EP4267881A1

EP4267881A1 - Sealed and thermally insulating tank comprising a wave stopper

Info

Publication number: EP4267881A1
Application number: EP21844002.2A
Authority: EP
Inventors: Vincent LORIN; Marc BOYEAU; Benoît MOREL
Original assignee: Gaztransport et Technigaz SA
Current assignee: Gaztransport et Technigaz SA
Priority date: 2020-12-23
Filing date: 2021-12-22
Publication date: 2023-11-01
Also published as: FR3118119A1; WO2022136599A1; CN116783421A; KR20230122047A; FR3118119B1

Abstract

The invention relates to a tank in which a tank wall comprises at least one thermally insulating barrier (1, 5) and at least one sealing membrane (4, 7), the sealing membrane comprising a series of parallel corrugations (25, 26), the thermally insulating barrier (1, 5) being situated between the sealing membrane and the support structure, the thermally insulating barrier (1, 5) comprising a series of parallel grooves (14, 15) receiving the series of corrugations (25, 26), wherein the tank comprises at least one wave stopper (32) situated between a corrugation of the series of corrugations (25, 26) and an insulating panel, wherein the wave stopper (32) comprises a core made from compressible material and a casing completely covering the core, the wave stopper (32) being compressed between the sealing membrane and the thermally insulating barrier.

Description

Title of the invention: Sealed and thermally insulating tank comprising a wave shutter

Technical area

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 around -162°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.

Technology background

[0002] In the state of the art, sealed and thermally insulating tanks are known for storing liquefied natural gas, integrated into a supporting structure, such as the double hull of a ship intended for the transport of liquefied natural gas. . Generally, such tanks comprise a multilayer structure having successively, in the direction of the thickness, from the outside towards the inside of the tank, a secondary thermally insulating barrier retained on the load-bearing structure, a secondary sealing membrane resting against the secondary thermally insulating barrier, a primary thermally insulating barrier resting against the secondary sealing membrane and a primary sealing membrane resting against the primary thermally insulating barrier and intended to be in contact with the liquefied natural gas contained in the tank.

The document WO2019102163 describes a secondary thermally insulating barrier and a primary thermally insulating barrier formed of juxtaposed insulating panels. In this document WO2019102163, the secondary sealing membrane consists of a plurality of metal sheets comprising undulations projecting outwards from the tank and thus allowing the secondary sealing membrane to deform under the effect of thermal and mechanical stresses generated by the fluid stored in the tank. An internal face of the insulating panels of the secondary thermally insulating barrier has grooves receiving the corrugations of the corrugated metal sheets of the secondary waterproof membrane. These undulations and these grooves form a mesh of channels developing along the walls of the tank.

[0004] In order to close said channels, the document W02019102163 further describes that the thermally insulating barrier comprises a housing intersecting the groove and having a width greater than the width of the groove. The tank thus comprises a shutter arranged in the housing so that the shutter closes a portion of the groove located on the projecting side of the sealing membrane by creating a pressure drop for a flow circulating in the groove. The obturator can thus move in the housing to adapt to the position of the corrugation in the groove.

Summary

[0005] One idea underlying the invention is to make the wave shutters more adaptable while simplifying assembly in the tank.

Another idea underlying the invention is to limit the presence of continuous circulation channels in the thermally insulating barriers in order to limit the phenomena of natural convection in said thermally insulating barriers.

According to one embodiment, the invention provides a sealed and thermally insulating tank for storing a fluid fixed to a support structure, in which a tank wall comprises at least one thermally insulating barrier and at least one membrane of sealing, the sealing membrane comprising a series of parallel undulations having a longitudinal direction, and flat portions located between said undulations, said undulations protruding from flat portions, said thermally insulating barrier being located against the sealing membrane, the thermally insulating barrier, comprising insulating panels, the insulating panels being juxtaposed to each other, in which the tank comprises at least one wave shutter located in line with a corrugation of the series of corrugations, between a corrugation of the series of undulations and a bottom of a groove of the series of grooves, the wave shutter being configured to shutter a space left free between said corrugation and one of the insulating panels, in which the corrugation shutter comprises a core of compressible material and a flexible envelope entirely covering said core so as to form a container for the core of compressible material, the wave shutter being compressed between the sealing membrane and the thermally insulating barrier.

[0008] Thanks to these characteristics, such a tank offers the possibility of flexibly closing grooves accommodating the undulations of the membrane despite a tolerance affecting the position of the corrugations in the grooves. Such a tolerance may in particular arise from the manufacture and assembly of the undulations in the grooves. Furthermore, thanks to these characteristics, the space between the convex side of the corrugation and the bottom of the groove, formed by the thermally insulating barrier, can be closed by the wave shutter for different positions of the ripple in the groove. Indeed, the core of compressible material makes it possible during its compression to simply fill this space by adapting to the position of the corrugation and by compressing more in line with the corrugation.

[0009] Thus, the wave shutter makes it possible to limit the formation of flows in the channels of the thermally insulating barrier, in particular the formation of thermosiphons between these channels and any flow channel located closer to the hull, by example a masticated space between the thermally insulating barrier and the load-bearing structure.

According to embodiments, such a tank may include one or more of the following characteristics.

[001 1] According to one embodiment, the thermally insulating barrier is located between the sealing membrane and the supporting structure, the corrugations projecting inwards from the tank, each insulating panel comprising a flat rigid plate forming the face in contact with the sealing membrane, the wave shutter being located between a corrugation of the series of corrugations and a rigid plate of an insulating panel.

[0012] According to one embodiment, said corrugations protrude from flat portions on a projecting side of the sealing membrane, said thermally insulating barrier being located on the projecting side of the sealing membrane, the thermally insulating barrier comprising a series of parallel grooves receiving the series of corrugations, said corrugation shutter being located to the right of a corrugation of the series of corrugations, between a corrugation of the series of corrugations and a bottom of a groove of the series of grooves.

According to one embodiment, the wave shutter is compressed by the sealing membrane so that the dimension in a direction of thickness decreases locally by at least 20% between the thickness before compression and the thickness after compression, preferably at least 30%, more preferably at least 40%, and for example of the order of 50%.

According to one embodiment, the envelope comprises a first ply and a second ply, the first ply being located in contact with the sealing membrane, the first ply and the second ply being fixed to one another. other on at least one part a perimeter of the first ply and of the second ply so as to form the container for the core of compressible material.

[0015]According to one embodiment, the first ply and the second ply are fixed to each other over the entire periphery of the first ply and the second ply so as to form a closed container for the core of material compressible.

[0016]According to one embodiment, the first ply is made of a more flexible material than the material of the second ply.

[0017] According to one embodiment, the envelope comprises a single ply comprising an internal surface located in contact with the sealing membrane, the single ply being made in the form of a flexible cylinder so as to form the container for the core in compressible material.

[0018]According to one embodiment, the single ply, the first ply and/or the second ply comprises at least one perforation so as to promote the exit of air during the compression of the shutter. In the case of the single ply, the latter may comprise at least one perforation on an external surface and/or on the internal surface of the single ply.

According to one embodiment, the core represents at least 50% by volume, preferably at least 90% by volume of the wave shutter, in the compressed state or in the state before compression.

[0020]According to one embodiment, the core is made of a non-woven, powdery or foam fibrous material.

According to one embodiment, the core is made of a material chosen from: mineral wool, melamine foam, polyester wadding, polyethylene wadding, synthetic plastic foam, polyamide fibers, acrylic fibers or combinations thereof.

[0022] For example, the polyester wadding can be produced in the form of a mat, a ball, a ball or a quilting of fibers.

[0023] According to one embodiment, the casing is preferably made of a material that is not gastight and capable of creating a high pressure drop.

[0024]According to one embodiment, the casing comprises a woven or non-woven textile ply, consisting of mineral and/or synthetic fibers, for example glass fibers or polymer fibers of the polyester, polyamide or acrylic type. Such a sheet is optionally combined with an aluminum sheet or a plastic film, this sheet or this film preferably being perforated to avoid complete sealing. Such a sheet can also be coated in order to improve the sealing property of the sheet.

According to one embodiment, the tank comprises a plurality of wave shutters, each wave shutter being located between a corrugation and a groove in which said corrugation is housed.

According to one embodiment, the tank comprises a plurality of wave shutters, each wave shutter being located between a corrugation and an insulating panel.

[0027]According to one embodiment, the tank comprises a plurality of wave shutters located in line with a corrugation of the series of corrugations, between a corrugation of the series of corrugations and a groove of the series of grooves, each corrugation shutter being configured to close a space left free between said corrugation and said groove in which said corrugation is housed, the corrugation shutters being regularly spaced from each other in the longitudinal direction by a series of ripples.

[0028] According to one embodiment, the tank comprises a plurality of corrugation shutters located in line with a corrugation of the series of corrugations, between the corrugation of the series of corrugations and an insulating panel formed at the right of the corrugation, each corrugation shutter being configured to close a space left free between said corrugation and said insulating panel, the corrugation shutters being regularly spaced from each other in the longitudinal direction of the series of corrugations.

[0029]According to one embodiment, the tank comprises a plurality of wave shutters located in line with a corrugation of the series of corrugations, between a corrugation of the series of corrugations and a groove of the series of grooves, each wave shutter being configured to close a space left free between said corrugation and said groove in which said corrugation is housed, the wave shutters of said corrugations being regularly spaced from each other in the longitudinal direction.

According to one embodiment, the thermally insulating barrier is a first thermally insulating barrier and the tank comprises a second thermally insulating barrier located opposite the projecting side of the sealing membrane, and in which the tank comprises at at least one complementary wave shutter located opposite the at least one wave shutter so as to sandwich an undulation of the sealing membrane between the wave shutter and the complementary wave shutter, the complementary wave shutter being configured to close a space left free between said corrugation and the second thermally insulating barrier. [0031] According to one embodiment, the thermally insulating barrier has an internal surface, the series of grooves being made on the internal surface and the corrugations projecting outwards from the tank.

[0032]According to one embodiment, the sealing membrane is a secondary sealing membrane, the thermally insulating barrier is a primary thermally insulating barrier, the corrugations projecting towards the inside of the tank, and in which the tank comprises a secondary thermally insulating barrier retained on the support structure and carrying the secondary sealing membrane, the primary thermally insulating barrier being carried by the secondary sealing membrane, the tank comprising a primary sealing membrane carried by the thermally insulating barrier primary and intended to be in contact with the fluid in the tank, the series of grooves being formed on an outer surface of the primary thermally insulating barrier.

According to one embodiment, the thermally insulating barrier comprises insulating panels, the insulating panels being juxtaposed to each other, the insulating panels being provided with grooves forming the series of grooves so that the grooves of two insulating panels adjacent panels are aligned in the longitudinal direction, the at least one wave shutter being housed in the groove of one of the insulating panels.

According to one embodiment, an inter-panel space is delimited between two adjacent insulating panels, the at least one wave shutter being housed in the groove of one of the two insulating panels and being able to overflow into the inter-panel space.

According to one embodiment, the thermally insulating barrier comprises at least one insulating joint housed in the inter-panel space and extending in a longitudinal direction of the inter-panel space, and at least one bridging element arranged above the insulating joint, and in which the bridging element comprises a bridging plate, the bridging plate extending astride two adjacent insulating panels and being fixed to an internal face of the two insulating panels so as to oppose a separation of the two insulating panels, the internal faces of the insulating panels forming the internal surface of the thermally insulating barrier.

According to one embodiment, the thermally insulating barrier comprises at least one insulating seal housed in the inter-panel space and extending in a longitudinal direction of the inter-panel space, and at least one bridging element belonging to a chain of bridging elements and arranged above the insulating joint, and in which a first bridging element of the chain of bridging elements extends between two successive undulations of the series of undulations, the wave shutter being located between said first bridging element and a second bridging element of the chain of bridging elements.

According to one embodiment, the bridging element comprises an insulating strip assembled to the bridging plate, the insulating strip having a dimension smaller than the bridging plate in the longitudinal direction so as to be housed in the space between the panels and being compressed between the bridging plate and the insulating joint in a thickness direction of the thermally insulating barrier.

According to one embodiment, the thermally insulating barrier comprises a chain of bridging elements extending in the longitudinal direction of the interpanel space and comprising a plurality of bridging elements arranged astride two adjacent insulating panels and attached to each other.

According to one embodiment, a first bridging element of the chain of bridging elements extends between two successive undulations of the series of undulations, the wave shutter being located between said first bridging element and a second bridging element of the chain of bridging elements in line with an undulation of the series of undulations, between the sealing membrane and the thermally insulating barrier.

According to one embodiment, the first bridging element is fixed to the second bridging element via the wave shutter.

According to one embodiment, the wave shutter is fixed to a flexible sheet, two adjacent bridging elements of said chain are fixed to each other using the flexible sheet.

According to one embodiment, each insulating panel comprises a layer of insulating polymer foam and a rigid plate forming the face in contact with the sealing membrane, the groove of the series of grooves being formed in the rigid plate.

According to one embodiment, the series of corrugations is a first series of corrugations, and in which the corrugated metal sheets comprise a second series of parallel corrugations extending parallel to the transverse direction and planar portions located between said undulations.

[0044] Such a tank can be part of an onshore storage facility, for example for storing 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.

[0045] According to one embodiment, a ship for transporting a cold liquid product comprises a double hull and an aforementioned tank arranged in the double hull.

[0046] 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 an installation floating or onshore storage facility 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 ship's tank.

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 towards or from the vessel's tank.

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 for illustrative purposes only. and non-limiting, with reference to the accompanying drawings.

[0049] [Fig. 1] Figure 1 shows a perspective view, cut away, of a vessel wall.

[0050] [Fig. 2] Figure 2 is a partial sectional view of a thermally insulating barrier on which rests a corrugated sealing membrane comprising a corrugation housed in a groove of the thermally insulating barrier and illustrating different possible positions of the corrugation in the groove .

[0051] [Fig. 3] Figure 3 is a perspective view of a thermally insulating barrier comprising a plurality of wave shutters according to a first embodiment.

[0052] [Fig. 4] Figure 4 is a sectional view along the line IV-IV of Figure 3 illustrating a wave shutter housed in a groove and before arrangement of the sealing membrane.

[0053] [Fig. 5] Figure 5 is a sectional view along the line IV-IV of Figure 3 illustrating a wave shutter housed in a groove and illustrating a first position of the corrugation in the groove. [0054] [Fig. 6] Figure 6 is a sectional view along the line IV-IV of Figure 3 illustrating a wave shutter housed in a groove and illustrating a second position of the corrugation in the groove.

[0055] [Fig. 7] Figure 7 is an exploded perspective view of insulating panels of a thermally insulating barrier and of a chain of bridging elements according to one embodiment intended to be positioned astride between two rows of adjacent insulating panels.

[0056] [Fig. 8] Figure 8 is a partial perspective view of the thermally insulating barrier provided with a chain of bridging elements.

[0057] [Fig. 9] Figure 9 is a sectional view along the line IX-IX of Figure 8, with the illustration of the sealing membrane positioned on the thermally insulating barrier.

[0058] [Fig. 10] Figure 10 is a sectional view along line X-X of Figure 8.

[0059] [Fig. 1 1] Figure 11 is a schematic sectional view of a shutter housed in a corrugation before compression, according to a second embodiment.

[0060] [Fig. 12] Figure 12 is a schematic sectional view of a shutter housed in a corrugation after compression against an insulating panel, according to the second embodiment.

[0061] [Fig. 13] Figure 13 is a cutaway diagrammatic representation of an LNG carrier tank and a loading/unloading terminal for this tank.

Description of embodiments

[0062] By convention, the terms "external" and "internal" are used to define the relative position of one element with respect to another, with reference to the inside and the outside of the tank.

In Figure 1, there is shown the multilayer structure of a sealed and thermally insulating tank for storing a fluid according to one embodiment.

Each wall of the tank comprises, from the outside towards the inside of the tank, a secondary thermally insulating barrier 1 comprising insulating panels 2 juxtaposed and anchored to a support structure 3 by secondary retaining members, a membrane secondary sealing 4 carried by the insulating panels 2 of the secondary thermally insulating barrier 1, a primary thermally insulating barrier 5 comprising insulating panels 6 juxtaposed and anchored to the insulating panels 2 of the secondary thermally insulating barrier 1 by primary retaining members 19 and a primary sealing membrane 7, carried by the insulating panels 6 of the primary thermally insulating barrier 5 and intended to be in contact with the cryogenic fluid contained in the vessel.

[0065] The load-bearing structure 3 may in particular be a self-supporting sheet metal or, more generally, any type of rigid partition having appropriate mechanical properties. The load-bearing structure 3 can in particular be formed by the hull or the double hull of a ship. The support structure 3 comprises a plurality of walls defining the general shape of the tank, usually a polyhedral shape.

The secondary thermally insulating barrier 1 comprises a plurality of insulating panels 2 anchored to the supporting structure 3 by means of resin cords, not shown, and/or studs welded to the supporting structure 3. The resin cords must be sufficiently adhesive when they ensure alone the anchoring of the insulating panels 2 but are not necessarily adhesive when the insulating panels 2 are anchored by means of studs. The insulating panels 2 substantially have the shape of a rectangular parallelepiped.

As illustrated in particular in Figures 3 to 10, the insulating panels 2, 6 each comprise a layer of insulating polymer foam 9 provided on its internal face with an internal rigid plate 10 and optionally on its external face with a plate external rigid (not shown). The rigid plates, internal 10 and external, are, for example, plywood plates bonded to said layer of insulating polymer foam 9. The insulating polymer foam may in particular be a polyurethane-based foam. The polymer foam is advantageously reinforced with glass fibers helping to reduce its thermal contraction.

The insulating panels 2, 6 are juxtaposed in parallel rows and separated from each other by inter-panel spaces 12 guaranteeing a functional mounting clearance. The inter-panel spaces 12 are filled with an insulating joint 13, represented in FIGS. 5 and 6 in particular, such as glass wool, rock wool or flexible synthetic foam with open cells for example, and which can be wrapped in kraft paper. The insulating joint 13 is advantageously made of a porous material so as to provide gas flow spaces in the inter-panel spaces 12 between the insulating panels 2. Such gas flow spaces are advantageously used in order to allow a circulation of inert gas, such as nitrogen, within the secondary thermally insulating barrier 1 so as to maintain it under an inert atmosphere and thus prevent combustible gas from being in an explosive concentration range and/or in order to place the thermally insulating barrier secondary 1 in depression in order to increase its insulating power. This circulation of gas is also important to facilitate the detection of any leaks of combustible gas. The inter-panel spaces 12 have, for example, a width of the order of 30 mm. Insulating joints 13 are thus placed in a longitudinal direction corresponding to the greatest length of the insulating panels 2, 6, while insulating joints 13 are placed in a transverse direction perpendicular to the longitudinal direction. The insulating seals 13 are sized so that their internal face directed towards the secondary sealing membrane 4 is aligned with the limit of the layer of insulating polymer foam 9 as shown in Figure 6.

An inner plate 10 according to one embodiment is shown in detail in Figures 3, 7 and 8. The inner plate 10 has two series of grooves 14, 15, perpendicular to each other, so to form a network of grooves. Each of the series of grooves 14, 15 is parallel to two opposite sides of the insulating panels 2. The grooves 14, 15 are intended to receive corrugations, projecting towards the outside of the tank, formed on the metal sheets of the secondary sealing barrier 4. In the embodiment shown, the inner plate 10 comprises three grooves 14 extending along the longitudinal direction of the insulating panel 2 and nine grooves 15 extending along the transverse direction of the insulating panel 2.

[0070] The grooves 14, 15 pass entirely through the thickness of the inner plate 10 and thus emerge at the level of the layer of insulating polymer foam 9. Furthermore, the insulating panels 2 comprise, in the crossing zones between the grooves 14, 15, clearance orifices 16 formed in the layer of insulating polymer foam 9. The clearance orifices 16 allow the accommodation of the node zones, formed at the intersections between the corrugations of the metal sheets of the secondary sealing barrier 4. These zones node have a top projecting outward from the tank.

Furthermore, the inner plate 10 is equipped with metal plates 17, 18 for anchoring the edge of the corrugated metal sheets of the secondary sealing membrane 4 on the insulating panels 2. The metal plates 17, 18 are extend in two perpendicular directions which are each parallel to two opposite sides of the insulating panels 2. The metal plates 17, 18 are fixed to the inner plate 10 of the insulating panel 2, by screws, rivets or staples, for example. The metal plates 17, 18 are placed in recesses made in the internal plate 10 so that the internal surface of the metal plates 17, 18 is flush with the internal surface of the internal plate 10. The inner plate 10 is also equipped with threaded studs 19 projecting inwards from the tank, and intended to ensure the fixing of the primary thermally insulating barrier 5 on the insulating panels 2 of the secondary thermally insulating barrier 1. The metal studs 19 pass through holes made in the metal plates 17.

Furthermore, the inner plate 10 has along its edges, in each interval between two successive grooves 14, 15, a recess 21 intended to receive a bridging element 20 which will be described in more detail later.

As visible in Figures 1 and 9, it is observed that the secondary sealing membrane 4 comprises a plurality of corrugated metal sheets 24 each having a substantially rectangular shape. The corrugated metal sheets 24 are arranged offset with respect to the insulating panels 2 of the secondary thermally insulating barrier 1 so that each of said corrugated metal sheets 24 extends jointly over four adjacent insulating panels 2.

Each corrugated metal sheet 24 has a first series of parallel corrugations 25 extending in the transverse direction and a second series of parallel corrugations 26 extending in the longitudinal direction. Each of the series of corrugations 25, 26 is parallel to two opposite edges of the corrugated metal sheet 24. The corrugations

25, 26 project outwards from the tank, that is to say in the direction of the support structure 3. The corrugated metal sheet 24 comprises between the corrugations 25, 26, a plurality of flat surfaces. At each crossing between two undulations 25,

26, the sheet metal has a knot area. In the embodiment shown, the undulations 25, 26 of the first series and of the second series have identical heights. It is however possible to provide that the undulations 25 of the first series have a greater height than the undulations 26 of the second series or vice versa.

As shown in Figure 9, the corrugations 25, 26 of the corrugated metal sheets 24 are housed in the grooves 14, 15 made in the inner plate 10 of the insulating panels 2. The adjacent corrugated metal sheets 24 are welded together at recovery. The anchoring of the corrugated metal sheets 24 on the metal plates 17, 18 is carried out by tacking welds.

The corrugated metal sheets 24 are, for example, made of Invar®: that is to say an alloy of iron and nickel whose coefficient of expansion is typically between 1, 2.10-6 and 2.10-6 K-1 , or in an iron alloy with a high manganese content whose coefficient of expansion is typically of the order of 7.10-6 K-1 . Alternatively, the corrugated metal sheets 24 can also be made of stainless steel or aluminum.

The primary thermally insulating barrier 5 comprises a plurality of insulating panels 6 of substantially rectangular parallelepipedic shape. The insulating panels 6 are offset here with respect to the insulating panels 2 of the secondary thermally insulating barrier 1 so that each insulating panel 6 extends over four insulating panels 2 of the secondary thermally insulating barrier 1. An insulating panel 6 comprises a structure analogous to an insulating panel 2 of the secondary thermally insulating barrier 1 .

[0079] The primary sealing membrane 7, visible in Figure 1, is obtained by assembling a plurality of corrugated metal sheets 27. Each corrugated metal sheet 27 comprises a first series of parallel undulations 28, called high, s' extending in the longitudinal direction and a second series of parallel undulations 29, called low, extending in the transverse direction. The node zones have a structure close to that of the node zones of the corrugated metal sheets 24 of the secondary sealing membrane 4. The corrugations 28, 29 protrude towards the inside of the tank. The corrugated metal sheets 27 are, for example, made of stainless steel or aluminum.

[0080] During manufacture of the tank, the grooves 14, 15 are sized to form a zone for adjusting the arrangement of the corrugations 25, 26 in the tank. In particular, these grooves 14, 15 must be dimensioned to allow variations in the dimensions of the corrugations 25, 26 linked to the manufacturing tolerances of said corrugations 25, 26 in the corrugated metal sheets 24. In addition, these dimensioning must take into account the tolerances positioning insulating panels 2 and corrugated metal sheets 24 relative to each other.

[0081] Figure 2 illustrates a central position 35 and end positions 36 defining a range of possible positions of an undulation 25, 26 housed in a groove 14, 15. Preferably, the groove 14, 15 is dimensioned so to have a width 37, taken in a transverse direction perpendicular to a longitudinal direction of the corrugation 25, 26 and parallel to an internal face of the internal plate 10, greater than or equal to a width 38 of the corrugation 25, 26 according to said direction, increased by a predetermined tolerance dimension corresponding to twice the positioning tolerance of the corrugation 25, 26 in the groove 14, 15 on either side of the central position 35. Due to these dimensions, a space remains in the grooves 14, 25 between the thermally insulating barrier 1 and the sealing membrane 4. These grooves 14, 15 could therefore constitute a network of circulation channels. Such channels developing continuously between the sealing membrane and the thermally insulating barrier throughout the vessel wall would promote convection movements, in particular on vessel walls having a significant vertical component such as transverse vessel walls. . Such a network of continuous channels could generate thermosiphon phenomena promoting heat transfer by gas convection in the thermally insulating barrier.

One aspect of the invention starts from the idea of preventing these convection movements in the walls of the tank. For this, one aspect of the invention starts from the idea of limiting the length of the channels formed by the grooves 14, 15 of the thermally insulating barrier.

According to one embodiment, wave shutters 32 are inserted into one, some, or all of the grooves 14, 15 of the thermally insulating barrier. These wave shutters 32 are arranged in the grooves 14, 15 in order to be arranged between the sealing membrane 4 and the thermally insulating barrier 1.

The wave shutters 32 will be described below in relation to the secondary thermally insulating barrier 1 and the secondary sealing membrane 4 described above. It is obvious that the wave shutters can also be used at the level of the primary between the primary thermally insulating barrier 5 and the primary sealing membrane 7 in the case of undulations 25, 26 projecting towards the outside of the tank. , or even between the primary thermally insulating barrier 5 and the secondary sealing membrane 4 in the case of undulations 25, 26 projecting towards the inside of the tank. Finally, these wave shutters 32 could also be used for a tank provided with a single sealing membrane.

[0086] Figure 3 shows a first embodiment with a secondary thermally insulating barrier 1 comprising a plurality of juxtaposed insulating panels 2 provided with series of grooves 14, 15. In this embodiment, wave shutters 32 are housed in a plurality of grooves 14 of the first series of grooves of the same insulating panel 2 at a distance from the inter-panel space 12 so as to be supported by the layer of insulating polymer foam 9 and to be framed by two parts of the internal rigid plate 10.

[0087] In this illustration, the shutters 32 are aligned in the transverse direction so as to form a shutter line on the insulating panel 2. In another mode of realization, the shutters 32 could be positioned staggered or even be housed in a groove 14 out of two.

In the embodiment shown, the grooves 14 of the same insulating panel 2 comprises a single shutter 32 so that the pitch between two shutters of a groove 14 of the secondary thermally insulating barrier 1 is equal to the dimension of the insulating panel 2 in the longitudinal direction of the corrugations 25. It is obvious that in another embodiment, this pitch could be different, for example by housing two shutters 32 in a groove 14 of the same insulating panel 2.

As illustrated in particular in Figures 4 to 6, the wave shutter 32 is formed of a core 33 of compressible material and an envelope 34 completely covering the core 33. The core 33 is for example formed of mineral wool, melamine foam, polyamide fibers, acrylic fibers, polyethylene wadding or polyester wadding, and makes it possible to create a pressure drop in the groove 14 while making the wave shutter deformable 32 in order to adapt to the space left free between the corrugation 25 and the groove 14. Indeed, with the uncertainty of placement of the corrugation in the groove 14 due in particular to the assembly and manufacturing tolerances, it It is advantageous to place a wave shutter 32 of larger dimension, highly deformable, and of a generally complementary shape to the space remaining between the corrugation and the groove 14 so that it is thus compressed so as to fill all space.

[0090] The envelope 34 is for its part made for example of glass fiber fabric and acts as a container for the core 33 and an additional pressure loss role for the flow of fluid passing through the channel formed between the corrugation and the groove 14. Indeed, the material of the casing 34 can be chosen more or less filtering so as to fix the pressure drop of a flow passing through it. Thus, a wave shutter 32 with such an envelope 34 can achieve, for example, a pressure drop of the order of 3 to 5 Pa under normal operating conditions of the vessel. In this embodiment, the casing 34 is formed of an internal layer 41 in contact with the secondary sealing membrane 4 and an outer layer 39 in contact with the insulating panel 2. The two layers 39, 41 are for example fixed to each other over their entire periphery so as to form the closed container for the core 33 of compressible material. In addition, it has been found that it could be more advantageous to make an inner ply 41 more flexible than the outer ply 39 so that the inner ply 41 can be deformed more easily in contact with the corrugation 25 and that the ply external 39 continues to play its role of support and maintenance in the groove 14. The external ply 39 of the shutter wave 32 is for example glued or stapled on the two parts of the internal rigid plates 10.

[0091] In an embodiment not shown, an additional flexible ply can be located under the outer ply 39 so that the role of maintaining in the groove 14 is transferred to this additional flexible ply and not to the outer ply 39 forming the container for the core 33.

[0092] Figures 4 to 6 show a wave shutter 32 in a groove 14 of an insulating panel 2 at different stages of the assembly of the vessel wall and according to different placements of the corrugation 25 in the groove 14 .

Indeed, Figure 4 shows the wave shutter 32 before the secondary sealing membrane 4 is installed so the wave shutter is in an uncompressed state. Figures 5 and 6 represent the wave shutter 32 after the positioning of the secondary sealing membrane 4 and therefore of an undulation 25 in the groove 14 where the wave shutter 32 is housed, the the wave shutter 32 thus being in a compressed state. With reference to the range of possible positions illustrated in FIG. 2, FIG. 5 represents a first case in which the corrugation 25 is in a central position 35 while FIG. 6 represents a second case in which the corrugation 25 is in a extreme position 36.

In Figure 4, the wave shutter 32 is fixed by the two ends of the outer layer 39 to the inner rigid plate 10 of the insulating panel 2 while the central part of the outer layer 39 rests on the layer of foam 9. The corrugation stopper 30 is thus fixed in the groove 14 and already largely closes off the groove 14 by forming a corrugation stopper 30 with a U-section. The core 33 of compressible material is here in a uncompressed state so that the wave shutter 32 has a generally constant initial thickness.

In Figure 5, the corrugation 25 has been placed in a central position 35 inside the groove 14. The corrugation 25 has thus compressed more significantly the central portion 42 of the obturator of corrugation 32 in line with the crest of corrugation 25 so as to locally greatly reduce the thickness of corrugation shutter 32, for example of the order of 50% relative to its initial value. The shutter, using its core 33 of compressible material thus compressed, thus obstructs the space left free between the insulating panel 2 and the sealing membrane 4 by adapting to the position of the corrugation 25. Similarly in Figure 6, the corrugation 25 has been placed in an extreme position 36 (here right side of the groove 14) inside the groove 14. The corrugation 25 has thus compressed so more important a first part 43 of the wave shutter 32 located to the right of the undulation while a second part 44 of the wave shutter 32 is not compressed. Thus the straight part 43 has had its thickness greatly reduced compared to its initial value, for example of the order of 50%. In the example shown, the left part 44 has seen its thickness slightly increased in view of the transfer by creep in this part of the compressible material of the core 33. Therefore, the shutter using its core 33 in compressible material thus compressed thus obstructs the space left free between the insulating panel 2 and the sealing membrane 4 by adapting to the position of the corrugation 25.

The bridging elements 20 are shown in particular in Figures 7 to 10. In these figures, the bridging elements 20 each comprise a bridging plate 22 which is arranged astride between two adjacent insulating panels 2, spanning the inter-panel space 12 between the insulating panels 2. Each bridging plate 22 is fixed against each of the two adjacent insulating panels 2 so as to oppose their mutual spacing. The bridging plates 22 have a rectangular parallelepipedal shape and are for example made of a plywood plate.

The outer face of the bridging plates 22 is fixed against the bottom of the recesses 21. The depth of the recesses 21 is substantially equal to the thickness of the bridging plates 22 so that the inner face of the bridging plates 22 reaches substantially at the level of the other flat zones of the internal plate 10 of the insulating panel 2. Thus, the bridging plates 22 are able to ensure continuity in the carrying of the secondary sealing membrane 4.

In order to ensure a good distribution of the connection forces between the adjacent panels, a plurality of bridging plates 22 extend along each edge of the internal plate 10 of the insulating panels 2, a bridging plate 22 being disposed in each interval between two adjacent grooves 14, 15 of a series of parallel grooves.

[0100] Advantageously, the bridging plates 22 extend over substantially the entire length of the interval between two adjacent grooves 14, 15. In addition, the recesses 21 on either side of the interspace panel 12 form a housing for the bridging plate 22, that is to say the space formed between the edges of the recesses 21 of two insulating panels 2. The housing has a transverse dimension slightly greater than the transverse dimension of the bridging plate 22 so as to overcome assembly and/or manufacturing tolerances when inserting the bridging plate 22 into the housing.

The bridging plates 22 can be fixed against the inner plate 10 of the insulating panels 2 by any suitable means. For example and as represented in FIG. 3, the application of an adhesive 40 in the recess 21 between the external face of the bridging plates 22 and the internal plate 10 of the insulating panels 2 makes it possible to fix the bridging plates 22 to the insulating panels 2 satisfactorily.

The bridging elements 20 also each comprise an insulating strip 23 fixed to the outer face of the bridging plates 22, for example by gluing. When assembling the bridging elements 20 with the insulating panels 2, the insulating strip

23 is housed in the inter-panel space 12 between the bridging plate 22 and the insulating joint 13, and is compressed between these two elements. In order to be easily accommodated in the inter-panel space 12, the insulating strip 23 has a dimension in the transverse direction of the inter-panel space 12 equal to the dimension of the inter-panel space 12 in the transverse direction. of the inter-panel space 12. The insulating strip 23 is for example made of a polymer foam such as polyurethane foam. The insulating strip 23 has for example a longitudinal dimension equal to that of the bridging plate 22.

In addition, as shown in the embodiment illustrated in Figures 7 and 8 in particular, the bridging elements 20 overlapping the same two adjacent insulating panels 2 are connected in pairs so as to form a chain of bridging 30 extending in the longitudinal direction of the inter-panel space 12. However, in another embodiment not shown, the bridging elements 20 may all be independent of one another.

[0104] Two adjacent bridging elements 20 of the chain of bridging elements 30 are fixed to each other using a wave shutter 32, as can be seen in particular in FIGS. 7 and 8. More in particular, the outer ply 39 of the wave shutter 32 is fixed to the inner plates 10 of the two insulating panels 2, for example by stapling or gluing. In this embodiment the corrugation shutter 32 is thus placed at the level of the inter-panel space and in the extension of two grooves 14 so as to be positioned between a corrugation and the insulating joint 13.

[0105] In an embodiment not shown, two adjacent bridging elements 20 of the chain of bridging elements 30 are fixed to each other using a flexible web 31, for example by stapling . On the flexible sheet 31, a wave shutter 32 is fixed, for example by gluing. [0106] Furthermore, according to one embodiment particularly illustrated in Figure 7, the bridging plates 22 located in the extension of the directions of the metal plates 17, 18 fixed on the insulating panels 2 are equipped with thermal protection strips 45, fixed against the inner face of said bridging plates 22 and intended to protect the bridging plate 22 during the welding of the sheets forming the sealing membrane.

In Figure 7, the chain of bridging elements 30 has been illustrated during the step of gluing with the glue 40 on the insulating panels 2 at the level of the recesses 21 while in Figure 8, the chain of bridging elements 30 is already fixed on the insulating panels 2.

[0108] Figures 9 and 10 are sectional illustrations of Figure 8 to better distinguish the relative arrangement of the various elements relative to each other in two different cutting directions.

In Figure 9, the corrugated metal sheets 24 of the secondary sealing membrane 4 have also been illustrated, the corrugations 25 and 26 of which are arranged in the grooves 14, 15 of the insulating panels 2 of the secondary thermally insulating barrier 1 . Figure 9 is thus a section taken in the longitudinal direction of the interpanel space at the level of said interpanel space 12.

[01 10] Thus, it is possible to distinguish the bridging plates 22 on which the ends have been beveled, the outer layers 39 being stapled or glued to these beveled surfaces. The insulating strip 23 extends at its ends the beveled end of the bridging plates 22 so as to obtain an external ply 39 of V-section, the bottom of the V of which rests on the insulating joint 13. The external ply 39 thus connects well by their ends two adjacent bridging plates 22. Wave shutter 32 is placed on flexible sheet 31 and is compressed between flexible sheet 31 and corrugation 25.

[01 1 1] Figure 10 is a section taken in the transverse direction of the interpanel space 12. In this figure, it is thus possible to distinguish the insulating strip 23 which is compressed between the bridging plate 22 and the insulating joint 13 and which fills all the space left free by the insulating joint 13 in the direction of thickness and in the transverse direction. The bridging plate 22 is housed on either side thereof in two recesses 21 of the two adjacent insulating panels 2.

[01 12] In the first embodiment of Figures 2 to 10, the wave shutter 32 is housed in a groove 15 so as to be compressed between a corrugation and the bottom of a groove 15. The shutter of wave 32 is also glued or stapled to the walls of the groove formed by the rigid plates 10. This embodiment corresponds in particular to the case where the corrugations of the waterproofing membrane protrude outward from the tank and are housed in a groove.

[01 13] Figures 1 1 and 12 correspond to a second embodiment which differs from the first embodiment in that the shutter 32 is this time stuck inside the corrugation and is compressed between a corrugation and the flat rigid plate 10 of an insulating panel 2, 6. In addition, this second embodiment corresponds in particular to the case where the undulations of the sealing membrane protrude towards the inside of the tank 71 .

[01 14] Figure 1 1 thus schematically represents a wave shutter 32 housed in a corrugation and before compression so that the wave shutter has a greater height than the peak height of the corrugation. Moreover, before compression, the wave shutter 32 does not necessarily have a shape complementary to the wave.

[01 15] Figure 12 also schematically shows a wave shutter 32 housed in a corrugation but this time after compression between the flat rigid plate 10 of an insulating panel 2, 6 and the corrugation of the membrane of sealing 4, 7. The wave shutter 32 has thus been compressed and deformed so as to fill all the space left free between the corrugation of one of the series of corrugations 25, 26 and the rigid plate 10.

[01 16] Referring to Figure 13, 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.

[01 17] 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 tub 71 .

[01 18] Figure 13 shows an example of a marine terminal comprising a loading and unloading station 75, an underwater pipe 76 and a shore installation 77. The loading and unloading station 75 is a fixed installation off- shore comprising a movable arm 74 and a tower 78 which supports the movable arm 74. The movable arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the pipes loading/unloading 73. The adjustable 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.

[01 19] 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 75.

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.

[0121] 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.

[0122] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

[Claim 1] [Sealed and thermally insulating tank for storing a fluid fixed to a supporting structure, in which a wall of the tank comprises at least one thermally insulating barrier (1, 5) and at least one sealing membrane (4 , 7), the sealing membrane comprising a series of parallel undulations (25, 26) having a longitudinal direction, and flat portions located between said undulations (25, 26), said undulations (25, 26) protruding from flat portions, said thermally insulating barrier (1, 5) being located against the sealing membrane (4, 7), the thermally insulating barrier (1, 5) comprising insulating panels (2, 6), the insulating panels (2 , 6) being juxtaposed to each other, in which the tank comprises at least one corrugation (32) located in line with a corrugation of the series of corrugations (25, 26), between a corrugation of the series corrugations (25, 26) and one of the insulating panels (2, 6), the obturateu r wave (32) being configured to close a space left free between said corrugation and said groove in which said corrugation is housed, in which the wave shutter (32) comprises a core of compressible material, and a flexible envelope completely covering said core so as to form a container for the core of compressible material, the wave shutter (32) being compressed or flowed between the sealing membrane and the thermally insulating barrier.

[Claim 2] Tank according to claim 1, wherein said corrugations (25, 26) project from flat portions on a projecting side of the sealing membrane, said thermally insulating barrier (1, 5) being located on the projecting side of the sealing membrane, the thermally insulating barrier (1, 5) comprising a series of parallel grooves (14, 15) receiving the series of undulations (25, 26), said wave shutter (32) being located to the right of a corrugation of the series of corrugations (25, 26), between a corrugation of the series of corrugations (25, 26) and a bottom of a groove of the series of grooves (14, 15).

[Claim 3] A tank according to claim 2, wherein the insulating panels are provided with grooves forming the series of grooves such that the grooves (14, 15) of two adjacent insulating panels (2, 6) are aligned in the longitudinal direction , the at least one wave shutter (32) being housed in the groove of one of the insulating panels.

[Claim 4] Tank according to claim 2 or claim 3, in which the thermally insulating barrier (1) is a first barrier thermally insulating and the tank comprises a second thermally insulating barrier located opposite the projecting side of the sealing membrane, and in which the tank comprises at least one complementary wave shutter located opposite the at least one shutter corrugation (32) so as to sandwich a corrugation of the sealing membrane between the corrugation shutter and the complementary corrugation shutter, the complementary corrugation shutter being configured to obturate a space left free between said corrugation and the second thermally insulating barrier.

[Claim 5] Tank according to one of Claims 2 to 4, in which the thermally insulating barrier comprises an internal surface, the series of grooves (14, 15) being formed on the internal surface and the corrugations projecting towards exterior of the tank.

[Claim 6] Tank according to one of Claims 2 to 4, in which the sealing membrane is a secondary sealing membrane (4), the thermally insulating barrier is a primary thermally insulating barrier (5), the corrugations forming projects towards the interior of the tank, and in which the tank comprises a secondary thermally insulating barrier (1) retained on the supporting structure and carrying the secondary sealing membrane (4), the primary thermally insulating barrier (5) being carried by the secondary sealing membrane (4), the tank comprising a primary sealing membrane (7) carried by the primary thermally insulating barrier (5) and intended to be in contact with the fluid in the tank, the series of grooves (14, 15) being formed on an outer surface of the primary thermally insulating barrier (5).

[Claim 7] Tank according to one of Claims 2 to 6, in which each insulating panel (2) comprises a layer of insulating polymer foam (9) and a rigid plate (10) forming the face in contact with the membrane of sealing, the groove of the series of grooves (14, 15) being formed in the rigid plate.

[Claim 8] Tank according to claim 1, in which the thermally insulating barrier (1, 5) is located between the sealing membrane (4, 7) and the support structure, the corrugations projecting towards the inside of the tank , each insulating panel (2) comprising a flat rigid plate (10) forming the face in contact with the sealing membrane, the wave shutter (32) being located between a corrugation of the series of corrugations (25, 26) and a rigid plate (10) of an insulating panel (2).

[Claim 9] Tank according to one of Claims 1 to 8, in which the wave shutter (32) is compressed by the sealing membrane so that that the dimension in a direction of thickness decreases locally by at least 20% between the thickness before compression and the thickness after compression.

[Claim 10] Tank according to one of claims 1 to 9, in which the casing (34) comprises a first ply (41) and a second ply (39), the first ply being located in contact with the membrane of sealing, the first ply and the second ply being fixed to each other over at least part of a circumference of the first ply and of the second ply so as to form the container for the core of compressible material, the first ply being made of a more flexible material than the material of the second ply.

[Claim 1 1] Tank according to one of claims 1 to 9, in which the envelope (34) comprises a single ply comprising an internal surface located in contact with the sealing membrane, the single ply being produced under the form of a flexible cylinder so as to form the container for the core of compressible material.

[Claim 12] Tank according to claim 10 or 11, in which the single ply, the first ply (41) and/or the second ply (39) comprises at least one perforation.

[Claim 13] Vessel according to one of Claims 1 to 12, in which the core (33) represents at least 90% by volume of the wave shutter (32), in the compressed state or in the before compression.

[Claim 14] Tank according to one of Claims 1 to 13, in which the core (33) is made of a non-woven, powdery or foamed fibrous material, preferably chosen from: mineral wool, melamine foam, polyester wadding, polyethylene wadding, synthetic plastic foam, polyamide fibers, acrylic fibers or combinations thereof.

[Claim 15] Tank according to one of Claims 1 to 14, in which the casing (34) comprises a woven or non-woven textile web, consisting of mineral and/or synthetic fibres.

[Claim 16] Tank according to one of Claims 1 to 15, in which the tank comprises a plurality of wave shutters (32), each wave shutter (32) being located between a corrugation and an insulating panel.

[Claim 17] Tank according to one of Claims 1 to 16, in which the tank comprises a plurality of wave shutters (32) located in line with a corrugation of the series of corrugations (25, 26), between a corrugation of the series of corrugations (25, 26) and an insulating panel formed in line with the corrugation, each corrugation shutter (32) being configured to close a space left free between said corrugation and said insulating panel, the corrugation shutters (32) being regularly spaced from each other in the longitudinal direction of a series of corrugations.

[Claim 18] Vessel (70) for transporting a cold liquid product, the vessel comprising a double hull (72) and a tank (71) according to one of the claims

1 to 17 arranged in the double hull.

[Claim 19] Transfer system for a cold liquid product, the system comprising a vessel (70) according to claim 18, insulated pipes (73, 79, 76, 81) arranged so as to connect the tank (71) installed in the ship's hull at a floating or onshore storage facility (77) and a pump for driving a flow of cold liquid product through the insulated pipes to or from the floating or onshore storage facility to or from the tank of the vessel.

[Claim 20] A method of loading or unloading a ship (70) according to claim 18, in which a cold liquid product is conveyed through insulated pipes (73, 79, 76, 81) from or to a storage installation floating or land (77) to or from the ship's tank (71). ]