FUEL CELL SYSTEM, GAS TANK DEVICE AND SHUT-OFF VALVE FOR A GAS TANK DEVICE

Description

Technical field

[0001] The present invention relates to a fuel cell system, a gas tank device, in particular for a fuel cell system and a shut-off valve for a gas tank device. State of the art

[0002] Fuel cell systems typically comprise a fuel cell array, for example, a stack with multiple fuel cells connected in series, to which gaseous fuel, such as hydrogen, is supplied from a tank via a fuel supply line. In both stationary and mobile applications, such as in a vehicle, the gaseous fuel in the tank is usually under high pressure, which can be up to 700 bar or more. The tank thus forms a high-pressure reservoir. The fuel is typically supplied to the fuel cell array at a lower pressure, for example, between 2 and 20 bar. The fuel supply line serves as a delivery line. This line may be connected to the tank via a pressure regulating device that reduces the fuel pressure.The line between the tank and the pressure regulating device is typically a high-pressure line and is referred to below as the supply line, since it supplies the fuel cell system with fuel. The tank is usually equipped with a shut-off valve to prevent fuel from escaping, for example, when the fuel cell system is taken out of service or in the event of a malfunction.

[0003] Such shut-off valves for high-pressure gas tanks are generally designed as normally closed solenoid valves. Typically, a valve needle is biased against a sealing seat by a spring and can be lifted from the sealing seat against the spring's bias force by a magnetic force generated by a coil. Due to the high pressure in the tank, high opening forces may be required depending on the valve design, which complicates the miniaturization of the valve.

[0004] DE 10 2006 027 712 A1 discloses a shut-off valve for a gas tank device, comprising: a housing with an inlet opening for connection to a high-pressure tank, an outlet opening for connection to a supply line and a control opening suitable for connection to the supply line, wherein the housing defines an interior space extending along a longitudinal axis and has a partition which divides the interior space with respect to the longitudinal axis into an outlet chamber and a control chamber, wherein the partition has a guide bore which extends between the outlet chamber and the control chamber.

[0005] From US 9 347 580 B2, a valve device is known which comprises a main valve body arranged between a first pressure chamber of a main passage and a second pressure chamber, and which comprises a pilot valve body provided in the second pressure chamber.

[0006] US patent 2018 / 038507 A1 shows a valve device comprising a main valve element that divides a valve element space of a housing into a first and second pressure chamber.

[0007] US Patent 9,194,354 B2 discloses a fuel gas supply and filling system for a fuel gas consumption unit that is able to use a supply channel for both filling and feeding, and improves the airtightness and reliability of a filling channel. Disclosure of the invention

[0008] According to the invention, a shut-off valve with the features of claim 1, a gas tank device with the features of claim 10 and a fuel cell system with the features of claim 12 are provided.

[0009] According to a first aspect of the invention, a shut-off valve for a gas tank device comprises a housing with an inlet opening for connection to a high-pressure tank, an outlet opening for connection to a supply line, and a control opening for connection to the supply line, wherein the housing defines an interior space extending along a longitudinal axis and has a partition which divides the interior space with respect to the longitudinal axis into an outlet chamber and a control chamber, wherein the partition has a guide bore which extends between the outlet chamber and the control chamber.Furthermore, the shut-off valve has an electrical coil received in the separating web and surrounding the guide bore, and a servo valve needle arranged in the control chamber, which is biased along the longitudinal axis into a closed position in which the servo valve needle seals the control opening, and can be moved by means of a magnetic field generated by the coil into an open position in which the servo valve needle releases the control opening and rests against the separating web, wherein the servo valve needle has a connecting channel which connects the control chamber to the guide bore in the open position of the servo valve needle.Furthermore, the shut-off valve includes a main valve needle movably guided in the guide bore along the longitudinal axis, which is biased along the longitudinal axis into a closed position in which the main valve needle seals the outlet opening, and, when the servo valve needle is arranged in its open position, can be moved by means of the magnetic field generated by the coil into an open position in which the main valve needle releases the outlet opening.

[0010] According to a second aspect of the invention, a gas tank device, in particular for a fuel cell system, comprises a high-pressure gas tank for receiving gas, such as hydrogen, and a shut-off valve according to the first aspect of the invention, wherein the inlet opening of the housing of the shut-off valve is connected to an outlet opening of the high-pressure gas tank.

[0011] According to a second aspect of the invention, a fuel cell system comprises a fuel cell arrangement with at least one fuel cell, a fuel inlet for supplying gaseous fuel, an oxidation gas inlet for supplying oxidation gas and a product outlet for removing reaction products, a fuel supply line connected to the fuel inlet and a gas tank device according to the second aspect of the invention, wherein the outlet opening and the control opening of the housing of the shut-off valve are each connected to the fuel supply line.

[0012] One of the underlying ideas of the invention is to arrange a servo valve needle and a main valve needle in a housing, both of which can be actuated by one and the same coil. A control orifice that can be closed by the servo valve needle and a high-pressure outlet that can be closed by the main valve needle are both connectable to the same supply line, so that the same pressure level is present at both.

[0013] The fuel supply reliability of the fuel cell can be improved if the shut-off valve can be reliably opened at both low and high pressure levels in the supply line, as well as at the same pressure level in the tank and in the supply line.

[0014] The following is an example of how the opening process works when the pressure level in the supply line is lower than in the tank.

[0015] When the coil is energized, a primary magnetic circuit is formed, generating a magnetic force that acts on the servo valve needle and moves it into an open position. This opens the control port, reducing the pressure in a control chamber of the housing where the servo valve needle is located. The main valve needle is axially guided in a guide bore formed in a partition wall of the housing that separates the control chamber from an outlet chamber. The outlet chamber is connected, or can be connected, to a gas tank or high-pressure reservoir via an inlet. A fluidic connection exists between the guide bore and the control chamber via a channel provided in the servo valve needle. Consequently, opening the valve results in a pressure drop in the guide bore, thus exerting a tensile force on the main valve needle.When the servo valve needle is open, it also rests against the partition wall of the housing, so that, with continued energization of the coil, a secondary magnetic circuit is formed, which generates a magnetic force acting on the main valve needle. Since the main valve needle is also subjected to a tensile force due to the reduced pressure in the control chamber, even a small magnetic force generated by the coil can cause the main valve needle to open. A pressure gradient and a minimum possible pressure level in the control chamber result from the outflow throttling (A-throttle) at the valve seat of the servo valve needle and the inflow throttling (Z-throttle), a pneumatic connection between the control chamber and the outlet chamber, as well as the respective pressure levels on the outflow and inflow sides.

[0016] The opening process is described below when the pressure level in the supply line and tank is the same or nearly the same.

[0017] When the coil is energized, a primary magnetic circuit is re-established, generating a magnetic force that acts on the servo valve needle and moves it into the open position. Due to the equal pressure levels in the supply line, control chamber, and outlet chamber, the pressure difference at the servo valve seat and main valve seat is zero or nearly zero. Therefore, once the servo valve has opened, the secondary magnetic field at the main valve armature is sufficient to fully open the main valve against the spring force, even without pneumatic assistance from the control chamber.

[0018] An advantage of the invention is therefore that the main valve needle can be moved from the closed to the open position with a low opening force, even with large pressure differences between the high-pressure gas tank and the supply line. Consequently, the coil, which at least partially generates the opening force, can be dimensioned relatively small, resulting in a compact shut-off valve. Furthermore, the design of the shut-off valve according to the invention is advantageous in that the stroke of the servo valve needle is independent of the stroke of the main valve needle. In particular, a large stroke of the main valve needle compared to the stroke of the servo valve needle can be achieved with a compact coil design. Another advantage is that even with pressure equalization between the control chamber and the outlet chamber, the main valve needle is prevented from closing, as it is held in its open position by the magnetic force generated by the coil.This advantageously reduces the wear and tear on the shut-off valve.

[0019] Advantageous designs and further developments result from the further sub-claims as well as from the description with reference to the figures in the drawing.

[0020] According to some embodiments, the separating web may have a receiving recess surrounding the guide bore, which extends from the control chamber along the longitudinal axis as a blind hole, and the coil is arranged in the receiving recess. The receiving recess may, for example, extend as an annular opening from a surface facing the control chamber. A residual web is thus provided between the bottom of the receiving recess and a surface of the separating web facing the outlet chamber. When the servo valve needle rests against the separating web in its open position, the coil can be energized such that magnetic saturation occurs in the residual web. This facilitates the generation of a secondary magnetic circuit or field that acts efficiently on the main valve needle.

[0021] According to some embodiments, the main valve needle may have a shaft which is guided in the guide bore at a first end region, and a sealing section which is formed in a second end region of the shaft and rests against a main valve seat defined by the outlet opening when the main valve needle is closed. The shaft may, for example, be made of a magnetizable material and advantageously acts as a plunger.

[0022] According to some embodiments, a sealing element for fluidic separation of the control chamber from the exhaust chamber may be provided between the first end region of the main valve needle shaft and the guide bore. For example, the sealing element may be designed as a sealing ring and attached to the main valve needle shaft. According to some embodiments, a throttle bore may fluidically connect the control chamber to the exhaust chamber. A pneumatic connection between the control chamber and the exhaust chamber can thus be achieved via a guide clearance between the main valve needle or the main valve needle shaft and the guide bore, or, if sealing elements are used on the main valve needle shaft, also separately via a throttle bore as a bypass to the seal.

[0023] According to some embodiments, the stem of the main valve needle may have a first cross-sectional area in its first end region that is larger than a second cross-sectional area of ​​the main valve seat. This allows the tensile force generated by the pressure drop in the control chamber to be advantageously increased further, in particular to such an extent that this tensile force alone is sufficient to lift the main valve needle from the main valve seat. This further reduces the force to be generated by the coil, which is advantageous with regard to a compact coil design.

[0024] According to some embodiments, the main valve needle may have a flat armature projecting from the shaft, which is spaced apart from the separating bridge in the closed position of the main valve needle and rests against the separating bridge in the open position of the main valve needle. The separating bridge is made of a magnetizable material. Due to the radial extension of the flat armature, a gap is formed between the separating bridge and the flat armature in the closed position of the main valve needle. Particularly in combination with the arrangement of the coil in the receiving recess described above, the force exerted on the main valve needle by the secondary magnetic field generated by the coil can be advantageously increased further.

[0025] According to some embodiments, the servo valve needle may have a shaft, a sealing section formed at a first end region of the shaft, and a flat armature projecting from the shaft and connected to a second end region of the shaft. In the closed position of the servo valve needle, the sealing section rests against a servo valve seat defined by the control orifice, and the flat armature is spaced apart from the separating web. In the open position of the servo valve needle, the sealing section is spaced apart from the servo valve seat, and the flat armature rests against the separating web. The flat armature of the servo valve needle offers the particular advantage that a large opening force can be generated with a small stroke of the servo valve needle.

[0026] In some embodiments, the servo valve needle and the main valve needle can be pre-tensioned into their respective closed positions by a common spring located in the guide bore. This advantageously reduces the number of parts.

[0027] According to some embodiments, the shut-off valve may have a control line that fluidically connects the outlet port and the control port outside the interior and has a connection for connection to the supply line. According to alternative embodiments, the housing may have a first port connected to the outlet port for connection to the supply line and a second port connected to the control port for connection to the supply line. In both alternatives, the same low-pressure level can be easily set at the control port and the outlet port.

[0028] According to some embodiments of the gas tank device, the housing of the shut-off valve may be located in the outlet opening of the high-pressure gas tank. For example, the high-pressure gas tank may be a gas cylinder with a substantially cylindrical section and an outlet section or neck that tapers relative to the cylindrical section, in which the outlet opening is formed. The compact design of the shut-off valve allows it to be housed within the outlet section, thus providing better protection against mechanical damage.

[0029] The invention will now be explained with reference to the figures in the drawings. The figures show: Fig. 1 a schematic sectional view of a shut-off valve according to an embodiment of the invention, wherein a servo valve needle and a main valve needle are each arranged in a closed position; Fig. 2 the in Fig. 1 The shut-off valve shown, wherein the servo valve needle is arranged in an open position and the main valve needle in a closed position; Fig. 3 the in Fig. 1 The shut-off valve shown, wherein the servo valve needle and the main valve needle are each arranged in an open position; and Fig. 4 a schematic representation of a hydraulic circuit diagram of a fuel cell system according to an embodiment of the invention.

[0030] In the figures, the same reference symbols denote identical or functionally equivalent components, unless otherwise stated.

[0031] In Fig. 4 An exemplary and schematic representation of a 300-unit fuel cell system is shown. As in Fig. 4 As shown schematically, the fuel cell system 300 comprises a fuel cell assembly 310, a fuel supply line 302, an optional pressure control device 320 and a gas tank device 200.

[0032] The fuel cell assembly 310 is in Fig. 4 The assembly is shown only as a block and comprises at least one fuel cell (not shown), a fuel inlet 311, an oxidation gas inlet 313, and a product outlet 314. The fuel cell arrangement can, for example, include a multitude of fuel cells connected electrically in series, e.g., in the form of a so-called stack. Each fuel cell has an anode, a cathode, and an electrolyte layer, e.g., in the form of a membrane, arranged between the anode and cathode. Gaseous fuel, e.g., hydrogen, can be supplied to the anode(s) of the fuel cell(s) 210 via the fuel inlet 311. Similarly, oxidation gas, e.g., oxygen-containing ambient air, can be supplied to the cathode(s) of the fuel cell(s) 210 via the oxidation gas inlet 213. The reaction products can be discharged from the cathode via the product outlet 214.At least one fuel cell is thus designed to convert the chemical energy stored in the fuel, together with oxidation gas, directly into electrical energy.

[0033] The gas tank device 200 comprises a high-pressure gas tank 210 and a shut-off valve 100. The high-pressure gas tank 210, hereinafter referred to simply as the tank for the sake of clarity, is designed to hold gas, such as hydrogen, and can store gas at a pressure of up to 700 bar. As in Fig. 4 In schematic representation, the tank 210 can be designed as an essentially cylindrical tank. An outlet opening 211 of the tank 210 can, for example, be arranged at an axial end of the tank 210. The shut-off valve 100 is in Fig. 4 This is merely a symbolic representation and will be explained in detail below. As in Fig. 4 As shown schematically, the shut-off valve 100 is connected to the outlet opening 211 and a low-pressure connection 261 of the tank 210. Optionally, a check valve 220 can be connected in parallel to the shut-off valve 100, as shown in Fig. 4 The fuel supply line 302 connects the low-pressure port 261 of the gas tank device 200 to the fuel inlet 311 of the fuel cell assembly 310. The optional pressure regulating device 320 is arranged between the low-pressure port 261 and the fuel inlet 311 in the fuel supply line 302 and is configured to reduce the pressure of the gas flowing from the tank 210 and / or to vary the flow rate. For example, the pressure regulating device 320 can have a flow-controllable throttle valve.

[0034] In Fig. 1 Figure 1 shows a schematic sectional view of an exemplary shut-off valve 100, as used, for example, in the following: Fig. 4 The gas tank device shown can be used with the 200mm device shown. As shown in Fig. 1 In schematic representation, the shut-off valve 100 comprises a housing 1, an electrical coil or induction coil 2, a servo valve needle 3, a main valve needle 4, and a spring 5. Optionally, the shut-off valve 100 may also have a control line 6, as shown in Fig. 1 is shown schematically.

[0035] The housing 1 can in particular have a base body 1A which defines an interior space 10 extending along a longitudinal axis L1. As in Fig. 1 As shown schematically, a partition or divider 14 is arranged in the interior 10 of the housing 1, which divides the interior 10 with respect to the longitudinal axis L1 into a first chamber or outlet chamber 10A and a second chamber or control chamber 10B. The partition 14 can, in particular, extend in a radial direction R1 transverse to the longitudinal axis L1, as shown in Fig. 1 This is shown as an example. The separating web 14 can in particular be made of a magnetizable material.

[0036] A guide bore 15 is formed in the separating web 14, which connects the control chamber 10B and the outlet chamber 10A. The guide bore 15 can, for example, be arranged and aligned coaxially with the longitudinal axis L1, as shown in Fig. 1 shown schematically. Optionally, the separating web 14 can also have a receiving recess 16. As shown in Fig. 1 In schematic representation, the receiving recess can extend from a surface of the separating web 14 facing the control chamber 10B along the longitudinal axis L1 and terminate at a distance from a surface of the separating web 14 facing the outlet chamber 10A. The receiving recess 16 thus extends from the control chamber 10B along the longitudinal axis L1 as a blind hole. A residual web 16A is therefore present between the surface of the separating web 14 facing the control chamber 10B and the bottom or end of the receiving recess 16. As shown in Fig. 1 As further shown schematically, the receiving recess 16 encloses the longitudinal axis L1 or the guide bore 15. For example, the receiving recess 16 can be formed in a ring or frame shape around the guide bore 16.

[0037] As in Fig. 1 As further shown, the housing 1 has an inlet opening 11, an outlet opening 12, and a control opening 13. The inlet opening 11 serves for connection to a high-pressure reservoir. For example, the inlet opening 11 can be connected to the outlet opening 211 of the tank 210. As shown in Fig. 1 As shown by way of example, the base part 1A of the housing 1 can have several recesses extending in the radial direction R1 between the outlet chamber 10A and an outer surface as inlet openings 11. Generally, the inlet opening 11 is connected to the first chamber or the outlet chamber 10A. As shown in Fig. 1 Furthermore, it can be seen that a filter 17 can optionally be arranged in the inlet opening 11.

[0038] The outlet opening 12 can in particular be arranged coaxially to the longitudinal axis L1 and extend in the base part 1A between the outlet chamber 10A and the outer surface, as shown in Fig. 1 This is shown as an example. In general, the outlet opening 12 is connected to the outlet chamber 10A.

[0039] The control opening 13 can be arranged in relation to the longitudinal axis L1, in particular opposite the outlet opening 12, as shown in Fig. 1 This is shown as an example. Tax opening 13 is connected to tax chamber 10B. As shown in Fig. 1 As shown, the control opening 13 can, for example, be arranged coaxially to the longitudinal axis L1 and extend in the base part 1A between the control chamber 10B and the outside.

[0040] As in Fig. 1 As shown purely by way of example and schematically, the outlet opening 11 and the control opening 13 can be fluidically connected to each other by the optional control line 6, wherein the control line 6 runs outside the interior 10 or is fluidically separated or insulated from the interior 10 of the housing 1. The control line 61 can, for example, have a connection 61 for connection to the supply line 302. For example, the connection 61 of the control line 61 can form the low-pressure connection 261 of the gas tank device 200, as shown in Fig. 4 is shown schematically. Alternatively, the housing 1 can have a first connection connected to the outlet opening 11 (in Fig. 1 (not shown) and a second connection connected to the control opening 13 (in Fig. 1 (not shown) have, wherein the first and second connections can each be connected to the supply line 302. In this case, the first and second connections together form the low-pressure connection 261 of the gas tank device 200. In general, the control opening 13 and the outlet opening 12 can each be connected to the same pressure level, in particular to the same supply line.

[0041] Coil 2 has a multitude of windings made of an electrical conductor and is in Fig. 1 merely symbolically represented. As in Fig. 1 As shown, the coil 2 can, for example, be received in the receiving recess 16 of the separating web 14. A magnetically insulating layer 2A can, in particular, be arranged between the bottom of the receiving recess 16 and the coil 2. Likewise, the receiving recess 16 can be closed at its end facing the control chamber 10B by a magnetically insulating layer 2B, as shown in Fig. 1 This is shown as an example. The coil 2 is generally received in the separating web 14 and surrounds the guide bore 15.

[0042] The servo valve needle 3 is located in the control chamber 10B. As in Fig. 1 As shown by way of example, the servo valve needle 3 can have a shaft 30, a connecting channel 33, and a sealing section 34. Furthermore, the servo valve needle 3 can optionally have a flat armature 35. The shaft 30 extends between a first end region 31 and a second end region 32 opposite it. The sealing section 34 is formed in the first end region 31 of the shaft 30 and can, in particular, form a first end of the shaft 30. For example, the sealing section 34 can be conical, as shown in Fig. 1 The connecting channel 33 can, for example, be formed by a transverse bore extending across the shaft 30 and an axial bore extending between a second end and the transverse bore, as shown in Fig. 1 is shown schematically. Alternatively, it would also be conceivable to realize the connecting channel by means of a bore extending obliquely between a circumferential surface of the shaft 30 and the second end of the shaft 30. The optional flat anchor 35 is arranged in the second end region of the shaft 30 and connected to it. As in Fig. 1 In schematic representation, the flat anchor 35 extends transversely to the shaft 30 and projects from it. The flat anchor 35 can, for example, be designed as a web running around the shaft 30, as shown in Fig. 1 is shown schematically. At least the flat armature 35, and preferably also the shaft 30, is made of a magnetizable material.

[0043] As in Fig. 1 In schematic representation, the servo valve needle 3 is arranged and aligned in the control chamber 10B such that the shaft 30 extends along the longitudinal axis L1 and the flat armature 35 extends along the radial direction R1, wherein the shaft 30 can in particular be arranged or aligned coaxially with the longitudinal axis L1. The first end region 31 with the sealing section 31 faces the control opening 13, and the second end region 32 with the flat armature 35 faces the separating web 14.

[0044] As in Fig. 1 As further shown schematically, the spring 5 pre-tensions the servo valve needle 3 into a closed position in which the servo valve needle 3 seals the control opening 13. In particular, in the closed position of the servo valve needle 3, the sealing section 34 can bear against a servo valve seat 13S defined by the control opening 13, and the flat armature 35 can be arranged at a distance from the separating web 14, as shown in Fig. 1 The sealing seat 13S can be formed, in particular, by a region of the housing 1 surrounding the control opening 13. A gap is formed between the flat armature 35 and the separating web 14 in the closed position of the servo valve needle 3, as shown in Fig. 1 The servo valve needle 3 is shown schematically. The servo valve needle 3 is generally pre-tensioned along the longitudinal axis L1 into a closed position, in which the servo valve needle 3 seals the control opening 13.

[0045] By applying an electrical voltage to coil 2, which induces a current flow through coil 2, a magnetic field, in particular a primary magnetic field M1, can be generated around coil 2, which exerts an attractive force on the control valve needle 30. This moves the servo valve needle 3 towards the separating web 14 against the preload force exerted by spring 5, thereby lifting the sealing section 34 from the sealing seat 13S. In general, the servo valve needle 3 can thus be moved into an open position along the longitudinal axis L1 by means of a magnetic field generated by coil 2. The open position of the servo valve needle 3 is shown schematically in Fig. 2 depicted. As shown in Fig. 2 As shown schematically, the sealing section 34 is arranged at a distance from the servo valve seat 13S in the open position of the servo valve needle 3, and the flat armature 35 rests against the separating web 14. In general, the servo valve needle 3 thus releases the control orifice 13 in the open position and rests against the separating web 14. As shown in Fig. 2 As shown schematically, the guide bore 15 in the open position of the servo valve needle 3 is fluidically connected to the guide bore 15 via the connecting channel 33.

[0046] The main valve needle 4 is located in the exhaust chamber 10A. As shown in Fig. 1 In schematic representation, the main valve needle 40 can have a shaft, a sealing section 43, and an optional flat anchor 44. The shaft 40 of the main valve needle 4 extends between a first end region 41 and a second end region 42 opposite it. The sealing section 43 is formed in the second end region 42 of the shaft 40 and can, in particular, form a second end of the shaft 40. For example, the sealing section 43 can be conical, as shown in Fig. 1 The optional flat anchor 44 is shown schematically. It is arranged adjacent to the first end region 41 of the shaft 40 and is connected to the shaft 40. As shown in Fig. 1 In schematic representation, the flat armature 44 extends transversely to the shaft 40 and projects from it. At least the flat armature 44, and preferably also the shaft 40 of the main valve needle 4, is made of a magnetizable material.

[0047] As in Fig. 1 In schematic representation, the main valve needle 4 is arranged in the exhaust chamber 10A such that the first end section 41 of the shaft projects into and is guided through the guide bore 15, and the second end section 42, with the sealing section 43, faces the exhaust opening 12. In particular, the shaft 40 of the main valve needle 4 can be aligned coaxially with the longitudinal axis L1. The flat anchor 44, which can, for example, be designed as a web circumferential around the shaft 40, thus projects from the shaft 40 in the radial direction R1.

[0048] Fig. 1 The main valve needle 4 is shown in a closed position, in which it seals the outlet opening 12. As in Fig. 1 As shown schematically, the main valve needle 4 is biased into the closed position by the spring 5. Optionally, one and the same spring 5, which can be arranged in the guide bore 15, can be used as in Fig. 1 As shown by way of example, the main valve needle 4 and the servo valve needle 3 are each pre-tensioned into their closed position. However, it is also conceivable that separate springs are provided for the main valve needle 4 and the servo valve needle 3. These can also be arranged outside the guide bore 15. As shown in Fig. 1 In a schematic representation, the sealing section 43 rests against a main valve seat 12S defined by the outlet opening 12 in the closed position of the main valve needle 4, and the flat armature 44 is arranged at a distance from the separating web 14, so that a gap is formed between the separating web 14 and the flat armature 44. The main valve seat 12S can, for example, be formed by a region surrounding the outlet opening 12. The stem 40 of the main valve needle has a first cross-sectional area A41 in the first end region 41. A second cross-sectional area A12 is defined by a surface that delimits the main valve seat 12S.

[0049] As in Fig. 1 In schematic terms, the first cross-sectional area A12 is larger than a second cross-sectional area A12.

[0050] When the servo valve needle 3 is in its open position, as is the case in Fig. 2 As shown schematically, the control chamber 10B is fluidically connected to the pressure level of the port 61 via the control port 13, which typically leads to a pressure drop in the control chamber 10B. Generally, pressure equalization occurs between the control chamber 10B and the port 61, which is why pressure equalization also occurs between the control port 13 and the outlet port 12. A pressure drop relative to the outlet chamber 10A also occurs in the guide bore 15 via the connecting channel 33, which is why the main valve needle 4 is subjected to a tensile force that acts opposite to the preload force generated by the spring 5. Depending on the pressure difference between the guide bore 15 and the outlet chamber 10A, this tensile force may be sufficient to lift the sealing section 43 of the main valve needle 40 from the main valve seat 12S. This is particularly facilitated if the second surface A12 is smaller than the first surface A41.Since coil 2 continues to be energized when the servo valve needle 3 is in the open position, a secondary magnetic field M2 is formed, which is in . Fig. 2 The diagram is shown purely schematically. The secondary magnetic field M2 also exerts a tensile force on the main valve needle 4, acting against the spring force, so that it moves into the position shown in the diagram. Fig. 3 The indicated opening position is moved. As in Fig. 3 As shown, the optional flat anchor 44 rests against the separating web 14 in the open position of the main valve needle 4, thus advantageously forming a stop. The sealing section 43 of the main valve needle 4 is arranged at a distance from the main valve seat 12S in its open position. In general, the main valve needle 4 thus exposes the outlet opening 11 in its open position.

[0051] The main valve needle 4 can thus be moved into the open position by means of the magnetic field generated by the coil 2 when the servo valve needle 3 is in its open position. The pressure drop in the control chamber 10B resulting from the opening of the servo valve needle 3 advantageously reduces the force required for this movement, allowing for a compact design of the coil 2. However, the shut-off valve 100 can also be designed such that the main valve needle 4 can open even without a pressure difference between the control chamber 10B and the outlet chamber 10A. Since the servo valve needle 3 rests against the separating web 14 in its closed position, a state of magnetic saturation can occur in the optional residual web 16A, provided it is sufficiently thin. This generates a high magnetic attraction force in the gap between the flat armature 44 of the main valve needle 4 and the separating web 14.This generally makes it easier to open the main valve needle 4, not only in situations where there is no pressure difference between control chamber 10B and exhaust chamber 10A.

[0052] Due to the compact design of the 100 shut-off valve, it can be used in the Fig. 4 The gas tank device 200, shown schematically, can optionally be accommodated in the outlet opening 211 of the high-pressure gas tank 210. Generally, the inlet opening 11 of the shut-off valve 100 is connected to the outlet opening 211 of the tank 210. The outlet opening 12 and the control opening 13 of the housing 1 of the shut-off valve 100 are each connected to the fuel supply line 302, e.g., via the connection 61.

[0053] Although the present invention has been explained above by way of example, it is not limited to such embodiments but can be modified in many ways. In particular, combinations of the aforementioned embodiments are also conceivable. Furthermore, the invention is not limited to application in a fuel cell system. For example, the gas tank device can also be used in conjunction with other systems in which gas, in particular hydrogen, is used as a fuel or reaction product. By way of purely exemplary illustration, a vehicle that uses gaseous fuel to operate an internal combustion engine may be mentioned.

Claims

1. Shut-off valve (100) for a gas-tank device (200), having a housing (1) with an inlet opening (11) for connection to a high-pressure tank (210), having an outlet opening (12) for connection to a supply line (302), and having a control opening (13) for connection to the supply line (302), wherein the housing (1) defines an interior space (10) extending along a longitudinal axis (L1) and has a separating web (14) which subdivides the interior space (10), in relation to the longitudinal axis (L1), into an outlet chamber (10A) and a control chamber (10B), wherein the separating web (14) has a guide bore (15) which extends between the outlet chamber (10A) and the control chamber (10B), characterized in that the shut-off valve (100) has an electric coil (2) which is accommodated in the separating web (14) and which surrounds the guide bore (15), wherein the shut-off valve (100) has a servo-valve needle (3) which is arranged in the control chamber (10B) and which is preloaded into a closed position along the longitudinal axis (L1), in which closed position the servovalve needle (3) seals off the control opening (13), and which is movable into an open position by means of a magnetic field able to be generated by the coil (2), in which open position the servo-valve needle (3) opens up the control opening (13) and abuts against the separating web (14), wherein the servo-valve needle (3) has a connecting channel (33) which connects the control chamber (10B) to the guide bore (15) in the open position of the servo-valve needle (3), and wherein the shut-off valve (100) has a main-valve needle (4) which is guided movably along the longitudinal axis (L1) in the guide bore (15) and which is preloaded into a closed position along the longitudinal axis (L1), in which closed position the main-valve needle (4) seals off the outlet opening (12), and which, when the servo-valve needle (3) is arranged in its open position, is movable into an open position by means of the magnetic field able to be generated by the coil (2), in which open position the main-valve needle (4) opens up the outlet opening (12).

2. Shut-off valve (100) according to Claim 1, wherein the separating web (14) has an accommodating recess (16) which surrounds the guide bore (15) and which extends from the control chamber (10B) along the longitudinal axis (L1) as a blind hole, and wherein the coil (2) is arranged in the accommodating recess (16).

3. Shut-off valve (100) according to Claim 1 or 2, wherein the main-valve needle (4) has a shank (40), which is guided in the guide bore (15) in a first end region (41), and a sealing portion (43), which is formed in a second end region (42) of the shank (40) and, in the closed position of the main-valve needle (4), abuts against a main-valve seat (12S) defined by the outlet opening (12).

4. Shut-off valve (100) according to Claim 3, wherein the shank (40) of the main-valve needle has in the first end region (41) a first cross-sectional area (A41) that is larger than a second cross-sectional area (A12) of the main-valve seat (12S).

5. Shut-off valve (100) according to Claim 3 or 4, wherein the main-valve needle (4) has a flat armature (44) which projects from the shank (40) and which, in the closed position of the main-valve needle (4), is arranged spaced from the separating web (14) and which, in the open position of the main-valve needle (4), abuts against the separating web (14).

6. Shut-off valve (100) according to one of the preceding claims, wherein the servo-valve needle (3) has a shank (30), a sealing portion (34), which is formed on a first end region (31) of the shank (30), and a flat armature (35), which is connected to a second end region (32) of the shank (30) and which projects from the shank (30), wherein, in the closed position of the servovalve needle (3), the sealing portion (34) abuts against a servo-valve seat (13S) defined by the control opening (13) and the flat armature (35) is arranged spaced apart from the separating web (14), and wherein, in the open position of the servo-valve needle (3), the sealing portion (34) is arranged spaced apart from the servo-valve seat (13S) and the flat armature (35) abuts against the separating web (14).

7. Shut-off valve (100) according to one of the preceding claims, wherein the servo-valve needle (3) and the main-valve needle (4) are preloaded into the respective closed position by a common spring (5) which is arranged in the guide bore (15).

8. Shut-off valve (100) according to one of the preceding claims, additionally having: a control line (6) which fluidically connects the outlet opening (12) and the control opening (13) to one another outside the interior space (10) and has a connection (61) for connection to the supply line (302).

9. Shut-off valve (100) according to one of Claims 1 to 7, wherein the housing (1) has a first connection, connected to the outlet opening (11), for connection to the supply line (302) and has a second connection, connected to the control opening (13), for connection to the supply line (302).

10. Gas-tank device (200), in particular for a fuel-cell system (300), having a high-pressure gas tank (210) for holding gas, and a shut-off valve (100) according to one of the preceding claims, characterized in that the inlet opening (11) of the housing (1) of the shut-off valve (100) is connected to an outlet opening (211) of the high-pressure gas tank (210).

11. Gas-tank device (200) according to Claim 10, wherein the housing (1) of the shut-off valve (100) is accommodated in the outlet opening (211) of the high-pressure gas tank (210).

12. Fuel-cell system (300) having a fuel-cell arrangement (310), which has at least one fuel cell and one fuel inlet (311) for feeding of gaseous fuel and one oxidation-gas inlet (313) for feeding of oxidation gas and one product outlet (314) for discharge of reaction products, and a fuel-feeding line (302) connected to the fuel inlet (311), and a gas-tank device (200) according to Claim 10 or 11, characterized in that the outlet opening (12) and the control opening (13) of the housing (1) of the shut-off valve (100) are each connected to the fuel-feeding line (302).