KR20210134978A - Container wall with improved insulation around the bushing - Google Patents

Abstract

The present invention relates to a container wall comprising a primary thermal insulation layer 224 extending predominantly in a primary plane P1 and a secondary thermal insulation layer 226 extending predominantly in a secondary plane P2. The vessel wall 22 comprises a bushing 3 provided on the upper wall of the vessel 22b around which a peripheral region 229 extends in the secondary plane P2 of the secondary thermal insulation layer 226 . .

Description

Container wall with improved insulation around the bushing

The field of the present invention is the field of transport tanks with corrugated sealed membranes for the storage and/or transport of liquids, in particular sealed and insulated tanks for transporting gases in liquid state.

The present invention is suitable for transporting liquefied petroleum gas (LPG) having a temperature of -50°C to 0°C, or for transporting liquefied natural gas (LNG) at about -162°C at atmospheric pressure. It relates to the field of sealed and insulated tanks for storing and/or transporting liquids. Such tanks may be installed onshore or on a floating structure. In the case of a floating structure, the tank may be intended to transport the liquefied gas or to contain the liquefied gas serving as fuel for propelling the floating structure.

Typically, tanks used to store liquids at low temperatures have a number of pipes for the passage of which may be intended, for example, for loading or offloading liquids, or for trapping gases in a vapor space. Includes bushings. All these pipes are surrounded by a coaming, ie a vertical structural element that brackets the pipes.

In some situations where the number or dimensions of pipes are limited, the use of coaming may be avoided. Nevertheless, there is a need to provide an opening that allows the pipe to pass through the wall of the tank.

Nevertheless, these openings are not suitable for the passage of pipes for offloading the cargo present in the tank, which necessitates creating an opening in the wall of the tank of considerable size.

The size of these openings thus creates difficulties for the secondary insulating layer of the tank, since there is a significant temperature difference between the element located in the opening and passing through the wall and the secondary insulating layer.

It is an object of the present invention to overcome the previously mentioned disadvantages by eliminating coaming, joining several pipes of a tank to one and the same bushing and managing the temperature difference between the bushing and the secondary insulating layer.

Accordingly, a subject of the present invention is a wall of a tank capable of receiving a liquid cargo and configured to be installed on a transport vessel, the wall comprising at least one primary insulating layer mainly extending in a primary plane and a secondary insulating layer extending mainly in a secondary plane; wherein the primary insulating layer and the secondary insulating layer overlap in a direction transverse to the plane of the insulating layers, the wall of the tank having at least one bushing in the form of a hollow cylinder passing through the insulating layers, and a pipe extending in the bushing wherein the primary insulating layer comprises a peripheral region extending around the bushing and in a secondary plane of the secondary insulating layer.

Here, it is understood that a portion of the primary thermal insulation layer extends upwardly along the bushing and crosses the general plane of extension of the secondary thermal insulation layer, which portion is defined by the peripheral zone.

According to the invention, the tank can contain liquefied gas, in particular liquefied natural gas, liquefied petroleum gas and generally any liquefied hydrocarbon. The transport may then include several tanks capable of storing and transporting gas in a liquid state.

The primary insulating layer and the secondary insulating layer are sets of parts that make it possible to insulate the tank and may have different thicknesses. Then, the primary plane and the secondary plane are defined as planes passing through the middle of the thickness of the primary insulating layer and the middle of the thickness of the secondary insulating layer, respectively.

The bushing has a cylindrical shape, in particular a circular shape. The bushing takes the form of a duct of circular cross-section passing directly through the wall of the tank, which is the subject of the present invention. The bushing then makes it possible to extend the pipe, which may be a pipe for offloading a liquid cargo or a pipe for discharging a gaseous phase of a liquid cargo. For offloading a maximum of liquid cargo, an offloading pipe extends from the outside of the tank to just near the bottom of the tank. A discharge tube extends from the outside of the tank to the vapor space. The bushing according to the invention may of course comprise an offloading pipe and at least one discharge pipe.

According to the invention, the peripheral zone is connected with a portion of the primary insulating layer extending in the primary plane, so that they form only one and the same volume. This feature makes it possible to flush with one and the same inert gas the part of the primary thermal insulation layer located in the primary plane and the part of this primary thermal insulation layer extending in the secondary plane.

According to one feature of the invention, the peripheral zone receives at least one peripheral piece extending over a radius of 400 mm to 1000 mm about the bushing axis of the bushing in the secondary plane of the secondary insulating layer. It is then understood that the portion of the primary insulating layer located in the primary plane and the surrounding pieces are flushed by the same inert gas stream.

A piece or zone is peripheral in that it surrounds the bushing. It may be a piece or an annular or polygonal area. Although a constituent part of the primary insulating layer, the perimeter piece is separated from the insulating panel of the primary insulating layer extending in the primary plane.

According to one feature of the invention, the thickness of the peripheral zone is equal to the thickness of the secondary thermal insulation layer. This feature ensures the absence of coaming around the bushing. The thickness is measured on a straight line parallel to the axis of rotation of the bushing, and the thickness of the peripheral piece is also equal to or substantially equal to the thickness of the secondary insulating layer within manufacturing and mounting tolerances.

According to one feature of the invention, a septum extends between the secondary insulating layer and the peripheral zone, at least around the bushing. Such a partition separates the interior volume of the secondary thermal insulation layer and the interior volume of the peripheral zone forming part of the primary thermal insulation layer. The septum may be cylindrical and may be formed by an assembly composed of a circular ring and an insulating material, which may be, for example, glass wool.

According to one feature of the present invention, the barrier rib ensures airtightness between the primary thermal insulation layer and the secondary thermal insulation layer. Thus, such a bulkhead separates the primary insulating layer volume from the secondary insulating layer volume in the vicinity of the perimeter zone.

According to one feature of the invention, at least one gas evacuation tube extends within the bushing, the at least one gas evacuation tube having an outer end exiting the tank and an interior end exiting the vapor space of the tank. The vapor space contains gases due to evaporation of the liquid cargo and is therefore close to the upper wall of the tank. The gas exhaust tube then makes it possible to suck in the gas present in the vapor space and supply it to the heat engine equipped on the transport, or even to adjust the pressure in the vapor space.

According to another aspect, the pipe is a liquid cargo offloading pipe and comprises in particular a first end which exits out of the interior volume of the tank and a second end which exits into the tank near the lower wall of the tank.

The present invention also covers a wall comprising a plurality of bushings as described above.

The invention also covers a transport vessel, for example a methane tanker, comprising at least one wall of a tank comprising the above features.

According to one feature of the transport, the transport comprises at least one deck of the transport, the edge of the deck being at a non-zero distance from the bushing.

The deck of the transport ship is non-zero from the bushings to allow movement due to thermal expansion between the bushings capable of contacting the cargo in the liquid state and the deck insulated from such cargo by at least one primary and secondary insulation layer. extended into the street.

According to one aspect, the non-zero distance separating the bushing from the edge of the deck is filled by the insulating piece.

According to one feature of the transport, the edge of the deck at least partially extends axially in line with the peripheral zone on a straight line parallel to the bushing axis.

According to one feature of the transport, a cylinder positioned around the bushing is supported by the outer surface of the deck and, together with the bushing, defines a space for receiving the insulating material, the space being closed by the top. Cylindrical insulation can be composed, for example, of glass wool, foamed foam or perlite. Then, it is understood that the cylindrical body reinforces the heat insulating material around the bushing and the upper part hermetically seals the space of the cylindrical body.

According to one feature of the transport, the edge of the deck is positioned radially between the bushing and the inner surface of the cylinder. Such a configuration makes it possible to use the deck to absorb the axial load that arises from the internal pressure of the tank around the bushing and is subjected to the primary insulating layer.

Further, according to one feature of the transport vessel, a duct passes through the cylinder and the surrounding region and exits the primary insulating layer, the duct being configured to be linked to an inert gas supply device. The first duct opening, the second duct opening and the third duct opening are formed at least in the cylindrical body, in the deck of the transport ship and through the cylindrical piece, respectively, to allow passage of the duct through the cylindrical insulation and the primary insulation layer, respectively. Preferably, the inert gas is nitrogen.

The present invention also covers a transport vessel comprising a wall of a tank capable of receiving a liquid cargo, the wall of the tank being configured to be installed on the transport, the wall comprising at least one primary insulating layer extending primarily in a primary plane; a secondary thermal insulation layer extending mainly in a plane, the primary thermal insulation layer and the secondary thermal insulation layer overlapping in a direction transverse to the plane of the thermal insulation layers, and the wall of the tank is at least one in the form of a hollow cylinder passing through the thermal insulation layers. a bushing and a pipe extending within the bushing, wherein the transport includes at least one deck of the transport, wherein an edge of the deck is at a non-zero distance from the bushing, the edge of the deck is positioned about the bushing and the outer surface of the deck It is positioned radially between the bushing and the inner surface of the cylinder supported by the .

According to one aspect of the transport, the edge of the deck at least partially extends axially in line with the peripheral zone on a straight line parallel to the bushing axis.

The invention also relates to a method for loading liquid natural gas into or offloading liquid natural gas from a tank comprising a wall according to the above features, or a liquefied natural gas carrier according to one of the above features.

Other features, details and advantages of the present invention will become more apparent upon reading the description given below, timely in connection with the drawings:
1 is a side view of a transport vessel showing at least one tank for transporting a liquid cargo and a bushing therethrough;
Fig. 2 is a cross-sectional view taken along the vertical line of the tank, of the tank top wall on which the bushing is formed;
FIG. 3 is an enlarged cross-sectional view taken along the vertical line of the tank, in the area around the bushing penetration in the upper wall of the tank of FIG. 2 ;

First of all, it should be noted that the drawings illustrate the present invention in detail for the purpose of carrying out the present invention, and that the drawings clearly can be better used to define the present invention as needed.

1 shows a transport vessel 1, for example a methane tanker, comprising four tanks 2 for transporting or storing liquefied natural gas. At least one of the tanks 2 comprises a tank wall 22 defining an interior cavity 20 in which liquefied gas is stored. The tank wall 22 comprises a tank bottom wall 22a, a tank top wall 22b opposite to the tank bottom wall 22a in a vertical line V of the tank 2, a tank bottom wall 22a and the tank and a side wall 22c extending between the top wall 22b.

FIG. 2 shows a cross-sectional view of the tank 2 and the bushing 3 formed in the tank upper wall 22b, with respect to the vertical line V of the tank shown in FIG. 1 . This bushing 3 takes the form of a hollow cylinder, with a first end located in the external environment of the tank 2 , the other end of which is an internal cavity 20 close to the upper wall 22b of the tank wall 22 . ), that is, located in the vapor space 21 of the tank 2 corresponding to that part of the tank 2 where the gas in the liquid state is not present under normal conditions of use.

The bushing 3 extends around and along the axis of rotation, referred to as the bushing axis R, and extends circumferentially around the bushing axis R of the bushing 3 and defines a passage through the tank top wall 22b. and a bushing wall that The bushing 3 then allows the passage of at least one pipe 31 , in particular a pipe for offloading liquefied gas, and/or a gas outlet tube 32 . The bushing 3 also has a cover 33 which covers the outer part of the tank 2 and makes it possible to hermetically close the bushing 3 when the pipe 31 and/or the gas outlet tube 32 are installed. include

The pipe 31 extends from the liquid part of the cargo to the immediate vicinity of the tank lower wall 22a for offloading the maximum amount of liquefied gas out of the tank 2 , if it is a pipe for offloading gas in liquid state. do. A gas discharge tube 32 extends from the outside of the tank into the inside of the tank 2 and opens in a part of the tank 2 called the vapor space 21 of the tank 2 where natural gas is in the gaseous state. The vapor space 21 of the tank 2 is the space adjacent the tank top wall 22b which receives the gas phase of the liquid cargo resulting from evaporation. The gas discharge tube 32 then makes it possible to suck in the gas phase of the liquid cargo and supply it to a heat engine (not shown) equipped on the transport, or even to reduce the pressure in the vapor space 21 of the tank 2 . make it possible to adjust

The tank top wall 22b consists of an overlap of insulating and sealing layers, insulating the inner cavity 20 and ensuring a seal-tightness. The tank top wall 22b then comprises at least a primary thermal insulation layer 224 and a secondary thermal insulation layer 226, respectively, from the interior cavity 20 to the exterior environment of the tank 2 . Other walls of the tank may also include such a primary insulating layer 224 and a secondary insulating layer 226 .

The primary insulating layer 224 includes a primary membrane 222 including a plurality of plates welded to each other and including corrugations 2221 , and a plurality of primary insulating panels 221 . The primary membrane 222 constitutes the face in direct contact with the liquefied gas contained in the interior cavity 20 .

The secondary thermal insulation layer 226 consists of a secondary membrane 225 facing the primary thermal insulation layer 224 and several secondary thermal insulation panels 220 . Next, the secondary thermal insulation layer 226 of the tank top wall 22b is covered by a deck 228 in contact with the exterior of the tank 2 .

According to one feature of the invention, the primary insulating layer 224 defines a volume that is flushed by an inert gas, on one side by the primary membrane 222 and on the other side by the secondary membrane 225 . is defined by In an equivalent manner, the secondary insulating layer 226 defines a volume that is flushed with an inert gas, separate from the volume of the primary insulating layer 224 , on one side by the secondary membrane 225 and on the other side. is defined by deck 228 .

The circulation of the inert gas in the primary insulating layer 224 and the secondary insulating layer 226 makes it possible to detect, for example, leakage of cargo out of the inner cavity 20 of the tank 2 . The leak detection is then performed differently for the primary thermal insulation layer 224 and the secondary thermal insulation layer 226 . Advantageously, the inert gas used is nitrogen.

The tank top wall 22b also includes a cylindrical body 233 extending radially around the bushing 3 . This cylindrical body 233 has a rotation axis coincident with the bushing axis R.

3 shows an enlarged cross-sectional view along the vertical line V of the tank, the bushing 3 and the area surrounding it. In the following description, overlap is understood to mean the overlap with respect to the vertical line V of the tank from the inner cavity 20 of the tank to the outside of the tank.

The bushing 3 is formed of a pipe 31 , in particular a pipe for offloading liquid cargo, and/or of the tank upper wall 22b for a gas discharge tube 32 , for sucking gas from the vapor space 21 . confine the passage.

The tank top wall 22b includes a primary insulating layer 224 partially composed of a primary membrane 222 overlaid with a primary insulating panel 221 . The primary membrane 222 is in contact with the liquefied gas stored in the interior cavity 20 of the tank. The primary membrane 222 consists of a plurality of plates comprising corrugations 2221 distributed over its surface and surrounds a bushing 3 , which is nevertheless a non-zero distance from this bushing 3 . zero distance) is maintained. Such a configuration of the primary membrane 222 allows greater response to stresses induced in the tank, particularly thermal contraction as the tank cools, hydrostatic pressure due to loading of liquid cargo, and dynamic pressure due to movement of cargo, particularly swell. provides resistance. The pleats 2221 on the primary membrane 222 allow the primary membrane 222 to deform to relieve these stresses. The primary membrane 222 is preferably made of stainless steel.

A bracket 236 is disposed in the inner cavity 20 of the tank to contact the primary membrane 222 and the bushing 3 . Only the ends of bracket 236 are welded to primary membrane 222 and bushing 3 respectively. Such a configuration of the bracket 236 makes it possible to close the space between the primary membrane 222 and the bushing 3 , and also to provide flexibility in this area to absorb the dynamic stresses of the tank. In practice, the bushing 3 may cut several corrugations 2221 , and thus it is necessary to restore flexibility to the passage region of the bushing 3 . This flexibility is provided, for example, by the fact that the bracket 236 is only welded at its ends.

The primary thermal insulation panel 221 is made of an insulating material and contributes to the thermal insulation of the tank required to store liquefied natural gas at a low temperature (-163° C.).

The primary insulating layer 224 is defined by a thickness T1 measured on a straight line parallel to the bushing axis R, this thickness extending from the primary membrane to the secondary membrane. A primary insulating layer 224 extends around the bushing 3 to a non-zero distance D1 to adapt to the expansion and contraction of the bushing 3 caused by temperature changes during loading or offloading of the tank. The function of the primary insulating layer 224 is to form a first insulating barrier of the tank.

A primary plate 223 extends between the primary membrane 222 and the primary insulating panel 221 . The primary plate 223 is a plywood that may include a strip of stainless steel (not shown) that makes it possible to weld the edges of the plate of the primary membrane 222 .

A secondary insulating layer 226 is superposed on the primary insulating layer 224 and is a secondary membrane extending to a non-zero distance D2 in the vicinity of the bushing 3, and a distance strictly greater than the aforementioned distance D1. (225) (also called triplex). The secondary membrane 225 is a material comprising three layers, two outer layers of fiberglass fabric, and an intermediate layer of a thin metal sheet, for example an aluminum sheet about 0.1 mm thick. The secondary membrane 225 has bending flexibility, which makes it possible to follow the deformation of the tank due to the deformation of the hull due to the cooling or expansion of the tank. Flexural flexibility is understood to mean the ability of a material to fold to form a curve without breaking.

The secondary thermal insulation panel 220 is overlaid on the secondary membrane 225 . The secondary thermal insulation panel 220 is made of a thermal insulation material, and together with the primary thermal insulation panel 221 contributes to thermal insulation of the tank. The secondary insulating layer 226 is then defined by a thickness T2 measured along a straight line parallel to the bushing axis R between the secondary membrane and the secondary plate 227 glued to the deck.

The secondary insulating layer 226 extends around the bushing 3 to a non-zero distance D2, which distance D2 is strictly greater than the distance referred to as D1. The secondary insulating layer 226 includes a first side 2261 facing the deck 228 and a second side 2262 facing the secondary membrane 225 .

A secondary plate 227 extends between the deck 228 and the secondary insulating panel 220 . The secondary plate 227 makes it possible to reinforce the secondary insulating panel 220 , and may in particular be made of plywood.

According to one aspect of the present invention, perimeter piece 240 extends in peripheral region 229 , which perimeter region 229 is in the insulating plane P2 of secondary thermal insulation layer 226 and with secondary thermal insulation layer 226 . It is defined as a zone extending radially between the bushings 3 , at least over a radial distance corresponding to the distance D2 mentioned above. The perimeter piece 240 has a thickness T3 measured along a straight line parallel to the bushing axis R, the thickness T3 being the thickness T2 of the secondary insulation layer 226 within manufacturing and/or mounting tolerances. same or similar to This thickness T3 also defines the portion of the primary thermal insulation layer 224 that extends around the bushing 3 and is in the secondary plane P2 of the secondary thermal insulation layer 226 . In this description, this portion is the peripheral zone 229 .

The perimeter piece 240 is a piece that contributes to the thermal insulation of the tank, and may be made of the same material as the thermal insulation panel of the primary thermal insulation layer 224 . Peripheral piece 240 is received in perimeter zone 229 .

According to the present invention, the perimeter piece 240 passes through at least the primary thermal insulation layer 224 and the bushing space 242 defined by the distance D1 between the perimeter piece 240 and the bushing 3 . 224) is connected to the volume portion. This bushing space 242 may be filled with an insulating material 241, preferably glass wool, which absorbs cold play of the bushing 3 due to its flexibility, while absorbing an inert gas. makes it possible to allow the circulation of It is then understood that the peripheral zone 229 is flushed by the inert gas circulating within the volume of the primary insulating layer 224 . With this feature, the perimeter piece 240 is considered to form part of the primary thermal insulation layer 224 .

The secondary insulating layer 226 thus comprises a countersink surrounding the bushing 3 , which countersink is formed by the peripheral region 229 and is filled by the peripheral piece 240 .

Preferably and in a non-limiting manner, the peripheral piece 240 has a radius of 400 mm to 1000 mm about the bushing axis R of the bushing 3 in the secondary plane P2 of the secondary thermal insulation layer 226 . extended across

A first annular plate 2291 extends between the perimeter piece 240 and the deck 228 . A second annular plate 2292 may be positioned between the primary thermal insulation panel 221 and the peripheral piece 240 . The first annular plate 2291 and the second annular plate 2292 may, in a non-limiting manner, be made of densified wood or polyurethane, whose function is to reinforce the peripheral piece 240 .

Finally, the tank top wall 22b covers the secondary plate 227 and extends axially in line with the peripheral piece 240, i.e. along a straight line parallel to the bushing axis R, the deck of the transport vessel ( 228).

Accordingly, the deck 228 at least partially covers the first annular plate 2291 . The deck 228 also includes an edge 2280 extending to a non-zero distance from the bushing 3 and positioned radially between the bushing 3 and the inner surface 2334 of the cylindrical body 233 . . Thus, the edge 2280 defines a passage 2332 between the deck 228 and the bushing 3 . Such a configuration of deck 228 makes it possible to allow for thermal expansion due to loading or offloading of liquid cargo. Passage 2332 may be filled with insulation, which is then positioned between edge 2280 and bushing 3 .

Deck 228 includes an outer surface 2281 facing the external environment of the tank and an inner surface 2282 facing secondary plate 227 and first annular plate 2291 . An adhesive 230 may be positioned between the interior surface 2282 of the deck 228 and the first annular plate 2291 and the secondary plate 227 . Adhesive 230 may be, for example, in the form of a lump of glue, which enables fixing of first annular plate 2291 and secondary plate 227 to deck 228 .

The bulkhead 232 extends radially parallel to the bushing axis R between at least the peripheral piece 240 and the secondary thermal insulation layer 226 . The septum 232 emerges at right angles from the interior surface 2282 of the deck 228 to contact the secondary membrane 225 . The bulkhead 232 is made of a ring 2321 and an insulating material 2322, for example glass wool. According to the present invention, the ring 2321 of the septum 232 has a straight circle cylinder profile. The function of the partition wall 232 is then understood to insulate and hermetically separate the peripheral piece 240 from the secondary thermal insulation layer 226 so that the inert gas circulating in each volume does not mix. According to this feature, the junction between the ring 2321 and the secondary membrane 225 may be, for example, welded to make this junction hermetic. In general, the bulkhead 232 is considered to separate the volume of the secondary thermal insulation layer 226 from the volume of the peripheral region 229 .

The tank top wall 22b includes a cylinder 233 positioned supported on the exterior surface 2281 of the deck 228 . The cylinder 233 extends radially around the bushing 3 and axially in line with the peripheral piece 240 . The cylinder 233 includes a space 2331 filled with an insulating material called a cylindrical insulating layer 242, which can be, for example, glass wool, expanded foam or perlite. have. The function of the cylinder 233 is to enhance the insulation around the bushing 3 . The space 2331 of the cylinder 233 is defined by the bushing 3 , the cylinder 233 , the portion of the deck 228 having an edge 2280 , and a circular top 234 . The circular upper part 234 covers the space 2331 opposite the deck 228 and extends from the bushing 3 to the cylindrical body 233 at right angles to the bushing axis R. Thus, the space 2331 of the cylindrical body 233 is the volume of the primary thermal insulation layer 224 and the peripheral piece 240 by the passage 2332 formed between the edge 2280 of the deck 228 and the bushing 3 . ) is connected to the volume occupied by

From the above characteristics, it is understood that the primary insulating layer 224 , the peripheral piece 240 and the cylindrical insulating layer 242 are connected to form a single volume that is flushed by the same inert gas stream.

A tubular duct 235 partially extends from the primary insulating layer 224 . To this end, the tank top wall 22b has a first duct opening 2351 formed through the cylindrical body 233 and a second formed through the deck 228 close to the edge 2280 of the deck 228 . A plurality of openings are formed including a duct opening 2352 and a third duct opening 2353 formed through the second annular plate 2292 . The duct 235 then circulates from the outside of the tank to the primary thermal insulation layer 224, in particular by passing through the cylindrical insulating layer 242 and the peripheral piece 240 by the duct openings 2351, 2352, 2353 described above. is understood to be

The duct 235 is configured to be linked to an inert gas supply (not shown), and its function is to contribute to gas flushing of the primary insulating layer 224 . Injection of an inert gas into the primary thermal insulation layer 224 makes it possible to confirm the absence of flooding of the primary thermal insulation layer 224 via an external analysis device (not shown). The same is true for the secondary thermal insulation layer 226 which is also connected to the inert gas supply and an external analysis device that checks the flooding of the secondary thermal insulation layer 226 .

Accordingly, the present invention achieves the object set by eliminating coaming and improving the insulation and airtightness of such bushings by means of a perimeter and a cylindrical body extending radially around the bushing, while joining several pipes of a tank to one and the same volume. achieve

However, the present invention is not to be limited to the exclusively described and illustrated means and configurations, but applies equally to all equivalent means or configurations and to any combination of such means or configurations. In particular, it goes without saying that the present invention applies to any bushing shape and/or dimension.

Claims (15)

A wall (22) of a tank (2) capable of receiving a liquid cargo and configured to be installed on a transport vessel (1), said wall (22) having at least one primary insulating layer (224) extending mainly in a primary plane (P1) and a secondary thermal insulation layer 226 mainly extending in a secondary plane P2, wherein the primary thermal insulation layer 224 and the secondary thermal insulation layer 226 are formed in a plane P1 of the thermal insulation layers 224 and 226. At least one bushing 3 in the form of a hollow cylinder, superimposed in the direction transverse to P2), and passing through the insulating layers 224 , 226 , the wall 22 of the tank, in the bushing 3 . In the wall (22) of the tank (2) comprising a pipe (31) extending from
characterized in that the primary insulating layer (224) comprises a peripheral region (229) extending around the bushing (3) and in the secondary plane (P2) of the secondary insulating layer (226).
the wall of the tank. The method of claim 1,
The peripheral zone 229 has at least one perimeter extending over a radius of 400 mm to 1000 mm about the bushing axis R of the bushing 3 in the secondary plane P2 of the secondary thermal insulation layer 226 . accommodating piece 240
the wall of the tank. 3. The method according to claim 1 or 2,
The thickness T3 of the peripheral region 229 is equal to the thickness T2 of the secondary thermal insulation layer 226 .
the wall of the tank. 4. The method according to any one of claims 1 to 3,
A partition wall 232 extends between the secondary insulating layer 226 and the peripheral region 229 at least around the bushing 3 .
the wall of the tank. 5. The method of claim 4,
The partition wall 232 ensures airtightness between the primary thermal insulation layer 224 and the secondary thermal insulation layer 226 .
the wall of the tank. 6. The method according to any one of claims 1 to 5,
At least one gas outlet tube 32 extends within the bushing 3 , the at least one gas outlet tube 32 having an outer end 322 coming out of the tank 2 and the tank ( 2) having an inner end 321 exiting the vapor space 21 of
the wall of the tank. 7. The method according to any one of claims 1 to 6,
The pipe 31 is a liquid cargo offloading pipe.
the wall of the tank. In the transport ship (1),
at least one wall (22) of the tank (2) according to any one of claims 1 to 7
transport ship. 9. The method of claim 8,
at least one deck (228) of the transport (1), wherein one edge (2280) of the deck (228) is at a non-zero distance from the bushing (3).
transport ship. 10. The method of claim 9,
The edge 2280 of the deck 228 extends axially at least partially in line with the peripheral region 229 on a straight line parallel to the bushing axis R.
transport ship. 11. The method of claim 9 or 10,
A cylindrical body 233 positioned around the bushing 3 is supported by an outer surface 2281 of the deck 228 and, together with the bushing 3, defines a space 2331 for receiving an insulating material. and the space 2331 is closed by the upper part 234
transport ship. 12. The method of claim 11,
The edge 2280 of the deck 228 is positioned radially between the bushing 3 and the inner surface 2334 of the cylindrical body 233 .
transport ship. 11. The method of claim 10,
A duct (235) passes through the cylinder (233) and the peripheral region (229) and exits the primary insulating layer (224), wherein the duct (235) is configured for linkage to an inert gas supply device.
transport ship. A transport vessel (1) comprising a wall (22) of a tank (2) capable of receiving a liquid cargo, the transport vessel (1) comprising:
A wall 22 of the tank 2 is configured to be installed on a transport vessel 1, said wall 22 comprising at least one primary insulating layer 224 extending mainly in a primary plane P1 and a secondary plane ( a secondary thermal insulation layer 226 extending mainly from P2), wherein the primary thermal insulation layer 224 and the secondary thermal insulation layer 226 are transverse to the planes P1, P2 of the thermal insulation layers 224, 226 at least one bushing 3 in the form of a hollow cylinder passing through the insulating layers 224 , 226 and a pipe extending in the bushing 3 , overlapping in the direction of 31 ), wherein the transport vessel ( 1 ) comprises at least one deck ( 228 ) of the transport vessel ( 1 ), the edge ( 2280 ) of the deck ( 228 ) being at a non-zero distance from the bushing ( 3 ) The edge 2280 of the deck 228 has an inner surface 2334 of the cylinder 233 positioned around the bushing 3 and supported by the outer surface 2281 of the deck 228 and located radially between the bushings (3).
transport ship. Liquid natural gas into a tank (2) comprising a wall (22) according to any one of claims 1 to 7, or into a liquid natural gas transport (1) according to any one of claims 8 to 12. to load or offload liquid natural gas from
Way.

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