Multi-hull tanks and vessels

Abstract

This multi-shell tank comprises: an inner tank that retains liquefied gas; a single or multiple outer tanks that are arranged with a gap outside the inner tank so as to surround the inner tank; and a planar insulating material that is fixed to two or more surfaces among the outer surface of the inner tank, the inner surface of the outer tanks, and the outer surface of the outer tanks so as to cover the surfaces, and inhibits thermal radiation, thermal conduction, and thermal convection. The tank wall has high thermal insulation properties that are achieved without the need for high vacuum between the inner tank and the outer tank.

Description

[Technical field]

[0001] The present invention relates to a multi-hull tank and a ship equipped with a multi-hull tank. [Background technology]

[0002] Conventionally, ships equipped with multi-shell tanks as cargo tanks have been known. The multi-shell tank has multiple tanks including an inner tank for storing low-temperature fluid cargo such as liquefied gas, and an outer tank covering the inner tank. Multi-shell tanks are known to have vacuum spaces formed between the tanks to improve thermal insulation. Patent Document 1 discloses a double-shell tank to be installed on a ship.

[0003] The double-shell tank disclosed in Patent Document 1 includes an inner tank for storing liquefied gas, an outer tank that surrounds the inner tank and forms a vacuum space between the inner tank and the outer tank, at least one metal sheet attached to the inner tank so that at least a portion of the metal sheet faces the bottom surface of the inner tank, an adsorbent for gas molecules placed on the metal sheet, and a heat insulating sheet that covers the inner tank and the metal sheet. The heat insulating sheet includes radiation shield films and sheet-like spacers with low thermal conductivity that are stacked alternately. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication WO2019 / 078048 Summary of the Invention [Problem to be solved by the invention]

[0005] In the double-shell tank of Patent Document 1, a high vacuum is created between the inner and outer tanks to prevent the intrusion of radiant heat and inhibit natural convection, thereby achieving a high thermal insulation effect. However, it takes time to evacuate the space between the tanks, which have a huge volume, which can be one of the factors that lengthen the time required for manufacturing and maintenance. In addition, the tank wall needs to be sufficiently thick to be vacuum-resistant, which can be one of the factors that increase the tank weight. In addition, it is necessary to add many reinforcing members to the tank, and the complicated structure makes it very difficult to manufacture.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a multi-shell tank for storing liquefied gas with high thermal insulation performance without relying on creating a high vacuum between the inner and outer shells. [Means for solving the problem]

[0007] A multi-shell tank according to one embodiment of the present invention comprises: an inner tank for storing liquefied gas; a single or multiple outer tanks arranged outside the inner tank with a gap therebetween so as to surround the inner tank; a planar heat insulating material fixed to two or more of the outer surface of the inner tank, the inner surface of the outer tank, and the outer surface of the outer tank so as to cover the two or more surfaces and inhibit heat conduction and heat convection; The space between each tank is filled with gas.

[0008] In addition, a ship according to one aspect of the present invention includes: The hull and The multi-shell tank is mounted on the hull.

[0009] According to the multi-shell tank and ship of the above configuration, thermal conduction and thermal convection are inhibited by two or more insulating layers made of planar insulation material, so that the tank walls of the multi-shell tank have sufficiently high insulating performance even when gas is filled between the tanks. Effect of the Invention

[0010] According to the present invention, in a multi-shell tank for storing liquefied gas, high thermal insulation performance can be provided without relying on creating a high vacuum between the inner and outer shells. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a side view showing the overall configuration of a ship equipped with a multi-shell tank according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view illustrating the structure of a multi-shell tank installed on a ship. [Diagram 3] FIG. 3 is a cross-sectional view of the multi-shell tank according to the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating a method for fixing the sheet insulating material. [Diagram 5] FIG. 5 is a cross-sectional view of a first example of a multi-shell tank in which granular insulating material is filled between the tanks. [Figure 6] FIG. 6 is a cross-sectional view of a multi-shell tank according to a second embodiment. [Figure 7] FIG. 7 is a cross-sectional view of a multi-shell tank according to a third embodiment. [Figure 8] FIG. 8 is a cross-sectional view of a multi-shell tank according to a fourth embodiment. [Figure 9] FIG. 9 is a cross-sectional view of a multi-shell tank according to a fifth embodiment. [Figure 10] FIG. 10 is a cross-sectional view of a multi-shell tank according to the sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] FIG. 1 shows a ship 1 equipped with a multi-shell tank 3 according to one embodiment of the present invention. The ship 1 includes a hull 2 ​​and two multi-shell tanks 3 mounted on the hull 2. The multi-shell tanks 3 are cargo tanks for transporting cryogenic fluids. In this embodiment, the multi-shell tanks 3 are lined up in the longitudinal direction of the ship, but may be lined up in the transverse direction if the ship is wide. Furthermore, the number of multi-shell tanks 3 mounted on the hull 2 ​​may be one, or three or more.

[0013] The two multi-shell tanks 3 have substantially the same structure. In this embodiment, the multi-shell tanks 3 are configured as double-shell tanks. As shown in FIG. 2, each multi-shell tank 3 includes an inner tank 4 for storing cargo and an outer tank 5 for enclosing the inner tank 4. The inner tank 4 and the outer tank 5 are spaced apart from each other at approximately equal intervals, and a tank gap 30 is formed between the inner tank 4 and the outer tank 5 in the thickness direction of the tank wall. The insulating structure of the tank wall of the multi-shell tank 3 will be described in detail later.

[0014] The cargo may be liquefied gas such as liquefied petroleum gas (LPG, about -45°C), liquefied ethylene gas (LEG, about -100°C), liquefied natural gas (LNG, about -160°C), liquefied oxygen (LO2, about -180°C), liquefied hydrogen (LH2, about -250°C), and liquefied helium (LHe, about -270°C). However, the cargo does not necessarily have to be liquid and may be gas.

[0015] The inner tank 4 includes an inner tank main body 41 having a cylindrical shape elongated in the horizontal direction, and an inner tank dome 42 protruding upward from the inner tank main body 41. In this embodiment, the axial direction of the inner tank main body 41 is parallel to the longitudinal direction of the ship. In this embodiment, the axial direction of the inner tank dome 42 is parallel to the vertical direction, but may be slightly inclined with respect to the vertical direction.

[0016] The outer tank 5 includes an outer tank body 51 having a cylindrical shape elongated in the horizontal direction, and an outer tank dome 52 protruding upward from the outer tank body 51. The outer tank body 51 surrounds the inner tank body 41. The outer tank dome 52 surrounds the inner tank dome 42. The axial direction of the outer tank body 51 is parallel to the ship length direction, similar to the inner tank body 41, and the axial direction of the outer tank dome 52 is parallel to the vertical direction, similar to the inner tank dome 42. However, the inner tank body 41 and the outer tank body 51 do not necessarily have to be cylindrical in shape elongated in the horizontal direction, and may be cylindrical in shape elongated in the vertical direction. Alternatively, the inner tank body 41 and the outer tank body 51 may be spherical, cubic, or rectangular.

[0017] Two cargo holds 21 that open upward are formed in the hull 2. The cargo holds 21 are lined up in the longitudinal direction of the ship and are separated from each other by a bulkhead 22. The lower part of a multi-shell tank 3 is inserted into each cargo hold 21.

[0018] A pair of saddles 25 spaced apart from each other in the ship's length direction are provided inside each cargo hold 21. The saddles 25 support the outer tank body 51 of the outer tank 5 of the multi-shell tank 3. A pair of support members 35 supporting the inner tank body 41 are provided between the inner tank 4 and the outer tank 5 of the multi-shell tank 3. In this embodiment, the support members 35 are provided at the same position as the saddles 25, but the support members 35 may be provided at a position different from the saddles 25.

[0019] A tank cover 6 is disposed above each multi-shell tank 3. Each tank cover 6 covers the corresponding multi-shell tank 3 from above, and forms a holding space 7 filled with inert gas between the tank cover 6 and the hull 2. The outer tank body 51 of the outer tank 5 described above is located below the tank cover 6, and the outer tank dome 52 penetrates the tank cover 6.

[0020] [Thermal insulation structure of multi-shell tank 3] Here, the heat insulating structure provided in the multi-shell tank 3 having the above-mentioned configuration will be described. Fig. 3 is a cross-sectional view of the multi-shell tank 3 according to the first example. As shown in Fig. 3, the multi-shell tank 3 includes an inner tank 4 for storing liquefied gas, a single- or multiple-layer outer tank 5 arranged with a gap outside the inner tank 4 so as to surround the inner tank 4, and a planar heat insulating material 9 provided so as to cover two or more surfaces among the outer surface of the inner tank 4, the inner surface of the outer tank 5, and the outer surface of the outer tank 5, and inhibits heat radiation, heat conduction, and heat convection.

[0021] The planar heat insulating material 9 is in the form of a panel. The planar heat insulating material 9 has a thickness of 0.01 to 1 times the gap between the inner tank 4 and the outer tank 5 (first outer tank 5A) disposed immediately outside the inner tank 4. The planar heat insulating material 9 may be a multi-layer panel in which a heat insulating material is sandwiched between plate-shaped base materials. However, the planar heat insulating material 9 is not limited to a panel shape, and may be in the form of a sheet. Examples of such planar heat insulating material 9 include a urethane foam panel, an aerogel sheet, and a sheet-shaped glass wool.

[0022] The sheet insulation material 9 is fixed to the surface of the inner tank 4 or the outer tank 5 by a fixing device. As shown in FIG. 4, a metal base plate 81 is joined to the inner tank 4 (or the outer tank 5) by welding or the like. A stud bolt 82 is joined to this base plate 81 by a screw structure, welding or the like. The material of the stud bolt 82 is not particularly limited, but it is preferable that it is a material with low thermal conductivity such as glass fiber reinforced plastic (GFRP). The stud bolt 82 is inserted into a hole provided in the sheet insulation material 9 and screwed into a nut 83. In this example, the stud bolt 82 and the nut 83 correspond to the fixing device. However, the sheet insulation material 9 may be fixed to the surface of the inner tank 4 or the outer tank 5 by a self-adhesive function such as an adhesive or urethane foam.

[0023] A low-temperature gas (e.g., gas vaporized from liquefied gas of cargo) is filled in the space between the inner tank 4 and the outer tank 5 (first outer tank 5A) located immediately outside the inner tank 4 (first space between the tanks 30A). The gas filled in the first space between the tanks 30A may be gas vaporized from the inner tank 4 by communicating the inner tank 4 with the first space between the tanks 30A.

[0024] The pressure in the first space between the tanks 30A is 1 kPa or more. The pressure in the first space between the tanks 30A is sufficiently high compared to conventional vacuum insulation. The pressure in the first space between the tanks 30A may be 1 kPa or more and a negative pressure relative to atmospheric pressure. In this case, the degree of vacuum in the first space between the tanks 30A is sufficiently low compared to conventional vacuum insulation.

[0025] A gap 31 is provided in the first tank space 30A in the thickness direction of the tank wall of the multi-shell tank 3. No planar heat insulating material 9 is present in the gap 31. This gap 31 is used as a working space and has a sufficient size for the work. The gap 31 may be used for arranging piping. The size of the gap 31 in the thickness direction of the tank wall is, for example, 0.1 to 0.99 times the gap between the tanks 30. When the gap 31 is made large, a worker can enter the gap 31 during construction to fix the planar heat insulating material 9 to the inner tank 4 and the outer tank 5. In addition, a worker can enter the gap 31 during maintenance to inspect the planar heat insulating material 9 or perform maintenance on the planar heat insulating material 9. In this embodiment, each of the planar heat insulating materials 9 is fixed to the surface of the inner tank 4 or the outer tank 5 by a fixing device, so that it is particularly useful to provide the gap 31 for moving the planar heat insulating material 9 or handling the fixing device. On the other hand, if the sheet insulation material 9 and the gap 31 are made large, the outer tank 5 will become larger, which may affect costs due to the increased installation space and tank weight. With the multi-shell tank 3, the thickness of the sheet insulation material 9, the distance between the tanks 30, and the gap 31 can be flexibly selected according to the required heat insulation performance and the restrictions on installation space.

[0026] The gap 31 between the first tanks 30A may be filled with a granular insulating material 95 such as perlite as shown in Fig. 5. This can further improve the insulating performance of the multi-shell tank 3.

[0027] Hereinafter, an example of the arrangement of the planar insulating material 9 in the multi-shell tank 3 will be described. Desirably, the planar insulating material 9 includes a first planar insulating material provided so as to cover either the inner surface of the first outer vessel 5A, which is located immediately outside the inner vessel 4 of the outer vessel 5, or the outer surface of the first outer vessel 5A, and a second planar insulating material provided so as to cover the outer surface of the inner vessel 4, the inner surface of the outer vessel 5, and the outer surface of the outer vessel 5 that are not covered by the first planar insulating material.

[0028] The heat insulating performance of the first and second planar insulating materials may differ depending on the location of the planar insulating material 9. By appropriately adjusting the type and thickness of the first and second planar insulating materials depending on the temperature and atmospheric conditions of the first and second inter-vessel spaces 30A and 30B, the multi-shell tank 3 can have sufficiently high insulating performance even if the inter-vessel space 30 is not a high vacuum.

[0029] <Example 1> The multi-shell tank 3A shown in Fig. 3 is a double-shell tank, and has an inner tank 4 and a single-layer outer tank 5. A sheet-shaped insulating material 9 is fixed to the outer surface of the inner tank 4 so as to cover the outer surface of the inner tank 4. In addition, a sheet-shaped insulating material 9 is fixed to the outer surface of the outer tank 5 so as to cover the outer surface of the outer tank 5.

[0030] <Second Example> The multi-shell tank 3B shown in Fig. 6 is a double-shell tank, and has an inner vessel 4 and a single-layer outer vessel 5. A sheet-shaped insulating material 9 is fixed to the inner surface of the outer vessel 5 so as to cover the inner surface of the outer vessel 5. In addition, a sheet-shaped insulating material 9 is fixed to the outer surface of the outer vessel 5 so as to cover the outer surface of the outer vessel 5.

[0031] <Example 3> The multi-shell tank 3C shown in Fig. 7 is a double-shell tank, and has an inner tank 4 and a single-layer outer tank 5. A sheet-shaped insulating material 9 is fixed to the inner surface of the inner tank 4 so as to cover the outer surface of the inner tank 4. A sheet-shaped insulating material 9 is fixed to the inner surface of the outer tank 5 so as to cover the inner surface of the outer tank 5. Furthermore, a sheet-shaped insulating material 9 is fixed to the outer surface of the outer tank 5 so as to cover the outer surface of the outer tank 5.

[0032] <Example 4> 8 is a triple-shell tank having an inner tank 4 and a double outer tank 5. The double outer tank 5 is composed of a first outer tank 5A disposed immediately outside the inner tank 4 and a second outer tank 5B disposed outside the first outer tank 5A. The space between the first outer tank 5A and the second outer tank 5B (the second space between the tanks 30B) is filled with an inert gas (such as nitrogen) having a higher boiling point than the gas filled in the first space between the tanks 30A.

[0033] In the multi-shell tank 3D, a planar insulating material 9 is fixed to the outer surface of the inner tank 4 so as to cover the outer surface of the inner tank 4. A planar insulating material 9 is fixed to the outer surface of the first outer tank 5A so as to cover the outer surface of the first outer tank 5A. Furthermore, a planar insulating material 9 is fixed to the outer surface of the second outer tank 5B so as to cover the outer surface of the second outer tank 5B. In the multi-shell tank 3D, instead of the planar insulating material 9 covering the outer surface of the first outer tank 5A, a planar insulating material 9 may be fixed to the inner surface of the first outer tank 5A so as to cover the inner surface of the first outer tank 5A. Also, in the multi-shell tank 3D, instead of the planar insulating material 9 covering the outer surface of the second outer tank 5B, a planar insulating material 9 may be fixed to the inner surface of the second outer tank 5B so as to cover the inner surface of the second outer tank 5B.

[0034] <5th Example> The multi-shell tank 3E shown in Fig. 9 is a triple-shell tank, and has an inner tank 4 and a double outer tank 5 (a first outer tank 5A and a second outer tank 5B). In this multi-shell tank 3E, a planar heat insulating material 9 is fixed to the inner surface of the first outer tank 5A so as to cover the inner surface of the first outer tank 5A. Furthermore, a planar heat insulating material 9 is fixed to the outer surface of the first outer tank 5A so as to cover the inner surface of the first outer tank 5A. In the multi-shell tank 3E, in addition to the inner and outer surfaces of the first outer tank 5A, at least one of the outer surface of the inner tank 4, the inner surface of the second outer tank 5B, and the outer surface of the second outer tank 5B may be covered with the planar heat insulating material 9.

[0035] <Example 6> The multi-shell tank 3F shown in FIG. 10 is a triple-shell tank, and has an inner tank 4 and a double outer tank 5 (a first outer tank 5A and a second outer tank 5B). In this multi-shell tank 3F, a planar heat insulating material 9 is fixed to the inner surface of the first outer tank 5A so as to cover the inner surface of the first outer tank 5A. Furthermore, a planar heat insulating material 9 is fixed to the inner surface of the second outer tank 5B so as to cover the inner surface of the second outer tank 5B. In the multi-shell tank 3F, instead of the planar heat insulating material 9 covering the inner surface of the first outer tank 5A, a planar heat insulating material 9 may be fixed to the outer surface of the first outer tank 5A so as to cover the outer surface of the first outer tank 5A. Also, in the multi-shell tank 3F, instead of the planar heat insulating material 9 covering the inner surface of the second outer tank 5B, a planar heat insulating material 9 may be fixed to the outer surface of the second outer tank 5B so as to cover the outer surface of the second outer tank 5B. In addition, in the multi-shell tank 3F, instead of the sheet insulation material 9 covering the inner surface of the second outer tank 5B, a sheet insulation material 9 may be fixed to the outer surface of the inner tank 4 so as to cover the outer surface of the inner tank 4.

[0036] [Summary] As described above, the multi-shell tank 3 of this embodiment comprises an inner tank 4 for storing liquefied gas, a single- or multiple-layer outer tank 5 arranged with a gap outside the inner tank 4 so as to surround the inner tank 4, and planar insulation material 9 fixed to the outer surface of the inner tank 4, the inner surface of the outer tank 5, and the outer surface of the outer tank 5 so as to cover two or more of these surfaces and inhibit heat conduction and heat convection, and is characterized in that the space between each tank 30 is filled with gas.

[0037] When the outer vessel 5 has a single layer, the layout of the sheet insulating material 9 may be exemplified as follows. (First Example) A sheet-shaped heat insulating material 9 is provided so as to cover the outer surface of the inner vessel 4 and the inner surface of the outer vessel 5. (Second Example) A sheet-shaped heat insulating material 9 is provided so as to cover two surfaces, that is, the outer surface of the inner vessel 4 and the outer surface of the outer vessel 5. (Third Example) A sheet-shaped heat insulating material 9 is provided so as to cover two surfaces, the inner surface of the outer vessel 5 and the outer surface of the outer vessel 5 . (Fourth Example) A sheet heat insulating material 9 is provided so as to cover three surfaces, namely, the outer surface of the inner vessel 4, the inner surface of the outer vessel 5, and the outer surface of the outer vessel 5.

[0038] The ship 1 according to this embodiment is characterized by including a hull 2 ​​and a multi-shell tank 3 mounted on the hull 2.

[0039] In the multi-shell tank 3 and ship 1 configured as above, the two insulating layers made of the sheet insulation material 9 inhibit thermal conduction and thermal convection, so that the tank wall of the multi-shell tank 3 has sufficiently high insulating performance even when gas is filled between the tanks 30. Furthermore, in the multi-shell tank 3 configured as above, the sheet insulation material 9 is fixed to the surface of the inner tank 4 or the outer tank 5, so that even if the inner tank 4 and the outer tank 5 thermally shrink, the sheet insulation material 9 is unlikely to shift or become biased in position relative to the surface to which it is attached, and the reliability of the insulating performance in each part of the tank wall can be improved.

[0040] In the multi-shell tank 3 having the above-mentioned configuration, the pressure in the space between the inner tank 4 and the outer tank 5 (first outer tank 5A) disposed immediately outside the inner tank 4 may be 1 kPa or more.

[0041] Furthermore, the pressure in the first tank space 30A may be negative relative to atmospheric pressure, which allows the tank wall of the multi-shell tank 3 to have even higher heat insulating performance.

[0042] In the multi-shell tank 3 having the above-mentioned configuration, the sheet insulating material 9 may be in the form of a panel.

[0043] In the multi-shell tank 3 having the above-described configuration, the sheet insulation material 9 may be fixed to the surface covered by the sheet insulation material 9 by fasteners (a stud bolt 82 and a nut 83).

[0044] Since the sheet insulation material 9 is fixed in place by fasteners in this manner, it can be attached and detached relatively easily, thereby simplifying on-site construction.

[0045] In the multi-shell tank 3 having the above-mentioned configuration, each of the spaces between the tanks 30 may have a working gap 31 in the thickness direction. Here, the gap 31 means a space in the space between the tanks 30 that is not occupied by the sheet insulation material 9 and through which objects other than gas (e.g., workers, piping, etc.) can pass.

[0046] By providing a gap 31 between the tanks 30 in this manner, workers can use this gap 31 during construction to install the sheet insulation 9 and perform piping work, etc., and during maintenance, inspection equipment can be introduced into this gap 31 to inspect the sheet insulation 9, or workers can use the gap 31 to replace the sheet insulation 9.

[0047] In the multi-shell tank 3 having the above-mentioned configuration, it is desirable that the planar insulation material 9 includes a first planar insulation material arranged to cover either the inner surface of the first outer vessel 5A, which is located immediately outside the inner vessel 4 of the outer vessel 5, or the outer surface of the first outer vessel 5A, and a second planar insulation material arranged to cover the outer surface of the inner vessel 4, the inner surface of the outer vessel 5, and the outer surface of the outer vessel 5 that are not covered by the first planar insulation material.

[0048] This provides intensive insulation between the inside and outside of the first outer tank 5A.

[0049] Although the preferred embodiment of the present invention has been described above, the present invention also includes modifications of the specific structure and / or details of the above embodiment without departing from the spirit of the present invention. The above configuration can be modified, for example, as follows.

[0050] For example, in the above embodiment, the multi-shell tank 3 is mounted on the ship 1, but the structure of the multi-shell tank 3 may also be applied to a tank for storing liquefied gas installed on land. [Explanation of symbols]

[0051] 1: Ship 2: Hull 3, 3A~3F: Multi-shell tank 4: Inner tank 5: Outer tank 5A: 1st outer tank 9: Sheet insulation material 30: Between tanks 31 :Void

Claims

1. an inner tank for storing liquefied gas; a single or multiple outer tanks arranged outside the inner tank with a gap therebetween so as to surround the inner tank; a planar heat insulating material fixed to two or more of the outer surface of the inner tank, the inner surface of the outer tank, and the outer surface of the outer tank so as to cover the two or more surfaces and inhibit heat conduction and heat convection; Gas is filled between each tank. Multi-hull tank.

2. The pressure between the inner tank and the outer tank disposed immediately outside the inner tank is 1 kPa or more.

2. The multi-shell tank of claim 1.

3. The planar heat insulating material is in the form of a panel.

3. A multi-shell tank according to claim 1 or 2.

4. The planar insulation material is fixed to a surface to be covered by the planar insulation material by a fixing device. The multi-shell tank according to any one of claims 1 to 3.

5. Each of the tanks has a working gap through the thickness of the tank wall. The multi-shell tank according to any one of claims 1 to 4.

6. The planar heat insulating material is a first planar insulating material provided to cover either an inner surface of a first outer tank disposed immediately outside the inner tank of the outer tank or an outer surface of the first outer tank; a second planar insulation material provided to cover an outer surface of the inner tank, an inner surface of the outer tank, and a surface of the outer tank that is not covered by the first planar insulation material, The multi-shell tank according to any one of claims 1 to 5.

7. The outer tank is single-layered, The sheet insulation material is provided so as to cover an outer surface of the inner tank and an inner surface of the outer tank. The multi-shell tank according to any one of claims 1 to 5.

8. The outer tank is single-layered, The sheet-shaped heat insulating material is provided so as to cover two surfaces, that is, an outer surface of the inner tank and an outer surface of the outer tank. The multi-shell tank according to any one of claims 1 to 5.

9. The outer tank is single-layered, The sheet insulation material is provided so as to cover two surfaces, an inner surface of the outer tank and an outer surface of the outer tank. The multi-shell tank according to any one of claims 1 to 5.

10. The outer tank is single-layered, The sheet insulation material is provided so as to cover three surfaces, which are an outer surface of the inner tank, an inner surface of the outer tank, and an outer surface of the outer tank. The multi-shell tank according to any one of claims 1 to 5.

11. The hull and and a multi-shell tank according to any one of claims 1 to 10 mounted on the hull. ship.

Images