CN114599912A

CN114599912A - Shipborne liquefied natural gas tank

Info

Publication number: CN114599912A
Application number: CN202080074762.XA
Authority: CN
Inventors: A.托卡特利安; E.杜克洛伊
Original assignee: Gaztransport et Technigaz SA
Current assignee: Gaztransport et Technigaz SA
Priority date: 2019-10-25
Filing date: 2020-10-23
Publication date: 2022-06-07
Anticipated expiration: 2040-10-23
Also published as: WO2021078981A1; FR3102532B1; EP4048935A1; KR20220087469A; FR3102532A1; CN114599912B

Abstract

The invention relates to a sealed and thermally insulated tank (26) designed to store a fluid and to rest on a load-bearing structure (6) of a ship, the sealed tank (26) comprising a plurality of tank walls, including a first tank wall (30) and at least one second tank wall (32), the first tank wall (30) extends mainly in a first plane, the second tank wall (32) extends mainly in a second plane, the first and second planes being perpendicular to each other, the first and second tank walls (30, 32) being connected by an angled joint part (34), characterized in that the angled engagement member (34) has a first portion (56) extending primarily in the first plane, a second portion (58) extending primarily in the second plane, and at least one intermediate portion (60) extending primarily in an intersection plane intersecting the first plane and the second plane.

Description

Shipborne liquefied natural gas tank

Technical Field

The present invention relates to the field of lng tanks used in marine transportation.

Background

Liquefied natural gas is transported by sea in sealed and thermally insulated storage tanks carried on transport vessels. The natural gas is maintained in a liquid state to increase the amount of natural gas that can be loaded in the tank, since the volume of one liter of liquid natural gas is much smaller than the volume of one liter of gaseous natural gas. These tanks maintain the liquefied natural gas at a very low temperature, more specifically, at a temperature below-163 ℃, at which the natural gas is in a liquid state at atmospheric pressure.

Such liquefied natural gas tanks may also be used as fuel tanks for certain ships. In other words, the ship loads and stores the liquefied natural gas in the tank before using the liquefied natural gas as fuel.

The lng tanks are usually parallelepipeds, the walls of which are carried by the inner hull of the ship on which the tank or tanks are mounted. More specifically, the hull of the tank-mounted ship has an outer hull in contact with the external environment of the ship and an inner hull which serves as a load-bearing structure for the tank. A reinforcing member is disposed between the outer hull and the inner hull to support the inner hull and the walls of the one or more tanks.

Once loaded into the tank, the liquefied natural gas exerts pressure on the tank walls. The aforementioned reinforcement members enable the wall to withstand such pressure. The joining areas of the walls of the tank, in other words the corners of the parallelepiped shape of said tank, are particularly vulnerable to this pressure, and the sealing of the tank in these joining areas of the walls should be ensured in order to prevent the tank walls from being contaminated with liquefied natural gas, or even leaking from the storage tank in some cases, resulting in a loss of stored liquefied natural gas.

Disclosure of Invention

In this case, the invention relates firstly to a sealed, thermally insulated tank designed to rest on a load-bearing structure of a ship, the sealed tank comprising a plurality of tank walls, including a first tank wall extending mainly in a first plane and at least one second tank wall extending mainly in a second plane, the first and second planes being mutually perpendicular, the first and second tank walls being connected by an angled joint part, characterized in that the angled joint part has a first portion extending mainly in a plane parallel to the first plane, a second portion extending mainly in a plane parallel to the second plane, and at least one intermediate portion extending mainly in a plane intersecting the first and second planes, the first portion of the angled joint part having a thickness equal to the thickness of the first tank wall and being arranged to extend the first tank wall, the second portion of the angled engagement member has a thickness equal to a thickness of the second tank wall and is arranged to extend the second tank wall.

The tank is designed to receive liquefied natural gas, which must not exceed a temperature of-160 ℃ in order to remain liquid at atmospheric pressure. Thus, the tank comprises a series of layers, firstly to ensure that the lng is maintained at a temperature of no more than-160 ℃, and secondly to provide an optimum seal to reduce the risk of lng leakage. Such tanks are particularly useful for storing liquefied natural gas, for example while underway or while parked prior to unloading, or to power machinery of a ship carrying the tank. The temperature of the liquefied natural gas may be increased if the liquefied natural gas is stored in a tank at a pressure higher than atmospheric pressure. For example, the tank may be used at 1 bar gauge, in which case the natural gas may remain liquid at a maximum temperature of-152 ℃.

The tank is supported by the inner hull of the vessel forming the load bearing structure, since such a tank with a membrane is not a self-supporting structure. The inner hull is designed to receive the tank and withstand the pressure exerted on the walls of the tank by the liquefied natural gas stored in the tank.

The tank has at least two walls, and the two walls are perpendicular to each other. The stored liquefied natural gas exerts a pressure on each of these walls and the structure of the tank with the joint member according to the invention enables to manage the pressure exerted on the joint area between the two walls in order to limit the risk of leakage of liquefied natural gas from this joint area.

Notably, the engagement member includes three portions, two of which (referred to herein as first and second portions) are respectively disposed in planes parallel to a plane containing one of the tank side walls, and a third portion (referred to as a middle portion) that is inclined with respect to each of the other portions. This third section forms an intermediate section arranged between the two other sections and designed to distribute the pressure exerted by the liquefied natural gas towards each tank side wall. As specified, the thickness of the angled engagement members and/or angled engagement elements is similar or substantially similar to the thickness of the first tank wall and/or the thickness of the second tank wall within manufacturing tolerances such that the angled engagement members provide structural continuity of the tank at the corners of the tank and structural connection between two vertical side walls that form primarily the tank but are discontinuous from one another.

According to another optional feature of the invention, the sealable tank has at least one third tank wall extending mainly in a third plane perpendicular to the first plane, the second plane and the intersecting plane and having a joining region with the first tank wall and the second tank wall, wherein the joining region has an angled joining element having a first portion with a first section extending mainly in the first plane, a second section extending mainly in the second plane and an intermediate section extending mainly in the intersecting plane and a second portion with a return wall extending mainly in the third plane and perpendicular to the first portion.

The third tank wall extends in a plane perpendicular to a plane containing the first tank wall, a plane containing the second tank wall, and a plane containing the first portion, the second portion, and the intermediate portion of the joining member.

The joining element provides a connection between the third tank wall and the first tank wall, the second tank wall and the joining member, due to a first portion lying in a plane extending the first tank wall, in a plane extending the second tank wall and in a plane extending the angled joining member, and due to a second portion lying in a plane containing the third tank wall.

The angled engagement elements also distribute pressure exerted by the liquefied natural gas on the interior face of the tank at the engagement areas of the first tank wall, the second tank wall, and the third tank wall.

According to an optional feature of the invention, the angled engagement members and/or the angled engagement elements each have an inner face forming an inner chamfer at the middle portion or section and an outer face forming an outer chamfer at the middle portion or section, the inner and outer chamfers being inclined at an angle of between 120 ° and 150 ° relative to the first and second planes.

The third, i.e. intermediate, portion of the joint part between the first and second tank walls is advantageously inclined by 135 ° ± 15 ° with respect to each plane extending the first and second portions of the joint part (respectively referred to as first and second portions) so that the pressure exerted by the liquefied natural gas is well evenly distributed on the one or other side wall connected by the joint part.

Similar to the angled engagement member, the third portion of the engagement member between the first and second tank walls is inclined 135 ° ± 15 ° with respect to each plane extending the first and second portions of the engagement member.

According to another optional feature of the invention, the dimension of the intermediate portion of the angled engagement member, measured between the first and second portions of the member, and/or the dimension of the intermediate section of the angled engagement element, measured between the first and second sections of the element, increases from the inner face towards the outer face.

Thus, the inner face, more particularly the inner chamfer as described above, is narrower than the outer face, more particularly the outer chamfer, the width being the dimension perpendicular to the longitudinal direction in which the engaging members mainly extend.

According to another optional feature of the invention, the angled engagement member and/or the angled engagement element comprise, in order in the thickness direction from the outside to the inside of the sealed tank, a secondary insulating barrier designed to be in contact with the load-bearing structure, a secondary sealing film carried by the secondary insulating barrier, a primary insulating barrier resting on the secondary sealing film and a primary sealing film carried by the primary insulating barrier, the primary insulating barrier being designed to be in contact with the fluid contained in the sealed tank.

The tank wall and the joint part of the liquefied natural gas tank comprise at least one secondary space and one primary space, the secondary space of the tank wall resting on the inner hull of the ship by means of adhesive beads. The secondary space comprises, in sequence from the external face towards the internal face of the tank, a secondary insulating barrier and a secondary sealing membrane. The primary space comprises, in order from the outer face of the tank towards the inner face of the tank, a primary insulating barrier and a primary sealing membrane.

According to another optional feature of the invention, the secondary space of the engagement member comprising at least one secondary insulating barrier and one secondary sealing membrane is arranged to extend the secondary space of the tank wall extended by the engagement member, the two secondary spaces having the same composition. Similarly, the primary space of the joint part comprising at least one primary thermal insulation barrier and one primary sealing membrane is arranged to extend the primary space of the tank wall extended by the joint part, the two primary spaces having the same composition.

The insulating barrier helps maintain the temperature of the liquefied natural gas stored in the storage tank by limiting heat exchange between the environment outside the storage tank and the interior of the storage tank. The sealing membrane prevents any leakage of the liquefied natural gas.

According to another optional feature of the invention, the secondary insulating barrier and the secondary sealing membrane of the angled engagement member and/or the angled engagement element each have a dimension in a given direction that is greater than a corresponding dimension of the primary insulating barrier and the primary sealing membrane in the same direction.

The first portion of the angled engagement member is primarily vertically within the first plane of the intermediate portion. The size of the secondary space measured in the vertical direction is larger than the size of the primary space also measured in the vertical direction in the first section. The same applies to the first section of the angled engagement element.

The second portion of the angled engagement member lies primarily in a second plane of the intermediate portion in the transverse direction. The size of the secondary space measured in the transverse direction is larger than the size of the primary space also measured in the transverse direction in the second section. The same applies to the second section of the angled engagement element.

The first, second and intermediate portions of the angled engagement member extend in a longitudinal direction that is common to all three portions. The dimension of the secondary space measured in the longitudinal direction is greater than the dimension of the space also measured in the longitudinal direction in each portion of the angled engagement member. The same applies to each segment of the angled engagement element.

The secondary space is uncovered at the ends of the engagement members so that the secondary sealing membrane is free. During assembly of the tank, the primary space panel is then positioned to overlap both the first portion of the joint component and the first tank wall, the panel rigidly connecting the joint element to the first tank wall. The same assembly is used between the second portion of the engagement member and the second tank wall, and in the first section, the second section and the return wall of the angled engagement element.

The return wall lies in a plane perpendicular to the first plane, the second plane and the intersecting plane and parallel to the vertical and lateral directions. The size of the secondary space measured in the vertical direction is larger than the size of the primary space also measured in the vertical direction in the return wall. Furthermore, the size of the secondary space measured in the transverse direction is larger than the size of the primary space also measured in the transverse direction in the return wall.

According to another optional feature of the invention, the size of the first and/or second portion of the angled engagement member is equal to the size of the intermediate portion.

The invention also relates to a ship comprising at least one seal can as described above.

According to an optional feature of the invention, the vessel has an outer hull and a load bearing structure, the load bearing structure being designed to receive the sealpot, the load bearing structure having a first load bearing wall extending mainly in a first plane and a second load bearing wall extending mainly in a second plane, the first load bearing wall and the second load bearing wall being substantially perpendicular, characterised in that a clearance region is provided between the load bearing wall of the load bearing structure in the joint region and a middle portion of the angled joint part, and in that the stiffening element is located in said clearance region.

The reinforcing element provides a bearing surface for the angled engagement member that is substantially perpendicular to the direction of pressure exerted by the liquefied natural gas present in the tank at the engagement region of the tank wall.

According to another optional feature of the invention, the reinforcing element has a triangular cross-section and an apex of the reinforcing element has an angle equal to a right angle formed between the first and second load-bearing walls, the reinforcing element having a contact face opposite said apex in contact with the intermediate portion.

The contact surface of the reinforcing element may be flat and form a square, so that after contact between the reinforcing element and the intermediate portion of the angled engagement member, the stress is evenly distributed over the entire contact surface forming the bearing surface. Alternatively, the contact face may have a multi-faceted profile, formed by a plurality of flat surfaces inclined with respect to each other, so as to form a profile curved towards the inside of the reinforcing element. Alternatively, and in particular to facilitate the construction of the reinforcement element arranged at the junction of the load-bearing walls of the load-bearing structure, the contact face may have a curved profile having the substantially concave shape of the reinforcement element. With respect to curved surfaces, a reinforcement member and/or filler material may be disposed in the space thus formed between the contact surface and the intermediate portion of the angled engagement member.

According to another optional feature of the invention, the outer hull has a plurality of strengthening members in contact with the load bearing structure and the strengthening members are less concentrated near the angled engagement members and/or near the angled engagement elements.

In other words, the distance between two adjacent reinforcement members of the plurality of reinforcement members arranged between the outer hull and the load bearing structure varies as a function of proximity to the angled engagement member, the distance being greater closer to the angled engagement member.

These reinforcing members help to transfer the pressure exerted by the liquefied natural gas in the tank to the outer hull of the ship. The presence of the angled engagement members and/or angled engagement elements helps to better distribute the pressure exerted by the liquefied natural gas to the tank walls, thereby reducing the need for reinforcement members at these engagement areas.

According to another optional feature of the invention, the intermediate portion of the angled engagement member is dimensioned as a function of the position of the reinforcement member closest to the corner of the inner load bearing structure in which the angled engagement member is located such that:

where D60 is the dimension of the intermediate portion and D is the distance between the first reinforcement member and the corner of the internal load bearing structure.

The above-mentioned dimension of the intermediate portion is the length of the outer face of the intermediate portion between a first connecting edge forming a joint between the intermediate portion and the first portion and a second connecting edge forming a joint between the intermediate portion and the second portion.

Drawings

Further characteristics, details and advantages of the invention will be more clearly illustrated in the following description and in several exemplary embodiments thereof, provided by way of non-limiting example with reference to the accompanying drawings, in which:

fig. 1 is a side view of a carrier, showing at least one lng tank,

figure 2 is a schematic cross-sectional view of a tank comprising at least one angled joint part arranged between different tank side walls and a hull, the hull comprising an outer hull, a reinforcing member and an inner load-bearing structure accommodating the tank,

figure 3 is an internal view of a plurality of engagement members,

figure 4 is a cross-section of the tank, the inner load-bearing structure and the outer hull at the connection between the two tank side walls,

figure 5 is a view of the angled engagement element and the first transverse tank wall from the interior of the tank,

figure 6 is a view of at least one angled engagement member and at least one angled engagement element from the inside of the can,

figure 7 is a cross-sectional view of a particular embodiment of the tank, inner load-bearing structure, reinforcing members and outer hull in a view similar to figure 4,

fig. 8 shows a modification of the embodiment of fig. 7.

Detailed Description

The features, variations and different embodiments of the present invention can be associated with each other in different combinations, not incompatible or mutually exclusive with each other. In particular, if a selection of features described separately from other described features is sufficient to provide technical advantages or to distinguish the invention from the prior art, it is envisaged that the variants of the invention comprise only a selection of said features.

Fig. 1 shows a carrier 200, such as an lng carrier, having four tanks 26 for transporting or storing lng, wherein one of the tanks is visible for ease of understanding. The carrier 200 may be designed to store and transport only such liquefied natural gas, or to operate the carrier using liquefied natural gas as fuel.

As shown in particular in fig. 2, the vessel has a hull 2, the hull 2 comprising at least one outer hull 4 and an inner load-bearing structure 6, a plurality of

reinforcement members

8, 10 being arranged between the outer hull 4 and the inner load-bearing structure 6. The outer hull 4 is in contact with the environment outside the vessel, typically a marine and/or river environment. The inner load bearing structure 6 extends away from the outer hull. The dimensions of the reinforcing members determine the gap between the outer hull 4 and the inner load-bearing structure 6, each reinforcing member being rigidly connected to the outer hull 4 at a first end 12 and in contact with the inner load-bearing structure 6 at a second end 14. The reinforcement members are advantageously provided over the entire inner load-bearing structure 6.

The inner load bearing structure 6 has a plurality of load bearing walls including a first load bearing side wall 18 and at least one second load bearing side wall 20 that lie in a vertical plane. The first load bearing sidewall 18 has a first longitudinal side 21 and the second load bearing sidewall 20 has a second longitudinal side 23, wherein the second load bearing sidewall 20 is adjacent to the first load bearing sidewall 18.

In other words, the first load bearing sidewall 18 and the second load bearing sidewall 20 are perpendicular to each other at a junction area 24 between the first longitudinal side 21 of the first load bearing sidewall 18 and the second longitudinal side 23 of the second load bearing sidewall 20.

The internal load-bearing structure 6 comprises at least one sealed and thermally insulated tank 26, said tank 26 being designed to contain liquefied natural gas. The hermetically insulated tank 26 has an inner face 27 and an outer face 29, the inner face 27 being in contact with the liquefied natural gas when stored therein, the outer face 29 abutting against a plurality of load bearing walls, in particular the first or second load bearing

side walls

18, 20 of the inner load bearing structure 6.

The sealed and thermally insulated tank 26 is advantageously a rectangular parallelepiped. Thus, the hermetically sealed and insulated tank 26 has a plurality of tank walls, including a first tank sidewall 30 and at least one second tank sidewall 32.

Each of the

tank side walls

30, 32 abuts a respective load bearing

side wall

18, 20. More specifically, in the example shown, the exterior face 29 of the first tank sidewall 30 rests against the first load-bearing sidewall 18 of the inner load-bearing structure 6, and the exterior face of the second tank sidewall 32 rests against the second load-bearing sidewall 20 of the inner load-bearing structure 6.

For the reasons described above, the second can side wall 32 and the first can side wall 30 lie in planes that are perpendicular to each other.

According to the invention, the first and second

tank side walls

30, 32 are connected to each other by being rigidly connected to at least one angled joint part 34 according to the invention, which angled joint part 34 is arranged in the aforementioned joint region 24.

As shown particularly in fig. 2, 4, 7 and 8, the angled engagement member 34 extends each can sidewall and has a thickness that is similar or substantially similar (within manufacturing tolerances) to the thickness of the first and/or second can sidewalls 30, 32. In other words, the angled engagement members provide structural continuity to the tank by forming a connection between two vertical side walls that in principle form the tank but are not continuous with each other.

In this case, the thickness of either of the

tank side walls

30, 32 is measured between the inner face 27 and the outer face 29 in a direction perpendicular to the plane in which the

tank side wall

30, 32 concerned lies predominantly. Thus, in the illustrated example, the thickness of the first tank sidewall 30 is measured in a direction parallel to the transverse axial direction B, and the thickness of the second tank sidewall 32 is measured along the longitudinal axis C.

More specifically, the first portion of the angled engagement member is arranged to extend the first tank side wall 30, said first portion and said first tank side wall having similar or substantially similar thickness values, respectively, measured along axes parallel to each other (in this case parallel to the transverse axis B). Similarly, the second portion of the angled engagement member is arranged to extend the second tank sidewall 32, said second portion and said second tank sidewall having similar or substantially similar thickness values, respectively, measured along axes parallel to each other (in this case parallel to the vertical axial direction C).

Advantageously, the angled engagement member 34 has a first thickness similar to the thickness of the first tank sidewall 30 at least in the area of contact between the angled engagement member 34 and the first tank sidewall 30, and a second thickness similar to the thickness of the second tank sidewall 32 at least in the area of contact between the angled engagement member 34 and the second tank sidewall 32.

The structure of the angled engagement member 34 will be described in more detail below with particular reference to fig. 3 and 4. The sections include, in order from the outer face to the inner face, a secondary insulation barrier 36, a secondary sealing film 38, a primary insulation barrier 40 and a primary sealing film 42, depending on the configuration of the

tank walls

30, 32 connected by the angled engagement members 34. The secondary thermal insulation barrier 36 and the secondary sealing film 38 form a secondary space 37, and the primary thermal insulation barrier 40 and the primary sealing film 42 form a primary space 41.

In accordance with the foregoing and as described in greater detail below, first, the primary space of the angled engagement member formed by the primary insulation barrier 40 and the primary sealing film 42 extends the same primary space of the first can side wall 30 and the same primary space of the second can side wall 32, and second, the secondary space of the angled engagement member formed by the secondary insulation barrier 36 and the secondary sealing film 38 extends the same secondary space of the first can side wall 30 and the same secondary space of the second can side wall 32.

The secondary insulating barrier 36 includes, in order from the exterior of the tank toward the secondary sealing film 38, a first insulating wall 44 and a first insulating layer 46. The first insulating wall 44 is a plate having a substantially rectangular parallelepiped shape. The board is advantageously made of plywood, for example wood plywood. The size of the plate is adapted to the size of the blocks of the secondary thermal barrier 36.

The first thermal insulation layer 46 may be made of a foamed plastic material, such as polyurethane foam, providing effective, well-distributed thermal insulation between the insulating walls.

Further, the angled engagement member 34 includes a second insulating wall 51 overlapping the first thermal insulation layer 46 between the first layer and the secondary sealing film 38. This second insulating wall 51 is also formed by a plate advantageously made of plywood, for example wood plywood, this second insulating wall 51 being provided in particular in the angled joint part and not necessarily in the composition of the tank wall. This second thermally insulated wall 51 is particularly arranged to better withstand the pressure generated by the natural gas in the tank at the wall joint.

The secondary insulating barrier 36, and more specifically the second insulating wall 51, is rigidly connected to the secondary sealing film 38, for example by gluing.

Secondary sealing membrane 38 includes a flexible secondary sealing membrane 48 and a rigid secondary sealing membrane 49.

More specifically, there is a rigid secondary sealing membrane 49 for each

portion

56, 58, 60 of the angled engagement member 34 and a flexible secondary sealing membrane 48 common to all portions, which at least partially covers each of the rigid secondary sealing membranes 49, the rigid secondary sealing membrane 49 covering the flat surface of the secondary insulating barrier 36. The secondary thermal barriers of each portion of the angled engagement member 34 are covered by a rigid secondary sealing membrane 49, but the intersections between each portion remain uncovered. The flexible secondary sealing membrane 48 is positioned to cover the intersection between each

portion

56, 58, 60 of the angled engagement member 34 and between each rigid secondary sealing membrane 49 covering said

portions

56, 58, 60, thereby reducing the risk of contamination in these risk areas. The flexible secondary sealing membrane 48 is a triple band comprising an aluminum plate bonded between two woven glass mats. These components of the triple band are not shown in all of the figures. The flexible secondary sealing film 48 is in contact with and bonded to the rigid secondary sealing film 49 and the primary insulating barrier 40.

The rigid secondary sealing membrane 49 comprises an aluminum plate bonded between two woven glass mats impregnated in a polymer resin.

The primary insulating barrier 40 includes a second insulating layer 52 and a third insulating wall 54, each of which is composed and functions as described above.

In assembling the sealed, thermally insulated tank 26, the angled engagement member 34 and the plurality of tank walls are installed using assembly panels arranged alongside one another, each assembly panel comprising different elements that make up the angled engagement member 34 and the plurality of tank walls. These assembled panels may be covered by a primary sealing membrane 42, which primary sealing membrane 42 may be made of stainless steel and corrugated. Primary seal membrane 42 may also be made of Invar (Invar)

) And (4) manufacturing a steel plate.

Each of the

tank side walls

30, 32 lies in a main plane of extension, which planes of extension are perpendicular to each other, and the angled engagement member 34 extends in three different planes, the angled engagement member 34 having at least three different portions that each extend in one of the three different planes.

According to the first embodiment, the angled engagement member 34 has a first portion 56, a second portion 58, and at least one intermediate portion 60. The number of intermediate portions is not limited and the present invention should be understood to include an angled engagement member 34 having, for example, four portions, with two intermediate portions connecting the first portion 56 to the second portion 58.

As shown, the first portion 56 extends a middle portion 60 in a vertical direction substantially parallel to the vertical axis C, and the second portion 58 extends a middle portion in a perpendicular lateral direction substantially parallel to the lateral axis B.

The first portion 56 and the second portion 58 each have primary and

secondary spaces

41, 37 that do not extend in the same dimension in a given direction from the intermediate portion. As shown in fig. 3, the size of the primary space 41 of the first portion 56 measured in the vertical direction is shorter than the size of the secondary space 37 of this first portion 56 also measured in the vertical direction, so that the primary space 41 does not completely cover the secondary space 37. Similarly, the dimensions of the primary space 41 of the second portion 58, measured in the transverse direction, are shorter than the dimensions of the secondary space 37 of this second portion 58, also measured in the transverse direction, so that the primary space 41 in this case also does not completely cover the secondary space 37.

The first portion 56 of the angled engagement member 34 extends primarily in a major plane of extension of the first tank sidewall 30 to extend the first tank sidewall. The first portion 56 has a first free edge 62 and a second free edge 64 which extend opposite the intermediate portion 60 and are distinguished by the difference in length of the primary and secondary spaces. More specifically, the primary spaces 41 of the first portion 56 contribute to forming the first free edge 62, and the secondary spaces 37 of the first portion 56 contribute to forming the second free edge 64. Thus, from the first free edge 62 to the second free edge 64, the secondary sealing film 38 is uncovered on the first portion 56 of the angled engagement member 34 and is designed to be covered by the primary thermal barrier 40 of the first can sidewall 30.

As noted above, and as shown in greater detail in fig. 4, the first portion 56 structurally extends at least along the vertical axis C toward the intermediate portion 58 and has a similar thickness as the first tank sidewall 30. More specifically, the secondary space 37 forming the first portion 56 extends (in this case vertically) to form the secondary space 37 of the first tank sidewall 30, and the primary space 41 forming the first portion 56 extends in the same vertical direction to form the primary space 41 of the first tank sidewall 30. Further, the primary sealing membrane 42 and the secondary sealing membrane 38 are continuous between the first portion 56 of the angled engagement member 34 and the first can sidewall 30.

The second portion 58 of the angled engagement member 34 extends primarily in a major plane of extension of the second tank sidewall 32 to extend the second tank sidewall. The above description with respect to the first portion 56 also applies to the structure of the second portion 58, the third free edge 68 and the fourth free edge 70 being formed by the primary space 41 and the secondary space 37 of this second portion 58, respectively.

Further, the second portion 58 of the angled engagement member 34 structurally extends along the transverse axis B toward the intermediate portion 58 and has a thickness similar to the second can sidewall 32. More specifically, the secondary space 37 forming the second portion 58 extends laterally in this case to form the secondary space 37 of the second tank side wall 32, and the primary space 41 forming the second portion 58 extends in the same lateral direction to form the primary space 41 of the second tank side wall 32. Further, the primary sealing film 42 and the secondary sealing film 38 are continuous between the second portion 58 of the angled engagement member 34 and the second can sidewall 32.

The first portion 56 and the second portion 58 of the angled engagement member 34 extend in mutually perpendicular planes. The first portion 56 is not adjacent to the second portion 58 due to the presence of the intermediate portion 60, which intermediate portion 60 is rigidly connected to the first portion 56 and the second portion 58 of the angled engagement member 34. The first portion 56 is rigidly connected to the intermediate portion 60 at a first connecting edge 66, and the second portion 58 is rigidly connected to the intermediate portion 60 at a second connecting edge 72.

The intermediate portion 60 extends mainly in an inclined plane which firstly intersects the main extension plane of the first portion 56 and secondly of the second portion 58. The aforementioned connecting

edges

66, 72 form a junction between each portion and each respective major plane.

Thus, according to the invention, the intermediate portion 60 forms a wall inclined with respect to two portions respectively extending one of the tank side walls, the two portions being perpendicular to each other.

More specifically, in the example shown, a single intermediate portion 60 is arranged between the two

portions

56, 58, the inclined plane in which the intermediate portion is mainly contained having an angle of about 135 ° with the first portion 56 and the first lateral wall 30 extending on one side thereof and with the second portion 58 and the second lateral wall 32 extending on the other side thereof.

This arrangement of the different portions of the angled engagement member 34 means that the dimension measured between the first portion 56 and the second portion 58 of the intermediate portion 60 increases from the inner face 27 towards the outer face 29 of the sealed, thermally insulated tank 26. In other words, the dimension of the intermediate portion 60 between the first connecting edge 66 of the first portion 56 and the second connecting edge 72 of the second portion 58 at the inner face 27 is smaller than the dimension of the intermediate portion between the first connecting edge 66 of the first portion 56 and the second connecting edge 72 of the second portion 58 at the outer face 29.

The angled engagement member 34 according to the invention aims at optimizing the distribution of the pressure exerted by the liquefied natural gas on the engagement zone 24 of the walls constituting the plurality of tank walls of the hermetically insulated tank 26, this pressure being indicated by the arrow D in fig. 4. The pressure exerted by the liquefied natural gas in the tank 26 on the inner face 27 at the first portion 56 or the second portion 58 is exerted on the primary space 41 corresponding to the angled engagement member 34 and is distributed over the entire corresponding secondary space 37 towards the outer face 29, i.e. over a larger area. The pressure exerted by the liquefied natural gas on the inner face 27 of the intermediate portion 60 is distributed over the entire outer face 29 of the intermediate portion 60, also over a larger area. The pressure from the lng is distributed over a larger bearing surface on the outer face 29, which is designed to be in contact with the inner load-bearing structure 6.

As shown in fig. 3, the angled engagement member 34 facilitates the formation of an angled engagement module 74, which angled engagement module 74 may be arranged sequentially one after the other with other similar modules along a longitudinal axis a, which is an axis shared by two tank side walls. Thus, the first, second, and

intermediate portions

56, 58, 60 of each angled engagement member 34 are aligned with the first, second, and intermediate portions of the other angled engagement members 34 of the angled engagement module 74.

Each angled engagement module 74 has a first longitudinal end 75 and a second longitudinal end 77. The sealing membrane 38 of the secondary space 37 is uncovered at least one longitudinal end of the plurality of angled junction modules 74.

As shown in FIG. 4, each angled joint module 74 cooperates with the first and

second tank walls

30, 32. The first portion 56 of the angled joint component 34 of each angled joint module 74 is designed to contact the first tank wall 30 at the first free edge 62 and the second free edge 64. Thus, the secondary space 37 of the first portion 56 of each component forming an angled joining module 74 is arranged as a continuation of the secondary space 37 of the first tank wall 30, and the primary space 41 of the first portion 56 of each component forming each angled joining module 74 is also arranged as a continuation of the primary space 41 of the first tank wall 30. The secondary space 37 of the first part 56 of the component forming each angled joining module 74 is covered, in its part not covered by the primary space, by the primary space 41 of the first tank wall 30 up to the first free edge 62. Similarly, the secondary space 37 forming the second portion 58 of each component of the angled joining module 74 is arranged as a continuation of the secondary space 37 of the second tank wall 32, and the primary space 41 forming the second portion 58 of each component of the angled joining module 74 is arranged as a continuation of the primary space 41 of the second tank wall 32. The secondary space 37 forming the second part 58 of the component of each angled joint module 74 is covered, in its part not covered by the primary space, by the primary space 41 of the second tank wall 32 up to the third free edge 68.

The

side walls

30, 32 of the hermetically sealed and insulated tank 26 rest directly on the load-

bearing walls

18, 20 of the internal load-bearing structure 6. As do the exterior faces of the first and second portions of the angled engagement members that extend substantially perpendicularly relative to each other. More specifically, the outer face 29 of the first tank sidewall 30 and the outer face of the first portion 56 of the angled engagement member rest on the first load-bearing wall 18 of the inner load-bearing structure 6 via a bead of glue (not shown), while the outer face 29 of the second tank sidewall 32 and the outer face of the second portion 58 of the angled engagement member rest on the second load-bearing wall 20 of the inner load-bearing structure 6 via a bead of glue (not shown).

The outer face 29 at the intermediate portion 60, which extends in a plane inclined with respect to the main extension plane of the first and second tank side walls, forms a chamfer, thus forming a clearance area 76 between the intermediate portion 60 and the inner load-bearing structure 6 at the joining area 24.

As shown in fig. 4, the internal load-bearing structure 6 has, in this junction zone 24, i.e. at the corner formed between the first load-bearing side wall 18 and the second load-bearing side wall 20, a reinforcing element 78, this reinforcing element 78 being designed to be in contact with the external face 29 of each load-bearing side wall and of the intermediate portion 60. In other words, the inner load-bearing structure 6 is provided with a reinforcing element 78, which reinforcing element 78 is designed to fill the gap region 76. In this case, the reinforcing element 78 has a triangular cross-section similar to the shape of the clearance zone and has a contact surface 80 and an opposite vertex 82, the contact surface 80 forming a stop against the movement of the intermediate portion under the effect of the pressure exerted by the liquefied natural gas in the tank, the vertex 82 having an angle substantially equal to 90 ° to match the shape of the corner of the joining zone 24. Advantageously, the reinforcing element 78 extends mainly along the longitudinal axis a to form a reinforcement member for each angled engagement member 34. The reinforcing element 78 may in particular be a plate forming a longitudinal rib arranged at 135 ° to each bearing wall of the inner bearing structure.

As shown particularly in fig. 4, the contact surface 80 faces the intermediate portion 60 of the angled engagement member 34. In the starting position, no pressure is exerted on the angled engagement member by the liquefied gas, and the reinforcing element 78 and the angled engagement member 34 help to define a space extending from the contact face 80 of the reinforcing element to the outer face 29 of the intermediate portion 60 of the angled engagement member 34. In this case, the space is regular along both faces, i.e. the dimension measured between the contact face 80 and the outer face 29 of the intermediate portion 60 along an axis perpendicular to the main plane containing the contact face 80 and the outer face 29 of the reinforcing element 78 and/or the intermediate portion 60 is constant. In other words, the contact face 80 of the reinforcing element 78 and the outer face 29 of the intermediate portion 60 each lie in a plane parallel to the plane containing the other face.

The pressure exerted by the liquefied gas on the inner face 27 of the intermediate portion 60 includes direct planar contact between the outer face 29 of the intermediate portion 60 and the contact face 80 of the reinforcing element 78.

Thus, the outer faces 29 of the intermediate portions 60 of the plurality of angled engagement members 34 rest on the reinforcing elements 78. The pressure exerted on the inner face 27 of the intermediate portion 60 by the liquefied natural gas stored in the sealed and thermally insulated tank 26 is then more easily distributed on the outer face 29 of each portion of the respective angled joint part 34, the reinforcing elements 78 forming faces at the contact faces substantially perpendicular to the general direction of the liquefied natural gas pressure in this joint area 24 of the tank. Thus, the pressure exerted by the liquefied natural gas stored in the sealed and thermally insulated tank 26 is better distributed and the risk of leaks in the primary sealing membrane 42 is reduced.

Advantageously, such a pressure distribution over the different elements of the sealed, thermally insulated tank 26 and the internal load-bearing structure 6 affects the aforementioned concentration of the

reinforcement members

8, 10, more particularly the concentration of the first plurality of reinforcement members 8 arranged between the outer hull 4 and the first load-bearing wall 18 of the internal load-bearing structure 6, and the concentration of the second plurality of reinforcement members 10 arranged between the outer hull 4 and the second load-bearing wall 20 of the internal load-bearing structure 6.

As shown in particular in fig. 2 and 4, the

reinforcement members

8, 10 are therefore less required in the vicinity of the joining region 24, and only one

first reinforcement member

84, 90 of each plurality of

reinforcement members

8, 10 can be in contact with the

respective carrier wall

18, 20 of the internal carrier structure 6 at the joining region 24, while

several reinforcement members

86, 88, 92, 94 can be in contact with the

carrier wall

18, 20 away from this joining region 24. Thus, the concentration of reinforcement members is reduced near the angled engagement features.

For each plurality of reinforcement members facing one or the other of the

load bearing walls

18, 20, respectively, the

second reinforcement member

86, 92 is positioned between the

first reinforcement member

84, 90 and the

third reinforcement member

88, 94. The reduced concentration of the reinforcement members at the joint area and the angled joint means that the distance separating the

second reinforcement members

86, 92 and the

third reinforcement members

88, 94 is less than the distance separating the

second reinforcement members

86, 92 and the

first reinforcement members

84, 90.

In the example shown in FIG. 4, the

first reinforcement member

84, 90 of each plurality of reinforcement members is in contact with the load-bearing side wall of the inner load-bearing structure 6 at the reinforcing element 78, but this is not a limitation of the present invention.

As shown in fig. 2 and 7, the

first fastener member

84, 90 may be disposed in a region of engagement remote from the reinforcing element, and more particularly, in a region covered by the first or second portion of the angled engagement member.

Each

side wall

18, 20 of the tank may have a proximal region 101 and a distal region 103, the proximal region 101 and the distal region 103 being determined according to their position relative to the nearest joining region 24, the two regions being delimited relative to each other by a dividing line in the extension of the free edge of the secondary space of the angled joining part, in particular the free edge being the second free edge 64 of the first tank side wall 18 and the fourth free edge 70 of the second tank side wall 20. The proximal region 101 is a region between the joining region 24 and the boundary line, and the distal region 103 is a region beyond the boundary line with respect to the joining region. As shown in FIG. 7, only the

first reinforcement members

84, 90 are advantageously located in the proximal region 101, while several of the

reinforcement members

86, 88, 92, 94 are disposed in the distal region 103. As discussed above, the distance between the

first fastener members

84, 90 and the

second fastener members

86, 92 is greater than the distance separating the

second fastener members

86, 92 from the

third fastener members

88, 94.

The first fastener member 84 of the first plurality of fastener members 8 may be laterally aligned, in particular, with the first free edge 62 of the angled engagement member 34, and the first fastener member 90 of the second plurality of fastener members 10 may be vertically aligned, in particular, with the third free edge 68 of the angled engagement member 34.

As shown in fig. 7, at least one first reinforcement member of the plurality of

reinforcement members

8, 10 is located at a distance d from the corner of the internal load-bearing structure 6, i.e. from the apex 82 of the reinforcing element 78 and the

first reinforcement members

84, 90. More specifically, in the example shown, each first reinforcement member of the plurality of reinforcement members is arranged at the distance d from a corner of the inner load-bearing structure 6.

According to a feature of the invention, the angled engagement portion is dimensioned as a function of the positioning of the first reinforcement member and the distance d. More specifically, a dimension D60 of the middle portion 60 measured between the first and second connecting

edges

66, 72 along the exterior face 29 of the middle portion 60 may be calculated as:

in the illustrated example, the dimensions D56, D58 of the first and

second portions

56, 58, respectively, measured between the intermediate portion and the area corresponding to the location of the respective

first fastener members

84, 90, are equal to the previously determined dimension D60 of the intermediate portion. More specifically, the dimension D56 of the first portion 56 is equal to the dimension D60 of the intermediate portion, which dimension D56 of the first portion 56 is in this case measured vertically along the outer surface between the first connecting edge 66 and the contact area with the first reinforcement member 84 of the first plurality of reinforcement members 8 (i.e., flush with the first free edge 62). The dimension D58 of the second portion 58, in this case measured transversely along the outer surface between the second connecting edge 72 and the area of contact with the first fastener member 90 of the second plurality of fastener members 10 (i.e., flush with the third free edge 68), is equal to the aforementioned dimensions D60 and D56.

Thus, the force exerted by the pressure of the liquefied gas is more evenly distributed between the reinforcing element and each tank sidewall in the junction area and the reinforcement member supporting these sidewalls.

In a variant of the embodiment described above, as shown in fig. 8, the contact surface 80 of the reinforcing element 78 has a shape different from the aforementioned flat surface, forming a rounded corner 91 instead of a right angle. More specifically, the contact surface 80 has an advantageously concave curvature such that the space between the contact surface 80 and the reinforcing element 78 and the outer face 29 of the intermediate portion 60 is no longer constant and is greater closer to the center of the intermediate portion 60. This space is filled with one or more spacers 93, for example in the form of panels and/or columns made of plywood, and/or a filler material 95, for example mastic as shown by the hatched area in figure 8, this list not being exhaustive. It should be noted that if the structure of the reinforcement element comprises rounded corners, the structure is easier to produce and is less likely to break at the junction with the load-bearing wall of the load-bearing structure under the pressure exerted by the liquefied gas, the additional presence of the reinforcement material filling the space ensuring a correct transfer of force.

A variant embodiment of the invention is described below with reference to fig. 5 and 6. Each angled joint module 74 described above is arranged to provide a joint between the first tank wall 30 and the second tank wall 32 of the sealed and insulated tank 26. However, the tank 26 may have other tank walls, and the angled joint module 74 according to the present invention may also be designed to be positioned facing the second tank wall joint area.

In this example, the plurality of tank walls also includes a third tank wall or first transverse tank wall 96 that extends in a plane perpendicular to the first side wall 30 and perpendicular to the second side wall 32. Further, the first transverse tank wall 96 is perpendicular to a main extension axis, i.e. the longitudinal axis a, of the plurality of angled engagement members 34.

According to the present invention, each wall of the canister 26 may be connected to another wall of the canister 26 by an angled joint module 74. According to the examples described herein, the joint between the third tank wall 96 and the first tank wall 30 may have an angled joint module 74, as may the joint between the third tank wall 96 and the second tank wall 32.

In this case, the sealed and thermally insulated tank 26 according to the invention comprises an angled engagement element 98, which angled engagement element 98 is different from the angled engagement member 34 in that it comprises a return portion.

As shown in FIG. 5, the angled engagement element 98 has a first portion 100 and a second portion 102. Each of the two

portions

100 and 102 has substantially the same structure as that described above, specifically, from the outer face 29 to the inner face 27, a secondary space 37 including a secondary thermal barrier 36 and a secondary sealing film 38, and a primary space 41 including a primary thermal barrier 40 and a primary sealing film 42.

The secondary insulating barrier 36 comprises, from the outer face 29 to the inner face 27, an insulating wall 44 covered by a first insulating layer 46, followed by a second insulating wall 51, this second insulating wall 51 being particularly present in the angled joining elements for angled joining components as described above. In the first case, the secondary thermal barrier 36 maintains the temperature inside the hermetically insulated tank 26, advantageously when liquefied natural gas is stored therein. The secondary insulating barrier 36 is covered by a secondary sealing film 38.

In the event of a leak of liquefied natural gas in the primary space 41, the secondary sealing membrane 38 retains the liquefied natural gas stored in the sealed, thermally insulated tank 26.

The secondary sealing membrane 38 includes a flexible secondary sealing membrane 48 covering a plurality of rigid secondary sealing membranes 49.

The triple strip forming the first flexible sealing membrane 48 is designed to adhere firstly to the rigid secondary sealing membrane 49, more particularly to cover the joining areas of these rigid membranes, and secondly to the primary insulating barrier 40, preventing contamination at the various joints. Thus, the primary thermal barrier 40 includes a second thermal insulation layer 52 and a third thermal insulation wall 54 from the outer face 29 to the inner face 27. The primary insulating barrier 40 is covered by a primary sealing film 42.

As described above, the angled engagement element 98 includes a first portion 100 and a second portion 102. The first portion 100 of the angled engagement element 98 is arranged to align and mate with the plurality of angled engagement modules or

components

74, 34 and the first and second

tank side walls

30, 32. The second portion 102 of the angled engagement member 98 is perpendicular to the first portion 100 so as to face the first transverse tank wall 96.

As with the angled engagement member 34, the first portion 100 of the angled engagement element 98 includes a first section 104, a second section 106, and at least one intermediate section 108.

The first section 104 of the angled engagement element 98 lies predominantly in a plane parallel to the main plane of extension of the first tank side wall 30 and the first portion 56 of the angled engagement member 34, and as mentioned above, the primary and

secondary spaces

41, 37 are not of the same size both relative to the longitudinal axis a and relative to the vertical axis C, it being understood that the main plane of extension of the first tank side wall 30 extends longitudinally and vertically in this case.

The first section 104 has a first free end edge 110 and a second free end edge 112, which are perpendicular to each other. The secondary space 37 of the first section 104 is not covered by the primary space 41 in the vicinity of the first free end edge 110 and in the vicinity of the second free end edge 112.

The second segment 106 is shaped the same as the first segment 104, having a third free end edge 116 and a fourth free end edge 118. Also, in the vicinity of the third and fourth free end edges, the secondary space 37 is not covered by the primary space 41.

The first and

second sections

104, 106 of the angled engagement element 98 extend primarily in mutually perpendicular planes. The first section 104 is not adjacent to the second section 106 due to the presence of the intermediate section, which is rigidly connected to the first and

second sections

104, 106 at the respective connecting

sides

114, 120.

The intermediate section 108 extends mainly in an inclined plane which firstly intersects the main extension plane of the first section 104 and secondly the main extension plane of the second section 106. The intersecting planes are parallel to the longitudinal axis a and are oriented so as to advantageously form an angle of about 135 ° with each of the aforementioned main extension planes. Thus, the intermediate section 108 advantageously intersects the first section 104 at an angle of about 135 °, while also advantageously intersecting the second section 106 at an angle of about 135 °.

At the fifth free side 115 of the middle section 108, the secondary space 37 is not covered by the primary space 41. In practice, the primary space 41 and the secondary space 37 do not extend along the longitudinal axis a for the same length. The primary space 41 is shorter than the secondary space 37 along the longitudinal axis a towards the fifth free side 115 of the intermediate section 108. Thus, the secondary sealing film 38 is uncovered on the fifth free side 115, without overlapping or adhesive elements.

Also, the size of the intermediate section 108 increases with distance from the inner face 27, particularly for better distribution of the pressure exerted by the liquefied natural gas in the tank, as described above. It should be noted that in this variant embodiment, the intermediate section 108 is again opposite to the clearance zone, which may be filled with a reinforcing element against which the engaging elements abut at the outer face of the intermediate section. Furthermore, the stiffening element may have contact faces extending in a plane or forming rounded corners, as described above, and the middle section 108 may comprise a spacer and/or a filling material to fill the space between the outer face 29 of the stiffening element and the contact faces.

The second portion 102 of the engaging element 98 extends mainly in a plane perpendicular to the longitudinal axis a, i.e. in a plane perpendicular to each section of the first portion 100 of the engaging element. In other words, the second section 102 of the angled engagement element 98 forms a return portion of the first portion 100 of the vertically extending angled engagement element 98.

More specifically, the second portion 102 includes a return wall 121, the return wall 121 having a free lateral side 122, a connecting lateral side 124, a free vertical side 126, and a connecting vertical side 128. The free lateral side 122 and the connecting lateral side 124 extend along a lateral axis B perpendicular to the longitudinal axis a and the vertical axis C, while the free vertical side 126 and the connecting vertical side 128 extend along the vertical axis C. The second portion 102 is rigidly connected to the first portion 100 at connecting lateral sides 124 and connecting vertical sides 128.

At the free lateral side 122 and the free vertical side 126 of the second portion 102 of the angled engagement element 98, the secondary space 37 is not covered by the primary space 41. In fact, the primary space 41 and the secondary space 37 do not extend along the transverse axis B and along the vertical axis C for the same length. As mentioned above, the primary space 41 is shorter than the secondary space 37, in this case shorter along the transverse axis B towards the free vertical side 126, and also shorter along the vertical axis C towards the free transverse side 122.

The angled joint element 98 according to the invention aims at optimizing the distribution of the pressure exerted by the liquefied natural gas on the joining zones of the walls forming the tank 26, in particular due to the shape of the intermediate section 108 and the clearance zones between this section and the joining sections of the carrying

walls

18, 20, while forming a connection between the first transverse tank wall 96 and the plurality of angled joint modules 74. The pressure exerted by the liquefied natural gas stored in the sealed, thermally insulated tank 26 on the inner face 27 at the intermediate section 108 of the angled engagement element 98 is distributed over the angled engagement element 98 up to a return wall 121 extending opposite the first transverse tank wall 96.

The primary space 41 of the first portion 100 and the primary space of the second portion 102 of the angled engagement element 98 may be integral with one another. In particular, the primary sealing film 42 of the first portion 100 may be welded to the primary sealing film 42 of the second portion 102, or made as a single element.

As shown in FIG. 6, the first portion 100 of the angled engagement element 98 is designed to contact the angled engagement member 34 of the angled engagement module 74. The first, second, and

intermediate portions

56, 58, 60 of the angled engagement module 74 closest to the angled engagement element 98 are aligned with the first, second, and

intermediate sections

104, 106, 108, respectively, of the first portion 100 of the angled engagement element 98. More specifically, the secondary space 37 of the angled engagement element 98 is in contact with the secondary space of the angled engagement module 74. To rigidly connect the angled engagement element 98 to the angled engagement module 74, a primary space panel 41 (not shown) is secured by gluing and welding to the secondary space 37 between the primary space 41 associated with the angled engagement module 74 and the primary space 41 associated with the angled engagement element 98.

The first section 104 of the angled engagement element 98 and the first portion 56 of the angled engagement member 34 are designed to contact the first tank sidewall 30. The angled engagement element 98 and the angled engagement member 34 are secured to the first tank sidewall 30 in a manner similar to the securing of the angled engagement element 98 with the nearest angled engagement module 74. The panels of the primary space 41 are glued and welded at the connections between the first tank sidewall 30 and the angled engagement elements 98 and the plurality of angled engagement members 34.

The second section 106 of the angled engagement element 98 and the second section 58 of the angled engagement member 74 are designed to contact the second can sidewall 32. The angled engagement element 98 and the angled engagement member 34 are secured to the second tank sidewall 32 in a manner similar to the securing of the angled engagement element 98 with the nearest angled engagement module 74. The panels of the primary space 41 are glued and welded at the connections between the second tank sidewall 32 and the angled engagement elements 98 and the plurality of angled engagement members 34.

The first tank sidewall 30, the second tank sidewall 32 and the first transverse tank wall 98 are rigidly connected to one another by a first conventional engagement element 130 and a second conventional engagement element 132, respectively, made in a known manner.

The first conventional engagement element 130 and the second conventional engagement element 132 each have two portions. Each portion of the engaging element is perpendicular to each other and each portion extends in a main plane containing one of the tank walls mentioned above.

Thus, the angled engagement element 98 contacts at least one of the ends of at least one conventional engagement element 130. In the example shown, the angled engagement element 98 is in contact first with the closest angled engagement module 74 and second with the first and second

conventional engagement elements

130, 132.

According to a variant embodiment not shown, the seal can according to the invention can be made so that a third or first transverse wall 96, perpendicular to the first 30 and second 32 side walls, is connected to each of these walls by an angled joint module 74. In this case, the angled engagement elements 98 arranged at the junctions of these three walls are noteworthy in that an intermediate portion similar to that described above is arranged between the sections of the angled engagement elements of each of the extension walls. The angled engagement element is thus adapted to have a shape similar to the first portion as described above at each of the joints of the two walls, and it should be noted that in this case the reinforcement member 78 provided to fill the gap between the angled engagement element and the inner load bearing structure 6 has a pyramidal shape.

Claims

1. A sealed and thermally insulated tank (26) designed to rest on a load-bearing structure (6) of a ship, the sealed tank (26) comprising a plurality of tank walls, including a first tank wall (30) and at least one second tank wall (32), the first tank wall (30) extending mainly in a first plane, the second tank wall (32) extending mainly in a second plane, the first and second planes being mutually perpendicular, the first tank wall (30) and the second tank wall (32) being connected by an angled joint part (34), characterized in that the angled joint part (34) has a first portion (56) extending mainly in the first plane, a second portion (58) extending mainly in the second plane, and at least one intermediate portion (60) extending mainly in an intersecting plane intersecting the first and second planes, a first portion (56) of the angled engagement member (34) has a thickness equal to a thickness of the first tank wall (30) and is arranged to extend the first tank wall (30), and a second portion (58) of the angled engagement member (34) has a thickness equal to a thickness of the second tank wall (32) and is arranged to extend the second tank wall (32).

2. The sealable tank (26) of claim 1, wherein the sealable tank (26) has at least one third tank wall (96), said at least one third tank wall extending mainly in a third plane perpendicular to said first plane, said second plane and said intersecting plane, and having a joining region with the first tank wall (30) and the second tank wall (32), wherein the engagement zone has an angled engagement element (98), the angled engagement element (98) having a first portion (100) and a second portion (102), the first portion (100) having a first section (104) extending mainly in the first plane, a second section (106) extending mainly in the second plane, and an intermediate section (108) extending mainly in the intersecting plane, the second portion (102) has a return wall (121) perpendicular to the first portion (100) and extending mainly in the third plane.

3. A sealable tank (26) according to claim 1 or 2, wherein the angled joint part (34) and/or the angled joint element (98) each have an inner face (27) and an outer face (29), the inner face (27) forming an inner chamfer at the intermediate portion (60) or the intermediate section (108), the outer face (29) forming an outer chamfer at the intermediate portion (60) or the intermediate section (108), the inner and outer chamfers being inclined at an angle of between 120 ° and 150 ° relative to the first and second planes.

4. The seal pot (26) of claim 3, wherein a dimension of the intermediate portion (60) of the angled engagement member (34) measured between the first and second portions (56, 58) of the angled engagement member (34), and/or a dimension of the intermediate section (108) of the angled engagement element (98) measured between the first and second sections (104, 106) of the angled engagement element (98), increases from the inner face (27) toward the outer face (29).

5. The sealable tank (26) according to any one of the preceding claims, wherein the angled engagement member (34) and/or the angled engagement element (98) comprise, in order in the thickness direction from the outside to the inside of the sealable tank, a secondary insulating barrier (36) designed to be in contact with the load-bearing structure (6), a secondary sealing membrane (38) carried by the secondary insulating barrier (36), a primary insulating barrier (40) resting on the secondary sealing membrane (38), and a primary sealing membrane (42) carried by the primary insulating barrier (40), the primary insulating barrier (40) being designed to be in contact with a fluid contained in the sealable tank (26).

6. The seal pot (26) of claim 5, wherein the angled engagement member (34) and/or the secondary insulating barrier (36) and the secondary sealing membrane (38) of the angled engagement element (98) each have a dimension in a given direction that is greater than a corresponding dimension of the primary insulating barrier (40) and the primary sealing membrane (42) in the same direction.

7. The sealable canister (26) according to any of the preceding claims, wherein the first portion (56) and/or the second portion (58) of the angled engagement member (34) has a dimension (D56, D58) equal to the dimension (D60) of the intermediate portion (60).

8. A ship (200) comprising at least one seal pot (26) according to any one of the preceding claims.

9. Vessel according to claim 8, with an outer hull (4) and a load-bearing structure (6), the load-bearing structure (6) being designed to receive the seal pot (26), the load-bearing structure (6) having a first load-bearing wall (18) extending mainly along the first plane and a second load-bearing wall (20) extending mainly along the second plane, the first load-bearing wall (18) and the second load-bearing wall (20) being substantially perpendicular, characterized in that a clearance area is provided between the load-bearing structure load-bearing wall and the intermediate portion (60) of the angled joint part (34) in the joint area (24), and in that the stiffening element (78) is located in the clearance area.

10. Vessel according to claim 9, wherein the reinforcing element (78) has a triangular cross section and the angle of the apex (82) of the reinforcing element (78) is equal to the right angle formed between the first load-bearing wall (18) and the second load-bearing wall (20), the reinforcing element having a contact face (80) opposite the apex in contact with the intermediate portion (60).

11. Vessel according to claim 10, wherein the contact face (80) has a multi-faceted profile, formed by a plurality of flat surfaces inclined with respect to each other, so as to form a profile curved towards the inside of the reinforcing element (78).

12. Vessel according to claim 10, wherein the contact surface (80) has a curved profile such that the stiffening element (78) has a substantially concave shape.

13. Vessel according to any of the claims 9 to 12, wherein the outer hull (4) has a plurality of reinforcement members (8, 10) in contact with the load-bearing structure (6), and the reinforcement members (8, 10) are less concentrated near the angled joint part (34) and/or near the angled joint element (98).

14. Vessel according to claim 13, wherein the intermediate portion (60) of the angled junction part (34) is dimensioned (D60) as a function of the position of the reinforcement member (8, 10) closest to the corner of the load-bearing structure (6) in which the angled junction part (34) is located.

15. Method for loading or unloading liquefied natural gas into or from a tank (26) according to any one of claims 1 to 7 or a vessel (20) according to any one of claims 8 to 14.