Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C3/00—Vessels not under pressure
  • F17C3/02—Vessels not under pressure with provision for thermal insulation
  • F17C3/025—Bulk storage in barges or on ships
  • F17C3/027—Wallpanels for so-called membrane tanks
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C6/00—Methods and apparatus for filling vessels not under pressure with liquefied or solidified gases
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C7/00—Methods or apparatus for discharging liquefied, solidified, or compressed gases from pressure vessels, not covered by another subclass
  • F17C7/02—Discharging liquefied gases
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2201/00—Vessel construction, in particular geometry, arrangement or size
  • F17C2201/01—Shape
  • F17C2201/0147—Shape complex
  • F17C2201/0157—Polygonal
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2201/00—Vessel construction, in particular geometry, arrangement or size
  • F17C2201/05—Size
  • F17C2201/052—Size large (>1000 m3)
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2203/00—Vessel construction, in particular walls or details thereof
  • F17C2203/03—Thermal insulations
  • F17C2203/0304—Thermal insulations by solid means
  • F17C2203/0358—Thermal insulations by solid means in form of panels
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2203/00—Vessel construction, in particular walls or details thereof
  • F17C2203/06—Materials for walls or layers thereof; Properties or structures of walls or their materials
  • F17C2203/0602—Wall structures; Special features thereof
  • F17C2203/0612—Wall structures
  • F17C2203/0626—Multiple walls
  • F17C2203/0629—Two walls
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2203/00—Vessel construction, in particular walls or details thereof
  • F17C2203/06—Materials for walls or layers thereof; Properties or structures of walls or their materials
  • F17C2203/0634—Materials for walls or layers thereof
  • F17C2203/0636—Metals
  • F17C2203/0648—Alloys or compositions of metals
  • F17C2203/0651—Invar
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2203/00—Vessel construction, in particular walls or details thereof
  • F17C2203/06—Materials for walls or layers thereof; Properties or structures of walls or their materials
  • F17C2203/0634—Materials for walls or layers thereof
  • F17C2203/0658—Synthetics
  • F17C2203/066—Plastics
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2205/00—Vessel construction, in particular mounting arrangements, attachments or identifications means
  • F17C2205/03—Fluid connections, filters, valves, closure means or other attachments
  • F17C2205/0302—Fittings, valves, filters, or components in connection with the gas storage device
  • F17C2205/0352—Pipes
  • F17C2205/0355—Insulation thereof
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2221/00—Handled fluid, in particular type of fluid
  • F17C2221/03—Mixtures
  • F17C2221/032—Hydrocarbons
  • F17C2221/033—Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2223/00—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel
  • F17C2223/01—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel characterised by the phase
  • F17C2223/0146—Two-phase
  • F17C2223/0153—Liquefied gas, e.g. LPG, GPL
  • F17C2223/0161—Liquefied gas, e.g. LPG, GPL cryogenic, e.g. LNG, GNL, PLNG
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2223/00—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel
  • F17C2223/03—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel characterised by the pressure level
  • F17C2223/033—Small pressure, e.g. for liquefied gas
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2227/00—Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
  • F17C2227/01—Propulsion of the fluid
  • F17C2227/0128—Propulsion of the fluid with pumps or compressors
  • F17C2227/0135—Pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2260/00—Purposes of gas storage and gas handling
  • F17C2260/03—Dealing with losses
  • F17C2260/031—Dealing with losses due to heat transfer
  • F17C2260/033—Dealing with losses due to heat transfer by enhancing insulation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2270/00—Applications
  • F17C2270/01—Applications for fluid transport or storage
  • F17C2270/0102—Applications for fluid transport or storage on or in the water
  • F17C2270/0105—Ships
  • F17C2270/0107—Wall panels

Definitions

• the invention relates to the field of tanks, sealed and thermally insulating, with membranes, for the storage and/or the transport of fluid, such as a cryogenic fluid.
• Sealed and thermally insulating membrane tanks are used in particular for the storage of liquefied natural gas (LNG), which is stored at atmospheric pressure at around -162°C. These tanks can be installed on land or on a floating structure. In the case of a floating structure, the tank may be intended for the transport of liquefied natural gas or to receive liquefied natural gas used as fuel for the propulsion of the floating structure.
• LNG liquefied natural gas
• sealed and thermally insulating tanks are known for the storage of liquefied natural gas, integrated into a supporting structure, such as the double hull of a ship intended for the transport of liquefied natural gas.
• a supporting structure such as the double hull of a ship intended for the transport of liquefied natural gas.
• such tanks comprise a multilayer structure having successively, in the direction of the thickness, from the outside towards the inside of the tank, a secondary thermally insulating barrier retained on the support structure, a secondary sealed membrane resting against the secondary thermally insulating barrier, a primary thermally insulating barrier resting against the secondary sealed membrane and a primary sealed membrane resting against the primary thermally insulating barrier and intended to be in contact with the liquefied natural gas contained in the tank.
• the document WO2014167214 A2 describes a sealed and thermally insulating multilayer tank corner structure in which the secondary thermally insulating barrier at the level of an angle between two walls of the tank comprises two insulating panels forming an edge, the secondary sealed membrane comprising at right of said edge a flexible waterproof film connecting portions of secondary waterproof membrane of said two vessel walls.
• a central portion of this flexible waterproof film that is to say inserted between the portions of said flexible waterproof film anchored on the secondary waterproof membrane portions of the two vessel walls, is not anchored on the secondary thermally insulating barrier and is therefore free relative to said secondary thermally insulating barrier.
• the thermal contraction of the insulating panels forming the edge and of the sealed membrane is absorbed by a deformation of the central portion of the flexible sealed film, typically said flexible sealed film is suitable to stretch to absorb the stresses associated with this contraction.
• the flexible film stretches, a space appears or increases between said central portion of the flexible waterproof film and the thermally insulating barrier. This space develops along the entire length of the ridge.
• Such a space forms a channel favoring convection and is therefore likely to degrade the thermal insulation performance of the vessel, in particular in the context of edges presenting a component parallel to the direction of earth gravity.
• One idea underlying the invention is to provide a sealed and thermally insulating tank in which convection phenomena are reduced.
• an idea underlying the invention is to provide a sealed and thermally insulating tank limiting the presence of continuous circulation channels in the thermally insulating barriers, and more particularly between the thermally insulating barriers and the sealed membranes, in order to limit natural convection phenomena in said thermally insulating barriers.
• the invention provides a leaktight and thermally insulating fluid storage tank, in which a wall of the tank comprises, from the outside towards the inside of the tank, a secondary thermally insulating barrier and a secondary leaktight membrane , the secondary sealed membrane being anchored on the secondary thermally insulating barrier, a primary thermally insulating barrier resting against the secondary sealing membrane and a primary sealing membrane resting against the primary thermally insulating barrier and intended to be in contact with a fluid contained in the vessel , wherein said secondary thermally insulating barrier has a first planar portion and a second planar portion oriented at an angle relative to the first planar portion, a junction between the first secondary thermally insulating barrier planar portion and the second planar thermally insulating barrier portion secondary forming an edge, the first flat portion forming a first anchoring zone for the secondary waterproof membrane, the first anchoring zone being remote from the edge, the second flat portion forming a second anchoring zone for the waterproof membrane secondary, the second anchoring zone being remote from the
• the pressure drop shutter makes it possible to generate a pressure drop in a flux flow that may occur in the channel while allowing the circulation of gas, for example inert gas.
• pressure drop shutter is defined according to the invention as a shutter allowing dissipation, by friction, of the mechanical energy of a moving fluid. That is, a shutter causing a drop in fluid pressure due to the resistance encountered by the fluids flowing over or through the shutter.
• such a sealed and thermally insulating tank may comprise one or more of the following characteristics.
• the channel is parallel to the direction of earth gravity. In other words, the channel is parallel to a vertical direction of the tank.
• Such vertical channels are the most likely to promote convection phenomena so that the arrangement of pressure drop shutter(s) in such a channel is particularly advantageous and effectively reduces convection phenomena.
• the channel has a component parallel to the direction of earth gravity.
• the channel can be vertical or oblique with respect to the vertical direction of the tank.
• the channel is perpendicular to the direction of earth gravity.
• the channel has a component perpendicular to the direction of earth gravity.
• the channel extends along the waterproof membrane.
• the pressure drop shutter comprises at least one fixing zone.
• the pressure drop shutter comprises at least one flexible element allowing the pressure drop.
• the pressure drop shutter comprises an anchoring strip and a flexible portion, the anchoring strip developing in a secant direction to the longitudinal direction of the channel, the flexible portion comprising a plurality of flexible elements projecting from the anchoring strip in the direction of the waterproof membrane, a free end of the flexible elements opposite the anchoring strip being in contact with the waterproof membrane so as to create a pressure drop for a flow circulating in the channel, said flexible elements being capable of elastically bending in contact with the waterproof membrane .
• the pressure drop shutter comprises a first portion and a second portion, the anchoring strip of the pressure drop shutter comprising a first portion of anchoring strip formed by the first portion of the pressure drop shutter and a second portion of anchoring strip formed by the second portion of the pressure drop shutter, the flexible portion of the pressure drop shutter comprising a first flexible portion formed by the first portion of the pressure drop shutter and a second flexible portion formed by the second portion of the pressure drop shutter.
• the pressure drop shutter extending between the bottom of the channel and the sealed membrane on the one hand and, on the other hand, the anchoring strip developing in a direction secant to the longitudinal direction of the channel and the portion flexible extending to the waterproof membrane allow a good obturation of the canal.
• the elasticity of the flexible portion as well as the support of the sealed membrane on said flexible portion make it possible in a simple way to close the channel in a gas-permeable manner while generating a pressure drop for a flow of circulating gas. in the channel.
• this elasticity of the flexible portion makes it possible to easily overcome manufacturing and/or positioning tolerances of the thermally insulating barrier and/or of the waterproof membrane while maintaining good sealing of the channel.
• the flexible elements being deformable independently of each other, the deformations of the various flexible elements make it possible to absorb the channel section variations linked to these manufacturing or positioning tolerances while sealing the channel satisfactorily.
• the plurality and the length of the flexible elements forming the flexible portion allow simple deformation of the flexible portion.
• These flexible elements also allow a modular pressure drop depending on the number of flexible elements, the greater this number, the greater the number of passages for the circulation of the gas, the gas being able to circulate between two adjacent flexible elements, in particular when one of said adjacent flexible elements is more deformed than the other by the support of the waterproof membrane.
• the flexible elements are flexible and elastic strips.
• the flexible elements are juxtaposed so that, in the absence of stress on said flexible elements, said flexible elements develop in the same plane.
• the flexible elements develop in a secant plane, preferably perpendicular, to the longitudinal direction of the groove.
• a portion of these lamellae may in particular extend in a plane perpendicular to the longitudinal direction of the channel.
• the flexible elements are able to flex elastically in the longitudinal direction of the channel.
• Such flexible elements arranged in the same plane, allow good sealing of the channel.
• Such lamellae can develop in different directions.
• the lamellae develop in a direction perpendicular to the thickness direction of the thermally insulating barrier.
• the lamellae develop in a direction parallel to the thickness direction of the thermally insulating barrier.
• At least two of said lamellae develop along distinct respective directions.
• the slats develop in a direction perpendicular to a portion of the anchoring strip from which said slats respectively protrude.
• the lamellae develop in a plane secant to the longitudinal direction of the channel.
• a portion of these lamellae may in particular extend in a plane perpendicular to the longitudinal direction of the channel.
• the flexible elements are elastic and flexible rods, for example of a shape similar to the bristles of a paintbrush.
• the flexible portion of the pressure drop shutter is easily deformed under the effect of a stress exerted by the waterproof membrane.
• such flexible elements provide good sealing of the channel.
• the flexible elements are juxtaposed so that, in the absence of stress on said flexible elements, the free ends of said flexible elements develop in the same plane.
• the flexible elements develop, in the absence of stress on said flexible elements, over a distance, taken along the thickness direction of the thermally insulating barrier, greater than or equal to the depth of the channel taken according to said thickness direction of the thermally insulating barrier.
• the pressure drop stopper makes it possible to close the channel during the use of the tank.
• such flexible elements remain in contact with the membrane even if the tank is cooled, generating a contraction of the sealed membrane.
• the flexible elements two by two adjacent are in contact in the absence of stress on the flexible portion, typically in the absence of deformation related to the support of the waterproof membrane.
• the flexible portion develops, in projection in a plane perpendicular to the longitudinal direction of the channel, over the entire section of the channel taken in said plane perpendicular to the longitudinal direction of the channel.
• the flexible portion ensures a good sealing of the channel while allowing the flow of a flow with a pressure drop. Indeed, the contact between the flexible elements does not make it possible to block the flow of the flux.
• the anchoring strip is fixed to the bottom of the channel.
• Attaching the anchor strip to the bottom of the channel ensures that the headloss plug develops from the bottom of the channel, thus ensuring effective plugging of the headloss plug
• the anchor band rests on the bottom of the channel.
• the pressure drop shutter comprises a textile sheet covering flexible elements of the pressure drop shutter or even the entire flexible portion and the anchoring strip of the pressure drop shutter.
• the textile sheet of the shutter covers part of the flexible elements.
• the textile ply of the pressure drop shutter covers between 20% and 70% of one face of the flexible elements, for example, 50% or 60% of one face of the flexible elements. This characteristic makes it possible to control the flow of gas in the channel.
• the textile web covers one face of the pressure drop shutter receiving the flow of the flow first, that is to say facing upstream with respect to the flow.
• This arrangement is particularly advantageous and allows effective retention of the textile ply on the flexible portion and the anchoring strip while limiting the risk of detachment of the textile ply.
• the flow of the fluid exerts a force in the direction of the various elements of the pressure drop shutter, thus the textile web is then pressed firmly against the flexible portion and the anchoring strip of the pressure drop shutter.
• the textile sheet covers the other face of the pressure drop shutter, facing downstream with respect to the flow.
• the pressure drop shutter can comprise a plurality of materials.
• a first fabric covers a first surface of the pressure drop valve and a second fabric covers a second surface of the pressure drop valve.
• Another example is a superposition of at least two fabrics covering the same surface of the pressure drop shutter.
• the pressure drop shutter comprises a textile layer permeable to gas, for example made of fabric or non-woven material, covering flexible elements of the pressure drop shutter.
• the textile web can be fixed on one face of the anchoring strip and/or on one face of the flexible portion of the pressure drop shutter, for example by gluing. Polyurethane or epoxy glues can in particular be used.
• the textile sheet can be made of mineral fibers, for example fiberglass, or synthetic.
• the sealed membrane exerts a greater stress on the flexible portion of the pressure drop shutter, causing a greater deformation of said flexible portion, when the tank is at room temperature than when the tank is placed cold, that is to say when the storage space of the tank comprises a cold liquid such as a cryogenic liquid, for example liquefied natural gas.
• the textile sheet is flexible.
• the textile web does not hinder the elastic deformation of the flexible portion.
• the pressure drop shutter comprises a flexible film, said flexible film comprising a first fixing zone and a second fixing zone, the first attachment zone extending transversely to the longitudinal direction of the channel, the first attachment zone of said flexible film being fixed to the bottom of the channel, the second attachment zone extending transversely to the longitudinal direction of the channel, the second attachment zone being fixed to the external face of the secondary waterproof membrane delimiting the channel, the flexible film comprising a closure portion extending from the first attachment zone to the second attachment zone, said closure portion extending across the channel between the bottom of the channel and the secondary waterproof membrane so as to create a pressure drop in the channel.
• attachment zone extending transversely to the longitudinal direction of the channel is meant a zone of the flexible film extending secantly, preferably perpendicularly, to the longitudinal direction of the channel.
• the pressure drop shutter makes it possible to generate a pressure drop in a flux flow that may occur in the channel while allowing the circulation of gas, for example inert gas.
• the closure portion develops between the bottom of the channel and the external face of the waterproof membrane, thus allowing good sealing of the channel.
• the second attachment zone being attached to the waterproof membrane, said second attachment zone follows the deformations of the waterproof membrane so that this sealing portion is present including during deformation of the waterproof membrane.
• the first attachment zone and the second attachment zone are offset in the longitudinal direction of the channel.
• the first attachment zone and the second attachment zone are not contiguous so that the closure portion develops with a component parallel to the longitudinal direction of the channel.
• one end, preferably two opposite ends, of the first attachment zone and/or of the second attachment zone protrudes from the channel so as to be inserted between the waterproof membrane and the thermally insulating barrier.
• the fixing of the first fixing zone and/or of the second fixing zone is simple and reliable, said end being pinched between the waterproof membrane and the thermally insulating barrier.
• one end, preferably two opposite ends, of the first attachment zone and/or of the second attachment zone protrudes from the channel so as to be inserted between two contiguous portions of the waterproof membrane, said two adjoining portions being connected in a sealed manner.
• the fixing of the first fixing zone and/or of the second fixing zone is simple and reliable, said end being clamped between said two contiguous portions of the waterproof membrane.
• the closure portion is movable relative to the bottom of the channel. According to one embodiment, the closure portion is movable relative to the waterproof membrane. In other words, according to one embodiment, the closure portion is free relative to the bottom of the channel and to the sealed membrane. Thus, the closure portion closes the channel in a non-sealed manner and therefore allows the circulation of inert gas in the channel while creating the pressure drop in the flow.
• the closure portion is deformable between the bottom of the channel and the sealed membrane. This deformability of the obturation portion can be obtained in many ways.
• the flexible film is made of an elastically deformable material.
• the closure portion has a length, when said closure portion is arranged in a plane, greater than the distance between a fixing surface of the first fixing zone on the bottom of the channel and a surface for fixing the second fixing zone to the waterproof membrane. In other words, according to one embodiment, the closure portion is in a loose state in the channel, in particular at room temperature.
• the first attachment zone and the second attachment zone are located at two opposite ends of the flexible film and are arranged at the same level in the longitudinal direction of the channel.
• the closure portion located between the bottom of the channel and the sealed membrane is deformable and comprises at least one folding along an axis transverse to the longitudinal direction of the channel.
• the shutter then has, for example, a particularly advantageous U-shape and is suitable for installation in situ in the tank.
• Such an obturator can be installed with a tool, for example a blade allowing the insertion of the obturator in the channel without damaging it.
• the obturator comprises a compressible element which is prestressed and housed in the folding between the first and the second fixing zone so as to exert a reaction force pressing the first fixing zone against the bottom of the channel and the second fixing zone against the outer face of the sealed membrane delimiting the channel.
• the compressible element is made of a material chosen from wadding, felt, glass wool, rock wool, polymer foams, polyethylene wadding or others and extending in the direction of the thickness between the first attachment zone and the second attachment zone. Thanks to this characteristic, fixing by gluing is facilitated.
• an anti-adhesive film is inserted in the folding to avoid sticking together the two sides of the flexible film folded over one another, for example under the effect of any overflows of adhesive.
• the release film can be a sheet of polyethylene or PTFE.
• the anti-adhesive film inserted in the folding has one end located in the folding and a second end located outside the folding. This feature facilitates the installation of the stopper in the tank and prevents any spillage of adhesive from disturbing the installation of the stopper.
• the release film can be inserted alone or in combination with a compressible element. To facilitate the installation of the obturator in the tank, the non-stick film and the flexible film can be successively folded around the end edge of the blade in order to push them into the channel.
• the closure portion comprises two mutually spaced folds in the longitudinal direction of the channel, each fold being made along an axis transverse to the longitudinal direction of the channel.
• the shutter has for example a Z shape.
• the pressure drop shutter is made of woven textile material and has a direction of elongation extending between the first attachment zone and the second attachment zone, the fibers of the woven textile being oriented between 35° and 55° (degrees) relative to the direction of elongation of the channel, preferably, the fibers of the woven fabric are oriented at 45° relative to the direction of elongation of the channel. Thanks to this characteristic, the pressure drop shutter obtains flexibility by the deformation of the weft threads and the warp threads of the woven textile.
• the closure portion makes it possible to follow the variations in relative positioning and dimension of the thermally insulating barrier and/or of the sealed membrane while effectively obstructing the channel in order to create the pressure drop in a flow within said channel.
• a pressure drop shutter allows this effective sealing of the channel including when the tank is cold, that is to say in the event of thermal contraction of the sealed membrane and of the thermally insulating barrier and therefore variation of the gap between the first attachment zone and the second attachment zone.
• the closure portion of the flexible film is a first closure portion
• the flexible film comprises a third fixing zone extending transversely to the longitudinal direction of the channel, the third fixing zone being fixed on the bottom of the channel, the second attachment area being interposed between the first attachment area and the third attachment area, the flexible film comprising a second closure portion extending from the second attachment area to the third attachment area , said second closure portion extending across the channel between the bottom of the channel and the secondary sealed membrane so as to create a pressure drop in the channel.
• Such a pressure drop shutter allows a good sealing of the channel and therefore a significant flow flow pressure drop.
• the third attachment zone is offset along the longitudinal direction of the channel relative to the first attachment zone and to the second attachment zone.
• the second closure portion is movable relative to the bottom of the channel.
• the second closure portion is movable relative to the waterproof membrane.
• the second closure portion is free relative to the bottom of the channel and to the sealed membrane.
• the second closure portion closes the channel in a non-sealed manner and therefore allows the circulation of inert gas in the channel while creating the pressure drop in the flow.
• the second closure portion is deformable between the bottom of the channel and the sealed membrane. This deformability of the second closure portion can be obtained in many ways, for example analogously to the examples above for the first closure portion.
• the flexible film is made of a material chosen from the group consisting of a glass mat, a polyethylene film and/or a polyamide film.
• the film can be: a glass-based fabric, a polyethylene fabric, a polyamide fabric, a polyimide fabric, a polyetherimide fabric, this list being non-exhaustive.
• Such materials have good resistance to cold while retaining flexibility allowing the flexible film to follow the deformations of the waterproof membrane.
• the first attachment zone develops in a plane secant to the longitudinal direction of the channel.
• the first attachment zone develops in a plane perpendicular to the longitudinal direction of the channel.
• the second attachment zone develops in a plane secant to the longitudinal direction of the channel.
• the second attachment zone develops in a plane perpendicular to the longitudinal direction of the channel.
• Such anchoring zones arranged perpendicular to the longitudinal direction of the channel allow effective sealing of the channel by the sealing portion(s).
• the first fixing zone and/or the second fixing zone is fixed by gluing.
• the tank comprises a double-sided adhesive tape interposed between the first fixing portion and the bottom of the channel in order to fix said first fixing portion to the bottom of the channel.
• the tank comprises a double-sided adhesive tape interposed between the waterproof membrane and the second fixing zone in order to fix said second fixing zone on the waterproof membrane.
• adhesive strips make it possible to fix the first and second fixing zones simply and quickly.
• adhesive strips allow the attachment of the flexible film in a simple manner by simple application or pressure of the flexible film on said adhesive strips or vice versa.
• the pressure drop shutter is arranged in a fixed and reliable manner in the channel.
• the sealed and thermally insulating tank comprises a plurality of pressure drop shutters arranged in the channel along the longitudinal direction of the channel.
• the sealed and thermally insulating tank comprises a plurality of pressure drop shutters arranged in the channel along the longitudinal direction of the channel, said pressure drop shutters each comprising an anchoring strip and a flexible portion, said pressure drop shutters extending between the bottom of the channel and the waterproof membrane, the anchoring strip developing in a direction secant to the longitudinal direction of the channel, the flexible portion comprising a plurality of flexible elements projecting from the anchoring strip in the direction of the waterproof membrane, a free end of the flexible elements opposite the anchoring strip being in contact with the secondary waterproof membrane so as to create a pressure drop for a flow circulating in the channel, said flexible elements being capable of elastically bending in contact with the membrane waterproof.
• the pressure drop shutters of the plurality of pressure drop shutters are arranged in the channel at regular intervals along the longitudinal direction of the channel.
• the plurality of pressure drop shutters are arranged in the channel at irregular intervals along the longitudinal direction of the channel.
• the pressure drop shutters of the plurality of pressure drop shutters arranged in the channel are identical.
• the pressure drop shutters of the plurality of pressure drop shutters are different and may correspond to different embodiments described in this text.
• the thermally insulating barrier forming the bottom of the channel comprises a plurality of spaced insulating panels, for example in a regular or irregular manner, and a plurality of junction zones located between the insulating panels, for example with a regular pitch. or irregular between two junction areas.
• the shutters can be arranged opposite the insulating panels so that the junction zones at each end of a panel are between the shutters.
• the shutters are mutually spaced by an interval corresponding to the regular or irregular pitch of the junction zones.
• at least one shutter is arranged opposite each insulating panel. Thus, there is systematically at least one shutter which blocks the flow between two successive junction zones.
• the pressure drop shutters are arranged at irregular intervals.
• the sealed and thermally insulating tank comprises a first tank wall and a second tank wall, the first tank wall and the second tank wall forming an edge of the thermally insulating barrier, the first tank wall comprising a first anchoring surface and the second vessel wall forming a second anchoring surface, the bottom of the channel being formed by the thermally insulating barrier between the first anchoring surface and the second anchoring surface, the bottom of the channel forming the ridge, and the waterproof membrane comprises a corner waterproof part, the corner waterproof part comprising a first portion anchored on the first anchoring surface and a second portion anchored on the second anchoring surface, the sealed corner piece further comprising a central portion interposed between the first portion and the second portion, said central portion being free with respect to the thermally insulating barrier of my able to absorb the stresses by deformation in the waterproof membrane in line with the edge, the channel being delimited by the outer face of the corner waterproof part.
• the sealed and thermally insulating tank comprises a corner structure, said corner structure comprising a first insulating panel and a second insulating panel, the first insulating panel forming one end of the thermally insulating barrier of the first vessel wall, the second insulating panel forming one end of the thermally insulating barrier of the second vessel wall, the first insulating panel and the second insulating panel jointly forming the edge, the corner structure further comprising a first portion of waterproof membrane and a second portion of waterproof membrane, the first portion of waterproof membrane resting on the first insulating panel, the said first portion of waterproof membrane forming one end of the waterproof membrane of the first tank wall, the second portion of waterproof membrane resting on the second insulating panel, said second portion of waterproof membrane forming one end of the waterproof membrane of the second tank wall.
• the first portion of waterproof membrane comprises a first composite film fixed to the first insulating panel and the second portion of waterproof membrane comprises a second composite film fixed to the second insulating panel.
• the first portion of waterproof membrane comprises a laminated composite waterproof film comprising a metal sheet interposed between two layers of resinated fibers. According to one embodiment, the first portion of waterproof membrane is glued to the first insulating panel. According to one embodiment, the second portion of waterproof membrane comprises a laminated composite waterproof film comprising a metal sheet interposed between two layers of resinated fibers. According to one embodiment, the second portion of sealed membrane is glued to the second insulating panel.
• the first portion of sealed membrane is a metal plate anchored on the first portion of thermally insulating barrier.
• the second portion of sealed membrane is a metal plate anchored on the second portion of thermally insulating barrier.
• the first insulating panel forms the first anchoring surface.
• the second insulating panel forms the second anchoring surface.
• the first portion of waterproof membrane for example an edge of said first portion of waterproof membrane, forms the first anchoring surface.
• the second portion of sealed membrane for example an edge of said second portion of sealed membrane, forms the second anchoring surface.
• the corner seal can be attached in many ways to the first and second anchoring surfaces. According to one embodiment, the corner sealed piece is glued to one or the first and second anchoring surfaces. According to one embodiment, the sealed corner piece is welded to one or the first and second anchoring surfaces.
• the corner sealed piece comprises a composite flexible waterproof film, for example a laminated composite comprising a metal sheet sandwiched between two layers of glass fibers.
• the sealed corner piece is a metal angle iron.
• the corner of a sealed and thermally insulating tank can be manufactured simply and quickly without the risk of generating a convection phenomenon.
• these characteristics allow the use of a corner piece in the form of a metal angle iron or a flexible waterproof film to produce the waterproof membrane in the corner of the tank while ensuring the absence of convection between the sealed membrane and the thermally insulating barrier in said corner of the tank.
• a corner piece in the form of a metal angle iron or a waterproof film does not is not attached to the thermally insulating barrier at the corner portion of the thermally insulating barrier.
• the central portion of the corner piece is stretched under the effect of the stresses in said sealed membrane, for example stresses linked to the contraction of the sealed membrane or to the contraction of the thermally insulating barrier on which the waterproof membrane is anchored.
• This voltage moves said central portion away from the corner portion of the thermally insulating barrier, and therefore causes the section of a channel to appear or increase between said corner portion of the thermally insulating barrier and the central portion of the part of angle.
• the presence of the pressure drop shutter in this channel makes it possible to avoid convection phenomena in this channel.
• the sealed and thermally insulating tank further comprises a wedge, said wedge comprising a first external face resting against the thermally insulating barrier of the first wall of the vessel and a second external face resting against the thermally insulating barrier of the second vessel wall, the wedge further comprising a concave internal face, the channel being delimited by the internal face of the wedge.
• 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, in particular an LNG carrier, a floating storage and regasification unit (FSRU) , a floating production and remote storage unit (FPSO) and others.
• FSRU floating storage and regasification unit
• FPSO floating production and remote storage unit
• Such a tank can also serve as a fuel tank in any type of ship.
• the invention also provides a vessel for the transport of a cold liquid product comprising a double hull and an aforementioned tank arranged in the double hull.
• the invention also provides a method for loading or unloading such a ship, in which a cold liquid product is conveyed through insulated pipes from or to a floating or terrestrial storage installation to or from the ship's tank.
• the invention also provides a transfer system for a cold liquid product, the system comprising the aforementioned vessel, insulated pipes arranged so as to connect the tank installed in the hull of the vessel to a floating storage installation or land and a pump to cause a flow of cold liquid product through the insulated pipes from or to the floating or land storage facility to or from the tank of the ship.
• The is a diagrammatic view in section and in perspective of a sealed and thermally insulating vessel portion arranged in a supporting structure;
• the is a cutaway schematic representation of an LNG tank comprising a sealed and thermally insulating tank and a loading/unloading terminal for this tank.
• a sealed and thermally insulating tank for the storage and transport of a cryogenic fluid for example Liquefied Natural Gas (LNG) comprises a plurality of tank walls each having a multilayer structure.
• LNG Liquefied Natural Gas
• Such a tank wall comprises, from the outside towards the inside of the tank, a secondary thermally insulating barrier 1 anchored to a supporting structure 2 by secondary retaining members, a secondary waterproof membrane 3 carried by the secondary thermally insulating barrier 1, a primary thermally insulating barrier 4 resting on the secondary sealed membrane 3, and a primary sealed membrane 5, carried by the primary thermally insulating barrier 4 and intended to be in contact with the cryogenic fluid contained in the vessel.
• the load-bearing structure 2 can in particular be a self-supporting sheet metal or, more generally, any type of rigid partition having suitable mechanical properties.
• the load-bearing structure 2 can in particular be formed by the hull or the double hull of a ship, as illustrated in the .
• the support structure 2 comprises a plurality of walls defining the general shape of the tank, usually a polyhedral shape. Some tanks may also have only one thermally insulating barrier and one sealed membrane, for example for the storage of LPG.
• the vessel here of polyhedral shape, comprises side vessel walls 6 and transverse walls 7 (a single transverse wall being illustrated on the ) which have a vertical component, that is to say a component parallel to the direction of earth's gravity.
• a vertical component that is to say a component parallel to the direction of earth's gravity.
• the presence of channels developing over the entire height of the vessel wall 6, 7 are likely to promote natural convection phenomena.
• thermosiphon phenomena can occur which leads to a degradation of the insulating performance of the thermally insulating barriers 1, 4.
• One aspect of the invention starts from the idea of limiting or even eliminating these phenomena of natural convection.
• the secondary thermally insulating barrier 201 comprises a first corner insulating panel 35 forming one end of the secondary thermally insulating barrier 201 of the first vessel wall 33.
• the secondary thermally insulating barrier 201 comprises a second insulating panel of corner 36 forming one end of the secondary thermally insulating barrier 201 of the second tank wall 34.
• the first corner insulating panel 35 and the second corner insulating panel 36 form an edge 37 of the secondary thermally insulating barrier 201 at an angle of the secondary thermally insulating barrier 201 formed by the junction of the first tank wall 33 and the second tank wall 34.
• ridge refers to the junction area between the two vessel walls which can have different shapes with a greater or lesser curvature. It therefore includes a sharp edge, a rounding or a fillet.
• the secondary thermally insulating barrier 201 comprises a first corner insulating panel 35 forming one end of the secondary thermally insulating barrier 201 of the first vessel wall 33.
• the secondary thermally insulating barrier 201 comprises a second corner insulating panel 36 forming one end of the secondary thermally insulating barrier 201 of the second vessel wall 34.
• the first corner insulating panel 35 and the second corner insulating panel 36 form an edge 37 of the secondary thermally insulating barrier 201 at an angle of the secondary thermally insulating barrier 201 formed by the junction of the first tank wall 33 and the second tank wall 34.
• first anchoring zone 39 is arranged on the internal face of the first corner insulating panel 35 at a distance from the edge 37 and, similarly, the second anchoring zone 40 is arranged on the internal face of the second insulating corner panel 36 at a distance from the edge 37.
• first and second anchoring zones 39 and 40 comprise a metal plate (not shown) similar to the plates 13 described above developing parallel to the edge 37.
• the secondary waterproof membrane 203 comprises a corner piece.
• a corner piece is, for example, a metal bracket 41.
• This angle iron 41 makes it possible to connect in a leaktight manner a portion of the secondary leaktight membrane 203 belonging to the first wall of the tank 33 and a portion of the secondary leaktight membrane 203 belonging to the second wall of the tank 34.
• a first portion 42 of the angle iron 41 is anchored in a leaktight manner on the first anchoring zone 39 and a second portion 43 of the angle iron 41, opposite the first portion 42, is anchored in an airtight manner on the second anchoring zone 40.
• the anchoring of the first and second portions 42 and 43 of the angle iron 41 on the metal plate forming the first and second anchoring zones 39 and 40 can be direct, for example by direct welding on said metal plate, or indirect, for example by lap welding on a portion of the secondary sealed membrane 203 carried by the corresponding vessel wall which is inserted between the portion 42 or 43 of the angle iron 41 and the corresponding anchoring zone 39 or 40.
• a central portion 44 of the angle iron 41 inserted between the first portion 42 and the second portion 43 is left free with respect to the secondary thermally insulating barrier 201.
• the first and second anchoring portions 42, 43 of the angle iron 41 remain anchored to the anchoring zones 39 and 40 of the secondary thermally insulating barrier 201 and the stresses, such as the contraction stresses of the secondary sealed membrane 203 or of the secondary thermally insulating barrier 201 moving the anchoring zones 39, 40 away from each other, at the level of the angle are absorbed by a deformation of the central portion 44 of the angle iron 41.
• the central portion 44 stretches between the first and second portions 42 and 43 of the said angle iron 41 so that the said portion ce ntral 44 moves away from edge 37 by deforming.
• This distance between the central portion 44 of the angle iron 41 and the edge 37 causes a channel to appear or expand between the secondary thermally insulating barrier 201 and the angle iron 41 of the secondary waterproof membrane 203.
• This channel develops over the entire length of the edge 37, parallel to the vertical direction of the tank and is therefore, as explained above, likely to promote natural convection and to degrade the insulating performance of the tank.
• the secondary waterproof membrane illustrated in Figures 2 and 3 can be made with a bonded composite sheet, instead of a welded metal membrane.
• the metal angle 41 can be replaced by a flexible composite sheet 41, for example a laminated waterproof film comprising a metal sheet sandwiched between two layers of fiber such as fiberglass for example.
• a corner piece in the form of a flexible composite sheet 41 may have, for example, a first portion glued to the first anchoring zone of the thermally insulating barrier and a second portion glued to the second anchoring zone of the thermally insulating barrier.
• a secondary waterproof membrane comprising such a flexible composite sheet at the level of a corner of the tank is for example described in the document WO2014167214.
• the contraction of the flexible composite sheet 41 in line with the edge 37 causes a channel to appear or widen between the secondary thermally insulating barrier 201 and the secondary waterproof membrane 203.
• a pressure drop shutter 217 is arranged in the channel, as illustrated in the .
• the pressure drop shutter 217 is illustrated in the .
• the pressure drop shutter 217 is made in the form of a sheet 132 which comprises a continuous lower portion forming the anchoring strip 224 and slats 229 regularly spaced between them over its entire width.
• the slats 229 are flexible and arranged in the same plane at rest.
• Each strip 229 has a first end 330 contiguous with the anchoring strip 224 and a second end 331 free.
• the anchoring strip 224 is fixed to a corner portion of the secondary thermally insulating barrier formed by the internal face of the first corner insulating panel 35 between the first anchoring zone 39 and the edge 37 and the internal face of the second corner insulating panel 36 between the second anchoring zone 40 and the edge 37.
• this corner portion forms the bottom 220 of the channel.
• the first corner insulating panel 35 and the second corner insulating panel 36 each comprise a slot (not shown) developing in the thickness of the internal plate of said corner insulating panels 35, 36 from the first zone of anchoring 39 or the second anchoring zone 40 up to a contiguous plane 45 between said insulating corner panels 35, 36.
• slots are advantageously contiguous at the level of the plane 45 of junction between the insulating panels of angle 35, 36 in order to jointly form a housing for the pressure drop shutter 217, such a pressure drop shutter 217 in the form of a sheet having a shape that is simple to produce and being simple to insert into said housing.
• Such pressure drop shutters 217 are preferably installed in prefabrication during the manufacture of a corner insulating block formed from the first corner insulating panel 35 and the second corner insulating panel 36.
• the slats 229 are deformed by the support of the angle bracket 41 or flexible composite sheet 41 on said slats 229. of the channel, the stress exerted by the angle iron 41 or flexible composite sheet 41 on the slats 229 is reduced and the elasticity and the length of the slats 229 allow said slats 229 to accompany the increase in section of the channel by maintaining contact with the outer surface of the angle iron 41 or flexible composite sheet 41 in order to obstruct said channel.
• the pressure drop shutter 317 is made in the form of a sheet 132 partially covered with a fabric 50.
• the sheet 132 includes a continuous lower portion forming the anchoring strip 324.
• Each strip 329 has a first end 330 contiguous with the anchoring strip 324 and a second end 331 free.
• the slats 329 are regularly spaced from one another over the entire width of the sheet 132.
• the fabric 50 of the pressure drop shutter 317 covers and is glued to the anchoring strip 324 and the slats 329.
• the fabric 50 has a over-length so as to form expansion bellows 82 in line with the separations between the slats 329.
• the slats 329 remain relatively decoupled from each other in bending.
• the tank At the junction between a first wall 8 of the tank, for example a side wall 6, and a second wall 9 of the tank, for example a transverse wall 7, the tank comprises a corner structure 51 illustrated on the .
• This corner structure 51 is advantageously prefabricated.
• the corner structure 51 illustrated in the comprises a first secondary corner insulating panel 52 and a second secondary corner insulating panel 53.
• the secondary corner insulating panels have, from the outside of the tank towards the inside of the tank, an external rigid plate 54 , an insulating gasket 55 and an internal rigid plate 15.
• the first secondary corner insulating panel 52 and the second secondary corner insulating panel 53 also have a bevelled face, the bevelled faces of said two secondary corner insulating panels 52 , 53 being contiguous.
• the secondary corner insulating panels form an edge 16 of the secondary thermally insulating barrier 1.
• the first secondary corner insulating panel 52 carries a first secondary sealed membrane portion 56 and the second secondary corner insulating panel 53 carries a second secondary sealed membrane portion 18.
• These first and second secondary sealed membrane portions 56, 18 can be done in many ways.
• the first and second portions of secondary waterproof membrane 56, 18 are made of laminated waterproof film.
• Such a laminated waterproof film comprises a metal sheet, for example aluminum, interposed between two layers of resinated fibers.
• Such portions of secondary waterproof membrane 56, 18 in laminated waterproof film are for example glued to the internal face of the secondary corner insulating panels 52, 53.
• the first and second portions of secondary waterproof membrane 56 , 18 are metal plates anchored to the secondary corner insulating panels 52, 53.
• the secondary sealed membrane portions 56, 18 comprise a longitudinal edge developing parallel to the edge 16 of the secondary thermally insulating barrier 1, said edge being arranged at a distance from the edge 16.
• the first sealed membrane portion secondary 56 forms one end of the secondary waterproof membrane 3 of the first wall 8 and the second portion of secondary waterproof membrane 18 forms one end of the secondary waterproof membrane 3 of the second wall 9.
• the corner structure 51 comprises a secondary corner waterproof membrane portion 19.
• This secondary corner waterproof membrane portion 19 connects the first portion of secondary waterproof membrane 56 and the second portion of secondary waterproof membrane 18 in a leaktight manner.
• This secondary corner leaktight membrane portion can be made in many ways.
• the secondary corner waterproof membrane portion 19 is made of laminated waterproof film, for example comprising a metal sheet sandwiched between two layers of non-resinated fibers. Such a portion of secondary waterproof membrane at an angle 19 in laminated waterproof film is for example glued to the first and second portions of secondary waterproof membrane 56, 18.
• the corner secondary waterproof membrane portion 19 is formed by a metal angle anchored in a leaktight manner on the first and second secondary waterproof membrane portions 56, 18.
• the secondary corner waterproof membrane portion 19 develops along the edge 16.
• the secondary corner waterproof membrane portion 19 has longitudinal edges parallel to the edge 16.
• a first longitudinal edge of the corner portion secondary corner waterproof membrane 19 forms a first anchoring zone 20, illustrated in dotted lines on the , which is fixed in a leaktight manner to the first portion of secondary leaktight membrane 56.
• a second longitudinal edge of the corner portion of secondary leaktight membrane 19 forms a second anchoring zone 21, illustrated in dotted lines on the , which is fixed in a sealed manner to the second portion of secondary sealed membrane 18.
• the fixing in a sealed manner of the anchoring zones 20, 21 of the corner secondary sealed membrane portion 19 on the secondary sealed membrane portions 56, 18 can be achieved in many ways, for example by gluing in the frame of a secondary corner waterproof membrane portion 19 in the form of a laminated waterproof film or else by welding as part of a secondary corner waterproof membrane portion 19 in the form of a metal angle iron.
• the internal rigid plate 15 of the secondary corner insulating panels 52, 53 may include a thermal protection strip housed in a counterbore in order to protect said secondary corner insulating panels 52, 53 during such welding.
• the corner structure 51 further comprises a plurality of primary insulating elements 22 juxtaposed along the edge 16 of the secondary thermally insulating barrier 1.
• Each primary insulating element 22 comprises a first primary insulating block 23 resting on the first portion of secondary waterproof membrane 56 and a second primary insulating block 24 resting on the second portion of secondary waterproof membrane 18.
• the plurality of primary insulating elements 22 form the primary thermally insulating barrier 4.
• the primary waterproof membrane 5 comprises a plurality of metal angle brackets 25 each resting on a respective primary insulating block 23, 24.
• each metal angle has a first wing 26 resting on the first primary insulating block 23 of a primary insulating element 22 and a second wing 27 resting on the second primary insulating block 24 of said primary insulating element 22.
• the second corner waterproof membrane portion 19 comprises a central zone 28 interposed between the first anchoring zone 20 and the second anchoring zone 21.
• This central zone 28 is arranged in line with the ridge 16 and develops along the along the edge 16.
• This central zone 28 is not fixed to the secondary thermally insulating barrier 1.
• the central zone 28 is free with respect to the secondary thermally insulating barrier 1 and, more particularly, with respect to the edge 16.
• Other details and characteristics of such a corner structure are described for example in the document WO2014167214A2.
• the secondary waterproof membrane 3 and therefore the secondary corner waterproof membrane portion 19 contracts, which causes deformation by tensioning of said secondary waterproof membrane portion d angle 19 as shown in the .
• the secondary corner insulating panels 52, 53 contract, which moves the anchoring zones 20, 21 of the secondary corner waterproof membrane portion 19 away from each other and therefore also causes a deformation by tensioning of said portion of secondary waterproof membrane at the corner 19.
• the deformation by tensioning of the secondary corner sealed membrane portion 19 moves the central zone 28 away from the edge 16 which substantially increases the volume of the empty space between the secondary corner sealed membrane portion 19 and the secondary thermally insulating barrier 1 at the level of the edge 16.
• a channel 29 appears or grows between the secondary sealed membrane 3 and the secondary thermally insulating barrier 1. This channel 29 develops over the entire length of the ridge 16 and has a longitudinal direction parallel to the ridge 16.
• this channel is delimited by an outer face of the central portion 28 of the secondary corner sealed membrane portion 19 and by a portion of the inner faces of the plates 15 of the secondary corner insulating panels 52, 53 between the edge 16 and the first and second portions of secondary waterproof membrane 56 and 18, said portion of the internal faces of the rigid plates 15 forming a bottom 60 of channel 29.
• the tank has a pressure drop shutter.
• a pressure drop shutter is arranged in the channel 29 between an internal face of the secondary thermally insulating barrier 1 and an external face of the secondary sealed membrane 3. It can be achieved in several ways.
• This pressure drop shutter is made in the form of a flexible film 30.
• the flexible film 30 can be made of many materials, for example a thermoplastic material comprising polyethylene (PE), polyethylene terephthalate (PET), polyamide, polyimide, polyetherimide, polypropylene in the form of a textile film or not or any other material or textile with cold flexibility.
• the pressure drop shutter can also be made of woven fabric, possibly coated.
• the woven textile can be made from different types of fibers, for example based on mineral fibers, such as glass fibers, basalt or natural fibers, for example based on hemp, linen or wool or thermoplastic fibers (PE, PET, PP, PI, PEI, etc.).
• the flexible film 30 illustrated in the comprises a first attachment area 31, a second attachment area 32 and a third attachment area 57.
• the first attachment area 31 and the third attachment area 57 are formed at two opposite ends of the flexible film 30.
• These first and third fixing zones 31, 57 are for example formed by opposite transverse edges of the flexible film 30.
• the second attachment area 32 is interposed between the first attachment area 31 and the third attachment area 57, for example at a substantially equal distance from the first and third attachment areas 31 and 57.
• the flexible film 30 also comprises a first sealing portion 58 inserted between the first attachment zone 31 and the second attachment zone 32 and a second sealing portion 59 inserted between the second attachment zone 32 and the third attachment zone 57.
• the first fixing zone 31 and the third fixing zone 57 are fixed on the secondary thermally insulating barrier 1. More particularly, the first fixing zone 31 and the third zone 57 are fixed on the bottom 60 of the channel 29 so as to s extend transversely, preferably perpendicularly, to the longitudinal direction of the channel 29.
• This fixing of the first and third fixing zones 31 and 57 on the bottom 60 of the channel 29 can be achieved in many ways.
• This fixing is for example carried out by gluing or by means of a double-sided adhesive tape, for example comprising polytetrafluoroethylene (PTFE), interposed between each of said first and third fixing zones 31 and 57 and the bottom 60 of the channel 29.
• PTFE polytetrafluoroethylene
• the second attachment zone 32 is attached to the outer face of the central portion 28 of the secondary corner sealed membrane portion 19.
• the attachment of the second attachment zone 32 can be produced in many ways, for example by gluing or by means of a double-sided adhesive tape inserted between the second attachment zone 32 and the outer face of the central zone 28 of the secondary sealed membrane portion corner 19.
• the installation of the flexible film 30 in the tank first comprises fixing, by gluing or by means of an adhesive tape, the first and third fixing zones 31 and 57 on the bottom 60 of the channel 29. Furthermore, a double-sided adhesive tape is applied to the outer face of the central portion 28 of the secondary corner waterproof membrane portion 19 at the place where the second fixing zone 32 is to be fixed. Secondary corner waterproof membrane 19, provided with said double-sided adhesive tape, is then anchored to the first and second secondary waterproof membrane portions 56 and 18. The anchoring of the secondary corner waterproof membrane portion on said secondary waterproof membrane portions 56 and 18 brings the double-sided adhesive tape against the second fixing zone 32 and thus fixes said second fixing zone 32 on the corner secondary waterproof membrane portion 19.
• pressure exerted on an internal face of said laminated waterproof film in line with the double-sided adhesive tape can improve the fixing of the second fixing zone 32 on said laminated waterproof film.
• the first closure portion 58 and the second closure portion 59 are free with respect to the secondary thermally insulating barrier 1 and to the secondary sealed membrane 3. In other words, said first and second closure portions 58 and 59 are not not fixed either on the secondary thermally insulating barrier 1 or on the secondary sealed membrane 3.
• the longitudinal edges 61 of the closure portions 58 and 59 are loose and allow on the one hand a reduced gas circulation in the channel 29, that is to say with a pressure drop linked to the arrangement of said closure portions 58 and 59 in the channel 29, and on the other hand the deformation of the flexible film 30 to accompany the deformation by tensioning of the corner secondary waterproof membrane portion 19.
• the portion of secondary sealed membrane at the corner 19 is stretched.
• the second fixing zone 32 of the flexible film 30 fixed to the central zone 28 of the secondary corner waterproof membrane portion 19 accompanies the variation in position of said central zone 28 linked to the deformation of the secondary corner waterproof membrane portion 19.
• the first and third fixing zones 31 and 57 of the flexible film 30 being fixed on the secondary thermally insulating barrier 1, the sealing portions 58 and 59 of the flexible film 30 are tensioned between said fixing zones 31, 32 and 57 and develop in the channel 29 between the secondary thermally insulating barrier 1 and the secondary sealed membrane 3.
• the channel 29 is closed by the first closure portion 58 and the second closure portion 59 between the central zone 28 of the secondary corner sealed membrane portion 19 and the secondary thermally insulating barrier 1 while p allowing gas circulation with pressure drop in the flow.
• the closure portions 58 and 59 may slightly deform and have a conical shape.
• Such head loss shutters are advantageously arranged in the tank at the corners of the tank, the edge 16 of which has a component parallel to the earth's gravity, typically between the side walls 6 and the transverse walls 7 of the tank.
• Such pressure drop shutters can also be arranged in a tank at the corners of the tank, the edge 16 of which is perpendicular to the earth's gravity.
• a plurality of pressure drop shutters can be arranged, for example at regular intervals, along the channel 29, thus controlling the pressure drop throughout the channel 29.
• Such a wedge 62 is arranged on the bottom 60 of the channel 29, along the edge 16 and has a first face 63 resting on the internal rigid plate 15 of a secondary corner insulating panel and a second face 64 resting on the internal rigid plate 15 of a secondary corner insulating panel.
• This wedge 62 further comprises an internal face 65 connecting the first and second faces 63 and 64 of the wedge 62.
• This internal face 65 has a concave shape, the concavity of which faces the inside of the tank.
• the central zone 28 of said secondary corner waterproof membrane portion 19 is arranged so as to rest on the internal face 65 of the spacer 62.
• the corner secondary waterproof membrane portion 19 is easily positioned for the bonding of the first and second fixing zones 20 and 21 respectively on the first and second secondary waterproof membrane portions 56 and 18.
• Such a shim 62 thus makes it possible to control the radius of curvature of the central zone 28 of the corner secondary sealed membrane portion 19 during the bonding of said secondary corner sealed membrane portion 19, typically during the manufacture of the tank.
• Such a wedge 62 also makes it possible to reduce the dimensions of the channel 29, but cannot prevent the enlargement of said channel 29 when the vessel is cooled, as illustrated by the portion of secondary corner waterproof membrane 19 illustrated on this represented in a state of tension related to thermal contraction, as explained above. In such a channel 29, the inner face 65 then forms the bottom 60 of said channel 29.
• the first fixing zone 31 and the third fixing zone 57 of the pressure drop shutter can be fixed directly on the internal face 65 of the wedge 62.
• a first end of one or more of the attachment zones 31, 32 and/or 57 of the flexible film 30 is interposed between the first portion of sealed membrane 56 and the first anchoring zone 20 of the portion secondary corner waterproof membrane 19.
• a second end of one or more attachment zones 31, 32 and/or 57 are interposed between the second portion of secondary waterproof membrane 18 and the second anchoring zone 21 of the secondary corner waterproof membrane portion 19.
• these ends of said fixing zones 31, 32 and/or 57 are thus pinched between the first and second secondary waterproof membrane portions 56 or 18 and the secondary corner waterproof membrane portion 19, thus ensuring the fixing of the fixing zones 31, 32 and/or 57 in a simple manner.
• the pressure drop shutter is produced in the form of a flexible film 130, which comprises a first fixing zone 69 and a second fixing zone 332.
• the first fixing zone attachment 69 and the second attachment area 332 are formed at two opposite ends of the flexible film.
• the first fixing zone 69 is fixed on a bottom 236 of the channel 68.
• the second fixing zone 332 is fixed on an outer face of the secondary waterproof membrane 203.
• the first fixing zone 69 and the second fixing zone 332 are offset along the longitudinal direction of the channel 68. In other words, the first attachment zone and the second attachment zone are not opposite each other so that the closure portion 235 develops with a component parallel to the longitudinal direction of the channel 68.
• the closure portion 235 comprises two spaced apart folds and thus has a Z shape.
• the pressure drop shutter 130 can be installed in prefabrication in the corner structure 51 before the installation of the corner structure 51 in the sealed tank. and thermally insulating.
• the structure of the shutter 130 is easier to put in place during factory prefabrication of the panels with a portion of the waterproof membrane covering them.
• the pressure drop shutter is also made in the form of a flexible film 230 is also made in the form of a flexible film which is folded around an axis transverse to the longitudinal direction of the channel, substantially under the U-shaped.
• the shutter 230 comprises a first attachment zone 231, a second attachment zone 232 and a closure portion folded back on itself.
• the first attachment zone 231 and the second attachment zone 232 are formed at two opposite ends of the flexible film.
• the first fixing zone 231 is fixed on a bottom 236 of the channel.
• the second attachment area 232 is attached to an outer face of the waterproof membrane 203.
• the first attachment area 231 and the second attachment area 232 are opposite each other.
• the flexible film has a length, when the closure portion is arranged in a plane, greater than the distance between a fixing surface of the first fixing zone 231 on the bottom of the channel 229 and a fixing surface of the second zone fixing 232 on the waterproof membrane.
• the flexible film forms a fold in which, according to one embodiment, is housed a compressible element 99, for example made of wadding, felt, glass wool, rock wool, polymer foam.
• the compressible element 99 is compressed between the first and second fixing zones 231, 232 and thus exerts a reaction force which facilitates the fixing by gluing of the first fixing zone 231 and of the second fixing zone 232 on the bottom respectively. of the channel and on the external face of the waterproof membrane.
• the shutter 230 is inserted into the sealed and thermally insulating tank in the gap between the bottom of the channel 236 and the sealed membrane.
• an anti-adhesive film (not shown) which prevents the two parts of the flexible film folded relative to each other from sticking is inserted into the folding of the flexible film, instead of or in combination with the compressible element 99.
• a tool in the form of a blade if necessary a curved blade whose curvature corresponds to the shape of the bottom of the channel, for example the curvature of the wedge 62
• the anti-adhesive film and the flexible film are successively folded around the end edge of the slat in order to push them into the channel 236, for example between the wedge 62 and the portion of the secondary waterproof membrane at the angle 19.
• the technique described above for producing a leaktight and thermally insulating tank can be used in different types of tanks, for example in an LNG tank in an onshore installation or in a floating structure such as an LNG carrier or other.
• loading/unloading pipes 73 arranged on the upper deck of the ship can be connected, by means of appropriate connectors, to a maritime or port terminal to transfer a cargo of LNG from or to the tank 71.
• the represents an example of a maritime terminal comprising a loading and unloading station 75, an underwater pipeline 76 and an installation on land 77.
• the loading and unloading station 75 is a fixed offshore installation comprising a mobile arm 74 and a tower 78 which supports the mobile arm 74.
• the mobile arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the loading/unloading pipes 73.
• the orientable mobile arm 74 adapts to all sizes of LNG carriers.
• a connecting pipe, not shown, extends inside the tower 78.
• the loading and unloading station 75 allows the loading and unloading of the LNG carrier 70 from or to the shore installation 77.
• This comprises liquefied gas storage tanks 80 and connecting pipes 81 connected by the underwater pipe 76 to the loading or unloading station 75.
• the underwater pipe 76 allows the transfer of the liquefied gas between the loading or unloading station 75 and the shore installation 77 over a great distance, for example 5 km, which makes it possible to keep the LNG carrier 70 at a great distance from the coast during loading and unloading operations.
• pumps on board the ship 70 and/or pumps fitted to the shore installation 77 and/or pumps fitted to the loading and unloading station 75 are used.
• a pressure drop shutter comprising one or two fixing zones cooperating with the thermally insulating barrier and a fixing zone cooperating with the secondary sealed membrane, however the number of fixing zones attachment that can cooperate with the waterproof membrane and the number of attachment zones that can cooperate with the thermally insulating barrier can be different.
• a pressure drop shutter can thus comprise a plurality of fixing zones intended to cooperate with the thermally insulating barrier alternately with a plurality of fixing zones intended to cooperate with the sealed membrane so that the closure portions between a zone fixing on the thermally insulating barrier and a fixing zone on the sealed membrane develops in the channel to close said channel.
• pressure drop shutters can thus be installed in any interstice linked to a positioning or manufacturing play likely to form or generate during the use of a tank a channel favoring the phenomena of convection. .

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Ocean & Marine Engineering (AREA)

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• 2021
  • 2021-07-07 EP EP21739698.5A patent/EP4182596A1/fr active Pending
  • 2021-07-07 WO PCT/EP2021/068798 patent/WO2022013031A1/fr active Application Filing
  • 2021-07-07 US US18/016,628 patent/US20230288028A1/en active Pending
  • 2021-07-07 KR KR1020237005616A patent/KR20230040365A/ko active Search and Examination

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