Tank system for cooling liquid using thermal stratification

Abstract

The invention relates to a tank system (1) for cooling, storing and removing a liquid, comprising a tank (2) for cooling the liquid and storing the liquid in a volume (V), thermally stratifying along a stratification axis (L) of the volume. Wherein the tank (2) can be filled by means of a filling device (4) which has a filling inlet (5) in an inlet region along the layering axis (L) and which can be emptied by means of an outlet in an outlet region opposite the inlet region along the layering axis (L). For flexible handling, in order to prevent mixing, the supplied liquid is fed into a flow which extends completely or partially in a plane perpendicular to the layering axis (L) and is supplied to the liquid stored in the tank (2) such that the flow runs tangentially to an arc extending in the plane perpendicular to the layering axis (L).

Description

Technical Field

[0001] The invention relates to a tank system for cooling, storing and extracting liquids according to the preamble of claim 1 . Background Art

[0002] In the prior art, for example in CN 205856155 U, a tank system for cooling, storing and dispensing liquids has been disclosed, which in particular provides a system for producing cooled soda water or carbonated water.

[0003] Most tanks used for cooling, storing and pumping liquids are filled from the top and center. In this case, the incoming liquid usually enters the tank directly. Summary of the invention

[0004] The object of the present invention is to provide an improved tank system for cooling, storing and extracting liquids, from which the cooled liquid can be extracted as much as possible or for as long as possible, because the uncooled liquid that subsequently flows in mixes as little as possible with the already cooled liquid and thus warms the latter. Furthermore, the present invention is intended to make this effect according to the invention possible in a tank-in-tank system.

[0005] This object is achieved by means of a tank system of the type mentioned at the outset and by the characterizing features of claim 1 .

[0006] Advantageous embodiments and further developments of the invention are possible through the measures mentioned in the dependent claims.

[0007] The tank system according to the invention is used primarily for cooling liquids, in particular water, primarily drinking water or mineral water or bottled water, can be processed. Such liquids can be temporarily stored in a tank of the tank system, cooled and subsequently removed. In the actual tank as a container for storing liquids, there is a volume extending along a stratification axis of the tank. Usually, the stratification axis is approximately perpendicular to the surface of the liquid and is therefore usually parallel to the direction of gravity. As a rule, therefore, during storage, a thermal stratification of the liquid in the tank can occur along the stratification axis; that is, the liquid is distributed in the tank in such a way that cold liquid is deposited in the lower region of the tank, while warm liquid tends to rise to the top.

[0008] For example, the can can have a volume with an elongated shape, its orientation being upright (with the longitudinal axis oriented vertically) or lying down (with the longitudinal axis oriented horizontally). In a dynamic situation, if extraction takes place while filling, the orientation of the layering axis may also differ from the direction of gravity.

[0009] The tank can be filled by a filling device, and the filling device has a filling inlet, from which liquid can flow into the tank.

[0010] For example, the tank can be filled in the direction of the layering axis parallel to the direction of gravity. Then, the filling inlet is directed downwards, for example, in the direction of gravity. In this case, the flow guide device can be positioned downstream of the filling inlet.

[0011] Yet, tank body also can be filled from the side.In this case, filling inlet is oriented in a plane perpendicular to the layering axis, that is to say for example make, liquid can flow into substantially horizontally or parallel to the liquid surface.

[0012] Typically, the filling inlet is located in the region of or above the liquid surface, in particular in the fully filled state or in the case of a maximum preset filling state of the tank.

[0013] If the liquid in the tank is cooled, thermal stratification will occur at least after a certain time, since cold water tends to flow to the bottom, while warm water tends to flow upwards. Then, when the cooled liquid is withdrawn from the tank, new uncooled liquid is injected into the tank through the filling inlet. The purpose of the tank system is to ensure that the withdrawn liquid remains at a constant low temperature for as long as possible. The invention makes use of the fact that, for this purpose, it is generally advantageous to withdraw the cooled liquid at the end of the stratification axis opposite the inlet, for example at the bottom of the tank, since the probability of encountering cold liquid is greatest in this area.

[0014] Since the time of extraction can generally be arbitrary, it should be possible in principle to extract the cooling liquid at any time.

[0015] The tank system according to the invention is characterized in that the thermal stratification effect in the storage volume persists during the refilling of the tank and is maintained as long as possible and is utilized in a targeted manner. To achieve this, according to the invention, when refilling the tank with uncooled liquid, there is as little turbulence or mixing as possible between the newly flowing uncooled liquid and the more or less cooled liquid already in the tank. In this way, the thermal stratification conditions in the tank can be maintained in an optimal manner during the refilling of the uncooled liquid. In this way, as much cooling water or cooling liquid as possible can be drawn off in an advantageous manner while the cooling temperature remains as low as possible.

[0016] The measures taken according to the invention are therefore to technically avoid mixing of the liquid in the tank when refilling the tank, by which the thermal stratification can be disrupted. In principle, it is advantageous to introduce the liquid from above into the upper region of the liquid stratification, as seen from the direction of gravity. However, if the liquid is introduced into the tank in an uncontrolled manner, turbulence will occur, which can lead to mixing of the liquid stratification.

[0017] For this purpose, either a flow guide device is provided below the filling inlet in the tank body, which prevents mixing of the liquids by directing the liquid supplied through the filling inlet into a flow having a component in a plane perpendicular to the layering axis, for example having a horizontal component.

[0018] Alternatively, the liquid may be introduced directly through the fill inlet in a manner such that at least one horizontal component is parallel to the liquid surface.

[0019] The outlet is arranged on the opposite side of the inlet along the stratification axis, so that thermal stratification can be utilized and newly introduced liquid is not transported directly through the outlet. As a rule, with a vertically arranged stratification axis, the inlet can therefore be arranged in the upper area of ​​the tank body and the outlet in the lower area. In principle, however, the stratification axis can also deviate from the vertical arrangement, for example in the case of dynamic filling and simultaneous extraction, so that the inlet and outlet can also be arranged offset to each other in the horizontal direction. It is particularly preferred that these measures produce a completely horizontal flow or a flow in a plane perpendicular to the stratification axis, so that the flow in this plane flows tangentially around the arc of the stratification axis. The inflow of the supplied liquid does not initially cause any vertical or gravity-directed flow, which would disrupt the thermal stratification along the stratification axis.

[0020] Since the inflowing liquid initially moves horizontally, currents or eddies can form, but these also initially run primarily in a horizontal plane. When viewed parallel to the stratification axis, the liquid moves in circles. As a result of this flow, an influence on the vertically oriented thermal layer may also partially occur. However, this influence is usually much smaller than when the liquid flows vertically into the tank.

[0021] In order to further suppress the formation of eddies, the introduced liquid can be divided into two or more partial flows. If these flows are in opposite directions (they can, for example, form opposite rotations along the surface), they partially cancel each other out. Therefore, eddies that are conducive to mixing can be suppressed.

[0022] The effect according to the invention, namely maintaining the existing thermal stratification and avoiding turbulence or mixing, not only affects the static thermal stratification produced by natural convection, but also applies to dynamic situations, which is particularly important when liquid is being pumped and thus when the tank is being refilled. In this operation, the invention avoids mixing of the incoming uncooled liquid with the cooled liquid already in the tank. It is advantageous to maintain this stratification for as long as possible in order to maintain the supply of chilled water for as long as possible.

[0023] If chilled water has been pumped out, water can be added again in the upper area to refill the tank. The amount of water added may depend on how much chilled water has been pumped out. The water in the tank is essentially cooled. If the water in the tank has been in the tank for some time, it can generally be assumed that the overall temperature of the water is more uniform than if the water has just been added. However, thermal stratification may always exist. However, the temperature differences within the thermal stratification may vary depending on whether the water has just been filled up and is still cooling, or whether the water has been in the tank for some time and has undergone cooling and has dropped in temperature.

[0024] However, due to thermal stratification, at least a certain amount of cooling water can always be extracted.

[0025] Basically, stratification can be maintained even until all the cooling water is removed, so that the outlet water can have a nearly constant low temperature.

[0026] However, if the tank is completely empty, the cooling unit may have to cool the refilled warm liquid again.

[0027] Thermal stratification by the invention is also advantageous if only part of the cooled liquid in the tank is removed, since it is more likely to be maintained by natural convection. This in turn means that if cooled liquid is to be removed again, it is also possible to continue removing cooled liquid without the most cooled water being directly mixed with the refilled liquid, which would otherwise be mixed and warmed.

[0028] If the liquid is re-injected into the tank, it will be gradually cooled down in the tank by the corresponding cooling system.

[0029] The flow guide device is characterized by the fact that it is essentially a purely mechanical means and can be implemented without much effort and can also be retrofitted into existing tank systems. In addition, the flow direction is determined so that the disruption of mixing and thermal stratification is minimized and it is also suitable for essentially all possible tank shapes. In addition, part of the kinetic energy of the liquid to be introduced, encountering the flow guide device and having to flow through it, can be used up by the flow guide device, so that the formation of vortices and mixing can be suppressed to a greater extent.

[0030] Advantageously, in one embodiment of the invention, the flow guide device is arranged to be offset from the stratification axis in the radial direction. Since the flow formed by the flow guide device has a significant horizontal component, it is advantageous that this flow can be biased towards the center or the stratification axis, for example, running along the tank wall around the stratification axis for as long a distance as possible to avoid turbulence or eddies. In this way, it is possible to avoid the liquid from hitting the wall, for example, head-on, which may be conducive to the formation of eddies. In particular, according to a variant of the embodiment, this is facilitated by the fact that the flow guide device is correspondingly offset from the stratification axis in the radial direction, that is, not arranged directly in the center, so that the liquid can move over the longest possible distance without hitting the wall head-on and causing turbulence.

[0031] In order to increase the path length of the feed liquid and thus avoid splashing or other turbulence of the liquid, the guide device can form an arc around the stratification axis, and the feed water must follow this arc accordingly. In particular, the distance over which the flowing liquid releases its kinetic energy can thus be maximized.

[0032] In particular, in one embodiment of the present invention, the filling inlet can also be opened into the flow guide device which is deviated from the radial direction of the layering axis. Even if the liquid enters the tank body through the center of the layering axis area, it can be directed to the edge of the tank body in the radial direction before reaching the flow guide device or the liquid stored in the tank body. In principle, the filling device and the flow guide device can also be designed as one component. In addition, the flow guide device can also be open in the upper area, and the filling inlet is located directly above this opening, so that the liquid can flow into the flow guide device from above.

[0033] The flow-guiding device can have a lateral inlet or, in principle, several lateral inlets, from which the liquid flows out to form a liquid flow which is completely or substantially in a plane perpendicular to the stratification axis. In an advantageous manner, the flow-guiding device is designed in such a way that the liquid moves for a period of time in a defined manner in the predetermined channel of the flow-guiding device after it flows out of the filling inlet, so that no turbulence occurs, but rather a laminar flow or at least an approximately laminar flow is particularly preferably formed. In particular, if the flow-guiding device is approximately circular, the inlet from the flow-guiding device can be designed as a tangential inlet. In principle, one inlet on the flow-guiding device is sufficient. If the flow-guiding device has a circular arc shape, tangential inlets can also be provided on both sides of the circular element. The choice of how many tangential inlets to provide may also depend, in particular, on the geometry and size of the tank. For example, if the diameter of the tank is relatively small, it can be avoided to provide two tangential inlets in opposite directions, whereby the flows caused by the tangential inlets would then collide with each other and generate turbulence. It is also conceivable that only two inlets can ensure that the entire flow is weakened, so that mixing of thermal stratification is more effectively avoided.

[0034] The filling inlet is positioned so that it can release liquid to the flow guide device. For example, it can be arranged so that the liquid from the filling device flows through the flow guide device in opposite directions in different parts of the flow guide device. In principle, it is also conceivable that the filling inlet is arranged at one end of the flow guide device, so that the liquid can flow through the flow guide device over as long a distance as possible in one direction, which may help to form as much laminar flow as possible.

[0035] In order to create a flow that is as horizontal as possible, the flow guide device itself can be arranged essentially horizontally or in a plane perpendicular to the layer axis. This applies in particular to the pipeline path formed by the flow guide device itself. A relatively simple design of the flow guide device is that it has a bottom plate, which is correspondingly horizontal or in a plane perpendicular to the layer axis. The bottom plate prevents the water or liquid from flowing in a vertical direction at least to a certain extent and guides it along the path determined by the flow guide device.

[0036] In another embodiment of the invention, the flow guide device comprises at least two guide elements, in particular along a circular arc, for guiding the liquid in the device. These guide elements can be arranged vertically on the base plate. The liquid thus flows in a predetermined direction. It is particularly advantageous if the channel for the water formed by these predetermined guide elements is not too wide, so that an almost laminar flow can be formed relatively quickly and turbulence can be prevented as much as possible. In this way, the existing thermal stratification can be maintained for as long as possible.

[0037] A barrier element can be provided on the floor in the tangential inlet region. This reduces the flow cross section from the outset, especially when flowing to the tank. However, this measure can weaken or intercept more vertical flow components and thus, in particular, prevent the liquid from funneling out of the flow guide, which itself has a vertical flow component. This measure can therefore reduce turbulence.

[0038] Furthermore, in one embodiment of the invention, further guide elements may be provided. For example, horizontal guide elements may also be provided in the region of the tangential inlet in order to restrict the flow to the horizontal flow section as much as possible. For example, such a platform may be arranged above or below the tangential dimension in the direction of gravity. Thus, such a platform may also contribute to stratification and avoid turbulence. If the flow guide device is arranged to open upwards in the direction of gravity and the liquid is introduced into the flow guide device from there, then the provision of such a platform above the horizontal tangential inlet may also be particularly useful as a supplement.

[0039] The tank system according to one embodiment of the invention can in principle comprise one or more tanks. In an advantageous manner, for example, a nested structure can be provided in which a tank in turn has an additional inner tank which is completely contained in its volume. It is also conceivable that a further hollow volume is provided inside the tank. For example, other components, such as a pump, can also be contained in this hollow volume.

[0040] The inner tank that has been provided can also be used to process liquids, for example to carbonate water. In an advantageous manner, cooling and carbonation are separated from each other. In any case, if gas is introduced to produce sparkling water, for example, the entire volume will be mixed. Furthermore, in an advantageous manner, the tank for cooling and the inner tank for carbonation can be connected in series, so that already cooled water can enter the inner tank and finally be carbonated there. Thus, cooled fresh carbonated water can then be drawn from the inner tank. The inner tank can be filled with water from the tank by means of a pressure pump. In turn, a refrigerant can flow through the cooling system, in particular the coil or double-walled coil.

[0041] Preferably, the shape of the tank and the inner tank is rotationally symmetrical, in particular rotationally symmetrical about the layering axis. If the tank is a hollow cylindrical container, the flow in the hollow cylinder can flow mainly in the horizontal direction about the layering axis like in the channel, and vertical mixing is substantially avoided.

[0042] To this end, there are two aspects of influence that can be utilized in a targeted manner.

[0043] If the flow guide is designed with two openings in opposite tangential directions, the liquid flowing in through the filling inlet is divided into two partial flows, which flow tangentially in different directions in a circumferential manner. When the two partial flows subsequently meet during the flow through the channel, the inflowing liquid dissipates kinetic energy, thereby avoiding or greatly reducing turbulence and mixing with the cooling liquid already in the tank. In this way, according to the present invention, thermal stratification in the tank body can be promoted and maintained for a longer time.

[0044] If the flow guiding device is designed to have only one tangential opening in one direction, the liquid flowing in through the filling inlet will basically flow tangentially in only one direction, or in other words, circulate, thereby causing a rotational movement of the liquid in the tank.

[0045] Furthermore, this design can also be realized in a particularly compact manner, thus saving space. Especially in modular design, such a component can be regarded as a self-contained unit.

[0046] In order to cool the entire volume, a cooling coil or a double-walled coil of one of the tanks can be provided, for example. The coil shape facilitates cooling in a spiral manner within the entire tank volume. The coil can be rushed around so that the liquid in the tank volume can be cooled down effectively and quickly. In particular, in order to save space, the coil can be arranged around the inner tank. Thus, a certain cooling effect can also be achieved for the inner tank at the same time, i.e. the cooling of the inner tank is cooled together with the tank volume.

[0047] Since the tank system is particularly advantageously suitable for beverage preparation, it can be made at least partially of a plastic suitable for drinking water. It is conceivable that the tank or the inner tank is made of stainless steel, while for example the extraction tube, the filling device and / or the guide device are made of a plastic suitable for drinking water.

[0048] In a particularly preferred further development of the invention, the opening of at least one extraction pipe for extracting liquid from the tank body or inner tank body is arranged in the lower area of ​​the corresponding tank body, so that the liquid can be extracted as much as possible and the advantages of thermal stratification are utilized.

[0049] Furthermore, according to the invention, the inner tank can also be equipped with a flow guide so that the thermal stratification can also be maintained there for a longer period of time. This may also depend on the type of preparation carried out in the inner tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Embodiments of the invention are shown in the accompanying drawings and will be explained in more detail below with further details and advantages. Specifically, the following are shown:

[0051] Figure 1 : A schematic illustration of a tank system according to the invention,

[0052] Figure 2 : a schematic illustration of a flow guiding device for a tank system according to the invention, and

[0053] Figure 3 : A schematic illustration of the flow conditions under the flow guiding device, which is arranged in the inner tank body here. DETAILED DESCRIPTION

[0054] Figure 1 A tank system 1 is shown with a tank 2, in the space of which an inner tank 3 is arranged. The tank 2 is initially used for cooling water, which is introduced into the upper region of the tank 2 via the cover D on the cover side by means of a filling device 4. The filling device 4 comprises a pipe which is radially offset to the wall of the tank 2 relative to the layering axis L. This pipe of the filling device 4 comprises a filling inlet 5 which opens into a flow guide 6. The flow guide 6 extends in the shape of a circular arc along the wall of the tank 2 and will be combined with the filling device 4. Figure 2 Describe in detail.

[0055] The volume V of the tank 2 forms a hollow cylinder which surrounds the inner tank 3. A cooling coil 8 is arranged around the inner tank 3. Furthermore, an extraction pipe 9 is provided which is designed as a nozzle and passes from the cover D through the volume V to the lower region of the tank 2. Thus, if the liquid to be cooled is continuously cooled by the coil 8 and the cooled water is mainly deposited in the lower region, the tank 2 and the tank system 1 can benefit from thermal stratification, so that corresponding cooled water can also be extracted via the nozzle 9.

[0056] The cooled water is finally fed into the inner tank 3 via the extraction pipe 9 and the pipeline 7. The inner tank has a connector 10, by means of which carbon dioxide can be introduced into the tank to carbonate the water. The extraction pipe 9 and the filling device 4 can also be made of a plastic suitable for drinking water, which also has thermal conductivity to assist cooling.

[0057] Figure 2 A flow guide 6 is shown, which is designed as an arc-shaped element. In the present example, the flow guide has two tangential inlets 20, which are arranged at the ends of the arc section. In the upper region in the direction of gravity, the flow guide 6 is configured to be open. In the lower region, the flow guide ends at the bottom plate 21. Perpendicular to the bottom plate 21 is a guide element 22, which follows an arc and can guide water in the form of a channel. A barrier 23 is arranged below the tangential inlet 20, which again reduces the cross-section of the inlet so that the water can flow out as horizontally as possible through the tangential outlet. In order to support stratification, a horizontally running guide platform 24 is arranged above the tangential outlet 20.

[0058] Figure 3 A filling device 4 is shown, but for an inner tank 7, wherein the filling device 4 opens into a filling inlet 5 which in turn is arranged directly above the guide device 6. In this device, the vortex W is formed completely in the guide plate 6, and the water flows out substantially horizontally through the tangential water inlet 20. Likewise, a bottom plate 21 and a barrier 23 are provided in the region of the tangential outlet 20, which is supplemented by a horizontal guide platform 24. Since the introduced water flows substantially horizontally, mixing of thermal stratification can be avoided and it is advantageous that cold water is always available for extraction in the lower region of the tank.

[0059] Reference numerals list

[0060] 1 Tank system

[0061] 2 Tank

[0062] 3 inner tank

[0063] 4 Filling device

[0064] 5 Filling inlet

[0065] 6. Flow diversion device

[0066] 7 Pipeline

[0067] 8 Cooling coil

[0068] 9 Extraction pipe / nozzle

[0069] 10 Carbonation / CO2 feed inlet

[0070] 20 Tangential entry

[0071] 21 substrate

[0072] 22 Guide element

[0073] 23 Barrier elements

[0074] 24 level platforms

[0075] D Cover

[0076] L Layered Axis

[0077] V Tank volume

[0078] W Turbulence

Claims

1. A tank system (1) for cooling, storing and extracting liquid, comprising: For cooling the liquid and storing the liquid in the volume (V) along a stratification axis (L) of the volume (V), thereby at least partially forming a thermal stratification of the liquid in the tank body (2) along the stratification axis (L), wherein the tank body (2) can be filled by a filling device (4) having a filling inlet (5) in an inlet area along the stratification axis (L), and can be emptied via an outlet in an outlet area opposite to the inlet area along the stratification axis (L), characterized in that in order to prevent the liquid from mixing in the volume (V) along the stratification axis (L) in the tank body (2), the filling device is constructed to: guide the liquid into at least one water flow that runs completely or partially in a plane perpendicular to the stratification axis (L), and feed the liquid into the liquid already stored in the tank body (2), so that the water flow is tangent to an arc in a plane perpendicular to the stratification axis (L), wherein The filling device is provided with a guide device (6) below the filling inlet (5), the guide device being used to guide the liquid coming out of the filling inlet into a water flow at least partially perpendicular to the stratification axis (L), wherein the tank body can be filled from above via the filling inlet (5) in an orientation at least partially or completely parallel to the stratification axis (L), wherein the guide device for forming the liquid flow has at least one lateral opening, liquid can flow out from the at least one lateral opening of the guide device, the liquid flow is completely or substantially in a plane perpendicular to the stratification axis, and wherein the guide device (6) has one tangential inlet (20) or two tangential outlets (20).

2. The tank system (1) according to claim 1, characterized in that: The filling device and / or the flow guiding device are configured to divide the liquid into at least two liquid flows, the at least two liquid flows flow in respectively different directions, and feed the liquid stored in the tank (2), thereby avoiding the formation of vortexes.

3. The tank system (1) according to claim 2, characterized in that: The at least two liquid streams flow in opposite directions to each other.

4. The tank system (1) according to claim 1, characterized in that: The flow guide device (6) is arranged to be offset from the layering axis (L) in the radial direction.

5. The tank system (1) according to claim 1, characterized in that: The flow guiding device (6) forms an arc around the layering axis (L).

6. The tank system (1) according to claim 1, characterized in that: The filling inlet (5) opens to the flow guide device (6) in a manner radially offset from the layering axis (L).

7. The tank system (1) according to claim 1, characterized in that: The flow-guiding device (6) is arranged relative to the filling inlet (5) in such a way that the liquid originating from the filling device (4) flows through the flow-guiding device (6) in opposite directions in a partial section thereof.

8. The tank system (1) according to claim 1, characterized in that: The flow guide device (6) is arranged horizontally and / or arranged in a plane perpendicular to the layering axis (6); and / or A substrate (21) is provided, which is arranged horizontally and / or in a plane perpendicular to the layering axis (L).

9. The tank system (1) according to claim 1, characterized in that: The flow guiding device (6) has at least two guiding elements (22) for guiding liquid in the flow guiding device (6), wherein the guiding elements (22) are arranged perpendicular to the base plate (21).

10. The tank system (1) according to claim 9, characterized in that The at least two guide elements (22) follow a circular arc shape.

11. The tank system (1) according to claim 1, characterized in that The flow guiding device (6) is provided with a substrate-side barrier element (23) at at least one of the tangential inlets (20) for mixing the liquid inside the flow guiding device (6); and / or At least one horizontal platform (24) is provided for stratifying and vertically fanning the liquid at at least one of the tangential inlets.

12. The tank system according to claim 1, characterized in that: The tank body (2) forms a hollow volume.

13. The tank system according to claim 1, characterized in that: The tank (2) comprises an inner tank (3) for carbonation of the cooled liquid in the tank, wherein the inner tank is completely contained in the volume (V) of the tank (2). Wherein, the tank body (2) and / or the inner tank body (3) have a rotationally symmetrical shape.

14. The tank system according to claim 13, characterized in that: The tank body (2) and / or the inner tank body (3) has a shape that is rotationally symmetrical around the layering axis (L).

15. The tank system (1) according to claim 13, characterized in that A cooling system is arranged around the inner tank (3) and is constructed as a coil (8) or a double-walled coil.

16. The tank system (1) according to claim 1, characterized in that The tank system (1) is at least partially made of a plastic suitable for drinking water.

17. The tank system (1) according to any one of claims 13 to 16, characterized in that The at least one outlet opening is provided toward the lower region of the corresponding tank body (2, 3), and an extraction pipe (9) is provided for extracting the liquid from the tank body (2) and / or the inner tank body (3).

18. The tank system (1) according to any one of claims 13 to 16, characterized in that When the inner tank (3) is filled, a device is provided for mixing a gas containing carbon dioxide into the liquid.

19. The tank system (1) according to any one of claims 13 to 16, characterized in that: The tank body (2) and the inner tank body (3) are connected to one another via one of the extraction pipes (9) in such a way that liquid originating from the tank body (2) can be introduced into the inner tank body (3).

Images