Tank system and method for inspecting a separing valve in a tank system

Abstract

The invention relates to a method for checking a switchable separating valve of a valve arrangement, which connects a tank container, in which a gas having a first pressure is stored, to a line system, in which a second pressure is present, which is lower than the first pressure. The method comprises: actuating the separating valve in order to switch the separating valve from a closed position, in which the separating valve closes an extraction path of the valve arrangement connecting the line system to the tank container, into an open position, in which the separating valve opens the extraction path; detecting a pressure change process in a tank-side section of the extraction path, said tank-side section extending between the tank container and the separating valve; ascertaining whether a pressure drop is contained after actuation of the separating valve during the detected pressure change; and outputting an error signal if it is determined that a pressure drop is not included after the separation valve is actuated during the detected pressure change.

Description

Technical Field

[0001] The present invention relates to a tank system, and more particularly to a tank system for storing a gaseous fuel (such as hydrogen) and supplying the gaseous fuel to a consumer system, and a method for checking a separation valve in the tank system. Background Art

[0002] Hydrogen and other gaseous fuels can be used in mobile applications, especially in road vehicles, to operate a drive unit. This includes both the operation of fuel cells and the operation of internal combustion engines or other thermal engines. Gaseous fuels can also be advantageously used in stationary applications to generate energy. Generally, the gas is stored in a tank system having one or more tank containers and is transported to a consumer system, such as a fuel cell or an internal combustion engine, through a pipeline system connected to one or more tank containers.

[0003] US 7,367,349 B2 describes a supply system for a fuel cell, in which a plurality of tanks are connected in parallel to a pipeline system through respective extraction pipelines for supplying the fuel cell. A switchable separation valve is arranged in each extraction pipeline to connect or disconnect the respective tank from the pipeline system. When starting the system, first only one of the separation valves is opened to increase the pressure in the pipeline system, and then the remaining valves are opened. This is for the purpose of reducing the wear of the valves by reducing the pressure difference between the tank and the high-pressure pipeline system at the time of opening the remaining valves.

[0004] Generally, it is desirable to reliably open the separation valve when starting the system to improve the operating safety. This applies both to systems having only one tank container and to systems having a plurality of tank containers. Summary of the Invention

[0005] In this context, the present invention provides a method having the features of claim 1 and a tank system having the features of claim 8.

[0006] According to a first aspect of the present invention, a method for inspecting a switchable isolation valve of a valve device is provided, the valve device connecting a tank container to a pipeline system, wherein a gas with a first pressure is stored in the tank container and a second pressure exists in the pipeline system, the second pressure being less than the first pressure. The method includes: manipulating the isolation valve so as to switch the isolation valve from a closed state to an open state, in the closed state the isolation valve closes an extraction path connecting the pipeline system to the tank container, and in the open state the isolation valve opens the extraction path; detecting a pressure change process in a tank-side section of the extraction path, the tank-side section extending between the tank container and the isolation valve; determining whether a pressure drop is included after the manipulation of the isolation valve in the detected pressure change process; and when it is determined that no pressure drop is included after the manipulation of the isolation valve in the detected pressure change process, outputting an error signal.

[0007] According to a second aspect of the present invention, a tank system includes: at least one tank container for storing a gas, in particular hydrogen; a pipeline system for supplying a consumer system (such as a fuel cell or a heat engine); a valve device having an extraction path and a switchable isolation valve arranged in the extraction path, the extraction path connecting the tank container to the pipeline system, the isolation valve being able to be switched between a closed state and an open state, in the closed state the isolation valve closes the extraction path, and in the open state the isolation valve opens the extraction path; a pressure sensor connected to a tank-side section of the extraction path extending between the tank container and the isolation valve and configured to detect the pressure in the tank-side section of the extraction path; and a control device in signal connection with the valve device and the pressure sensor and configured to cause the tank system to perform the steps of the method according to any one of the preceding claims.

[0008] The idea underlying the present invention is to detect the pressure change process on the tank side of the isolation valve and evaluate this pressure change process after manipulating the valve. Since there is a lower pressure in the pipeline system than in the tank container and thus lower than the pressure on the tank side of the isolation valve before opening the isolation valve, opening the isolation valve causes a brief pressure drop on the tank side. That is to say, when the isolation valve is switched from its closed state to the open state, an undershoot occurs in the pressure change process in the tank-side section of the extraction path of the valve device. With the control device, such a brief pressure drop can be determined or detected in the pressure signal provided by the pressure sensor. If such a pressure drop is determined, it can be inferred that the corresponding isolation valve has been correctly opened. If no pressure drop is determined, it can be inferred that the isolation valve has not been switched from the closed state to the open state due to the manipulation.

[0009] The advantage of the present invention is that it is possible to reliably identify an isolation valve that has not been switched.

[0010] Advantageous configurations and expansion schemes are derived from the descriptions of other dependent claims and the reference drawings.

[0011] According to some embodiments, it may be provided that the actuating isolation valve includes generating a first opening force for opening the isolation valve, wherein, when it is determined that there is no pressure drop after actuating the isolation valve during the detected pressure change process, the isolation valve is re-actuated with a second opening force, the second opening force being greater than the first opening force, and the steps of detecting and determining the pressure change process are re-executed. Thus, if it is determined that the isolation valve is not opened during the first actuation of the isolation valve, the isolation valve can be re-actuated, more precisely, with an increased opening force. Thereby, the operating safety can be further improved because if the isolation valve can be opened with an increased opening force, the tank system can continue to operate completely normally.

[0012] According to some embodiments, it may be provided that an error signal is output only when it is re-determined that there is no pressure drop after re-actuating the isolation valve with the second opening force during the detected pressure change process. Optionally, if no pressure drop is determined during the detected pressure change process after the first actuation of the isolation valve, a first error signal may be output, and if it is re-determined that there is no pressure drop after re-actuating the isolation valve with the second opening force during the detected pressure change process, a second error signal may be output.

[0013] According to some embodiments, it may be provided that the isolation valve is configured as an electrically actuatable, fail-safe solenoid valve, wherein generating the first opening force includes energizing the isolation valve with a first control current, and generating the second opening force includes energizing the isolation valve with a second control current, the second control current being greater than the first control current.

[0014] According to some embodiments, it may be provided that a release signal is output when it is determined that there is a pressure drop after actuating the isolation valve during the detected pressure change process. For example, outputting the release signal may include generating a release message and writing the release message into a data memory.

[0015] According to some embodiments, it can be provided that a plurality of tank containers are connected to a pipeline system via a plurality of valve devices, each of the plurality of valve devices having a switchable isolation valve, wherein each isolation valve is manipulated to switch this isolation valve from a closed state to an open state, wherein, after the corresponding isolation valve is manipulated, each isolation valve detects a pressure change process in the tank-side section of the extraction path, wherein, for each isolation valve, it is determined whether a pressure drop is included in the detected pressure change process after the isolation valve is manipulated, and an error signal is output for each isolation valve for which it is determined that no pressure drop is included in the corresponding detected pressure change process after the corresponding isolation valve is manipulated. In particular, in the case of a plurality of tank containers, if one of the isolation valves is not opened, it will lead to undesirable effects. On the one hand, the gas stored in the tank container whose isolation valve is not opened cannot be used by the consumer system. On the other hand, uneven emptying of the tank container will occur. If the unopened isolation valve is opened at a subsequent time point (such as when the system is restarted), this will lead to additional pressure equalization and / or backfilling of the tank container. With this method, such situations can be reliably avoided.

[0016] According to some embodiments, it can be provided that the isolation valves are manipulated successively or simultaneously.

[0017] According to some embodiments, it can be provided that the determination of whether a pressure drop is included in the detected pressure change process after the isolation valve is manipulated includes determining the pressure gradient of the detected pressure change process, and if the pressure gradient within a predetermined time period after the manipulation has a value less than zero, a pressure drop is determined.

[0018] According to some embodiments, it can be provided that outputting the error signal includes generating an error message and writing the error message into a data memory. Alternatively or additionally, it can be provided that outputting the error signal includes outputting a warning signal to a user interface. For example, an optical signal can be output at a display device or a warning light of the user interface, or an acoustic or tactile signal can be output.

[0019] According to some embodiments, it can be provided that the isolation valve is configured as an electrically manipulable, fail-closed solenoid valve.

[0020] According to some embodiments, it can be provided that a tank system has a plurality of tank containers, the plurality of tank containers being connected to a pipeline system via a plurality of valve devices, each of the plurality of valve devices having a switchable isolation valve.

[0021] Features and advantages disclosed herein in connection with one aspect of the invention are also disclosed for the corresponding other aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be illustrated below with reference to the accompanying drawings. These drawings show:

[0023] Figure 1 Schematic diagram of a hydraulic circuit of a tank system according to an embodiment of the present invention;

[0024] Figure 2 Detailed view of a valve device of a tank system according to an embodiment of the present invention; and

[0025] Figure 3 Flowchart of a method according to an embodiment of the present invention. Detailed description of the invention

[0026] In the drawings, unless otherwise specified, the same reference numerals denote the same or functionally identical components.

[0027] Figure 1 Schematically shown is a tank system 100 for supplying a gaseous fuel (such as hydrogen) to a consumer system 200. The consumer system 200 can be, for example, a fuel cell or a thermal engine. The tank system 100 can be used, for example, in mobile applications, such as in a vehicle. However, the present invention is not limited thereto.

[0028] As Figure 1 exemplarily shown in, the tank system 100 has a plurality of tank containers 1, a pipeline system 2, a plurality of valve devices 3, and a control device 5. Optionally, a user interface 6 can also be provided. In Figure 1 exemplarily shown in purely by way of example is a tank system 100 having three tank containers 1. It is also conceivable that the tank system 100 has only one tank container 1, or has a number of tank containers 1 different from three. Furthermore, in Figure 1 exemplarily shown in, for each tank container 1, a valve device 3 is respectively provided, and the corresponding tank container 1 is connected to the pipeline system 2 via this valve device. Alternatively, it is also conceivable that a plurality of tank containers 1 are connected to the pipeline system 2 via a common valve device 3.

[0029] Generally, the tank container 1 defines an internal volume and can be configured, for example, to store hydrogen at a nominal pressure of up to 700 bar.

[0030] The pipeline system 2 can be, for example, a high-pressure pipeline system 2, which is connected to the consumer system via an optional medium-pressure pipeline system 7, and the optional medium-pressure pipeline system is only symbolically represented as a box in Figure 1 As Figure 1 schematically shown in, the tanks 1 are connected to the pipeline system 2 in parallel with each other.

[0031] The valve device 3 is assigned to the corresponding tank 1 and connects the tank to the pipeline system 2. Figure 2 Schematically and highly simplified, an exemplary structure of the valve device 3 is shown. As Figure 2As shown in, the valve device 3 has a first internal connection 3A and an external connection 3C, the first internal connection being connected to the internal volume of the tank 1 and the external connection being connected to the pipeline system 2. Further optionally, a second internal connection 3B can be provided. As Figure 2 As shown in, the valve device 3 has a switchable isolation valve 30 and a pressure sensor 4. Optionally, a check valve 33 can additionally be provided. Similarly optionally, the valve device 3 can have a temperature sensor 35, as Figure 2 purely exemplarily shown in.

[0032] The first internal connection 3A and the external connection 3C are connected to each other via an extraction path 31, and the isolation valve 30 (for example, in the form of an electrically switchable, non-current closing solenoid valve) is arranged in this extraction path. The isolation valve 30 divides the extraction path 31 into a tank-side section 31A and a pipeline-side section 31B, the tank-side section extending between the first internal connection 3A and the isolation valve 30 and the pipeline-side section extending between the isolation valve 30 and the external connection 3C. The isolation valve 30 can be switched between a closed state and an open state. In Figure 2 As shown in, the isolation valve 30 in the closed state is shown. In this closed state, the isolation valve closes the extraction path, that is, the isolation valve interrupts the fluid-conducting connection between the tank-side section and the pipeline-side section 31A, 31B of the extraction path 31, and thus prevents the gas from the tank container 1 from flowing from the first internal connection 3A to the external connection 3C. In the open state, the isolation valve 30 opens the extraction path, that is, the isolation valve establishes the fluid-conducting connection between the tank-side section and the pipeline-side section 31A, 31B of the extraction path 31, and allows the gas from the tank container 1 to flow from the first internal connection 3A to the external connection 3C.

[0033] As Figure 2 further shown in, the second internal connection 3B can be connected to the external connection 3C via a filling path 32. The optional check valve 33 is arranged in the filling path 32 and is configured to only allow flow from the external connection 3C to the second internal connection 3B. If there is a higher pressure in the pipeline system 2 than in the tank container 1, then even when the isolation valve 30 is closed, the gas from the pipeline system 2 can flow into the tank container 1 from the external connection 3C via the second internal connection 3B.

[0034] As Figure 2 further shown in, the pressure sensor 4 is connected to the tank-side section 31A of the extraction path 31. Thus, the pressure in the tank-side section 31A of the extraction path 31 can be detected by means of the pressure sensor 4.

[0035] The optional temperature sensor 35 can be part of the valve device 3, as Figure 2As shown purely by way of example. Here, the temperature sensor 35 is arranged to be connected to the interior volume of the tank container 1. Thus, the temperature in the tank container 1 can be measured using the temperature sensor 35.

[0036] The control device 5 is shown only as a block in Figure 1 and can in particular be an electronic control device 5. The control device 5 can for example have a processor 50 and a data memory 51. The processor 50 can for example be implemented as a CPU, FPGA, ASIC or the like. The data memory 51 can in particular be a non-volatile data memory, such as a flash memory, SD memory, hard disk or the like. The data memory 51 can be read by the processor 50 and can for example store software which can be executed by the processor 50 and which causes this processor to generate an output signal (for example a signal in the form of a control signal) based on an input signal (for example a signal in the form of a measured value). The control device 5 is signal-connected to the valve device 3 and the corresponding pressure sensor 4, for example via a data bus (for example, CAN bus, USB, etc.) in a wired connection or (for example via WiFi, Bluetooth, etc.) in a wireless connection.

[0037] In particular, the control device 5 can be configured to cause the tank system 100 to carry out a method M for checking the switchable isolation valve 30 of the respective valve device 3. The flow of the method M for checking the switchable isolation valve 30 of the respective valve device 3 is schematically shown in Figure 3 and is based on an initial situation in which a gas (for example hydrogen) having a first pressure is stored in the tank container 1 and a second pressure exists in the pipeline system 2, the second pressure being less than the first pressure. Here, the isolation valve 30 is closed. Such an initial situation can for example exist before the consumer system 200 connected to the tank system 100 is started up or increases its power. Below, the method M will be explained with reference to the above-mentioned tank system 100.

[0038] In a first step M1, the isolation valve 30 is actuated in M1 by means of the control device 5, for example by outputting a control signal to the isolation valve 30 so that the isolation valve switches from its closed position to its open position. The control signal can in particular cause a first opening force to be generated for opening the isolation valve 30. As Figure 2 exemplarily shown in, if the isolation valve 30 is configured as an electrically actuatable, non-current-carrying closed solenoid valve, generating the first opening force can include energizing the isolation valve 30 with a first control current. As Figure 1 exemplarily shown in, if there are a plurality of tank containers 1 with a plurality of valve devices 3, the isolation valves 30 of different valve devices 3 can be actuated successively or simultaneously.

[0039] In step M2, the pressure in the tank-side section 31A of the extraction path 31 is detected at time intervals by means of the pressure sensor 4. The control device 5 thus obtains a pressure signal representing the pressure change process.

[0040] In step M3, the control device 5 determines whether a pressure drop is included in the detected pressure change process after the actuation of the separation valve 30 (step M1). Therefore, the control device 5 evaluates the pressure signals detected since the actuation of the separation valve 30 and checks whether these pressure signals show a pressure drop at least limited in time. For example, the control device 5 can determine the pressure gradient of the detected pressure change process, where a pressure drop is determined or detected if the pressure gradient within a predetermined time period after the actuation has a value less than zero.

[0041] If it is determined in step M3 that a pressure drop is included in the detected pressure change process after the actuation M1 of the separation valve 30, as indicated by the symbol “+” in Figure 3 then the method can proceed to step M5. The presence of a pressure drop indicates that the corresponding separation valve 30 has opened after the actuation (step M1). Since the pressure in the pipeline system 2 is less than the pressure in the tank container 1, a usually time-limited pressure drop occurs after the separation valve 30 is opened. Therefore, the pressure change process includes a downrush.

[0042] In step M5, the control device 5 can, for example, output a release signal. This can include, for example, generating a release message and writing the release message into the data memory 51.

[0043] If it is determined in step M3 that a pressure drop is not included in the detected pressure change process after the actuation of the separation valve 30 (step M1), as indicated by the symbol “-” in Figure 3 then the method M directly proceeds to step M4, in which the control device 5 outputs an error signal. Outputting an error signal can include, for example, generating an error message and writing the error message into the data memory 51. Alternatively or additionally, the control device 5 can also output a warning signal to the user interface 6. For example, the user interface 6 (which is only symbolically shown as a box in Figure 1 can have a display device or a warning light, and the control device 5 prompts it to output an optical signal, or an acoustic or tactile warning signal can be output to the user interface 6. An error signal is output for each separation valve 30 for which it is determined that a pressure drop is not included in the corresponding detected pressure change process after the actuation (step M1) of the corresponding separation valve 30, for example, together with the index of the corresponding separation valve.

[0044] Optionally, if it is determined in step M3 that there is no pressure drop after the actuation of the separation valve 30 (step M1) during the detected pressure change, method M may first proceed to step M31. In step M31, the control device 5 increments a count value that indicates the frequency of actuation of the separation valve 30 to switch it from the closed state to the open state since the last time the separation valve 30 was closed. When the separation valve 30 switches to its closed state, the count value is set to zero.

[0045] In step M32, the control device 5 checks whether the count value is less than a predetermined limit value. The limit value can be, for example, an integer between 2 and 10. If it is determined in step M32 that the count value is less than the limit value, as Figure 3 indicated by the symbol “+” in, the method may return to step M1. In this case, the separation valve 30 is actuated again by the control device 5, wherein the re-actuation of the separation valve 30 is effected with a second opening force that is greater than the first opening force. For example, generating the second opening force may include energizing the separation valve 30 with a second control current that is greater than the first control current. Subsequently, steps M2 and M3 are performed again as described above. If it is determined in step M3 that there is a pressure drop after re-actuating the separation valve 30 with the second opening force during the detected pressure change ( Figure 3 the symbol “+” in), the method proceeds to step M5. Otherwise, i.e., if it is determined that there is no pressure drop after re-actuating the separation valve with the second opening force during the detected pressure change, steps M31 and M32 are then executed. As long as it is determined in step M32 that the count value is less than the limit value (symbol “+”), steps M1 - M3 may be executed again, wherein the opening force may optionally be further increased in each iteration. If it is determined in step M32 that the count value has reached the limit value (symbol “-”), the method proceeds to step M4.

[0046] Optionally, therefore, an error signal is only output in step M4 if it is determined at least once that there is no pressure drop after re-actuating the separation valve with the second opening force during the detected pressure change.

[0047] Alternatively, whenever it is determined in step M3 that no pressure drop is included after re-manipulating the separation valve 30 during the detected pressure change, step M4 can be executed while additionally implementing steps M31 and M32. For example, whenever it is determined in step M32 that the count value is less than the limit value, a first error signal can be output in step M4. When it is determined in step M32 that the count value reaches the limit value (symbol "-"), a second error signal can be output in step M4. Outputting the first error signal can, for example, only include generating an error message and writing it into the data memory 51, and alternatively or additionally thereto, outputting the second error signal can include outputting a warning signal to the user interface.

[0048] Although the present invention has been exemplarily illustrated above based on the embodiments, the present invention is not limited thereto, but can be modified in various ways. In particular, combinations of the above embodiments are also conceivable.

Claims

1. A method (M) for checking a switchable isolation valve (30) of a valve arrangement (3), which valve arrangement connects a tank container (1) to a pipeline system (2), wherein, A gas with a first pressure is stored in the tank container (1), and a second pressure exists in the pipeline system (2), and the second pressure is less than the first pressure, wherein the method (M) includes: Controlling (M1) the isolation valve (30) to switch the isolation valve from a closed state to an open state, in the closed state, the isolation valve (30) closes the extraction path (31) that connects the pipeline system (2) to the tank container (1), and in the open state, the isolation valve (30) opens the extraction path (31); Detecting (M2) the pressure change process in the tank-side section (31A) of the extraction path (31), and the tank-side section extends between the tank container (1) and the isolation valve (30); Determining (M3) whether a pressure drop is included after the manipulation (M1) of the isolation valve (31) in the detected pressure change process; and When it is determined that the detected pressure change process does not include a pressure drop after the manipulation (M1) of the isolation valve (31), an error signal is output (M4).

2. The method (M) according to claim 1, wherein The manipulation (M1) of the isolation valve (31) includes generating a first opening force for opening the isolation valve (30), wherein when it is determined that the detected pressure change process does not include a pressure drop after the manipulation (M1) of the isolation valve (31), the isolation valve (30) is re-manipulated (M1) with a second opening force, and the second opening force is greater than the first opening force, wherein the steps of detecting (M2) the pressure change process and determining (M3) are re-executed, and preferably, the error signal is output (M4) only when it is re-determined that the detected pressure change process does not include a pressure drop after the isolation valve is re-manipulated with the second opening force.

3. The method (M) according to claim 2, wherein, The isolation valve (30) is configured as an electrically controllable, fail-closed solenoid valve, wherein the generation of the first opening force includes energizing the isolation valve (30) with a first control current, and the generation of the second opening force includes energizing the isolation valve (30) with a second control current, and the second control current is greater than the first control current.

4. The method (M) according to any one of the preceding claims, additionally including: When it is determined that the detected pressure change process includes a pressure drop after the manipulation (M1) of the isolation valve (30), a release signal is output (M5).

5. The method (M) according to any one of the preceding claims, wherein, A plurality of tank containers (1) are connected to the pipeline system (2) via a plurality of valve devices (3), and each of the plurality of valve devices has a switchable isolation valve (30), wherein each isolation valve (3) is controlled to switch this isolation valve from the closed state to the open state, and wherein, after the control of the respective isolation valve (30), a pressure change process in the tank-side section (31A) of the extraction path (31) is detected by each isolation valve (30), and wherein, for each isolation valve (30), it is determined (M3) whether a pressure drop is included in the detected pressure change process after the control (M1) of the isolation valve (30), and for each isolation valve (30) for which it is determined that no pressure drop is included in the corresponding detected pressure change process after the control (M1) of the corresponding isolation valve (30), the error signal is output (M4).

6. The method (M) according to claim 5, wherein, The isolation valves (30) are controlled successively or simultaneously.

7. The method (M) according to any one of the preceding claims, wherein, The output (M4) of the error signal includes generating an error message and writing the error message into a data memory (51), and / or includes outputting a warning signal to a user interface (6).

8. A tank system (100), comprising: At least one tank container (1) for storing a gas, in particular hydrogen; A pipeline system (2) for supplying a consumer system (200); A valve device (3) having an extraction path (31) and a switchable isolation valve (30) arranged in the extraction path (31), the extraction path connecting the tank container (1) to the pipeline system (2), the isolation valve being switchable between a closed state and an open state, in the closed state the isolation valve closing the extraction path (31), and in the open state the isolation valve opening the extraction path (31); A pressure sensor (4) connected to the tank-side section (31A) of the extraction path (31) extending between the tank container (1) and the isolation valve (30), and arranged to detect the pressure in the tank-side section (31A) of the extraction path (31); and A control device (5) signal-connected to the valve device (3) and the pressure sensor (4), and arranged to cause the tank system (100) to perform the steps of the method (M) according to any one of the preceding claims.

9. The tank system (100) according to claim 8, wherein, The isolation valve (30) is configured as an electrically controllable, fail-closed solenoid valve.

10. The can system (100) according to claim 8 or 9, wherein, The tank system (100) has a plurality of tank containers (1), the plurality of tank containers being connected to the pipeline system (2) via a plurality of valve devices (3), and each of the plurality of valve devices having a switchable isolation valve (30).

Images