JP7499753B2 - Insulated sealed tank wall - Google Patents

Description

The present invention relates to the field of sealed insulated tanks with a membrane. In particular, the present invention relates to the field of sealed insulated tanks for storing and/or transporting low-temperature liquefied gases, such as tanks for transporting liquefied petroleum gas (also called LPG) having a temperature between -50°C and 0°C, or for transporting liquefied natural gas (LNG) at about -162°C under atmospheric pressure. These tanks can be installed on land or on water structures. In the case of water structures, the tanks can be intended to transport or receive liquefied gas to be used as fuel for propelling the water structure.

Document WO2014/167227 discloses a sealed insulated tank for storing liquefied gas in a structure with a support wall. The tank comprises a tank wall attached to the support wall, the tank wall including an insulating barrier consisting of a plurality of juxtaposed insulating blocks, and a sealing membrane consisting of a plurality of corrugated sheets sealably welded together.

To attach the sealing membrane to the insulating barrier, a retaining element in the form of a rail is inserted into a groove formed in the insulating block of the insulating barrier. The sheets forming the sealing membrane are then welded via their edges to the rail inserted at their edges in the groove. Each sheet of the sealing membrane is thus attached to the insulating barrier in such a way that it maintains a translational mobility in the longitudinal direction of the rail. In fact, due to the rail being slidably attached in the groove, the membrane sheet maintains the same mobility as the rail. The edges of the membrane sheets are thus free to displace, reducing stresses in the membrane.

However, the retaining elements of the prior art documents have some drawbacks. Indeed, they relate to a particularly complex and expensive design. Furthermore, it is necessary to improve the mechanical resistance of these elements in order to absorb the stresses to which the sealing membrane is subjected over the long term.

One idea behind the present invention is to improve the sliding attachment of the sealing membrane to the insulating barrier while maintaining sufficient mechanical resistance to withstand the stresses exerted by the sealing membrane during attachment.

According to one embodiment, the present invention provides a sealed, insulated tank wall for forming a sealed, insulated tank for storing liquefied gas, comprising:
a sealing membrane intended to be in contact with the liquefied gas contained in the tank, the sealing membrane having a corrugated metal plate;
an insulating barrier forming a support surface for the sealing membrane and having a longitudinally extending groove;
At least one weld support supported by the thermal barrier, the weld support having a lower part held in a groove of the thermal barrier in a direction perpendicular to the support surface, an upper part parallel to the support surface, and an intermediate part connecting the lower part to the upper part, the intermediate part being disposed in the groove in the thickness direction of the thermal barrier,
At least one weld support is slidably mounted in the groove in the longitudinal direction, and the corrugated metal plate is welded to an upper portion of the weld support;
The upper portion of the welded support is received in a countersink formed in the insulating barrier adjacent the groove, thereby providing a tank wall in which the upper portion of the welded support is positioned between the sealing membrane and the insulating barrier and in the extension of the support surface.

The longitudinal direction is defined as the direction parallel to one of the edges of the corrugated metal plate.

These features allow the welded support to attach the sealing membrane to the insulating barrier while still maintaining longitudinal freedom due to the sliding assembly of the welded support in the groove. This freedom allows the edges of the metal plate to move slightly relative to the insulating barrier during temperature fluctuations, which reduces stress concentrations and improves the distribution of forces and movements experienced by the corrugated plate, thereby reducing fatigue of the sealing membrane.

Furthermore, the top of the welded support rests in a counterbore created in the insulating barrier, which allows the welded support to be placed in the extension of the support surface of the insulating barrier, thus reducing the manufacturing costs of the assembly by eliminating the need for additional machining of the corrugated metal plate. Furthermore, the counterbore allows the top of the welded support to be supported by the insulating barrier, so that the mechanical forces of the top of the welded support, in particular the pressure stresses acting on the sealing membrane in the thickness direction of the tank wall, are transferred to the insulating barrier.

According to various embodiments, such tank walls may have one or more of the following features:

According to one embodiment, the weld support is an elongated element that extends in the same direction as the groove.

According to one embodiment, the tank wall comprises a plurality of weld supports held in the grooves. The weld supports may be spaced apart from one another or may be arranged continuously within the grooves.

According to one embodiment, the longitudinally extending edges of the corrugated metal plate are welded to the top of the weld support.

According to one embodiment, the groove is a longitudinal groove, the edge is a first edge, the weld support is a first weld support, the insulating barrier has a transverse groove extending laterally perpendicular to the longitudinal direction, the wall has a second weld support whose lower portion is held in the transverse groove of the insulating barrier, and the second edge of the transversely extending corrugated metal plate is welded to an upper portion of the second weld support.

According to one embodiment, the groove has an entrance zone extending in the thickness direction in the insulating barrier, the groove has a retention zone arranged below the entrance zone and established parallel to the support surface over a width larger than the entrance zone, and the lower part of the weld support is received in the retention zone.

This allows the retention zone to prevent movement of the lower part of the weld support, and therefore improves the prevention of movement of the entire weld support, through the thickness of the insulating barrier.

According to one embodiment, the retaining zones are established parallel to the support surface on both sides of the inlet zone, the welded support has a first segment and a second segment, the first segment has a lower part retained in the retaining zone of the insulating barrier in a direction perpendicular to the support surface, an upper part parallel to the support surface and accommodated in a counterbore adjacent to the groove, whereby the upper part of the first segment is located between the sealing membrane and the insulating barrier and in the extension of the support surface, and an intermediate part connecting the lower part of the first segment to the upper part of the first segment and arranged in the groove in the thickness direction of the insulating barrier, the second segment has a lower part retained in the retaining zone of the insulating barrier in a direction opposite to the direction of the lower part of the first segment and an intermediate part welded to the intermediate part of the first segment, the upper part of the first segment being welded to the corrugated metal plate.

Due to these characteristics, the first segment allows the sealing membrane to be slidably attached to the insulating barrier. Furthermore, the second segment allows the weld support to be strengthened, especially in the middle part, and allows the movement of the weld support to be restricted in the lateral direction, i.e. in the direction of the lower part of the weld support. The second segment also allows the forces experienced by the corrugated metal plate to be distributed over twice the surface area of the insulating barrier, thereby increasing the vertical load resistance of the weld support as well as the resistance of the weld support to being pulled out of the groove.

According to one embodiment, the counterbore is a first counterbore and the insulating barrier has a second counterbore, the first and second counterbore are arranged on either side of the groove, the second segment has an upper portion parallel to the support surface and accommodated in the second counterbore, whereby the upper portion of the second segment is arranged between the sealing membrane and the insulating barrier and in the extension of the support surface, and the middle portion of the second segment connects the lower portion of the second segment to the upper portion of the second segment.

These features allow the upper part of the second segment to rest in a second counterbore created in the insulating barrier, which allows the welded support to be placed in the extension of the support surface of the insulating barrier, thus reducing the manufacturing costs of the assembly by eliminating the need for additional machining of the corrugated metal plate. Furthermore, the second counterbore allows the upper part of the second segment to be supported by the insulating barrier, which improves the resistance of the welded support when stresses are applied to the sealing membrane, especially in the thickness direction of the tank wall.

According to one embodiment, the groove has an inlet zone extending through the thickness of the insulating barrier, the inlet zone having a fastener attached to the wall of the groove, and the lower part of the weld support is slidably received in the fastener.

This allows the fastener to prevent movement of the lower part of the weld support, thereby improving the prevention of movement of the weld support as a whole through the thickness of the insulating barrier.

According to one embodiment, the lower portion has a hook, the fastener has an opposing hook, and the hook is received in the opposing hook.

According to one embodiment, the fastener is a first fastener, the inlet zone has a second fastener attached to the wall of the groove opposite the first fastener, the welded support has a first segment and a second segment, the first segment has a lower part held by the first fastener of the insulating barrier in a direction perpendicular to the support surface and an upper part parallel to the support surface and accommodated in a counterbore adjacent to the groove, whereby the upper part of the first segment is located between the sealing membrane and the insulating barrier and in the extension of the support surface, the middle part of the first segment connects the lower part to the upper part, the middle part being arranged in the inlet zone in the thickness direction of the insulating barrier, the second segment has a lower part held by the second fastener of the insulating barrier and a middle part of the second segment welded to the middle part of the first segment.

Due to these features, the first segment allows the sealing membrane to be slidably attached to the insulating barrier. Furthermore, the second segment allows the weld support to be strengthened, especially in the middle part, and also allows the weld support to be restricted from movement in the lateral direction, i.e., in the direction of the lower part of the weld support.

According to one embodiment, the counterbore is a first counterbore and the insulating barrier has a second counterbore, the first and second counterbore are arranged on either side of the groove, the second segment has an upper portion parallel to the support surface and accommodated in the second counterbore, whereby the upper portion of the second segment is arranged between the sealing membrane and the insulating barrier and in the extension of the support surface, and the middle portion of the second segment connects the lower portion of the second segment to the upper portion of the second segment.

According to one embodiment, the metal plate welded to the top of the weld support is a first metal plate, the sealing membrane has a second corrugated metal plate having an offset portion welded above the first metal plate to form a sealed overlap between the two metal plates, and the weld between the top of the weld support and the first metal plate is located below the offset portion of the second metal plate.

According to one embodiment, the insulating barrier has a plurality of juxtaposed parallelepiped insulating panels, the upper portion of the welded support is held to one insulating panel of the insulating barrier, and the counterbore is formed in said insulating panel.

According to one embodiment, the insulation barrier has a plurality of juxtaposed parallelepiped insulation panels, and the groove is disposed between two adjacent insulation panels of the insulation barrier, whereby the inlet zone is the interpanel space.

Due to these features, the inlet zone does not require machining of the insulation panel, but only requires placing two panels a specific distance apart.

According to one embodiment, the insulation barrier has a plurality of juxtaposed parallelepiped insulation panels, and the groove is located in the center of one insulation panel of the insulation barrier.

According to one embodiment, the insulating barrier has a plurality of juxtaposed parallelepiped insulating panels, with the groove being located near the edge of one of the insulating panels.

The expression "near the edge of the insulation panel" means that the element is located at a distance from the edge that is between 0 and 10% of the lateral dimension of the insulation panel.

According to one embodiment, the groove is a first groove, the insulating barrier has a second groove extending longitudinally at a distance from the first groove, the counterbore extends between the two grooves, the upper part of the weld support is received in the counterbore extending between the two grooves, the lower part is a first lower part, the middle part is a first middle part, and the weld support has a second lower part and a second middle part connecting the second lower part to the upper part of the weld support, whereby the first lower part and the first middle part are disposed in the first groove, and the second lower part and the second middle part are disposed in a second groove separate from the first groove.

According to one embodiment, at least one or each of the lower portions is formed by a plurality of lower portions spaced apart from one another in the longitudinal direction, and at least one or each of the intermediate portions is formed by a plurality of intermediate portions spaced apart from one another in the longitudinal direction, whereby each intermediate portion connects one of the lower portions to the upper portion.

According to one embodiment, the top is a first top, the insulating barrier has a third transversely extending groove and a fourth transversely extending groove adjacent the third groove, the weld support has a second top received in a transverse counterbore extending between the third and fourth grooves, and the third and fourth grooves intersect the first and second grooves.

According to one embodiment, the third intermediate portion is disposed in the third groove and connected to the second upper portion, and the fourth intermediate portion is disposed in the fourth groove and connected to the second upper portion.

According to one embodiment, the insulating barrier is a primary insulating barrier, the sealing membrane is a primary sealing membrane, and the tank wall further comprises a secondary sealing membrane disposed below the primary insulating barrier, and a secondary insulating barrier having a plurality of juxtaposed parallelepiped insulating panels disposed below the secondary sealing membrane and forming a support surface for the secondary sealing membrane.

According to one embodiment, the secondary sealing membrane has a plurality of longitudinally parallel strakes, one of which has a flat central portion that rests on the upper surface of the insulating panel of the secondary insulating barrier and two raised edges that project relative to the central portion toward the primary sealing membrane, the strakes are juxtaposed laterally perpendicular to the longitudinal direction according to a repeating pattern and are sealably welded together at the raised edges, and a stator is fixed to the insulating panel of the secondary insulating barrier and is positioned between the longitudinally parallel juxtaposed strakes to hold the secondary sealing membrane on the secondary insulating barrier.

According to one embodiment, the secondary insulation barrier has a plurality of longitudinally parallel secondary rows, each secondary row having a plurality of juxtaposed parallelepiped secondary insulation panels, the secondary rows being juxtaposed laterally according to a repeating pattern, the dimensions of the repeating pattern of the secondary rows being an integer multiple of the dimensions of the strakes in the transverse direction.

According to one embodiment, the primary insulation barrier has a number of longitudinally parallel primary rows, one primary row having a number of juxtaposed parallelepiped primary insulation panels stacked on top of a secondary row, the primary rows being juxtaposed laterally according to a repeating pattern, the dimensions of the repeating pattern of the primary rows being equal to the dimensions of the repeating pattern of the secondary rows in the transverse direction.

According to one embodiment, the primary sealing membrane has first corrugations parallel to the longitudinal direction and arranged in a repeating pattern in the transverse direction, and flat portions disposed between the first corrugations and resting on an upper surface of the primary insulation panel;
a dimension of the repeat pattern of the primary sequence is an integer multiple of a dimension of the repeat pattern of the first waveform;
the primary sealing membrane has a plurality of longitudinally parallel rows of metal sheets, one row of metal sheets including a plurality of rectangular metal sheets sealably welded together via edge zones, the rows of metal sheets being juxtaposed in a transverse direction and sealably welded together, the dimensions of the one row of metal sheets in the transverse direction being equal to an integer multiple of the dimensions of the repeating pattern of the primary rows;
The rows of metal sheets are laterally offset relative to the primary rows such that the weld joints between the rows of metal sheets are spaced a distance from the interface between the primary rows.

According to one embodiment, the present invention provides a sealed insulated tank disposed within a support structure, the tank comprising a plurality of walls sealably attached together to form an interior space for receiving liquefied gas, at least one of the walls being a wall as described above.

Such tanks may form part of, for example, land-based storage facilities for storing LNG, or may be installed on water, coastal or deep-sea structures, in particular LNG tanker ships, floating storage and regasification units (FSRUs), floating production and storage units (FPSOs), etc. Such tanks may also be used as fuel tanks in any type of ship.

According to one embodiment, a vessel for transporting cryogenic liquid products comprises a double hull and the above tank disposed within the double hull.

According to one embodiment, the present invention also provides a method for loading or unloading such a vessel, in which a cryogenic liquid product is conveyed through an insulated pipeline between a surface or land-based storage facility and the vessel's tanks.

According to one embodiment, the present invention also provides a transfer system for cryogenic liquid products comprising a vessel as described above, an insulated pipeline arranged to connect a tank installed within the vessel's hull to a surface or land-based storage facility, and a pump for conveying a flow of cryogenic liquid product through the insulated pipeline between the surface or land-based storage facility and the vessel's tank.

The invention will be better understood and further objects, details, features and advantages thereof will appear more clearly through the following description of several particular embodiments thereof, which are given by way of non-limiting example only with reference to the accompanying drawings, in which:
FIG. 2 is a perspective cutaway view of a tank wall according to one embodiment. FIG. 2 is an exploded view of zone II of FIG. 1 . FIG. 2 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is an exploded view of Zone IV of FIG. 3 showing the welded supports attaching the primary sealing membrane to the primary insulating barrier according to a first embodiment. FIG. 4 is an exploded view of zone IV of FIG. 3 showing a welded support according to a second embodiment; FIG. 4 is an exploded view of zone IV of FIG. 3 showing a welded support according to a third embodiment; FIG. 4 is an exploded view of zone IV of FIG. 3 showing a welded support according to a fourth embodiment; FIG. 5 is an exploded view of zone IV of FIG. 3 showing a welded support according to a fifth embodiment; FIG. 10 is an exploded view of zone IV of FIG. 3 showing a welded support according to a sixth embodiment; FIG. 13 is a perspective view of a welding support according to a seventh embodiment. FIG. 13 is a perspective view of a welding support according to an eighth embodiment. FIG. 1 is a cutaway schematic view of a tank of an LNG tanker ship and a terminal for loading/unloading said tank.

Figure 1 shows the multi-layer structure of a wall 1 of a sealed, insulated tank for storing a liquefied fluid such as liquefied natural gas (LNG). Each wall 1 of the tank comprises, in order in the thickness direction from the outside to the inside of the tank, a secondary insulating barrier 3 held on a support structure 2, a secondary sealing membrane 4 supported on the secondary insulating barrier 2, a primary insulating barrier 5 supported on the secondary sealing membrane 4, and a primary sealing membrane 6 intended to be in contact with the liquefied natural gas contained in the tank.

In particular, the support structure may be formed by the hull or double hull of a ship. The support structure has a number of support walls 2 that define the overall shape of the tank, typically a polyhedral shape.

The secondary insulation barrier 3 has a number of secondary insulation panels 7 secured to the support wall 2 by a retaining device. The secondary insulation panels 7 have a general parallelepiped shape and are arranged in parallel rows. Three rows are designated by the letters A, B and C. A sealing bead 99 is inserted between the secondary insulation panel 7 and the support wall 2 to close the gap of the support wall 2 against a flat reference surface. Kraft paper is inserted between the sealing bead 99 and the support wall 2 to prevent the sealing bead 99 from adhering to the support wall 2.

3, the secondary insulation panel 7 has, for example, three plates, namely a base plate 8, an intermediate plate 9 and a cover plate 10. The base plate 8, the intermediate plate 9 and the cover plate 10 are made, for example, of plywood. The secondary insulation panel 7 also has a first insulating polymer foam layer 11 sandwiched between the base plate 8 and the intermediate plate 9 and a second insulating polymer foam layer 12 sandwiched between the intermediate plate 9 and the cover plate 10. The secondary insulation panel 7 may have another general structure, for example as described in document WO2012/127141. The secondary insulation panel 7 is then manufactured in the form of a casing having a base plate, a cover plate and a supporting web extending between the base plate and the cover plate in the thickness direction of the tank wall 1 and separating a number of compartments filled with an insulating lining such as perlite, glass wool or rock wool.

The secondary sealing membrane 4 comprises a continuous layer of metal strakes 13 with raised edges. The strakes 13 are welded via their raised edges 14 to parallel weld supports mounted in grooves in the cover plate 10 of the secondary insulation panel 7. The strakes 13 are made, for example, of Invar®, an alloy of iron and nickel, the coefficient of expansion of which 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, the coefficient of expansion of which is typically of the order of 7.10 ⁻⁶ K ⁻¹ .

The primary insulation barrier 5 comprises a number of primary insulation panels 15 fixed to the support wall 2 by a retaining device. The primary insulation panels 15 have a general parallelepiped shape. Furthermore, as shown in FIG. 1, they have the same dimensions as the secondary insulation panels 7, except that they may have a different, and in particular a thinner, thickness in the thickness direction of the tank wall 1. Each of the primary insulation panels 15 is located to the right of one of the secondary insulation panels 7 and is aligned with it in the thickness direction of the tank wall 1.

As can be seen in FIG. 3, the primary insulation panel 15 has a multi-layer structure similar to the secondary insulation panel 7. Furthermore, the primary insulation panel 15 has, in order, a base plate 16, a first insulating polymer foam layer 17, an intermediate plate 18, a second insulating polymer foam layer 19, and a cover plate 20. The insulating polymer foam may in particular be a polyurethane-based foam, optionally reinforced with fibers.

The base plate 16 has a groove intended to accommodate the raised edge 14 of the strake 13 of the secondary sealing membrane 4. The structure of the primary insulation panel 15 is as described above by way of example. Furthermore, in other embodiments, the primary insulation panel 15 may have another general structure, for example as described in document WO 2012/127141.

The tank wall 1 includes a welded support 26 for fixing the primary sealing membrane 6 to the primary insulating barrier 5. The welded support 26 is described below.

Figure 1 also shows that the primary sealing membrane 6 comprises a continuous layer of rectangular corrugated metal plate 21 having two series of mutually perpendicular corrugations. The first series of corrugations 22 extend to rows A, B, C of the insulation panels and are therefore perpendicular to the raised edges 14 of the strakes 13 and have equal spacing 40. The second series of corrugations 23 extend parallel to rows A, B, C of the insulation panels and are therefore parallel to the raised edges 14 of the strakes 13 and have equal spacing 41. Preferably, the first series of corrugations 22 are taller than the second series of corrugations 23.

The corrugated metal plates 21 are welded together according to known techniques by forming an overlap 24 along their visible edges as shown in Figures 4 to 9. Indeed, in the overlap between two adjacent corrugated metal plates 21, one of the corrugated metal plates 21 comprises an offset portion 25 that is located above the other of the corrugated metal plates 21.

The corrugated metal plate 21 preferably has width and length dimensions equal to an integer multiple of the spacing of the corresponding corrugations and an integer multiple of the dimensions of the primary insulation panel 15. Figure 1 shows a corrugated metal plate 21 whose size is 4 times the spacing 40 by 12 times the spacing 41. Preferably, the spacings 40 and 41 are equal. Thus, the orientation of the corrugations 22 and 23 in the tank can be easily adapted to the requirements of the application without causing significant changes in the manufacture of the insulation barrier.

For example, in an alternative embodiment, the primary sealing membrane 6 is rotated 90° so that the second series of corrugations 23 run parallel to rows A, B, C of the insulation panels and thus parallel to the raised edges 14 of the strakes 13.

The primary insulation panel 15 and the secondary insulation panel 7 have the same dimension across the width of rows A, B, and C. By convention, this dimension is referred to as the length of the insulation panel. The row width is an integer multiple of the spacing of the corrugations in the same direction, in this case spacing 41, and an integer multiple of the width of the strake 13, to facilitate modular manufacturing of the tank wall by forming a repeating pattern substantially across the entire support wall 2.

Preferably, the width of the strake 13 is an integer multiple, for example twice, of the spacing between the corrugations in the same direction.

In the length direction of rows A, B, C, the primary insulation panels 15 may have the same dimension as the secondary insulation panels 7 or an integer multiple of this dimension. This dimension is an integer multiple of the spacing of the corrugations in the same direction, in this case spacing 40, to facilitate modular manufacturing of the tank wall by forming a repeating pattern a significant number of times throughout the support wall 2.

Preferably the primary insulation panel 15 and secondary insulation panel 7 are square, which makes it easier to adapt the relative orientation of the strakes and corrugations in the tank without requiring significant changes to the insulation panel design.
Suitable dimensions example

Waveform interval 40, 41: PO.
Width of primary insulation panel 15 and secondary insulation panel 7: 4 PO.
Length of primary insulation panel 15 and secondary insulation panel 7: 4PO (square).
Width of strake 13: 2PO.
Length of corrugated metal plate 21: 12 PO (FIG. 1) or 8 PO (not shown).
Width of corrugated metal plate: 4PO.
PO=300 mm.

These dimensions provide a good compromise between the ease of handling of the parts forming the tank wall and the number of parts that need to be assembled. This arrangement also simplifies the corrugated connection between the two walls of the tank.
Dimension example 2

Waveform spacing 40: PO.
Waveform interval 41:GO.
Width of primary insulation panel 15 and secondary insulation panel 7: 3GO.
Length of primary insulation panel 15 and secondary insulation panel 7: 4PO (rectangle).
Width of strake 13: 2PO.
Length of corrugated metal plate 21: 12 PO.
Width of corrugated metal plate 21: 3GO.
PO=300 mm.
GO=340 mm.
Example 3

The corrugations are not equidistant but are arranged according to a repeating pattern of four corrugations spaced successively at 340, 340, 340 and 180mm intervals.

Preferably, the 180 mm gap is divided into two 90 mm sections located on two opposite edges of the corrugated metal plate 21.

The repeat pattern therefore has a dimension of 1,200 mm. For the rest, the dimensions of the first example are maintained.
Example 4

The corrugations are not equidistant but are arranged according to a repeating pattern of four corrugations with successive intervals of 300, 400, 300 and 200 mm.

Preferably, the 200mm gap is divided into two 100mm sections located on two opposite edges of the corrugated metal plate.

The repeat pattern dimension is therefore 1,200 mm. For the remainder, the dimensions of the first example are maintained.

Figure 2 shows a detailed view of the attachment of the metal plate 21 of the primary sealing membrane 6 to the primary insulation barrier using a welded support 26.

Each primary insulation panel 15 has grooves 27 on the cover plate 20. As shown in Figures 1 and 2, the grooves 27 can be made continuous by creating intersections between the grooves 27. At the intersection between two grooves 27, one groove can include one fixed support 26 that continuously crosses the intersection, and the other groove can include two fixed supports 26 disposed on either side of the intersection.

To attach the metal plate 21 of the primary sealing membrane 6 to the primary insulating barrier 5, at least one edge of the longitudinally extending metal plate 21 is welded to a weld support 26 arranged in the longitudinally oriented groove 27, and at least one edge of the transversely extending metal plate 21 is welded to a weld support 26 arranged in the transversely oriented groove 27.

The weld support 26, e.g. metal, is slidably received in a groove 27 cut out of the cover plate 20 of the primary insulation barrier 5. This freedom allows slight movement of the edge of the metal plate 21 relative to the primary insulation panel 15 during temperature fluctuations, which reduces stress concentrations and therefore fatigue of the primary sealing membrane 6.

As seen in the embodiment shown in FIG. 2, the weld supports 26 are spaced apart in grooves 27. These spaces formed between two weld supports 26 can vary from a few millimeters to a spacing slightly larger than the corrugations of the corrugated metal plate 21. The spaces formed between the two weld supports 26 in the grooves 27 can be filled with a thermal insulating material.

Figure 3 shows the tank wall 1 in a cross-sectional view in which the various layers forming the tank wall can be distinguished. Figures 4 to 9 show detailed views of the zone for attaching the primary sealing membrane 6 to the primary insulating barrier 5 in several embodiments.

A first embodiment for attaching the primary sealing membrane 6 to the primary insulating barrier 5 is shown in Figure 4.

In this embodiment, the weld support 26 has a lower portion 28 held in a groove 27 of the primary insulating barrier 5 in a direction perpendicular to the support surface 31, an upper portion 30 parallel to the support surface 31 and disposed on the insulating barrier 5, and an intermediate portion 29 connecting the lower portion 28 to the upper portion 30, the intermediate portion 29 being disposed within the groove 27 in the thickness direction of the primary insulating barrier 5.

The upper portion 30 of the weld support 26 is received in a counterbore 32 adjacent to the groove 27 and formed in the primary insulation panel 15 of the primary insulation barrier 5, so that the upper portion 30 of the weld support 26 is positioned between the primary sealing membrane 6 and the primary insulation barrier 5 and in the extension of the support surface 31.

The groove 27 has an entrance zone 33 extending in the thickness direction and a retention zone 34 disposed below the entrance zone 33 and established parallel to the support surface 31 over a width greater than the entrance zone 33. The lower portion 28 of the weld support 26 is received in the retention zone 34, whereby the weld support is retained in the groove 27. The retention zone 34 is formed in one or more cover plates 20 of the primary insulation barrier 5.

The primary sealing membrane 6 is attached to the primary insulation barrier 5 by the overlapping attachment of two adjacent metal plates 21 of the primary sealing membrane 6. In fact, a first metal plate 21 without an offset portion 25 at its edge is welded to the top 30 of the weld support 26, and a second metal plate 21 with an offset portion 25 at its edge to be welded covers the weld support 26 together with the edge of the first metal plate 21. The offset portion 25 is then welded to the first metal plate so as to produce a sealed overlap, i.e. completely covering the weld support with a continuous weld bead over the entire length of the edge of the metal plate 21.

Figure 5 shows a second embodiment of a weld support 26 for attaching the primary sealing membrane 6 to the primary insulating barrier 5.

In this embodiment, the weld support 26 is inserted into two adjacent grooves 27 extending in the same direction. The counterbore 32 in this case is generated in the part of the cover plate 20 located between the two grooves 27. The upper part 30 of the weld support 26 is accommodated in the counterbore 32 extending between the two grooves. The weld support 26 has a first lower part 28 inserted in the retention zone 34 of the first groove 27 and a second lower part 28 inserted in the retention zone 34 of the second groove 27. The weld support 26 also has a first intermediate part 29 arranged in the entry zone 33 of the first groove 27 and connecting the first lower part 28 to one end of the upper part 30, and a second intermediate part arranged in the entry zone 33 of the second groove 27 and connecting the second lower part 28 to the other end of the upper part 30 of the weld support 26. The lower part 28 and the intermediate part 29 are formed continuously in the longitudinal direction.

The cover plate 20 may be made of plywood or composite material and may be 9 to 24 mm thick.

Figure 6 shows a third embodiment of a weld support 26 for attaching the primary sealing membrane 6 to the primary insulating barrier 5.

In this embodiment, the retention zones 34 are established parallel to the support surface 31 on both sides of the inlet zone 33. The welded support 26 has a first segment 35 and a second segment 36. The first segment 35 has a lower portion 28 accommodated in the retention zone 34 of the groove 27 and an upper portion 30 accommodated in a counterbore 32 parallel to the support surface and adjacent to the groove 27, so that the upper portion 30 of the first segment 35 is located between the primary sealing membrane 6 and the primary insulating barrier 5 and in the extension of the support surface 31, as in the first embodiment. The first segment 35 also has an intermediate portion 29 connecting the lower portion 28 of the first segment 35 to the upper portion 30 of the first segment 35, the intermediate portion 29 being arranged in the inlet zone 33 of the groove 27. The second segment 36 has a lower portion 28 received in the retaining zone 34 of the groove 27 in a direction opposite to that of the lower portion 28 of the first segment 35, and an intermediate portion 29 welded to the intermediate portion 29 of the first segment 35 by a weld 98.

Figure 7 shows a fourth embodiment of a weld support 26 for attaching the primary sealing membrane 6 to the primary insulating barrier 5.

This embodiment is very similar to the second embodiment. In fact, the main difference between these two embodiments is in the second segment 36. As can be seen in FIG. 7, the insulating barrier 5 in this case has two counterbores 32 on either side of the groove 27, one of which receives the upper part 30 of the first segment 35. In addition to the lower part 28 and the middle part 29, the second segment 36 has an upper part 30 that is parallel to the support surface 31 and is received in the other of the counterbores 32 so as to face in a direction opposite to that of the upper part 30 of the first segment 35. Thus, the upper part 30 of the second segment 36 is also located between the primary sealing membrane 6 and the primary insulating barrier 5. The middle part 29 of the second segment 36, like that of the first segment 35, connects the lower part 28 of the second segment 36 to the upper part 30 of the second segment 36.

The groove 27 in each of the above-described embodiments may be located in the center of the primary insulation panel 15 as shown in FIG. 1 or near the edge of the primary insulation panel 15.

Figure 8 shows a fifth embodiment of a weld support 26 for attaching the primary sealing membrane 6 to the primary insulating barrier 5.

The fifth embodiment of FIG. 8 is very similar to the first embodiment of FIG. 4. However, this embodiment of FIG. 8 differs in the location of the groove 27. Indeed, as can be seen in FIG. 8, the inlet zone 33 of the groove 27 corresponds in this embodiment to the inter-panel space, i.e. the groove 27 is located between two adjacent primary insulation panels 15 of the primary insulation barrier 5. Thus, a retention zone 34 is created in one direction in the first primary insulation panel 15 and in the opposite direction in the second primary insulation panel 15.

Figure 9 shows a sixth embodiment of a weld support 26 for attaching the primary sealing membrane 6 to the primary insulating barrier 5.

The sixth embodiment of FIG. 9 is very similar to the embodiment of FIG. 8. In fact, the inlet zone 33 of the groove 27 also corresponds to the interpanel space. However, in this embodiment, the retention zone 34 is replaced by a fastener 37. The fastener 37 is attached to the wall of the inlet zone 33, which corresponds to the side of the primary insulation panel 15. The lower part 28 of the welded support 26 is then slidably received in the fastener 36 so as to be held in the thickness direction and transverse direction of the tank wall 1, in particular for the longitudinally extending groove 27. To this end, the lower part 28 has a hook 38, the shape of which matches the opposing hook 39 arranged on the fastener 37. Thus, the hook 38 of the lower part 28 is received in the opposing hook 39 of the fastener 37 so as to achieve a sliding attachment. This embodiment can also be used in the center of the primary insulation panel 15 or near the edge of the primary insulation panel 15.

Figure 10 shows a seventh embodiment of a weld support 26 for attaching the primary sealing membrane 6 to the primary insulating barrier 5.

The seventh embodiment of FIG. 10 is very similar to the embodiment of FIG. 5. However, in this embodiment, the lower portion 28 and the middle portion 29 of the weld support are made discontinuous in the longitudinal direction so as to form lugs connected to the upper portion 30 and spaced apart in the longitudinal direction.

Figure 11 shows an eighth embodiment of a weld support 26 for attaching the primary sealing membrane 6 to the primary insulating barrier 5.

In this embodiment, the weld support 26 is inserted in the center of the primary insulation panel 15 into two adjacent longitudinal grooves 27 and two adjacent transverse grooves 97 (shown in dashed lines in FIG. 11 ) that intersect the two longitudinal grooves 27. In fact, the weld support 26 in this embodiment is produced by a longitudinally formed portion 26A and a transversely formed portion 26B, which intersect to form a cross. Thus, the upper portion 30 extends into a first counterbore 32 formed between the two longitudinal grooves 27 and into a second counterbore 32 formed between the two transverse grooves 97.

Thus, the part 26A has a portion of the upper part 30 extending in the longitudinal direction, and also has a first lower part 28 inserted in the retention zone 34 of the first groove 27 and a second lower part 28 inserted in the retention zone 34 of the second longitudinal groove 27. The part 26A also has a first intermediate part 29 located in the inlet zone 33 of the first longitudinal groove 27 and connecting the first lower part 28 to the upper part 30, and a second intermediate part 29 located in the inlet zone 33 of the second transverse groove 27 and connecting the second lower part 28 to the upper part 30.

Contrary to the part 26A, the part 26B does not have a lower part 28. The part 26B is formed from a part of the upper part 30 extending laterally and has a first intermediate part 29 located in the first transverse groove 97 and connected to the upper part 30, and a second intermediate part 29 located in the inlet zone 33 of the second transverse groove 97 and connected to the upper part 30. The transverse groove 97 has a large opening to provide sufficient clearance for the weld support 26 in the longitudinal direction.

This allows the weld support 26 to maintain sufficient freedom in the longitudinal direction. Similarly, in this embodiment, the longitudinal groove 27 may also have a large opening to allow lateral clearance to be provided.

Furthermore, to allow the lower portion 28 and the middle portion 29 to be accommodated in the longitudinal groove 27 and the lateral groove 97, the weld support 26 is forcibly inserted into the intersection of the longitudinal groove 27 and the lateral groove 97.

In other embodiments not shown, the embodiments shown in Figures 4 to 11 may be combined if their features are compatible with each other.

For example, the embodiment shown in FIG. 5 may have a fastener 36 in each of the grooves 27 instead of the retaining zone 34. In this case, the two lower parts 28 of the weld support 26 are provided with hooks 38 that are received in opposing hooks 39 of the fasteners 36.

In another embodiment, not shown, the embodiment described in FIG. 7 may have, instead of the retention zone 34, fasteners 36, i.e. a first fastener 36 attached to the wall of the groove 27 closer to the first segment 35 and a second fastener 36 attached to the wall of the groove 27 closer to the second segment 36. The lower portion 28 of the first segment 35 and the lower portion 28 of the second segment 36 are provided with hooks 38 that are received in opposing hooks 38 of each fastener 36.

The above techniques for manufacturing sealed tank walls can be used in various types of tanks, for example to form tank walls for LNG tanks in land-based facilities or waterborne structures such as LNG tanker ships.

Referring to FIG. 12, a cutaway view of an LNG tanker ship 70 shows a sealed, insulated tank 71 of a general prismatic shape mounted on the ship's double hull 72. The walls of the tank 71 have a primary sealing barrier intended to be in contact with the LNG contained in the tank, a secondary sealing barrier located between the primary sealing barrier and the ship's double hull 72, and two insulating barriers located between the primary sealing barrier and the secondary sealing barrier and between the secondary sealing barrier and the double hull 72, respectively.

In a manner known per se, a loading/unloading pipeline 73 located on the upper deck of the vessel can be connected by suitable connectors to an offshore or port terminal for transferring the LNG cargo to and from the tank 71.

12 shows an example of a marine terminal with a loading and unloading station 75, an underwater pipe 76, and an onshore facility 77. The loading and unloading station 75 is a fixed offshore facility with a movable arm 74 and a turret 78 supporting the movable arm 74. The movable arm 74 supports a bundle of insulated flexible hoses 79 that can be connected to a loading/unloading pipeline 73. The orientable movable arm 74 accommodates any form of LNG tanker. A connecting pipe, not shown, extends inside the turret 78. The loading and unloading station 75 allows loading and unloading of LNG tankers 70 between a liquefied gas storage tank 80 and an onshore facility 77 with a connecting pipe 81 connected to the loading or unloading station 75 by an underwater pipe 76. The underwater pipes 76 allow the transport of liquefied gas over significant distances, e.g. 5 km, between the loading or unloading station 75 and the onshore facility 77, thereby allowing the LNG tanker 70 to be kept at a significant distance from shore during loading and unloading operations.

Pumps on board the vessel 70 and/or pumps provided at the onshore facility 77 and/or pumps provided at the loading and unloading station 75 are used to generate the pressure required to transport the liquefied gas.

Although the present invention has been described with reference to several specific embodiments, it is in no way limited thereto, and it is to be understood that the present invention includes all technical equivalents of the described means and combinations thereof, provided they fall within the scope of the present invention.

The use of the words "have" or "include" and their conjugations does not exclude the presence of elements or steps other than those stated in a claim.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims (20)

A sealed, insulated tank wall (1) for forming a sealed, insulated tank for storing liquefied gas, comprising:
a sealing membrane (6) intended to be in contact with the liquefied gas contained in the tank, the sealing membrane (6) having a corrugated metal plate (21);
a thermal barrier (5) forming a support surface (31) for said sealing membrane (6) and having a longitudinally extending groove (27);
at least one weld support (26) supported by the thermal insulation barrier (5), the weld support (26) having a lower part (28) held in the groove (27) of the thermal insulation barrier (5) in a direction perpendicular to the support surface (31), an upper part (30) parallel to the support surface (31) and resting on the thermal insulation barrier (5), and an intermediate part (29) connecting the lower part (28) to the upper part (30), the intermediate part (29) being arranged in the groove (27) in the thickness direction of the thermal insulation barrier (5),
the at least one weld support (26) is slidably mounted in the groove (27) in the longitudinal direction, and an edge of the corrugated metal plate (21) is welded to the top (30) of the weld support (26);
the upper part (30) of the weld support (26) is received in a counterbore (32) formed in the insulating barrier (5) adjacent to the groove (27), so that the upper part (30) of the weld support (26) is located between the sealing membrane (6) and the insulating barrier (5) and in the extension of the support surface (31);
1. A tank wall (1), wherein the corrugated metal plate (21) welded to the upper part (30) of the weld support (26) is a first corrugated metal plate (21), the sealing membrane (6) has a second corrugated metal plate (21) having an offset portion (25) welded above the first corrugated metal plate (21) to form a sealed overlap (24) between the two corrugated metal plates (21), and a weld (98) between the upper part (30) of the weld support (26) and the first corrugated metal plate (21) is located below the offset portion (25) of the second corrugated metal plate (21). The tank wall (1) according to claim 1, wherein the groove is a longitudinal groove, the edge is a first edge, the weld support is a first weld support, the insulating barrier has a transverse groove extending in a transverse direction perpendicular to the longitudinal direction, the wall comprises a second weld support whose lower part is held in the transverse groove of the insulating barrier, and a second edge of the transversely extending corrugated metal plate is welded to an upper part of the second weld support. The tank wall (1) according to claim 1 or claim 2, wherein the groove (27) has an inlet zone (33) extending in the thickness direction in the insulating barrier (5), the groove (27) has a retention zone (34) arranged below the inlet zone (33) and established parallel to the support surface (31) over a width greater than the inlet zone (33), and the lower part (28) of the welded support (26) is accommodated in the retention zone (34). The retaining zone (34) is established parallel to the support surface (31) on both sides of the inlet zone (33), and the welded support (26) has a first segment (35) and a second segment (36), the first segment (35) having a lower portion (28) retained in the retaining zone (34) of the insulating barrier (5) in a direction perpendicular to the support surface (31), and an upper portion (30) parallel to the support surface (31) and accommodated in the counterbore (32) adjacent to the groove (27), whereby the upper portion (30) of the first segment (35) is positioned between the sealing membrane (6) and the insulating barrier (5) and in the extension of the support surface (31); 3. The tank wall (1) according to claim 2, wherein the first segment (35) has an intermediate portion (29) that connects the lower portion (28) to the upper portion (30) of the first segment (35), the intermediate portion (29) being arranged in the groove (27) in the thickness direction of the insulating barrier (5), and the second segment (36) has a lower portion (28) that is held in the holding zone (34) of the insulating barrier (5) in a direction opposite to the direction of the lower portion (28) of the first segment (35) and an intermediate portion (29) that is welded to the intermediate portion (29) of the first segment (35), and the upper portion (30) of the first segment (35) is welded to the corrugated metal plate (21). The tank wall (1) according to claim 4, wherein the counterbore (32) is a first counterbore (32), the insulating barrier (5) has a second counterbore (32), the first counterbore (32) and the second counterbore (32) are arranged on either side of the groove (27), the second segment (36) has an upper portion (30) parallel to the support surface (31) and accommodated in the second counterbore (32), whereby the upper portion (30) of the second segment (36) is arranged between the sealing membrane (6) and the insulating barrier (5) and in the extension of the support surface (31), and the intermediate portion (29) of the second segment (36) connects the lower portion (28) of the second segment (36) to the upper portion (30) of the second segment (36). The tank wall (1) according to claim 1 or claim 2, wherein the groove (27) has an inlet zone (33) extending in the thickness direction in the insulating barrier (5), the inlet zone (33) having a fastener (37) attached to the wall of the groove (27), and the lower part (28) of the welded support (26) is slidably received in the fastener (37). The tank wall (1) according to claim 6, wherein the lower portion (28) has a hook (38), the fastener (37) has an opposing hook (39), and the hook (38) is received in the opposing hook (39). The tank wall (1) according to any one of claims 1 to 7, wherein the insulating barrier (5) has a plurality of juxtaposed parallelepiped insulating panels (15), the lower part (28) of the welded support (26) is held to one insulating panel (15) of the insulating barrier (5), and the counterbore (32) is formed in the insulating panel (15). The tank wall (1) according to any one of claims 3 to 7, wherein the insulating barrier (5) comprises a plurality of juxtaposed parallelepiped insulating panels (15), and the groove (27) is arranged between two adjacent insulating panels (15) of the insulating barrier (5), whereby the inlet zone (33) is an interpanel space. A tank wall (1) according to any one of claims 1 to 8, wherein the insulating barrier (5) has a plurality of juxtaposed parallelepiped insulating panels (15) and the groove (27) is arranged in the center of one insulating panel (15) of the insulating barrier (5). A tank wall (1) according to any one of claims 1 to 8, wherein the insulating barrier (5) comprises a plurality of juxtaposed parallelepiped insulating panels (15), and the groove (27) is arranged near the edge of one insulating panel (15). The groove (27) is a first groove (27), the insulating barrier (5) has a second groove (27) extending in the longitudinal direction at a distance from the first groove (27), the counterbore (32) extends between the two grooves (27), the upper part (30) of the weld support (26) is received in the counterbore (32) extending between the two grooves (27), the lower part (28) is a first lower part (28), the middle part (29) is a first middle part (29), and the weld support ( 26) has a second lower part (28) and a second intermediate part (29) that connects the second lower part (28) to the upper part (30) of the welded support (26), whereby the first lower part (28) and the first intermediate part (29) are arranged in the first groove (27), and the second lower part (28) and the second intermediate part (29) are arranged in the second groove (27) that is separate from the first groove (27). The tank wall (1) according to any one of claims 1 to 7. A tank wall (1) according to claim 12, in which each lower portion (28) is formed by a plurality of lower portions spaced apart from one another in the longitudinal direction, and each intermediate portion (29) is formed by a plurality of intermediate portions spaced apart from one another in the longitudinal direction, whereby each intermediate portion connects one of the lower portions to the upper portion (30). The tank wall (1) according to claim 12 or 13, wherein the upper portion (30) is a first upper portion (30), the insulating barrier (5) has a third groove (27) extending laterally perpendicular to the longitudinal direction and a fourth groove (27) adjacent to the third groove (27) and extending laterally, the weld support (26) has a second upper portion (30) accommodated in a transverse counterbore (32) extending between the third groove (27) and the fourth groove (27), and the third and fourth grooves (27) intersect the first and second grooves (27). The tank wall (1) according to claim 14, wherein a third intermediate portion (29) is arranged in an inlet zone (33) of the third groove (27) and connected to the second upper portion (30), and a fourth intermediate portion (29) is arranged in an inlet zone (33) of the fourth groove (27) and connected to the second upper portion (30). A tank wall (1) according to any one of claims 1 to 15, wherein the insulating barrier (5) is a primary insulating barrier (5), the sealing membrane (6) is a primary sealing membrane (6), and the tank wall (1) further comprises a secondary sealing membrane (4) arranged below the primary insulating barrier (5) and a secondary insulating barrier (3) arranged below the secondary sealing membrane (4) and having a plurality of juxtaposed parallelepiped insulating panels (7) forming a support surface (31) for the secondary sealing membrane (4). A sealed insulated tank (71) disposed within a support structure, the tank having a plurality of walls sealably attached together to form an interior space for receiving liquefied gas, at least one of the tank walls (1) being a tank wall according to any one of claims 1 to 16. A ship (70) for transporting cryogenic liquid products, comprising a double hull (72) and a tank (71) according to claim 17 arranged within the double hull. A transfer system for cryogenic liquid products comprising a vessel (70) according to claim 18, an insulated pipeline (73, 79, 76, 81) arranged to connect the tank (71) installed within the hull of the vessel to a water-based or land-based storage facility (77), and a pump for conveying a flow of cryogenic liquid product through the insulated pipeline between the water-based or land-based storage facility and the vessel tank. A method for loading or unloading a vessel (70) as described in claim 18, in which the cryogenic liquid product is conveyed through an insulated pipeline (73, 79, 76, 81) between a waterborne or land-based storage facility (77) and the vessel's tank (71).

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