A membrane cargo tank

Abstract

The present application provides a membrane liquid cargo tank, including a main shield and a support plate, the main shield includes a plurality of first standard parts, each of the first standard parts has a plurality of arc-shaped protrusions extending in a predetermined direction arranged in parallel, the outer edges of the plurality of first standard parts are connected in a preset direction so that the arc-shaped protrusions in two adjacent first standard parts are arranged crosswise, the plurality of first standard parts are welded by automatic welding, and after welding, a cavity directly in contact with liquid cargo is formed. The support plate includes a plurality of second standard parts, the second standard parts have the same structure as the first standard parts, a second standard part is arranged correspondingly below each of the first standard parts, the arc-shaped protrusions in the second standard parts are arranged in affixed with the arc-shaped protrusions in the first standard parts, and the second standard parts are made of memory material. The present application improves the construction quality and construction efficiency of the membrane liquid cargo tank.

Description

Technical Field

[0001] The present application relates to the technical field of liquefied gas ships, and in particular to a membrane liquid cargo tank. Background Art

[0002] With the rapid economic development and the continuous improvement of environmental governance requirements, liquefied natural gas has become the preferred alternative energy source to oil with its green, environmentally friendly and efficient advantages. At the same time, liquefied natural gas has also become one of the fastest growing energy industries in the world. As a special ship for transporting liquefied natural gas, liquefied gas ships have also experienced a development process from small, simple and single to the current large, complex and diversified. As one of the core technologies of liquid cargo tanks in liquefied gas ships, the containment system has the main function of ensuring that liquefied natural gas does not leak through the shielding layer. In addition, the containment system has good thermal insulation and insulation capabilities, which can prevent the hull from losing strength and toughness due to the -163℃ low-temperature liquid cargo stored inside.

[0003] At present, different types of liquid cargo tanks (including C-type pressure tanks, MOSS spherical tanks, GTT MARKⅢ membrane type, GTT NO 96 membrane type and IHI SPB type) usually adopt different containment systems. Therefore, there are many containment systems on the market. Among them, membrane liquid cargo tanks are favored by shipowners for their advantages such as high tank capacity utilization, low fuel consumption, large hull visibility and small wind resistance area. The containment system of membrane liquid cargo tanks usually includes main shielding and secondary shielding, but the main shielding is usually composed of staggered overlap of corrugated plates. When arranging the main shielding, personnel are required to weld each overlap position. The welding work is complicated and the construction is difficult, which makes it impossible to use automatic welding and the welding quality fluctuates greatly. In addition, a large number of reinforcing wedges are usually arranged under the main shielding to strengthen the supporting strength of the main shielding and reduce the deformation of the corrugated plate. However, during the construction and actual navigation process, the reinforcing wedges have little effect and the main shielding will still undergo irreversible deformation. Summary of the invention

[0004] The purpose of the embodiment of the present application is to provide a membrane liquid cargo tank, which sets the main shield in the containment system as multiple standard parts, and provides an arc-shaped protrusion inside each standard part. The main shield is constructed by welding the edges of the standard parts, and a support plate is arranged under the main shield to repair the deformation of the main shield, thereby solving the above-mentioned problem.

[0005] The present application provides a membrane liquid cargo tank, comprising:

[0006] The hull surface, the first insulating plate, the secondary shield, the second insulating plate, the support plate and the main shield are arranged in sequence from the outside to the inside;

[0007] The main shield comprises a plurality of first standard parts, each of which has a plurality of arc-shaped protrusions extending in a predetermined direction arranged in parallel, the outer edges of the plurality of first standard parts are connected in a preset direction so that the arc-shaped protrusions in two adjacent first standard parts are arranged crosswise, and the plurality of first standard parts are welded by automatic welding to enclose a cavity directly contacting the liquid cargo after welding;

[0008] The support plate is located between the main shield and the second insulating plate and is arranged in close contact with the main shield. The support plate includes multiple second standard parts. The second standard parts have the same structure as the first standard parts. A second standard part is arranged under each of the first standard parts. The inner arc-shaped protrusions of the second standard parts are arranged in close contact with the inner arc-shaped protrusions of the first standard parts. The second standard parts are made of memory materials.

[0009] In one embodiment, the cross section of the arc-shaped protrusion is a shape composed of three arcs with the same radius connected tangentially in sequence, wherein the center of the middle arc is located at the base surface of the first standard component, and the arcs on both sides are connected tangentially to the base surface of the first standard component.

[0010] In one embodiment, the first standard component is set to a square shape, and a plurality of arc-shaped protrusions parallel to the sides are evenly arranged in the first standard component; two adjacent first standard components are connected by rotating 90 degrees to achieve a cross arrangement of the arc-shaped protrusions in the two first standard components.

[0011] In one embodiment, the plurality of second standard parts in the support plate are welded by automatic welding.

[0012] In one embodiment, the support plate is made of nickel-titanium alloy material.

[0013] In one embodiment, the first insulating plate includes a plurality of first insulating modules, the second insulating plate includes a plurality of second insulating modules, and the first insulating modules and the second insulating modules are staggered so that the connection seams of the plurality of first insulating modules and the connection seams of the plurality of second insulating modules are staggered.

[0014] In one embodiment, the secondary shield is made of low-temperature resistant material with a thickness of 1-3 mm.

[0015] In one embodiment, the first insulation module and the second insulation module are standard prefabricated parts made of the same material and with the same size, and the length and width of the standard prefabricated parts are consistent with those of the first standard parts.

[0016] In one embodiment, the first insulating plate and the second insulating plate are made of polyurethane foam material with a density of 50-400 kg / m3 and a thickness of 15-500 mm.

[0017] In one embodiment, a support body is arranged between the hull inner shell, the second insulating plate, the secondary shield, the first insulating plate, the support plate and the main shield, and the material of the support body is any one of wood, fiberglass and tetrafluoroethylene.

[0018] The membrane tank in this application has the following beneficial effects:

[0019] 1. Compared with the existing main shielding corrugated structure, this application sets the main shielding of the membrane liquid cargo tank as multiple standard parts, and sets arc-shaped protrusions in the standard parts. During the construction process, the edges of the standard parts can be welded. The standard parts are rotated at a predetermined angle to achieve the staggered direction of the corrugation, which reduces the component types of the system, facilitates standardized production and management, and improves the production efficiency and accuracy of standard parts. In addition, different standard parts are connected to each other during the installation process, and only the edge planes of the standard parts are butted, without corrugated arc surfaces, which facilitates automatic welding, greatly improves construction efficiency, and shortens production time.

[0020] 2. Compared with the existing method of arranging a large number of wooden or aluminum pads or reinforcing wedges under the main shield, the present application arranges a support plate under the main shield. The support plate has the same arc-shaped protrusion as the main shield. The support plate is made of memory material, which solves the problem that the main shield cannot be repaired at sea.

[0021] 3. In the present application, the first insulating module and the second insulating module are set as prefabricated parts of the same specifications to improve the versatility of the insulating modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic structural diagram of a membrane liquid cargo tank according to an embodiment of the present application;

[0024] Figure 2 for Figure 1 AA section of a membrane cargo tank is shown;

[0025] Figure 3 is a schematic structural diagram of a first standard component according to an embodiment of the present application;

[0026] Figure 4 A schematic diagram of a partial structure of a main shield according to an embodiment of the present application;

[0027] Figure 5 It is a cross-sectional view of an arc-shaped protrusion according to an embodiment of the present application.

[0028] 100, liquefied gas ship; 110, hull inner shell; 200, enclosure system; 210, first insulation board; 211, first insulation module; 220, secondary shield; 230, second insulation board; 231, second insulation module; 240, support plate; 250, primary shield; 251, first standard part; 2511, arc-shaped protrusion; 2511a, first arc; 2511b, middle arc; 2511c, second arc; 2512, base surface. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0031] See also Figure 1 and Figure 2 The present application provides a membrane liquid cargo tank, which is arranged in a liquefied gas ship 100. The liquid cargo tank includes a hull inner shell surface 110, a first insulating plate 210, a secondary shield 220, a second insulating plate 230, a support plate 240 and a main shield 250 which are sequentially connected and arranged from the outside to the inside. The first insulating plate 210, the secondary shield 220, the second insulating plate 230, the support plate 240 and the main shield 250 constitute an enclosure system 200.

[0032] The main shield 250 includes a plurality of first standard parts 251, in which a plurality of arc-shaped protrusions 2511 extending in a predetermined direction are arranged in parallel (see Figure 3 ), the outer edges of the plurality of first standard components 251 are connected in a preset direction so that the arc-shaped protrusions 2511 in two adjacent first standard components 251 are arranged crosswise (see Figure 4 ), multiple first standard parts 251 are welded by automatic welding, and after welding, they form a cavity that directly contacts the liquid cargo (see Figure 1 );

[0033] The support plate 240 is located between the main shield 250 and the second insulating plate 230, and is arranged in close contact with the main shield 250. The support plate 240 includes a plurality of second standard parts, and the second standard parts have the same structure as the first standard parts 251. A second standard part is arranged under each first standard part 251, and the inner arc-shaped protrusion of the second standard part is arranged in close contact with the inner arc-shaped protrusion 2511 of the first standard part 251. The second standard part is made of memory material. The memory material can be a nickel-titanium alloy material.

[0034] In the above implementation process, the main shield is connected by several first standard parts. The first standard parts are uniformly constructed, which reduces the types of components, facilitates standardized production and management, and improves the production efficiency and accuracy of standard parts. In addition, the installation of the main shield can be completed by welding the outer edge of the first standard part, which reduces the welding difficulty of the main shield, and adopts fully automatic welding to improve the manufacturing quality of the membrane liquid cargo tank. Then, a support plate of the same structure is tightly arranged under the main shield. The support plate is made of memory material. In actual application, the support plate will deform with the main shield. By heating the dry air or inert gas in the hull to warm up the cabin, the temperature in the membrane liquid cargo tank is increased so that the support plate automatically returns to its shape before deformation, thereby restoring the main shield to its shape before deformation. By locally heating up, the corrugation of the deformed part can be restored without removing the installed insulation board.

[0035] Figure 5 is a cross-sectional view of an arc-shaped protrusion according to an embodiment of the present application, see Figure 5 The cross-sectional shape of the arc-shaped protrusion 2511 is a shape composed of three circular arcs with the same radius connected tangentially in sequence. Among them, the center of the middle arc 2511b is located at the base surface 2512 of the first standard part 251, and the arcs on both sides (the first arc 2511a and the second arc 2511c) are tangentially connected to the base surface 2512 of the first standard part 251. The arc-shaped protrusion 2511 is composed of three circles with the same radius and tangential to each other. While improving the strength of the main shield 250 and the support plate 240, it ensures that the corrugated plate of the first standard part 251 is smooth and continuous without corners or sudden changes in curvature. When the support plate 240 is heated and restored to shape, the deformation recovery effect is best.

[0036] Figure 3 FIG. 1 is a schematic diagram of a structure of a first standard component according to an embodiment of the present application, see Figure 3 , the first standard part 251 is set to a square shape, and a plurality of arc-shaped protrusions 2511 parallel to the sides are evenly arranged in the first standard part 251; two adjacent first standard parts 251 are connected by rotating 90 degrees to achieve a cross arrangement of the arc-shaped protrusions in the two first standard parts (see Figure 4). By providing an arc-shaped protrusion 2511 inside the first standard part 251, a complex structure of the connection is avoided. The corrugations of the main shield 250 and the support plate 240 are only within the size of a single standard part. During the installation process, different standard parts are connected to each other, and only the edge planes of the standard parts are butted, without corrugated arc surfaces, which facilitates automatic welding, greatly improves construction efficiency, and shortens production time.

[0037] In one embodiment, the first insulating plate 210 includes a plurality of first insulating modules 211, and the second insulating plate 230 includes a plurality of second insulating modules 231. The first insulating modules 211 and the second insulating modules 231 are arranged in a staggered manner so that the connection seams of the plurality of first insulating modules 211 and the connection seams of the plurality of second insulating modules 231 are arranged in a staggered manner. The two layers of insulating modules are arranged in a staggered manner, and the staggered length of the connection seams can be half the length of a single module to minimize the heat transmission problem in the gap between the plates. The gaps between the insulating modules are filled with insulating fillers of the same material to ensure insulation and thermal insulation performance.

[0038] In one embodiment, the secondary shield 220 is made of a low temperature resistant material with a thickness of 1-3 mm. The low temperature resistant material is stainless steel, high nickel steel, invar steel plate, aluminum alloy steel plate, etc. In addition, the secondary shield 220 is made of a flexible film material, which is complex to construct, has low rigidity, and poor protection capability.

[0039] In one embodiment, the first insulation module 211 and the second insulation module 231 are standard prefabricated parts of the same material and size, and the length and width of the standard prefabricated parts are consistent with those of the first standard part 251. The use of standard insulation module prefabricated parts of the same material, thickness and size improves the versatility of the components, reduces the difficulty of procurement, warehousing and construction management, and reduces the cost of insulation module production and installation. It improves the degree of component standardization and reduces the number of component categories.

[0040] In one embodiment, the first insulating plate 210 and the second insulating plate 230 are made of polyurethane foam material with a density of 50-400 kg / m3 and a thickness of 150-500 mm.

[0041] In one embodiment, a support body is arranged between the hull inner shell 110, the first insulating plate 210, the secondary shield 220, the second insulating plate 230, the support plate 240 and the main shield 250, and the material of the support body is any one of wood, fiberglass and tetrafluoroethylene.

[0042] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A membrane liquid cargo tank, characterized in that: include: The hull surface, the first insulating plate, the secondary shield, the second insulating plate, the support plate and the main shield are arranged in sequence from the outside to the inside; The main shield comprises a plurality of first standard parts, each of which has a plurality of arc-shaped protrusions extending in a predetermined direction arranged in parallel, the outer edges of the plurality of first standard parts are connected in a preset direction so that the arc-shaped protrusions in two adjacent first standard parts are arranged crosswise, and the plurality of first standard parts are welded by automatic welding to enclose a cavity directly contacting the liquid cargo after welding; The support plate is located between the main shield and the second insulating plate and is arranged in close contact with the main shield. The support plate includes multiple second standard parts. The second standard parts have the same structure as the first standard parts. A second standard part is arranged under each of the first standard parts. The inner arc-shaped protrusions of the second standard parts are arranged in close contact with the inner arc-shaped protrusions of the first standard parts. The second standard parts are made of memory materials.

2. A membrane liquid cargo tank according to claim 1, characterized in that: The arc-shaped protrusion is composed of three circular arcs with the same radius connected tangentially in sequence, wherein the center of the middle circular arc is located on the base surface of the first standard component, and the circular arcs on both sides are connected tangentially to the base surface of the first standard component.

3. A membrane liquid cargo tank according to claim 1, characterized in that: The first standard component is set to a square shape, and a plurality of arc-shaped protrusions parallel to the sides are evenly arranged in the first standard component; two adjacent first standard components are connected by rotating 90 degrees to achieve a cross arrangement of the arc-shaped protrusions in the two first standard components.

4. A membrane liquid cargo tank according to claim 1, characterized in that: The plurality of second standard parts in the support plate are welded together by automatic welding.

5. A membrane liquid cargo tank according to claim 1, characterized in that: The support plate is made of nickel-titanium alloy material.

6. A membrane liquid cargo tank according to claim 1, characterized in that: The first insulating plate includes a plurality of first insulating modules, the second insulating plate includes a plurality of second insulating modules, and the first insulating modules and the second insulating modules are staggered so that the connection seams of the plurality of first insulating modules and the connection seams of the plurality of second insulating modules are staggered.

7. A membrane liquid cargo tank according to claim 1, characterized in that: The secondary shield is made of low-temperature resistant material with a thickness of 1-3 mm.

8. A membrane liquid cargo tank according to claim 6, characterized in that: The first insulating module and the second insulating module are standard prefabricated parts of the same material and size, and the length and width of the standard prefabricated part are consistent with those of the first standard part.

9. A membrane liquid cargo tank according to claim 1, characterized in that: The first insulating plate and the second insulating plate are made of polyurethane foam material with a density of 50-400kg / m3 and a thickness of 150-500mm.

10. A membrane liquid cargo tank according to claim 6, characterized in that: A support body is arranged between the inner shell surface of the hull, the second insulating plate, the secondary shield, the first insulating plate, the support plate and the main shield. The material of the support body is any one of wood, fiberglass and tetrafluoroethylene.

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