Liquefied gas storage facility with tensioned secondary membrane

Abstract

To provide a structure in which strakes of a thermal insulation barrier of a tank are less likely to peel off.SOLUTION: A secondary thermal insulation barrier (7) of a ceiling wall (4) includes a first row (60) of first insulation panels (62) arranged between a rear transverse edge (49) of a cargo handling opening (14) and a rear cofferdam wall (82). A secondary sealing membrane (9) of the ceiling wall (4) includes, between the rear transverse edge (49) and the rear cofferdam wall (82), a plurality of parallel first strakes (64) which extend in a longitudinal direction and are interrupted by the rear transverse edge (49). Each first strake (64) has a flat central portion (65) and two raised edges (66), and strake anchor devices (69, 81) are provided on the first insulation panels (62). The flat portion (65) of each first strake (64) is welded to one of the strake anchor devices (69, 81).SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to the field of liquefied gas storage facilities equipped with a sealed adiabatic tank provided with a sealed membrane.

[0002] In particular, the present invention relates to a sealed adiabatic tank for storing and / or transporting liquefied gas at low temperatures, for example, a tank for transporting liquefied petroleum gas (also known as "LPG") at a temperature of, for example, -50°C to 0°C, or a tank for transporting liquefied natural gas (LNG) at about -162°C at atmospheric pressure, etc. Such a tank can be installed on the shore or on a floating structure. In the case of a floating structure, the above-mentioned tank can be used as a tank for transporting liquefied gas to be used as propulsion fuel for the tank or for receiving the liquefied gas.

[0003] The above storage facilities can be installed on the shore or on a floating structure. In the case of a floating structure, the above facilities can be used for transporting liquefied gas, or can be used for containing liquefied gas to be used as propulsion fuel for the floating structure.

Background Art

[0004] Korean Patent Publication No. 2020-0144697 describes a liquefied gas storage facility equipped with a tank incorporated in a support structure of a carrier. The tank has a multi-layer structure that, in the direction of its thickness from the outside to the inside, includes a secondary heat insulation barrier fixed to the support structure, a secondary sealing membrane attached to the secondary heat insulation barrier, a primary heat insulation barrier attached to the secondary heat insulation barrier via the secondary sealing membrane, and a primary sealing membrane attached to the primary heat insulation barrier and in contact with the liquefied gas stored in the tank. The secondary sealing membrane has a plurality of parallel strakes. Each strake has a flat central portion extending in the longitudinal direction of the tank and two raised edge portions disposed on both sides of the flat central portion and protruding toward the inside of the tank from the central portion. Such a secondary sealing membrane is generally referred to as a "tensioned membrane", which, unlike a corrugated membrane, cannot absorb longitudinal tensile or compressive forces.

[0005] The ceiling wall of the tank is interrupted at a cargo handling opening through which pipes for loading and / or unloading the liquefied gas pass. The secondary sealing membrane is provided to absorb tensile and compressive forces by abutting against the support structure using secondary connection brackets and being directly connected to the support structure. These tensile and compressive forces are particularly caused by the thermal contraction of the secondary sealing membrane and the deformation of the hull of the carrier related to the deflection of the carrier beam. To reduce the load on the above secondary connection brackets, the secondary heat insulation barrier has a special structure along the front lateral edge of the cargo handling opening. This special structure particularly includes a plurality of secondary mounting support portions made of metal, and a secondary abutting beam to which one of the above secondary connection brackets is attached is attached to the secondary mounting support portion.

[0006] The rear lateral edge of the cargo hatch opening is arranged relatively close to the rear coaming wall of the tank. Therefore, the force received by the secondary connection bracket arranged along the rear lateral edge is smaller than the force received by the secondary connection bracket arranged along the front lateral edge. Further, the secondary heat insulation barrier does not have the above special structure including the secondary contact beam or the secondary mounting support portion at the location along the rear lateral edge. Also, only the end portion of the strake is attached by a mechanical welding structure at the location along the rear coaming wall in the region at the rear of the cargo hatch opening, and is attached to the connection bracket at the location along the rear lateral edge of the cargo hatch opening.

[0007] Such a structure is not completely sufficient. In particular, since there is no attachment of the strake between the mechanical welding structure and the secondary connection bracket, it is not completely sufficient in that there is a possibility that the strake may peel off especially when excessive pressure is applied to the strake in the secondary heat insulation barrier.

Summary of the Invention

[0008] One idea underlying the present invention is to provide a liquefied gas storage facility of the above type with increased strength in the region between the cargo hatch opening and the rear coaming wall.

[0009] In a first aspect, the present invention provides a liquefied gas storage facility including a support structure and a hermetic heat insulation tank supported by the support structure, the support structure includes an upper support wall, the tank includes a ceiling wall attached to the upper support wall, the ceiling wall faces from the outside to the inside in the thickness direction of the tank, a secondary heat insulation barrier attached to the upper support wall, a secondary hermetic membrane arranged in the secondary heat insulation barrier, a primary heat insulation barrier arranged in the secondary hermetic membrane, and a primary hermetic membrane arranged in the primary heat insulation barrier and contacting the liquefied gas, and includes them. The ceiling wall is locally interrupted so as to define a handling opening through which a handling pipe passes. The handling opening is defined by a front lateral edge and a rear lateral edge parallel to the lateral direction, and a first longitudinal edge and a second longitudinal edge parallel to the longitudinal direction perpendicular to the lateral direction. The secondary heat insulation barrier of the ceiling wall includes a first row of first heat insulation panels aligned in the lateral direction and arranged between the rear lateral edge and the rear cofferdam wall. The secondary sealing membrane of the ceiling wall includes a plurality of parallel first strakes that extend in the longitudinal direction and are interrupted by the rear lateral edge between the rear lateral edge and the rear cofferdam wall. Each of the first strakes has a flat central portion disposed on the first heat insulation panel and two raised edges protruding toward the inside of the tank from the central portion. The first strakes are arranged in a repeating pattern in the lateral direction and are welded to each other so as to be sealed at the raised edges. A strake anchor device is provided on the first heat insulation panel. The flat portion of each of the first strakes is welded to one of the strake anchor devices.

[0010] In this way, the strake anchor device can properly fix the strakes of the secondary membrane in the region located between the rear cofferdam wall and the handling opening, thereby preventing the strakes from peeling off when excessive pressure is applied in the secondary heat insulation barrier.

[0011] In a plurality of embodiments, the above equipment can include one or more of the following configurations.

[0012] In one embodiment, there is one strake anchor device provided on each of the first heat insulation panels. With such a configuration, when the first heat insulation panel comes into contact while the tank is being cooled, the pressure applied to the secondary sealing membrane can be suppressed.

[0013] In one embodiment, each of the strake anchor devices is disposed at the central portion in the lateral direction of each corresponding first heat insulation panel.

[0014] In one embodiment, the strake anchor device is disposed at the central portion in the longitudinal direction of each corresponding first heat insulation panel.

[0015] In one embodiment, the strake anchor device is disposed at the central portion in the lateral direction of the strake.

[0016] In one embodiment, the lateral dimension of the first heat insulation panel is equal to the lateral dimension of the first strake, and each of the first heat insulation panels is aligned with one of the first strakes such that the raised edge portion of the first strake is aligned with the gap between two adjacent first heat insulation panels.

[0017] In one embodiment, the first heat insulation panel does not have a welding support for attaching the raised edge portion of the strake to the first heat insulation panel. In other words, the raised edge portions of the first strakes are directly welded to each other in the region of the first heat insulation panel.

[0018] In one embodiment, each of the strake anchor devices - includes a plaque attached to one of the first heat insulation panels, - and a peg attached to the plaque, and each of the pegs penetrates from the plaque in the thickness direction of the ceiling wall so as to seal a hole formed in the flat portion of one of the first strakes and extends toward the inside of the tank. ​The peg is provided with a flange attached so as to seal around the hole of the first strake. The configuration of such a strake anchor device is advantageous in that it is easy to arrange and use.

[0019] In one embodiment, the secondary heat insulation barrier of the ceiling wall includes a second row of second heat insulation panels arranged in the lateral direction and disposed between the first row of the first heat insulation panels and the rear cofferdam wall.

[0020] In one embodiment, a strake anchor device is provided on the second heat insulation panel, and the flat portion of at least a part of the first strakes among the first strakes is welded to one of the strake anchor devices of the second heat insulation panel.

[0021] In one embodiment, the second heat insulation panel does not have grooves for receiving welding supports to which one of the raised edge portions of two adjacent second heat insulation panels is welded.

[0022] In one embodiment, the first strake is welded to a secondary connection bracket at a location along the rear lateral edge, and the secondary connection bracket is connected to an upper support wall.

[0023] In one embodiment, the secondary heat insulation barrier of the ceiling wall is - at least a first secondary mounting support portion and a second secondary mounting support portion arranged along the rear lateral edge, including a secondary base fixed to the upper support wall, a secondary cap welded to the secondary base and extending in a plane parallel to the longitudinal direction and parallel to the upper support wall, and a plate piece attached to the secondary cap by an attachment member, respectively, the first secondary mounting support portion and the second secondary mounting support portion; - at least one boundary secondary heat insulation block disposed between the first secondary mounting support portion and the second secondary mounting support portion along the first lateral edge; - At least one secondary abutment beam extending along the rear lateral edge portion, which is disposed at least on one of the secondary caps of the first secondary mounting support portion and the second secondary mounting support portion and the boundary secondary heat insulation block, and is immovably provided between the plate piece and the secondary caps of the first secondary mounting support portion and the second secondary mounting support portion respectively in the thickness direction of the ceiling wall. Comprising: The secondary connection bracket includes a first wing portion disposed on the secondary abutment beam and a second wing portion connected to the upper support wall.

[0024] By arranging the secondary heat insulation barrier along the rear edge portion in this way, it becomes possible to reduce the load on the corresponding secondary connection bracket. As a result, it is possible to move the cargo opening further away from the rear coferdam wall without causing an excessive force to be applied to the secondary connection bracket arranged along the rear lateral edge portion.

[0025] In one embodiment, the first secondary mounting support portion and the second secondary mounting support portion support a primary anchor device for fixing the primary heat insulation barrier, and some of the strake anchor devices provided on the first heat insulation panel are aligned with the primary anchor device in the longitudinal direction.

[0026] In one embodiment, the primary heat insulation barrier of the ceiling wall includes a primary heat insulation panel arranged to straddle a heat insulation element of a corner structure disposed at a connecting portion between the ceiling wall and the rear coferdam wall and the secondary abutment beam, and is provided in a region disposed between the rear coferdam wall and the rear lateral edge portion. Thereby, it becomes possible to prevent, or at least suppress, step phenomena on the support surface of the primary sealing membrane.

[0027] In one embodiment, the primary insulation panel in the region disposed between the rear cofferdam wall and the rear lateral edge portion has a recess for receiving the strake anchor device.

[0028] In one embodiment, the first strake is welded to a mechanical welding structure extending along the edge where the ceiling wall and the rear cofferdam wall are in contact, and the mechanical welding structure is attached to the ceiling wall and the rear cofferdam wall.

[0029] The facility of any of the above embodiments can be installed in, for example, coastal storage facilities such as for LNG storage, or coastal or deep - sea floating structures, particularly LNG or ethane carriers, floating storage regasification units (FSRUs), remote floating production storage facilities (FPSOs), etc. In the case of a floating structure, the above - mentioned tank can be for containing liquefied natural gas used as propulsion fuel for the floating structure.

[0030] In one embodiment, the present invention relates to a carrier for transporting fluids, comprising a facility having the above - described configuration.

[0031] In one embodiment, the carrier has a double hull, and the double hull constitutes the support structure.

[0032] In one embodiment, the present invention also provides a system for transferring fluids, the system comprising the above - mentioned carrier, a heat - insulating pipeline arranged to connect the tank of the carrier to a floating or coastal storage facility, and a pump for pumping the flow of fluid from the floating or coastal storage facility to the tank of the carrier or from the tank of the carrier to the floating or coastal storage facility through the heat - insulating pipeline.

[0033] In one embodiment, the present invention also provides a method for loading or discharging the above-described carrier, in which fluid is sent from a floating or coastal storage facility to the tank of the carrier or from the tank of the carrier to the floating or coastal storage facility via a heat-insulating pipeline.

[0034] In a second aspect that can be implemented independently of the first aspect described above, the present invention provides a liquefied gas storage facility including a support structure and a hermetic heat-insulating tank disposed on the support structure. The support structure includes an upper support wall. The tank includes a ceiling wall attached to the upper support wall. The ceiling wall extends from the outside to the inside in the thickness direction of the tank. a secondary heat-insulating barrier attached to the upper support wall; a secondary hermetic membrane disposed on the secondary heat-insulating barrier; a primary heat-insulating barrier disposed on the secondary hermetic membrane; a primary hermetic membrane disposed on the primary heat-insulating barrier and in contact with the liquefied gas; and includes. The ceiling wall is locally interrupted so as to define a handling opening through which a handling pipe passes. The handling opening is defined by a front lateral edge and a rear lateral edge parallel to the lateral direction, and a first longitudinal edge and a second longitudinal edge parallel to the longitudinal direction perpendicular to the lateral direction. The secondary heat-insulating barrier of the ceiling wall is - at least a first secondary mounting support portion and a second secondary mounting support portion disposed along the rear lateral edge, each including a secondary base fixed to the upper support wall, a secondary cap welded to the secondary base and extending in a plane parallel to the longitudinal direction and parallel to the upper support wall, and a plate piece attached to the secondary cap by a mounting member; - At least one boundary secondary heat insulation block disposed between the first secondary mounting support portion and the second secondary mounting support portion along the first lateral edge portion; - At least one secondary abutment beam extending along the rear lateral edge portion and disposed at least on one of the secondary caps of each of the first secondary mounting support portion and the second secondary mounting support portion and the boundary secondary heat insulation block, and a secondary abutment beam immovably provided between the plate piece and the secondary caps of each of the first secondary mounting support portion and the second secondary mounting support portion in the thickness direction of the ceiling wall; It is provided with.

[0035] By arranging the secondary heat insulation barrier along the rear edge portion in this way, it becomes possible to reduce the load on the corresponding secondary connection bracket. As a result, it is possible to move the cargo handling opening further away from the rear cofferdam wall without causing an excessive force to be applied to the secondary connection bracket arranged along the rear lateral edge portion.

[0036] By reading the following description of numerous specific embodiments of the present invention with reference to the accompanying drawings, the present invention can be better understood, and other objects, details, features and advantages of the present invention will become clearer. The specific embodiments described below are merely illustrative and do not limit the present invention.

Brief Description of the Drawings

[0037]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0038] Following the convention, the terms "outer" and "inner" are used to define the relative position of one member with respect to other members based on the outside and inside of the tank. Further, in each figure, the arrow L corresponds to the longitudinal direction of the tank, and the arrow T corresponds to the lateral direction of the tank, and these two directions are perpendicular to each other. In each illustrated embodiment, this is extended such that the arrow L corresponds to the longitudinal direction of the carrier ship, and the arrow T corresponds to the lateral direction of the carrier ship. This is because the orientation of the tank is the same as that of the carrier ship in each embodiment.

[0039] FIG. 1 is a diagram showing a carrier 70 for storing and transporting liquefied gas, which is, for example, an LNG carrier. The carrier 70 is provided with a storage facility 1, and the storage facility 1 includes a plurality of tanks 71 arranged on the inner hull of the carrier. To achieve this, the inner hull has a plurality of polyhedral compartments defined by a plurality of support walls, and each compartment is configured to form a support structure for accommodating one tank 71 of the carrier 1. The inner hull is provided with cofferdam support walls extending in a direction transverse to the longitudinal direction L of the carrier 70, and these cofferdam support walls define a cofferdam space that divides the inner hull into a plurality of compartments.

[0040] Each tank 71 has a polyhedral shape and includes a plurality of tank walls assembled with each other and fixed to the support walls. In particular, the tank walls are a ceiling wall 4, a rear cofferdam wall 82, and a front cofferdam wall 83. The front cofferdam wall 83 and the rear cofferdam wall 82 are spaced apart in the longitudinal direction L of the carrier 70, and the front cofferdam wall 83 is fixed to one of the two cofferdam support walls, and the rear cofferdam wall 82 is fixed to the other cofferdam support wall, respectively.

[0041] In order to perform the loading and unloading operation of liquefied gas on the tank, a loading and unloading opening (not shown in FIG. 1) is formed in the ceiling wall 4, and a pipe for performing the loading and unloading operation of liquefied gas is passed through this loading and unloading opening. The loading and unloading opening is provided in the vicinity of the rear cofferdam wall 82 on the ceiling wall 4 (region II in FIG. 1).

[0042] The upper support wall of the support structure 2 also has holes for passing pipes through the support structure 2. The cargo handling opening serves as an inlet point for a plurality of components of the device for handling liquefied natural gas, and in particular, as an inlet point for one or more of a filling line, an emergency pumping line, a discharge line connected to a discharge pump, a spray line, a supply line connected to a spray pump, etc. In one embodiment, a cargo handling tower (not shown) is passed through the cargo handling opening. This loading tower includes a plurality of vertical masts, and these masts are attached to each other by crossbars. Since the vertical masts are hollow, each mast becomes a loading line, a loading line, or a relief well for recessing the relief well.

[0043] Figure 2 is a perspective view of the area near the cargo handling opening 14 of the ceiling wall 4 as seen from inside the tank. The cargo handling opening 14 is rectangular and is defined by two longitudinal edges 5 parallel to the longitudinal direction L of the tank and two transverse edges, namely a front transverse edge 6 and a rear transverse edge 49 parallel to the transverse direction.

[0044] Figure 3 shows the multi-layer structure of the ceiling wall 4. The ceiling wall 4 includes, in order from the outside to the inside of the tank in the thickness direction, a secondary heat insulation barrier 7 held by the upper support wall 8, a secondary sealing membrane 9 installed on the secondary heat insulation barrier 7, a primary heat insulation barrier 10 installed on the secondary sealing membrane 9, and a primary sealing membrane 11 installed on the primary heat insulation barrier 10 and in contact with the liquefied natural gas entering the tank.

[0045] The secondary heat insulation barrier 7 includes a plurality of secondary heat insulation panels 12, and these secondary heat insulation panels 12 are fixed to the upper support wall 8 by bonding with an anchor device (not shown in Figure 3) or mastic. The overall shape of the secondary heat insulation panel 12 is parallelepiped-shaped, and these plurality of secondary heat insulation panels 12 are arranged in a plurality of parallel rows, for example, in the longitudinal direction L and the transverse direction T.

[0046] The secondary sealing membrane 9 of the ceiling wall 4 comprises a continuous layer formed by connecting a plurality of metal strakes, and these strakes have raised edges. Each strake extends in the longitudinal direction L and has a flat central portion installed on the secondary heat insulation panel 12. Also, each strake has two raised edges arranged on both sides of the flat central portion, and the raised edges protrude toward the inside of the tank from the central portion. The strakes are welded to a plurality of parallel welding supports at the raised edges, and these welding supports are installed in grooves formed on the inner surface of the secondary heat insulation panel, that is, the surface in contact with the secondary sealing membrane 9, excluding the strakes of the ceiling wall 4 with different fixing methods arranged at the rear of the handling opening 14. The strakes are made of, for example, Invar (registered trademark) which is an alloy of iron and nickel or an alloy of iron and manganese, and the expansion coefficient of Invar (registered trademark) of the alloy of iron and nickel is typically 1.2×10 -6 ~2×10 -6 K -1 and the expansion coefficient of the alloy of iron and manganese is typically 7×10 -6 ~9×10 -6 K -1 is.

[0047] The primary heat insulation barrier 10 comprises a plurality of primary heat insulation panels 13, and these primary heat insulation panels 13 are fixed to the secondary heat insulation panel 12 using primary anchor devices. This primary anchor device is not shown in FIG. 3. The overall shape of the primary heat insulation panel 13 is parallelepiped-shaped. The primary heat insulation panel 13 can be arranged so as to be offset with respect to the secondary heat insulation panel 12 in the longitudinal direction L, and optionally, can also be arranged so as to be offset with respect to the secondary heat insulation panel 12 in the transverse direction T.

[0048] In one embodiment, the secondary heat insulation panel 12 and the primary heat insulation panel 13 include a bottom plate, a cover plate, and one or more layers of heat-insulating polymer foam sandwiched between the bottom plate and the cover plate and attached to the cover plate. The heat-insulating polymer foam can be particularly a polyurethane-based foam, and can be optionally reinforced with fibers, particularly with glass fibers.

[0049] The primary sealing membrane 11 includes a plurality of corrugated metal plates arranged side by side in the longitudinal direction L and the transverse direction T and welded to each other at the edges. The primary sealing membrane 11 includes a plurality of corrugations extending parallel to the longitudinal direction L and a plurality of corrugations extending parallel to the transverse direction T.

[0050] To form the loading opening 14, the ceiling wall 4 is locally interrupted. Therefore, the sealing membrane is interrupted at the entire periphery of the loading opening 14 for both the primary sealing membrane 11 and the secondary sealing membrane 9, and for both the primary heat insulation barrier 10 and the secondary heat insulation barrier 7.

[0051] Referring again to FIG. 2, a cover 15 arranged in the loading opening 14 is shown in the figure. The cover 15 includes a metal sealing wall 16 and a heat insulation structure 17 located between the metal sealing wall 16 and the upper support wall 8. The cover 15 is attached to the upper support wall 8. The metal sealing wall 16 realizes the sealing continuity with the primary sealing membrane 11 of the ceiling wall 4, and the heat insulation structure 17 realizes the heat insulation continuity.

[0052] The heat insulation structure 17 includes one or more cover heat insulation blocks. The cover heat insulation blocks are, for example, in the form of a box having a bottom plate, a cover plate, and a support spacer. The support spacer extends between the bottom plate and the cover plate in the thickness direction and defines a plurality of compartments filled with a heat insulation filler such as perlite, glass wool, or rock wool. The one or more cover heat insulation blocks have one or more holes (not shown) for passing the loading pipe.

[0053] The metal sealing wall 16 of the cover 14 includes, for example, a structure formed by welding a plurality of metal plates together. The metal sealing wall 16 is further provided with a plurality of cover holes (not shown) through which the handling pipes pass. As shown in FIG. 2, the metal connection strip 18 can be used to connect the metal sealing wall 16 of the cover 14 and the primary sealing membrane 11 of the ceiling wall 4 in a sealed manner.

[0054] The primary sealing membrane 11 is connected to the metal sealing wall 16 of the cover 14 at the handling opening 14, while the secondary sealing membrane 9 is interrupted at the longitudinal edge 5 and the transverse edges 6 and 49 of the handling opening 14, and the secondary sealing membrane 9 is directly connected to the upper support wall 8 in a sealed manner. This connection is made by the secondary connection bracket 19, which can be seen particularly in FIG. 3. The secondary connection bracket 19 includes a first wing portion 20 and a second wing portion 21 connected to the first wing portion 20. The first wing portion 20 extends in the horizontal plane and is connected to the secondary sealing membrane 9, while the second wing portion 21 extends in the vertical plane and is welded to the anchor flat region 22 of the upper support wall 8. Therefore, a part of the strake of the secondary sealing membrane 9 is interrupted by the handling opening 14 and is connected to the upper support wall 8.

[0055] The secondary sealing membrane 9 can transmit the tensile force related to the operation of the secondary sealing membrane 9 to the secondary connection bracket 19 at the connection location with the upper support wall 8, particularly when the tank is cooled. Further, in order to reduce the load on the secondary connection bracket 19 and the load on the welded portion with the secondary sealing membrane 9, the secondary heat insulation barrier 7 has a special arrangement configuration along the front transverse edge 6 and the rear transverse edge 49 of the handling opening 14.

[0056] The secondary heat insulation barrier 7 along the lateral edge, a partial special arrangement configuration of the secondary heat insulation barrier 7 along the rear lateral edge 49 in this example, is shown in FIG. 4. The secondary heat insulation barrier 7 includes a plurality of secondary mounting support portions 23, and the secondary mounting support portions 23 are regularly distributed along the rear lateral edge 49 of the handling opening 14 and are spaced apart from each other in the lateral direction T, and are also welded to the upper support wall 8.

[0057] One of the above-mentioned secondary mounting support portions 23 is shown in FIG. 5. Each secondary mounting support portion 23 includes a secondary cap 24 that extends parallel to the longitudinal direction in a plane parallel to the ceiling wall 4. The secondary cap 24 is joined to a secondary base 25 fixed to the upper support wall 8, for example, by welding. The secondary base 25 has two branch portions 26, 27, and these branch portions 26, 27 are connected to each other by a central web 28. The above-mentioned two branch portions 26, 27 are welded to both ends of the secondary cap 24 and extend parallel to each other in a plane parallel to the lateral direction and parallel to the thickness direction of the ceiling wall 4. The central web 28 extends in a plane parallel to the longitudinal direction and parallel to the thickness direction of the ceiling wall 4. The central web 28 is welded to the secondary cap 24 and the two branch portions 26, 27. In the illustrated embodiment, the central web 28 is U-shaped. The interval between the two branch portions 26, 27 in the longitudinal direction L determines the base length, and rocking or bending of the secondary connection bracket 19 in this direction can be avoided.

[0058] The secondary mounting support portion 23 supports a primary anchor device 29 for fixing the secondary heat insulation barrier 10. The primary anchor device 29 is attached to a plate piece 30, and the plate piece 30 is attached to the secondary cap 24 by an attachment member 31 such as a screw. The longitudinal direction of the plate piece 30 is parallel to the longitudinal direction of the tank.

[0059] Furthermore, a screw shaft portion 32 is attached to the plate piece 30, and this screw shaft portion 32 extends toward the inside of the tank in the thickness direction. The screw shaft portion 32 penetrates through the hole formed in the secondary sealing membrane 9 so as to seal it. The primary anchor device 29 further includes a support element 33, and this support element 33 is supported in the support region of the boundary primary heat insulation block 51 of the primary heat insulation barrier 10 particularly shown in FIG. 3, and these boundary primary heat insulation blocks 51 are arranged along the lateral edges 6, 49 of the handling opening 14. In the illustrated embodiment, the support region of the boundary primary heat insulation block 51 is formed, for example, by battens attached to the ends of the boundary primary heat insulation block 51.

[0060] Also, the primary anchor device 29 includes a nut 34, which can be particularly seen in FIG. 5. The nut 34 interacts with the threaded portion of the screw shaft portion 32 and, together with the Belleville washer 35 attached to the screw shaft portion 32 and sandwiched between the nut 34 and the support element 33, attaches the support element 33 to the screw shaft portion 32. The primary anchor device 29 further includes a flange 36 disposed around the screw shaft portion 32, and the flange 36 is welded to the secondary sealing membrane 9 so as to seal around the entire circumference of the hole through which the screw shaft portion 32 passes.

[0061] Referring again to FIG. 4, it can be seen that the secondary heat insulation barrier 7 also includes boundary secondary heat insulation blocks 37 along the lateral edges 6, 49. Each boundary secondary heat insulation block 37 is sandwiched between two adjacent secondary mounting support portions 23. The boundary secondary heat insulation blocks 37 are advantageously joined to the upper support wall 8 by adhesion, for example, using mastic. The boundary secondary heat insulation blocks 37 are constituted, for example, by a wooden box filled with heat insulating materials such as perlite, glass wool, or rock wool.

[0062] The secondary heat insulation barrier 7 further includes a secondary abutment beam 38, and the first wing portion 20 of the secondary connection bracket 19 is attached to the secondary abutment beam 38. The secondary abutment beam 38 is made of wood, for example, and the secondary abutment beam 38 also helps to fix the boundary secondary heat insulation block 37 to the upper support wall 8. In this way, the secondary abutment beam 38 is sandwiched between the boundary secondary heat insulation block 37 and the first wing portion 20 of the secondary connection bracket 19 in the thickness direction.

[0063] Each of the secondary abutment beams 38 is attached so as to straddle two secondary mounting support portions 23. In the illustrated embodiment, the central portion of the secondary abutment beam 38 is also attached to the secondary mounting support portion 23. To attach the secondary abutment beam 38, the end portion of the secondary abutment beam 38 is sandwiched between the plate piece 30 and the secondary cap 24. In this way, since the attachment member 31 is adjustable, the end portion of the secondary abutment beam 38 is immovable between the plate piece 30 and the secondary cap 24 in the thickness direction of the ceiling wall.

[0064] As shown in FIG. 7, the secondary abutment beam 38 has a recess 39 for receiving the plate piece 30, and the plate piece 30 is received in the recess 39 such that the plate piece 30 substantially aligns with the inner surface of the secondary abutment beam 38. Thereby, the flatness of the support surface on which the first wing portion 20 of the secondary connection bracket 19 and the secondary sealing membrane 9 are disposed can be ensured.

[0065] Advantageously, the secondary abutment beam 38 can also include one or more metal reinforcements in a ready-made state, thereby improving rigidity. The metal reinforcements are, for example, a plurality of metal reinforcement strips 40 in a direction parallel to the length direction of the secondary abutment beam 38, that is, in the lateral direction of the tank. The metal reinforcement 48 can be attached to the secondary abutment beam 38 by any means, and in particular, can be attached by fixing screws, by adhesion, or by rivet bonding.

[0066] In an advantageous embodiment, a mastic bead or strip (not shown) is disposed between the secondary abutment beam 38 and the boundary secondary insulation block 37 and / or the secondary cap 24 of the secondary mounting support portion 23. Thereby, the position of the secondary abutment beam 38 in the thickness direction of the ceiling wall 4 can be adjusted.

[0067] As shown in FIG. 7, the secondary abutment beam 38 also includes a metal L-shaped support bracket 41, and the support bracket 41 functions as a support portion of the abutting member 42 as can be seen from FIGS. 4 to 6, which will be described below. Since the support bracket 41 is harder than the secondary abutment beam 38, the support bracket 41 can prevent the secondary abutment beam 38 from being recessed in the region where it contacts the abutting member 42. The secondary abutment beam 38 further has a notch 43, and the notch 43 is configured to allow the abutting member 42 to be inserted when the secondary abutment beam 38 is disposed in contact with the secondary mounting support portion 23. Each support bracket 41 has a first tab 44 disposed in contact with the outer surface of the secondary abutment beam 38 and a second tab 45 disposed in contact with the edge of any one of the notches 43. The support bracket 41 can be attached to the secondary abutment beam 38 by any means, and in particular can be attached by fixing screws, by adhesion, or by rivet bonding. Advantageously, the first tab 44 is embedded in a recess formed in the inner surface of the secondary abutment beam 38.

[0068] Furthermore, as shown in FIG. 6, each secondary abutting beam 38 is blocked from making a rectilinear movement in the longitudinal direction L in the secondary mounting support portion 23 that interacts with itself. To achieve this, each secondary mounting support portion 23 is provided with an abutting member 42 attached to the secondary cap 24. The abutting member 42 includes a plate 43 perpendicularly attached to the secondary cap 24 by welding. In the illustrated embodiment, a reinforcing member in the form of a gusset 46 is welded between the plate 43 and the secondary cap 24 to reinforce the rigidity of the abutting member 42. The plate 43 has two tapped holes, the axes of these tapped holes are parallel to the longitudinal direction L of the tank, and set screws 44 are respectively passed through each tapped hole. Each set screw 44 is supported in contact with one support bracket 41, and such a configuration has the effect of pressing the corresponding secondary abutting beam 38 against one end 45 of the branch portion 27, thereby preventing the secondary abutting beam 38 from making a rectilinear movement in the longitudinal direction L.

[0069] In this way, the secondary abutting beam 38 is firmly supported by the secondary mounting support portion 23 in both the longitudinal direction L and the thickness direction of the ceiling wall 4, thereby enabling the secondary sealing membrane 9 to absorb such tensile or compressive forces during operation.

[0070] As shown in FIG. 4, the secondary heat insulation barrier 7 includes a covering plate 47, and the covering plate 47 is placed in a ledge formed on the secondary abutting beam 38 and covers the notch 43 for placing the abutting member 42. The covering plate 47 ensures that the support surface for supporting the secondary sealing membrane 9 is flat.

[0071] Here, referring to FIGS. 3, 8, and 9, the secondary heat insulation barrier 7 and the secondary sealing membrane 9 in the region between the rear cofferdam wall 82 of the ceiling wall 4 and the rear lateral edge portion 49 of the cargo handling opening 14 will be described.

[0072] A corner structure 50 is arranged at the corner portion at the connection portion between the ceiling wall 4 and the rear cofferdam wall 82.

[0073] As shown in FIGS. 2 and 8, the corner structure 50 has an X-shaped mechanical welding structure 51, and the mechanical welding structure 51 extends parallel to the edge where the ceiling wall 4 and the rear cofferdam wall 82 are in contact. The mechanical welding structure includes two wing portions 52 and 53 perpendicular to each other, and each of the wing portions 52 and 53 is parallel to either the ceiling wall 4 or the rear cofferdam wall 62. Each of the wing portions 52 and 53 is welded to anchor flat regions 54 and 55 protruding from the upper support wall 8 or the rear support wall 56, respectively.

[0074] The corner structure 50 of the secondary heat insulation barrier 7 further includes a heat insulation element 57 disposed in a region located between the upper support wall 8, the rear support wall 56, and the two wing portions 52 and 53 of the mechanical welding structure 51, and heat insulation elements 58 and 59 disposed in each region defined between one of the wing portions 52 and 53 of the mechanical welding structure 51 and either the upper support wall 8 or the rear support wall 56.

[0075] As shown in FIG. 9, the secondary heat insulation barrier further includes two rows of heat insulation panels arranged horizontally between a structure disposed along the rear lateral edge 49 of the cargo handling opening 14 and the corner structure 50. According to convention, the row of heat insulation panels disposed closest to the rear lateral edge 49 of the cargo handling opening 14 is referred to as the "first row 60", and the heat insulation panels of the first row 60 are referred to as the "first heat insulation panels 62". In contrast, the row of heat insulation panels disposed closest to the rear cofferdam wall 82 is referred to as the "second row 61", and the heat insulation panels of the second row 61 are referred to as the "second heat insulation panels 63".

[0076] The secondary sealing membrane 9 includes a plurality of streaks 64 extending longitudinally in a region between the corner structure 50 and the rear lateral edge 49 of the cargo handling opening 14 and interrupted by the rear lateral edge 49, which can be seen in FIG. 8. Each of the above streaks 64 is attached to one of the wing portions 53 of the mechanical welding structure 51 and a secondary connection bracket 19 extending along the rear lateral edge 49, respectively.

[0077] The strake 64 has a flat central portion 65 installed on the first heat insulation panel 62 and the second heat insulation panel 63, and two raised edge portions 66 arranged on both sides of the flat central portion 65. The raised edge portions 66 protrude toward the inside of the tank from the central portion 65.

[0078] The strakes 64 are welded to each other at their raised edge portions 66. However, in this region, the raised edge portions 66 of the strakes 64 are not welded to the welding support. In the embodiment shown in FIG. 9, the second heat insulation panel 63 supports three strakes 64 respectively. One of these three strakes 64 is arranged at the center of the second heat insulation panel 63, and the other two strakes 64 are respectively arranged on both lateral sides of the above-mentioned strake 64, and are arranged so as to straddle the second heat insulation panel 63 and any one of the adjacent second heat insulation panels 63.

[0079] Similarly, the first heat insulation panel 62 is also not provided with a welding support.

[0080] Therefore, in the region between the corner structure 50 and the structure arranged along the rear lateral edge portion 49 of the handling opening 14, the strake 64 is not fixed to the welding support at the raised edge portion 66. Also, in order to prevent the strake 64 from peeling off when excessive pressure is applied to the secondary heat insulation barrier 7, strake anchor devices 69, 81 are provided on the first heat insulation panel 62 to fix the strake 64 to the first heat insulation panel 62 as described above. Each central portion 65 of the strake 64 is welded to the strake anchor devices 69, 81. Thereby, the fixing method of the strake 64 in this region can be simplified in the same manner as in other regions of the membrane, and the use of a complicated welded portion that was too short to be produced by a welding machine in this region can be avoided, and the procedure of hermetically welding the strakes 64 to each other can also be simplified.

[0081] In the illustrated embodiment, there are two types of strake anchor devices. One type is labeled 69 and shown in FIG. 10, and is provided only for fixing the strake. In contrast, the other type is labeled 81 and shown in FIG. 11, and serves a dual function as it is also used for fixing the primary insulation panel.

[0082] The strake anchor device 69 includes a peg 85, which is passed through a hole formed in the central portion 65 of one strake 64. The peg 85 has a threaded end (not shown) that is screwed into a threaded hole of a metal plate piece (not shown), and is received and attached to a recess formed in the inner surface of the first insulation panel 62.

[0083] The peg 85 further includes a flange 86 that extends radially with respect to the axis of the peg 85. The flange 86 is pressed against the central portion 65 of the strake 64 when the peg 85 is screwed into the threaded hole of the plate piece attached to any of the first insulation panels 62. Further, the flange 86 is sealed and welded around the entire circumference of the hole in the central portion 65 of the strake 64, thereby ensuring that the peg 85 penetrates the secondary sealing membrane 9 in a sealed state.

[0084] The strake anchor device 81 shown in FIG. 11 has the same structure as FIG. 10, but further includes a shaft portion 87 for attaching the primary insulation panel 13. To do this, the shaft portion 87 protrudes into a recess formed in the primary insulation panel 13. Further, a support plate (not shown) includes a hole that mates with the above shaft portion and a nut (not shown), and this nut interacts with the threaded end of the shaft portion to attach the support plate to the shaft portion. By supporting the support plate on a support surface formed in one of the recesses of the primary insulation panel 13, the primary insulation panel 13 is held toward the support structure. Further, in an advantageous embodiment, a Belleville washer is screwed onto the shaft portion 87 and sandwiched between the nut and the support plate, thereby enabling the elastic mooring of the primary panel to the secondary insulation barrier.

[0085] Furthermore, referring again to FIGS. 8 and 9, each strake 64 interrupted by the rear lateral edge 49 is fixed to each corresponding first heat insulation panel 62. Further, the width of the first heat insulation panel 62 is substantially equal to the width of the strake 64, and the raised edge 66 of the strake 64 is substantially aligned with the gap between adjacent first heat insulation panels 62.

[0086] As also shown in FIGS. 8 and 9, the second heat insulation panel 63 is provided with a strake anchor device 84 similar to that described above with reference to FIG. 11, which also functions to fix the primary heat insulation panel 13.

[0087] As can also be seen from FIGS. 8 and 9, the secondary heat insulation panels 62 of the first row 60 are alternately provided with a strake anchor device 69 that only fixes the strake and a strake anchor device 81 that also functions to fix the primary heat insulation panel 13. As can be seen from the figure, the strake anchor device 81 of the first secondary heat insulation panel 62 is longitudinally aligned with the primary anchor device 29 attached to the secondary attachment support portion 23 together with the strake anchor device of the second secondary heat insulation panel 63. The reason why such alignment is advantageous is that it can limit the stress applied to the strake during tank cooling.

[0088] Such an arrangement means that in the region located at the rear of the handling opening 14, the primary heat insulation panels are each arranged horizontally between two primary anchor devices 29 attached to the secondary attachment support portion 23.

[0089] Therefore, since each first heat insulation panel 62 is provided with only one strake anchor device 69, this can prevent the stress that is likely to occur in the secondary sealing membrane 9 due to the thermal contraction of the first heat insulation panel 62 when the plurality of strake anchor devices 69 attached to each first heat insulation panel 62 approach each other during tank cooling.

[0090] Furthermore, as shown in FIG. 2, in the region located between the rear cofferdam wall 82 and the rear lateral edge 49, the primary heat insulation panel 13 is arranged so as to straddle the secondary abutment beam 38 and the heat insulation element 58 of the corner structure 50. The reason why such an arrangement configuration is advantageous is that it can prevent or at least suppress the step phenomenon on the support surface of the primary sealing membrane 11. Furthermore, the above-mentioned primary heat insulation panel 13 has recesses formed on its outer surface, and each of these recesses can accommodate one of the above-mentioned strake anchor devices 69 as described above.

[0091] Referring to FIG. 12, a view of a part of the liquefied gas carrier 70 cut away shows a hermetic heat insulation tank 71 having an overall shape of a prism installed inside the double hull 72 of the ship. The wall of the tank 71 includes a primary hermetic barrier in contact with the LNG contained in the tank, a secondary hermetic barrier arranged between the primary hermetic barrier and the double hull 72 of the carrier, and two heat insulation barriers respectively arranged between the primary hermetic barrier and the secondary hermetic barrier and between the secondary hermetic barrier and the double hull 72.

[0092] As a matter of course, in order to transfer the LNG cargo to or from the tank 71, the handling pipeline 73 arranged on the upper deck of the carrier can be connected to an offshore or port terminal using appropriate connectors.

[0093] Figure 12 shows an example of an offshore terminal including a cargo handling station 75, a subsea pipe 76, and coastal facilities 77. The cargo handling station 75 is a fixed offshore facility consisting of a movable arm 74 and a tower 78 that supports the movable arm 74. The movable arm 74 supports a bundle of heat-insulated flexible pipes 79 that can be connected to the cargo handling pipeline 73. This movable arm 74, which can be adjusted in direction, can be adjusted to fit LNG carriers of all sizes. Inside the tower 78, a connecting pipe (not shown) extends. The cargo handling station 75 is capable of discharging cargo from the LNG carrier 70 to the coastal facilities 77 and loading cargo from the coastal facilities 77 onto the carrier 70. The coastal facilities 77 include a tank 80 for storing liquefied gas and a connecting pipe 81 connected to the cargo handling station 75 via the subsea pipe 76. The subsea pipe 76 is for transferring liquefied gas over a long distance, for example, about 5 km, between the cargo handling station 75 and the coastal facilities 77, thereby enabling the LNG carrier 70 to be maintained at a location far from the coast during cargo handling operations.

[0094] To generate the pressure required for the transfer of liquefied gas, pumps mounted on the carrier 70 and / or pumps installed in the coastal facilities 77 and / or pumps installed in the cargo handling station 75 are used.

[0095] Although the present invention has been described with reference to a plurality of specific embodiments, the present invention is not limited to these specific embodiments at all, and it is obvious that all technical equivalents of the above means and technically equivalent combinations of the above means are included in the present invention as long as they belong to the scope of the present invention.

[0096] The use of the verb "include" or "comprise" and its conjugates does not exclude the presence of elements or steps other than those recited in the claims.

[0097] In the claims, any reference signs in parentheses shall not be construed as limiting the claims.

Claims

1. A liquefied gas storage facility comprising a support structure (2) and a sealed insulated tank (71) supported by the support structure (2), The support structure (2) is equipped with an upper support wall (8), The sealed insulated tank (71) is equipped with a ceiling wall (4) attached to the upper support wall (8), The ceiling wall (4) extends from the outside to the inside in the thickness direction of the sealed insulated tank. A secondary heat insulating barrier (7) attached to the upper support wall (8), The secondary sealing membrane (9) is placed in the secondary insulating barrier (7), The primary insulating barrier (10) is placed in the secondary sealing membrane (9), A primary sealing membrane (11) is placed in the primary insulating barrier (10) and comes into contact with the liquefied gas, It is equipped with, The aforementioned ceiling wall (4) is locally interrupted to define a cargo handling opening (14) through which a cargo handling pipe passes. The loading / unloading opening (14) is defined by a front lateral edge (6) and a rear lateral edge (49) parallel to the lateral direction (T), and a first longitudinal edge and a second longitudinal edge (5) parallel to the longitudinal direction (L) perpendicular to the lateral direction (T). The secondary thermal insulation barrier (7) of the ceiling wall (4) comprises a first row (60) of first thermal insulation panels (62) that are aligned laterally and positioned between the rear lateral edge (49) and the rear cofadam wall (82), The secondary sealing membrane (9) of the ceiling wall (4) is provided with a plurality of parallel first strakes (64) that extend in the longitudinal direction and are interrupted by the rear lateral edge (49) between the rear lateral edge (49) and the rear cofadam wall (82). Each of the first strakes (64) has a flat central portion (65) positioned on the first insulation panel (62) and two raised edges (66) that protrude from the central portion (65) toward the interior of the sealed insulation tank. The first strakes (64) are arranged in a repeating pattern in the lateral direction and are welded to each other so as to be sealed at the raised edges (66). The first insulation panel (62) is provided with a strake anchor device (69, 81), Each of the first strakes (64) has a flat portion (65) which is welded to one of the strake anchor devices (69, 81). A liquefied gas storage facility characterized by the following.

2. Each of the first insulation panels (62) is provided with one of the strake anchor devices (69, 81). The liquefied gas storage facility according to claim 1.

3. The lateral dimension of the first insulation panel (62) is equal to the lateral dimension of the first strake (64), Each of the first insulation panels (62) is aligned with one of the first strakes (64) such that the raised edge (66) of the first strake (64) aligns with the gap between two adjacent first insulation panels (62). A liquefied gas storage facility according to claim 1 or 2.

4. Each of the strake anchor devices (69, 81) is, A plate attached to one of the first insulation panels (62), A peg (85) attached to the aforementioned plate piece (84), Each of them is equipped with, Each of the aforementioned pegs (85) extends in the thickness direction of the ceiling wall from the plate piece (84) through a hole formed in the flat portion (65) of one of the first strakes (64) in order to seal the hole, and toward the interior of the sealed insulated tank (71). The peg (85) is equipped with a flange (86) that is fitted to seal around the hole of the first strake (64). A liquefied gas storage facility according to claim 1 or 2.

5. The secondary insulation barrier (7) of the ceiling wall (4) comprises a second row (61) of second insulation panels (63) which are aligned laterally and positioned between the first row (60) of the first insulation panels (62) and the rear cofadam wall (82). A liquefied gas storage facility according to claim 1 or 2.

6. A strake anchor device (81) is provided on the second insulation panel (63), At least a portion of the flat portion (65) of the first strake (64) is welded to one of the strake anchor devices of the second insulation panel (63). The liquefied gas storage equipment according to claim 5.

7. The first strake (64) is welded along the rear lateral edge (49) to a secondary connecting bracket (19) connected to the upper support wall (8). A liquefied gas storage facility according to claim 1 or 2.

8. The secondary insulation barrier (7) of the ceiling wall (4) is At least a first secondary mounting support portion and a second secondary mounting support portion (23) are arranged along the rear lateral edge portion (49), each comprising: a secondary base (25) fixed to the upper support wall (8); a secondary cap (24) welded to the secondary base (25) and extending in a plane parallel to the longitudinal direction and parallel to the upper support wall (8); and a plate piece (30) attached to the secondary cap (24) by a mounting member (31), At least one boundary secondary insulation block (37) is positioned between the first secondary mounting support portion (23) and the second secondary mounting support portion (23) along the first lateral edge portion (T), A secondary contact beam (38) extending along the rear lateral edge (49), wherein at least one secondary contact beam (38) is provided between the secondary cap (24) of the first secondary mounting support portion and the second secondary mounting support portion (23) and one of the boundary secondary insulation block (37), and is immovably provided between the plate piece (30) and the secondary cap (24) of the first secondary mounting support portion and the second secondary mounting support portion in the thickness direction of the ceiling wall, It is equipped with, The secondary connecting bracket (19) comprises a first wing portion (20) positioned on the secondary contact beam (38) and a second wing portion (21) connected to the upper support wall (8). The liquefied gas storage equipment according to claim 7.

9. The first secondary mounting support section and the second secondary mounting support section support the primary anchor device (29) for fixing the primary heat insulating barrier (10). Some of the strake anchor devices (69, 81) provided on the first insulation panel (62) are aligned with the primary anchor device (29) in the longitudinal direction (L). The liquefied gas storage equipment according to claim 8.

10. The primary thermal barrier of the ceiling wall (4) includes a primary thermal panel (13) positioned to straddle the thermal insulation element (58) of the corner structure (50) located at the connection between the ceiling wall (4) and the rear cofadam wall (82), and the secondary contact beam (38), in a region located between the rear cofadam wall (82) and the rear lateral edge (49). The liquefied gas storage equipment according to claim 8.

11. The primary insulation panel (13) in the region located between the rear cofadam wall (82) and the rear lateral edge (49) has a recess for inserting the strake anchor device (69, 81). The liquefied gas storage equipment according to claim 10.

12. The first strake (64) is welded to a mechanically welded structure (51) that extends along the edge where the ceiling wall (4) and the rear cofadam wall (82) meet. The mechanically welded structure (51) is attached to the ceiling wall (4) and the rear cofadam wall (82). A liquefied gas storage facility according to claim 1 or 2.

13. A carrier (70) for transporting liquefied gas, equipped with the liquefied gas storage facility described in claim 1 or 2.

14. A system for transporting liquefied gas, The carrier (70) described in claim 13, Insulated pipelines (73, 79, 76, 81) are arranged to connect the sealed insulated tank (71) installed in the hull of the transport vessel (70) to a floating or coastal storage facility (77), A system characterized by having the following features.

15. A method for loading or unloading cargo from a transport vessel (70), Liquefied gas is delivered via insulated pipelines (73, 79, 76, 81) from a floating or coastal storage facility (77) to the sealed insulated tank (71) of the transport vessel (70) according to claim 13, or from the sealed insulated tank (71) of the transport vessel (70) to the floating or coastal storage facility (77). A method characterized by the following:

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