LIQUEFIED GAS STORAGE FACILITY WITH A TANK AND A DOME STRUCTURE

Abstract

The invention relates to a liquefied gas storage installation comprising a load-bearing structure (1), a sealed and thermally insulated tank arranged within the load-bearing structure (1), and a dome structure (19) passing through an opening (18) made in a ceiling wall (11) of the tank and in an upper load-bearing wall (3). The dome structure (19), comprising a drum (22) extending in the thickness direction, is fixed to the upper load-bearing wall (3) and is hermetically welded to the sealing membrane (17) of the ceiling wall (11). The drum (22) has a lower end (33) directed towards the internal space of the tank and a closing plate (25) positioned opposite the lower end (33) of the drum (22) so as to cover it. The storage installation comprises at least one pipe (20, 21, 31) for conveying liquefied gas, which traverses the dome structure (19) and the orifice (27, 28,29) provided in the closing plate (25).,

Description

technical field

[0001] The invention relates to the field of liquefied gas storage facilities comprising a sealed and thermally insulated tank for the storage and / or transport of a liquefied gas, such as tanks for the transport of Liquefied Petroleum Gas (also called LPG) having, for example, a temperature between -50°C and 0°C, or for the transport of Liquefied Natural Gas (LNG) at about -162°C at atmospheric pressure.

[0002] These installations can be located on land or on a floating structure. In the case of a floating structure, the installation's tank can be used for transporting liquefied gas or for receiving liquefied gas to serve as fuel for the propulsion of the floating structure.

[0003] The invention relates more particularly to a liquefied gas storage installation comprising a dome structure which passes through an opening made in the ceiling wall of the tank. Technological background

[0004] Document WO2019215414 discloses a liquefied gas storage facility comprising a support structure formed by the double hull of a ship and a sealed, thermally insulated tank housed within the support structure. The tank walls have a multi-layered structure comprising, successively from the outside in, a secondary thermally insulating barrier, a secondary sealing membrane, a primary thermally insulating barrier, and a primary sealing membrane intended to be in contact with the liquefied gas stored in the tank. The upper wall of the tank has, near the rear wall of the support structure, an upward-projecting rectangular space called a liquid dome.The tank includes a loading / unloading tower with three hollow masts that pass through a lid of the liquid dome and define either a loading or unloading line for loading or unloading fluid into or from the tank, or a relief shaft for lowering a backup pump and unloading line in case of failure of the other unloading pumps. Such a liquid dome is not entirely satisfactory. In particular, the interior of the liquid dome is susceptible to dynamic pressures due to the phenomenon of sloshing, i.e., the movement of the cargo within the tank.Furthermore, thermal insulation is provided by insulating blocks fixed inside the liquid dome, while the liquid dome's watertightness is ensured by a sealing membrane attached to the thermally insulating barrier and hermetically sealed to the primary sealing membrane of the tank's upper wall. Thus, the structure of such a liquid dome is relatively complex to manufacture. Summary

[0005] One idea behind the invention is to propose a sealed and thermally insulating tank with a dome structure that is protected against the movement of liquefied gas inside the tank.

[0006] Another idea behind the invention is to offer a sealed and thermally insulating tank equipped with a dome structure that has a simple structure to manufacture.

[0007] According to one embodiment, the invention provides a liquefied gas storage installation comprising a load-bearing structure and a sealed and thermally insulated tank arranged in the load-bearing structure, said sealed and thermally insulated tank having an internal space, the load-bearing structure comprising an upper load-bearing wall and the tank comprising a ceiling wall fixed to the upper load-bearing wall, the ceiling wall comprising, in a thickness direction from the outside to the inside of the tank, at least one thermally insulating barrier and at least one sealing membrane supported by the thermally insulating barrier and intended to be in contact with the liquefied gas contained in the tank, the storage installation comprising a dome structure passing through an opening made in the ceiling wall and in the upper load-bearing wall, the dome structure comprising a shaft extending along the thickness direction,said drum comprising a lower end which is directed towards the internal space of the tank and at least one closing plate which is positioned opposite the lower end of the drum so as to cover it, the closing plate comprising at least one orifice, the storage installation comprising at least one pipe which is intended to carry liquefied gas, said pipe passing through the dome structure and through the orifice provided in the closing plate.

[0008] Thus, the closure plate helps to protect the dome structure against the movement of liquefied gas inside the tank.

[0009] According to other advantageous embodiments, such a sealed and thermally insulating tank may have one or more of the following characteristics.

[0010] According to one embodiment, the barrel is cylindrical in shape with a circular cross-section.

[0011] According to one embodiment, the shaft is fixed to the upper load-bearing wall.

[0012] According to one embodiment, the barrel is hermetically welded to the ceiling wall sealing membrane.

[0013] According to one embodiment, the dome structure includes a ceiling which is fixed, for example by welding, to an upper end of the shaft.

[0014] According to one embodiment, the ceiling is domed, which allows the dome structure to withstand higher pressures inside the tank.

[0015] In one embodiment, the closure plate is fixed to the drum, and the pipe is mounted freely, moving in translation along the thickness direction, inside the orifice. In other words, the closure plate is not fixed to the pipe but to the drum, which allows the pipe to move relative to the closure plate when subjected to thermal contraction, particularly during cooling or when loading the tank.

[0016] According to one embodiment, the closing plate is fixed to the barrel by a plurality of fixing elements.

[0017] According to one embodiment, the fastening elements are gussets which are each fixed, on the one hand, to an internal surface of the barrel and, on the other hand, to an upper surface of the closing plate.

[0018] According to one embodiment, the gussets are welded to the inner surface of the barrel and welded to the upper surface of the closure plate.

[0019] According to another embodiment, the closing plate is fixed to the pipe by means of at least two gussets.

[0020] According to one embodiment, each gusset has one edge welded to the pipe and one edge welded to the closing plate, for example to the upper surface of the closing plate.

[0021] According to one embodiment, the gussets are oriented radially with respect to the axis of the pipe and are distributed regularly around the axis of the pipe.

[0022] According to one embodiment, the pipe to which the closing plate is attached is centered with respect to the shaft of the dome structure.

[0023] According to one embodiment, the installation comprises two closing plates fixed to each other by at least two sheet metal plates forming a spacer maintaining the spacing between the two closing plates.

[0024] According to one embodiment, the sheet metal plates also act as stiffeners.

[0025] In one embodiment, the dome structure includes an insulating lining that fills the interior of the shaft and rests on the closing plate. Thus, the insulation of the dome structure is effective and easy to install.

[0026] In one embodiment, a mesh is interposed between the insulating lining and the closing plate. The mesh thus retains the insulating lining within the drum.

[0027] According to one embodiment, the insulating lining is chosen from glass wool, rock wool and insulating foam, such as polyurethane foam.

[0028] In one embodiment, the insulating lining comprises one or more foam blocks. In another embodiment, the insulating lining comprises sprayed foam.

[0029] According to another embodiment, the dome structure includes an insulating lining that covers an external surface of the shaft that protrudes beyond the upper load-bearing wall of the load-bearing structure.

[0030] According to one embodiment, the insulating lining also covers an external surface of the ceiling of the dome structure.

[0031] In one embodiment, the pipe is connected to a spray bar which is attached to the closing plate and which has one or more spray nozzles. This allows for a simpler installation of the spray bar than when it is attached to the upper wall of the tank, as in the prior art.

[0032] According to one embodiment, the spray boom has an annular shape.

[0033] According to one embodiment, the spray nozzles are distributed around a central axis of the annular shape of the spray boom.

[0034] In one embodiment, the closing plate is positioned within the internal space of the sealed and thermally insulated tank. The closing plate is thus located below the lower end of the drum.

[0035] In one embodiment, the closing plate is positioned within the sealed and thermally insulated tank, at a distance from the lower end of the drum. This facilitates the operation of attaching the closing plate to the drum.

[0036] In one embodiment, the closing plate extends in a plane positioned at a vertical distance from the plane of the lower end of the drum that is less than 50 cm, advantageously greater than 5 cm, and preferably between 10 and 25 cm. This distance facilitates the operation of attaching the closing plate to the drum while positioning the closing plate above the maximum filling limit of the tank.

[0037] According to one embodiment, when projected into the plane of the lower end of the shaft, the closing plate covers at least 80%, and preferably more than 95%, of the section of the lower end of the shaft.

[0038] According to one embodiment, the closing plate has a plurality of orifices and the liquefied gas storage installation has a plurality of pipes for conducting liquefied gas, each pipe passing through the dome structure and through one of the orifices provided in the closing plate.

[0039] According to one embodiment, at least one of the pipes is intended for the discharge of liquefied gas stored in the tank, said pipe extending to near a bottom wall of the tank and being equipped with a discharge pump.

[0040] According to one embodiment at least one of the pipes is intended for loading liquefied gas stored in the tank.

[0041] The installation, according to one of the aforementioned embodiments, may be an onshore storage facility, for example for storing LNG, or be installed in a floating structure, whether coastal or deep-water, including an ethane or LNG carrier, a floating storage and regasification unit (FSRU), a floating production and storage unit (FPSO), and others. In the case of a floating structure, the installation's tank may be designed to receive liquefied natural gas used as fuel for the propulsion of the floating structure.

[0042] According to one embodiment, a vessel for the transport of a fluid comprises a hull, such as a double hull, and a liquefied gas storage facility as described above, the hull of the vessel forming the load-bearing structure.

[0043] According to one embodiment, the invention also provides a method for loading or unloading such a vessel, in which a fluid is conveyed through insulated pipes from or to a floating or land-based storage facility to or from the vessel's tank.

[0044] According to one embodiment, the invention also provides a transfer system for a fluid, the system comprising the aforementioned vessel, insulated pipes arranged to connect the tank installed in the hull of the vessel to a floating or land-based storage facility, and a pump to drive a flow of fluid through the insulated pipes from or to the floating or land-based storage facility to or from the vessel's tank. Brief description of the figures

[0045] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from the following description of several particular embodiments of the invention, given solely by way of illustration and not limitation, with reference to the accompanying drawings. [ fig.1 ] There figure 1 This is a schematic perspective view of a load-bearing structure designed to support a sealed and thermally insulated tank for storing a liquefied gas; the dome structure is not shown. fig.2 ] There figure 2 is a schematic view of the multilayer structure of the tank walls. fig.3 ] There figure 3 is a schematic cross-sectional view of a dome structure of a sealed and thermally insulating tank. fig.4 ] There figure 4 is a perspective view of the lower end of the dome structure of the figure 3in which the spraying device is not shown. fig.5 ] There figure 5 is a perspective view, from above, of the lower end of the dome structure of the figure 3 . [ fig.6 ] There figure 6 is a view from below of the dome structure of the figure 3 . [ fig.7 ] There figure 7 is a cross-sectional view of a dome structure of a sealed and thermally insulating tank according to another embodiment. fig.8 ] There figure 8 is a detailed view of the conduit and closure plates in the figure. fig.9 ] There figure 9 a cross-sectional view of a dome structure of a sealed and thermally insulating tank according to yet another embodiment. fig.10 ] There Figure 10 is a schematic cutaway representation of a ship with a liquefied natural gas storage tank and a loading / unloading terminal for this tank. Description of the implementation methods

[0046] In relation to the figure 1 A load-bearing structure 1 is described, against which a sealed and thermally insulated liquefied gas storage tank is intended to be fixed. The load-bearing structure 1 is, for example, formed by the double hull of a ship. The load-bearing structure 1 has a generally polyhedral shape. It has two load-bearing walls, front and rear, 2, here octagonal in shape, of which only the rear load-bearing wall 2 is shown in the diagram. figure 1 The forward and aft walls 2 are, for example, cofferdam walls of the ship that extend transversely to the longitudinal direction of the ship. The load-bearing structure 1 also includes an upper load-bearing wall 3, a lower load-bearing wall 4, and lateral load-bearing walls 5, 6, 7, 8, 9, 10.

[0047] The sealed and thermally insulated liquefied gas storage tank comprises a plurality of tank walls, each of which is anchored against one of the load-bearing walls 2, 3, 5, 6, 7, 8, 9, 10 of the load-bearing structure 1, thus defining an internal space intended to contain the liquefied gas.

[0048] As depicted on the figure 2, each wall of the tank presents successively, from the outside to the inside, according to the thickness direction of the wall, a secondary thermally insulating barrier 12 comprising insulating elements 13 fixed to the load-bearing structure 1, a secondary sealing membrane 14 anchored to the insulating elements 13 of the secondary thermally insulating barrier 12, a primary thermally insulating barrier 15 comprising insulating elements 16 fixed to the insulating elements 13 of the secondary thermally insulating barrier 12 or to the load-bearing structure 1 and resting against the secondary sealing membrane 14 and a primary sealing membrane 17 anchored to the insulating elements 16 of the primary thermally insulating barrier 15 and intended to be in contact with the liquefied gas contained in the tank.As an example, such membrane tanks are described in particular in patent applications WO14057221, FR2691520 and FR2877638 relating respectively to the Mark V ®<, Mark III ®< and NO96 ®< products developed by the applicant.

[0049] The liquefied gas intended to be stored in the tank may include liquefied natural gas (LNG), i.e. a gaseous mixture consisting mainly of methane and one or more other hydrocarbons, ethane or liquefied petroleum gas (LPG), i.e. a mixture of hydrocarbons from oil refining consisting mainly of propane and butane.

[0050] As depicted on the figure 3The upper load-bearing wall 3 and the ceiling wall 11 of the tank are locally interrupted so as to delimit an opening 18. The tank also includes a dome structure 19 which projects upwards from the upper load-bearing wall 3 around the opening 18 and which defines a passage 24 which is crossed by pipes 20, 21, 31 intended respectively for loading the tank with the liquefied gas, for unloading it or for cooling it.

[0051] The dome structure 19 includes a shaft 22 extending along the thickness direction of the ceiling wall 11. The shaft 22 is cylindrical with a circular cross-section. The dome structure 19 also includes a ceiling 23 welded to the upper end of the shaft 22. The ceiling 23 is advantageously domed with a downward-facing concavity, enabling the dome structure 19 to withstand higher pressures inside the tank. The lower end 33 of the shaft 22 faces the internal space of the tank and is hermetically welded to the primary sealing membrane 17. The shaft 22 and the ceiling 23 are, for example, made of stainless steel. The shaft 22 is fixed to the upper load-bearing wall 3, for example, by means of a ring-shaped fixing device 32.

[0052] Furthermore, the dome structure 19 includes a closing plate 25 which is attached to the shaft 22. The closing plate 25 is fixed to the lower end of the shaft 22 by a plurality of gussets 26, shown in the figures 4 And 5 The gussets 26 are regularly distributed around the closing plate 25. The gussets 26 are, on one side, welded against the inner surface of the barrel 22 and, on the other side, welded against the upper surface of the closing plate 25. The gussets 26 here have two wings perpendicular to each other, one of which is fixed to the barrel 22 and the other to the closing plate 25.

[0053] The end cap 25 is positioned opposite the lower end 33 of the barrel 22 so as to cover it at least partially. In the embodiment shown, the end cap 25 is slightly offset downwards relative to the lower end 33 of the barrel 22. For example, the vertical distance between the plane of the end cap 25 and that of the lower end 33 of the barrel 22 is less than 50 cm and greater than 5 cm, preferably between 10 and 25 cm. This spacing between the end cap 25 and the lower end 33 of the barrel 22 makes it easier to weld the gussets 26 to the end cap 25.

[0054] Advantageously, when projected along a vertical axis in the plane of the lower end 33 of the drum 22, the closing plate 25 and its orifices 27, 28, 29 cover at least 80%, advantageously at least 90% and preferably 100% of the cross-section of the drum 22. The closing plate 25 has a plurality of orifices 27, 28, 29 through which the conduits 20, 21, 31 pass. The closing plate 25 is advantageously made of stainless steel.

[0055] Furthermore, in the embodiment shown, to ensure the insulation of the dome structure 19, an insulating lining 30 is housed within the shaft 22 so as to fill the space inside the shaft 22. According to one embodiment, the insulating lining 30 is selected from glass wool, rock wool, and insulating foam, such as polyurethane foam. When the insulating lining includes insulating foam, this may consist of one or more insulating blocks or be obtained by spraying an expanding foam solution inside the shaft 22.

[0056] The insulating lining 30 rests against the closing plate 25. Advantageously, a mesh 34, shown on the figure 3, is interposed between the closing plate 25 and the insulating lining 30 so as to retain the insulating lining 30 inside the barrel 22. Thus, the closing plate 25 provides support for the insulating lining 30 inside the barrel 22.

[0057] According to another embodiment not shown, in addition or as an alternative to the insulating lining 30 which is housed in the shaft 22, the shaft 22 and ceiling 23 of the dome structure 19 are covered with insulating lining on their outer surface projecting from the upper load-bearing wall 3 in order to form thermal continuity with the thermal insulation of the ceiling wall 11 of the tank.

[0058] The closing plate 25 also forms a protection which protects the dome structure 19 and more particularly the barrel 22 as well as the insulating lining 30 against the sloshing phenomena of the liquefied gas which could degrade them.

[0059] Furthermore, the closing plate 25 also allows the installation, near the ceiling wall 11 of the tank, of a spraying device 35, shown in the figures 3 And 6, designed to spray liquefied gas into the internal space of the tank. Such a spraying device allows, in particular, the tank to be cooled prior to loading the liquefied gas into it. This cooling aims to reduce the temperature inside the tank, notably to prevent excessive vaporization of the liquefied gas during loading, to limit the intensity of thermal stresses in certain components housed within the tank, and to avoid situations that could compromise the safety and / or integrity of the tank. The spraying device 35 includes the pipe 31, which passes successively through the shaft 22 or the ceiling 23 of the dome structure 19 and the insulating lining 30, which is housed in the shaft 22. The pipe 31 also passes through the opening 29 provided in the closure plate 25. The pipe 31 connects to a spray bar 36, illustrated in the figure 6, which is fixed against the lower surface of the closing plate 25.

[0060] The spray bar 36 comprises a plurality of spray nozzles 37. The spray nozzles 37 are oriented to ensure distribution of the gas spray within the internal space of the tank. In the embodiment shown, the spray bar 36 has an annular shape, and the spray nozzles 37 are evenly distributed around the central axis of this annular shape. The spray bar 36 can be attached to the inner surface of the closing plate 25 by any suitable means, such as fastening clamps or clips, for example.

[0061] Pipe 20 is used for loading liquefied gas into the tank. It passes through the drum 22 and has a bent section followed by a vertical section that passes through the end cap 25. The lower end of pipe 20 thus opens into the internal space of the tank. Furthermore, pipe 20 is connected outside the tank to a loading pipeline that includes a manifold for connection to a marine or port terminal or to a bunkering vessel.

[0062] Pipe 21 is used for discharging liquefied gas from the tank. In the embodiment shown, pipe 21 passes through the ceiling 23 of the dome structure 19 and then through the end plate 25. Pipe 21 extends substantially the entire height of the tank to near the bottom wall of the tank. Pipe 21 is also equipped with a discharge pump, not shown.

[0063] The dome structure 19 can also be equipped with level sensors and a temperature measurement device comprising a plurality of temperature sensors distributed vertically within the internal space of the tank. The level and temperature sensors are, for example, mounted along vertical supports that pass through one of the openings in the closure plate 25 and extend along one of the pipes 20, 21, 31, and are fixed to it.

[0064] THE figures 7 and 8 illustrate a dome structure according to another embodiment. This embodiment differs from that described above in relation to the figures 3 to 6in particular in that the installation includes a pipe 38 for venting gas in vapor phase, in that the dome structure 19 includes a second closing plate 39 and in that the closing plate 25 as well as the second closing plate 39 are not fixed to the shaft 22 of the dome structure 19 but directly to the pipe 38. Such a pipe 38 makes it possible to vent the gas in vapor phase from the internal space of the tank in order to bring it, for example, to the propulsion system of a ship, a reliquefaction unit or a burner.

[0065] As depicted on the figure 8The closing plate 25 has an opening through which the pipe 38 passes. Furthermore, the closing plate 25 is fixed to the pipe 38 by means of gussets 40 which have one edge welded to the pipe 38 and one edge which is welded against the upper surface of the closing plate 25. In the embodiment shown, the closing plate 25 is fixed to a lower portion of the pipe 38 which is fixed to the rest of the pipe 38, for example by means of flanges equipped with bolts.

[0066] Furthermore, the second end plate 39 is positioned parallel to and below the end plate 25, and sheet metal plates 41 are placed between the end plate 25 and the second end plate 39 and welded to them. The sheet metal plates 41 thus act as spacers, maintaining the gap between the two end plates 25 and 39, and as stiffeners, reinforcing the rigidity of the end plates 25 and 39. In the embodiment shown, the pipe 38 does not pass through the second end plate 39, but the latter has an opening allowing the passage of vapor gas so as to allow the vapor gas stored in the internal space of the tank to reach the pipe 38.

[0067] There figure 9This illustrates a dome structure according to yet another embodiment. In this embodiment, the shaft 22 and ceiling 23 of the dome structure 19 are covered with an insulating lining 42 on their outer surface, projecting from the upper load-bearing wall 3 in order to create thermal continuity with the thermal insulation of the ceiling wall 11 of the tank. Furthermore, the dome structure 19 includes a gas supply line 43 that opens into the interior of the shaft 22, as well as a line 44 that passes through an opening in the closure plate 25 and has a lower end that opens into the internal space of the tank, for example, near its bottom wall. The lines 43 and 44 can, for example, be used during tank commissioning or maintenance operations, particularly for heating, purging, or venting.Thus, for example, during the inerting of the tank, an inert gas is injected into the internal space of the tank through the gas supply line 43. The inert gas thus pushes the gas composing the initial atmosphere of the tank towards the bottom of the tank, in the manner of a piston, or it is drawn in through the line 44. It should be noted that for such an embodiment in which gas is injected inside the dome structure 19, it is more advantageous for the insulating lining 42 to be placed outside and not inside the barrel 22 in order to limit pressure losses.

[0068] With reference to the Figure 10A cutaway view of a methane tanker 70 shows a sealed and insulated tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary sealing membrane intended to be in contact with the LNG contained in the tank, a secondary sealing membrane arranged between the primary sealing membrane and the double hull 72 of the ship, and two thermally insulating barriers arranged respectively between the primary sealing membrane and the secondary sealing membrane and between the secondary sealing membrane and the double hull 72.

[0069] As is known per se, loading / unloading pipelines 73 arranged on the upper deck of the ship can be connected, by means of suitable connectors, to a marine or port terminal to transfer a cargo of LNG to or from the tank 71.

[0070] There Figure 10This also represents an example of a marine terminal comprising a loading and unloading berth 75, a subsea pipeline 76, and an onshore facility 77. The loading and unloading berth 75 is a fixed offshore installation comprising a movable arm 74 and a tower 78 that supports the movable arm 74. The movable arm 74 carries a bundle of insulated flexible pipes 79 that can be connected to the loading / unloading pipelines 73. The steerable movable arm 74 accommodates all LNG carrier sizes. A connecting pipeline (not shown) extends inside the tower 78. The loading and unloading berth 75 allows the loading and unloading of the LNG carrier 70 to and from the onshore facility 77. The onshore facility comprises liquefied gas storage tanks 80 and connecting pipelines 81 linked by the subsea pipeline 76 to the loading or unloading berth 75.The subsea pipeline 76 allows the transfer of liquefied gas between the loading or unloading station 75 and the onshore facility 77 over a long distance, for example 5 km, which allows the LNG carrier 70 to be kept a long distance from the coast during loading and unloading operations.

[0071] To generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and / or pumps equipping the land installation 77 and / or pumps equipping the loading and unloading station 75 are used.

[0072] Although the invention has been described in connection with several particular embodiments, it is clearly evident that it is by no means limited to them and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention, as defined by the claims.

[0073] The use of the verb "comporter", "comprendre" or "include" and its conjugated forms does not exclude the presence of other elements or steps than those stated in a claim.

[0074] In claims, any reference sign in parentheses shall not be interpreted as a limitation of the claim.

Claims

1. Liquefied gas storage installation comprising a load-bearing structure (1) and a sealed and thermally insulated tank arranged in the load-bearing structure (1), said sealed and thermally insulated tank having an internal space, the load-bearing structure (1) comprising an upper load-bearing wall (3) and the tank comprising a ceiling wall (11) fixed to the upper load-bearing wall (3), the ceiling wall (11) comprising, in a thickness direction from the outside to the inside of the tank, at least one thermally insulating barrier (12, 15) and at least one sealing membrane (17) supported by the thermally insulating barrier (12, 15) and intended to be in contact with the liquefied gas contained in the tank, the storage installation comprising a dome structure (19) passing through an opening (18) made in the ceiling wall (11) and in the upper load-bearing wall (3),the dome structure (19) comprising a barrel (22) extending along the thickness direction, said barrel (22) comprising a lower end (33) directed towards the internal space of the tank and at least one closure plate (25, 39) positioned opposite the lower end (33) of the barrel (22) so as to cover it, the closure plate (25) comprising at least one orifice (27, 28, 29), the storage installation comprising at least one conduit (20, 21, 31, 38, 44) intended to conduct liquefied gas, said conduit (20, 21, 31) passing through the dome structure (19) and through the orifice (27, 28, 29) provided in the closure plate (25).

2. Liquefied gas storage installation according to claim 1, wherein the closing plate (25) is fixed to the drum (22) and the pipe (20, 21, 31) is mounted freely, in translation along the thickness direction, inside the orifice (27, 28, 29).

3. Liquefied gas storage installation according to claim 2, wherein the closing plate (25) is fixed to the drum (22) by a plurality of fixing elements (26).

4. Liquefied gas storage installation according to claim 3, wherein the fastening elements are gussets (26) which are each fixed, on the one hand, to an internal surface of the drum (22) and, on the other hand, to an upper surface of the closure plate (25).

5. Liquefied gas storage installation according to claim 1, wherein the closing plate (25) is fixed to the pipe (38) by means of at least two gussets (40).

6. Liquefied gas storage installation according to any one of claims 1 to 5, comprising two closing plates (25, 39) fixed to each other by at least two sheet metal plates (41) forming a spacer maintaining the spacing between the two closing plates (25, 39).

7. Liquefied gas storage installation according to any one of claims 1 to 6, wherein the dome structure (19) includes an insulating lining (30) which fills the interior of the drum (22) and which rests on the closing plate (25).

8. Liquefied gas storage installation according to claim 7, in which a mesh (34) is interposed between the insulating lining (30) and the closing plate (25).

9. Liquefied gas storage installation according to claim 7 or 8, wherein the insulating packing (30) is selected from glass wool, rock wool and insulating foam.

10. Liquefied gas storage installation according to any one of claims 1 to 6, wherein the dome structure (19) comprises an insulating lining (42) which covers an outer surface (30) of the drum (22) which protrudes beyond the upper load-bearing wall (3) of the load-bearing structure (1).

11. Liquefied gas storage installation according to any one of claims 1 to 10, wherein the pipe is connected to a spray boom (36) which is fixed to the closing plate (25) and which has one or more spray nozzles (37).

12. Liquefied gas storage installation according to claim 11, wherein the spray boom (36) has an annular shape.

13. Liquefied gas storage installation according to any one of claims 1 to 12, wherein the closure plate (25) is disposed in the internal space of the sealed and thermally insulated tank, at a distance from the lower end (33) of the drum (22).

14. Liquefied gas storage installation according to any one of claims 1 to 13, wherein, in vertical projection in the plane of the lower end (33) of the drum (22), the closing plate (25) covers at least 80% of the cross-section of the lower end (33) of the drum (22).

15. Liquefied gas storage installation according to any one of claims 1 to 14, wherein the closing plate (25) has a plurality of orifices (27, 28, 29) and the liquefied gas storage installation has a plurality of pipes (20, 21, 31) for conducting liquefied gas, each pipe (20, 21, 31) passing through the dome structure (19) and through one of the orifices (27, 28, 29) provided in the closing plate (25).

16. Liquefied gas storage installation according to claim 15, wherein at least one of the pipes (21) is intended for the discharge of liquefied gas stored in the tank, said pipe (21) extending to near a bottom wall of the tank and being equipped with a discharge pump.

17. Liquefied gas storage installation according to claim 15 or 16, wherein at least one of the pipes (20) is intended for loading liquefied gas stored in the tank.

18. Vessel (70) for the transport of a fluid, the vessel comprising a hull (72) and a liquefied gas storage installation according to any one of claims 1 to 17, the hull of the vessel (70) forming the load-bearing structure.

19. Transfer system for a liquefied gas, the system comprising a vessel (70) according to claim 18, insulated pipes (73, 79, 76, 81) arranged to connect the tank (71) installed in the hull of the vessel to a floating or land-based storage facility (77) and a pump for conveying a fluid through the insulated pipes from or to the floating or land-based storage facility to or from the vessel's tank.

20. Method of loading or unloading a ship (70) according to claim 18, wherein a fluid is conveyed through insulated pipes (73, 79, 76, 81) from or to a floating or land-based storage facility (77) to or from the ship's tank (71).