Valve assembly for a fuel gas tank, fuel gas tank comprising a valve assembly

Abstract

The invention relates to a valve assembly (1) for a fuel gas tank (2), comprising a base body (3) in which an extraction path (4) with an integrated shut-off valve (6) for extracting fuel gas from the fuel gas tank (2) and a refuelling path (5) with an integrated non-return valve (7) for refuelling the fuel gas tank (2) with fuel gas are formed, wherein the extraction path (4) and the refuelling path (5) are brought together within the base body (3) in a path (9) which opens into a common gas connection (8). According to the invention, at least two further gas flow paths (10, 11) are formed in the base body (3), each of which bypasses the shut-off valve (6) and connects an outflow-side section (4.2) of the extraction path (4) arranged downstream of the shut-off valve (6) in the extraction direction with an inflow-side section (4. 1) of the extraction path (4) and / or to a storage volume formed in the fuel gas tank (2), wherein the flow direction in the extraction path (4) is predetermined by a first non-return valve (12) arranged in the inflow-side section (4.1) and a second non-return valve (13) arranged in the outflow-side section (4.2) and the flow through the two further gas flow paths (10, 11) in the extraction direction is blocked by a respective non-return valve (14, 15). The invention further relates to a fuel gas tank (2) having the claimed valve assembly (1).

Description

[0001] Description

[0002] Valve assembly for a fuel gas tank, fuel gas tank with valve assembly

[0003] The invention relates to a valve assembly for a fuel gas tank. Furthermore, the invention relates to a fuel gas tank with a valve assembly according to the invention. The fuel gas can, in particular, be hydrogen or natural gas, which is stored under pressure in a fuel gas tank.

[0004] The preferred field of application of the invention is fuel cell and / or gas vehicles that are powered by a fuel gas.

[0005] State of the art

[0006] Mobile fuel gas tank systems are known, consisting of at least one fuel gas tank for storing fuel gas, such as hydrogen or natural gas. The fuel gas tank is typically designed as a high-pressure tank, particularly a high-pressure gas cylinder. A high-pressure tank always requires a shut-off valve to seal the tank tightly when the vehicle is not in use. For safety reasons, the shut-off valve is usually designed as a normally closed valve.

[0007] The shut-off valve is usually integrated into a valve assembly that enables both the withdrawal of fuel gas from the fuel gas tank and the refueling of the fuel gas tank with fuel gas. For this purpose, the valve assembly has a base body in which a withdrawal path and a refueling path are formed. A controllable shut-off valve is integrated into the withdrawal path and a check valve is integrated into the refueling path. The check valve prevents fuel gas from escaping from the fuel gas tank via the refueling path. A further check valve can be arranged in the withdrawal path so that the flow direction in both paths is determined via the check valves. DE 10 2016 008 443 A1 discloses, by way of example, a tank valve for mounting on a compressed gas container. The tank valve has a base body with a gas connection via which the compressed gas container can be refueled on the one hand and gas can be withdrawn from the compressed gas container on the other.Within the base body, the gas connection is divided into a refueling line and a withdrawal line, with a withdrawal valve located in the withdrawal line. A check valve connected in series with the withdrawal valve blocks the flow in the opposite direction to the intended direction when gas is withdrawn. The check valve thus prevents gas from flowing into the compressed gas cylinder via the withdrawal line during refueling. Another check valve is integrated into the refueling line, which opens in the refueling direction and closes in the withdrawal direction.

[0008] The present invention is concerned with the object of specifying a valve assembly for a fuel gas tank which, for example in the event of a blocked refueling path or a jammed check valve in the refueling path, allows emergency refueling of the fuel gas tank via the withdrawal path.

[0009] To achieve this objective, the valve assembly having the features of claim 1 is proposed. Advantageous further developments of the invention are set forth in the subclaims. Furthermore, a fuel gas tank having a valve assembly according to the invention is specified.

[0010] Disclosure of the invention

[0011] The valve assembly proposed for a fuel gas tank comprises a base body in which a withdrawal path with an integrated shut-off valve for withdrawing fuel gas from the fuel gas tank and a refueling path with an integrated check valve for refueling the fuel gas tank with fuel gas are formed, wherein the withdrawal path and the refueling path are combined within the base body in a path that opens into a common gas connection. According to the invention, at least two further gas flow paths are formed in the base body, each of which, bypassing the shut-off valve, connects a downstream section of the withdrawal path arranged downstream of the shut-off valve in the withdrawal direction with an inflow section of the withdrawal path arranged upstream of the shut-off valve and / or with a storage volume formed in the fuel gas tank.The flow direction in the extraction path is determined by a first check valve arranged in the upstream section and a second check valve arranged in the downstream section, and the flow through the two further gas flow paths in the extraction direction is blocked by a check valve each.

[0012] The two additional gas flow paths, together with the shut-off valve, form an emergency refueling path that can be used to refuel the fuel gas tank in the event of a malfunction in the main refueling path. To do this, simply open the shut-off valve. The refueling pressure then opens the check valves located in the two additional gas flow paths, allowing the fuel gas tank to be refueled via the two additional gas flow paths and the open shut-off valve. At the same time, the two check valves integrated into the withdrawal path ensure that flow can only pass through the shut-off valve in the forward direction and thus only when activated. This prevents the shut-off valve from opening accidentally during a normal refueling process.

[0013] Preferably, a first gas flow path branches off from the extraction path upstream of the check valve integrated into the downstream section of the extraction path and flows into the extraction path or directly into the storage volume of the fuel gas tank upstream of the check valve integrated into the upstream section of the extraction path. Pressure relief can thus be achieved via the first gas flow path, ensuring that the pressure on the downstream side of the shut-off valve is never greater than the pressure in the fuel gas tank. The first gas flow path can therefore be referred to as a pressure relief path. The shut-off valve can be bypassed via the pressure relief path in order to connect the downstream side with the upstream side or with the storage volume of the fuel gas tank.

[0014] Furthermore, a second gas flow path preferably branches off from the extraction path downstream of the check valve integrated into the downstream section of the extraction path and flows into the extraction path downstream of the check valve integrated into the upstream section of the extraction path—on the upstream side of the shut-off valve. Pressure equalization can be achieved via the second gas flow path, ensuring that the pressure on the upstream side of the shut-off valve is never lower than the pressure in the area of ​​the gas connection.

[0015] In a further development of the invention, it is proposed that two check valves that open in opposite directions be combined into a single component. This allows the valve assembly to be simplified and, at the same time, more compact.

[0016] For this purpose, the component can comprise two valve closing elements, between which a spring is arranged, preloading each valve closing element toward a valve seat. The component can be connected to the inflow side of the shut-off valve via the space between the two valve closing elements that accommodates the spring.

[0017] Alternatively, the component can have a one-piece valve closing element with a circumferential groove and longitudinal grooves that can move back and forth between two valve seats. The component can be connected to the inflow side of the shut-off valve via the circumferential groove. The longitudinal grooves connect the circumferential groove to the gas volumes at the valve seats. Depending on the pressure conditions outside the two valve seats, the valve element is moved purely pneumatically into either one or the other end position, so that one valve seat is open and the other closed. Both valve seats are never open or closed at the same time. The opening and closing of the check valves can therefore be achieved purely pneumatically. This means that a spring is dispensable.

[0018] The shut-off valve is preferably electrically controllable and / or designed as a normally closed valve. As an electrically controllable valve, the shut-off valve can be designed to be particularly compact and robust. In addition, the shut-off valve can be actively opened to withdraw fuel gas from the fuel gas tank or to carry out emergency refueling. In the design as a normally closed valve, it meets the safety requirements placed on a fuel gas tank. Furthermore, it is proposed that the common gas connection be designed as a connecting piece, preferably as a connecting piece with an external thread. The connecting piece facilitates the connection of an external gas line, via which fuel gas can be withdrawn from the fuel gas tank and fuel gas can be supplied to the fuel gas tank during refueling.If the connection piece has an external thread, the external gas line can be screwed onto the connection piece so that a high-pressure-resistant connection is created between the gas line and the valve assembly via the screw connection.

[0019] Furthermore, the base body preferably has a connecting section for connection to the fuel gas tank. The valve assembly can be easily mounted on a fuel gas tank via the connecting section. For example, the valve assembly can be inserted into the bottle neck of a fuel gas tank designed as a high-pressure gas cylinder via the connecting section. The connecting section can also have an external thread so that it can be screwed into the bottle neck to achieve a high-pressure-resistant connection via the screw connection.

[0020] The further proposed fuel gas tank is characterized by having a valve assembly according to the invention. The valve assembly is preferably inserted into the fuel gas tank in sections, so that the common gas connection is accessible from the outside. Since the extraction path and the refueling path are combined and lead as a single path into the common gas connection of the valve assembly, only one gas line needs to be connected for extracting fuel gas and for refueling the fuel gas tank with fuel gas.

[0021] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings. These show:

[0022] Fig. 1 is a schematic representation of a valve assembly according to the invention inserted into a fuel gas tank with arrows to show the gas flow directions during the removal of fuel gas from the fuel gas tank as well as during the regular refueling of the fuel gas tank with fuel gas, Fig. 2 is a schematic representation of a further valve assembly according to the invention inserted into a fuel gas tank with arrows to show the gas flow directions during the removal of fuel gas from the fuel gas tank as well as during the regular refueling of the fuel gas tank with fuel gas,

[0023] Fig. 3 is a schematic representation of the valve assembly of Figure 2 with an arrow to show the gas flow direction during emergency refuelling of the fuel gas tank via the actively opened shut-off valve,

[0024] Fig. 4 shows a longitudinal section through two check valves opening in opposite directions, which are combined to form a component with two valve closing elements, wherein a spring arranged between the two valve closing elements applies a closing force to both valve closing elements in the direction of a valve seat,

[0025] Fig. 5 shows a longitudinal section through two check valves opening in opposite directions, which are combined to form a component with a one-piece valve closing element,

[0026] Fig. 6 a cross section through the component of Figure 5 and

[0027] Fig. 7 shows a further longitudinal section through the component of Figure 5, but in a different switching position.

[0028] Detailed description of the drawings

[0029] The valve assembly 1 according to the invention shown in Figure 1 serves to remove fuel gas from a fuel gas tank 2 and to fill the fuel gas tank 2 with fuel gas, in particular with hydrogen or with natural gas.

[0030] The illustrated valve assembly 1 comprises a base body 3 with a connecting section 16, via which the valve assembly 1 is connected to the fuel gas tank 2. At the other end, the base body 3 forms a gas connection 8 for connecting an external gas line (not shown). To ensure that only one gas line needs to be connected, a withdrawal path 4 formed in the base body 3 and a refueling path 5 formed in the base body 3 are combined to form a path 9, which opens into the gas connection 8.

[0031] A shut-off valve 6 is integrated into the extraction path 4, which is electrically controllable and designed as a normally closed valve. A first check valve 12, which opens in the extraction direction, is arranged upstream of the shut-off valve 6 in the extraction direction (arrow 18), i.e., on the inflow side of the shut-off valve 6. A second check valve 13, which also opens in the extraction direction, is arranged downstream of the shut-off valve 6 in the extraction direction, i.e., on the outflow side of the shut-off valve 6. The extraction path 4 thus leads via an inflow-side first section 4.1, into which the check valve 12 is integrated, the shut-off valve 6, and a downflow-side second section 4.2, into which the check valve 13 is integrated. The downstream section 4.2 is connected to the upstream section 4.1 via two further gas flow paths 10, 11, bypassing the shut-off valve 6.In order to prevent fuel gas from escaping from the fuel gas tank 2 via the two further gas flow paths 10, 11, a check valve 14, 15 is arranged in each of these gas flow paths 10, 11 in such a way that it blocks in the withdrawal direction.

[0032] The first gas flow path 10 branches off in the extraction direction (arrow 18) upstream of the check valve 13 from the downstream section 4.2 of the extraction path 4 and flows upstream of the check valve 12 into the upstream section 4.1 of the extraction path 4. Via the first gas flow path 10, pressure relief in the direction of the fuel gas tank 2 (see arrow 27) can be ensured, which prevents the pressure p ou t on the downstream side of the shut-off valve 6 rises above the pressure pi in the fuel gas tank 2.

[0033] The second gas flow path 11 branches off in the extraction direction (arrow 18) downstream of the check valve 13 and downstream of the shut-off valve 6 from the downstream section 4.2 of the extraction path 4 and opens downstream of the check valve 12 and upstream of the shut-off valve 6 into the inflow section 4.1 of the extraction path 4. Via the second gas flow path 11, a pressure equalization in the direction of the inflow side (arrow 28) of the shut-off valve 6 can be effected, which prevents the inflow-side pressure pi n at the shut-off valve 6 falls below the pressure P2 at the gas connection 8. Since the check valve 12 ensures that the pressure pi n on the inflow side of the shut-off valve 6 does not fall below the pressure pi in the fuel gas tank 2 and at the same time the check valve 13 ensures that the pressure p ou t on the downstream side of the shut-off valve 6 does not rise above the pressure P2 at the gas connection 8, it is certain that the pressure p out on the downstream side of the shut-off valve 6 the pressure pi n on the inflow side of the shut-off valve 6. This prevents the shut-off valve 6 from opening unintentionally and / or flowing through in the reverse direction.

[0034] A further check valve 7 is integrated into the refueling path 5, which opens in the refueling direction (arrow 17) when the pressure P2 in the area of ​​the gas connection 8 is greater than the pressure pi in the fuel gas tank 2. If the refueling path 5 is blocked, emergency refueling can be carried out via the two gas flow paths 10, 11 and the section of the withdrawal path 4 leading via the shut-off valve 6 by actively opening the shut-off valve 6.

[0035] Figures 2 and 3 show a further preferred embodiment of a valve assembly 1 according to the invention. This differs from that of Figure 1 only in that the first gas flow path 10 does not open into the inflow-side section 4.1 of the extraction path 4, but directly into the fuel gas tank 2 or into the storage volume of the fuel gas tank 2. This means that at least three bores are formed in the connecting section 16, which open into the fuel gas tank 2, namely one for the extraction path 4, one for the refueling path 5, and one for the gas flow path 10. However, this makes it possible to dispense with a bore intersection, so that the high-pressure resistance of the valve assembly 1 is increased.

[0036] In Figure 2, arrow 17 indicates the refueling direction in which the fuel gas flows into the fuel gas tank 2 via the refueling path 5 during refueling of the fuel gas tank 2. Arrow 18 indicates the withdrawal direction in which the fuel gas flows when withdrawing fuel gas from the fuel gas tank 2. Arrows 27 and 28, in turn, indicate the gas flow direction in the other gas flow paths 10, 11 to achieve pressure relief or pressure equalization. In Figure 3, the gas flow direction during emergency refueling of the fuel gas tank 2 via the actively opened shut-off valve 6 and the gas flow paths 10, 11 is indicated by an arrow 19.

[0037] In order to create a valve assembly 1 that is as compact as possible, the two check valves 12 and 15, which open in opposite directions and are connected via their respective downstream sides, can be combined into a single component 20. Possible embodiments are shown in Figures 4 to 7.

[0038] A first preferred embodiment of a component 20 is shown in Figure 4. Here, the component 20 has two valve closing elements 23.1, 23.2, wherein each valve closing element 23.1, 23.2 is pretensioned in the direction of an associated valve seat 21, 22 via an intermediate, common spring 24. The spring 24 is accommodated in a valve chamber 29, which connects the component 20 to the inflow side of the shut-off valve 6 or to the inflow-side section 4.1 of the extraction path 4. When fuel gas is extracted from the fuel gas tank 2, the check valve 12 opens against the spring force of the spring 24, while the valve closing element 23.2 is pressed against the valve seat 22 and closes the check valve 15. During pressure equalization via the gas flow path 11 or during emergency refueling, the check valve 15 opens with the valve closing element 23.2 against the spring force of the spring 24, while the valve closing element 23.1 is pressed against the valve seat 21 and closes the check valve 12.

[0039] Another preferred embodiment of a component 20 is shown in Figures 5 to 7. Here, the valve closing element 23 is constructed in one piece and is controlled solely by pressure, i.e., pneumatically, so that a spring 24 is unnecessary. For this purpose, the valve closing element 23 has a circumferential groove 25, via which the valve chamber 29 is connected to the inflow side of the shut-off valve 6 or to the inflow-side section 4.1 of the extraction path 4.

[0040] Since the valve closing element 23 is guided radially, it also has at least one longitudinal groove 26 on each side of the circumferential groove 25, which opens into the circumferential groove 25 and serves as a gas flow channel (see Figure 6). When the valve seat 21 is open, the gas flows from there to the valve chamber 29 via the at least one longitudinal groove 26 between the circumferential groove 25 and the end of the guide of the valve closing element 23 facing the valve seat 21. When the valve seat 22 is open, the gas flows from there to the valve chamber 29 via the at least one longitudinal groove 26 between the circumferential groove 25 and the end of the guide of the valve closing element 23 facing the valve seat 22.

[0041] Figure 5 shows the valve closing element 23 in a switching position that it assumes when P2 > pi. Pressure equalization can then be achieved via the open check valve 15, preventing the shut-off valve 6 from opening accidentally. During emergency refueling, the valve closing element 23 also assumes the switching position shown in Figure 5. The check valve 12 is closed in this switching position.

[0042] Figure 7 shows the valve closing element 23 in a switching position that it assumes when P2 < pi and the shut-off valve 6 is actively open. Fuel gas can then be drawn from the fuel gas tank 2 via the open check valve 12, the open shut-off valve 6, and the likewise open check valve 13 and fed to the gas connection 8. The check valve 15 is closed in this switching position.

[0043] A valve assembly according to the invention may comprise additional valves and / or components in addition to the valves shown. For example, a manual shut-off and / or blow-off valve, a thermal and / or pressure-controlled safety valve, and a temperature and / or pressure sensor may be integrated into the valve assembly.

Claims

Claims 1. Valve assembly (1) for a fuel gas tank (2), comprising a base body (3) in which a withdrawal path (4) with an integrated shut-off valve (6) for withdrawing fuel gas from the fuel gas tank (2) and a refueling path (5) with an integrated check valve (7) for refueling the fuel gas tank (2) with fuel gas are formed, wherein the withdrawal path (4) and the refueling path (5) are combined within the base body (3) in a path (9) which opens into a common gas connection (8), characterized in that at least two further gas flow paths (10, 11) are formed in the base body (3), each of which, bypassing the shut-off valve (6), connects a downstream section (4.2) of the withdrawal path (4) arranged downstream of the shut-off valve (6) in the withdrawal direction with an inflow section arranged upstream of the shut-off valve (6) (4.1) of the extraction path (4) and / or with a storage volume formed in the fuel gas tank (2), wherein the flow direction in the extraction path (4) is predetermined by a first check valve (12) arranged in the inflow-side section (4.1) and a second check valve (13) arranged in the outflow-side section (4.2), and the flow through the two further gas flow paths (10, 11) in the extraction direction is blocked by a respective check valve (14, 15).

2. Valve assembly (1) according to claim 1, characterized in that a first gas flow path (10) branches off from the extraction path (4) upstream of the check valve (13) integrated in the downstream section (4.2) and opens into the extraction path (4) or directly into the storage volume of the fuel gas tank (2) upstream of the check valve (12) integrated in the upstream section (4.1).

3. Valve assembly (1) according to claim 1 or 2, characterized in that a second gas flow path (11) branches off from the extraction path (4) downstream of the check valve (13) integrated into the downstream section (4.2) and opens into the extraction path (4) downstream of the check valve (12) integrated into the upstream section (4.1).

4. Valve assembly (1) according to one of the preceding claims, characterized in that two check valves (12, 15) opening in opposite directions are combined to form one component (20).

5. Valve assembly (1) according to claim 4, characterized in that the component (20) has two valve closing elements (23.1, 23.2), between which a spring (24) is arranged, by means of which each valve closing element (23.1, 23.2) is prestressed in the direction of a valve seat (21, 22).

6. Valve assembly (1) according to claim 4, characterized in that the component (20) has a one-piece valve closing element (23) which can be moved back and forth between two valve seats (21, 22) and has a circumferential groove (25) and longitudinal grooves (26).

7. Valve assembly (1) according to one of the preceding claims, characterized in that the shut-off valve (6) is electrically controllable and / or is designed as a normally closed valve.

8. Valve assembly (1) according to one of the preceding claims, characterized in that the common gas connection (8) is designed as a connecting piece, preferably as a connecting piece with an external thread.

9. Valve assembly (1) according to one of the preceding claims, characterized in that the base body (3) has a connecting section (16) for connection to the fuel gas tank (2).

10. Fuel gas tank (2) with a valve assembly (1) according to one of the preceding claims, wherein the valve assembly (1) is preferably inserted in sections into the fuel gas tank (2) so that the common gas connection (8) is accessible from the outside.

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