JP2012111558A - Tank with reinforced membrane having corrugation part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid or remove plastic deformation which may occur in a thin film constituted of a sheet member formed of metal by improving strength against the pressure of the thin film in relation a the tank for transporting liquefied natural gas or the like.SOLUTION: A tank with a reinforced membrane having a corrugation part relates to a thermally insulating container to perform sealing for a fluid including: at least one wall having the thin film which is disposed to be in contact with a product stored in the container; and a thermally insulating layer disposed to adjoin the film. The thin film is constituted of at least one plate (1) having at least one corrugation part (2, 3). A reinforcing member (5) inserted between the thin film and the thermally insulating layer under the corrugation part is disposed in the container. An internal channel (9) is disposed in the reinforcing member, that is, the internal channel (9) is disposed through the reinforcing member so that gas flows across the reinforcing member between the corrugation part and the support part via the internal channel (9).

Description

  The present invention relates to a tank for sealing a fluid, and more particularly, to a fluid-sealing and heat-insulating tank for ship transportation of liquefied natural gas (LNG).

  French Patent No. 2,781,557 describes a tank provided in the structure of a ship, the tank being configured to allow the transport of liquefied natural gas.

  The partition wall of the tank is composed of a primary partition wall that seals the fluid, a heat insulating primary partition wall, a secondary partition wall that seals the fluid, and a heat insulating secondary partition wall in order from the inside of the tank toward the outside. . The primary partition wall for sealing the fluid is a thin film made of a metal sheet member that is provided with a corrugation portion and made of stainless steel. More precisely, each sheet member has a series of corrugations parallel to the ship axis and another series of corrugations perpendicular to the ship axis.

  During operation, mechanical stresses are generated in the thin film. There are multiple sources of these mechanical stresses. These include the thermal reaction when the tank is cooled, the influence of the beam of the ship, the hydrostatic pressure due to filling, and the dynamic pressure due to the movement of the cargo, especially the movement of the cargo due to wave swells.

  The plurality of corrugation portions provided on the plurality of metal sheet members of the thin film are configured to deform a thin film to limit a mechanical stress caused by a thermal reaction and an influence of a ship beam. ing.

French Patent No. 2,781,557 French Patent No. 2,861,060

  It is known that dynamic pressure causes plastic deformation of the corrugation part. And in the said use, such a deformation | transformation can lead to the fall of the flexibility of a sheet | seat member and impairing the fluid-sealing property of a thin film, especially in the junction part of several sheet | seat members.

  In order to improve the strength of the thin film against pressure and reduce plastic deformation of the thin film, French Patent 2,861,060 proposes providing reinforcing ribs in the corrugation part. However, it is beneficial to further increase the strength of the thin film against pressure.

  The problem to be solved by the present invention is to provide a tank that eliminates at least a part of the disadvantages found in the prior art. In particular, it is an object of the present invention to improve the strength of the thin film to pressure, thereby avoiding or eliminating plastic deformation.

  The solution proposed by the present invention is a tank for sealing a fluid with at least one wall, the at least one wall being in contact with a product contained in the tank for sealing the fluid. A thin film for sealing a fluid and a support portion provided adjacent to the thin film are provided, and the thin film is constituted by at least one sheet member having at least one corrugation portion, A reinforcement member is inserted under the corrugation portion so as to be disposed between the thin film and the support portion, and a contour having a shape corresponding to the shape of the corrugation portion is provided outside the reinforcement member. And the reinforcing member is provided with an internal passage (9), and the corrugation portion and the support portion are connected via the internal passage (9). Wherein the reinforcing member across to flow the gas, it said internal passage (9) resides in the tank, characterized in that are provided through the reinforcing member in the.

  It can be seen that such a reinforcing member can limit the mechanical stress generated in the thin film. Of course, the thin film may be composed of a plurality of sheet members, the sheet member may have a plurality of corrugations, and the one reinforcing member is one or more of the sheet members. You may arrange | position under a some corrugation part. For example, the support portion may be a heat insulating layer, or more precisely, a panel made of plywood made of a heat insulating layer.

  According to an embodiment, an external passage for allowing the gas to flow around the reinforcing member between the corrugation part and the support part is provided.

  Advantageously, the reinforcing member is made of a material selected from the group consisting of plywood, polyethylene, polycarbonate, glass-reinforced polycarbonate, polyetherimide, and polystyrene foam.

  Preferably, at least one cobweb-shaped reinforcing portion is provided inside the contour portion of the reinforcing member.

  Advantageously, the shortest distance between the reinforcing member and the corrugation part when no product is present in the tank is 0% to 5% of the height of the corrugation part.

  Preferably, the sheet member includes a first row corrugation portion including a plurality of corrugation portions parallel to each other, and a second row corrugation portion including a plurality of corrugation portions parallel to each other, and the second row corrugation portion. Is provided across the first row corrugation section, and the reinforcing member is inserted under one of the corrugation sections belonging to the first row corrugation section.

  According to an embodiment, the reinforcing member has a length corresponding to a distance between two corrugation parts belonging to the second row corrugation part.

  As a modification, the length of the reinforcing member may be longer or shorter than the length defined in the previous paragraph.

  Advantageously, the reinforcing member is inserted under the corrugation part so as to be slidable with respect to the thin film and the support part.

  As a modification, the reinforcing member is fixed to the thin film or the support portion.

  According to an embodiment, the thin film is provided with an undercut, and the reinforcing member is locked or pushed into the undercut.

  According to an embodiment, at least two of the reinforcing members are respectively disposed under two corrugation portions of the adjacent thin films, and one of the two reinforcing members is the other of the two reinforcing members. It is a stop part against.

  Advantageously, the reinforcing member is provided with at least one part configured to be easily deformed or broken when a stress exceeding a predetermined threshold is applied.

  Thereby, the pressure which the said thin film receives can be determined by the controlled plastic deformation of the said thin film, and the potential risk of the damage with respect to the support part arrange | positioned under it can be determined.

  Preferably, the thin film is in contact with the support portion on a side away from the corrugation portion.

  Similarly, the present invention can also provide a floating body including the tank of the present invention described below. For ships or other types of floating facilities.

  The following description of the embodiments of the present invention will make the present invention easier to understand, and other objects, details, features and advantages of the present invention will be more clearly understood. The description of the embodiments of the present invention has been made solely for the purpose of explanation with reference to the accompanying drawings, and is not intended to limit the scope of the present invention.

It is the perspective view which showed the sheet | seat member which has a corrugation part in the tank which concerns on one Embodiment of this invention. It is a cross-sectional perspective view of the corrugation part in the sheet | seat member which has a corrugation part of FIG. 1, and the reinforcement member which concerns on a 1st modification. It is the perspective view which showed the modification of the reinforcement member. It is the perspective view which showed the modification of the reinforcement member. It is the perspective view which showed the modification of the reinforcement member. It is the perspective view which showed the modification of the reinforcement member. It is the perspective view which showed the modification of the reinforcement member. It is the perspective view which showed the modification of the reinforcement member. It is the perspective view which showed the modification of the reinforcement member. It is sectional drawing which showed the other modification of the reinforcement member. It is sectional drawing which showed the other modification of the reinforcement member. It is a top view of the sheet | seat member shown in FIG. 1 in the cross | intersection part of a corrugation part, Moreover, it is a fragmentary sectional perspective view of the reinforcement member fixed under the corrugation part by clipping. It is the figure which showed the reinforcement member comprised so that it might be simultaneously arrange | positioned under the several corrugation part. It is a disassembled perspective view of two reinforcement members comprised so that it might mutually cooperate.

  A tank according to an embodiment of the present invention has a multilayer structure similar to the tank described in French Patent No. 2,781,557 and French Patent No. 2,861,060 cited in the description regarding the background art. It is what has. In particular, this tank is provided with a primary thin film for sealing a fluid, which is composed of a plurality of metal sheet members 1 provided with a corrugation portion, and the primary thin film for sealing the fluid is a heat insulating primary layer. It is arranged on a panel composed of plywood 4. The general aspect of such a multilayer structure is as described above, but the detailed part of the tank according to an embodiment of the present invention will be described below.

  As shown in FIG. 1, the sheet member 1 is a corrugated sheet member made of stainless steel and having a substantially rectangular shape. The primary thin film that seals the fluid in the tank is formed by welding the ends of a plurality of sheet members of this type. As shown in FIG. 1, the sheet member 1 includes three large corrugations 2 extending in the longitudinal direction of the sheet member 1 and nine small corrugations extending in the width direction of the sheet member 1. Part 3. Here, the reason why the plurality of large corrugations 2 can be distinguished from the plurality of small corrugations 3 is that the height of the plurality of large corrugations 2 is larger than the height of the plurality of small corrugations 3. by.

  As a modification, the sheet member 1 may include a different number of large corrugations 2 and / or small corrugations 3. Similarly, as a modification, a plurality of reinforcing ribs as described in French Patent No. 2,861,060 may be provided in the plurality of corrugation portions of the sheet member 1. In addition, the plurality of corrugations of the sheet member 1 may have other configurations, such as French Patent No. 2,735,847 or Korean Patent Publication No. 10-2005-0050170. You may have the structure as described in.

  As shown in FIG. 2, the sheet member 1 is disposed on a plywood 4 of a heat insulating layer extending below the sheet member 1. As a modification, the sheet member 1 may be disposed on another type of support. Moreover, in this figure, it turns out that the reinforcing member 5 is provided under the said large corrugation part 2 and between the said sheet | seat member 1 and the said plywood 4. FIG.

  In the present specification, “under” means that the reinforcing member 5 is covered with the corrugation part, but the reinforcing member 5 is always disposed below the corrugation part. It does not mean that That is, the reinforcing member 5 may be disposed at the same height as the corrugation covering the partition walls as long as they are above a plurality of vertical partition walls of the tank. In the example shown in FIG. 2, the length of the reinforcing member 5 corresponds to the distance between the two small corrugations 3.

  The plurality of reinforcing members 5 can be disposed under each large corrugation part 2 between two small corrugation parts 3. The score and distribution of the reinforcing member 5 may be determined according to a stress distribution assumed to act on the primary thin film that seals the fluid in the tank during operation.

  As a modification, the length of the reinforcing member 5 may be smaller than the distance between the two small corrugations 3, or the geometric shape of the intersection between the plurality of corrugations is allowed. If present, the distance may be larger than the distance.

  As a modification, the plurality of reinforcing members 5 may be disposed under the plurality of small corrugations 3. The reinforcing member 5 is realized in the manner shown in FIG. 2 and is not fixed to the sheet member 1 or the plywood 4. It can therefore slide under the large corrugation part 2 if necessary. Therefore, the manufacture of the tank of the present invention does not include the step of fixing the reinforcing member 5. As a modification, the reinforcing member 5 may be fixed to a primary thin film or plywood 4 that seals the fluid.

  Many shapes can be envisaged for the reinforcing member 5. 3 to 11 show other different forms that can be imagined. 3 to 9 are perspective views of the sliced reinforcing member 5, and the length of the reinforcing member 5 may be larger than that shown.

  10 and 11 are sectional views (of the reinforcing member 5). In these different drawings, similar elements are denoted by the same reference numerals.

  The reinforcing member 5 in FIG. 3 has a solid cross section. The two side surfaces 6 of the reinforcing member 5 are curved and have a shape corresponding to the shape of the large corrugation part 2. However, the plurality of side surfaces 6 do not extend to the top of the large corrugation unit 2, and the reinforcing member 5 is provided with a flat upper surface 7. A gas can flow between the top of the large corrugation unit 2 and the upper surface 7.

  The reinforcing member 5 of FIG. 4 is provided with a contour portion 7 having an outer shape corresponding to the shape of the large corrugation portion 2. Further, gas can pass through the reinforcing member 5 through the circular passage 9.

  In the modification shown in FIG. 5, the passage 9 has a shape corresponding to the outer shape of the contour portion 8, which is to ensure a larger area of the passage.

  The reinforcing member 5 shown in FIG. 6 has a contour portion 8 having an external shape corresponding to the shape of the large corrugation portion 2 and a passage 9. In order to improve the mechanical strength of the reinforcing member 5, a plurality of cobweb-shaped reinforcing portions 10 formed inside the passage 9 are provided across the passage 9. 7 to 9 are views showing alternative configurations of the plurality of cobweb-shaped reinforcing portions 10.

  The reinforcing member shown in FIGS. 3 to 9 can be configured using any of the following materials as an example: polyethylene, polycarbonate, glass fiber reinforced polycarbonate, polyetherimide, and polystyrene foam. The reinforcing member can be manufactured using any suitable technique (injection molding, casting, extrusion, machining, etc.).

  The plurality of reinforcing members 5 shown in FIGS. 10 and 11 have a solid cross section, and each side surface 6 has two flat bands. As in the reinforcing member shown in FIG. 3, gas can pass between the upper surface 7 and the top of the corrugation portion. The plurality of reinforcing members 5 shown in FIGS. 10 and 11 can be realized by, for example, machined plywood.

  The reinforcing member 5 of FIG. 11 may include a protrusion 22 fixed to the back surface 23 thereof. The protrusion 22 is provided to fix the reinforcing member 5 to the plywood 4, and may be provided, for example, at a joint portion between two sheet members of the plywood.

  FIG. 12 shows the geometric shape of the corrugation part at the intersection of the large corrugation part 2 and the small corrugation part 3 on the right side. It can be seen that the membrane has an undercut 20 at this site. The right side portion of FIG. 12 shows that the reinforcing member 5 disposed below the large corrugation portion 2 has a plurality of tabs 21 at the end portions. The reinforcing member 5 is configured to be fixed to the thin film by being locked to the undercut 20. As a variant, the plurality of tabs 21 may be pushed into (undercut 20).

  FIG. 13 is a perspective view of the reinforcing member 5 disposed under the plurality of large corrugation portions 2 and the small corrugation portions 3 at the same time. The shape of the reinforcing member 5 corresponds to the shape of the corrugation part including the intersecting part. The plurality of passages 9 extending inside are provided so as to extend below the plurality of small corrugations 3 and similarly below the plurality of large corrugations 2. FIG. 14 shows two reinforcing members 5, one of which is arranged below one large corrugation part 2 at the intersection of the corrugation part and the other is one small corrugation part 3. It is configured to be arranged below. Here, each of the plurality of reinforcing members 5 includes a notch 24 for positioning with respect to each other. As understood from the figure, the plurality of reinforcing members 5 have a rectangular cross section.

  The reinforcing member 5 having a plurality of different shapes described herein allows the corrugation part to be deformed when it is thermally contracted, and the corrugation part when the corrugation part is deformed due to hydrostatic pressure and dynamic pressure. Provides support for the part. To achieve this purpose, when the tank is empty (and therefore there is no thermal load, hydrostatic pressure or dynamic pressure), the reinforcing member 5 and the reinforcing member 5 are present below it. It is conceivable that the shortest distance between the corrugation part is 0% to 5% of the height of the corrugation part.

  Each of the reinforcing members 5 having a plurality of different forms has specific properties. That is, manufacturing cost and ease of manufacture, mechanical strength, raw material requirements, and the like. In a specific application aspect, the most appropriate form can be selected as appropriate.

In order to verify the effect of the reinforcing member 5 on the stress generated in the thin film when compared with a thin film having no reinforcing member, a numerical simulation was performed. With these simulations,
-In the case of thermal load (shrinkage of the thin film due to cold air), even if the reinforcing member 5 is present, undesirable stress is not generated in the thin film.
-In the case of a thermal load and a uniform pressure load (corresponding to the hydrostatic pressure of the cargo), the reinforcing member 5 is provided, whereby the stress in the thin film can be reduced, and
-In the case of a thermal load and an asymmetric pressure load (corresponding to the dynamic pressure of a ship), it is shown that the stress in the thin film can be reduced by providing the reinforcing member 5.

  While the invention has been described in connection with specific embodiments, it is obvious that the invention is not limited to such specific embodiments, and without departing from the scope of the invention. Obviously, technical equivalents and combinations thereof corresponding to the described embodiments are also included.

DESCRIPTION OF SYMBOLS 1 Sheet | seat member 2 Large corrugation part 3 Small corrugation part 4 Plywood 5 Reinforcement member 6 Side surface 7 Upper surface 8 Outline part 9 Passage 10 Cobweb reinforcement part 20 Undercut 21 Tab 22 Protrusion 23 Back surface 24 Notch

Claims (15)

In a tank for sealing a fluid with at least one wall,
(A) The at least one wall portion is provided so as to be in contact with a product contained in a tank that seals the fluid, and is provided adjacent to the thin film that seals the fluid. And a support part,
(B) the thin film is composed of at least one sheet member having at least one corrugation part;
(C) A reinforcing member is inserted under the corrugation part so as to be disposed between the thin film and the support part,
(D) Outside the reinforcing member, a contour portion having a shape corresponding to the shape of the corrugation portion is provided, and
(E) The reinforcing member is provided with an internal passage, and the internal passage is arranged such that gas flows across the reinforcing member between the corrugation portion and the support portion via the internal passage. Is provided through the reinforcing member.   The internal passage has a shape corresponding to the outer shape of the contour portion of the reinforcing member, and the contour portion has a contour wall portion having a uniform thickness over a peripheral edge portion of the contour portion. The tank according to claim 1, wherein   The contour portion of the reinforcing member has a flat base surface in contact with the support portion, and the contour wall portion of the contour portion has an increased thickness at both ends of the base surface. The tank according to claim 2, wherein a portion is provided.   The tank according to claim 2 or 3, wherein at least one cobweb-shaped reinforcing portion is provided inside the contour portion of the reinforcing member.   Inside the internal passage, at least one cobweb-like reinforcing portion is provided across the internal passage, and the internal passage is divided into a plurality of portions by the cobweb-like reinforcing portion. The tank according to claim 4, wherein   The tank according to claim 1, wherein the internal passage is circular.   The said reinforcing member is comprised with the material chosen from the group which consists of a plywood, polyethylene, a polycarbonate, glass reinforcement | strengthening polycarbonate, polyetherimide, and a polystyrene foam, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. Tank. The shortest distance between the reinforcing member and the corrugation part in a state where the product is not present in the tank is 0% to 5% of the height of the corrugation part. The tank according to claim 1, 2, 3 or 6.   The sheet member includes a first row corrugation unit composed of a plurality of corrugation units parallel to each other and a second row corrugation unit composed of a plurality of corrugation units parallel to each other, wherein the second row corrugation unit is The first row corrugation unit is provided across the first row corrugation unit, and the reinforcing member is inserted under one of the corrugation units belonging to the first row corrugation unit. The tank according to 3 or 6.   The tank according to claim 9, wherein the reinforcing member has a length corresponding to a distance between two corrugation parts belonging to the second row corrugation part.   The tank according to claim 1, 2, 3, or 6, wherein the reinforcing member is inserted under the corrugation part so as to be slidable with respect to the thin film and the support part.   The tank according to claim 1, wherein the reinforcing member is fixed to the thin film or the support portion.   The tank according to claim 12, wherein the thin film is provided with an undercut, and the reinforcing member is locked or pushed into the undercut.   At least two of the reinforcing members are respectively disposed under two corrugation portions of the adjacent thin film, and one of the two reinforcing members is a stop portion for the other of the two reinforcing members. The tank according to claim 1, 2, 3 or 6.   A floating body comprising the tank according to claim 1, 2, 3 or 6.

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