EP3421864A1 - Liquefied natural gas tank for motor vehicles - Google Patents

Abstract

The invention relates to a tank (5, 9) for a motor vehicle for containing liquefied gas, such as liquefied natural gas, comprising: a container (500, 900) for storing liquefied gas, the container comprising an internal reinforcing structure, and an outer protective envelope (50) disposed around said container, said container and said outer casing each having a substantially parallelepipedal general shape and said container (500, 900) being secured to said outer casing (50) by suspension means (MS1, MS2) allowing relative movement of said container (500, 900 ) relative to said outer shell (50).

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 heavy goods vehicles operating on liquefied natural gas, has entered a significant growth phase.

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

Liquefaction reduces the gaseous volume of natural gas and stores 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 feed the truck engine.

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

Liquefied natural gas tanks of trucks are designed to meet strict safety requirements, including pressure and maintaining a very low temperature, to maintain the gas in its liquid phase.

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

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

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

3. Presentation of the invention

The invention proposes 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 reservoir comprises:

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

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

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

The fastening of the container to said outer envelope by suspension means allows to provide a degree of freedom between the two elements, so as to limit heat transfer by conduction and to compensate the thermal expansion / retraction due to the cooling of the internal container by limiting the stress inputs.

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

The parallelepipedal shape of the container optimizes its storage capacity in liquefied gas and the parallelepipedal shape of the outer casing allows optimal integration of the reservoir to the vehicle architecture.

Preferably, these suspension means allow a relative displacement of said container with respect to said outer envelope less than 10 mm, for example between 1 and 6 mm, and more specifically between 1 and 4 mm.

The thermal contraction of said container may 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 outer envelope by suspension straps and to a second lateral end of said outer envelope by a suspension ring.

According to a particular aspect of the invention, said suspension ring is attached to the inner surface of a side wall of said outer envelope and is fitted on a stud carried by the outer 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 may alternatively be springs or silentblocs when these suspension means are insulating.

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

These suspension straps are made of a thermally insulating material.

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

This reinforcing framework optimizes the mechanical strength of the container at the internal pressure of the liquefied gas and avoids the phenomena of inertia of the contained fluid.

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

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

According to a preferred embodiment, said internal reinforcing structure comprises a plurality of angle reinforcing plates fixed on the inner wall of said container and each connecting two adjacent inner 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 outer envelope is made of a fire-resistant material.

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

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

A fire resistant coating may be arranged alternatively or in addition to the outer surface of the container.

The internal reinforcing structure may 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 outer casing are distant from each other, the space between these walls being filled with insulating means.

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

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

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

Advantageously, said reinforcing plates are solid and have at least one orifice for passing the 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 through said reinforcing plates.

This reinforcing rod allows the maintenance of the bottoms, or side walls, of the container.

According to a particular embodiment of the invention, the internal reinforcing structure further comprises a reinforcement frame having a generally parallelepipedal shape and disposed against the inner wall of said container.

In a particular aspect, said reinforcing plates have a solid central portion from which extend several branches passing through the wall of said reinforcing framework.

Advantageously, the ends of the branches protruding from the outer surface of said reinforcement frame have a passage slot of a securing strip of the reinforcing plates to said reinforcement framework.

Advantageously, the securing strips extend in longitudinal grooves formed around the periphery of the outer surface of said reinforcing framework.

• 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 outer surface of at least one side and / or longitudinal wall of the container or of the outer casing 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 device for filling the container.

The invention also relates to a motor vehicle, such as a heavy vehicle, 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 oeuvre 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 oeuvre 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 oeuvre 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 oeuvre 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 oeuvre 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 oeuvre dans un réservoir conforme à l'invention,
• la figure 9A illustre de façon schématique un contenant, selon un sixième mode de réalisation mis en oeuvre 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 features and advantages of the invention will emerge more clearly on reading the following description of embodiments, given as simple illustrative and non-limiting examples, and the appended drawings, among which:

• the figure 1 is a perspective view of a first embodiment of a container implemented in a tank according to the invention;
• the figure 2 is a perspective view of a second embodiment of a container implemented in a tank according to the invention;
• the figure 3 is a perspective view of a third embodiment of a container implemented in a tank according to the invention;
• the figure 4 is a perspective view of a fourth embodiment of a container implemented in a tank according to the invention;
• the Figure 5A is a perspective view of a fifth embodiment of a container implemented 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 at the outer casing;
• the Figures 6B and 6D are detailed 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 illustrate schematically examples of section of containers that can be implemented 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 reinforcement framework of the container of the Figure 9A ,
• the Figures 10A to 10C illustrate a particular approach of suspension by straps of a container to the outer shell of a tank according to the invention,
• the Figures 11A to 11C illustrate another particular approach of suspension by straps of a container to the outer shell of a tank according to the invention,
• the Figures 12A to 12C illustrate yet another particular approach of suspension by straps of a container to the outer shell 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 outer shell of a tank according to the invention.

5. Detailed description of the invention

The invention relates to a tank for a motor vehicle for containing 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 reservoir comprises:

• a liquefied gas storage container, the container comprising an internal reinforcing structure, and
• an outer protective envelope disposed around said container, said inner container and said outer casing each having a generally parallelepipedal general shape.

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

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

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

The container 100 and the outer envelope each have a generally parallelepipedal 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 corners are rounded (the cross section of the container could be rectangle).

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

The container 100 further comprises a plurality of reinforcing plates 110 planes or having reliefs, disposed within 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 inner wall of the container 100.

The reinforcing plates 110 have a plurality of openings 111. Such openings allow the homogeneous distribution of the fluid under pressure throughout the container 100.

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

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

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

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 corners are rounded.

The container 200 is intended to be housed in an outer casing (not shown) of the reservoir.

The container 200 and the outer casing each have a generally parallelepipedal general shape.

The side faces 202, 203 at the longitudinal ends of the container 200 are slightly curved inwardly or curved outwardly therefrom.

The container 200 further comprises a plurality of plane reinforcing plates 210 disposed within 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 inner wall of the container 200.

The reinforcing 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 rod 240 longitudinally through the container 200 passing through the central opening of each internal reinforcing plate 210.

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

The tube or the rod 240 makes it possible to hold the bottoms or side walls of the container 200, and thus serves as a 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 device for filling the container.

Note that all or part of these elements may alternatively be carried by at least one of the side walls and / or longitudinal outer casing 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 corners are rounded.

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

The container 300 and the outer casing each have a generally parallelepipedal general shape.

The side faces 302, 303 located at the longitudinal ends of the container 300 are flat.

The container 300 further comprises a plurality of flat 310 reinforcing plates disposed within the reservoir 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 inner wall of the container 300.

The reinforcing plates 310 have a single central opening 312.

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

As illustrated, the recesses 305 have a semicircular 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 strength of the container 300 at the internal pressure of the liquefied natural gas.

It can also be envisaged, alternatively, 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 corners are rounded.

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

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

The container 400 comprises a plurality of flat reinforcing plates 410 disposed within the container 400 and spaced along the longitudinal axis Ax. These reinforcing plates 410 extend transversely to the longitudinal axis Ax and their outer periphery comes into contact with the inner wall of the container 400.

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

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

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

The tube or rod 440 protrudes 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 (shown without its side walls) is intended to be housed in an outer shell (not shown) of the tank.

The container 500 and the outer envelope each have a generally parallelepipedal general shape, the section of the container 500 being slightly smaller than that of the outer envelope so that it can be accommodated.

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 (188 kg of gas).

The tank has a weight of 329 kg.

Compared to a stainless steel tank of the same length and 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 saving fuel and reducing CO2 emissions.

The parallelepipedal shape of the container 500 optimizes its fuel storage capacity and the parallelepipedal shape of the outer shell allows optimal integration of the tank with the vehicle architecture.

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 inner wall of the container 500, of generally parallelepipedal shape and whose cross section, along the longitudinal axis Ax, is substantially square (the corners being rounded). The reinforcement framework 550 comprises a plurality of longitudinal grooves 551, having a "U" shape, which extend over its outer surface and in which through holes are provided at regular intervals along the longitudinal axis Ax.
• several reinforcing plates 510 planes. Each reinforcing plate 510 has a central portion 510 'full from which extend in the plane of the central portion 510' several branches 515 spaced from each other around this central portion 510 '.

The ends 516 of the branches 515 pass through the slots in the grooves 551 of the reinforcement frame 550 and protrude from the bottom of the grooves (without 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 securing bar 560 of the reinforcing plates 510 to the reinforcement frame 550.

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

These securing strips 560 allow a distribution of stresses along the container 500 and the maintenance of the internal reinforcing plates 510.

Thus, the reinforcing plates 510 are disposed within the reinforcement framework 550 and are spaced along the longitudinal axis Ax.

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

As illustrated, the solid center portion section 510 'of the backing plate 510 is square, the corners being rounded. From each of these rounded angles extend three rectilinear branches 515 spaced 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 '.

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

It will be noted that the container 500, the reinforcement frame 550 and the reinforcing plates 510 are made of aluminum, for example, and that the reinforcement frame 550 and the reinforcement plates 510 are, for example, welded to each other. other.

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

In one variant, the reinforcement 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 lateral (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 device for filling the container.

Note that all or part of these elements may alternatively be carried by at least one of the side walls and / or longitudinal outer casing 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 reservoir.

The container 900 and the outer envelope each have a generally parallelepipedal shape, with rounded corners, the section of the container 900 being slightly smaller than that of the outer 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 parallelepipedal shape of the container 900 optimizes its fuel storage capacity and the parallelepipedal shape of the outer shell allows optimal integration of the tank with the vehicle architecture.

• 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 framework 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 reinforcement framework 950 is intended to bear against the inner longitudinal walls of the container 900. The cross section of the reinforcement framework 950 is substantially octagonal. The reinforcement frame 950 also comprises reinforcement rails 920 and reinforcement bars 930 configured to secure the plurality of reinforcing rings 940 at each of their angles to the inner longitudinal walls of the container 900. Reinforcement bars 930 allow to space and secure the plurality of reinforcing rings 940 between them. To do this, the reinforcement bars 930 have spaced 9301 notches along which the reinforcement rings 940 pass (lengthwise, a single cable can be wound in the manner of a winding around the reinforcement bars 930 and pass in the notches 9301). These reinforcing bars 930 are each secured to a reinforcing rail 920 fixed by welding, for example, along an inner longitudinal wall of the container 900. Four pairs of reinforcing rails 920 are fixed in the center of each of the four longitudinal walls. The reinforcing rails 920 and reinforcing bars 930 extend along the inner walls of the container 900, parallel to the longitudinal axis Ax of the latter. Each reinforcing rail 920 has a groove in which a bead of a reinforcing bar 930 is partially slidably housed as illustrated in FIG. Figure 9C . The mounting of the reinforcement framework 950 in the container 900 is thus relatively easy;
• several 910 flat reinforcing plates. These reinforcing plates 910 are pierced with several openings for the circulation of gas and extend along the four corners of the inner longitudinal wall of the container 900. These reinforcing plates 910 are fixed on their side edges to two adjacent inner faces of the container 900, so that a space is provided between the reinforcing plate 910 of corresponding rounded corner and angle of the container 900.

The Figure 9B is a cross-sectional view of the container 900 showing the arrangement of a ring 940 of the backing frame 950, corner reinforcing plates 910, reinforcing rails 920, and 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 inner wall of the container 900 by sliding reinforcing bars 930 in the grooves of the reinforcing rails 920 attached to the inner wall container 900.

It is noted that the container 900, the elements constituting the reinforcement framework 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 device for filling the container.

Note that all or part of these elements may alternatively be carried by at least one of the side walls of the outer casing in which the container is to be housed.

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

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

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

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

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

The reservoir 6 uses suspension means MS1, MS2 from the container 600 to the outer casing 60.

These suspension means in particular make it possible to compensate for the thermal expansion / shrinkage of the internal container due to cooling by limiting the contribution 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 comprise:

• a frustoconical stud 606 carried by a first external lateral face 602 of the container 600, and
• a suspension ring 64 carried by a first internal lateral face of the outer casing 60 and intended to be fitted on the pad 606, the internal lateral face of the outer casing 60 being located opposite the first external lateral face 602 of the containing 600.

In addition, the height of the stud 606 is smaller than the thickness of the suspension ring 64.

Thus, when the suspension ring 64 is fitted on the pad 606, the flat surface of the pad 606 is not in contact with the first internal lateral face of the outer casing 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 exchange by direct contact between the container 600 and the outer shell 60. It is indeed crucial to prevent the temperature of the liquefied natural gas from increasing and remaining in liquid form. .

As illustrated on Figures 6C and 6D the second suspension means MS2 comprise a plurality of straps 67 located on the side of the second external lateral face 603 of the container 600 and the second internal lateral face of the outer envelope 60 which are arranged facing each other.

In the example shown on the Figure 6C there are provided four straps 67 connecting each edge or edge of the container 600 to each edge or edge of the outer shell 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 a Y-shaped element 632 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 ) the element 632 in the form of "Y" and thus to adjust 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 collision of the vehicle.

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 frustoconical stud 606 carried by each external lateral face 602 of the container 600, and
• a suspension ring 64 carried by each internal lateral face of the outer casing 60 and intended to be fitted on a pad 606, each inner lateral face of the outer casing 60 being situated facing 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 outer envelope 60.

This makes it possible to resume the efforts symmetrically.

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

This relative movement of the container 600 with respect to the outer 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 may 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 casing 60 is allowed because of this suspension.

Several other strap suspension approaches from the container 600 to the outer shell 60 are illustrated in connection with the Figures 10A to 13 .

In the illustrated approach to Figures 10A to 10C , the straps 67 of insulating material are disposed 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:

• a support 631 secured to the outer casing 60 at a first end, and
• to a block member 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 is wound one end of the strap 67.

A ring 638 made of aluminum or stainless steel is positioned against a stop welded to the outer casing 60. This ring 638 makes it possible to wedge the bottom of the container 600. It is made 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 system for adjusting the tension of each strap 67 is carried by the corresponding block element 635 which has a generally "U" shape.

This block element 635 comprises fastening screws 639A of the block element 635 on the container 600, a first slider 640 on which is mounted the pin 637 of the strap 67 and a second slider 641 serving as a nut with two screws. 639B setting. 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, it acts 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 provided by the implementation of inclined planes on each of the slides 640, 641 which are arranged vis-à-vis ( Figure 10C ).

In the illustrated approach to Figures 11A to 11C , the straps 67 of insulating material are disposed 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:

• a support 631 welded to the outer shell 60 at a first end, and
• to a block member 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 is wound one end of the strap 67.

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

This block element 635 comprises fixing screws 639A of the block element 635 on the container 600, a slide 640 on which is mounted the axis 637 of the strap 67 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 adjusting screws 639B on which come to rest the slide 640.

In the illustrated approach to Figures 12A to 12C , the straps 67 of insulating material are disposed 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:

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

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

Two adjustment screws 639B which pass through the supports 643, 644 make it possible to move 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 thus to 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 sliders 646 carrying the axis 636 of the strap 67, the sliders 646 being able to slide along the longitudinal axis of the container 600 in a rail 645 welded to the outer envelope 60.

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

In this figure, the attachment 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 truck, of which only the support frames 9, 9 'are visible.

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

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

Such a reservoir 7 thus comprises an outer envelope 70 surrounding a container 700, the latter comprising a reinforcement 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 framework 750 by reinforcing bars 760.

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

The fixing of the tank 7 and the technical box 8 on the support frames 9, 9 'of the vehicle is carried out by means of straps 10, 10'.

There are insulating means disposed in the space between the walls of the outer casing 70 and the container 700.

In all the embodiments described above, the outer shell of the tank may be made of any material adapted to withstand fire and possibly other safety constraints.

According to one particular embodiment, the outer surface of the outer envelope may be covered with at least one layer of material adapted to withstand fire.

It may be a fire-resistant paint or other type of coating that is applied to the outer and / or inner surface of the outer shell and / or the outer 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 integral container structures use longitudinally extending internal reinforcements.

• 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 outer section of square shape with rounded edges and an internal structure comprising:

• four drop-shaped water channels that are arranged edge-to-edge on the figure 8a ,
• four tubular channels on the figure 8b ,
• four teardrop-shaped channels that overlap on the figure 8c ,
• a central channel bordered by peripheral canals 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 tubular central channel surrounded by partially tubular channels on the figure 8I .

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

The container of the figure 8m has a four-leaf clover outer section with an internal reinforcing channel.

The reservoir 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 chassis of the vehicle.

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

Moreover, the longitudinal sides of the container (defining the body of the container) may have a curve.

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

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

Of course, the invention is not limited to the examples that have just been described and many adjustments can be made to these examples without departing from the scope of the invention. In particular, the various features, shapes, variants and embodiments of the invention can be associated with each other in various combinations to the extent that they are not incompatible or exclusive of each other. In particular all the variants and embodiments described above are combinable with each other.

Claims (15)

Tank (5, 9) for a motor vehicle intended to contain liquefied gas, such as liquefied natural gas, characterized in that it comprises: a container (500, 900) for storing liquefied gas, the container comprising an internal reinforcing structure, and an outer protective envelope (50) disposed around said container, said container and said outer casing each having a substantially parallelepipedal general shape, said container (500, 900) being secured to said outer casing (50) by suspension means (MS1, MS2) allowing relative movement of said container (500, 900 ) relative to said outer shell (50). Tank (5, 9) according to claim 1, characterized in that the suspension means (MS1, MS2) allow a relative movement of said container (500, 900) relative to said outer casing (50) less than 10 mm. Tank (5, 9) according to claim 1 or 2, characterized in that said container (500, 900) is connected to a first lateral end of said outer shell (50) by suspension straps (67) and to a second lateral end of said outer shell (50) by a suspension ring (64). Tank (5, 9) according to claim 3, characterized in that said suspension ring (64) is fixed to the inner surface of a side wall of said outer shell (50) and is fitted on a stud (606) worn by the outer surface of a side wall (602) of the container (500, 900). Tank (5, 9) according to claim 3 or 4, characterized in that said suspension straps (67) and said suspension ring (64) are made of thermally insulating material. Tank (5, 9) according to claim 1 or 2, characterized in that said container (500, 900) is connected to a first lateral end of said outer shell (50) by suspension straps (67) and to a second lateral end of said outer shell (50) by suspension straps (67). Tank (5, 9) according to any one of the preceding claims, characterized in that said internal reinforcement structure comprises a reinforcing framework (950) secured to the inner wall of said container (900), said reinforcement framework (950) comprising a plurality of reinforcing rings (940) spaced along the longitudinal axis Ax of said container (900) and extending transversely to said longitudinal axis Ax. Tank (5, 9) according to claim 7, characterized in that said reinforcing rings (940) are mounted spaced apart on reinforcement bars (930) extending parallel to the longitudinal axis Ax and arranged around the rings. reinforcement (940), said reinforcing bars (930) being each secured to a reinforcing rail (920) fixed on the inner wall of said container (900). Tank (9) according to claim 7 or 8, characterized in that said internal reinforcing structure comprises a plurality of angle reinforcing plates (910) fixed on the inner wall of said container (900) and each connecting two adjacent inner faces of said container (900). Tank (5, 9) according to any one of the preceding claims, characterized in that the container (500, 900) is made of aluminum. Tank (5, 9) according to any one of the preceding claims, characterized in that said outer casing (50) is made of a fireproof material. Tank (5, 9) according to any one of claims 1 to 10, characterized in that said outer casing (50) is covered with a fire resistant coating. Tank (5, 9) according to any one of the preceding claims, characterized in that the wall of the container (500, 900) and the wall of the outer casing (50) are distant from each other, intermediate space between these walls being filled with insulating means. Tank (5, 9) according to any one of the preceding claims, characterized in that the outer surface of at least one side and / or longitudinal wall of the container (500, 900) or the outer casing (50) comprises a connection plate (220, 230) carrying in particular at least one of the following elements: - a connection element to another tank; - a level gauge; - a safety valve; a device for filling the container. Motor vehicle, such as a heavy vehicle, comprising at least one tank according to one of claims 1 to 14.

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