EP3421864B1 - Liquefied natural gas tank for motor vehicles - Google Patents

Description

1. Technical field of the invention

The technical field of the present invention is that of liquefied gas tanks, such as liquefied natural gas (G.N.L), intended to equip motor vehicles.

2. State of the art

The market for motor vehicles, and in particular for heavy goods vehicles, operating on liquefied natural gas has entered a phase of significant growth.

Liquefied natural gas is natural gas processed in liquid form. This liquid state is reached when the gas is cooled to a temperature of about -161 ° C at atmospheric pressure.

Liquefaction makes it possible to reduce the gas volume of natural gas and to store it in one or more tanks installed, for example, on the chassis of the truck.

In known manner, the liquefied natural gas contained in the tank is regasified so as to supply the engine of the truck.

This fuel is less polluting than petrol and diesel, and the autonomy of heavy goods vehicles using this fuel makes them suitable for long-distance road transport.

Heavy duty liquefied natural gas tanks are designed to meet strict safety requirements, particularly pressure and keeping the temperature very low, to keep the gas in its liquid phase. Such a reservoir is known from FR2857082 A1 .

The tanks usually used have a cylindrical shape and have a double stainless steel wall between which an insulator is placed. multi-layered and vacuum classically. Their weight is therefore relatively large and their useful volume is reduced.

The cylindrical shape of such tanks allows a uniform distribution of the stresses, related to the pressure of the gas, on the internal wall of the tank.

However, the tanks having this shape occupy a large space and are not suitable for spaces / compartments of various shapes of the vehicle in which they are intended to be installed.

3. Statement of the invention

The invention provides for this purpose a tank for a motor vehicle intended to contain liquefied gas, such as liquefied natural gas.

• un contenant de stockage de gaz liquéfié, le contenant comprenant une structure de renfort interne, et
• une enveloppe externe de protection disposée autour dudit contenant, ledit contenant et ladite enveloppe externe présentant chacun une forme générale sensiblement parallélépipédique, et ledit contenant étant solidarisé à ladite enveloppe externe par des moyens de suspension autorisant un déplacement relatif dudit contenant par rapport à ladite enveloppe externe.

According to the invention, the tank comprises:

• a liquefied gas storage container, the container comprising an internal reinforcing structure, and
• an external protective envelope disposed around said container, said container and said external envelope each having a generally substantially parallelepiped shape, and said container being secured to said external envelope by suspension means allowing relative movement of said container relative to said external envelope .

The invention provides a liquefied gas tank (LNG for example) with a double wall of generally substantially parallelepipedal shape comprising a container forming an internal wall and an external envelope disposed around said container forming an external protective wall.

Between these walls, which are not in contact, an intermediate space is formed containing a vacuum and / or an insulating material.

The attachment of the container to said external envelope by suspension means makes it possible to provide a degree of freedom between the two elements, so as to limit the heat transfers by conduction and to compensate for the thermal expansion / shrinkage due to the cooling of the internal container while limiting the stresses.

In addition to these thermal movements, the suspension means also allow mechanical movement of the container relative to said external envelope.

The parallelepiped shape of the container optimizes its storage capacity in liquefied gas and the parallelepiped shape of the external envelope allows optimal integration of the tank into the architecture of the vehicle.

Preferably, these suspension means allow relative movement of said container relative to said external envelope of less than 10 mm, for example between 1 and 6 mm, and even more precisely between 1 and 4 mm.

The thermal contraction of said container can be equal to 4 mm on each side of the container for example. The suspension means thus make it possible to compensate for this retraction of the internal container.

The liquefied gas can be LNG (liquid methane), or liquid nitrogen for refrigerated trucks, for example.

According to a particular aspect of the invention, said container is connected to a first lateral end of said external envelope by suspension straps and to a second lateral end of said external envelope by a suspension ring.

According to a particular aspect of the invention, said suspension ring is fixed to the internal surface of a side wall of said external envelope and is fitted onto a stud carried by the external surface of a side wall of the container.

According to a particular aspect of the invention, said suspension straps and said suspension ring are made of a thermally insulating material.

These suspension means can alternatively be springs or silentblocks when these suspension means are insulating.

According to a particular implementation of the invention, said container is connected to a first lateral end of said external envelope by suspension straps and to a second lateral end of said external envelope by suspension straps.

These suspension straps are made of a thermally insulating material.

According to a particular embodiment of the invention, said internal reinforcement structure comprises a reinforcement framework secured to the internal wall of said container, the internal reinforcement structure comprising a plurality of reinforcement rings, substantially octagonal, spaced along the longitudinal axis of the container, and extending transversely to said longitudinal axis.

This reinforcing frame optimizes the mechanical resistance of the container to the internal pressure of the liquefied gas and avoids the phenomena of inertia of the fluid contained.

Rather than reinforcement rings, a coiled cable could be used.

Preferably, said reinforcement rings are mounted spaced apart on reinforcement bars extending parallel to the longitudinal axis and disposed around the periphery of the reinforcement rings, said reinforcement bars being each secured to a reinforcement rail fixed to the wall. internal of said container.

According to a preferred implementation, said internal reinforcement structure comprises several corner reinforcement plates fixed on the internal wall of said container and each connecting two adjacent internal faces of said container.

According to a particular aspect of the invention, the container is made of aluminum.

According to a particular aspect of the invention, said external envelope is made of a fire-resistant material.

In a variant, said external envelope is covered on its surface exterior or interior of a fire resistant coating.

In this case, the outer casing can be made of aluminum or of composite materials.

A fire-resistant coating can be arranged alternatively or additionally on the outer surface of the container.

The internal reinforcement structure can be made of aluminum, or a composite material, for example.

According to a particular aspect of the invention, the wall of the container and the wall of the external envelope are spaced from each other, the intermediate space between these walls being filled with insulating means.

The space between the wall of the container and the wall of the outer envelope is, for example, between 25 and 50 mm.

According to a particular embodiment of the invention, the internal reinforcing structure comprises several reinforcing plates spaced along the longitudinal axis of said container and extending transversely to said longitudinal axis.

These reinforcing plates optimize the mechanical resistance of the container to the internal pressure of the liquefied gas and avoids the phenomena of inertia of the fluid contained.

Advantageously, said reinforcing plates are full and have at least one orifice for the passage of liquefied gas within said container.

Advantageously, the container comprises a reinforcing rod extending parallel to said longitudinal axis and connecting the side walls of the container by crossing said reinforcing plates.

This reinforcing rod allows the funds, or side walls, of the container to be maintained.

According to a particular embodiment of the invention, the internal reinforcing structure further comprises a reinforcing framework having a general shape substantially parallelepiped and disposed against the internal wall of said container.

According to a particular aspect, said reinforcing plates have a solid central portion from which extend several branches crossing the wall of said reinforcing framework.

Advantageously, the ends of the branches projecting from the outer surface of said reinforcing frame have a slot for passage of a bar for securing the reinforcing plates to said reinforcing frame.

Advantageously, the securing bars extend in longitudinal grooves formed on the periphery of the outer surface of said reinforcing frame.

• un élément de connexion à un autre réservoir ;
• une jauge de niveau ;
• une soupape de sécurité ;
• un dispositif de remplissage du contenant.

According to a particular aspect of the invention, the external surface of at least one lateral and / or longitudinal wall of the container or of the external envelope comprises a connection plate carrying in particular at least one of the following elements:

• a connection element to another tank;
• a level gauge;
• a safety valve;
• a container filling device.

The invention also relates to a motor vehicle, such as a truck, comprising at least one tank as described above.

4. List of figures

• la figure 1 est une vue en perspective d'un premier mode de réalisation d'un contenant mis en œuvre dans un réservoir conforme à l'invention ;
• la figure 2 est une vue en perspective d'un deuxième mode de réalisation d'un contenant mis en œuvre dans un réservoir conforme à l'invention ;
• la figure 3 est une vue en perspective d'un troisième mode de réalisation d'un contenant mis en œuvre dans un réservoir conforme à l'invention ;
• la figure 4 est une vue en perspective d'un quatrième mode de réalisation d'un contenant mis en œuvre dans un réservoir conforme à l'invention ;
• la figure 5A est une vue en perspective d'un cinquième mode de réalisation d'un contenant mis en œuvre dans un réservoir conforme à l'invention ;
• la figure 5B est une vue de détail du contenant de la figure 5A montrant le passage d'une barrette de renfort dans les branches des plaques de renfort du contenant ;
• les figures 6A et 6C sont des vues en perspective d'un réservoir conforme à l'invention présentant des premiers et seconds moyens de suspension du contenant à l'enveloppe externe ;
• les figures 6B et 6D sont des vues de détail des figures 6A et 6C respectivement montrant les premiers et seconds moyens de suspension,
• la figure 7 est une vue en perspective d'une installation possible d'un réservoir conforme à l'invention sur un véhicule automobile,
• les figures 8a à 8m illustrent de façon schématique des exemples de section de contenants pouvant être mis en œuvre dans un réservoir conforme à l'invention,
• la figure 9A illustre de façon schématique un contenant, selon un sixième mode de réalisation mis en œuvre dans un réservoir de véhicule automobile conforme à l'invention,
• la figure 9B est une vue en coupe transversale du contenant de la figure 9A,
• les figures 9C et 9D sont des vues de détail des éléments constituant l'ossature de renfort du contenant de la figure 9A,
• les figures 10A à 10C illustrent une approche particulière de suspension par sangles d'un contenant à l'enveloppe externe d'un réservoir conforme à l'invention,
• les figures 11A à 11C illustrent une autre approche particulière de suspension par sangles d'un contenant à l'enveloppe externe d'un réservoir conforme à l'invention,
• les figures 12A à 12C illustrent encore une autre approche particulière de suspension par sangles d'un contenant à l'enveloppe externe d'un réservoir conforme à l'invention, et
• la figure 13 illustre partiellement une autre approche particulière de suspension par sangles d'un contenant à l'enveloppe externe d'un réservoir conforme à l'invention.

Other characteristics and advantages of the invention will appear more clearly on reading the following description of embodiments, given by way of simple illustrative and nonlimiting examples, and of the appended drawings, among which:

• the figure 1 is a perspective view of a first embodiment of a container used in a tank according to the invention;
• the figure 2 is a perspective view of a second embodiment of a container used in a tank according to the invention;
• the figure 3 is a perspective view of a third embodiment of a container used in a tank according to the invention;
• the figure 4 is a perspective view of a fourth embodiment of a container used in a tank according to the invention;
• the figure 5A is a perspective view of a fifth embodiment of a container used in a tank according to the invention;
• the figure 5B is a detail view of the container of the figure 5A showing the passage of a reinforcement bar in the branches of the reinforcement plates of the container;
• the Figures 6A and 6C are perspective views of a tank according to the invention having first and second means for suspending the container from the external envelope;
• the figures 6B and 6D are detail views of Figures 6A and 6C respectively showing the first and second suspension means,
• the figure 7 is a perspective view of a possible installation of a tank according to the invention on a motor vehicle,
• the figures 8a to 8m schematically illustrate examples of section of containers that can be used in a tank according to the invention,
• the figure 9A schematically illustrates a container, according to a sixth embodiment implemented in a motor vehicle tank according to the invention,
• the figure 9B is a cross-sectional view of the container of the figure 9A ,
• the Figures 9C and 9D are detailed views of the elements constituting the reinforcing framework of the container of the figure 9A ,
• the Figures 10A to 10C illustrate a particular approach for suspending by straps from a container to the external envelope of a tank according to the invention,
• the Figures 11A to 11C illustrate another particular approach for suspending by straps from a container to the external envelope of a tank according to the invention,
• the Figures 12A to 12C illustrate yet another particular approach for suspending by straps of a container from the external envelope of a tank according to the invention, and
• the figure 13 partially illustrates another particular approach of suspension by straps of a container to the external envelope of a reservoir according to the invention.

5. Detailed description of the invention

The invention relates to a tank for a motor vehicle intended to contain liquefied gas, such as liquefied natural gas.

• un contenant de stockage de gaz liquéfié, le contenant comprenant une structure de renfort interne, et
• une enveloppe externe de protection disposée autour dudit contenant, ledit contenant interne et ladite enveloppe externe présentant chacun une forme générale sensiblement parallélépipédique.

According to the invention, the tank comprises:

• a liquefied gas storage container, the container comprising an internal reinforcing structure, and
• an external protective envelope disposed around said container, said internal container and said external envelope each having a generally substantially parallelepiped shape.

We have represented on the figure 1 , in perspective, a container, according to a first embodiment, implemented in a motor vehicle tank according to the invention.

The interior space of the container 100 constitutes a sealed enclosure for the storage of liquefied natural gas under pressure (up to 20 bars, for example).

The container 100 is intended to be housed in an external envelope (not shown) of the tank.

The container 100 and the external envelope each have a generally substantially parallelepiped shape.

In this example, the container 100 is made of aluminum and has a length of two meters.

The container 100 extends longitudinally along the longitudinal axis Ax and its cross section to the axis Ax is a square whose angles are rounded (the cross section of the container could be rectangle).

The lateral faces 102, 103 situated at the longitudinal ends of the container 100 are slightly curved or curved towards the outside thereof in order to improve the distribution of the stresses linked to the pressure of the liquefied natural gas under pressure.

The container 100 further comprises several reinforcing plates 110 that are flat or have reliefs, disposed inside the container 100 and spaced along the longitudinal axis Ax.

These plates extend transversely to the longitudinal axis Ax and their outer periphery comes into contact with the internal wall of the container 100.

The reinforcement plates 110 have a plurality of openings 111. Such openings allow the homogeneous distribution of the pressurized fluid throughout the container 100.

As shown, the container 100 comprises seven reinforcing plates 110 each comprising five openings 111, namely a central opening 112 and four peripheral openings 113.

The openings 111 of each reinforcement plate 110 are aligned with the openings 111 of the adjacent reinforcement plates 110.

The parallelepiped shape of the container 100 optimizes its fuel storage capacity and allows optimal integration into the architecture of the vehicle.

The figure 2 illustrates a container, according to a second embodiment, implemented in a motor vehicle tank according to the invention.

The container 200 extends longitudinally along the axis Ax and its cross section along the axis Ax is a square (or a rectangle) whose angles are rounded.

The container 200 is intended to be housed in an external envelope (not shown) of the tank.

The container 200 and the outer envelope each have a generally substantially parallelepiped shape.

The lateral faces 202, 203 situated at the longitudinal ends of the container 200 are slightly curved towards the inside of the latter or curved towards the outside of the latter.

The container 200 further comprises several planar reinforcing plates 210 disposed inside the container 200 and spaced along the longitudinal axis Ax.

These plates extend transversely to the longitudinal axis Ax and their outer periphery comes into contact with the internal wall of the container 200.

The reinforcement plates 210 have a single central opening 212.

The lateral faces 202, 203 of the container 200 each carry a plate 220, 230 respectively.

The plates 220, 230 are connected by a tube or a rod 240 passing longitudinally through the container 200 passing through the central opening of each internal reinforcement plate 210.

The tube or rod 240 projects from the outer surface of each of the plates 220, 230.

The tube or rod 240 allows the funds, or side walls, of the container 200 to be maintained, and thus serves as reinforcement.

• un élément de connexion à un autre réservoir ;
• une jauge de niveau ;
• une soupape de sécurité ;
• un dispositif de remplissage du contenant.

At least one of the plates 220, 230 carries in particular at least one of the following elements:

• a connection element to another tank;
• a level gauge;
• a safety valve;
• a container filling device.

It will be noted that all or part of these elements can, as a variant, be carried by at least one of the side and / or longitudinal walls of the external envelope in which the container is intended to be housed.

The figure 3 illustrates a container, according to a third embodiment, implemented in a motor vehicle tank according to the invention.

The container 300 extends longitudinally along the axis Ax and its cross section along the axis Ax is a square (or a rectangle) whose angles are rounded.

The container 300 is intended to be housed in an external envelope (not shown) of the tank.

The container 300 and the outer envelope each have a generally substantially parallelepiped shape.

The lateral faces 302, 303 situated at the longitudinal ends of the container 300 are planar.

The container 300 further comprises several planar reinforcement plates 310 disposed inside the tank 300 and spaced along the longitudinal axis Ax. These plates extend transversely to the longitudinal axis Ax and their outer periphery comes into contact with the internal wall of the container 300.

The reinforcement plates 310 have a single central opening 312.

Furthermore, several parallel recesses 305 extend around the periphery of the outer surface of the container 300.

As illustrated, the recesses 305 have a semi-circular section and extend transversely to the longitudinal axis Ax over the entire periphery of the container 300.

Such recesses 305 make it possible to improve the mechanical resistance of the container 300 to the internal pressure of the liquefied natural gas.

It can also be envisaged, as an alternative, that the recesses have a different shape and / or that they extend partially around the periphery of the outer surface of the container.

The figure 4 illustrates a container, according to a fourth embodiment, implemented in a motor vehicle tank according to the invention.

The container 400 extends longitudinally along the axis Ax and its cross section along the axis Ax is a square (or a rectangle) whose angles are rounded.

The container 400 is intended to be housed in an external envelope (not shown) of the tank.

The container 400 and the outer envelope each have a generally substantially parallelepiped shape.

The container 400 comprises several flat reinforcement plates 410 arranged inside the container 400 and spaced along the longitudinal axis Ax. These reinforcement plates 410 extend transversely to the longitudinal axis Ax and their outer periphery comes into contact with the internal wall of the container 400.

Each reinforcement plate 410 comprises a single central opening 412 and several lateral slots 414.

Such slots 414 allow the passage of reinforcement crosspieces 450 disposed against the internal wall of the container 400 and extending along the longitudinal axis Ax over the entire length of the container 400.

A tube or rod 440 passing longitudinally through the container 400 passing through the central opening 412 of each internal reinforcement plate 410.

The tube or rod 440 projects from the outer surface of the side faces 402, 403, and serves as a reinforcement.

The figure 5A illustrates a container, according to a fifth embodiment, implemented in a motor vehicle tank according to the invention, the figure 5B being a detail view of the container.

The container 500 (illustrated without its side walls) is intended to be housed in an external envelope (not shown) of the tank.

The container 500 and the external envelope each have a generally substantially parallelepiped shape, the section of the container 500 being slightly smaller than that of the external envelope so that it can be accommodated there.

The square (or rectangular) section of the container 500 allows an increase in the useful volume of the latter.

In this example, the container 500 is made of aluminum, has a length of 2.30 m and a storage capacity of 584 liters of gas (or 188 kg of gas).

The tank has a weight of 329 kg.

Compared to a stainless steel tank of the same length and of cylindrical section, the parallelepipedal aluminum tank of the invention has a reduced weight of the order of 3% and a useful volume of the container increased by 4%, which allows fuel savings and reduced CO2 emissions.

The parallelepiped shape of the container 500 optimizes its fuel storage capacity and the parallelepiped shape of the external envelope allows optimal integration of the tank into the architecture of the vehicle.

For a similar vehicle architecture, a tank according to the invention has a higher fuel storage capacity of the order of 12 to 25% compared to the cylindrical tanks of the prior art.

• une ossature de renfort 550, destinée à être disposée contre la paroi interne du contenant 500, de forme générale sensiblement parallélépipédique et dont la section transversale, selon l'axe longitudinale Ax, est sensiblement carrée (les angles étant arrondis). L'ossature de renfort 550 comprend plusieurs rainures longitudinales 551, présentant une forme en "U", qui s'étendent sur sa surface extérieure et dans lesquelles des lumières traversantes sont ménagées à intervalles réguliers selon l'axe longitudinal Ax.
• plusieurs plaques de renfort 510 planes. Chaque plaque de renfort 510 présente une portion centrale 510' pleine à partir de laquelle s'étendent dans le plan de la portion centrale 510' plusieurs branches 515 espacées les unes des autres autour de cette portion centrale 510'.

The container 500 here has a reinforcing structure comprising:

• a reinforcing frame 550, intended to be disposed against the internal wall of the container 500, of generally substantially parallelepiped shape and whose cross section, along the longitudinal axis Ax, is substantially square (the angles being rounded). The reinforcing frame 550 comprises several longitudinal grooves 551, having a "U" shape, which extend over its outer surface and in which through lights are formed at regular intervals along the longitudinal axis Ax.
• several 510 flat reinforcement plates. Each reinforcement plate 510 has a solid central portion 510 ′ from which extend in the plane of the central portion 510 ′ several branches 515 spaced apart from each other around this central portion 510 ′.

The ends 516 of the branches 515 pass through the openings made in the grooves 551 of the reinforcing frame 550 and project relative to the bottom of the grooves (without however exceeding the portions of the outer surface of the frame connecting the grooves).

Each of these projecting ends 516 has a slot 517 for the passage of a connecting bar 560 of the reinforcement plates 510 to the reinforcement frame 550.

As illustrated on Figures 5A and 5B , the securing bars 560 pass through the aligned slots of each of the reinforcement plates 510.

These connecting bars 560 allow a distribution of the stresses along the container 500 and the maintenance of the internal reinforcement plates 510.

Thus, the reinforcement plates 510 are arranged inside the reinforcement framework 550 and are spaced along the longitudinal axis Ax.

These reinforcement plates 510 extend transversely to the longitudinal axis Ax and have a star structure.

As illustrated, the solid central portion section 510 ′ of the reinforcement plate 510 is square, the angles being rounded. From each of these rounded angles extend three straight branches 515 spaced apart from each other by an angle α of 45 ° in this example and whose central branch is aligned, or substantially aligned, with the diagonal of the central portion full 510 '.

Furthermore, a reinforcement tube or rod 540 extends parallel to the longitudinal axis Ax and passes through the reinforcement plates 510 in the middle.

Note that the container 500, the reinforcing frame 550 and the reinforcing plates 510 are made of aluminum, for example, and that the reinforcing frame 550 and the reinforcing plates 510 are, for example, welded together. other.

The reinforcement frame 550 is a corrugated aluminum sheet welded around the reinforcement plates 510.

Alternatively, the reinforcing frame 550 is made of another material, such as a composite material.

• un élément de connexion à un autre réservoir ;
• une jauge de niveau ;
• une soupape de sécurité ;
• un dispositif de remplissage du contenant.

At least one of the side (bottom) and / or longitudinal walls of the container 500 carries in particular at least one of the following elements:

• a connection element to another tank;
• a level gauge;
• a safety valve;
• a container filling device.

It will be noted that all or part of these elements can, as a variant, be carried by at least one of the side and / or longitudinal walls of the external envelope in which the container is intended to be housed.

The figure 9A illustrates a container 900, according to a sixth embodiment implemented in a motor vehicle tank according to the invention.

The container 900 is intended to be housed in an external envelope (not shown) for protecting the tank.

The container 900 and the external envelope each have a generally substantially rectangular shape, with rounded angles, the section of the container 900 being slightly smaller than that of the external envelope so that it can be accommodated therein.

The substantially square section of the container 900 allows an increase in the useful volume of the latter.

The parallelepiped shape of the container 900 optimizes its fuel storage capacity and the parallelepiped shape of the external envelope allows optimal integration of the tank into the architecture of the vehicle.

• une ossature de renfort 950 comprenant une pluralité d'anneaux de renfort 940 constitués chacun d'un câble souple en acier inoxydable, de diamètre égal à 10 mm dans cet exemple. L'ossature de renfort 950 est destinée à venir en appui contre les parois longitudinales internes du contenant 900. La section transversale de l'ossature de renfort 950 est sensiblement octogonale. L'ossature de renfort 950 comprend également des rails de renfort 920 et des barres de renforts 930 configurés pour fixer la pluralité d'anneaux de renfort 940 au niveau de chacun de leurs angles sur les parois longitudinales internes du contenant 900. Les barres de renfort 930 permettent d'espacer et de solidariser la pluralité d'anneaux de renfort 940 entre eux. Pour ce faire, les barres de renfort 930 présentent sur leur longueur des encoches 9301 espacées dans lesquelles passent les anneaux de renfort 940 (en variante, un unique câble peut être enroulé à la manière d'un bobinage autour des barres de renforts 930 et passer dans les encoches 9301). Ces barres de renfort 930 sont chacune solidarisées à un rail de renfort 920 fixé par soudure, par exemple, le long d'une paroi longitudinale interne du contenant 900. Quatre paires de rails de renfort 920 sont fixées au centre de chacune des quatre parois longitudinales internes du contenant 900. Les rails de renfort 920 et les barres de renforts 930 s'étendent le long des parois internes du contenant 900, parallèlement à l'axe longitudinal Ax de ce dernier. Chaque rail de renfort 920 présente une rainure dans laquelle vient se loger en partie par coulissement un bourrelet d'une barre de renfort 930 comme illustré sur la figure 9C. Le montage de l'ossature de renfort 950 dans le contenant 900 est ainsi relativement aisé ;
• plusieurs plaques de renfort 910 planes. Ces plaques de renfort 910 sont percées de plusieurs ouvertures pour la circulation du gaz et s'étendent le long des quatre angles de la paroi longitudinale interne du contenant 900. Ces plaques de renfort 910 sont fixées sur leurs bords latéraux à deux faces internes adjacentes du contenant 900, de manière à ce qu'un espace soit ménagé entre la plaque de renfort 910 d'angle et l'angle arrondis correspondant du contenant 900.

The container 900 here has a reinforcing structure comprising:

• a reinforcing frame 950 comprising a plurality of reinforcing rings 940 each consisting of a flexible stainless steel cable, of diameter equal to 10 mm in this example. The reinforcing frame 950 is intended to come into abutment against the internal longitudinal walls of the container 900. The cross section of the reinforcing frame 950 is substantially octagonal. The reinforcement frame 950 also includes reinforcement rails 920 and reinforcement bars 930 configured to fix the plurality of reinforcement rings 940 at each of their angles on the internal longitudinal walls of the container 900. The reinforcement bars 930 allow the plurality of reinforcement rings 940 to be spaced and joined together. To do this, the reinforcement bars 930 have spaced apart slots 9301 along their length through which the reinforcement rings 940 pass (in a variant, a single cable can be wound in the manner of a winding around the reinforcement bars 930 and pass in notches 9301). These reinforcement bars 930 are each secured to a reinforcement rail 920 fixed by welding, for example, along an internal longitudinal wall of the container 900. Four pairs of reinforcement rails 920 are fixed to the center of each of the four longitudinal walls internal of the container 900. The reinforcement rails 920 and the reinforcement bars 930 extend along the internal walls of the container 900, parallel to the longitudinal axis Ax of the latter. Each reinforcement rail 920 has a groove in which is housed in part by sliding a bead of a reinforcement bar 930 as illustrated in the figure 9C . The mounting of the reinforcing frame 950 in the container 900 is thus relatively easy;
• several 910 flat reinforcement plates. These reinforcing plates 910 are pierced with several openings for the circulation of gas and extend along of the four corners of the internal longitudinal wall of the container 900. These reinforcement plates 910 are fixed on their lateral edges to two adjacent internal faces of the container 900, so that a space is provided between the reinforcement plate 910 of corresponding rounded angle and angle of container 900.

The figure 9B is a cross-sectional view of the container 900 showing the arrangement of a ring 940 of the reinforcing frame 950, the reinforcing plates 910 at an angle, the reinforcing rails 920, and the reinforcing bars 930.

The figure 9D is a detail view showing the attachment of several rings 940 on the reinforcement bars 930 of the reinforcement frame 950. Successive rings 940 of substantially octagonal shape are thus fixed to several reinforcement bars 930, thus forming a group of rings spaced at regular intervals along the longitudinal axis Ax of the container 900. This group of rings 940 is fixed to the internal wall of the container 900 by sliding the reinforcement bars 930 in the grooves of the reinforcement rails 920 fixed to the internal wall from container 900.

It is noted that the container 900, the elements constituting the reinforcing frame 950 (with the exception of the reinforcing rings 940) and the reinforcing plates 910 are made of aluminum, for example.

• un élément de connexion à un autre réservoir ;
• une jauge de niveau ;
• une soupape de sécurité ;
• un dispositif de remplissage du contenant.

At least one of the side and / or longitudinal walls of the container 900 carries in particular at least one of the following elements:

• a connection element to another tank;
• a level gauge;
• a safety valve;
• a container filling device.

It will be noted that all or part of these elements can, in a variant, be carried by at least one of the side walls of the external envelope in which the container is intended to be housed.

The Figures 6A to 6D illustrate a reservoir 6 according to the invention comprising a container 600 and an outer envelope 60, the walls of which are spaced apart.

The space between the wall of the container and the wall of the outer envelope is, for example, between 25 and 50 mm.

These two elements, which are visible in transparency on the figure 6A , each have a generally substantially parallelepiped shape, the section of the container 600 being slightly smaller than that of the outer casing 60 so that it can be accommodated there.

The container 600 can be one of the containers of the six embodiments described above.

Between the spaced walls of the container 600 and the outer envelope 60 are arranged a multi-layer insulator and / or a vacuum (which thus make it possible to avoid heat exchanges by indirect contact between the container and the outer envelope).

The reservoir 6 implements suspension means MS1, MS2 from the container 600 to the external envelope 60.

These suspension means make it possible in particular to compensate for the thermal expansion / retraction of the internal container due to cooling by limiting the contributions of stresses.

The Figures 6A and 6B show the first means of suspension MS1 and the Figures 6C and 6D show the second suspension means MS2.

• un plot 606 de forme tronconique porté par une première face latérale 602 externe du contenant 600, et
• un anneau de suspension 64 porté par une première face latérale interne de l'enveloppe externe 60 et destiné à être emmanché sur le plot 606, la face latérale interne de l'enveloppe externe 60 étant située en regard de la première face latérale 602 externe du contenant 600.

As illustrated on Figures 6A and 6B , the first suspension means MS1 include:

• a stud 606 of frustoconical shape carried by a first lateral lateral face 602 of the container 600, and
• a suspension ring 64 carried by a first internal lateral face of the external envelope 60 and intended to be fitted onto the stud 606, the internal lateral face of the external envelope 60 being situated opposite the first external lateral face 602 of the containing 600.

Furthermore, the height of the stud 606 is less than the thickness of the suspension ring 64.

Thus, when the suspension ring 64 is fitted onto the pad 606, the flat surface of the pad 606 is not in contact with the first internal lateral face of the external envelope 60.

The suspension ring 64 is made of a thermally insulating material to limit heat transfer by conduction.

These aspects thus make it possible to avoid heat exchanges by direct contact between the container 600 and the external envelope 60. It is indeed crucial to prevent the temperature of the liquefied natural gas from increasing and that it remains in liquid form. .

As illustrated on Figures 6C and 6D , the second suspension means MS2 comprise several straps 67 located on the side of the second external lateral face 603 of the container 600 and of the second internal lateral face of the external envelope 60 which are arranged opposite.

In the example illustrated on the figure 6C , four straps 67 are provided, connecting each of the edges or edges of the container 600 to each of the edges or edges of the external envelope 60.

Each of the straps 67 is made of a thermally insulating material to limit heat transfer by conduction.

• à une première extrémité à un support 631 solidaire de l'enveloppe externe 60, et
• à une deuxième extrémité d'un élément 632 en forme de "Y" qui est monté mobile sur un support 607 solidaire du contenant 600 (figure 6D).

Each strap 67 is pivotally connected:

• at a first end to a support 631 secured to the outer casing 60, and
• at a second end of an element 632 in the shape of a "Y" which is movably mounted on a support 607 secured to the container 600 ( figure 6D ).

A nut 634 which is mounted on a threaded rod 633 forming the base of the "Y" makes it possible to move in translation (in the directions of the double arrow of the figure 6D ) element 632 in the shape of a "Y" and therefore of adjusting the tension of the strap 67.

The tension of the straps 67 is chosen so as to minimize the sloshing of the container 600, even in the event of a vehicle collision.

The first and second suspension means may take other forms and be, for example, in the form of springs or silentblocs.

• un plot 606 de forme tronconique porté par chaque face latérale 602 externe du contenant 600, et
• un anneau de suspension 64 porté par chaque face latérale interne de l'enveloppe externe 60 et destiné à être emmanché sur un plot 606, chaque face latérale interne de l'enveloppe externe 60 étant située en regard d'une face latérale 602 externe du contenant 600.

In a particular embodiment, the first and second suspension means MS1, MS2 each comprise:

• a stud 606 of frustoconical shape carried by each external lateral face 602 of the container 600, and
• a suspension ring 64 carried by each internal lateral face of the external envelope 60 and intended to be fitted onto a stud 606, each internal lateral face of the external envelope 60 being situated opposite an external lateral face 602 of the container 600.

In another particular embodiment, the first and second suspension means MS1, MS2 comprise several straps 67 located on the side of each external lateral face 603 of the container 600 disposed opposite an internal lateral face of the external envelope 60.

This allows the forces to be resumed symmetrically.

The suspension means offer a minimum degree of freedom and allow movement of the container 600 relative to the external envelope 60.

This relative movement of the container 600 relative to the external envelope 60, along at least one of the three axes x, y and z ( figure 6C ), is less than or equal to 10 mm and can be in particular between 1 and 6 mm, preferably between 1 and 4 mm.

Thus, a slight movement of the container 600 relative to the outer envelope 60 is allowed due to this suspension.

Several other approaches for suspending by straps from the container 600 to the external envelope 60 are illustrated in relation to the Figures 10A to 13 .

In the approach illustrated on Figures 10A to 10C , the straps 67 of insulating material are arranged on the periphery of each side face of the container 600 (only one side face being visible in these figures).

• à un support 631 solidaire de l'enveloppe externe 60 à une première extrémité, et
• à un élément bloc 635 vissé sur le contenant 600 à une deuxième extrémité.

Each strap 67 is pivotally connected:

• to a support 631 secured to the outer casing 60 at a first end, and
• to a block element 635 screwed onto the container 600 at a second end.

The block element 635 and the support 631 each comprise an axis 637, 636 respectively around which comes to wind one end of the strap 67.

An aluminum or stainless steel ring 638 is positioned against a stop welded to the outer casing 60. This ring 638 allows the bottom of the container 600 to be wedged. It is made up of several mechanically welded parts. The strap supports 631 are welded to the ring 638 and in the same material as the latter (aluminum or stainless steel).

The tension adjustment system of each strap 67 is carried by the corresponding block element 635 which has a general "U" shape.

This block element 635 comprises fixing screws 639A of the block element 635 on the container 600, a first slide 640 on which the axis 637 of the strap 67 is mounted and a second slide 641 serving as a nut for two screws. setting 639B. It is possible to adjust the tension of the strap 67 by adjusting the position of the first slide 640 carrying the axis 637 in the direction of the double arrow F1 relative to the second slide 641. To do this, we act on the adjusting screw 639B so as to move the second slide 641 in the direction of the double arrow F2, that is to say in a direction perpendicular to the direction of movement of the first slide 640. These movements of the slides in two perpendicular planes are ensured by the implementation of inclined planes on each of the slides 640, 641 which are arranged opposite ( figure 10C ).

In the approach illustrated on Figures 11A to 11C , the straps 67 of insulating material are arranged on the periphery of each side face of the container 600 (only one side face being visible in these figures).

• à un support 631 soudé sur l'enveloppe externe 60 à une première extrémité, et
• à un élément bloc 635 vissé sur le contenant 600 à une deuxième extrémité.

Each strap 67 is pivotally connected:

• to a support 631 welded to the outer casing 60 at a first end, and
• to a block element 635 screwed onto the container 600 at a second end.

The block element 635 and the support 631 each comprise an axis 637, 636 respectively around which comes to wind one end of the strap 67.

The tension adjustment system of each strap 67 is carried by the corresponding block element 635 which has a general "U" shape.

This block element 635 comprises fixing screws 639A of the block element 635 on the container 600, a slide 640 on which the axis 637 of the strap 67 is mounted and adjustment screws 639B. It is possible to adjust the tension of the strap 67 by adjusting the position of the slide 640 carrying the axis 637 in the direction of the double arrow F1. To do this, one acts on the adjustment screws 639B on which the slide 640 rests.

In the approach illustrated on Figures 12A to 12C , the straps 67 of insulating material are arranged on the periphery of each side face of the container 600 (only one side face being visible in these figures).

• à un support 642 en forme de "U" soudé sur l'enveloppe externe 60 à une première extrémité, et
• à un support 643 en forme de "U" qui est monté mobile sur un support 644 fixe en forme de "U" solidaire du contenant 600 à une deuxième extrémité.

Each strap 67 is pivotally connected:

• to a U-shaped support 642 welded to the outer casing 60 at a first end, and
• to a support 643 in the shape of a "U" which is movably mounted on a fixed support 644 in the shape of "U" secured to the container 600 at a second end.

The supports 642, 643 each comprise an axis 636, 637 respectively around which comes to wind one end of the strap 67.

Two adjustment screws 639B which pass through the supports 643, 644 allow movement in translation (in the directions of the double arrow F1 of the figure 12C ) the support 643 movable relative to the fixed support 644 and therefore adjust the tension of the strap 67.

Another approach is partially illustrated on the figure 13 .

This particular approach implements, for each strap 67, two slides 646 carrying the axis 636 of the strap 67, the slides 646 being able to slide along the longitudinal axis of the container 600 in a rail 645 welded to the external envelope. 60.

Adjusting the tension of the strap 67 therefore requires adjusting the position of the two slides 646.

In this figure, the fixing of the strap 67 to the container 600 is not shown.

The figure 7 illustrates an example of installation of a tank according to the invention on a motor vehicle, in this case a heavy goods vehicle, of which only the support frames 9, 9 ′ are visible.

A section through the wall of the reservoir 7 makes it possible to distinguish the various constituent elements of such a reservoir.

The structure of the reservoir 7 as shown corresponds to that of the reservoir of the embodiment illustrated in the Figures 5A and 5B .

Such a reservoir 7 therefore comprises an external envelope 70 surrounding a container 700, the latter comprising a reinforcing frame 750. The branches 715 of the reinforcing plates 710, extend transversely to the longitudinal axis of the reservoir 7, and are secured to the reinforcement frame 750 by reinforcement bars 760.

A side and / or longitudinal wall of the tank 7 is mechanically and fluidly coupled to a technical box 8.

The tank 7 and the technical box 8 are fixed to the support frames 9, 9 'of the vehicle by means of straps 10, 10'.

A distinction is made between the insulating means arranged in the space between the walls of the external envelope 70 and of the container 700.

In all the embodiments described above, the external envelope of the tank can be made of any material adapted to resist fire and possibly other safety constraints.

According to a particular implementation, the external surface of the external envelope can be covered with at least one layer of material adapted to resist fire.

It may be a fire-resistant paint or another type of coating which is applied to the external and / or internal surface of the external envelope and / or to the external surface of the container.

Other aspects and variants

The tank according to the invention can be installed on other types of motor vehicles, such as buses.

The figures 8a to 8m illustrate the section of different containers of a tank according to the invention obtained by an extrusion process.

These container structures in one piece use internal reinforcements extending longitudinally.

• quatre canaux en forme de goutte d'eau qui sont disposés bords à bords sur la figure 8a,
• quatre canaux tubulaires sur la figure 8b,
• quatre canaux en forme de goutte d'eau qui se chevauchent sur la figure 8c,
• un canal central bordé par des canaux périphériques sur la figure 8d,
• un canal tubulaire central bordé par des canaux tubulaires périphériques sur la figure 8e,
• des rangées de canaux tubulaires sur les figures 8f et 8i,
• une combinaison de canaux en forme de nid d'abeille entourant quatre canaux de section carrée sur la figure 8g,
• des canaux en nid d'abeilles entourant un canal central sur la figure 8h,
• un canal central tubulaire entouré de canaux partiellement tubulaires sur la figure 8I.

On the Figures 8a to 8i , each of the containers has an external section of square shape with rounded edges and an internal structure comprising:

• four drop-shaped channels that are arranged edge to edge on the figure 8a ,
• four tubular channels on the figure 8b ,
• four overlapping teardrop channels on the figure 8c ,
• a central channel bordered by peripheral channels on the figure 8d ,
• a central tubular channel bordered by peripheral tubular channels on the figure 8e ,
• rows of tubular channels on the Figures 8f and 8i ,
• a combination of honeycomb shaped channels surrounding four square section channels on the figure 8g ,
• honeycomb channels surrounding a central channel on the figure 8h ,
• a central tubular channel surrounded by partially tubular channels on the figure 8I .

The containers of figures 8j and 8k have a curved and polygonal external section respectively without internal reinforcement structure.

The container of the figure 8m has an external section in four-leaf clover with an internal reinforcement channel.

The tank of the invention can be assembled with other tanks of the same type.

Thus, the tank obtained by such an assembly can be housed in vehicle compartments of complex shapes.

In other words, the shape of the tank can be adapted to the volumes available on the vehicle chassis.

It should be noted that the lateral faces situated at the longitudinal ends of the container can be curved, curved or flat.

Furthermore, the longitudinal faces of the container (defining the body of the container) may have a curve.

The tank of the invention can contain any type of liquefied gas, such as LNG (liquid methane), or liquid nitrogen for refrigerated trucks, for example.

Furthermore, the number of suspension straps is not limited to the examples illustrated.

Of course, the invention is not limited to the examples which have just been described and numerous modifications can be made to these examples without departing from the scope of the invention. In particular, the different characteristics, forms, variants and embodiments of the invention can be associated with one another in various combinations insofar as they are not incompatible or mutually exclusive of each other. In particular, all the variants and embodiments described above can be combined with one another.

Claims (15)

1. Tank (5, 9) for a motor vehicle, intended for containing liquefied gas, such as liquefied natural gas, characterised in that it comprises:

   - a liquefied gas storage container (500, 900), the container comprising an internal reinforcement structure, and

   - a protective external shell arranged around said container,

   said container and said external shell each having a substantially parallelepiped general shape, said container (500, 900) being secured to said external shell by suspension means (MS1, MS2) allowing a relative movement of said container (500, 900) with respect to said external shell.
2. Tank (5, 9) according to claim 1, characterised in that the suspension means (MS1, MS2) allow a relative movement of said container (500, 900) with respect to said external shell of less than 10 mm.
3. Tank (5, 9) according to claim 1 or 2, characterised in that said container (500, 900) is connected to a first side end of said external shell by suspension straps (67) and to a second side end of said external shell by a suspension ring (64).
4. Tank (5, 9) according to claim 3, characterised in that said suspension ring (64) is attached to the inner surface of a side wall of said external shell and is fitted on to a stud (606) supported by the outer surface of a side wall (602) of the container (500, 900).
5. Tank (5, 9) according to claim 3 or 4, characterised in that said suspension straps (67) and said suspension ring (64) are made of a thermally insulating material.
6. Tank (5, 9) according to claim 1 or 2, characterised in that said container (500, 900) is connected to a first side end of said external shell by suspension straps (67) and to a second side end of said external shell by suspension straps (67).
7. Tank (5, 9) according to any one of the preceding claims, characterised in that said internal reinforcement structure comprises a reinforcement frame (950) secured to the internal wall of said container (900), said reinforcement frame (950) comprising multiple reinforcement rings (940) spaced out along the longitudinal axis Ax of said container (900) and extending transversely to said longitudinal axis Ax.
8. Tank (5, 9) according to claim 7, characterised in that said reinforcement rings (940) are mounted spaced out on reinforcement bars (930) extending parallel to the longitudinal axis Ax and arranged on the perimeter of the reinforcement rings (940), said reinforcement bars (930) each being secured to a reinforcement rail (920) attached to the internal wall of said container (900).
9. Tank (9) according to claim 7 or 8, characterised in that said internal reinforcement structure comprises multiple corner reinforcement plates (910) attached to the internal wall of said container (900) and each one connecting two adjacent internal faces of said container (900).
10. Tank (5, 9) according to any one of the preceding claims, characterised in that the container (500, 900) is made of aluminium.
11. Tank (5, 9) according to any one of the preceding claims, characterised in that said external shell is made of a fire-resistant material.
12. Tank (5, 9) according to any one of claims 1 to 10, characterised in that said external shell is covered with a fire-resistant coating.
13. Tank (5, 9) according to any one of the preceding claims, characterised in that the wall of the container (500, 900) and the wall of the external shell are spaced apart, the space between these walls being filled with insulating means.
14. Tank (5, 9) according to any one of the preceding claims, characterised in that the outer surface of at least one side wall and/or longitudinal wall of the container (500, 900) or of the external shell comprises a connection board (220, 230) supporting in particular at least one of the following elements:

    - an element for connecting to another tank;

    - a level gauge;

    - a safety valve;

    - a container filling device.
15. Motor vehicle, such as a heavy goods vehicle, comprising at least one tank according to any one of claims 1 to 14.

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