Leaktight and thermally insulating wall

Abstract

The invention relates to a leaktight and thermally insulating wall for a tank for storing a liquefied gas, the wall comprising: a primary sealing membrane (6) comprising first corrugations (9) which are parallel to one another and second corrugations (10) which are parallel to one another and perpendicular to the first corrugations (9) and which intersect the first corrugations (9) in node zones (36); the wall (1) comprising at least one reinforcing system (11) comprising first reinforcing elements (12) inside one of the first corrugations (9) and a second reinforcing element (13) which is positioned in line with the node zone (36) and extends into one of the second corrugations (10) on either side of the node zone (36), the first reinforcing elements (12) being hollow profiled elements and the second reinforcing element (13) having a solid section and being made of plywood.

Description

Waterproof and thermally insulating wall

[0001] The invention relates to the field of sealed tanks with corrugated metal membranes, for the storage and / or transport of liquefied gas.

[0002] In particular, the invention relates to the field of sealed and thermally insulating tanks for the storage and / or transport of liquefied gas, such as tanks for the transport of Liquefied Petroleum Gas (also called LPG) having for example a temperature between -50°C and 0°C, for the transport of ammonia at approximately -33°C, or for the transport of Liquefied Natural Gas (LNG) at approximately -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 can be intended for the transport of liquefied gas or for receiving liquefied gas used as fuel for the propulsion of the floating structure. Technological background

[0003] In the state of the art, sealed and thermally insulating tanks for storing liquefied gas are known, comprising a corrugated primary sealing membrane which is intended to be in contact with the liquefied gas contained in the tank and which is reinforced using reinforcing elements. The reinforcing elements are arranged under the corrugations of the primary sealing membrane, between said primary sealing membrane and the primary thermally insulating barrier supporting it. Such reinforcing elements make it possible to reduce the stresses which are likely to be exerted in the primary sealing membrane, in particular under the effect of hydrostatic pressures and dynamic pressures due to the movement of the cargo in the tank, due to the swell.

[0004] Different types of reinforcement elements are known. In particular, there are tanks with reinforcement elements in the form of plywood wedges and others with reinforcement elements in the form of metal profiled elements. The choice of the type of reinforcement to be used is guided in particular by the hydrostatic and dynamic pressures likely to be exerted on the primary waterproofing membrane. Thus, the use of metal profiled elements is generally preferred for large tanks, for example when the maximum pressure on the membrane waves is around 80 to 100 bars, while the use of plywood wedges is preferred for standard-sized tanks, for example when the maximum pressure is around 50 bars.

[0005] However, there is no reinforcement system that is suitable for pressure ranges intermediate between the two aforementioned pressure ranges, i.e., which is sufficiently robust to withstand such pressures without being oversized, which would lead to an unnecessary increase in the cost and complexity of the sealed and thermally insulating tank. This is, for example, the case for intermediate or standard size tanks when they are intended to store ethane or ammonia because these have higher densities than methane, namely 544 kg / m 3 for ethane and 681 kg / m 3 for ammonia against 423 kg / m 3 for methane.

[0006] One idea behind the invention is therefore to propose a wall for a sealed and thermally insulating tank which is optimally reinforced, particularly for intermediate pressure ranges.

[0007] According to one embodiment, the invention provides a sealed and thermally insulating wall for a tank intended for the storage of a liquefied gas, said wall comprising: a primary sealing membrane intended to be in contact with the fluid contained in the tank and resting against a primary thermally insulating barrier, the sealing membrane comprising at least a first series of corrugations comprising first corrugations which are parallel to each other and a second series of corrugations comprising second corrugations which are parallel to each other, perpendicular to the first corrugations and which intersect the first corrugations in node zones; the first corrugations having a height in a thickness direction of the wall which is greater than a height of the second corrugations;the wall comprising at least one reinforcement system comprising first reinforcement elements which are positioned in abutment against the primary thermally insulating barrier, inside one of the first corrugations, on either side of one of the node zones and a second reinforcement element which is positioned in abutment against the primary thermally insulating barrier, at the node zone and extends into one of the second corrugations on either side of the node zone, the first reinforcement elements being profiled hollow elements and the second reinforcement element having a solid section and being made of wood, for example plywood.;

[0008] Thanks to these characteristics, the reinforcement system can be optimized for intermediate pressure ranges since the highest corrugation(s), i.e. those subject to the greatest stresses, are reinforced by hollow profiled elements while the lowest corrugation(s), i.e. those subject to the least stresses, are only reinforced with wooden reinforcement elements, for example plywood.

[0009] According to embodiments, such a waterproof and thermally insulating wall may comprise one or more of the following characteristics.

[0010] According to one embodiment, the reinforcement system comprises a connecting member which is arranged inside the first corrugation and which is fixed to the first reinforcement elements and to the second reinforcement element. The connecting member makes it possible to ensure relative positioning of the reinforcement elements with respect to each other. The connecting member also makes it possible to prevent the first reinforcements from coming into contact with the node.

[0011] According to one embodiment, the connecting member comprises a metal blade which is fixed to the first reinforcing elements and to the second reinforcing element.

[0012] According to one embodiment, the blade is engaged in a slot which is provided in each of the first reinforcing elements, the blade being fixed in said slot. Thus, the blade and the slot of the first reinforcing elements form a sliding connection which makes it easier to put the connecting member in place before fixing the blade to the first reinforcing elements.

[0013] According to one embodiment, the slot is deformed locally in order to pinch the blade inside said slot.

[0014] According to one embodiment, the blade is fixed to the first reinforcing elements by means of fixing members, such as screws, for example of the self-drilling type.

[0015] According to one embodiment, the blade comprises holes, preferably oblong.

[0016] According to one embodiment, the blade is fixed by clipping to the first reinforcing elements.

[0017] According to one embodiment, the blade is attached to the first reinforcing elements by an assembly mechanism, such as a quarter-turn assembly mechanism.

[0018] According to one embodiment, the blade is engaged in a groove which is formed in the second reinforcing element, transversely to a longitudinal direction of said second reinforcing element, the blade being fixed in said groove by at least one fixing member, such as a staple or a screw, for example of the self-drilling type.

[0019] According to one embodiment, the reinforcement system comprises several second reinforcement elements which are arranged in several adjacent node areas and which are connected to each other by the connecting member, the node areas being formed at intersections of the first corrugation with several of the second corrugations.

[0020] According to one embodiment, the connecting member is a first connecting member and the first reinforcing elements to which the first connecting member is fixed are a first plurality of first reinforcing elements positioned inside a first of the first corrugations, the reinforcing system further comprising a second plurality of first reinforcing elements which are positioned bearing against the primary thermally insulating barrier, inside a second of the first corrugations and a second connecting member which is arranged inside the second of the first corrugations and which is fixed to the second plurality of first reinforcing elements and to said or to each second reinforcing element,said or each second reinforcing element extending in the second corrugation between the first and second of the first corrugations and on either side of the node zones formed at intersections of the second corrugation with the first and second of the first corrugations.,

[0021] Thanks to these characteristics, the reinforcement system can have the form of a lattice.

[0022] According to one embodiment, the reinforcement system comprises several first reinforcement elements, spaced from each other, in at least one inter-corrugation interval positioned between two node zones. This makes it possible to further limit the cost and weight of the reinforcement system.

[0023] According to one embodiment, the waterproof and thermally insulating wall comprises a plurality of reinforcement systems such that second reinforcement elements are arranged in each of the node zones of the waterproofing membrane and extend on either side of said node zone in one of the second corrugations and that first reinforcement elements are arranged in each inter-corrugation interval of the second corrugations positioned between two node zones.

[0024] According to one embodiment, the first reinforcing elements are made of a metallic material, preferably chosen from aluminum and aluminum alloys or of a polymer material, preferably chosen from polyethylene, polycarbonate, polystyrene and polyether imide.

[0025] According to one embodiment, the wood of the second reinforcing element is solid wood, plywood or wood fibers impregnated with polymer resin.

[0026] According to one embodiment, the plywood of the second reinforcing element has fibers oriented perpendicular to a thickness direction of the wall.

[0027] According to another embodiment, the plywood of the second reinforcing element has fibers oriented parallel to a thickness direction of the wall. Thus, the compressive strength of the second reinforcing elements is greatest in the direction in which the majority of compressive forces are exerted.

[0028] According to one embodiment, the profiled hollow elements comprise a lower flange which is intended to rest against the internal surface of the primary thermally insulating barrier and an upper support portion. According to one embodiment, the support portion has a shape corresponding to the shape of the interior of the first corrugation.

[0029] According to one embodiment, the support portion comprises intersecting reinforcing webs which extend from one edge to the other of the profiled hollow element and which intersect at its plane of symmetry.

[0030] According to one embodiment, the second reinforcing element has a lower flange which is intended to rest against the internal surface of the primary thermally insulating barrier.

[0031] According to one embodiment, the second reinforcing element has lateral faces which do not extend to the top of the second corrugation and a flat upper face which connects the two lateral faces.

[0032] According to one embodiment, the invention also provides a sealed and thermally insulating tank comprising at least one sealed and thermally insulating wall of the aforementioned type.

[0033] According to one embodiment, the invention also provides a sealed and thermally insulating tank comprising two thermally insulating barriers and two sealing membranes.

[0034] An installation according to one of the aforementioned embodiments may be a land-based storage installation, for example for storing LNG or may be installed in a floating, coastal or deep-water structure, in particular an ethane or methane carrier, a floating storage and regasification unit (FSRU), a floating production and remote storage unit (FPSO) and others. In the case of a floating structure, the tank may be intended to receive liquefied natural gas used as fuel for the propulsion of the floating structure.

[0035] According to one embodiment, the invention relates to a ship for transporting a fluid which comprises an installation of the aforementioned type.

[0036] According to one embodiment, the vessel comprises a double hull which forms the supporting structure.

[0037] According to one embodiment, the invention also provides a transfer system for a fluid, the system comprising the aforementioned vessel, insulated pipes arranged to connect the vessel tank to a floating or land-based storage facility and a pump for driving a flow of fluid through the insulated pipes from or to the floating or land-based storage facility to or from the vessel tank.

[0038] According to one embodiment, the invention also provides a method of loading or unloading such a vessel, in which a fluid is conveyed through insulated pipes from or to a floating or land-based storage facility to or from the vessel's tank.

[0039] According to one embodiment, the invention relates to a ship for transporting a fluid which comprises an installation of the aforementioned type. Brief description of the figures

[0040] The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes, with reference to the accompanying drawings.

[0041] This is an exploded perspective view of a tank wall.

[0042] This is a perspective view of a corrugated metal plate intended for the construction of a waterproof membrane.

[0043] This is a top view of a reinforcement system according to a first embodiment intended to be arranged under the corrugations of the primary waterproofing membrane.

[0044] This is a partial perspective view of the reinforcement system.

[0045] This is a sectional view illustrating a method of fixing a connecting member to a first reinforcing element, intended to be arranged under a high corrugation, according to a first variant.

[0046] This is a schematic view illustrating a method of fixing a connecting member to a second reinforcing element intended to be arranged under a low corrugation, according to the first variant of the.

[0047] This is a schematic view illustrating a method of fixing a connecting member to a first reinforcing element, intended to be arranged under a high corrugation, according to a second variant.

[0048] This is a schematic view illustrating a method of fixing a connecting member to a second reinforcing element intended to be arranged under a low corrugation, according to the second variant of the.

[0049] This is a schematic view illustrating a method of fixing a connecting member to a first reinforcing element, intended to be arranged under a high corrugation, according to a third variant.

[0050] This is a bottom view of a first reinforcing element, intended to be arranged under a high corrugation, according to a fourth variant.

[0051] This is a schematic view of a first reinforcing element and a connecting member according to the fourth variant before they are fixed to each other.

[0052] This is a schematic cutaway representation of an LNG tank and a loading / unloading terminal for this tank.

[0053] This is a perspective view of a reinforcement system according to a second embodiment.

[0054] 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 outside of the tank. Furthermore, the terms "upper" and "lower" are also used to define the relative position of one element with respect to another, the term "upper" designating an element closer to the inside of the tank and, by contrast, the term "lower" designating an element further from the inside of the tank; and this regardless of the relative position of said elements with respect to the direction of the gravity field.

[0055] In connection with the, a wall 1 is described for a sealed and thermally insulating tank intended for the storage of a liquefied gas.

[0056] Each wall 1 comprises a multi-layer structure which successively presents, from the outside to the inside, in the direction of thickness of the wall 1, a secondary thermally insulating barrier 3 retained on the supporting structure 2, a secondary sealing membrane 4 bearing against the secondary thermally insulating barrier 3, a primary thermally insulating barrier 5 bearing against the secondary sealing membrane 4 and a primary sealing membrane 6 bearing against the primary thermally insulating barrier 5 and intended to be in contact with the liquefied natural gas contained in the tank.

[0057] The supporting structure 2 is, for example, formed by the double hull of a ship but can more generally be formed from any type of rigid partition having appropriate mechanical properties.

[0058] The primary sealing membrane 6 comprises a plurality of metal sheets 7 which are overlap-welded to each other in a leaktight manner. The metal sheets 7 are also anchored to the primary thermally insulating barrier 5. To this end, in the embodiment shown, the metal sheets 7 are welded, for example by spot welding, along their edges to anchoring strips 8. The anchoring strips 8 are housed and fixed in recesses provided in the inner surface of the primary thermally insulating barrier 5 such that the anchoring strips 8 are flush with the inner surface of the primary thermally insulating barrier 5.

[0059] As shown in the, each metal sheet 7 comprises a first series of parallel corrugations, called high corrugations 9, and a second series of parallel corrugations, called low corrugations 10, which extend perpendicular to the corrugations of the first series. Note that the terms “high” and “low” have a relative meaning here and mean that the low corrugations 10 have a height lower than that of the high corrugations 9. At each intersection between two corrugations 9, 10, the primary sealing membrane 6 comprises a node zone 36. The node zone 36 comprises a central portion having a peak projecting towards the inside of the tank. Furthermore, the central portion is bordered, on the one hand, by a pair of concave undulations formed in the crest of the upper undulation 9 and, on the other hand, by a pair of recesses into which the lower undulation 10 penetrates.The corrugations 9, 10 of the metal sheets 7 allow the primary sealing membrane 6 to be flexible so that it can deform under the effect of the thermal and mechanical stresses generated by the liquefied gas stored in the tank.

[0060] For example, the high corrugations 9 have a height of between 45 and 70 mm depending on the thickness of the insulation and the low corrugations 10 have a height of between 20 and 44 mm depending on the thickness of the insulation.

[0061] For example, the metal sheets 7 can in particular be made of stainless steel, aluminum, invar ®, that is to say an alloy of iron and nickel whose coefficient of expansion is typically between 1.10 -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 at 9.10 -6 K -1. However, other metals or alloys are also possible. For example, sheet metal has a thickness of between 1 and 1.5 mm, for example 1.2 mm. Other thicknesses are also possible, knowing that thickening the sheet metal leads to an increase in its cost and generally increases the rigidity of the corrugations.

[0062] In the embodiment shown, the tank wall 1 is similar to that described in application FR2691520 relating to the Mark III ® products and reference may be made thereto to obtain further details concerning the primary and secondary thermally insulating barriers and the secondary sealing membrane 4. Alternatively, the tank walls 1 may also be produced using other technologies, and in particular those described in patent applications WO14057221 and FR3125323 relating respectively to the Mark V and GTT NEXT1 ® products.

[0063] It should be noted that the reinforcement system is particularly optimized for use in combination with insulating panels of the primary and secondary thermally insulating barriers which comprise a layer of insulating polymer foam, advantageously made of polyurethane foam reinforced with fibers, such as glass fibers and whose density is between 130 and 210 kg / m 3 , preferably between 150 and 170 kg / m 3 .

[0064] In relation to figures 3 to 11, a reinforcement system 11 is described, intended to be arranged under the corrugations 9, 10 of the primary waterproofing membrane 6, according to a first embodiment.

[0065] The reinforcement system 11 comprises, on the one hand, reinforcement elements, designated “first reinforcement elements 12” hereinafter, which are intended to be placed inside the upper corrugations 9 of the primary waterproofing membrane 6, and on the other hand, reinforcement elements designated “second reinforcement elements 13” hereinafter, which are intended to be placed inside the lower corrugations 10 of the primary waterproofing membrane 6. The reinforcement system 11 further comprises a connecting member 14 which is fixed to the first and second reinforcement elements 12, 13 and thus makes it possible to ensure the relative positioning of said first and second reinforcement elements 12, 13 with respect to each other.

[0066] The first reinforcing elements 12 are profiled hollow elements. They are made of a metallic material, such as aluminum or an aluminum alloy for example, or of a polymer material, such as polyethylene, polycarbonate, polystyrene or polyether imide, advantageously reinforced by fibers, such as glass fibers.

[0067] As illustrated for example in Figures 4 and 5, the profiled hollow elements comprise a lower sole 15, which is intended to rest against the internal surface of the primary thermally insulating barrier 5 and an upper support portion 16.

[0068] The support portion 16 can be produced according to various geometries, as illustrated for example in the document FR2936784. Preferably, the external shape of the support portion 16 corresponds to the shape of the interior of the high corrugation 9, so as to provide effective support for substantially the entire surface of the high corrugation 9. In the embodiment shown, the general section of the support portion 16 is a semi-elliptical dome. Furthermore, the sole 15 has a lower wall which is flat and which rests against the internal surface of the primary thermally insulating barrier 5. The support portion 16 comprises secant reinforcing webs 17 which extend from one edge to the other of the profiled hollow element and which intersect at its plane of symmetry.

[0069] In the embodiment shown, the reinforcement system 11 comprises several first reinforcement elements 12 which are spaced in each inter-corrugation interval between two low corrugations 10. Furthermore, as described in publication FR2861060, reinforcement ribs, not shown, can be provided on the lateral faces of the high corrugations 9. In this case, the reinforcement ribs are preferably located between the first reinforcement elements 12 which are spaced in each inter-corrugation interval between two low corrugations 10.

[0070] However, in another embodiment not shown, the reinforcement system 11 may also comprise only a single first reinforcement element arranged in each inter-corrugation interval between two low corrugations 10. In such a case, the longitudinal dimension of the single reinforcement element 12 is adapted accordingly in order to exert effective support over a major part of the length of the inter-corrugation interval between two low corrugations 10.

[0071] Furthermore, the second reinforcing elements 13 have a solid section and are made of plywood. The second reinforcing elements 13 have a lower flange 18, which is intended to rest against the internal surface of the primary thermally insulating barrier 5. The second reinforcing elements 13 have lateral faces 19 which do not extend to the top of the lower corrugation 10 and the second reinforcing elements 13 have a flat upper face which connects the two lateral faces 19. The second reinforcing elements 13 therefore have a section in the shape of an isosceles trapezoid. Thus, gas can circulate between the top of the corrugation and the upper face 20. The second reinforcing elements 13 have a shape complementary to that of the lower portion of the lower corrugations 10.In the embodiment illustrated, each second reinforcing element 13 is arranged in line with one of the node zones 36 and extends into the low corrugation 10, on either side of the node zone 36.

[0072] Advantageously, the fibers of the plywood in which the second reinforcing elements 13 are formed are oriented parallel to the thickness direction of the wall 1. Thus, the compressive strength of the second reinforcing elements 13 is greatest in the thickness direction of the wall 1, which corresponds to the direction in which the majority of the compressive forces are exerted on the second reinforcing elements 13.

[0073] The connecting members are formed by blades 21 which are advantageously made of metal and for example stainless steel.

[0074] In a first embodiment illustrated in Figures 3, 5 and 6, the blade 21 has a rectangular section. Furthermore, as shown in the, the blade 21 is engaged in a slot 22 which is formed in each of the first reinforcing elements 12 and passes through the first reinforcing elements 12 in their longitudinal direction. The slot 22 has a rectangular section complementary to that of the blade 21 and thus forms a sliding connection. Thus, the mounting of the first reinforcing elements 12 on the blade 21 is simple to implement by sliding said first reinforcing elements 12 along the blade 21. Furthermore, to ensure the fixing of the first reinforcing elements 12 to the blade 21 in a determined position, the first reinforcing elements 12 can be punched in order to locally deform the slot 22 so as to pinch the blade 21.Alternatively, the blades 21 may also be fixed to the first reinforcing elements 12 by means of fixing members, such as screws, for example of the self-drilling type, which avoids prior drilling operations. Alternatively, the blade 21 may have holes to facilitate the use of a fixing screw or rivet, preferably the hole may be oblong.

[0075] Furthermore, as shown in the, the second reinforcing elements 13 have a groove 23 in which the blade 21 is engaged. The groove 23 is formed in the second reinforcing elements 13, in a transverse direction perpendicular to the longitudinal direction of the second reinforcing elements 13. The blade 21 is fixed to the second reinforcing elements 13, by fixing members, such as staples 24, one of which is shown schematically in the, or screws for example of the self-drilling type.

[0076] In a second embodiment, shown in Figures 7 and 8, the blade 21 is fixed by clipping to the first reinforcing elements 12. The blade 21 has an L-shaped section, one of the branches of which has a curved end 25. As shown in the, the slot 26 formed in the first reinforcing elements 12 also has an L-shaped section and opens into the sole 15. The curved end 23 of the branch of the blade 21 is shaped to deform when the blade 21 is engaged in the slot 26 and to generate a reaction force which presses said curved end 23 against one of the walls of the slot 26. This makes it possible to ensure fixing of the first reinforcing elements 12 to the blade 21.

[0077] As shown in the, the groove 27 formed in the second reinforcing elements 13 also has an L shape. The curved end 23 can also deform and press against the walls of the groove 27. Alternatively or additionally, the blade 21 is fixed to the second reinforcing elements 13 by fixing members, such as staples 28, one of which is shown schematically in the, or self-drilling screws for example.

[0078] La represents a first reinforcing element 12 and a connecting member 14 according to a third embodiment variant. The connecting member 14 is a profiled metal blade 29 whose section has a male element 30 having a shape complementary to that of the slot 31 formed in the first reinforcing element 12. Thus, the male element 30 and the slot 31 form a sliding connection allowing the first reinforcing elements 12 to slide along the connecting member 14 when they are put in place. Furthermore, as in the first embodiment variant, the first reinforcing elements 12 are advantageously punched in order to locally deform the slot 31 so as to pinch the male element 30 of the connecting member inside the slot 31.

[0079] Figures 10 and 11 illustrate another variant of fixing the first reinforcing elements 12 to the connecting member 14. In this variant embodiment, the first reinforcing elements 12 are fixed to the connecting member 14 by an assembly mechanism, for example a “quarter-turn assembly mechanism”. Such an assembly mechanism comprises a male part 32, visible in Figures 11 and 12, and which is here secured to the blade 21 of the connecting member 14, and a female part 33 which here corresponds to an opening made in the sole of the first reinforcing elements 12. In the embodiment shown, the male part 32 is formed on a shim 35, for example made of aluminum or stainless steel, which is fixed to the blade 21.

[0080] The male part 32 has lugs, not shown, which are intended to engage in notches 34 formed in the opening of the female part 33. Thus, to fix the first reinforcing elements 12 to the connecting member 14, the reinforcing elements 12 are, in a first step, positioned relative to the connecting member in a relative position, shown in the, in which the lugs of the male part 32 each pass through one of the notches 34 of the female part 33. In a second step, the first reinforcing elements 12 are rotated about an axis parallel to the thickness direction of the wall to an assembled position, shown in the, in which the profile direction of the first reinforcing elements 12 is aligned with the longitudinal direction of the blade 21 of the connecting member 14.

[0081] In the reinforcement system 111 according to the second embodiment shown in the, elements identical or similar to those of the first embodiment bear the same reference number increased by 100 and will only be described to the extent that they differ from the first embodiment.

[0082] The reinforcement system 111 comprises a plurality of reinforcement frames 50 intended to be positioned inside several successive high corrugations 9 of the primary waterproofing membrane 6. Each reinforcement frame 50 comprises, similarly to the reinforcement system 11, several first reinforcement elements 112 intended to be positioned inside one of the high corrugations 9 and a connecting member 114 fixed to the first reinforcement elements 112 of the reinforcement frame 50. Three reinforcement frames 50 are present in the reinforcement system 111 of the for illustrative purposes.

[0083] The reinforcing frames 50 of the reinforcing system 111 are attached to each other by second reinforcing elements 113 intended to be placed inside the lower corrugations 10 of the primary waterproofing membrane 6. For this, the connecting members 114 of all the reinforcing frames 50 of the reinforcing system 111 are fixed to each of the second reinforcing elements 113. The second reinforcing element 113 is therefore long enough to extend through at least two successive node zones 36 along a lower corrugation 10. The second reinforcing element 113 is long enough to extend through three successive node zones 36 in the reinforcing system 111 of the for illustrative purposes. Thus, the reinforcement system 111 forms a reinforcement lattice intended to be positioned in the high corrugations 9 and the low corrugations 10 of an entire rectangular zone of the primary waterproof membrane 6.Depending on the size of the mesh, i.e. depending on the number of reinforcing frames 50 in a width direction of the reinforcing system 111 and depending on the number of second reinforcing elements 113 in a length direction of the reinforcing system 111, the rectangular area may correspond to a corrugated metal plate, several corrugated metal plates or a portion of a corrugated metal plate.

[0084] At each of its longitudinal ends, the reinforcement system 111 may be terminated by a second reinforcement element 113 or by first reinforcement elements 112. The two possibilities are illustrated in the, in which the reinforcement system 111 has different structures at its two longitudinal ends. Alternatively, the reinforcement system 111 could have an identical structure at its two longitudinal ends.

[0085] According to one embodiment, the second reinforcing element 113 is formed from several components assembled together, each component being similar to the second reinforcing element 13 of the first embodiment. In this case, the reinforcing system 111 can be obtained by assembling several reinforcing systems 11.

[0086] With reference to the, a cutaway view of an LNG carrier 70 shows a sealed and thermally insulating tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary sealed membrane intended to be in contact with the LNG contained in the tank, a secondary sealed membrane arranged between the primary sealed membrane and the double hull 72 of the ship, and two thermally insulating barriers arranged respectively between the primary sealed membrane and the secondary sealed membrane and between the secondary sealed membrane and the double hull 72.

[0087] In a manner known per se, loading / unloading pipelines 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.

[0088] The represents an example of a maritime terminal comprising a loading and unloading station 75, an underwater pipeline 76 and an onshore installation 77. The loading and unloading station 75 is a fixed offshore installation comprising a mobile 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 pipelines 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 onshore installation 77. The latter comprises liquefied gas storage tanks 80 and connecting pipes 81 connected by the underwater pipe 76 to the loading or unloading station 75.The subsea pipeline 76 allows the transfer of liquefied gas between the loading or unloading station 75 and the onshore installation 77 over a long 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.

[0089] To generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and / or pumps equipping the onshore installation 77 and / or pumps equipping the loading and unloading station 75 are used.

[0090] 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 technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0091] The use of the verb "comprise", "comprise" or "include" and its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

[0092] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

A sealed and thermally insulating wall (1) for a tank intended for storing a liquefied gas, said wall (1) comprising: a primary sealing membrane (6) intended to be in contact with the fluid contained in the tank and resting against a primary thermally insulating barrier (5), the primary sealing membrane (6) comprising at least a first series of corrugations comprising first corrugations (9) which are parallel to each other and a second series of corrugations comprising second corrugations (10) which are parallel to each other, perpendicular to the first corrugations (9) and which intersect the first corrugations (9) in node zones (36); the first corrugations (9) having a height in a thickness direction of the wall which is greater than a height of the second corrugations (10);the wall (1) comprising at least one reinforcement system (11, 111) comprising first reinforcement elements (12, 112) which are positioned in abutment against the primary thermally insulating barrier (5), inside one of the first corrugations (9), on either side of one of the node zones (36) and a second reinforcement element (13, 113) which is positioned in abutment against the primary thermally insulating barrier (5), at the level of the node zone (36) and extends in one of the second corrugations (10) on either side of the node zone (36), the first reinforcement elements (12, 112) being profiled hollow elements and the second reinforcement element (13, 113) having a solid section and being made of wood.; Waterproof and thermally insulating wall (1) according to claim 1, in which the reinforcement system (11, 111) comprises a connecting member (14, 114) which is arranged inside the first corrugation (9) and which is fixed to the first reinforcement elements (12, 112) and to the second reinforcement element (13, 113). Waterproof and thermally insulating wall (1) according to claim 2, in which the connecting member (14) comprises a metal blade (21, 30) which is fixed to the first reinforcing elements (12, 112) and to the second reinforcing element (13, 113). Waterproof and thermally insulating wall (1) according to claim 3, in which the blade (21, 30) is engaged in a slot (22, 26, 31) which is formed in each of the first reinforcing elements (12, 112) and in which the blade (21, 30) is fixed in said slot (22, 26, 31). Waterproof and thermally insulating wall (1) according to claim 4, in which the slot (22, 26, 31) is deformed locally in order to pinch the blade (21, 30) inside said slot (22, 26, 31). Waterproof and thermally insulating wall (1) according to claim 4 or 5, in which the blade (21, 30) is fixed to the first reinforcing elements (12, 112) by means of fixing members, such as screws. Waterproof and thermally insulating wall (1) according to any one of claims 4 to 6, in which the blade (21) is fixed by clipping to the first reinforcing elements (12, 112). Waterproof and thermally insulating wall (1) according to claim 4, in which the blade (21) is fixed to the first reinforcing elements (12) by an assembly mechanism, such as a quarter-turn assembly mechanism. Waterproof and thermally insulating wall (1) according to any one of claims 4 to 8, in which the blade (21, 30) is engaged in a groove (23) which is formed in the second reinforcing element (13, 113), transversely to a longitudinal direction of said second reinforcing element (13, 113) and in which the blade (21, 30) is fixed in said groove (23) by at least one fixing member (24), such as a staple or a screw. Waterproof and thermally insulating wall (1) according to any one of claims 2 to 9, in which the reinforcement system (11, 111) comprises several second reinforcement elements (13, 113) which are arranged in several adjacent node areas (36) and which are connected to each other by the connecting member (14, 114), the node areas being formed at intersections of the first corrugation (9) with several of the second corrugations (10). Waterproof and thermally insulating wall (1) according to one of claims 2 to 10, in which the connecting member is a first connecting member (114) and the first reinforcing elements to which the first connecting member (114) is fixed are a first plurality of first reinforcing elements (112) positioned inside a first of the first corrugations (9), the reinforcing system (111) further comprising a second plurality of first reinforcing elements (112) which are positioned bearing against the primary thermally insulating barrier (5), inside a second of the first corrugations (9) and a second connecting member (114) which is arranged inside the second of the first corrugations (9) and which is fixed to the second plurality of first reinforcing elements (12) and to said or to each second reinforcing element (113),said or each second reinforcing element (113) extending in the second corrugation (10) between the first and second of the first corrugations (9) and on either side of the node zones (36) formed at intersections of the second corrugation (10) with the first and second of the first corrugations (9)., Waterproof and thermally insulating wall (1) according to any one of claims 1 to 11, in which the reinforcement system (11) comprises several first reinforcement elements (12), spaced from each other, in at least one inter-corrugation gap positioned between two node zones (36). Waterproof and thermally insulating wall (1) according to any one of claims 1 to 12, in which the first reinforcing elements (12) are made of a metallic material, preferably chosen from aluminum and aluminum alloys or of a polymer material, preferably chosen from polyethylene, polycarbonate, polystyrene and polyether imide. Waterproof and thermally insulating wall (1) according to any one of claims 1 to 13, in which the wood of the second reinforcing element (13) is plywood and has fibers oriented parallel to a thickness direction of the wall. Sealed and thermally insulating tank comprising at least one sealed and thermally insulating wall (1) according to any one of claims 1 to 14. Vessel (70) for transporting a liquefied gas, the vessel comprising a double hull (72) and a tank (71) according to claim 15, the double hull comprising the supporting structure. A transfer system for liquefied gas, the system comprising a vessel (70) according to claim 16, insulated pipes (73, 79, 76, 81) arranged to connect the tank (71) installed in the hull of the vessel to a floating or land-based storage facility (77) and a pump for driving a flow of liquefied gas through the insulated pipes from or to the floating or land-based storage facility to or from the vessel tank. A method of loading or unloading a ship (70) according to claim 16, wherein a liquefied gas is conveyed through insulated pipes (73, 79, 76, 81) from or to a floating or land-based storage facility (77) to or from the tank (71) of the ship (70).

Images