Vertical tank

Abstract

To provide a vertical tank that includes an inner tank and an outer tank, facilitates the attachment of a laminated vacuum heat insulation sheet to the inner tank, and can restrain heat input to the inner tank.SOLUTION: A vertical liquefied hydrogen tank 1 comprises an outer tank 2, an inner tank 3 including a vertical side peripheral surface 31A, an attachment seat 5 provided on the side peripheral surface 31A, a first hook-and-loop fastener 6 arranged on the attachment seat 5, a rivet 8 for fixing the first hook-and-loop fastener 6 to the attachment seat 5, and a laminated vacuum heat insulation sheet 4 including a second hook-and-loop fastener 7 capable of being attached to and detached from the first hook-and-loop fastener 6, on one surface. The rivet 8 includes: a tip part 8A penetrating the first hook-and-loop fastener 6 in a thickness direction, and engaged with the attachment seat 5; and a head part 8B appearing on a surface of the first hook-and-loop fastener 6. The second hook-and-loop fastener 7 is attached to the first hook-and-loop fastener 6 while covering the head part 8B.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a vertical tank for storing, for example, cryogenic liquefied gas. [Background technology]

[0002] As a tank for storing low-temperature liquefied gas, a double-shell tank with an inner tank, an outer tank, and a heat insulating layer between these tanks is sometimes used. The tank shape may be a spherical shape, a horizontal type that is long in the horizontal direction, a vertical type that is long in the vertical direction, etc. Among these, from the viewpoint of reducing the installation area of ​​the tank, it is desirable to adopt a vertical tank.

[0003] For example, in the case of a tank for storing liquefied hydrogen, a vacuum insulation layer is provided between the tanks to suppress heat input from an outer tank, which uses air as a heat carrier, to an inner tank. A technology is known in which the heat input due to radiant heat is suppressed by covering the surface to be insulated that is exposed to a vacuum with a laminated vacuum insulation sheet (for example, Patent Document 1). A laminated vacuum insulation sheet is a sheet in which metal-deposited resin films and spacers are alternately laminated in multiple layers. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-79998 A Summary of the Invention [Problem to be solved by the invention]

[0005] For example, in a storage tank for liquefied hydrogen, if a vacuum is drawn between the inner and outer tanks and an insulation structure is adopted in which the inner tank is covered with a laminated vacuum insulation sheet and a radiant heat shield is applied, there is an advantage that the insulation layer between the tanks can be narrowed. In the case of a horizontal tank, the laminated vacuum insulation sheet can be installed in such a manner that the sheet's own weight is supported by the inner tank, for example by wrapping the laminated vacuum insulation sheet around the body of the horizontal inner tank. However, in the case of a vertical tank, there is a problem in that the laminated vacuum insulation sheet cannot be installed in such a way that its own weight is simply placed on the inner tank.

[0006] An object of the present disclosure is to provide a vertical tank including an inner tank and an outer tank, in which a laminated vacuum insulation sheet can be easily attached to the inner tank and heat input to the inner tank can be suppressed. [Means for solving the problem]

[0007] A vertical tank according to one aspect of the present disclosure comprises an outer tank, an inner tank arranged at a distance inside the outer tank and including a vertical side surface, a mounting seat provided on the side surface, a first hook-and-loop fastener arranged on the mounting seat, a fastener for fixing the first hook-and-loop fastener to the mounting seat, the fastener including a tip portion which penetrates the first hook-and-loop fastener in the thickness direction and engages with the mounting seat and a head portion which appears on the surface of the first hook-and-loop fastener, and a laminated vacuum insulation sheet including a second hook-and-loop fastener on one side which can be attached and detached to the first hook-and-loop fastener, and the second hook-and-loop fastener is attached to the first hook-and-loop fastener with the laminated vacuum insulation sheet covering the head. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a vertical tank including an inner tank and an outer tank, in which a laminated vacuum insulation sheet can be easily attached to the inner tank and heat input to the inner tank can be suppressed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of a vertical liquefied hydrogen tank according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a front view of the inner vessel with a portion of the laminated vacuum insulation sheet removed. [Diagram 3] 3 is a cross-sectional view taken along line III-III in FIG. 2, and is a side cross-sectional view of a portion where the laminated vacuum insulation sheet is attached to the inner vessel. [Figure 4] FIG. 4(A) is a diagram showing the installation state of the mounting seat on the side peripheral surface of the inner tank, FIG. 4(B) is a plan view of the mounting seat, and FIG. 4(C) is a cross-sectional view taken along line IVC-IVC in FIG. 4(B). [Diagram 5] 5(A) is a plan view of the surface fastener unit, and FIG. 5(B) is a cross-sectional view taken along line VB-VB of FIG. 5(A). [Figure 6] FIG. 6(A) is a view showing a state in which the hook-and-loop fastener unit is attached to the circumferential surface of the inner tank, and FIG. 6(B) is a cross-sectional view taken along line VIB-VIB in FIG. 6(A). [Figure 7] FIG. 7(A) is a diagram showing a state in which the laminated vacuum insulation sheet is attached to the peripheral surface of the inner vessel side, and FIG. 7(B) is a cross-sectional view showing a method of attaching the laminated vacuum insulation sheet. [Figure 8] FIG. 8 is a front view showing an example of installation of end laminated vacuum insulation sheets on the top and bottom of the inner vessel. [Figure 9] FIG. 9 is a cross-sectional view showing an example in which laminated vacuum insulation sheets are arranged in multiple stages in the radial direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of a vertical tank according to the present disclosure will be described in detail with reference to the drawings. In this embodiment, a vertical liquefied hydrogen tank having a double shell structure for storing liquefied hydrogen is illustrated as an example of a vertical tank. The vertical tank of the present disclosure may be a tank having a multi-shell structure including an inner tank and an outer tank, and may be, for example, a triple shell structure. In addition, the fluid to be stored may be a low-temperature liquefied gas other than liquefied hydrogen, for example, liquefied natural gas.

[0011] [Vertical tank overview] FIG. 1 is a cross-sectional view of a vertical liquefied hydrogen tank 1 according to an embodiment of the present disclosure. The vertical liquefied hydrogen tank 1 comprises an outer tank 2, an inner tank 3, and a laminated vacuum insulation sheet 4. The outer tank 2 is a sealed body made of a metal such as carbon steel. The inner tank 3 is disposed at an interval inside the outer tank 2. The inner tank 3 is a sealed body made of a metal such as a stainless steel plate, and has a storage space 3A therein for storing liquefied hydrogen. The storage space 3A of the inner tank 3 can have a capacity of, for example, 300 m 3 The capacity of the storage space 3A may be set to a class or lower. Of course, the storage space 3A may be set to a larger capacity. The inner tub 3 has a vertical side peripheral surface 31A. The side peripheral surface 31A is a cylindrical shape extending in the vertical direction. The outer tub 2 that houses the inner tub 3 also has a similar side peripheral surface.

[0012] The laminated vacuum insulation sheet 4 is attached to the inner vessel 3 so as to cover the entire outer periphery of the inner vessel 3. As the laminated vacuum insulation sheet 4, for example, a multi-layer insulation (MLI) sheet made by laminating a plastic film formed by vapor-depositing a metal such as aluminum and a spacer such as a glass fiber cloth in multiple layers can be used. The laminated vacuum insulation sheet 4 blocks radiant heat from the outer vessel 2 toward the inner vessel 3.

[0013] The space between the inner surface of the outer vessel 2 and the outer surface of the inner vessel 3 is evacuated when the vertical liquefied hydrogen tank 1 is in operation, forming a vacuum insulation layer VA that provides thermal insulation. The vacuum insulation layer VA suppresses thermal conduction and convection heat transfer between the outer vessel 2 and the inner vessel 3. Furthermore, the laminated vacuum insulation sheet 4 blocks radiant heat that cannot be blocked by the vacuum insulation layer VA. By using the vacuum insulation layer VA in combination with the laminated vacuum insulation sheet 4, the width between the outer vessel 2 and the inner vessel 3, which forms the insulated space, can be reduced, thereby making it possible to reduce the size of the vertical liquefied hydrogen tank 1.

[0014] The vertical liquefied hydrogen tank 1 is supported by a support 11 on a mounting surface GR such as the ground so that the side peripheral surface 31A is oriented vertically. The inner tank 3 is supported inside the outer tank 2 by a hanging support part 12 and a strap 13. The hanging support part 12 is a vertical support part of the inner tank 3, and connects the vicinity of the center of the body of the inner tank 3 to the vicinity of the upper end of the body of the outer tank 2. The strap 13 is a horizontal support part of the inner tank 3, and connects the vicinity of the lower end of the outer tank 2 to the vicinity of the lower end of the inner tank in the horizontal direction. Note that, although FIG. 1 shows an example in which the vertical length of the side peripheral surface 31A of the inner tank 3 is about twice the inner diameter of the inner tank 3, the side peripheral surface 31A may be longer or shorter.

[0015] Fig. 2 is a schematic front view of the inner vessel 3 with part of the laminated vacuum insulation sheet 4 removed. The inner vessel 3 includes a cylindrical body 31 having a vertical side peripheral surface 31A, a dome-shaped top 32 located at the upper end of the body 31 and bulging upward, and a dome-shaped bottom 33 located at the lower end of the body 31 and bulging downward. In Fig. 2, the entire laminated vacuum insulation sheet 4 covering the top 32 and bottom 33 and part of the laminated vacuum insulation sheet 4 covering the body 31 have been removed.

[0016] The side circumferential surface 31A of the inner tank 3 is provided with a mounting seat 5 and a first hook-and-loop fastener 6 arranged on the mounting seat 5. The laminated vacuum insulation sheet 4 has a second hook-and-loop fastener 7 on one side, which is detachable from the first hook-and-loop fastener 6. The laminated vacuum insulation sheet 4 is attached to the inner tank 3 by attaching the second hook-and-loop fastener 7 to the first hook-and-loop fastener 6. FIG. 2 shows an example in which the laminated vacuum insulation sheet 4 is provided in two layers in the vertical direction of the side circumferential surface 31A as the laminated vacuum insulation sheet 4 attached to the body part 31. In the following description, the upper layer laminated vacuum insulation sheet 4 is referred to as the upper layer sheet 4A, and the lower layer laminated vacuum insulation sheet 4 is referred to as the lower layer sheet 4B. When the body part 31 is longer in the vertical direction, the laminated vacuum insulation sheet 4 may be formed in multiple layers of three or more layers, or may be formed in only one layer. In addition, the laminated vacuum insulation sheet 4 divided in the circumferential direction may be used in each layer.

[0017] The first hook-and-loop fasteners 6 are strip-shaped hook-and-loop fasteners extending in the circumferential direction of the side peripheral surface 31A. FIG. 2 shows an example in which the first hook-and-loop fasteners 6 are provided in three tiers, one above the other. The first hook-and-loop fasteners 6 in the upper tier support the upper sheet 4A, and the first hook-and-loop fasteners 6 in the middle tier support the lower sheet 4B. The lower tier shows the state before the first hook-and-loop fasteners 6 are attached, and the mounting seats 5 are exposed, with multiple fasteners attached in a scattered manner in the circumferential direction of the side peripheral surface 31A. The first hook-and-loop fasteners 6 in the lower tier support a group of end-laminated vacuum insulation sheets (bottom sheet group 46 in FIG. 8) that cover the bottom 33.

[0018] As described above, in this embodiment, the laminated vacuum insulation sheet 4 is attached to the body 31 and bottom 33 of the inner tank 3 by engaging the first hook-and-loop fastener 6 supported by the mounting seat 5 with the second hook-and-loop fastener 7 previously integrated with the laminated vacuum insulation sheet 4. It is also possible to attach the laminated vacuum insulation sheet 4 to the inner tank 3 using an adhesive, but in this case, there is a problem of outgassing from the adhesive into the vacuum insulation layer VA. In addition, there is no general-purpose adhesive that has environmental resistance to exposure to the cold heat of liquefied hydrogen. In contrast, by applying the engagement of the hook-and-loop fasteners 6 and 7, the laminated vacuum insulation sheet 4 can be attached easily and the problems of outgassing and resistance to extremely low temperatures can be solved.

[0019] [Details of the support structure of the laminated vacuum insulation sheet] Next, the support structure of the laminated vacuum insulation sheet 4 and its construction procedure will be described in detail with reference to Fig. 3 and Figs. 4 to 7 which will be referred to in sequence. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. The support structure is generally as follows. A hook-and-loop fastener unit 6U having a first hook-and-loop fastener 6 is attached to a mounting seat 5 provided on a side peripheral surface 31A of the inner tank 3 by using a rivet 8. A head 8B which is a part of the rivet 8 appears on the surface of the first hook-and-loop fastener 6. A second hook-and-loop fastener 7 integrated with the laminated vacuum insulation sheet 4 is attached to the first hook-and-loop fastener 6 in a state where it covers the head 8B of the rivet 8.

[0020] In the support structure, the first thing provided on the side circumferential surface 31A of the inner tank 3 is the mounting seat 5. The mounting seat 5 is made of a square metal block having a required thickness. The mounting seat 5 can be fixed to the side circumferential surface 31A by, for example, fillet welding. It is preferable to use the same metal material as the constituent material of the inner tank 3 for the mounting seat 5, since this allows the thermal expansion behavior to be consistent with that of the inner tank 3.

[0021] 4(A) is a diagram showing the state in which the mounting seats 5 are installed on the side peripheral surface 31A of the inner tank 3. A plurality of mounting seats 5 are welded to the side peripheral surface 31A so as to be scattered at a predetermined distance d in the circumferential direction of the side peripheral surface 31A. The mounting seats 5 may be rectangular, polygonal, or round in shape other than a square. Also, instead of being scattered, band-shaped mounting seats 5 may be wound around the side peripheral surface 31A. However, from the viewpoint of simplifying the welding work, it is preferable to use scattered mounting seats 5 rather than band-shaped.

[0022] FIG. 4(B) is a plan view of one mounting seat 5, and FIG. 4(C) is a cross-sectional view taken along line IVC-IVC in FIG. 4(B). The mounting seat 5 includes two through holes 51 arranged vertically, and a rivet engagement portion 52 connected to the through holes 51. The through holes 51 are holes for inserting the rivet 8 shown in FIG. 3. The rivet 8 is a fastener for fixing the first surface fastener 6 to the mounting seat 5, and includes a shaft portion 80 having a circular cross section, and a tip portion 8A and a head portion 8B having a diameter larger than that of the shaft portion 80. The through hole 51 is a hole of a size that does not allow the tip portion 8A to pass through, but allows the shaft portion 80 to pass through. The rivet engagement portion 52 is a hole having a diameter capable of accommodating the tip portion 8A. The tip portion 8A is engaged at a step portion based on the diameter difference between the shaft portion 80 and the rivet engagement portion 52.

[0023] Next, a hook-and-loop fastener unit 6U to be attached to the mounting seat 5 is prepared. FIG. 5(A) is a plan view of the hook-and-loop fastener unit 6U, and FIG. 5(B) is a cross-sectional view taken along the line VB-VB in FIG. 5(A). The hook-and-loop fastener unit 6U includes the above-mentioned first hook-and-loop fastener 6 and a metal band 61 as a support member located on the back surface of the first hook-and-loop fastener 6. For example, a stainless steel band can be used as the metal band 61. The metal band 61 has a length that goes around the side peripheral surface 31A of the inner tub 3 in the circumferential direction. The length of one circumference of the side peripheral surface 31A may be covered by a divided metal band 61.

[0024] The first hook-and-loop fastener 6 has approximately the same circumferential length and vertical length as the metal band 61. The first hook-and-loop fastener 6 is fixed to the metal band 61 by using a fastener rivet 83. The first hook-and-loop fastener 6 and the metal band 61 are aligned and overlapped, and through holes are drilled at predetermined locations. The fastener rivet 83 is inserted into the through holes. One end and the other end of the fastener rivet 83 are crushed to form a flange, and a hook-and-loop fastener unit 6U in which the first hook-and-loop fastener 6 is engaged with the metal band 61 is completed. It is also possible to directly attach the first hook-and-loop fastener 6 to the mounting seat 5 without using the metal band 61 to form a unit. However, by backing the first hook-and-loop fastener 6 with a support member such as the metal band 61, shape retention can be imparted even if the first hook-and-loop fastener 6 is a flexible member, and handling is improved.

[0025] Next, the hook-and-loop fastener unit 6U is attached to the mounting seat 5. Fig. 6(A) is a diagram showing the hook-and-loop fastener unit 6U attached to the side peripheral surface 31A, and Fig. 6(B) is a cross-sectional view taken along line VIB-VIB in Fig. 6(A). In this embodiment, the hook-and-loop fastener unit 6U is fixed to the mounting seat 5 by riveting using the rivets 8. Note that instead of the rivets 8, fastening members such as screws and bolts may be used as fixing devices.

[0026] The hook-and-loop fastener unit 6U is provided with a through hole for inserting the rivet 8 at a position corresponding to the through hole 51 of the mounting seat 5. This through hole can be provided near the middle of fastener rivets 83 adjacent in the circumferential direction, as shown in FIG. 6(A). The mounting seat 5 is welded to the side peripheral surface 31A with the rivet 8 inserted in the through hole 51 in advance. That is, the tip portion 8A fits into the rivet engagement portion 52, and the shaft portion 80 passes through the through hole 51 and partially protrudes from the mounting seat 5.

[0027] The hook-and-loop fastener unit 6U is applied to the mounting seat 5 so that the shaft 80 of the rivet 8 is inserted into the through-hole of the hook-and-loop fastener unit 6U. Thereafter, the projecting end of the shaft 80 is crushed or the like to form a head 8B that serves as a flange. As a result, the shaft 80 of the rivet 8 penetrates the first hook-and-loop fastener 6 and the metal band 61 in the thickness direction, the tip 81 engages with the mounting seat 5, and the head 8B engages with the first hook-and-loop fastener 6. In other words, the hook-and-loop fastener unit 6U and the mounting seat 5 are sandwiched between the tip 8A and the head 8B, and as a result, the first hook-and-loop fastener 6 is fixed to the mounting seat 5. According to this embodiment, the first hook-and-loop fastener 6 can be attached to the side peripheral surface 31A by simple riveting. However, the head 8B is exposed on the surface of the first hook-and-loop fastener 6.

[0028] Thereafter, the laminated vacuum insulation sheet 4 having the second hook-and-loop fastener 7 on one side is attached. FIG. 7(A) is a diagram showing the attached state to the side peripheral surface 31A of the laminated vacuum insulation sheet 4, and FIG. 7(B) is a cross-sectional view showing the method of attaching the laminated vacuum insulation sheet 4. The second hook-and-loop fastener 7 is attached in advance to the upper end region 4U of the laminated vacuum insulation sheet 4. There is no limitation on the attachment method, but it is preferable to attach the second hook-and-loop fastener 7 to the upper end region 4U by sewing with thread, for example. In this embodiment, an example in which the second hook-and-loop fastener 7 is attached only to the upper end region 4U is shown, but the second hook-and-loop fastener 7 may be attached to other parts of the laminated vacuum insulation sheet 4. Alternatively, the second hook-and-loop fastener 7 may be attached to the upper end edge of the laminated vacuum insulation sheet 4.

[0029] The second hook-and-loop fastener 7 is attached to the first hook-and-loop fastener 6. As a result, the head 8B of the rivet 8 exposed on the surface of the first hook-and-loop fastener 6 is covered by the upper end region 4U of the laminated vacuum insulation sheet 4 provided with the second hook-and-loop fastener 7. In other words, the second hook-and-loop fastener 7 is attached to the first hook-and-loop fastener 6 with the laminated vacuum insulation sheet 4 covering the head 8B. This results in the head 8B not being directly exposed to the vacuum insulation layer VA. If the head 8B is exposed to the vacuum insulation layer VA, the rivet 8 can be a heat input path from the outer tank 2 to the inner tank 3. In other words, the radiant heat received by the head 8B can be transferred to the inner tank 3 via the mounting seat 5. However, in this embodiment, the head 8B is covered by the second hook-and-loop fastener 7 and the laminated vacuum insulation sheet 4, so that the problem of heat input can be eliminated.

[0030] When the second hook-and-loop fasteners 7 are attached to the first hook-and-loop fasteners 6 from the state shown in Fig. 7(B), the laminated vacuum insulation sheet 4 is installed in the manner shown in Fig. 3. Because the second hook-and-loop fasteners 7 are attached to the upper end region 4U, the laminated vacuum insulation sheet 4 is suspended and supported by the first hook-and-loop fasteners 6. In detail, the first hook-and-loop fasteners 6 are fixed to the mounting seats 5 of each stage, the upper stage sheet 4A is suspended and supported by the first hook-and-loop fasteners 6 of the upper stage, and the lower stage sheet 4B is suspended and supported by the first hook-and-loop fasteners 6 of the middle stage.

[0031] In this way, the second hook-and-loop fastener 7 is provided only in the upper end region 4U, and the entire laminated vacuum insulation sheet 4 is suspended and supported, so that the laminated vacuum insulation sheet 4 can be supported with a minimum number of hook-and-loop fasteners. In addition, the laminated vacuum insulation sheet 4 having an appropriate vertical width is connected in multiple stages in the vertical direction, such as the upper sheet 4A and the lower sheet 4B, to cover the inner vessel 3. This means that even if the inner vessel 3 has a long vertical length of the side peripheral surface 31A, the vertical width of one laminated vacuum insulation sheet 4 does not need to be excessively long, that is, the weight does not need to be heavy. Therefore, there is no need to make the hook-and-loop fastener joint strength of each stage of the laminated vacuum insulation sheet 4, that is, the upper sheet 4A and the lower sheet 4B, excessively strong, and the fixing can be performed using inexpensive hook-and-loop fasteners 6, 7.

[0032] As shown in Fig. 3, the lower end of the upper sheet 4A and the upper end of the lower sheet 4B are butted together in the vertical direction without being overlapped in the radial direction, forming an butted portion 4J. A metal tape 4S is attached to the outer circumferential surface of the butted portion 4J. The metal tape 4S is a fixing sheet that fixes the lower end of the upper sheet 4A and the upper end of the lower sheet 4B from the outside. For example, an aluminum tape can be used as the metal tape 4S.

[0033] By attaching the metal tape 4S, the upper sheet 4A and the lower sheet 4B can be connected and integrated, and the lower end of the upper sheet 4A can be prevented from curling up. Furthermore, by forming the butt joint 4J, the sheet thickness of the laminated vacuum insulation sheet 4 becomes constant in the vertical direction. If there is a thick portion due to the overlap of the sheets 4A and 4B, the temperature difference between the inner and outer surfaces of the thick portion will be larger than other portions, and this may become a heat input path toward the inner tank 3. If the sheets 4A and 4B are connected vertically at the butt joint 4J as in this embodiment, the disturbance of thermal behavior due to the change in sheet thickness can be prevented.

[0034] [Installation of laminated vacuum insulation sheets on top and bottom] As described above, the inner tank 3 has a dome-shaped top 32 and bottom 33 at the upper and lower ends, respectively, of a cylindrical body 31. Fig. 8 is a front view showing an example of installation of laminated vacuum insulation sheets on the top 32 and bottom 33. The top 32 is covered by a top sheet group 45, and the bottom 33 is covered by a bottom sheet group 46 (end laminated vacuum insulation sheet group). As described above, the body 31 is covered by the laminated vacuum insulation sheet 4 consisting of the upper sheet 4A, lower sheet 4B,..., bottom sheet 4N, by engagement between the first hook-and-loop fastener 6 and the second hook-and-loop fastener 7.

[0035] The top sheet group 45 includes a top sector sheet 45A and a top circular sheet 45B made of a laminated vacuum insulation sheet. The top sector sheet 45A is a sheet formed by processing a laminated vacuum insulation sheet into a sector shape that fits the curved surface of the dome-shaped top 32. Multiple top sector sheets 45A are densely arranged in the circumferential direction of the top 32, covering the top 32 except for the apex. The top circular sheet 45B covers a circular opening made on the inner diameter side of the array of multiple top sector sheets 45A.

[0036] The outer periphery of the top circular sheet 45B and the inner periphery of the top sectorial sheet 45A are butted together, and a metal tape such as aluminum tape is applied to fill the gap between them. That is, the top sectorial sheet 45A and the top circular sheet 45B are connected by the metal tape. Adjacent top sectorial sheets 45A may also be connected by the metal tape. The top sheet group 45 can be installed by placing it on the top 32. That is, the top sheet group 45 can be installed on the top 32 by resting its own weight on the inner tank 3. Therefore, the support structure using the mounting seat 5 and the hook-and-loop fasteners 6 and 7 can be omitted.

[0037] The bottom sheet group 46 includes a bottom sector sheet 46A and a bottom circular sheet 46B made of a laminated vacuum insulation sheet. The bottom sector sheet 46A is a sheet formed by processing a laminated vacuum insulation sheet into a sector shape that fits the curved surface of the dome-shaped bottom 33. A plurality of bottom sector sheets 46A are densely arranged in the circumferential direction of the bottom 33, and cover the bottom 33 except for the vicinity of the apex that is the lower end of the inner tank 3. The bottom circular sheet 46B covers a circular opening made on the inner diameter side of the array of a plurality of bottom sector sheets 46A.

[0038] Because the bottom sheet group 46 is attached to the bottom 33 which faces downward, it cannot be installed by resting its own weight on the inner tub 3 as with the top sheet group 45. Therefore, a support structure using a mounting seat 5 and hook-and-loop fasteners 6, 7 is applied to the bottom sheet group 46. This support structure is the same as the structure previously described with reference to Figures 3 to 7. The bottom sector sheet 46A has a second hook-and-loop fastener 7 in its upper end region. The second hook-and-loop fastener 7 is joined to the first hook-and-loop fastener 6 installed at the lowest level of the body 31.

[0039] The lower end of the bottom sector sheet 46A is butted against the outer periphery of the bottom circular sheet 46B, and is joined by applying a metal tape to fill the gap between them. A support structure using hook-and-loop fasteners 6 and 7 may be applied to the bottom circular sheet 46B, or the bottom sector sheet 46B may be attached to the bottom sector sheet 46A by applying the metal tape. Adjacent bottom sector sheets 46A may also be connected to each other by a metal tape. According to this embodiment, the laminated vacuum insulation sheet can be easily attached to the dome-shaped bottom 33, which cannot be installed to support its own weight.

[0040] [Example of radially arranged laminated vacuum insulation sheets] In the above example, the laminated vacuum insulation sheet 4 is arranged in only one layer in the radial direction of the inner vessel 3, but the laminated vacuum insulation sheet 4 may be attached in multiple layers in the radial direction. Fig. 9 is a cross-sectional view showing an example of arranging the laminated vacuum insulation sheet 4 in multiple layers in the radial direction. In the example of Fig. 9, the laminated vacuum insulation sheet 4 including the above-mentioned upper sheet 4A and lower sheet 4B is set as the first layer, and second layer sheets 41, 43 and third layer sheets 42, 44, all of which are made of laminated vacuum insulation sheets, are further attached so as to overlap one another in the radial direction.

[0041] The attachment of the laminated vacuum insulation sheet 4 including the upper sheet 4A and the lower sheet 4B to the side peripheral surface 31A is the same as that described in Figs. 3 to 7, so a description thereof will be omitted. The second sheet 41, 43 and the third sheet 42, 44 are laminated vacuum insulation sheets for a multi-stage arrangement that are additionally attached in two stages to the peripheral surface of the laminated vacuum insulation sheet 4. The second sheet 41, 43 is the first sheet of the multi-stage arrangement that is superimposed on the laminated vacuum insulation sheet 4, and is supported by the hook-and-loop fastener support portion 9 to the sheets 4A, 4B, respectively. The third sheet 42, 44 is the second sheet of the multi-stage arrangement, and is supported by the hook-and-loop fastener support portion 9 to the second sheet 41, 43, respectively.

[0042] The hook-and-loop fastener support portion 9 is interposed between the laminated vacuum insulation sheet 4 and the second layer sheets 41, 43, or between the second layer sheets 41, 43 and the third layer sheets 42, 44, and is composed of a pair of a third hook-and-loop fastener 91 and a fourth hook-and-loop fastener 92 which engage with each other. Fig. 9 shows an example in which the multi-layer sheets attached to the upper layer sheet 4A are the upper second layer sheet 41 and the upper third layer sheet 42, and the multi-layer sheets attached to the lower layer sheet 4B are the lower second layer sheet 43 and the lower third layer sheet 44.

[0043] A third hook-and-loop fastener 91 is attached by sewing to a position shifted downward from the attachment position of the second hook-and-loop fastener 7 on the outer surface of the upper sheet 4A. A fourth hook-and-loop fastener 92 is attached by sewing to the upper end region 41U of the second upper sheet 41. The second upper sheet 41 is attached to the upper sheet 4A by joining the hook-and-loop fasteners 91, 92. A similar hook-and-loop fastener support portion 9 is also interposed between a position shifted downward from the upper end region 41U on the outer peripheral surface of the second upper sheet 41 and the upper end region 42U of the third upper sheet 42. The hook-and-loop fastener support portion 9 attaches the third upper sheet 42 to the second upper sheet 41.

[0044] A hook-and-loop fastener support portion 9 is interposed between a position on the outer surface of the lower sheet 4B shifted downward from the attachment position of the second hook-and-loop fastener 7 and the upper end region 43U of the second lower sheet 43. Furthermore, a hook-and-loop fastener support portion 9 is interposed between a position on the outer circumferential surface of the second lower sheet 43 shifted downward from the upper end region 43U and the upper end region 44U of the third lower sheet 44. These hook-and-loop fastener support portions 9 attach the second lower sheet 43 to the lower sheet 4B, and the third lower sheet 44 to the second lower sheet 43, respectively.

[0045] The lower end region 41L of the second upper sheet 41 covers the upper end region 4U of the lower sheet 4B and is continuous with the upper end of the second lower sheet 43. Moreover, the lower end region 42L of the third upper sheet 42 covers the upper end region 43U of the second lower sheet 43 and is continuous with the upper end of the third lower sheet 44. This achieves a heat insulating structure in which all parts of the side peripheral surface 31A in the vertical direction are covered with three layers of laminated vacuum insulation sheets in the radial direction.

[0046] According to the embodiment shown in FIG. 9, the laminated vacuum insulation sheet 4 attached to the mounting seat 5 can be further arranged in multiple layers using the hook-and-loop fastener support part 9. That is, the laminated vacuum insulation sheet is arranged in multiple layers in the radial direction of the inner tank 3, so that the heat insulating effect can be improved. In addition, the hook-and-loop fastener support part 9 is arranged in a position shifted downward from the joining position of the first hook-and-loop fastener 6 and the second hook-and-loop fastener 7. Therefore, for example, the second hook-and-loop fastener 7 and the third hook-and-loop fastener 91 can be sewn to the upper sheet 4A at positions shifted vertically from each other. This makes it possible to easily attach the hook-and-loop fasteners 7 and 91 to the upper sheet 4A.

[0047] [Summary of this disclosure] The specific embodiments described above include disclosures having the following configurations.

[0048] A vertical tank according to a first aspect of the present disclosure comprises an outer tank, an inner tank arranged at a distance inside the outer tank and including a vertical side surface, a mounting seat provided on the side surface, a first hook-and-loop fastener arranged on the mounting seat, a fastener for fixing the first hook-and-loop fastener to the mounting seat, the fastener including a tip portion that penetrates the first hook-and-loop fastener in the thickness direction and engages with the mounting seat and a head portion that appears on the surface of the first hook-and-loop fastener, and a laminated vacuum insulation sheet including a second hook-and-loop fastener on one side that can be attached and detached to the first hook-and-loop fastener, and the second hook-and-loop fastener is attached to the first hook-and-loop fastener with the laminated vacuum insulation sheet covering the head portion.

[0049] According to the first aspect, the laminated vacuum insulation sheet can be supported by the mounting seat by attaching the second hook-and-loop fastener to the first hook-and-loop fastener. Therefore, it is possible to attach the laminated vacuum insulation sheet to an inner tank including a vertical side peripheral surface without causing the sheet to slip down due to gravity. In addition, since the second hook-and-loop fastener is attached to the first hook-and-loop fastener in a state where it covers the head of the fastener, the fastener is not exposed. Therefore, it is possible to suppress heat input to the inner tank through the fastener.

[0050] The vertical tank of the second aspect is the vertical tank of the first aspect, further comprising a support member located on the back side of the first hook-and-loop fastener, and the tip of the fixing device penetrates the first hook-and-loop fastener and the support member and engages with the mounting seat.

[0051] According to the second aspect, the first hook-and-loop fastener can be supported by the support member as a support base. Therefore, even if the first hook-and-loop fastener is a flexible material, the support member can provide shape retention. Therefore, the attachment work to the attachment seat can be easily performed.

[0052] The vertical tank of the third aspect is the vertical tank of the first or second aspect, wherein the second hook-and-loop fastener is attached to the upper end region of the laminated vacuum insulation sheet, and the laminated vacuum insulation sheet is suspended and supported by the first hook-and-loop fastener.

[0053] According to the third aspect, the second hook-and-loop fastener attached to the upper end region of the laminated vacuum insulation sheet is attached to the first hook-and-loop fastener, so that the entire laminated vacuum insulation sheet is suspended and supported. Therefore, the laminated vacuum insulation sheet can be supported with a minimum number of hook-and-loop fasteners.

[0054] A vertical tank according to a fourth aspect is the vertical tank according to the first or second aspect, wherein the second hook-and-loop fastener is attached only to an upper end region of the laminated vacuum insulation sheet.

[0055] According to the fourth aspect, the second hook-and-loop fastener is attached only to the upper end region of the laminated vacuum insulation sheet, and the laminated vacuum insulation sheet can be suspended and supported by relying on the second hook-and-loop fastener.

[0056] A vertical tank according to a fifth aspect is any one of the first to fourth aspects, wherein the mounting seats are scattered in the circumferential direction of the side peripheral surface.

[0057] According to the fifth aspect, for example, the work of fixing the mounting seat to the side circumferential surface of the inner tank by welding can be reduced compared to when a band-shaped mounting seat is used.

[0058] The vertical tank of the sixth aspect is the vertical tank of the third or fourth aspect, wherein the mounting seats are provided in multiple stages in the vertical direction of the side surface, the first hook-and-loop fasteners are respectively fixed to the mounting seats of each stage, the laminated vacuum insulation sheet is respectively supported in a suspended manner by the first hook-and-loop fasteners of each stage, and the vertical tank further comprises a fixing sheet that fixes from the outside the butt joint between the lower end of the laminated vacuum insulation sheet of the upper stage and the upper end of the laminated vacuum insulation sheet of the lower stage.

[0059] According to the sixth aspect, even if the inner vessel has a long vertical length of the side periphery, the vertical width of one laminated vacuum insulation sheet is not excessively long, i.e., the weight is not increased. In other words, the inner vessel can be covered by connecting multiple layers of laminated vacuum insulation sheets having an appropriate vertical width in the vertical direction. Therefore, it is not necessary to make the bonding strength of the hook-and-loop fastener of each layer of the laminated vacuum insulation sheet excessively strong. In addition, since the ends of the upper and lower layers of the laminated vacuum insulation sheets are butted against each other without being overlapped, it is possible to suppress disturbance of thermal behavior caused by partial changes in sheet thickness.

[0060] The vertical tank of the seventh aspect is a vertical tank of any of the first to sixth aspects, further comprising a multi-stage laminated vacuum insulation sheet for a multi-stage arrangement that is attached in one or more stages to the outer peripheral surface of the laminated vacuum insulation sheet in the radial direction of the side peripheral surface, and a hook-and-loop fastener support portion consisting of a pair of hook-and-loop fasteners interposed between the laminated vacuum insulation sheet and the first stage of the multi-stage laminated vacuum insulation sheet, or between adjacent multi-stage laminated vacuum insulation sheets.

[0061] According to the seventh aspect, a multi-layered vacuum insulation sheet can be further arranged on the laminated vacuum insulation sheet attached to the mounting seat using a hook-and-loop fastener support part. Since the laminated vacuum insulation sheet is arranged in multiple layers in the radial direction of the side peripheral surface of the inner tank, the insulating effect can be improved.

[0062] The vertical tank of the eighth aspect is the vertical tank of the seventh aspect, wherein the hook-and-loop fastener support portion is positioned at a position shifted downward relative to the attachment position of the first hook-and-loop fastener and the second hook-and-loop fastener.

[0063] According to the eighth aspect, for example, when attaching a hook-and-loop fastener to a laminated vacuum insulation sheet by sewing, the second hook-and-loop fastener and the hook-and-loop fastener support part can be sewn at positions shifted vertically from each other, which makes it possible to easily attach the hook-and-loop fastener to the laminated vacuum insulation sheet.

[0064] A ninth aspect of the vertical tank is a vertical tank according to any one of the first to eighth aspects, wherein the inner tank includes a dome-shaped bottom at the lower end of a cylindrical body having a vertical side surface, and further includes a bottom sheet group made of a laminated vacuum insulation sheet attached to cover the surface of the bottom, the bottom sheet group including a plurality of bottom sector sheets arranged circumferentially around the dome-shaped bottom, and a bottom circular sheet covering a circular opening made on the inner diameter side of the arrangement of the plurality of sector sheets, the bottom sector sheet having an upper end region having the second hook-and-loop fastener attached to the first hook-and-loop fastener arranged near the lower end of the side surface, and a lower end joined in an abutting state to the outer circumferential edge of the bottom circular sheet.

[0065] When the inner vessel includes a dome-shaped bottom, the laminated vacuum insulation sheet cannot be attached to the bottom by resting its own weight on the inner vessel. According to the ninth aspect, the laminated vacuum insulation sheet can be easily attached to the dome-shaped bottom as well. [Explanation of symbols]

[0066] 1. Vertical liquefied hydrogen tank (vertical tank) 2 Outer tank 3 Inner tank 31 Torso 31A Side surface 32 Top 33 Bottom 4. Laminated vacuum insulation sheet 4A Upper Seat 4B Lower Seat 4J butt joint 4S Metal Tape (Fixing Sheet) 4U top area 41, 43 Second layer sheet (multi-layered vacuum insulation sheet) 42, 44 Third sheet (multi-layered vacuum insulation sheet) 46 Bottom sheet group (edge ​​laminated vacuum insulation sheet group) 46A Bottom fan-shaped sheet 46B Bottom circular sheet 5 Mounting base 6 First hook-and-loop fastener 61 Metal strip (support member) 6U hook and loop fastener unit 7 Second hook-and-loop fastener 8 Rivets (fixtures) 8A tip 8B Head 9 Hook and loop fastener support

Claims

1. The outer tank and an inner tank disposed inside the outer tank at a distance from the outer tank and including a vertical side peripheral surface; A mounting seat provided on the side peripheral surface; A first hook-and-loop fastener disposed on the mounting seat; a fastener for fastening the first hook-and-loop fastener to the mounting seat, the fastener including a tip portion penetrating the first hook-and-loop fastener in a thickness direction and engaging with the mounting seat, and a head portion appearing on a surface of the first hook-and-loop fastener; A laminated vacuum insulation sheet including a second hook-and-loop fastener on one side that is detachable from the first hook-and-loop fastener, A vertical tank, wherein the second hook-and-loop fastener is attached to the first hook-and-loop fastener with the laminated vacuum insulation sheet covering the head.

2. The vertical tank according to claim 1, Further comprising a support member located on a back surface of the first hook-and-loop fastener, The tip portion of the fixing device penetrates the first hook-and-loop fastener and the support member and engages with the mounting seat.

3. The vertical tank according to claim 1, The second hook-and-loop fastener is attached to the upper end region of the laminated vacuum insulation sheet, The laminated vacuum insulation sheet is suspended and supported by the first hook-and-loop fastener.

4. The vertical tank according to claim 1, A vertical tank, wherein the second hook-and-loop fastener is attached only to an upper end region of the laminated vacuum insulation sheet.

5. In the vertical tank according to any one of claims 1 to 4, The mounting seats are scattered in a circumferential direction on the side peripheral surface of the vertical tank.

6. The vertical tank according to claim 3 or 4, The mounting seats are provided in a plurality of stages in the up-down direction of the side peripheral surface, and the first hook-and-loop fasteners are fixed to the mounting seats of each stage, The laminated vacuum insulation sheet is suspended and supported by the first hook-and-loop fasteners of each stage, The vertical tank further comprises a fixing sheet that fixes from the outside the butt joint between the lower end of the upper layer of the laminated vacuum insulation sheet and the upper end of the lower layer of the laminated vacuum insulation sheet.

7. In the vertical tank according to any one of claims 1 to 4, A multi-stage laminated vacuum insulation sheet for multi-stage arrangement that is attached in one or more stages in the radial direction of the side peripheral surface to the outer peripheral surface of the laminated vacuum insulation sheet; The vertical tank further comprises a hook-and-loop fastener support portion consisting of a pair of hook-and-loop fasteners interposed between the laminated vacuum insulation sheet and the first layer of the multi-layered vacuum insulation sheet, or between adjacent multi-layered vacuum insulation sheets.

8. The vertical tank according to claim 7, A vertical tank, wherein the hook-and-loop fastener support portion is positioned at a position shifted downward relative to the attachment position of the first hook-and-loop fastener and the second hook-and-loop fastener.

9. The vertical tank according to claim 1, The inner tank includes a dome-shaped bottom at a lower end of a cylindrical body portion having the vertical side surface, Further provided is a bottom sheet group consisting of a laminated vacuum insulation sheet attached so as to cover the surface of the bottom, The bottom sheet group includes a plurality of bottom sector sheets arranged in a circumferential direction of the dome-shaped bottom, and a bottom circular sheet covering a circular opening formed on the inner diameter side of the array of the plurality of sector sheets, The bottom sector sheet is a vertical tank having an upper end region having the second hook-and-loop fastener attached to the first hook-and-loop fastener arranged near the lower end of the side surface, and a lower end that is joined in a butt-fitting state to the outer peripheral edge of the bottom circular sheet.

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