DE102022212019A1 - Tank system and method for testing an isolating valve in a tank system - Google Patents

Abstract

A method is disclosed for testing a switchable isolating valve of a valve device which connects a tank container to a line system, wherein a gas is stored in the tank container at a first pressure and a second pressure is present in the line system which is lower than the first pressure. The method comprises controlling the isolating valve in order to switch it from a closed position in which the isolating valve closes a removal path of the valve device connecting the line system and the tank container to an open position in which the isolating valve opens the removal path, detecting a pressure curve in a tank-side section of the removal path which extends between the tank container and the isolating valve, determining whether the detected pressure curve after the isolating valve is activated includes a pressure drop, and outputting an error signal if it is determined that the detected pressure curve after the isolating valve is activated does not include a pressure drop.

Description

Technical area

The present invention relates to a tank system, in particular a tank system for storing a gaseous fuel, such as hydrogen, and for supplying a consumer system with the gaseous fuel, as well as a method for testing an isolating valve in a tank system.

State of the art

Hydrogen and other gaseous fuels can be used in mobile applications, particularly in road vehicles, to operate drive systems. This includes the operation of fuel cells as well as combustion engines or other heat engines. Gaseous fuels can also be used advantageously in stationary applications to generate energy. The gas is usually stored in a tank system with one or more tank containers and fed to the consumer system, e.g. a fuel cell or a combustion engine, via a line system that is connected to the tank container or containers.

In the US 7 367 349 B2 A supply system for a fuel cell is described in which several tanks are connected in parallel to a line system for supplying the fuel cell via a respective extraction line. A switchable isolating valve is arranged in each extraction line to connect the respective tank to the line system or to disconnect it from it. When the system is started, only one of the isolating valves is opened first to increase the pressure in the line system, and then the remaining valves are opened. This serves the purpose of reducing wear on the valves by reducing the pressure difference between the tanks and the high-pressure line system at the time the remaining valves are opened.

In general, it is desirable that the isolation valves open reliably when the system is started in order to increase operational safety. This applies to systems with just one tank as well as to systems with multiple tanks.

Disclosure of the invention

Against this background, the present invention provides a method having the features of claim 1 and a tank system having the features of claim 8.

According to a first aspect of the invention, a method is provided for testing a switchable isolating valve of a valve device which connects a tank container to a line system, wherein a gas is stored in the tank container at a first pressure and a second pressure is present in the line system which is lower than the first pressure. The method comprises controlling the isolating valve in order to switch it from a closed position in which the isolating valve closes a removal path of the valve device connecting the line system and the tank container to an open position in which the isolating valve opens the removal path, detecting a pressure curve in a tank-side section of the removal path which extends between the tank container and the isolating valve, determining whether the detected pressure curve after the isolating valve is activated includes a pressure drop, and outputting an error signal if it is determined that the detected pressure curve after the isolating valve is activated does not include a pressure drop.

According to a second aspect of the invention, a tank system comprises at least one tank container for storing gas, in particular hydrogen, a line system for supplying a consumer system, such as a fuel cell or a heat engine, a valve device with a removal path which connects the tank container and the line system, and a switchable isolating valve arranged in the removal path, which can be switched between a closed position in which it closes the removal path and an open position in which it opens the removal path, a pressure sensor which is connected to a tank-side section of the removal path which extends between the tank container and the isolating valve and is designed to detect the pressure in the tank-side section of the removal path, and a control device which is signal-connected to the valve device and the pressure sensor and is designed to cause the tank system to carry out the steps of a method according to one of the preceding claims.

One idea underlying the invention is to record a pressure curve on the tank side of the isolating valve and to evaluate it after the valve has been activated. Since the pressure in the line system before the isolating valve is opened is lower than in the tank container and thus on the tank side of the isolating valve, opening the isolating valve leads to a short-term pressure drop on the tank side. This means that an undershoot in the pressure curve occurs in a tank-side section of a removal path of the valve device when the isolating valve moves from its closed position to its open position. This short-term pressure drop can be determined or detected by a control device in the pressure signal provided by the pressure sensor. If such a pressure drop is detected, it can be concluded that the respective isolating valve has opened correctly. If no pressure drop is detected, it can be concluded that the isolating valve was not switched from the closed position to the open position as a result of the control.

An advantage of the invention is that a non-switching isolating valve can be reliably detected.

Advantageous embodiments and further developments emerge from the further subclaims and from the description with reference to the figures of the drawing.

According to some embodiments, it can be provided that the actuation of the isolating valve comprises generating a first opening force for opening the isolating valve, wherein, if it is determined that the recorded pressure curve after the actuation of the isolating valve does not contain a pressure drop, the isolating valve is actuated again with a second opening force that is greater than the first opening force, wherein the steps of recording the pressure curve and determining are carried out again. Accordingly, if it is determined during the first actuation of the isolating valve that it does not open, the isolating valve can be actuated again, specifically with an increased opening force. This can further increase operational reliability, since the tank system can continue to be fully functional if the isolating valve can be opened with the increased opening force.

According to some embodiments, it can be provided that the error signal is only output when it is determined again that a pressure drop is not included in the recorded pressure curve after the isolation valve is activated again with the second opening force. Optionally, a first error signal can be output when a pressure drop is not identified in the recorded pressure curve after the isolation valve is activated for the first time, and a second error signal can be output when it is determined again that a pressure drop is not included in the recorded pressure curve after the isolation valve is activated again with the second opening force.

According to some embodiments, it can be provided that the isolating valve is designed as an electrically controllable, normally closed solenoid valve, wherein the generation of the first opening force comprises energizing the isolating valve with a first control current, and wherein the generation of the second opening force comprises energizing the isolating valve with a second control current that is greater than the first control current.

According to some embodiments, it can be provided that an enable signal is output when it is determined that the detected pressure curve contains a pressure drop after the isolation valve is activated.

For example, issuing the release signal may include generating a release message and writing the release message to a data memory.

According to some embodiments, it can be provided that several tank containers are connected to the line system via several valve devices, each of which has a switchable isolating valve, wherein each isolating valve is controlled in order to switch it from the closed position to the open position, wherein a pressure curve in the tank-side section of the extraction path is detected by each isolating valve after the respective isolating valve is controlled, wherein the determination of whether the detected pressure curve after the isolating valve is included in a pressure drop is carried out for each isolating valve, and wherein the error signal is output for each isolating valve for which it is determined that the respective detected pressure curve after the isolating valve is included in a pressure drop. In particular, with a plurality of tank containers, undesirable effects can occur if one of the isolating valves does not open. On the one hand, the gas stored in the tank container whose isolating valve does not open is not available for the consumer system. On the other hand, the tank containers are unevenly emptied. If the non-opening isolation valve opens at a later point in time, e.g. when the system is restarted, this leads to pressure equalization and/or backfilling of the other tank containers. Such situations can be reliably avoided using the procedure.

According to some embodiments, it can be provided that the isolation valves are controlled sequentially or simultaneously.

According to some embodiments, it can be provided that determining whether the detected pressure curve after the activation of the isolating valve contains a pressure drop comprises determining a pressure gradient of the detected pressure curve, and a pressure drop is determined if the pressure gradient assumes values less than zero within a predetermined period of time after the activation.

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

According to some embodiments, the isolating valve can be designed as an electrically controllable, normally closed solenoid valve.

According to some embodiments, it can be provided that the tank system has a plurality of tank containers which are connected to the line system via a plurality of valve devices, each of which has a switchable isolating valve.

The features and advantages disclosed herein in connection with one aspect of the invention are also disclosed for the other aspect.

• 1 eine schematische Ansicht eines hydraulischen Schaltbilds eines Tanksystems gemäß einem Ausführungsbeispiel der Erfindung;
• 2 eine Detailansicht einer Ventileinrichtung eines Tanksystems gemäß einem Ausführungsbeispiel der Erfindung; und
• 3 den Ablauf eines Verfahrens gemäß einem Ausführungsbeispiel der Erfindung.

The invention is explained below with reference to the figures of the drawings. The figures show:

• 1 a schematic view of a hydraulic circuit diagram of a tank system according to an embodiment of the invention;
• 2 a detailed view of a valve device of a tank system according to an embodiment of the invention; and
• 3 the sequence of a method according to an embodiment of the invention.

In the figures, the same reference symbols designate identical or functionally identical components, unless otherwise stated.

1 shows a schematic of a tank system 100 for supplying a consumer system 200 with a gaseous fuel, eg hydrogen. The consumer system 200 can be, for example, a fuel cell or a heat engine. The tank system 100 can be used, for example, in a mobile application, such as a vehicle. However, the invention is not limited to this.

As in 1 As shown by way of example, the tank system 100 comprises a plurality of tank containers 1, a line system 2, a plurality of valve devices 3 and a control device 5. Optionally, a user interface 6 can also be provided. In 1 a tank system 100 with three tank containers 1 is shown purely as an example. It is also conceivable that the tank system 100 has only one tank container 1 or a number other than three tank containers 1. Furthermore, in 1 It is shown by way of example that a valve device 3 is provided for each tank container 1, via which the respective tank container 1 is connected to the line system 2. Alternatively, it is also conceivable that several tank containers 1 are connected to the line system 2 via a common valve device 3.

The tank containers 1 generally define an internal volume and can, for example, be designed to store hydrogen at a nominal pressure of up to 700 bar.

The line system 2 can be, for example, a high-pressure line system 2, which has an optional medium-pressure line system 7, which is 1 is only symbolically represented as a block, is connected to the consumer system 2. As in 1 As shown schematically, the tanks 1 are connected parallel to each other to the piping system 2.

The valve devices 3 are assigned to the respective tank 1 and connect it to the pipe system 2. 2 shows schematically and very simplified an example structure of the valve device 3. As in 2 As shown, the valve device 3 has a first internal connection 3A, which is connected to the internal volume of the tank 1, and an external connection 3C, which is connected to the line system 2. Furthermore, a second internal connection 3B can optionally be provided. The valve device 3 has, as shown in 2 shown, a switchable isolating valve 30 and a pressure sensor 4. Optionally, a check valve 33 can also be provided. Also optionally, the valve device 3 can have a temperature sensor 35, as in 2 shown purely as an example.

The first internal connection 3A and the external connection 3C are connected to one another by a removal path 31 in which the isolating valve 30, e.g. in the form of an electrically switchable, normally closed solenoid valve, is arranged. The isolating valve 30 divides the removal path 31 into a tank-side section 31A, which extends between the first internal connection 3A and the isolating valve 30, and a line-side section 31B, which extends between the isolating valve 30 and the external connection 3C. The isolating valve 30 can be switched between a closed position and an open position. In 2 is the isolation valve 30 in the closed position. In this position, it closes the extraction path, i.e., it interrupts the fluidic connection of the tank-side and line-side sections 31A, 31B of the extraction path 31 and thus prevents gas from flowing out of the tank container 1 from the first internal connection 3A to the external connection 3C. In the open position, the isolating valve 30 opens the extraction path, i.e., it creates a fluidic connection of the tank-side and line-side sections 31A, 31B of the extraction path 31 and allows gas to flow out of the tank container 1 from the first internal connection 3A to the external connection 3C.

As in 2 further shown, the second internal connection 3B can be connected to the external connection 3C by a filling path 32. The optional check valve 33 is arranged in the filling path 32 and designed such that it only allows a flow from the external connection 3C to the second internal connection 3B. If there is a higher pressure in the line system 2 than in the tank container 1, gas from the line system 2 can flow from the external connection 3C via the second internal connection 3B into the tank container 1 even when the isolating valve 30 is closed.

As in 2 Further shown, the pressure sensor 4 is connected to the tank-side section 31A of the extraction path 31. The pressure in the tank-side section 31A of the extraction path 31A can thus be detected by means of the pressure sensor 4.

The optional temperature sensor 35 can be part of the valve device 3, as shown in 2 shown purely as an example. The temperature sensor 35 is arranged such that it is connected to the inner volume of the tank container 1. The temperature sensor 35 can thus measure a temperature in the tank container 1.

The control device 5 is in 1 only shown as a block 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 be implemented, for example, as a CPU, as an FPGA, as an ASIC or the like. The data memory 51 can in particular be a non-volatile data memory, e.g. a flash memory, an SD memory, a 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 causes it to generate output signals, e.g. in the form of control signals, based on input signals, e.g. in the form of measured values. The control device 5 is signal-connected to the valve devices 3 and the respective pressure sensor 4, e.g. wired via a data bus, such as a CAN bus, USB or the like, or wirelessly, e.g. via WiFi, Bluetooth or the like.

In particular, the control device 5 can be designed to cause the tank system 100 to carry out a method M for testing the switchable isolating valve 30 of the respective valve device 3. The sequence of a method M for testing the switchable isolating valve 30 of the respective valve device 3 is shown in 3 shown schematically. The method M is based on an initial situation in which a gas, eg hydrogen, is stored in the tank container 1 at a first pressure, and a second pressure, which is lower than the first pressure, is present in the line system 2. The isolating valves 30 are closed. Such an initial situation can exist, for example, before the consumer system 200 connected to the tank system 100 is started or started up. The method M is explained below with reference to the tank system 100 described above.

In a first step M1, the isolating valve 30 is controlled by means of the control device 5, e.g. by outputting a control signal to the isolating valve 30 in order to switch it from its closed position to its open position. The control signal can in particular cause a first opening force to be generated to open the isolating valve 30. If the isolating valve 30, as in 2 shown by way of example, is designed as an electrically controllable, normally closed solenoid valve, the generation of the first opening force can comprise energizing the isolating valve 30 with a first control current. If, as in 1 If, as shown by way of example, several tank containers 1 with several valve devices 3 are provided, the isolating valves 30 of the different valve devices 3 can be controlled successively or simultaneously.

In step M2, the pressure in the tank-side section 31A of the extraction path 31 is recorded in time steps by means of the pressure sensor 4. The control device 5 thus receives a pressure signal which represents a pressure curve.

In step M3, the control device 5 determines whether the recorded pressure curve after the activation (step M1) of the isolating valve 30 contains a pressure drop. The control device 5 thus evaluates the pressure signals that were recorded from the activation of the isolating valve 30 and checks whether the pressure signals indicate a pressure drop, at least for a limited period of time. For example, the control device 5 can determine a pressure gradient of the recorded pressure curve. tel, whereby a pressure drop is determined or detected if the pressure gradient assumes values less than zero within a predetermined period of time after activation.

If it is determined in step M3 that the recorded pressure curve after the activation M1 of the isolating valve 30 contains a pressure drop, as is shown in 3 is shown by the symbol "+", the method can proceed to step M5. The presence of a pressure drop indicates that the respective isolating valve 30 was opened upon activation (step M1). As a result of the pressure in the line system 2, which is lower than the pressure in the tank container 1, a pressure drop occurs after the isolating valve 30 is opened, which is usually limited in time. The pressure curve therefore contains a type of undershoot.

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

If it is determined in step M3 that the recorded pressure curve after the activation (step M1) of the isolation valve 30 does not contain a pressure drop, as in 3 represented by the symbol "-", the method M can go directly to step M4, in which the control device 5 outputs an error signal. The output of the error signal can, for example, comprise 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 in 1 is only symbolically shown as a block, have a display device or a warning light, which is caused by the control device 5 to output an optical signal, or an acoustic or haptic warning signal can be output at the user interface 6. The error signal can be output for each isolating valve 30 for which it is determined that the respective recorded pressure curve after the activation (step M1) of the respective isolating valve 30 does not contain a pressure drop, e.g. together with an index of the respective isolating valve.

Optionally, if it is determined in step M3 that the recorded pressure curve after the activation (step M1) of the isolating valve 30 does not contain a pressure drop, the method M can first proceed to step M31. In step M31, the control device 5 can increase a count value by one, which indicates how often the isolating valve 30 has been activated since the last closing of the isolating valve 30 in order to switch it from the closed position to the open position. When the isolating valve 30 is switched to its closed position, the count value is set to zero.

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 two and ten. If it is determined in step M32 that the counter value is less than the limit value, as in 3 represented by the symbol "+", the method can go back to step M1. In this case, the isolating valve 30 is again controlled by the control device 5, wherein the renewed control of the isolating valve 30 takes place with a second opening force that is greater than the first opening force. For example, generating the second opening force can include energizing the isolating valve 30 with a second control current that is greater than the first control current. Steps M2 and M3 are then run through again as described above. If it is determined in step M3 that the recorded pressure curve after the renewed control of the isolating valve 30 with the second opening force contains a pressure drop (symbol "+" in 3 ), the method proceeds to step M5. Otherwise, i.e. if it is determined that the recorded pressure curve does not contain a pressure drop after the isolation valve is activated again with the second opening force, steps M31 and M32 follow. As long as it is determined in step M32 that the count value is less than the limit value (symbol "+"), steps M1-M3 can follow again, whereby the opening force can optionally be increased further with each iteration. If it is determined in step M32 that the count value reaches the limit value (symbol "-"), the method proceeds to step M4.

Optionally, the error signal is output in step M4 only if it is determined again at least once that the recorded pressure curve does not contain a pressure drop after the isolation valve has been activated again with the second opening force.

Alternatively, step M4 can be carried out each time it is determined in step M3 that the recorded pressure curve after the isolation valve 30 has been reactivated does not contain a pressure drop, while steps M31 and M32 are also carried out. For example, a first error signal can be output in step M4 each time it is determined in step M32 that the count value is less than the limit value. If 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. The output of the first error signal can e.g., it may merely comprise generating and writing an error message into the data memory 51, while outputting the second error signal may alternatively or additionally comprise outputting a warning signal at the user interface.

Although the present invention has been explained above using exemplary embodiments, it is not limited thereto, but can be modified in many ways. In particular, combinations of the above exemplary embodiments are also conceivable.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• US 7367349 B2 [0003]

Claims (10)

Method (M) for testing a switchable isolating valve (30) of a valve device (3) which connects a tank container (1) to a line system (2), wherein a gas is stored in the tank container (1) at a first pressure and a second pressure is present in the line system (2) which is lower than the first pressure, wherein the method (M) comprises: Controlling (M1) the isolating valve (30) in order to switch it from a closed position in which the isolating valve (30) closes a removal path (31) of the valve device (3) connecting the line system (2) and the tank container (1) to an open position in which the isolating valve (30) opens the removal path (31); Detecting (M2) a pressure curve in a tank-side section (31A) of the removal path (31) which extends between the tank container (1) and the isolating valve (30); Determining (M3) whether the recorded pressure curve after the activation (M1) of the isolating valve (31) contains a pressure drop; and Outputting (M4) an error signal if it is determined that the recorded pressure curve after the activation (M1) of the isolating valve (31) does not contain a pressure drop. Procedure (M) according to Claim 1 , wherein the actuation (M1) of the isolating valve (30) comprises generating a first opening force for opening the isolating valve (30), wherein, if it is determined that the detected pressure curve after the actuation (M1) of the isolating valve (31) does not contain a pressure drop, the isolating valve (30) is actuated again (M1) with a second opening force which is greater than the first opening force, wherein the steps of detecting (M2) the pressure curve and determining (M3) are carried out again, and wherein the output (M4) of the error signal preferably only takes place if it is determined again that the detected pressure curve after the isolating valve is actuated again with the second opening force does not contain a pressure drop. Procedure (M) according to Claim 2 , wherein the isolating valve (30) is designed as an electrically controllable, normally closed solenoid valve, wherein the generation of the first opening force comprises energizing the isolating valve (30) with a first control current, and wherein the generation of the second opening force comprises energizing the isolating valve (30) with a second control current which is greater than the first control current. Method (M) according to one of the preceding claims, additionally comprising: Outputting (M5) a release signal when it is determined that the detected pressure curve after the activation (M1) of the isolating valve (30) contains a pressure drop. Method (M) according to one of the preceding claims, wherein a plurality of tank containers (1) are connected to the line system (2) via a plurality of valve devices (3), each of which has a switchable isolating valve (30), wherein each isolating valve (3) is controlled in order to switch it from the closed position to the open position, wherein a pressure curve in the tank-side section (31A) of the removal path (31) of each isolating valve (30) is detected after the respective isolating valve (30) has been controlled, wherein the determination (M3) of whether the detected pressure curve after the control (M1) of the isolating valve (30) contains a pressure drop is carried out for each isolating valve (30), and wherein the output (M4) of the error signal for each isolating valve (30) for which it is determined that the respective detected pressure curve after the control (M1) of the respective isolating valve (30) does not contain a pressure drop. Procedure (M) according to Claim 5 , wherein the isolating valves (30) are controlled successively or simultaneously. Method (M) according to one of the preceding claims, wherein the outputting (M4) of the error signal comprises generating an error message and writing the error message into a data memory (51) and/or outputting a warning signal to a user interface (6). Tank system (100), comprising: at least one tank container (1) for storing gas, in particular hydrogen; a line system (2) for supplying a consumer system (200); a valve device (3) with a removal path (31) which connects the tank container (1) and the line system (2), and a switchable isolating valve (30) arranged in the removal path (31), which can be switched between a closed position in which it closes the removal path (31) and an open position in which it opens the removal path (31); a pressure sensor (4) which is connected to a tank-side section (31A) of the removal path (31) which extends between the tank container (1) and the isolating valve (30) and is designed to detect the pressure in the tank-side section (31A) of the removal path (31A); and a control device (5) which is signal-connected to the valve device (3) and the pressure sensor (4) and is designed to control the tank system (100) to carry out the steps of a method (M) according to one of the preceding claims. Tank system (100) after Claim 8 , wherein the isolating valve (30) is designed as an electrically controllable, normally closed solenoid valve. Tank system (100) after Claim 8 or 9 , wherein the tank system (100) comprises a plurality of tank containers (1) which are connected to the line system (2) via a plurality of valve devices (3), each of which has a switchable isolating valve (30).

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