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] 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 be, in particular, hydrogen or natural gas, which is stored under pressure in a fuel gas tank.

[0002] The preferred application area of ​​the invention is fuel cell and / or gas vehicles that are powered by a fuel gas. State of the art

[0003] Mobile fuel gas tank systems are known to have 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, especially 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 operation. For safety reasons, the shut-off valve is usually designed as a normally closed (NC) valve.

[0004] The shut-off valve is typically integrated into a valve assembly that allows both the withdrawal of fuel gas from the fuel gas tank and the refueling of the fuel gas tank with fuel gas. This valve assembly comprises a main body containing a withdrawal path and a refueling path. 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 may be located in the withdrawal path, thus defining the flow direction in both paths.

[0005] German patent application DE 10 2016 008 443 A1 discloses an exemplary tank valve for mounting on a pressurized gas cylinder. This valve comprises a base body with a gas connection through which the pressurized gas cylinder can be both filled and gas can be withdrawn. Within the base body, the gas connection splits into a filling 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 of gas against the intended flow direction during withdrawal. The check valve thus prevents gas from flowing into the pressurized gas cylinder via the withdrawal line during filling. A further check valve is integrated into the filling line, which opens in the filling direction and closes in the withdrawal direction.

[0006] DE 10 2016 008 442 A1 discloses a tank valve for a pressurized gas container with a common gas connection, which internally divides into a refueling path and a withdrawal path with a shut-off valve.

[0007] The present invention is concerned with the objective of providing 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.

[0008] To solve the problem, a valve assembly with the features of claim 1 is proposed. Advantageous embodiments of the invention are described in the dependent claims. Furthermore, a fuel gas tank with a valve assembly according to the invention is described. Disclosure of the invention

[0009] The proposed valve assembly 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 into a single path that terminates in 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 an outflow-side section of the withdrawal path arranged downstream of the shut-off valve in the withdrawal direction with an inflow-side 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 inflow-side section and a second check valve arranged in the outflow-side section, and the flow through the two further gas flow paths in the extraction direction is blocked by a check valve in each case.

[0010] 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, the shut-off valve simply needs to be actively opened. 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 these two gas flow paths and the open shut-off valve. At the same time, the two check valves integrated into the extraction path ensure that the shut-off valve can only be opened in the forward direction, and thus only when activated. This prevents the shut-off valve from opening unintentionally during a normal refueling process.

[0011] 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 opens 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. This first gas flow path thus provides pressure relief, ensuring that the pressure on the downstream side of the shut-off valve never exceeds the pressure in the fuel gas tank. The first gas flow path can therefore be referred to as a pressure relief path. The pressure relief path allows the shut-off valve to be bypassed, connecting the downstream side to the upstream side or the storage volume of the fuel gas tank.

[0012] Furthermore, a second gas flow path preferably branches off from the extraction path downstream of the check valve integrated into the outflow-side section of the extraction path and opens into the extraction path downstream of the check valve integrated into the inflow-side section of the extraction path – on the inflow side of the shut-off valve. Pressure equalization can be achieved via the second gas flow path, ensuring that the pressure on the inflow side of the shut-off valve is never lower than the pressure in the area of ​​the gas connection.

[0013] In a further development of the invention, it is proposed that two oppositely opening check valves are combined into a single component. This allows the valve assembly to be simplified and made more compact.

[0014] The component can have two valve closing elements, between which a spring is arranged, biasing each valve closing element towards a valve seat. The component can be connected to the inlet side of the shut-off valve via the space between the two valve closing elements, which accommodates the spring.

[0015] Alternatively, the component can be a one-piece, reciprocating valve closing element with a circumferential groove and longitudinal grooves. The circumferential groove allows the component to be connected to the inlet side of the shut-off valve. 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 pneumatically to either one end position or the other, so that one valve seat is open and the other closed. Both valve seats are never open or closed simultaneously. The opening and closing of the check valves can therefore be achieved purely pneumatically. This means that a spring is unnecessary.

[0016] The shut-off valve is preferably electrically actuated and / or designed as a normally closed (NC) valve. As an electrically actuated valve, the shut-off valve can be made particularly compact and robust. Furthermore, the shut-off valve can be actively opened to withdraw fuel gas from the fuel gas tank or to perform emergency refueling. In its normally closed (NC) configuration, it meets the safety requirements for a fuel gas tank.

[0017] Furthermore, it is proposed that the common gas connection be designed as a connection fitting, preferably with an external thread. This connection fitting facilitates the connection of an external gas line, allowing fuel gas to be drawn from the fuel tank and fuel gas to be supplied to the tank during refueling. If the connection fitting has an external thread, the external gas line can be screwed onto it, creating a high-pressure-resistant connection between the gas line and the valve assembly.

[0018] Furthermore, the base preferably has a connecting section for connection to the fuel gas tank. The valve assembly can be easily mounted to a fuel gas tank via this connecting section. For example, the valve assembly can be inserted into the neck of 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 cylinder neck to create a high-pressure-resistant connection.

[0019] The proposed fuel gas tank is further characterized by the fact that it incorporates a valve assembly according to the invention. Preferably, the valve assembly is inserted section by section into the fuel gas tank, so that the common gas connection is accessible from the outside. Since the withdrawal path and the refueling path are combined and merge as a single path into the common gas connection of the valve assembly, only one gas line needs to be connected for both the withdrawal of fuel gas and the refueling of the fuel gas tank.

[0020] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings. These show: Fig. 1 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 when fuel gas is withdrawn from the fuel gas tank and when the fuel gas tank is regularly refueled with fuel gas, Fig. 2 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 when fuel gas is withdrawn from the fuel gas tank and when the fuel gas tank is regularly refueled with fuel gas, Fig. 3 a schematic representation of the valve assembly of the Figure 2 with an arrow to indicate the direction of gas flow during emergency refueling of the fuel gas tank via the actively opened shut-off valve, Fig. 4 a longitudinal section through two oppositely opening check valves, which are combined to form a component with two valve closing elements, wherein a spring arranged between the two valve closing elements exerts a closing force on both valve closing elements in the direction of a valve seat, Fig. 5a longitudinal section through two oppositely opening check valves, which are combined into a single component with a one-piece valve closing element, Fig. 6 a cross-section through the component of the Figure 5 and Fig. 7 another longitudinal section through the component of the Figure 5 , but in a different switch position. Detailed description of the drawings

[0021] The one in Figure 1 The valve assembly 1 shown according to the invention serves to extract fuel gas from a fuel gas tank 2 and to refuel the fuel gas tank 2 with fuel gas, in particular with hydrogen or with natural gas.

[0022] The illustrated valve assembly 1 has 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 require the connection of only one gas line, a withdrawal path 4 and a refueling path 5 formed in the base body 3 are combined to form a path 9, which leads into the gas connection 8.

[0023] A shut-off valve 6, which is electrically controlled and designed as a normally closed valve, is integrated into the extraction path 4. Upstream of the shut-off valve 6 in the extraction direction (arrow 18), i.e., on the inlet side of the shut-off valve 6, a first check valve 12 is arranged, which opens in the extraction direction. Downstream of the shut-off valve 6 in the extraction direction, i.e., on the outlet side of the shut-off valve 6, a second check valve 13 is arranged, which also opens in the extraction direction. The extraction path 4 thus leads via an inlet-side first section 4.1, in which the check valve 12 is integrated, the shut-off valve 6, and an outlet-side second section 4.2, in 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.To prevent fuel gas from escaping from the fuel gas tank 2 via the two other 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 direction of withdrawal.

[0024] The first gas flow path 10 branches off in the direction of withdrawal (arrow 18) upstream of the check valve 13 from the outflow-side section 4.2 of the withdrawal path 4 and opens upstream of the check valve 12 into the inflow-side section 4.1 of the withdrawal path 4. The first gas flow path 10 ensures pressure relief towards fuel gas tank 2 (see arrow 27), preventing the pressure p out on the outflow side of the shut-off valve 6 from rising above the pressure p 1 in the fuel gas tank 2.

[0025] The second gas flow path 11 branches off in the direction of withdrawal (arrow 18) downstream of the check valve 13 and downstream of the shut-off valve 6 from the outflow-side section 4.2 of the withdrawal path 4 and opens downstream of the check valve 12 and upstream of the shut-off valve 6 into the inflow-side section 4.1 of the withdrawal path 4. Pressure equalization towards the inflow side (arrow 28) of the shut-off valve 6 can be achieved via the second gas flow path 11, preventing the inflow-side pressure pin at the shut-off valve 6 from falling below the pressure p2 at the gas connection 8.Since the check valve 12 ensures that the pressure pin on the inlet side of the shut-off valve 6 does not fall below the pressure p1 in the fuel gas tank 2, and at the same time the check valve 13 ensures that the pressure pout on the outlet 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 pout on the outlet side of the shut-off valve 6 never exceeds the pressure pin on the inlet side of the shut-off valve 6. This prevents the shut-off valve 6 from opening unintentionally and / or allowing backflow.

[0026] A further check valve 7 is integrated into the refueling path 5, which opens in the refueling direction (arrow 17) when the pressure p 2 in the area of ​​the gas connection 8 is greater than the pressure p 1 in the fuel gas tank 2. Should the refueling path 5 be blocked, emergency refueling can be carried out by actively opening the shut-off valve 6 via the two gas flow paths 10, 11 and the section of the withdrawal path 4 leading via the shut-off valve 6.

[0027] The Figures 2 and 3 A further preferred embodiment of a valve assembly 1 according to the invention can be seen from the Figure 1This is achieved solely by the fact that the first gas flow path 10 does not open into the inlet-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: one for the extraction path 4, one for the refueling path 5, and one for the gas flow path 10. However, bore intersection can be omitted, thus increasing the high-pressure resistance of the valve assembly 1.

[0028] In the Figure 2Arrow 17 indicates the refueling direction, in which the fuel gas flows into fuel gas tank 2 via refueling path 5 when refueling. Arrow 18 indicates the withdrawal direction, in which the fuel gas flows when withdrawing fuel gas from fuel gas tank 2. Arrows 27 and 28, in turn, indicate the gas flow direction in the further gas flow paths 10 and 11 to achieve pressure relief and pressure equalization, respectively.

[0029] In the Figure 3 The direction of gas flow 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.

[0030] To create a valve assembly 1 with the most compact design possible, the two oppositely opening check valves 12 and 15, connected via their respective outflow sides, can be combined into a single component 20. Possible embodiments are shown in the Figures 4 to 7 depicted.

[0031] A first preferred embodiment of a component 20 shows the Figure 4Here, the component 20 has two valve closing elements 23.1, 23.2, each of which is biased towards a corresponding valve seat 21, 22 by an intermediate, common spring 24. The spring 24 is housed in a valve chamber 29, which connects the component 20 to the inlet side of the shut-off valve 6 or to the inlet-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. In the event of 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 the check valve 12 closes.

[0032] Another preferred embodiment of a component 20 is described in the Figures 5 to 7 The valve closing element 23 is shown here as a single 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 inlet side of the shut-off valve 6 or to the inlet-side section 4.1 of the extraction path 4.

[0033] Since the valve closing element 23 is guided radially, it also has at least one longitudinal groove 26 opening into the circumferential groove 25 on each side as a gas flow channel (see Figure 6When the valve seat 21 is open, the gas flows from there 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 to the valve chamber 29. When the valve seat 22 is open, the gas flows from there 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 to the valve chamber 29.

[0034] Figure 5 The valve closing element 23 is shown in a switching position that it assumes when p2 > p1. Pressure equalization can then be achieved via the open check valve 15, preventing unintentional opening of the shut-off valve 6. During emergency refueling, the valve closing element 23 also assumes the position shown in the Figure 5 The switch position shown is activated. The check valve 12 is closed in this switch position.

[0035] Figure 7The diagram shows the valve closing element 23 in a switching position it assumes when p2 < p1 and the shut-off valve 6 is actively open. Fuel gas can then be drawn from the fuel gas tank 2 and routed to the gas connection 8 via the open check valve 12, the open shut-off valve 6, and the also open check valve 13. The check valve 15 is closed in this switching position.

[0036] A valve assembly according to the invention can comprise, in addition to the valves shown, further valves and / or components. 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 can be integrated into the valve assembly.

Claims

1. Valve assembly (1) for a fuel-gas tank (2), comprising a main body (3) in which an extraction path (4) with an integrated shut-off valve (6) for extraction of fuel gas from the fuel-gas tank (2) and a tank-filling path (5) with an integrated check valve (7) for filling the fuel-gas tank (2) with fuel gas are formed, wherein the extraction path (4) and the tank-filling path (5) within the main body (3) are combined into a path (9) which opens out into a common gas connection (8), characterized in that, in the main body (3), there are formed at least two further gas-flow paths (10, 11), each of which, while bypassing the shut-off valve (6), connects an outflow-side portion (4.2) of the extraction path (4), which is arranged downstream of the shut-off valve (6) in the extraction direction, to an inflow-side portion (4.1) of the extraction path (4), which is arranged upstream of the shut-off valve (6), and / or to a storage volume formed in the fuel-gas tank (2), wherein the flow direction in the extraction path (4) is predefined by a first check valve (12) arranged in the inflow-side portion (4.1) and a second check valve (13) arranged in the outflow-side portion (4.2) and the flow through the two further gas-flow paths (10, 11) in the extraction direction is blocked by in each case one 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 into the outflow-side portion (4.2) and opens out into the extraction path (4) upstream of the check valve (12) integrated into the inflow-side portion (4.1) or opens out directly into the storage volume of the fuel-gas tank (2).

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 outflow-side portion (4.2) and opens out into the extraction path (4) downstream of the check valve (12) integrated into the inflow-side portion (4.1).

4. Valve assembly (1) according to one of the preceding claims, characterized in that two check valves (12, 15) which open in a mirror-inverted manner are combined to form a component (20).

5. Valve assembly (1) according to Claim 4, characterized in that the component (20) has two valve closure elements (23.1, 23.2) between which there is arranged a spring (24) by way of which each valve closure element (23.1, 23.2) is preloaded 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-part valve closure element (23) which is movable back and forth between two valve seats (21, 22) and which 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 actuatable 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 connection piece, preferably as a connection piece with an external thread.

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

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

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