EP3473915B1 - Sealed and thermally insulating vessel - Google Patents

Description

Technical area

The invention relates to the field of sealed and thermally insulating tanks. In particular, the invention relates to the field of sealed and thermally insulating tanks in the context of the storage or transport of liquid at low temperature such as ship tanks for the transport of Liquefied Petroleum Gas (also called LPG) having by for example a temperature between -50°C and 0°C, or for the transport of liquefied natural gas (LNG) at approximately -162°C at atmospheric pressure.

Technology background

Sealed and thermally insulating tanks for ships are known for example from the document WO-A-2017064413 . This document describes a propane tank or LNG tank comprising a plurality of tank walls. Each wall of the tank comprises at least one sealing membrane and at least one thermal insulation barrier.

The document JP2009079736 proposes a terrestrial tank for cryogenic liquid having a supporting concrete structure and a thermal insulation barrier including an M-shaped piece designed to adapt to the thickness of the thermal insulation barrier by changing the height of a M-shaped piece. However, the M-shaped piece requires complicated shaping.

The document JPS55140200 presents a tank for cryogenic liquid comprising a support structure made of concrete and having a corner structure between a first wall and a second wall of the support structure. The corner structure is made up of two anchoring wings on which an angle iron rests. However the corner structure is not suitable for all types of angles formed by the two walls of the load-bearing structure.

Summary

An object of the invention is to provide a corner structure capable of supporting one or more waterproofing membranes at the level an angle between two tank walls and can be adapted to different thicknesses of the thermal insulation barrier.

The invention provides a sealed and thermally insulating tank for storing a fluid comprising a first wall and a second wall, the first and the second wall each comprising, in a direction of thickness, a load-bearing wall, an insulating barrier thermal insulation fixed to the load-bearing wall, a sealing membrane parallel to the load-bearing wall and fixed to the thermal insulation barrier, the sealed and thermally insulating tank comprising, at an edge between the load-bearing wall of the first wall and the load-bearing wall of the second wall, a corner structure, the corner structure comprising a first anchoring wing fixed to the load-bearing wall of the second wall, a second anchoring wing fixed to the load-bearing wall of the first wall, a sealing angle fixed, on the one hand, to the first anchoring wing by means of a first connecting piece, and on the other hand, to the second anchoring wing by means of a second connecting piece is lying. The sealing angle is connected in a leaktight manner to the sealing membrane of the first wall and to the sealing membrane of the second wall, the sealing angle comprising a first planar branch extending in the plane of the sealing membrane of the second wall, and a second planar branch extending in the plane of the sealing membrane of the first wall, the first connecting piece comprising a first planar branch parallel to the first anchoring wing, and a second planar branch parallel to the sealing membrane of the second wall, the second connecting piece comprising a first planar branch parallel to the second anchoring wing, and a second planar branch parallel to the sealing membrane of the first wall, the first planar leg of the first connecting piece being welded to the first anchoring wing, the first planar leg of the second connecting piece being welded to the second wing e anchor, the first flat leg of the angle iron sealing being welded to the second planar branch of the first connecting piece, and the second planar branch of the sealing angle being welded to the second planar branch of the second connecting piece, the sealing membrane of the first wall being welded to the second flat branch of the sealing angle, and the sealing membrane of the second wall being welded to the first flat branch of the sealing angle.

This corner structure makes it possible to adjust the position of the corner sealing membranes by adapting the position of the anchoring of the connecting pieces on the anchoring flanges to the desired position of the sealing angle. This adjustment of the position of the sealing angle makes it possible to easily adapt the corner structure to the thickness of the insulation barriers of the vessel walls. Indeed, the position of the first planar branch of the first connecting piece on the first anchoring wing makes it possible to adjust the distance between the second planar branch of the first connecting piece and the load-bearing wall of the second wall and therefore between the first flat branch of the sealing angle and the bearing wall of the second wall. Similarly, the position of the second planar branch of the second connecting piece on the second anchoring wing makes it possible to adjust the distance between the second planar branch of the second connecting piece and the load-bearing wall of the first wall and therefore between the second flat branch of the sealing angle and the bearing wall of the first wall.

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

According to certain embodiments, the first anchoring wing is also fixed to the supporting wall of the first wall and the second anchoring wing is fixed to the supporting wall of the second wall. In others terms, the first and second anchoring wings are fixed at the intersection of the bearing walls of the first and second walls in this case.

According to certain embodiments, the sealing angle comprises a plurality of cross sections, two adjacent cross sections being sealingly connected to one another by means of a corrugated connection projecting in the direction of the inside the tank, the sealing membrane of the first and of the second wall each comprising a series of corrugations projecting in the direction of the interior of the tank and developing in a direction perpendicular to the edge, each corrugation of the first wall and the second wall being aligned with a corrugated connection of the sealing angle. Such corrugated connections are simple to make and to fit on a corrugation of the first wall and on a corrugation of the second wall, so as to ensure the continuity of the seal between the sealing angle and the sealing membranes while being able to deform with the waterproofing membranes.

According to certain embodiments, the sealing angle comprises a plurality of cross sections, two adjacent cross sections being sealingly connected to one another by means of a corrugated connection projecting in the direction of the inside the tank, the sealing membrane of the first and of the second wall each comprising a series of undulations projecting in the direction of the outside of the tank and developing in a direction perpendicular to the edge, each undulation of the first wall and the second wall being aligned with a corrugated connection of the sealing angle.

According to certain embodiments, a corrugated connector comprises a central part, a first bent end, and a second bent end, the first bent end fitting, on the one hand, on a corrugation of the sealing membrane of the first wall, and on the other hand, on the central part, the second bent end fitting, on the one hand, on a corrugation of the sealing membrane of the second wall, and on the other hand, on the central part. The fact that the corrugated couplings are in three parts simplifies the connection with the waterproofing membranes and makes it possible to rectify misalignments between the corrugations.

According to certain embodiments, the first anchoring wing extends parallel to the load-bearing wall of the first wall, the second anchoring wing extending parallel to the load-bearing wall of the second wall.

According to certain embodiments, at the level of the edge, the bearing wall of the first and the bearing wall of the second wall together form a projecting angle on the inside of the tank, the first anchoring wing extending in the extension of the load-bearing wall of the first wall, and the second anchoring wing extending in the extension of the load-bearing wall of the second wall.

According to certain embodiments, at the level of the edge, the bearing wall of the first and the bearing wall of the second wall together form a re-entrant angle on the interior side of the vessel, the first anchoring wing extending parallel to distance from the load-bearing wall of the first wall, the second anchoring wing extending parallel away from the load-bearing wall of the second wall.

According to certain embodiments, the thermally insulating barrier of the first wall and/or of the second wall comprises a plurality of heat-insulating elements, each heat-insulating element comprising a cover panel facing the interior of the vessel, the internal face of the heat-insulating element bordering the ridge comprising a step facing the sealing membrane, a connecting plate being housed in the step and flush with the level of the inner face of the heat-insulating element and of the face interior of the flat leg of the angle iron to which the waterproofing membrane is attached to form a continuous planar support surface for the waterproofing membrane.

According to certain embodiments, slots are formed in the first anchoring wing and/or in the second anchoring wing, the slots being arranged at the level of the corrugated connections. These slots make it possible to limit, at least in part, the mechanical stresses undergone by the welds between the corrugated connections and the cross sections of the sealing angle.

According to certain embodiments, the thermal insulation barrier fixed to the load-bearing wall is a secondary thermal insulation barrier, the sealing membrane fixed to the secondary thermal insulation barrier being a secondary sealing membrane, the angle sealing connected in a leaktight manner to the secondary sealing membrane of the first wall and to the secondary sealing membrane of the second wall being a secondary sealing angle, the first and the second wall further comprising, in the thickness direction of the tank, from outside to inside, over the secondary thermal insulation barrier and the secondary sealing membrane, a primary thermal insulation barrier and a primary sealing membrane intended to be in contact with the liquid contained in the tank, the corner structure further comprising a primary sealing angle connected in leaktight manner to the primary sealing membrane area of the first wall and to the primary waterproofing membrane of the second wall.

According to certain embodiments, the primary sealing angle is fixed to the secondary sealing angle via one or more spacers.

According to certain embodiments, an outer face of the primary sealing angle carries primary studs, each spacer comprising at least one orifice through which a primary stud passes, the spacer being held against the outer face of the primary sealing angle by a primary nut mounted on the primary stud, an inner face of the secondary sealing angle carrying secondary studs, a spacer having fixing lugs, a stud secondary being positioned between the fixing lugs of two adjacent spacers, a support plate having an orifice being mounted on the secondary stud, the two adjacent spacers being held in abutment by said support plate against an inner face of the angle iron Secondary sealing by a secondary nut mounted on the secondary stud.

According to certain embodiments, the secondary sealing membranes are composite membranes, the secondary sealing angle comprising a plurality of cross sections, two adjacent cross sections being connected in a leaktight manner to one another via of a composite sealing strip.

According to certain embodiments, the composite sealing strips are glued between the angles.

Such a tank can be part of an onshore storage installation, for example to store liquefied gas or be installed in a floating, coastal or deep-water structure, in particular an LNG carrier, an LPG transport ship, a floating unit storage and regasification unit (FSRU), a floating production and remote storage unit (FPSO) and others.

According to one embodiment, a vessel for the transport of a cold liquid product comprises a hull and an aforementioned tank placed in the hull.

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

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

Brief description of figures

• La figure 1 est une vue en perspective d'une cuve selon un mode de réalisation de l'invention.
• La figure 2 est une vue en perspective d'une portion de la cuve de la figure 1 illustrant le dôme gaz vu de l'intérieur de la cuve.
• Les figures 3 à 6 sont des vues en perspective d'une structure d'angle saillante selon un mode de réalisation de l'invention au cours de différentes étapes de sa construction.
• La figure 7 est une vue en coupe de la structure d'angle de la figure 6.
• Les figures 8 à 11 sont des vues en coupe d'une structure d'angle pour une cuve comportant deux membranes d'étanchéité intercalées avec deux barrières d'isolation thermique, selon différentes variantes de réalisation de l'invention. En particulier, les figures 9 et 10 illustrent un mode de réalisation particulier d'ancrage de la cornière d'étanchéité primaire sur la cornière d'étanchéité secondaire, la figure 10 étant une vue en coupe dans le plan de deux goujons fixés à la cornière d'étanchéité primaire tandis que la figure 9 est une vue en coupe dans le plan de deux goujons fixés à la cornière d'étanchéité secondaire. Les figures 10b à 10f sont des vues en coupe dans un plan perpendiculaire à la cornière d'étanchéité primaire et parallèle à l'arête et illustrent les différentes étapes d'un mode de réalisation particulier du montage de la cornière d'étanchéité primaire sur la cornière d'étanchéité secondaire. La figure 11 illustre un mode de réalisation alternative d'ancrage de la cornière d'étanchéité primaire sur la cornière d'étanchéité secondaire.
• La figure 12 est une vue de profil d'une cornière d'étanchéité.
• La figure 13 est une vue en coupe d'une structure d'angle rentrante selon un autre mode de réalisation de l'invention.
• La figure 14 est une vue écorchée d'un navire méthanier ou propanier comportant une cuve selon un mode de réalisation de l'invention.
• La figure 15 est une vue en perspective partielle d'une structure d'angle saillante selon certains modes de réalisation de l'invention.

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

• The figure 1 is a perspective view of a tank according to one embodiment of the invention.
• The figure 2 is a perspective view of a portion of the tank of the figure 1 illustrating the gas dome seen from inside the tank.
• The figures 3 to 6 are perspective views of a protruding corner structure according to one embodiment of the invention during various stages of its construction.
• The figure 7 is a sectional view of the corner structure of the figure 6 .
• The figures 8 to 11 are cross-sectional views of a corner structure for a tank comprising two sealing membranes interposed with two thermal insulation barriers, according to different variant embodiments of the invention. In particular, the figures 9 and 10 illustrate a particular embodiment of anchoring the sealing angle primary on the secondary sealing angle, the figure 10 being a cross-sectional view in the plane of two studs fixed to the primary sealing angle while the figure 9 is a cross-sectional view in plan of two studs attached to the secondary sealing angle. The figures 10b to 10f are cross-sectional views in a plane perpendicular to the primary sealing angle and parallel to the edge and illustrate the various stages of a particular embodiment of the assembly of the primary sealing angle on the secondary sealing angle . The figure 11 illustrates an alternative embodiment of anchoring the primary sealing angle to the secondary sealing angle.
• The figure 12 is a side view of a sealing angle.
• The figure 13 is a sectional view of a re-entrant corner structure according to another embodiment of the invention.
• The figure 14 is a cutaway view of an LNG or propane tanker comprising a tank according to one embodiment of the invention.
• The figure 15 is a partial perspective view of a protruding corner structure according to some embodiments of the invention.

Detailed description of embodiments

The figures are described below in the context of a load-bearing structure constituted by the internal walls of a double hull of a ship for the transport of liquefied gas. Such a carrier structure may in particular have a polyhedral geometry, for example of prismatic shape. The figure 1 illustrates such a load-bearing structure in which walls longitudinal, comprising an upper wall 104, a lower wall 105 and side walls 106, 107, 108, 109, 110, 111, of the supporting structure extend parallel to the longitudinal direction of the ship and form a polygonal section in a plane perpendicular to the longitudinal direction of the ship. The general structure of a ship equipped with such polyhedral tanks is for example described with regard to the figure 1 of the document FR3008765 .

The longitudinal walls 104, 105, 106, 107, 108, 109, 110, 111 are interrupted in the longitudinal direction of the ship by transverse bearing walls 101, 103 which are perpendicular to the longitudinal direction of the ship. The longitudinal walls 104, 105, 106, 107, 108, 109, 110, 111 and the transverse walls 101, 103 meet at reentrant edges.

Each wall of the support structure carries a respective tank wall. On the figures 2 to 7 , each of the vessel walls is composed of a thermally insulating barrier carrying a sealing membrane in contact with a fluid stored in the vessel such as liquefied petroleum gas comprising butane, propane, propene or other and having an equilibrium temperature comprised for example between -50°C and 0°C.

The upper wall 104 comprises a space, for example of rectangular parallelepipedal shape, projecting upwards, called liquid dome 112.

As illustrated in more detail on the figure 2 , the liquid dome 112 is defined by two transverse walls, front 113 and rear 114, and by two side walls 115, 116 which extend vertically and project from the upper wall 104 upwards. The liquid dome 112 further comprises a horizontal cover, not shown in the figure 2 , which is intended to cover the opening formed between the front 113, rear 114 and side walls 115, 116 of the liquid dome 112. The horizontal cover is crossed by a series of pipes intended to load or unload the liquids and gases mentioned above. The upper longitudinal wall 104 and the walls of the liquid dome 112 meet at projecting edges 100. The front 113 and side walls 115, 116 of the liquid dome 112 meet at reentrant edges 201.

The picture 3 is a view from inside the vessel of a vessel corner at a projecting edge 100 between a first bearing wall 5 and a second bearing wall 25 carrying respectively a first vessel wall 1 and a second wall tank 2. The first bearing wall 5 and the second bearing wall 25 form an angle α between them. The first tank wall 1 and the second tank wall 2 meet at a corner structure 10 of the tank.

In particular, as will be described in connection with the figures 3 to 6 , the corner structure 10 can be a protruding corner structure (the angle α towards the inside of the tank between the two supporting walls is between 180° and 360°, so that the edge is protruding seen from inside the tank), which is for example the case for an edge between the upper longitudinal wall 104, and one of the front 113, rear 114 and side 115, 116 walls of the liquid dome 112. figures 3 to 6 illustrate the particular case of an angle α of 270°.

As will be described in connection with the figure 13 , the corner structure 10 can be a re-entrant corner structure (the angle α is between 0° and 180°, so that the edge is re-entrant seen from inside the vessel), which is for example the case for an edge between the longitudinal walls 104, 105, 106, 107, 108, 109, 110, 111 and the transverse walls 101, 103. The figure 13 illustrates the particular case of an angle α of 90°.

As illustrated by the figure 6 , the first vessel wall 1 comprises, in a direction of thickness, a bearing wall 5, a thermal insulation barrier 6 fixed to the bearing wall 5, a sealing membrane 27 parallel to the bearing wall 5. The second vessel wall 2 comprises, in a direction of thickness, a bearing wall 25, an insulation barrier 26 fixed to the load-bearing wall 25, a sealing membrane 7 parallel to the load-bearing wall 25.

As illustrated by the picture 3 , the thermal insulation barrier 6 of the first vessel wall 1 consists of a plurality of heat-insulating elements 61 anchored on the first load-bearing wall 5. These heat-insulating elements 61 together form a flat surface on which the membrane is anchored. sealing 27. Similarly, the thermal insulation barrier 26 of the second wall of the vessel 2 consists of a plurality of heat-insulating elements 61 anchored on the second bearing wall 25. These heat-insulating elements 61 together form a flat surface on which is anchored the sealing membrane 7. The heat-insulating elements 61 are anchored to the supporting structure by any suitable means.

In one embodiment, the heat-insulating elements 61 are made in the form of boxes anchored to the load-bearing wall by studs, as described in the publication WO-A-2017064413 .

As illustrated by the figure 6 , the sealing membrane 7, 27 consists of a plurality of metal plates juxtaposed to each other with overlap. These metal plates are preferably rectangular in shape. The metal plates are welded together to ensure the tightness of the waterproofing membrane. The metal plates are for example made of stainless steel, an iron-based alloy with a high nickel or manganese content 0.5 to 1.5 mm thick.

In order to allow the deformation of the sealing membrane in response to the various stresses undergone by the tank, in particular in response to the thermal contraction resulting from the loading of liquefied gas in the tank, the metal plates comprise a plurality of undulations 71, 72 facing the inside of the tank. More particularly, the sealing membrane 7 comprises a first series of undulations 71 and a second series of undulations 72 forming a regular rectangular pattern. The first one series of undulations 71 is perpendicular to edge 100 and the second series of undulations 72 is parallel to edge 100. Preferably, the undulations 71, 72 develop parallel to the edges of the rectangular metal plates. The distance between two successive undulations 71, 72 of a series of undulations is for example of the order of 300 mm to 800 mm and ideally 600 mm.

As illustrated by the picture 3 , the corner structure 10 comprises a first anchoring wing 11 extending from and in the extension of the load-bearing wall 5 of the first vessel wall 1, and a second anchoring wing 211 extending to from and in the extension of the bearing wall 25 of the second vessel wall 2. The first anchoring wing 11 may not extend in the extension of the bearing wall 5 of the first vessel wall 1 as long as it extends in a direction that is not parallel to the load-bearing wall 25 of the second wall 2. In other words, the first anchoring wing 11 extends from the load-bearing wall 25 in a direction that is not parallel to said wall carrier 25. As illustrated in the figures, the first anchoring wing 11 extends, preferably, perpendicular to the carrier wall 25. On the figures 1 to 10 and on the figure 11 , the first anchoring wing 11 extends from the intersection of the load-bearing walls 5 and 25 and parallel to the load-bearing wall 5. The row of heat-insulating elements 61 of the thermally insulating barrier 6 bordering the edge 100 are arranged so as to provide a space between the row of heat-insulating elements 61 bordering the edge 100 and the second anchoring wing 211.

Similarly, the second anchoring wing 211 may not extend in the extension of the bearing wall 25 of the second vessel wall 2 as long as it extends in a direction that is not parallel to the bearing wall 5 of the first wall 1. In other words, the second anchoring wing 211 extends from the load-bearing wall 5 in a direction not parallel to said load-bearing wall 5. As illustrated in the figures, the second anchoring wing 211 extends, preferably, perpendicular to the bearing wall 5. On the figures 1 to 10 and on the figure 11 , the second anchoring wing 211 extends from the intersection of the load-bearing walls 5 and 25, and parallel to the load-bearing wall 25. The row of heat-insulating elements 61 of the thermally insulating barrier 26 bordering the edge 100 are arranged so as to provide a space between the row of heat-insulating elements 61 bordering the edge 100 and the first anchoring wing 11.

As illustrated by the figure 4 , the corner structure 1 includes a first connecting piece 12 and a second connecting piece 212. The first connecting piece 12 includes a first planar branch 122 fixed to the anchoring wing 11 and extending in the extension of the anchoring wing 11, and a second planar branch 121 extending parallel to the load-bearing wall 25 in the space provided between the first anchoring wing 11 and the row of heat-insulating elements 61 of the barrier thermal insulation 26 bordering the edge 100. The first connecting piece 12 may in particular be composed of a plurality of successive sections 125. Similarly, the second connecting piece 212 comprises a first planar branch 2122 fixed to the anchoring wing 211 and extending in the extension of the anchoring wing 211, and a second planar branch 2121 extending parallel to the load-bearing wall 5 in the space provided between the first anchoring wing 211 and the row of heat-insulating elements 61 of the thermal insulation barrier 6 bordering the edge 100. The second connecting piece 212 can in particular be composed of a plurality of successive sections 215. The connecting part 12, 212 is welded indifferently on the face of the anchoring wing 11, 211 facing the insulating blocks 61 of the wall of the vessel 1 or 2. As illustrated by the figure 7 , the connecting pieces 12 and 212 may comprise a reinforcement between their two planar branches to increase their rigidity.

The spaces provided between the first anchoring wing 11, the row of heat-insulating elements 61 of the thermal insulation barrier 26 bordering the edge 100, the second planar branch 121 and the bearing wall 25 are advantageously filled with heat-insulating lining such than glass wool or polyurethane foam. The spaces between the second anchoring wing 211, the row of heat-insulating elements 61 of the thermal insulation barrier 6 bordering the edge 100, the second planar branch 211 and the bearing wall 5 are advantageously filled with heat-insulating lining such than glass wool or polyurethane foam.

As illustrated by the figure 5 , the corner structure 10 further comprises a sealing angle 13 fixed, on the one hand, to the first anchoring wing 11 via the first connecting piece 12, and on the other hand, to the second anchoring wing 211 via the second connecting piece 212.

The sealing angle 13 is a plate, for example metallic, having a thickness greater than that of the sealing membrane 7, 27. The sealing angle 13 has for example a thickness of between 3 mm and 10 mm. confers sufficient rigidity to support itself, which is not necessarily the case with the sealing membranes 7, 27.

The sealing angle 13 comprises a first planar branch 131 extending in the plane of the sealing membrane 7 of the second vessel wall 2, and a second planar branch 132 extending in the plane of the membrane of sealing 27 of the first vessel wall 1. The first flat branch 131 is fixed to the first connecting piece 12 (more precisely welded to the second flat branch 121 of the first connecting piece 12), and the second flat branch 132 is welded to the second connecting part 212 (more precisely welded to the second planar branch 2121 of the second connecting part 212). As illustrated on the figure 12 , the sealing angle 13 may include a reinforcement 134 on its outer face.

Such a corner structure makes it possible to adjust the position of the sealing angle 13 by adapting on the one hand the position of the anchoring of the first planar branches 122, 2122 of the connecting pieces 12, 212 on the wings of anchoring 11, 211 and on the other hand the position of the anchoring of the flat branches 131, 132 of the sealing angle 13 on the second flat branches 121, 2121 of the connecting pieces 12, 212. This adjustment of the position of the sealing angle 13 makes it possible to easily adapt the corner structure to the thickness of the heat-insulating elements 61 of the insulation barriers 6, 26.

The first branch 131 of the sealing angle forms a flat support for the sealing membrane 7 of the second vessel wall 2, and the second branch 132 of the sealing angle forms a flat support for the sealing membrane 27 of the first tank wall 1.

As illustrated by the figure 6 , the sealing membrane 7 of the second wall rests on the first branch 131 of the sealing angle 13. The sealing membrane 27 of the first wall rests on the second branch 132 of the sealing angle 13. For ensure continuity between the sealing membrane 7 of the second wall and the sealing membrane 27 of the first wall at the level of the corner structure 10, the sealing angle 13 is connected in a leaktight manner to the sealing membrane sealing 7 of the second wall and the sealing membrane 27 of the first wall. For example, the sealing membrane 7 of the second wall can be welded to the first branch 131 of the sealing angle 13 on which it rests, and the sealing membrane 27 of the first wall welded to the second branch 132 of the sealing angle on which it rests.

As illustrated by the figure 5 , the sealing angle 13 may comprise a plurality of cross sections 135. The cross sections 135 of the sealing angle are for example fixed in overlap on two adjacent sections 125 of the first connecting piece 12 and on two adjacent sections 215 of the second connecting piece 212.

As illustrated by the figure 6 , two adjacent cross-sections 135 can be sealingly connected to each other via a corrugated connection 15. Each corrugation of the first series of corrugations 71 of the first wall and of the second wall is aligned with a corrugated connection 15 of the sealing angle. The corrugated coupling 15 fits over a corrugation 71 of the sealing membrane 27 of the first wall and over a corrugation 71 of the sealing membrane 7 of the second wall. The corrugated fittings 15 allow the sealing angle 13 to deform with the sealing membranes 7, 27.

As best seen on the figure 7 , the corrugated connector 15 comprises a central part 153, a first bent end 151, and a second bent end 152. The central part 153 comprises two lateral legs, one of the lateral legs being welded to the central part 133 of a section 155 of the sealing angle, and the other lateral tab being welded to the central part of an adjacent section 155 of the sealing angle. The first bent end 151 fits on the one hand on a corrugation 71 of the first wall, and on the other hand on the central part 153. The first bent end 151 comprises two lateral tabs, one of the lateral tabs being welded on a section 155 of the sealing angle, and the other lateral tab being welded to the adjacent section 155 of the sealing angle, covering the area of overlap between the sealing angle 13 and the sealing membrane 7 with the second tank wall 2. Similarly, the second bent end 152 has two side tabs, one of the side tabs being welded to a section 155 of the sealing angle, and the other side tab being welded to the adjacent section 155 of the sealing angle, covering the area of overlap between the angle seal 13 and the sealing membrane 27 of the first tank wall 1.

Such corrugated connections 15 are simple to make and to fit on a corrugation 71 of the first wall and on a corrugation 71 of the second wall, so as to ensure the continuity of the seal between the sealing angle 13 and the membranes sealing 7, 27, while being able to deform with the sealing membranes 7, 27. The fact that the corrugated connections 15 are in three parts simplifies the connection with the sealing membranes 7, 27 and makes it possible to rectify misalignments between corrugations 71.

As illustrated by the figure 15 , slots 119 are optionally provided in the first anchoring wing 11. Similarly, slots 2119 are optionally provided in the second anchoring wing 211. The slots 119 and/or 2119 can in particular extend from the end of the anchoring wing 11, 211 in a direction perpendicular to the edge 100, and, in particular, over a distance equal to between ½ and 2/3 of the dimension of the anchoring wing 11 , 211 in that direction. The slots 119 and/or 2119 can in particular be placed at the level of the corrugated connectors 15, that is to say typically every 600mm. These slots 119, 2119 make it possible to release the mechanical stresses undergone by the welds between the corrugated fittings 15 and the cross sections 135 of the sealing angle 13.

As illustrated on the figure 5 , each heat-insulating element 61 comprises a cover panel facing the inside of the tank. By convention, the adjective "interior" applied to an element of the tank designates the part of this element oriented towards the inside of the tank and the adjective "exterior" designates the part of this element oriented towards the outside of the tank. vessel, regardless of the orientation of the vessel wall with respect to the earth's gravity field. On the side of the heat insulating elements 61 immediately adjacent to the corner structure 10, the inner face of the cover panel has a recess 62 vis-à-vis the connecting piece 12, 212. As illustrated in the figure 6 , a connecting plate 63 is housed in the recess 62 and is flush with the inner face of the heat-insulating element 61 and the inner face of the flat leg 132 of the sealing angle on which the membrane is fixed. sealing 27 in order to form a continuous planar support surface for the sealing membrane 27. Furthermore, the connecting plate 63 makes it possible to make up for construction clearances which may appear during the construction of the tank. The connecting plate 63 may also have a recess on its outer face, the first branch 2122 of the connecting piece 212 on which the flat branch 132 of the sealing angle is fixed being housed in the recess of the connecting plate. connection 63. The connection plate 63 is thus supported both on the inner face of the heat-insulating element 61 and on the inner face of the first branch 2122 of the connecting piece 212. The connecting plate 63 is described in relative to the first tank wall 1, but it is understood that a similar connecting plate can be provided on the second tank wall 2.

The technique described above for making a tank with a single sealing membrane can be used in different types of tanks, for example to form a double membrane tank for liquefied natural gas (LNG) in an onshore installation or in a structure. floating like an LNG carrier or other. In this context, it can be considered that the waterproofing membrane illustrated in the previous figures is a secondary waterproofing membrane, and that a primary thermal insulation barrier as well as a primary waterproofing membrane must still be added on this secondary waterproofing membrane. In this way, this technique can also be applied to tanks having a plurality of thermally insulating barriers and superimposed sealed membranes.

The figure 8 represents two walls of the tank at the level of an edge 100 according to a variant embodiment in which the first wall of the tank 1 comprises, in the thickness direction of the tank, from the outside inwards, a barrier of secondary thermal insulation 6, which corresponds to the thermal insulation barrier 6 described in relation to the preceding figures, a secondary sealing membrane 27, which corresponds to the sealing membrane 27 described in relation to the preceding figures, a primary thermal insulation barrier 6 and a primary sealing membrane 9 intended to be in contact with the liquid contained in the tank. Likewise, the second vessel wall 2 comprises, in the thickness direction of the vessel, from the outside inwards, a secondary thermal insulation barrier 26, which corresponds to the thermal insulation barrier 26 described in relation to the preceding figures, a secondary sealing membrane 7, which corresponds to the sealing membrane 7 described in relation to the preceding figures, a primary thermal insulation barrier 26 and a primary sealing membrane 29 intended to be in contact with the liquid contained in the tank.

The primary thermal insulation barrier 6, 26 and the primary sealing membrane 29, 9 may be similar to the secondary thermal insulation barrier 6, 26 and the secondary sealing membrane 27, 7 will not be described further. in detail.

In a version not shown, the primary sealing membranes 9, 29 are different from the secondary sealing membranes 7, 27 for example, the corrugations of the secondary sealing membrane 7, 27 can be turned towards the outside of the tank wall.

In another version not shown, the primary sealing membranes 9,29 and the secondary sealing membrane 7, 27 have corrugations facing outward from the vessel wall

Another version not shown, the secondary sealing membranes 7, 27 are composite sealing barriers. A composite connecting strip is glued on one side to the secondary sealing angle 13 on the second flat branch 132 and on the other to the composite sealing barrier present on top of the insulating blocks 61. Alternatively, the strip composite connecting piece can be glued on one side to the second connecting piece 212 and on the other to the composite sealing barrier present on top of the insulating blocks 61. In order to ensure the sealing of the secondary barrier, composite sealing strips are glued between the angles 135. The composite sealing barrier may in particular be made of a composite material comprising three layers: the two outer layers are fabrics of glass fibers and the intermediate layer is a thin metal foil, for example aluminum foil with a thickness of about 0.1 mm. This metal sheet constitutes the secondary sealing barrier and it is glued on the insulating blocks 61 of the thermal insulation barrier 6, 26. The composite connecting strips and the composite sealing strips can in particular be glued with polyurethane or epoxy glue.

A primary sealing angle 913 is fixed to the secondary sealing angle 13, which corresponds to the sealing angle 13 described in relation to the figures 3 to 6 . The primary sealing angle 913 will not be described in detail because it is similar to the sealing angle 13 described in relation to the figures 3 to 6 . The primary sealing angle 913 is connected in a leaktight manner to the primary sealing membrane 29 of the first tank wall 1 and to the primary sealing membrane 9 of the second tank wall 2.

Several possibilities exist for fixing the primary sealing angle 913 to the secondary sealing angle 13. As illustrated by the figures 9 to 11 , the primary sealing angle 913 can in particular be fixed to the secondary sealing angle 13 by anchoring members 30.

As illustrated by the figures 9 and 10 , the anchoring members 30 may comprise one or more spacers 32 fixed to the primary sealing angle 913 before the assembly formed by the spacers 32 and the primary sealing angle 913 is fixed to the sealing angle secondary 13.

As illustrated on the figure 9 , the inner face of the secondary sealing angle 13 can carry secondary studs 31 fixed by welding and/or screwing. The figure 9 is a sectional view in the plane of two studs 31 fixed to the secondary sealing angle 13. In particular, each cross section 135 of the secondary sealing angle 13 can comprise two studs 31. Each stud 31 develops perpendicular to the central part 133 of the secondary sealing angle 13 towards the inside of the tank.

As illustrated by the figure 10 , the outer face of the primary sealing angle 913 can carry primary studs 35 fixed by welding and/or screwing. The figure 10 is a sectional view in the plane of two studs 35 fixed to the primary sealing angle 913. In particular, each cross section of the primary sealing angle 913 can comprise two studs 35. Each stud 35 develops perpendicular to the central part of the primary sealing angle towards the outside of the tank.

An embodiment of the assembly of the primary sealing angle 913 on the secondary sealing angle 13 is now described in relation to the figures 10b to 10f .

As illustrated by the figure 10b , each cross section 9135 of the primary sealing angle 913 comprises one or more primary studs 35. One end of the studs opposite the sealing angle primary 913 has a thread. Each spacer 32 has one or more holes 322 extending from its inside face. In particular, each spacer 32 may include two orifices 322 extending from its inner face.

As illustrated by the figure 10c , each spacer 32 is mounted on one or more studs 35 so that each orifice 322 of the spacer is crossed by a stud 35.

As illustrated by the figure 10d , a nut 351 is mounted on the threaded end of each stud 35. The inner face of the spacer 32 is thus held in abutment by said nut 351 against the outer face of the primary sealing angle 913. A chimney 321 formed in the spacer 32 to the right of the hole through which the stud 31 allows the screwing of the nut 351 on the stud and is filled with an insulator after the screwing of the nut 351.

As illustrated by the figures 10e and 10f , the outer face of the spacer 32 (that is to say the face of the spacer 32 opposite the primary sealing angle 913) is then fixed by any means, for example gluing, riveting, or screwing, on the inside face of the secondary sealing angle 13.

As illustrated by the figure 10e , each cross section 135 of the secondary sealing angle 13 comprises one or more studs 31. One end of the studs 31 opposite the secondary sealing angle 13 comprises a thread. A spacer 32 has fixing lugs 323 extending in alignment with the outer face of the spacer. A stud 31 is positioned between the fixing lugs 323 of two adjacent struts 32.

As illustrated by the figure 10f , a support plate 33 having an orifice is mounted on the pin 31. A nut 311 is mounted on the threaded end of the pin 31. The two adjacent spacers 32 are thus maintained supported by said bearing plate 33 against an inner face of the secondary sealing angle 13.

Alternatively, according to a variant not shown, the studs 31 extending from the secondary sealing angle 31 pass through holes in the primary sealing angle 913, the nut being mounted on the inner face of the primary sealing 913, the primary sealing angle 913 thus being held in abutment by said nut against the inner face of the spacer 32, the spacer 32 itself being held in abutment by said nut against an inner face of the angle secondary seal 13.

As illustrated on the figure 11 , the primary sealing angle 913 may alternatively comprise two planar branches forming between them an angle equal to the angle α between the bearing walls of the edge, that is to say 90° in the case illustrated by the figure 11 . The primary sealing angle 913 is then fixed on a support 37 forming an angle equal to the angle a. Such a support 37 can for example be a beam of isosceles triangular section, the base of the triangle being fixed on the outer face of the spacer 32.

A similar angle structure can also be used in a re-entrant edge 201 of the tank. The figure 13 represents a vessel edge between two vessel walls forming an interior angle α of the order of 90°. Such a tank edge comprises a corner structure 510 similar to the corner structure 10 as described with regard to the figures 2 to 6 , with the difference that the first anchoring wing 11 extends parallel at a distance from the load-bearing wall 5 of the first vessel wall 1, and that the second anchoring wing 211 extends parallel at a distance from the load-bearing wall 25 of the second vessel wall 2.

With reference to the figure 14 , a cutaway view of an LNG or propane tanker 1070 shows a sealed and insulated tank 1000 of generally prismatic shape mounted in the double hull 1072 of the ship. The wall of the tank comprises at least one tight barrier intended to be in contact with the liquefied gas contained in the tank and at least one insulating barrier arranged between the tight barrier and the double shell 1072.

In a manner known per se, loading/unloading pipes 1073 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 liquefied gas from or to the tank 1000.

The figure 14 represents an example of a maritime terminal comprising a loading and unloading station 1075, an underwater pipe 1076 and an installation on land 1077. The loading and unloading station 1075 is a fixed off-shore installation comprising a mobile arm 1074 and a tower 1078 which supports the mobile arm 1074. The mobile arm 1074 carries a bundle of insulated flexible pipes 1079 which can be connected to the loading/unloading pipes 1073. The orientable mobile arm 1074 adapts to all the templates of LNG carriers. A connecting pipe, not shown, extends inside the tower 1078. The loading and unloading station 1075 allows the loading and unloading of the ship 1070 from or to the shore installation 1077. This comprises liquefied gas storage tanks 1080 and connection pipes 1081 connected by the underwater pipe 1076 to the loading or unloading station 1075. The underwater pipe 1076 allows the transfer of the liquefied gas between the loading or unloading station 1075 and the installation on land 1077 over a great distance, for example 5 km, which makes it possible to keep the ship 1070 at a great distance from the coast during loading and unloading operations.

To generate the pressure necessary for the transfer of the liquefied gas, pumps on board ship 1070 and/or pumps equipping the shore installation 1077 and/or pumps equipping the loading and unloading station 1075.

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

The scope of the invention is that as defined by the claims.

The use of the verb "to comprise", "to understand" or "to include" and of its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim. The use of the indefinite article “un” or “une” for an element or a step does not exclude, unless otherwise stated, the presence of a plurality of such elements or steps.

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

Claims (15)

1. Sealed and thermally insulating tank (1000) for storing a fluid comprising a first wall (1) and a second wall (2), the first (1) and the second (2) wall each comprising, in a thickness direction, a bearing wall (5, 25), a thermal insulation barrier (6, 26) fixed to the bearing wall (5, 25), a sealing membrane (7, 27) parallel to the bearing wall (5, 25) and fixed to the thermal insulation barrier (6, 26), the sealed and thermally insulating tank (1000) comprising, at an edge corner (100, 201) between the bearing wall (5) of the first wall (1) and the bearing wall (25) of the second wall (2), a corner structure (10), the corner structure comprising:

   - a first anchoring flange (11) fixed to the bearing wall (5) of the second wall (1),

   - a second anchoring flange (211) fixed to the bearing wall (25) of the first wall (2),

   - a sealing corner piece (13) fixed, on the one hand, to the first anchoring flange (11) via a first connecting piece (12) and, on the other hand, to the second anchoring flange (211) via a second connecting piece (212), the sealing corner piece (13) being connected in a sealed manner to the sealing membrane (27) of the first wall and to the sealing membrane (7) of the second wall,

   the sealing corner piece (13) comprising a first flat branch (131) extending in the plane of the sealing membrane (7) of the second wall (2), and a second flat branch (132) extending in the plane of the sealing membrane (27) of the first wall (1),

   the first connecting piece (12) comprising a first flat branch (122) parallel to the first anchoring flange (11),

   the second connecting piece (212) comprising a first flat branch (2122) parallel to the second anchoring flange (211),

   the first flat branch (122) of the first connecting piece (12) being welded to the first anchoring flange (11),

   the first flat branch (2122) of the second connecting piece (212) being welded to the second anchoring flange (211),

   characterised in that the first connecting piece (12) comprise a second flat branch (121) parallel to the sealing membrane (7) of the second wall (2), and the second connecting piece (212) comprise a second flat branch (2121) parallel to the sealing membrane (27) of the first wall (1),

   the first flat branch (131) of the sealing corner piece (13) being welded to the second flat branch (121) of the first connecting piece (12), and the second flat branch (132) of the sealing corner piece (13) being welded to the second flat branch (2121) of the second connecting piece (212),

   the sealing membrane (27) of the first wall (1) being welded to the second flat flat branch (132) of the sealing corner piece (13),

   and the sealing membrane (7) of the second wall (2) being welded to the first flat branch (131) of the sealing corner piece (13).
2. Tank (1000) according to the preceding claim, in which the sealing corner piece (13) comprises a plurality of cross sections (135), two adjacent cross sections (135) being connected to one another in a sealed manner via a corrugated coupling (15) projecting towards the inside of the tank, the sealing membrane (27, 7) of the first and of the second wall each comprising a series of corrugations (71, 271) projecting towards the inside of the tank and developing in a direction perpendicular to the edge corner (100, 201), each corrugation (71) of the first wall and of the second wall being aligned with a corrugated coupling (15) of the sealing corner piece.
3. Tank (1000) according to Claim 1, in which the sealing corner piece (13) comprises a plurality of cross sections (135), two adjacent cross sections (135) being connected to one another in a sealed manner via a corrugated coupling (15) projecting towards the inside of the tank, the sealing membrane (27, 7) of the first and of the second wall each comprising a series of corrugations (71, 271) projecting towards the outside of the tank and developing in a direction perpendicular to the edge corner (100, 201), each corrugation (71) of the first wall and of the second wall being aligned with a corrugated coupling (15) of the sealing corner piece.
4. Tank (1000) according to one of Claims 2 to 3, in which a corrugated coupling (15) comprises a central part (153), a first bent end (151) and a second bent end (152), the first bent end (151) fitting, on the one hand, over a corrugation (71) of the sealing membrane (27) of the first wall and, on the other hand, over the central part (153), the second bent end (152) fitting, on the one hand, over a corrugation (71) of the sealing membrane (7) of the second wall and, on the other hand, over the central part (153).
5. Tank (1000) according to one of the preceding claims, in which the first anchoring flange (11) extends parallel to the bearing wall (5) of the first wall (1), the second anchoring flange (211) extending parallel to the bearing wall (25) of the second wall (2).
6. Tank (1000) according to one of the preceding claims, in which, at the edge corner (100), the bearing wall (5) of the first wall and the bearing wall (25) of the second wall together form a salient angle (α) on the inside of the tank, the first anchoring flange (11) extending in the continuation of the bearing wall (5) of the first wall (1), and the second anchoring flange (211) extending in the continuation of the bearing wall (25) of the second wall (2).
7. Tank (1000) according to one of Claims 1 to 5, in which, at the edge corner (100), the bearing wall (5) of the first wall and the bearing wall (25) of the second wall together form a re-entrant angle (α) on the inside of the tank, the first anchoring flange (11) extending parallel to and some distance away from the bearing wall (5) of the first wall (1), the second anchoring flange (211) extending parallel to and some distance away from the bearing wall (25) of the second wall (2).
8. Tank (1000) according to one of the preceding claims, in which the thermally insulating barrier (6, 26) of the first wall (1) and/or of the second wall (2) comprises a plurality of lagging elements (61), each lagging element (61) comprising a cover panel facing towards the inside of the tank, the interior face of the lagging element (61) bordering the edge corner (100) comprising a discontinuity (62) facing the sealing membrane (27), a connecting plate (63) being housed in the discontinuity (62) and lying flush with the interior face of the lagging element (61) and with the interior face of the flat branch (132) of the sealing corner piece (13) to which the sealing membrane (27) is fixed so as to form a continuous flat support surface for the sealing membrane (27).
9. Tank (1000) according to one of the preceding claims, in which the thermal insulation barrier (6, 26) fixed to the bearing wall (5, 25) is a secondary thermal insulation barrier, the sealing membrane (7, 27) fixed to the secondary thermal insulation barrier (6, 26) being a secondary sealing membrane, the sealing corner piece (13) connected in a sealed manner to the secondary sealing membrane (27) of the first wall and to the secondary sealing membrane (7) of the second wall being a secondary sealing corner piece, the first (1) and second (2) walls further comprising, in the thickness direction of the tank, from the outside towards the inside, on top of the secondary thermal insulation barrier (6, 26) and the secondary sealing membrane (7, 27), a primary thermal insulation barrier (8, 28) and a primary sealing membrane (9, 29) intended to be in contact with the liquid contained in the tank, the corner structure (10) further comprising a primary sealing corner piece (913) connected in a sealed manner to the primary sealing membrane (9) of the first wall and to the primary sealing membrane (29) of the second wall.
10. Tank (1000) according to Claim 9, in which the primary sealing corner piece (913) is fixed to the secondary sealing corner piece (13) via one or more spacers (32).
11. Tank (1000) according to Claim 10, in which an exterior face of the primary sealing corner piece (913) bears primary studs (35), each spacer (32) comprising at least one orifice through which a primary stud (35) passes, the spacer (32) being kept pressed against the exterior face of the primary sealing corner piece (913) by a primary nut mounted on the primary stud (35), an interior face of the secondary sealing corner piece (13) bearing secondary studs (31), a spacer (32) exhibiting fixing tabs (323), a secondary stud (31) being positioned between the fixing tabs (323) of two adjacent spacers (32), a support plate (33) comprising an orifice being mounted on the secondary stud (31), the two adjacent spacers (32) being kept pressed by the said support plate (33) against an interior face of the secondary sealing corner piece (13) by a secondary nut (311) mounted on the secondary stud (31).
12. Tank (1000) according to one of Claims 9 to 11, in which the secondary sealing membranes (27, 7) are composite membranes, the secondary sealing corner piece (13) comprising a plurality of cross sections (135), two adjacent cross sections (135) being connected to one another in a sealed manner via a composite sealing strip.
13. Ship (1070) for transporting a cold liquid product, the ship comprising a hull (1072) and a tank (1000) according to one of Claims 1 to 12 arranged in the hull.
14. Transfer system for a cold liquid product, the system comprising a ship (1070) according to Claim 13, insulated pipes (1073, 1079, 1076, 1081) arranged in such a way to connect the tank (1071) installed in the hull of the ship to a floating or on-shore storage facility (1077), and a pump for driving a flow of cold liquid product through the insulated pipes from or to the floating or on-shore storage facility to or from the tank of the ship.
15. Method for loading or offloading from a ship (1070) according to Claim 13, in which a cold liquid product is conveyed through insulated pipes (1073, 1079, 1076, 1081) from or to a floating or on-shore storage facility (1077) to or from the hull of the ship.

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