Method for manufacturing a sealing membrane for manufacturing a sealed and thermally insulated tank for storing a liquefied gas

Abstract

The present invention relates to a method for manufacturing a sealing film for a sealed and thermally insulated container for storing liquefied gases, the method comprising the steps of positioning a first metal sheet (144) and a second metal sheet (44), wherein the second metal sheet (44) covers the first metal sheet (144) in an overlap region (ZR). The first metal sheet (144) carries an additional thickness portion (90) positioned to align with at least a portion of the overlap region (ZR) to thicken the first metal sheet (144) at least at a connection (156a) between a corrugated portion (185a) and two flat portions (186) of the first metal sheet (144). The method further comprises forming a continuous weld between the second metal sheet (44) and the first metal sheet (144) along the overlap region (ZR), wherein the continuous weld extends directly over the additional thickness portion (90).

Description

Technical Field

[0001] This invention relates to the field of sealed and thermally insulated containers with membranes. Specifically, this invention relates to the field of sealed and thermally insulated containers for storing and / or transporting liquefied gases, such as liquefied hydrogen at atmospheric pressure of about -253°C. Background Technology

[0002] In the prior art, there are known sealed and thermally insulated tanks for storing liquefied gases, such as liquefied natural gas (LNG) or liquefied hydrogen.

[0003] Document WO 2023 / 198637 A1 discloses a tank in which the wall has a multi-layer structure, namely, in the thickness direction of the wall, from the outside to the inside, it has: a secondary thermal insulation barrier held on a supporting structure; a secondary sealing membrane disposed against the secondary thermal insulation barrier; a primary thermal insulation barrier disposed against the secondary sealing membrane; and a primary sealing membrane for contacting the liquefied gas contained in the tank.

[0004] The primary thermal barrier includes rows of carrier elements, each of which is fastened to an outer plate and an inner plate. The outer plate is fastened to a secondary thermal barrier and presses the secondary sealing membrane against the secondary thermal barrier. The inner plate forms a support surface for the primary sealing membrane.

[0005] The primary sealing membrane comprises multiple corrugated metal sheets, the edges of which are welded to an inner plate, and the metal sheets are overlapped along their edges to ensure the fluid tightness of the primary sealing membrane.

[0006] This type of container is suitable for storing liquefied hydrogen at atmospheric pressure of -253°C.

[0007] However, when the tank is filled with liquefied hydrogen at -253°C at atmospheric pressure, the primary sealing membrane is subjected to very high thermal stress. Therefore, it is important to ensure the mechanical strength of the primary sealing membrane.

[0008] On the other hand, in order to provide a primary thermal barrier with the required thermal insulation performance, the primary thermal barrier has a gas phase portion placed at a very low absolute pressure. Importantly, this vacuum setup is not degraded by the primary sealing membrane. Summary of the Invention

[0009] One factor affecting the mechanical strength of the primary sealing membrane and its impact on the vacuum setting of the primary thermal insulation barrier is the presence of residual porosity in the weld joints between the corrugated metal sheets of the primary sealing membrane. If the welding operation leads to over-melting of the metal alloy of the corrugated metal sheets, the weld joints between the corrugated metal sheets may have a high risk of residual porosity. This risk is greater when the welding operation is not performed in an inert atmosphere, as the metal alloy will subsequently undergo high-temperature oxidation due to the high temperature and the presence of oxygen in the atmosphere. The higher the residual porosity of the weld joints between the corrugated metal sheets, the higher the surface irregularity of the metal sheets, which is detrimental to the mechanical strength of the primary sealing membrane and makes the metal sheets more likely to degrade the performance of the vacuum setting of the primary thermal insulation barrier.

[0010] One of the underlying concepts of this invention is to propose a method for manufacturing a sealing film that tends to limit residual porosity in the weld between corrugated metal sheets.

[0011] According to one embodiment, the present invention provides a method for manufacturing a sealing membrane for use as the tank wall of a sealed and thermally insulated tank for storing liquefied gas. The manufacturing method includes the following steps: - A first metal sheet and a second metal sheet are disposed on a flat support surface. Each of the first and second metal sheets includes two flat portions disposed on the flat support surface and a corrugated portion formed between the two flat portions, the corrugated portion protruding relative to the two flat portions. Align the corrugated portions of the first metal sheet and the second metal sheet. The second metal sheet overlaps with the first metal sheet in an overlapping area, which is defined between the edges of the first and second metal sheets. The edges of the first and second metal sheets are parallel to each other. The corrugated portion of the first metal sheet extends to the edge of the first metal sheet, and the corrugated portion of the second metal sheet extends to the edge of the second metal sheet. The corrugated portion of the second metal sheet overlaps with the corrugated portion of the first metal sheet in the overlapping region, and the two flat portions of the second metal sheet overlap with the two flat portions of the first metal sheet in the overlapping region. The first metal sheet is located between the second metal sheet and the support surface in the overlapping region. The first metal sheet is equipped with a component that increases the thickness, the component being positioned to align with at least a portion of the overlapping area to thicken the first metal sheet at least at the junction between the corrugated portion of the first metal sheet and the two flat portions of the first metal sheet. - A continuous weld is formed between the second metal sheet and the first metal sheet along the overlapping area, the continuous weld extending in a manner consistent with the increased thickness of the component.

[0012] According to one embodiment, the present invention also provides a sealed and thermally insulated tank for storing liquefied gases, the tank including a tank wall comprising a sealing membrane and a flat supporting surface. The sealing membrane includes a first metal sheet and a second metal sheet disposed on a flat support surface. Each of the first and second metal sheets includes two flat portions disposed on the flat support surface and a corrugated portion formed between the two flat portions, the corrugated portion protruding relative to the two flat portions. The corrugated portions of the first metal sheet and the second metal sheet are aligned. The second metal sheet overlaps with the first metal sheet in an overlapping region defined between the edges of the first and second metal sheets. The edge of the first metal sheet is parallel to the edge of the second metal sheet. A corrugated portion of the first metal sheet extends to the edge of the first metal sheet, and a corrugated portion of the second metal sheet extends to the edge of the second metal sheet. The end of the corrugated portion of the second metal sheet overlaps with the end of the corrugated portion of the first metal sheet in the overlapping region, and the two flat portions of the second metal sheet overlap with the two flat portions of the first metal sheet in the overlapping region. The first metal sheet is located between the second metal sheet and the supporting surface in the overlapping region. The first metal sheet carries a component for increasing thickness, which is positioned to align with at least a portion of the overlapping area to thicken the first metal sheet at least at the junction between the corrugated portion of the first metal sheet and the two flat portions of the first metal sheet. The sealing film includes a continuous welded portion along the overlapping area between the second metal sheet and the first metal sheet, the continuous welded portion extending in a manner consistent with the increased thickness of the component.

[0013] The presence of the thickened component tends to prevent over-melting of the metal alloy of the first metal sheet and high-temperature oxidation of the metal alloy of the first metal sheet, and thus tends to prevent the weld between the second metal sheet and the first metal sheet from having high residual porosity after recrystallization of the metal alloy. Therefore, by means of the thickened component, the sealing film has improved mechanical strength and minimizes damage to the vacuum setting of the thermal insulation barrier beneath the sealing film.

[0014] Furthermore, since the increased thickness of the component tends to isolate the metal alloy of the first metal sheet from the atmosphere, it is not necessary to form a continuous weld in an inert atmosphere as a backing.

[0015] According to the embodiments, this manufacturing method or this can may have one or more of the following features.

[0016] For components with increased thickness, various geometries can be conceived.

[0017] According to one embodiment, the increased thickness member extends continuously across the width of the corrugated portion of the first metal sheet from one of the two flat portions of the first metal sheet to the other flat portion of the two flat portions of the first metal sheet.

[0018] According to one embodiment, the thickened component has a constant thickness. In this way, the thickened component can be manufactured at low cost, for example, by pressing.

[0019] According to one embodiment, the thicker component is thicker at the connection between the corrugated portion and the two flat portions of the first metal sheet than at the ridge portion of the corrugated portion.

[0020] Specifically, the risk of over-melting of the metal alloy at the connection portion of the first metal sheet tends to be greater than the risk of over-melting of the metal alloy at the ridge portion of the first metal sheet; therefore, it is preferable that the thickened component is thicker at the connection portion.

[0021] According to one embodiment, the thickened component is attached to two flat portions of the first metal sheet.

[0022] According to one embodiment, the thickened component, the first metal sheet, and the second metal sheet are made of the same metal alloy. According to another embodiment, the thickened component may be made of a different metal alloy than the first and second metal sheets; in particular, the thickened component may be made of a less expensive metal alloy because the thickened component contributes less to the mechanical strength of the sealing membrane.

[0023] According to one embodiment, the second metal sheet includes an overlap along the edge of the second metal sheet.

[0024] According to one embodiment, an automatic welding machine performs the step of forming a continuous weld between a second metal sheet and a first metal sheet along an overlapping area, the automatic welding machine moving parallel to the edges of the first metal sheet and the edges of the second metal sheet.

[0025] According to one embodiment, the step of forming a continuous weld along the overlapping area between the second metal sheet and the first metal sheet is not performed under an inert atmosphere as a back-side protection.

[0026] Specifically, an inert atmosphere as a back cover is not necessary because the increased thickness of the component tends to isolate the weld between the second metal sheet and the first metal sheet from the atmosphere present on the back of the sealing film.

[0027] According to one embodiment, providing a first metal sheet and a second metal sheet on a support surface includes positioning the first metal sheet by inserting a component of increased thickness into a recess included in the support surface.

[0028] According to one embodiment, the supporting surface is the inner surface of a thermal insulation barrier.

[0029] According to one embodiment, the sealing membrane is a primary sealing membrane, the thermal insulation barrier is a primary thermal insulation barrier, and the tank wall also includes a secondary sealing membrane and a secondary thermal insulation barrier. The secondary thermal insulation barrier is configured to abut against the bearing wall, the secondary sealing membrane is configured to abut against the secondary thermal insulation barrier, and the primary thermal insulation barrier is configured to abut against the secondary sealing membrane.

[0030] According to one embodiment, the primary thermal barrier includes rows of carrier elements, each of which is fastened to an outer plate and an inner plate. The outer plate is fastened to a secondary thermal barrier and presses a secondary sealing film against the secondary thermal barrier. The inner plate forms the support surface, and wherein providing a first metal sheet and a second metal sheet on the support surface includes welding the first metal sheet and the second metal sheet to the inner plate.

[0031] According to another embodiment, the secondary thermal insulation barrier includes a plurality of secondary insulation blocks juxtaposed on a support wall, and the primary thermal insulation barrier includes a plurality of primary insulation blocks. The plurality of primary insulation blocks are juxtaposed on the secondary sealing membrane and anchored to the secondary thermal insulation barrier by anchoring members supported by the secondary insulation blocks. The primary insulation blocks include anchoring plates, and the provision of a first metal sheet and a second metal sheet on the support surface includes welding the first metal sheet and the second metal sheet to the anchoring plates.

[0032] According to one embodiment, the present invention also provides a sealed and thermally insulated container, the container comprising a sealing membrane manufactured by the manufacturing method of any of the embodiments described above.

[0033] Since the second metal sheet is welded to the first metal sheet along the overlapping area, and the thicker component is carried by the first metal sheet, the thicker component is always kept in the sealing film.

[0034] In one implementation, the liquefied gas is liquefied hydrogen.

[0035] These tanks can be integrated into onshore storage facilities or installed in floating, near-shore, or offshore structures, particularly in vessels used for transporting liquefied hydrogen, such as hydrogen carriers, floating storage and regasification units (FSRUs), and floating production storage and offloading (FPSO) units. These tanks can also be used as fuel tanks on any type of vessel.

[0036] According to one embodiment, a vessel for transporting liquefied gas includes a twin hull and the aforementioned tank disposed within the twin hull.

[0037] According to one embodiment, the present invention also provides a transmission system for liquefied gases, the system including the aforementioned vessel and an isolation conduit arranged to connect tanks installed in the hull of the vessel to a floating or onshore storage facility.

[0038] According to one embodiment, the transmission system further includes a pump for causing liquefied gas to flow from a floating or onshore storage facility through an insulated pipe to a tank on a ship, or from a tank on a ship through an insulated pipe to a floating or onshore storage facility.

[0039] According to one embodiment, the present invention also provides a method for loading or unloading such a vessel, wherein liquefied gas is transported from a floating or onshore storage facility to a tank on the vessel via an insulated pipeline or from a tank on the vessel to a floating or onshore storage facility via an insulated pipeline. Attached Figure Description

[0040] The invention will be better understood in the following description of several particular embodiments of the invention, given by way of non-limiting example only, with reference to the accompanying drawings, and other objects, details, features and advantages of the invention will become clearer and more apparent.

[0041] [ Figure 1 ] Figure 1 It is a partial three-dimensional view of the wall of a sealed and thermally insulated tank.

[0042] [ Figure 2 ] Figure 2 It is a partial three-dimensional view of a corrugated metal sheet carrying components with increased thickness.

[0043] [ Figure 3 ] Figure 3 yes Figure 2 The corrugated portion of the corrugated metal sheet in the middle is based on Figure 2 The side view of arrow A in the image.

[0044] [ Figure 4 ] Figure 4 It is a partial 3D view, showing Figure 1The arrangement of corrugated metal sheets on the tank wall within the primary thermal insulation barrier.

[0045] [ Figure 5 ] Figure 5 yes Figure 4 A three-dimensional view of a partial cross-section of detail V in the image.

[0046] [ Figure 6 ] Figure 6 It is along including Figure 5 A cross-sectional schematic diagram of the plane in the visible overlapping region.

[0047] [ Figure 7 ] Figure 7 This is a cross-sectional diagram of the ship's tank and the dock used for loading / unloading the tank. Detailed Implementation

[0048] By convention, the terms “external” and “internal” are used to refer to the interior and exterior of a container to define the position of one element relative to another.

[0049] Figure 1 The tank wall 11 of a sealed and thermally insulated vessel for storing liquefied gas is shown in partial perspective. The wall 11 shown is manufactured according to the teachings of document WO 2023 / 198637 A1.

[0050] As described in document WO 2023 / 198637 A1, wall 11 is fastened to abut against a support wall forming, for example, a polyhedral support structure 1. Support structure 1 is formed, for example, by the double hull of a ship. Wall 11 has a multi-layered structure that includes, from the outside to the inside, the following in the thickness direction of wall 11: a secondary thermal insulation barrier 12; a secondary sealing membrane 13; a primary thermal insulation barrier 14; and a primary sealing membrane 15 for contact with the liquefied gas contained within the tank.

[0051] The secondary thermal insulation barrier 12 includes a plurality of insulation panels 16 anchored to the supporting structure 1. Each insulation panel 16 includes an insulating polymer foam layer 17 disposed between an inner sheet 18 and an outer sheet 19. The inner sheet 18 and the outer sheet 19 are, for example, plywood sheets adhesively bonded to the insulating polymer foam layer 17. According to a variation, the inner sheet 18 and the outer sheet 19 are made of a fiber-reinforced polymer matrix, such as glass fiber. The insulating polymer foam may in particular be a polyurethane-based foam. The polymer foam is advantageously reinforced with fibers such as glass fiber, thereby helping to reduce the thermal shrinkage of the polymer foam.

[0052] Each insulating panel 16 includes an insulating polymer foam layer 17 disposed between an inner sheet 18 and an outer sheet 19. The inner sheet 18 and the outer sheet 19 are, for example, plywood sheets adhesively bonded to the insulating polymer foam layer 17. According to a variation, the inner sheet 18 and the outer sheet 19 are made of a fiber-reinforced polymer matrix, such as glass fiber. The insulating polymer foam can, in particular, be a polyurethane-based foam. The polymer foam is advantageously reinforced with fibers, such as glass fiber, thereby helping to reduce the thermal shrinkage of the polymer foam.

[0053] Advantageously, the adhesive portion 20 is arranged between the outer sheet 19 of the insulating panel 16 and the supporting structure 1. The adhesive portion 20 thus helps to compensate for surface irregularities of the supporting structure 1. According to an advantageous embodiment variation, the adhesive portion 20 is attached to both the outer sheet 19 of the insulating panel 16 and the supporting structure 1. The adhesive portion 20 thus helps to anchor the insulating panel 16 to the supporting structure 1. In this embodiment variation, a secondary anchoring device is optional.

[0054] The insulating panels 16 are approximately rectangular parallelepipeds in shape, and are arranged side-by-side in parallel rows, separated from each other by gaps 21, thereby ensuring functional installation clearance. The gaps 21 are filled with an insulating filler (not shown), such as glass wool, rock wool, or open-cell flexible polymer foam. The gaps may also be filled with insulating plugs, as described in, for example, applications WO2019155157 or WO2021028624.

[0055] In the illustrated embodiment, the inner surface of the insulating panel 16 presents two sets of grooves 22, which are perpendicular to each other and are used to receive corrugated portions 24 protruding towards the outside of the can formed on the corrugated metal sheet 25 of the secondary sealing film 13. Each of the set of grooves 22 is parallel to opposite sides of the insulating panel 16. In the illustrated embodiment, the grooves 22 extend through the entire thickness of the inner sheet 18 and into the inner portion of the insulating polymer foam layer 17. Advantageously, the grooves 22 have a shape complementary to the shape of the corrugated portions included in the secondary sealing film 13.

[0056] Furthermore, the insulating panel 16 has relaxation slots 27, which reduce the stiffness of the insulating panel 16, allowing the secondary thermal barrier 12 to deform as uniformly as possible. This enables the corrugations of the secondary sealing membrane 13 to deform as uniformly as possible. Advantageously, the insulating panel 16 has relaxation slots 27 at least for each corrugation facing the secondary sealing membrane 13. Further details regarding the thermal barrier 12 and the secondary sealing membrane 13 can be found in document WO 2023 / 198637A1.

[0057] The primary thermal insulation barrier 14 includes a plurality of support elements 30 extending in the thickness direction of the wall 11. The support elements 30 support the primary sealing membrane 15 and thus react to the loads caused by the hydrostatic and dynamic pressures exerted on the primary sealing membrane 15 by the liquefied gas contained in the tank. The support elements 30 are aligned in a parallel row.

[0058] Further details regarding the load-bearing element 30 can be found in document WO 2023 / 198637 A1. Specifically, as described in that document, the load-bearing element 30 is respectively fastened to the outer plate and the inner plate 42 (…). Figure 1 Not shown in the image, but... Figure 4 As shown in the figure, the outer panel is fastened to the secondary thermal insulation barrier 12 and the secondary sealing film 13 is pressed against the secondary thermal insulation barrier 12.

[0059] The primary sealing membrane 15 is obtained by assembling multiple corrugated metal sheets 44. Each corrugated metal sheet 44 has a generally rectangular shape. The corrugated metal sheets 44 are made, for example, of Invar®: an alloy of iron and nickel, and the coefficient of thermal expansion of the corrugated metal sheets 44 is typically 1.2 × 10⁻⁶. -6 K -1 Up to 2×10 -6 K -1 Between; or made of high-manganese iron alloys, corrugated metal sheets 44 typically have a coefficient of thermal expansion of about 7 × 10⁻⁶. -6 K -1 As an alternative, the corrugated metal sheet 44 can also be made of stainless steel or aluminum.

[0060] Corrugated metal sheets 44 are overlapped and welded along their edges to ensure the fluid tightness of the primary sealing membrane 15. The primary sealing membrane 15 includes corrugated portions 45. More specifically, the primary sealing membrane 15 includes a first set of corrugated portions 45a extending parallel to a first direction and a second set of corrugated portions 45b extending parallel to a second direction. The directions of the groups of corrugated portions 45a, 45b are perpendicular to each other and parallel to or perpendicular to the rows of support elements 30. Each corrugated portion in the group of corrugated portions 45a, 45b is parallel to two opposite edges of the corrugated metal sheet 44. The corrugated portions 45 protrude toward the interior of the tank, i.e., in a direction away from the support structure 1. Each corrugated metal sheet 44 includes a plurality of flat regions 46 located between the corrugated portions 45. In this case, the corrugated portions 45b have a smaller height than the corrugated portions 45a. In another embodiment, the corrugated portions 45a and 45b may have the same height.

[0061] The spacing of the corrugations in the secondary sealing membrane 13 is equal to the spacing of the corrugations 45 in the primary sealing membrane 15, or the spacing of the corrugations in the secondary sealing membrane 13 is an integer multiple of the spacing of the corrugations 45 in the primary sealing membrane 15. Furthermore, each corrugation in the secondary sealing membrane 13 is configured to face the corrugations 45 in the primary sealing membrane 15 in the thickness direction of the wall 11. Therefore, each flat region 46 of the primary sealing membrane 15 is positioned to face the flat region of the secondary sealing membrane 13 in the thickness direction of the wall 11. Thus, the axis of each supporting member 30 passes through both the center of the flat region 46 of the primary sealing membrane 15 and the center of the flat region of the secondary sealing membrane 13.

[0062] The corrugated metal sheet 44 of the primary sealing membrane 15 is anchored to the inner plate 42 by welding, at least along its edges. For this purpose, the edges of the corrugated metal sheet 44 are welded to the inner plate 42, for example, by spot welding. According to an advantageous embodiment, the corrugated metal sheet 44 is also anchored to the inner plate 42 outside the edge region of the metal sheet. For this purpose, the corrugated metal sheet 44 can be welded to the inner plate 42, particularly by transparent welds. According to an advantageous embodiment, the corrugated metal sheet 44 is welded to each of the inner plates 42 that support the metal sheet. This embodiment is particularly advantageous because it allows for a more uniform distribution of stress among the corrugations 45 of the primary sealing membrane 15.

[0063] Further details regarding the primary thermal barrier 14 can be found in document WO 2023 / 198637 A1. As described in that document, wall 11 is suitable for manufacturing a sealed and thermally insulated container for storing liquefied hydrogen. Liquefied hydrogen is a liquefied gas with the unique characteristic of being stored at approximately -253°C at atmospheric pressure. When the container is filled with liquefied hydrogen at -253°C at atmospheric pressure, the primary sealing membrane 15 is subjected to very high thermal stress. Therefore, it is important to ensure the mechanical strength of the primary sealing membrane 15.

[0064] Furthermore, as described in document WO 2023 / 198637 A1, in order to provide the required thermal insulation performance to the primary thermal insulation barrier 14, the primary thermal insulation barrier 14 has a gas phase portion, which is placed at an absolute pressure of less than 1 Pa, advantageously less than 10 Pa. -1 The absolute pressure of Pa, preferably less than 10 Pa. - ² Pa absolute pressure, for example, about 10 -3 The absolute pressure is Pa. This absolute pressure can be obtained by a vacuum pump and / or by cryogenic pumping. Therefore, it is important that this vacuum setup is not damaged by the primary sealing diaphragm 15.

[0065] As described above, the corrugated metal sheets 44 are overlapped along their edges to ensure the fluid tightness of the primary sealing membrane 15. During the welding operation, the metal alloy constituting the corrugated metal sheets 44 undergoes melting and recrystallization. If the welding operation results in over-melting of the metal alloy, the weld between the corrugated metal sheets 44 risks having a high residual porosity after recrystallization. This risk is greater when the welding operation is not performed in an inert atmosphere, as the metal alloy subsequently undergoes high-temperature oxidation due to the high temperature and the presence of oxygen in the atmosphere. The higher the residual porosity of the weld between the corrugated metal sheets 44, the higher the surface irregularity of the metal sheets, which is more likely to cause crack initiation. This is detrimental to the mechanical strength of the primary sealing membrane 15 and makes the metal sheets more likely to degrade the performance of the vacuum setting of the primary thermal insulation barrier 14. Residual porosity will primarily increase the specific surface area of ​​the metal surface, and will also increase the theoretical degassing rate calculated based on an underestimated nominal surface area. The performance of a vacuum setup can also be degraded by creating nearly enclosed spaces that house gas volumes. Since the flow resistance at the outlets of these spaces is high, venting these gases by pumping becomes more difficult. Therefore, it is particularly desirable to limit residual porosity caused by welding operations in the welded sections between the corrugated metal sheets 44.

[0066] The following describes an embodiment of a method for manufacturing a primary sealing membrane 15 that tends to limit such residual porosity. This manufacturing method uses a corrugated metal sheet 144 (hereinafter referred to as "sheet 144"), which is the same as a corrugated metal sheet 44 (hereinafter referred to as "sheet 44"), except that the metal sheet 144 carries... Figures 2 to 6 The increased thickness of component 90 is shown. Therefore, the following description of sheet 144 also applies to sheet 44, where the same elements as those in sheet 44 are labeled with the same reference numerals and increased by 100.

[0067] exist Figure 2 The image shows a partial perspective view of sheet 144, which includes a flat portion 186 for mounting on the inner plate 42 and corrugated portions 185a and 185b protruding relative to the flat portion 186. Each corrugated portion 185a and 185b is formed between two flat portions 186. The corrugated portions 185a and 185b are used to form the corrugated portions 45a and 45b of the primary sealing membrane 15, respectively (see Figure 144). Figure 1 As part of the corrugated portion 185a, in this case, the corrugated portion 185b has a smaller height than the corrugated portion 185a. In another embodiment, the corrugated portions 185a and 185b may have the same height.

[0068] Reference numerals 156a and 156b respectively denote the connection between the flat portion 186 and the corrugated portion 185a. A node 155 is formed at the intersection of the corrugated portions 185a and 185b. To avoid overcrowding in the figures, the node 155 is... Figure 1 and Figure 4 The middle part has been omitted.

[0069] The sheet 144 has an outer contour that is generally rectangular and is defined by four straight edges 168 that are orthogonal to each other. Figure 2 Three of the four edges 168 are visible. As shown, the corrugated portions 185a and 185b extend to edge 168.

[0070] The sheet 144 carries a component 90 with increased thickness at each corrugated portion 185a. For example... Figure 2 As shown, the edge of the thickened component 90 is preferably aligned with the edge 168 to which the corrugated portion 185a extends, or the edge of the thickened component 90 is less than 5 mm away from the edge 168. In the figures, the thickened component 90 is shown as a single component. However, other implementations are possible, such as the thickened component comprising multiple parts, for example, the thickened component comprising two small thickened sheets. According to a non-limiting example, the thickened component 90 includes a first small portion with a thickness of 2 mm at the foot of the corrugated portion and a second small portion with a thickness of 1.5 mm at the ridge of the corrugated portion.

[0071] Figure 3 It is based on one of the corrugated portions in corrugated portion 185a. Figure 2 The side view of arrow A in the image. (As shown in...) Figure 3 As can be seen more clearly, the thickened components 90 are positioned to thicken the sheet 144 at the corrugated portion 185a, at the connecting portion 156a, and at a portion of the flat portion 186 near the connecting portion 156a.

[0072] Still referencing Figure 2 The sheet 144 overlaps along at least one other edge of the edge 168, such that the sheet 144 includes an overlap 167 (an overlapping bend or a bent portion) along the edge 168. Preferably, as Figure 4As can be seen more clearly, the sheet 144, or each sheet 144, overlaps along two vertical edges 168, the two edges corresponding to overlap 167 and overlap 67 respectively. (In this case, overlap 67 is shown located on another rectangular sheet 44.) Preferably, the thicker components are placed in the corrugated portions of one or more edges 168 of the sheet 144 that do not have overlaps, for example, the thicker components are placed along the two edges 168 that do not have overlaps 167 and 67.

[0073] In the first step of the manufacturing method, sheet 144 and sheet 44 are set. This first step is... Figure 4 and Figure 5 As shown, Figure 5 yes Figure 4 A three-dimensional view of a partial cross-section of detail V. Figure 5 In order to avoid making the accompanying drawings too crowded, the inner plate 42 is omitted, and only the sheet 144 and sheet 44 are shown.

[0074] like Figure 4 As shown, a recess 429 is provided on the inner plate 42 to receive the components 90 with increased thickness. Figure 4 As can also be seen, the inner plate 42 includes through holes 423. These through holes 423 are used to receive rivets distributed around the axis of the support element 30 to fasten the support element 30 to the inner plate 42, as described in document WO 2023 / 198637 A1.

[0075] The sheet 144 is positioned by inserting the thickened components 90 into the recesses 429.

[0076] After sheet 144 has been positioned in this manner, sheet 44 is positioned, and the overlapping portion 67 of sheet 44 overlaps with sheet 144 in the overlapping area ZR. (Reference) Figure 5 The overlapping region ZR is defined between the edge 168 of sheet 144 and the edge 68 of sheet 44 parallel to the edge 168. Figure 5 The dashed lines in the diagram indicate the location of the overlapping region ZR. For example... Figure 5 As shown, the corrugated portion 185a of sheet 144 and the corrugated portion 85a of sheet 44 are aligned; the end of the corrugated portion 85a overlaps with the end of the corrugated portion 185a in the overlap region ZR; and the flat portions 86 on both sides of the corrugated portion 85a overlap with the flat portions 186 on both sides of the corrugated portion 185a in the overlap region ZR. Figure 5 Only one flat portion of the flat portion 86 is visible in the image. The sheet 44 has been cut along the corrugated portion 85a to show the thickened component 90. The thickened component 90 is positioned to align with at least a portion of the overlapping region ZR.

[0077] It should be understood that when sheet 44 and sheet 144 are positioned in this manner, the flat portion 86 of sheet 44 and the flat portion 186 of sheet 144 rest on the inner plate 42 (see [reference]). Figure 4 These inner plates 42 form support surfaces for sheets 44 and 144, and thus form support surfaces for the primary sealing membrane 15. Prior to the second step, sheets 44 and 144 are anchored to the inner plates 42 by welding along their edges 68, 168, as described above. For example, sheet 144 is welded to the inner plates 42 before sheet 44 is positioned to overlap with sheet 144 in the overlap region ZR.

[0078] In the second step of the manufacturing method, a continuous weld is formed between sheet 44 and sheet 144 along the overlapping region ZR, the continuous weld extending in a manner consistent with the increased thickness of the component 90. This second step is shown in... Figure 6 In the middle, the continuous welding section is produced by a welding torch according to known welding techniques. For example, the welding torch is mounted on an automatic welding machine that moves parallel to the edges 168, 68 that define the overlapping area ZR. Figure 5 The arrow W in the diagram indicates the forward movement direction of the automatic welding machine. The automatic welding machine can be constructed, for example, as described in document EP 0 611 217 A1. At the end of the second step, sheet 44 is thus lap-welded to sheet 144 along the overlapping area ZR.

[0079] The above steps of the manufacturing method are repeated as needed until the manufacturing of the primary sealing film 15 is completed.

[0080] It should be noted that since sheet 44 is lap-welded to sheet 144 along the overlapping area ZR, and the thickened component 90 is carried by sheet 144, the thickened component 90 is always retained in the primary sealing film 15 at the end of the manufacturing process.

[0081] Despite Figure 4 Although not shown in the diagram, the invention also applies to cases where an inner panel 42 is connected to another inner panel 42 adjacent to it via a connector having a translational degree of freedom in a direction perpendicular to the wall thickness direction and a connection degree of freedom in the wall thickness direction. This allows relative movement between the inner panels to which the flat portion 186 of the sealing membrane is fastened and the inner panels to be moved in a direction perpendicular to the wall thickness direction.

[0082] On the other hand, it should be noted that, as an alternative to or in addition to the corrugated portion 185a, the sheet 144 may carry a component with increased thickness, similar to the increased thickness component 90, at the corrugated portion 185b. The lap weld between the sheets 44 and 144, aligned with this increased thickness component, is the same as described above. In other words, the sheet 144 may carry the increased thickness component in the large corrugated portion and / or the small corrugated portion.

[0083] Figure 6 yes Figure 5 The diagram shows a cross-sectional view of sheets 44 and 144 along a plane included in the overlapping region ZR and parallel to the forward movement direction W. It should be noted that, for ease of explanation below, sheets 44, 144 and the thickened component 90 are shown schematically in lines.

[0084] Figure 6 The dashed lines indicate three consecutive positions of the welding torch 900 during the second step of the manufacturing process. (See figure.) Figure 6 As shown, the welding torch 900 can be rotatably mounted to follow the outer contours of the corrugated portions 85a and 185a. The welding torch 900 can be mounted on an automatic welding machine as described above. Due to the presence of the thickened component 90, the sheet 144 has increased thermal inertia at the corrugated portion 185a, the connecting portion 156a, and a portion of the flat portion 186 near the connecting portion 156a. Furthermore, the thickened component 90 isolates the weld between the sheets 44 and 144 from the atmosphere. The presence of the thickened component 90 tends to prevent over-melting of the metal alloy of the sheet 144 and high-temperature oxidation of the metal alloy of the sheet 144, and thus tends to prevent the weld between the sheets 44 and 144 from having high residual porosity after recrystallization of the metal alloy. Therefore, by means of the thickened component 90, the primary sealing film 15 has improved mechanical strength and minimizes damage to the vacuum setting of the primary thermal insulation barrier 14. Furthermore, since the increased thickness of component 90 tends to isolate the metal alloy of sheet 144 from the atmosphere, it is not necessary to form a continuous weld in an inert atmosphere that serves as back protection.

[0085] According to a variant, the thickened component 90 is made of the same metal alloy as sheets 44 and 144. According to another variant, the thickened component 90 can be made of a different metal alloy than that of sheets 44 and 144, particularly a lower-cost and metallurgically compatible metal alloy (that is, the alloy must be weldable without difficulty and without galvanic corrosion), because the thickened component 90 contributes less to the mechanical strength of the primary sealing membrane 15.

[0086] exist Figures 2 to 6In the illustrated embodiment, the thickened component 90 extends continuously across the width of the corrugated portion 185a between two flat portions 186 on either side of the corrugated portion 185a, and has a constant thickness. In this way, the thickened component 90 can be manufactured at low cost, for example, by pressing.

[0087] In one variation, the thicker component 90 can have different geometries.

[0088] In particular, according to one variant, the thicker component 90 at the connecting portion 156a is thicker than the ridge portion 185at of the corrugated portion 185a (see [link]). Figure 3 The thickness is greater. Specifically, because the welding torch 900 rotates to follow the outer contours of the corrugated portions 85a and 185a, the risk of over-melting of the metal alloy at the joint 156a of the sheet 144 is greater than the risk of over-melting of the metal alloy at the ridge portion 185at of the sheet 144; therefore, preferably, the thickened component 90 is thicker at the joint 156a to obtain further increased thermal inertia at the joint 156a.

[0089] Therefore, it is also conceivable that, according to another variation, the thickened component 90 is positioned to thicken the sheet 144 only at the connecting portion 156a. In other words, according to this variation, the sheet 144 carries the thickened component 90 at each connecting portion 156a, and these thickened components 90 extend only in the width of the corrugated portion 185a to another connecting portion 156a corresponding to the corrugated portion.

[0090] In the above variation, the thickened component 90 is preferably attached to the sheet 144 to facilitate the manufacture of the sheet 144. For example, the thickened component 90 is attached to the sheet 144 by spot welding. More preferably, the thickened component 90 is attached to both the flat portion 186 and the corrugated portions 185a and / or 185b of the sheet 144 by spot welding. Therefore, this ensures that the thickened component 90 is adequately attached for retention during sheet handling.

[0091] The manufacturing method has been described in the context of sealed and thermally insulated tanks for storing liquefied hydrogen. In one variation, the sealed and thermally insulated tank can be used to store other liquefied gases, particularly liquefied natural gas (LNG), liquefied petroleum gas (LPG), ethane, or ammonia.

[0092] This manufacturing method has been described in the context of a tank wall manufactured according to the teachings of document WO 2023 / 198637 A1. However, this manufacturing method is also applicable to any other tank wall in which the sealing membrane is manufactured by lap welding of corrugated metal sheets. This manufacturing method is particularly applicable to tank walls in which a secondary thermal insulation barrier comprises a plurality of secondary insulation blocks juxtaposed on a supporting wall, a primary thermal insulation barrier comprises a plurality of primary insulation blocks juxtaposed on the secondary sealing membrane and anchored to the secondary thermal insulation barrier by anchoring members supported by the secondary insulation blocks, the primary insulation blocks comprising anchor plates. Such a tank wall can be manufactured according to, for example, the teachings of document FR 2 691 520 A1, document WO 2014 / 057221 A2, or document WO 2017 / 006044 A1. Sheets 44 and 144 are anchored to the anchor plates by the edges of the sheets, but not to the aforementioned inner plate 42.

[0093] refer to Figure 7 The cross-sectional view of the vessel 70 shows a sealed and thermally insulated tank 71 with a prismatic overall shape installed in the vessel's twin hulls 72. The walls of the tank 71 include: a primary sealing membrane for contact with the liquefied gas, preferably liquefied hydrogen, contained in the tank; a secondary sealing membrane disposed between the primary sealing membrane and the vessel's twin hulls 72; and thermally insulated barriers disposed between the primary sealing membrane and the secondary sealing membrane and between the secondary sealing membrane and the twin hulls 72, respectively.

[0094] As is known per se, the loading / unloading pipe 73 located on the upper deck of a ship can be connected to a sea dock or port terminal by appropriate connectors to transfer liquefied gas cargo from tank 71 or to tank 71.

[0095] Figure 7 An example of an offshore terminal is also shown, comprising a loading and unloading station 75, underwater pipelines 76, and onshore facilities 77. The loading and unloading station 75 is a fixed offshore facility, comprising a boom 74 and a tower 78 supporting the boom 74. The boom 74 carries bundles of flexible insulated conduits 79, which can be connected to loading / unloading pipelines 73. The directional boom 74 is suitable for hydrogen carriers of all sizes. Connecting pipelines (not shown) extend within the tower 78. The loading and unloading station 75 allows loading from the onshore facility 77 to the hydrogen carrier 70 or unloading from the hydrogen carrier 70 to the onshore facility 77. The facility includes liquefied gas storage tanks 80 and connecting pipelines 81 connected to the loading or unloading station 75 via underwater pipelines 76. The underwater pipeline 76 enables the transfer of liquefied gas over long distances, such as 5 kilometers, between the loading or unloading station 75 and the onshore facility 77, thereby allowing the methane carrier 70 to remain anchored at sea at long distances during loading and unloading operations.

[0096] To generate the pressure required to transfer the liquefied gas, pumps carried on the ship 70 and / or pumps equipped on the land facility 77 and / or pumps equipped on the loading and unloading station 75 may be used, or the pressure inside the tank may be allowed to rise due to the evaporation of the liquefied gas stored in the tank.

[0097] Although the invention has been described in conjunction with several specific embodiments, it is obvious that the invention is by no means limited thereto, but includes all technical equivalents and combinations thereof of the described apparatus, provided that such technical equivalents and combinations thereof fall within the scope of the invention.

[0098] The use of the verbs “having,” “comprising,” or “including,” and their variant forms, does not exclude the presence of elements or steps other than those described in the claims.

[0099] In the claims, any reference numerals between parentheses shall not be construed as limiting the claims.

Claims

1. A method for manufacturing a sealing membrane for use as the tank wall of a sealed and thermally insulated tank for storing liquefied gas, the method comprising the following steps: - A first metal sheet (144) and a second metal sheet (44) are disposed on a flat support surface. Each of the first metal sheet (144) and the second metal sheet (44) includes two flat portions (186, 86) disposed on the flat support surface and a corrugated portion (185a, 85a) formed between the two flat portions (186, 86). The corrugated portion (185a, 85a) protrudes relative to the two flat portions (186, 86). Align the corrugated portion (185a) of the first metal sheet (144) and the corrugated portion (85a) of the second metal sheet (44). The second metal sheet (44) overlaps with the first metal sheet (144) in an overlap region (ZR), the overlap region (ZR) being defined between the edge (168) of the first metal sheet (144) and the edge (68) of the second metal sheet (44), the edge (68) of the second metal sheet (44) being parallel to the edge (168) of the first metal sheet (144), the corrugated portion (185a) of the first metal sheet (144) extending to the edge (168) of the first metal sheet (144), and the corrugated portion (85a) of the second metal sheet (44) extending to the edge (68) of the second metal sheet (44). The end of the corrugated portion (85a) of the second metal sheet (44) overlaps with the end of the corrugated portion (185a) of the first metal sheet (144) in the overlapping region (ZR), and the two flat portions (86) of the second metal sheet (44) overlap with the two flat portions (186) of the first metal sheet (144) in the overlapping region (ZR), wherein the first metal sheet (144) is located between the second metal sheet (44) and the supporting surface in the overlapping region (ZR). The first metal sheet (144) is provided with a component (90) that increases the thickness, the component (90) being positioned to align with at least a portion of the overlapping region (ZR) to thicken the first metal sheet (144) at least at the connection (156a) between the corrugated portion (185a) of the first metal sheet (144) and the two flat portions (186) of the first metal sheet (144); - A continuous weld is formed between the second metal sheet (44) and the first metal sheet (144) along the overlapping region (ZR), the continuous weld extending in a manner consistent with the increased thickness of the component (90).

2. The manufacturing method according to claim 1, wherein, The thickened component (90) extends continuously across the width of the corrugated portion (185a) of the first metal sheet (144) from one of the two flat portions (186) of the first metal sheet (144) to the other flat portion of the two flat portions (186) of the first metal sheet (144).

3. The manufacturing method according to claim 2, wherein, The thickened component (90) is thicker at the connection (156a) between the corrugated portion (185a) and the two flat portions (186) of the first metal sheet (144) than at the ridge portion (185at) of the corrugated portion (185a).

4. The production method according to any one of claims 1 to 3, wherein The thickened component (90) is attached to two flat portions (186) of the first metal sheet (144).

5. The production method according to any one of claims 1 to 4, wherein The thickened component (90), the first metal sheet (144), and the second metal sheet (44) are manufactured using the same metal alloy.

6. The production method according to any one of claims 1 to 5, wherein The second metal sheet (44) includes an overlap (67) along the edge (68) of the second metal sheet (44).

7. The production method according to any one of claims 1 to 6, wherein The step of forming a continuous weld between the second metal sheet (44) and the first metal sheet (144) along the overlapping area (ZR) is performed by an automatic welding machine, which moves parallel to the edge (168) of the first metal sheet (144) and the edge (68) of the second metal sheet (44).

8. The production method according to any one of claims 1 to 7, wherein Providing the first metal sheet (144) and the second metal sheet (44) on the support surface includes positioning the first metal sheet (144) by inserting the thickened component (90) into a recess (429) included in the support surface.

9. The production method according to any one of claims 1 to 8, wherein The supporting surface is the inner surface of the thermal insulation barrier.

10. The manufacturing method according to claim 9, wherein, The sealing membrane is a primary sealing membrane (15), the thermal insulation barrier is a primary thermal insulation barrier (14), and the tank wall (11) further includes a secondary sealing membrane (13) and a secondary thermal insulation barrier (12), the secondary thermal insulation barrier (12) being configured to abut against the bearing wall, the secondary sealing membrane (13) being configured to abut against the secondary thermal insulation barrier (12), and the primary thermal insulation barrier (14) being configured to abut against the secondary sealing membrane (13). The primary thermal barrier (14) includes rows of support elements (30), each of which is fastened to an outer plate and an inner plate (42). The outer plate is fastened to the secondary thermal barrier (12) and presses the secondary sealing membrane (13) against the secondary thermal barrier (12). The inner plate (42) forms the support surface. The provision of the first metal sheet (144) and the second metal sheet (44) on the support surface includes welding the first metal sheet (144) and the second metal sheet (44) to the inner plate (42).

11. A sealed and thermally insulated tank for storing liquefied gas, the tank comprising a tank wall including a sealing membrane and a flat supporting surface. wherein The sealing membrane includes a first metal sheet (144) and a second metal sheet (44) disposed on the flat support surface. Each of the first metal sheet (144) and the second metal sheet (44) includes two flat portions (186, 86) disposed on the flat support surface and a corrugated portion (185a, 85a) formed between the two flat portions (186, 86). The corrugated portion (185a, 85a) protrudes relative to the two flat portions (186, 86). The corrugated portion (185a) of the first metal sheet (144) and the corrugated portion (85a) of the second metal sheet (44) are aligned. The second metal sheet (44) overlaps with the first metal sheet (144) in an overlap region (ZR), the overlap region being defined between the edge (168) of the first metal sheet (144) and the edge (68) of the second metal sheet (44), the edge (68) of the second metal sheet (44) being parallel to the edge (168) of the first metal sheet (144), a corrugated portion (185a) of the first metal sheet (144) extending to the edge (168) of the first metal sheet (144), and a corrugated portion (85a) of the second metal sheet (44) extending to the edge (68) of the second metal sheet (44). The end of the corrugated portion (85a) of the second metal sheet (44) overlaps with the end of the corrugated portion (185a) of the first metal sheet (144) in the overlapping region (ZR), and two flat portions (86) of the second metal sheet (44) overlap with two flat portions (186) of the first metal sheet (144) in the overlapping region (ZR), wherein the first metal sheet (144) is located between the second metal sheet (44) and the supporting surface in the overlapping region (ZR). The first metal sheet (144) carries a thickness-enhancing component (90) which is positioned to align with at least a portion of the overlapping region (ZR) to thicken the first metal sheet (144) at least at the connection (156a) between the corrugated portion (185a) of the first metal sheet (144) and the two flat portions (186) of the first metal sheet (144); The sealing film includes a continuous welded portion along the overlapping region (ZR) between the second metal sheet (44) and the first metal sheet (144), the continuous welded portion extending in a manner consistent with the increased thickness of the component (90).

12. A vessel (70) for transporting liquefied gas, the vessel comprising a twin hull (72) and a tank (71) according to claim 11 disposed in the twin hull.

13. A transfer system for a liquefied gas, the system comprising: The vessel (70) according to claim 12; isolation conduits (73, 79, 76, 81) arranged to connect the tank (71) installed in the hull of the vessel to a floating or onshore storage facility (77); and a pump for causing liquefied gas to flow from the floating or onshore storage facility through the isolation conduits to the tank of the vessel, or from the tank of the vessel through the isolation conduits to the floating or onshore storage facility.

14. A method for loading or unloading a vessel (70) according to claim 12, wherein, The liquefied gas is transported from the floating or onshore storage facility (77) to the tank (71) of the vessel (70) via insulated pipes (73, 79, 76, 81); or the liquefied gas is transported from the tank (71) of the vessel (70) to the floating or onshore storage facility (77) via insulated pipes (73, 79, 76, 81).

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