DE202011108934U1 - Device for storing gas under high pressure - Google Patents

Abstract

Device (1) for storing gas under high pressure, with at least one pressurized gas container (2) with a valve device (3), which has a safety device with a thermal release unit (5), characterized in that, when used as intended, below the pressurized gas container (2 ) at least one shielding plate (7) is arranged which has at least one hot air duct (8) which has an opening (9) in the area of the thermal release unit or in an area below the thermal release unit (5).

Description

The invention relates to a device for storing gas under high pressure according to the closer defined in the preamble of claim 1.

Compressed gas containers are known from the general state of the art. The containers are typically formed substantially cylindrical and are used for storing gases under high pressure. In particular, pressurized gas containers can be used to store hydrogen under pressures of the order of 350 or 700 bar.

The DE 199 11 530 A1 describes a safety device for such a compressed gas container. The safety device described there is now well known and commonplace. It consists essentially of a burst body, which may be formed in particular in the form of a glass ampule. This is filled with a liquid which has a very high thermal expansion coefficient. The rupture body holds a closure member sealingly in a first position in an opening for pressure relief of the compressed gas container. If there is now a thermal overheating in the area of the safety device, the bursting body is destroyed by the internal pressure, which develops in the area of the bursting body. He thus releases the closure body, which is moved by the internal pressure in the pressurized gas container from the line, which he had closed. Through suitable openings in the area of the safety device, the gas can then flow out of the pressurized gas container and the overpressure can degrade before it represents a potential risk of explosion.

The problem with this design is now, in particular, that there must be a local connection between the thermal load and the safety device. If a pressurized gas container is used, for example, as a hydrogen tank in a vehicle, then there is typically a valve for filling and removal of the gas on one side of the pressurized gas container and in the region of which the safety device is also arranged. If, for example, a wheel fire occurs on the side of the compressed gas container facing away from the valve, then extremely high temperatures can occur in the region of the compressed gas container without sufficiently heating the bursting body arranged on the opposite side in order to trigger the safety device.

To remedy this problem, proposes the German patent DE 10 2006 009 537 B3 a compressed gas tank in particular for fuels. This compressed gas tank contains a relief valve, which is loaded with a corresponding pressure to keep it closed. The pressure then lies in a line element, in particular a high-pressure hose, through medium enclosed in the relief valve. In the region of the high-pressure hose, one or more thermal tripping units can be arranged, which in turn for example have a bursting body. If there is a corresponding increase in temperature in the region of these tripping units, the respective bursting body will burst and release the medium from the high-pressure hose in the above-mentioned manner. This flows into the environment and thus releases the relief valve, which opens the compressed gas tank. This makes it possible to install a temperature control not in the region of the valve of the compressed gas container, but also on the high-pressure hose in remote from the valve areas of the gas cylinder.

In principle, this functionality is to be welcomed. However, the structure described in the German patent has three serious disadvantages. It works via a pressure drop in the high pressure line. Destroying the high pressure line, without this being done by a thermal emergency, also opens the relief valve and leaves the gas from the pressurized gas container uncontrolled and possibly unwanted. Another disadvantage is that the high pressure hose, for example, when used in a vehicle when it comes to an accident, can be trapped. Thus, a pressure relief between the clamped area and the relief valve is no longer possible, unless the high-pressure hose is accidentally destroyed in this area. If the area of pinching between the relief valve and the first trip unit, then it may happen that the trip unit does not work safely and reliably and the pressure vessel remains closed against the desired effect. The safety device according to the patent can also only monitor the areas where bursting bodies connected to the high-pressure hose are arranged. If the area of the valve is to be additionally monitored, then another safety device, such as has been described above, is necessary here. To monitor a compressed gas container at two or three points so that two or three bursting body with the corresponding closure elements are necessary. This is complex, expensive and requires a comparatively large space.

Regardless of these problems, any type of remote release of the thermal tripping unit also adds a significant extra Expenditure on components and functionalities. Since these components and functionalities are highly relevant for the safety of the device for storing the gas under high pressure, this high demands are to be addressed. Accordingly, these components are complicated and expensive.

The object of the present invention is now to improve the safety in the field of a device for storing gas under high pressure, and in particular in the area of a device used as a hydrogen tank in a vehicle, and simple, efficient, small and inexpensive one to provide safe and reliable working thermal protection of the device.

According to the invention this object is achieved by the features in the characterizing part of claim 1. Further advantageous embodiments of the solution according to the invention will become apparent from the remaining dependent claims.

The solution of the invention provides in the apparatus for storing gas under high pressure in addition to the at least one compressed gas container in the intended use below the compressed gas container at least one shielding plate. This at least one shielding plate shields the compressed gas container from a thermal load, for example, by flames occurring below the compressed gas container. The shielding plate, which of course likewise heats up in the event of a fire and thereby thermally loads the compressed gas container, also has at least one hot air duct which has an opening in the region of the thermal tripping unit or in a region below the thermal tripping unit. Such a hot air duct in the shielding plate can guide the hot air produced during the fire in the duct into the region of the thermal tripping unit which is already present or must be present in the compressed gas tank. As a result of this dissipation of the hot gases into the region of the thermal tripping unit, these or the areas surrounding them are strongly heated. Before the pressurized gas container, especially at its end remote from the thermal tripping unit, becomes so hot that it leads to a safety problem, the hot air duct and, if appropriate, exhaust gases are also heated accordingly via the hot air duct into the region of the thermal tripping unit can trigger from a critical temperature, so that the gas can flow out of the compressed gas container and damage, in particular an explosion of the gas cylinder, is prevented. Without additional design effort in the area of the compressed gas container and the thermal trip unit can be achieved on a simple shield with at least one hot air duct a significant improvement in security, as by the targeted management of hot air in the field of thermal trip unit unilateral heating of the gas cylinder delayed the thermal tripping unit side facing away and the temperature of the thermal trip unit is supplied. Unlike remote release devices, as described in the aforementioned prior art, here are not highly complex components which, for example, as a hydraulic power transmission or the like work, but it is only a simple introduced into a shielding hot air duct necessary. This is very easy and inexpensive to produce.

In a further very favorable and advantageous embodiment of the device according to the invention, it is further provided that the at least one hot air duct is formed rising in the direction of the opening in the intended use. In particular, such in the intended use in the direction of the opening rising hot air duct can direct the hot gases ideally in the region of the thermal trip unit or in an area below the thermal trip unit. The then rising in the thermal tripping unit hot gases heat them accordingly.

In an advantageous development of the hot air duct may in particular be designed so that it ends in the region of the opening, so that therefore no separate opening is necessary, but which results directly through the open end of the hot air duct.

In a further very advantageous embodiment of the device according to the invention, it is also provided that the hot air duct is open at the bottom. Such a downwardly open hot air channel below the compressed gas container is particularly simple and efficient to produce, since it can be realized for example by the impressing of a channel or a channel structure in the shield. He also has the advantage that he collects the hot air, which occurs below the shielding plate over a comparatively large area and the opening or its end to the means of hot air, the critical occurring below the compressed gas tank temperature in the region of the thermal trip unit transferred to.

The above object is also achieved by a vehicle having a device according to the invention, in which the at least one shielding plate is part of a subfloor construction of the vehicle. Frequently, the devices for Storing gas under high pressure in a vehicle used to store, for example, gaseous fuel. Such fuel tanks are typically found in the lower area, often in the lower rear of the vehicle. Therefore, waiving a specially trained shield and a corresponding configuration of the underbody construction of the vehicle, which is already necessary and available anyway, be used in a suitable manner to form the at least one shield with the at least one hot air duct. As a result, it is entirely possible to dispense with additional components. It is only necessary to choose a slightly different shape of the underbody construction of the vehicle, in particular to introduce corresponding hot air ducts and / or openings in an already existing floor panel.

In particular, in this embodiment, already existing carriers, which are typically tubular or rectangular with a hollow cross-section, are used as hot air ducts.

A preferred use of the device according to one of claims 1 to 7 is in particular in the storage of hydrogen at a nominal pressure of more than 300 bar. In particular, in the case of hydrogen, a comparatively high nominal pressure of the compressed gas container is advantageous since in this way a comparatively larger amount of energy can be stored. Current hydrogen storage systems currently have nominal pressures of the order of 350, but in particular of the order of 700 bar. For such hydrogen tanks in the form of one or more compressed gas tanks, safety is crucial. With the device according to the invention, this safety can be ensured simply and efficiently, in particular also very space-saving and very cost-effective, which predestines the device for storing gas under high pressure as hydrogen storage for a vehicle. The vehicle may be formed, for example, as a fuel cell vehicle according to an advantageous development, wherein in the device for storing gas under high pressure then the hydrogen is stored to operate the fuel cell system accordingly.

Further advantageous embodiments of the device according to the invention will become apparent from the remaining dependent claims and are further apparent from the embodiment, which will be described below with reference to the figures.

Showing:

1 an apparatus for storing gas under high pressure with a conventional compressed gas container according to the prior art;

2 a schematic diagram of the device according to the invention;

3 a sectional view along the line III-III in 2 ;

4 an alternative embodiment of the device analog 2 ;

5 a side view of a device according to the invention in a first embodiment; and

6 a side view of a device according to the invention in a second embodiment.

In the presentation of the 1 is a device 1 for storing gas under high pressure, for example for storing hydrogen gas at a nominal pressure of 700 bar in a fuel cell vehicle. The device 1 consists essentially of a pressurized gas container 2 which is a valve device 3 having. This valve device is often inside the compressed gas tank 2 arranged. It is then also referred to as OTV (On Tank Valve). To improve the illustration, the valve is here at least partially outside the compressed gas tank 2 shown. This valve device 3 typically has a valve 4 on, which for refueling the gas cylinder 2 and for removing the gas from the pressurized gas container 2 is provided. in the area of the valve device 3 is also a thermal trip unit 5 arranged, which at a thermal overload in the region of the valve device 3 the compressed gas tank 2 opens so as to pressurize the gas from the pressurized gas container 2 to let off.

The thermal trip unit 5 may preferably be formed in a manner known per se so that a closure body in one with the interior of the compressed gas container 2 is arranged in connection line and seals it tight. It is held in its position via a bursting body, for example a glass element with liquid therein. Does it now come to a warming of the thermal trip unit 5 , then the liquid expands inside the glass container and causes it to burst. It is therefore also called a burst body. If the bursting body no longer holds the closure element in the line, then the pressure of the gas in the compressed gas container 2 push this closure element out of the line and can escape. This structure is known per se and usual.

Does it now come to a thermal load of the gas cylinder 2 or the device 1 , For example, by a wheel fire in a vehicle, it may be that this thermal load on one side in the region of the compressed gas tank 2 occurs. In the presentation of the 1 is the thermal load, for example, by the with 6 indicated arrows indicated. These are intended to symbolize either flames or, in particular, hot air and hot flue gases caused by the fire. The problem now is that the compressed gas tank 2 in his the valve device 3 opposite end is heated very strongly, so that it can lead to overheating here, up to a failure or exploding the gas cylinder 2 , Since the temperature occurs only at certain points, destruction of the compressed gas tank will typically occur before the thermal trip unit 5 in the area of the valve device 3 has been heated so far that it triggers. This represents a significant security problem.

In the presentation of the 2 the device is modified to the effect that under normal operation below the compressed gas tank 2 a shielding plate 7 is arranged. This shielding plate 7 holds, at least for a certain time, flames and hot exhaust gases or hot air from the compressed gas tank 2 and protects it. The shielding plate 7 Also, as shown in the sectional view of 3 is better to recognize a hot air duct 8th on. This hot air duct 8th points in the area below the thermal trip unit 5 an opening 9 on or ends in the in 2 illustrated embodiment open there. Hot air and hot flue gas, which in turn analogous to the representation in 1 by the arrows on the valve device 3 remote end of the device 1 is symbolized, then flows through this hot air duct 8th as by the arrows 10 symbolizes. The hot air duct 8th can be formed as a single channel or as a channel system, for example, several V-shaped converging channels. It can, as shown here, be designed to be open at the bottom, so hot air and hot flue gases, which below the gas cylinder 2 can occur at any point, collect accordingly. It is preferably designed so that it is in the direction of its opening 9 or its end is formed slightly ascending in the intended use, so that an ideal flow of hot air or hot flue gases in the region of the opening 9 or the end can take place. There, the hot gases or the hot air escape and flow around the valve device 3 , They thus heat the thermal trip unit 5 and trigger them from a critical temperature. This allows a safe and reliable triggering of the thermal trip unit 5 be reached, even if the heat at certain points under another location of the gas cylinder 2 takes place as the thermal trip unit 5 is arranged. The shielding 7 can absorb some of the thermal energy from the compressed gas tank 2 Shield until through the hot air duct 8th flowing hot gases the trip unit 5 reached and warmed up so that it triggers.

The construction is very simple and efficient and can be achieved by one or more shielding plates 7 be realized without highly complex functional elements, such as thermally highly resistant hydraulic lines or the like, are necessary.

An alternative embodiment analogous to the representation in FIG 2 is in 4 shown. The only difference here is that the hot air duct 8th down is not completely open, but from an underbody panel 11 the vehicle is shielded accordingly. This underbody sheet, which is present anyway, can thus either alone or together with the shield form a common construction, which via suitable openings and / or introduced hot air ducts 8th ensures the functionality described above. In particular, the shield may be part of the underbody construction, so that in addition to the introduction of additional openings 9 and hot air channels 8th No additional measures and components in the area of the vehicle are necessary. Also in itself except the opening 9 completely closed hot air ducts 8th are conceivable in principle. If these are heated, for example, by a fire from below, then the air trapped in the channel, due to the heating, flows through the opening 9 and heats the thermal trip device 5 , This could be, for example, in the area of a subfloor construction 12 used hollow carrier than hot air ducts, even if this only one opening 9 exhibit.

In the presentation of the 5 is now the device 1 to recognize again in a side view. Typically, such a device 1 several of the compressed gas tanks 2 on. in the embodiment shown here are four individual compressed gas tank, which here from the valve device 3 bearing side are seen from. Below the compressed gas tank is a subfloor construction 12 indicated the vehicle. On this underbody construction 12 are under each of the pressurized gas containers 2 the shielding plates 7 with inserted therein hot air duct 8th indicated as part the underbody construction 12 , The hot air channels 8th ends below the valve device 3 and can thus trigger the thermal trip unit 5 contribute as soon as there is a formation of hot gases 10 or hot air below one or the other compressed gas tank 2 comes. The construction is therefore essentially as another line of sight of in 4 To understand side view shown.

Finally, an alternative embodiment in the representation of 5 to be shown. The structure is analogous to that in 4 Understand structure described. However, he is running optimized in terms of construction volume. The hot air channels 8th are each between the pressurized gas containers 2 are arranged in the lower area. You have each on their pressure gas tank 2 facing side an opening 9 on. Through these openings 9 can the hot gas 10 then back into the area of the thermal trip unit 5 stream. Overall, this creates a structure which individual hot air channels 8th for adjacent compressed gas tanks 2 uses twice and this with an approximately trapezoidal cross-section in anyway remaining areas below between the two in each case round in cross section compressed gas containers 2 arranges. The structure is therefore particularly space-saving and very efficient in terms of construction volume. The underfloor construction 12 could also only from the shield 7 exist and on the underbody panel 11 completely renounce.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19911530 A1 [0003]
• DE 102006009537 B3 [0005]

Claims (10)

Contraption ( 1 ) for storing gas under high pressure, with at least one pressurized gas container ( 2 ) with a valve device ( 3 ), which includes a safety device with a thermal trip unit ( 5 ), characterized in that in the proper use below the compressed gas tank ( 2 ) at least one shielding plate ( 7 ) is arranged, which at least one hot air duct ( 8th ), which in the region of the thermal trip unit or in an area below the thermal trip unit ( 5 ) an opening ( 9 ) having. Contraption ( 1 ) according to claim 1, characterized in that the at least one hot air duct ( 8th ) in the direction of the opening ( 9 ) is formed rising in the intended use. Contraption ( 1 ) according to claim 1 or 2, characterized in that the hot air duct ( 8th ) in the region of the opening ( 9 ) ends. Contraption ( 1 ) according to claim 1, 2 or 3, characterized in that the hot air duct ( 8th ) is designed to be open at the bottom. Contraption ( 1 ) according to one of claims 1 to 4, characterized in that a plurality of compressed gas containers ( 2 ) are present, each of the compressed gas containers ( 2 ) a hot air duct ( 8th ) and under the compressed gas tank ( 2 ) is arranged. Contraption ( 1 ) according to one of claims 1 to 4, characterized in that the at least one pressurized gas container ( 2 ) two, optionally together with an adjacent pressurized gas container ( 2 ), hot air channels ( 8th ), which in the lower area laterally next to the compressed gas container ( 2 ) are arranged. Contraption ( 1 ) according to one of claims 1 to 6, characterized in that the thermal trip unit ( 5 ) has a closure element and a bursting body which holds this in a closed position. Vehicle with a device ( 1 ) according to one of claims 1 to 7, characterized in that the at least one shielding plate ( 7 ) Part of a subfloor construction ( 12 ) of the vehicle. Use of the device ( 1 ) according to one of claims 1 to 7, for storing hydrogen at a nominal pressure of more than 300 bar. Use according to claim 9, characterized in that the hydrogen is stored as fuel for a fuel cell vehicle.

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