Method and system for detecting fault in fuel cell system

Abstract

The invention relates to a method for detecting a malfunction of a valve assembly (15) in a tank system (11) for a fuel cell system (10), the tank system (11) comprising a plurality of fuel tanks (12, 13, 14), a fuel line assembly (15) for guiding fuel from the fuel tanks (12, 13, 14), and a valve assembly (16), which has a respective discharge valve (17, 18, 19) for each fuel tank (12, 13, 14), the invention relates to a fuel cell system (10) for conducting fuel from a fuel tank (12, 13, 14) through a fuel line arrangement (15) in a controlled manner, comprising the following steps: ascertaining a cumulative actual fuel demand starting from the operation of the fuel cell system (10); calculating a reference fuel demand starting from the operation as a function of an analog change in the fill level state of the fuel tank (12, 13, 14); performing a comparison between the actual fuel demand and the calculated reference fuel demand; and detecting a fault of the valve assembly (16) based on the comparison. The invention also relates to a tank system (11) and a computer program product (23) for carrying out the method according to the invention. The invention also relates to a computer-readable storage medium (24) on which a computer program product (23) according to the invention is stored.

Description

Technical Field

[0001] The invention relates to a method and a system for detecting faults in a fuel cell system and in particular in a tank system of a fuel cell system. The invention also relates to a computer program product for executing such a method and to a computer-readable storage medium on which such a computer program product is stored. Background Art

[0002] Fuel cell systems often have complex tank systems. For example, DE 10 2017 212 485 A1 describes a system for storing fuel in a tank system for a vehicle, wherein the tank system comprises a tubular tank container and a high-pressure fuel distributor with integrated regulation and safety technology. The tank container is made of metal and is modularly connected to the high-pressure fuel distributor with integrated regulation and safety technology in a flexible geometry to form a module.

[0003] During driving operation, the tank container should be protected as well as possible from mechanical and / or thermal loads such as vibrations, braking or acceleration. This also applies to the protection of the tank container in the event of an accident. In addition, it is desirable to continuously monitor the tank system in order to detect possible faults in the tank system as early as possible. This is always a challenge when using multiple tank containers. Summary of the invention

[0004] Within the scope of the present invention, a method and a system for detecting faults in a tank system of a fuel cell system are proposed. In particular, a method according to claim 1, a tank system according to claim 6, a computer program product according to claim 8 and a computer-readable storage medium according to claim 9 are proposed. Further embodiments of the invention are derived from the dependent claims, the description and the drawings. In this case, the features described in connection with the method also apply to the tank system according to the invention, the computer program product according to the invention, the storage medium according to the invention and vice versa, so that the disclosures concerning the various aspects of the invention are always mutually referenced or can be mutually referenced.

[0005] According to a first aspect of the present invention, a method for detecting a fault of a valve assembly in a tank system for a fuel cell system is provided. The tank system comprises a plurality of fuel tanks, a fuel line assembly for guiding fuel from the fuel tanks, and a valve assembly, wherein the valve assembly has a discharge valve for each fuel tank for guiding fuel from the fuel tank through the fuel line assembly in a controlled manner. The method comprises the following steps:

[0006] - determining the cumulative and / or overall actual fuel requirement since the start of operation of the fuel cell system;

[0007] - According to the simulated change of the fuel tank level state (virtuelle ) calculate the reference fuel requirement from the start of the operation;

[0008] - perform a comparison between the actual fuel requirement and the calculated reference fuel requirement;

[0009] - Detecting a malfunction of the valve assembly based on the comparison.

[0010] It has been found within the scope of the present invention that, based on the comparison of the actual fuel demand and the calculated reference fuel demand, convincing conclusions about possible faults of the valve assembly can be derived. Based on the comparison according to the invention or the comparison according to the invention, a fault can be detected in particular by identifying that the outlet valve cannot be switched and / or cannot be opened, in particular during the operation of the fuel cell system and / or during the removal of mass and / or fuel from the fuel tank. Therefore, a fault can be understood as an inability of the outlet valve to switch and / or cannot be opened. If the inability to switch and / or cannot be opened is identified, corresponding countermeasures can be taken in order to deal with problems that may arise from this. In particular, the operation of the fuel cell system or the tank system can be prevented when one of the outlet valves is accidentally closed, as a result of which the associated fuel tank will or may not be emptied as desired.

[0011] In the context of the method, it is also possible to initiate predetermined measures based on the detected and / or displayed faults. That is, if the fault and / or at least one fault is detected, at least one predetermined measure can be initiated. A measure can be understood as the emission of an optical and / or acoustic warning signal. The warning signal can be emitted in a manner that can be perceived acoustically and / or optically for a user of the tank system and / or the fuel cell system (for example in the form of a driver of a vehicle with the fuel cell system).

[0012] The fault can be detected and then displayed. The display of the fault can be understood as the previously described output of a warning signal. Furthermore, the display of the fault can also be understood as the generation of a warning signal stored in a memory, from which a specialist can read the warning signal, for example, when checking the tank system. From the read warning signal, it can be inferred that a fault may have occurred or still exists. Measures can then be taken in order to at least avoid the fault in the future.

[0013] In the method according to the invention, the outlet valves can all be electrically actuated simultaneously or substantially simultaneously. In particular, the outlet valves can be actuated in parallel during startup of the fuel cell system or during operation of the fuel cell system. Electrical actuation can be understood as meaning that, whenever possible, the outlet valves are actuated into a release state for conducting fuel from the corresponding fuel tank into the fuel line assembly.

[0014] The accumulated actual fuel requirement is preferably determined after the electrical activation of the discharge valve, i.e. after the start-up of the fuel cell system and during the operation or normal operation of the fuel cell system. The accumulated actual fuel requirement can be determined by means of suitable measuring sensors and a computing unit connected to the measuring sensor signals. The accumulated actual fuel requirement can be understood as the accumulated fuel consumption and / or accumulated fuel mass requirement starting from the start-up of the fuel cell system.

[0015] The outlet valve may be understood as a tank valve which is respectively mounted directly or substantially directly on the fuel tank. The fuel tank may preferably be understood as a hydrogen tank. The detection and possible display of a fault of the valve assembly based on the comparison may be understood as being able to detect and display at least one fault based on the comparison or based on a corresponding comparison result. That is, the comparison result may be correspondingly evaluated and / or taken into account in appropriate calculations for the detection and display of the fault. The method may be performed in particular for detecting a fault of a valve assembly in a fuel cell system of a vehicle, in particular during operation of the fuel cell system in the vehicle.

[0016] The method steps according to the invention do not have to be performed in the order given. Individual method steps can also be performed in a different order and / or simultaneously. Thus, for example, it is possible to first calculate a reference fuel requirement and then determine the accumulated actual fuel requirement.

[0017] If, for example, it is determined within the scope of the comparison that the calculated reference fuel requirement is greater than the determined actual fuel requirement, it can be concluded that there is a fault, in particular that at least one discharge valve cannot be switched and / or cannot be opened. Within the scope of the comparison, the difference between the determined actual fuel requirement and the calculated reference fuel requirement can be calculated. This difference can be compared with a predetermined threshold value and / or a reference difference value. If this difference (possibly plus a predetermined tolerance) is greater than a predetermined threshold value or a reference difference, it can be concluded that there is a fault as described above. The calculated reference fuel requirement can be understood as a theoretical fuel requirement and / or a theoretical fuel consumption.

[0018] The method can be carried out not only for detecting faults of valve assemblies in tank systems for fuel cell systems, but also in principle for alternative tank systems of chemical and / or electrochemical energy converters.

[0019] According to another embodiment of the invention, the reference fuel requirement can be calculated from the start of operation as a function of a simulated change in the filling level of the fuel tank. This means that a simulated and / or theoretical filling level of the fuel tank is first determined in order to calculate the reference fuel requirement or the corresponding theoretical fuel consumption as a function of this value in order to use it for the comparison according to the invention. In this way, the method can be carried out particularly easily.

[0020] In the method of the present invention, the reference fuel demand can be calculated based on the temperature determined in the fuel line assembly and / or the gas pressure determined in the fuel line assembly. In this way, the reference fuel demand can be calculated quickly, simply and reliably. For the calculation, the measured value can be obtained with the help of a standard configuration sensor. Therefore, the reference fuel demand can be obtained without or with only a small amount of additional technical measures. In order to obtain the temperature and / or gas pressure, a measuring sensor device having at least one pressure sensor for obtaining the line pressure in the fuel line assembly and / or at least one temperature sensor for obtaining the temperature in the fuel line assembly can be used. In the case of using a single pressure sensor in the fuel line assembly, the use of multiple pressure sensors in the fuel tank can be eliminated. Based on the gas pressure in the fuel line assembly determined or measured, it can be said that the simulated line pressure in different pipeline sections on different fuel tanks can be obtained, from which the simulated level state of the fuel tank described above can be derived. The reference fuel demand can be calculated in particular based on at least one temperature value determined in at least one fuel tank.

[0021] According to another embodiment of the invention, it can be that in the method, a fault of the valve assembly is detected when the actual fuel requirement is determined based on the comparison to be less than the calculated reference fuel requirement by a predetermined reference value. The comparison of different fuel cell systems can be adapted in a simple and / or flexible manner and performed accordingly based on the predetermined reference value.

[0022] Furthermore, in the method according to the invention, if a fault is detected, the main method steps of the invention are repeated and the outlet valve is electrically actuated with a higher current than before the fault was detected. In other words, if a fault is detected, an alternative reaction is carried out, so to speak, for repeated attempts to open the outlet valve with an increased pull-in current. Depending on whether the opening is successful or not, the type and / or severity of the fault can be inferred. In other words, the type and / or severity of the fault can thus be detected and displayed more accurately. For repeated attempts to open, the outlet valve can be actuated or energized accordingly, in particular, with the maximum permissible pull-in current.

[0023] Another aspect of the present invention relates to a tank system for a fuel cell system, the tank system having a plurality of fuel tanks, a fuel line assembly for guiding fuel from the fuel tanks, and a valve assembly, the valve assembly having a discharge valve for each fuel tank, for guiding the fuel from the fuel tank through the fuel line assembly in a controlled manner. The tank system also has a determination unit for determining the accumulated actual fuel demand from the start of operation of the fuel cell system; and the tank system also has a calculation unit for calculating the reference fuel demand from the start of operation based on the simulated change of the level state of the fuel tank, so as to compare the actual fuel demand with the calculated reference fuel demand and detect the failure of the valve assembly based on the comparison. Therefore, the tank system according to the present invention brings the same advantages as described in detail about the method according to the present invention. The tank system can be configured and configured as part of a fuel cell system. The fuel cell system can be configured and configured as part of a vehicle.

[0024] According to the invention, a tank system is also provided which is configured and designed to carry out the method described above. That is, the tank system can have suitable sensors, suitable computing units and / or suitable actuators for carrying out the method.

[0025] Another aspect of the invention relates to a computer program product, which includes instructions that cause the method steps according to the invention to be carried out in a tank system as described above. The invention also relates to a computer-readable, in particular non-volatile, storage medium on which such a computer program product is stored. The computer program product and the storage medium according to the invention therefore also bring about the advantages described above.

[0026] The computer program product can be executed as a computer-readable instruction code in any suitable programming language and / or machine language (such as JAVA, C++, C# and / or Python). The computer program product can be stored on a computer-readable storage medium such as a data disk, a replaceable storage device, a volatile or non-volatile memory or a built-in memory / processor. The instruction code can program a computer or other programmable device such as a controller of a fuel cell system and / or a controller of a vehicle with a fuel cell system so that the required functions are implemented. In addition, the computer program product can be provided in a network, such as the Internet, and can be downloaded by a user when necessary. The computer program product can be implemented not only by software, but also by one or more specialized electronic circuits, that is, in hardware or in any combination, that is, by software components and hardware components. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Measures for improving further advantages of the invention are derived from the following description of various embodiments of the invention, which are schematically shown in the drawings. All features and / or advantages highlighted by the claims, the description or the drawings, including structural details and spatial arrangements, may be important to the invention both individually and in various combinations.

[0028] The accompanying drawings schematically show:

[0029] Figure 1 : A fuel cell system with a tank system according to an embodiment of the present invention;

[0030] Figure 2 : A tank system according to an embodiment of the present invention;

[0031] Figure 3 : A storage medium having a computer program product stored thereon according to an embodiment of the present invention;

[0032] Figure 4 : A flow chart for illustrating a method according to one embodiment of the present invention.

[0033] In the figures, elements having the same function and mode of action are respectively provided with the same reference symbols. DETAILED DESCRIPTION

[0034] Figure 1 A fuel cell system 10 is shown which is configured and constructed for mobile use in a vehicle. The fuel cell system 10 has a filling section 30 which has a tank connection 35 in the form of a connecting pipe. The fuel cell system 10 also has a storage section 31 which has a fuel line assembly 15, a fuel tank assembly 38 and a valve 36 in the form of a shut-off or stop valve. In addition, the fuel cell system 10 has a supply section 32 which has a pressure regulator 37, by which the fuel can be directed from the storage section 31 to the fuel cell section 33 of the fuel cell system 10 in a controlled manner. In addition, the fuel cell system 10 has a power section 34 in which the current or voltage generated in the fuel cell section 10 can be converted into driving power for the vehicle.

[0035] exist Figure 2 As shown in Figure 1 The tank system 11 of the fuel cell system 10 shown in FIG. Figure 2The tank system 11 shown in FIG. 1 has three fuel tanks 12, 13, 14, a fuel line assembly 15 for guiding fuel from the fuel tanks 12, 13, 14, and a valve assembly 16 for guiding the fuel from the fuel tanks 12, 13, 14 through the fuel line assembly 15 in a controlled manner. The fuel tanks 12, 13, 14 are connected to the fuel line assembly 15 in parallel with each other. The valve assembly 16 has three outlet valves 17, 18, 19, wherein the outlet valves 17, 18, 19 are respectively installed on one fuel tank 12, 13, 14. In addition, a temperature sensor 25 is configured in each tank for determining the temperature in each fuel tank 12, 13, 14. The tank system 11 also has a determination unit 21 for determining the accumulated actual fuel demand from the start of the operation of the fuel cell system 10. Furthermore, the tank system 11 has a calculation unit 22 for calculating a reference fuel requirement from the start of operation based on a simulated change in the filling level state of the fuel tanks 12, 13, 14, for performing a comparison between the actual fuel requirement and the calculated reference fuel requirement and for detecting a malfunction of the valve assembly 16 based on the comparison. Furthermore, the tank system 11 has a control unit 20 for electrically actuating the discharge valves 17, 18, 19. The control unit 20 is schematically shown and can have a plurality of components spaced apart from one another. The control unit 20 can be a controller, in particular in the form of a vehicle controller. According to the invention, the control unit 20 can be a controller, in particular in the form of a vehicle controller. Figure 2 In the embodiment shown in , the computing unit 22 is a component of the control unit 20 .

[0036] exist Figure 3 2 shows a computer-readable non-volatile storage medium 24 in the form of a memory stick. A computer program product 23 is stored on the storage medium 24. The computer program product 23 includes instructions that cause the Figure 1 and Figure 2 The tank system 11 shown in the drawings performs a method, which is subsequently referred to as Figure 4 Explain.

[0037] Reference Figure 4The flowchart shown in explicates a method for detecting a fault in the previously described valve assembly 16. More precisely, the method can be used to find out whether the valve assembly 16 has a fault, in particular a fault in the form of at least one outlet valve that cannot be opened. To this end, in a first step S1, the fuel cell system 10 or its normal operation is first started. In a second step S2, the accumulated actual fuel demand from the start of operation of the fuel cell system 10 is determined. In a third step S3, a reference fuel demand from the start of operation is calculated based on a simulated change in the level state of the fuel tanks 12, 13, and 14. In a fourth step S4, a comparison is performed between the actual fuel demand and the calculated reference fuel demand. In a fifth step S5, a possible fault of the valve assembly is detected based on the comparison or the comparison result obtained therefrom, or whether there is a fault in the valve assembly 16 is found. If a fault is detected, in particular in the form of at least one outlet valve 17 , 18 , 19 that cannot be opened, steps S1 to S5 or S1n to S5 are executed again, wherein in step S1n outlet valves 17 , 18 , 19 are energized more strongly than before or than in the previous cycle.

[0038] In addition to the embodiment shown, the invention also allows other configuration principles. That is, the invention should not be seen as being limited to the embodiments described with reference to the drawings. Thus, it is possible to calculate a reference fuel demand from the start of operation based on a simulated change in the filling level state of the fuel tanks 12, 13, 14. The reference fuel demand can be calculated based on the determined temperature in the fuel line assembly 15 and / or the determined gas pressure in the fuel line assembly 15. If it is determined based on the comparison that the actual fuel demand is less than the calculated reference fuel demand by a predetermined reference value, a fault in the valve assembly 16 can be detected in particular.

Claims

1. A method for detecting a fault in a valve assembly (15) in a tank system (11) for a fuel cell system (10), wherein: The tank system (11) comprises a plurality of fuel tanks (12, 13, 14), a fuel line assembly (15) for guiding fuel from the fuel tanks (12, 13, 14), and a valve assembly (16), wherein the valve assembly has a discharge valve (17, 18, 19) for each fuel tank (12, 13, 14) and is used to guide the fuel from the fuel tank (12, 13, 14) through the fuel line assembly (15) in a controlled manner. Features: - determining the accumulated actual fuel requirement since the start of operation of the fuel cell system (10); - calculating a reference fuel requirement from the start of the operation based on a simulated change in the filling level state of the fuel tanks (12, 13, 14); - performing a comparison between said actual fuel requirement and said calculated reference fuel requirement; and - detecting a malfunction of the valve assembly (16) based on the comparison.

2. The method according to claim 1, It is characterized in that A reference fuel requirement from the start of the operation is calculated based on a simulated change in the filling level state of the fuel tank (12, 13, 14).

3. The method according to any one of the preceding claims, It is characterized in that The reference fuel requirement is calculated as a function of the determined temperature in the fuel line component (15) and / or the determined gas pressure in the fuel line component (15).

4. The method according to any one of the preceding claims, It is characterized in that If it is determined based on the comparison that the actual fuel demand is less than the calculated reference fuel demand by a predetermined reference value, a malfunction of the valve assembly (16) is detected.

5. The method according to any one of the preceding claims, It is characterized in that If a fault is detected, the method steps according to claim 1 are repeated and the outlet valve (17, 18, 19) is electrically actuated with a higher current than before the fault was detected.

6. A tank system (11) for a fuel cell system (10), comprising a plurality of fuel tanks (12, 13, 14), a fuel line assembly (15) for guiding fuel from the fuel tanks (12, 13, 14), and a valve assembly (16), wherein the valve assembly has a discharge valve (17, 18, 19) for each fuel tank (12, 13, 14), respectively, for guiding fuel from the fuel tanks (12, 13, 14) through the fuel line assembly (15) in a controlled manner, Features: - a determination unit (21) for determining the actual fuel requirement accumulated since the start of operation of the fuel cell system (10), and - a calculation unit (22) for calculating a reference fuel requirement from the start of the operation based on a simulated change in the filling level state of the fuel tanks (12, 13, 14), for performing a comparison between the actual fuel requirement and the calculated reference fuel requirement and for detecting a malfunction of the valve assembly (16) based on the comparison.

7. The tank system (11) according to claim 6, which is configured and designed to carry out the method according to any one of claims 1 to 5.

8. A computer program product (23) comprising instructions causing the method steps according to any one of claims 1 to 5 to be performed in a tank system (11) according to any one of claims 6 to 7.

9. A computer-readable storage medium (24) on which a computer program product according to claim 8 is stored.

Images