JP2024109540A - Liquefied gas storage installation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the boil-off rate in a storage installation while maintaining resistance to thermal contraction.

SOLUTION: A liquefied gas storage installation comprises a sealed, thermally insulating tank, and a sealed duct 8 passing through a tank wall of the tank. A thermally insulating barrier 15 comprises at least one hollow insulating panel 16 through which the sealed duct passes. A sealed membrane 17 comprises a perforated strake 21 through which the sealed duct passes. The tank comprises a collar 27 fixed to the sealed duct and fixed to the perforated strake. The hollow insulating panel comprises an insulating support device 26 disposed in a hollow portion 25 and configured to support the collar. The insulating support device has a coefficient of thermal contraction in the thickness direction greater than or equal to that of the sealed duct in the thickness direction and less than that of the insulating foam block of the hollow insulating panel in the thickness direction.

SELECTED DRAWING: Figure 3

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to the field of sealed insulated membrane tanks. In particular, the present invention relates to the field of sealed insulated tanks for storing and/or transporting liquefied gases at low temperatures, such as tanks for transporting liquefied petroleum gas (also called LPG) having a temperature ranging between minus 50 degrees and 0 degrees, or tanks for transporting liquefied natural gas (LNG) at about minus 162 degrees at atmospheric pressure. These tanks can be installed on land or on floating structures. In the case of floating structures, the tanks can be intended to transport or receive liquefied gas that serves as fuel for the propulsion of the floating structure.

From WO 2019162594, a liquefied gas storage installation is known that comprises a sealed insulating membrane tank, the ceiling wall of which is penetrated by a sealing duct. The ceiling wall has a multi-layer structure that includes, from the outside to the inside, a secondary insulating barrier abutting the support structure, a secondary sealing membrane abutting the secondary insulating barrier, a primary insulating barrier abutting the secondary sealing membrane, and a primary sealing membrane intended to be in contact with the liquefied gas contained in the tank.

In this document, the sealing duct penetrates the secondary and primary insulation panels and is connected to the sealing membrane using a collar. The thus penetrated secondary and primary insulation panels are manufactured in the form of a plywood box with partitions and filled with insulating packing.

Such construction has the disadvantage that the boil-off rate is not optimal due to the limited level of insulation performance of the plywood box. The boil-off rate is defined as the amount of liquefied gas that is converted to vapor by evaporation over a given period of time.

One idea underlying this invention is to improve the boil-off rate of storage facilities while maintaining good resistance to thermal shrinkage.

According to one embodiment, the present invention provides a storage facility for liquefied gas, the storage facility being a sealed insulated tank for storing liquefied gas in a two-phase equilibrium state of liquid and vapor, supported by a bearing structure, the sealed insulated tank comprising a tank wall including at least one sealing membrane provided for contacting the liquefied gas and at least one insulating barrier disposed between the sealing membrane and the bearing structure, and a sealing duct penetrating the tank wall, the insulating barrier including a plurality of insulating panels arranged in parallel with each other, the plurality of insulating panels having at least one hollow insulating panel including a hollow portion through which the sealing duct penetrates, the at least one hollow insulating panel including a bottom plate, a cover plate, and an insulating foam block disposed between the bottom plate and the cover plate in a thickness direction, the sealing membrane being a protrusion The method includes a method of manufacturing a hollow insulation panel, the method comprising: providing a plurality of strakes having protruding edges and welded together edge-to-edge, each strake including a flat portion disposed between two of the protruding edges; the plurality of strakes including perforated strakes including a hole through which the sealing duct passes; the sealed insulation tank including a collar including an inner periphery secured to the sealing duct around the entire circumference of the sealing duct and an outer periphery secured to the perforated strake around the entire circumference of the perforated strake; the insulation barrier including an insulation support device disposed within the hollow portion, the insulation support device configured to at least partially support the collar; a thermal contraction coefficient in the thickness direction of the insulation support device is greater than or equal to the thermal contraction coefficient in the thickness direction of the sealing duct and less than the thermal contraction coefficient in the thickness direction of the insulation foam block of the hollow insulation panel.

Due to these characteristics, the boil-off rate at least in this zone is improved by replacing the plywood box of the prior art with a panel made of insulating foam around the sealed duct. Moreover, by providing an insulating support device in this hollow insulating panel that at least partially supports the collar, the "step" phenomenon or level-difference phenomenon associated with a significant difference between the thermal contraction coefficient of the sealed duct and the thermal contraction coefficient of the insulating panel foam can be limited. In fact, the foam of the hollow insulating panel shrinks much more than the sealed duct. As a result, the collar bends because it is fixed on the one hand to the sealed duct and on the other hand to the sealing membrane supported by the hollow insulating panel. By providing an intermediate thermal contraction coefficient between the thermal contraction coefficient of the sealed duct and the thermal contraction coefficient of the foam of the hollow insulating panel, the "step" phenomenon in this zone can be significantly reduced and the mechanical resistance of the collar to thermal contraction can be improved.

When defining the thermal contraction coefficient in the thickness direction of an element made of several different materials, the thermal contraction coefficient of the material that extends in the thickness direction and shrinks the least will have the greatest influence on the thermal contraction coefficient of the element. For example, if the element includes a plywood box with a sheet of plywood extending in the thickness direction and a non-structural insulating packing inside the box, it is the sheet of plywood that will give the most influence on the thermal contraction coefficient of the element. In other words, for such an element, only the thermal contraction coefficient of the material that extends in the thickness direction and shrinks the least will be considered. In another example, for an insulating panel that includes a laminate of a plywood cover plate, an insulating foam block made of polyurethane foam with a structural function, and a bottom plywood sheet in the thickness direction, only the thermal contraction coefficient of the material of the insulating foam block will be considered.

According to some embodiments, such storage facilities have one or more of the following features:

According to one embodiment, the insulating support has an orifice and the duct passes through the orifice of the insulating support.

According to one embodiment, the insulation support device is fixed to the bottom plate of the hollow insulation panel.

The insulating support device is fixed, for example, by gluing, screwing, or stapling.

According to one embodiment, the hollow portion is formed in the cover plate and the insulating foam block of the hollow insulating panel, and the base plate includes an opening through which the sealed duct passes.

According to one embodiment, the insulating support device consists of a box manufactured using plates joined together, the box being filled with insulating packing.

According to one embodiment, the box is a first box, the insulating support device includes a second box, and the first box and the second box are arranged to surround the sealed duct.

According to one embodiment, the sheet of the box is made of plywood, solid wood or composite material, preferably made of plywood.

According to another embodiment, the insulating support device comprises a reinforced insulating foam block, the reinforced insulating foam block including fibers extending through its thickness.

According to one embodiment, the reinforced insulating foam block is a first block of reinforced insulating foam, the insulating support device includes a second block of reinforced insulating foam, and the first block of reinforced insulating foam and the second block of reinforced insulating foam are arranged to surround the periphery of the enclosed duct.

According to one embodiment, these blocks of reinforced insulating foam are manufactured using polyurethane foam reinforced with glass fibers, the glass fibers being oriented with their lengths parallel to the thickness direction.

According to one embodiment, the insulating support device is configured to support at least the outer periphery of the collar.

According to one embodiment, the flat portion of the sealing membrane is formed in a plane and the insulating support device extends parallel to said plane on either side of the circumference of the collar.

According to one embodiment, the flat portion of the sealing membrane is formed in a plane and the dimensions of the collar in the plane are limited to be smaller than the dimensions of the insulating support device.

As a result, the collar is fully supported by the insulating support device.

According to one embodiment, the thermal contraction coefficient of the insulating support device through its thickness is in the range between 6×10 ⁻⁶ K ⁻¹ and 25×10 ⁻⁶ K ⁻¹ .

According to one embodiment, the thermal contraction coefficient through the thickness of the reinforced insulating foam block of the insulating support device is in the range between 15×10 ⁻⁶ K ⁻¹ and 25×10 ⁻⁶ K ⁻¹ .

According to one embodiment, the thermal contraction coefficient in the thickness direction of said box is in the range between 6×10 ⁻⁶ K ⁻¹ and 10×10 ⁻⁶ K ⁻¹ .

According to one embodiment, the thermal contraction coefficient through the thickness of the insulating foam block of said hollow insulation panel is in the range between 40×10 ⁻⁶ K ⁻¹ and 70×10 ⁻⁶ K ⁻¹ .

According to one embodiment, the thermal contraction coefficient of the sealing duct through its thickness is in the range between 1×10 ⁻⁶ K ⁻¹ and 14×10 ⁻⁶ K ⁻¹ .

According to one embodiment, said sealing duct is made from an alloy of iron and nickel having a thermal contraction coefficient in the range between 1×10 ⁻⁶ K ⁻¹ and 2×10 ⁻⁶ K ⁻¹ .

According to one embodiment, said sealing duct is made from an alloy of iron and manganese having a thermal contraction coefficient in the range between 6×10 ⁻⁶ K ⁻¹ and 10×10 ⁻⁶ K ⁻¹ .

According to one embodiment, said sealing duct is made from an alloy of stainless steel having a thermal contraction coefficient in the range between 10×10 ⁻⁶ K ⁻¹ and 14×10 ⁻⁶ K ⁻¹ .

According to one embodiment, the strakes are made of an alloy of iron and nickel having a thermal contraction coefficient in the range between 1×10 ⁻⁶ K ⁻¹ and 2×10 ⁻⁶ K ⁻¹ .

According to one embodiment, the insulating foam block of the hollow insulation panel is manufactured using polyurethane foam reinforced with glass fibers, the glass fibers being oriented perpendicular to the thickness direction, and the thermal contraction coefficient of the insulating foam block of the hollow insulation panel in the thickness direction is in the range between 40×10 ⁻⁶ K ⁻¹ and 70×10 ⁻⁶ K ⁻¹ , for example equal to 60×10 ⁻⁶ K ⁻¹ .

According to one embodiment, the hollow portion is fabricated in the center of the hollow insulation panel.

According to one embodiment, the plurality of insulating panels includes two hollow insulating panels arranged on either side of the sealed duct, each of the hollow insulating panels including a hollow portion located at an end of the hollow insulating panel such that the hollow portion of one hollow insulating panel is adjacent to the hollow portion of the other hollow insulating panel, and the two hollow insulating panels are configured to frame the sealed duct.

According to one embodiment, the insulation support device is positioned in both the hollow portion of one hollow insulation panel and the hollow portion of the other hollow insulation panel.

According to one embodiment, the insulation support device comprises two separate insulation elements, one insulation element is inserted into the hollow portion of one hollow insulation panel, and the other insulation element is inserted into the hollow portion of the other hollow insulation panel.

According to one embodiment, the tank wall is a ceiling wall of the tank, and the sealed duct is an exhaust sealed duct configured to define a passage for discharging the gas phase of the liquefied gas from the inside of the tank to the outside.

Such facilities may be, for example, land-based storage facilities for storing LNG, or floating, coastal or deep-sea storage facilities, in particular methane tankers, floating storage and re-gasification units (FSRUs) and floating production and storage offshore (FPSO) units. The tanks can also serve as fuel tanks for any kind of ship.

According to one embodiment, a vessel for transporting liquefied gas comprises a double hull and the above-mentioned storage facility disposed within the double hull.

According to one embodiment, the present invention further provides a system for transferring liquefied gas, said system comprising a vessel as described above, an insulated pipeline arranged to connect a tank installed in the hull of the vessel to a floating or onshore storage facility, and a pump driving the flow of the liquefied gas through the insulated pipeline from the floating or onshore storage facility to the vessel tank or from the vessel tank to the floating or onshore storage facility.

According to one embodiment, the present invention further provides a method for loading or unloading a vessel, in which liquefied gas is transported via an insulated pipeline from a floating or onshore storage facility to a tank on the vessel, or from a tank on the vessel to the floating or onshore storage facility.

The present invention, as well as other objects, details, features and advantages thereof, will become more apparent in the following description of specific embodiments of the invention, taken in conjunction with the following non-limiting drawings and the accompanying reference numerals.

1 is a schematic cross-sectional view of a ship equipped with a storage facility according to an embodiment; FIG. 1 is a partial cross-sectional view of a storage facility in a ship transporting liquefied natural gas, the storage facility having a vapor exhaust duct penetrating the ceiling wall of a tank and the upper deck of the ship. FIG. 3 is an exploded partial view of detail 3 in FIG. 2 in the first embodiment; A cross-sectional view of a hollow insulation panel and an insulation support device along the hollow portion in the first embodiment. FIG. 3 is an exploded partial view of detail 3 in FIG. 2 in a second embodiment; FIG. 3 is a cross-sectional view of detail 3 in FIG. 2 in a third embodiment. FIG. 1 is a schematic cross-sectional view of a ship with storage facilities and a terminal for loading/unloading the tanks.

Figure 1 shows a ship 70 equipped with a liquefied gas storage facility, which in the example shown comprises a number of sealed and insulated tanks 71. Each tank 71 is associated with one degassing mast 1. The degassing masts 1 are provided on the upper deck 2 of the ship 70 and allow the escape of gas in gas phase in case of overpressure in the associated tank 71.

Aft of the vessel 70 is provided a machinery room 3 which typically contains an engine or turbine with mixed feed steam which can be powered either by the combustion of diesel or by the combustion of boil-off gas generated from tank 71.

The tanks 71 have a longitudinal dimension that extends along the length of the vessel 70. At its longitudinal ends, each tank 71 is bounded by a pair of transverse bulkheads 5 that define enclosed, separated spaces known as "cofferdams" 6.

These tanks 71 are separated from each other by transverse cofferdams 6. It can therefore be seen that each of these tanks 71 is formed within a bearing structure constituted, on the one hand, by the double hull 7 of the vessel 70 and, on the other hand, by one of the transverse bulkheads 5 of each cofferdam 6 adjacent to the tank 71.

The liquefied gas to be stored in the tank 71 may in particular be liquefied natural gas (LNG), i.e. a gaseous mixture containing mainly methane and one or more other hydrocarbons. The liquefied gas may also be ethane, liquefied petroleum gas (LPG), i.e. a mixture of hydrocarbons obtained from the refining of petroleum, essentially including propane and butane, or liquid hydrogen.

Referring to FIG. 2, the vessel 70 is depicted as being partially tilted at one tilt angle. The illustrated sealed insulated tank 71 has a general polyhedral shape defined by a ceiling wall 4, a bottom wall, transverse walls and side walls, shown only in FIG. 2, and according to the prior art, the transverse walls and side walls connect the bottom wall and the ceiling wall.

A sealed duct 8 is provided for the discharge of the vapour phase in case of tilting and connects the internal space of the tank 71 to a gas dome 9. This is itself connected to the main steam manifold circuit 10 and to the degassing mast 1 via an overpressure valve 11. For this purpose, the sealed duct 8 penetrates the wall of the tank, here the ceiling wall 4. Such a vapour phase discharge duct is described in more detail in WO2016120540.

The portion of the ceiling wall 4 through which the sealed duct 8 penetrates for the exhaust of the gas phase is described in more detail below with reference to Figures 3 to 6. However, in other embodiments not described, the sealed duct may be a separate duct penetrating the ceiling wall or another wall of the tank, and the penetrated wall may have the same structure as described below.

As shown in particular in FIG. 3, the ceiling wall 4 comprises, from the outside to the inside, a secondary insulation barrier 12 comprising a secondary insulation panel abutting the bearing structure, here the double hull 7, a secondary sealing membrane 14 abutting the secondary insulation barrier 12, a primary insulation barrier 15 comprising a primary insulation panel abutting the secondary sealing membrane 14, and a primary sealing membrane 17 in contact with the liquefied gas contained in the tank 71. By way of example, such a membrane tank is described in particular in patent application FR-A-2 877 638.

The primary sealing membrane 17 and the secondary sealing membrane 14 comprise a continuous sheet including metal strakes 18 with protruding edges, which are welded by their protruding edges onto weld supports 19, as shown in Figure 6, which are held in parallel grooves 20 formed in the secondary and primary insulation panels, respectively. The metal strakes 18 are made, for example, of Invar, an alloy of iron and nickel with a typical coefficient of expansion in the range between ^1x10-6 K ^-1 and ^2x10-6 K ^-1 .

The primary sealing membrane 17 and the secondary sealing membrane 14 each further include a perforated strake 21, which is penetrated by the sealing duct 8 and welded to the other strake 18, as shown in Figures 3 and 5.

Similarly, as shown in FIG. 3, the primary insulation barrier 15 and the secondary insulation barrier 12 each include a hollow insulation panel 16 and a hollow insulation panel 13, respectively. The hollow insulation panel 16 and the hollow insulation panel 13 are penetrated by a sealed duct 8. The hollow insulation panel 16 and the hollow insulation panel 13 each include a base plate 22, a cover plate 23, and an insulating foam block 24 that separates the base plate 22 and the cover plate 23 in the thickness direction.

Above, an embodiment has been described that includes two insulating barriers that are penetrated by a sealing duct. However, the invention can also be applied to tanks that include a single insulating barrier. In the following, it will be explained in more detail that the primary part constituted by the primary insulating barrier 15 and the primary sealing membrane 17 is penetrated by the sealing duct 8. The secondary part penetrated by the sealing duct 8 may be made in the same way as the primary part, or in a different way.

In fact, due to its proximity to the liquefied gas, the primary section is subject to the most extreme temperature changes. Therefore, elements with little contraction, such as the sealing duct 8, and elements with large contraction, such as the hollow insulation panel 16, can cause high stresses when the tank is cooled, especially in elements connected or supported by both the sealing duct 8 and the hollow insulation panel 16, such as the collar 27 described below.

Figure 3 shows an exploded view of the primary section penetrated by the sealed duct 8, particularly in the first embodiment.

The hollow primary insulation panel 16 includes a hollow section 25 through which the sealed duct 8 passes, as shown particularly in FIG. 3. The hollow section 25 is created in the cover plate 23 and the insulating foam block 24 of the hollow primary insulation panel 16. The bottom plate 22 of the hollow primary insulation panel 16 has as part thereof an opening through which the sealed duct 8 passes. In the first embodiment, the hollow section 25 is created in the center of the hollow primary insulation panel 16.

The insulating barrier 15 includes an insulating support device 26 that is provided in the hollow portion 25 and fixed to the bottom plate 22.

As shown in FIG. 3, the primary sealing membrane 17 has a collar 27 that includes an inner periphery 28 that is welded to the sealing duct 8 around the entire circumference of the sealing duct 8 and an outer periphery 29 that is welded to the perforated strake 21 around the entire circumference of the holes in the perforated strake 21.

The insulating support device 26 is configured to at least partially support the collar 27, in particular to support the outer periphery 29 of the collar 27. As shown in FIG. 3, in the first embodiment, the dimensional relationship in the plane of the primary sealing membrane 17 allows the insulating support device 26 to completely support the collar 27. Indeed, in this example, the hollow portion 25 and the insulating support device 26 are cubic in shape, whereas the collar 27 is annular in shape. The side of the cube formed by the insulating support device 26 is larger than the outer diameter of the collar 27.

To compensate for the difference in shrinkage between the sealed duct 8 and the insulating foam block 24, the insulating support device 26 is designed to have a thermal shrinkage coefficient in the thickness direction that is greater than or equal to the thermal shrinkage coefficient in the thickness direction of the sealed duct 8 and less than the thermal shrinkage coefficient in the thickness direction of the insulating foam block of the hollow insulating panel.

In the first embodiment, also as shown in Figures 3 and 4, the insulating support 26 includes a box 30 made using plywood sheets bonded together. The box 30 is also filled with insulating packing (not shown), such as glass walls or perlite. The side plywood sheets 31 of the box 30 extend over the entire thickness dimension of the insulating support 26. The plywood sheets thus provide a thermal contraction coefficient in the thickness direction of the insulating support 26. The plywood sheets 31 have a thermal contraction coefficient in the thickness direction lying in the range between ^{6x10-6K -1} and ^{10x10-6K -1} . The sealing duct 8 made of an alloy of iron and nickel has a thermal contraction coefficient in the thickness direction lying in the range between ^{1x10-6K -1} and ^{2x10-6K -1} . The containment duct 8 can also be manufactured from an alloy of iron and manganese having a thermal contraction coefficient in the range between 6×10 ⁻⁶ K ⁻¹ and 10×10 ⁻⁶ K ⁻¹ . Finally, the insulating foam block 24 of the primary hollow insulation panel 16 is manufactured using polyurethane foam reinforced with glass fibers and has a thermal contraction coefficient in the range between 40×10 ⁻⁶ K ⁻¹ and 70×10 ⁻⁶ K ⁻¹ .

The box 30 further comprises a through opening 32 through which the sealing duct 8 passes. To supplement the thermal insulation, the following provisions are advantageously made: an insulating material such as glass wool is placed between the wall of the through opening 32 and the wall of the sealing duct 8, as shown in particular in FIG. 4. For free circulation of the gas present in the primary insulating barrier 15, holes can be made in the side walls 31.

The box 30 has foam filling the hollow portion 25, and the bottom wall 34 of the box 30 is secured to the bottom plate 22 of the hollow primary insulation panel 16, for example, by stapling and/or gluing.

Figure 5 shows an exploded view of the primary section penetrated by the sealed duct 8, particularly in accordance with the second embodiment.

The second embodiment differs from the first embodiment, particularly in terms of the position of the hollow portion 25 relative to the hollow primary insulation panels 16. Indeed, in this embodiment, the primary insulation barrier 15 comprises two hollow primary insulation panels 16 arranged on either side of the sealed duct 8. Thus, each hollow primary insulation panel 16 comprises a hollow portion 25 located at a longitudinal edge 35 of the hollow primary insulation panel 16, such that the hollow portion 25 of the first hollow primary insulation panel 16 is adjacent to the hollow portion 25 of the second hollow primary insulation panel 16. Thus, the two hollow primary insulation panels 16 are arranged to frame the sealed duct 8.

Furthermore, in the second embodiment, the insulation support device 26 includes two boxes 30 fabricated in a manner similar to that of the first embodiment. One box 30 is fixed to the hollow portion 25 of the first hollow primary insulation panel 16, and the other box 30 is fixed to the hollow portion 25 of the second hollow primary insulation panel 16. Thus, the two boxes 30 are configured to frame the sealed duct 8.

Figure 6 shows a third embodiment, which differs from the first and second embodiments in terms of the material used to construct the insulating support device 26.

In fact, in this third embodiment, the box 30 filled with insulating packing is replaced by a reinforced insulating foam block 36. The reinforced insulating foam block 36 of the insulating support device 26 contains fibers oriented in the thickness direction, unlike the fibers oriented perpendicular to the thickness direction as in the insulating foam block 24 of the hollow insulation panel. Due to this orientation of the fibers in the thickness direction, the thermal contraction coefficient of the insulating support device 26 is greater than that of the hollow primary insulation panel 16 in the thickness direction. In this example, due to the polyurethane foam and glass fiber, the reinforced insulating foam block 36 of the insulating support device 26 has a thermal contraction coefficient in the thickness direction that is in the range between 15×10 ⁻⁶ K ⁻¹ and 25×10 ⁻⁶ K ⁻¹ . The sealing duct 8 is manufactured from an alloy of iron and nickel having a thermal contraction coefficient in the range between 1×10 ⁻⁶ K ⁻¹ and 2×10 ⁻⁶ K ⁻¹ , or from an alloy of iron and manganese having a thermal contraction coefficient in the range between 6×10 ⁻⁶ K ⁻¹ and 10×10 ⁻⁶ K ⁻¹ , or from an alloy of stainless steel having a thermal contraction coefficient in the range between 10×10 ⁻⁶ K ⁻¹ and 14×10 ⁻⁶ K ⁻¹ .

The insulating support device 26 according to the third embodiment can be arranged in a hollow portion 25 located in the center as in the first embodiment, or in two hollow portions 25 on the vertical edge 35 as in the second embodiment. Therefore, the insulating support device 26 can include one or more reinforced insulating foam blocks 36 depending on the purpose of surrounding the sealed duct 8.

Referring to FIG. 7, a cross-sectional view of a membrane tank 70 shows a generally prismatic sealed insulated tank 71 mounted within a double hull 72 of a vessel 70. The walls of the tank 71 include a primary sealing membrane intended to contact the LNG contained within the tank, a secondary sealing membrane disposed between the double hull 72 of the vessel 70 and the primary sealing membrane, and two insulating barriers disposed between the primary sealing membrane and the secondary sealing membrane, and between the secondary sealing membrane and the double hull 72, respectively.

In a manner known per se, for transporting a cargo of LNG from an offshore or port terminal to the tank 71 or from the tank 71 to the offshore or port terminal, a loading/unloading pipeline 73 located on the upper deck of the vessel can be coupled to the offshore or port terminal by means of a suitable connector.

7 shows a venue terminal including a loading and unloading station 75, a subsea duct 76, and an onshore storage facility 77. The loading and unloading station 75 is a fixed offshore facility including a movable arm 74 and a tower 78 supporting the movable arm 74. The movable arm 74 has a bundle of insulated flexible pipes 79 that can be connected to a loading/unloading pipeline 73. The orientable movable arm 74 accommodates all membrane tanker styles. A link duct, not shown, extends inside the tower 78. The loading and unloading station 75 allows loading of the membrane tanker 70 from the onshore storage facility 77 and unloading of the membrane tanker 70 from the onshore storage facility 77. The onshore storage facility 77 includes a liquefied gas storage tank 80 and a link duct 81 that is connected to the loading and unloading station 75 by a subsea duct 76. The subsea duct 76 allows the transfer of liquefied gas between the loading and unloading station 75 and the onshore storage facility 77 over long distances, such as 5 km. This allows the membrane tanker 70 to be kept far from shore during loading and unloading operations.

Pumps embedded in the vessel 70 and/or onshore storage facilities 77 and/or pumps equipped at the loading and unloading stations 75 are implemented to generate the pressure required for the transfer of liquefied gas.

Although the present invention has been described with reference to some specific embodiments, it is clear that the invention is in no way limited thereto, and that all technical equivalents of the described means and combinations thereof, provided that the conditions are met, are included within the scope of the present invention.

The use of the terms "comprise" or "include" and their conjugations does not exclude the presence of other elements or steps in addition to those stated in a claim.

In the claims, any reference signs placed between parentheses shall not be construed as construing as limiting the claim.

Claims (16)

A sealed, insulated tank (71) for storing a liquefied gas in a two-phase equilibrium state of liquid and vapor, supported by a bearing structure, the tank comprising a tank wall (4) including at least one sealing membrane (17) provided for contacting the liquefied gas, and at least one insulating barrier (15) arranged between the sealing membrane and the bearing structure;
a sealed duct (8) penetrating the tank wall (4);
Equipped with
The insulation barrier (15) includes a plurality of insulation panels arranged in parallel with one another, the plurality of insulation panels having at least one hollow insulation panel (16) including a hollow portion (25) through which the sealing duct (8) passes, the at least one hollow insulation panel (16) including a base plate (22), a cover plate (23), and an insulation foam block (24) arranged between the base plate (22) and the cover plate (23) in a thickness direction;
the sealing membrane (17) includes a plurality of strakes having protruding edges and welded together edge-to-edge, each strake including a flat portion disposed between two of the protruding edges, the plurality of strakes including perforated strakes (21) including holes through which the sealing ducts (8) pass;
The sealed insulated tank includes a collar (27) including an inner periphery (28) fixed to the sealed duct (8) over the entire circumference of the sealed duct (8) and an outer periphery (27) fixed to the perforated strake (21) over the entire circumference of the perforated strake (21);
The insulating barrier (15) includes an insulating support device (26) arranged in the hollow portion (25), the insulating support device (26) being configured to at least partially support the collar (27), and a thermal contraction coefficient in the thickness direction of the insulating support device (26) is greater than or equal to the thermal contraction coefficient in the thickness direction of the sealed duct (8) and is less than the thermal contraction coefficient in the thickness direction of the insulating foam block (24) of the hollow insulating panel (16). The liquefied gas storage facility of claim 1, wherein the insulating support device (26) is fixed to the bottom plate (22) of the hollow insulating panel (16). The liquefied gas storage facility according to claim 1 or 2, wherein the insulating support device (26) includes a box (30) manufactured using a plurality of plates connected to each other, and the box (30) is filled with insulating packing. The liquefied gas storage facility of claim 1 or claim 2, wherein the insulating support device (26) includes a reinforced insulating foam block (36), the reinforced insulating foam block (36) having fibers extending in the thickness direction. The liquefied gas storage facility according to any one of claims 1 to 4, wherein the insulating support device (26) is configured to support at least the outer periphery (29) of the collar (27). The liquefied gas storage facility according to any one of claims 1 to 5, wherein the insulating support device (26) has a thermal contraction coefficient in the thickness direction in the range between ^{5x10-6K -1} and ^25x10-6K - ¹ . The liquefied gas storage facility according to any one of claims 1 to 6, wherein the thermal contraction coefficient in the thickness direction of the insulating foam block (24) of the hollow insulating panel (16) is in the range between ^{40x10-6K -1} and ^{70x10-6K -1} . The liquefied gas storage facility according to any one of claims 1 to 7, wherein the thermal contraction coefficient in the thickness direction of the sealing duct (8) is in the range between ^{1x10-6K -1} and ^{14x10-6K -1} . The liquefied gas storage facility according to any one of claims 1 to 8, wherein the hollow portion (25) is created in the center of the hollow insulation panel (16). The liquefied gas storage facility according to any one of claims 1 to 8, wherein the plurality of insulation panels include two hollow insulation panels (16) arranged on both sides of the sealed duct (8), each hollow insulation panel (16) includes a hollow portion (25) located at an edge of the hollow insulation panel (16), the hollow portion (25) of one hollow insulation panel (16) is adjacent to the hollow portion (25) of the other hollow insulation panel (16), and the two hollow insulation panels (16) are configured to frame the sealed duct (8). The liquefied gas storage facility according to claim 10, wherein the insulating support device (26) is disposed in both the hollow portion (25) of one of the hollow insulating panels (16) and the hollow portion (25) of the other of the hollow insulating panels (16). The liquefied gas storage facility according to claim 10, wherein the insulating support device (26) comprises two separate insulating elements, one of which is inserted into the hollow portion (25) of one of the hollow insulating panels (16), and the other of which is inserted into the hollow portion (25) of the other of the hollow insulating panels (16). The liquefied gas storage facility according to any one of claims 1 to 12, wherein the tank wall is the ceiling wall (4) of the tank, and the sealed duct (8) is an exhaust sealed duct configured to define a passage for discharging the gas phase of the liquefied gas from the inside of the tank to the outside. A vessel comprising a double hull (72) and the liquefied gas storage facility according to any one of claims 1 to 13 arranged within the double hull,
A vessel (70) for transporting liquefied gas. The vessel (70) of claim 14;
an insulated pipeline (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);
a pump driving the flow of the liquefied gas through the insulated pipeline from the floating or onshore storage facility to the tanks of the vessel or from the tanks of the vessel to the floating or onshore storage facility;
1. A transfer system for liquefied gas comprising: A method for loading or unloading a vessel (70), in which liquefied gas is transported from a floating or onshore storage facility to the tank (71) of the vessel (70) described in claim 14 or from the tank (71) of the vessel (70) described in claim 14 to the floating or onshore storage facility via the insulated pipeline (73, 79, 76, 81).