EP3755939A2

EP3755939A2 - System for storing and transporting a cryogenic fluid on a ship

Info

Publication number: EP3755939A2
Application number: EP19710045.6A
Authority: EP
Inventors: Sébastien COROT; Sébastien DELANOE
Original assignee: Gaztransport et Technigaz SA
Current assignee: Gaztransport et Technigaz SA
Priority date: 2018-02-20
Filing date: 2019-02-12
Publication date: 2020-12-30
Also published as: CN111788429B; FR3078135B1; JP7219772B2; CN111788429A; JP2021514327A; KR102596193B1; KR20200122357A; FR3078135A1; RU2020126271A; US20200398943A1; WO2019162594A2; US11407478B2; WO2019162594A3

Abstract

The invention relates to a system for storing and transporting a cryogenic fluid on a ship, said system comprising: a sealed, thermally insulated tank (2) having a ceiling wall which includes, from the outside towards the inside of the tank (2) in the direction of a thickness of the wall, a primary thermally insulating barrier (11) and a primary sealing membrane (10) that is to be inw contact with the cryogenic fluid; a sealed pipe (14) which penetrates the ceiling wall of the tank (2), said pipe (14) having a lower portion (15), a first end of which is located inside the ceiling wall of the tank (2) and a second end of which is located outside the ceiling wall of the tank (2) in a direction of the thickness of the ceiling wall, and an upper portion (16) that is attached to the second end of the lower portion (15); the lower portion (15) is made of an alloy having a low coefficient of thermal expansion, and the primary sealing membrane (10) is attached in a sealed manner to the lower portion (15) of the pipe (14) around the pipe (14).

Description

Installation for storing and transporting a cryogenic fluid onboard a ship

Technical area

The invention relates to the field of storage and transport facilities for a cryogenic fluid on board ships and comprising one or more sealed tanks and thermally insulating membranes.

The vessel (s) may be for carrying cryogenic fluid or for receiving cryogenic fluid as a fuel for the propulsion of the vessel.

Technological background

Liquefied natural gas transport vessels have a plurality of tanks for storing the cargo. The liquefied natural gas is stored in these tanks, at atmospheric pressure, at about -162 ° C and is thus in a state of two-phase liquid-vapor equilibrium so that the heat flow exerted through the walls of the tanks tends to cause evaporation of liquefied natural gas.

In order to avoid generating overpressure inside the tanks, each tank is associated with a sealed pipe for evacuation of the vapor produced by evaporation of the liquefied natural gas. Such a sealed pipe for steam evacuation is described in particular in WO2013093261, for example. The pipe passes through a wall of the tank and opens into the upper part of the internal space of the tank and thus defines a passage of steam between the interior of the tank and a steam collector arranged outside the tank. The vapor thus collected can then be passed to a re-liquefaction plant to then reintroduce the fluid in the tank, to a power generation equipment or to a degassing mast provided on the deck of the vessel.

In certain damaged conditions, when the filling level of the tank is maximum and the ship is stranded in a position in which it has a slope of the cottage and / or an important attitude inclination (s), there is a risk that the steam discharge pipe opens into the liquid phase and is therefore no longer in contact with the vapor phase stored in the tank. In In such circumstances, insulated pockets of vapor-phase gas are likely to form inside the tanks. However, such gas pockets are likely to induce overpressures that can damage the tanks and / or cause an expulsion of the liquid phase to the outside of the tank through the evacuation pipe of the aforementioned steam.

However, the gas leakproof pipes of the prior art have large dimensions, are quite complex and are not adapted to significant temperature variations.

summary

An idea underlying the invention is to provide a solution for penetrating a sealed pipe through the wall of a membrane vessel, which is relatively simple and resistant to temperature variations between room temperature and the temperature of storage of the cryogenic fluid.

Another idea underlying the invention is to propose a solution that is resistant to deformations of the ship during the sea transport, in particular to the bending of the beam vessel

Another idea underlying the invention is to provide a solution that easily adapts to existing storage tank structures.

Another idea underlying the invention is to propose an installation for storing and transporting a cryogenic fluid on board a ship which makes it possible to reduce the risks that such isolated vapor phase gas pockets can not form at all. inside a tank without being able to be evacuated.

According to one embodiment, the invention provides an installation for storing and transporting a cryogenic fluid onboard a ship, the installation comprising:

a sealed and thermally insulating tank for storing the cryogenic fluid in a diphasic liquid-vapor equilibrium state, the tank having a ceiling wall comprising, in the direction of a thickness of the wall, from the outside towards the inside; a primary heat-insulating barrier and a primary sealing membrane for contact with the cryogenic fluid; a leaktight pipe penetrating through the ceiling wall of the tank so as to define a passage for discharging the vapor phase of the cryogenic fluid from the inside to the outside of the tank, the pipe comprising a lower portion, one of which first end is located inside the ceiling wall of the tank and a second end is located outside the ceiling wall of the tank in a thickness direction of the ceiling wall, and a top portion attached to the second end of the lower portion;

in which the lower portion is composed of an alloy with a low coefficient of thermal expansion,

and wherein the primary waterproofing membrane is sealingly attached to the lower portion of the pipe around the pipe.

Thanks to these characteristics, the sealed pipe penetrating through the wall makes it possible to reduce the risks that such insulated vapor phase gas pockets are formed inside a tank by defining an evacuation passage. In addition, the lower portion of the pipe that is in contact with the cryogenic fluid is in a low thermal expansion coefficient material which ensures that the pipe is resistant to temperature variations between the ambient temperature and the storage temperature. cryogenic fluid avoiding that it is deformed.

According to other advantageous embodiments, such an installation may have one or more of the following characteristics.

In one embodiment, the conduit passes through the ceiling wall at one end of the ceiling wall.

In one embodiment, the conduit is a first conduit and the storage facility includes a second conduit similar to the first conduit, the second conduit passing through the ceiling wall at an opposite end of the end through which the first conduit passes.

According to one embodiment, the storage facility comprises a gas dome located in the center of the ceiling wall.

According to one embodiment, the first end of the lower portion of the pipe is a collection end opening inside the tank for collect a vapor phase of the liquefied gas. Such a pipe for collecting the vapor phase in the tank may be provided with a relatively small diameter, for example less than 100 mm.

According to one embodiment, the second end of the upper portion of the sealed pipe is connected to a gas dome of the tank and / or to a main gas manifold and / or pressure relief valves of the tank.

According to one embodiment, the lower portion of the pipe and the primary waterproofing membrane are composed of an iron-nickel alloy whose thermal expansion coefficient is between 1, 2 and 2.0 × 10 ^-6 K ¹ , or an iron alloy with a high manganese content whose expansion coefficient is typically of the order of 7.10 ⁶ K ¹

According to one embodiment, the lower portion is composed of an iron-nickel alloy with 36% Ni by weight.

According to one embodiment, the upper portion is made of stainless steel.

According to one embodiment, the upper portion has a greater thickness than the lower portion.

According to one embodiment, the lower portion is sealed to the primary waterproofing membrane by means of a flanged ring.

Thus, a tight connection is provided between the lower portion of the pipe and the primary waterproofing membrane by the collar ring.

According to one embodiment, the ceiling wall of the tank further comprises, in the direction of the thickness of the wall outside the primary heat-insulating barrier, a secondary heat-insulating barrier and a secondary sealing membrane.

Thanks to these characteristics, the thermal insulation and the tightness of the storage tank is ensured by two layers of primary and secondary waterproofing membranes, as well as two layers of thermally insulating barriers, primary and secondary, which allows According to one embodiment, the primary and secondary membranes are composed of an iron-nickel alloy with 36% Ni by weight, the coefficient of thermal expansion of which is between 1.2 and 2.0 × 10 ⁶ K ¹ or an iron alloy with a high manganese content whose expansion coefficient is typically of the order of 7 × 10 ⁶ K ¹

According to one embodiment, the primary thermally insulating barrier and the secondary thermally insulating barrier each consist of a plurality of insulating boxes, the conduit passing right through one of the boxes of the plurality of boxes of each of the thermally protected barriers. primary and secondary insulators.

According to one embodiment, the pipe passes through a box in a central zone of the box.

According to one embodiment, a box of the plurality of boxes is composed of plywood plates forming a grid, the box being filled inside the grid of expanded perlite or glass wool or other insulating material.

According to one embodiment, the primary waterproofing membrane and / or the secondary waterproofing membrane comprise a plurality of elongate strakes with raised edges welded edge to edge in the longitudinal direction of the strake, each strake comprising a flat zone between two longitudinal raised edges, the pipe passing through the primary sealing member and / or the secondary sealing membrane by the flat area of an elongated strake.

According to one embodiment, the strake of the primary waterproofing membrane and / or the secondary sealing membrane traversed by the pipe comprises a reinforced portion, the reinforced portion having a thickness greater than the rest of the strake and comprising a zone plane between two longitudinal raised edges, the pipe passing through the reinforced portion.

Thus, the reinforced portion stiffens and reinforces the junction between the primary or secondary sealing membrane and the sealed pipe or sheath respectively. For example, in the case where a strake has a thickness of less than 1 mm, for example 0.7 mm, the reinforced portion has a thickness greater than or equal to 1 mm, for example of 1.5 mm.

According to one embodiment, the sealed pipe passes through the reinforced portion of the primary waterproofing membrane and / or the secondary waterproofing membrane by the flat zone of the reinforced portion.

Thanks to these characteristics, the pipe passes through the reinforced portion in an area where it is easier to make a tight connection between the pipe and the strake. In addition, it also avoids having to interrupt the raised edges of the strakes with the sealed pipe.

According to one embodiment, the installation comprises a sheath surrounding the pipe with a spacing in a radial direction and fixed to the upper portion of the pipe, the sheath extending from the upper portion at least to the membrane of the pipe. secondary sealing, and the secondary sealing membrane being sealed to the sheath all around the sheath.

Thus, the attachment of the secondary waterproofing membrane is made on a sheath surrounding the pipe, the sheath being itself fixed to the upper portion which allows for a double wall throughout the lower portion of the pipe thus avoiding that in case of rupture of the pipe the cryogenic fluid does not spread out of the storage tank. The sheath thus plays the role of continuity of the secondary sealing membrane. In addition, the attachment of the sheath on the upper portion of the pipe facilitates maintenance operations. Finally, the radial spacing between the sheath and the pipe makes it possible to take into account the greater deformation of the sheath due to its greater flexibility with respect to the pipe.

According to one embodiment, the sheath extends from the upper portion at least to the secondary sealing membrane and beyond.

According to one embodiment, the secondary sealing membrane is sealed to the sheath all around the sheath. According to one embodiment, a filling of insulating material is arranged between the sheath and the sealed pipe.

According to one embodiment, the sheath is welded to the secondary sealing membrane by means of a collar ring.

Thus, a tight connection is provided between the lower portion of the pipe and the secondary sealing membrane by the collar ring.

According to one embodiment, the ring or rings have a thickness greater than the strakes. For example, in the case where the strake is less than 1 mm, for example 0.7 mm, the collar ring has a thickness of between 1 and 2 mm, preferably 1.5 mm.

Thus, the collar ring stiffens and reinforces the junction between the primary or secondary sealing membrane and the pipe or sheath respectively.

According to one embodiment, the flange ring is composed of a base, preferably annular and flat, and a flange projecting from the base. The base may have a thickness greater than the strakes, preferably a thickness of between 1 and 2 mm, preferably of 1.5 mm. The flange may have a thickness greater than the strakes, preferably a thickness of between 1 and 2 mm, preferably of 1.5 mm.

According to one embodiment, the sheath is composed of an iron-nickel alloy with 36% Ni by weight, the coefficient of thermal expansion of which is between 1.2 and 2.0 × 10 ^-6 K ¹ , or of an iron alloy with a high manganese content whose expansion coefficient is typically of the order of 7.10 ⁶ K ¹

According to one embodiment, the invention provides a vessel comprising an installation according to the invention, the ceiling wall being attached to a lower surface of an intermediate bridge of the ship.

According to one embodiment, the pipe comprises an accordion compensator on one end of the upper portion remote from the lower portion, the compensator being configured to secure the pipe to a surface upper deck of the ship, the compensator having corrugations configured to allow the thermal contraction of the pipe.

Thanks to these features, the accordion compensator allows the pipe, including the upper portion, to have at its attachment a set of connection allowing it to shrink / expand thermally without risk of rupture of the pipe or the link .

According to one embodiment, the accordion compensator is made of stainless steel.

According to one embodiment, the pipe comprises an insulating sleeve surrounding a portion of the upper portion of the pipe and located between the intermediate bridge of the ship and a top deck of a ship.

Thus, the insulating sleeve thermally isolates a portion of the upper portion so that the low temperatures of the cryogenic fluid do not propagate in the steerage that may damage equipment located there.

According to one embodiment, the intermediate bridge and the upper bridge comprise an orifice, the orifice having a diameter greater than an outer diameter of the upper portion of the pipe, the pipe passing through the intermediate bridge and the upper bridge through the orifice. intermediate bridge and the upper deck opening respectively.

Thanks to these characteristics, there is a spacing between the pipe and the upper bridge opening and the intermediate bridge opening, which provides a mounting clearance between the pipe and the two bridges. In particular, the mounting clearance facilitates assembly and allows bridges to be deformed without damaging the pipe.

According to one embodiment, the intermediate bridge comprises a coaming on an upper surface of the intermediate bridge, the coaming surrounding the intermediate bridge port and being traversed by the pipe, and wherein the pipe is fixed to the coaming. Thus, the coaming allows to deport the fixing of the pipe to the intermediate bridge which provides flexibility to the fixing. This attachment offset allows the pipe to better withstand the deformations of the intermediate bridge by avoiding that the pipe is damaged.

According to one embodiment, the pipe is welded tightly around the coaming.

According to one embodiment, the coaming comprises an upper portion and a lateral portion connecting the upper portion to the intermediate bridge, the fixing of the pipe being in the upper part of the coaming.

According to one embodiment, the coaming is composed of a metal including stainless steel.

According to one embodiment, the invention provides a method for loading or unloading a ship according to the invention, in which a cryogenic fluid is conveyed through isolated pipes from or to a floating or land storage facility to or from a tank of the ship.

According to one embodiment, the invention provides a transfer system for a cryogenic fluid, the system comprising a vessel according to the invention, insulated ducts arranged to connect the vessel installed in the double hull of the vessel to an installation of floating or ground storage and a pump for driving a flow of cryogenic fluid through the insulated pipelines from or to the floating or land storage facility to or from the vessel vessel.

Brief description of the figures

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

FIG. 1 is a cutaway schematic representation of a vessel comprising a cryogenic fluid storage tank FIG. 2 is a partial schematic representation of an installation for storing and transporting a cryogenic fluid onboard a ship.

FIG. 3 is an enlarged view of detail III of the storage facility of FIG. 2.

FIG. 4 is an enlarged view of detail IV of the storage facility of FIG. 2.

FIG. 5 is an exploded view of a tank wall, in particular of the secondary thermally insulating barrier and of the secondary sealing membrane;

- Figure 6 is an exploded view of a vessel wall, in particular of the primary heat-insulating barrier and the primary sealing membrane.

- Figure 7 is a schematic sectional view of an inclined cryogenic fluid storage tank.

- Figure 8 is a schematic cutaway representation of a vessel comprising a cryogenic fluid storage tank and a loading / unloading terminal of this vessel.

Detailed description of embodiments

By convention, the terms "superior", "inferior", "above", and "below" are used to define a relative position of one element or part of one element over another in a directed direction from the tank 2 to the upper deck 9 of the ship 1.

In Figure 1 is shown a vessel 1 equipped with a cryogenic fluid storage and transport facility, including liquefied natural gas, which comprises a plurality of sealed and thermally insulating tanks 2. Each tank 2 is associated with a degassing mast 4 which is provided on an upper deck 9 of the vessel 1 and allowing the escape of the gas in the vapor phase during an overpressure inside the associated tank 2. At the rear of the ship 1 is provided a machine compartment 3 which conventionally comprises a steam turbine with mixed feed capable of operating either by combustion of diesel fuel or by combustion of evaporation gas from the tanks 2.

The tanks 2 have a longitudinal dimension extending along the longitudinal direction of the ship 1. Each tank 2 is lined at each of its longitudinal ends by a pair of transverse partitions 5 delimiting a sealed spacer space, known as "cofferdam" 6.

The tanks are thus separated from each other by a transverse cofferdam 6. It is thus observed that the tanks 2 are each formed inside a supporting structure which is constituted, on the one hand, by the double hull 7 of the vessel 1 1 and, on the other hand, by one of the transverse partitions. 5 of each of the cofferdams 6 bordering the tank 2.

FIG. 2 schematically represents a pipe 14 making it possible to define a passage for discharging the vapor phase of the cryogenic fluid from the inside to the outside of the tank 2, the pipe 14 passing successively through the tank 2, the intermediate bridge 8 of the ship 1 and the upper deck 9 of the ship 1.

The sealed and thermally insulating tank 2 has a ceiling wall attached to the intermediate bridge 8, the wall comprising in the direction of a thickness of the wall from the outside to the inside of the tank 2: a secondary heat-insulating barrier 13 , a secondary sealing membrane 12, a primary heat-insulating barrier 11 and a primary sealing membrane 10.

The pipe 14 is formed of a lower portion 15 and an upper portion 16. The lower portion 15 is formed from an alloy of iron and nickel whose expansion coefficient is typically between 1, 2 × 10 ⁶ and 2.10 ^-6 K ¹ , or in an iron alloy with a high manganese content whose expansion coefficient is typically of the order of 7.10 ⁶ K ¹ , ie a low coefficient of thermal expansion. The lower portion 15 has a first end located inside the tank 2 and a second end located outside the tank 2.

The upper portion 16 is formed from stainless steel and is welded at a first end to the second end of the lower portion 15 of in order to create a continuity of the pipe 14. The second end of the upper portion 16 is connected to a channel of the ship 1. The upper portion 16 has a greater wall thickness than the lower portion 15.

The lower portion 15 of the pipe 14 passes firstly through the primary waterproofing membrane 10 and the primary heat-insulating barrier 1 1. The primary waterproofing membrane 10 is welded all around the lower portion 15 of the sealed way to guarantee the continuity of the tightness of the primary waterproofing membrane 10.

A sheath 21 surrounds the pipe 14 with a spacing in a radial direction and fixed to the upper portion 16 of the pipe 14. The sheath extends from the upper portion 16 at least as far as the secondary sealing membrane 12. secondary sealing membrane 12 is welded around the sheath 21 in a sealed manner to ensure the continuity of the sealing of the secondary sealing membrane 12. The pipe 14 therefore passes through the secondary sealing membrane 12 and the heat barrier secondary insulation 13 through the sheath 21.

The lower portion 15 is thus welded to the upper portion 16 inside the sheath 21, so that the sheath 21 ensures the sealing and sealing of the secondary membrane in case of rupture of the lower portion 15, by example at the welding.

The lower portion 15 therefore acts as part of the primary sealing membrane 10 while the sheath 21 acts as part of the secondary sealing membrane 12. Thus there are always two layers of membranes , even at the level of the pipe 14.

The pipe 14 then passes through the intermediate bridge 8 of the ship 1 at an intermediate bridge orifice 27. The intermediate bridge orifice 27 has a diameter greater than the outside diameter of the sheath 21 so that there is a connecting clearance allowing the intermediate bridge 8 to deform without causing deformation of the sheath 21 and the pipe 14.

The intermediate bridge 8 comprises on its upper surface a coaming 22. The coaming 22 comprises an upper portion 23 and a lateral portion 24 connecting the upper portion 23 of the intermediate bridge 8. The upper portion 16 of the pipe 14 passes through the upper part 23 of the coaming 22. The upper portion 16 of the pipe 14 is welded all around the upper part 23 of the coaming 22 so waterproof.

The conduit 14 then passes through the space between the intermediate bridge 8 and the upper deck 9 called steerage where the pipe is coated with an insulating sleeve 26 so that the low temperatures of the cryogenic gas contained in the pipe 14 do not cause a leak high thermal in the tween.

The pipe 14 finally crosses the upper deck 9 of the ship 1 at an upper deck opening 28. The upper deck opening 28 has a diameter greater than the outside diameter of the pipe 14 so that there is a connecting set allowing the upper bridge 9 to deform without causing deformation of the pipe 14.

The pipe 14 comprises an accordion compensator 25 on the second end of the upper portion 16 remote from the lower portion 15. The compensator ensures the attachment of the pipe 14 to an upper surface of the upper deck 9 of the ship 1. The accordion compensator 25 has corrugations configured to allow thermal contraction of the pipe 14 including the upper portion 16 which is stainless steel, a material that has a high coefficient of expansion relative to the alloy of the lower portion 15.

Figures 3 and 4 show enlarged details III and IV of Figure 2.

FIG. 3 makes it possible to distinguish the fastening of the primary sealing membrane 10 to the pipe 14 and the fixing of the secondary waterproofing membrane 12 to the sheath 21. Indeed, the fixing of the primary waterproofing membrane 10 to the pipe 14 is made using a collar ring 17 provided with a base and a flange. The flange of the ring 17 is welded to the pipe 14 and the base of the ring 17 is welded to the primary waterproofing membrane 10 which allows a tight fixing.

In the same way, the attachment of the secondary sealing membrane 12 to the sheath 21 is carried out using a collar ring 17 provided with a base and a flange. The flange of the ring 17 is welded to the sheath 21 and the base of the ring 17 is welded to the secondary sealing membrane 12 which allows a sealed fastening.

The base of the collar ring 17 may in particular be of flat annular shape comprising an inner diameter and an outer diameter. The flange of the collar ring 17 projects from the inside diameter of the base of the collar ring 17. The base and flange of the collar ring have a thickness of 1.5 mm greater than the thicknesses of the flanges. primary and secondary waterproofing membranes 10, 12 of 0.7 mm.

FIG. 4 makes it possible to distinguish the junction between the lower portion 15 and the upper portion 16 of the pipe 14 as well as the fastening of the sheath 21 to the upper portion 16. Indeed, the welding attachment of the second end of the portion 15 and the first end of the upper portion 16 of the pipe 14 is of equal thickness of the two portions 15, 16 of the pipe 14. For this, the thickness of the first end of the upper portion 16 decreases, by linear example, the thickness of the upper portion 16 to the thickness of the lower portion 15 so as to facilitate the welding of these portions 15, 16 and improve the strength of the fastener.

The fixing of the sheath 21 to the upper portion 16 is performed by welding all around the upper portion 16 just after the first end of the upper portion 16 so that the sheath 21 is fixed to the upper portion 16 at a location where its thickness is maximum but also close to the first end of the upper portion 16 to limit as much as possible the length of the sheath 21 where it is not necessary to act as a secondary sealing membrane 12.

FIGS. 5 and 6 show schematic views of the primary and secondary sealing membranes 12 as well as the primary and secondary heat-insulating barriers 11 and 13. The sealing membranes 10, 12 and the thermally insulating barriers 11, 13 are carried out according to technology N096 which is described in particular in document WO2012072906 A1.

Thus, the thermally insulating barriers 11, 13 are for example formed by insulating boxes 18 comprising a bottom panel and a panel parallel covers, spaced in the direction of thickness of the insulating casing 18, the supporting elements 19 extending in the thickness direction, optionally the peripheral walls, and a heat insulating lining housed inside the insulating boxes. The bottom and lid panels, the peripheral partitions and the support elements 19 are for example made of wood, for example plywood or composite thermoplastic material. The heat-insulating lining may consist of glass wool, wadding or polymer foam, such as polyurethane foam, polyethylene foam or polyvinyl chloride foam or granular or powdery material - such as perlite, vermiculite or glass wool - or a nanoporous material of the airgel type. In addition, the primary and secondary sealing membranes 12 comprise a continuous sheet of metal strakes with raised edges, said strakes being welded by their raised edges to parallel welding supports held on the insulating housings. The metal strakes 20 are, for example, made of Invar ®: that is to say an alloy of iron and nickel whose expansion coefficient is typically between 1, 2.10 ^e and 2.10 ⁶ K ¹ , or in a high manganese iron alloy whose expansion coefficient is typically of the order of 7.10 ⁶ K ¹ .

Figures 5 and 6 distinguish where the pipe 14 passes through the sealing membranes 10, 12 and thermally insulating barriers 1 1, 13. Indeed, it is preferable not to weaken the structure of the box 18 to avoid that the pipe 14 does not pass through the caisson on the ends of the caisson 18. Preferably, the pipe 14 passes through the primary thermally insulating barrier 1 1 and the secondary thermally insulating barrier 13 in a central zone of the caisson 18 between a plurality of support elements 19.

To facilitate the tight fixing of the primary waterproofing membrane 10 and the pipe 14 and the sealing connection of the secondary sealing membrane 12 and the sheath 21, it is preferable to prevent the pipe 14 from passing through the sealing membranes. at the level of the raised edges of the strakes 20. Indeed, the area where the edges are raised, is geometrically complex and is already subject to the bonding bonding two adjacent strakes and a support wing. That's why driving 14 crosses the sealing membranes 10, 12 in a flat zone of a strake 20 between two raised edges.

The strakes 20 of the primary sealing membrane 10 and the secondary sealing membrane 12 traversed by the pipe 14 comprise a reinforced portion 32 so as to maintain continuity of the primary and secondary sealing membranes. Indeed, the reinforced portion 32 represents a portion of the strake 20 traversed by the pipe 14.

The reinforced portion 32 has a thickness greater than the rest of the strake 20, for example a thickness of 1.5 mm compared to a 0.7 mm thick strake. The reinforced portion 32 comprises a flat area between two longitudinal raised edges. The conduit 14 passes through the reinforced portion 32 of the primary sealing membrane 10 and the reinforced portion 32 of the secondary sealing membrane 12 by the flat area. The sheath 21 passes through the reinforced portion 32 of the secondary sealing membrane 12 also through the flat zone.

FIG. 7 represents a sealed and thermally insulating tank 2 filled with liquefied gas and transported by a ship 1, the vessel having fifteen degrees of heel due to, for example, damage.

In a normal case of use, with a vessel having zero degree of heel, the tank 2 evacuates the liquefied gas which evaporates to avoid generating overpressure inside the tank 2 by a gas dome 29 passing through the wall ceiling of the tank 2 in the center.

In the case of an aforementioned damage, with a vessel having fifteen degrees of heel, the gas dome 29 is completely immersed in the liquefied gas and no longer fulfills its role of evacuation of the evaporated liquefied gas. In order to prevent the overpressure damaging the tank 2, two ducts 14 situated at the ends of the ceiling wall and on either side of the gas dome 29 are placed in the tank 2 passing through the ceiling wall 29. The ducts 14 are then connected to the main gas manifold 30 of the ship 1 which conveys the gas to the engine compartment 3 and / or to a reliquefaction unit. The lines 14 are also connected to pressure valves 31 which open if the pressure is too high, thus redirecting a portion of the gas to the degassing rods 4. Preferably, the lines 14 are connected to the main gas manifold 30 and the overpressure valves 31 via the gas dome 29 outside the double shell 7.

Further details as to the number and position of the gas discharge pipes can be found in WO2016120540 A1.

Referring to Figure 8, a cutaway view of a LNG vessel 1 shows a sealed and insulated tank 2 of generally prismatic shape mounted in the double hull 7 of the ship 1.

In a manner known per se, loading / unloading lines 40 arranged on the upper deck 9 of the ship 1 can be connected, by means of appropriate connectors, to a marine or port terminal to transfer a cargo of liquefied gas from or to the tank 2.

FIG. 8 represents an example of a marine terminal comprising a loading and unloading station 42, an underwater pipe 43 and an onshore installation 44. The loading and unloading station 42 is a fixed off-shore installation comprising an arm mobile 41 and a tower 45 which supports the movable arm 41. The movable arm 41 carries a bundle of insulated flexible pipes 46 that can connect to the loading / unloading pipes 40. The movable arm 41 can be adapted to all gauges LNG carriers . A connecting pipe (not shown) extends inside the tower 45. The loading and unloading station 42 allows the loading and unloading of the LNG carrier 1 from or to the shore installation 44. This includes liquefied gas storage tanks 47 and connecting lines 48 connected by the underwater line 43 to the loading or unloading station 42. The underwater line 43 allows the transfer of the liquefied gas between the loading or unloading station 42 and the onshore installation 44 for a great distance, for example 5 km, which makes it possible to keep the LNG ship 1 at a great distance from the coast during the loading and unloading operations.

In order to generate the pressure necessary for the transfer of the liquefied gas, pumps on board the vessel 1 and / or pumps fitted with the onshore installation 44 and / or pumps equipping the loading and unloading station 42.

Although the invention has been described in connection with several particular embodiments, it is obvious that it is not limited thereto and that it comprises all the technical equivalents of the means described and their combinations if they are within the scope of the invention.

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

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

Claims

1. Installation for storing and transporting a cryogenic fluid onboard a ship (1), the installation comprising:

a sealed and thermally insulating tank (2) intended for storage of the cryogenic fluid in a state of two-phase liquid-vapor equilibrium, the tank (2) having a ceiling wall comprising in the direction of a thickness of the wall since exterior to the interior of the vessel (2) a primary thermally insulating barrier (1 1) and a primary sealing membrane (10) for contacting the cryogenic fluid;

a sealed pipe (14) penetrating through the ceiling wall of the tank (2) so as to define a passage for discharging the vapor phase of the cryogenic fluid from the inside to the outside of the tank (2) , the pipe (14) having a lower portion (15) having a first end located inside the ceiling wall of the tank (2) and a second end is located outside the ceiling wall of the vessel (2) in a thickness direction of the ceiling wall, and an upper portion (16) attached to the second end of the lower portion (15); in which the lower portion (15) is composed of an alloy with a low coefficient of thermal expansion,

and wherein the primary waterproofing membrane (10) is sealingly attached to the lower portion (15) of the pipe (14) around the pipe (14).

2. Installation according to claim 1, wherein the lower portion (15) of the pipe (14) and the primary sealing membrane (10) are composed of an iron-nickel alloy whose thermal expansion coefficient is between 1, 2 and 2.0 x 10 ^-6 K ¹ .

3. Installation according to claim 1 or claim 2, wherein the lower portion (15) is sealingly welded to the primary sealing membrane (10) via a collar ring (17).

4. Installation according to any one of the preceding claims, wherein the ceiling wall of the vessel (2) further comprises in the direction of the thickness of the wall outside the primary thermally insulating barrier. (1 1), a secondary heat-insulating barrier (13) and a secondary sealing membrane (12).

5. Installation according to claim 4, wherein the primary thermally insulating barrier (1 1) and the secondary thermally insulating barrier (13) each consist of a plurality of insulating caissons (18), the pipe (14) passing through apart from one of the boxes (18) of the plurality of boxes (18) of each of the primary and secondary thermally insulating barriers.

6. Installation according to claim 4 or 5, wherein the primary sealing membrane (10) and / or the secondary sealing membrane (12) comprise a plurality of stretches (20) elongate with raised edges welded edge to edge in the longitudinal direction of the strake, each strake (20) comprising a planar zone between two longitudinal raised edges, the pipe (14) passing through the primary sealing member and / or the secondary sealing membrane (12) through the flat zone an elongated strake (20).

7. Installation according to claim 6, wherein the strake (20) of the primary (10) and / or secondary (12) sealing membrane comprises a reinforced portion (32), the reinforced portion (32) having a greater thickness the remainder of the strake (20) and comprising a flat area between two longitudinal raised edges, the pipe (14) passing through the flat area of the reinforced portion (32).

8. Installation according to any one of claims 4 to 7, wherein the installation comprises a sheath (21) surrounding the pipe (14) with a spacing in a radial direction and fixed to the upper portion (16) of the pipe (14), the sheath (21) extending from the upper portion (16) at least to the secondary sealing membrane (12), and the secondary sealing membrane

(12) being sealed to the sheath (21) around the sheath (21).

9. Installation according to claim 8, wherein the sheath (21) is welded to the secondary sealing membrane (12) via a collar ring (17).

10. Installation according to claim 6 and claim 3 and / or claim 9, wherein the one or more flanged rings (17) have a thickness greater than the strakes (20).

1 1. Ship (1) comprising an installation (1) according to any one of claims 1 to 10, the ceiling wall being attached to a lower surface of an intermediate bridge (8) of the ship (1).

12. Ship (1) according to claim 1 1, wherein the pipe (14) comprises an accordion compensator (25) on one end of the upper portion (16) remote from the lower portion (15), the compensator (25). ) being configured to secure the line (14) to an upper surface of an upper deck (9) of the ship (1), the compensator (25) having corrugations configured to allow thermal contraction of the line (14). ).

The vessel (1) according to claim 11 or claim 12, wherein the conduit (14) comprises an insulating sleeve (26) surrounding a portion of the upper portion (16) of the conduit (14) and located between the intermediate bridge (8) of the ship (1) and an upper deck (9) of a ship (1).

The vessel (1) according to claim 13, wherein the intermediate bridge (8) and the upper bridge (9) comprise an orifice (27,28), the orifice (27,28) having a diameter greater than a diameter. outside the upper portion (16) of the pipe (14), the pipe (14) passing through the intermediate bridge (8) and the upper bridge (9) through the intermediate bridge port (27) and the bridge port higher (28) respectively.

The vessel (1) according to claim 14, wherein the intermediate bridge (8) comprises a coaming (22) on an upper surface of the intermediate bridge (8), the coaming (22) surrounding the intermediate bridge port (27). ) and being traversed by the pipe (14), and wherein the pipe (14) is fixed to the overbeam (22).

16. A method of loading or unloading a ship (1) according to any one of claims 11 to 15, wherein a cryogenic fluid is conveyed through insulated pipes (40, 43, 46, 48) from or to a floating or land storage facility (44) to or from a vessel (2) of the vessel (1).

17. Transfer system for a cryogenic fluid, the system comprising a ship (1) according to any one of claims 1 1 to 15, insulated pipes (40, 43, 46, 48) arranged to connect the vessel ( 2) installed in the double hull (7) of the vessel (1) at a floating or land storage facility (44) and a pump for driving a flow of cryogenic fluid through the isolated pipes to or from the floating storage facility or terrestrial to or from the vessel (2) of the vessel (1).