FR3108383A1 - Sealed and thermally insulating tank - Google Patents

Abstract

The invention relates to a sealed and thermally insulating tank wall, said wall comprising a thermally insulating barrier (4) comprising rows of first and second inter-panel spaces (19) aligned parallel to a first, respectively a second, direction (30). , 31), the first direction (30) and the second direction (31) being intersecting, the second direction (31) comprising a component parallel to the direction of terrestrial gravity, the thermally insulating barrier (4) further comprising rows of first and second intermediate panels (28, 29) arranged in the rows of inter-panel spaces (19), and in which the row of first intermediate panels (28) is continuous in the row of first inter-panel spaces (19) , a first intermediate panel (28) of the row of first intermediate panels (28) being received in an intersection (32) between the rows of inter-panel spaces such that an edge (24) parallel the second direction (31) of a second intermediate panel (29) juxtaposed to said first intermediate panel (28) is arranged in line with said first intermediate panel (28). Figure to be published: 3

Description

Watertight and thermally insulated tank

The invention relates to the field of sealed and thermally insulating membrane tanks. In particular, the invention relates to the field of sealed and thermally insulating tanks for the storage and/or transport of liquefied gas at low temperature, such as tanks for the transport of Liquefied Petroleum Gas (also called LPG) having for example a temperature between -50°C and 0°C, or for the transport of Liquefied Natural Gas (LNG) at approximately -163°C at atmospheric pressure. These tanks can be installed on land or on a floating structure. In the case of a floating structure, the tank may be intended for the transport of liquefied gas or to receive liquefied gas used as fuel for the propulsion of the floating structure.

In one embodiment, the liquefied gas is LNG, namely a mixture with a high methane content stored at a temperature of approximately -163°C at atmospheric pressure. Other liquefied gases can also be considered, in particular ethane, propane, butane or ethylene. Liquefied gases can also be stored under pressure, for example at a relative pressure of between 2 and 20 bar, and in particular at a relative pressure close to 2 bar. The tank can be made using different techniques, in particular in the form of an integrated membrane tank or a self-supporting tank.

Technology background

FR-A-2781557 describes a sealed and thermally insulating tank comprising a tank wall fixed to a supporting structure, in which said tank wall has a multilayer structure which successively comprises a primary sealing membrane intended to be in contact with a product contained in the tank, a primary thermally insulating barrier, a secondary sealing membrane and a secondary thermally insulating barrier.

The secondary thermally insulating barrier, the secondary waterproofing membrane and the primary thermally insulating barrier essentially consist of a set of prefabricated elements fixed to the load-bearing structure. Each prefabricated element successively comprises a secondary insulating panel, a waterproof covering which completely covers the secondary insulating panel, this waterproof covering forming a portion of the secondary waterproofing membrane, and a primary insulating panel covering a central zone of the waterproof covering.

The primary insulating panel has dimensions smaller than the dimensions of the secondary insulating panel so that a peripheral zone of the waterproof coating is uncovered. The prefabricated elements are juxtaposed on a supporting structure parallel to each other, so that the peripheral zone of the waterproof coating of a first of the prefabricated elements is each time close to the peripheral zone of the waterproof coating of a second of the prefabricated elements adjacent. The secondary waterproof membrane is completed by sealing strips sealingly connecting the peripheral areas of the waterproof coating of said two adjacent prefabricated elements.

Thus, when the prefabricated elements are arranged on the supporting structure, the thermally insulating barrier comprises a plurality of primary insulating panels spaced from each other. The vessel wall then comprises a plurality of rows of inter-panel spaces, these inter-panel spaces being delimited by the primary insulating panels and the secondary sealed membrane formed by the peripheral zone of the sealed coatings and the sealing strips.

To complete the primary thermally insulating barrier, the vessel wall further comprises intermediate insulating panels arranged in these rows of inter-panel spaces. These intermediate insulating panels are glued to the peripheral zones of the waterproof coverings and to the sealing strips. These intermediate panels have lower chamfers making it possible to receive the overflows of glue resulting from the bonding of said intermediate panels.

However, due to the arrangement of the intermediate panels in the rows of inter-panel spaces favoring ease of assembly of the intermediate panels, these chamfers are aligned in a row of inter-panel spaces which can lead to the formation of channels developing over a significant length in the primary thermally insulating barrier. Such channels are likely to promote natural convection, in particular in the case of channels having a vertical component, and can therefore degrade the insulating characteristics of the vessel wall.

Summary

One idea underlying the invention is to limit convection phenomena in a vessel wall. In particular, an idea underlying the invention is to limit the presence in the thermally insulating barrier of channels developing over a large distance in a direction having a component parallel to the direction of Earth gravity.

According to one embodiment, the invention provides a sealed and thermally insulating vessel wall, said wall comprising a thermally insulating barrier and a sealed membrane,
the thermally insulating barrier comprising a plurality of parallelepipedic insulating panels (9),
the thermally insulating barrier comprising a row of first inter-panel spaces aligned parallel to a first direction and a row of second inter-panel spaces aligned parallel to a second direction, said first inter-panel spaces and second inter-panel spaces being delimited by the opposite edges of two respective adjacent insulating panels of the plurality of insulating panels, the first direction and the second direction being intersecting so that the first row of inter-panel spaces and the second row of inter-spaces -panels form an intersection, the second direction comprising a component parallel to the direction of earth gravity,
the thermally insulating barrier further comprising a row of first intermediate panels and a row of second intermediate panels, the first intermediate panels being arranged in the row of first inter-panel spaces, the second intermediate panels being arranged in the row of second inter-spaces -panels,
and wherein the row of first intermediate panels is continuous in the row of first inter-panel spaces such that the row of second intermediate panels is discontinuous at the intersection between the row of first inter-panel spaces and the row of second inter-panel spaces,
a first intermediate panel of the row of first intermediate panels being housed in said intersection so that an edge parallel to the second direction of a second intermediate panel juxtaposed with said first intermediate panel is arranged in line with said first intermediate panel.

Thanks to these characteristics, the vessel wall does not have channels developing over a significant length with a component parallel to the direction of earth gravity. In particular, a channel formed at the edges parallel to the second direction, that is to say having a vertical component, of the second intermediate panels aligned along the second direction is interrupted by the first intermediate panel housed in the intersection of so that said channel does not develop continuously in the vessel wall. The interruption of such a channel makes it possible to limit the phenomena of convection within the thermally insulating barrier. It is thus understood that the invention applies to all the faces of a tank except the bottom and the ceiling of the latter.

According to embodiments, such a sealed and thermally insulating vessel wall may comprise one or more of the following characteristics.

According to one embodiment, the edge of said second intermediate panel is a first longitudinal edge of said second intermediate panel, said second intermediate panel comprising a second longitudinal edge parallel to the second direction, said second longitudinal edge being arranged in line with a first panel middle of the row of first intermediate panels.

Thanks to these characteristics, convection phenomena are limited, as explained above.

According to one embodiment, the edges of the second intermediate panels parallel to the second direction have a lower chamfer. Thanks to these characteristics, the intermediate panels can be glued to a bottom of the inter-panel space, for example formed by a secondary waterproof membrane, without the glue overflowing in a detrimental way into the spaces separating the intermediate panel from the insulating panels. adjacent.

According to one embodiment, said first intermediate panel housed in said intersection passes through said intersection. Thus, according to one embodiment, the first insulating panel housed in the intersection has a length, taken along the first direction, greater than the width, taken along said first direction, of a second inter-panel space at the level of the 'intersection. In other words, the first longitudinal edge and the second longitudinal edge of the second intermediate panel juxtaposed at the intersection are arranged opposite the same first intermediate panel.

According to one embodiment, the first intermediate panels have transverse edges parallel to the second direction, the first intermediate panels being arranged in the row of first inter-panel spaces so that said transverse edges are offset, along the first direction , relative to the edges parallel to the second direction of the second intermediate panels.

According to one embodiment, the first intermediate panels are arranged in the row of first inter-panel spaces so that the transverse edges of the first intermediate panels are offset, along the first direction (30), with respect to edges of the insulating panels delimiting the second row of inter-panel spaces so that said edges of said insulating panels are arranged in line with a said first intermediate panel. Thanks to these characteristics, channels formed between the edges of the second intermediate panels and the adjacent insulating panels are interrupted by the first intermediate panels, including in the presence of an assembly clearance between said second intermediate panels and said insulating panels.

According to one embodiment, the thermally insulating barrier comprises a plurality of rows of first inter-panel spaces aligned in directions parallel to the first direction and a plurality of rows of second inter-panel spaces aligned in directions parallel to the second direction , the thermally insulating barrier comprising a plurality of intersections formed by the plurality of rows of first inter-panel spaces and the plurality of rows of second inter-panel spaces, the thermally insulating barrier further comprising a plurality of rows of first intermediate panels and a plurality of rows of second intermediate panels, said rows of first intermediate panels being arranged continuously in a respective row of first inter-panel spaces, said rows of second intermediate panels being arranged discontinuously in a said row of second spaces respective inter-panels so that the edges parallel to the second direction of said second intermediate panels are arranged opposite a respective first intermediate panel.

According to one embodiment, the thermally insulating barrier is a primary thermally insulating barrier, the waterproof membrane is a primary waterproof membrane and the insulating panels are primary insulating panels, the wall further comprising a secondary thermally insulating barrier and a secondary waterproof membrane , the vessel wall comprising a plurality of prefabricated elements (6), said prefabricated elements comprising a secondary parallelepiped insulating panel, a portion of sealed film resting on the secondary insulating panel and a primary insulating panel resting on the portion of sealed film ( 8), the primary insulating panel having dimensions smaller than the dimensions of the secondary insulating panel so that the sealed film portion has an uncovered peripheral zone,
and in which said prefabricated elements are juxtaposed according to a regular mesh so that the secondary insulating panels form the secondary thermally insulating barrier, the peripheral zones of the sealed film portion of two adjacent prefabricated elements being connected in a sealed manner by a strip of film waterproof, the portions of waterproof film of the prefabricated elements and the strips of waterproof film jointly forming the secondary waterproof membrane, the intermediate insulating panels being anchored on the peripheral zones of the portions of waterproof film (8) and on the corresponding anchoring tapes.

According to one embodiment, the invention also provides a sealed and thermally insulating tank comprising a tank wall as above.

According to one embodiment, the tank comprises two transverse walls, front and rear, as well as an upper wall, a lower wall and side walls which connect the front and rear transverse walls, one to the other.

According to one embodiment, the front and rear transverse walls as well as the side walls are vessel walls of the aforementioned type.

Such a tank can be part of an onshore storage facility, for example to store LNG or be installed in a floating, coastal or deep water structure, in particular an LNG carrier, a floating storage and regasification unit (FSRU) , a floating production and remote storage unit (FPSO) and others. Such a tank can also serve as a fuel tank in any type of ship.

According to one embodiment, the invention also provides a vessel for the transport of a cold liquid product comprises a double hull and a aforementioned tank arranged in the double hull.

According to one embodiment, the invention also provides a method for loading or unloading such a ship, in which a cold liquid product is conveyed through insulated pipes from or to a floating or terrestrial storage installation to or from the ship's tank.

According to one embodiment, the invention also provides a transfer system for a cold liquid product, the system comprising the aforementioned vessel, insulated pipes arranged so as to connect the tank installed in the hull of the vessel to a floating storage installation or land and a pump to cause a flow of cold liquid product through the insulated pipes from or to the floating or land storage facility to or from the tank of the ship.

Brief description of figures

. The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely by way of illustration and not limitation. , with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view of a multi-layer vessel wall portion comprising prefabricated elements and intermediate panels interposed in inter-panel spaces formed by the primary insulating panels of said prefabricated elements;

Figure 2 is a sectional view of a portion of sealed and thermally insulating vessel wall of Figure 1 illustrating the arrangement of an intermediate panel of the primary thermally insulating barrier in the inter-panel space formed by two panels primary insulation of adjacent prefabricated elements;

Figure 3 is a schematic representation illustrating the arrangement of the intermediate panels in the rows of inter-panel spaces in a sealed and thermally insulating vessel wall of Figure 1;

FIG. 4 is a cutaway schematic representation of an LNG carrier tank and a loading/unloading terminal for this tank.

Figure 5 is a sectional view illustrating the general shape of a tank according to one embodiment.

Figure 6 is a sectional view illustrating the general shape of a tank according to another embodiment.

By convention, the terms "external" and "internal" are used to define the relative position of one element in relation to another, with reference to the inside and outside of the tank.

A sealed and thermally insulating tank for the storage and transport of a cryogenic fluid, for example Liquefied Natural Gas (LNG) comprises a plurality of tank walls each having a multilayer structure. Each of these vessel walls is anchored to a corresponding wall of a supporting structure 1.

The load-bearing structure 1 can in particular be a self-supporting sheet metal or, more generally, any type of rigid partition having suitable mechanical properties. The load-bearing structure 1 can in particular be formed by the hull or the double hull of a ship, as illustrated in FIG. 1. The load-bearing structure 1 comprises a plurality of walls defining the general shape of the tank, usually a polyhedral shape. Some tanks may also have only one thermally insulating barrier and one sealed membrane, for example for the storage of LPG.

In Figure 5, we observe the general polyhedral shape of a tank according to one embodiment. The tank has a plurality of walls 35, 36, 37, 38, 39, 40, 41, 42, 43. The tank has an upper wall 35 and a lower wall 36 horizontal as well as two transverse walls, front and rear 37, vertical . In Figure 5, the front transverse wall is not shown. The tank also has side walls 38, 39, 40, 41, 42, 43. The upper 35, lower 36, and side 38, 39, 40, 41, 42, 43 walls extend in a longitudinal direction and connect the front and rear transverse walls 37, one to the other. In the embodiment shown, the transverse walls 37 are octagonal in shape. Also, the side walls include two vertical side walls 38, 39, two upper oblique side walls 40, 41 which each connect one of the vertical side walls 38, 39 to the upper wall 35 and two lower oblique side walls 42, 43 which each connect one of the vertical side walls 38, 39 to the lower wall 36. The upper oblique side walls 40, 41, also designated by the term "upper chamfers", as well as the lower oblique side walls 42, 43, also designated by the term "lower chamfer" are for example inclined with respect to the vertical by an angle of between 10 and 45°

Figure 6 designates the general shape of a tank according to another embodiment.

Each vessel wall comprises, from the outside towards the inside of the vessel, a secondary thermally insulating barrier 2 anchored to the load-bearing structure 1 by secondary retaining members, a secondary waterproof membrane 3 carried by the secondary thermally insulating barrier 2 , a primary thermally insulating barrier 4 resting on the secondary sealed membrane 3 and a primary sealed membrane 5, carried by the primary thermally insulating barrier 4 and intended to be in contact with the cryogenic fluid contained in the vessel.

Referring to Figure 1, we now describe an embodiment of a sealed and thermally insulating vessel wall in which the secondary thermally insulating barrier 2, the secondary sealed membrane 3 and the primary thermally insulating barrier 4 are made from prefabricated elements 6.

The prefabricated elements 6 are fixed to the supporting structure 2 in a juxtaposed manner according to a repeated pattern. As illustrated in Figures 1 and 2, a prefabricated element 6 comprises each time a secondary insulating panel 7, a waterproof coating 8 and a primary insulating panel 9.

The secondary insulating panel 7 consists of an external rigid plate 10, for example in plywood 9 or 12 mm thick, surmounted by a layer of secondary thermal insulation 11.

The waterproof coating 8 covers the layer of secondary thermal insulation 11. This waterproof coating 8 is for example a rigid film including an aluminum sheet 0.07 mm thick sandwiched between two fabrics of glass fibers impregnated with a polyamide resin. The waterproof coating 8 is bonded to the secondary thermal insulation layer 11, for example using a two-component polyurethane adhesive.

The primary insulating panel 9 comprises a layer of primary thermal insulation 12 and an internal rigid plate 13. The primary thermal insulating layer 12 is glued to the waterproof coating 8. The internal rigid plate 13 is for example made of plywood 12 mm thick glued on the primary thermal insulation layer 12.

The secondary insulating panel 7 and the primary insulating panel 9 are of rectangular parallelepiped shape. The primary insulating panel 9 has sides parallel to the sides of the secondary insulating panel 7. Furthermore, the primary insulating panel 9 has dimensions smaller than the dimensions of the secondary insulating panel 7 so that said primary insulating panel 9 leaves a peripheral zone 14 of the waterproof coating 8 all around said primary insulating panel 9.

The layers of thermal insulation 11 and 12 can be constituted by a cellular plastic material such as a polyurethane foam. Preferably, glass fibers are embedded in the polyurethane foam to reinforce it.

The various components described above of the prefabricated element 6 can be glued on top of each other in the arrangement indicated above. Each prefabricated element 6 therefore forms a portion of the secondary thermally insulating barrier 2, a portion of the secondary sealed membrane 3 and a portion of the primary thermally insulating barrier 4.

To ensure the fixing of the prefabricated elements 6 on the supporting structure 1, there are provided, regularly distributed over the two longitudinal edges of the prefabricated element, wells 15 to cooperate with studs fixed to the supporting structure 2. of polymerizable resin are arranged between the outer rigid plate 10 and the support structure 1 in order to compensate for the flatness defects of the support structure 1.

In order to ensure the continuity of the thermal insulation in the secondary thermally insulating barrier 2, the wells 15 are plugged by inserting plugs 16 of thermally insulating material therein, these plugs 16 being flush with the level of the secondary thermal insulating layer 11 of the secondary insulating panel 7. In addition, it is possible to place in the interstices which separate the secondary insulating panels 7 from two adjacent prefabricated elements 6 a thermal insulation material 17 consisting, for example, of a sheet of plastic foam or of glass wool inserted in the interstice.

To constitute the secondary waterproofing membrane 3 continuously, a flexible waterproof strip 18 is placed on the peripheral zones 14 adjacent to the waterproof coating 8 of two adjacent prefabricated elements 6. This waterproof strip 18 is glued to the peripheral zones 14 so as to close off the perforations located in line with each well 15 and to cover the gap between the two secondary insulating panels 7.

The waterproof strip 18 is made of a composite material comprising three layers: the two outer layers are fabrics of glass fibers and the intermediate layer is a thin metal sheet, for example an aluminum sheet with a thickness of approximately 0.1mm. This metal sheet ensures the continuity of the secondary sealing membrane 3. Its flexibility in bending, due to the flexible nature of the binder between the aluminum sheet and the glass fibers, allows it to follow the deformations of the secondary insulating panels. 7 due to the deformation of the hull by the swell or by the cooling of the tank. Flexibility refers to the ability of the material to be bent to form waves without breaking. An example of such a composite material is for example called triplex®.

Between the primary insulating panels 9 of two adjacent prefabricated elements 6 there remains an inter-panel space 19 located to the right of the peripheral zones 14 and the gap between the secondary insulating panels 7. In order to complete the primary thermally insulating barrier 4, this space inter-panels 19 is filled by intermediate panels 20 insulators. Each intermediate panel 20 comprises a layer of thermal insulation 21 covered with a rigid plate 22 in a manner analogous to the primary insulating panels 9.

The intermediate panels 20 have a dimension such that they completely fill the inter-panel space 19. These intermediate panels ensure continuity of the insulation of the primary thermally insulating barrier 4 and offer, with the primary insulating panels 9, a surface substantially continuous support for the primary waterproof membrane 5

These intermediate panels 20 have a width equal to the distance between two primary insulating panels 9 of adjacent prefabricated elements 6 and may have a greater or lesser length. A reduced length allows, if necessary, easier installation in the event of a slight misalignment of two adjacent prefabricated elements 6. The intermediate panels 20 are glued to the waterproof strip 18 and press against the latter.

As illustrated in Figure 1, the primary sealing membrane is formed of a membrane of corrugated sheets 23 having two series of intersecting undulations to give it sufficient flexibility in the two directions of the plane of the vessel wall.

Longitudinal edges 24 of the intermediate panels 20, that is to say edges joined to the primary insulating panels 9 delimiting the inter-panel space 19, have a lower bevel 25. These lower bevels 25 connect an underside 26 of the panel intermediate, said lower face 26 being glued to the waterproof strip 18, to a longitudinal face 27 attached to the primary insulating panel 9 adjacent. This lower chamfer 25 makes it possible to accommodate the overflows of glue resulting from the bonding of the intermediate panel 20 to the waterproof strip 19.

The primary insulating panels 9 having a rectangular shape and the prefabricated elements 6 being juxtaposed according to a regular mesh, the longitudinal edges of a primary insulating panel 9 each delimit, together with a longitudinal edge facing an insulating panel primary 9 adjacent, a first inter-panel space 19 respectively. Similarly, the side edges of said primary insulating panel 9 each delimit, together with a side edge facing an adjacent primary insulating panel 9, a second inter-panel space 19.

Thus, as illustrated in FIG. 3, due to the arrangement according to a regular mesh of the prefabricated elements 6, the primary thermally insulating barrier 4 has rows of first inter-panel spaces 19 and rows of second inter-panel spaces 19 The first inter-panel spaces 19 of a said row of first inter-panel spaces 19 are aligned parallel to a first direction 30, for example the longitudinal direction of the primary insulating panels 9. Similarly, the second inter-panel spaces 19 of a said row of second inter-panel spaces 19 are aligned parallel to a second direction 31, for example the width direction of the primary insulating panels 9. This first direction 30 and this second direction 31 are perpendicular to one of the another so that the rows of first inter-panel spaces 19 and the rows of second inter-panel spaces 19 form intersections 32.

In order to ensure the continuity of the primary thermally insulating barrier 4 at said intersections 32, the primary thermally insulating barrier 4 comprises rows of intermediate panels 20 arranged continuously in one of the rows of first inter-panel spaces 19 and the rows of second inter-panel spaces 19.

Thus, rows of first intermediate panels 28 or of second intermediate panels 29 are arranged so that said first or second intermediate panels 28, 29 are successively joined to each other in said rows of inter-panel spaces 19. These rows of first or second intermediate panels 28, 29 arranged continuously therefore cross the intersections 32 formed between the rows of first inter-panel spaces 19 and the rows of second inter-panel spaces 19.

Consequently, the intermediate panels 20 arranged in the other rows of inter-panel spaces 19 among the rows of first inter-panel spaces 19 and the rows of second inter-panel spaces 19 form discontinuous rows of second or first intermediate panels 29 , 28, that is to say that these rows of second or first intermediate panels 29, 28 are interrupted by the rows of first or second intermediate panels 28, 29 arranged continuously and crossing the intersections 32.

In other words, during manufacture of the tank, one direction among the first direction 30 and the second direction 31 is selected. The rows of intermediate panels 20 aligned parallel to the selected direction 30 or 31 are arranged continuously so as to cross the intersections 32. Accordingly, the rows of intermediate panels 20 arranged parallel to the other direction 31 or 30 are arranged discontinuous way.

However, in a row of intermediate panels 20 arranged continuously, the lower bevels 25 are aligned along the entire length of said row. However, these lower bevels 25 are sized so as to fully accommodate the maximum overflow of glue resulting from the bonding of the intermediate panel 20 to the waterproof strip 18. Thus, these overflows of glue are likely to only partially fill the lower bevels 25 so that these lower chamfers 25 form an empty space developing along the longitudinal direction of the intermediate panel 20 between said intermediate panel 20, the adjacent primary insulating panel 9 and the secondary waterproof membrane 3. Thus, the alignment of the intermediate panels 20 in a continuous manner generates the alignment of the empty spaces formed by the lower chamfers 25. In other words, a row of intermediate panels 20 arranged in a continuous manner forms at the level of the lower chamfers 25 a channel developing over the entire length of the row.

Such a channel is particularly detrimental in the context of a row developing parallel to a direction having a component parallel to the direction of earth's gravity, when the vessel wall is a transverse wall 37 or a side wall 38, 39, 40, 41, 42, 43. Indeed, such channels developing over the entire height of a sealed and thermally insulating vessel wall promote natural convection and the generation of a thermosiphon phenomenon, such a thermosiphon phenomenon degrading the properties thermal insulation of the primary thermally insulating barrier 4.

To avoid, or at least limit, these thermosiphon phenomena, the direction selected from the first direction 30 and the second direction 31 to align the intermediate panels 28 or 29 continuously is the direction 30 or 31 having the lowest parallel component. to Earth's gravity.

For example, in the context of a vessel wall having a first direction 30 perpendicular to the direction of earth's gravity and a second direction 31 parallel to the direction of earth's gravity, the first direction 30 is selected to align the first intermediate panels 28 continuously in the rows of first inter-panel spaces 19 parallel to the first direction 30. Thus, the rows of first intermediate panels 28 are continuous and horizontal while the rows of second intermediate panels 29 are discontinuous and parallel to the direction of earth's gravity. Consequently, the channels formed by the lower chamfers 25 of the second intermediate panels 29, which are therefore parallel to the direction of earth's gravity, are interrupted at each intersection 32 between the rows of first inter-panel spaces 19 and the rows of second spaces inter-panels 19. This interruption of the channels developing parallel to the earth's gravity makes it possible to limit convection phenomena in the vessel wall.

Preferably, the first intermediate panels 28 are arranged so that the longitudinal edges 24 of the second intermediate panels 29, that is to say the edges of said second intermediate panels 29 parallel to the second direction 31, are in line with a first intermediate panel 28. In other words, the first intermediate panels 28 are arranged so that side edges 33 of the first intermediate panels 28, that is to say the edges of said first intermediate panels 28 which are parallel to the second direction 31 , are offset along the first direction 30 with respect to the longitudinal edges 24 of the second intermediate panels 29. Thus, the channels formed by the lower chamfers 25 of the second intermediate panels 29 are offset with respect to an interface 34 between two first intermediate panels 28 successive and are therefore not extended by said interface 34. The channels formed by the lower chamfers 25 of the second intermediate panels 29 are thus interrupted by the first intermediate panels 28 at the intersections 32.

In Figure 3, the first intermediate panels 28 have a length, in the first direction 30, and are arranged so that the intersections 32 are crossed by a first intermediate panel 28 respectively. Thus, the lower chamfers 25 of the longitudinal edges 24 of the second intermediate panels 29 are interrupted at an intersection 32 by the presence of said first intermediate panel 28 crossing said intersection 32. By way of example, the length of the first intermediate panel 28 is 1 m for panels with a length of 3 m. By way of example, the length of the second intermediate panel 29 is 0.66 m for panels with a width of 1 m

In an embodiment not shown, the first intermediate panels 28 are arranged so that the interface 34 between two successive first intermediate panels 34 is housed in the intersection 32, and therefore offset along the first direction 30 with respect to the longitudinal edges 24 of the second intermediate panels 29.

In an embodiment not illustrated, the two directions 30 and 31 have a component parallel to the direction of the earth's gravity. In this case, the direction 30 or 31 selected for arranging the intermediate panels 19 continuously is the direction having the component parallel to the weakest direction of earth gravity.

For a tank having polyhedral general shapes, as shown in Figures 5 and 6, the arrangements of the intermediate panels 19 as described above are advantageously implemented for the two transverse walls, front and rear 37 vertical, the two vertical side walls 38, 39, the two upper oblique side walls 40, 41 and the two lower oblique side walls 42, 43.

The technique described above for making a leaktight and thermally insulating tank wall can be used in different types of tanks, for example to form the tank wall of an LNG tank in a land installation or in a floating structure such as a LNG carrier or other.

Referring to Figure 4, a cutaway view of an LNG carrier 70 shows a sealed and insulated tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary leaktight barrier intended to be in contact with the LNG contained in the tank, a secondary leaktight barrier arranged between the primary leaktight barrier and the double hull 72 of the ship, and two insulating barriers arranged respectively between the primary waterproof barrier and the secondary waterproof barrier and between the secondary waterproof barrier and the double hull 72.

In a manner known per se, loading/unloading pipes 73 arranged on the upper deck of the ship can be connected, by means of appropriate connectors, to a maritime or port terminal to transfer a cargo of LNG from or to the tank 71.

FIG. 4 represents an example of a maritime terminal comprising a loading and unloading station 75, an underwater pipe 76 and an onshore installation 77. The loading and unloading station 75 is a fixed off-shore installation comprising an arm 74 and a tower 78 which supports the mobile arm 74. The mobile arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the loading/unloading pipes 73. The orientable mobile arm 74 adapts to all sizes of LNG carriers . A connecting pipe, not shown, extends inside the tower 78. The loading and unloading station 75 allows the loading and unloading of the LNG carrier 70 from or to the shore installation 77. This comprises liquefied gas storage tanks 80 and connecting pipes 81 connected by the underwater pipe 76 to the loading or unloading station 75. The underwater pipe 76 allows the transfer of the liquefied gas between the loading or unloading station 75 and the shore installation 77 over a great distance, for example 5 km, which makes it possible to keep the LNG carrier 70 at a great distance from the coast during loading and unloading operations.

To generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and/or pumps fitted to the shore installation 77 and/or pumps fitted to the loading and unloading station 75 are used.

Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention as claimed.

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

In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims (12)

Sealed and thermally insulating vessel wall, said wall comprising a thermally insulating barrier (4) and a sealed membrane (1),
the thermally insulating barrier (4) comprising a plurality of parallelepipedic insulating panels (9),
the thermally insulating barrier (4) comprising a row of first inter-panel spaces (19) aligned parallel to a first direction (30) and a row of second inter-panel spaces (19) aligned parallel to a second direction (31), said first inter-panel spaces (19) and second inter-panel spaces (19) being delimited by the facing edges of two respective adjacent insulating panels (9) of the plurality of insulating panels (9), the first direction (30) and the second direction (31) being secant so that the first row of inter-panel spaces (19) and the second row of inter-panel spaces (19) form an intersection (32), the second direction (31) comprising a component parallel to the direction of earth gravity,
the thermally insulating barrier (4) further comprising a row of first intermediate panels (28) and a row of second intermediate panels (29), the first intermediate panels (28) being arranged in the row of first inter-panel spaces (19 ), the second intermediate panels (29) being arranged in the row of second inter-panel spaces (19),
and wherein the row of first intermediate panels (28) is continuous in the row of first inter-panel spaces (19) such that the row of second intermediate panels (29) is discontinuous at the intersection (32) between the row of first inter-panel spaces (19) and the row of second inter-panel spaces (19),
a first intermediate panel (28) of the row of first intermediate panels (28) being received in said intersection (32) so that an edge (24) parallel to the second direction (31) of a second intermediate panel (29 ) juxtaposed with said first intermediate panel (28) is arranged in line with said first intermediate panel (28). Sealed and thermally insulating tank wall according to claim 1, in which said edge (24) of said second intermediate panel (29) is a first longitudinal edge of said second intermediate panel (29), said second intermediate panel (29) comprising a second longitudinal parallel to the second direction (31), said second longitudinal edge being arranged in line with a first intermediate panel (28) of the row of first intermediate panels (28). Sealed and thermally insulating tank wall according to Claim 1 or 2, in which the edges (24) of the second intermediate panels (29) parallel to the second direction (31) have a lower chamfer (25). Sealed and thermally insulating tank wall according to one of Claims 1 to 3, in which the said first intermediate panel (28) housed in the said intersection (32) passes through the said intersection (32). Sealed and thermally insulating tank wall according to one of Claims 1 to 4, in which the first intermediate panels (28) have transverse edges parallel to the second direction (31), the first intermediate panels (28) being arranged in the row of first inter-panel spaces (19) so that said transverse edges are offset, along the first direction (30), with respect to the edges (24) parallel to the second direction (31) of the second intermediate panels (29 ). Sealed and thermally insulating tank wall according to claim 5, in which the first intermediate panels (28) are arranged in the row of first inter-panel spaces (19) so that the transverse edges of the first intermediate panels (28) are staggered , along the first direction (30), with respect to the edges of the insulating panels (9) delimiting the second row of inter-panel spaces (19) so that the said edges of the said insulating panels (9) are arranged at right of a said first intermediate panel (28). Leaktight and thermally insulating vessel wall according to one of Claims 1 to 6, in which the thermally insulating barrier (4) comprises a plurality of rows of first inter-panel spaces (19) aligned in directions parallel to the first direction ( 30) and a plurality of rows of second inter-panel spaces (19) aligned along directions parallel to the second direction (31), the thermally insulating barrier comprising a plurality of intersections (32) formed by the plurality of rows of first inter-panel spaces (19) and the plurality of rows of second inter-panel spaces (19),
the thermally insulating barrier (4) further comprising a plurality of rows of first intermediate panels (28) and a plurality of rows of second intermediate panels (29), said rows of first intermediate panels (28) being arranged continuously in a respective row of first inter-panel spaces (19), said rows of second intermediate panels (29) being discontinuously arranged in a respective said row of second inter-panel spaces (19) so that the edges (24) parallel to the second direction (31) of said second intermediate panels (29) are arranged opposite a respective first intermediate panel (28). Sealed and thermally insulating tank wall according to one of Claims 1 to 7, in which the thermally insulating barrier is a primary thermally insulating barrier (4), the sealing membrane is a primary sealing membrane (5) and the insulating panels are primary insulating panels (9), the wall further comprising a secondary thermally insulating barrier (2) and a secondary waterproof membrane (3), the vessel wall comprising a plurality of prefabricated elements (6), the said prefabricated elements comprising a panel parallelepipedic secondary insulation (7), a portion of waterproof film (8) resting on the secondary insulating panel (7) and a primary insulation panel (9) resting on the portion of waterproof film (8), the primary insulation panel (9) having dimensions smaller than the dimensions of the secondary insulating panel (7) so that the sealed film portion (8) has an uncovered peripheral zone (14),
and in which said prefabricated elements (6) are juxtaposed according to a regular mesh so that the secondary insulating panels (7) form the secondary thermally insulating barrier (2), the peripheral zones (14) of the sealed film portion (8) of two adjacent prefabricated elements (6) being connected in a leaktight manner by a strip of leakproof film (18), the portions of leakproof film (8) of the prefabricated elements (6) and the strips of leakproof film (18) jointly forming the membrane secondary waterproof (3), the intermediate insulating panels (28, 29) being anchored to the peripheral zones 14 of the portions of waterproof film (8) and to the corresponding anchoring strips (18). Sealed and insulating tank (71) arranged in a supporting structure, the tank comprising a sealed and thermally insulating tank wall according to one of claims 1 to 8. Vessel (70) for transporting a cold liquid product, the vessel comprising a double hull (72) and a tank (71) according to claim 9 arranged in the double hull. Transfer system for a cold liquid product, the system comprising a ship (70) according to claim 10, insulated pipes (73, 79, 76, 81) arranged to connect the tank (71) installed in the hull of the ship to a floating or onshore storage facility (77) and a pump for driving a flow of cold liquid product through the insulated pipes from or to the floating or onshore storage facility to or from the vessel's tank. Method of loading or unloading a ship (70) according to claim 10, in which a cold liquid product is conveyed through insulated pipes (73, 79, 76, 81) from or to a floating or terrestrial storage installation ( 77) to or from the ship's tank (71).