Sealed and thermally insulating tank with several areas

Abstract

A tank in which a tank wall comprises a secondary insulating barrier, a primary insulating barrier, a primary sealed membrane and a secondary sealed membrane, the tank wall comprising: a first area (11) in which insulating modules comprise spacers extending in a thickness direction of the tank wall between a cover panel and a bottom panel of said insulating modules, a second area (12) in which a cover panel of the insulating modules is kept at a distance from a bottom panel by a structural insulating foam, a transition area (14) interposed between the first area and the second area, said transition area having a thermal contraction coefficient and / or an elasticity modulus in the thickness direction of the tank wall between that of the first area and that of the second area.

Description

technical field

[0001] The invention relates to the field of sealed and thermally insulating membrane tanks for the storage and / or transport of fluid, such as a cryogenic fluid.

[0002] Leak-proof, thermally insulated membrane tanks are used, in particular, for storing liquefied natural gas (LNG), which is stored at atmospheric pressure at approximately -163°C. These tanks can be installed on land or on a floating structure. In the case of a floating structure, the tank can be used for transporting liquefied natural gas or for receiving liquefied natural gas to serve as fuel for the propulsion of the floating structure. Technological background

[0003] In the prior art, leak-proof and thermally insulated tanks for the storage of liquefied natural gas are known, integrated into a load-bearing structure, such as the double hull of a ship intended for the transport of liquefied natural gas. Generally, such tanks comprise a multi-layered structure having successively, in the thickness direction from the outside to the inside of the tank, a secondary thermal insulation barrier attached to the load-bearing structure, a secondary sealing membrane resting against the secondary thermal insulation barrier, a primary thermal insulation barrier resting against the secondary sealing membrane, and a primary sealing membrane resting against the primary thermal insulation barrier and intended to be in contact with the liquefied natural gas contained in the tank.

[0004] Document FR2867831 describes a watertight and thermally insulated tank comprising a thermal insulation barrier formed by juxtaposed insulating panels. These panels have a lid plate and a base plate held apart by load-bearing spacer plates and the sides of the panels. These insulating panels are filled with insulating material and form a substantially flat support surface for a watertight tank membrane. Such insulating panels offer significant resistance to stresses within the tank, but the load-bearing spacer plates and the sides of the panels create areas of higher thermal conductivity, thus limiting the thermal insulation properties of the panels.

[0005] Document WO2013124556 describes a sealed and thermally insulated tank in which a thermal insulation barrier is formed by a plurality of juxtaposed insulating blocks. These insulating blocks comprise, successively along the thickness direction of the tank wall, a base plate, a lower structural insulating foam, an intermediate plate, an upper structural insulating foam, and a lid plate. Within these insulating blocks, the plates are held apart from each other along the thickness direction of the tank wall by the structural insulating foam.

[0006] Document WO2015001240 describes a sealed and thermally insulated tank in which a thermally insulating barrier comprises a plurality of juxtaposed parallelepiped insulating blocks. Each of these insulating blocks comprises a bottom panel, a lid panel, a plurality of pillars interposed between said bottom and lid panels, and a heat-insulating lining arranged between the pillars. Summary

[0007] One idea behind the invention is to create a sealed and thermally insulating tank by combining several types of insulation of different natures and / or structures while maintaining a sealed membrane carried in a substantially uniform and continuous manner.

[0008] Thus, one idea underlying the invention is to manage the phenomena of thickness variation between zones of the tank exhibiting different behaviors. To this end, one idea underlying the invention is to create a smooth transition between insulating modules in a first zone exhibiting a first operational behavior in thickness and insulating modules in a second zone exhibiting a second operational behavior in thickness when they are subjected to pressure and / or temperature variations that generate a thickness differential in the tank wall.

[0009] According to one embodiment, the invention provides a sealed and thermally insulated fluid storage tank integrated into a load-bearing structure, in which a tank wall comprises, in a thickness direction: a secondary thermally insulating barrier and a primary thermally insulating barrier made up of juxtaposed insulating modules, an insulating module of each of the secondary and primary thermally insulating barriers comprising a cover panel, a bottom panel and an insulating lining interposed between the bottom panel and the cover panel, a primary waterproof membrane resting on the primary thermally insulating barrier, and a secondary waterproof membrane resting on the secondary thermally insulating barrier, the tank wall comprising in a longitudinal direction: a first zone in which the insulating modules have spacers extending along the thickness direction of the tank wall between the cover panel and the bottom panel of said insulating modules,said spacers being distributed over the surface of the cover panel and the bottom panel such that the bottom panel and the cover panel of said insulating modules are kept apart from each other by said spacers, a second zone in which the insulating lining of the insulating modules comprises structural insulating foam interposed between the cover panel and the bottom panel on the surface of the cover panel and the bottom panel such that the cover panel of said insulating modules is mainly kept apart from the bottom panel by said structural insulating foam, a transition zone interposed between the first zone and the second zone,in which the insulating modules are constructed such that the tank wall in said transition zone has at least one parameter chosen from the coefficient of thermal contraction and the modulus of elasticity in the thickness direction of the tank wall, the value of which is between the value of said at least one parameter of the first zone of the tank wall in the thickness direction of the tank wall and the value of said at least one parameter of the second zone of the tank wall in the thickness direction of the tank wall.

[0010] An idea underlying the invention is that the operational behavior of the tank wall in the thickness direction can be essentially characterized by two physical properties which are the coefficient of thermal contraction, which qualifies the response of the tank wall to temperature variations, and the modulus of elasticity in the thickness direction which qualifies the response of the tank wall to pressures.

[0011] According to one embodiment, the value of said at least one parameter along the thickness direction of the tank wall of the insulating modules in the first zone is substantially determined by the value of said at least one parameter along said thickness direction of the spacers, the bottom panel, and the lid panel. In other words, the operational contraction behavior through the thickness, determined by at least one parameter selected from the coefficient of thermal contraction and the elastic modulus through the thickness, of an insulating module comprising spacers distributed on the surface of the lid panel and the bottom panel, is primarily determined by the operational contraction behavior through the thickness of the load-bearing spacers, the lid panels, and the bottom panels.

[0012] According to one embodiment, the value of said at least one parameter along the thickness direction of the tank wall of the insulating modules in the second zone is substantially determined by the value of said at least one parameter along said thickness direction of the structural insulating foam, the bottom panel, and the lid panel. In other words, the operational contraction behavior through the thickness, determined by at least one parameter selected from the coefficient of thermal contraction and the elastic modulus through the thickness, of an insulating module comprising structural insulating foam distributed over the surface of the lid panel and the bottom panel, is primarily determined by the operational contraction behavior through the thickness of the structural insulating foam and the lid and bottom panels.Thus, characteristics such as the coefficient of thermal contraction and the modulus of elasticity in thickness are not the same for these different insulating modules.

[0013] The sealed and thermally insulating tank according to the invention advantageously limits the presence of steps between the thermally insulating barriers of said zones thanks to the presence of a transition zone between the first zone and the second zone of the tank wall.

[0014] According to embodiments, such a tank may include one or more of the following characteristics.

[0015] According to one embodiment, the insulating modules of the second zone have a higher coefficient of thermal contraction in the direction of the thickness of the tank wall than the coefficient of thermal contraction of the insulating modules of the first zone in the direction of the thickness of the tank wall.

[0016] According to one embodiment, the insulating modules of the transition zone are constituted such that the tank wall in said transition zone has a coefficient of thermal contraction in the thickness direction of the tank wall between the coefficient of thermal contraction of the first zone of the tank wall in the thickness direction of the tank wall and the coefficient of thermal contraction of the second zone of the tank wall in the thickness direction of the tank wall.

[0017] According to one embodiment, the insulating modules of the first zone have a higher modulus of elasticity in the direction of the thickness of the tank wall than the modulus of elasticity of the insulating modules of the second zone in the direction of the thickness of the tank wall.

[0018] According to one embodiment, the insulating modules of the transition zone are constituted such that the tank wall in said transition zone has a modulus of elasticity in the thickness direction of the tank wall between the modulus of elasticity of the first zone of the tank wall in the thickness direction of the tank wall and the modulus of elasticity of the second zone of the tank wall in the thickness direction of the tank wall.

[0019] In one embodiment, the first zone corresponds to a highly stressed area of ​​the tank wall, and the second zone corresponds to a less stressed area of ​​the tank wall. In one embodiment, the first zone of the tank wall is an area in which the sealing membrane(s) are fixed relative to the supporting structure. In another embodiment, the first zone is an area of ​​the tank wall in which at least one sealing membrane is anchored to the supporting structure. In one embodiment, the first zone is, for example, a corner area of ​​the tank, a gas dome, a liquid dome, or a mounting area for a pump support foot. In one embodiment, the second zone is located in a central portion of the tank wall.

[0020] Thanks to these characteristics, the sealed and thermally insulating tank according to the invention advantageously exhibits good resistance characteristics to stress in highly stressed areas and good insulation characteristics.

[0021] Depending on the embodiments, the spacers of the insulating modules in the first zone can be made in many ways.

[0022] In one embodiment, the spacers of the insulating modules in the first zone form the sides of said insulating modules, such that said insulating modules are boxes having one or more internal spaces delimited by the spacers, the bottom panel, and the cover panel. In one embodiment, the insulating lining is arranged in said internal space(s). In one embodiment, the spacers of the insulating modules in the first zone include load-bearing pillars arranged between the bottom panel and the cover panel. In one embodiment, the spacers of the insulating modules in the first zone include spacer plates extending between the bottom panel and the cover panel. In one embodiment, the spacers include spacers as described above in combination between the bottom panel and the cover panel of the modules.

[0023] According to one embodiment, the insulating lining of the insulating modules of the first zone is a non-load-bearing or non-structural insulating lining such as perlite, glass wool, aerogels or other or even mixtures thereof.

[0024] According to one embodiment, the insulating packing arranged in the internal space(s) of the boxes is a non-structural insulating packing such as perlite, glass wool, aerogels or other or even mixtures thereof.

[0025] According to one embodiment, the structural insulating foam is a polyurethane foam. According to another embodiment, this structural insulating foam is a high-density foam, for example with a density greater than 100 kg / m³, preferably greater than or equal to 120 kg / m³, in particular equal to 210 kg / m³.

[0026] According to one embodiment, structural insulating foam is reinforced foam, for example reinforced with fibers such as glass fibers.

[0027] In one embodiment, the base panel is a plywood panel. In another embodiment, the lid panel is a plywood panel.

[0028] According to one embodiment, the spacers also develop with a component in a plane perpendicular to the thickness direction of the tank wall, that is to say in an oblique direction relative to the thickness direction.

[0029] According to one embodiment, the first zone is arranged on all or part of a perimeter of the wall.

[0030] According to one embodiment, the insulating modules of the transition zone comprise a first insulating module arranged in the secondary thermally insulating barrier, the first insulating module having a first value of said at least one parameter along the thickness direction of the tank wall, and a second insulating module arranged in the primary thermally insulating barrier, the second insulating module having a second value of said at least one parameter along the thickness direction of the tank wall, the first insulating module and the second insulating module being superimposed in the direction of the thickness of the tank wall.

[0031] Thanks to these characteristics, the tank is easy to manufacture. The transition zone can be created using standardized insulating modules that can be easily integrated into the thermally insulating barriers. Furthermore, the difference in value of at least one parameter between the transition zone and the first and second zones of the tank wall is straightforward, as this difference in value simply results from the superposition of two separate insulating modules. Specifically, it is possible to superimpose an insulating module from the first zone and an insulating module from the second zone to form the transition zone.

[0032] According to one embodiment, the coefficient of thermal contraction of the first insulating module along the thickness direction of the tank wall is between the coefficient of thermal contraction along said thickness direction of the insulating modules of the secondary thermally insulating barrier of the first zone and the coefficient of thermal contraction along said thickness direction of the insulating modules of the secondary thermally insulating barrier of the second zone inclusive.

[0033] According to one embodiment, the modulus of elasticity of the first insulating module along the thickness direction of the tank wall is between the modulus of elasticity along said thickness direction of the insulating modules of the secondary thermally insulating barrier of the first zone and the modulus of elasticity along said thickness direction of the insulating modules of the secondary thermally insulating barrier of the second zone inclusive.

[0034] According to one embodiment, the coefficient of thermal contraction of the first insulating module along said thickness direction is equal to the coefficient of thermal contraction along said thickness direction of the insulating modules of the first zone.

[0035] According to one embodiment, the modulus of elasticity of the first insulating module along said thickness direction is equal to the modulus of elasticity along said thickness direction of the insulating modules of the first zone.

[0036] According to one embodiment, the coefficient of thermal contraction along said thickness direction of the first insulating module is greater than the coefficient of thermal contraction along said thickness direction of the insulating modules of the first zone.

[0037] According to one embodiment, the modulus of elasticity along said thickness direction of the first insulating module is less than the modulus of elasticity along said thickness direction of the insulating modules of the first zone.

[0038] According to one embodiment, the coefficient of thermal contraction of the second insulating module along the thickness direction of the tank wall is between the coefficient of thermal contraction along said thickness direction of the insulating modules of the primary thermally insulating barrier of the first zone and the coefficient of thermal contraction along said thickness direction of the insulating modules of the primary thermally insulating barrier of the second zone inclusive.

[0039] According to one embodiment, the modulus of elasticity of the second insulating module along the thickness direction of the tank wall is between the modulus of elasticity along said thickness direction of the insulating modules of the primary thermally insulating barrier of the first zone and the modulus of elasticity along said thickness direction of the insulating modules of the primary thermally insulating barrier of the second zone inclusive.

[0040] According to one embodiment, the coefficient of thermal contraction of the second insulating module along said thickness direction is equal to the coefficient of thermal contraction along said thickness direction of the insulating modules of the second zone.

[0041] According to one embodiment, the modulus of elasticity of the second insulating module along said thickness direction is equal to the modulus of elasticity along said thickness direction of the insulating modules of the second zone.

[0042] According to one embodiment, the coefficient of thermal contraction along said thickness direction of the second insulating module is less than the coefficient of thermal contraction along said thickness direction of the insulating modules of the second zone.

[0043] According to one embodiment, the modulus of elasticity along said thickness direction of the second insulating module is greater than the modulus of elasticity along said thickness direction of the insulating modules of the second zone.

[0044] According to one embodiment, the coefficient of thermal contraction along the thickness direction of the tank wall of the first insulating module is less than the coefficient of thermal contraction along said thickness direction of the second insulating module.

[0045] According to one embodiment, the modulus of elasticity along the thickness direction of the tank wall of the first insulating module is greater than the modulus of elasticity along said thickness direction of the second insulating module.

[0046] According to one embodiment: one of the first insulating module and the second insulating module comprises struts extending along a thickness direction of the tank wall between the cover panel and the bottom panel of said insulating module, said struts being distributed over the surface of the bottom panel and the cover panel so that the bottom panel and the cover panel of said insulating module are kept apart from each other by said struts, and the other of the first insulating module and the second insulating module comprises structural insulating foam interposed between the cover panel and the bottom panel on the surface of the cover panel and the bottom panel so that the cover panel of said other insulating module is kept apart from the bottom panel of said other insulating module by said structural insulating foam.

[0047] Thanks to these characteristics, the insulating modules in the transition zone have structures similar to those in the first and second zones. Therefore, the insulating modules in the transition zone are simple to manufacture and do not require the use of insulating modules with a structure distinct from those in the other zones of the tank wall. The insulating modules used to manufacture the tank wall can thus be standardized for the different zones of the tank wall.

[0048] According to one embodiment, the first insulating module is identical to the insulating modules of the second zone, for example identical to the insulating modules of the primary thermally insulating barrier or of the secondary thermally insulating barrier of the second zone of the tank wall.

[0049] According to one embodiment, the second module is identical to the insulating modules of the first zone, for example identical to the insulating modules of the primary thermally insulating barrier or of the secondary thermally insulating barrier of the first zone of the tank wall.

[0050] According to one embodiment, said other among the first insulating module and the second insulating module develops jointly in the transition zone and in the second zone of the tank wall.

[0051] According to one embodiment, said other among the first insulating module and the second insulating module is an insulating module of the primary thermally insulating barrier. In other words, said other among the first insulating module and the second insulating module is the second insulating module.

[0052] According to one embodiment, said one of the first insulating module and the second insulating module develops jointly in the transition zone and in the first zone of the tank wall.

[0053] According to one embodiment, said one of the first insulating module and the second insulating module is an insulating module of the secondary thermally insulating barrier. In other words, said one of the first insulating module and the second insulating module is the first insulating module.

[0054] According to one embodiment, the value of said at least one parameter of the other among the first insulating module and the second insulating module is less than the value of said at least one parameter of one among the first insulating module and the second insulating module.

[0055] According to one embodiment, the first zone corresponds to a corner zone of the tank comprising a connecting ring, and the transition zone is directly adjacent to the connecting ring, and in which the second insulating module comprises a structural insulating foam interposed between the cover panel and the bottom panel on the surface of the cover panel and the bottom panel such that the cover panel of said other insulating module is kept away from the bottom panel of said other insulating module by said structural insulating foam.

[0056] According to one embodiment, the first insulating module includes spacers extending along a thickness direction of the tank wall between the lid panel and the bottom panel of said insulating module, said spacers being distributed over the surface of the bottom panel and the lid panel so that the bottom panel and the lid panel of said insulating module are kept apart from each other by said spacers.

[0057] According to one embodiment, the insulating modules of the transition zone comprise: a third insulating module arranged in the secondary thermally insulating barrier, the third insulating module being closer to the second zone than the first insulating module and having a third value of said at least one parameter along the thickness direction of the tank wall, a fourth insulating module arranged in the primary thermally insulating barrier, the fourth insulating module being closer to the second zone than the second insulating module and having a fourth value of said at least one parameter along the thickness direction of the tank wall, and in which the third value of said at least one parameter of the third insulating module is between the first value of said at least one parameter of the first insulating module and the second value of said at least one parameter of the second insulating module.

[0058] According to one embodiment, the third insulating module is a mixed module comprising an intermediate panel arranged between the bottom panel and the cover panel, the insulating trim comprising a lower trim arranged between the intermediate panel and the bottom panel and an upper trim arranged between the intermediate panel and the cover panel, the mixed module having a coefficient of thermal expansion between the coefficient of thermal expansion of an insulating module of the first zone and the coefficient of thermal expansion of an insulating module of the second zone.

[0059] According to one embodiment, the fourth insulating module is identical to the second insulating module, so that the fourth value of said at least one parameter is equal to the second value of said at least one parameter.

[0060] According to one embodiment, the insulating modules of the transition zone comprise a third insulating module (arranged in the secondary thermally insulating barrier, the third insulating module being closer to the second zone than the first insulating module and having a third value of said at least one parameter along the thickness direction of the tank wall, and wherein the second insulating module extends over the entire length of the transition zone in the primary thermally insulating barrier, the third value of said at least one parameter of the third insulating module being between the first value of said at least one parameter of the first insulating module and the second value of said at least one parameter of the second insulating module.

[0061] According to one embodiment, the transition zone has a coefficient of thermal contraction along the thickness direction of the tank wall increasing in the length direction of the tank wall from the first zone towards the second zone of the tank wall.

[0062] According to one embodiment, the transition zone has a modulus of elasticity along the thickness direction of the tank wall decreasing in the length direction of the tank wall from the first zone towards the second zone of the tank wall.

[0063] According to one embodiment, the primary thermally insulating barrier and the secondary thermally insulating barrier comprise a plurality of insulating modules in the transition zone.

[0064] According to one embodiment, the insulating modules of the primary thermally insulating barrier and / or the secondary thermally insulating barrier located in the transition zone have distinct thermal contraction coefficients along the thickness direction of the tank wall.

[0065] According to one embodiment, the insulating modules of the primary thermally insulating barrier and / or the secondary thermally insulating barrier located in the transition zone have distinct moduli of elasticity along the thickness direction of the tank wall.

[0066] According to one embodiment, an insulating module located in the transition zone close to the first zone has a coefficient of thermal contraction along said thickness direction lower than the coefficient of thermal contraction along said thickness direction of an insulating module located in the transition zone in the same thermally insulating barrier and further away from the first zone.

[0067] According to one embodiment, an insulating module located in the transition zone close to the first zone has a modulus of elasticity along said thickness direction greater than the modulus of elasticity along said thickness direction of an insulating module located in the transition zone in the same thermally insulating barrier and further away from the first zone.

[0068] Thanks to these characteristics, the transition zone subdivides the difference in behavior between the insulating modules of the first zone and those of the second zone into a plurality of small steps. This subdivision provides a sufficiently flat support surface for the waterproofing membranes. Specifically, the difference in amplitude between the first and second zones is subdivided into a plurality of small steps, which do not degrade the performance or lifespan of the waterproofing membranes. Furthermore, such a transition zone, using separate insulating modules to create a gentle slope, is easy to implement.

[0069] According to one embodiment, the coefficient of thermal contraction along the thickness direction of the tank wall in the transition zone increases continuously progressively from the first zone towards the second zone.

[0070] According to one embodiment, the modulus of elasticity along the thickness direction of the tank wall in the transition zone decreases continuously progressively from the first zone towards the second zone.

[0071] According to one embodiment, an insulating module of the transition zone comprises a structural insulating foam interposed between the cover panel and the bottom panel on the surface of the cover panel and the bottom panel of said insulating module such that the cover panel of said insulating module is kept away from the bottom panel of said insulating module by said structural insulating foam, said structural insulating foam having a coefficient of thermal contraction along the thickness direction of the tank wall lower than the coefficient of thermal contraction along said thickness direction of the structural insulating foam of the second zone.

[0072] According to one embodiment, the structural insulating foam of said insulating module of the transition zone comprises a first portion of structural insulating foam and a second portion of structural insulating foam, the first portion of structural insulating foam being closer to the first zone than the second portion of structural foam, the first portion of structural insulating foam having a coefficient of thermal contraction along the thickness direction of the tank lower than the coefficient of thermal contraction of the second portion of structural insulating foam along said thickness direction.

[0073] According to one embodiment, an insulating module of the transition zone comprises a structural insulating foam interposed between the cover panel and the bottom panel on the surface of the cover panel and the bottom panel of said insulating module such that the cover panel of said insulating module is kept away from the bottom panel of said insulating module by said structural insulating foam, said structural insulating foam having a modulus of elasticity along the thickness direction of the tank wall greater than the modulus of elasticity along said thickness direction of the structural insulating foam of the second zone.

[0074] According to one embodiment, the structural insulating foam of said insulating module of the transition zone comprises a first portion of structural insulating foam and a second portion of structural insulating foam, the first portion of structural insulating foam being closer to the first zone than the second portion of structural foam, the first portion of structural insulating foam having a modulus of elasticity along the thickness direction of the tank greater than the modulus of elasticity of the second portion of structural insulating foam along said thickness direction.

[0075] Such a module is simple to make because it uses materials of the same nature to generate a progressive change in the coefficient of thermal contraction and / or the modulus of elasticity according to the thickness direction of the tank wall.

[0076] According to one embodiment, the structural insulating foam of said module is a fiber-reinforced polyurethane foam, the first portion of structural insulating foam having a fiber orientation along a thickness direction of the tank wall and the second portion of structural insulating foam having a fiber orientation perpendicular to the thickness direction of the tank wall.

[0077] According to one embodiment, the thickness of the first portion gradually decreases from the first zone towards the second zone and the thickness of the second portion gradually increases from the first zone towards the second zone.

[0078] According to one embodiment, the insulating modules of the transition zone comprise a mixed module having an intermediate panel arranged between the bottom panel and the cover panel, the insulating trim having a lower trim arranged between the intermediate panel and the bottom panel and an upper trim arranged between the intermediate panel and the cover panel.

[0079] According to one embodiment, the first insulating module is a mixed module.

[0080] According to one embodiment, the mixed module comprises load-bearing spacers extending along a thickness direction of the tank wall between the intermediate panel and one of the bottom panel and the lid panel, said spacers being distributed over the surface of the intermediate panel and said one of the bottom panel and the lid panel such that the intermediate panel and said one of the bottom panel and the lid panel are kept apart from each other by said load-bearing spacers,

[0081] According to one embodiment, the insulating lining arranged between the intermediate panel and the other between the bottom panel and the cover panel comprises a structural insulating foam distributed over the surface of the intermediate panel and said other between the bottom panel and the cover panel such that the intermediate panel and said other between the bottom panel and the cover panel are kept apart by said structural insulating foam.

[0082] In one embodiment, the intermediate panel is developed in a plane inclined relative to the bottom panel and the lid panel. Thus, the coefficient of thermal contraction of the composite module gradually increases along the length of the tank wall from the first zone of the tank wall towards the second zone of the tank wall, and / or the modulus of elasticity of the composite module gradually decreases along the length of the tank wall from the first zone of the tank wall towards the second zone of the tank wall.

[0083] Thus, the mixed modulus exhibits a coefficient of thermal contraction along the thickness direction of the tank wall increasing progressively from the first zone towards the second zone of the tank wall and / or a modulus of elasticity along the thickness direction of the tank wall decreasing progressively from the first zone towards the second zone of the tank wall.

[0084] According to one embodiment, the intermediate panel is distant from an edge of the mixed module located near one of the first zone and the second zone.

[0085] According to one embodiment, the intermediate panel is distant from one of the bottom panel and the cover panel of the mixed module.

[0086] In one embodiment, the primary and secondary waterproofing membranes are essentially made of metal strips extending lengthwise and having raised longitudinal edges. The raised edges of two adjacent metal strips are welded together in pairs to form expansion gussets that allow the waterproofing membrane to deform in a direction perpendicular to the length. In another embodiment, the primary and / or secondary waterproofing membranes comprise corrugated metal plates.

[0087] According to one embodiment, the angle of the tank comprises a primary anchoring wing and a secondary anchoring wing, a first end of said anchoring wings being anchored to the supporting structure and a second end of said anchoring wings being welded in a watertight manner to the corresponding sealing membrane.

[0088] According to one embodiment, the primary sealing membrane has undulations extending perpendicularly to the raised edges and arranged at the right of the first zone.

[0089] According to one embodiment, the secondary waterproofing membrane is essentially made up of metal strips extending in the length direction and having raised longitudinal edges, the raised edges of two adjacent metal strips being welded in pairs so as to form expansion bellows allowing deformation of the waterproofing membrane in a direction perpendicular to the length direction, wherein the corner of the tank has a secondary anchoring wing, a first end of said anchoring wing being anchored to the supporting structure and a second end of said anchoring wing being welded in a watertight manner to the secondary waterproofing membrane, and wherein the primary waterproofing membrane has corrugated metal plates.

[0090] Such a tank can be part of an onshore storage facility, for example to store LNG, or be installed in a floating, coastal or deep-water structure, including an LNG carrier, a floating storage and regasification unit (FSRU), a floating production and remote storage unit (FPSO), and others.

[0091] According to one embodiment, the invention also provides a vessel for the transport of a cold liquid product comprising a double hull and a aforementioned tank disposed in the double hull.

[0092] According to one embodiment, the invention also provides a method for loading or unloading such a vessel, in which a cold liquid product is conveyed through insulated pipes from or to a floating or land-based storage facility to or from the vessel's tank.

[0093] 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 to connect the tank installed in the hull of the vessel to a floating or land-based storage facility, and a pump to drive a flow of cold liquid product through the insulated pipes from or to the floating or land-based storage facility to or from the vessel's tank.

[0094] According to one embodiment, the invention also provides an insulating module comprising a lid panel, a bottom panel and an insulating lining interposed between the bottom panel and the lid panel, said insulating module further comprising an intermediate panel arranged between the bottom panel and the lid panel and separating the insulating module into an upper part and a lower part, the insulating lining comprising a lower lining arranged between the intermediate panel and the bottom panel and an upper lining arranged between the intermediate panel and the lid panel, said insulating module having at least one parameter selected from the coefficient of thermal contraction and the modulus of elasticity in the thickness direction of the tank wall whose value is distinct between the upper part of the insulating module and the lower part of the insulating module.

[0095] According to one embodiment, said insulating module comprises load-bearing spacers extending along a thickness direction of the tank wall between the intermediate panel and at least one of the bottom panel and the lid panel, said spacers being distributed over the surface of the intermediate panel and said at least one of the bottom panel and the lid panel such that the intermediate panel and said at least one of the bottom panel and the lid panel are kept apart from each other by said load-bearing spacers,

[0096] According to one embodiment, the insulating lining arranged between the intermediate panel and at least one of the bottom panel and the cover panel comprises structural insulating foam distributed over the surface of the intermediate panel and of said at least one of the bottom panel and the cover panel such that the intermediate panel and said at least one of the bottom panel and the cover panel are kept apart by said structural insulating foam.

[0097] According to one embodiment, the intermediate panel develops in a plane inclined relative to the bottom panel and the cover panel.

[0098] According to one embodiment, one of the upper lining and the lower lining is a fiber-reinforced polyurethane foam having a fiber orientation along a thickness direction of the tank wall and the other of the lower lining and the upper lining is a fiber-reinforced polyurethane foam having a fiber orientation perpendicular to the thickness direction of the tank wall.

[0099] In one embodiment, the inclined intermediate panel is positioned at an edge of the insulating module such that the lower or upper lining forms the entire thickness of the insulating module's lining at that edge. This embodiment allows for a high-strength edge by avoiding the presence of a thin layer of lower or upper lining that could degrade.

[0100] In one embodiment, the side of the inclined intermediate panel closest to the bottom panel is distanced from the bottom panel. Thus, the insulating lining consists solely of the lining below the bottom panel, providing a uniform structure that advantageously offers good mechanical resistance, for example, for attaching an anchoring element to the bottom panel of the insulating module. Brief description of the figures

[0101] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from 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. There figure 1is a highly schematic representation of a sealed and thermally insulating tank wall comprising two structurally distinct zones in two distinct tank loading states: empty at an ambient temperature of 20°C and filled with LNG at -163°C; The figure 2 is a schematic representation of a sealed and thermally insulating tank wall according to an embodiment of the invention comprising two structurally distinct zones between which is arranged a transition zone in two tank loading states, empty at an ambient temperature of 20°C and filled with LNG at -163°C; The figure 3 is a schematic representation of a sealed and thermally insulating tank wall according to a first embodiment of the invention; The figure 4 is a schematic representation of a sealed and thermally insulating tank wall according to a second embodiment of the invention; The figure 5is a detailed representation of the sealed and thermally insulating tank wall according to the second embodiment; The figures 6 to 8 are schematic representations of sealed and thermally insulating tank walls according to variant embodiments of a third embodiment of the invention; The figure 9 is a schematic representation of a sealed and thermally insulating tank wall according to a fourth embodiment of the invention; The Figure 10 is a detailed representation of the sealed and thermally insulating tank wall according to the fourth embodiment; The Figures 11 And 12 are schematic representations of sealed and thermally insulating tank walls according to variant embodiments of a fifth embodiment of the invention; The figure 13 is a detailed representation of the sealed and thermally insulating tank wall according to the fifth embodiment; The figure 14 is an illustration of an insulating module of the transition zone of the figure 13 ; There figure 15 is a schematic representation of a sealed and thermally insulating tank wall according to a sixth embodiment of the invention; The figure 16 is a detailed representation of the sealed and thermally insulating tank wall according to the sixth embodiment; The figure 17 is an illustration of an insulating module of the transition zone of the figure 16 ; There figure 18 is a schematic representation of a transverse wall of a sealed and thermally insulating tank comprising a first zone, a transition zone and a second zone according to the invention; The figure 19 is a schematic cutaway representation of a LNG carrier tank and a loading / unloading terminal for that tank. Figure 20is a detailed representation of the sealed and thermally insulating tank wall according to a seventh embodiment. Detailed description of implementation methods

[0102] With reference to the figure 1 , we will describe a sealed and thermally insulating tank wall according to an embodiment useful for understanding the invention.

[0103] A sealed and thermally insulated tank for the transport of LNG comprises a plurality of tank walls delimiting an internal space intended for the storage of LNG. Each tank wall comprises, from the outside to the inside of the tank, a secondary thermal insulation barrier 1, a secondary sealing membrane 2, a primary thermal insulation barrier 3 and a primary sealing membrane 4 intended to be in contact with a cryogenic fluid contained in the tank.

[0104] The secondary thermal insulation barrier 1, hereinafter referred to as secondary insulating barrier 1, comprises secondary insulating blocks 5. These secondary insulating blocks 5 are juxtaposed and anchored to a load-bearing structure 6 by secondary retaining devices, for example studs or couplers welded to the load-bearing structure 6. These secondary insulating blocks 5 form a secondary support surface on which the secondary sealing membrane 2 is retained.

[0105] Similarly, the primary thermally insulating barrier 3, hereinafter referred to as primary insulating barrier 3, comprises primary insulating blocks 7. These primary insulating blocks 7 are placed side-by-side and held onto the secondary waterproofing membrane 2 by primary retaining elements. These primary insulating blocks 7 form a primary support surface onto which the primary waterproofing membrane 4 is held.

[0106] The load-bearing structure 6 may be, in particular, a self-supporting metal plate or, more generally, any type of rigid bulkhead with suitable mechanical properties. The load-bearing structure 6 may, in particular, be formed by the hull or double hull of a ship. The load-bearing structure 6 comprises a plurality of walls defining the overall shape of the tank, usually a polyhedral shape.

[0107] The secondary insulating blocks 5 and primary insulating blocks 7 are essentially rectangular in shape. Each of these secondary insulating blocks 5 and primary insulating blocks 7 comprises a layer of insulating lining 8 sandwiched between a base plate 9 and a cover plate 10.

[0108] There figure 1 illustrates the behavior of two zones of a tank wall comprising insulating blocks 5, 7 having different structures. On this figure 1, a first zone 11 and a second zone 12 of the sealed and thermally insulating tank wall are schematically represented.

[0109] The first zone 11 of the tank wall illustrated on the right side of the figure 1 represents an area of ​​the tank wall subjected to high stresses within the tank. The second area 12 of the tank wall illustrated on the left side of the figure 1 represents an area of ​​the tank wall subjected to less stress in the tank.

[0110] In the following description, the first zone 11 contains insulating blocks 5, 7 exhibiting good resistance to stress and the second zone 12 contains insulating blocks 5, 7 exhibiting less resistance to stress but better thermal insulation properties.

[0111] The insulating blocks 5, 7 of the first zone 11 have spacers extending along the thickness direction of the tank wall between the cover plate 10 and the base plate 9 of said insulating blocks 5, 7. These spacers are distributed over the surface of the cover plate 10 and the base plate 9 such that the base plate 9 and the cover plate 10 of said insulating blocks 5, 7 are kept apart by said spacers. Preferably, these spacers are distributed over the entire surface of the cover plate 10 and the base plate 9. Due to the presence of the spacers and their distribution between the base plate 9 and the cover plate 10, the mechanical resistance along the thickness direction of the insulating blocks 5, 7 of the first zone is primarily determined by the spacers.Similarly, the behavior of the insulating blocks 5 and 7 in the first zone, in the thickness direction, is primarily determined by the thermal contraction coefficient of the spacers, which is on the order of 4 to 10 x 10⁻⁶ K⁻¹ when they are made of plywood. In other words, the insulating lining 8 contributes little or nothing to maintaining the distance between the base and lid plates. Such an insulating lining 8 is, for example, glass wool, perlite, or low-density polymer foam, for example, with a density between 30 and 40 kg / m³.

[0112] Such insulating blocks 5, 7 of the first zone 11 can be made in many ways. In particular, the spacers can take many forms such as, for example, the shape of spacer plates, load-bearing pillars, lateral sides of the insulating blocks 5, 7, etc.

[0113] For example, the insulating blocks 5, 7 of the first zone can be made in the form of boxes having side edges and load-bearing spacer plates between the base plate 9 and the cover plate 10. The insulating lining 8 of such blocks is housed in internal spaces delimited by the side edges and the load-bearing spacers between the base plate and the cover plate. Documents FR2798358, FR2867831, FR2877639 and FR2683786 describe embodiments of such insulating blocks 5, 7 of the first zone in the form of boxes.

[0114] Similarly, the insulating blocks 5 and 7 of the first zone may include load-bearing pillars, with the base plate 9 and the cover plate 10 being held apart by these pillars, which extend along the thickness direction of the insulating blocks. These load-bearing pillars are distributed between the base plate 9 and the cover plate 10 to ensure a uniform spacing between the base and cover plates. Embodiments of such blocks with load-bearing pillars are described, for example, in documents WO2016097578, FR2877638, and WO2013017773.

[0115] The insulating blocks 5, 7 of the second zone 12 comprise an insulating lining 8 in the form of structural insulating foam sandwiched between the cover plate 10 and the base plate 9 over the surface of both the cover plate 10 and the base plate 9. Preferably, this structural insulating foam is sandwiched between the cover plate 10 and the base plate 9 over substantially the entire surface of both the cover plate 10 and the base plate 9. Thus, the cover plate 10 of said insulating blocks 5, 7 of the second zone 12 is kept at a distance from the base plate 9 by said structural insulating foam. Such structural insulating foam has, in the direction of the tank wall thickness, a higher coefficient of thermal contraction than the coefficient of thermal contraction of the spacers in said direction of the tank wall thickness.Similarly, such structural insulating foam has, in the direction of the thickness of the tank wall, a lower modulus of elasticity than the modulus of elasticity of the spacers in said direction of the thickness of the tank wall.

[0116] Such structural insulating foam can take many forms, its function being, in addition to its thermal insulation function, to keep the base plates 9 and cover plates 10 apart. Thus, the mechanical resistance along the thickness direction of the insulating blocks 5, 7 of the second zone 12 is primarily determined by the characteristics of the structural insulating foam. Insulating blocks 5, 7 incorporating such structural insulating foam can take many forms.

[0117] For example, such blocks 5, 7 of the second zone may include a structurally suitable polyurethane foam to maintain a distance between the base plate and the cover plate. The structural insulating foam is, for example, a polyurethane foam reinforced with glass or aramid fibers having a density of 120 to 140 kg / m³. The structural insulating foam may also be a high-density reinforced polyurethane foam having a density greater than or equal to 170 kg / m³, preferably equal to 210 kg / m³. Such insulating blocks 5, 7 are, for example, described in document FR2813111. Similarly, documents WO2013124556 and WO2013017781 describe insulating blocks 5, 7 comprising a layer of structural insulating foam sandwiched between and maintaining a distance between a base plate and a cover plate.

[0118] The insulating blocks 5, 7 of the second zone 12 may have areas of point reinforcement. However, with the exception of these point reinforcement areas, the base and cover plates of the insulating blocks in these documents are held apart primarily by the structural insulating foam. For example, the insulating blocks 5, 7 of the second zone 12 may have corner pillars to reinforce the anchoring areas of the insulating block 5, 7. However, these corner pillars constitute singular point reinforcement areas, the base plate 9 and the cover plate 10 being primarily held apart by the structural insulating foam. Document WO2013017781 describes an example of an embodiment of such insulating blocks 5, 7 of the second zone 12 with corner pillars.

[0119] The documents indicated above also give further details on the manufacture of watertight and thermally insulating tanks, in particular on secondary sealing membranes 2 and primary sealing membranes 4, anchoring devices for insulating barriers 1, 3. Other examples of possible implementation of sealing membranes, based on corrugated metal sheets, are also described in document WO2016 / 046487, document WO2013004943 or document WO2014057221.

[0120] The insulating blocks 5 and 7 in the first zone 11 exhibit good stress resistance characteristics due to the spacers. However, these spacers also create areas of increased thermal conductivity between the base plate 9 and the cover plate 10.

[0121] Conversely, the insulating blocks 5, 7 of the second zone 12 exhibit good thermal insulation properties, better than those of the first zone 11. However, these insulating blocks 5, 7 of the second zone 12 exhibit less resistance to stress than the insulating blocks 5, 7 of the first zone 11.

[0122] Preferably, the first zone 11 is adjacent to a corner of the tank, and the second zone 12 is located in the central part of the wall. This is because the insulating blocks in the tank are subjected to different stresses depending on their location. In particular, the insulating blocks arranged in the corner areas of the tank, namely the first zone 11, are generally subjected to greater stresses than the insulating blocks located in the flat areas of the tank, namely the second zone 12.

[0123] In an embodiment not shown, the first zone 11 may be adjacent to a portion of the tank wall where the sealing membranes must be interrupted, for example, a portion of the tank wall through which a pipe passes, in particular a gas dome pipe, a portion of the tank wall through which a support foot passes, for example, for a pump, or a portion of the tank wall at the end of a liquid dome. Portions of tank walls through which a pipe or a pump support foot passes are described, for example, in document WO2014128381. Indeed, in these specific areas of the tank, the insulating blocks may also be subjected to high stresses.

[0124] Thanks to the layout of the figure 1The type of insulating blocks was adapted to the specific areas of the tank where they are arranged, and more specifically to the stresses these blocks must withstand in those areas. This arrangement of the insulating blocks within the tank results in an optimized tank in terms of both thermal insulation and resistance to stress.

[0125] However, the use of insulating blocks with different structures and materials leads to operational differences in the functioning of said insulating blocks, in particular in compression, creep, dimensional deviation in the thickness of the insulating blocks, under the effect of thermal changes, hydrostatic and hydrodynamic pressure in the tank etc.

[0126] The upper part of the figure 1 illustrates these two zones 11, 12 in the context of an empty tank at ambient temperature, for example 20°C. The lower part of the figure 1 illustrates these two zones 11, 12 within the context of a tank full of LNG at -163°C.

[0127] The first zone 11 and the second zone 12 have the same thickness at room temperature in order to provide a flat support surface for the sealing membranes 2, 4.

[0128] In the following description, the expression coefficient of thermal contraction is used in reference to the coefficient of thermal contraction of an element along the thickness direction of the tank wall.

[0129] Due to the different structure of the insulating blocks 5 and 7, the first zone 11 and the second zone 12 exhibit different coefficients of thermal contraction, different stiffnesses, different creep resistance, etc. In other words, the first zone 11 and the second zone 12 behave differently under thermal, cargo, sloshing, etc. loads.

[0130] Consequently, the first zone 11 and the second zone 12 exhibit different thickness changes when the tank is filled with LNG. Thus, while the first zone 11 and the second zone 12 have the same thickness when the tank is empty, as illustrated in the upper part of the figure 1 A step 13 along the thickness direction of the tank wall appears between the first zone 11 and the second zone 12 when the tank is filled with LNG as illustrated on the lower part of the figure 1This step 13 is particularly important at the level of the primary support surface supporting the primary waterproofing membrane 4 because this step 13 is generated by the differential change in thickness of the two insulating barriers 1 and 3. For example, in the case of a first zone comprising insulating blocks in the form of plywood boxes and a second zone comprising insulating blocks in structural foam, a primary insulating barrier 3 of 230mm thickness and a secondary insulating barrier 1 of 300mm thickness, we can observe a step 13 that can reach approximately 8 to 12mm mainly under the combined effects of sloshing and thermal contraction for two-thirds and to a lesser extent under the combined effect of cargo pressure and creep.

[0131] However, the 2 and 4 sealing membranes function optimally in a flat geometry and can exhibit weaknesses under excessive steps. Therefore, prior art thermally insulating barriers use insulating blocks with similar structures across the entire surface of the tank walls. This issue is particularly prevalent with Invar strip sealing membranes with raised edges, although it also arises, albeit to a lesser extent, with corrugated metal sheet sealing membranes.

[0132] There figure 2is a schematic representation illustrating the principle of a tank wall in which the thermally insulating barriers 1, 3 comprise insulating blocks 5, 7 arranged according to the stresses experienced in the tank, while also presenting a support surface adapted to support the sealing membranes 2, 4. Numerous embodiments are described in more detail below with regard to the figures 3 to 17 in order to implement such a tank wall.

[0133] The tank wall illustrated on the figure 2 behaves in a manner similar to the tank wall described opposite the figure 1The tank wall comprises a first zone 11 and a second zone 12, each containing insulating blocks 5 and 7 with different structures. It also includes a transition zone 14 interposed between the first zone 11 and the second zone 12. This transition zone 14 contains insulating blocks 5 and 7 selected so that its compressive behavior is intermediate between that of the first zone 11 and that of the second zone 12.

[0134] As illustrated on the upper part of the figure 2The insulating blocks 5 and 7 of the transition zone 14 are selected to be flush with the insulating blocks 5 and 7 of the first and second zones 11 and 12 when the tank is empty at ambient temperature in order to provide a flat support surface for the sealing membranes. However, the insulating blocks 5 and 7 of the transition zone 14 are also selected so that the transition zone 14 has a thickness between the thickness of the first zone 11 and the thickness of the second zone 12 when the tank is full of LNG, as illustrated on the lower part of the figure 2 .

[0135] According to a preferred embodiment, the insulating blocks 5, 7 of the transition zone 14 are selected so that the coefficient of thermal contraction of the transition zone 14 is between the coefficient of thermal contraction of the first zone 11 and the coefficient of thermal contraction of the second zone 12.

[0136] The insulating blocks 5 and 7 in transition zone 14 can also be selected based on other characteristics. For example, these blocks can be selected based on their impact stiffness, to account for the effects of sloshing of the liquid inside the tank. They can also be selected based on their static compressive stiffness to account for the pressure due to the weight of the liquid in the tank. Other characteristics, such as Young's modulus in compression or creep resistance over time, can also be considered.

[0137] Thus, in one embodiment, the description given with regard to the coefficient of thermal contraction applies by analogy to the modulus of elasticity of the tank wall zones. The first zone 11 has a modulus of elasticity greater than the modulus of elasticity of the second zone 12, and the transition zone has a modulus of elasticity between the modulus of elasticity of the first zone 11 and the modulus of elasticity of the second zone 12. Furthermore, the modulus of elasticity of the transition zone 14 can decrease from the first zone 11 towards the second zone 12.

[0138] In any event, the insulating blocks 5, 7 of the transition zone are selected so that the transition zone 14 has a compression behavior intermediate between the compression behavior of the first and second zones 11, 12 and that the thickness of the transition zone 14 is between the thickness of the first zone 11 and the thickness of the second zone 12 when the tank is full of LNG.

[0139] Such a transition zone 14 allows for a smooth transition between the first zone 11 and the second zone 12. Indeed, thanks to the transition zone 14, the step 13 between the first zone 11 and the second zone 12 is subdivided into a first step 15 and a second step 16 of reduced size. The first step 15 is located between the first zone 11 and the transition zone 14, and the second step 16 is located between the transition zone 14 and the second zone 12. The tank wall thus no longer presents a significant step 13 as illustrated in the figure 1 which could degrade the sealing membranes 2, 4 while presenting areas whose resistance and insulation properties are adapted to the stresses within the tank. The term "reduced-size steps" 15, 16 refers to steps smaller than step 13 between the first zone 11 and the second zone 12.

[0140] On the figures 3 to 18 And 20, the first zone 11 comprises in the primary insulating barrier 3 and in the secondary insulating barrier 1 structurally analogous insulating blocks 5, 7. On these figures 3 to 18 And 20 The second zone 12 comprises structurally similar insulating blocks 5 and 7 in the primary insulating barrier 3 and in the secondary insulating barrier 1. For the sake of clarity, only one primary insulating block 7 and one secondary insulating block 5 from the first zone 11 and the second zone 12 are shown in the figures. figures 3 to 17 and 20, the first zone 11 and the second zone 12 being able to comprise one or a plurality of primary insulating blocks 7 and secondary insulating blocks 5 juxtaposed according to the desired dimensions of said first zone 11 and second zone 12.

[0141] There figure 3This illustrates a first embodiment of the transition zone 14 in a tank wall. In this first embodiment, the transition zone 14 comprises a superimposed secondary insulating block 5 and a primary insulating block 7. The secondary insulating block 5 of the transition zone 14 is identical to the secondary insulating blocks 5 of the first zone 11. The primary insulating block 7 of the transition zone 14 is identical to the primary insulating blocks 7 of the second zone 12. Consequently, the coefficient of thermal contraction of the transition zone 14 is the sum of the coefficients of thermal contraction of a secondary insulating block 5 of the first zone 11 and a primary insulating block 7 of the second zone. Thus, the coefficient of thermal contraction of the transition zone 14 lies between the coefficient of thermal contraction of the first zone 11 and the coefficient of thermal contraction of the second zone 12.

[0142] This first embodiment has the advantage of being simple to implement since it uses standardized insulating blocks 5, 7 from the first zone 11 and the second zone 12 to form the transition zone 14. This first embodiment thus allows the step 13 of the primary support surface to be subdivided into two steps 15, 16 of reduced sizes.

[0143] According to an unillustrated variant of the first embodiment, the primary insulating block 7 of the transition zone 14 is identical to the primary insulating blocks 7 of the first zone 11 and the secondary insulating block 5 of the transition zone 14 is identical to the secondary insulating blocks 5 of the second zone 12. This unillustrated variant also makes it possible to obtain a simple transition zone 14 by using insulating blocks 5, 7 identical to the insulating blocks 5, 7 of the first zone 11 and the second zone 12 while providing a transition zone 14 subdividing the step 13 between the first zone 11 and the second zone 12 into steps 15, 16 acceptable for the primary waterproofing membrane 4.

[0144] There figure 4illustrates a second embodiment of the transition zone 14. In this second embodiment, the transition zone 14 comprises a secondary insulating block 5 identical to the secondary blocks 5 of the first zone 11. However, the primary insulating barrier 3 of the transition zone 14 is formed by a primary insulating block 7 developing jointly in the transition zone 14 and in the second zone 12.

[0145] A secondary insulating block 17 at the end of the second zone 12 has a similar structure but smaller dimensions than the other secondary insulating blocks 5 in the second zone 12. Thus, a primary insulating block 18 at the end of the second zone 12, resting on the secondary insulating block 17, has a projecting portion 19 extending towards the first zone 11 beyond the secondary insulating block 17. This projecting portion 18 rests on the secondary insulating block 5 in the transition zone 14. In other words, this projecting portion 19 forms the primary insulating barrier 3 in the transition zone 14.

[0146] In this second embodiment, the transition zone 14 is thus formed, on the one hand, by the secondary insulating block 5, identical to the secondary insulating blocks 5 of the first zone 11, and, on the other hand, by the projecting portion 19 of the primary end insulating block 17 of the second zone 12. The transition zone 14 therefore has a coefficient of thermal contraction identical to the coefficient of thermal contraction of the transition zone 14 described with regard to the first embodiment of the figure 3However, in this second embodiment, the primary insulating barrier 3 does not have a step 16 between the transition zone 14 and the second zone 12. Indeed, this step 16 present in the first embodiment is advantageously absorbed by the primary end insulating block 18 developing jointly in the transition zone 14 and in the second zone 12, the latter having a flat and inclined support surface between the transition zone 14 and the second zone 12.

[0147] There figure 5 illustrates a possible realization of the second embodiment of the figure 4 .

[0148] In this figure, the first zone 11 is a tank wall corner zone. Such a tank corner is described in documents FR2798358 or WO2015007974, for example. This tank corner comprises insulating blocks 5, 7 in the form of plywood boxes delimiting an internal space filled with an insulating material such as perlite. Load-bearing struts are distributed throughout the internal space of the boxes to provide them with good resistance to stress. Boxes of a similar structure are used to create the primary thermally insulating barrier and the secondary thermally insulating barrier.

[0149] The second zone consists of insulating blocks 5, 7 comprising an insulating lining 8 in the form of structural insulating foam arranged between the base plate 9 and the cover plate 10. These insulating blocks 5, 7 further comprise an intermediate plate 20 housed within the insulating lining 8, said insulating lining 8 thus comprising an upper insulating foam 21 arranged between the cover plate 10 and the intermediate plate 20, and a lower insulating foam 22 arranged between the intermediate plate 20 and the base plate 9. The upper insulating foam 21 and the lower insulating foam 22 are, for example, polyurethane foam with a density of 130 kg / m³. In the embodiment illustrated in the figure 5 , the secondary insulating block 5 of the second zone 12 is, for example, a secondary insulating block as described in document WO2014096600. On this figure 5, the primary insulating block 7 of the second zone 12 is for example a primary insulating block as described in document WO2013124556.

[0150] The secondary 2 and primary 4 sealing membranes are here made using Invar strips with raised edges, for example, 500 mm wide. The raised edges of two adjacent Invar strips are welded in pairs to weld supports anchored in the cover plate 10 of the insulating blocks 5, 7, which form the support surface on which the Invar strips rest. A connecting ring has primary and secondary anchoring wings 23, one end of which is welded to the supporting structure 6 and the other end of which is welded to the end of the primary 4 and secondary 2 sealing membranes, respectively, in order to anchor the primary 4 and secondary 2 sealing membranes to the supporting structure 6. Such a connecting ring is described, for example, in document FR2798358, document WO8909909, or document WO2015007974.

[0151] In another embodiment, the connecting ring consists solely of secondary anchoring wings 23, one end of which is welded to the supporting structure 6 and the other end is welded to the end of the secondary sealing membrane 2 in order to anchor said secondary sealing membrane 2 to the supporting structure 6.

[0152] To improve the absorption of the steps 15, 16 related to the structural differences of the insulating blocks 5, 7 between the different zones 11, 12, 14 of the tank wall, the primary sealing membrane 4 advantageously includes a portion of the membrane with corrugations 24. Such corrugations 24 develop along the steps 15, 16. These corrugations 24 are, for example, made using a corrugated metal sheet such as those described in document FR2691520. This corrugated metal sheet is interposed between one end 25 of the Invar strips of the primary sealing membrane 4 and the primary anchoring flange 23 of the connecting ring. Various unillustrated metal parts can also be inserted between the corrugated metal sheet and the primary anchoring wing 23, for example an angle bracket forming the edge of the primary sealing membrane 4 at the corner of the tank.

[0153] There figure 5The diagram illustrates a first zone 11 comprising, on the one hand, insulating blocks 5 and 7 within the connecting ring and, on the other hand, a primary insulating block 7 and a secondary insulating block 5 outside the connecting ring. This configuration is advantageous because the primary insulating block 7 and the secondary insulating block 5 of the first zone 11, located outside the connecting ring, contribute to the proper retention of the connecting ring in the corner of the tank and of the welds between the connecting ring and the membranes. However, this first zone could consist only of the insulating blocks located within the connecting ring, so that the transition zone 14 would be directly adjacent to the connecting ring.

[0154] THE figures 6 to 8illustrate a third embodiment of the transition zone 14. This third embodiment differs from the first embodiment in that the transition zone 14 comprises at least one insulating block 26 distinct from the insulating blocks 5, 7 of the first zone 11 and the second zone 12. This or these distinct insulating blocks 26 have a coefficient of thermal contraction between the coefficients of thermal contraction of the adjacent insulating blocks 5, 7 in the corresponding insulating barrier 1, 3.

[0155] Thus, on the figure 6, the transition zone 14 comprises a secondary insulating block 5 identical to the secondary insulating block 5 of the first zone 11 and a separate insulating block 26 arranged in the primary insulating barrier 1. This separate insulating block 26 constitutes a primary insulating block 7 of the transition zone 14 having a coefficient of thermal contraction between the coefficient of thermal contraction of the primary insulating blocks 7 of the first zone 11 and of the second zone 12.

[0156] Conversely, on the figure 7, the transition zone 14 comprises a primary insulating block 7 identical to the primary insulating blocks 7 of the second zone 12 and a separate insulating block 26 arranged in the secondary insulating barrier 1. This separate insulating block 26 constitutes a secondary insulating block 5 of the transition zone 14 having a coefficient of thermal contraction between the coefficient of thermal contraction of the secondary insulating blocks 5 of the first zone 11 and of the second zone 12.

[0157] On the figure 8 The transition zone 14 comprises two superimposed distinct insulating blocks 26. These distinct insulating blocks 26 constitute a primary insulating block 7 and a secondary insulating block 5 of the transition zone, both having similar structures and a coefficient of thermal contraction between those of the adjacent insulating blocks 5, 7 of the first zone 11 and the second zone 12.

[0158] The separate insulating blocks 26 of the transition zone 14 in this third embodiment are, for example, insulating blocks comprising a cover plate 10 and a base plate 9 held apart by a separate structural insulating foam 27, this separate structural insulating foam 27 being different from the structural insulating foam of the insulating blocks 5, 7 of the second zone 12. For example, the insulating blocks 5, 7 of the second zone 12 may comprise a polyurethane foam having a density of 130 kg / m³, whereas the separate structural insulating foam 27 is a reinforced polyurethane foam with a density of 210 kg / m³. Thus, the transition zone 14 has a coefficient of thermal contraction between the coefficient of thermal contraction of the first zone 11 and the coefficient of thermal contraction of the second zone 12.

[0159] There figure 9illustrates a fourth embodiment of the transition zone 14. In this fourth embodiment, the transition zone 14 comprises a plurality of primary insulating blocks 7 and a plurality of secondary insulating blocks 5. This embodiment allows the transition zone 14 to be subdivided into several sub-zones, each with distinct thermal contraction coefficients, and thus the step 13 between the first zone 11 and the second zone 12 to be subdivided into a plurality of smaller steps. On this figure 9 , the transition zone 14 is divided into a first sub-zone 28 and a second sub-zone 29. The first sub-zone 28 is contiguous with the first zone 11 and the second sub-zone 28 is contiguous with the second zone 12.

[0160] The first sub-zone 28 of the transition zone 14 comprises a secondary insulating block 5 identical to the secondary insulating blocks 5 of the first zone 11 and a primary insulating block 7 identical to the primary insulating blocks 7 of the second zone 12. In other words, this first sub-zone 28 is implemented according to the first embodiment described above with regard to the figure 3 .

[0161] The second sub-zone 29 of the transition zone 14 contains a primary insulating block 7 identical to the primary insulating blocks 7 of the second zone 12. However, the secondary insulating block 5 of the second sub-zone 29 is a mixed secondary insulating block 30. This mixed secondary insulating block 30 has a coefficient of thermal contraction between the coefficient of thermal contraction of the secondary insulating block 5 of the first zone 11 and the coefficient of thermal contraction of the secondary insulating block 5 of the second zone 12. Thus, the second sub-zone 29 has a coefficient of thermal contraction between the coefficient of thermal contraction of the first sub-zone 28 and the coefficient of thermal contraction of the second zone 12.As a result, step 14 between the first zone 11 and the second zone 12 is subdivided into a first step separating the first zone 11 and the first sub-zone 28, a second step separating the first sub-zone 28 and the second sub-zone 29 and a third step separating the second sub-zone 29 and the second zone 12.

[0162] To achieve a suitable coefficient of thermal contraction, the mixed secondary insulating block 30 comprises an upper element 31 and a lower element 32 superimposed along their thickness. For example, the mixed secondary insulating block 30 comprises a lower element 32 formed by the base plate 9 and a lower structural insulating lining 33, and an upper element 31 formed by an insulating box. Such an insulating box includes an intermediate plate 34 and a cover plate 10 held apart by load-bearing spacers in a manner similar to the insulating blocks 5, 7 of the first zone 11.

[0163] Other embodiments can be implemented to obtain a mixed secondary insulating block 30 whose thermal contraction coefficient falls between the thermal contraction coefficients of the secondary insulating blocks 5 of the first zone 11 and the second zone 12. In one embodiment, the upper element 31 can be made of structural insulating foam with a density greater than that of the structural insulating foam of the secondary insulating blocks 5 of the second zone 12. In another embodiment, the lower element 32 is a box and the upper element 31 comprises structural insulating foam. In yet another embodiment, the respective thicknesses of the upper element 31 and the lower element 32 are adapted to the desired thermal contraction coefficient of the mixed secondary insulating block 30.

[0164] There Figure 10is an illustration of an implementation of the fourth embodiment of the figure 9 In this embodiment, the first zone 11 and the second zone 12 are implemented in a manner analogous to the first and second zones 11, 12 described above with regard to the figure 5 .

[0165] The first sub-zone 28 of the transition zone 14 comprises a secondary insulating block 5 in the form of a box identical to the secondary insulating blocks 5 of the first zone 11. The primary insulating block 7 of the first sub-zone 28 comprises a high-density reinforced polyurethane foam 35 having a density greater than the density of the structural insulating foam of the primary insulating blocks 7 of the second zone 12 so that the first sub-zone 28 of the transition zone 14 has a coefficient of thermal contraction greater than the coefficient of thermal contraction of the first zone 11 but less than the coefficient of thermal contraction of the second zone 12.The primary insulating block 7 of the transition zone 14 may further comprise an intermediate plate 20 housed in the high-density reinforced polyurethane foam 35, said high-density reinforced polyurethane foam 35 being thus arranged between the cover plate 10 and the intermediate plate 20 and between the intermediate plate 20 and the base plate 9.

[0166] The second sub-zone 29 of the transition zone 14 comprises a mixed secondary insulation block 30. This second sub-zone 29 comprises a primary insulation block 7 identical to the primary insulation block 7 of the first sub-zone 28. The mixed secondary insulation block 30 has a lower element 32 made of structural insulating foam identical to the structural insulating foam of the secondary insulation blocks 5 of the second zone 12. The upper element 31 of the mixed secondary insulation block 30 is a box with a structure analogous to the structure of the secondary insulation blocks 5 of the first zone 11. Thus, the mixed secondary insulation block 30 has a coefficient of thermal contraction between the coefficient of thermal contraction of the secondary insulation block 5 of the first sub-zone 28 and the coefficient of thermal contraction of the secondary insulation blocks 5 of the second zone 12.As a result, the second sub-zone 29 of the transition zone 14 has a thermal contraction coefficient between the thermal contraction coefficient of the first sub-zone 28 of the transition zone 14 and the thermal contraction coefficient of the second zone 12.

[0167] THE Figures 11 And 12schematically illustrate a fifth embodiment of the transition zone 14. In this fifth embodiment, the secondary insulating block 5 of the transition zone 14 is identical to the secondary insulating block 5 of the first zone 11. The primary insulating block 7 of the transition zone 14 is a mixed primary insulating block 36. Similar to the mixed secondary insulating block 30, this mixed primary insulating block 36 comprises a superimposed upper element 37 and a superimposed lower element 38 with different structures and coefficients of thermal contraction. However, the mixed primary insulating block 36 of the fifth embodiment differs from the mixed secondary insulating block 30 of the fourth embodiment in that the interface between the lower element 38 and the upper element 37 of said mixed primary insulating block 36 is inclined relative to the base plates 9 and cover plates 10.In other words, the lower element 38 of the primary mixed insulating block 36 has a thickness that gradually decreases from the first zone 11 towards the second zone 12, and the upper element 37 has a thickness that gradually increases from the first zone 11 towards the second zone 12. Furthermore, the coefficient of thermal contraction of the lower element 38 is lower than the coefficient of thermal contraction of the upper element 37, so that the coefficient of thermal contraction of the primary mixed insulating block 36 gradually increases from the first zone 11 towards the second zone 12.

[0168] This fifth embodiment advantageously reduces the steps between the transition zone 14 and the first and second zones 11, 12, the primary mixed insulating block 36 absorbing part of the thickness difference between the first zone 11 and the second zone 12 during its deformation due to its progressive modification of its thermal contraction coefficient.

[0169] In an embodiment not shown, the inclination of the interface is reversed so that the thickness of the upper element 37 decreases progressively from the first zone 11 towards the second zone 12 and the thickness of the lower element 38 increases progressively from the first zone 11 towards the second zone 12. In this embodiment not shown, the coefficient of thermal contraction of the upper element 37 is less than the coefficient of thermal contraction of the lower element 38.

[0170] The upper element 37 and lower element 38 are dimensioned so that the thickness of the primary mixed insulating block 36 is constant at ambient temperature in the tank.

[0171] In a first variant illustrated on the figure 11 The lower element 38 is a box delimited along a thickness direction of the tank wall by the bottom plate 9 of the primary mixed insulating block 36 and by an intermediate plate 39. The intermediate plate 39 is inclined relative to the bottom plate 9 so that the thickness of said box decreases from the first zone 11 towards the second zone 12. This box has load-bearing spacers maintaining the bottom plate 9 of the primary mixed insulating block 36 at a distance from the intermediate plate 39.

[0172] The upper element 37 comprises a structural insulating foam sandwiched between the intermediate plate 39 and the cover plate 10 of the primary mixed insulating element 36. On the figure 11 , this structural insulating foam is identical to the structural insulating foam of the primary insulating blocks 7 of the second zone 12.

[0173] Thus, the mixed primary insulating block 36 has a thermal contraction coefficient that increases progressively from the first zone 11 towards the second zone 12. More specifically, the thermal contraction coefficient of the mixed primary insulating block 36 is identical to the thermal contraction coefficient of a primary insulating block 7 from the first zone 11 on the side of said first zone 11 and increases progressively towards the second zone 12 until it reaches substantially the value of the thermal contraction coefficient of a primary insulating block 7 from the second zone 12.

[0174] In another variant illustrated on the figure 12The lower element 38 of the primary mixed insulating block 36 has a thermal contraction coefficient between the thermal contraction coefficient of the primary insulating blocks 7 of the first zone 11 and the thermal contraction coefficient of the primary insulating blocks 7 of the second zone 12. For example, the lower element 38 is formed using a high-density structural insulating foam 40 whose thermal contraction coefficient is lower than the thermal contraction coefficient of the structural insulating foam of the primary insulating blocks 7 of the second zone 12. The upper element 37 of said primary mixed insulating block 36 is, in this variant, identical to the upper element 37 of the primary mixed insulating block 36 described opposite the figure 11 that is to say with a structural insulating foam identical to the structural insulating foam of the second zone 12.

[0175] In an unillustrated variant, the lower element 38 of the mixed primary insulating block 36 is a box as described above opposite the figure 11 and the upper element 37 of said mixed insulating block 36 comprises a structural insulating foam whose density is greater than the density of the structural insulating foam of the primary insulating blocks 7 of the second zone 12.

[0176] There figure 13 is an illustration of an implementation of the fifth embodiment of one of the Figures 11 Or 12 . There figure 14 is an illustration of an insulating module of the transition zone of the figure 13 .

[0177] There figure 15schematically illustrates a sixth embodiment of the transition zone 14. Analogously to the mixed primary insulating block 36 of the fifth embodiment, the primary insulating block 7 of the transition zone 14 in this sixth embodiment has a coefficient of thermal contraction that gradually decreases from the first zone 11 towards the second zone 12. However, in this sixth embodiment, the gradual decrease in the coefficient of thermal contraction of the primary insulating block 7 of the transition zone 14 is achieved by using structural foam blocks having distinct coefficients of thermal contraction in said primary insulating block 7.

[0178] Thus, the primary insulating block 7 of the transition zone comprises a structural insulating foam that maintains a distance between the base plate 9 and the cover plate 10. This structural insulating foam has two portions: a first portion 41 located near the first zone 11 and a second portion 42 located near the second zone 12. The interface between the first portion 41 and the second portion 42 has at least one step 43 in the thickness direction of the primary insulating block 7 of the transition zone 14. This step 43 allows for a gradual decrease in the thickness of the first portion 41 and a gradual increase in the thickness of the second portion 42 from the first zone 11 towards the second zone 12.

[0179] The first portion 41 of structural insulating foam has a lower coefficient of thermal contraction than the coefficient of thermal contraction of the second portion 42. Thus, the primary insulating block 7 of the transition zone 14 has a coefficient of thermal contraction increasing from the first zone 11 towards the second zone 12.

[0180] There figure 16 is an illustration of an implementation of the sixth embodiment of the figure 15 . There figure 17 is an illustration of an insulating module of the transition zone of the figure 15In these figures, the first section 41 and the second section 42 are made of polyurethane foam reinforced with fibers such as glass fibers. However, the polyurethane foam in the first section 41 is arranged so that the fibers are oriented along the thickness direction of the primary insulating block 7, as illustrated by arrows 44. The polyurethane foam in the second section 42 is arranged so that the fibers are oriented perpendicular to the thickness direction of the primary insulating block 7, as illustrated by arrows 45. This arrangement resembles the steps of a staircase formed by the first section 41 and the second section 42.

[0181] This difference in fiber orientation between the first section 41 and the second section 42 results in a different coefficient of thermal contraction between the first section 41 and the second section 42, even though the polyurethane foam used to make both sections 41 and 42 is the same. Thus, the first section 41, made of polyurethane foam with fibers oriented along the thickness of the primary insulating block 7, exhibits, for example, a coefficient of thermal contraction of approximately 25 x 10⁻⁶ K⁻¹ to 27 x 10⁻⁶ K⁻¹ for 10% by mass of glass fiber, while the second section 42, made of polyurethane foam with fibers oriented perpendicular to the thickness of the primary insulating block 7, exhibits, for example, a coefficient of thermal contraction of approximately 60 x 10⁻⁶ K⁻¹.

[0182] Another method for obtaining thermal contraction coefficients between the first portion 41 and the second portion 42 could be to modify the fiber ratio and its nature in the polyurethane foam to adjust the thermal contraction coefficient between 15 and 60.10 -6< K -1< .

[0183] In one embodiment, the first zone 11 is arranged on all edges of the tank walls, the second zone 12 on all central portions of the tank walls, and the transition zone 14 between all the first and second zones 11, 12 of the tank walls. figure 18 is a schematic representation of a transverse wall of a sealed and thermally insulating tank comprising a first zone, a transition zone and a second zone according to the invention arranged according to this embodiment.

[0184] There Figure 20is an illustration of the sealed and thermally insulating tank wall according to a seventh embodiment.

[0185] In the illustrated embodiment Figure 20 The first zone 11 is a corner zone of the tank wall comprising insulating blocks 5, 7 in the form of plywood boxes delimiting an internal space filled with insulating material such as perlite or glass wool. Load-bearing struts are distributed throughout the internal space of the boxes to provide them with good resistance to stress. The first zone 11 is therefore located at the connection ring, and insulating blocks 5, 7 are located within the connection ring.

[0186] The second zone 12 consists of insulating blocks 5, 7 comprising an insulating lining 8 in the form of structural insulating foam arranged between the base plate 9 and the cover plate 10. These insulating blocks 5, 7 further comprise an intermediate plate 20 housed within the insulating lining 8, said insulating lining 8 thus comprising an upper insulating foam 21 arranged between the cover plate 10 and the intermediate plate 20 and a lower insulating foam 22 arranged between the intermediate plate 20 and the base plate 9. The upper insulating foam 21 and the lower insulating foam 22 are, for example, polyurethane foam having a density of 130 kg / m³. In the embodiment illustrated in the figure 5 , the secondary insulating block 5 of the second zone 12 is, for example, a secondary insulating block as described in document WO2014096600. On this figure 5, the primary insulating block 7 of the second zone 12 is for example a primary insulating block as described in document WO2013124556.

[0187] The first sub-zone 28 of the transition zone 14 comprises a secondary insulating block 5 in the form of a box identical to the secondary insulating blocks 5 of the first zone 11. The primary insulating block 7 of the first sub-zone 28 comprises a high-density reinforced polyurethane foam 35 having a density greater than the density of the structural insulating foam of the primary insulating blocks 7 of the second zone 12 so that the first sub-zone 28 of the transition zone 14 has a coefficient of thermal contraction greater than the coefficient of thermal contraction of the first zone 11 but less than the coefficient of thermal contraction of the second zone 12.The primary insulating block 7 of the transition zone 14 comprises in this embodiment an intermediate plate 20 housed in the high-density reinforced polyurethane foam 35, said high-density reinforced polyurethane foam 35 being thus arranged between the cover plate 10 and the intermediate plate 20 and between the intermediate plate 20 and the base plate 9.

[0188] The second sub-zone 29 of the transition zone 14 comprises a mixed secondary insulation block 30. This second sub-zone 29 comprises a primary insulation block 7 identical to the primary insulation block 7 of the first sub-zone 28. The mixed secondary insulation block 30 has a lower element 32 made of structural insulating foam identical to the structural insulating foam of the secondary insulation blocks 5 of the second zone 12. The upper element 31 of the mixed secondary insulation block 30 is a box with a structure analogous to the structure of the secondary insulation blocks 5 of the first zone 11. Thus, the mixed secondary insulation block 30 has a coefficient of thermal contraction between the coefficient of thermal contraction of the secondary insulation block 5 of the first sub-zone 28 and the coefficient of thermal contraction of the secondary insulation blocks 5 of the second zone 12.As a result, the second sub-zone 29 of the transition zone 14 has a thermal contraction coefficient between the thermal contraction coefficient of the first sub-zone 28 of the transition zone 14 and the thermal contraction coefficient of the second zone 12.

[0189] As illustrated on the Figure 20The primary waterproof membrane 4 is composed of corrugated metal plates. These corrugated metal plates are, for example, made of stainless steel, approximately 1.2 mm thick and measuring 3 m by 1 m. The rectangular metal plate has a first series of parallel corrugations, called the lower corrugations, extending along a y-direction from one edge of the plate to the other, and a second series of parallel corrugations, called the upper corrugations, extending along an x-direction from one edge of the metal plate to the other. The x and y directions of the corrugation series are perpendicular. The corrugations are, for example, protruding on the inner face of the metal plate 1, which is intended to be in contact with the fluid contained in the tank. The edges of the metal plate are parallel to the corrugations.Note that the terms "high" and "low" have a relative meaning and signify that the undulations, referred to as low, have a lower height than the undulations, referred to as high. In a variation, the undulations can have the same height.

[0190] The metal plate has a plurality of flat surfaces between the corrugations. Some of the corrugations may be located between the insulating blocks 7 or remain on the flat parts of the insulating blocks 7. At each intersection between a lower corrugation and a higher corrugation, the metal plate has a node zone. The node zone has a central portion with a crest projecting inwards or outwards from the tank. Furthermore, the central portion is bordered, on one side, by a pair of concave corrugations formed in the crest of the higher corrugation and, on the other side, by a pair of recesses 8 into which the lower corrugation penetrates.

[0191] A primary waterproof membrane has been described above in which the undulations are continuous at the intersections between the two sets of undulations. The primary waterproof membrane can also have two mutually perpendicular sets of undulations with discontinuities in some of the undulations at the intersections between the two sets. For example, the discontinuities are distributed alternately in the first and second sets of undulations, and within a set of undulations, the discontinuities of one undulation are offset by one wave step relative to the discontinuities of an adjacent parallel undulation.

[0192] This type of waterproof membrane, composed of corrugated sheets, being less sensitive to the stepping phenomenon during the thermal contraction of the thermally insulating barriers 1, 3 and more resistant to stresses, it is not necessary, as in the embodiment of the Figure 10to place in the first zone a primary insulating block 7 and a secondary insulating block 5 outside the connecting ring. In this way, the first zone 11 consists only of the insulating blocks 5, 7 within the connecting ring. The transition zone 14 is then directly adjacent to the connecting ring.

[0193] In an embodiment not shown, the first zone 11 can also be a gas dome, a gas dome, or a mounting area for a pump support foot. For example, in the case of a mounting area for a pump support foot, the first zone 11 is located all around the support foot, and the secondary membrane 2 is attached to an anchoring flange 23 of the mounting area. The transition zone 14 then extends all around the first zone 11.

[0194] The technique described above for making a tank can be used in different types of tanks, for example to make an LNG tank in an onshore installation or in a floating structure such as a methane tanker or other.

[0195] With reference to the figure 19 A cutaway view of a methane tanker 70 shows a sealed and insulated tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary watertight barrier intended to be in contact with the LNG contained in the tank, a secondary watertight barrier arranged between the primary watertight barrier and the double hull 72 of the ship, and two insulating barriers arranged respectively between the primary watertight barrier and the secondary watertight barrier and between the secondary watertight barrier and the double hull 72.

[0196] As is known per se, loading / unloading pipelines 73 arranged on the upper deck of the ship can be connected, by means of suitable connectors, to a marine or port terminal to transfer a cargo of LNG to or from the tank 71.

[0197] There figure 19Figure 75 represents an example of a marine terminal comprising a loading and unloading berth, a subsea pipeline, and an onshore facility. The loading and unloading berth is a fixed offshore installation comprising a movable arm, a boom, and a tower, a tower, and a support, a boom. The boom carries a bundle of insulated flexible hoses, a hose, and a hose ...The subsea pipeline 76 allows the transfer of liquefied gas between the loading or unloading station 75 and the onshore facility 77 over a long distance, for example 5 km, which allows the LNG carrier 70 to be kept a long distance from the coast during loading and unloading operations.

[0198] To generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and / or pumps equipping the land installation 77 and / or pumps equipping the loading and unloading station 75 are used.

[0199] Although the invention has been described in connection with several particular embodiments, it is clearly evident that it is by no means limited to them and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention, as defined by the claims.

[0200] Thus, the examples above show a tank wall with insulating barriers forming substantially flat support surfaces in a vacuum tank and exhibiting thickness variations between different areas of the tank walls when the tank is filled with LNG. However, the arrangement could be reversed so that the tank walls exhibit thickness variations in a vacuum tank and flat support surfaces when the tank is filled with LNG.

[0201] In addition, the examples of realization of the transition zone given above can be combined with each other, for example within a transition zone comprising a plurality of primary insulating blocks 7 and secondary insulating blocks 5 so as to generate a plurality of sub-zones of the transition zone 14 whose thermal contraction coefficients are increasing from the first zone 11 towards the second zone 12.

[0202] The use of the verbs "to include," "to comprise," or "to include" and their conjugated forms does not preclude the presence of elements or steps other than those stated in a claim. The use of the indefinite article "a" or "an" for an element or step does not preclude, unless otherwise specified, the presence of multiple such elements or steps.

[0203] In claims, any reference sign in parentheses shall not be interpreted as a limitation of the claim.

Claims

1. A sealed and thermally insulating tank for storing a fluid, integrated in a support structure (6), in which a tank wall comprises, in a thickness direction: a secondary thermally insulating barrier (1) and a primary thermally insulating barrier (3) made up of juxtaposed insulating modules (5, 7, 17, 18, 26, 30, 36), an insulating module (5, 7, 17, 18, 26, 30, 36) of each of the secondary thermally insulating barrier (1) and primary thermally insulating barrier (3) comprising a cover panel (10), a bottom panel (9) and an insulating lining (8) interposed between the bottom panel (9) and the cover panel (10), a primary sealed membrane (4) resting on the primary thermally insulating barrier (3), and a secondary sealed membrane (2) resting on the secondary thermally insulating barrier (1), the tank wall comprising, in a length direction: - a first area (11) in which the insulating modules (5, 7) include spacers extending in the thickness direction of the tank wall between the cover panel (10) and the bottom panel (9) of said insulating modules (5, 7), said spacers being distributed over the surface of the cover panel (10) and of the bottom panel (9) in such a way that the bottom panel (9) and the cover panel (10) of said insulating modules (5, 7) are kept at a distance from one another by said spacers, characterized in that the tank wall comprises, in a length direction: - a second area (12) in which the insulating lining (8) of the insulating modules (5, 7) comprises a structural insulating foam interposed between the cover panel (10) and the bottom panel (9) on the surface of the cover panel (10) and of the bottom panel (9) in such a way that the cover panel (10) of said insulating modules (5, 7) is principally kept at a distance from the bottom panel (9) by said structural insulating foam, - a transition area (14) interposed between the first area (11) and the second area (12), in which the insulating modules (5, 7, 18, 26, 30, 36) are formed in such a way that the tank wall in said transition area (14) has at least one parameter, chosen from the coefficient of thermal contraction and the modulus of elasticity in the thickness direction of the tank wall, the value of which lies between the value of said at least one parameter of the first area (11) of the tank wall in the thickness direction of the tank wall and the value of said at least one parameter of the second area (12) of the tank wall in the thickness direction of the tank wall.

2. The sealed and thermally insulating tank as claimed in claim 1, in which the first area (11) is arranged over all or part of a periphery of the wall.

3. The sealed and thermally insulating tank as claimed in claim 1, in which the first area (11) is a corner area of the tank, a gas dome, a liquid dome or an area for attaching a support stand for a pump.

4. The sealed and thermally insulating tank as claimed in one of claims 1 to 3, in which the insulating modules (5, 7, 18, 26, 30, 36) of the transition area (14) comprise: - a first insulating module (5, 26, 30) arranged in the secondary thermally insulating barrier (1), the first insulating module (5, 26, 30) having a first value of said at least one parameter in the thickness direction of the tank wall, and - a second insulating module (7, 18, 26, 36) arranged in the primary thermally insulating barrier, the second insulating module (7, 18, 26, 36) having a second value of said at least one parameter in the thickness direction of the tank wall, the first insulating module (5, 26, 30) and the second insulating module (7, 18, 26, 36) being superposed in the direction of the thickness of the tank wall.

5. The sealed and thermally insulating tank as claimed in claim 4, in which - one out of the first insulating module (5, 30) and the second insulating module (7, 36) comprises spacers extending in a thickness direction of the tank wall between the cover panel (10) and the bottom panel (9) of said insulating module, said spacers being distributed over the surface of the bottom panel (9) and of the cover panel (10) in such a way that the bottom panel (9) and the cover panel (10) of said insulating module are kept at a distance from one another by said spacers, and - the other out of the first insulating module (5, 26) and the second insulating module (7, 18, 26) comprises a structural insulating foam interposed between the cover panel (10) and the bottom panel (9) on the surface of the cover panel (10) and of the bottom panel (9) in such a way that the cover panel (10) of said other insulating module is kept at a distance from the bottom panel (9) of said other insulating module by said structural insulating foam.

6. The sealed and thermally insulating tank as claimed in claim 5, in which the value of said at least one parameter of the other out of the first insulating module (5, 26) and the second insulating module (7, 18, 26) is lower than the value of said at least one parameter of the one out of the first insulating module (5, 30) and the second insulating module (7, 36).

7. The sealed and thermally insulating tank as claimed in one of claims 4 to 6, in which the first area (11) corresponds to a corner area of the tank comprising a connection ring, and the transition area (14) is directly adjacent to the connection ring, the second insulating module (7, 18, 26) comprises a structural insulating foam interposed between the cover panel (10) and the bottom panel (9) on the surface of the cover panel (10) and of the bottom panel (9) in such a way that the cover panel (10) of said other insulating module is kept at a distance from the bottom panel (9) of said other insulating module by said structural insulating foam.

8. The sealed and thermally insulating tank as claimed in claim 7, in which the first insulating module comprises spacers extending in a thickness direction of the tank wall between the cover panel (10) and the bottom panel (9) of said insulating module, said spacers being distributed over the surface of the bottom panel (9) and of the cover panel (10) in such a way that the bottom panel (9) and the cover panel (10) of said insulating module are kept at a distance from one another by said spacers.

9. The sealed and thermally insulating tank as claimed in claim 7 or claim 8, in which the insulating modules (5, 7, 18, 26, 30, 36) of the transition area (14) comprise: - a third insulating module (26) arranged in the secondary thermally insulating barrier (1), the third insulating module being closer to the second area (12) than the first insulating module (5, 26, 30) and having a third value of said at least one parameter in the thickness direction of the tank wall, - a fourth insulating module (7, 18, 26, 36) arranged in the primary thermally insulating barrier (3), the fourth insulating module (7, 18, 26, 36) being closer to the second area (12) than the second insulating module (7, 18, 26, 36) and having a fourth value of said at least one parameter in the thickness direction of the tank wall, and in which the third value of said at least one parameter of the third insulating module (26) is between the first value of said at least one parameter of the first insulating module (5, 26, 30) and the second value of said at least one parameter of the second insulating module (7, 18, 26, 36).

10. The sealed and thermally insulating tank as claimed in claim 9, in which the third insulating module (26) is a mixed module comprising an intermediate panel (20) arranged between the bottom panel and the cover panel, the insulating lining comprising a lower lining arranged between the intermediate panel and the bottom panel and an upper lining arranged between the intermediate panel and the cover panel, the mixed module having a coefficient of thermal expansion which is between the coefficient of thermal expansion of an insulating module of the first area (11) and the coefficient of thermal expansion of an insulating module of the second area (12).

11. The sealed and thermally insulating tank as claimed in claim 9 or claim 10, in which the fourth insulating module (7, 18, 26, 36) is identical to the second insulating module (7, 18, 26, 36), such that the fourth value of said at least one parameter is equal to the second value of said at least one parameter.

12. The sealed and thermally insulating tank as claimed in one of claims 4 to 6, in which the insulating modules (5, 7, 18, 26, 30, 36) of the transition area (14) comprise a third insulating module (26) arranged in the secondary thermally insulating barrier (1), the third insulating module being closer to the second area (12) than the first insulating module (5, 26, 30) and having a third value of said at least one parameter in the thickness direction of the tank wall, and in which the second insulating module (7, 18, 26) extends over the entire length of the transition area in the primary thermally insulating barrier (3), the third value of said at least one parameter of the third insulating module (26) being between the first value of the first insulating module (5, 26, 30) of said at least one parameter and the second value of said at least one parameter of the second insulating module (7, 18, 26, 36).

13. The sealed and thermally insulating tank as claimed in claim 5, in which said other out of the first insulating module and the second insulating module (18) extends jointly in the transition area (14) and in the second area (12) of the tank wall.

14. The sealed and thermally insulating tank as claimed in one of claims 1 to 13, in which the transition area (14) has a coefficient of thermal contraction in the thickness direction of the tank wall increasing in the length direction of the tank wall from the first area (11) toward the second area (12) of the tank wall.

15. The sealed and thermally insulating tank as claimed in one of claims 1 to 14, in which the transition area (14) has a modulus of elasticity in the thickness direction of the tank wall decreasing in the length direction of the tank wall from the first area (11) toward the second area (12) of the tank wall.

16. The sealed and thermally insulating tank as claimed in claim 14, in which the coefficient of thermal contraction in the thickness direction of the tank wall in the transition area (14) increases continuously and gradually from the first area (11) toward the second area (12).

17. The sealed and thermally insulating tank as claimed in one of claims 1 to 16, in which an insulating module (7, 26) of the transition area (14) comprises a structural insulating foam (27, 41, 42) interposed between the cover panel (10) and the bottom panel (9) on the surface of the cover panel (10) and of the bottom panel (9) of said insulating module (7, 26) in such a way that the cover panel (10) of said insulating module (7, 26) is kept at a distance from the bottom panel (9) of said insulating module by said structural insulating foam, (27, 41, 42), said structural insulating foam (27, 41) having a coefficient of thermal contraction in the thickness direction of the tank wall which is lower than the coefficient of thermal contraction in said thickness direction of the structural insulating foam of the second area (12).

18. The sealed and thermally insulating tank as claimed in claim 17, in which the structural insulating foam (41, 42) of said insulating module (7) of the transition area comprises a first portion (41) of structural insulating foam and a second portion (42) of structural insulating foam, the first portion (41) of structural insulating foam being closer to the first area (11) than the second portion (42) of structural foam, the first portion (41) of structural insulating foam having a coefficient of thermal contraction in the thickness direction of the tank which is lower than the coefficient of thermal contraction of the second portion (42) of structural insulating foam in said thickness direction.

19. The sealed and thermally insulating tank as claimed in one of claims 1 to 16, in which an insulating module (7, 26) of the transition area (14) comprises a structural insulating foam (27, 41, 42) interposed between the cover panel (10) and the bottom panel (9) on the surface of the cover panel (10) and of the bottom panel (9) of said insulating module (7, 26) in such a way that the cover panel (10) of said insulating module (7, 26) is kept at a distance from the bottom panel (9) of said insulating module by said structural insulating foam (27, 41, 42), said structural insulating foam (27, 41) having a modulus of elasticity in the thickness direction of the tank wall which is higher than the modulus of elasticity in said thickness direction of the structural insulating foam of the second area (12).

20. The sealed and thermally insulating tank as claimed in claim 19, in which the structural insulating foam (41, 42) of said insulating module (7) of the transition area comprises a first portion (41) of structural insulating foam and a second portion (42) of structural insulating foam, the first portion (41) of structural insulating foam being closer to the first area (11) than the second portion (42) of structural foam, the first portion (41) of structural insulating foam having a modulus of elasticity in the thickness direction of the tank which is higher than the modulus of elasticity of the second portion (42) of structural insulating foam in said thickness direction.

21. The sealed and thermally insulating tank as claimed in claim 17 or 19, in which the structural insulating foam (41, 42) of said module (7) of the transition area is a fiber-reinforced polyurethane foam, the first portion (41) of structural insulating foam having the fibers oriented in a thickness direction of the tank wall and the second portion (42) of structural insulating foam having the fibers oriented perpendicular to the thickness direction of the tank wall.

22. The sealed and thermally insulating tank as claimed in claim 15, in which the thickness of the first portion (41) gradually decreases from the first area (11) toward the second area (12) and the thickness of the second portion gradually increases from the first area (11) toward the second area (12).

23. The sealed and thermally insulating tank as claimed in one of claims 1 to 20, in which the insulating modules of the transition area comprise a mixed module (30, 36) comprising an intermediate panel (34, 39) arranged between the bottom panel (9) and the cover panel (10), the insulating lining (8) comprising a lower lining arranged between the intermediate panel (34, 39) and the bottom panel (9) and an upper lining arranged between the intermediate panel (34, 39) and the cover panel (10), the mixed module (30, 36) comprising support spacers extending in a thickness direction of the tank wall between the intermediate panel (34, 39) and one out of the bottom panel (9) and the cover panel (10), said spacers being distributed over the surface of the intermediate panel (34, 39) and of said one out of the bottom panel (9) and the cover panel (10) in such a way that the intermediate panel (34, 39) and said one out of the bottom panel (9) and the cover panel (10) are kept at a distance from one another by said support spacers, the insulating lining arranged between the intermediate panel (34, 39) and the other out of the bottom panel (9) and the cover panel (10) comprising a structural insulating foam distributed over the surface of the intermediate panel (34, 39) and of said other out of the bottom panel (9) and the cover panel (10) in such a way that the intermediate panel (34, 39) and said other out of the bottom panel (9) and the cover panel (10) are kept at a distance by said structural insulating foam.

24. The sealed and thermally insulating tank as claimed in claim 23, in the intermediate panel (39) extends in a plane which is inclined relative to the bottom panel (9) and to the cover panel (10).

25. The sealed and thermally insulating tank as claimed in claim 23 or claim 24, in which the intermediate panel (39) is at a distance from an edge of the mixed module (36) located close to one out of the first area (11) and the second area (12).

26. The sealed and thermally insulating tank as claimed in one of claims 1 to 25, in which the primary and secondary sealed membranes are made up essentially of metal strips extending in the length direction and having raised longitudinal edges, the raised edges of two adjacent metal strips being welded in pairs so as to form expansion bellows allowing deformation of the sealed membrane in a direction perpendicular to the length direction, in which the corner of the tank comprises a primary anchoring wing (23) and a secondary anchoring wing, a first end of said anchoring wings (23) being anchored to the support structure (6) and a second end of said anchoring wings (23) being leaktightly welded to the corresponding sealing membrane.

27. The sealed and thermally insulating tank as claimed in claim 26, in which the primary sealing membrane comprises corrugations extending perpendicular to the raised edges and arranged in line with the first area (11).

28. The sealed and thermally insulating tank as claimed in one of claims 1 to 25, in which the secondary sealed membrane (2) is made up essentially of metal strips extending in the length direction and having raised longitudinal edges, the raised edges of two adjacent metal strips being welded in pairs so as to form expansion bellows allowing deformation of the sealed membrane in a direction perpendicular to the length direction, in which the corner of the tank comprises a secondary anchoring wing (23), a first end of said anchoring wing (23) being anchored to the support structure (6) and a second end of said anchoring wing (23) being leaktightly welded to the secondary sealing membrane, and in which the primary sealed membrane (4) comprises corrugated metal plates.

29. A carrier (70) for the transport of a cold liquid product, the carrier comprising a double hull (72) and a tank (71) as claimed in one of claims 1 to 28, arranged in the double hull.

30. A transfer system for a cold liquid product, the system comprising a carrier (70) as claimed in claim 29, insulated pipelines (73, 79, 76, 81) arranged so as to connect the tank (71) installed in the hull of the carrier to a floating or onshore storage facility (77), and a pump for pumping a flow of cold liquid product through the insulated pipelines from or to the floating or onshore storage facility, to or from the tank of the carrier.

31. A method for loading or unloading a carrier (70) as claimed in claim 29, in which a cold liquid product is conveyed through insulated pipelines (73, 79, 76, 81) from or to a floating or onshore storage facility (77), to or from the tank of the carrier (71).

Images