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

Description

Technical area

[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 device for a gas tank device. State of the art

[0002] Fuel cell systems typically comprise a fuel cell arrangement, e.g. in the form of a stack with a large number of fuel cells connected electrically in series, to which gaseous fuel, e.g. 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 typically under high pressure, which can be up to 700 bar or more, for example. The tank thus forms a high-pressure reservoir. The fuel is normally supplied to the fuel cell arrangement at a lower pressure, e.g. at a pressure in the range between 2 bar and 20 bar. The fuel supply line can be connected to the tank, for example, by a pressure regulating device in which the pressure of the fuel is reduced.The line between the tank and the pressure control device is typically designed as a high-pressure line and is referred to below as the supply line, as it supplies the fuel cell system with fuel. The tank is typically equipped with a shut-off valve to prevent fuel from escaping from the tank, e.g., when the fuel cell assembly is shut down or in the event of a failure.

[0003] Shut-off valves for high-pressure gas tanks are typically designed as normally closed solenoid valves. Typically, a valve needle is spring-loaded against a sealing seat and can be lifted from the sealing seat by a magnetic force generated by a coil, counteracting the spring's preload. Due to the high pressure in the tank, high opening forces may be required, depending on the valve design. This requires powerful coils and complicates valve miniaturization.

[0004] DE 10 2006 027 712 A1 discloses a shut-off 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, which valve stem carries spaced-apart first and second sealing elements on its outer circumference. In a closed position of the valve, the sealing elements are biased against the valve seats by a spring in order to seal an inlet from an outlet formed between the valve seats in the housing. The valve stem has a first opening, which forms a fluid connection between the inlet and a high-pressure side of the first sealing element. As a result, a closing force is exerted on the first sealing element as a result of the pressure applied at the inlet. Furthermore, the valve stem has a through-bore, which connects a secondary chamber located on a low-pressure side of the second sealing element to the inlet.This exerts an opening force on the second sealing element that opposes the closing force acting on the first sealing element. The goal of this design is to reduce the force acting on the valve stem or sealing elements due to the pressure difference, thereby reducing the opening force generated by the electric coil to open the valve.

[0005] JP 2016 156485 A discloses a valve device comprising: a housing having a primary passage, a secondary passage and a valve element space between the primary passage and the secondary passage, wherein the primary passage and the secondary passage form a main passage.

[0006] CN 113 137 570 shows a vehicle-mounted ultra-high-pressure hydrogen storage cylinder combination valve comprising a valve body.

[0007] DE 10 2018 221 600 A1 discloses a method for operating a tank device for storing compressed fluids with a tank, a valve device, a supply line, a flow element arranged in the supply line and a control unit.

[0008] DE 10 2018 215 380 A1 shows a valve device for a gaseous medium, in particular hydrogen, with a valve housing and a first magnet armature arranged therein which is movable along a longitudinal axis. Disclosure of the invention

[0009] According to the invention, a shut-off device for a gas tank device having the features of claim 1, a gas tank device having the features of claim 8 and a fuel cell system having the features of claim 10 are provided.

[0010] According to a first aspect of the invention, a shut-off device for a gas tank device comprises a first connection for connection to a high-pressure tank, a second connection for connection to a supply line, a main valve chamber which has a first opening fluidically connected to the first connection, a second opening fluidically connected to the second connection, and a first control opening, a main valve designed as a switchable solenoid valve with a main valve needle arranged in the main valve chamber, which main valve needle can be moved between a closed position in which it rests against a main valve seat surrounding the second opening in order to seal the second opening from the first opening, and an open position in which it is lifted off the main valve seat.The main valve needle divides the main valve chamber into an outlet chamber, into which the first and second openings open, and a control chamber, into which the first control opening opens and which is fluidically connected to the outlet chamber.

[0011] The shut-off device further comprises a servo valve chamber which is spatially separated from the main valve chamber and which has a second control opening which is fluidically connected to the first control opening and a servo opening which is fluidically connected to the second connection, and a servo valve designed as a switchable solenoid valve with a servo valve needle arranged in the servo valve chamber, which servo valve needle can be moved between a closed position in which it rests against a servo valve seat surrounding the servo opening in order to seal the servo opening from the second control opening, and an open position in which it is lifted off the servo valve seat.

[0012] According to a second aspect of the invention, a gas tank device, in particular for a fuel cell system, is provided. The gas tank device according to the invention comprises a high-pressure gas tank for accommodating gas, such as hydrogen, and a shut-off device according to the first aspect of the invention, wherein the first connection of the shut-off device is connected to an outlet opening of the high-pressure gas tank.

[0013] According to a third aspect of the invention, a fuel cell system comprises a fuel cell arrangement having at least one fuel cell, a fuel inlet for supplying gaseous fuel, an oxidizing gas inlet for supplying oxidizing gas and a product outlet for discharging 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 second connection of the shut-off device is connected to the fuel supply line.

[0014] One idea underlying the invention is to create a shut-off device in which a main valve and a servo valve are each arranged spatially separate from one another. In particular, a main valve needle is arranged in a first chamber or main valve chamber and is movable between an open and a closed position by means of a first coil, while a servo valve needle is arranged in a second chamber or servo valve chamber, which is spatially separated from the main valve chamber and fluidically connected to it, and is movable between an open and a closed position by means of a separate, second coil.The main valve needle is slidably guided in the first chamber and divides it into a control chamber, which is fluidically connected to the second chamber, and an outlet chamber, which has a first opening connected to a high-pressure connection or first connection and a second opening connected to a supply connection or second connection, which is covered or closed by the main valve needle in its closed position. The second chamber is also fluidically connected to the supply connection via a servo opening, which is covered or closed by the servo valve needle in its closed position.

[0015] One advantage of the invention is that the servo valve and main valve, or rather their valve needles, are housed in spatially separate chambers and can be moved by their own coils. This facilitates a space-optimized arrangement of the servo valve and main valve. By opening the servo valve, a fluidic connection can be established between the second connection or the supply connection, which is provided for connection to a low-pressure reservoir such as the fuel supply line, and the control chamber of the main valve chamber with relatively little opening force. Since the control chamber is fluidically connected via the outlet chamber to the first connection or the high-pressure connection, which is provided for connection to a high-pressure reservoir such as the gas tank, pressure equalization takes place between the second connection and the control chamber.This reduces the pressure in the control chamber while simultaneously increasing the pressure in the second port. This creates a force in the closed position of the main valve needle that is directed away from the main valve seat, thus assisting the main valve spool in lifting the main valve needle from the main valve seat. This allows the main valve spool to be smaller, further facilitating miniaturization of the shut-off device.

[0016] Advantageous embodiments and further developments emerge from the further subclaims and from the description with reference to the figures of the drawing.

[0017] According to some embodiments, the main valve chamber and the servo valve chamber can be formed in a common housing. Due to the spatially separate arrangement of the main and servo valve chambers in the housing, the valve needles can be oriented in any desired manner relative to one another, which further facilitates a space-optimized arrangement or design.

[0018] According to some embodiments, it may be provided that the first control opening and the second control opening are connected by a connecting bore.

[0019] According to some embodiments, the fluidic connection between the outlet chamber and the control chamber of the main valve chamber can be dimensioned such that, when the servo valve is open and the main valve is closed, it acts as a throttle for fluid flow from the outlet chamber into the control chamber. This slows down the pressure equalization between the outlet chamber and the control chamber, thereby further increasing the opening force acting on the main valve needle.

[0020] According to some embodiments, it can be provided that the outlet chamber and the control chamber of the main valve chamber are fluidically connected to one another through a bore in the main valve needle. According to alternative embodiments, it can be provided that the outlet chamber and the control chamber of the main valve chamber are fluidically connected to one another through a gap formed between an outer circumference of the main valve needle and a wall surrounding the main valve chamber. The width of the gap can be defined, for example, by the fit provided between the wall and the main valve needle, e.g., a clearance fit. However, the gap can also be formed only locally, e.g., by forming a groove in the wall and / or the outer circumference of the valve needle. This creates connecting lines between the control chamber and the outlet chamber that are structurally simple and inexpensive to produce.

[0021] According to some embodiments, it can be provided that the main valve is designed as a normally closed solenoid valve and has a spring which biases the main valve needle into the closed position.

[0022] According to some embodiments, it can be provided that the servo valve is designed as a normally closed solenoid valve and has a spring which preloads the servo valve needle into the closed position.

[0023] According to some embodiments, it can be provided that the shut-off device is accommodated in the outlet opening of the high-pressure gas tank.

[0024] The invention is explained below with reference to the figures of the drawings. The figures show: Fig. 1 is a schematic representation of a hydraulic circuit diagram of a fuel cell system according to an embodiment of the invention; and Fig. 2 is a schematic sectional view of a shut-off device according to an embodiment of the invention.

[0025] In the figures, the same reference symbols denote identical or functionally identical components, unless otherwise stated.

[0026] In Fig. 1 A fuel cell system 300 is shown schematically and by way of example. As shown in Fig. 1 Shown schematically, the fuel cell system 300 includes a fuel cell assembly 310, a fuel supply line 302, an optional pressure control device 320, and a gas tank device 200.

[0027] The fuel cell assembly 310 is in Fig. 1 shown only as a block and has at least one fuel cell (not shown), a fuel inlet 311, an oxidizing gas inlet 313 and a product outlet 314. The fuel cell arrangement can, for example, have a large number 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 arranged between the anode and cathode, e.g. in the form of a membrane. Gaseous fuel, e.g. hydrogen, can be supplied to the anodes of the fuel cell(s) via the fuel inlet 311. In the same way, oxidizing gas, e.g. oxygen-containing ambient air, can be supplied to the cathodes of the fuel cell(s) via the oxidizing gas inlet 213. The reaction products can be removed from the cathode via the product outlet 314.The at least one fuel cell is thus designed to convert the chemical energy stored in the fuel together with oxidizing gas directly into electrical energy.

[0028] The gas tank device 200 comprises a high-pressure gas tank 210 and a shut-off device 100. The high-pressure gas tank 210, hereinafter referred to simply as tank for reasons of clarity, is designed to accommodate

[0029] of gas, such as hydrogen, and can store gas at a pressure of up to 700 bar. As in Fig. 1 schematically shown, the tank 210 can be designed, for example, as a substantially cylindrical tank. An outlet opening 211 of the tank 210 can be arranged, for example, at an axial end of the tank 210. The shut-off device 100 is in Fig. 1 shown only symbolically and will be explained in more detail below. As in Fig. 1 As shown schematically, the shut-off device 100 is connected to the outlet opening 211 of the tank 210 and a low-pressure connection 261 of the gas tank device 200. Optionally, a check valve 220 can be connected in parallel to the shut-off device 100, as shown in Fig. 1 shown by way of example. 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 control 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 out of the tank 210 and / or to vary the flow rate. For example, the pressure control device 320 can comprise a flow-controllable throttle valve.

[0030] Fig. 2 shows schematically and by way of example a shut-off device 100 as used in the gas tank device 200 in Fig. 1 can be installed. As in Fig. 2 schematically shown, the shut-off device 100 has 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.

[0031] As in Fig. 2 As shown, 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 delimited, for example, by walls 20, 40. As in Fig. 2 purely schematically shown, the main valve chamber 2 and the servo valve chamber 4 can be formed in a common housing 1.

[0032] The first connection 11 is provided for connection to the high-pressure tank 210 and can be designed, for example, as an opening or as a connection piece on the housing 1. The second connection 12 is provided for connection to the supply line or the fuel supply line 302 and can also be designed as an opening or as a connection piece on the housing 1.

[0033] The main valve chamber 2 has a first opening 21, a second opening 22 and a first control opening 23. As in Fig. 2 As shown by way of example, the first and second openings 21, 22 can each be formed in a first end region of the main valve chamber 2. For example, the first opening 21 can be formed on a peripheral wall and the second opening 22 in a first end wall extending transversely to the peripheral wall, as shown in Fig. 2 is shown as an example. The first control opening 23 can be formed in particular in a second end region of the main valve chamber 2, e.g. in a second end wall opposite the first end wall, as in Fig. 2 shown.

[0034] The first opening 21 is fluidically connected to the first connection 11, e.g. via a bore or line 14. The second opening 22 is fluidically connected to the second connection 12, e.g. via a bore or line 15, as shown in Fig. 2 is shown as an example.

[0035] As in Fig. 2 As further shown, the servo valve chamber 4 has a second control opening 41 and a servo opening 42. The servo opening 42 can be formed, for example, in an end wall of the servo valve chamber 4, and the second control opening 41 can be formed, for example, in a peripheral wall 40 extending transversely to the end wall, as shown in Fig. 2 is shown as an example.

[0036] The first control opening 23 of the main valve chamber 2 and the second control opening of the servo valve chamber 4 are fluidically connected to each other, e.g. via a bore or line 13, as shown in Fig. 2 is shown schematically. The servo opening 42 is fluidically connected to the second connection 12, e.g., via a bore or line 16.

[0037] The main valve 3 is designed as a normally closed solenoid valve 3 and has 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 displaceably on its outer circumference 30a by the wall 20, in particular the peripheral wall. As shown in Fig. 2 As shown schematically, the main valve needle 30 may, for example, have a columnar or cylindrical main section 35 and a guide section 36 which projects radially from the main section 35 at a first axial end. A second axial

[0038] The end of the main section 35 has a sealing surface 35a, which can be conical, for example. The guide section 36 can, for example, have a cylindrical outer peripheral surface, which is guided along the wall 20.

[0039] As in Fig. 2 schematically shown, 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 can form a partition wall, as in Fig. 2 shown schematically. The first and second openings 21, 22 each open into the outlet chamber 2A. The first control opening 23 opens into the control chamber 2B. The control chamber 2B and the outlet chamber 2A are fluidically connected, e.g., by a bore 33 formed in the main valve needle 30, in particular the guide section 36, or by a gap 34 formed between the outer circumference 30a of the main valve needle 30, in particular the outer circumference of the guide section 36, and the wall 20.

[0040] The gap 34 is in Fig. 2 Enlarged for clarity. For example, the width of the gap 34 may be determined by the fit between the valve needle 30 and the bore diameter defined by the peripheral wall 20.

[0041] The main valve needle 30 is movable between a closed position and an open position by means of the coil 32, which is arranged enclosing the main valve needle 30, e.g., outside the main valve chamber 2. The spring 31 biases the main valve needle 30 into the closed position and can be arranged, e.g., in the control chamber 2B, as shown in Fig. 2 is shown schematically. Fig. 2 shows the closed position of the main valve needle 30. In the closed position, the main valve needle 30, in particular its sealing surface 35a, rests against a main valve seat surrounding the second opening 22 in order to seal the second opening 22 from the first opening 21. In the open position, the main valve needle 30, in particular its sealing surface 35a, 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.

[0042] The servo valve 5 is also designed as a normally closed solenoid valve and has a servo valve needle 50, a spring 51 and a coil 352. The servo valve needle 50 is arranged in the servo valve chamber 4 and is axially

[0043] As in Fig. 2 Schematically illustrated, the servo valve needle 50 can, for example, have a columnar or cylindrical main section 55 and a guide section 56, which protrudes radially from the main section 55 at a first axial end thereof. A second axial end of the main section 55 has a sealing surface 55a, which can, for example, be conical in shape. The guide section 56 can, for example, have a cylindrical outer peripheral surface, which is guided on the wall 40.

[0044] The servo valve needle 50 is movable between a closed position and an open position by means of the coil 52, which is arranged enclosing the servo valve needle 50, e.g., outside the servo valve chamber 4. The spring 51 biases the servo valve needle 50 into the closed position and can be arranged, e.g., inside the servo valve chamber 4, as shown in Fig. 2 is shown schematically. Fig. 2 shows the closed position of the servo valve needle 50.

[0045] In the closed position, the servo valve needle 50, in particular its sealing surface 55a, rests against a servo valve seat surrounding the servo opening 42 in order to seal the servo opening 42 from the second control opening 41. In the open position, the servo valve needle 50, in particular its sealing surface 55a, 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.

[0046] In the Fig. 2 In the situation shown, in which both the main valve 3 and the servo valve 5 are closed, the pressure present at the first connection 11 is present in the outlet chamber 2A, the control chamber 2B, and the servo valve chamber 4. The main valve needle 3 has a first cross-sectional area A35 in a first end region facing the control chamber 2B. A second cross-sectional area A22 is defined by an area bounded by the main valve seat. As shown in Fig. 2 As shown schematically, the first cross-sectional area A35 is larger than the second cross-sectional area A22. If the pressure at the first port 11 is greater than the pressure at the second port 12, in addition to the force applied by the spring 31 to the main valve needle 30, a pressure force also acts, urging the main valve needle 30 into its closed position.

[0047] To open the main valve 3, the servo valve 5 is first opened, i.e., 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 thus fluidly connected to the pressure level of the second port 12 via the first and second control openings 23, 42 and the servo opening 42, which typically leads to a pressure reduction in the control chamber 2B. Generally, pressure equalization occurs between the control chamber 2B and the second port 12, which is why pressure equalization also occurs between the first control opening 23 and the second opening 22. Thus, the pressure force acting as a result of the different cross-sectional areas A35, A22 is increasingly reduced as a result of the pressure equalization. This reduces the magnetic force generated by energizing the coil 32 to move the main valve needle 35 into the open position.The fluidically conductive connection between the outlet chamber 2A and the control chamber 2B of the main valve chamber 2, that is to say, for example, the gap 34 or the bore 33, can in particular be dimensioned such that, when the servo valve 5 is open and the main valve 3 is closed, it acts as.

[0048] Throttle for fluid flow from the outlet chamber 2A into the control chamber 2B. This further reduces the magnetic force generated by energizing the coil 32 to move the main valve needle 35 into the open position.

[0049] The spatially separate arrangement of the main valve chamber 2 and the servo valve chamber 4 allows for the main and servo valves 3 and 5 to be accommodated in a space-optimized manner. In particular, the main valve needle 30 and the servo valve needle 50 can extend relative to each other in any desired manner, which significantly increases the flexibility of the arrangement.

[0050] Although the present invention has been explained above using exemplary embodiments, it is not limited thereto, but can be modified in a variety of ways without deviating from the scope of the claims. In particular, combinations of the above exemplary embodiments are also conceivable. For example, the shut-off device 100 was described in connection with a gas tank device 200 for a fuel cell system 300, but is not limited thereto. In principle, the shut-off device 100 can be used in any gas line system.

Claims

1. Shut-off device (100) for a gas tank apparatus (200), comprising a first connector (11) for connection to a high-pressure tank (210) and a second connector (12) for connection to a supply line (302), a main valve chamber (2), which has a first opening (21) connected to the first connector (11) in a fluidically conductive manner, a second opening (22) connected to the second connector (12) in a fluidically conductive manner, and a first control opening (23), and a main valve (3), which is designed as a switchable solenoid valve and has a main valve needle (30) arranged in the main valve chamber (2), which can be moved between a closed position, in which it bears against a main valve seat surrounding the second opening (22) in order to seal the second opening (22) with respect to the first opening (21), and an open position, in which it is lifted from the main valve seat, wherein the main valve needle (30) divides the main valve chamber (2) into an outlet chamber (2A), into which the first and the second opening (21, 22) open, and a control chamber (2B), into which the first control opening (23) opens and which is connected to the outlet chamber (2A) in a fluidically conductive manner, wherein the shut-off device (100) has a servo valve chamber (4) spatially separated from the main valve chamber (2), which comprises a second control opening (41) connected to the first control opening (23) in a fluidically conductive manner and a servo opening (42) connected to the second connector (12) in a fluidically conductive manner, characterized in that the shut-off device (100) has a servo valve (5), which is designed as a switchable solenoid valve, having a servo valve needle (50) arranged in the servo valve chamber (5), which can be moved between a closed position, in which it bears against a servo valve seat surrounding the servo opening (42) in order to seal the servo opening (42) with respect to the second control opening (41), and an open position, in which it is lifted from the servo valve seat.

2. Shut-off device (100) according to Claim 1, wherein the main valve chamber (2) and the servo valve chamber (4) are formed in a common housing (1).

3. Shut-off device (100) according to Claim 2, wherein the first control opening (23) and the second control opening (41) are connected by a connecting bore (13).

4. Shut-off device (100) according to one of the preceding claims, wherein the fluidically conductive connection between the outlet chamber (2A) and the control chamber (2B) of the main valve chamber (2) is dimensioned such that it acts as a restrictor for a fluid flow from the outlet chamber (2A) into the control chamber (2B) with the servo valve (5) open and the main valve (3) closed.

5. Shut-off device (100) according to one of the preceding claims, wherein the outlet chamber (2A) and the control chamber (2B) of the main valve chamber (2) are connected to each other in a fluidically conductive manner by a hole (33) in the main valve needle (30) or by a gap (34), which is formed between an outer circumference (30a) of the main valve needle (30) and a wall (20) surrounding the main valve chamber (2).

6. Shut-off device (100) according to one of the preceding claims, wherein the main valve (3) is formed as a normally closed solenoid valve and has a spring (31) which preloads the main valve needle (30) into the closed position.

7. Shut-off device (100) according to one of the preceding claims, wherein the servo valve (5) is formed as a normally closed solenoid valve and has a spring (51) which preloads the servo valve needle (50) into the closed position.

8. Gas tank apparatus (200), in particular for a fuel cell system (300), having: a high-pressure gas tank (210) for holding gas; and a shut-off device (100) according to one of the preceding claims; wherein the first connector (11) of the shut-off device (100) is connected to an outlet opening (211) of the high-pressure gas tank (210).

9. Gas tank apparatus (200) according to Claim 8, wherein the shut-off device (100) is accommodated in the outlet opening (211) of the high-pressure gas tank (210).

10. Fuel cell system (300), having: a fuel cell assembly (310) comprising at least one fuel cell, a fuel inlet (311) for supplying gaseous fuel, an oxidation gas inlet (313) for supplying oxidation gas, and a product outlet (314) for discharging reaction products; a fuel supply line (302) connected to the fuel inlet (311); and a gas tank apparatus (200) according to Claim 8 or 9; wherein the second connector (12) of the shut-off device (100) is connected to the fuel supply line (302).