Shut-off valve for a hydrogen tank system, compressed gas container, and hydrogen tank system

Abstract

The invention relates to a shut-off valve (1) for a hydrogen tank system with at least one compressed gas container (2), comprising a main valve (3) and a control valve (4) for controlling the main valve (3), the main valve (3) having a reciprocable valve piston (6) cooperating with a valve seat (5), the valve piston (6) defining at its end (7) opposite the valve seat (5) a control chamber (8), the control chamber (8) being connected via an inlet throttle (9) to a storage volume (10) of the compressed gas container (2) and being connectable via an outlet throttle (11) to a gas outlet (12) depending on a switching position of the control valve (4), the main valve (3) having a solenoid coil (13) capable of generating an opening and / or holding force acting on the valve piston (6). The invention further relates to a compressed gas container comprising the shut-off valve (1) according to the invention, as well as a hydrogen tank system comprising at least one compressed gas container (2) and the shut-off valve (1) according to the invention.

Description

Technical Field

[0001] The present invention relates to a shut-off valve for a hydrogen tank system having at least one compressed gas container. The present invention further relates to a compressed gas container for a hydrogen tank system provided with the shut-off valve according to the present invention, and a hydrogen tank system provided with at least one compressed gas container and the shut-off valve according to the present invention.

[0002] Background Art Portable hydrogen tank systems for motor vehicles for reacting hydrogen in a fuel cell or in a hydrogen internal combustion engine are known. In the event of a pipeline break or an accident, the hydrogen tank must be closed by a shut-off valve in order to prevent uncontrolled hydrogen leakage. For this reason, the shut-off valve must be designed as a valve that automatically closes in the de-energized state in accordance with current guidelines.

[0003] The automatic closing function is usually realized by a spring that acts directly or indirectly in the closing direction on the reciprocating valve piston of the shut-off valve.

[0004] The opening function is usually realized indirectly via an electromagnetically operable control valve. By opening the control valve, the control pressure acting on the valve piston of the main valve and applying a closing force to this valve piston can be reduced. Therefore, as the pressure reduction progresses, the main valve can be opened. Since the pressure reduction can be realized by the relatively small seat diameter of the control valve, the force required to open the control valve is relatively small. At the same time, by increasing the seat diameter of the main valve, a large volume flow rate can be obtained. This is advantageous in a hydrogen tank system. However, when the leakage amount of the control valve is supplied to the valve outlet of the main valve, in the fully open state, equal pressure occurs everywhere, and there is a risk that the shut-off valve will drop based on the automatic closing function. Thereafter, as the load decreases, the pressure decreases again and the shut-off valve is opened. This continuous opening and closing of the shut-off valve causes an increase in wear in the seat area in the case of a general plastic or elastomer seat in the hydrogen region.

[0005] Starting from the above-described prior art, the problem underlying the present invention is to improve the shut-off valve for a hydrogen tank system, and in particular to enable the incorporation of a shut-off valve into the neck of a compressed gas container formed as a compressed gas cylinder, and to provide a shut-off valve having a controlled opening behavior and requiring as little structural space as possible at the same time.

[0006] To solve this problem, a shut-off valve having the features of claim 1 is provided. Advantageous refinements of the present invention can be known from the dependent claims. Furthermore, a compressed gas container equipped with the shut-off valve according to the present invention, as well as a hydrogen tank system comprising at least one compressed gas container and the shut-off valve according to the present invention, are proposed.

[0007] Disclosure of the Invention The proposed shut-off valve comprises a main valve and a control valve for controlling the main valve. The main valve has a reciprocable valve piston that cooperates with a valve seat. This valve piston defines a control chamber at the end opposite to the valve seat. This control chamber is connected to the storage volume of the compressed gas container via an inlet throttle and can be connected to a gas outlet via an outlet throttle according to the switching position of the control valve. The main valve further has a solenoid coil capable of generating an opening force and / or a holding force acting on the valve piston.

[0008] The opening force and / or the holding force acting on the valve piston of the main valve can eliminate the disadvantages of the indirect control described at the beginning. In particular, it is possible to prevent the main valve from dropping when equal pressure occurs anywhere in the fully open state. Therefore, the solenoid coil acting on the valve piston can temporarily disable the automatic closing function of the shut-off valve.

[0009] The holding force of the solenoid coil is only required when the throttle of the main valve is almost eliminated, so a relatively small holding force is sufficient. Furthermore, as a result of the upward movement of the valve piston, a minimum gap is generated, making it possible to use a small solenoid coil. The small structural size of the solenoid coil enables the desired miniaturization of the shut-off valve.

[0010] When the pressure is completely equalized between the gas outlet of the shut-off valve and the storage pressure in the compressed gas container, decompression and thus pneumatic opening in the control chamber are also impossible. Therefore, advantageously, the magnetic force in the main valve is set to be large enough to magnetically open the main valve against the closing force of the spring, thereby obtaining the defined open position of the main valve during the entire operation. Depending on the design objective, a combination of pneumatic opening and magnetic opening of the main valve can also be advantageously realized.

[0011] According to a preferred embodiment of the present invention, the solenoid coil is formed in an annular shape and is arranged coaxially with the valve piston of the main valve. Therefore, the solenoid coil can generate a magnetic field in which the magnetic force acts uniformly on the valve piston.

[0012] More preferably, the solenoid coil is located on the side of the control chamber opposite to the valve piston. That is, the solenoid coil is arranged with an axial interval with respect to the valve piston. Due to the upward movement of the valve piston, this interval and thus the gap between the solenoid coil and the valve piston are reduced. Therefore, the gap is minimized during the maximum upward movement, and only a small force is required to hold the valve piston in this position.

[0013] Advantageously, the solenoid coil is incorporated within the valve housing which defines a control chamber and forms an outflow throttle. Thereby, the solenoid coil can be arranged sealed relative to the control chamber. Further, the space surrounding the outflow throttle can be utilized for accommodating the solenoid coil. Thus, preferably, the outflow throttle passes through the solenoid coil. In this way, an assembly which is particularly compact is provided.

[0014] To reliably close the main valve, it is proposed that a spring force of a spring be applied to the valve piston of the main valve in the direction of the valve seat. For this purpose, preferably, the spring is supported on the one hand by the valve piston and on the other hand by a sealing sleeve which surrounds the end of the valve piston on the control chamber side for defining the control chamber. Thus, preferably, the control chamber is defined in the axial direction by the valve piston on the one hand and the valve housing accommodating the solenoid coil on the other hand, and in the radial direction by the sealing sleeve. Thus, the main valve can be configured relatively simply. By means of the sealing sleeve, moreover, compensation for errors due to manufacturing and / or assembly, in particular axial offset errors, is easily possible.

[0015] The inflow throttle connecting the control chamber to the storage volume of the compressed gas container compensates for the increase in volume of the control chamber caused by the closing movement of the valve piston and thus causes reliable closing behavior of the main valve. To reduce the number of components, the inflow throttle may be formed by a guide gap guiding the valve piston of the main valve. To reduce the accuracy requirements imposed on the guide, a sealing element may be arranged in the region of the guide. In this case, the inflow throttle may be formed separately by a fluid guide connection path, in particular a throttle hole.

[0016] The control valve is preferably electromagnetically operable and has an annular solenoid coil acting on a solenoid armature that is connected to or forms the valve element of the control valve. When the solenoid armature and the valve element are separate members and are merely connected, different materials can be used to form both members. Thus, the optimal material can be selected according to the respective function each time. When the solenoid armature simultaneously forms the valve element, the number of members can be reduced, and thus the configuration of the control valve can be simplified.

[0017] Also, the valve piston of the main valve may be formed by or connected to the solenoid armature, whereby the valve piston is acted upon by a solenoid coil corresponding to the valve piston.

[0018] To close the control valve, the control valve preferably comprises a closing spring, whereby the closing is effected by the spring force. For this purpose, preferably, the closing spring is axially supported on the solenoid armature of the control valve. More preferably, due to the spring force of the closing spring, an axial preload is applied to the solenoid armature and optionally the valve element connected to the solenoid armature in the direction of the sealing seat formed by the valve housing defining the control chamber. Thus, an axially compact assembly can be provided.

[0019] Advantageously, the main valve and the control valve are arranged coaxially and separated from each other by an axial gap, and a disc-shaped object made of preferably a non-magnetic material is accommodated in this axial gap. This object is used to magnetically separate the magnetic circuit of the control valve from the solenoid coil accommodated in the valve housing for generating a holding force acting on the valve piston.

[0020] Furthermore, a compressed gas container for a hydrogen tank system equipped with the shut-off valve according to the present invention is proposed. Since the required structural space of this shut-off valve is small, the shut-off valve can be easily incorporated into the compressed gas container. Preferably, the shut-off valve is arranged in the region of the container outlet of the compressed gas container. By doing so, in the case of a pipeline break or an accident, the compressed gas container can be closed by the shut-off valve, so that the gas does not flow out without control. The region of the container outlet may particularly have the form of a cylinder neck. The container outlet shaped in such a way is particularly stable and, thus, particularly suitable as a location for incorporating the shut-off valve.

[0021] By incorporating the shut-off valve according to the present invention into the compressed gas container, on the one hand, the safety requirements are met. This is because this shut-off valve is automatically closed. On the other hand, a large hydrogen volume flow rate through the valve seat of the main valve becomes possible. This is because this main valve is indirectly controlled, specifically by an electromagnetically operable control valve. By providing another solenoid coil, it is further possible to generate a holding force that particularly prevents the shut-off valve from dropping inconveniently, especially in the fully open state. Since only a small holding force is required, a solenoid coil with a small structural size can be used. This assists in miniaturizing the structure of the shut-off valve.

[0022] Furthermore, a hydrogen tank system is proposed that includes at least one compressed gas container and the shut-off valve according to the present invention for shutting off the compressed gas container. Advantageously, the hydrogen tank system includes a plurality of identical compressed gas containers, and each of these compressed gas containers is equipped with the shut-off valve according to the present invention. Therefore, these compressed gas containers can be shut off independently of each other and replaced as required.

[0023] Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings.

Brief Description of the Drawings

[0024]

Figure 1

[0025] Detailed description of the drawings The shut-off valve 1 for the compressed gas container 2 shown in the drawing has a main valve 3 and a control valve 4. The control valve 4 is electromagnetically operable.

[0026] The main valve 3 has a reciprocating valve piston 6, and this valve piston 6 cooperates with a valve seat 5. An end portion 7 of the valve piston 6 on the side opposite to the valve seat 5 is accommodated in a sealing sleeve 16, and this sealing sleeve 16 defines a control chamber 8 together with the valve piston 6 and a valve housing 14. An axial preload is applied to the sealing sleeve 16 with respect to the valve housing 14 by the spring force of a spring 15. At the same time, the spring force of the spring 15 presses the valve piston 6 against the valve seat 5.

[0027] In order to open the main valve 3, first the control valve 4 must be opened. For this purpose, a magnetic field is formed by energizing the solenoid coil 17, and the magnetic force of this magnetic field acts on the reciprocable solenoid armature 18 connected to the valve element 19 of the control valve 4. Accordingly, the control valve 4 is opened by the movement of the solenoid armature 18. When the control valve 4 is opened, gas flows out from the control chamber 8 through the outflow throttle 11 formed in the valve housing 14, so the pressure in the control chamber 8 decreases, and depending on the ratio of the forces applied to the valve piston 6, the main valve 3 can be opened. Next, the gas flows out from the storage volume 10 of the compressed gas container 2 through the valve seat 5 at the gas outlet 12. Since the bypass amount of the control valve 4 is also introduced into the gas outlet 12, when the shut-off valve 1 is fully open, an equal pressure is generated everywhere. This means that the pressure in the control chamber 8 also rises again. In order to prevent the shut-off valve 1 from dropping inconveniently, another solenoid coil 13 capable of generating a holding force acting on the valve piston 6 is incorporated in the valve housing 14. The solenoid coil 13 has a small configuration size. This is because a large force is not required to keep the main valve 3 in the open state. This is especially because when the throttle of the main valve 3 is completely eliminated, the gap between the solenoid coil 13 and the valve piston 6 is extremely small.

[0028] In order to close the shut-off valve 1, the energization of the solenoid coil 17 of the control valve 4 is terminated. As a result, the closing spring 20 returns the solenoid armature 18 and the valve element 19 to their respective starting positions, closing the control valve 4. When the control valve 4 is closed, gas can no longer flow out from the control chamber 8 through the outflow throttle 11, and the gas can only flow into the control chamber 8 through the inflow throttle 9 connecting the control chamber 8 to the storage volume 10 of the compressed gas container 2, so the pressure in the control chamber 8 rises again. This pressure applies a closing force to the valve piston 6 of the main valve 3, and this closing force, together with the spring force of the spring 15, causes the main valve 3 to close.

[0029] In order to separate the solenoid coil 13 corresponding to the valve piston 6 of the main valve 3 from the magnetic circuit of the control valve 4, an axial gap 21 is provided between the control valve 4 and the valve housing 14, and a disk-shaped object 22 made of a non-magnetic material is disposed within this axial gap 21.

[0030] The shut-off valve 1 shown in the drawing is simply configured and requires almost no configuration space, so that the shut-off valve 1 can be incorporated into the compressed gas container 2 in the region of the container outlet 23.

Claims

1. A shut-off valve (1) for a hydrogen tank system comprising at least one compressed gas container (2), the shut-off valve (1) comprising a main valve (3) and a control valve (4) for controlling the main valve (3), wherein the main valve (3) has a reciprocable valve piston (6) cooperating with a valve seat (5), the valve piston (6) defining a control chamber (8) at an end (7) opposite to the valve seat (5), the control chamber (8) being connected to a storage volume (10) of the compressed gas container (2) via an inlet throttle (9) and being connectable to a gas outlet (12) via an outlet throttle (11) depending on the switching position of the control valve (4), and the main valve (3) having a solenoid coil (13) capable of generating an opening force and / or a holding force acting on the valve piston (6). The solenoid coil (13) is located on a side of the control chamber (8) opposite to the valve piston (6), the shut-off valve (1).

2. A shut-off valve (1) for a hydrogen tank system comprising at least one compressed gas container (2), the shut-off valve (1) comprising a main valve (3) and a control valve (4) for controlling the main valve (3), wherein the main valve (3) has a reciprocable valve piston (6) cooperating with a valve seat (5), the valve piston (6) defining a control chamber (8) at an end (7) opposite to the valve seat (5), the control chamber (8) being connected to a storage volume (10) of the compressed gas container (2) via an inlet throttle (9) and being connectable to a gas outlet (12) via an outlet throttle (11) depending on the switching position of the control valve (4), and the main valve (3) having a solenoid coil (13) capable of generating an opening force and / or a holding force acting on the valve piston (6). The solenoid coil (13) is incorporated in a valve housing (14), the valve housing (14) defining the control chamber (8) and preferably forming the outlet throttle (11) passing through the solenoid coil (13), the shut-off valve (1).

3. A shut-off valve (1) for a hydrogen tank system comprising at least one compressed gas container (2), comprising a main valve (3) and a control valve (4) for controlling the main valve (3), wherein the main valve (3) has a reciprocable valve piston (6) cooperating with a valve seat (5), the valve piston (6) defining a control chamber (8) at an end (7) opposite to the valve seat (5), the control chamber (8) being connected to the storage volume (10) of the compressed gas container (2) via an inlet throttle (9) and being connectable to a gas outlet (12) via an outlet throttle (11) according to the switching position of the control valve (4), and the main valve (3) having a solenoid coil (13) capable of generating an opening force and / or a holding force acting on the valve piston (6). A spring force of a spring (15) is applied to the valve piston (6) of the main valve (3) in the direction of the valve seat (5), the spring (15) being preferably supported on the valve piston (6) on one hand and on a sealing sleeve (16) on the other hand, the sealing sleeve (16) surrounding the end (7) of the valve piston (6) for defining the control chamber (8), characterized in that it is a shut-off valve (1).

4. A shut-off valve (1) for a hydrogen tank system comprising at least one compressed gas container (2), comprising a main valve (3) and a control valve (4) for controlling the main valve (3), wherein the main valve (3) has a reciprocable valve piston (6) cooperating with a valve seat (5), the valve piston (6) defining a control chamber (8) at an end (7) opposite to the valve seat (5), the control chamber (8) being connected to the storage volume (10) of the compressed gas container (2) via an inlet throttle (9) and being connectable to a gas outlet (12) via an outlet throttle (11) according to the switching position of the control valve (4), and the main valve (3) having a solenoid coil (13) capable of generating an opening force and / or a holding force acting on the valve piston (6). The main valve (3) and the control valve (4) are arranged coaxially and separated from each other by an axial gap (21), and a disk-shaped object (22) made of preferably a non-magnetic material is accommodated in the axial gap (21), characterized in that it is a shut-off valve (1).

5. The shut-off valve (1) according to any one of claims 1 to 4, wherein the solenoid coil (13) is formed in a ring shape and is arranged coaxially with the valve piston (6).

6. The shut-off valve (1) according to any one of claims 1 to 4, wherein the control valve (4) is electromagnetically operable and has an annular solenoid coil (17) that acts on a solenoid armature (18) connected to or forming the valve element (19) of the control valve (4).

7. The shut-off valve (1) according to claim 6, wherein the control valve (4) preferably includes a closing spring (20) supported axially on the solenoid armature (18).

8. A compressed gas container (2) for a hydrogen tank system, comprising the shut-off valve (1) according to any one of claims 1 to 4, wherein preferably the shut-off valve (1) is arranged in the region of the container outlet (23).

9. A hydrogen tank system comprising at least one compressed gas container (2) and the shut-off valve (1) according to any one of claims 1 to 4 for shutting off the compressed gas container (2).

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