WO2024104675A1

WO2024104675A1 - Tank system and method for testing an isolating valve in a tank system

Info

Publication number: WO2024104675A1
Application number: PCT/EP2023/078694
Authority: WO
Inventors: Christian Kuhnert; Birgit LENZ; Stefan Kieferle; Markus Strasser; Nicolas WUSSLER; Martin Schwab; Christian Schugger
Original assignee: Robert Bosch Gmbh
Priority date: 2022-11-14
Filing date: 2023-10-16
Publication date: 2024-05-23
Also published as: DE102022212019A1

Abstract

Disclosed is a method for testing a switchable isolating valve of a valve device that connects a tank vessel to a pipe system, wherein a gas is stored at a first pressure in the tank vessel, and a second pressure that is lower than the first pressure prevails in the pipe system. The method comprises: actuating the isolating valve in order to switch it from a closed position, in which the isolating valve closes an extraction path of the valve device, which extraction path connects the pipe system and the tank vessel, into an open position, in which the isolating valve opens the extraction path; detecting a pressure profile in a tank-side portion of the extraction path which extends between the tank vessel and the isolating valve; determining whether the pressure profile detected after the actuation of the isolating valve includes a pressure drop; and outputting a fault signal if it is determined that the pressure profile detected after the actuation of the isolating valve does not include a pressure drop.

Description

Title

Tank system and method for testing an isolating valve in a tank system

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.

US 7367349 B2 describes a supply system for a fuel cell in which several tanks are connected in parallel via a respective extraction line to a line system for supplying the fuel cell. A switchable isolating valve is arranged in each extraction line in order to connect the respective tank to the line system or to disconnect it from it. When starting the system, initially only one of the isolating valves is opened to increase the pressure in the piping system and subsequently the remaining valves are opened. This serves the purpose of reducing the wear and tear on the valves by reducing the pressure difference between the tanks and the high pressure piping 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 brief drop in pressure on the tank side. This means that in a tank-side section of a removal path of the valve device, an undershoot in the pressure curve occurs when the isolating valve switches from its closed position to its open position. This brief drop in pressure can be determined or detected by means of a control device in the pressure signal supplied by the pressure sensor. If such a drop in pressure is detected, it can be concluded that the respective isolating valve has opened correctly. If no drop in pressure 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 activation.

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 the 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 the pressure drop is not included. 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.

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

Fig. 1 is a schematic view of a hydraulic circuit diagram of a tank system according to an embodiment of the invention;

Fig. 2 is a detailed view of a valve device of a tank system according to an embodiment of the invention; and

Fig. 3 shows 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. Fig. 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 shown by way of example in Fig. 1, the tank system 100 has a plurality of tank containers 1, a line system 2, a plurality of valve devices 3 and a control device 5. A user interface 6 can also be provided optionally. In Fig. 1, a tank system 100 with three tank containers 1 is shown purely by way of 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, Fig. 1 shows 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 a plurality of 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, for example, be a high-pressure line system 2 which is connected to the consumer system 2 via an optional medium-pressure line system 7, which is only symbolically shown as a block in Fig. 1. As shown schematically in Fig. 1, the tanks 1 are connected to the line system 2 in parallel to one another.

The valve devices 3 are assigned to the respective tank 1 and connect it to the line system 2. Fig. 2 shows schematically and in a highly simplified manner an exemplary structure of the valve device 3. As shown in Fig. 2, 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 Fig. 2, a switchable isolating valve 30 and a pressure sensor 4. Optionally, a check valve 33 can also be provided. Likewise optionally, the valve device 3 can have a temperature sensor 35, as shown purely by way of example in Fig. 2.

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 Fig. 2, the isolating valve 30 is shown 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 establishes 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 further shown in Fig. 2, 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 further shown in Fig. 2, 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 purely by way of example in Fig. 2. 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 be used to measure a temperature in the tank container 1.

The control device 5 is shown in Fig. 1 only 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, for example, be implemented 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 that 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 schematically in Fig. 3. The method M is based on an initial situation in which a gas, e.g. hydrogen, 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. The isolating valves 30 are closed in this case. Such an initial situation can be present, for example, before starting or booting up the consumer system 200 connected to the tank system 100. 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 M1 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 shown by way of example in Fig. 2, is designed as an electrically controllable, normally closed solenoid valve, the generation of the first opening force can include energizing the isolating valve 30 with a first control current. If, as shown by way of example in Fig. 1, several tank containers 1 with several valve devices 3 are provided, the isolating valves 30 of the various valve devices 3 can be controlled one after the other or simultaneously.

In step M2, the pressure in the tank-side section 31A of the removal path 31 in magazines is detected 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 after 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, with a pressure drop being determined or detected if the pressure gradient assumes values less than zero within a predetermined period of time after the activation.

If it is determined in step M3 that the detected pressure curve after the activation M1 of the isolating valve 30 contains a pressure drop, as shown in Fig. 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 actuation (step M1) of the isolating valve 30 does not contain a pressure drop, as shown by the symbol in Fig. 3, the method M can go directly to step M4, in which the control device 5 outputs an error signal. Outputting the error signal can, for example, comprise generating an error message and writing the error message to 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 shown only symbolically as a block in Fig. 1, can 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 a pressure drop is not included in the respective detected pressure curve after the activation (step M1) of the respective isolating valve 30, e.g. together with an index of the respective isolating valve.

Optionally, in the event that 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 move 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 shown in Fig. 3 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 isolating valve 30 is again controlled 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 carried out again as described above. If it is determined in step M3 that the recorded pressure curve after the isolating valve 30 is actuated again with the second opening force contains a pressure drop (symbol “+” in Fig. 3), the method proceeds to step M5. Otherwise, i.e. if it is determined that the recorded pressure curve after the isolating valve 30 is actuated again with the second opening force does not contain a pressure drop, steps M31 and M32 follow. As long as it is determined in step M32 that the count value is smaller 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 renewed activation of the isolating valve 30 does not contain a pressure drop, while additionally steps M31 and M32 are carried out. For example, each time a first error signal is output in step M4 if 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, for example, only involve the generation and writing of a

Error message in the data memory 51, while the output of the second error signal may alternatively or additionally comprise output of a warning signal at the user interface. Although the present invention has been described above with reference to

Although the embodiments have been explained by way of example, it is not limited to this but can be modified in many different ways. In particular, combinations of the above embodiments are also conceivable.

Claims

Expectations

1. 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, the method (M) comprising:

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 (31 A) of the removal path (31) which extends between the tank container (1) and the isolation 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 detected pressure curve after the activation (M1) of the isolation valve (31) does not contain a pressure drop.

2. Method (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 occurs when it is determined again that the recorded pressure curve does not contain a pressure drop after the isolation valve has been activated again with the second opening force. Method (M) according to claim 2, wherein the isolation valve (30) is designed as an electrically controllable, normally closed solenoid valve, wherein the generation of the first opening force comprises energizing the isolation valve (30) with a first control current, and wherein the generation of the second opening force comprises energizing the isolation valve (30) with a second control current that 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 contains a pressure drop after the activation (M1) of the isolating valve (30). 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 (31 A) 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. Method (M) according to claim 5, wherein the isolation valves (30) are controlled sequentially 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 (31 A) 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 (31 A) of the removal path (31 A); and a control device (5) which is signal-connected to the valve device (3) and the pressure sensor (4) and is designed to cause the tank system (100) to carry out the steps of a method (M) according to one of the preceding claims. Tank system (100) according to claim 8, wherein the isolating valve (30) is designed as an electrically controllable, normally closed solenoid valve. Tank system (100) according to claim 8 or 9, wherein the tank system (100) has 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).