Fuel cell system, gas tank device, and shutoff device for gas tank device

Abstract

The shutoff device comprises a first connection for connection with a high pressure tank, a second connection for connection with a supply line, a main valve chamber having a first opening fluidly connected to the first connection, a second opening fluidly connected to the second connection, and a first control opening, and a main valve formed as a switchable solenoid valve having a main valve needle arranged in the main valve chamber, the main valve needle being movable between a closed position in which the main valve needle abuts a main valve seat surrounding the second opening and an open position in which the main valve needle is lifted from the main valve seat, the main valve needle separating the main valve chamber from an outlet chamber into which the first and second openings open, and a first control opening. The system comprises a main valve dividing the valve chamber into a control chamber having an opening therein and connected to an outlet chamber in fluid communication with the control chamber; a servo valve chamber spatially isolated from the main valve chamber, the servo valve chamber having a second control opening connected to the first control opening in fluid communication with the control chamber and a servo opening connected to a second connection in fluid communication with the control chamber; and a servo valve formed as a switchable solenoid valve, the servo valve having a servo valve needle disposed within the servo valve chamber, the servo valve needle being movable between a closed position in which the servo valve needle abuts a servo valve seat surrounding the servo opening and an open position in which the servo valve needle is lifted from the servo valve seat.

Description

[Technical field]

[0001] The present invention relates to a fuel cell system, a gas tank arrangement, in particular a gas tank arrangement for a fuel cell system, and a shut-off device for a gas tank arrangement. [Background technology]

[0002] A fuel cell system generally comprises a fuel cell assembly, for example in the form of a stack with a number of fuel cells electrically connected in series, to which a gaseous fuel, for example hydrogen, is fed from a tank via a fuel feed line. Whether for stationary or mobile, for example in a vehicle, the gaseous fuel in the tank is generally under high pressure, for example up to 700 bar or even more. The tank thereby forms a high-pressure reservoir. The fuel is fed to the fuel cell assembly usually at a lower pressure, for example in the range of 2 bar to 20 bar. The fuel feed line can be connected to the tank, for example through a pressure regulator, whereby the pressure of the fuel is reduced. The line between the tank and the pressure regulator is generally configured as a high-pressure line, and is hereinafter referred to as a supply line, since it is via this line that the fuel is fed to the fuel cell system. The tank is generally provided with a shut-off valve, by which the outflow of fuel from the tank can be blocked, for example when the fuel cell assembly is shut off or in the event of a malfunction.

[0003] Shut-off valves for high-pressure gas tanks are usually designed as solenoid valves that are normally closed. Typically, a valve needle is biased by a spring towards a sealing seat and can be lifted from the sealing seat against the biasing force of the spring by a magnetic force that can be generated by a coil. Due to the high pressure in the tank, depending on the design of the valve, a high opening force may be required. This requires a high-power coil and makes it difficult to miniaturize the valve.

[0004] Patent document 1 discloses a shutoff valve for a hydrogen pressure tank, comprising a housing having a first valve seat and a second valve seat, and a valve stem movable by an electric coil, the valve stem carrying spaced apart first and second sealing elements on its outer periphery. In the closed position of the valve, the sealing elements are biased by a spring towards the valve seat to seal the inlet against an outlet formed in the housing between the valve seats. The valve stem has a first opening, which forms a fluid connection between the inlet and the high pressure side of the first sealing element. A closing force is thereby exerted on the first sealing element as a result of the pressure applied to the inlet. The valve stem further has a through hole, which connects a subchamber located on the low pressure side of the second sealing element to the inlet. An opening force is thereby exerted on the second sealing element, which opening force acts in a direction opposite to the closing force acting on the first sealing body. The purpose of this design is to reduce the force acting on the valve stem or sealing element due to the pressure differential so as to reduce the opening force that must be generated by the electrical coil to open the valve. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] DE 102006027712 Summary of the Invention [Means for solving the problem]

[0006] According to the invention there is provided a shut-off device for a gas tank arrangement with the features of claim 1, a gas tank arrangement with the features of claim 8 and a fuel cell system with the features of claim 10.

[0007] According to a first aspect of the invention, a shutoff device for a gas tank arrangement comprises a first connection for connection with a high pressure tank, a second connection for connection with a supply line, a main valve chamber having a first opening fluidly connected to the first connection, a second opening fluidly connected to the second connection, and a first control opening, and a main valve formed as a switchable solenoid valve with a main valve needle arranged in the main valve chamber, the main valve needle being movable between a closed position in which the main valve needle abuts against a main valve seat surrounding the second opening to seal the second opening against the first opening, and an open position in which the main valve needle is lifted from the main valve seat. The main valve needle divides the main valve chamber into an outlet chamber in which the first and second openings are open, and a control chamber in which the first control opening is open and which is fluidly connected to the outlet chamber.

[0008] The shut-off device further includes a servo valve chamber spatially isolated from the main valve chamber, the servo valve chamber having a second control opening connected to the first control opening in a fluid-conducting manner and a servo opening connected to the second connection portion in a fluid-conducting manner, and a servo valve formed as a switchable solenoid valve, the servo valve having a servo valve needle disposed in the servo valve chamber, the servo valve needle being movable between a closed position in which the servo valve needle abuts a servo valve seat surrounding the servo opening to seal the servo opening from the second control opening, and an open position in which the servo valve needle is lifted from the servo valve seat.

[0009] According to a second aspect of the invention, a gas tank arrangement, in particular a gas tank arrangement for a fuel cell system, is provided, comprising a high pressure gas tank containing a gas, for example hydrogen, and a shut-off device according to the first aspect of the invention, a first connection of the shut-off device being connected to an outlet opening of the high pressure gas tank.

[0010] According to a third aspect of the present invention, a fuel cell system comprises a fuel cell assembly having at least one fuel cell, a fuel inlet for the delivery of a gaseous fuel, an oxidant gas inlet for the delivery of an oxidant gas, and a product outlet for the discharge of reaction products, a fuel delivery line connected to the fuel inlet, and a gas tank device according to the second aspect of the present invention, wherein a second connection of the shut-off device is connected to the fuel delivery line.

[0011] The idea behind the invention is to realize a shut-off device in which a main valve and a servo valve are arranged spatially separated from each other, in particular in which a main valve needle is arranged in a first chamber or main valve chamber and is movable between an open position and a closed position by a first coil, while a servo valve needle is arranged in a second chamber or servo valve chamber, spatially arranged from the main valve chamber and connected to it in a fluid-conducting manner, and is movable between an open position and a closed position by a separate second coil, in which the main valve needle is slidably guided in the first chamber and divides the first chamber into a control chamber, connected to the second chamber in a fluid-conducting manner, and an outlet chamber, which has a first opening connected to a high-pressure connection or a first connection and a second opening connected to a supply connection or a second connection, the second opening being covered or closed by the main valve needle in the closed position of the main valve needle. The second chamber is also fluidly connected to the supply connection via a servo opening which is covered or blocked by the servo valve needle in the closed position of the servo valve needle. Effect of the Invention

[0012] One advantage of the invention is that the servo valve and the main valve or their valve needles are housed in spatially separated chambers and are movable by their own coils. This facilitates a space-optimized arrangement of the servo valve and the main valve. By opening the servo valve, a fluid-conducting connection between a second or supply connection, which is provided for connection to a low-pressure reservoir, for example a fuel delivery line, and a control chamber of the main valve chamber can be formed with a comparatively small opening force. The control chamber is fluidly connected via the outlet chamber to a first or high-pressure connection, which is provided for connection to a high-pressure reservoir, for example a gas tank, so that a pressure compensation between the second connection and the control chamber is performed. On the one hand, the pressure in the control chamber is then reduced and at the same time the pressure in the second connection is increased. In this way, in the closed position of the main valve needle, a force is generated that is directed away from the main valve seat, which assists the coil of the main valve in lifting the main valve needle off the main valve seat. This allows the main valve coil to be sized smaller, which further facilitates miniaturization of the shutoff device.

[0013] Advantageous configurations and developments can be seen from the further dependent claims and from the description with reference to the drawing figures.

[0014] According to various embodiments, the main valve chamber and the servo valve chamber may be formed in a common housing. Due to the spatially isolated arrangement of the main valve chamber and the servo valve chamber in the housing, the valve needles can be arbitrarily oriented relative to each other, which further facilitates a space-optimized arrangement or configuration.

[0015] According to some embodiments, the first control opening and the second control opening may be connected by a connecting hole.

[0016] According to various embodiments, the fluid-conducting connection between the outlet chamber of the main valve chamber and the control chamber may be dimensioned to act as a throttle for fluid flow from the outlet chamber to the control chamber when the servo valve is open and the main valve is closed, whereby pressure compensation between the outlet chamber and the control chamber is slowed down and thus the opening force acting on the main valve needle is further magnified.

[0017] According to various embodiments, the outlet chamber of the main valve chamber and the control chamber can be connected to each other in fluid communication by a hole in the main valve needle. According to alternative embodiments, the outlet chamber of the main valve chamber and the control chamber can be connected to each other in fluid communication by a gap formed between the outer circumference of the main valve needle and a wall surrounding the main valve chamber. The width of the gap can be determined, for example, by a fit, for example a clearance fit, between the wall and the main valve needle. The gap can, however, only be formed locally, for example by the formation of a groove in the wall and / or in the outer circumference of the valve needle. This allows for a structurally simple and cost-effectively manufacturable connecting line between the control chamber and the outlet chamber.

[0018] According to various embodiments, the main valve is configured as a normally closed solenoid valve and may include a spring biasing the main valve needle to a closed position.

[0019] According to various embodiments, the servo valve is configured as a normally closed solenoid valve and may include a spring biasing a servo valve needle to a closed position.

[0020] According to various embodiments, the shutoff device may be accommodated within an outlet opening of the high pressure gas tank.

[0021] The invention will now be described with reference to the figures of the drawings. [Brief description of the drawings]

[0022] [Figure 1] 1 is a schematic hydraulic circuit diagram of a fuel cell system according to an embodiment of the present invention. [Diagram 2] 1 is a schematic cross-sectional view of an interrupter according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] In the drawings, like numbers refer to the same or functionally identical components unless stated to the contrary.

[0024] An exemplary fuel cell system 300 is shown generally in Figure 1. As shown generally in Figure 1, the fuel cell system 300 includes a fuel cell assembly 310, a fuel delivery line 302, an optional pressure regulator 320, and the gas tank arrangement 200.

[0025] The fuel cell assembly 310 is shown in Fig. 1 only as a block and comprises at least one fuel cell (not shown), a fuel inlet 311, an oxidizing gas inlet 313 and a product outlet 314. The fuel cell assembly may comprise a number of fuel cells, for example electrically connected in series, for example in the form of a so-called stack. Each fuel cell comprises an anode, a cathode and an electrolyte layer, for example in the form of a membrane, arranged between the anode and the cathode. Via the fuel inlet 311, a gaseous fuel, for example hydrogen, can be delivered to the anode of one or more fuel cells. Similarly, the oxidizing gas inlet 313 An oxidizing gas, e.g., ambient air containing oxygen, may be delivered to the cathode of one or more fuel cells via product outlet 314. Reaction products may be conducted away from the cathode via product outlet 314. At least one fuel cell is thereby configured to convert chemical energy stored in the fuel together with the oxidizing gas directly into electrical energy.

[0026] The gas tank arrangement 200 comprises a high-pressure gas tank 210 and a shutoff device 100. The high-pressure gas tank 210 (hereinafter also simply referred to as tank for reasons of simplicity) is designed to contain a gas, for example hydrogen, and can store the gas at a pressure of up to 700 bar. As shown diagrammatically in FIG. 1, the tank 210 can be designed, for example, as a substantially cylindrical tank. The outlet opening 211 of the tank 210 can be arranged, for example, at one axial end of the tank 210. The shutoff device 100 is only symbolically shown in FIG. 1 and will be explained in more detail below. As shown diagrammatically in FIG. 1, the shutoff device 100 is connected to the outlet opening 211 of the tank 210 and to a low-pressure connection 261 of the gas tank arrangement 200. Optionally, a check valve 220 can be connected in parallel to the shutoff device 100. This is exemplarily shown in FIG. 1. A fuel delivery line 302 connects a low pressure connection 261 of the gas tank arrangement 200 to a fuel inlet 311 of the fuel cell assembly 310. An optional pressure regulator 320 is disposed in the fuel delivery line 302 between the low pressure connection 261 and the fuel inlet 311 and is configured to reduce the pressure and / or vary the flow rate of gas exiting the tank 210. For example, the pressure regulator 320 may include a throttle valve that allows for adjustable flow.

[0027] Fig. 2 shows a schematic and exemplary shutoff device 100. The shutoff device 100 may be incorporated in the gas tank device 200 shown in Fig. 1. As shown in Fig. 2, the shutoff device 100 includes a first connection 11, a second connection 12, a main valve chamber 2, a main valve 3, a servo valve chamber 4, and a servo valve 5.

[0028] As shown in Fig. 2, the main valve chamber 2 and the servo valve chamber 4 are arranged spatially separated from each other. In general, the chambers 2, 4 each define a cavity, which is surrounded, for example, by walls 20, 40. As shown purely diagrammatically in Fig. 2, the main valve chamber 2 and the servo valve chamber 4 may be formed in a common housing 1.

[0029] The first connection 11 is provided for connection to the high-pressure tank 210 and may be formed, for example, as an opening or as a connecting tube in the housing 1. The second connection 12 is provided for connection to a supply or fuel delivery line 302 and may also be formed, for example, as an opening or as a connecting tube in the housing 1.

[0030] The main valve chamber 2 has a first opening 21, a second opening 22 and a first control opening 23. As shown exemplarily in FIG. 2, the first and second openings 21, 22 may each be formed in a first end region of the main valve chamber 2. For example, the first opening 21 may be formed in the peripheral wall and the second opening 22 may be formed in a first end wall extending transversely to the peripheral wall. This is exemplarily shown in FIG. 2. The first control opening 23 may in particular be formed in a second end region of the main valve chamber 2, for example in a second end wall opposite the first end wall as shown in FIG. 2.

[0031] The first opening 21 is fluidly connected to the first connection 11, for example via a hole or a line 14. The second opening 22 is fluidly connected to the second connection 12, for example via a hole or a line 15. This is exemplarily shown in FIG.

[0032] As further shown in Fig. 2, the servo valve chamber 4 has a second control opening 41 and a servo opening 42. The servo opening 42 may be formed, for example, in one end wall of the servo valve chamber 4, and the second control opening 41 may be formed, for example, in a peripheral wall 40 extending transversely to this end wall. This is exemplarily shown in Fig. 2.

[0033] The first control opening 23 of the main valve chamber 2 and the second control opening of the servo valve chamber 4 are fluidly connected to one another, for example via a hole or a line 13. This is shown diagrammatically in Figure 2. The servo opening 42 is fluidly connected to the second connection 12, for example via a hole or a line 16.

[0034] The main valve 3 is configured as a de-energized solenoid valve 3 and includes a main valve needle 30, a spring 31, and a coil 32. The main valve needle 30 is arranged in the main valve chamber 2 and is guided axially and slidably at its outer periphery 30a by a wall 20, in particular a peripheral wall. As shown diagrammatically in FIG. 2, the main valve needle 30 may have, for example, a cylindrical main section 35 and a guide section 36, which protrudes radially from the main section 35 at a first axial end of the main section 35. A second axial end of the main section 35 has a sealing surface 35a, which may be configured, for example, conically. The guide section 36 may have, for example, a cylindrical outer periphery, which is guided by the wall 20.

[0035] As shown diagrammatically in FIG. 2, the main valve needle 30 divides the main valve chamber 2 into an outlet chamber 2A and a control chamber 2B. For example, the guide section 36 may form a partition, as shown diagrammatically in FIG. 2. The first and second openings 21, 22 open into the outlet chamber 2A, respectively. The first control opening 23 opens into the control chamber 2B. The control chamber 2B and the outlet chamber 2A are connected in a fluid-conducting manner, for example, by a hole 33 formed in the main valve needle 30, in particular in the guide section 36, or by a gap 34 formed between the outer periphery 30a of the main valve needle 30, in particular the outer periphery of the guide section 36, and the wall 20. The gap 34 is shown enlarged in FIG. 2 for reasons of clarity. For example, the width of the gap 34 may be provided by a fit between the valve needle 30 and a hole diameter defined by the peripheral wall 20.

[0036] The main valve needle 30 is movable between a closed position and an open position by a coil 32, which is arranged, for example, outside the main valve chamber 2, surrounding the main valve needle 30. A spring 31 biases the main valve needle 30 to the closed position and can be arranged, for example, in the control chamber 2B. This is shown diagrammatically in FIG. 2. FIG. 2 shows the closed position of the main valve needle 30. In the closed position, the main valve needle 30, in particular the sealing surface 35a of the main valve needle 30, abuts against a main valve seat surrounding the second opening 22 to seal the second opening 22 against the first opening 21. In the open position, the main valve needle 30, in particular the sealing surface 35a of the main valve needle 30, is lifted from the main valve seat, so that fluid can flow from the first connection 11 into the outlet chamber 2A and through the second opening 22 to the second connection 12.

[0037] The servo valve 5 is also configured as a solenoid valve that is closed when not energized, and includes a servo valve needle 50, a spring 51, and a coil. 52 The servo valve needle 50 is arranged in the servo valve chamber 4 and is guided axially and slidably by the wall 40, in particular the circumferential wall, at its outer periphery. As shown diagrammatically in FIG. 2, the servo valve needle 50 may have, for example, a cylindrical main section 55 and a guide section 56, which protrudes radially from the main section 55 at a first axial end of the main section 55. A second axial end of the main section 55 has a sealing surface 55a, which may be configured, for example, conically. The guide section 56 may have, for example, a cylindrical outer periphery, which is guided by the wall 40.

[0038] The servo valve needle 50 is movable between a closed position and an open position by a coil 52, which is arranged, for example, outside the servo valve chamber 4, surrounding the servo valve needle 50. A spring 51 biases the servo valve needle 50 to the closed position and can be arranged, for example, in the servo valve chamber 4. This is shown diagrammatically in FIG. 2. FIG. 2 shows the closed position of the servo valve needle 50. In the closed position, the servo valve needle 50, in particular the sealing surface 55a of the servo valve needle 50, abuts against a servo valve seat surrounding the servo opening 42 to seal the servo opening 42 against the second control opening 41. In the open position, the servo valve needle 50, in particular the sealing surface 55a of the servo valve needle 50, is lifted from the servo valve seat, so that a fluid exchange can take place through the servo valve chamber 4 via the second control opening 41 and the servo opening 42.

[0039] In the situation shown in FIG. 2, in which both the main valve 3 and the servo valve 5 are closed, there is pressure in the outlet chamber 2A, in the control chamber 2B and in the servo valve chamber 4, respectively, which is applied at the first connection 11. The main valve needle 3 has a first cross-sectional area A35 in the first end region facing the control chamber 2B. The second cross-sectional area A22 is determined by the area surrounded by the main valve seat. As shown diagrammatically in FIG. 2, the first cross-sectional area A35 is greater than the second cross-sectional area A22. When the pressure at the first connection 11 is greater than the pressure at the second connection 12, this results in an additional pushing force acting in addition to the force exerted by the spring 31 on the main valve needle 30, which pushes the main valve needle 30 into its closed position.

[0040] To open the main valve 3, the servo valve 5 is first opened. That is, the coil 52 of the servo valve 5 is energized to lift the servo valve needle 50 from the servo valve seat. The control chamber 2B is thereby opened to the first and second control openings 23, 412B. In this embodiment, the main valve needle 2B is connected to the pressure level of the second connection 12 in a fluid conducting manner via the servo opening 42, which typically leads to a pressure drop in the control chamber 2B. Generally, a pressure compensation is performed between the control chamber 2B and the second connection 12, since a pressure compensation also occurs between the first control opening 23 and the second opening 22. As a result of this pressure compensation, the pressing force acting as a result of the different cross-sectional areas A35, A22 is reduced. This causes the main valve needle 2B to be pressed against the main valve needle 2B, which must be generated by energizing the coil 32. 30 The magnetic force which moves the main valve needle to its open position is reduced. The fluid-conducting connection between the outlet chamber 2A and the control chamber 2B of the main valve chamber 2, i.e. for example the gap 34 or the hole 33, can be dimensioned to act as a throttle for the fluid flow from the outlet chamber 2A into the control chamber 2B, in particular when the servo valve 5 is open and the main valve 3 is closed. This is achieved by the energization of the coil 32, which must be generated by the main valve needle. 30 This further reduces the magnetic force that moves the switch to the open position.

[0041] Due to the spatially isolated arrangement of the main valve chamber 2 and the servo valve chamber 4, the main valve and the servo valves 3, 5 can be stored in an optimized assembly space. In particular, the main valve needle 30 and the servo valve needle 50 can extend relative to one another in any manner, which greatly expands the flexibility of the arrangement.

[0042] The present invention has been described above by way of example only, but the present invention is not limited to these examples and can be modified in various ways. In particular, combinations of the above-mentioned examples are also possible. For example, the shutoff device 100 has been described in relation to the gas tank device 200 for the fuel cell system 300, but is not limited to the gas tank device 200 for the fuel cell system 300. In principle, the shutoff device 100 can be used in any gas pipeline system. [Explanation of symbols]

[0043] 1. Housing 2 Main valve chamber 2A Exit chamber 2B Control Room 3 Main valve 4 Servo valve chamber 5 Servo valve 11 First connection 12 Second connection 13 Holes or pipes 14 Holes or pipes 15 Holes or pipes 16 Holes or pipes 20. Wall 21 First opening 22 Second Opening 23 First Control Aperture 30 Main valve needle 30a outer periphery 31 Spring 32 Coil 33 holes 34 Gap 35 Main Section 35a Sealing surface 36 Guide Section 40 Wall 41 Second Control Aperture 42 Servo Aperture 50 Servo valve needle 51 Spring 52 Coil 55 Main Section 55a Sealing surface 56 Guide Section 100 Circuit Breaker 200 Gas Tank Device 211 Exit opening 210 High Pressure Gas Tank 220 Check valve 261 Low voltage connection 300 Fuel Cell System 302 Fuel feed line 310 Fuel Cell Assembly 311 Fuel inlet 313 Oxidizing gas inlet 314 Product outlet 320 Pressure Regulating Device A22 Second Cross-sectional Area A35 First Cross-sectional Area

Claims

1. A shutoff device (100) for a gas tank device (200), comprising: a first connection (11) for connection to a high pressure tank (210); a second connection (12) for connection with a supply line (302); a main valve chamber (2) having a first opening (21) fluidly connected to said first connection (11), a second opening (22) fluidly connected to said second connection (12), and a first control opening (23); a main valve (3) formed as a switchable solenoid valve, comprising a main valve needle (30) arranged in the main valve chamber (2), the main valve needle (30) being movable between a closed position in which the main valve needle (30) abuts against a main valve seat surrounding the second opening (22) to seal the second opening (22) against the first opening (21), and an open position in which the main valve needle (30) is lifted from the main valve seat, the main valve needle (30) dividing the main valve chamber (2) into an outlet chamber (2A) opening into the first and second openings (21, 22) and a control chamber (2B) opening into the first control opening (23) and connected in fluid communication to the outlet chamber (2A); a servo valve chamber (4) spatially isolated from the main valve chamber (2), the servo valve chamber (4) having a second control opening (41) fluidly connected to the first control opening (23) and a servo opening (42) fluidly connected to the second connection (12); a servo valve (5) formed as a switchable solenoid valve, the servo valve (5) having a servo valve needle (50) arranged in the servo valve chamber (5), the servo valve needle (50) being movable between a closed position in which the servo valve needle (50) abuts against a servo valve seat surrounding the servo opening (42) to seal the servo opening (42) against the second control opening (41), and an open position in which the servo valve needle (50) is lifted off the servo valve seat; A shutoff device (100) for a gas tank device (200), comprising:

2. 2. The shutoff device (100) of claim 1, wherein the main valve chamber (2) and the servo valve chamber (4) are formed in one common housing (1).

3. 3. The shutoff device (100) according to claim 2, wherein the first control opening (23) and the second control opening (41) are connected by a connecting hole (13).

4. 4. The shutoff device (100) according to any one of claims 1 to 3, wherein the fluid-conducting connection between the outlet chamber (2A) of the main valve chamber (2) and the control chamber (2B) is dimensioned to act as a throttle for fluid flow from the outlet chamber (2A) into the control chamber (2B) when the servo valve (5) is open and the main valve (3) is closed.

5. 4. The shutoff device (100) according to claim 1, wherein the outlet chamber (2A) and the control chamber (2B) of the main valve chamber (2) are connected to each other in fluid communication by a hole (33) provided in the main valve needle (30) or by a gap (34) formed between an outer periphery (30a) of the main valve needle (30) and a wall (20) surrounding the main valve chamber (2).

6. 4. The shutoff device (100) according to claim 1, wherein the main valve (3) is configured as a solenoid valve that is closed when de-energized and has a spring (31) that biases the main valve needle (30) towards the closed position.

7. 4. The shutoff device (100) according to claim 1, wherein the servo valve (5) is configured as a solenoid valve that is closed when de-energized and has a spring (51) that biases the servo valve needle (50) towards the closed position.

8. A gas tank device (200), in particular a gas tank device (200) for a fuel cell system (300), comprising: A high pressure gas tank (210) for storing gas; A blocking device (100) according to any one of claims 1 to 3, Equipped with The first connection part (11) of the shutoff device (100) is connected to an outlet opening (211) of the high-pressure gas tank (210). A gas tank device (200).

9. 9. The gas tank arrangement (200) according to claim 8, wherein the shut-off device (100) is accommodated within the outlet opening (211) of the high pressure gas tank (210).

10. A fuel cell system (300), comprising: a fuel cell assembly (310) having at least one fuel cell, a fuel inlet (311) for delivery of a gaseous fuel, an oxidizing gas inlet (313) for delivery of an oxidizing gas, and a product outlet (314) for delivery of reaction products; a fuel delivery line (302) connected to the fuel inlet (311); A gas tank arrangement (200) according to claim 8, Equipped with the second connection (12) of the shutoff device (100) is connected to the fuel delivery line (302); A fuel cell system (300).

11. A fuel cell system (300), comprising: a fuel cell assembly (310) having at least one fuel cell, a fuel inlet (311) for delivery of a gaseous fuel, an oxidizing gas inlet (313) for delivery of an oxidizing gas, and a product outlet (314) for delivery of reaction products; a fuel delivery line (302) connected to the fuel inlet (311); A gas tank arrangement (200) according to claim 9, Equipped with the second connection (12) of the shutoff device (100) is connected to the fuel delivery line (302); A fuel cell system (300).

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