JP7595092B2 - A self-supporting case suitable for supporting and insulating a sealing membrane - Google Patents

Description

The invention relates to the field of sealed, insulated tanks for containing fluids that are integrated into a support structure, and in particular to the field of tanks with a membrane for containing liquefied gases, in particular fuel gases. The invention also relates in particular to a free-standing wooden case suitable for supporting and insulating the membrane of the tanks mentioned above.

Sealed insulated tanks can be used to store fluids in various industries. For example, in the energy sector, liquefied natural gas (LNG) is a liquid with high methane content that can be stored at atmospheric pressure and approximately -163°C in tanks installed on floating structures or in shore storage tanks. Liquefied petroleum gas (LPG) can be stored at temperatures between -50°C and 0°C.

In the case of a floating structure, the tank may be for containing liquefied gas used as propulsion gas for the floating structure or for transporting liquefied gas.

Known, for example from FR 2 867 831 A1, is a free-standing wooden case suitable for supporting and insulating a sealing membrane for containing fluids, which case:
A bottom panel;
a side web secured to the bottom panel and projecting perpendicularly from one side of the bottom panel to define an interior space of the case;
a cover panel supported and secured to the upper edges of the side webs, the cover panel being parallel to and spaced from the bottom panel and closing the interior space of the case, the cover panel comprising an upper plate and a lower plate secured to one another in overlapping relation;
at least one groove formed in the cover panel, the groove being open at the upper surface of the cover panel and adapted to receive a welding support for fixing a sealing membrane to the cover panel;
at least one support partition extending longitudinally, vertically along the or each groove and parallel thereto, the support partition being disposed perpendicular to the bottom panel and the cover panel, extending between the side webs and dividing the interior space into a plurality of compartments for receiving insulating stuffing, the support partition having an upper surface in contact with the lower plate of the cover panel and a lower surface in contact with the bottom panel;
a fastener that engages the lower plate and the upper surface of the support partition perpendicularly to secure the support partition to the cover panel;
It is equipped with:

In FR-A-2 867 831, the above-mentioned self-supporting case is used to manufacture a primary insulation barrier supporting a primary sealing membrane. The primary sealing membrane is welded to a welded support which forms a slip joint with a mounting strip stapled in a groove. To do this, a longitudinal groove passes through the two boards of the cover panel and the upper part of the supporting partition below it, between the two rows of staples.

It is also common to use secondary self-supporting cases with a simple cover plate in which a groove with a T-shaped section is formed to receive a welded support in the form of a right-angled wing, as described, for example, in FR-A-2 867 831 or WO-A-8 909 909. In FR-A-2 867 831, no upper or lower support partitions are provided along the groove. In WO-A-8 909 909, the cover plate is fixed to the lower support partition by means of a screw accommodated in the bottom of the groove.

One object of the present invention is to provide a high strength, self-supporting case that can be used to manufacture the primary insulation barrier of tanks that are subject to dynamic pressures and shocks caused by cargo movement. Another object of the present invention is to enable the use of welded supports, e.g. in the form of right angle bent wings, also in the primary sealing membrane, in order to simplify or standardize the manufacturing procedure of the parts and reduce part inventory.

To achieve the above object, the present invention provides the above-mentioned freestanding case, characterized in that the groove has a portion having a wide bottom portion and a narrow opening portion in the thickness direction of the upper plate, the upper surface of the support partition is wider than the bottom portion of the groove, and the fastener engages with an area of the lower plate that is offset laterally from the bottom portion of the groove.

The above configuration means that the fastener that engages with the lower plate to secure the support partition to the cover panel does not weaken the cover panel in the vertical direction along the groove. Therefore, the above configuration can reliably secure the support partition while improving the mechanical strength of the cover panel compared to conventional cases.

In an embodiment, the freestanding case may have one or more of the following configurations:

Preferably, the groove is formed only in the top plate of the cover panel.

Preferably, the fastener fastens the support partition to the cover panel independently of the upper plate. With this configuration, the upper plate of the cover panel is not weakened by the presence of the fastener.

In one embodiment, the groove has a T-shaped portion, the bottom portion of the groove corresponds to the horizontal bar portion of the T-shape, and the opening portion corresponds to the vertical bar portion of the T-shape.

In one embodiment, the bottom portion of the groove has a width of 20-30 mm.

In one embodiment, the difference between the width of the bottom portion of the groove and the width of the top surface of the support partition is more than 10 mm.

In one embodiment, the center line of the bottom portion of the groove is disposed vertically along the central plane of the support partition.

In one embodiment, the fasteners are arranged on both sides of the central plane of the support partition.

In one embodiment, the support divider is made from wood, plywood or composite material.

In one embodiment, the width of the support partition is uniform and is wider than the bottom portion of the groove.

In another embodiment, the internal partition has an upper base plate arranged parallel to the lower plate and a central portion arranged below the upper base plate, the upper base plate being wider than the bottom portion of the groove, and the width of the central portion being equal to or less than the width of the bottom portion of the groove.

In one embodiment, the support partition has a multi-layer structure in the width direction, the multi-layer structure comprises a core made of an insulating material and two side plates having a higher rigidity than the insulating material, the fasteners engaging the side plates. For example, the insulating material is selected from polymer foams, in particular polyurethane foams, mineral fibers, in particular glass wool, cotton wool and expanded polystyrene.

In one embodiment, two of the grooves are formed in the cover panel parallel to each other, and the internal partitions extend vertically along each of the grooves.

In one embodiment, the overall shape of the case is a rectangular parallelepiped.

In one embodiment, the present invention also provides a sealed, insulated tank for storing a fluid, comprising a tank wall secured to a support wall,
The tank wall comprises, in a thickness direction from the outside to the inside of the tank, a secondary insulation barrier fixed to the support wall, a secondary sealing membrane fixed to the secondary insulation barrier, a primary insulation barrier fixed to the secondary sealing membrane, and a primary sealing membrane fixed to the primary insulation barrier, the primary insulation barrier essentially consisting of a number of the above-mentioned cases arranged side by side and filled with insulating stuffing, and the primary sealing membrane is fixed to the cover panel of the case by weld supports placed in the grooves.

In one embodiment, the fluid is a liquefied gas, such as liquefied natural gas, liquefied petroleum gas, or liquefied ethylene.

The tanks described above may be part of a coastal storage facility, e.g. for storing LNG, a storage facility located on the seabed, or may be located on a floating, coastal or deep sea structure, in particular a methane tanker vessel, a floating storage and regasification unit (FSRU), a floating production and storage offshore facility (FPSO), etc.

In one embodiment, a vessel for transporting a fluid comprises a double hull and the tank described above disposed within the double hull. In one embodiment, the inner hull of the double hull provides a support wall for the tank.

In one embodiment, the present invention also provides a method for loading or unloading the vessel described above, transporting fluid from the floating or onshore storage facility to the tank of the vessel or from the tank of the vessel to the floating or onshore storage facility via the insulated pipeline.

In one embodiment, the present invention also provides a transfer system for a fluid, the transfer system comprising a vessel as described above, an insulated pipeline arranged to connect the tank installed in the hull of the vessel to a floating or onshore storage facility, and a pump for driving a fluid from the floating or onshore storage facility to the tank of the vessel or from the tank of the vessel to the floating or onshore storage facility via the insulated pipeline.

The present invention will be better understood and other objects, details, features and advantages of the present invention will become more apparent from the following description of several specific embodiments of the present invention, taken in conjunction with the accompanying drawings. The specific embodiments described below are merely illustrative and are not intended to limit the present invention.

FIG. 1 is a cutaway perspective view of a sealed insulated tank wall that may use a freestanding case. FIG. 2 is a side view of a free-standing case suitable for the primary insulation barrier of the tank wall of FIG. FIG. 3 is an enlarged view of region III of FIG. 2 showing one embodiment of the support divider; FIG. 3 is an enlarged view of region III of FIG. 2, showing another embodiment of the support partition; FIG. 3 is an enlarged view of region III of FIG. 2, showing another embodiment of the support partition; FIG. 1 is a schematic extract showing a methane tanker ship tank and a terminal for carrying out loading and unloading operations of said tank.

Figure 1 shows the overall structure of a sealed, insulated tank wall 1, which is assembled and fixed to a support wall 2. The tank wall 1 can be part of tanks of various geometric shapes, for example polyhedral. Figure 1 shows a top view of the tank wall 1, with a cutaway portion thereof shown to illustrate the structure. Such a structure can be realized on a wide range of surfaces in various orientations, for example covering the bottom, ceiling and side walls of a polyhedral tank. Thus, the orientation of Figure 1 is not limiting in this respect. By convention, "up" refers to a position closer to the inside of the tank and "down" refers to a position closer to the support wall 2, regardless of the orientation of the tank wall relative to the Earth's gravitational field.

The tank wall 1 is composed of, in order in the thickness direction, a secondary insulation barrier 3 consisting of a support wall 2 on which a number of cases are arranged and fixed to the support wall 2 by secondary fixing members, a secondary sealing membrane 4 supported by the secondary insulation barrier 3, a primary insulation barrier consisting of a secondary sealing membrane 4 on which a number of cases 5 are arranged and fixed to the secondary sealing membrane 4 by primary fixing members fixed to the secondary fixing members, and a primary sealing membrane 6 supported by the cases 5. The secondary and primary fixing members are described, for example, in French Patent Application Publication No. 2 798 902.

The primary sealing membrane 6 may consist of a continuous layer of strakes 10 made of a steel with a high nickel content, for example 37%, known under the name Invar®, whose expansion coefficient is typically between 1.2×10 ⁻⁶ and 2×10 ⁻⁶ K ⁻¹ . It is also possible to use an alloy of iron and manganese, whose expansion coefficient is typically of the order of 7 to 9×10 ⁻⁶ K ⁻¹ . The strakes 10 are sealingly welded with their raised side edges to parallel weld supports 8 held in grooves in the cover panel 7 of the case 5. The secondary sealing membrane 4 may also be made identically, as shown in FIG. 1, or differently. Reference numeral 9 denotes grooves for receiving the weld supports of the secondary sealing membrane 4.

A part of the case 5 is shown in FIG. 1, and the overall shape of the case 5 is a parallelepiped. FIG. 2 is a plan side view of the case 5 at the point indicated by the arrow II in FIG. 1.

2, the lower plate 22 and the upper plate 21 are fixed to each other, for example by screwing, gluing and/or stapling, to form a cover plate. The upper plate 21 and the lower plate 22 are fixed to each other, for example, at the periphery of the support partition 26, 126 or 226, along the secondary partition 25 in the up-down direction, while the upper plate 21 and the lower plate 22 are fixed by the secondary partition 25. The bottom panel 23 and the cover panel 7 have a rectangular outline and are separated from each other by two longitudinal end webs 27 and two lateral end webs 24, forming the outline of the internal space of the case 5. This internal space is divided by two support partitions 26 arranged in the up-down direction along the groove 30 and, if necessary, by a secondary partition 25, which can be narrower than the support partition 26. The support dividers 26 and the secondary dividers 25 extend longitudinally at right angles to the two longitudinal end webs 27 and parallel to the two lateral end webs 24. All the above elements are fixed as required by stapling, screwing and/or gluing. For example, the secondary dividers 25 have a width of 12 mm, and the longitudinal end webs 27 and the lateral end webs 24 have a width of 12-24 mm.

To provide the case 5 with an insulating function, the above-mentioned compartments are filled with an insulating filler, which is made of a material selected from the group consisting of expanded perlite, particulate or fibrous aerogel material, expanded polystyrene, glass wool, cellulosic cotton wool, low-density polymer foams such as polyethylene or polyurethane.

The dimensions of the case 5 can of course be different from the example shown in FIG. 2. The case 5 can have one support partition 26 and one groove 30 in its width, or there can be more than two support partitions 26 and more than two grooves 30 in its width.

As can be seen in FIG. 3, the groove 30 has an inverted T-shaped section with a wide horizontal base portion 32 and a narrow vertical opening portion 31 to accommodate the right-angled wings of the known art. Alternatively, the base portion 32 could extend to one side of the opening portion so that the groove has an L-shaped section.

The support partition 26 is a single piece of plywood, the width of which is greater than the width of the bottom portion 32. This excess width allows the row of staples 35 to be laterally offset from the bottom portion 32, i.e., outside the area directly aligned with the groove 30 in the vertical direction, to be fixed to the lower plate 22. This configuration ensures the rigidity of the cover panel 7, even though the groove 30 is relatively wide, for example its bottom portion 32 being 24 mm wide. Indeed, even if the staples 35 can locally reduce the rigidity of the lower plate 22 of the cover panel, the places where this weakening occurs are not the same as the narrow places of the groove 30. Preferably, the excess width of the support partition 26 is more than 10 mm. For example, the width W is 36 mm or more, preferably 42 mm.

In FIG. 3, the stiffness of the cover panel 7 is further increased by the following measures:
The grooves 30 are only formed in the upper plate 21 of the cover panel, so that they do not affect the stiffness of the lower plate 22.
The fasteners 35 do not affect the stiffness of the top plate 21 .
The support partition 26 is centred below the groove 30 and is symmetrical with respect to the mid-plane.
The fasteners 35 are arranged on either side of the central plane of the support compartment.

Figure 4 shows another embodiment of the support partition 126, which has a multi-layer structure in the width direction, including a core 41 made of insulating material and two side plates 42, which are more rigid than the insulating material, and which are provided on either side of the core 41. The fasteners 35 engage the side plates 42, which are made of plywood, for example. This configuration reduces thermal bridges and weight for the support partition 26. For example, the side plates 42 have a width of 12 mm.

Figure 5 shows another embodiment of the support partition 226, which has, in order in the thickness direction of the case 5, an upper base plate 52 arranged parallel to the lower plate 22 and a central portion 51 arranged below the upper base plate 52. The width of the upper base plate 52 is greater than the width of the bottom portion 32. Conversely, the width of the central portion 51 can be less than or equal to the width of the bottom portion 32 of the groove 30. The upper base plate 52 and the central portion 51 are made of plywood, for example. This configuration can reduce thermal bridges and weight relative to the support partition 26. For example, the width of the central portion 51 is 18 to 30 mm, preferably 24 mm. For example, the width of the upper base plate 52 is greater than 24 mm, such as 42 mm, 50 mm, or 60 mm.

In one embodiment, the width of the upper shim 52 can be equal to or less than the spacing between the support partition 226 and the secondary partition adjacent to the support partition 226. In one embodiment, the support partitions 226 and, if present, the secondary partitions 25, are distributed at a uniform spacing pitch, and the width of the upper shim 52 can be equal to or less than the uniform spacing pitch.

FIG. 2 also shows other configurations of the free-standing case 5 that can be used depending on the following requirements:
- Holes 28 are formed in the webs 27 of the case 5 to allow circulation of an inert gas within the primary insulating barrier.
- in front of each hole 28, a gas-permeable plug 17 made of woven glass fibre is glued to the inner surface of the web 27 to avoid leakage of the insulating filling.
- Fixing tenons 19, which serve as a bearing surface for the primary fixing members, are fixed to webs 27 at the edges of the bottom panel 23;
Between the webs 24, the stiffener comb 16 extends perpendicular to the support partition 26 and the secondary partition 25 at a right angle to the bottom panel 23. At the intersection of the stiffener comb 16 with the support partition 26 and the secondary partition 25, the stiffener comb 16 has a notch which fits into the support partition 26 and the secondary partition 25.
- the grooves 18 formed in the bottom panel 23 and the support partition 26 allow the protruding portion of the secondary sealing membrane 4 to be accommodated.

Instead of plywood, composite materials can be used to make all or part of the freestanding case. For example, WO 2015/079135 teaches suitable composite materials.

The case 5 can be used to form the entire primary insulation barrier or only in certain parts of the tank. For example, the case 5 can be used near the edge of the tank and other insulation blocks can be used in other parts of the tank wall. Such an arrangement is described, for example, in WO 2019/077253.

With reference to FIG. 6, a cutaway view of a methane tanker ship 70 shows a sealed, insulated tank 71, of prismatic overall shape, mounted within the double hull 72 of the ship. The walls of the tank 71 comprise a primary containment barrier in contact with the liquefied gas contained in the tank, a secondary containment barrier disposed between the primary containment barrier and the ship's double hull 72, and two insulating barriers disposed between the primary containment barrier and the secondary containment barrier and between the secondary containment barrier and the double hull 72, respectively. In one simplified variant, the ship comprises a single hull.

As will be appreciated, a suitable connector may be used to connect the cargo pipeline 73 located on the upper deck of the vessel to an offshore or port terminal for transferring a cargo of liquefied gas to or from the tank 71.

6 shows an example of a marine terminal with a loading station 75, a subsea line 76 and a shore facility 77. The loading station 75 is a fixed offshore facility consisting of a movable arm 74 and a tower 78 supporting the movable arm 74. The movable arm 74 supports a bundle of insulated flexible pipes 79 that can be connected to a loading pipeline 73. The movable arm 74 is directional adjustable and is suitable for all types of methane tankers. A connecting line (not shown) runs inside the tower 78. The loading station 75 allows unloading from the methane tanker 70 to the shore facility 77 and loading from the shore facility 77 to the methane tanker. The shore facility 77 includes a liquefied gas storage tank 80 and a connecting line 81 connected to the loading station 75 by a subsea line 76. The undersea line 76 is for transporting liquefied gas over long distances, such as 5 km, between the loading station 75 and the coastal facility 77, allowing the methane tanker vessel 70 to be located far from the coast during loading and unloading operations.

To generate the pressure required for the transport of liquefied gas, pumps installed on the ship 70 and/or pumps installed on the shore facility 77 and/or pumps installed on the loading station 75 are provided.

Although the present invention has been described with reference to several specific embodiments, it is clear that the present invention is in no way limited to these specific embodiments, and that all technical equivalents of the above means and all technically equivalent combinations of the above means fall within the framework of the present invention.

The use of the verb "comprise" or "include" and its conjugated forms does not exclude the presence of elements or steps other than those stated in a claim.

In the claims, any reference signs in parentheses shall not be construed as limiting the scope of the claims.

Claims (17)

A self-supporting case (5) for containing a fluid, suitable for supporting and insulating a sealing membrane (6),
A bottom panel (23);
a side web (24, 27) fixed to the bottom panel and projecting perpendicularly from one side of the bottom panel to define the interior space of the case;
a cover panel (7) supported and fixed on the upper edges of the side webs, parallel to and spaced from the bottom panel, closing the interior space of the case, the cover panel (7) comprising an upper plate (21) and a lower plate (22) fixed one on top of the other;
At least one groove (30) formed in the cover panel, the groove (30) opening on a top surface of the cover panel;
at least one support partition (26, 126, 226) extending longitudinally, vertically along and parallel to said groove (30), said support partition (26, 126, 226) being arranged perpendicular to said bottom panel (23) and said cover panel (7) and extending between said side webs (27) to divide said interior space into a number of compartments for containing insulating padding, said support partition (26, 126, 226) having an upper surface in contact with said lower plate (22) of said cover panel and a lower surface in contact with said bottom panel;
a fastener (35) that engages the lower plate (22) and the upper surface of the support partition (26, 126, 226) perpendicularly to secure the support partition to the cover panel;
In case (5) with
The groove (30) has, in the thickness direction of the upper plate, a wide bottom portion (32) and a narrow opening portion (31),
the grooves are shaped to receive welding supports (8) in the form of right-angled wings for fastening the sealing membrane (6) to the cover panel (7);
the top surface of the support partition (26, 126, 226) is wider than the wide bottom portion (32) of the groove;
The case is characterized in that the fastener (35) engages in an area of the lower plate (22) that is offset laterally from the wide bottom portion (32) of the groove. The groove (30) is formed only in the top plate (21) of the cover panel;
The case according to claim 1. The fastener (35) fastens the support partition (26, 126, 226) to the cover panel independently of the top plate (21).
3. A case according to claim 1 or 2. The groove (30) has a T-shaped portion, the wide bottom portion (32) of the groove corresponds to the horizontal bar of the T-shape, and the narrow opening portion (31) corresponds to the vertical bar of the T-shape.
A case according to any one of claims 1 to 3. The wide bottom portion (32) of the groove has a width of 20 to 30 mm.
A case according to any one of claims 1 to 4. The difference between the width of the wide bottom part (32) of the groove and the width (W) of the upper surface of the support partition is more than 10 mm;
A case according to any one of claims 1 to 5. the center line of the wide bottom portion (32) of the groove is disposed vertically along the center plane of the support partition (26, 126, 226);
A case according to any one of claims 1 to 6. The fasteners (35) are arranged on either side of the central plane of the support partition.
A case according to any one of claims 1 to 7. the support partition (26, 126, 226) is made of wood, plywood or composite material;
A case according to any one of claims 1 to 8. The width of the support partition (26, 226) is uniform and is wider than the wide bottom portion of the groove.
A case according to any one of claims 1 to 9. The support partition (226) has an upper base plate (52) arranged parallel to the lower plate (22) and a central portion (51) arranged below the upper base plate,
The upper liner (52) is wider than the wide bottom portion (32) of the groove, and the width of the central portion (51) is equal to or less than the width of the wide bottom portion (32) of the groove.
A case according to any one of claims 1 to 9. The support partition (126) has a multi-layer structure in the width direction,
The multi-layer structure comprises a core (41) made of insulating material and two side plates (42) of higher rigidity than the insulating material,
The fastener (35) engages the side plate (42);
A case according to any one of claims 1 to 10. The two grooves (30) are formed in the cover panel parallel to each other, and the internal partitions (26, 126, 226) extend vertically along each of the grooves.
A case according to any one of claims 1 to 12. A sealed, insulated tank for storing a fluid, comprising a tank wall (1) fixed to a support wall (2),
The tank wall includes, in a thickness direction from the outside to the inside of the tank, a secondary insulating barrier (3) fixed to the support wall (2), a secondary sealing membrane (4) fixed to the secondary insulating barrier, a primary insulating barrier fixed to the secondary sealing membrane, and a primary sealing membrane (6) fixed to the primary insulating barrier.
The primary insulation barrier comprises a plurality of cases (5) according to any one of claims 1 to 13 arranged side by side and filled with an insulating fill,
1. A tank sealed and insulated according to claim 1, wherein the primary sealing membrane (6) is fixed to the cover panel of the case by means of welded supports (8) placed in the grooves (30). A vessel (70) for transporting a fluid, comprising:
A ship (70) comprising a double hull (72) and the sealed insulated tank of claim 14 disposed within the double hull (72). 1. A transfer system for a fluid, comprising:
A vessel (70) according to claim 15;
an insulated pipeline (73, 79, 76, 81) arranged to connect the sealed insulated tank (71) of the vessel to a floating or coastal storage facility (77);
a pump for driving fluid from the floating or onshore storage facility to the sealed insulated tank of the vessel or from the sealed insulated tank of the vessel to the floating or onshore storage facility through the insulated pipeline;
A transfer system comprising: 16. A method for loading or unloading a vessel (70) according to claim 15, comprising the steps of:
A method for transporting fluid from said floating or coastal storage facility (77) to said sealed, insulated tank (71) of said vessel or from said sealed, insulated tank (71) of said vessel to said floating or coastal storage facility (77) via an insulated pipeline (73, 79, 76, 81).

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