Shut-off valve and control method for controlling hydrogen flow from a pressure tank

Description

State of the art

[0001] Hydrogen is often used as a fuel to power fuel cells and internal combustion engines. Because hydrogen is highly explosive, it must be safely stored in a pressurized tank. Check valves are used to control the flow of hydrogen from a pressurized tank. A prior art check valve is shown in document US2018 / 038507 A. Disclosure of the invention

[0002] Within the scope of the invention presented, a shut-off valve, a control method, a pressure tank, and a vehicle are presented with the features of the respective independent patent claims. Further features and details of the invention emerge from the respective subclaims, the description, and the drawings. Features and details described in connection with the shut-off valve according to the invention naturally also apply in connection with the control method according to the invention, the pressure tank according to the invention, and the vehicle according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0003] The invention presented is particularly intended to enable robust and reliable control of a hydrogen flow from a pressure tank.

[0004] Thus, in a first aspect of the invention, a shut-off valve for controlling the flow of hydrogen from a compressed gas container into a system-side chamber is presented. The shut-off valve comprises a main valve, such as a nozzle needle, a servo valve, a coil, and a tension spring.

[0005] The coil is configured to move the servo valve from a first servo valve position to a second servo valve position when the coil is energized with electrical current.

[0006] In the first servo valve position, the servo valve closes a control channel in the main valve between a control chamber of the shut-off valve and the system-side chamber in a gas-tight manner.

[0007] In the second servo valve position, the servo valve releases the control channel in the main valve and is retracted into a control chamber above the servo valve.

[0008] The tension spring mechanically couples the servo valve to the main valve and provides a tensile force on the main valve to move the main valve from a first main valve position to a second main valve position when the servo valve moves to the second servo valve position.

[0009] In the first main valve position, the main valve closes a main channel that connects the compressed gas container with the system-side space in a gas-tight manner and opens the main channel in the second main valve position.

[0010] In the context of the invention presented, a shut-off valve is understood to be a shut-off valve for shutting off and releasing a fluidic path.

[0011] In the context of the invention presented, a tension spring is understood to be a spring element, such as a mechanical spring or an elastic element, which, in the deflected state, provides a tensile force in order to move into an undeflected position or a rest position.

[0012] In the context of the invention presented, a compressed gas container is understood to be a space in which hydrogen is stored at high pressure, in particular at a pressure of up to 1100 bar.

[0013] In the context of the invention presented, a system-side space is understood to mean a space that is arranged downstream of the shut-off valve and can usually assume pressures between atmospheric pressure and storage pressure in the compressed gas container.

[0014] The presented invention is based on two movable valves, namely a servo valve that adjusts a hydrogen flow or gas flow and, thereby, a pressure curve in the shut-off valve, and a main valve that adjusts a hydrogen flow out of the shut-off valve or through the shut-off valve.

[0015] According to the invention, the servo valve and the main valve cooperate to enable a robust and reliable movement of the main valve between a first main valve position, for example a blocking position, and a second main valve position, for example a release position.

[0016] The presented check valve connects a compressed gas container, usually a pressure tank, to a system-side space via a main channel, which can usually supply a fuel cell system or an internal combustion engine with fuel, in particular hydrogen, via a fluidic connection. In order to adjust a pressure level, for example in the fuel cell system or an internal combustion engine, these are usually indirectly connected to the system-side space via pressure reducers. The main valve of the check valve is movably arranged in the main channel, so that the main valve prevents or blocks the flow of hydrogen or gas from the compressed gas container into the system-side space when the main valve is in the first main valve position and, for example, projects into the main channel or closes the main channel gas-tight.In the second main valve position, the main valve releases a flow of hydrogen from the compressed gas container into the system-side space, which occurs, for example, via a position spaced apart from the main channel.

[0017] In order to enable the main valve to move from the first main valve position to the second main valve position, the proposed check valve combines a pneumatic pressure force generated by a pressure difference within the check valve with a mechanical force provided by the tension spring provided according to the invention.

[0018] The pneumatic pressure force in the shut-off valve presented here is provided by a control chamber principle. This means that a control chamber is used to regulate a back pressure that counteracts a high pressure acting on the main valve from the compressed gas container. Accordingly, no moving force acts on the main valve if the same high pressure is present in the control chamber as that acting on the main valve from the compressed gas container. This means that a moving force acts on the main valve if the pressure in the control chamber is lower than the high pressure acting on the main valve from the compressed gas container, so that the high pressure moves the main valve due to a pressure difference between the compressed gas container and the control chamber, or a pressure force acts on the main valve.

[0019] To control a pressure difference between the compressed gas container and the control chamber, the proposed shut-off valve comprises a servo valve. The servo valve is movable between a first servo valve position, in which the servo valve seals a control channel in the main channel in a gas-tight manner, and a second servo valve position, in which the servo valve opens the control channel.

[0020] In a basic position in which the shut-off valve prevents hydrogen from flowing out of the compressed gas container, the high pressure in the compressed gas container acts on the servo valve and presses the servo valve into or onto the control channel so that the control channel is sealed gas-tight.

[0021] To allow hydrogen to flow out of the compressed gas container, the shut-off valve coil is energized, i.e., supplied with electricity, creating a magnetic force that pulls the servo valve into the second servo valve position. Due to the applied high pressure, the servo valve is initially raised only slightly or moved into an auxiliary servo valve position in which hydrogen can flow through the control channel, allowing hydrogen to flow from the control chamber into the system-side chamber, and reducing the pressure in the control chamber. Due to the reduced pressure, the magnetic force can pull the servo valve into the second servo valve position.

[0022] When the servo valve is moved to the second servo valve position, a receiving space below the servo valve or between the servo valve and the main valve is released, into which the main valve can move when a pressure in the receiving space is minimized by hydrogen flowing into the system-side space via the control channel.

[0023] To support the movement of the main valve from the first main valve position to the second main valve position or into the receiving chamber, or to enable this movement even with a small pressure difference and correspondingly quickly, the tension spring provided according to the invention provides a tensile force to the main valve when the servo valve moves to the second servo valve position. Accordingly, the tensile force acts together or additively with a pneumatic pressure force acting on the main valve through the compressed gas container.

[0024] To close or shut off the shut-off valve, the current supply to the coil is interrupted so that a pressure force provided by a compression spring pushes the servo valve into the first servo valve position, the servo valve closes the control channel gas-tight and a high pressure is built up in the control chamber, which pushes the servo valve onto the main valve and the main valve into the main channel or into the first main valve position.

[0025] It can be provided that the control chamber is arranged above the servo valve and the servo valve comprises an additional control channel which connects the control chamber to the control channel in the main valve, so that the servo valve moves into the control chamber when moving into the second servo valve position.

[0026] A control chamber located above the servo valve allows the pressure acting on the servo valve to be adjusted and the movement of the servo valve to be controlled accordingly. A control chamber, in which a pressure lower than that of a compressed gas container can be adjusted, allows the servo valve to be moved reliably and quickly using additive forces, namely a magnetic force provided by the coil and a pneumatic pressure force provided by a pressure difference. For this purpose, an additional control channel allows hydrogen to flow from the control chamber through the servo valve and through the control channel into the system-side chamber.

[0027] It can further be provided that the shut-off valve comprises a receiving space for receiving the main valve in the second main valve position, wherein the receiving space is arranged between the servo valve and the main valve and fluidically connects the additional control channel to the control channel.

[0028] In an advantageous embodiment, a throttle point is present in the additional control channel, which is configured to dampen or slow down the opening movement of the servo valve and thus prevent bouncing at the stroke stop.

[0029] It can further be provided that a movement of the servo valve into the second servo valve position causes a release of the receiving space for receiving the main valve in the second main valve position.

[0030] A receiving chamber for receiving the main valve in the second main valve position, which is blocked by the servo valve in the first servo valve position, ensures a successive movement of the servo valve first from the first servo valve position to the second servo valve position and a subsequent movement of the main valve from the first main valve position to the second main valve position.

[0031] It can be provided that the main valve has a stroke limitation on the housing side, such that the main valve stroke is smaller than the servo valve stroke and when the servo valve (103) and the main valve are fully open, the servo valve seat remains open and pressure equalization can take place between the control channel, the receiving chamber, the additional control channel and the control chamber.

[0032] It can be provided that the pneumatic separation of the control chamber from the compressed gas container takes place via guides between the servo valve and the housing or the main valve and the servo valve.

[0033] In a further advantageous embodiment, the pneumatic separation can alternatively be achieved by conventional sealing elements such as O-rings, sealing lips or membranes in or on the guides, which enables a strong pressure reduction in the control chamber and thus also a particularly large opening force on the servo valve and main valve. In order to ensure reliable closing in this case during the closing process after the magnetic force has been switched off, an alternative pneumatic throttling connection must be provided between the control chamber and the compressed gas container. In contrast to a guide, however, this can be achieved in a particularly simple way in terms of production, for example via a radial throttle bore between the additional control bore and the high-pressure area at the level of the tension spring or, for example, radially in the main valve between the receiving chamber and the high-pressure area. However, a throttle bore can also be provided in the housing between the high-pressure area and the control chamber.

[0034] It may further be provided that the check valve comprises a compression spring configured to press the servo valve into the first servo valve position and the main valve into the first main valve position when the coil is de-energized.

[0035] A compression spring enables safe and reliable shut-off of the shut-off valve even in the event of a fault in the electrical supply to the shut-off valve.

[0036] It can further be provided that the servo valve comprises a first coupling element for mechanically coupling to a first counter-coupling element of the tension spring, and the main valve comprises a second coupling element for mechanically coupling to a second counter-coupling element of the tension spring.

[0037] By means of coupling elements and counter-coupling elements, such as hooks and eyes, a secure connection of the servo valve, the tension spring and the main valve can be achieved, so that a force flow from the servo valve to the main valve is ensured when the servo valve moves from the first servo valve position to the second servo valve position.

[0038] In a second aspect, the presented invention relates to a control method for controlling a hydrogen flow from a pressure tank by means of a check valve, wherein the check valve comprises a main valve, a servo valve, a coil and a tension spring.The control method comprises an opening step for opening the shut-off valve, in which the coil is energized with electrical current to move the servo valve from a first servo valve position to a second servo valve position, so that the servo valve opens a control channel in the main valve between a control chamber of the shut-off valve and a system-side chamber, and hydrogen located in the control chamber flows into the system-side chamber, wherein the tension spring mechanically couples the servo valve to the main valve and a tensile force is provided to the main valve, which moves the main valve from a first main valve position to a second main valve position and a main channel connecting a compressed gas container to the system-side chamber is opened.Furthermore, the control method comprises a shut-off step for shutting off the shut-off valve, in which the coil is de-energized so that a compression spring moves the servo valve from the second servo valve position to the first servo valve position, and the servo valve closes the control channel in the main valve in a gas-tight manner, and the main valve closes the main channel in a gas-tight manner.

[0039] The presented control method is used in particular to operate the presented shut-off valve.

[0040] In a third aspect, the presented invention relates to a pressure tank system with a possible embodiment of the presented check valve.

[0041] In a fourth aspect, the presented invention relates to a vehicle with a possible embodiment of the presented pressure tank system.

[0042] Further advantages, features and details of the invention will become apparent from the following description, in which embodiments of the invention are described in detail with reference to the drawings.

[0043] They show: Figures 1a to 1f a sequence of a possible embodiment of the presented control method with a possible embodiment of the presented check valve, Figure 2 a possible design of the presented vehicle with a possible design of the presented pressure tank system.

[0044] In Figure 1a A check valve 100 is shown. The check valve 100 comprises a main valve 101, a servo valve 103, a coil 105, and a tension spring 107.

[0045] In Figure 1athe shut-off valve 100 is shown in a shut-off state in which an outflow of hydrogen from a compressed gas container 109 into a system-side space 111 is prevented or blocked by the main valve 101.

[0046] In an opening step 201 for opening the shut-off valve 100, the coil 105 is energized so that a magnetic force is provided which moves the servo valve 103 against a spring force of a compression spring 113 into a deflected position or into a servo valve auxiliary position, as shown in Figure 1b in which a control channel 115 in the main valve 101 is released.

[0047] By releasing the control channel 115, hydrogen or gas flows from a control chamber 117 via an additional control channel 119 and the control channel 115 into the system-side chamber 111, as shown in Figure 1cThe control channel 115 and the additional control channel 119 each act as a throttle. Accordingly, the pressure in the control chamber 117 decreases, so that the magnetic force provided by the coil 105 moves the servo valve 103 to the Figure 1d shown second servo valve position.

[0048] Furthermore, it can be provided that the main valve 101 can also be opened via purely electromagnetic forces, which are transmitted from the servo valve to the main valve via the spring, for example in the case of the same or similar pressure levels in the high-pressure area 109 and in the system-side area 111, i.e. an operating state in which no or only slight supporting pneumatic opening forces are present on the main valve due to the control chamber principle.

[0049] The servo valve 103 is mechanically coupled to the main valve 101 via the tension spring 107, so that the tension spring 107 is deflected when the servo valve 103 moves from the first servo valve position to the second servo valve position and a tensile force provided by the tension spring 107 is gradually transmitted to the main valve 101 in order to move the main valve 101 from the Figure 1c shown first main valve position to the one shown in Figure 1d to move to the second main valve position shown.

[0050] In Figure 1dThe servo valve 103 is shown in the second servo valve position, in which the servo valve 103 is fully deflected and retracted into the control chamber 117. Accordingly, a maximum tensile force on the main valve 101 acts through the tension spring 107 together with a compressive force applied to the main valve 101 due to a pressure difference between a receiving chamber 121 and the compressed gas container 109 in order to move the main valve 101 into the second main valve position, as in Figure 1e shown.

[0051] As soon as the main valve 101 is in the second main valve position, a main channel 123 for connecting the compressed gas container 109 to the system-side space 111 is opened, so that hydrogen or gas can flow from the compressed gas container 109 into the system-side space 111.

[0052] To shut off the main channel 123 in a shut-off step 203, the coil 105 is actuated as shown in Figure 1fshown, de-energized, so that the compression spring 113 executes a closing movement of the servo valve 103 from the second servo valve position towards the main valve. As soon as the servo valve touches the main valve, the control channel 115 is closed and a mechanical force is exerted on the main valve via the servo valve seat. In addition, the pressure in the control chamber rises again due to the filling via the throttle gap. The combination of the compression spring 113, which mechanically exerts a closing force on the main valve via the servo valve seat, and the simultaneous filling of the control chamber leads to a joint closing movement of the assembly consisting of the servo and main valves.

[0053] In Figure 2 a vehicle 200 is shown. The vehicle 200 includes a pressure tank system with a shut-off valve 100 according to Figure 1 .

Claims

1. Shut-off valve (100) for controlling a flow of compressed gas from a compressed gas vessel (109) into a system-proximal chamber (111), wherein the shut-off valve (100) comprises: - a main valve (101), - a servo valve (103), - a coil (105), wherein the coil (105) is configured to move the servo valve (103) from a first servo valve position to a second servo valve position when the coil (105) is energized with electric current, wherein the servo valve (103) in the first servo valve position closes in a gas-tight manner a control duct (115) in the main valve (101) between a control chamber (117) of the shut-off valve (100) and the system-proximal chamber (109), and the servo valve (103) in the second servo valve position releases the control duct (115) in the main valve (101) and is retracted into the control chamber (117) above the servo valve (103), characterized by a tension spring (107), wherein the tension spring (107) mechanically couples the servo valve (103) to the main valve (101) and provides a tensile force at the main valve (101) to move the main valve (101) from a first main valve position to a second main valve position when the servo valve (103) moves to the second servo valve position, wherein main valve (101) in the first main valve position closes in a gas-tight manner a main duct (123) which connects the compressed gas vessel (109) to the system-proximal chamber (111), and the main valve (101) in the second main valve position releases the main duct (123).

2. Shut-off valve (100) according to Claim 1, characterized in that the control chamber (117) is disposed above the servo valve (103), and the servo valve (103) comprises an auxiliary control duct (119) which connects the control chamber (117) to the control duct (115) in the main valve (101) in such a way that the servo valve (103) moves into the control chamber (117) as it moves to the second servo valve position.

3. Shut-off valve (100) according to Claim 2, characterized in that the shut-off valve (100) comprises a receptacle chamber (121) for receiving the main valve (101) in the second main valve position, wherein the receptacle chamber (121) is disposed between the servo valve (103) and the main valve (101) and fluidically connects the auxiliary control duct (119) to the control duct (115).

4. Shut-off valve (100) according to one of the preceding claims, characterized in that there is a restrictor point in the auxiliary control duct (119).

5. Shut-off valve (100) according to Claim 3, characterized in that a movement of the servo valve (103) to the second servo valve position causes the receptacle chamber (121) to be released so as to receive the main valve (101) in the second main valve position.

6. Shut-off valve (100) according to one of the preceding claims, characterized in that the main valve (101) has a housing-proximal stroke delimitation which causes a main valve stroke to be smaller than a servo valve stroke and, with the servo valve (103) fully open and the main valve (101) fully open, the servo valve seat remains open and pressure equalization between the control duct (115), the receptacle chamber (121), the auxiliary control duct (119) and the control chamber (117) can take place.

7. Shut-off valve (100) according to one of the preceding claims, characterized in that a pneumatic separation of the control chamber and the compressed gas vessel is performed by way of guides on the servo valve or main valve.

8. Shut-off valve (100) according to Claim 7, characterized in that a pneumatic separation of the control chamber and the compressed gas vessel is performed in the guide regions of the servo valve or main valve by a sealing element such as an O-ring, sealing lip or membrane.

9. Shut-off valve (100) according to Claim 8, characterized in that there is a pneumatically restricting connection between the control chamber and the compressed gas vessel.

10. Shut-off valve (100) according to one of the preceding claims, characterized in that the shut-off valve (100) comprises a compression spring (13) configured to push the servo valve (103) to the first servo valve position and the main valve (101) to the first main valve position when the coil (105) is de-energized.

11. Shut-off valve (100) according to one of the preceding claims, characterized in that the servo valve (103) comprises a first coupling element for mechanically coupling to a first mating coupling element of the tension spring (107), and the main valve (101) comprises a second coupling element for mechanically coupling to a second mating coupling element of the tension spring (107).

12. Control method for controlling a flow of compressed gas from a pressurized tank (300) by means of a shut-off valve (100), wherein the shut-off valve (100) comprises: - a main valve (101), - a servo valve (103), - a coil (105), - a tension spring (107), wherein the control method comprises the following steps: - an opening step (201) for opening the shut-off valve (100), in which the coil (105) is energized with electric current to move the servo valve (103) from a first servo valve position to a second servo valve position, so that the servo valve (103) releases a control duct (115) in the main valve (101) between a control chamber (117) of the shut-off valve (100) and a system-proximal chamber (111), and a compressed gas located in the control chamber (117) flows into the system-proximal chamber (111), wherein the tension spring (107) mechanically couples the servo valve (103) to the main valve (101) and a tensile force is provided at the main valve (101), which moves the main valve (101) from a first main valve position to a second main valve position and a main duct (123) which connects a compressed gas vessel (109) to the system-proximal chamber (111) is released, - a shutting-off step (203) to shut off the shut-off valve (100), in which the coil (105) is de-energized so that a compression spring (113) moves the servo valve (103) from the second servo valve position to the first servo valve position, and the servo valve (103) closes in a gas-tight manner the control duct (115) in the main valve (101), and the main valve (101) closes in a gas-tight manner the main duct (123).

13. Pressurized tank system (300) having a shut-off valve (100) according to one of Claims 1 to 11.

14. Vehicle (200) having a pressurized tank system (300) according to Claim 13.