FR3100306A1 - Sealed and thermally insulating tank with anti-convective insulating gaskets - Google Patents

Abstract

The invention relates to a sealed and thermally insulating tank comprising a first insulating panel (4, 23) and a second adjacent insulating panel (4, 24) delimiting an inter-panel space (11), the tank further comprising: - a first insulating joint (16) housed in the inter-panel space (11), said first insulating joint (16) comprising an internal portion (19) and an external portion (18), and - a second insulating joint (17) housed in the inter-panel space (11) and juxtaposed along a width direction (14) of the inter-panel space (11) with one of the internal portion (19) and the external portion (18) of the first joint insulation (16), - a spacer (22) inserted between the first insulating joint (16) and the second insulating joint (17) so as to exert a bearing on the insulating joints (16, 17) in the direction of the panels insulation (4, 23, 24), and in which an inter-joint space (21) in which the spacer (22) is housed is delimited by the second insulating joint (17), the inner portion (19) of the first insulating joint (16) and the outer portion (18) of the first insulating joint (16). Figure to be published: 2

Description

Watertight and thermally insulated tank with anti-convective insulating joints

The invention relates to the field of sealed and thermally insulating membrane tanks. In particular, the invention relates to the field of sealed and thermally insulating tanks for the storage and/or transport of liquefied gas at low temperature, such as tanks for the transport of Liquefied Petroleum Gas (also called LPG) having for example a temperature between -50°C and 0°C, or for the transport of Liquefied Natural Gas (LNG) at around -162°C at atmospheric pressure. These tanks can be installed on land or on a floating structure. In the case of a floating structure, the tank may be intended for the transport of liquefied gas or to receive liquefied gas used as fuel for the propulsion of the floating structure.

In one embodiment, the liquefied gas is LNG, namely a mixture with a high methane content stored at a temperature of approximately -162°C at atmospheric pressure. Other liquefied gases can also be considered, in particular ethane, propane, butane or ethylene. Liquefied gases can also be stored under pressure, for example at a relative pressure of between 2 and 20 bar, and in particular at a relative pressure close to 2 bar. The tank can be made using different techniques, in particular in the form of an integrated membrane tank or a self-supporting tank.

Technology background

A wall structure has been described, for example in document FR2724623 or document FR2527544, for producing the flat wall of a sealed and thermally insulating tank. Such a tank wall comprises a multilayer structure comprising, from the outside of the tank towards the inside of the tank, a secondary thermally insulating barrier, a secondary sealed membrane, a primary thermally insulating barrier and a primary sealing membrane intended to be in contact with the liquid contained in the tank. Such tanks comprise insulating panels juxtaposed so as to form thermally insulating barriers. In addition, in order to ensure continuity of the insulating characteristics of said thermally insulating barriers, insulating joints are inserted in the inter-panel spaces formed by the adjacent insulating panels.

However, during operation of the vessel, it is desirable to prevent the thermally insulating barrier from having channels developing over the entire thickness of the thermally insulating barrier. The presence of such channels could be linked to numerous causes, for example due to the manufacturing tolerances of the insulating panels, the insulating joints or even due to thermal contraction when the vessel is cooled, for example during loading LNG at -162°C into the tank. Such channels would promote natural convection in the thermally insulating barrier, in particular when these channels have a vertical component with respect to the earth's gravity and can generate a thermosiphon phenomenon reducing the insulating characteristics of the thermally insulating barrier.

Summary

An idea underlying the invention is to propose a sealed and thermally insulating tank in which the phenomena of convection in the thermally insulating barriers are effectively prevented. An idea underlying the invention is to provide a sealed and thermally insulating tank limiting the presence or appearance of channels developing over the entire thickness of the thermal insulation barriers in order to limit the phenomena of natural convection in said thermal insulation barriers. In particular, an idea underlying the invention is to limit the presence or appearance of such channels in the inter-panel spaces separating two adjacent insulating panels. An idea underlying the invention is also to facilitate the manufacture of such a tank. In particular, an idea underlying the invention is to facilitate the insertion of insulating joints in the inter-panel spaces and to effectively fill the inter-panel spaces.

According to one embodiment, the invention provides a sealed and thermally insulating tank comprising a supporting structure and a thermally insulating barrier anchored to the supporting structure, the thermally insulating barrier comprising a first insulating panel and a second adjacent insulating panel, an interspace -panels being delimited between the first insulating panel and the second insulating panel, the tank further comprising:
- a first insulating joint housed in the inter-panel space, said first insulating joint comprising an internal portion and an external portion superimposed along the direction of thickness of the thermally insulating barrier, and
- a second insulating joint housed in the inter-panel space, the second insulating joint being juxtaposed along a width direction of the inter-panel space with one of the internal portion and the external portion of the first insulating joint,
- a spacer inserted along the width direction of the inter-panel space in an inter-joint space between the first insulating joint and the second insulating joint so as to exert a bearing on the first insulating joint in the direction of the first insulating panel and a support on the second insulating joint in the direction of the second insulating panel,
and wherein the other of the inner portion and the outer portion of the first insulating joint is overlapped with said inter-joint space, and wherein the said other of the inner portion and the outer portion of the first insulating joint closes one end of the space inter-joints in the thickness direction of the thermally insulating barrier so that the inter-joint space in which the spacer is accommodated is delimited by the second insulating joint, the inner portion of the first insulating joint and the portion external of the first insulating joint.

Such a sealed and thermally insulating tank has good insulation characteristics of the thermally insulating barrier. In particular, such a tight and thermally insulating tank makes it possible to limit convection phenomena in the thermally insulating barrier. Indeed, the spacer makes it possible to guarantee the support of the first insulating joint and the second joint on the insulating panels so that the insulating joints fill the entire width of the inter-panel space. This therefore avoids the presence or formation of channels favoring natural convection. In particular, this spacer avoids the presence or the formation of channels between the first insulating joint and the first insulating panel on the one hand and, on the other hand between the second insulating joint and the second insulating panel. In addition, the superposition of the inter-joint space and of the other among the internal portion and the external portion of the first insulating joint makes it possible to limit the height, according to the direction of thickness of the thermally insulating barrier, of the inter-joint space in which the spacer is housed. Convection phenomena in the inter-panel space are therefore limited, the inter-panel space not being able to present channels developing over the entire thickness of the thermally insulating barrier.

In addition, the installation of such insulating joints are simple and easy to install due to the reduced size of the insulating joints and due to their positioning in only a portion of the inter-panel space.

According to embodiments, such a sealed and thermally insulating tank may comprise one or more of the following characteristics.

According to one embodiment, the inter-joint space is made between the inner portion of the first insulating joint and the second insulating joint and the spacer has a shape that widens from its outer end towards its inner end of so as to be able to be inserted through an internal end of the inter-panel space.

Thanks to these characteristics, the inter-joint space is located in an internal portion of the inter-panel space and has an opening at the level of the internal end of the inter-panel space. Thus, it is possible to insert the spacer simply and quickly into the inter-joint space directly from above the inter-panel space.

According to one embodiment, the spacer widens progressively from its outer end towards its inner end.

According to one embodiment, the outer end of the spacer forms a point. According to one embodiment, the spacer has a "V" shaped section.

Thanks to these features, the spacer is easy to insert into the inter-panel space. In particular, the spacer can be easily inserted from above the inter-panel space by causing its thinnest end, typically its outer end, to penetrate first into the inter-panel space.

According to one embodiment, the spacer piece is an elastic piece.

Thanks to these characteristics, the spacer changes from a free state to a compressed state simply by inserting it into the inter-joint space from above the inter-panel space.

According to one embodiment, the first insulating panel and the second insulating panel comprise a rigid cover plate developing directly above the inter-panel space, the spacer having a compressed state in which a width of the spacer, taken along the width direction of the inter-panel space, is less than the width of a passage separating the cover plate of the first insulating panel and the cover plate of the second insulating panel so as to be able to be inserted into the inter-panel space through said passage and, when the spacer is seated in the inter-panel space interposed between the first insulating joint and the second insulating joint, a semi-compressed state in which the spacer is compressed between the first insulating joint and the second insulating joint and exerts pressure on the first insulating joint in the direction of the first insulating panel and pressing on the second insulating joint in the direction of the second insulating panel. Thus, the insulating panels present a good support surface for the waterproof membrane. Furthermore, the insertion of the spacer between the cover plates of the insulating panels is sufficient to change said spacer from its free state to its compressed state.

According to one embodiment, the spacer also has a free state in which the assembly formed by the spacer in said free state, the first insulating joint in a free state and the second insulating joint in a state free has a width, taken along the width direction of the inter-panel space, greater than the width of said inter-panel space.

According to one embodiment, the spacer is a metal blade having a bent portion and, on either side of the bent portion, two portions joined elastically by said bent portion.

According to one embodiment, the spacer is a rigid wedge-shaped piece. Such a spacer makes it possible, by the simple fact of its shape and its insertion in the inter-joint space, to spread and compress the insulating joints against the insulating panels.

According to one embodiment, the cumulative width on the one hand of said one of the internal portion and the external portion of the first insulating joint and, on the other hand, of the second insulating joint, according to the width direction of the interspace -panels, is less than the width of the inter-panel space.

According to one embodiment, the cumulative width on the one hand of said one of the internal portion and the external portion of the first insulating joint and, on the other hand, of the second insulating joint, according to the width direction of the interspace -panels and in a free state of said one of the inner portion and the outer portion of the first insulating joint and of the second insulating joint, is less than the width of the inter-panel space

Thanks to these characteristics, the insulating joints are easy to accommodate in the inter-panel space. In addition, such insulating joints allow the spacer to be easily accommodated in the inter-joint space.

According to one embodiment, said other of the inner portion and the outer portion of the first insulating joint fills the entire width of the inter-panel space, apart from any assembly play.

According to one embodiment, said other of the internal portion and the external portion of the first insulating joint has a width taken along the width direction of the inter-panel space greater than the width of said one of the internal portion and the external of the first insulating joint.

According to one embodiment, said other of the inner portion and the outer portion of the first insulating joint is compressed along the width direction of the inter-panel space between the first insulating panel and the second insulating panel.

Thus, the presence or appearance of channels developing along the direction of thickness of the thermally insulating barrier is limited at the level of the portion of the inter-panel space in which said other of the internal portion and the portion is housed. external of the first insulating joint.

According to one embodiment, the second insulating joint is generally parallelepipedic in shape. According to one embodiment, the internal portion of the first insulating joint is generally parallelepipedic in shape. According to one embodiment, the outer portion of the first insulating joint is generally parallelepipedic in shape. Such parallelepipedic joints are easy to handle and accommodate in the inter-panel space. In addition, such parallelepipedic joints have large cooperation surfaces with the adjacent insulating panels, avoiding the presence or appearance of channels along the thickness direction of the thermally insulating barrier. By globally parallelepipedal is meant the fact that an element has a parallelepipedic shape with the exception of any local deformations such as a recess to accommodate a cleat or a local protrusion to match the shape of another element, for example.

According to one embodiment, the first insulating joint and the second insulating joint are movable relative to each other in the width direction of the inter-panel space. According to one embodiment, the first seal and the second seal are formed by two distinct and independent blocks. Thus, each of said seals has a reduced size facilitating its handling and its positioning in the inter-panel space.

According to one embodiment, the first seal and the second seal are mounted sliding relative to each other in the inter-panel space.

According to one embodiment, the invention also provides a method for mounting a thermally insulating barrier of a sealed and thermally insulating tank on a support structure, comprising:
- anchor a first insulating panel on the supporting structure,
- arranging a first insulating joint against a side wall of the first insulating panel, said first insulating joint comprising an internal portion and an external portion superimposed along the thickness direction of the thermally insulating barrier,
- arranging a second insulating joint in juxtaposed fashion, in a direction perpendicular to the side wall of the first insulating panel, to one of the inner portion and the outer portion of the first insulating joint so as to form an inter-joint space between said second gasket and said one of the inner portion and the outer portion of the first insulating gasket, the other of the inner portion and the outer portion of the first insulating gasket being superposed on said inter-joint space and closing one end of said inter-joint space in the thickness direction of the thermally insulating barrier so that the inter-joint space is delimited by the second insulating joint, the internal portion of the first insulating joint and the external portion of the first insulating joint,
- anchoring a second insulating panel to the load-bearing structure adjacent to the first insulating panel so that the first insulating panel and the second insulating panel delimit an inter-panel space in which the first insulating joint and the second insulating joint are housed,
- inserting into said joint space a spacer, said spacer being inserted through one end of the inter-joint space so that the spacer is interposed along the width direction of the inter-space panels between the first insulating joint and the second insulating joint and exerts a bearing on the first insulating joint in the direction of the first insulating panel and a bearing on the second insulating joint in the direction of the second insulating panel.

Such a tank can be part of an onshore storage facility, for example to store LNG or be installed in a floating, coastal or deep water structure, in particular an LNG carrier, a floating storage and regasification unit (FSRU) , a floating production and remote storage unit (FPSO) and others. Such a tank can also serve as a fuel tank in any type of ship.

According to one embodiment, the invention also provides a vessel for the transport of a cold liquid product comprises a double hull and a aforementioned tank arranged in the double hull.

According to one embodiment, the invention also provides a method for loading or unloading such a ship, in which a cold liquid product is conveyed through insulated pipes from or to a floating or terrestrial storage installation to or from the ship's tank.

According to one embodiment, the invention also provides a transfer system for a cold liquid product, the system comprising the aforementioned vessel, insulated pipes arranged so as to connect the tank installed in the hull of the vessel to a floating storage installation or land and a pump to cause a flow of cold liquid product through the insulated pipes from or to the floating or land storage facility to or from the tank of the ship.

Brief description of figures

The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely by way of illustration and not limitation. , with reference to the accompanying drawings.

Figure 1 is a schematic perspective view of a sealed and thermally insulating vessel portion with cutaway,

FIG. 2 is a sectional view of a portion of the thermally insulating barrier illustrated in FIG. 1 at the level of an inter-panel space within the framework of a sealed and thermally insulating tank at ambient temperature,

FIG. 3 is a sectional view of a portion of the thermally insulating barrier illustrated in FIG. 1 at the level of an inter-panel space within the framework of a sealed and thermally insulating tank at low temperature, that is to say i.e. when the inside of the vessel contains cryogenic liquid such as Liquefied Natural Gas and comprising an alternative embodiment of the spacer,

FIG. 4 is a cutaway schematic representation of an LNG carrier tank and a loading/unloading terminal for this tank.

By convention, the terms "external" and "internal" are used to define the relative position of one element to another, with reference to the inside and outside of the vessel. Thus, an element close to or facing the inside of the tank is qualified as internal as opposed to an element close to or facing outside the tank which is qualified as external.

A sealed and thermally insulating tank for the storage and transport of a cryogenic fluid, for example Liquefied Natural Gas (LNG) comprises a plurality of tank walls each having a multilayer structure.

Figure 1 partially shows a vessel wall portion having such a multilayer structure. Such a multilayer structure comprises, from the outside towards the inside of the tank, a thermally insulating barrier 1 resting against a supporting structure 2 and a sealed membrane 3 resting against the thermally insulating barrier.

The load-bearing structure 2 can in particular be a self-supporting sheet metal or, more generally, any type of rigid partition having suitable mechanical properties. The load-bearing structure can in particular be formed by the hull or the double hull of a ship. The support structure comprises a plurality of walls defining the general shape of the tank, usually a polyhedral shape.

Furthermore, the thermally insulating barrier can be made in many ways, in many materials. In FIG. 1 for example, the thermally insulating barrier 1 comprises a plurality of insulating panels 4 of parallelepipedal shape. More particularly, in the example illustrated in Figure 1, each insulating panel 4 is made in the form of a wooden box comprising a bottom plate 5, a cover plate 6 and side walls 7 now spaced apart and parallel bottom plate 6 and the cover plate 7. An insulating gasket 8 is housed in the internal space of the box delimited by the bottom plate 5, the cover plate 6 and the side walls 7. In addition, internal veils can be accommodated in this internal space and develop between the bottom plate 5 and the cover plate 6 in order to provide said insulating panel 4 with good resistance to stress. As illustrated in Figure 1, the cover plate 6 has on its internal face anchoring strips 8 allowing the anchoring of corrugated metal plates 9.

In order to form the thermally insulating barrier 1, such insulating panels 4 are juxtaposed in a regular pattern on the supporting structure 2. These insulating panels 4 anchored on the supporting structure 2 by anchoring members 10 fixed on the supporting structure 2.

As illustrated in Figure 1, the waterproof membrane 3 is formed by a plurality of corrugated metal plates 9. These metal plates 9 are anchored to the insulating panels 4 by welding to the anchor strips 8.

Other details on the structure and the arrangement of the thermally insulating barrier 1, of the sealed membrane 3 as well as on the anchoring of the thermally insulating barrier 1 are for example described in the documents WO2017064413 A1 or WO2017064423 A1.

As illustrated in FIG. 1, the juxtaposition of the insulating panels 4 to form the secondary thermally insulating barrier 1 generates the presence, between two adjacent insulating panels 4, of inter-panel spaces 11. In other words, an inter-panel space 11 separates the side walls 7 facing two adjacent insulating panels 4.

In order to ensure the continuity of the insulation in the secondary thermally insulating barrier 1, an insulating gasket is inserted in the inter-panel spaces 11 separating the side walls 7 vis-à-vis the adjacent insulating panels 4.

The description below with regard to Figures 2 and 3 is made in the context of an insulating gasket housed in an inter-panel space 11, this description applying to one, several or all of the insulating gaskets arranged in the inter-spaces -panels 11 of the secondary thermally insulating barrier 1. In addition, in this description, the width of an element is considered according to the width direction of the inter-panel space 11 and the thickness of an element is considered according to a direction of thickness of the thermally insulating barrier 1.

Figure 2 illustrates the inter-panel space 11 between two adjacent insulating panels 4.

In this figure 2, the bottom plates 5 of the insulating panels 4 project beyond the side walls 7. Thus, the bottom plates 5 each form a rim 12 on which is arranged a cleat 13. This cleat 13 forms a bearing surface to cooperate with a support member (not illustrated in FIG. 2) in order to anchor the insulating panel 4 to the supporting structure 2. This cleat 13 preferably develops on a reduced portion of the rim 12, typically the necessary portion and sufficient to form the bearing surface for the anchoring member, as explained above or in the documents WO2017064413 A1 or WO2017064423 A1.

Likewise, in order to provide the largest possible support surface for the secondary waterproof membrane 3, the cover plates 6 also project beyond the side walls 7. Thus, when the insulating panels 4 are anchored to the supporting structure 2, the plates cover 6 of the insulating panels 4 are adjacent in such a way and separated by a space of reduced size compared to the width 14 of the inter-panel space 11. This space forms a passage 15 as explained below.

The insulating gasket housed in the inter-panel space comprises a first insulating joint 16 and a second insulating joint 17.

The first insulating joint 16 has an outer portion 18 and an inner portion 19.

The outer portion 18 of the first insulating joint 16 has a shape complementary to the shape of an outer portion of the inter-panel space 11. Typically, the outer portion 18 has a parallelepipedal shape with a width substantially equal to the width 14 of the inter-panel space 11. In addition, the outer corners, that is to say at the level of the bottom plates 5 of the insulating panels 4, of the outer portion 18 have recesses to accommodate the cleats 13, as illustrated in Figures 2 and 3. This outer portion 18 develops towards the supporting structure 2 substantially up to the bottom plates 5 of the insulating panels 4, with the exception of the recesses in which the cleats 13 are housed. The outer portion 18 further has a substantially planar internal face 20.

In order to allow the circulation of inert gas, for example nitrogen, in the thermally insulating barrier 1, the side walls 7 of the insulating panels 4 may have orifices 28 for gas circulation. The outer portion 18 of the first insulating joint 16 may also have one or more passages (not shown) developing along the width direction 14 of the inter-panel space 11 to facilitate the circulation of inert gas in the thermally insulating barrier 1 at the through said external portion 18. Such passages in the external portion 18 developing along the width direction 14 of the inter-panel space 11 have only a small thickness along the thickness direction of the thermally insulating barrier 1 so that they do not form sufficient spaces to be able to generate convection problems in the thermally insulating barrier 1.

The internal portion 19 of the first seal 16 develops from the internal face 20 of the external portion 18 in the direction of the cover plates 6 of the insulating panels 4. This internal portion 19 has a width less than the width of the external portion 18, and therefore less than the width 14 of the inter-panel space 11. Thus, in the example illustrated in FIGS. 2 and 3, the internal portion 19 has a width slightly less than the width of the portion of the cover plate 6 projecting from the side wall 7 of an insulating panel 4. In addition, this internal portion 19 develops at one side of the external portion 18 so as to be housed on only one side of the inter-panel space 11. Thus, the internal portion 19 is housed in the inter-panel space 11 interposed, along the direction of thickness of the secondary thermally insulating barrier 1, between said projecting portion of the cover plate 6 and the external portion 18.

The second insulating seal 17 has a parallelepipedic shape. Analogously to the internal portion 19 of the first insulating joint 16, the second insulating joint 17 has a width less than the width of the inter-panel space 11. Similarly, the second insulating joint 17 develops over a thickness substantially equal at the distance separating the internal face 20 from the external portion 18 of the first insulating joint 16 and the cover plate 6 of an insulating panel 4.

This second insulating joint 17 is movable relative to the first joint 16 and, in particular, movable relative to the internal portion 19 of the first insulating joint 16. By movable is meant the fact that there is a relative displacement in the direction of width, by elastic deformation, by sliding or otherwise, between the second insulating joint 17 and the first insulating joint 16. Thus, in the embodiment illustrated in FIG. 2, the second insulating joint 17 and the first insulating joint 16 are not not one-piece and are made from two separate parts.

The inner portion 19 of the first insulating joint 16 and the second joint 17 have a combined width less than the width 14 of the inter-panel space 11. The second insulating joint 17 and the inner portion 19 of the first insulating joint 16 are juxtaposed in the width of the inter-panel space 11. More particularly, said internal portion 19 and the second insulating joint 17 are juxtaposed along the width direction of the inter-panel space 11 with an inter-joint space separating said internal portion 19 and said second seal 17.

Thus, the internal portion 19 of the first insulating joint 16, the second insulating joint 17 and the internal face 20 of the external portion 18 of the first insulating joint 16 together form a housing 21. In addition, the internal portion 19 of the first insulating joint 16 and the second insulating joint 17 are arranged on the sides of the inter-panel space 11, typically in contact with the side walls 7 delimiting the inter-panel space 11, so that the housing 21 is arranged in line with the passage 15 formed by the space separating the cover plates 6 from the adjacent insulating panels 4.

A spacer 22 is housed in the housing 21. This spacer 22 is inserted, along the width direction of the inter-panel space 11, between the internal portion 19 of the first insulating joint 16 and the second joint insulation 17. This spacer 22 has the function of separating the internal portion 19 of the first insulating joint 16 and the second insulating joint 17 in order to press said internal portion 19 against the side wall 7 of one of the insulating panels 4 and pressing the second insulating joint 17 against the other insulating panel 4.

By pressing the internal portion 19 of the first insulating joint 16 against the side wall 7 of one of the insulating panels, the spacer 22 avoids the presence or the appearance of a channel developing along the thickness direction of the secondary thermally insulating barrier 1 in the inter-panel space 11 between said internal portion 19 and said side wall 7. The same reasoning applies for the plating of the second insulating joint 17 on the side wall 8 of the other insulating panel 4 by said spacer 22.

When mounting the secondary thermally insulating barrier 1, due to the overhanging portions of the cover plates 6, it is difficult to insert and correctly position the insulating seals 16 and 17 through the passage 15. In addition, the presence of the cleats 13 also makes it difficult to insert and position said insulating joints 16 and 17 from the side of the inter-panel space 11.

Consequently, after a first insulating panel 23 has been anchored to the load-bearing structure 2, the first insulating joint 16 is arranged against the side wall 8 of said first insulating panel 23 prior to the anchoring of a second adjacent insulating panel 24 .

Secondly, the second insulating joint 17 is then arranged so as to rest on the inner face 20 of the outer portion 18 of the first insulating joint 16. The positioning of the second insulating joint 17 on said inner face 20 is carried out so as to that a forming space separates the internal portion 19 of the first insulating joint 16 and said second insulating joint 17 in order to form the housing 21.

Then, in a third step, the second insulating panel 24 is mounted and anchored on the supporting structure 2, thus delimiting the inter-panel space 11 in which the first insulating joint 16 and the second insulating joint 17 are housed.

Fourthly, the spacer 22 is added to the housing 21 after the second insulating panel 24 has been installed. Indeed, if the spacer 22 was installed in the housing 21 prior to the installation of the second insulating panel 24, it would make it difficult to hold the second insulating joint 17 in position.

In the embodiment illustrated in Figure 2, the spacer 22 is formed by a bent metal blade. This spacer 22 has a first planar portion 25 and a second planar portion 26 connected by a bent portion 27. The bent portion 27 has a "V" shaped section. This bent portion 27 forms an elastic point tending to move the flat portions 25 and 26 away from each other.

This pointed shape of the angled portion 27 is particularly advantageous because it allows simple and rapid insertion of the spacer 22 through the inner end of the inter-panel space 11 via the passage 15 separating the plates cover 6 of the insulating panels. Typically, the spacer 22 is inserted by its angled portion 27, the point towards the outside of the tank, via the passage 15. Thus, the simple insertion of the spacer 22 by its point in the passage 15 allows the elastic deformation of said spacer 22 during its insertion.

In addition, the flat portions 25 and 26 and the angled portion 27 of the spacer 22 have dimensions allowing said spacer 22 to be fully housed in the housing 21. Thus, when the spacer 22 is fully inserted into the housing 21, the flat portions 25 and 26 are no longer constrained by the cover plates 6 and are elastically separated from each other by the bent portion 27. The flat portions 25 and 26 then press against the internal portion 19 of the first insulating joint 16 and on the second insulating joint 17 in order to move them away from each other and to press them against the side walls 7 of the insulating panels 23 and 24.

Furthermore, the passage 15 has a width less than the width of the housing 21. Thus, the ends of the cover plates 6 delimiting the passage 15 are located directly above the housing 21 in which the spacer 22 is housed. As indicated above, when the spacer 22 is completely housed in the housing 21, it bears against the internal portion 18 of the first insulating joint 16 and against the second insulating joint 17. The spacer 22 has then a width greater than the width of the passage 15. The spacer 22 is thus blocked in the housing 21 by the cover plates 6 and therefore cannot come into contact with the waterproof membrane 3.

In order to improve the insulation properties of the secondary thermally insulating barrier 1, the internal portion 19 of the first insulating joint 16 and the second insulating joint 17 can have a shape complementary to the bent portion 27 of the spacer 22. This complementary shape ensures the presence of an insulator in the space that does not disturb the proper functioning of the spacer 22. Thus, in FIG. 2, an outer end of the inner portion 19 of the first insulating joint 16 and an outer end of the second insulating joint 17 has a beveled shape. In other words, an outer end of the housing 21 has a "V" shape complementary to the angled portion 27.

In an embodiment not illustrated, the internal portion 19 of the first insulating joint 16 and the second insulating joint 17 can have an entirely parallelepipedic shape, and therefore not complementary to the bent portion 27, in order to allow the passage of cables for sensors. .

In the embodiment illustrated in Figures 2 and 3, the first insulating seal 16 is made of a rigid insulating material. Thus, when the tank is at ambient temperature as illustrated in FIG. 2, the outer portion 18 of the first seal substantially fills the entire width of the inter-panel space 11. Furthermore, as explained above, the part of spacer 22 presses the internal portion 19 of the first insulating joint 16 against the first insulating panel 23 and presses the second insulating joint 17 against the second insulating panel 24.

As illustrated in Figure 3, when the tank is cold, a channel may appear between the outer portion 18 of the first insulating seal 16 and the insulating panels 23, 24 due to thermal contraction. However, the relative mobility between the internal portion 18 of the first insulating joint 16 and the second insulating joint 17 as well as the spacer 22 make it possible to maintain contact between the internal portion 18 of the first insulating joint 16 and the first insulating panel 23 and between the second insulating joint 17 and the first insulating panel 24, thus avoiding the appearance of channels favoring convection. In other words, the spacer 22 allows the internal portion 19 and the second insulating joint 17 to be pressed against the side walls 8 of the insulating panels 23 and 24 in order to advantageously take up the various clearances linked to manufacturing tolerances or linked to the thermal contraction that may appear in the inter-panel space 11 in order to avoid the presence or appearance of channels that may promote convection in said inter-panel space 11.

In an embodiment not shown, the outer portion 18 of the first insulating joint 16 and the second insulating joint 17 have means of cooperation in order to remain united during the assembly of the tank while allowing relative mobility between the first insulating joint 16 and the second insulating joint 17 along the width direction 14 of the inter-panel space 11. Thus, the inner face 20 of the outer portion 18 of the first insulating joint 16 and the second insulating joint 17 can cooperate with a sliding system allowing the relative movement between the insulating joints 16 and 17 along the width direction 14 of the inter-panel space 11 but blocking the relative movement between these two insulating joints 16 and 17 along another direction. For example, one of the internal face 20 of the external portion 18 and an external face of the second insulating joint 17, typically the face of the second insulating joint 17 in contact with said internal face 20, has grooves developing in the direction 14 wide and the other of said internal face 20 and said external face has complementary ribs or tenons.

In Figure 3, the spacer 22 is a variant of that described with reference to Figure 2. In this Figure 3, the spacer 22 is made by a simple folded metal blade, the bent portion 27 being made by the fold of said metal blade.

In an embodiment not illustrated, the insulating joints 16 and 17 are made of an insulating compressible material. The outer portion 18 of the first insulating joint can thus be compressed in the inter-panel space 11 in order to fill the entire width 14 of the inter-panel space 11 despite the manufacturing tolerances or even despite a spacing between the insulating panels 23 and 24 related to thermal contraction.

In an embodiment not shown, the spacer 22 is a rigid wedge-shaped piece, for example having a "V" shaped cross-section. This "V" shaped part has a width greater at least locally than the distance separating the internal portion 19 of the first insulating joint 16 and the second insulating joint 17 so that the simple insertion of this spacer part 22 in the shape of "V" between said internal portion 19 and the second insulating joint 17 is sufficient to separate them from each other and press them against the side walls 7 of the insulating panels 4.

The technique described above for producing a leaktight and thermally insulating tank can be used in different types of tanks, for example to form an LNG tank in an onshore installation or in a floating structure such as an LNG carrier or other.

Referring to Figure 4, a cutaway view of an LNG carrier 70 shows a sealed and insulated tank 71 of generally prismatic shape mounted in the double hull 72 of the ship. The wall of the tank 71 comprises a primary leaktight barrier intended to be in contact with the LNG contained in the tank, a secondary leaktight barrier arranged between the primary leaktight barrier and the double hull 72 of the ship, and two insulating barriers arranged respectively between the primary waterproof barrier and the secondary waterproof barrier and between the secondary waterproof barrier and the double hull 72.

In a manner known per se, loading/unloading pipes 73 arranged on the upper deck of the ship can be connected, by means of appropriate connectors, to a maritime or port terminal to transfer a cargo of LNG from or to the tank 71.

FIG. 4 represents an example of a maritime terminal comprising a loading and unloading station 75, an underwater pipe 76 and an onshore installation 77. The loading and unloading station 75 is a fixed off-shore installation comprising an arm 74 and a tower 78 which supports the mobile arm 74. The mobile arm 74 carries a bundle of insulated flexible pipes 79 which can be connected to the loading/unloading pipes 73. The orientable mobile arm 74 adapts to all sizes of LNG carriers . A connecting pipe, not shown, extends inside the tower 78. The loading and unloading station 75 allows the loading and unloading of the LNG carrier 70 from or to the shore installation 77. This comprises liquefied gas storage tanks 80 and connecting pipes 81 connected by the underwater pipe 76 to the loading or unloading station 75. The underwater pipe 76 allows the transfer of the liquefied gas between the loading or unloading station 75 and the shore installation 77 over a great distance, for example 5 km, which makes it possible to keep the LNG carrier 70 at a great distance from the coast during loading and unloading operations.

To generate the pressure necessary for the transfer of the liquefied gas, pumps on board the ship 70 and/or pumps fitted to the shore installation 77 and/or pumps fitted to the loading and unloading station 75 are used.

Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention as defined by the claims.

Thus, Figures 1 to 3 illustrate the case of insulating seals 16 and 17 housed in the inter-panel spaces 11 of the thermally insulating barrier 1 of a tank comprising only a single thermally insulating barrier and a single sealed membrane. However, such insulating joints 16 and 17 could be arranged in a thermally insulating barrier of a tank comprising a plurality of thermally insulating barriers and sealed membranes. For example, such seals could be integrated into a sealed and thermally insulating tank comprising, from the outside towards the inside of the tank, a secondary thermally insulating barrier resting against the load-bearing structure, a secondary sealed membrane resting against the thermally secondary insulating barrier, a primary thermally insulating barrier resting against the secondary sealed membrane and a primary sealed membrane resting against the primary thermally insulating barrier and intended to be in contact with the liquid contained in the tank. In such a tank, the insulating joints 16 and 17 could be arranged in the secondary thermally insulating barrier and/or in the primary thermally insulating barrier.

Similarly, the above description is made in the context of insulating panels 4 in the form of a box filled with insulating gasket, but this description could apply analogously to any type of thermally insulating barrier comprising insulating panels defining spaces inter-panels such as reinforced polyurethane foam insulating blocks juxtaposed in a regular or other pattern.

Furthermore, the spacer 22 can be made of many materials and in many shapes to fulfill the function of separating the internal portion 19 of the first insulating joint 16 and the second insulating joint 17 in order to support said internal portion 19 against the side wall 7 of one of the insulating panels 4 and press the second insulating gasket 17 against the other insulating panel 4. According to one embodiment, the spacer 22 could be made of composite material. According to one embodiment, the spacer could also be made of extensible insulating material, thus making it possible to improve the thermal insulation properties of the thermally insulating barrier 1. In addition, such a spacer 22 made of Expandable insulation could take many shapes other than the "V" shape described above. Preferably, the shape of the spacer 22 is such that its inner end has a width greater than the width of the passage 15 when said spacer 22 is housed in the housing 21, the spacer 22 thus being blocked in movement in the direction of the waterproof membrane 3 by abutment of said internal end on the ends of the cover plates 6 delimiting the passage 15.

The use of the verb "to comprise", "to understand" or "to include" and of its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims (15)

Sealed and thermally insulating tank comprising a supporting structure (2) and a thermally insulating barrier (1) anchored to the supporting structure (2), the thermally insulating barrier (1) comprising a first insulating panel (4, 23) and a second panel adjacent insulating panels (4, 24), an inter-panel space (11) being delimited between the first insulating panel (4, 23) and the second insulating panel (4, 24), the tank further comprising:
- a first insulating joint (16) housed in the inter-panel space (11), said first insulating joint (16) comprising an internal portion (19) and an external portion (18) superposed along the thickness direction of the thermally insulating barrier (1), and
- a second insulating joint (17) housed in the inter-panel space (11), the second insulating joint (17) being juxtaposed along a width direction (14) from the inter-panel space (11) to the one of the inner portion (19) and the outer portion (18) of the first insulating joint (16),
- a spacer (22) inserted along the width direction of the inter-panel space (11) in an inter-joint space (21) between the first insulating joint (16) and the second insulating joint (17) so as to exert a bearing on the first insulating joint (16) in the direction of the first insulating panel (4, 23) and a bearing on the second insulating joint (17) in the direction of the second insulating panel (4, 24),
and wherein the other of the inner portion (19) and the outer portion (18) of the first insulating joint (16) is superimposed on said inter-joint space (21), and wherein said other of the inner portion (19) and the outer portion (18) of the first insulating joint (16) closes one end of the inter-joint space (21) in the thickness direction of the heat-insulating barrier (1) so that the inter-joint space (21) in which the spacer (22) is housed is delimited by the second insulating joint (17), the inner portion (19) of the first insulating joint (16) and the outer portion (18) of the first insulating joint (16). Sealed and thermally insulating tank according to claim 1, in which the inter-joint space (21) is produced between the internal portion (19) of the first insulating joint (16) and the second insulating joint (17) and in which the part spacer (22) has a shape widening from its outer end towards its inner end so as to be able to be inserted through an inner end of the inter-panel space (11). Sealed and thermally insulating tank according to Claim 1 or 2, in which the spacer (22) is an elastic part. Sealed and thermally insulating tank according to Claim 3, in which the first insulating panel (4, 23) and the second insulating panel (4, 24) comprise a rigid cover plate (6) developing directly above the space inter-panel (11), the spacer (22) having a compressed state in which a width of the spacer (22), taken in the width direction of the inter-panel space (11), is less than the width of a passage (15) separating the cover plate (6) of the first insulating panel (4, 23) and the cover plate (6) of the second insulating panel (4, 24) so as to be able to be inserted into the inter-panel space (11) through said passage (11) and, when the spacer (22) is housed in the inter-panel space (11) interposed between the first insulating joint (16 ) and the second insulating joint (17), a semi-compressed state in which the spacer (22) is compressed between the first insulating joint (16) and the second insulating joint (17) and exerts pressure on the first insulating joint (16) towards the first insulating panel (4, 23) and pressing the second insulating joint (17) towards the second insulating panel (4, 24). Sealed and thermally insulating tank according to Claim 3 or 4, in which the spacer (22) is a metal blade having a bent portion (27) and, on either side of the bent portion (27), two portions (25, 26) elastically joined by said bent portion (27). Sealed and thermally insulating tank according to Claim 1 or 2, in which the spacer is a rigid wedge-shaped piece. Sealed and thermally insulating tank according to one of Claims 1 to 6, in which the cumulative width of a part of said one of the internal portion (19) and the external portion (18) of the first insulating joint (16) and, on the other hand, of the second insulating joint (17), in the width direction of the inter-panel space (11), is less than the width (14) of the inter-panel space (11). Sealed and thermally insulating tank according to one of Claims 1 to 7, in which the said other of the internal portion (19) and the external portion (18) of the first insulating joint (16) fills the entire width (14) of the inter-panel space (11). A sealed and thermally insulating tank according to claim 8, wherein said other of the inner portion (19) and the outer portion (18) of the first insulating joint (16) is compressed along the width direction of the inter-panel space ( 11) between the first insulating panel (4, 23) and the second insulating panel (4, 24). Sealed and thermally insulating tank according to one of Claims 1 to 9, in which the second insulating joint (17), the internal portion (19) of the first insulating joint (16) and the external portion (18) of the first insulating joint ( 16) are globally parallelepipedic in shape. Sealed and thermally insulating tank according to any one of Claims 1 to 10, in which the first insulating joint (16) and the second insulating joint (17) are movable with respect to each other along the width direction of the inter-panel space (11). Vessel (70) for transporting a cold liquid product, the vessel comprising a double hull (72) and a tank (71) according to one of Claims 1 to 11 arranged in the double hull. Transfer system for a cold liquid product, the system comprising a vessel (70) according to claim 12, insulated pipes (73, 79, 76, 81) arranged to connect the tank (71) installed in the hull of the vessel to a floating or onshore storage facility (77) and a pump for driving a flow of cold liquid product through the insulated pipes from or to the floating or onshore storage facility to or from the vessel's tank. Method of loading or unloading a ship (70) according to claim 12, in which a cold liquid product is conveyed through insulated pipes (73, 79, 76, 81) from or to a floating or terrestrial storage installation ( 77) to or from the ship's tank (71). Method of mounting a thermally insulating barrier (1) of a sealed and thermally insulating tank on a supporting structure (2), comprising:
- anchoring a first insulating panel (4, 23) on the supporting structure,
- arranging a first insulating joint (16) against a side wall (8) of the first insulating panel (4, 23), said first insulating joint (16) comprising an internal portion (19) and an external portion (18) superimposed according to the direction of thickness of the thermally insulating barrier (1),
- arranging a second insulating joint (17) juxtaposed, in a direction perpendicular to the side wall (8) of the first insulating panel (4, 23), at one of the internal portion (19) and the external portion ( 18) of the first insulating joint (16) so as to form an inter-joint space (21) between said second joint (17) and said one of the inner portion (19) and the outer portion (18) of the first insulating joint ( 16), the other of the internal portion (19) and the external portion (18) of the first insulating joint (16) being superposed on said inter-joint space (21) and closing one end of said inter-joint space (21) in the direction of thickness of the thermally insulating barrier (1) so that the inter-joint space (21) is delimited by the second insulating joint (17), the internal portion (19) of the first insulating joint (16) and the outer portion (18) of the first insulating joint (16),
- anchoring a second insulating panel (4, 24) to the supporting structure adjacent to the first insulating panel (4, 23) so that the first insulating panel (4, 23) and the second insulating panel (4, 24) delimit an inter-panel space (11) in which the first insulating joint (16) and the second insulating joint (17) are housed,
- inserting into said joint space a spacer (22), said spacer (22) being inserted through one end of the inter-joint space (21) so that the spacer (22) is interposed along the width direction of the inter-panel space (11) between the first insulating joint (16) and the second insulating joint (17) and exerts a bearing on the first insulating joint (16) in the direction of the first insulating panel (4, 23) and pressing on the second insulating joint (17) towards the second insulating panel (4, 24).