EP3850263A1

EP3850263A1 - Tank

Info

Publication number: EP3850263A1
Application number: EP19772982.5A
Authority: EP
Inventors: Marian Krol; Christina SCHMIDEDER; Till Waas; Fabian HANSLMAIER; Peter ASEN
Original assignee: Linde GmbH
Current assignee: Linde GmbH
Priority date: 2018-09-11
Filing date: 2019-09-09
Publication date: 2021-07-21
Also published as: WO2020052810A1

Abstract

The invention relates to a tank (1) for storing a cryogenic fluid (2), in particular for storing liquefied natural gas, comprising an outer tank (5), an inner tank (9) arranged inside the outer tank (5), base insulation (15) arranged between an outer tank base (7) of the outer tank (5) and an inner tank base (11) of the inner tank (9), a liquid-tight first film (24) arranged between the outer tank base (7) and the inner tank base (11), and a gas-tight second film (25) arranged between the first film (24) and the outer tank base (7). The outer tank base (7) and an outer tank wall (6) are produced from concrete and the inner tank (9) is produced from a metal material.

Description

description

tank

The invention relates to a tank for storing a cryogenic fluid.

Closed flat-bottom tanks are known for storing cryogenic fluids, such as liquefied natural gas, which comprise an outer tank and an inner tank arranged inside the outer tank. Thermal insulation can be provided between the outer tank and the inner tank. This thermal insulation can in particular also be arranged between a bottom of the inner tank and a bottom of the outer tank. If the outer tank is made of concrete, a vapor barrier, a so-called liner, can be provided on the inside of the outer tank. This liner ensures that the outer tank is gas-tight. The liner can comprise a steel membrane. In order to prevent penetration of the cryogenic fluid from the inner tank into the thermal insulation arranged between the bottom of the inner tank and the outer tank or penetration to the bottom of the outer tank, thermal insulation with a steel membrane, in particular with a so-called Second bottom, to be protected. This second bottom is also made of interconnected steel plates. When the cryogenic fluid emerges from the inner tank, the second bottom prevents the cryogenic fluid from penetrating into the thermal insulation, penetrating to the bottom of the outer tank and thus forming a foundation of the tank in

is undesirably subjected to cryogenic temperatures. This prevents stresses from occurring in the foundation as a result of temperature differences, which could lead to damage to the foundation.

Against this background, the object of the present invention is to provide an improved tank for storing a cryogenic fluid.

Accordingly, a tank for storing a cryogenic fluid, in particular for storing liquefied natural gas, is proposed. The tank comprises an outer tank, an inner tank which is arranged inside the outer tank, a floor insulation which is arranged between an outer tank bottom of the outer tank and an inner tank bottom of the inner tank, a liquid-tight first film which is between the Outer tank bottom and the inner tank bottom is arranged, and a gas-tight second film, which is arranged between the first film and the outer tank bottom. The outer tank floor and an outer tank wall are made of concrete and the inner tank is made of a metal material.

The first film reliably prevents impermissibly low temperatures from being applied to a foundation of the tank, since this prevents penetration of a liquid phase of the cryogenic fluid into the floor insulation. The fact that foils and not a rigid steel membrane are used means that only minimal forces are applied to the outer tank wall even when the second foil is glued to an outer tank wall of the outer tank. In comparison to a second bottom made from steel plates as explained above, the first film can be made with less

Work deployment can be assembled much faster. This significantly reduces the assembly costs. Material costs are also significantly reduced. The assembly of the foils is further simplified by the fact that they can be laid as individual foil webs, which are bonded together after laying. A complex pre-assembly of the foils is not necessary. The layout of the

Foil sheets and the assembly direction and sequence can be customized in

Depending on the local conditions can be selected.

The first slide can be called a second bottom. The second film can be a liner lining the inside of the outer tank. In particular, the first film is set up to prevent fluid escaping from the inner tank from penetrating or seeping into the floor insulation and thereby due to

Temperature differences tensions are induced in the foundation of the tank.

In contrast to a steel membrane, a “film” is to be understood here as a flexible or elastically deformable component of small thickness. Due to their small thickness, the foils are very flexible and can be folded, bent or deformed without any noticeable effort. This enables easy installation of the foils. The foils are preferably elastically deformable.

The first film is preferably liquid-tight and gas-permeable. Alternatively, the first film can also be gas-tight. The second film is gas tight and

liquid-tight. The first film and the second film can be made from the same Material be made. The gas tightness of the material of the first film and the second film results in particular from a metal portion, in particular from a metal layer, which the first film and the second film have. Since the first film is not necessarily gas-tight, it does not necessarily require a metal component. Because of the required gas tightness of the second film, this preferably always includes a metal portion. In particular when the same material is used for the first film and the second film, the first film accordingly preferably has a liquid-tight and gas-permeable or non-gas-tight construction or construction. Accordingly, the second film has a liquid-tight and gas-impermeable or gas-tight construction or construction.

The cryogenic fluid is preferably liquefied natural gas. However, the cryogenic fluid can also be liquid ethene or ethylene (boiling point at ambient pressure 169.43 K = -103.72 ° C), liquid ethane (boiling point at ambient pressure 184.1 K = -88.9 ° C) or liquid propane (boiling point at ambient pressure 231, 15 K = -42.1 ° C). The cryogenic fluid can have a gaseous aggregate state and a liquid aggregate state and can be moved from the liquid aggregate state to the gaseous aggregate state and vice versa. The

Aggregate states can also be called phases. The cryogenic fluid can also be referred to as a cryogenic gas or as a liquefied cryogenic gas. The tank is in particular set up to store the cryogenic fluid in its liquid state of aggregation. When the cryogenic fluid is separated from the liquid

Aggregate state changes into the gaseous aggregate state, this can be referred to as a so-called boil-off gas. This boil-off gas can

can be blown off with the help of a blow-off valve.

The outer tank preferably comprises the outer tank floor, the previously mentioned outer tank wall connected to the outer tank floor, which is cylindrical and / or rotationally symmetrical with respect to a central or symmetry axis, and an outer tank roof. The outer tank roof is preferably dome-shaped and bulges outwards.

The inner tank is completely located inside the outer tank. In addition to the inner tank bottom, the inner tank includes an inner tank wall, which is also preferably cylindrical and rotationally symmetrical to the axis of symmetry. The The outer tank and the inner tank are preferably arranged concentrically to one another with respect to the axis of symmetry. The inner tank and the outer tank can also be cuboid or cube-shaped. The inner tank is preferably designed as an open cup. This means that the inner tank is not fluid-tight. The inner tank can be covered with a heat-insulating cover by a

Support structure, which can be suspended from the outer tank roof with the help of rods or struts. Alternatively, the inner tank can also be closed with a dome roof. When the cryogenic fluid is stored, the cryogenic fluid contacts the inner tank bottom and the inner tank wall.

The inner tank is preferably self-supporting. This means that the inner tank wall is designed to withstand its own weight load and the

Completely removes the weight load of the stored cryogenic fluid itself. In other words, this means that no tank component touching the inner tank wall from the inside or outside laterally carries the load of the inner tank wall or the cryogenic fluid.

The wall thickness of the inner tank wall, and preferably of the inner tank bottom, is preferably at least 2 mm, preferably at least 4 mm and particularly preferably at least 6 mm. The wall thickness of the inner tank wall, and preferably of the inner tank bottom, is preferably up to 50 mm, more preferably up to 40 mm and particularly preferably up to 30 mm.

According to one embodiment, the foils have a metal, in particular aluminum.

The foils can be made from the same material or from different materials. In particular, the foils can be metal foils, in particular

Aluminum foils, be or have. For example, the foils can each have a multi-layer structure, one layer being a metal foil. The metal foil can also be called a metal core, in particular an aluminum core, of the respective foil. However, the foils can also each be a metallized, in particular a metallized, plastic foil. A particularly good diffusion barrier effect can be achieved by using a metal. Instead of aluminum, other suitable metals can also be used. For example the first film and the second film each have an aluminum layer with a thickness of at least 0.05 mm, in order to be considered in particular as an impermeable material with an air layer thickness greater than 1500 m equivalent to water vapor diffusion. Alternatively, the first film can also be metal-free, since gas tightness is not required for the first film. The films can be compound films. This means that the foils can be made from a multi-layer composite material.

According to a further embodiment, the foils are fiber-reinforced, in particular glass-fiber reinforced.

The films can also be carbon fiber reinforced, aramid fiber reinforced or the like. As a result, the films are highly resilient.

According to a further embodiment, the second film is between the

Floor insulation and the outside tank floor arranged.

In particular, the second film lies on the outside of the tank bottom.

According to a further embodiment, the second film is integrally connected to an outer tank wall of the outer tank, in particular glued to it.

In the case of integral connections, the connection partners are held together by atomic or molecular forces. Integral connections are non-detachable connections that can only be separated by destroying the connection means and / or connection partner.

According to a further embodiment, the second film completely covers the outer tank wall.

The second film preferably completely covers the inside of the outer tank wall, that is to say faces the inner tank. The second film can, in particular in the event that the entire outer tank including the outer tank roof is made of concrete, line the entire outer tank on the inside. This ensures the gas tightness of the outer tank. In the event that the outer tank is partly made of steel a complete covering of the outer tank in the areas of the outer tank that are made of steel, with the second film is dispensable.

According to a further embodiment, the first film is arranged at least in sections within the floor insulation.

The first film can thus run through the floor insulation. The first film can also cover the top insulation.

According to a further embodiment, the floor insulation has a pressure-resistant insulation layer, in particular a foam glass block layer, a pearlite concrete layer, a wood layer or a reinforced polyurethane layer, the first film being arranged between the insulation layer and the inner tank floor.

The number of insulation layers is arbitrary. The insulating layer is preferably constructed from a large number of foam glass blocks. Foam glass can also be called cellular glass or foam glass.

According to a further embodiment, the floor insulation has several

Insulation layers, between which the first film is arranged.

The number of insulation layers is arbitrary. For example, two or three such insulation layers are provided. The first film can run between two adjacent insulation layers.

According to a further embodiment, the floor insulation has a

Load distribution plate, wherein the load distribution plate between the

Inner tank bottom and the insulation layer is arranged, and wherein the first film is arranged between the load distribution plate and the insulation layer.

The first film can also be placed on the load distribution plate. The

Load distribution plate can be made of concrete and / or wood, for example. The load distribution plate can comprise mineral and non-mineral materials. The load distribution plate is provided directly below the inner tank floor and distributes the load of the inner tank evenly over the floor insulation. For example, the load distribution plate is a cast concrete slab. The

Load distribution plate can also be annular, so that it is arranged only below the inner tank wall of the inner tank and supports it.

According to a further embodiment, the floor insulation has a

Compensation layer, the compensation layer being arranged between the outer tank floor and the insulation layer.

The floor insulation can be a first leveling layer between the

Outside tank floor and the insulation layer is arranged, and a second

Compensation layer, which is arranged between the insulation layer and the load distribution plate. The leveling layers can be cast concrete slabs. The load distribution plate can also have an annular shape, in which case the second compensation layer can then be located within the annular shape.

According to a further embodiment, the second film is between the

Outside tank bottom and the leveling layer arranged.

In particular, the second film is arranged between the outer tank bottom and the first compensation layer. The second film is then preferably on the

Outside tank floor.

According to a further embodiment, the floor insulation has a

cylindrical jacket, which is arranged between the outer tank and the inner tank, wherein the first film is provided on the inside and the second film on the outside of the jacket.

The jacket can also be referred to as thermal corner protection. The jacket is preferably also made up of a large number of foam glass blocks and can be connected to the insulation layer. "Inside" means facing the inner tank, and "outside" means facing the outside tank. The first film is preferably provided between the inner tank and the jacket and the second film is provided between the jacket and the outer tank. The films can be cohesive with the jacket and / or Be connected to the outer tank wall The second film preferably completely covers the outer tank wall.

According to a further embodiment, the first film is integrally connected to the second film.

The first film is preferably glued or welded to the second film. Each film can have a large number of film webs which are connected to one another in a materially integral manner. The first film and the second film can be the jacket that

Include the insulation layer and the two leveling layers in a bag. This means that the floor insulation is in particular partially positioned within the foils, so that the foils preferably have the floor insulation at least in sections

enclose. The first film and the second film are integrally connected to one another at a connecting section, in particular welded or glued to one another.

The outer tank roof can be made of concrete or steel. For example, the outer tank floor and the outer tank wall can be made of concrete and the outer tank roof made of steel. Alternatively, the outer tank floor, the outer tank wall and the outer tank roof can be made of concrete. For example, the outer tank can be a cast concrete component in which the outer tank floor, the outer tank wall and the outer tank roof are connected to one another, in particular in one piece. The inner tank is preferably made of steel. The inner tank can also be made of aluminum. The tank can also be used as a concrete metal tank,

especially as a concrete-steel tank.

Further possible implementations of the tank also include combinations of previously or below not explicitly mentioned with regard to the

Embodiments described features or embodiments. The specialist will also add individual aspects as improvements or additions to the respective basic shape of the tank.

Further advantageous refinements of the tank are the subject of the subclaims and the exemplary embodiments of the tank described below. In the further the tank is explained in more detail using preferred embodiments with reference to the accompanying figures.

1 shows a schematic sectional view of an embodiment of a tank for storing a cryogenic fluid; and

FIG. 2 shows the detailed view II according to FIG. 1.

In the figures, elements that are the same or have the same function are the same

Reference marks have been provided, unless otherwise stated.

1 shows a greatly simplified schematic sectional view of a

Embodiment of a tank 1 for storing a cryogenic fluid 2. The cryogenic fluid 2 is in particular a cryogenic or cryogenic liquefied gas. Examples of such cryogenic fluids are liquefied natural gas, liquid ethene or ethylene

(Boiling point at ambient pressure 169.43 K = -103.72 ° C), liquid ethane (boiling point at ambient pressure 184.1 K = -88.9 ° C) or liquid propane (boiling point at ambient pressure 231, 15 K = -42, 1 ° C).

However, the tank 1 is preferably suitable for storing liquefied natural gas (LNG). The cryogenic fluid 2 can have a liquid state of aggregation or a liquid phase and a gaseous state of aggregation or a gaseous phase or can be transferred from the liquid phase into the gaseous phase and vice versa. The cryogenic fluid 2 is stored in its liquid phase in the tank 1. However, the cryogenic fluid 2 can partially evaporate and pass into the gaseous phase. The vaporized cryogenic fluid 2 can be referred to as a boil-off gas.

The tank 1 has a plate-shaped foundation 3. The foundation 3 can be anchored directly in the ground 4. The foundation 3 can also have a multiplicity of supports or stands, so that the foundation 3 or the tank 1 is raised and is placed at a distance from the ground 4. The foundation 3 can be made of concrete, for example. For example, the foundation 3 can be a cast circular concrete slab. However, the foundation 3 can also have any other geometry. The tank 1 comprises a middle or Axis of symmetry M. The foundation 3 can be rotationally symmetrical to the

Axis of symmetry M be constructed.

Furthermore, the tank 1 comprises an outer tank 5 arranged on the foundation 3. The outer tank 5 has an outer tank wall 6. The outer tank wall 6 can also be referred to as an outer tank jacket. The outer tank wall 6 can

be circular cylindrical. In particular, the outer tank wall 6 can be constructed to be rotationally symmetrical to the axis of symmetry M of the tank 1. The outer tank 5 can also be referred to as an outer container.

The outer tank 5 has an outer tank bottom 7 which can be formed in one piece, in particular in one piece with the material, with the outer tank wall 6. The

Outside tank floor 7 is placed on the foundation 3. The outer tank floor 7 and the outer tank wall 6 are made of concrete. The outer tank wall 6 and the

Outside tank floor 7 can be cast in one piece. The outside tank floor

7 and the outer tank wall 6 can be designed in the form of an upwardly open cup, which can be referred to as an outer cup. In a preferred embodiment, the foundation 3, the outer tank floor 7 and the

Outside tank wall 6 to be cast in one piece.

Furthermore, the outer tank 5 comprises an outwardly domed dome-shaped one

Outer tank roof 8. For example, the outer tank floor 7 and

Outside tank wall 6 made of concrete and the dome-shaped outside tank roof 8 made of steel. If the outer tank roof 8 is also made of steel, it can

Outer tank roof 8 to be placed on the outer tank wall 6. Alternatively, the outer tank floor 7, the outer tank wall 6 and the outer tank roof 8 can be made of concrete. The outer tank floor 7, the outer tank wall 6 and the outer tank roof

8 can be monolithic, i.e. in one piece, cast from concrete.

The tank 1 further comprises an inner tank 9 arranged inside the outer tank 5. The inner tank 9 is preferably made of a steel material. The inner tank 9 is designed in the form of a cup or closed with a dome-shaped inner tank roof. The inner tank 9 comprises a circular cylindrical inner tank wall 10 and an inner tank bottom 11. The inner tank wall 10 can also be referred to as an inner tank jacket. The inner tank 9, like the outer tank 5, is preferably constructed to be rotationally symmetrical to the axis of symmetry M. The inner tank 9 can also be called an inner container or inner cup. The inner tank 9 is positioned within the outer tank 5 and with respect to the axis of symmetry M coaxial to it. During the storage of the cryogenic fluid 2, the cryogenic fluid 2 contacts the inner tank bottom 11 and the inner tank wall 10.

The cup-shaped inner tank 9 is one of the outer tank roof 8 of the

Outside tanks 5 covered cover 12 covered. The cover 12 is not connected to the inner tank 9 in a fluid-tight manner, so that the aforementioned boil-off gas, that is to say cryogenic fluid 2, which has changed from the liquid aggregate state to the gaseous aggregate state, can escape from the cup-shaped inner tank 9.

The cover 12 is suspended from the outer tank roof 8 with the aid of metallic rods or struts 13. The cover 12 is also thermally insulated upwards or towards the outer tank 5 with, for example, block-shaped insulation elements 14. The insulation elements 14 can be referred to as insulation blocks, insulation mats or insulation bags or can be designed as such. For example, the insulation elements 14 can be made from a foamed plastic material, such as polyurethane, polystyrene or the like. Furthermore, the insulation elements 14 can be made of mineral wool, such as slag wool, glass wool or rock wool. The insulation elements 14 can comprise mineral and / or non-mineral materials.

A floor insulation 15 is provided between the inner tank floor 11 of the inner tank 9 and the outer tank floor 7 of the outer tank 5. The floor insulation 15 can for example be partially made of foam glass. Foam glass can also be called foam glass or cellular glass. Furthermore, the

Floor insulation 15 can be constructed from individual block-shaped elements, in particular from foam glass blocks. The floor insulation 15 can also be made at least partially from concrete. The floor insulation 15 is a load-bearing insulation component and supports the inner tank 9.

A circumferential gap 16 is provided between the outer tank wall 6 and the inner tank wall 10. The gap 16 can be at least partially filled with an insulating material, such as pearlite or mineral wool. The floor insulation 15 can at least partially in the gap 16, that is, between the inner tank wall 10 and the outer tank wall 6.

2 shows an enlarged section of the tank 1 according to the detailed view II of FIG. 1. In the embodiment of the tank 1 according to FIGS. 1 and 2, the outer tank wall 6 and the outer tank bottom 7 are as a one-piece, in particular a one-piece, concrete component manufactured. As shown in Fig. 2, the

Floor insulation 15 is arranged at least in sections between the outer tank floor 7 and the inner tank floor 11. However, as previously mentioned, the floor insulation 15 can also be partially arranged in the gap 16.

The floor insulation 15 preferably comprises a plurality of pressure-resistant insulation layers 17, 18, in particular foam glass block layers, of which only two are shown in FIG. 2. The number of insulation layers 17, 18 is arbitrary. Each insulation layer 17, 18 can be constructed from a multiplicity of foam glass blocks 19. The

Insulating layers 17, 18 can comprise not only foam glass blocks 19 but also pearlite concrete, wood, reinforced polyurethane or other suitable insulating materials.

A first compensation layer 20 is provided between a bottom or bottom insulation layer 18 and the outer tank floor 7. The first leveling layer 20 can be a cast concrete slab. A second compensation layer 21 can be provided above an uppermost or upper insulation layer 17 and below the inner tank floor 11. The second leveling layer 21 can also be a cast concrete slab. The insulation layers 17, 18 are thus between the

Compensating layers 20, 21 arranged. There can only be one

Compensation layer 20, 21 may be provided. The leveling layers 20, 21 are preferably part of the floor insulation 15.

A load distribution plate 22 is also provided between the second compensation layer 21 and the inner tank floor 11. The load distribution plate 22 can

for example, also be made of concrete or wood. The

Load distribution plate 22 may have mineral and / or non-mineral materials. The inner tank 9 is supported on the load distribution plate 22. The load distribution plate 22 can, but need not, be part of the floor insulation 15. Furthermore, the floor insulation 15 comprises a cylindrical jacket 23, which is arranged in the gap 16. The jacket 23 can be constructed rotationally symmetrical to the axis of symmetry M. The jacket 23 thus runs completely around the inner tank 9, in particular around the inner tank wall 10. The jacket 23 is also constructed from foam glass blocks 19 and, as shown in FIG. 2, can be connected to the insulating layers 17, 18. The jacket 23 is arranged in particular between the inner tank wall 10 and the outer tank wall 6. The jacket 23 can be supported on the outer tank wall 6. The jacket 23 can also be referred to as thermal corner protection, since the jacket 23 thermally insulates a transition or a corner between the outer tank floor 7 and the outer tank wall 6.

The tank 1 further comprises a first film 24, which is shown in FIG

dash-dotted line is shown. The first film 24 is positioned in the orientation of FIG. 2 below the inner tank bottom 11. The first film 24 can also be referred to as the second bottom of the tank 1. Accordingly, the inner tank floor 11 is then a first floor or first bottom of the tank 1. The first film 24 is arranged in particular between the outer tank floor 7 and the inner tank floor 11. The first film 24 covers the floor insulation 15 upwards, that is, in the direction of the inner tank 9. The first film 24 fulfills the function of a second bottom as explained at the beginning and can therefore also be referred to as such. Unlike known second bottoms, however, the first film 24 is not made from steel plates. The first film 24 is preferably part of the floor insulation 15. However, the first film 24 does not have to be part of the floor insulation 15.

The first film 24 is liquid-tight, but not necessarily gas-tight. As already stated in the introduction, the first film 24 preferably has a liquid-tight and gas-permeable or non-gas-tight construction or construction.

For example, the first film 24 has an aluminum layer with a thickness of at least 0.05 mm in order to cover an impermeable material with a

water vapor diffusion equivalent air layer thickness greater than 1500 m. If the first film 24 is an impenetrable fabric with a

water vapor diffusion equivalent air layer thickness greater than 1500 m (this applies, for example, to an aluminum layer with a thickness of 0.05 mm), the first film 24 can be regarded as gas-tight. This is not for liquid tightness required. This means that the first film 24, which is only impervious to liquids, can also be metal-free.

Due to its small thickness, the first film 24 is very flexible and can be folded, bent or deformed without any noticeable effort. The first film 24 can be or comprise a metal film, for example an aluminum film, or a metal-coated plastic film, for example an aluminum-coated plastic film. The first film 24 is preferably fiber-reinforced, in particular glass-fiber-reinforced. However, the first film 24 can also be carbon fiber reinforced,

aramid fiber reinforced or the like.

The first film 24 can also be referred to as a liquid barrier or liquid barrier. The first film 24 is resistant to low temperatures, so that it also leaves the cryogenic fluid 2, for example in the event of a leak

Inner tank 9 emerges, is not damaged. The first film 24 can be constructed from a plurality of film webs arranged next to one another, which are integrally connected to one another, for example glued or welded to one another. This enables the first film 24 to be assembled very easily and quickly.

The tank 1 further comprises a second film 25 which lines the inside of the outer tank 5 made of concrete. The second film 25 is shown in FIG. 2 with a broken line. The second film 25 can line the outside of the tank bottom 7, the outside tank wall 6 and the outside tank roof 8 on the inside. The second film 25 is a liner or can be referred to as such. In contrast to the first film 24, the second film 25 is not only liquid-tight but also gas-tight. The second film 25 can also be referred to as a diffusion barrier, gas barrier or gas barrier. The second film 25 seals the outer tank 5 made of concrete in a gas-tight manner. Accordingly, the second film 25 has a liquid-tight and gas-impermeable or gas-tight construction or construction.

The second film 25 is preferably made of the same material as the first film 24. The films 24, 25 can be integrally connected to one another at a connecting section 26, for example welded or glued to one another. The first film 24 is between the second compensation layer 21 and the Load distribution plate 22 arranged and running inside, that is, the

Inner tank wall 10 facing upward on the jacket 23 and covers it.

The second film 25 is between the first compensation layer 20 and the

Outer tank bottom 7 is arranged and runs upwards on the outer tank wall 6, so that the second film 25 covers the jacket 23 on the outside. That is, the second film 25 is arranged between the jacket 23 and the outer tank wall 6. The second film 25 can be integrally connected, for example glued, to both the outer tank wall 6 and the jacket 23. In addition, the second film 25 can also be integrally connected to the outer tank bottom 7. The second film 25 can cover the entire outer tank wall 6. As FIG. 2 shows, the first compensation layer 20, the insulation layers 17, 18, the jacket 23 and the second compensation layer 21 are completely accommodated between the foils 24, 25.

When the cryogenic fluid 2 emerges from the inner tank 9, for example in the event of a leak, the first film 24 prevents the liquid phase of the cryogenic fluid 2 from penetrating into the floor insulation 15 in the direction of the foundation 3. This reliably prevents both the penetration of the cryogenic fluid 2 into the floor insulation 15 and the penetration of the cryogenic fluid 2 as far as the outer tank floor 7. Without the first film 24, the foundation 3 could be subjected to undesirably low temperatures in an undesirable manner, as a result of which strong

Bending stresses in the foundation 3 could be induced. This could damage the foundation 3. This applies in particular in the event that the foundation 3 is raised. The effects explained above are reliably avoided with the aid of the first film 24. The second film 25 ensures the gas tightness of the tank 1 and prevents the ingress of moisture from the outside into the floor insulation 15.

Due to the fact that the foils 24, 25 are very thin and thus also flexible, only minimal forces are applied to the latter, even when the second foil 25 is glued to the outer tank wall 6. Compared to a second bottom and a liner made of steel plates, the first film 24 can be installed much faster with less work. This significantly reduces the assembly costs. Material costs are also significantly reduced. The assembly of the foils 24, 25 is further simplified by laying them in the form of individual foil webs that can be connected to each other after installation. A pre-assembly of the foils 24, 25 is therefore not necessary.

Although the present invention has been described using exemplary embodiments, it can be modified in many ways.

References used

1 tank

2 fluid

3 foundation

4 ground

5 outside tank

6 outside tank wall

7 outside tank floor

8 outside tank roof

9 inner tank

10 inner tank wall

11 inner tank floor

12 cover

13 strut

14 insulation element

15 floor insulation

16 gap

17 insulation layer

18 insulation layer

19 foam glass block

20 leveling layer

21 leveling layer

22 Load distribution plate

23 coat

24 slide

25 slide

26 connecting section

M axis of symmetry

Claims

1. tank (1) for storing a cryogenic fluid (2), in particular for storing liquefied natural gas, with an outer tank (5), an inner tank (9) which is arranged inside the outer tank (5), a floor insulation (15), which is arranged between an outer tank floor (7) of the outer tank (5) and an inner tank floor (11) of the inner tank (9), a liquid-tight first film (24) which is arranged between the outer tank floor (7) and the inner tank floor (1 1) , and a gas-tight second film (25), which is arranged between the first film (24) and the outer tank bottom (7), the outer tank bottom (7) and an outer tank wall (6) made of concrete and the inner tank (9) made of a meta II material are made.

2. Tank according to claim 1, wherein the foils (24, 25) are a metal, in particular

Aluminum.

3. Tank according to claim 1 or 2, wherein the films (24, 25) fiber-reinforced,

especially glass fiber reinforced.

4. Tank according to one of claims 1-3, wherein the second film (25) between the floor insulation (15) and the outer tank floor (7) is arranged.

5. Tank according to one of claims 1-4, wherein the second film (25) integrally connected to the outer tank wall (6) of the outer tank (5), in particular glued to it.

6. Tank according to claim 5, wherein the second film (25) the outer tank wall (6)

completely covered.

7. Tank according to one of claims 1-6, wherein the first film (24) at least

is arranged in sections within the floor insulation (15).

8. Tank according to one of claims 1-7, wherein the floor insulation (15)

pressure-resistant insulation layer (17, 18), in particular a foam glass block layer, a pearlite concrete layer, a wood layer or a reinforced polyurethane layer, and the first film (24) is arranged between the insulation layer (17, 18) and the inner tank floor (11).

9. Tank according to claim 8, wherein the floor insulation (15) has a plurality of insulation layers (17, 18), between which the first film (24) is arranged.

10. Tank according to claim 8 or 9, wherein the floor insulation (15)

Load distribution plate (22), the load distribution plate (22) being arranged between the inner tank floor (11) and the insulation layer (17, 18), and wherein the first film (24) between the load distribution plate (22) and the insulation layer (17, 18 ) is arranged.

1 1. Tank according to one of claims 8 - 10, wherein the floor insulation (15) has a compensation layer (20), and wherein the compensation layer (20) between the outer tank floor (7) and the insulation layer (17, 18) is arranged.

12. The tank of claim 11, wherein the second film (25) between the

Outside tank bottom (7) and the compensating layer (20) is arranged.

13. Tank according to one of claims 1-12, wherein the floor insulation (15) has a cylindrical jacket (23) which is arranged between the outer tank (5) and the inner tank (9), and wherein the first film (24) on the inside and the second film (25) is provided on the outside of the jacket (23).

14. Tank according to one of claims 1-13, wherein the first film (24) is integrally connected to the second film (25).

15. Tank according to one of claims 1-14, wherein the outer tank (5)

Has outer tank roof (8), which is made of concrete or steel.