Cryogenic liquefied gas tank and method of construction thereof

Abstract

To provide a low temperature liquefied gas tank including a vacuum heat insulation structure which is excellent in processability and ease of assembly of outer tank panels and may be applied to achieve high capacity, and to provide a construction method of the low temperature liquefied gas tank.SOLUTION: A low temperature liquefied gas tank 1 includes: an inner tank 12 in which a low temperature liquefied gas LG is stored; an outer tank 11 formed by an assembly of multiple outer tank panels 2 and enclosing the inner tank 12; and a vacuum heat insulation layer 13 between the inner tank 12 and the outer tank 11. The outer tank panels 2 include: an inner panel 21 and an outer panel 22 which face each other while forming a predetermined space therebetween; and a honeycomb structure 23 disposed between the inner panel 21 and the outer panel 22. The honeycomb structure 23 is formed by an aggregate of multiple honeycomb hollow columns 24 arranged in a honeycomb form.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a cryogenic liquefied gas tank for storing cryogenic liquefied gas and a method for constructing the same. [Background technology]

[0002] Multi-shell tanks are known as facilities for storing low-temperature liquefied gas. Generally, multi-shell tanks include an inner tank for storing the low-temperature liquefied gas, an outer tank surrounding the inner tank, and an insulating layer between the inner tank and the outer tank. From the viewpoint of reducing the evaporation rate (BOR value) of the stored low-temperature liquefied gas, it is desirable for the insulating layer to have a vacuum insulating structure (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-104884 Summary of the Invention [Problem to be solved by the invention]

[0004] When adopting a vacuum insulation structure, the outer vessel must be thickened to withstand the external vacuum pressure. When building a tank with a large capacity, the outer vessel must be even thicker. The outer vessel is assembled by welding multiple steel panels that have been processed into a spherical shape. However, if the steel panels are made too thick, it becomes difficult to process them into a spherical shape and to weld them.

[0005] An object of the present disclosure is to provide a low-temperature liquefied gas tank with a vacuum insulation structure that has excellent workability and assembly properties for outer tank panels and is adaptable to large capacity, and a method for constructing the same. [Means for solving the problem]

[0006] A cryogenic liquefied gas tank according to one aspect of the present disclosure includes an inner tank for storing cryogenic liquefied gas, an outer tank formed by an assembly of a plurality of panels and surrounding the inner tank, and a vacuum layer between the inner tank and the outer tank, and the panels include an inner plate and an outer plate facing each other at a predetermined interval, and a plurality of cylindrical bodies disposed between the inner plate and the outer plate. The inner plate is a plate material to which one ends of the plurality of cylindrical bodies are fixed, and the outer plate is a plate material to which the other ends of each of the cylindrical bodies are fixed.

[0007] A method for constructing a cryogenic liquefied gas tank according to another aspect of the present disclosure is a method for constructing a cryogenic liquefied gas tank comprising an inner tank for storing cryogenic liquefied gas, an outer tank surrounding the inner tank, and a vacuum layer between the inner tank and the outer tank, comprising the steps of: preparing a cylindrical body having a first opening end at one end and a second opening end at the other end; fabricating the inner tank; fabricating a plurality of panel intermediates by fixing the first opening ends of a plurality of the cylindrical bodies to an inner plate made of spherical pieces of a predetermined size; assembling the plurality of panel intermediates to surround the inner tank by joining the inner plates together; and fabricating the outer tank by fixing a cover piece to each of the second opening ends of the cylindrical body. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a low-temperature liquefied gas tank with a vacuum insulation structure that has excellent workability and assembly properties for outer tank panels and is adaptable to large capacities, and a method for constructing the same. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing a cryogenic liquefied gas tank according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is an exploded perspective view of an outer vessel panel that constitutes the outer vessel of the low-temperature liquefied gas tank. [Figure 3] FIG. 3 is a perspective view of the outer tub panel. [Figure 4] FIG. 4 is a perspective view showing the honeycomb hollow columns, inner plates and hexagonal cover pieces that constitute the outer-tub panel. [Figure 5] FIG. 5 is a plan view of the honeycomb structure that constitutes the outer-tub panel. [Figure 6] FIG. 6 is a schematic diagram for explaining an example of a method for constructing a cryogenic liquefied gas tank according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, with reference to the drawings, embodiments of a cryogenic liquefied gas tank and a method for constructing the same according to the present disclosure will be described in detail. The cryogenic liquefied gas tank according to the present disclosure is a tank for storing cryogenic liquefied gas and has a multi-shell structure. In the embodiment shown below, a spherical double-shell tank is exemplified. The present disclosure is not limited to the shape of the tank and can also be applied to triple-shell tanks and flat-bottom multi-shell tanks. The liquefied gas to be stored is, for example, a cryogenic liquefied gas such as liquefied hydrogen, liquid helium, liquid nitrogen, liquefied natural gas, or liquefied petroleum gas. In particular, the cryogenic liquefied gas tank according to the present disclosure is suitable for storing liquefied hydrogen.

[0011] [Tank structure] 1 is a cross-sectional view showing a cryogenic liquefied gas tank 1 according to a first embodiment of the present disclosure. The cryogenic liquefied gas tank 1 is a multi-shell tank that stores cryogenic liquefied gas LG. The cryogenic liquefied gas tank 1 includes a tank body 10 having a spherical double-shell structure and supports 14 that support the tank body 10 at a position higher than the tank foundation GL.

[0012] The tank body 10 is a tank having a storage space 1A for storing low-temperature liquefied gas LG, and includes a spherical outer tank 11, a spherical inner tank 12 contained within the outer tank 11, and a vacuum insulation layer 13 (vacuum layer) disposed between the outer tank 11 and the inner tank 12. The outer tank 11 is supported near its equator by supports 14. The inner tank 12 is supported by the outer tank 11 via a hanger rod 15. More specifically, one end of the hanger rod 15 is fixed to the outer tank 11, and the other end of the hanger rod 15 is fixed to the inner tank 12, so that the inner tank 12 is suspended and supported by the outer tank 11.

[0013] The outer tub 11 is a sealed body made of metal such as carbon steel. The outer tub 11 is an assembly of multiple outer tub panels 2 assembled by butt welding or the like to surround the inner tub 12. FIG. 1 shows some of the multiple outer tub panels 2. Each outer tub panel 2 is bent to have a spherical surface in order to form part of the spherical outer tub 11. As will be described in detail later, the outer tub 11 of this embodiment includes an inner plate 21 and an outer plate 22 facing each other at a predetermined interval, and multiple cylindrical bodies disposed between the inner plate 21 and the outer plate 22.

[0014] The inner tank 12 is a tank that actually stores the low-temperature liquefied gas LG, and is a sealed body made of metal such as stainless steel plate. The inner tank 12 is also an assembly of multiple panels. The inner tank 12 is surrounded by the outer tank 11 with a predetermined space between them, which serves as a vacuum insulation layer 13. The inner tank 12 has a storage space 1A in which the low-temperature liquefied gas LG is stored. Vaporized gas from the low-temperature liquefied gas LG accumulates in the upper part of the storage space 1A.

[0015] The vacuum insulation layer 13 is a layer that utilizes the gap between the outer vessel 11 and the inner vessel 12 as a vacuum insulation space to improve the cold retention of the inner vessel 12. By creating a vacuum insulation space around the inner vessel 12, it is possible to suppress the BOR value to a predetermined low rate even when the low-temperature liquefied gas LG stored in the inner vessel 12 is liquefied hydrogen gas. The vacuum insulation layer 13 may contain a powder insulation material or a solid insulation material. For example, the vacuum insulation layer 13 may be filled with an insulation material such as granular perlite or glass wool.

[0016] The columns 14 are metal columns erected vertically from the tank foundation GL. The tank foundation GL is a concrete layer poured at least where the columns 14 are erected. A plurality of columns 14 are erected so as to surround the tank body 10 at a predetermined pitch in the circumferential direction. It is desirable to connect adjacent columns 14 with braces to reinforce the strength. Note that instead of the columns 14, the tank body 10 may be supported by a skirt structure.

[0017] As described above, the low-temperature liquefied gas tank 1 of this embodiment is a vacuum insulated tank equipped with a vacuum insulation layer 13. Another tank type is a normal pressure insulated tank. In a normal pressure insulated tank, the insulated space of a multi-shell tank structure is at normal pressure, and the insulated space is filled with a heat insulating material for cold insulation, and further, a gas having a boiling point equal to or lower than that of the low-temperature liquefied gas LG to be stored is sealed inside. When the low-temperature liquefied gas LG to be stored is liquefied natural gas or the like, it is possible to suppress the BOR value to a low rate in the normal pressure insulated tank. This is because the tank capacity is 10,000 m 3 The same applies to large tanks exceeding 1000m.

[0018] In contrast, the situation is different when the low-temperature liquefied gas LG to be stored is liquefied hydrogen gas, which must be stored at -253°C. When storing liquefied hydrogen gas, a tank with high insulation specifications, i.e., the vacuum-insulated low-temperature liquefied gas tank 1 described above, is required to achieve a low BOR value. In a vacuum-insulated tank, the gap between the outer vessel 11 and inner vessel 12 is evacuated, so that external vacuum pressure is applied to the outer vessel 11, which is in contact with atmospheric pressure. For this reason, the outer vessel 11 must have a thickness that can withstand the external vacuum pressure.

[0019] The required plate thickness of the outer vessel 11 increases as the tank capacity increases. For a small vacuum insulated tank with a small tank capacity, the required plate thickness of the outer vessel 11 can be set to a size that allows for relatively easy manufacturing. However, for a large tank with a large tank capacity, manufacturing becomes increasingly difficult. Specifically, problems arise in the outer vessel panel 2 that constitutes the outer vessel 11, such as difficulty in bending the outer vessel panel 2 to form a spherical surface due to the required plate thickness being too thick, and difficulty in butt welding the outer vessel panels 2 together. In consideration of these problems, the cryogenic liquefied gas tank 1 of this embodiment incorporates improvements to the outer vessel panel 2 so that it can accommodate larger tank capacities while still employing a vacuum insulation system. The outer vessel panel 2 of this embodiment will be described in detail below.

[0020] [Outer tank panel structure] Fig. 2 is an exploded perspective view of the outer tank panel 2 that constitutes the outer tank 11 of the cryogenic liquefied gas tank 1, and Fig. 3 is a perspective view of the outer tank panel 2 in an assembled state. The outer tank panel 2 includes an inner plate 21 and an outer plate 22 that face each other at a predetermined interval, and a honeycomb structure 23 disposed between the inner plate 21 and the outer plate 22.

[0021] The honeycomb structure 23 is made up of an assembly of honeycomb hollow columns 24. That is, the outer-tank panel 2 has a honeycomb sandwich structure in which a plurality of honeycomb hollow columns 24 arranged in a honeycomb pattern are sandwiched between an inner plate 21 and an outer plate 22. The honeycomb hollow columns 24 are rectangular tubular bodies with a regular hexagonal cross section, and the honeycomb structure 23 is formed by arranging a plurality of honeycomb hollow columns 24 in a honeycomb pattern with no gaps between them. The inner plate 21, the outer plate 22, and the honeycomb hollow columns 24 can be made of a highly rigid metal such as carbon steel.

[0022] Each honeycomb hollow column 24 has a first open end 241 at one end thereof that is fixed to the inner plate 21, and a second open end 242 at the other end thereof that is fixed to the outer plate 22. The inner plate 21 is formed from a flat plate material to which the first open ends 241 of the plurality of honeycomb hollow columns 24 can be fixed by welding or the like. The inner plate 21 is bent to have a spherical surface that fits the inner diameter of the outer vessel 11. The outer plate 22 may be formed from a single plate like the inner plate 21, or, as will be described later with reference to Figures 4 and 5, may have a configuration in which a cover piece is individually fixed to the second open end 242 of each honeycomb hollow column 24.

[0023] The honeycomb structure 23 is not limited to the honeycomb hollow columns 24 having a regular hexagonal cross section, and may be composed of tubular bodies having other shapes. However, it is preferable that the tubular bodies are rectangular tubes, and that the rectangular tubes have a shape that allows multiple tubes to be arranged without gaps. For example, the honeycomb structure 23 may be constructed by densely arranging multiple rectangular tubes having a square, hexagonal, or triangular cross section. In this case, the sides of adjacent rectangular tubes are in contact with each other, thereby realizing a honeycomb structure 23 in which multiple rectangular tubes are densely arranged. Alternatively, the honeycomb structure 23 may be constructed by arranging multiple cylindrical bodies as densely as possible. Among these, the outer-tank panel 2 formed by sandwiching a honeycomb structure 23 in which honeycomb hollow columns 24 having a regular hexagonal cross section are honeycomb-arranged between inner plates 21 and outer plates 22 is preferred because it is most easily rigid and can easily accommodate larger tank capacities.

[0024] [Example of outer tank panel manufacturing] Next, a preferred manufacturing example of the outer-tub panel 2 will be described with reference to Figures 4 and 5. Here, an example is shown in which the outer plate 22 is formed of a collection of hexagonal lid pieces 25 (lid pieces) individually fixed to the second open end 242 of each honeycomb hollow column 24. Figure 4 is a diagram showing the manufacturing process of the outer-tub panel 2, and is a perspective view showing the honeycomb hollow column 24, inner plate 21, and hexagonal lid piece 25. Figure 5 is a plan view of the outer-tub panel 2 seen from the outer plate 22 side.

[0025] First, a plurality of honeycomb hollow columns 24 are fixed to the inner plate 21 in a honeycomb arrangement. The inner plate 21 is previously bent to have the shape of a spherical piece of a predetermined size that will form part of the outer tank 11. Since the size of the outer tank panel 2 is smaller than the size of the tank body 10, the bending of one inner plate 21 is a bending process with a small curvature. The first open end 241 of the honeycomb hollow columns 24 is fixed to the inner plate 21 by welding.

[0026] Each honeycomb hollow column 24 is formed by combining a pair of half pieces 24A. One half piece 24A has three of the six side surfaces of the honeycomb hollow column 24. It is desirable to provide a groove for welding at the upper and lower ends of the half pieces 24A. As an example of assembly, first, one half piece 24A is placed upright on the inner plate 21, and the lower end of the half piece 24A is welded to the inner plate 21. In Figure 4, the welded portion is illustrated as a welded portion WE. The welded portion WE may also be formed by fillet welding without groove preparation.

[0027] Next, the other half piece 24A is placed against the already fixed half piece 24A so as to form one honeycomb hollow column 24. The lower end of the other half piece 24A is welded to the inner plate 21 to form a weld WE. Furthermore, the side edge 243 of one opposing half piece 24A is welded to the side edge 243 of the other half piece 24A to form a weld WE that fastens the half pieces 24A together. The side edges 243 of the half pieces 24A are desirably shaped so that a natural groove is formed where the one and other side edges 243 butt together. Alternatively, a pair of half pieces 24A may be welded together first to form a honeycomb hollow column 24, and then the honeycomb hollow column 24 may be welded to the inner plate 21.

[0028] Once one honeycomb hollow pillar 24 is formed, another honeycomb hollow pillar 24 is formed adjacent to it in the same procedure. Ultimately, as shown in FIG. 5, a plurality of honeycomb hollow pillars 24 are densely arranged in a honeycomb pattern on the inner plate 21, forming a honeycomb structure 23. There may be areas near the periphery of the inner plate 21 where a single honeycomb hollow pillar 24 does not fit. In such areas, only half pieces 24A can be placed, as shown in FIG. 5. Alternatively, these areas may be left empty, and a honeycomb hollow pillar 24 can be inserted after the inner plate 21 and the inner plate 21 of the other outer-shell panel 2 are welded together.

[0029] Thereafter, a hexagonal lid piece 25 is fixed to the second open end 242 of each honeycomb hollow column 24. The hexagonal lid piece 25 is a flat plate having a hexagonal shape in plan view and sized to close the opening portion of the second open end 242. The hexagonal lid piece 25 can be fixed by welding using a groove formed in the second open end 242 or a groove formed on the side edge of the hexagonal lid piece 25. Instead of welding, the hexagonal lid piece 25 may be fixed to the second open end 242 using a fastener such as a fastening bolt.

[0030] Hexagonal cover pieces 25 are fixed to all of the honeycomb hollow columns 24 fixed to the inner plate 21, and the assembly of these hexagonal cover pieces 25 forms the outer plate 22 of the outer tank panel 2. In order to improve the strength of the outer plate 22 consisting of the assembly of hexagonal cover pieces 25, it is desirable to form a welded joint WE by welding the edges of adjacent hexagonal cover pieces 25 together, as shown in Figure 5.

[0031] The following shows an example of the dimensions of each part constituting the outer tank panel 2. The thickness t1 of the inner plate 21 is desirably a thickness that allows easy bending and butt welding to adjacent inner plates 21, and can be selected, for example, from a range of 15 mm to 40 mm. The thickness t2 of the outer plate 22, i.e., the hexagonal lid piece 25, can be selected, for example, from a range of 10 mm to 30 mm. The thickness t3 of the honeycomb hollow pillars 24 can be selected from a range of approximately 8 mm to 15 mm, and the height h of the honeycomb hollow pillars 24 can be selected from a range of 100 mm to 200 mm. The width w of one honeycomb hollow pillar 24 can be set to approximately 2.0 m to 3.0 m, depending on the diameter of the tank body 10.

[0032] As described above, in this embodiment, the outer tank panel 2 used as a segment of the outer tank 11 has a sandwich structure composed of a honeycomb structure 23 consisting of an inner plate 21, an outer plate 22, and multiple honeycomb hollow columns 24. The outer tank panel 2 with such a sandwich structure is lightweight due to the use of multiple honeycomb hollow columns 24 with hollow portions, while having high rigidity due to the honeycomb structure. Furthermore, processing such as spherical machining of the outer tank panel 2 can be performed on the inner plate 21 or the outer plate 22 alone, and welding can be performed on adjacent inner plates 21 or outer plates 22. Furthermore, the rigidity of the outer tank panel 2 can be ensured by the honeycomb-arranged honeycomb hollow columns 24, allowing the thickness of the inner plate 21 and the outer plate 22 to be reduced. Therefore, a cryogenic liquefied gas tank 1 with excellent processability and assembly properties can be provided.

[0033] [How to build a tank] FIG. 6 is a schematic diagram illustrating an example of a method for constructing a cryogenic liquefied gas tank 1. Here, the procedure for constructing the tank body 10 is mainly shown. FIG. 6 divides the work into work on the factory side and work on the tank installation site side. In the factory, work is performed in process S11, in which multiple inner tank panels that will become segments of the inner tank 12 are fabricated, and in process S12, in which outer tank panel intermediates 20, which are intermediate products before the outer tank panel 2 is completed, are fabricated. At the tank installation site, work is performed in process S21, in which the inner tank 12 is assembled using the inner tank panels, and in process S22, in which the outer tank 11 is assembled using the outer tank panel intermediates 20.

[0034] In step S11, inner tank panels are fabricated by bending rectangular flat plates of a predetermined size, made of, for example, stainless steel, so as to fit the spherical diameter of the inner tank 12. The required number of fabricated inner tank panels are transported to the tank installation site. In step S21, the prepared inner tank panels are assembled and welded one after another to form a spherical shape, and the inner tank 12 is assembled. The method of constructing the inner tank 12 is the same as before, so details thereof will be omitted.

[0035] In step S12, the inner plate 21 and honeycomb hollow columns 24 that constitute the outer tank panel 2 are prepared. The inner plate 21 is a rectangular flat plate of a predetermined size made of, for example, carbon steel. The inner plate 21 is bent into a spherical piece so as to have a spherical surface that fits the inner diameter of the outer tank 11. The honeycomb hollow columns 24 are made of, for example, carbon steel, and are hexagonal tubular bodies having a first open end 241 that is fixed to the inner plate 21 and a second open end 242 that is fixed to the outer plate 22, as shown in FIG. 4.

[0036] When fabricating the outer-shell panel intermediate 20, multiple honeycomb hollow columns 24 are arranged in a honeycomb pattern on the convex surface of the bent inner plate 21, and their first open ends 241 are welded to each other. When a single honeycomb hollow column 24 is formed from a pair of half pieces 24A, as shown in FIG. 4, the pair of half pieces 24A may be welded together to form the honeycomb hollow column 24, and then the honeycomb hollow column 24 may be welded to the inner plate 21. Alternatively, each half piece 24A may be welded to the inner plate 21. The required number of honeycomb hollow columns 24 are fixed to the inner plate 21 to form the honeycomb structure 23, thereby completing fabrication of the outer-shell panel intermediate 20. In step S12, the hexagonal lid pieces 25 constituting the outer plate 22 are not attached to the second open ends 242 of the honeycomb hollow columns 24. The manufactured outer tank panel intermediate 20 is carried to the tank installation site.

[0037] The assembly of the outer tank 11 in step S22 includes step S23 of welding the inner plates 21 of adjacent outer tank panel intermediates 20 together, and step S24 of welding and fixing the hexagonal lid pieces 25 to the honeycomb hollow columns 24. In step S23, multiple outer tank panel intermediates 20 are assembled into a spherical shape to surround the inner tank 12, and the side edges of adjacent inner plates 21 are joined together, for example, by butt welding. Figure 6 simply shows a state in which three outer tank panel intermediates 20 are joined together at welds WE. In reality, the joined outer tank panel intermediates 20 have a spherically curved shape that fits the shape of the outer tank 11. The outer tank panel intermediates 20 are assembled into a spherical shape in such a way that adjacent inner plates 21 do not form a cross joint.

[0038] In step S24, a hexagonal lid piece 25 is prepared for each honeycomb hollow column 24. The hexagonal lid piece 25 is fixed to each second open end 242 of the honeycomb hollow column 24 by welding. Furthermore, as shown in FIG. 5, adjacent hexagonal lid pieces 25 are also fixed by welding. Through the above steps, the outer vessel 11 is produced. If there is a portion near the periphery of the inner plate 21 where a honeycomb hollow column 24 is not installed, the honeycomb hollow column 24 is welded so that it straddles the adjacent inner plate 21. At this time, it is desirable to remove scallops so that the welded portion WE between the inner plates 21 and the welded portion WE between the honeycomb hollow column 24 and the inner plate 21 do not overlap.

[0039] According to the method for constructing a cryogenic liquefied gas tank 1 described above, part of the construction work for the outer tank 11 using the outer tank panel 2 having a sandwich structure composed of the inner plate 21, the outer plate 22, and the honeycomb structure 23 can be performed in a factory, with the remaining work being performed at the tank installation site. In other words, because the outer tank panel intermediate 20 is manufactured in a factory, the workability of manufacturing the outer tank panel 2 is improved, and welding work at the tank installation site can be reduced. As a result, the workability of tank construction can be improved. Furthermore, the outer tank 11 using the outer tank panel 2 having a sandwich structure is lightweight and easy to bend and weld, while also having the strength to withstand large external vacuum pressure. Therefore, the cryogenic liquefied gas tank 1 of this embodiment is suitable, for example, as a large-capacity tank employing a vacuum insulation system for storing liquefied hydrogen gas.

[0040] Summary of this disclosure The specific embodiments described above include disclosures having the following configurations.

[0041] A low-temperature liquefied gas tank according to one aspect of the present disclosure comprises an inner tank for storing low-temperature liquefied gas, an outer tank consisting of an assembly of multiple panels surrounding the inner tank, and a vacuum layer between the inner tank and the outer tank, and the panels include inner and outer plates facing each other at a predetermined interval, and multiple cylindrical bodies arranged between the inner and outer plates.

[0042] According to this cryogenic liquefied gas tank, a sandwich-structured panel consisting of an inner plate, an outer plate, and multiple cylindrical bodies is used as a constituent member of the outer tank. Because multiple cylindrical bodies are used, this sandwich-structured panel is lightweight yet highly rigid. Furthermore, processing such as spherical processing of the panel can be performed on the inner plate or outer plate alone, while welding and other connections can be performed on adjacent inner plates or outer plates. Furthermore, because the panel's rigidity is ensured by the multiple cylindrical bodies, the inner and outer plates can be made thinner. Therefore, a cryogenic liquefied gas tank with excellent panel workability and assembly ease can be provided.

[0043] In the above-mentioned low-temperature liquefied gas tank, it is desirable that the cylindrical body has a first opening end that is fixed to the inner plate and a second opening end that is fixed to the outer plate, the inner plate being formed from a plate material to which the first opening ends of the multiple cylindrical bodies can be fixed, and the outer plate being formed from a collection of lid pieces that are individually fixed to the second opening ends of each of the cylindrical bodies.

[0044] With this cryogenic liquefied gas tank, the outer plate is made up of a set of lids fixed to the individual cylindrical bodies, which makes it easier to join the outer plate and the cylindrical bodies than when a single outer plate is used. Also, it is possible to construct a tank with excellent workability, for example by fabricating a panel intermediate in a factory, with multiple cylindrical bodies attached to an inner plate, and then assembling the panel intermediate at the tank installation site and attaching lid pieces to the second open ends of the cylindrical bodies to create the outer tank.

[0045] In the above-mentioned low-temperature liquefied gas tank, it is desirable that the cylindrical body is a rectangular cylinder, and that the rectangular cylinder has a shape that allows a plurality of such cylinders to be arranged without gaps.

[0046] With this low-temperature liquefied gas tank, the outer tank panel can have a honeycomb sandwich structure, in which a honeycomb-arranged rectangular cylinder is sandwiched between inner and outer plates. This increases the rigidity of the panel, making it easier to accommodate larger tank capacities.

[0047] In particular, it is desirable that the rectangular tube is a honeycomb hollow column having a regular hexagonal cross section, which can further increase the rigidity of the panel.

[0048] A method for constructing a cryogenic liquefied gas tank according to another aspect of the present disclosure is a method for constructing a cryogenic liquefied gas tank comprising an inner tank for storing cryogenic liquefied gas, an outer tank surrounding the inner tank, and a vacuum layer between the inner tank and the outer tank, comprising the steps of: preparing a cylindrical body having a first opening end at one end and a second opening end at the other end; fabricating the inner tank; fabricating a plurality of panel intermediates by fixing the first opening ends of a plurality of the cylindrical bodies to an inner plate made of spherical pieces of a predetermined size; assembling the plurality of panel intermediates to surround the inner tank by joining the inner plates together; and fabricating the outer tank by fixing a cover piece to each of the second opening ends of the cylindrical body.

[0049] According to this method for constructing a cryogenic liquefied gas tank, part of the work of constructing the outer tank can be done in a factory, and the remaining work can be done at the tank installation site, improving the workability of tank construction. That is, a panel intermediate body with multiple cylindrical bodies attached to an inner plate is fabricated in a factory and transported to the tank installation site. The inner plates are then joined together to assemble the panel intermediate body into the shape of the outer tank, and the outer tank can be produced by attaching a cover piece that constitutes the outer plate to the second open end. [Explanation of symbols]

[0050] 1. Cryogenic liquefied gas tank 11 Outer tank 12 Inner tank 13 Vacuum insulation layer (vacuum layer) 2 Outer tank panel (panel) 20 Outer tank panel intermediate body (panel intermediate body) 21 Inner plate 22 Outer Panel 23 Honeycomb structure 24 Honeycomb hollow column (square cylinder) 241 1st open end 242 2nd open end 25 Hexagonal lid piece (lid piece) LG cryogenic liquefied gas

Claims

1. an inner tank for storing low-temperature liquefied gas; an outer tub comprising an assembly of a plurality of panels and surrounding the inner tub; a vacuum layer between the inner tank and the outer tank, The panel includes an inner plate and an outer plate facing each other at a predetermined interval, and a plurality of cylindrical bodies disposed between the inner plate and the outer plate, the inner plate is a plate member to which one ends of the plurality of cylindrical bodies are fixed, The outer plate is a plate material fixed to the other end of each of the cylindrical bodies.

2. An inner tank for storing low-temperature liquefied gas; an outer tub comprising an assembly of a plurality of panels and surrounding the inner tub; a vacuum layer between the inner tank and the outer tank, The panel is a cryogenic liquefied gas tank including an inner plate and an outer plate facing each other at a predetermined interval, and a plurality of cylindrical bodies disposed between the inner plate and the outer plate, the cylindrical body has a first open end that is fixed to the inner plate and a second open end that is fixed to the outer plate, the inner plate is formed of a plate material to which the first open ends of the plurality of cylindrical bodies can be fixed, A cryogenic liquefied gas tank, wherein the outer plate is formed by a collection of lid pieces individually fixed to the second open end of each of the cylindrical bodies.

3. The low-temperature liquefied gas tank according to claim 1 or 2, The cylindrical body is a rectangular cylinder having a shape that allows multiple rectangular cylinders to be arranged without gaps between them.

4. The low-temperature liquefied gas tank according to claim 3, A low-temperature liquefied gas tank, wherein the rectangular cylindrical body is a honeycomb hollow pillar having a regular hexagonal cross section.

5. A method for constructing a cryogenic liquefied gas tank including an inner tank for storing cryogenic liquefied gas, an outer tank surrounding the inner tank, and a vacuum layer between the inner tank and the outer tank, comprising: A cylindrical body having a first open end on one end side and a second open end on the other end side is prepared; The inner tank is prepared, a plurality of panel intermediates are fabricated by fixing the first open ends of the plurality of cylindrical bodies to an inner plate made of a spherical piece of a predetermined size; A method for constructing a cryogenic liquefied gas tank, comprising assembling a plurality of panel intermediates to surround the inner tank by joining the inner plates together, and creating the outer tank by fixing a cover piece to each of the second opening ends of the cylindrical body.

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