Compressed gas reservoir and method for operating a compressed gas reservoir

Abstract

The invention relates to a compressed-gas reservoir (10), in particular for a motor vehicle, having a container (12) configured for storing compressed fuel and at least one pressure relief valve (22, 24). Fuel can be discharged from the container (12) into the surroundings (72) of the compressed-gas reservoir (10) as a result of the opening of the at least one pressure relief valve (22, 24). A catalyst device (58) of the compressed-gas reservoir (10) is configured for catalyzing an oxidation reaction of fuel from the container (12) with oxygen. The compressed-gas reservoir (10) has at least one piezoelectric element (30, 32) which is loaded with pressure by the opening of the at least one pressure relief valve (22, 24). At least one spark (28) can be generated by means of the at least one piezoelectric element (30, 32) by the pressure. Furthermore, the invention relates to a method for operating such a compressed-gas reservoir (10).

Description

TECHNICAL FIELD

[0001] The invention relates to a compressed-gas storage device having a container configured for storing compressed fuel and at least one pressure relief valve. Due to the opening of the at least one pressure relief valve, fuel can be discharged from the container into the surroundings of the compressed-gas storage device. A catalyst device of the compressed-gas storage device is configured for catalyzing an oxidation reaction of fuel from the container with oxygen. Furthermore, the invention relates to a method for operating such a compressed-gas storage device. BACKGROUND

[0002] Compressed-gas storage devices, such as cryogenic fuel storage devices for automobiles, are faced with the challenge that in the case of a stationary motor vehicle, i.e. in the case where the fuel of the container is not used to provide energy for the forward motion of the motor vehicle, gaseous fuel must be discharged into the surroundings of the compressed-gas storage device if there is a thermal input from the outside. The associated fuel loss when deep-cooled or cryogenic and in liquid form stored fuel is discharged in gaseous form or into the surroundings is also referred to as the so-called evaporation loss. The discharge of gaseous fuel into the surroundings takes place via a pressure relief valve, which opens automatically when the pressure in the container exceeds a threshold value for pressure relief of the container storing the compressed fuel.

[0003] Generally, in the case of the use of liquefied hydrogen as compressed fuel, such a pressure relief will occur at a pressure of less than 10 bar and in particular of approximately 6 bar. The gas discharged into the surroundings is an energy carrier, so that potential dangers associated with the release of such an energy carrier should be avoided. In particular, the discharge of gaseous hydrogen into a closed surroundings, such as a parking garage, a garage, a hall, an underground or a similar surroundings, must be avoided.

[0004] Against this background, there are methods for catalytically combusting fuel released from the container of the compressed-gas storage device and then discharging the products of the oxidation reaction of this fuel with oxygen into the surroundings.

[0005] For example, DE 102 97 661 T5 describes a catalytic combustion of an escaping gas, i.e. of a gas escaping from a pressure vessel. Here, a pressure relief valve is arranged on the pressure vessel, from which a tube extends to a catalytic reactor. In the catalytic reactor, the gas, in the case of hydrogen, reacts with the oxygen in the air to form water. The catalytic reactor has a first chamber, in which a catalytic burner is arranged, to which the gas and the air are fed. A spark plug extends into a second chamber of the catalytic reactor, which is separated from the chamber by means of a sieve. The spark plug serves to ignite the combustible gas which, without reaction in the catalytic burner, reaches the second chamber through the sieve. The ignition device in the form of the spark plug is used, in particular at the beginning of the catalytic combustion, to bring the catalytic burner to its ignition temperature by means of the flame formed by the ignition of the spark plug.

[0006] In view of the safety to be ensured, the flame burning in the chamber of the catalytic reactor has at least demanding requirements in terms of the design or operation of the reactor. This is because combustible gas is present in the adjacent pressure vessel and in the catalytic reactor itself.

[0007] Furthermore, it must be ensured by reliable ignition of the spark plug that no combustible gas reaches the surroundings from the catalytic reactor. This also involves corresponding expenditure. SUMMARY

[0008] It is therefore an object of the present application to provide a compressed gas storage of the type mentioned at the outset, which enables a particularly reliable and safe oxidation of the fuel from the vessel, and to specify a corresponding method for operating a compressed gas storage.

[0009] This object is achieved by a compressed gas storage having the features of patent claim 1 and by a method having the features of patent claim 10. Advantageous embodiments of the application having suitable refinements are specified in the dependent patent claims.

[0010] The compressed gas storage according to the application, which can be used in particular in a motor vehicle, comprises a vessel which is configured for storing compressed fuel. The compressed gas storage has at least one pressure relief valve, wherein, as a result of the opening of the at least one pressure relief valve, fuel can be discharged from the vessel into the surroundings of the compressed gas storage. The compressed gas storage has a catalyst device which is configured for catalyzing an oxidation reaction of the fuel from the vessel with oxygen. The compressed gas storage has at least one piezoelectric element, which can be loaded with a pressure by the opening of the at least one pressure relief valve. By means of this pressure, at least one spark can be generated by means of the at least one piezoelectric element.

[0011] In other words, by loading the at least one piezoelectric element with pressure, it is ensured that at least one spark is generated by means of the at least one piezoelectric element. The at least one piezoelectric element thus functions in the manner of an igniter, which is operated by the pressure that leads to the opening of the at least one pressure relief valve. By providing at least one spark, ignition energy is provided for starting the oxidation reaction of the fuel with oxygen. The starting of the exothermic oxidation reaction of the fuel with oxygen ensures that further fuel molecules are converted with oxygen in a chain reaction. In this way, the catalytic converter device can also reach a light-off temperature at which the catalytic conversion of the fuel with oxygen by oxidation takes place in the form of cold combustion.

[0012] Since the pressure applied at the opening of the at least one pressure relief valve also ensures that the at least one piezoelectric element is loaded with pressure, the at least one spark is provided in a particularly safe and reliable manner. A reliable and safe oxidation of the fuel from the container is thus also achieved.

[0013] The opening of the at least one pressure relief valve simultaneously triggers the operation of the at least one piezoelectric element and thus the provision of ignition energy in the form of at least one spark by the piezoelectric element, which functions as an ignition device.

[0014] The loss of fuel from the container can thus be safely converted into a low-energy product or medium by means of the passive and inherently safe device comprising the at least one piezoelectric element.

[0015] The passive safety of the pressurized gas reservoir is thus greatly improved. This applies in particular when the container of the compressed gas reservoir is used as a cryogenic fuel reservoir or fuel reservoir in a motor vehicle. Motor vehicles having such a compressed gas reservoir can also be parked in enclosed areas, such as enclosed halls, houses, parking garages, garages, workshops or similar areas, as long as sufficient oxygen is present in the ambient air for the oxidation reaction in which oxygen reacts with the fuel from the container.

[0016] The container can in particular be designed for storing compressed fuel in the form of liquid hydrogen (LH2) or cryo-compressed hydrogen (CcCH2) or also in the form of compressed hydrogen (CH2). In this case, the conversion of the fuel into water vapor (H2O) takes place in the case of cold combustion in the form of a catalytic oxidation reaction of hydrogen with oxygen.

[0017] If the compressed fuel is, for example, in the form of liquified petroleum gas (LPG) or liquified natural gas (LNG), further products can also be formed in the oxidation reaction with oxygen, such as CO2 and / or nitrogen oxides. The same applies to the case in which compressed natural gas (CNG) is used as compressed fuel.

[0018] Preferably, the at least one piezoelectric element is arranged between a valve disk of the at least one pressure relief valve and a support device for a spring element of the at least one pressure relief valve. Here, by the movement of the valve disk away from a valve seat of the at least one pressure relief valve, a pressure can be applied to the at least one piezoelectric element. By this integration of the at least one piezoelectric element into the pressure relief valve, it can be achieved particularly reliably that each opening of the pressure relief valve also results in the generation of at least one spark by means of the piezoelectric element. Furthermore, by the closing force of the pressure relief valve it can be ensured that the at least one piezoelectric element is compressed when the pressure relief valve is opened, so that the at least one piezoelectric element functions as a piezoelectric igniter. This ensures that the ignition energy for the start of the oxidation reaction of the fuel with the oxygen is reliably provided.

[0019] In particular, the spring element of the at least one pressure relief valve can be formed by the at least one piezoelectric element. The ignition device in the form of the at least one piezoelectric element thus also functions as a closing device for the pressure relief valve. By the closing device a pressure threshold value is predefined at which the at least one pressure relief valve is opened. When this threshold value is exceeded, thus not only is the pressure relief valve opened, but the piezoelectric element is also loaded with pressure, in particular the at least one piezoelectric element is compressed. By this design it can be achieved particularly reliably that the opening of the pressure relief valve results in the generation of at least one spark by means of the piezoelectric element or piezoelectric igniter. Furthermore, this construction of the pressure relief valve is less expensive, since in addition to the piezoelectric element no separate spring element needs to be provided.

[0020] It can be provided that the compressed gas reservoir has only one pressure relief valve and that the at least one piezoelectric element is loaded with pressure by the opening of this one pressure relief valve. In this way, a compressed gas reservoir is provided which is particularly inexpensive.

[0021] Alternatively, it can be provided that the compressed gas reservoir has a first pressure relief valve and a second pressure relief valve. Here, the second pressure relief valve is arranged downstream of the first pressure relief valve, viewed in the flow direction of the fuel escaping from the container. Furthermore, here the at least one piezoelectric element can be loaded with pressure by the opening of the second pressure relief valve. In this way, it is particularly reliably avoided that the energy released by the generation of at least one spark is input into the interior of the container. Thus, a particularly high safety can be achieved. This applies in particular to the case in which the pressure when the first pressure relief valve is opened is higher than in the case of the second pressure relief valve.

[0022] It is preferred that a valve device which prevents the fuel from flowing back into the container is arranged between the first pressure relief valve and the second pressure relief valve. This also contributes to increasing the safety, since the input of the thermal energy which is released in the exothermic oxidation reaction of the fuel with the oxygen into the interior of the container is prevented, in particular to a large extent.

[0023] When the valve device is configured as a passive valve device which has a smaller flow resistance in the flow direction than in the flow direction opposite to the flow direction, it is particularly easy to provide a valve device which prevents backflow. Such a passive valve device can be configured, in particular, as a Tesla valve. In such a valve device, in particular in the form of a Tesla valve, the configuration of the flow channel inside the valve device ensures that the flow in the flow direction is the preferred direction compared to the flow in the opposite direction.

[0024] Preferably, the compressed-gas reservoir has an outlet device through which the oxidation-reaction products of the fuel can be discharged into the surroundings of the compressed-gas reservoir. This makes it possible for the products formed in the oxidation process of the fuel with the oxygen to be discharged in a controlled manner.

[0025] It is additionally or alternatively possible for the outlet device to be configured as a partial region / subregion of the exhaust system of the motor vehicle. In particular when the fuel is to be delivered from the container of the compressed-gas reservoir to the internal combustion engine of the motor vehicle, there is already a partial region of the exhaust system which can discharge the exhaust gases of the internal combustion engine. It is therefore meaningful to use a partial region of the exhaust system as the outlet device of the compressed-gas reservoir.

[0026] In such a partial region of the exhaust system, so-called secondary air can be introduced into the exhaust gases by means of a corresponding device downstream of the internal combustion engine in order to provide oxygen for the oxidation reaction. Additionally or alternatively, the valve control of the internal combustion engine can be carried out in such a way that air can be delivered to the fuel to be oxidized via an at least partially open inlet valve and at the same time an at least partially open outlet valve. In this case, at least one combustion chamber of the internal combustion engine which is associated with the inlet valve and the outlet valve can be used as an air inlet of the outlet device without the need to provide a device for providing secondary air.

[0027] Even when the oxidation-reaction products of the fuel are to be discharged via an outlet device which is not configured as a partial region of the exhaust system into the surroundings of the compressed-gas reservoir, the compressed-gas reservoir preferably has an air inlet. In this way, it is possible to ensure a defined air delivery to the fuel in the region of the at least one piezoelectric element and / or in the region of the catalyst device.

[0028] Preferably, the catalyst device is arranged in a section of the outlet device. Since in this way it is possible to ensure that the oxidation reaction takes place catalytically via the catalyst, in which the fuel from the container reacts with the oxygen in a cold combustion, by means of a corresponding air delivery to the catalyst.

[0029] It has proven to be advantageous if the outlet device has a silencer. Because in the operation of the pressurized gas reservoir the products formed in the oxidation reaction of the oxygen and the fuel are subsequently discharged into the surroundings with particularly low noise.

[0030] It is preferred if the outlet device is oriented essentially vertically in the installed position of the pressurized gas reservoir. In this way, the chimney effect occurring when the fuel is converted in the oxidation reaction with the oxygen can be used particularly advantageously for discharging the products of the oxidation reaction into the surroundings of the pressurized gas reservoir. The vertical orientation of the outlet device is also meaningful in terms of the water formed during the oxidation reaction being able to flow out of the outlet device easily and reliably. This is particularly advantageous because in this way the passability of the outlet device can be largely avoided due to icing.

[0031] In particular, the vertically oriented outlet device can have a configuration similar to a blast furnace, wherein the shaft-shaped section of the outlet device is configured in the form of an elongated truncated cone. However, other configurations are also advantageous, which can in particular be accompanied by a tapering of the outlet device toward the outlet.

[0032] It is preferred if the outlet device tapers toward the outlet. With this configuration it can be particularly easy to ensure that the products formed in the exothermic oxidation reaction are reliably discharged into the surroundings. Because this outlet device has a particularly flow-advantageous shape.

[0033] In addition or alternatively, the outlet device has a cover on the end side. This cover reliably prevents the ingress of undesirable substances, in particular water, into the outlet device, thus ensuring good passability of the outlet device.

[0034] The gas inlet of the outlet device can have a non-return valve. In this way it can be ensured that no flames escape from the outlet device into the surroundings via the gas inlet.

[0035] In addition or alternatively, for this purpose the gas inlet can have a valve device whose flow resistance in a first flow direction is smaller than its flow resistance in a second flow direction opposite to the first flow direction. In particular, this valve device can thus be configured as a passive valve device, for example in the form of a Tesla valve.

[0036] It is preferred if at least one electrode of the at least one piezoelectric element has a coating with a catalytic material. The catalytic material is configured for catalyzing the oxidation reaction of the fuel with the oxygen from the container. In this way, the conversion of the fuel with the oxygen in the oxidation reaction can already be catalyzed by the piezoelectric element itself. Thus, an especially high degree of conversion of the fuel with the oxygen in the oxidation reaction can be achieved.

[0037] It has proven to be advantageous in the end that the compressed-gas reservoir has at least two piezoelectric elements which can be loaded with pressure. Thus, even in the event of a malfunction of one of the piezoelectric elements, at least one further piezoelectric element can provide or generate at least one spark on the basis of the loading pressure. This also contributes to the reliability and safety of the fuel oxidation.

[0038] In the method for operating a compressed-gas reservoir, which can be used in particular in a motor vehicle, according to the application, compressed fuel is stored in a container of the compressed-gas reservoir. As a result of the opening of at least one pressure relief valve of the compressed-gas reservoir, fuel is discharged from the container into the surroundings of the compressed-gas reservoir. Oxidation of the fuel from the container with oxygen is catalysed by means of a catalyst device of the compressed-gas reservoir. The compressed-gas reservoir has at least one piezoelectric element which is loaded with pressure by the opening of the at least one pressure relief valve. As a result of the loading of the at least one piezoelectric element with pressure, at least one spark is generated by the at least one piezoelectric element.

[0039] The oxidation of the fuel with oxygen is triggered by the at least one spark by means of the ignition energy. As a result, the fuel is converted with oxygen. It is thus possible in particular to reliably prevent the fuel from entering the surroundings in a form which has not yet been oxidised with oxygen. A particularly reliable and safe oxidation of the fuel from the container, in particular catalysed by means of the catalyst device, is thus achieved.

[0040] The advantages and preferred embodiments described for the compressed-gas reservoir according to the application also apply to the method according to the application and vice versa.

[0041] Further advantages, features and details of the application result from the following description of preferred embodiments and in conjunction with the drawings. The features and combinations of features mentioned in the description above and the features and combinations of features mentioned in the description of the drawings below and / or shown alone in the drawings can be used not only in the respective combinations indicated, but also in other combinations or alone, without departing from the scope of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0042] The drawings show:

[0043] Figure 1 A compressed-gas reservoir of a motor vehicle is shown schematically, in which at least one piezoelectric element is actuated when gaseous fuel is discharged from a container of the compressed-gas reservoir, which leads to the formation of a spark;

[0044] Figure 2 An arrangement of two pressure relief valves in the region of a pressure relief device of a compressed-gas reservoir is shown schematically; and

[0045] Figure 3The possibility of actuating at least one piezoelectric element upon opening one of the pressure relief valves is shown schematically and in a partially enlarged view.

[0046] In the figures, identical or functionally identical elements are provided with the same reference signs. DETAILED DESCRIPTION

[0047] Figure 1 The compressed gas reservoir 10, which is shown in a very schematic manner, comprises a container 12, which has a thermally insulated container wall 14. The container wall 14 encloses a receiving chamber 16 of the container 12, in which a compressed fuel can be stored. At present, it should be assumed by way of example that liquid hydrogen is stored in the receiving chamber 16, which is surrounded peripherally by the container wall 14. The fuel in the form of liquid hydrogen can thus have a density of 80 grams per liter and is stored in the receiving chamber 16 at a temperature of, for example, -253 degrees Celsius.

[0048] Due to a thermal loading of the fuel, for example, as a result of thermal radiation and / or thermal conduction and / or convection, it is possible for the liquid hydrogen to vaporize, and the gaseous hydrogen then has to be discharged from the container 12 in order to prevent the mechanical pressure load on the container wall 14 from becoming too great.

[0049] For this purpose, the compressed gas reservoir 10 has a pressure relief device 18, which comprises a line 20, which opens into the receiving chamber 16. Figure 1 The pressure relief device is shown in a schematic view in Figure 3 A section of the line 20 is shown schematically inIn the line 20, a first pressure relief valve 22 and a second pressure relief valve 24 are arranged at present. The second pressure relief valve 24 is arranged downstream of the first pressure relief valve 22, viewed in the flow direction of the gaseous fuel out of the receiving chamber 16 and correspondingly in the flow direction of the gaseous fuel through the line 20. The second pressure relief valve 24 is thus in series with the first pressure relief valve 22. Both the first pressure relief valve 22 and the second pressure relief valve 24 are opened as soon as a threshold value of a predetermined pressure is exceeded.

[0050] The first pressure relief valve 22 can be opened, for example, when the pressure acting on a closure body 26 of the first pressure relief valve 22 exceeds a value of approximately 6 bar. In an analogous manner, the second pressure relief valve 24 can be opened, for example, in the case of a pressure exceeding a threshold value of approximately 5 bar.

[0051] At present, the opening of the second pressure relief valve 24 causes the generation of at least one spark 28, which is shown schematically in Figure 1 and Figure 3 The at least one spark 28 is generated by a compression of at least one piezoelectric element 30, 32, wherein two piezoelectric elements 30, 32 are shown by way of example in a side-by-side arrangement in Figure 1

[0052] Figure 2The actuation of the at least one piezoelectric element 30, 32 caused by the opening of the second pressure relief valve 24 is shown more clearly. However, for the sake of clarity, Figure 2 only one of the two piezoelectric elements 30, 32 is shown. When both piezoelectric elements 30, 32 are actuated at the same time, each of them releases a spark 28. It is therefore advantageous to provide an ignition device in the form of two side-by-side arranged piezoelectric elements 30, 32.

[0053] To illustrate the conversion of the gaseous fuel escaping from the accommodation chamber 16 into low-energy or oxidized products, the case when only one of the piezoelectric elements 30, 32 is actuated is described by way of example below. However, the actuation of the other of the two piezoelectric elements 30, 32 takes place in a similar manner.

[0054] According to Figure 2 , the piezoelectric element 30 can have a crystal 34 and a plurality of electrodes 36, 38 in a manner known per se. Due to the application of pressure to the crystal 34 and the accompanying elastic deformation of the crystal 34, a spark discharge or the generation of a spark 28 can take place between the outer electrode 36 and the central electrode 38. Figure 3 In the case shown in

[0055] According to Figure 2 , the opening of the second pressure relief valve 24 simultaneously ensures the pressure loading of the piezoelectric element 30 and thus the generation of at least one spark 28. Here, the closing force of the second pressure relief valve 24 can in particular be adjusted such that, when the second pressure relief valve 24 is open, the at least one piezoelectric element 30, 32 functions as an ignition generator, which leads to the generation of at least one spark 28. Therefore, the ignition device in the form of the at least one piezoelectric element 30, 32 is preferably actuated when the second pressure relief valve 24 is open.

[0056] In connection with Figure 3 An exemplary design variant in which the at least one piezoelectric element 30 is integrated into the second pressure relief valve 24 shall be described. The second pressure relief valve 24 thus has a movable closure body in the form of a valve disc 42, which, when the pressure relief valve 24 is closed, rests against a valve seat 44 of the pressure relief valve 24. The piezoelectric element 30 is arranged here between the valve disc 42 and a support device 46 on which a spring element 48 of the pressure relief valve 24 is supported.

[0057] The spring element 48 supported on the support device 46 presses the valve disc 42 against the valve seat 44. Therefore, when the spring element 48 is compressed, the valve disc 42 is moved away from the valve seat 44, so that gaseous fuel can escape. The movement of the valve disc 42 towards the support device 46 here also causes the piezoelectric element 30 to be compressed, as is illustrated in Figure 3 by the arrow 40.

[0058] It is also possible to provide that the spring element 48 of the second pressure relief valve 24 is formed by the at least one piezoelectric element 30, 32. Thus, in addition to the at least one piezoelectric element 30, 32, no further spring element 48 needs to be provided. Thus, in this variant with particularly few components, the pressure threshold value for opening the second pressure relief valve 24 is predefined by the at least one piezoelectric element 30, 32.

[0059] The gas volume enclosed between the two pressure relief valves 22, 24 after opening the first pressure relief valve 22 and before opening the second pressure relief valve 24 now, i.e. after closing the first pressure relief valve 22 arranged on the tank side and in the case of simultaneous opening of the second pressure relief valve 24, escapes via the (not shown in Figure 1 and Figure 2 into the chimney-like outlet device 52. Figure 1 The respective flow path of the gaseous fuel through the opening 50 of the line 20 is illustrated in

[0060] Upon compression of the at least one piezoelectric element 30, 32, a spark 28 is generated. In addition, in the region of the opening 50, i.e. in the region of the coupling of the line 20 with the outlet device 52 which is currently configured in the type of a chimney, there is oxygen present. Since the outlet device 52 has an air inlet 56. Now, the at least one spark 28 provides ignition energy for the gaseous fuel (currently hydrogen) to start the oxidation reaction with the oxygen in the air. The exothermic oxidation reaction ensures that further fuel molecules also react with the oxygen molecules.

[0061] This in particular leads to the heating of the catalytic converter device 58 which is currently arranged in the lower section 60 of the outlet device 52. In the case of low ambient temperatures, a conversion of the fuel into fuel molecule oxidation products takes place on the catalytic material of the catalytic converter device 58. For example, in the case of hydrogen and oxygen, temperatures of 60 to 80 degrees Celsius can occur and thus cold / low-temperature combustion of hydrogen and oxygen can be achieved. Thus, in the oxidation reaction with the oxygen catalyzed by means of the catalytic converter device 58, the hydrogen is converted into water or water vapor.

[0062] When the fuel from the container 12 is, for example, compressed or liquid natural gas, then further oxidation products such as carbon dioxide and nitrogen oxides also occur accordingly. But here too, cold combustion of the fuel takes place in the catalytic converter device 58 and is thus converted into a low-energy medium which is no longer readily reactive.

[0063] From Figure 2 and Figure 3It can be seen that the gas inlet 56 can have a valve 62, which is preferably passive, which allows air to flow largely unhindered into the outlet device 52 and thus to the catalytic converter device 58, but which prevents air from escaping via the gas inlet 56 as far as possible.

[0064] For example, the valve 62 can be configured as a non-return valve or as a Tesla valve, which has a smaller flow resistance in the flow direction than in the flow direction opposite to the flow direction. Figure 2 and Figure 3 Such a Tesla valve is shown schematically in Fig. 6 and is shown partially sectioned in the region of the gas inlet 56 of the chimney-like outlet device 52.

[0065] In particular from Figure 1 It can be seen that the outlet device 52 preferably extends vertically. Thus, in the installed position of the compressed-gas reservoir 10 in a motor vehicle, the height direction z of the outlet device 52 is preferably oriented parallel to the vehicle vertical axis. In this way, it is possible, in particular in the section 64 of the outlet device 52 configured downstream of the catalytic converter device 58, for a chimney effect to occur in the operation of the pressure relief device 18. Fuel can thus be introduced into the outlet device 52, which has a particularly advantageous shape for the flow, via the through-opening 50 of the second pressure relief valve 24 having an integrated at least one piezoelectric element 30, 32 or piezoelectric igniter, which guides the fuel through.

[0066] For example, the outlet device 52 can have the shape of a blast furnace, wherein the section 64 coupled with the catalytic converter device 58 tapers towards an outlet 66 of the outlet device 52. In the region of the outlet 66, the outlet device 52 can have an end-side cover 68. The products formed in the course of the oxidation reaction thus do not flow upwards out of the cover 68, but are diverted at the cover 68 and flow laterally out of the outlet device 52.

[0067] Furthermore, an acoustic damper 70 is arranged or configured, in particular in this section 64 of the outlet device 52. Thereby, a particularly low sound emission occurs when the fuel is cold-burned at the catalytic converter device 58 and the products of the oxidation reaction are discharged into the surroundings 72 of the compressed-gas reservoir 10.

[0068] At present, as soon as the permissible pressure is exceeded again in the receiving chamber 16 of the container 12, the pressure is re-established when gaseous fuel is discharged via the pressure relief device 18. With each opening of the at least one pressure relief valve 22, 24, the ignition device in the form of the at least one piezoelectric element 30, 32 is also operated again, so that a spark 28 is re-generated or produced. In the operation of the compressed-gas reservoir 10, intermittent cold-burning thus also takes place before the gaseous fuel reaches the surroundings 72 of the compressed-gas reservoir 10 via the outlet device 52.

[0069] From Figure 1It can further be seen that a valve 74, which is preferably also configured as a Tesla valve, for example, can be arranged in the line 20 of the pressure relief device 18 between the first pressure relief valve 22 and the second pressure relief valve 24. This passive valve 74 prevents a fuel or hydrogen flow back to the first pressure relief valve 22.

[0070] Furthermore, in Figure 1 schematically shown, a further valve device 76 can be arranged on the container 12 via which fuel can be extracted from the receiving chamber 16 and introduced into the receiving chamber 16. The valve device 76 thus has an output 78 via which fuel can be delivered from the receiving chamber 16, for example, to a fuel cell stack and / or to an internal combustion engine of a motor vehicle.

[0071] Furthermore, the valve device 76 can be used to close a filling connection 80 of the compressed gas storage 10. When filling the container 12, fuel can be introduced into the receiving chamber 16 via the filling connection 80. The tank fitting in the form of the valve device 76 can be connected to the receiving chamber 16 of the container 12 via at least one line 82. Figure 1 The respective arrow 84 illustrates the introduction of fuel into the receiving chamber 16 when filling and the extraction of fuel when operating. Figure 1 The respective arrow 84 illustrates the introduction of fuel into the receiving chamber 16 when filling and the extraction of fuel when operating.

[0072] List of reference signs

[0073] 10 compressed gas storage

[0074] 12 container

[0075] 14 container wall

[0076] 16 receiving chamber

[0077] 18 pressure relief device

[0078] 20 line

[0079] 22 pressure relief valve

[0080] 24 pressure relief valve

[0081] 26 closure body

[0082] 28 spark

[0083] 30 piezoelectric element

[0084] 32 piezoelectric element

[0085] 34 crystal

[0086] 36 electrode

[0087] 38 electrode

[0088] 40 arrow

[0089] 42 valve disc

[0090] 44 valve seat

[0091] 46 support means

[0092] 48 spring element

[0093] 50 through-opening

[0094] 52 outlet means

[0095] 54 arrow

[0096] 56 inlet opening

[0097] 58 catalytic converter means

[0098] 60 section

[0099] 62 valve

[0100] 64 section

[0101] 66 outlet

[0102] 68 cover portion

[0103] 70 muffler

[0104] 72 ambient environment

[0105] 74 valve

[0106] 76 valve means

[0107] 78 output end

[0108] 80 filling connection

[0109] 82 line

[0110] 84 arrow

[0111] z height direction

Claims

1. A compressed gas storage device comprising: a container (12) configured for storing compressed fuel; and at least one pressure relief valve (22, 24), wherein, Due to the opening of at least one pressure relief valve (22, 24), fuel can be discharged from container (12) into the surrounding environment (72) of compressed gas storage tank (10); catalytic device (58), which is configured to catalyze the oxidation reaction of fuel with oxygen from container (12), Its features are, The compressed gas reservoir (10) has at least one piezoelectric element (30, 32), which can be pressured by opening at least one pressure relief valve (22, 24), wherein the pressure can cause at least one spark (28) to be generated by means of at least one piezoelectric element (30, 32).

2. The compressed gas storage device according to claim 1, characterized in that, The compressed gas storage device is used in motor vehicles.

3. The compressed gas storage device according to claim 1, characterized in that, At least one piezoelectric element (30, 32) is arranged between the valve disc (42) of at least one pressure relief valve (22, 24) and the support device (46) for the spring element (48) of at least one pressure relief valve (22, 24), wherein pressure can be applied to at least one piezoelectric element (30, 32) by moving away from the valve seat (44) of at least one pressure relief valve (22, 24) via the valve disc (42).

4. The compressed gas storage device according to claim 2, characterized in that, At least one piezoelectric element (30, 32) is arranged between the valve disc (42) of at least one pressure relief valve (22, 24) and the support device (46) for the spring element (48) of at least one pressure relief valve (22, 24), wherein pressure can be applied to at least one piezoelectric element (30, 32) by moving away from the valve seat (44) of at least one pressure relief valve (22, 24) via the valve disc (42).

5. The compressed gas storage device according to claim 3, characterized in that, The spring element (48) of at least one pressure relief valve (22, 24) is formed by at least one piezoelectric element (30, 32).

6. The compressed gas storage device according to claim 4, characterized in that, The spring element (48) of at least one pressure relief valve (22, 24) is formed by at least one piezoelectric element (30, 32).

7. The compressed gas storage device according to any one of claims 1 to 6, characterized in that, The compressed gas storage device (10) has a first pressure relief valve (22) and a second pressure relief valve (24), wherein, viewed in the direction of fuel flow from the container (12), the second pressure relief valve (24) is arranged downstream of the first pressure relief valve (22), and by opening the second pressure relief valve (24), pressure can be applied to at least one piezoelectric element (30, 32).

8. The compressed gas storage device according to claim 7, characterized in that, A valve device (74) is arranged between the first pressure relief valve (22) and the second pressure relief valve (24) to prevent fuel from flowing back to the container (12). The valve device (74) has less flow resistance in the flow direction than in the flow direction opposite to the flow direction.

9. The compressed gas storage device according to any one of claims 1 to 6, characterized in that, The compressed gas reservoir (10) has an outlet device (52) through which the products of the fuel oxidation reaction can be discharged into the surrounding environment (72) of the compressed gas reservoir (10), and / or when the compressed gas reservoir is used in a motor vehicle, the outlet device is configured as part of the exhaust system of the motor vehicle. The outlet device includes an air inlet (56).

10. The compressed gas storage device according to claim 9, characterized in that, The outlet device (52) is substantially vertically oriented in the installation position of the compressed gas reservoir and / or has an end-side cover (68), which tapers toward the outlet (66). And / or a catalyst unit (58) is arranged in a section (60) of an outlet unit (52) having a muffler (70).

11. The compressed gas storage device according to claim 9, characterized in that, The air inlet (56) has a check valve and / or a valve device (62) whose flow resistance in the first flow direction is less than the flow resistance in the second flow direction opposite to the first flow direction.

12. The compressed gas storage device according to any one of claims 1 to 6, characterized in that, At least one electrode (36, 38) of at least one piezoelectric element (30, 32) has a coating with a catalytic material configured to catalyze the oxidation reaction of fuel and oxygen from container (12), and / or the compressed gas storage device (10) has at least two piezoelectric elements (30, 32) capable of being pressure-loaded.

13. A method for operating a compressed gas storage tank (10), wherein, Compressed fuel is stored in the container (12) of the compressed gas storage tank (10), wherein the fuel is discharged from the container (12) into the surrounding environment (72) of the compressed gas storage tank (10) by the opening of at least one pressure relief valve (22, 24), and the oxidation reaction of the fuel from the container (12) with oxygen is catalyzed by the catalyst device (58) of the compressed gas storage tank (10). Its features are, The compressed gas reservoir (10) has at least one piezoelectric element (30, 32) which is pressured by the opening of at least one pressure relief valve (22, 24), wherein the pressure applied to the at least one piezoelectric element (30, 32) causes at least one spark (28) to be generated by the at least one piezoelectric element.

14. The method according to claim 13, characterized in that, The compressed gas storage device is used in motor vehicles.

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