Compressed gas storage tank and vehicle

Abstract

A pressurized gas storage container (7, 7A, 7B, 7C) for pressurized storage of a gas (H2), in particular hydrogen, comprising a wall (9) enclosing a receiving area (10) for receiving the gas (H2), a pressure relief unit (22) for venting the gas (H2) from the receiving area (10), and a pyroelectric sensor fiber (23, 23A, 23B) configured to trigger the pressure relief unit (22) in the event of a fire-related input of heat (Q) into the wall (9) in order to vent the gas (H2) from the receiving area (10).

Description

The present invention relates to a compressed gas storage container for the pressurised storage of a gas and to a vehicle having such a compressed gas storage container.For storing and transporting hydrogen, the latter can be stored either in gaseous form in a compressed gas storage container under a plurality of 100 bar superatmospheric pressures or in liquid form at cryogenic temperatures. For use in or on vehicles, in particular in or on passenger cars, it is advantageous for space reasons to store the hydrogen in gaseous form in a compressed gas storage container as mentioned above.According to legal regulations, it is necessary that in the event of a strong application of heat, for example in the event of a vehicle fire, the hydrogen can be blown off from the compressed gas storage container in a controlled manner, so that a burst of the compressed gas storage container is reliably prevented. For this purpose, according to internal findings in operation, so-called pressure release units (PRD or Thermally Activated Pressure Release Device, TPRD) can be used, which are thermally triggered in the event of a fire and blow off the hydrogen in a controlled manner.In this case, such a pressure relief unit may be triggered only mechanically or with the aid of an analog circuit on account of legal requirements. Triggering with the aid of software, for example via a control unit of the vehicle, is not permissible for safety reasons. The pressure relief unit can only be triggered when heat, for example due to a vehicle fire, is introduced directly into the pressure relief unit. Thus, substantially only local heat detection or fire detection is possible. This is to be improved.Against this background, it is an object of the present invention to provide an improved compressed gas storage container.Accordingly, a compressed gas storage container for the pressurised storage of a gas, in particular hydrogen, is proposed. The compressed gas storage container comprises a wall which encloses a receiving region for receiving the gas, a pressure relief unit for blowing off the gas from the receiving region and a pyroelectric sensor fiber which is configured to trigger the pressure relief unit in the event of a fire-induced input of heat into the wall in order to blow off the gas from the receiving region.Because the pyroelectric sensor fiber directly triggers the pressure relief unit, the pressure relief unit can be triggered without an external energy source and the gas can thus be blown off from the receiving region. This is advantageous in particular with regard to satisfying legal requirements in the case of a fire. Furthermore, a spatial separation of a detection of the introduction of heat into the wall with the aid of the pyroelectric sensor fiber from the pressure relief unit is possible. With the aid of the pyroelectric sensor fiber, a fire detection can therefore be decoupled from the pressure relief unit. There is thus advantageously no longer any restriction to local fire detection.The compressed gas storage container can also be referred to as a compressed gas storage tank, a hydrogen compressed gas storage container, a hydrogen compressed gas storage tank, a hydrogen storage container or the like. In particular, the compressed gas storage container is suitable for storing and / or transporting hydrogen. However, any other gases may be stored in the compressed gas storage container. It is assumed below that the gas is hydrogen. The terms "gas" and "hydrogen" can therefore be interchanged with one another as desired.The term "compressed gas storage container" means in the present case that the gas in its gaseous aggregate state can be stored under pressure in the compressed gas storage container. For example, the gas within the compressed gas storage container can be pressurized to a pressure of 800 to 1,000 bar. In the present case, liquefaction of the gas is in particular not provided. The gas can be introduced or injected in gaseous form into the receiving region.The compressed gas storage container is preferably part of a vehicle. The vehicle can have a plurality of such compressed gas storage containers. The compressed gas storage container may be suitable for making the gas available to a consumer, in particular a fuel cell, of the vehicle at a suitable supply pressure and a suitable supply temperature. The compressed gas storage container can be part of a gas supply system or hydrogen supply system of the consumer. The compressed gas storage container can, however, also be used in immobile applications, for example in building technology. In particular, the compressed gas storage container can be used in the area of building heating or for combined heat and power plants.The wall preferably comprises a load-bearing sheathing which is manufactured at least in sections from a fiber composite plastic. The jacket encloses an optional liner. The liner is disposed within the casing. The sheathing thus preferably completely encapsulates the lining. The lining is preferably gas-tight. The liner may also be referred to as a liner. The lining can comprise a plastic material, a metallic material and / or a fiber composite plastic.The compressed gas storage container and thus also the wall is preferably cylindrical. The compressed gas storage container or the wall is assigned a symmetry or central axis with respect to which the compressed gas storage container or the wall can be constructed rotationally symmetrically. The wall preferably comprises a hollow cylindrical or tubular base section which is closed on both sides by lid-shaped or dome-shaped wall end sections. The sheathing and the lining are provided both in the region of the base section and in the region of the wall end sections.The fact that the wall "encloses" or "bounds" the receiving region means in the present case in particular that the wall defines a geometry or boundaries of the receiving region. The gas is thus accommodated within the wall in the receiving region. The receiving region is in particular a cavity surrounded by the wall. The receiving region has in particular a cylindrical geometry. The receiving region is sealed gas-tightly from the surroundings of the compressed gas storage container with the aid of the wall. The receiving region can be constructed rotationally symmetrically to the central axis.The pressure relief unit is in particular a so-called pressure release device, PRD or thermally activated pressure release device, TPRD. The pressure relief unit preferably comprises a valve and a pyrotechnic charge for triggering or opening the valve. The fact that the pressure relief unit is configured to "blow off" the gas from the receiving region is to be understood in particular in the present case as meaning that, with the aid of the pressure relief unit, the gas can be discharged completely from the receiving region within a very short period of time, for example within a few milliseconds to a few seconds. An undesired increase in pressure within the compressed gas storage container in the event of a fire, which could lead to an explosion of the compressed gas storage container, is thereby reliably avoided.With the aid of the pyroelectric sensor fiber, the fire detection can be at least partially spatially decoupled from the pressure relief unit. The pyroelectric sensor fiber functions in the present case in particular both as a sensor and as an energy source. With the aid of the pyroelectric sensor fiber, complete monitoring over an entire outer side of the wall is possible. For this purpose, the pyroelectric sensor fiber is arranged on the outer side or embedded in the sheathing of the wall. The pressure relief unit forms together with the pyroelectric sensor fiber a pressure relief device of the compressed gas storage container. The pyroelectric sensor fiber is in particular elastically deformable and can therefore be wound onto the wall in a helical or spiral manner.The pyroelectric sensor fiber comprises a pyroelectric material. The pyroelectric material may be a piezoelectric semiconductor crystal. A temperature change of the pyroelectric material results in a measurable change in an electrical voltage between a first electrode and a second electrode of the pyroelectric sensor fiber. Thus, the pyroelectric sensor fiber provides electric energy. This electrical energy can be used to trigger the pressure relief unit. In the present case, the fact that the pressure relief unit is "triggered" is to be understood in particular as meaning that the pyrotechnic charge of the pressure relief unit is ignited, with the result that the valve of the pressure relief unit is opened in order to blow off the gas into the environment.A "fire-induced input of heat" is to be understood in the present case in particular as meaning that the compressed gas storage container is exposed to a fire or a fire, as a result of which heat, in particular in the form of infrared radiation or direct flame contact, is introduced into the storage container, in particular into the wall, and thus also into the pyroelectric sensor fiber.According to one embodiment, the pressure relief unit has a valve for blowing off the gas from the receiving region and a pyrotechnic charge, wherein the pyroelectric sensor fiber ignites the pyrotechnic charge for opening the valve.The valve is preferably closed in an initial state. By igniting the pyrotechnic charge, the valve is moved from a closed state to an open state. The valve is preferably an on-off valve. That is, the valve is either fully closed or fully open. The pyrotechnic charge can be ignited with the aid of a glow bridge, which can be energized with the aid of the pyroelectric sensor fiber. The glow bridge begins to glow, thereby igniting the pyrotechnic charge. This opens the valve to blow off the gas into the environment. By igniting the pyrotechnic charge, a component of the valve, for example a valve body or a valve tappet, can be moved in order to open the valve.According to a further embodiment, the pyroelectric sensor fiber comprises a first electrode, a second electrode and a pyroelectric material arranged between the first electrode and the second electrode.For example, the first electrode comprises a conductive material, such as a metal, a plastic filled with conductive particles, fibers based on carbon or the like. The same can apply to the second electrode. The pyroelectric material can be applied to the first electrode, which material is in turn coated with a further conductive material which forms the second electrode. The pyroelectric sensor fiber can have any geometry in cross section. For example, the pyroelectric sensor fiber has a wire-shaped first electrode and a tubular second electrode. The first electrode can be arranged within the second electrode. The pyroelectric material is arranged between the first electrode and the second electrode, in which the first electrode is embedded such that the first electrode and the second electrode do not contact each other. The pyroelectric material can also be referred to as sensor material. The electrodes can also be plate-shaped or foil-shaped.According to a further embodiment, the pyroelectric sensor fiber is arranged in or on the wall.The pyroelectric sensor fiber can be installed during a winding process of the sheathing of the wall during the winding thereof in the sheathing, in particular in the fiber composite plastic of the sheathing. A degree of coverage of the pyroelectric sensor fiber with the fiber composite plastic and thus a detection surface for fire detection can be adjusted by the winding process.According to a further embodiment, the pyroelectric sensor fiber is embedded at least in sections in the wall.In this case, the pyroelectric sensor fiber can be covered at least in sections by the fiber composite plastic. The pyroelectric sensor fiber can also be completely covered by the fiber composite plastic. As a result, the pyroelectric sensor fiber is protected from damage within the fiber composite plastic. Viewed in a radial direction of the compressed gas storage container, the pyroelectric sensor fiber can be embedded 1 mm to a maximum of 5 mm deep in the wall.According to a further embodiment, the pyroelectric sensor fiber wraps around the wall in a helical manner as viewed along a longitudinal direction of the compressed gas storage container.The longitudinal direction runs along the aforementioned central axis. This means in particular that the pyroelectric sensor fiber has a helical or helical geometry. A multiple helix or a crossed helix is also possible. Furthermore, the pyroelectric sensor fiber can be designed in particular in the form of a spiral, multiple helix, cross helix or the like. A pitch of this helical geometry of the pyroelectric sensor fiber can be selected as desired. For example, windings of the pyroelectric sensor fiber may be disposed closer together or further spaced apart from each other. This can influence the sensitivity of the pressure relief device. Viewed along the longitudinal direction, a spacing of the windings or a winding spacing of the pyroelectric sensor fiber can preferably be at most 100 mm. This aforementioned winding distance is particularly preferably at most 50 mm.According to a further embodiment, the compressed gas storage container has a plurality of pyroelectric sensor fibers, wherein all of the plurality of pyroelectric sensor fibers are jointly assigned to the pressure relief unit.This means in particular that a plurality of pyroelectric sensor fibers are assigned to a pressure relief unit. This allows the sensitivity of the pressure relief device to be improved. The pyroelectric sensor fibers may have different lengths.According to a further embodiment, the plurality of pyroelectric sensor fibers are arranged parallel to one another and / or cross over one another.The plurality of pyroelectric sensor fibers may also be arranged at least partially in parallel and partially cross each other. In the event that the pyroelectric sensor fibers cross over one another, a net-shaped arrangement of the pyroelectric sensor fibers can be realized on or in the wall.According to a further embodiment, the compressed gas storage container has a capacitor for storing electrical energy generated with the aid of the pyroelectric sensor fiber.The capacitor is in particular connected between the pyroelectric sensor fiber and the pressure relief unit. The capacitor may be a so-called surge or pulse capacitor. In the present case, a "pulse capacitor" of this type is understood to mean a DC voltage capacitor which serves for absorbing or emitting a strong, usually very short, but high-energy surge. This makes it possible to ignite the pyrotechnic charge with the aid of the impulse released by the capacitor.According to a further embodiment, the compressed gas storage container has an electrical circuit which has the capacitor and the pyroelectric sensor fiber, wherein the electrical circuit is configured to emit the electrical energy stored in the capacitor as a function of a variable indicative of a charging of the capacitor in order to trigger the pressure relief unit.The electrical circuit is in particular part of the pressure relief device. The electrical circuit is in particular an analog electrical circuit. The variable indicative of the charging of the capacitor can be a voltage measured or applied to the capacitor. For example, upon reaching a predetermined voltage, the capacitor is discharged to trigger the pressure relief unit by igniting the pyrotechnic charge of the pressure relief unit, thereby opening the valve of the pressure relief unit.According to a further embodiment, the electrical circuit has a control element which detects the indicative variable, and a switching element which can be controlled by the control element as a function of the indicative variable, in order to emit the electrical energy stored in the capacitor for triggering the pressure relief unit.In particular, the control element is connected to the switching element in such a way that the control element controls the switching element in such a way that the capacitor is discharged to trigger the pressure relief unit at a predefined value of the indicative variable.According to a further embodiment, the control element is connected in parallel with the capacitor, wherein the switching element is connected in parallel with the capacitor, and wherein the control element controls the switching element with the aid of a control output.Accordingly, the drive element is connected to the switching element by means of the control output. The switching element can be, for example, a relay or a transistor.According to a further embodiment, the drive element is a voltmeter, wherein the switching element is a transistor.In particular, the transistor can be an npn transistor (negative-positive-negative). The transistor has a base, an emitter, and a collector. The control output of the control element is connected to the base.According to a further embodiment, the pressure relief unit is attached to a dome-shaped wall end section of the wall.For example, an inlet nozzle for introducing the gas into the compressed gas storage container can be mounted on a first wall end section, wherein the pressure relief unit is mounted on a second wall end section. A reverse mounting may also be possible. Furthermore, the pressure relief unit can also be integrated into the inlet nozzle. This results in a compact construction.Furthermore, a vehicle, in particular a motor vehicle, having at least one such compressed gas storage container is proposed.The vehicle can have a plurality of such compressed gas storage containers. The compressed gas storage container can be arranged, for example, in the region of a floor of the vehicle. The vehicle can have a consumer, in particular a fuel cell, which is supplied with the gas with the aid of the compressed gas storage container. The vehicle can be, in particular, an electric vehicle or a hybrid vehicle. However, the vehicle may also have an internal combustion engine. The vehicle can also be a commercial vehicle, for example a truck. Furthermore, the vehicle can also be an aircraft, a watercraft or a rail vehicle. The vehicle is particularly preferably a passenger car.The embodiments and features described for the proposed compressed gas storage container apply correspondingly and vice versa to the proposed vehicle."An" is not necessarily to be understood as limiting to exactly one element. Rather, a plurality of elements, such as two, three or more, can also be provided. Any other counting word used here is also not to be understood as being limited to exactly the number of elements mentioned. Instead, numerical deviations upwards and downwards are possible, unless indicated to the contrary.Further possible implementations of the compressed gas storage container and / or of the vehicle also comprise combinations, not explicitly mentioned, of features or embodiments described above or below with respect to the exemplary embodiments. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic shape of the compressed gas storage container and / or of the vehicle.Further advantageous embodiments and aspects of the compressed gas storage container and / or of the vehicle are the subject matter of the dependent claims and of the exemplary embodiments of the compressed gas storage container and / or of the vehicle described below. The compressed gas storage container and / or the vehicle will be explained in more detail below on the basis of preferred embodiments with reference to the enclosed figures. FIG. 1 shows a schematic side view of an embodiment of a vehicle; FIG. 2 shows a schematic sectional view of an embodiment of a compressed gas storage container for the vehicle according to FIG. 1 ; FIG. 3 shows a further schematic sectional view of the compressed gas storage container according to the section line III-III of FIG. 2 ; FIG. 4 shows the detail view IV according to FIG. 2 ; FIG. 5 shows a schematic side view of the compressed gas storage container according to FIG. 2 ; FIG. 6 shows a schematic sectional view of an embodiment of a pyroelectric sensor fiber for the compressed gas storage container according to FIG. 2 ; FIG. 7 shows a schematic side view of a further embodiment of a compressed gas storage container for the vehicle according to FIG. 1 ; FIG. 8 is a schematic view of an embodiment of a pressure relief device for the compressed gas storage container; and FIG. 9 shows a schematic side view of a further embodiment of a compressed gas storage container for the vehicle according to FIG. 1.In the figures, identical or functionally identical elements have been provided with the same reference numerals, unless otherwise indicated.FIG. 1 shows a schematic side view of an embodiment of a vehicle 1. the vehicle 1 is a motor vehicle, in particular an electric vehicle or a hybrid vehicle. However, the vehicle 1 may be driven by an internal combustion engine. The vehicle 1 can also be a commercial vehicle, for example a truck, a harvester or a construction machine. Furthermore, the vehicle 1 can also be a military vehicle. In addition, the vehicle 1 can also be an aircraft, a watercraft or a rail vehicle. However, it is assumed below that the vehicle 1 is a motor vehicle, in particular a passenger car.The vehicle 1 comprises a body 2 which encloses a passenger compartment or vehicle interior 3 of the vehicle 1. A driver and passengers can be present in the vehicle interior 3. The body 2 delimits an environment 4 of the vehicle 1 from the vehicle interior 3. The vehicle interior 3 is accessible from the environment 4 with the aid of doors.The vehicle 1 comprises a chassis having a plurality of wheels 5, 6. The vehicle 1 preferably has four wheels 5, 6. However, the vehicle 1 can also have, for example, six wheels 5, 6. The wheels 5, 6 are part of a chassis of the vehicle 1. only two wheels 5, 6 can be driven. However, all wheels 5, 6 can also be driven. In this case, the vehicle 1 is an all-wheel vehicle.The vehicle 1 comprises a compressed gas storage container 7 for the pressurised storage of a gas, in particular hydrogen. The compressed gas storage device 7 is preferably placed on or in the region of a floor or a floor structure of the vehicle 1. The compressed gas storage container 7 can be arranged outside the body 2. The vehicle 1 can have a plurality of compressed gas storage containers 7.In principle, the compressed gas storage container 7 is not only suitable for use on a vehicle 1, but can be used, for example, for any other application cases. For example, the compressed gas storage container 7 can also be used for immobile applications, in particular in building technology or for an emergency power supply. Furthermore, the compressed gas storage container 7 can be used in the area of building heating or for combined heat and power plants. However, the following assumes the use of the compressed gas storage container 7 for a mobile application, namely in or on the vehicle 1.With the aid of the compressed gas storage container 7, the gas stored in the compressed gas storage container 7 can be provided to a consumer 8 of the vehicle 1 at a suitable supply pressure and a suitable supply temperature. The consumer 8 is preferably a fuel cell. A "fuel cell" is understood in the present case to mean a galvanic cell which converts the chemical reaction energy of a continuously supplied fuel, in the present case hydrogen, and of an oxidizing agent, in the present case oxygen, into electrical energy. By means of the electric energy obtained, for example, an electric motor, not shown, can be driven, which in turn drives the wheels 5, 6 or at least two of the wheels 5, 6.FIG. 2 shows a schematic sectional view of an embodiment of a compressed gas storage container 7A as mentioned above. FIG. 3 shows a further schematic sectional view of the compressed gas storage container 7A according to the section line III-III of FIG. 2, FIG. 4 shows the detailed view IV according to FIG. 2, and reference is made to FIGS. 2 to 4 at the same time below.The compressed gas storage container 7A is suitable for storing a gas, in the present case hydrogen H 2, under a high pressure in the form of a gas and releasing it again as required. For example, the compressed gas storage container 7A is operated under a pressure of several 100 bar, for example from 800 to 1,000 bar. The compressed gas storage tank 7A may also be referred to as a compressed gas storage tank, a hydrogen compressed gas storage tank, a hydrogen compressed gas storage tank, or a hydrogen storage tank.In principle, the compressed gas storage container 7A is suitable for receiving or storing any desired gas. However, it is assumed below that the gas is hydrogen H2. The terms "gas" and "hydrogen" can therefore be exchanged with one another as desired. As mentioned above, the hydrogen H2 is stored in its gaseous aggregate state in the compressed gas storage container 7A. The hydrogen H2 is thus single-phase. Therefore, preferably no liquid phase and thus also no phase boundary is present within the compressed gas storage container 7A.The compressed gas storage container 7A comprises a container wall or wall 9 which encloses a receiving region 10 for receiving the hydrogen H 2. The gaseous hydrogen H 2 is accommodated in the accommodation region 10. The receiving region 10 is cylindrical. A geometry or a spatial extent of the receiving region 10 is defined or limited by the wall 9. The receiving region 10 is a cavity completely surrounded by the wall 9. As will be explained below, the wall 9 is multilayer or multilayer. This means that different materials in a layered construction form the wall 9.The compressed gas storage container 7A is assigned a coordinate system having a length direction or x direction x, a transverse direction or y direction y and a vertical direction or z direction z. The directions x, y, z are oriented perpendicular to one another. A longitudinal direction L of the compressed gas storage container 7A runs along the x direction x. That is, the longitudinal direction L and the x direction x are identical. A direction of gravity g is oriented opposite and parallel to the z-direction z.The compressed gas storage container 7A or the wall 9 is assigned a symmetry or central axis 11 with respect to which the compressed gas storage container 7A or the wall 9 is constructed substantially rotationally symmetrically. "Substantially" includes an at least slightly oval cross section in this case in a rotationally symmetrical manner. The central axis 11 extends parallel to the x-direction x. Accordingly, the central axis 11 also extends along the longitudinal direction L. A radial direction R of the compressed gas storage container 7A or of the wall 9 is oriented perpendicular to the central axis 11 and away from it in the direction of the wall 9.The wall 9 can also be referred to as a container wall, casing, casing or wall. The wall 9 is constructed rotationally symmetrically to the central axis 11. In cross section, the wall 9 is thus preferably circular. The wall 9 can, however, also be oval or slightly oval in cross section, deviating therefrom. The wall 9 comprises a tubular or hollow cylindrical base section 12 which is constructed rotationally symmetrically to the central axis 11.In each case on the end face, that is to say on the left and right in the orientation of FIG. 2, a first cover section or first wall end section 13 and a second cover section or second wall end section 14 are provided on the base section 12. The wall end sections 13, 14 are domed or domed and each is constructed in a rotationally symmetrical manner with respect to the central axis 11 per se. The wall end sections 13, 14 can also be referred to as cover sections. The wall end sections 13, 14 are curved outwards with respect to the receiving region 10. The base section 12 and the wall end sections 13, 14 are connected to one another in a fixed, in particular non-detachable manner. The wall 9 has a cylindrical geometry.The wall 9 comprises a load-bearing sheathing 15 (FIGS. 3 and 4 ) which is manufactured from a fiber-reinforced plastic material or a fiber composite plastic. The sheathing 15 is situated on the outside and thus points toward the environment 4. This means that the sheathing 15 adjoins the environment 4. The fact that the casing 15 is "load-bearing" means in the present case in particular that the casing 15 absorbs all or at least a large part of the loads which act on the wall 9 or on the compressed gas storage container 7A. The loads can result from the pressurized hydrogen H 2 itself and / or from external loads, for example in the event of a traffic accident.The sheathing 15 can also be referred to as a jacket, a sheathing, a support layer, an outer layer or an outer layer of the wall 9. The sheathing 15 is preferably constructed in itself in layers or layers from the fiber composite plastic. However, this does not exclude that the sheathing 15 can also comprise metallic constituents. The casing 15 has an outer side 16 facing the environment 4 and an inner side 17 facing the receiving region 10 (FIG. 4 ).A fiber composite plastic as mentioned above comprises a plastic material, in particular a plastic matrix, in which fibers, for example natural fibers, glass fibers, carbon fibers, aramid fibers or the like, are embedded. The plastic material may be a thermosetting plastic, such as an epoxy resin or a vinyl ester-based resin. However, the plastic material can also be a thermoplastic. The fibers may be continuous fibers.The sheathing 15 is preferably a one-piece component, in particular a component of one piece of material. In the present case, "one-piece" or "one-piece" is to be understood as meaning that the sheathing 15 forms a component and is not composed of different components or components which can be separated from one another again. "Single-piece material" means in the present case that the sheathing 15 is produced continuously from the same material, namely the fiber composite plastic. The sheathing 15 is provided both on the base section 12 and on the two wall end sections 13, 14.In addition to the sheathing 15, the wall 9 has a lining 18 lining the sheathing 15. The lining 18 can also be referred to as an inner layer or inner layer of the wall 9. The jacket 15 may be wound onto the liner 18 or onto a mould or mandrel, not shown, to produce the same. The lining 18 is gas-tight. The sheathing 15 is not necessarily gas-tight. The lining 18 can comprise a fiber composite plastic, various plastic materials and / or metallic materials. The liner 18 is a so-called liner or may be referred to as a liner of the compressed gas storage container 7A.The lining 18 has a tubular or hollow cylindrical geometry. The lining 18 is constructed rotationally symmetrically with respect to the central axis 11. The liner 18 is provided on both the base portion 12 and the wall end portions 13, 14. The liner 18 may have a layered or sheet-like construction therein. The jacket 15 completely surrounds or completely encapsulates the liner 18.The lining 18 comprises an outer side 19 (FIG. 4 ) facing the inner side 17 of the casing 15 and an inner side 20 facing the receiving region 10. The inner side 20 can also be referred to as the inner side of the wall 9 or as the inner side of the compressed gas storage container 7A. The inner side 20 completely encloses the cylindrical receiving region 10 and thus defines its spatial extent.The sheathing 15 and the lining 18 are connected to one another in a materially integral manner, in particular glued to one another, on the inner side 17 of the sheathing 15 and on the outer side 19 of the lining 18. In the case of material-bonded connections, the connection partners are held together by atomic or molecular forces. Materially integral connections are non-detachable connections which can be separated from one another again only by destruction of the connecting means and / or the connecting partners.The compressed gas storage container 7A further includes an injection nozzle or inlet nozzle 21 (FIG. 2 ) for injecting or introducing the hydrogen H 2 into the accommodation portion 10. The inlet nozzle 21 is preferably provided on the first wall end portion 13 of the wall 9. Alternatively, the inlet nozzle 21 may be placed on the second wall end portion 14. Preferably, the inlet nozzle 21 is passed through both the shroud 15 and the liner 18. The inlet nozzle 21 may be made of a metallic material.The inlet nozzle 21 is preferably designed such that it is rotationally symmetrical to the central axis 11. In particular, the inlet nozzle 21 is centered or arranged centrally with respect to the central axis 11. In contrast thereto, the inlet nozzle 21 can also be arranged eccentrically, i.e. in a manner oriented offset with respect to the central axis 11. The inlet nozzle 21 is preferably tubular or hollow cylindrical and has in particular an annular cross section. In contrast thereto, however, the inlet nozzle 21 can also have any other desired cross section.The inlet nozzle 21 can have a multiplicity of channels, bores, nozzles, valves, switches and / or sensors which make it possible to tank or fill the compressed gas storage container 7A with the gaseous hydrogen H2. The inlet nozzle 21 can project beyond the inner side 20 of the lining 18 in the region of the first wall end section 13 and thus into the receiving region 10. The inlet nozzle 21 is configured to introduce or jet the hydrogen H 2 into the receiving region 10 parallel to the central axis 11 or along the longitudinal direction L or along the x-direction x.FIG. 5 shows a schematic side view of the compressed gas storage container 7A.According to legal regulations, it is necessary that in the event of a strong application of heat, for example in the event of a vehicle fire, the hydrogen H2can be blown off from the compressed gas storage container 7A in a controlled manner, so that a burst of the compressed gas storage container 7A is reliably prevented. For this purpose, the compressed gas storage container 7A has at least one pressure relief unit 22 (PRD or Thermally Activated Pressure Release Device, TPRD), which is mounted on the wall 9.In particular, the pressure relief unit 22 is mounted on the second wall end portion 14, whereas the inlet nozzle 21 can be mounted on the first wall end portion 13. A reverse mounting is also possible. Furthermore, the pressure relief unit 22 can also be integrated into the inlet nozzle 21.The pressure release unit 22 is configured to release the hydrogen H 2 from the compressed gas storage container 7A in a short period of time. For this purpose, the pressure relief unit 22 can have, for example, a valve and a pyrotechnic set or a pyrotechnic charge for opening the valve. In this case, the pressure relief unit 22 can be triggered only mechanically or with the aid of an analog circuit on the basis of legal requirements. Triggering with the aid of software, for example via a control unit of vehicle 1, is not permitted for safety reasons.Since the pressure relief unit 22 is attached to the end side of the wall 9, this can only be triggered when heat Q, in particular in the form of infrared radiation, for example due to a vehicle fire, is introduced into the pressure relief unit 22 and / or into the second wall end section 14. Thus, substantially only local heat detection or fire detection is possible.If the compressed gas storage container 7A has a large extent along the longitudinal direction L, it may occur that, for example, a heat input caused by the fire is localized too late at the first wall end section 13. To prevent this, it is possible to install additional pressure relief units 22. However, this leads to a higher installation outlay, higher costs and poorer use of installation space. This is to be improved.In order to avoid these aforementioned disadvantages, the fire detection is at least partially spatially decoupled from the pressure relief unit 22 in the compressed gas storage container 7A. For this purpose, the compressed gas storage container 7A has a sensor fiber 23, with the aid of which monitoring over the entire outer side 16 of the wall 9 is possible. For this purpose, the sensor fiber 23 is arranged on the outer side 16 or embedded in the sheathing 15. The pressure relief unit 22 forms together with the sensor fiber 23 a pressure relief device 24. the sensor fiber 23 is deformable or bendable and can therefore be wound helically or spirally onto the wall 9. The sensor fiber 23 can be embedded in the wall 9, in particular in the sheathing 15.FIG. 6 shows a schematic sectional view of an embodiment of a sensor fiber 23 as mentioned above.The sensor fiber 23 includes a wire-shaped inner or first electrode 25 and a tubular outer or second electrode 26. The first electrode 25 is arranged within the second electrode 26. However, the electrodes 25, 26 can also have any other desired geometry. For example, the electrodes 25, 26 may be film-shaped or band-shaped. Between the first electrode 25 and the second electrode 26, a pyroelectric material 27 is disposed in which the first electrode 25 is embedded such that the first electrode 25 and the second electrode 26 do not contact each other. The sensor fiber 23 may be referred to as a pyroelectric sensor fiber. The sensor fiber 23 can be circular or rectangular in cross section. The pyroelectric material 27 may be referred to as a sensor material.The first electrode 25 of the sensor fiber 23 includes a conductive material such as a metal, a plastic filled with conductive particles, carbon-based fibers, or the like. The pyroelectric material 27 is applied to the first electrode 25 and is in turn coated with a further conductive material which forms the second electrode 26.The pyroelectric material 27 may be a piezoelectric semiconductor crystal. A temperature change of the pyroelectric material 27 results in a measurable change of an electric voltage between the two electrodes 25, 26. This electrical energy can be used to trigger the pressure relief unit 22. The fact that the pressure relief unit 22 is "triggered" is to be understood in the present case in particular as meaning that the pyrotechnic charge of the pressure relief unit 22 is ignited, with the result that the pressure relief unit 22 blows the hydrogen H 2 into the environment 4.Since the pyroelectric material 27 is a piezoelectric semiconductor crystal, the pyroelectric material 27 also has piezoelectric characteristics at the same time. In the present case, "piezoelectricity" is to be understood as the change in the electrical polarization and thus the occurrence of an electrical voltage on solid bodies when they are elastically deformed. The sensor fiber 23 can accordingly also be referred to as pyro- and piezoelectric sensor fiber.During a winding process of the sheathing 15, the sensor fiber 23 can be installed in the sheathing 15, in particular in the fiber composite plastic of the sheathing 15, during the winding thereof. A degree of coverage of the sensor fiber 23 with the fiber composite plastic and thus a detection surface for fire detection can be adjusted by the winding process. The sensor fiber 23 reacts with a temporary stress, in particular, to infrared radiation introduced from the outside, as occurs in the event of a fire or fire. An amplitude of this voltage depends on the respective pyroelectric material 27 selected and the intensity of the infrared radiation.The electrical energy generated with the aid of the sensor fiber 23 can be used to trigger the pressure relief unit 22. For triggering the pressure relief unit 22, for example, a pyrotechnic charge as mentioned above can be ignited, which opens a valve as mentioned above of the pressure relief unit 22 in order to blow off the hydrogen H 2 from the compressed gas storage container 7A, which leads to a pressure relief. An additional energy source for triggering the pressure relief unit 22 is not required. The pressure relief device 24 thus advantageously does not require an additional energy source for detecting, outputting and processing a sensor signal of the sensor fiber 23.The pressure relief device 24 thus enables a decentralized and / or covering-the-surface location of a fire or fire on the outer side 16 of the compressed gas storage container 7A and thereby increases the system safety. The location of the pressure relief, namely a position of the pressure relief unit 22 on the compressed gas storage container 7A, can thereby be decoupled from the location of the detection, which has a directly positive influence on design freedom when designing an installation space for the compressed gas storage container 7A.The positioning of the sensor fiber 23 takes place primarily in an outermost layer of the sheathing 15, in particular of the fiber composite plastic, for example in the form of a laminate. However, the sensor fiber 23 can also be wound into deeper layers. The sensor fiber 23 can thereby be protected from external influences. Nevertheless, the sensor fiber 23 has sufficient access to a seat of fire for detection thereof.By selecting a suitable winding path during the production of the compressed gas storage container 7A, the degree of coverage of the sensor fiber 23 surrounding the compressed gas storage container 7A and thus a surface of the compressed gas storage container 7A capable of detection can be adjusted. In order to protect the sensor fiber 23 from damage during the winding process, it can be laid as part of a fiber strand, for example made of carbon fibers, glass fibers, plastic fibers or the like. In order to generate redundancies, a plurality of sensor fibers 23 can be introduced.Due to a fire occurring directly at the compressed gas storage container 7A and thus at the sensor fiber 23, an increase in a temporary voltage takes place due to a shift of the charge center of gravity. A temperature can be derived from an amplitude of this voltage, which can be used as a limit for triggering a valve of the pressure relief unit 22. This ensures the pressure reduction in the compressed gas storage container 7A.FIG. 7 shows a schematic side view of a further embodiment of a compressed gas storage container 7B. FIG. 8 shows a schematic view of an embodiment of a pressure relief device 24 for the compressed gas storage container 7B as mentioned above. Reference is made simultaneously to FIGS. 7 and 8 below.The compressed gas storage container 7B differs from the compressed gas storage container 7A only in that the compressed gas storage container 7B has a pressure relief device 24, which, in addition to a pressure relief unit 22 as mentioned above and a sensor fiber 23 as explained above, has a condenser 28 connected upstream of the pressure relief unit 22. The capacitor 28 may be a so-called surge or pulse capacitor. In the present case, a "pulse capacitor" of this type is understood to mean a DC voltage capacitor which serves for absorbing or emitting a strong, usually very short, but high-energy surge.As FIG. 8 shows, the pressure relief device 24 has an analog electrical circuit 29, with the aid of which the sensor fiber 23, the pressure relief unit 22 and the capacitor 28 are interconnected. The pressure relief unit 22 has a valve 30, in particular a gas valve, and a pyrotechnic charge 31 assigned to the valve 30. The first electrode 25 of the sensor fiber 23 is connected as a negative pole. The second electrode 26 is connected as a positive pole. A reverse polarity can also be provided. The pyroelectric material 27 is not shown in Fig. 8.The electrodes 25, 26 are connected to a first conductor track 32 and to a second conductor track 33. A third conductor track 34 connects the two conductor tracks 32, 33 to one another, wherein the capacitor 28 is connected into the third conductor track 34. The circuit 29 further comprises a driver 35. The control element 35 is connected in parallel to the capacitor 28 with the aid of a fourth conductor track 36 and a fifth conductor track 37, both of which branch off from the third conductor track 34. A capacitance of the capacitor 28 may be configured or selected such that the capacitance of the capacitor 28 defines a threshold for triggering the pressure relief unit 22.Furthermore, the circuit 29 comprises a switching element 38 which can be controlled with the aid of the control element 35. The switching element 38 is a transistor, in particular an npn transistor (negative-positive-negative). The switching element 38 can also be a relay. The switching element 38 has a base 39, an emitter 40, and a collector 41. A control output 42 of the control element 35 is connected to the base 39. The emitter 40 is connected to the pyrotechnic charge 31 via a sixth conductor track 43, which is additionally also connected to the first conductor track 32. The collector 41 is connected to the second conductive path 33.The functionality of the pressure relief device 24 is explained below. One or more seats 44, only one of which is labeled with a reference numeral in FIG. 8, introduce heat Q into the sensor fiber 23. As a result, an electrical voltage is present between the electrodes 25, 26. The capacitor 28 functions as an energy store which is charged with electrical energy with the aid of the sensor fiber 23. The capacitor 28 stores electrical energy until sufficient electrical energy is present to trigger the pressure relief unit 22. The voltage present at the capacitor 28, which is detected with the aid of the control element 35, is used as the variable indicative of the charging of the capacitor 28.If the capacitor 28 is sufficiently charged to ignite the pyrotechnic charge 31, the control element 35 energizes the base 39 of the switching element 38 via the control output 42. For example, a specific voltage can be specified as a triggering criterion, which at least has to be present at the capacitor 28.If the base 39 is energized, the switching element 38 switches in such a way that, in particular, an incandescent bridge igniting the pyrotechnic charge 31 is energized by the capacitor 28 via the conductor tracks 32, 33, 34, 43. The pyrotechnic charge 31 is ignited and the valve 30 opens to blow the hydrogen H 2 from the compressed gas storage container 7B. When the pyrotechnic charge 31 is ignited, it generates a blast or a pressure wave 45. With the aid of the pressure wave 45 a component of the valve 30, for example a valve body or a valve tappet, can be moved in order to open the latter.FIG. 8 shows a schematic side view of a further embodiment of a compressed gas storage container 7C.The compressed gas storage container 7C is different from the compressed gas storage container 7B only in that not one sensor fiber 23 but a plurality of short sensor fibers 23A, 23B, two of which are shown in FIG. 8, are provided. All sensor fibers 23A, 23B are supplied with current to a common capacitor 28, which allows the capacitor 28 to be charged up in an accelerated manner. This increases the sensitivity of the pressure relief device 24. The sensitivity can be adjusted via the length and / or the number of sensor fibers 23A, 23B.The sensor fibers 23A, 23B may be shorter than the aforementioned sensor fiber 23. The number of sensor fibers 23A, 23B is arbitrary. The sensor fibers 23A, 23B may cross each other. This results in a net-like arrangement of the sensor fibers 23A, 23B. However, such an arrangement of the sensor fibers 23A, 23B is optional. Any number of sensor fibers 23A, 23B of different lengths can be provided.Although the present invention has been described on the basis of exemplary embodiments, it can be modified in various ways.LIST OF REFERENCE CHARACTERS1 Vehicle 2 Body 3 Vehicle interior 4 Environment 5 Wheel 6 Wheel 7 Compressed gas storage container 7A Compressed gas storage container 7B Compressed gas storage container 7C Compressed gas storage container 8 Consumer 9 Wall 10 Receiving region 11 Central axis 12 Base portion 13 Wall end portion 14 Wall end portion 15 Casing 16 Outer side 17 Inner side 18 Lining 19 Outer side 20 Inner side 21 Inlet nozzle 22 Pressure relief unit 23 Sensor fiber 23A Sensor fiber 23B Sensor fiber 24 Pressure relief device 25 Electrode 26 Electrode 27 Material 28 Capacitor 29 Circuit 30 Valve 31 Pyrotechnic charge 32 Conductor track 33 Conductor track 34 Conductor track 35 Control element 36 Conductor track 37 Conductor track 38 Switching element 39 Base 40 Emitter 41 Collector 42 Control output 43 Conductor track 44 Focal point 45 Pressure wave H 2 Gas / hydrogen L Longitudinal direction q heat R radial direction x x direction y direction z direction

Claims

Compressed gas storage container (7, 7A, 7B, 7C) for the pressurised storage of a gas (H2), in particular of hydrogen, having a wall (9) which encloses a receiving region (10) for receiving the gas (H2), a pressure relief unit (22) for blowing off the gas (H2) from the receiving region (10), and a pyroelectric sensor fiber (23, 23A, 23B) which is designed to trigger the pressure relief unit (22) in the event of a fire-dependent input of heat (Q) into the wall (9) in order to blow off the gas (H2) from the receiving region (10).Compressed gas storage container according to Claim 1, characterized in that the pressure relief unit (22) has a valve (30) for blowing off the gas (H2) from the receiving region (10) and a pyrotechnic charge (31), wherein the pyroelectric sensor fiber (23, 23A, 23B) ignites the pyrotechnic charge (31) in order to open the valve (30).The compressed gas storage container according to claim 1 or 2, characterized in that the pyroelectric sensor fiber (23, 23A, 23B) comprises a first electrode (25), a second electrode (26), and a pyroelectric material (27) disposed between the first electrode (25) and the second electrode (26).Compressed gas storage container according to one of Claims 1 - 3, characterized in that the pyroelectric sensor fibre (23, 23A, 23B) is arranged in or on the wall (9).Compressed gas storage container according to Claim 4, characterized in that the pyroelectric sensor fibre (23, 23A, 23B) is embedded at least in sections in the wall (9).Compressed gas storage container according to one of Claims 1 - 5, characterized in that the pyroelectric sensor fibre (23, 23A, 23B) wraps around the wall (9) in a helical manner, as viewed along a longitudinal direction (L) of the compressed gas storage container (7, 7A, 7B, 7C).Compressed gas storage container according to one of Claims 1 - 6, characterized byseveral pyroelectric sensor fibers (23A, 23B), wherein all of the plurality of pyroelectric sensor fibers (23A, 23B) are jointly assigned to the pressure relief unit (22).Compressed gas storage container according to Claim 7, characterized in that the plurality of pyroelectric sensor fibres (23A, 23B) are arranged parallel to one another and / or intersect one another.Compressed gas storage container according to one of Claims 1 - 8, characterized bya capacitor (28) for storing electrical energy generated with the aid of the pyroelectric sensor fiber (23, 23A, 23B).Compressed gas storage container according to Claim 9, characterized byan electrical circuit (29) which has the capacitor (28) and the pyroelectric sensor fiber (23, 23A, 23B), wherein the electrical circuit (29) is configured to emit the electrical energy stored in the capacitor (28) as a function of a variable indicative of a charging of the capacitor (28) in order to trigger the pressure relief unit (22).Compressed gas storage container according to Claim 10, characterized in that the electrical circuit (29) has a control element (35) which detects the indicative variable, and a switching element (38) which can be controlled by the control element (35) as a function of the indicative variable in order to emit the electrical energy stored in the capacitor (28) for triggering the pressure relief unit (22).Compressed gas storage container according to Claim 11, characterized in that the control element (35) is connected in parallel with the capacitor (28), wherein the switching element (38) is connected in parallel with the capacitor (28), and wherein the control element (35) controls the switching element (38) with the aid of a control output (42).Compressed gas storage container according to Claim 11 or 12, characterized in that the control element (35) is a voltmeter, the switching element (38) being a transistor.Compressed gas storage container according to one of claims 1 - 13, characterised in that the pressure relief unit (22) is attached to a dome-shaped wall end section (13, 14) of the wall (9).Vehicle (1), in particular motor vehicle, having at least one compressed gas storage container (7, 7A, 7B, 7C) according to one of Claims 1 - 14.

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