Fluid transfer system, rotating joint device comprising such a system, stack of rotating joint devices and fluid exploitation installation

Abstract

Fluid transfer system (100) for transferring fluid comprising a concentric liquid transfer conduit (110) and a concentric gas transfer conduit (120), the gas transfer conduit (120) surrounding the liquid transfer conduit (110), and a buffer member (130), arranged between the liquid transfer conduit (110) and the gas transfer conduit (120) and at least partly surrounding the liquid transfer conduit (110), the buffer member (130) being configured to transfer an evaporated portion of the liquefied gas flowing in the liquid transfer conduit (110) from the liquid transfer conduit (110) to the gas transfer conduit (120). Rotary joint device (1000) comprising such a system (100), stack (1010) of rotary joint devices, and fluid exploitation installation (1). Figure for abstract: Fig. 3

Description

Title of the invention: Fluid transfer system, rotating joint device comprising such a system, stack of rotating joint devices and fluid exploitation installation Technical field of the invention

[0001] The invention relates to a fluid exploitation installation.

[0002] It also relates to a fluid transfer system used in such an installation.

[0003] The invention applies in particular to a fluid having at least one liquid state or one gaseous state depending on a temperature to which it is brought, and whose state, liquid or gaseous, has a strong impact on a volume occupied by the same quantity of fluid.

[0004] Such a fluid exploitation installation may be, for example, a hydrocarbon exploitation installation on an offshore type platform.

[0005] The invention may for example relate to a fluid transfer system, submerged or on the surface, used for transferring hydrocarbons, for example between a submerged PLEM (abbreviation for "Pipe Line End Manifold") and any floating vessel moored nearby, or a vessel and a carrier. Such a vessel includes an FPSO ("Floating Production Storage Offloading unit"), an FSO ("Floating Storage and Offloading"), an FSRU ("Floating Storage and Regasification Unit"), an FLNG ("Floating Liquified Natural Gas") or the like.

[0006] The invention may for example find a particular application for the transfer of liquefied gas, for example ammonia, or liquid methane (which is liquid at a temperature below approximately -160°C) which is a main constituent of liquefied natural gas (LNG) after separation of water, CO2 and the constituents of liquefied petroleum gas (LPG). State of the art

[0007] European patent EP 2 356 018 describes an installation for transferring fluid between an offshore unit for extracting and liquefying natural gas, and a liquefied natural gas (LNG) carrier. To carry out the transfer, the installation comprises, on one side, a cryogenic LNG transfer pipe between the offshore unit and the carrier, and on the other side, a gas return pipe.

[0008] In a particular case of exporting natural gas (NG), a difficulty is mainly linked to a strong dependence of a state of the natural gas (mainly gaseous or liquid) depending on temperature and pressure conditions of an environment in which the NG evolves.

[0009] Indeed, NG is naturally found in a gaseous state, under pressure, at a positive temperature, i.e. at least equal to 0°C (typically approximately 120°C at 300 bars in a reservoir rock), whereas it is in a liquid state when it is brought to a temperature lower than approximately -160°C, at 1 bar absolute, after refining.

[0010] Natural gas in the liquid state is called LNG (liquefied natural gas).

[0011] This change of state has a strong impact on a volume occupied by the same quantity of NG. It is possible to store approximately 600 times more NG in the liquid state than in the gaseous state in the same volume. Consequently, it is much more advantageous to store or transport NG in the liquid state (i.e. LNG) than in the gaseous state.

[0012] However, storing LNG requires very effective thermal insulation so that it can retain its liquid state and not return to a gaseous state because the pressure of the fluid would then be likely to increase to approximately 600 bars.

[0013] However, during a transfer of NG, for example from a ship to a carrier, a buoy or even a land site, while the NG is initially in a liquid state, a portion of the NG vaporizes. Preferably, this vaporized portion should then be returned to a liquefaction unit, for example located on the ship, to refine and liquefy it again to minimize any loss of production and possible greenhouse gas pollution.

[0014] In an installation such as that described in the aforementioned patent or similar, a floating unit at sea therefore has the function of extracting, refining, transforming and / or transferring raw fluids, or electrical energy obtained by combustion of vaporized NG.

[0015] A non-limiting example of such a floating unit is known in English terminology as an "FPSO" ("Floating Production Storage Offloading unit").

[0016] Such a floating unit is for example formed by a ship, which is mobile due to its environment, around a mooring turret, which is geostationary, via a main bearing. The ship can be temporarily secured to the turret.

[0017] Such an installation may comprise conduits which form a network of underwater pipes which allows fluid communication to transfer a fluid between the seabed and the vessel.

[0018] For this, the installation comprises at least one rotating joint device, or a stack of rotating joint devices known under the Anglo-Saxon name of "swivel stack".

[0019] To ensure the seal between the ship and the turret and thus ensure the integrity of the fluid transfer, the rotating joint device is provided with a first part, called fixed and considered geostationary, secured to the turret and a second part, called mobile, secured to the ship. The second part of the rotating joint device is therefore mobile in rotation relative to the first part, geostationary, of the joint device turning point.

[0020] A rotating joint device is further generally provided with several dynamic sealing members, called dynamic seals, arranged in spaces, often circular, provided between the first fixed part and the second mobile part of the rotating joint device.

[0021] In the example of natural gas exploitation, the latter is pumped, then generally freed from sand, water or other gases that it may contain to limit or even avoid scaling or blocking of pipes. Such separation is done for example by distillation for gases (ethane, propane, H2S, CO2, etc.), and by decantation or other to remove sand and water. The NG can then be liquefied, then pushed by floating conduits, for example flexible pipes, towards a storage and / or transport entity, for example an export gas carrier (for example an LNG tanker), for example moored in tandem, or a mooring buoy, to then be transferred to a refinery on land, or even directly to a particular site, on land.

[0022] At least one first rotating joint device can therefore be located on the ship in order to extract the NG and send it to a separation facility, while at least one other rotary joint device may be arranged to transfer the LNG from a liquefaction unit to the storage and / or transport entity, and to reroute a gas to the liquefaction unit.

[0023] The transfer of LNG thus involves passage through at least one rotating joint device capable of withstanding the cryogenic temperature of the LNG (i.e. approximately between -160°C and -100°C and between 1 bar and 25 bars absolute) so that it is kept in the liquid state as much as possible. Statement of the invention

[0024] The subject of the invention, according to a first aspect, is a fluid transfer system configured to equip a fluid exploitation installation, the fluid transfer system comprising: - a liquid transfer conduit, configured to convey a liquefied gas, and - a gas transfer conduit, configured to convey a gas in vapor form,

[0025] characterized in that the liquid transfer conduit and the gas transfer conduit are concentric, the gas transfer conduit surrounding the liquid transfer conduit,

[0026] and in that the fluid transfer system further comprises: - a buffer member, arranged between the liquid transfer conduit and the conduit gas transfer conduit and at least partially surrounding the liquid transfer conduit, the buffer member being configured to transfer a vaporized portion of the liquefied gas flowing in the liquid transfer conduit from the liquid transfer conduit to the gas transfer conduit.

[0027] A fluid here designates any deformable medium, mainly including a liquid and a gas, as opposed to a solid medium. A fluid therefore here designates indifferently a liquid or a gas, or a mixture of liquid and gas.

[0028] If the invention applies in particular to the transfer of LNG as liquefied gas, it can nevertheless be applied to any gas or mixture of gases, two-phase under so-called "normal" transfer conditions, such as for example, without being limiting, liquefied petroleum gas (LPG), carbon dioxide (CO2), possibly under pressure, for example at a pressure at least equal to 5.11 bar and a temperature at least equal to -56°C, ammonia (NH3), liquefied nitrogen (denoted LN2), liquefied argon (ArL), liquefied helium (HeL), etc.

[0029] In a particular exemplary implementation, the gas in vapor form circulating in the gas transfer conduit comprises vaporized liquefied gas.

[0030] The fluid transfer system according to the invention makes it possible to contribute to thermal insulation of the liquid transfer conduit forming a central path dedicated to liquefied gas, by using the gas transfer conduit to surround it, and makes it possible to separate the two flows (of liquid and gas) by an intermediate volume constituted by the buffer member.

[0031] Thus, the gas transfer conduit sheaths the liquid transfer conduit and forms a thermal barrier and a pressure differential damper.

[0032] Gas evaporated from the liquid can thus circulate in the buffer member and escape into the gas transfer conduit.

[0033] The gas transfer conduit is then configured to recover and circulate an evaporated portion, or fraction, of the liquid.

[0034] Leaks generated in the system can then be recovered.

[0035] In an exemplary implementation, a gas transfer conduit is a gas return conduit, configured to convey a vaporized portion of the liquefied gas.

[0036] Such a fluid transfer system is thus capable of transferring the liquefied gas, for example to a transport and / or storage unit, and of returning the vaporized fraction, for example to a liquefaction unit.

[0037] Such a fluid transfer system applies, for example, to installations capable of purifying natural gas extracted from underwater oil and gas deposits, liquefying it and storing it, and finally transferring it either via a stack of rotating joint devices, or a mooring and loading buoy - not limited to one or the other or to one of each - to an LNG carrier ensuring the transfer to a refinery or port, or via an unloading buoy allowing an LNG carrier to supply a refinery via a cryogenic underwater pipeline.

[0038] In use, a pressure in the gas transfer conduit is generally higher than that in the liquid transfer conduit.

[0039] Thanks to the buffer member, the system can thus tend towards a pressure balance. When liquid passes from the liquid transfer conduit to the buffer member, it will be in a hotter zone than the liquid transfer conduit and it will therefore vaporize and automatically counterbalance the liquid pressure.

[0040] The buffer member thus comprises an internal volume forming at least one airlock between the liquid transfer conduit and the gas transfer conduit.

[0041] For example, the buffer member includes a fluid inlet configured to introduce fluid, from the liquid transfer conduit, into the buffer member.

[0042] A wall of the liquid transfer conduit may for example comprise at least one orifice opening into the buffer member.

[0043] For example, the fluid inlet comprises at least one orifice in the wall of the liquid transfer conduit.

[0044] For example, the buffer member includes a fluid outlet configured to extract fluid from the buffer member to the gas transfer conduit.

[0045] A wall of the gas transfer conduit may for example comprise at least one orifice opening into the buffer member.

[0046] For example, the fluid outlet comprises at least one orifice in the wall of the gas transfer conduit.

[0047] In an exemplary embodiment, the fluid transfer system comprises at least one dynamic sealing member.

[0048] The dynamic sealing member may be arranged in the buffer member, for example at an interface between the buffer member and the liquid transfer conduit and / or the gas transfer conduit.

[0049] In an exemplary embodiment, the dynamic sealing member comprises a seal, a bearing, or a composite assembly.

[0050] In another exemplary embodiment, in particular if the fluid has no lubricating power, the dynamic sealing member may comprise a bearing.

[0051] A bearing makes it possible in particular to produce a natural leak.

[0052] Generally speaking, within the scope of the present invention, a seal may be made of very high molecular weight polyethylene (generally designated by the acronym “UHMWPE”).

[0053] Generally speaking, within the framework of the present invention, a bearing can be made of PTFE filled with powder or carbon fibers.

[0054] For example, the fluid inlet into the buffer member includes a leakage passage, for example produced by a dynamic sealing member.

[0055] For example, the fluid outlet of the buffer member comprises a leakage passage, for example produced by a dynamic sealing member.

[0056] In an exemplary embodiment, the fluid inlet comprises at least one safety valve.

[0057] The safety valve is for example configured to balance an overpressure between the liquid transfer conduit and the buffer member.

[0058] It thus makes it possible to manage fluid leaks, from the liquid transfer conduit, into the buffer member and then towards the gas transfer conduit.

[0059] Thus, any excess pressure in the liquid transfer conduit is released into the buffer member by at least one calibrated safety valve.

[0060] For example, the at least one orifice of the wall of the liquid transfer conduit is provided with the at least one safety valve.

[0061] In an exemplary embodiment, the fluid outlet comprises at least one exhaust valve.

[0062] The exhaust valve is for example configured to balance an overpressure between the buffer member and the gas transfer conduit.

[0063] Thus, any excess pressure in the buffer member is released into the gas transfer conduit by at least one calibrated exhaust valve.

[0064] For example, the at least one orifice of the wall of the gas transfer conduit is provided with the at least one exhaust valve.

[0065] In an exemplary embodiment, the buffer member comprises at least one inner wall forming a labyrinth for fluid flow in the buffer member.

[0066] In an exemplary embodiment, the inner wall divides the internal volume of the buffer member into at least two airlocks, the fluid inlet being arranged in a first of the two airlocks, and the fluid outlet being arranged in a second of the two airlocks.

[0067] Thus, the first of the two airlocks is the innermost of the two airlocks, i.e. juxtaposed to the liquid transfer conduit, and the second of the two airlocks is the outermost of the two airlocks, i.e. juxtaposed to the gas transfer conduit.

[0068] For example, the inner wall is configured to allow fluid passage from the first airlock to the second airlock.

[0069] In an exemplary embodiment, the inner wall comprises at least one fluid transmission orifice.

[0070] In an exemplary embodiment, the inner wall comprises at least one balancing valve, for example arranged in the fluid transmission orifice.

[0071] The balancing valve is for example configured to balance a pressure between the two airlocks of the buffer organ.

[0072] For example, the inner wall may comprise at least two walls, or portions, thereby dividing the internal volume of the buffer member into at least one third airlock. The third airlock is then formed between the first airlock and the second airlock.

[0073] At least one of the parts of the inner wall, or even each of the parts, may then comprise a fluid transmission orifice.

[0074] Where appropriate, a balancing valve formed in the portion of the inner wall between the first airlock and the third airlock, in particular in the corresponding fluid transmission orifice, then constitutes a first balancing valve.

[0075] Where appropriate, a balancing valve formed in the inner wall between the third airlock and the second airlock, in particular in the corresponding fluid transmission orifice, then constitutes a second balancing valve.

[0076] Generally, the at least one orifice provided in at least one part of the inner wall, and / or a valve (also called a micro-valve) which can optionally equip such an orifice, are sized according to the configuration of the buffer member, or more generally of the fluid transfer system, and the desired fluid pressure management in the buffer member.

[0077] There may therefore be several orifices, and / or several valves, arranged in one direction or another depending on the desired pressures.

[0078] A network of valves can therefore be configured, as desired, to manage an overpressure useful for energizing joints and for their maintenance.

[0079] Depending on the desired situation, each valve can therefore be arranged, in one direction or another, and sized, to control the different pressure transfers in the at least one airlock of the buffer member.

[0080] For example, the second balancing valve may be mounted in the opposite direction relative to the first balancing valve.

[0081] An assembly of balancing valves in opposite directions possibly makes it possible, for example, to generate an overpressure of a value of the setting of the safety valve in the first airlock while allowing maintenance or manual overpressure of the other two airlocks, for example with a gas injection as described below.

[0082] In an exemplary embodiment, the buffer member is annular and surrounds the liquid transfer conduit.

[0083] The buffer member thus contributes to the thermal insulation of the liquid transfer conduit and to the collection of any leaks which may arise from it.

[0084] Another advantage of a fluid transfer system having at least one buffer member is that it can use gravity.

[0085] Thus, a gaseous counterpressure helps to maintain the liquid in its circuit more than the sealing produced by a dynamic sealing member.

[0086] In an exemplary implementation, the fluid transfer system is configured so that a flow of liquid in the liquid transfer conduit is in a first direction, for example downward, i.e. according to gravity, and so that a flow of gas in the gas transfer conduit is also in the first direction.

[0087] In an exemplary implementation, the fluid transfer system is configured so that a flow of liquid in the liquid transfer conduit is in a first direction, for example downward, i.e. according to gravity, and so that a flow of gas in the gas transfer conduit is in a second direction, opposite to the first, for example upward.

[0088] In a particular exemplary implementation, the fluid transfer system is configured so that a liquid flow is downward, i.e. according to gravity, and so that a gas flow is upward, i.e. opposite to the liquid flow.

[0089] For example, the fluid inlet of the buffer member is offset from the fluid outlet relative to a longitudinal axis (X) of the liquid transfer conduit.

[0090] The longitudinal axis (X) of the liquid transfer conduit here corresponds to a mean line of fluid flow in the liquid transfer conduit.

[0091] In the case of a cylindrical conduit with a circular section, the longitudinal axis (X) is an axis of revolution of said conduit.

[0092] In an exemplary embodiment, at least a portion of the fluid inlet into the buffer member is disposed at a lower altitude than an altitude of at least a portion of the fluid outlet to provide a low level for liquid and a high level for gas.

[0093] In an exemplary embodiment, the fluid transfer system comprises an insulating sheath.

[0094] For example, the insulating sheath surrounds at least one section of the gas transfer conduit.

[0095] The insulating sheath may surround at least one section of the liquid transfer conduit, for example a section juxtaposed with the buffer member.

[0096] For example, the insulating sheath has a double-walled structure.

[0097] For example, the insulating sheath comprises an insulating coating.

[0098] The insulation of the external structure is for example ensured at critical locations by the presence of a double wall which can include any type of insulating material and / or be placed under vacuum inside the double wall.

[0099] In an exemplary embodiment, the fluid transfer system comprises a pressurization system that comprises a gas, the fluid transfer system being configured to inject gas from the pressurization system into the internal volume of the buffer organ.

[0100] The gas of the pressurization system is for example a neutral gas.

[0101] For example, the gas comprises at least one of: Nitrogen, Argon, Helium, or Methane, or any mixture thereof.

[0102] For example, the gas of the pressurization system is configured to be in a gaseous state at a temperature greater than or equal to about -160°C.

[0103] For example, the pressurization system gas is chosen to have a dew point below -160°C.

[0104] For example, the pressurization system comprises a pressurized dry gas cylinder.

[0105] For example, the fluid transfer system may include a pressure regulator configured to regulate a pressure in the buffer member.

[0106] By regulating the pressure in the buffer member, a volume of gas in the buffer member will pressurize according to a pre-established pressure in order to maintain this pressure in the buffer member. By injecting a sufficient volume of gas into the buffer member, a pressure will be established and oppose a possible leakage of liquid.

[0107] For example, for a determined pressure of 25 bar in the buffer member, and a pressure in the liquid transfer conduit varying between 10 bar and 20 bar, a setting pressure of the safety valve is approximately 5 bar, as well as at least that of a balancing valve if applicable.

[0108] Thus, the buffer member makes it possible to limit or even prevent leaks of liquid from the liquid transfer conduit.

[0109] In an exemplary embodiment, the buffer member comprises a gas injection port configured to inject a gas, in particular a neutral and dry gas, under pressure, into the buffer member, for example into at least one airlock of the buffer member.

[0110] In an exemplary embodiment, the fluid transfer system comprises at least one manifold configured to inject gas into the buffer member via the gas injection port, called the spill manifold.

[0111] The spill collector thus connects the buffer member with the pressurization system, which may include, for example, a pressurized dry gas cylinder.

[0112] Such a pressurization system (possibly manual), with a spill collector, makes it possible to control leak rates, and above all to purge and / or drain liquid and / or solid residues which may have been taken on board, despite at least one purification of the fluid.

[0113] In such a fluid transfer system, it is therefore possible to clean at least part of the fluid transfer system, for example the buffer member, by purges, possibly operated from outside the system, on the surfaces sealing and / or friction surfaces: for example bearings or seals depending on the technique used.

[0114] This contributes to better safety of the fluid transfer system because pressurizing with a neutral gas can be done without having to disassemble the system.

[0115] Furthermore, limiting fouling of the fluid transfer system makes it possible to reduce its wear and therefore produce better operational reliability.

[0116] In addition, such a fluid transfer system makes it possible to monitor the circulation pressure of the liquid and contributes to the quality of its sealing.

[0117] Depending on the nature of the fluid, this makes it possible to avoid atmospheric pollution and / or possible ignition of the gas in the open air.

[0118] In addition, this limits a cryopumping phenomenon, which can be risky, in which water can freeze and thus cause abrasion of seals, noise, and / or also form clathrates depending on the fluid operated, in particular methane clathrates where appropriate, i.e. compounds in which methane molecules are trapped in a mesh of water molecules. Such clathrates form a type of wax which contributes to the wear of the system and incidentally causes unwanted leaks. It is therefore preferable to be able to avoid the formation of clathrates.

[0119] The use of pressurization with a neutral and dry gas as described above, even during operation of the system, thus makes it possible to render inert, test, purge, drain and dry at least part of the buffer member.

[0120] In another exemplary embodiment, the buffer member may be pressurized by the flow of gas.

[0121] In such an exemplary embodiment, the spill collector is then fluidically connected to the gas transfer conduit on the one hand, and to the gas injection port of the buffer member on the other hand.

[0122] According to another example, as an alternative or supplement, the fluid transfer system may comprise a valve sized according to a desired pressure and / or controlled according to a target pressure.

[0123] According to another interesting option, the fluid transfer system is configured to compensate for a variation in length of the liquid transfer conduit.

[0124] The variation in length of the liquid transfer conduit is due to an axial deformation (expansion or contraction), i.e. along a length of the conduit.

[0125] As an illustration, when operating with LNG, the fluid in the liquid transfer conduit is preferably maintained at a temperature between -160°C and -140°C, so the conduit is at a temperature between approximately -160°C and -140°C. However, when the flow of fluid is initiated in the conduit, the liquid transfer conduit is at room temperature at the start of the operation. Due to the significant cooling, the liquid transfer conduit contracts, and therefore reduced in length.

[0126] However, the gas transfer conduit is not subject to the same contraction. Consequently, the liquid transfer conduit reduces in length compared to the gas transfer conduit which surrounds it.

[0127] Immobilizing the liquid transfer conduit relative to the gas transfer conduit would generate constraints that are too great to guarantee the integrity of the conduits, and / or would involve very high costs.

[0128] It is therefore of interest that the fluid transfer system be configured to compensate for such length variations.

[0129] In an exemplary embodiment, the liquid transfer conduit comprises an incident section provided with a tip, and a receiving section, forming a protective sleeve, into which the tip is inserted.

[0130] Thus, depending on the deformation of the liquid transfer conduit, the tip is pushed more or less deeply into the receiving section.

[0131] In an exemplary embodiment, the buffer member is configured to slide relative to at least one of the incident section and the receiving section, i.e. slide relative to the incident section and / or the receiving section.

[0132] The buffer member then acts as a ring which can move (for example, rise or fall) relative to the incident section, while remaining tight in rotation.

[0133] Optionally, the buffer member is attached, fixed, to at most one of the incident section and the receiving section.

[0134] Thus, the buffer member is configured to compensate for a deformation of the liquid transfer conduit, in particular by creating a junction between the incident section and the receiving section, by longitudinal sliding.

[0135] This can simplify the design of conduits, for example gas pipelines, of great length.

[0136] However, according to another embodiment, the buffer member could be an axially floating ring.

[0137] In one embodiment, the system described herein may produce reverse leaks, i.e., where gaseous fluid may reliquefy. Such a system is then configured to withstand overpressure in both directions.

[0138] The inlets and outlets described here then have their functions reversed. For example, the fluid inlet configured to introduce fluid, from the liquid transfer conduit, into the buffer member, then serves to extract fluid from the buffer member to the liquid transfer conduit. Likewise, the fluid outlet configured to extract fluid from the buffer member to the gas transfer conduit, then serves to introduce fluid, from the gas transfer conduit, into the buffer member.

[0139] Such a fluid transfer system comprising two concentric conduits allows for example to offer the following possibilities: - a gas transfer for loading or unloading a gaseous product; - protection (inerting) of a tank, upstream or downstream of the system; - insulation (“pipe in pipe”); - protection (called “boil off protection” in English), i.e. a gas is applied to the surface of a liquefied gas and thus prevents its liquefaction by creating a gaseous cloud; - a leak check: by applying a permanent vacuum in the gas transfer pipe, it is possible to check and / or analyze a possible introduction of gas into the buffer organ and thus check if there is a leak in the system which could come from the liquid transfer pipe.

[0140] The invention also relates, according to another aspect, to a rotating joint device which comprises a fluid transfer system comprising all or part of the characteristics described above.

[0141] For example, the rotating joint device comprises a first annular part, called fixed, and a second annular part movable in rotation around an axis of rotation X and relative to said first fixed annular part.

[0142] The rotating joint device generally has an internal space defined by a inner surface of the first fixed annular part.

[0143] The rotating joint device comprises a transfer conduit which enters through the first fixed annular part of the rotating joint device and opens out of the rotating joint device through an outlet connection connected to the second movable annular part.

[0144] A flow thus passes through the rotating joint device by entering the first fixed annular part via the transfer conduit and exiting through the second movable annular part via the outlet connection.

[0145] Here, the transfer conduit which enters the rotating joint device comprises at least the gas transfer conduit of the fluid transfer system, forming a gas inlet into the rotating joint device, and the second movable part comprises the outlet connector which forms a gas outlet of the rotating joint device.

[0146] In an exemplary embodiment, the liquid transfer conduit of the fluid transfer system is arranged in the internal space of the rotating joint device.

[0147] Such a rotating joint device thus makes it possible to simultaneously transfer liquid and transfer gas by ensuring rotation along the vertical axis (X) and sealing of said circuits.

[0148] In an exemplary embodiment in which the liquid transfer conduit comprises an incident section and a receiving section, one of the incident section or the receiving section may be fixed to the second movable annular part and / or the other of the incident section or receiving section can be fixed to the first fixed annular part.

[0149] For example, the second annular part is movable in rotation relative to the first annular part by means of an articulation member, at least partially interposed between the first annular part and the second annular part.

[0150] For example, the articulation member comprises a bearing member.

[0151] In one exemplary embodiment, the rotating joint device comprises a fluid injection port configured to inject a fluid into the articulation member.

[0152] In an exemplary embodiment, the rotating joint device comprises at least one manifold configured to inject fluid into the articulation member via the fluid injection port.

[0153] Similarly, a fluid can be injected onto a barrier which is located outside the articulation member, which encompasses the articulation member, and the barrier can be pressurized, for example to a pressure of 40 bar or 50 bar, possibly using a collector, and which will for example prevent sea water from entering (spray, rain, waves if floating system like a buoy, etc.).

[0154] According to another interesting option, the collector can be an oil or other lubricant collector (such as for example glycols or petroleum ethers which allow lubrication at -160°C), the oil or other lubricant being chosen so as not to solidify at the operating temperature (approximately -160°C maximum).

[0155] According to an alternative embodiment, if a rolling member is too complicated to lubricate, the articulation member may comprise at least one friction pad.

[0156] In an exemplary embodiment, the rotating joint device comprises an insulating sheath.

[0157] For example, the insulating sheath at least partially surrounds the first fixed annular part and / or the second movable annular part.

[0158] For example, the insulating sheath has a double-walled structure.

[0159] For example, the insulating sheath comprises an insulating coating.

[0160] The insulation of the external structure is for example ensured at locations considered critical by the presence of a double wall which can include any type of insulating material and / or be placed under vacuum inside the double wall.

[0161] One purpose of such insulation is to limit thermal exchanges which can cool the articulation member or promote heating of the liquid passage.

[0162] The invention also relates, according to yet another aspect, to a stack of rotating joint devices comprising at least two rotating joint devices, at least a first of the rotating joint devices of the stack of rotating joint devices being as described previously.

[0163] The invention also relates, according to yet another aspect, to a fluid exploitation installation which comprises at least: - a liquefaction unit, - a storage and / or transport entity, - a first rotating joint device comprising a fluid transfer system as described above, the first rotating joint device being connected by the outlet connector to the liquefaction unit and by the gas transfer conduit to the storage and / or transport entity, the liquid transfer conduit of the fluid transfer system connecting the liquefaction unit to the storage and / or transport entity, and - at least one second rotating joint device, which comprises an inlet conduit in the second rotating joint device which is connected to a conduit of an underwater pipeline network for extracting natural gas, and an outlet connection which is connected to the liquefaction unit.

[0164] For example, the second rotating joint device may be a high pressure high temperature rotating joint device (denoted HPHTS).

[0165] In an exemplary embodiment, the installation comprises a stack of rotating joint devices comprising at least two rotating joint devices, the stack of rotating joint devices comprising at least the first rotating joint device and the second rotating joint device.

[0166] In an exemplary embodiment, the installation further comprises a ship, and at least one of the first rotating joint device or the second rotating joint device is arranged on the ship. Brief description of the figures

[0167] The invention, according to an exemplary embodiment, will be well understood and its advantages will appear better on reading the detailed description which follows, given for information purposes and in no way limiting, with reference to the appended drawings in which:

[0168] [Fig. 1] schematically and partially represents a fluid exploitation installation on an offshore platform, provided with a ship, a mooring turret, a network of underwater pipes allowing fluid communication for the transfer of the fluid between the seabed and the ship, and at least one rotating joint device ensuring the seal between the ship and the turret and the integrity of the fluid transfer;

[0169] [Fig.2] is a schematic top view of a rotating joint device, as used for example in the installation illustrated in [Fig.l];

[0170] [Fig.3] represents a fluid transfer system according to a first embodiment;

[0171] [Fig.4] represents the system of [Fig.3] partially exploded;

[0172] [Fig.5] represents a fluid transfer system according to a second mode of realization ;

[0173] [Fig.6] represents a fluid transfer system according to a third mode of realization ;

[0174] [Fig.7] represents a fluid transfer system according to a fourth mode of realization ;

[0175] [Fig.8] represents a fluid transfer system according to a fifth mode of realization ;

[0176] [Fig.9] represents a fluid transfer system according to a sixth mode of rea lization forming a coaxial expansion joint;

[0177] [Fig. 10] represents a fluid transfer system according to a seventh mode of embodiment forming a coaxial expansion joint according to a first variant;

[0178] [Fig. 11] represents a fluid transfer system according to an eighth mode of embodiment forming a coaxial expansion joint according to a second variant;

[0179] [Fig. 12] represents a fluid transfer system according to a ninth mode of realization ;

[0180] [Fig. 13] represents the system of [Fig. 12] partially exploded; and

[0181] [Fig.14] illustrates alternative embodiments of the liquid transfer conduit in function of a liquid flow direction in the liquid transfer conduit. Detailed description

[0182] [Fig.l] illustrates a fluid exploitation installation 1 on an offshore platform, allowing the exploitation of hydrocarbon fields at sea 2.

[0183] This installation 1, also called a floating production, storage and offloading unit (FPSO), can be provided with a ship 3 which is mobile, due to its environment formed by the sea 2, and a mooring turret 4 which is geostationary and around which the ship 3 is mobile.

[0184] The mooring turret 4 can for example be mechanically secured to the seabed 2 via underwater anchors 5.

[0185] The vessel 3 can be movable relative to the mooring turret 4 by means of a rolling mechanism 7.

[0186] The installation 1 can be provided with conduits 6 which form a network of underwater pipes allowing fluid communication for a transfer of fluid (for example: water, methanol, detergents, etc.) between the mooring turret 4 and the seabed.

[0187] The fluid circulating in the conduits 6 can also come from a subsoil of the sea 2.

[0188] The fluid can then be treated and purified before the gas can be liquefied.

[0189] For this, the fluid exploitation installation 1 comprises a liquefaction unit 30, which can be located on the ship 3 as illustrated here, or be added to it on a floating unit moored alongside for example.

[0190] The liquefied fluid can then be pushed towards a storage and / or transport entity 40, for example via a mooring buoy.

[0191] A storage and / or transport entity 40 is for example an export gas carrier (for example a shuttle LNG carrier), which can be moored in tandem, or by a mooring buoy, to then transfer the fluid to a refinery on land, or even directly to a particular site, on land.

[0192] For example, the storage and / or transport entity 40 may be: - Either moored alongside (in tandem) or in line (called “piggy back”) and connected by 1012 floating hoses for LNG and 1011 floating hoses for gas transfer; - Either moored and connected to a buoy (not shown) by flexible hoses, coaxial or not, floating or underwater, which can for example be either floating between two waters or buried;

[0193] According to another example, the ship can also supply a refinery on land or even directly a particular site (not illustrated).

[0194] The installation 1 comprises a rotating joint device 10 ensuring: - the seal between the ship 3 and the mooring turret 4, and - the integrity of the fluid transfer.

[0195] The rotating joint device 10 may be formed from a rotating joint (“swivel joint” in English terminology) or be arranged in a stack of such joints.

[0196] At least one rotating joint device 10, for example an HPHTS rotating joint device, may therefore be located on the ship 3 in order to extract the NG and send it to the liquefaction unit 30, while at least one other rotating joint device may be arranged to transfer the LNG from the liquefaction unit 30 to the storage and / or transport entity 40, and to reroute a gas to the liquefaction unit 30.

[0197] The installation 1 can then in particular comprise at least one stack 1010 of rotating joint devices comprising at least two rotating joint devices.

[0198] As illustrated in [Fig.2], such a rotating joint device 10, for example HPHTS, is generally annular and comprises a first annular part 11, called fixed, which is generally configured to be secured to the mooring turret 4, and / or to the mooring anchors 5, as well as a second annular part 12, called mobile, which is configured to be secured to the ship 3.

[0199] In the example described here, the second annular part 12 is movable in rotation relative to the first annular part 11, by means of a rolling member 13 at least partially interposed between the first annular part 11 and the second annular part 12.

[0200] The rolling element is for example protected by seals.

[0201] The rotating joint device 10 has an internal space 14 defined here by an internal surface 15 of the first annular part 11.

[0202] The rotating joint device 10 further comprises a transfer conduit 16 connected, directly or indirectly, to at least one of the underwater conduits 6.

[0203] The transfer conduit 16 enters the first annular part 11 through the internal space 14 and opens out of the rotating joint device 10 through an outlet connection 17. The outlet connection 17 is for example connected to a treatment and / or liquefaction unit (not shown) in order to separate and then liquefy the gas and then transfer the liquefied gas to a shuttle tanker or a storage unit on land.

[0204] A flow thus passes through the rotating joint device 10 by entering the first fixed annular part 11 via the transfer conduit and exiting via the second movable annular part 12 via the outlet connection.

[0205] [Fig. 3] represents a fluid transfer system 100 according to a first embodiment of the invention. [Fig. 4] represents the system of [Fig. 3] partially exploded.

[0206] The fluid transfer system 100 comprises a liquid transfer conduit 110, configured to convey a liquefied gas (GL).

[0207] The liquid transfer conduit 110 is here a conduit with a circular section.

[0208] The circular section conduit then comprises a cylindrical wall delimiting a internal volume of the conduit in which a flow of fluid can flow, such as for example a flow of liquefied gas shown diagrammatically by arrow 111.

[0209] The liquid transfer conduit 110 here comprises two sections, including an incident section 112 and a receiving section 113.

[0210] The incident section 112 and the receiving section 113 are partly nested within each other, thus allowing a variation in length of the liquid transfer conduit 110, a variation in length being able to be induced as a function of the temperature (expansion) and the pressure (bottom effect).

[0211] The length here represents a dimension along a longitudinal axis X, illustrated [Fig.3]. The longitudinal axis (X) here corresponds to a mean line of fluid flow in the liquid transfer conduit 110. In the case of a cylindrical conduit with a circular section, it is an axis of revolution of the conduit.

[0212] As best seen [Fig.4] for example, the incident section 112 comprises an end piece 114, forming a part of reduced section of the incident section 112, configured to be inserted into the receiving section 113, which thus forms a protective sleeve.

[0213] Such a protective sleeve may for example be configured to protect seals and / or bearings against erosion which may be due to turbulence of a mixture of gas and liquid bubbles in the liquid transfer conduit 110. This sleeve may for example be guided by a bearing 115 arranged between the receiving section 113 and the end piece 114.

[0214] Depending on the deformation of the liquid transfer conduit, the tip is pushed more or less deeply into the receiving section 113.

[0215] The liquid transfer conduit 110 is thus configured to take a retracted configuration in which at least a portion of the tip 114 is inserted into the receiving section 113 and the liquid transfer conduit 110 then has a first length, and a deployed configuration in which the portion of the tip is outside the receiving section 113 and the liquid transfer conduit 110 then has a second length, greater than the first length.

[0216] In the retracted configuration, at least half of a length of the tip 114 is preferably engaged in the receiving section 113, considering for example a working temperature in the most difficult conditions, such as for example approximately 25 bar at -100°C.

[0217] Furthermore, the incident section 112 can rotate relative to the receiving section 113, for example here along the X axis.

[0218] The fluid transfer system 100 also comprises a gas transfer conduit 120.

[0219] The gas transfer conduit 120 is notably configured to convey an evaporated portion of the liquefied gas, notably towards the liquefaction unit.

[0220] The gas transfer conduit 120 is here a conduit with an annular section.

[0221] In other words, the annular section conduit has an inner cylindrical wall and an outer cylindrical wall which surrounds the inner cylindrical wall, and a fluid can then flow in the conduit between the inner cylindrical wall and the outer cylindrical wall.

[0222] In [Fig.3], a gas flow is represented by arrow 121.

[0223] The gas flow is here shown diagrammatically in the opposite direction to that of the liquid flow shown diagrammatically by arrow 111. However, the gas flow could be in the same direction as that of the liquid, depending on a context and / or a desired application.

[0224] In the present exemplary embodiment, the gas transfer conduit 120 surrounds the liquid transfer conduit 110.

[0225] Further, the liquid transfer conduit 110 and the gas transfer conduit 120 are concentric.

[0226] The fluid transfer system 100 further comprises a buffer member 130.

[0227] The buffer member 130 is notably configured to transfer an evaporated portion of liquefied gas circulating in the liquid transfer conduit 110, from the liquid transfer conduit 110 to the gas transfer conduit 120.

[0228] The buffer member 130 thus makes it possible to separate gas from liquid leaks which could have vaporized inside the liquid transfer conduit 110, and return this gas to a liquefaction unit via the gas transfer conduit 120.

[0229] The buffer member 130 is here arranged between the liquid transfer conduit 110 and the gas transfer conduit 120 and at least partially surrounds the liquid transfer conduit 110.

[0230] In other words, the buffer member 130 is here annular and surrounds the liquid transfer conduit 110.

[0231] The buffer member 130 thus contributes to thermal insulation of the liquid transfer conduit 110 and to the collection of any leaks which may come from it.

[0232] The fluid transfer system 100 thus makes it possible to contribute to thermal insulation of the liquid transfer conduit 110 forming a central path dedicated to liquefied gas, by using the gas transfer conduit 120 to surround it, and makes it possible to separate the two flows (of liquid and gas) by an intermediate volume constituted by the buffer member 130.

[0233] The gas transfer conduit 120 sheaths the liquid transfer conduit 110 and forms a thermal barrier and a gas / liquid differential pressure damper.

[0234] Gas evaporated from the liquid may flow into the buffer member 130 and escape into the gas transfer conduit 120.

[0235] The gas transfer conduit 120 is then configured to recover and circulate an evaporated portion, or fraction, of the liquid.

[0236] The buffer member 130 comprises on the one hand a fluid inlet 131 and on the other hand a fluid outlet 132.

[0237] The fluid inlet 131 is configured to introduce fluid into the buffer member 130, from the liquid transfer conduit 110.

[0238] For example, the fluid inlet 131 may comprise at least one orifice formed in the wall of the liquid transfer conduit 110 and opening into the buffer member 130.

[0239] The fluid inlet 131 may in particular comprise several orifices arranged around the liquid transfer conduit 110.

[0240] In the present exemplary embodiment, the fluid inlet 131 comprises at least one safety valve 141.

[0241] It may in particular comprise several safety valves arranged around the liquid transfer conduit 110.

[0242] The safety valve 141 is for example configured to balance an overpressure between the liquid transfer conduit 110 and the buffer member 130.

[0243] Thus, any excess pressure in the liquid transfer conduit 110 is released into the buffer member 130 by at least one safety valve 141 calibrated accordingly.

[0244] Here, the safety valve 141 is arranged in the wall of the liquid transfer conduit 110, in particular in the present exemplary embodiment, in the incident section 112, and for example in an orifice of the fluid inlet 131.

[0245] Alternatively or additionally, as illustrated herein, the fluid inlet 131 may also include a leakage passage 142, for example a passage bypassing a dynamic sealing member 143 described later.

[0246] A leakage passage here designates a gap formed by contact between parts.

[0247] In the present example, as best seen in [Fig.4], when the incident section 112 is inserted into the receiving section 113, contact between the end piece 114, the bearing 115 and the receiving section 113 may allow fluid to leak.

[0248] To nevertheless control such a leak, the fluid transfer system 100 comprises for example a dynamic sealing member 143.

[0249] In this example, the dynamic sealing member 143 comprises a piston seal.

[0250] The dynamic sealing member 143 is for example here arranged in the buffer member 130, and for example around a junction between the incident section 112 and the receiving section 113, for example opposite a gap between the buffer member 130 and the incident section 112.

[0251] The fluid outlet 132 is configured to extract fluid from the buffer member 130 to the gas transfer conduit 120.

[0252] For example, the fluid outlet 132 may comprise at least one orifice formed in the wall of the gas transfer conduit 120, in particular the internal cylindrical wall, and opening into the buffer member 130.

[0253] It may in particular comprise several orifices arranged around the gas transfer conduit 120, in particular the internal cylindrical wall.

[0254] In the present exemplary embodiment, the fluid outlet 132 comprises at least one exhaust valve 144.

[0255] It may in particular comprise several exhaust valves arranged around the gas transfer conduit 120, in particular the internal cylindrical wall.

[0256] The exhaust valve 144 is for example configured to balance an overpressure between the buffer member 130 and the gas transfer conduit 120.

[0257] Thus, any excess pressure in the buffer member 130 is released into the gas transfer conduit 120 by at least one exhaust valve 144 calibrated accordingly.

[0258] Here, the exhaust valve 144 is arranged in the internal cylindrical wall of the gas transfer conduit 120, in particular in an orifice of the fluid outlet 132.

[0259] Alternatively or additionally, as illustrated herein, the fluid outlet 132 may also include a leakage passage 145, for example a passage bypassing a dynamic sealing member 146 described later.

[0260] In the present example, as best seen in [Fig.4], the fluid transfer system 100 comprises a separating partition 151 against which the buffer member 130 is brought into abutment.

[0261] Contact between the partition wall 151 and the buffer member 130 may allow fluid to leak.

[0262] To limit such a leak, the fluid transfer system 100 comprises for example a dynamic sealing member 146, for example here a face seal.

[0263] The dynamic sealing member 146 is for example here arranged in the buffer member 130, and against the separating partition 151.

[0264] In practice, the fluid transfer system 100 is preferably configured so that a liquid flow is downward, i.e. according to gravity, as shown diagrammatically by the arrow 111, and so that a gas flow is upward, i.e. opposite to the fluid flow, as shown diagrammatically by the arrow 121.

[0265] It is then interesting that the fluid inlet 131 of the buffer member is offset relative to the fluid outlet 132 along the longitudinal axis (X) of the liquid transfer conduit 110.

[0266] As shown schematically here, at least a portion of the fluid inlet 131 in the buffer member (here the leak passage 142) is arranged at a lower altitude than an altitude of at least a portion of the fluid outlet 132 (here the leak passage 145) to ensure a lower level for liquid and a higher level for gas.

[0267] The buffer member 130 here comprises an internal volume 133 forming at least one airlock between the liquid transfer conduit 110 and the gas transfer conduit 120.

[0268] In the present exemplary embodiment, the buffer member 130 comprises at least one inner wall 147 forming a labyrinth for fluid flow in the buffer member.

[0269] Here, the inner wall 147 divides the internal volume 133 of the buffer member 130 into at least two airlocks, and even here three airlocks, the fluid inlet 131 being arranged in a first of the airlocks, and the fluid outlet 132 being arranged in a second of the airlocks; here a third airlock being formed between the first airlock and the second airlock.

[0270] For example, the inner wall 147 is configured to allow fluid passage from the first airlock to the second airlock.

[0271] In the present embodiment, the inner wall 147 comprises at least one balancing valve 148 arranged in an orifice, and an orifice without a valve 149.

[0272] The balancing valve 148 is for example configured to balance a pressure between two of the airlocks of the buffer member 130.

[0273] The safety valve 141 is for example configured to limit to 5 bar an overpressure in the liquid transfer conduit 110 relative to the buffer member 130. For example, if dynamic sealing members 143, 146 are sealed and liquid has passed into the buffer member, this liquid would vaporize and increase the pressure in the buffer member without however exceeding a setting of a balancing valve which would release the excess pressure from the buffer member to the liquid transfer conduit 110.

[0274] In the present embodiment, the balancing valve can be calibrated to a few bars and mounted in the opposite direction to the safety valve 141, or otherwise the at least one valveless orifice 149, of relatively small section, can be arranged at the bottom (in the direction of gravity) of the wall 147. Such an orifice 149 is intended to laminate transfers of fluids in both directions without reducing a mechanical rigidity of the buffer member 130, and to promote that the pressure inside an airlock cannot be too much higher than that present outside to prevent, at least in part, permanent deformations of the interior wall 147.

[0275] Here, at least one balancing valve 148 is formed in a portion of the inner wall 147 separating the first airlock from the third airlock and at least one balancing valve 148 is formed in another portion of the inner wall 147 separating the third airlock from the second airlock.

[0276] As better visible from [Fig.4] in the present exemplary embodiment, the buffer member 130 is here delimited on the one hand by the liquid transfer conduit 110 and on the other hand by the gas transfer conduit 120, and shares a common wall with each.

[0277] However, the buffer member could have its own walls on either side, which would then be adjacent on the one hand to the internal wall of the gas transfer conduit and on the other hand to the wall of the liquid transfer conduit.

[0278] At least the incident section 112 here has rotational mobility relative to the buffer member 130.

[0279] The fluid transfer system is here configured to compensate for a variation in length of the liquid transfer conduit 110.

[0280] The variation in length of the liquid transfer conduit is due to an axial deformation (expansion or contraction, possibly combined with the bottom effect), i.e. along a length of the conduit, along the X axis.

[0281] As an illustration, when operating with LNG, the fluid in the liquid transfer conduit is preferably maintained at a temperature between -160°C and -140°C. Therefore, the conduit is at a temperature between approximately -160°C and -140°C. However, when the flow of fluid is initiated in the conduit, the The liquid transfer line is initially at room temperature. Due to the significant cooling, the liquid transfer line contracts, and therefore reduces in length.

[0282] However, the gas transfer conduit is not subject to the same contraction. Consequently, the liquid transfer conduit reduces in length compared to the gas transfer conduit which surrounds it.

[0283] Immobilizing the liquid transfer conduit relative to the gas transfer conduit would generate constraints that are too great to guarantee the integrity of the conduits, and / or would involve very high costs.

[0284] It is therefore of interest that the fluid transfer system is configured to compensate for such length variations.

[0285] For this, in the present exemplary embodiment, the buffer member 130 is configured to slide relative to at least one of the incident section 112 and the receiving section 113, i.e. slide relative to the incident section and / or to the receiving section.

[0286] The buffer member 130 then acts as a ring which can translate, vertically, while being sealed in rotation, in particular here around the X axis.

[0287] As best seen [Fig.4], the buffer member 130 is fixed to at most one of the incident section and the receiving section, in this case to the receiving section 113.

[0288] Thus, in the present exemplary embodiment, the buffer member 130 is configured to slide relative to the incident section 112, and the receiving section 113 slides integrally with the buffer member 130 relative to the incident section 112.

[0289] The buffer member is thus configured to compensate for a deformation of the liquid transfer conduit, in particular by creating a junction between the incident section 112 and the receiving section 113, by longitudinal sliding along the longitudinal axis (X).

[0290] In the present exemplary embodiment, the buffer member comprises a gas injection port 161 configured to inject a gas, in particular under pressure, into the buffer member, for example into at least one airlock of the buffer member.

[0291] The fluid transfer system may then comprise at least one spill manifold 160 configured to inject gas into the buffer member via the gas injection port 161.

[0292] The spill collector 160 thus connects the buffer member with, for example, a pressurization system and / or the gas flow. In the latter case, the spill collector 160 is fluidically connected to the gas transfer conduit 120 on the one hand, and to the gas injection port 161 of the buffer member on the other hand.

[0293] For example, the seal of the dynamic sealing member 143 may be actuated by pressure through at least the valveless ports 149 of the inner wall 147.

[0294] The fluid transfer system 100 may comprise the pressurization system (shown according to a particular embodiment [Fig. 14]) which then comprises a gas.

[0295] The gas of the pressurization system is for example a neutral gas.

[0296] This is, for example, a neutral and dry gas whose boiling point at the operating pressure is lower than that of the liquid gas contained in the liquid transfer conduit 110.

[0297] For example, the gas of the pressurization system is configured to be in a gaseous state at a temperature greater than or equal to about -160°C.

[0298] For example, the gas in the pressurization system is chosen to be in the gaseous state at a temperature slightly below -160°C at atmospheric pressure when GL is Methane, at approximately -90°C when GL is Ethane, -42°C for Propane and -33°C for Ammonia.

[0299] For example, the gas comprises at least one of: Nitrogen, Argon, Helium, or Methane, or any mixture thereof.

[0300] For example, the pressurization system may include a pressurized gas cylinder.

[0301] For example, the fluid transfer system 100 may also include a pressure regulator (not shown) configured to regulate a predetermined pressure in the buffer member 130.

[0302] As also shown diagrammatically in Figures 3 and 4, the fluid transfer system described above is here part of a rotating joint device 1000.

[0303] The rotating joint device 1000 comprises a first annular part 1100 (see [Fig.4]), called fixed, and a second annular part 1200 movable in rotation around the axis of rotation (X) and relative to said first fixed annular part 1100.

[0304] The rotating joint device generally has an internal space defined by an internal surface of the first fixed annular part.

[0305] The rotating joint device 1000 comprises a transfer conduit 1110 which enters the first fixed annular part 1100, and opens out via an outlet connector 1210 connected to the second movable annular part 1200.

[0306] A flow thus passes through the rotating joint device 1000 by entering the first fixed annular part 1100 via the transfer conduit 1110 and exiting via the second movable annular part 1200 via the outlet connector 1210.

[0307] Here, the transfer conduit 1110 comprises at least the gas transfer conduit 120 of the fluid transfer system 100, forming a gas inlet into the rotating joint device 1000, and the second movable part 1200 comprises the outlet connector 1210 which forms a gas outlet of the rotating joint device 1000.

[0308] As also visible [Fig.4], the second movable annular part 1200 here comprises the separating partition 151.

[0309] Furthermore, the partition wall 151 comprises at least one passage 155 allowing to gas flowing from the gas transfer conduit 120 to pass from the first fixed annular part 1100 to the second movable annular part 1200 and thus pass through the rotating joint device 1000 and exit therefrom through the outlet connection 1210.

[0310] The liquid transfer conduit 110 of the fluid transfer system 100 is disposed in the internal space of the rotating joint device 1000.

[0311] Such a rotating joint device 1000 thus makes it possible to simultaneously transfer liquid and transfer gas by ensuring rotation along the vertical axis (X) and sealing of said circuits.

[0312] Furthermore, in the present exemplary embodiment in which the liquid transfer conduit 110 comprises an incident section 112 and a receiving section 113, the incident section 112 is fixed to the second movable annular part 1200 while the receiving section 113 is fixed to the first fixed annular part 1100.

[0313] For example here, the rotating joint device 1000 comprises an articulation member 152, for example with bearings, which is at least partially interposed between the first annular part 1100 and the second annular part 1200, so that the second annular part 1200 is movable in rotation relative to the first annular part 1100.

[0314] For example here, the articulation member 152 comprises a first part 153 secured to the first fixed annular part 1100 and a second part 154 secured to the second movable annular part 1200, the second part 154 of the articulation member 152 being movable in rotation relative to the first part 153 of the articulation member 152.

[0315] The rotating joint device 1000 further comprises here a fluid injection port. 156 configured to inject a fluid into the articulating member 152.

[0316] For example, the rotary joint device 1000 comprises at least one manifold 157 configured to inject fluid into the articulation member 152 via the fluid injection port 156.

[0317] The collector 157 may be a collector of oil or other lubricant (such as for example glycols or petroleum ethers which allow lubrication at -160°C), the oil or other lubricant being chosen so as not to solidify at the operating temperature (approximately -160°C at the lowest).

[0318] The rotating joint device 1000 may further comprise an environmental seal of protection 170, called a “weather seal”, i.e. a seal which protects the system from the marine environment. Such a seal is here configured to protect the articulation member 152.

[0319] In an exemplary embodiment, the rotating joint device 1000 comprises an insulating sheath 158.

[0320] The insulating sheath at least partially surrounds the first fixed annular part and / or the second movable annular part.

[0321] The insulating sheath here comprises a double-walled structure.

[0322] The insulation of the external structure is for example ensured at critical locations by the presence of a double wall which can include any type of insulating material and / or be placed under vacuum inside the double wall.

[0323] One purpose of such insulation is to limit thermal exchanges which can cool the articulation member 152 or promote the heating of the liquid transfer conduit 110.

[0324] When there is fluid flow, the liquid flows in the liquid transfer conduit 110, for example from top to bottom according to the embodiment illustrated in Figures 3 and 4.

[0325] A portion of the evaporating liquid enters the buffer member via the safety valve 141 and / or the leak passage 142, until substantially balancing of the pressures between the buffer member and the liquid transfer conduit 110 is ensured. Once in the first airlock, fluid can enter the third airlock via at least one balancing valve 148 and / or at least one valveless orifice 149, then into the second airlock via at least one other balancing valve 148 and / or at least one other valveless orifice 149 communicating between the third airlock and the second airlock.

[0326] The fluid leaves the buffer member 130 through at least the exhaust valve 144 and / or the leak passage 145. The leak passage 145 is used in particular during a temperature and pressure conditioning phase when commissioning the fluid transfer system 100.

[0327] The fluid inlet is for example secured by the at least one safety valve 141 for introducing fluid into the buffer member 130, from the liquid transfer conduit 110, while the fluid outlet is for example secured by the at least one exhaust valve 144, and possibly by the at least one balancing valve 148.

[0328] The fluid then ends up in the gas transfer conduit 120, entrained in the flow according to arrow 121.

[0329] In a rotating joint device 1000, the fluid then passes into the movable annular part 1200 through the passage 155 and then exits the device through the outlet connection 1210.

[0330] In the installation 1 of [Fig.l], the stack 1010 of rotating joint devices may for example comprise a first rotating joint device 1000 comprising such a fluid transfer system 100.

[0331] The first rotating joint device 1000 is then connected by the outlet connector 1210 to the liquefaction unit 30 and by the gas transfer conduit 120 to the storage entity. and / or transport 40. The liquid transfer conduit 110 of the fluid transfer system 100 connecting the liquefaction unit 30 to the storage and / or transport entity 40.

[0332] The stack 1010 of rotating joint devices may also comprise at least a second of the rotating joint devices 10 which comprises an inlet conduit 16 which is connected to a conduit 6 of a network of underwater pipes for extracting natural gas, and an outlet connection 17 which is connected to the liquefaction unit 30.

[0333] For example, the second of the rotary joint devices 10 of the stack 1010 of rotary joint devices is a high pressure high temperature rotary joint device (denoted HPHTS).

[0334] [Fig.5] represents a fluid transfer system according to a second embodiment.

[0335] This embodiment differs from the previous one in that the dynamic sealing member 143 here comprises a seal, one heel of which is arranged against the liquid transfer conduit 110.

[0336] This embodiment also differs in that the dynamic sealing member 146 here comprises two face-to-face seals, each seal comprising a pair of lips opposite the pair of lips of the other seal, and a spacer disposed between the lips of the two seals.

[0337] In other words, the dynamic sealing member 146 here comprises a double radial seal with a spacer between the two to prevent the lips from collapsing.

[0338] [Fig.6] represents a fluid transfer system according to a third embodiment.

[0339] This embodiment differs from the previous ones by the arrangement of the buffer member 130.

[0340] This is illustrated in comparison with a detail of [Fig.5] for ease of viewing.

[0341] In this example, the buffer member 130 is without a valve, since unclosed airlocks cannot self-pressurize and the control system can be entirely outside the rotating joint device 1000 via the port 161.

[0342] The fluid inlet 131 here only comprises the leak passage 142, and the fluid outlet only comprises the leak passage 145.

[0343] The dynamic sealing member 143 here comprises a bearing instead of a lip seal.

[0344] Another bearing 143' is also present, the bearing 143 and the other bearing 143' delimiting between them a first airlock of the buffer member.

[0345] At the outlet, the dynamic sealing member 146 comprises a lip seal whose lips are oriented towards an airlock of the buffer member into which pressurized gas can be injected via the port 161. Thus, here, a heel of the lip seal of the member dynamic sealing 146 is arranged against the partition wall 151.

[0346] On either side of the dynamic sealing member 146, the system comprises two bearings 146', 146”.

[0347] [Fig.7] represents a fluid transfer system according to a fourth embodiment.

[0348] This embodiment is also illustrated in comparison with a detail of [Fig.5] for ease of viewing.

[0349] However, this embodiment differs from the previous one by the leak passage 145 of the fluid outlet.

[0350] At the outlet, the dynamic sealing member 146 comprises two lip seals facing each other.

[0351] The two lip seals are separated here by two rims 147', 147” of parts of the inner wall 147, the two rims 147', 147” delimiting between them a passage towards an airlock of the buffer member into which pressurized gas can be injected via the port 161.

[0352] [Fig.8] represents a fluid transfer system according to a fifth embodiment.

[0353] This embodiment is also illustrated in comparison with a detail of [Fig.5] for ease of viewing.

[0354] However, this embodiment differs from the previous one by the presence of a third airlock, and by a configuration of the leak passage 145 of the fluid outlet.

[0355] In this example, the buffer member comprises two injection ports 161, a first of the two ports configured to inject pressurized gas into the second airlock, and a second of the two ports configured to inject pressurized gas into the third airlock.

[0356] At the outlet, the dynamic sealing member 146 comprises two lip seals, each lip seal being configured to be pressurized by one of the second airlock and the third airlock.

[0357] Furthermore, here, a heel of each of the lip seals of the dynamic sealing member 146 is disposed against the partition wall 151.

[0358] [Fig.9] represents a fluid transfer system according to a sixth embodiment forming a coaxial expansion joint.

[0359] A coaxial expansion joint is for example configured for LNG transfer in central passage to a user's storage and transfer of the vaporized liquid to a supplier's liquefaction / storage unit.

[0360] This type of seal makes it possible to absorb longitudinal differential movements between the liquid transfer conduit 110 and the gas transfer conduit 120.

[0361] It can operate in a horizontal position (orthogonal to gravity).

[0362] The gas transfer conduit 120 here has only one wall encircling the liquid transfer conduit 110, so that a gas flows between a wall of the liquid transfer conduit and the wall of the gas transfer conduit 120.

[0363] It should also be noted that the gas transfer conduit is formed here from two butted sections.

[0364] In such an embodiment, the buffer member 130 also forms a ring arranged around a junction of the incident section 112 and the receiving section 113 of the liquid transfer conduit 110.

[0365] The fluid inlet 131 into the buffer member 130 here comprises the leak passage 142 formed at the junction between the incident section 112 and the receiving section 113, and bypassing the dynamic sealing member 143.

[0366] The fluid outlet 132 comprises on the one hand the exhaust valve 144, and on the other hand the leak passage 145 which is due to the presence of the dynamic sealing member 146, which comprises for example here a seal and a bearing.

[0367] Here, the buffer member only comprises an airlock constituting the internal volume 133, defined between the dynamic sealing member 143, the dynamic sealing member 146 and the exhaust valve 144. The buffer member is therefore here devoid of an internal wall 147 dividing the internal volume 133.

[0368] [Fig. 10] schematically represents a part of a fluid transfer system according to a seventh embodiment forming a coaxial expansion joint according to a first variant.

[0369] This embodiment differs from the previous one in that it comprises an additional buffer member 2130, surrounding the gas transfer conduit 120.

[0370] The additional buffer member is for example configured to guide and / or close the gas transfer conduit 120.

[0371] The additional buffer member 2130 is for example integral with a first section 2121 of the gas transfer conduit 120, and movable in sliding relative to a second section 2122 of the gas transfer conduit 120.

[0372] This additional buffer member 2130 also comprises an internal volume 2133, without an internal wall 147, so that it only comprises one airlock.

[0373] A fluid inlet 2131 into the internal volume here comprises a leak passage 2142 formed by a bypass of a dynamic sealing member 2143 here comprising a seal.

[0374] In a case of integration of the system part represented in a fluid transfer system, a fluid outlet 2132 comprises a leakage passage 2145 which is due to the presence of a dynamic sealing member 2146, which comprises for example here a seal and a bearing.

[0375] The internal volume 2133 is thus delimited on either side by the sealing member dynamic 2143 and dynamic sealing member 2146.

[0376] This representation does not take into account the mechanical arrangement necessary to recover the background effects generated by fluid pressures.

[0377] This type of embodiment could accept small rotation angles between the two sections to the extent that pressure and temperature constraints can induce them in sections on winding paths.

[0378] In a case of integration of the system part shown in another system, for example to form a connector for joining two concentric conduits, it may be preferable that the leakage passage 2145 is avoided and that the dynamic sealing member 2146 is made watertight.

[0379] [Fig. 11] represents a fluid transfer system according to an eighth embodiment forming a coaxial expansion joint according to a second variant.

[0380] This embodiment differs from the previous one in that the gas transfer conduit 120 here comprises several sections, in particular three sections 3121, 3122, 3123.

[0381] This embodiment forms a rotating device allowing complete rotation. The rotation is enabled by an articulation member 3152, for example with rolling bearings, and / or bearings which can be pressurized, for example by the gas from the gas transfer conduit, or a lubricant accepting a temperature of -160°C without solidifying.

[0382] It comprises an additional buffer member 3130 here surrounding two sections 3121, 3122 of the three sections of the gas transfer conduit 120.

[0383] The additional buffer member 3130 is for example integral with a first section 3121 of the gas transfer conduit 120, and movable in sliding relative to a second section 3122 of the gas transfer conduit 120.

[0384] This additional buffer member 3130 also comprises an internal volume without an interior wall, so that it only comprises one airlock.

[0385] A fluid inlet 3131 into the internal volume here comprises a leak passage 3142 formed by a clearance between the sections 3121, 3122.

[0386] A fluid outlet 3132 here comprises a leak passage 3145 which is due to the presence of a dynamic sealing member 3146, which comprises for example here a schematically O-ring seal and a lip seal for the isolation of the articulation member 3152.

[0387] [Fig. 12] represents a fluid transfer system according to a ninth embodiment and [Fig. 13] represents the system of [Fig. 12] partially exploded.

[0388] This embodiment presents a fluid transfer system in a rotating joint device corresponding for example to a loading or unloading buoy at sea.

[0389] In this example, the articulation member 152 also comprises a first part 153 integral with the first fixed annular part and a second part 154 integral with the second movable annular part. The second part 154 of the articulation member 152 is here movable in rotation relative to the first part 153 of the articulation member 152.

[0390] However, the articulation member 152 here comprises radial joints 4153 and friction bearings 4154 instead of the bearing of figures 3 to 8 for example.

[0391] A feature of a purge and cleaning system is achieved using a neutral, dry gas - particularly nitrogen - which can also be used to activate radial seals.

[0392] To operate this device, two collectors, the spill collector 160 and the collector 157, are used: the spill collector 160 is configured to seal, purge or clean the buffer member 130, the collector 157 is configured for the same operations on the articulation member which is here configured to also seal the gas transfer conduit 120 with respect to an external environment.

[0393] A seal called a “weather seal”, that is to say an external seal which protects the system of the marine environment, can be added if necessary.

[0394] It is possible to duplicate the input / output ports for optimized scanning of the volumes concerned.

[0395] The use of bearings makes it possible, for example, to contribute to reducing thermal insulation to protect the articulation member 152.

[0396] The buffer member 130 here comprises a fluid inlet 4131 having a leak passage 4142 bypassing the bearing 115 and dynamic sealing members 4143, 4143', which here comprise radial seals.

[0397] The dynamic sealing members 4143, 4143' delimit between them a first airlock of the buffer member 130.

[0398] At outlet 4132, a leak passage 4145 is formed by a dynamic sealing member 4146 comprising a bearing. The dynamic sealing member is here arranged between a wall of the buffer member 130 and the separating partition 151 and bearing against them.

[0399] As illustrated in [Fig. 13], the fixed elements are secured together by studs.

[0400] The buffer member 130 can be made in several parts to allow mounting of the radial seals in open grooves. For clarity of illustration, static seals (i.e. annealed copper washers or fiber seals for cryogenic use) are not shown. The parts are assembled, for example, using hexagon screws.

[0401] [Fig. 14] illustrates alternative embodiments of the liquid transfer conduit 110 comprising the two incident 112 and receiving 113 sections, depending on a direction of liquid flow in the liquid transfer conduit 110, and / or a desired pressure control for joints of the system.

[0402] The receiving section 113 can be oriented upwards (figure A)) or downwards (figure B)).

[0403] This is of course transposable to all of the embodiments described previously, and in the context of an embodiment according to [Fig. 14] B), it is then the receiving section 113 which is configured to slide relative to the corresponding buffer member 130.

[0404] The fluid transfer system here comprises a pressurization system 180.

[0405] The pressurization system 180 is here configured to clean and / or drain the buffer organ 130.

[0406] In this example, the pressurization system 180 comprises at least one activation port 181 configured to activate a dynamic sealing member 143, 143', and at least one purge port 182, configured to drain at least a portion of the internal volume of the buffer member.

Claims

Claims

1. A fluid transfer system (100) configured to equip a fluid operating installation (1), the fluid transfer system comprising: - a liquid transfer conduit (110), configured to convey a liquefied gas, and - a gas transfer conduit (120), configured to convey a gas in vapor form, characterized in that the liquid transfer conduit (110) and the gas transfer conduit (120) are concentric, the gas transfer conduit (120) surrounding the liquid transfer conduit (110), and in that the fluid transfer system further comprises: - a buffer member (130), disposed between the liquid transfer conduit (110) and the gas transfer conduit (120) and at least partially surrounding the liquid transfer conduit (110),the buffer member (130) being configured to transfer a vaporized portion of the liquefied gas flowing in the liquid transfer conduit (110) from the liquid transfer conduit (110) to the gas transfer conduit (120).,

2. System (100) according to claim 1, comprising at least one dynamic sealing member (143, 146).

3. System (100) according to claim 2, wherein the dynamic sealing member (143, 146) is disposed in the buffer member (130), for example at an interface between the buffer member (130) and the liquid transfer conduit (110) and / or the gas transfer conduit (120).

4. The system (100) of any one of claims 2 or 3, wherein the dynamic sealing member (143, 146) comprises a seal, a bearing, or a composite assembly.

5. The system (100) of any one of claims 1 to 4, wherein the buffer member (130) comprises at least one inner wall (147) forming a labyrinth for fluid flow in the buffer member (130).

6. The system (100) of claim 5, wherein the inner wall (147) divides an internal volume (133) of the buffer member (130) into at least two airlocks, a fluid inlet (131) into the buffer member (130) being disposed in a first of the two airlocks, and a fluid outlet (132) of the buffer member (130) being disposed in a second of the two airlocks.

7. A system (100) according to any one of claims 1 to 6, wherein at least a portion of the fluid inlet (131) in the buffer member (130) is disposed at a lower elevation than an elevation of at least a portion of the fluid outlet (132) to provide a low level for liquid and a high level for gas.

8. A system (100) according to any one of claims 1 to 7, comprising a pressurization system (180) which comprises a gas, the fluid transfer system (100) being configured to inject gas from the pressurization system (180) into an internal volume (133) of the buffer member (130).

9. A system (100) according to any one of claims 1 to 8, configured to compensate for a variation in length of the liquid transfer conduit (110).

10. System (100) according to claim 9, in which the liquid transfer conduit (110) comprises an incident section (112) provided with a tip (114), and a receiving section (113) in which the tip is inserted, the buffer member (130) being fixed to at most one of the incident section (112) and the receiving section (113).

11. A rotary joint device (1000) comprising a fluid transfer system (100) according to any one of claims 1 to 10.

12. A stack (1010) of rotary joint devices comprising at least two rotary joint devices, at least a first of the rotary joint devices of the stack (1010) being according to claim 11.

13. Fluid exploitation installation (1) comprising at least: - a liquefaction unit (30), - a storage and / or transport entity (40), - a first rotating joint device (1000) comprising a fluid transfer system (100) according to any one of claims 1 to 10, the first rotating joint device being connected by the outlet connector to the liquefaction unit (30) and by the gas transfer conduit (120) to the storage and / or transport entity (40), the liquid transfer conduit (110) of the fluid transfer system connecting the liquefaction unit (30) to the storage and / or transport entity (40), and - at least one second rotating joint device (10), which comprises an inlet conduit in the rotating joint device which is connected to a conduit (6) of an underwater pipeline network for extracting natural gas, and an outlet connection which is connected to the liquefaction unit (30).

14. Installation (1) according to claim 13, comprising a stack (1010) of rotating joint devices comprising at least two rotating joint devices, the stack (1010) of rotating joint devices comprising at least the first rotating joint device (1000) and the second rotating joint device (10).

15. An installation (1) according to any one of claims 13 or 14, further comprising a vessel (3), and at least one of the first rotating joint device (1000) or the second rotating joint device (10) is arranged on the vessel (3).