WO2013045017A2

WO2013045017A2 - Device for storing gas

Info

Publication number: WO2013045017A2
Application number: PCT/EP2012/003665
Authority: WO
Inventors: David Wenger; Steffen Maus
Original assignee: Daimler Ag
Priority date: 2011-10-01
Filing date: 2012-08-31
Publication date: 2013-04-04
Also published as: WO2013045017A3; DE102012006367A1; DE202011108934U1

Abstract

The invention relates to a device (1) for storing gas in a motor vehicle (2) comprising at least one compressed-gas container (4), wherein the at least one compressed-gas container (4) is surrounded on at least one side by a screening element (10). The invention is characterized in that a clearance (x) remains between the screening element (10) and the at least one compressed-gas container (4).

Description

Device for storing gas

The invention relates to a device for storing gas in a motor vehicle according to the closer defined in the preamble of claim 1.

Compressed gas containers are known from the general state of the art. Such containers are typically formed substantially cylindrical and are used for storing gases under high pressure. In particular, pressurized gas containers can be used for storing hydrogen or natural gas in motor vehicles. In the storage of hydrogen while pressures in the order of 350 or 700 bar in the pressurized gas containers are well known and common. In order to ensure a sufficient mechanical strength of the compressed gas containers at maximum tightness, they are typically formed with an inner shell, a so-called liner, which is surrounded by an outer shell, often made of a fiber-reinforced plastic material. The structure provides the maximum possible tightness, especially against

Hydrogen, safe and allowed at a reasonable weight of the gas cylinder a sufficiently high mechanical strength to withstand pressures of 700 bar or more.

The problem with such a pressurized gas container lies in the fact that it may be exposed to a mechanical load due to an accident of the motor vehicle when used in a motor vehicle. It is particularly problematic that a deformation of the compressed gas container or its outer shell can be made so that it elastically deforms the compressed gas container by a local introduction of force. This can lead to structural damage to the

Compressed gas tank come, which are not or hardly recognized by visual inspection of the gas cylinder due to the largely elastic deformation can. This can be a compressed gas tank, which looks optically intact, quite a danger, since it is visually invisible damaged in its structure and no longer withstands the required operating pressures.

To be able to reliably and reliably exclude a potential hazard from the pressurized gas container, pressurized gas containers are currently exchanged after each potential damage in order to preclude a risk to the motor vehicle or its occupants due to the not reliably visually detectable and detectable damage to the container. This is correspondingly complicated and expensive, but is absolutely necessary in the currently conventional constructions of devices for storing gas in motor vehicles to ensure safety.

A potential risk to a device for storing gas under high pressure in a motor vehicle can of course be minimized by a suitable arrangement of the compressed gas tank, but not completely excluded. For example, WO 2006/029415 A2 shows a fuel cell vehicle in which the. Device for storing the hydrogen in the form of three

Compressed gas tanks in the middle of the vehicle within the support frame thereof is arranged. This, together with a shield on the underbody of the vehicle provides a comparatively good protection. Now, however, it is true that a deformation of the support frame of the vehicle can occur, which is transferred to the directly connected to this compressed gas tank. The same applies to a deformation of the shielding plate, which is connected via fastening elements directly to the compressed gas containers. In this case, too, force effects can occur on the pressurized gas containers, which are not detectable in the above-mentioned manner and, for safety reasons, force an exchange of the compressed gas containers.

The object of the present invention now is to address this problem and further develop a device for storing gas in a motor vehicle such that a potential damage to the compressed gas tank of the device can be determined in at least most cases certainly, and so without unnecessary replacement the best possible safety of the device is ensured by compressed gas tanks. This object is achieved according to the invention by a device having the features in the characterizing part of claim 1. Advantageous embodiments of

Device emerge from the dependent therefrom dependent claims. A preferred use is specified in claim 10.

The inventive device for storing gas in a motor vehicle thus provides at least one pressurized gas container which is surrounded on at least one side by a shielding element. According to the invention, a clearance remains between the shielding element and the pressurized gas container. Thus, it can be ensured that in the case of an external force first the shielding element, preferably a shielding plate, is deformed before a force is applied to the compressed gas container. This protects the compressed gas tank in light accidents completely against a force. In addition, the deformation of the

Shielding element Conclusions on the forces that occurred during the deformation as well as on a possible impairment of the compressed gas tank. trained

Skilled personnel, it is so easy to draw conclusions based on the deformation of the shielding in an accident on whether the compressed gas tank itself has also been deformed and therefore must be replaced for safety reasons. With a simple shielding element can be so by the plastic

Deformation of the same a kind of "record" of the previous crash achieve, which due to the degree of deformation conclusions about a possible

Impairment of compressed gas tank allows.

In an ideal development of the device according to the invention, it is provided that the shielding element has a defined distance to the at least one pressurized gas container at each point. This distance is ideally designed so that an elastic deformation of the shielding element does not lead to contact of the shielding element with the pressurized gas container. This can ensure that an impairment of the compressed gas container by external forces has only occurred when the shield is plastically deformed and remains in this plastically deformed state. This can additionally be supported by the shielding element being designed such that it bends in a defined manner. In this case, the force acting on the device can be recalculated, so as to further improve the conclusion about a potential damage to the compressed gas tank. The shielding element, in particular if it is designed as a shielding plate, can, in addition to the described object, also effect a thermal shielding of the at least one compressed gas container in the event of a fire. Is this

Shielding element formed, for example, below the at least one compressed gas tank and it comes through an accident, for example, with a gasoline fueled vehicle to leakage of gasoline and a fire below the vehicle, then the shield can in addition to the functionality described above, a thermal shield of at least one Ensure compressed gas tank against this fire. Because there is a defined distance between the shielding element and the pressurized gas container, a thermally insulating air layer thus arises between the shielding element and the pressurized gas container. The shield also prevents an immediate impact of flames on the at least one pressurized gas container.

In a preferred embodiment of the device according to the invention, it is provided that the at least one pressurized gas container with a thermal

Overpressure, in particular in the range of a valve device of the at least one compressed gas container, is provided, wherein the intended use below the thermal overpressure protection no material of the shielding is arranged. Such thermal overpressure protection is generally known and customary in compressed gas tanks. It may for example consist of a burst body which holds a plug in an opening. If there is a thermal load, then this bursting body will shatter and the mechanical protection of the plug will fall away. This is then pushed by the internal pressure of the gas cylinder from the opening and the gas can escape. For example, reference is made to DE 199 11 530 A1 with regard to such a thermal overpressure protection.

In the case of the development of the device just described, in addition to the thermal shielding of the compressed gas container by the shielding element, it is now achieved that triggering of this thermal overpressure protection is not prevented due to the fact that no material of the shielding element is present below it. The shielding element can end in the region of the thermal overpressure protection or have an opening here. Since heated gases rise upwards, it is ensured that the hot gases are kept away from the shielding element by the compressed gas container itself, but not by the thermal overpressure protection. In a further very favorable embodiment, it can further be provided that the shielding element is designed so that rising hot gases are conducted into the region below the thermal overpressure protection. The design therefore not only allows the thermal overpressure protection is not passively shielded, but can by a suitable embodiment of the

Shielding element, for example, if this is formed obliquely ascending in the direction of thermal overpressure, contribute to a fast and reliable triggering thereof.

In a further embodiment of the device according to the invention, it can also be provided that the shielding element is designed so that leakage gas is discharged from the at least one compressed gas storage in a predetermined area. The shielding element, which may surround, for example, the at least one pressurized gas container on four of its sides, can also be designed so that this is a targeted derivation of possibly by a leakage in the compressed gas container

allowing escaping gases. This allows on the one hand the detection of such gases with a single sensor in just this area, in which they

Abschirmelement be derived, and on the other hand allows a discharge of any leakage gases in an area in which they are not critical to the safety, for example, the occupants of the vehicle.

Of course, the device according to the invention can be used for any type of pressurized gases in vehicles, for example for vehicles powered by natural gas. In particular, however, it is suitable for use for storage of hydrogen, since it guarantees maximum safety of the same for the very high pressures used there construction of the compressed gas tank, without having to be renewed unnecessarily often, which would be associated with considerable costs ,

Further advantageous embodiments of the device according to the invention are specified in the remaining dependent claims and are based on the

Embodiments clear, which are described below with reference to the figures. Showing:

1 shows an exemplary motor vehicle with a fuel cell system.

Fig. 2 shows a first possible embodiment of the device according to the invention for

Storing gas in a plan view;

Fig. 3 shows a first possible embodiment of the device according to the invention for

Storing gas in a side view;

Fig. 4 is a representation analogous to Fig. 2 in an impaired by an accident

Status;

Fig. 5 shows a second possible embodiment of the device according to the invention for

Storing gas in a plan view; and

Fig. 6 shows a second possible embodiment of the device according to the invention for

Saving gas in a side view.

In the representation of FIG. 1, a device 1 for storing gas in an indicated motor vehicle 2 can be seen. The device 1 for storing gas intended to store high-pressure hydrogen for a

Fuel cell system 3 of the vehicle 2 serve. The device 1 itself comprises a plurality of compressed gas containers 4, which can be seen for example in the illustration of Figure 2 in more detail.

In the device 1, hydrogen gas is stored at a nominal pressure of 700 bar, for example. It serves to supply a fuel cell 5 of

Fuel cell system 3 with fuel. The fuel cell system 3 is indicated in the illustration of Figure 1 only highly schematic. The fuel cell 5 comprises an anode chamber 6, to which the hydrogen is supplied from the device 1. In addition, it comprises a cathode compartment 7, to which air is supplied as an oxygen supplier in a manner known per se. The supply and removal of the educts and products is indicated here only by arrows. The fuel cell 5 of

Fuel cell system 3 generates electrical power, which via a

Power electronics 8 a here shown in principle as a hub motor 9 electric traction motor of the vehicle 2 is provided. The vehicle 2 may in particular be a passenger car. The design of the motor vehicle 2 as a commercial vehicle, as a driverless transport system, as a watercraft or the like would of course be conceivable. To the device 1 now in the event of an accident of the vehicle 2 ideally in front of a

To protect the force due to this accident, the device 1, for example, in the middle of the vehicle 2 in the lower region, between not shown parts of a support frame, as it is known from the prior art, arranged.

However, the problem remains that a possible force on the individual compressed gas tank 4 of the device 1 to a structural

Damage may cause the same, without this being visible from the outside. On one side of the compressed gas container 4, in particular below the same, therefore, a recognizable in Figure 2 shielding element 10, preferably in the form of a shielding plate 10, is arranged. This shielding plate 10 is formed so that between the

Shielding plate 10 and the compressed gas containers 4 an example at several points of the structure according to Figure 2 marked clearance x between the shielding plate 10 and the gas cylinders 4 remains. This free space x, which is preferably defined as a defined distance between each point of the shielding plate 10 and the respectively nearest point of the respective compressed gas container 4, serves to ensure that the shielding plate 10 can be elastically deformed from the outside in the event of a force, without it Gas cylinder 4 even touched.

Does it come to a stronger force on the shielding plate 10, as for example, by the force designated F in the illustration of Figure 4

is indicated, then it may come in the designated A section of the shielding 10 to a plastic deformation thereof. Such a plastic one

Deformation may also be accompanied by a reduction of the free space x, so that in the embodiment shown in Figure 4, the right-hand pressurized gas container 4 may be affected accordingly and may also be elastically or plastically deformed. A plastic deformation of the gas cylinder 4 is not critical, since this is visually recognizable. However, an elastic deformation of the compressed gas container 4 can be very critical, since this can cause a structural damage to the compressed gas container 4, which is not visually recognizable and not detectable. Due to the structure of the device 1 chosen here can now due to the deformation of the

Shielding plate 10 in the area A, however, be concluded on a deterioration of the right in this case gas cylinder 4. Based on the deformation of the shielding plate 10 in the area A can be determined by skilled personnel, whether an exchange of the right-hand pressurized gas container 4 is necessary or not. The shielding plate 10 may in particular be designed so that a

Force is proportional to the deformation of the shielding plate 10, and that based on the deformation so on the size of the applied force F can be calculated back. This allows a safe and reliable assessment of whether, if necessary, an exchange of the right-hand pressurized gas container 4 is required in order to continue to ensure the safety of the device 1.

In addition to this functionality of the shielding plate 10 for assessing a potential damage to the compressed gas container 4, the shielding plate 10 can also take on an additional function. This consists in a thermal shielding of the compressed gas container 4 against a possible thermal load, for example by fire. This is easily and efficiently possible, for example, in the case of the shielding plate 10 of FIGS. 2 and 4, which is advantageously designed in the manner of a trough. Due to the design in the manner of a pan, a shield can be realized both directly from below and obliquely from below. In the side view of Figure 3, with cut shielding 10, this is again exemplified. The shielding plate 10 forms a kind of tub, which in the illustrated here

Embodiment of Figures 2, 3 and 4 is pulled laterally on three sides of the device 1. In addition, each of the compressed gas container 4 in a conventional manner, a valve device 1 1 on. About this valve device 1 1 can

For example, the refueling with and the removal of hydrogen from the individual gas cylinders 4 be realized. Typically, the valve device 11 will also have in a conventional manner a thermal overpressure protection 12, which is indicated in the valve device 11 shown here. Such overpressure protection 12 can be realized, for example, via a thermally triggered bursting body, which has a discharge opening for the hydrogen in the

Normally kept closed and releases in the event of bursting of the bursting body due to an increased ambient temperature.

The structure of the shielding plate 10 as a trough in the illustration of Figure 3 is now, as already mentioned, suitable for shielding the compressed gas container 4 thermally against a direction indicated by the arrows 13 fire below the device 1. Such a fire can occur, for example, by leaking gas in an accident of the provided with the fuel cell system 3 vehicle 2 with a conventional vehicle. Through the free space x creates an insulating layer of air between the shielding plate 10 and the compressed gas containers 4. Moreover, this prevents

Shield 10, the direct contact of any flames with the material of the pressurized gas container 4 and can thus ensure an effective shielding of the compressed gas container 4 with respect to the thermal impairment for a certain time. The trained as a pan shield 10 ends laterally below the

Valve device 11. Alternatively, suitable openings may be provided in the shielding plate 10 below the valve device 11. Through these openings or the ends of the shielding plate 10 below the valve device 11 ensures that no thermal shielding of the thermal

Overpressure 12 is effected by the shielding plate 10. This can thus be heated by the hot gases and triggers safely and reliably in the desired manner.

In the illustration of Figure 5, a further embodiment of the shield 10 is shown. In the embodiment shown there, the shielding element surrounds

10, the compressed gas container 4 of the device 1 at least four of its sides, thus ensuring an assessment of any critical force not only from below or obliquely below the compressed gas tank 4, but also from the side and the area above the compressed gas tank 4. Otherwise, the

Functionality the same, as already in the previously described trough-shaped

Shield 10 described.

In the illustration of FIG. 4, the embodiment shown in FIG. 5 can again be seen in a sectional side view of the device 1. The shielding plate 10 extends with a certain inclination of its central axis relative to the central axis of the compressed gas container 4. In particular, the compressed gas container 4 in the

intended use of the vehicle 2 horizontally, ie parallel to the underbody on which the vehicle 2 drives, be formed. The shielding plate 10, however, is slightly inclined, in such a way that the inclination in the direction of the valve device

11 is formed. If, as in the representation of FIG. 3, a fire occurs, for example, on the side of the compressed gas container 4 facing away from the shielding plate 10, then a flow of the heated air and the air can flow through the arrangement of the shielding plate 10 ascending in the direction of the thermal overpressure protection 12 Exhaust gases of the fire in the direction of the thermal

Overpressure 12 take place, so that they also in a fire under her remote end of the gas cylinder 4 triggers early and thus prevents bursting of the gas cylinder 4. Additionally or alternatively, the region of the shielding plate 10 arranged above the compressed gas container 4 can also be designed such that it is arranged ascending in one direction. If there is a leakage of hydrogen from the pressurized gas container 4, which is indicated here by the arrows denoted by 14, then the leakage hydrogen flows along the shielding plate 10 upwards and reaches a predetermined defined area, in which in the embodiment shown here, a hydrogen sensor 15 is indicated. About the hydrogen sensor 15 so the exiting

Leakage hydrogen can be detected and any measures required for the safety of the motor vehicle 2 or its occupants can be initiated. This can be achieved via only a single hydrogen sensor, and thus very cost, a high level of security.

When used for a gas which is heavier than the surrounding air, of course, a construction in the reverse manner would be conceivable, so that by a arranged below the compressed gas storage 4 sheet metal element a targeted

Discharge of the gases down, for example, could be done in a non-critical area or in an area also provided with a gas sensor area.

The shielding plate 10 itself is of course designed by skillful design so that it ensures the desired functionality and ideally deformed so that can be recalculated to the force acting on the shielding plate 10 force. At the same time, the sheet is minimized in terms of its mass and due to the choice of materials in terms of its cost.

In order to create additional synergies in addition to the described functionalities, it may further be provided that the shielding plate 10 assumes a supporting function either in the vehicle 2 itself or in a support frame for the device 1 within the vehicle 2. The mass introduced by the shielding plate 10 can thus additionally be used for the functionality of the reinforcement of the load-bearing elements, so that masses of load-bearing components can be saved in other areas.

Claims

claims

1. Device (1) for storing gas in a motor vehicle (2) with at least one pressurized gas container (4), wherein the at least one pressurized gas container (4) is surrounded on at least one side by a shielding element (10),

characterized in that

between the shielding (10) and the at least one pressurized gas container (4) remains a free space (x).

2. Device (1) according to claim 1,

characterized in that

the shielding element (10) is designed in the manner of a trough and is arranged below the at least one compressed gas container (4).

3. Device (1) according to claim 1,

characterized in that

the shielding element (10) surrounds the at least one pressurized gas container (4) on at least four of its sides.

4. Device (1) according to claim 1, 2 or 3,

characterized in that

the shielding element (10) is formed from sheet metal.

5. Device (1) according to one of claims 1 to 4,

characterized in that

the shielding element (10) has a defined distance to the at least one pressurized gas container (4) at each point.

6. Device (1) according to one of claims 1 to 5,

characterized in that

the shielding element (10) has a supporting function in the device (1) and / or in the motor vehicle (2) equipped with the device (1).

7. Device (1) according to one of claims 1 to 6,

characterized in that

the at least one pressurized gas container (4) with a thermal

Overpressure protection (12), in particular in the region of a valve device (11) of the at least one compressed gas container (4) is provided, wherein in

intended use below the thermal overpressure protection (12) no material of the shielding element (10) is arranged.

8. Device (1) according to claim 7,

characterized in that

the shielding element (10) is designed such that rising hot gases can be conducted into the region below the thermal overpressure safety device (12).

9. Device (1) according to one of claims 1 to 8,

characterized in that

the shielding member (10) is formed so that leakage gas from the

at least one compressed gas container (4) can be derived in a predetermined area.

10. Use of the device (1) according to one of claims 1 to 9

for storing hydrogen.