top arc section in a tangent mode, and the other end of the connecting portion arc section is connected to the plane region in a tangent mode.

Description

Low-temperature resistant sealing film for covering insulating materials, storage tank and manufacturing method

[0001] Related applications

[0002] This disclosure claims priority to the Chinese invention patent application with application number 202311175894.3 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 used in a sealed insulated storage tank on a cryogenic liquid / cryogenic liquefied gas transport ship, and a method for manufacturing and welding the storage tank and the sealing film. Background Art

[0004] Chinese patent number CN101959752B discloses a corrugated diaphragm for the liquid cargo tank of an LNG ship and a reinforcement member for corresponding corrugations. The corrugated diaphragm includes a corrugated portion and a flat portion. The longitudinal girders of the corrugated portion are staggered. The longitudinal corrugations and the transverse corrugations have different heights. Corrugated nodes are formed at the intersection of the corrugations due to extrusion. The corrugated diaphragm is in direct contact with liquefied natural gas, and sudden temperature changes will cause large displacement stress in the structure.

[0005] When this membrane is actually applied to the cargo tanks of LNG carriers, environmental conditions such as sea conditions and wind during navigation can cause sloshing motion between the tanks and the liquid within. Typically, irregular waves, when applied to the liquid, cause the free surface to fluctuate, leading to nonlinear, random motion of the liquid within the tank. This sloshing liquid inevitably creates a sloshing impact on the tanks. The impact stress generates peak loads depending on the amplitude and frequency of the waves. This peak impact stress can easily cause plastic deformation or even damage to the sealing membrane, which has already been deformed by temperature stress. Damage to the sealing membrane can lead to loss of its functionality, ultimately potentially causing leakage of the liquefied gas.

[0006] When the sealing membrane is installed on the inner wall of the insulating tank of the LNG ship's liquid cargo tank, it needs to withstand the displacement caused by temperature changes to avoid plastic deformation, and be able to better withstand the impact of liquid during liquid sloshing, effectively resist impact deformation, avoid rupture and failure of the sealing membrane or even the insulation layer, and ensure the sealing of the cryogenic storage tank.

[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 low-temperature resistant sealing film, a storage tank and a method for manufacturing the sealing film for covering insulating materials. The sealing film can withstand the displacement caused by temperature changes in the liquid cargo tank of an LNG ship during loading and unloading of liquefied natural gas, avoid excessive plastic deformation, and better withstand liquid impact during liquid sloshing, effectively resist impact deformation, avoid rupture and failure of the sealing film or even the insulating layer, and ensure the sealing of the low-temperature storage tank.

[0009] The present disclosure provides a low-temperature resistant sealing film for covering insulating materials. The sealing film includes at least one film plate. Each film plate in at least one module includes a plurality of plate units welded and fixed in a sealing welding manner. The plate units are arranged in a regular quadrilateral and include an undulating area and a flat area.

[0010] The undulating area is provided with main protrusions arranged in an arc-shaped strip and connected in a tangential manner. Each plate unit is provided with at least four main protrusions symmetrically arranged about a midline passing through the center of the plate unit and perpendicular to the planar area of ​​the plate unit. Each arc-shaped main protrusion has the corner endpoint of the corresponding plate unit on its inner side as the center of the circle. After two adjacent plate units are welded and fixed, the main protrusions on adjacent sides of the two adjacent plate units are butted together.

[0011] Each main protrusion is hollow, and the cross-section of the main protrusion includes a top arc segment and a connecting arc segment. The curvature of the top arc segment is continuous, one end of the connecting arc segment is connected to one end of the top arc segment in a tangential manner, and the other end of the connecting arc segment is connected to the plane area in a tangential manner.

[0012] In some embodiments of the present disclosure, the undulating region is further provided with a secondary convex portion concentrically arranged with each primary convex portion. The secondary convex portions are symmetrically arranged about the center and are all arranged in the shape of arc strips. After two adjacent plate units are welded and fixed, the secondary convex portions on adjacent sides of the two adjacent plate units are butted against each other.

[0013] The height of the secondary protrusion is not greater than the height of the primary protrusion, and the distance between the primary protrusion and the secondary protrusion is at least twice the width of the primary protrusion.

[0014] In some embodiments of the present disclosure, each secondary protrusion is hollow, and the cross section of the secondary protrusion is arc-shaped;

[0015] The distance between two adjacent sub-protrusions is at least twice the width of the sub-protrusions.

[0016] In some embodiments of the present disclosure, the height dimension of the cross section of the main protrusion is represented by H, and 40 mm ≤ H ≤ 60 mm;

[0017] The top arc segment includes a top arc with a radius represented by R1 and a transition arc connected to the top arc in a tangential manner and represented by R2, wherein R1 is smaller than R2;

[0018] The connecting arc segment is a circular arc and is represented by R3, then:

[0019] 1≤R1:R3≤2;

[0020] 5.5≤R2:R3≤10;

[0021] 1 <R2:H≤1.5。

[0022] In some embodiments of the present disclosure, the height dimension of the cross section of the main protrusion is represented by H, and is 36 mm ≤ H ≤ 48 mm;

[0023] The top arc segment satisfies the parabola expressed by the following formula:

[0024] The arc segment of the connecting part is an arc and is tangent to the parabola. The arc radius R3 satisfies:

[0025] 4≤H:R3≤8.

[0026] In some embodiments of the present disclosure, the height dimension of the cross section of the main protrusion is represented by H, and 40 mm ≤ H ≤ 50 mm;

[0027] The top arc segment satisfies the elliptical shape expressed by the following formula:

[0028] and 5 / 8≤a / H≤1;

[0029] The arc segment of the connecting portion is a circular arc with a radius represented by R3, which is tangent to the ellipses of the first quadrant and the second quadrant and satisfies 0.15≤R3:H≤0.25.

[0030] In some embodiments of the present disclosure, the plate units are made of stainless steel, aluminum alloy or high manganese steel with a yield strength between 170 MPa and 500 MPa, and a thickness between 2 and 4 mm. During the welding process, adjacent plate units are welded in the same direction.

[0031] In some embodiments of the present disclosure, each membrane sheet has a length of at least 0.6 m in both the transverse direction and the longitudinal direction.

[0032] The present disclosure also provides a storage tank using the low-temperature resistant sealing film for covering insulating materials according to the above embodiment, the storage tank comprising:

[0033] The tank wall, which encloses the interior space of the tank and is in contact with the cryogenic liquefied gas;

[0034] The insulating structure is attached to the tank wall and a low-temperature resistant sealing film is provided on the surface of the insulating structure away from the tank wall.

[0035] The present disclosure also provides a method for manufacturing the low-temperature resistant sealing film for covering insulating materials as described in the above embodiment, the method comprising:

[0036] Step 1: Design a mold for the undulating area based on the structural design drawing of the sealing film corresponding to the low-temperature resistant sealing film for covering the insulating material in the above embodiment, and make a corresponding mold for the undulating area based on the rebound prediction of the elasticity of the material used;

[0037] Step 2: Based on the predicted thickness reduction and shape rebound after stamping, a metal plate of corresponding thickness is selected and cut into plate units with a set margin. The plate units are then placed in a press for processing preparation. The press and the undulating area mold are used for stamping and forming to obtain plate units with the convex shape corresponding to the undulating area.

[0038] Step 3: According to the size of the insulation module corresponding to the insulation material to be covered, the plate units are arranged in the same direction so as to form a rectangular plate that matches the size of the insulation module, and the plate units are welded and fixed by sealing welding to form a membrane plate;

[0039] Step 4: After placing the membrane plate on the insulating layer formed by the insulating module, the membrane plates are welded and fixed in sequence by continuous lap welding according to the principle of butting the cross-sectional shapes of the undulating areas of adjacent membrane plates to form a complete sealing membrane.

[0040] Compared with the prior art, the beneficial effects of the low-temperature resistant sealing film, storage tank and manufacturing method for covering insulating materials provided by the embodiments of the present disclosure are: the main protrusions in the undulating area are arranged tangentially and intersecting with each other on the plane area, and the regular distribution greatly reduces the proportion of the plane area. While the deformation and extrusion in the horizontal plane caused by temperature changes are greatly reduced, the elastic shape of the protrusion, which is approximately U-shaped, also provides a larger deformation margin; further, the seamless distribution arrangement produced by the tangential connection of the main protrusions in the undulating area, plus the relatively tight arrangement of the secondary protrusions in the plane area, evenly disperses the sloshing impact load, thereby effectively avoiding damage to the sealing film and ensuring the sealing of the film. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG1 is an isometric view of a structure of a low-temperature resistant sealing film for covering insulating materials provided by an embodiment of the present disclosure.

[0042] FIG2 is an isometric view of a structure of a plate unit for a low-temperature-resistant sealing film covering an insulating material provided by an embodiment of the present disclosure.

[0043] FIG3 is an isometric view of another structure of a low-temperature resistant sealing film for covering insulating materials provided by an embodiment of the present disclosure.

[0044] FIG4 is an isometric view of another structure of a plate unit for covering a low-temperature resistant sealing film of an insulating material provided by an embodiment of the present disclosure.

[0045] FIG5 is a schematic cross-sectional view of a main raised portion in an undulating region of a low-temperature resistant sealing film for covering an insulating material provided by an embodiment of the present disclosure.

[0046] FIG6 is a schematic diagram of a first line shape of a cross section of a main protrusion in an undulating region of a low-temperature resistant sealing film for covering an insulating material provided by an embodiment of the present disclosure.

[0047] FIG7 is a schematic diagram of a second line shape of a cross section of a main protrusion in an undulating region of a low-temperature resistant sealing film for covering an insulating material provided by an embodiment of the present disclosure.

[0048] FIG8 is a schematic diagram of a third line shape of the cross section of the main protrusion of the undulating region of the low-temperature resistant sealing film for covering the insulating material provided by an embodiment of the present disclosure.

[0049] FIG9 is a schematic cross-sectional view of a storage tank on which a low-temperature-resistant sealing film for covering insulating materials provided in an embodiment of the present disclosure is installed.

[0050] Reference numerals: 1. sealing film; 2. plate unit; 3. main protrusion; 4. secondary protrusion; 5. plane area; 6. cross section; 7. top arc; 8. transition arc; 9. arc segment of connecting portion; 10. insulation structure. DETAILED DESCRIPTION

[0051] 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.

[0052] Various aspects and features of the present disclosure are described herein with reference to the accompanying drawings.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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 disclosed 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.

[0057] This disclosure 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.

[0058] The disclosed embodiment provides a low-temperature resistant sealing film for covering insulating materials, which is used for cryogenic liquid transport ships / cryogenic liquefied gas transport ships. The transport ship has a sealed and insulated tank structure for storing cryogenic liquids or cryogenic liquefied gases, which can be used to transport liquefied natural gas at a temperature of -163°C. At the same time, the storage tank for storing liquefied gas can be placed not only on a moving structure such as a hull, but also on a fixed tank structure on land, or on a floating structure at sea. As shown in Figures 1 to 9, the low-temperature resistant sealing film 1 includes at least one membrane plate, and each membrane plate in at least one module includes a plurality of plate units 2 welded and fixed in a sealed welding manner. The plate unit 2 is arranged in a regular quadrilateral and includes an undulating area and a plane area 5. Among them, the module can be the same as the membrane plate, that is, one module is one membrane plate; the module can also include multiple membrane plates, that is, multiple membrane plates together constitute a module, wherein,

[0059] The undulating area is provided with main protrusions 3 arranged in an arc-shaped strip and connected in a tangential manner. Each plate unit 2 is provided with at least four main protrusions 3 symmetrically arranged about a midline passing through the center of the plate unit 2 and perpendicular to the planar area 5 of the plate unit 2. Each arc-shaped main protrusion 3 has the corner endpoint of the corresponding plate unit 2 on its inner side as the center of the circle. After two adjacent plate units 2 are welded and fixed, the main protrusions 3 on adjacent sides of the two adjacent plate units 2 are butted together;

[0060] Each main protrusion 3 is hollow, and the cross-section 6 of the main protrusion 3 includes a top arc segment and a connecting arc segment 9. The curvature of the top arc segment is continuous, one end of the connecting arc segment 9 is connected to one end of the top arc segment in a tangential manner, and the other end of the connecting arc segment 9 is connected to the plane area 5 in a tangential manner. The tangent point of the main protrusion 3 transitions with a smooth curvature, and the cross-section obtained by intercepting the cross-section along the tangent direction perpendicular to the plane has a consistent curvature of the arc in the transition area between the cross-sections of the two main protrusions 3.

[0061] That is, in the above embodiment, when four panel units 2 are spliced ​​to form a regular quadrilateral, a circular ring is formed by the main protrusions 3 on the four panel units 2, with the corner endpoints of the four panel units 2 connected as the center of the circle. At the same time, a circular planar area 5 is generated around the main protrusion 3. The main protrusion 3 is a rotating graphic structure obtained by rotating 360 degrees around the axis, with the straight line normal to the center of the planar area 5 as the axis, the curved symmetry plane of the cross section 6 of the main protrusion 3 being perpendicular to the plane corresponding to the planar area 5, and the cross section 6 of the main protrusion 3 being placed in the same plane as the axis. As shown in Figure 1, it shows the sealing film 1 and its boundary.

[0062] In this embodiment, the plate unit 2 can have four planes of symmetry. After rotating 90 degrees along the centerline, the shape of the plate unit 2 remains exactly the same. The membrane is welded together by the plate units 2 using a sealing welding method. Due to the symmetry of the plate units 2, welding only requires symmetrical arrangement of the sides.

[0063] In some embodiments of the present disclosure, the undulating area is further provided with a secondary protrusion 4 which is respectively arranged concentrically with each main protrusion 3 and is formed by a single arc-shaped strip protrusion. The secondary protrusions 4 are symmetrically arranged about the center and are all in the shape of arc strips. After the two adjacent plate units 2 are welded and fixed, the secondary protrusions 4 on the adjacent sides of the two adjacent plate units 2 are butted, wherein the secondary protrusions 4 are symmetrically arranged about the center, which means that the secondary protrusions 4 are symmetrically arranged about the center of the plate unit 2; at least four main protrusions 3 and four secondary protrusions 4 can be seen on any plate unit 2, and the main protrusion 3 is composed of arc-shaped strip protrusions arranged tangentially, and each arc-shaped strip protrusion is self-intersecting and surrounded to form an approximately circular plane area 5, and the center of the plane area 5 is the secondary protrusion 4;

[0064] The height of the secondary protrusion 4 is not greater than the height of the primary protrusion 3 , and the distance between the primary protrusion 3 and the secondary protrusion 4 is at least twice the width of the primary protrusion 3 .

[0065] The width of the protrusion (including the width of the main protrusion 3 and the width of the secondary protrusion 4) refers to the distance between the connection area (connection arc segment 9) on both sides of the protrusion and the tangent line of the plane area 5.

[0066] As shown in Figures 3 and 4, a sealing membrane 1, a plate unit 2 and its boundary are shown, which are provided with a secondary protrusion 4. Specifically, the secondary protrusion 4 is similar in shape to the main protrusion 3, and is composed of a single arc-shaped long protrusion. The center of the plane part is used as the rotation center, and the circular shape obtained by rotating the protrusion cross section 360° is used as the secondary protrusion 4.

[0067] In this embodiment, each secondary protrusion 4 is hollow and has an arc-shaped cross section. The spacing between two adjacent secondary protrusions 4 is at least twice the width of the secondary protrusion 4. Specifically, the secondary protrusion 4 can have a similar cross-sectional shape to the primary protrusion 3. The secondary protrusion 4 can be formed by rotating the cross section of the secondary protrusion 4 360° around the center of the planar region 5 to form a circular ring.

[0068] In this embodiment, the plate unit 2 is made of stainless steel, aluminum alloy or high manganese steel with a yield strength between 170 MPa and 500 MPa, and a thickness between 2 and 4 mm. During the welding process, adjacent plate units 2 are welded in the same direction.

[0069] Furthermore, the length of each membrane plate in the transverse direction and the longitudinal direction is at least 0.6 m, and the lengths of the longitudinal and transverse membrane plates are inconsistent.

[0070] In some embodiments of the present disclosure, as shown in FIG6 , the height dimension of the cross section 6 of the main protrusion 3 is represented by H, and is 40 mm ≤ H ≤ 60 mm; the top arc segment includes a top arc 7 with a radius represented by R1 and a transition arc 8 connected to the top arc 7 in a tangential manner and represented by R2, wherein R1 is smaller than R2, and the top arc 7 and the transition arc 8 are inscribed in each other;

[0071] The connecting arc segment 9 is a circular arc and is represented by R3. The connecting arc segment 9 is circumscribed to the transition arc 8. Then:

[0072] 1≤R1:R3≤2;

[0073] 5.5≤R2:R3≤10;

[0074] 1 <R2:H≤1.5。

[0075] As an example, the height H of the cross section 6 of the main protrusion 3 is 41.58 mm, the radius R1 of the top arc 7 is 7.78 mm, the radius R2 of the transition arc 8 is 46.89 mm, and the radius R3 of the connecting arc segment 9 is 5.06 mm.

[0076] In other embodiments of the present disclosure, as shown in FIG7 , the height dimension of the cross section 6 of the main protrusion 3 is represented by H, and is 36 mm ≤ H ≤ 48 mm;

[0077] The top arc segment satisfies the parabola expressed by the following formula:

[0078] The top arc segment coincides with a portion of the curve at the top of the parabola defined by the formula.

[0079] The connecting arc segment 9 is an arc and is tangent to the parabola. The arc radius R3 satisfies:

[0080] 4≤H:R3≤8.

[0081] As an example, the height H of the cross section 6 of the main protrusion 3 is 48 mm, and the arc radius R3 of the connecting portion arc segment 9 is 6.41 mm.

[0082] In other embodiments of the present disclosure, as shown in FIG8 , the height dimension of the cross section 6 of the main protrusion 3 is represented by H, and 40 mm ≤ H ≤ 50 mm;

[0083] The top arc segment satisfies the elliptical shape expressed by the following formula:

[0084] and 5 / 8≤a / H≤1;

[0085] The top arc segment coincides with the curves of the ellipse defined by the formula in the first quadrant and the second quadrant.

[0086] The connecting arc segment 9 is a circular arc with a radius denoted by R3, is tangent to the ellipses of the first quadrant and the second quadrant, and satisfies 0.15≤R3:H≤0.25.

[0087] As an example, the height H of the cross section 6 of the main protrusion 3 is 45 mm, and the arc radius R3 of the connecting portion arc segment 9 is 8.2 mm.

[0088] It can be seen from the above technical solution that the low-temperature resistant sealing film for covering insulating materials provided by the above embodiment of the present disclosure has main protrusions in the undulating area arranged tangentially and intersecting with each other on the plane area 5. The regular distribution greatly reduces the proportion of the plane area 5. While the deformation and extrusion in the horizontal plane caused by temperature changes are greatly reduced, the elastic shape of the protrusion, which is approximately U-shaped, also provides a larger deformation margin; further, the seamless distribution arrangement produced by the tangential connection of the main protrusions 3 in the undulating area, plus the relatively tight arrangement of the secondary protrusions 4 in the plane area 5, evenly disperses the sloshing impact load, thereby effectively avoiding damage to the sealing film 1 and ensuring the sealing of the membrane.

[0089] The above-mentioned low-temperature resistant sealing film for covering insulating materials can be used in the liquid cargo tank of LNG transport ships. The liquid cargo tank is a low-temperature insulating storage tank. The storage tank includes a sealing film 1 and an insulating structure 10. The sealing film 1 is arranged on the insulating structure 10 and is formed by multiple film plates welded to each other by lap welding.

[0090] The sealing membrane can also be installed on the inner surface of the insulation tank of an onshore storage tank, for example, an onshore LNG storage tank or a storage tank of other floating structures on water, particularly a liquefied gas land tank, or a floating (production) storage unit on or under water. The liquefied gas in the insulation tank itself can also be used as a fuel reserve for the structure's operation.

[0091] Therefore, the embodiment of the present disclosure also provides a storage tank using the low-temperature resistant sealing film provided in the above embodiment for covering the insulating material. As shown in Figure 9, the storage tank includes: a tank wall, which encloses the internal space of the storage tank and is in contact with the low-temperature liquefied gas; an insulating structure 10, which is attached to the tank wall, and the insulating structure 10 is provided with a low-temperature resistant sealing film 1 on the surface away from the tank wall.

[0092] In the above-mentioned storage tank, since the regular distribution of the undulating areas on the sealing membrane 1 greatly reduces the proportion of the plane area 5, the deformation and extrusion in the horizontal plane caused by temperature changes are greatly reduced; in addition, the tangential connection of the undulating areas and the seamless distribution of the raised parts effectively and evenly disperse and withstand the sloshing impact load, thereby effectively avoiding damage to the sealing membrane 1 and ensuring the sealing of the membrane.

[0093] The present disclosure also provides a method for manufacturing a low-temperature resistant sealing film for covering an insulating material as provided in the above embodiment, wherein the plate units 2 divided from the metal plate are successively connected to form a membrane plate, and the membrane plates are then overlapped and welded to form a sealing film 1. The method includes:

[0094] Step 1: Design a mold for the undulating area based on the structural design drawing of the sealing film 1 corresponding to the low-temperature resistant sealing film 1 for covering the insulating material provided in the above embodiment, and make a corresponding mold for the undulating area based on the rebound prediction of the elasticity of the material used;

[0095] Step 2: Based on the thickness reduction and shape springback prediction after stamping, a metal plate of corresponding thickness is selected and cut into plate units 2 with a set margin, and the plate units 2 are placed in a press for processing preparation. The press and the undulating area mold are used for stamping and forming to obtain a plate unit 2 with a convex shape corresponding to the undulating area;

[0096] Step 3: Arrange the panel units 2 in the same direction according to the size of the insulation module corresponding to the insulation material to be covered, and assemble them into a rectangular panel that matches the size of the insulation module. The panel units 2 are then welded together by sealing welding to form a membrane panel.

[0097] Step 4: After placing the membrane panels on the insulating layer formed by the insulating modules, the membrane panels are fixed in sequence by continuous lap welding according to the principle of butting the cross-sectional shapes of the undulating regions of adjacent membrane panels to form a complete sealing membrane 1 .

[0098] The low-temperature resistant sealing membrane 1 manufactured by the above method has main protrusions in the undulating area arranged tangentially and intersecting with each other on the plane area 5. The regular distribution greatly reduces the proportion of the plane area 5. While the deformation and extrusion in the horizontal plane caused by temperature changes are greatly reduced, the elastic shape of the protrusion, which is approximately U-shaped, also provides a larger deformation margin; furthermore, the seamless distribution arrangement produced by the tangential connection of the main protrusions 3 in the undulating area, plus the relatively tight arrangement of the secondary protrusions 4 in the plane area 5, evenly disperses the sloshing impact load, thereby effectively avoiding damage to the sealing membrane 1 and ensuring the sealing of the membrane.

[0099] 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 low temperature resistant sealing film for covering insulating materials, characterized in that: The sealing membrane includes at least one membrane plate, and each membrane plate in at least one module includes a plurality of plate units welded and fixed in a sealing welding manner, wherein the plate units are arranged in a regular quadrilateral and include an undulating area and a plane area, wherein: The undulating area is provided with main protrusions arranged in arc-shaped strips and connected in a tangential manner, each of the plate units is provided with at least four main protrusions arranged symmetrically about a midline passing through the center of the plate unit and arranged perpendicularly to the plane area of ​​the plate unit, each of the main protrusions in arc-shaped has an angular end point of the plate unit corresponding to its inner side as the center of the circle, and after two adjacent plate units are welded and fixed, the main protrusions on adjacent sides of the two adjacent plate units are butted; Each of the main protrusions is hollow, and the cross-section of the main protrusions includes a top arc segment and a connecting arc segment, the curvature of the top arc segment is continuous, one end of the connecting arc segment is tangentially connected to one end of the top arc segment, and the other end of the connecting arc segment is tangentially connected to the plane area.

2. The low temperature resistant sealing film for covering insulating materials according to claim 1, characterized in that: The undulating area is also provided with secondary protrusions respectively arranged concentrically with each main protrusion, the secondary protrusions are symmetrically arranged about the center and are all arranged in arc-shaped strips, and after two adjacent plate units are welded and fixed, the secondary protrusions on adjacent sides of the two adjacent plate units are butted; The height dimension of the secondary protrusion is not greater than the height dimension of the primary protrusion, and the distance between the primary protrusion and the secondary protrusion is at least twice the width dimension of the primary protrusion.

3. The low temperature resistant sealing film for covering insulating materials according to claim 2, characterized in that: Each of the secondary protrusions is hollow, and the cross section of the secondary protrusion is arc-shaped; The distance between two adjacent sub-protrusions is at least twice the width of the sub-protrusions.

4. The low temperature resistant sealing film for covering insulating materials according to claim 1 or 2, characterized in that: The height dimension of the cross section of the main protrusion is represented by H, and is 40mm≤H≤60mm; The top arc segment includes a top arc with a radius represented by R1 and a transition arc connected to the top arc in a tangential manner and represented by R2, wherein R1 is smaller than R2; The arc segment of the connecting portion is a circular arc and is represented by R3, then: 1≤R1:R3≤2; 5.5≤R2:R3≤10; 1 <R2:H≤1.5。 5. The low temperature resistant sealing film for covering insulating materials according to claim 1 or 2, characterized in that: The height dimension of the cross section of the main protrusion is represented by H, and is 36mm≤H≤48mm; The top arc segment satisfies the parabola expressed by the following formula, specifically: The arc segment of the connecting portion is an arc and is tangent to the parabola, and the arc radius R3 satisfies: 4≤H:R3≤8.

6. The low temperature resistant sealing film for covering insulating materials according to claim 1 or 2, characterized in that: The height dimension of the cross section of the main protrusion is represented by H, and is 40mm≤H≤50mm; The top arc segment satisfies the ellipse shape expressed by the following formula, specifically: And 5 / 8≤a / H≤1; The arc segment of the connecting portion is a circular arc, the radius of which is represented by R3, which is tangent to the ellipses of the first quadrant and the second quadrant, and satisfies 0.15≤R3:H≤0.

25.

7. The low temperature resistant sealing film for covering insulating materials according to claim 1, characterized in that: The plate unit is made of stainless steel, aluminum alloy or high manganese steel with a yield strength between 170MPa and 500MPa, and a thickness between 2 and 4mm. During welding, adjacent plate units are welded in the same direction.

8. The low temperature resistant sealing film for covering insulating materials according to claim 1, characterized in that: The length of each of the membrane sheets in the transverse direction and the longitudinal direction is at least 0.6 m.

9. A storage tank using the low-temperature resistant sealing film for covering insulating materials according to any one of claims 1 to 8, characterized in that: The storage tank comprises: The tank wall, which encloses the interior space of the tank and is in contact with the cryogenic liquefied gas; The insulating structure is attached to the tank wall, and the low-temperature resistant sealing film is arranged on the surface of the insulating structure away from the tank wall.

10. A method for manufacturing a low-temperature resistant sealing film for covering an insulating material as claimed in any one of claims 1 to 8, characterized in that: The method comprises: Step 1: Designing a mold for the undulating area according to the structural design drawing of the sealing film corresponding to the low-temperature resistant sealing film for covering the insulating material as described in any one of claims 1 to 8, and making a corresponding mold for the undulating area in combination with the rebound prediction of the elasticity of the material used; Step 2: According to the prediction of the thickness reduction and shape rebound after stamping, a metal plate of corresponding thickness is selected to be cut into plate units with a set margin, and the plate units are put into a press for processing preparation, and the press and the undulating area mold are used for stamping and forming to obtain a plate unit with a convex shape corresponding to the undulating area; Step 3: according to the size of the insulation module corresponding to the insulation material to be covered, the plate units are arranged in the same direction to form a rectangular plate that matches the size of the insulation module, and the plate units are welded and fixed by sealing welding to form a membrane plate; Step 4: After placing the membrane plate on the insulating layer formed by the insulating module, the membrane plates are welded and fixed in sequence by continuous lap welding according to the principle of butt jointing the cross-sectional shapes of the undulating regions of adjacent membrane plates to form a complete sealing membrane.

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