Method for detecting a malfunction, tank system, computer program product, and storage means

Abstract

The present invention relates to a method for detecting a malfunction of a fuel outlet arrangement (16) in a tank system (11) for a fuel cell system (10), having the steps of: determining a transition from increased operation to reduced operation of the tank system (11) with a reduced fuel mass flow from fuel tanks (12, 13, 14) of the tank system (11), determining a pressure build-up gradient in a fuel line arrangement (15) during the reduced operation after a defined time has elapsed since the determined transition to reduced operation, providing a target pressure build-up gradient, performing a comparison between the determined pressure build-up gradient during the reduced operation and the provided target pressure build-up gradient, and detecting a malfunction of the fuel outlet arrangement (16) on the basis of the comparison. The invention furthermore relates to a tank system (11) and a computer program product (23) for carrying out the method, and to a computer-readable storage medium (24) on which such a computer program product (23) is stored.

Description

[0001] Description

[0002] title

[0003] Method for detecting a malfunction, tank system, computer program product and storage means

[0004] The present invention relates to a method for detecting a malfunction, in particular in a fuel cell system and in particular in a tank system of a fuel cell system. The invention further relates to a tank system in or with which such a method can be carried out, a corresponding computer program product, and a computer-readable storage medium on which such a computer program product is stored.

[0005] State of the art

[0006] Fuel cell systems typically 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. The tank system comprises tubular tank containers and a high-pressure fuel distributor with integrated control and safety technology. The tank containers are made of metal and are connected to the high-pressure fuel distributor with integrated control and safety technology to form a modular module with a flexible geometry.

[0007] During ferry operation, the tanks should be as well protected as possible against mechanical and / or thermal stresses such as vibrations, braking, or acceleration. This also applies to the protection of the tanks in the event of an accident. Furthermore, it is desirable to constantly monitor the tank system in order to detect any malfunctions in the tank system as early as possible. This always presents a challenge when using multiple tanks.

[0008] Within the scope of the present invention, approaches to solutions are proposed in order to improve known methods and systems for detecting a malfunction in a tank system, in particular in a fuel cell system. In particular, a method according to claim 1, a tank system according to claim 7, a computer program product according to claim 9 and a computer-readable storage medium according to claim 10 are proposed. Further embodiments of the invention emerge from the subclaims, the description and the figures. Features that are described in connection with the method also apply in connection with 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 with regard to the disclosure of the individual aspects of the invention, reference is and / or can always be made reciprocal.

[0009] According to a first aspect of the present invention, a method for detecting a malfunction of a fuel outlet arrangement in a tank system, in particular for a fuel cell system, is proposed, wherein the tank system comprises a plurality of fuel tanks, a fuel line arrangement for conducting fuel from the fuel tanks, and a fuel outlet arrangement with an outlet means for each fuel tank for the controlled conduction of fuel from the fuel tanks into the fuel line arrangement. The method comprises the following steps:

[0010] Determining a transition from increased operation to reduced operation of the tank system with a reduced fuel mass flow from the fuel tanks,

[0011] Determining a pressure build-up gradient in the fuel line arrangement during reduced operation after a defined time after the determined transition to reduced operation, providing a target pressure build-up gradient, performing a comparison between the determined pressure build-up gradient during reduced operation and the provided target pressure build-up gradient, and

[0012] Detecting a malfunction of the fuel outlet assembly based on the comparison.

[0013] Within the scope of the present invention, it was discovered that, based on a detectable pressure buildup gradient during reduced operation of the tank system, meaningful conclusions regarding a possible malfunction of the fuel outlet arrangement can be drawn in a relatively simple manner. If all outlet valves of the outlet means on the fuel tanks maintain the permissible pressure drop, a transition to a reduced fuel mass flow or

[0014] consumer mass flow, a short-term pressure increase can occur. This means that an increased valve throttling effect on an individual fuel tank leads to a higher tank pressure in this fuel tank than in the other fuel tanks during a tank-empty run with a high fuel mass flow or during increased operation with an increased or higher fuel mass flow. The one faulty fuel tank is, so to speak, lagging behind. If the tank system is then operated with a sufficiently small or with the predefined and / or pre-definable reduced fuel mass flow, this can lead to backfilling from one fuel tank into the other tanks. As a result, i.e. due to the backfilling, after a usual short pressure increase to the tank pressure level of the lowest tank pressure, a subsequent long or longer and overall even higher pressure increase can occur in the fuel line arrangement.By detecting this pressure increase, it is now possible to conclude that backfilling has occurred and thus that a corresponding malfunction in the form of asymmetric tank emptying has occurred. To detect the malfunction, a second pressure increase that is greater and / or longer than the first pressure increase is detected during reduced operation in the determined pressure buildup gradient and used for comparison.

[0015] Determining the pressure build-up gradient in the

[0016] Fuel line arrangement during reduced operation after a defined time, for example after electrical activation of the outlet means, can therefore be understood that the pressure build-up gradient during reduced operation is determined in a predefined time, in a predefinable time and / or simply in a time that is after the first small pressure increase. Reduced operation can be understood as an operation of the tank system in which the fuel mass flow is small enough so that the refilling described above is possible. As already mentioned above, reduced operation is to be understood in particular as an operation in which a lower fuel mass flow than during increased operation is present, in particular lower by a predefined or predefinable value.

[0017] Based on the comparison according to the invention or on the basis of the comparison according to the invention, a malfunction can be detected in particular by recognizing a clogged extraction filter of an outlet means. Accordingly, the malfunction can be understood as a clogging level of an extraction filter of at least one outlet means that exceeds a reference clogging level or a predefined and / or predefinable maximum permissible clogging level. If an excessively high clogging level is detected, appropriate countermeasures can be initiated to address any problems that may arise. In particular, operation of the fuel cell system or the tank system can be prevented in which a fuel tank would not or could not be emptied as desired or would not be available to provide the fuel as desired.Based on the comparison and / or the malfunction, it can also be concluded that one tank of the tank system has been backfilled and / or that several tanks of the tank system have been backfilled.

[0018] Within the scope of the method, predefined measures can also be initiated based on the detected and / or displayed malfunction and / or the knowledge of the backfilling. This means that if the malfunction or at least one malfunction is detected, at least one predefined measure can be initiated. This measure can be understood as the output of a visual and / or acoustic warning signal. The warning signal can be output acoustically and / or visually perceptible to 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.

[0019] The malfunction can be detected and subsequently displayed. Displaying the malfunction can be understood as the output of a warning signal as described above. Furthermore, displaying the malfunction can be understood as the generation of a warning signal that is stored in a memory from which it can be read by a specialist, for example, during an inspection of the tank system. Based on the read warning signal, conclusions can be drawn about a malfunction that may have occurred or is still present, such as backfilling. Measures can then be taken to prevent the malfunction, at least in the future.

[0020] The outlet means may comprise outlet valves, which, in a method according to the invention, can all be electrically controlled simultaneously or substantially simultaneously. In particular, the outlet valves can be controlled in parallel during the start-up of the fuel cell system or during the operation of the fuel cell system.

[0021] The pressure buildup gradient is preferably determined in a high-pressure line section of the fuel line arrangement. The pressure buildup gradient is preferably determined by pressure measurements and a pressure analysis of a line pressure in the fuel line arrangement over time. The pressure buildup gradient can therefore be determined using suitable measuring sensors and a computing unit that has a signal connection to the measuring sensors. The measuring sensors can have at least one pressure sensor for determining the pressure buildup gradient.

[0022] The inventive comparison between the determined pressure buildup gradient and the provided target pressure buildup gradient is carried out in particular when no pressure buildup is measured in a medium-pressure line section of the fuel line arrangement, in which the gas pressure is at least on average lower than in the high-pressure line section, or when no pressure buildup can be detected by measurement. In this way, the tightness of a pressure regulator in the fuel line arrangement can be checked to ensure that the mass flow through the respective outlet valve was effective exclusively for the pressure buildup in the high-pressure line section.

[0023] Providing the target pressure buildup gradient can be understood as either reading the target pressure buildup gradient from a memory and thus making it available for comparison, or first calculating it and only then making it available for comparison. This means that providing it can also be understood as determining and / or calculating the target pressure buildup gradient and then making it available.

[0024] The outlet valves can be understood as tank valves, each of which is installed directly or substantially directly on the fuel tanks. A suitable extraction filter can be positioned on each outlet valve. The outlet valve and extraction filter preferably form the essential and / or sole component of the respective outlet means. The fuel tanks are preferably understood to be hydrogen tanks. The detection and possible representation of a malfunction of the fuel outlet arrangement based on the comparison can be understood to mean that the at least one malfunction can be detected and represented based on the comparison or a comparison result. This means that the comparison result can be evaluated accordingly to detect and represent the malfunction and / or taken into account in a suitable calculation.The method can be carried out in particular for detecting a malfunction of a fuel outlet arrangement in a fuel cell system of a vehicle, in particular during operation of the fuel cell system in the vehicle. However, the method is not limited to an embodiment in a fuel cell system. For example, the malfunction can also be detected in a fuel outlet arrangement or gas outlet arrangement in a tank system for another gas system. Accordingly, fuel can in principle be understood to mean any combustible gas in the present case. The method steps according to the invention do not have to be carried out in the specified order. Individual method steps can also be carried out in a different order and / or simultaneously.For example, it is possible that the target pressure build-up gradient is provided and / or calculated first and only then is the actual pressure build-up gradient determined.

[0025] If, for example, the comparison reveals that the determined pressure build-up gradient is a predefined value lower than the target pressure build-up gradient, this may indicate a malfunction, particularly a clogged extraction filter. During the comparison, a difference between the target pressure build-up gradient and the determined pressure build-up gradients, or between the individual values ​​of the gradient or the value curve, can be calculated. This difference can be compared with a predefined threshold value and / or a reference difference. If the difference is greater than the predefined threshold value or the reference difference, this may indicate a malfunction as described above.

[0026] According to one embodiment, it is possible for a method to carry out the following steps:

[0027] Determining a tank pressure in the respective fuel tank during reduced operation,

[0028] Determining a line pressure in the fuel line arrangement, performing comparisons between the tank pressure in the respective fuel tank and the line pressure, and

[0029] Detecting a malfunction of at least one specific fuel tank and / or at least one specific outlet means based on the comparisons between the tank pressure in the respective fuel tank and the line pressure.

[0030] In this way, the malfunction can be identified particularly reliably and / or the actual existence of a malfunction can be easily checked. If the second or longer pressure increase in the fuel line arrangement described above indicates a malfunction, for example a blocked extraction filter, this can now be checked and clarified. In particular, it can be found out on which tank the possibly blocked extraction filter is located. However, such a determination and / or associated calculations only need to be carried out if there is reason to do so based on the detection of a possible malfunction described above. In other words, if no indication of a malfunction is found based on the initial comparison, subsequent calculations to determine a more precise cause of the error can be dispensed with.In this way, the process can be carried out with low computing capacity and thus in a correspondingly energy-saving manner.

[0031] For further verification, the following additional or alternative steps are possible:

[0032] - Determining a tank pressure in the respective fuel tank during reduced operation,

[0033] - Carrying out comparisons between the respective determined tank pressures in the fuel tanks, and

[0034] - Detecting a malfunction of at least one specific fuel tank and / or at least one specific outlet means based on the comparisons between the respectively determined tank pressures in the fuel tanks.

[0035] In addition, the following steps are possible in addition or as an alternative:

[0036] - Determining the fuel level in the respective fuel tank during reduced operation,

[0037] - Carrying out comparisons between the respective determined fuel levels in the fuel tanks, and

[0038] - Detecting a malfunction of at least one specific fuel tank and / or at least one specific outlet means based on the comparisons between the respectively determined fuel levels in the fuel tanks.

[0039] In this way, the malfunction can be detected, verified, and specified particularly reliably. Furthermore, it is possible for the defined time in a method according to the invention to be determined depending on a line pressure in the fuel line arrangement and / or a change in mass reduction during the transition to reduced operation. In this way, the most suitable point in time or a corresponding time for determining the pressure buildup gradient can be defined and thus used to perform a correspondingly meaningful comparison.

[0040] Furthermore, it is possible for a method according to the invention to only carry out the method steps after a defined or definable transition time following opening of the outlet means. This means that the method can be carried out in such a way that opening of the outlet means is detected, the transition time is then waited for, and only then or at a defined or definable start time are the further method steps carried out. In this way, it can be prevented in particular that a malfunction is detected which is not actually a malfunction. If, for example, a vehicle with a tank system is left standing on one side in the sun for an extended period of time, the tanks exposed to direct sunlight can heat up more than the tanks in the shade.If the outlet means are now activated to open them, different gas pressures initially apply to the tanks, which, however, equalize again over time. If the method according to the invention were to be carried out right at the beginning, i.e., immediately after the outlet means are activated, it might not be possible to distinguish between an undesirable pressure buildup gradient due to a malfunction and a pressure buildup gradient due to the solar radiation described above. The transition time can be defined or preset with a certain degree of certainty based on empirical values, or it can be defined depending on current operating and / or environmental parameters.

[0041] Furthermore, in a method according to the present invention, it is possible for a temperature in and / or at the respective fuel tank to be determined and for the transition time to be defined or set as a function of the determined temperature in and / or at the respective fuel tank. The at least one temperature is determined in particular in the respective fuel tank. Based on the temperature in and / or at the fuel tank, it is possible to relatively reliably determine the transition time that must be waited for until the desired pressure equalization occurs or until an equalization between the different tank pressures has been established. Nevertheless, in addition to the temperature in and / or at the respective fuel tank, further information can be taken into account in order to define the transition time.

[0042] In a method according to the invention, it is also possible for the target pressure build-up gradient to be calculated as a function of a current line pressure in the fuel line arrangement and made available for comparison. In this way, the target pressure build-up gradient can be calculated accordingly as a function of the operating state and / or functional state of the tank system. Consequently, the target pressure build-up gradient can always be provided relatively accurately in different operating and / or functional states of the fuel cell system. The fact that the target pressure build-up gradient is calculated as a function of the current line pressure can be understood to mean that the current line pressure is determined using suitable sensors and the target pressure build-up gradient is subsequently calculated using the determined line pressure. The current line pressure is determined in particular after the electrical control of the outlet means.

[0043] The target pressure buildup gradient can be calculated additionally or alternatively based on the current temperature in the fuel line arrangement and provided for comparison. This also allows the target pressure buildup gradient to be provided relatively accurately in various operating and / or functional states of the fuel cell system.

[0044] Furthermore, it is possible for the target pressure build-up gradient to be calculated, additionally or alternatively, as a function of a current tank pressure before the electrical control of the outlet means, in particular the outlet valves. This means that first, the current tank pressure can be determined, in particular using suitable sensors, and then the electrical outlet valves can be controlled. The target pressure build-up gradient can then be calculated using the current tank pressure and made available or used for comparison. The calculations described here are preferably carried out using a computing unit, which can, for example, be part of a control unit, in particular a vehicle control unit. Nevertheless, the computing unit or part of the computing unit can also be made available decentrally, for example in a cloud, and used to calculate the target pressure build-up gradient.The current tank pressure can be understood as a tank pressure that is determined as soon as possible before the electrical control of the outlet valves and / or as soon as possible after the start of operation of the fuel cell system. The current tank pressure can be calculated based on a line pressure determined during a previous operation of the fuel cell system, i.e. before the electrical control of the outlet valves in a subsequent operation of the fuel cell system. Based on the line pressure from the previous operation, a previous tank pressure can be determined, which can be corrected or changed based on determined temperature differences in the fuel tanks between the two operations to calculate the current tank pressure. In this way, the current tank pressure can be determined without a pressure sensor in the fuel tanks.The respective tank pressure can also be determined by a pressure sensor in the respective fuel tank. Furthermore, it is possible for a method according to the present invention to calculate the desired pressure buildup gradient as a function of a volume value of a volume in the fuel line arrangement and to make it available for comparison. This procedure helps in calculating the most accurate desired pressure buildup gradient possible or in calculating a desired pressure buildup gradient that is as close as possible to a desired ideal desired pressure buildup gradient. The volume value can correspond to a volume defined by the fuel line arrangement. The volume value preferably corresponds to a volume of a high-pressure line section of the fuel line arrangement.In tests conducted within the scope of the present invention, it has further proven advantageous if, in a method, the target pressure buildup gradient is calculated as a function of a number of exhaust valves and provided for comparison. Using this system-specific parameter, the target pressure buildup gradient can also be easily calculated relatively accurately or as desired. Alternatively or additionally, a throttling behavior of the exhaust valves can also be determined and used to calculate the target pressure buildup gradient.

[0045] A further aspect of the present invention relates to a tank system for a fuel cell system, comprising a plurality of fuel tanks, a fuel line arrangement for conducting fuel from the fuel tanks and a fuel outlet arrangement having an outlet means for each fuel tank for the controlled conduction of fuel from the fuel tanks through the fuel line arrangement.The tank system further comprises a determination unit for determining a transition from increased operation to reduced operation of the tank system with a reduced fuel mass flow from the fuel tanks and for determining a pressure buildup gradient in the fuel line arrangement during reduced operation after a defined time after the determined transition to reduced operation. A computing unit for performing a comparison between the determined pressure buildup gradient during reduced operation and the provided target pressure buildup gradient, and for detecting a malfunction of the fuel outlet arrangement based on the comparison, is also provided. Thus, the tank system according to the invention provides the same advantages as those described in detail with reference to the method according to the invention.The tank system can further comprise a control unit for electrically controlling the outlet means and thus correspondingly for opening and closing the outlet means. The target pressure buildup gradient can be calculated by a computing unit and / or read from a memory to perform the comparison. The computing unit can be configured and designed to calculate the target pressure buildup gradient in the manner described in detail above. The tank system can be configured and designed as part of a fuel cell system. The fuel cell system can be configured and designed as part of a vehicle.

[0046] The invention further proposes a tank system configured and designed to carry out a method as described above. This means that the tank system can have suitable sensors, a suitable computing unit, and / or suitable actuators for carrying out the method.

[0047] A further aspect of the invention relates to a computer program product comprising instructions that cause the method steps according to the invention to be executed 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. Thus, the computer program product according to the invention and the storage medium also provide the advantages described above.

[0048] The computer program product can be implemented as 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 removable drive, a volatile or non-volatile memory, or a built-in memory / processor. The instruction code can program a computer or other programmable devices, such as a control unit of the fuel cell system and / or a vehicle with the fuel cell system, to perform the desired functions. Furthermore, the computer program product can be provided and / or be provided on a network, such as the Internet, from which it can be downloaded by a user as needed.The computer program product can be and / or be implemented by means of software as well as by means of one or more special electronic circuits, i.e. in hardware or in any hybrid form, i.e. by means of software components and hardware components.

[0049] Further measures improving the invention will become apparent from the following description of various exemplary embodiments of the invention, which are schematically illustrated in the figures. All features and / or advantages apparent from the claims, the description, or the figures, including structural details and spatial arrangements, may be essential to the invention both individually and in various combinations.

[0050] They show schematically:

[0051] Figure 1 shows a fuel cell system with a tank system according to an embodiment of the present invention,

[0052] Figure 2 shows a tank system according to an embodiment of the present invention,

[0053] Figure 3 shows a storage means with a computer program product stored thereon according to an embodiment of the present invention, and

[0054] Figure 4 is a flowchart for explaining a method according to an embodiment of the present invention.

[0055] Elements with the same function and mode of operation are provided with the same reference symbols in the figures.

[0056] Fig. 1 shows a fuel cell system 10 configured and designed for mobile use in a vehicle. The fuel cell system 10 has a filling section 30 with a tank connection 35 in the form of a connecting piece. The fuel cell system 10 further has a storage section 31 with a fuel line arrangement 15, a fuel tank arrangement 38, and a valve 36 in the form of a shut-off or blocking valve. In addition, the fuel cell system 10 has a supply section 32 with a pressure regulator 37, through which the fuel from the storage section 31 can be fed in a controlled manner into a fuel cell section 33 of the fuel cell system 10. 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 drive power for the vehicle. In Fig.2 shows a tank system 11 for a fuel cell system 10 as shown in FIG. 1. The tank system 11 shown in FIG. 2 has three fuel tanks 12, 13, 14, a fuel line arrangement 15 for conducting fuel from the fuel tanks 12, 13, 14, and a fuel outlet arrangement 16 for the controlled conduction of fuel from the fuel tanks 12, 13, 14 through or into the fuel line arrangement 15. The fuel tanks 12, 13, 14 are connected parallel to one another on the fuel line arrangement 15. The fuel outlet arrangement 16 has three outlet means 17, 18, 19, with one outlet means 17, 18, 19 being installed on each fuel tank 12, 13, 14. Each outlet means 17, 18, 19 has an outlet valve and a removal filter (not shown in detail). Furthermore, a pressure sensor 25 is provided in each tank for determining a gas pressure in the respective fuel tank 12, 13, 14.The tank system 11 also has a control unit 20 for electrically controlling the outlet means 17, 18, 19. The control unit 20 is shown schematically and can comprise several spaced-apart components. The control unit 20 can comprise a control unit, in particular in the form of a vehicle control unit.

[0057] In addition, the tank system 11 has a determination unit 21 with a further pressure sensor for determining a transition from increased operation to reduced operation of the tank system 11 with a reduced fuel mass flow from the fuel tanks 12, 13, 14, as well as for determining a line pressure and in particular for determining a pressure build-up gradient in the fuel line arrangement 15 during reduced operation after a predefined time after a determined transition to reduced operation. According to the embodiment shown in Fig. 2, a component of the control unit 20 is a computing unit 22 for performing a comparison between the determined pressure build-up gradient during reduced operation and the provided target pressure build-up gradient, and for detecting a malfunction of the fuel outlet arrangement 16, in particular in the form of a clogged extraction filter, based on the comparison. In Fig.3 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 a method to be executed in the tank system 11 shown in FIGS. 1 and 2, which method will be explained below with reference to FIG. 4.

[0058] With reference to the flowchart shown in Fig. 4, a method for detecting a malfunction of the above-described fuel outlet assembly 16 is explained. More specifically, the method can determine whether or not the fuel outlet assembly 16 exhibits a malfunction, in particular in the form of at least one clogged extraction filter, in which tank backfilling occurs. For this purpose, the outlet means 17, 18, 19 are initially electrically controlled or energized in parallel in a first step S1 to simultaneously open the outlet valves.In a second step S2, a reduced operation of the tank system 11, and in particular a transition from increased operation to reduced operation, is determined in the fuel line arrangement 15 by means of the determination device 21, in which transition the fuel mass flow from the fuel tanks 12, 13, 14 is so small that a detectable backfilling of fuel tanks 12, 13, 14 is possible. In a defined time after or since the determined transition, a pressure build-up gradient in the fuel line arrangement is determined. In a third step S3, which does not necessarily have to be carried out after the second step S2, a desired pressure build-up gradient is provided. According to the described embodiment, the desired pressure build-up gradient is calculated taking into account or using a determined current line pressure in the fuel line arrangement 15 and then provided accordingly.In a subsequent step S4, the computing unit 22 performs a comparison between the determined pressure buildup gradient and the calculated and provided target pressure buildup gradient. In a fifth step S5, based on the comparison, a malfunction of the fuel outlet assembly 16 is detected and, based on the detected malfunction, is specified or displayed as a corresponding error signal. In other words, based on the comparison, a conclusion is drawn as to whether or not a malfunction, in particular in the form of at least one clogged extraction filter, exists in the fuel outlet assembly 16.

[0059] In addition to the embodiments shown, the invention allows for further design principles. This means that the invention should not be considered limited to the embodiments explained with reference to the figures. In particular, the pressure sensors 25 in the respective fuel tanks could be

[0060] 12, 13, 14 can be omitted. If the pressure sensors 25 are present, the following steps can be performed to detect the malfunction: determining a tank pressure in the respective fuel tank 12, 13, 14 during reduced operation, determining a line pressure in the fuel line arrangement 15, performing comparisons between the tank pressure in the respective fuel tank 12, 13, 14 and the line pressure, and detecting a malfunction of at least one specific fuel tank 12,

[0061] 13, 14 and / or at least one specific outlet means 17, 18, 19 based on the comparisons between the tank pressure in the respective fuel tank 12, 13, 14 and the line pressure. Alternatively or additionally, it is possible to perform the following steps: determining a tank pressure in the respective fuel tank 12, 13, 14 during reduced operation, performing comparisons between the respectively determined tank pressures in the fuel tanks 12, 13, 14, and detecting a malfunction of at least one specific fuel tank 12, 13, 14 and / or at least one specific outlet means 17, 18, 19 based on the comparisons between the respectively determined tank pressures in the fuel tanks 12, 13, 14.Furthermore, it is possible, alternatively or additionally, to carry out the following steps: determining a fuel level in the respective fuel tank 12, 13, 14 during the reduced operation, performing comparisons between the respectively determined fuel levels in the fuel tanks 12, 13, 14, and detecting a malfunction of at least one specific fuel tank 12.

[0062] 13, 14 and / or at least one specific outlet means 17, 18, 19 based on the comparisons between the respectively determined fuel levels in the fuel tanks 12, 13, 14.

Claims

Claims 1 . A method for detecting a malfunction of a fuel outlet arrangement (16) in a tank system (11), in particular for a fuel cell system (10), wherein the tank system (11) comprises a plurality of fuel tanks (12, 13, 14), a fuel line arrangement (15) for conducting fuel from the fuel tanks (12, 13, 14), and a fuel outlet arrangement (16) each having an outlet means (17, 18, 19) for each fuel tank (12, 13, 14) for the controlled conduction of fuel from the fuel tanks (12, 13, 14) through the fuel line arrangement (15), characterized by: - determining a transition from increased operation to reduced operation of the tank system (11) with a reduced fuel mass flow from the fuel tanks (12, 13, 14), - determining a pressure build-up gradient in the fuel line arrangement (15) during the reduced operation after a defined time after the determined transition to the reduced operation, - Providing a target pressure build-up gradient, - Performing a comparison between the determined pressure build-up gradient during reduced operation and the provided target pressure build-up gradient, and - detecting a malfunction of the fuel outlet assembly (16) based on the comparison. Method according to claim 1, characterized in that the defined time is determined as a function of a line pressure in the fuel line arrangement (15) and / or a change value of a mass reduction during the transition to reduced operation. Method according to one of the preceding claims, characterized in that the method steps are only carried out after a defined or definable transition time after opening of the outlet means (17, 18, 19). Method according to claim 3, characterized by Determining a temperature in and / or at the respective fuel tank (12, 13, 14) and defining the transition time depending on the determined temperature in and / or at the respective fuel tank (12, 13, 14). Method according to one of the preceding claims, characterized in that the desired pressure build-up gradient is calculated depending on a current line pressure in the fuel line arrangement (15) and is provided for comparison. Method according to one of the preceding claims, characterized in that the desired pressure build-up gradient is calculated depending on a current temperature in the fuel line arrangement (15) and is provided for comparison.Tank system (11) for a fuel cell system (10), comprising a plurality of fuel tanks (12, 13, 14), a fuel line arrangement (15) for conducting fuel from the fuel tanks (12, 13, 14) and a fuel outlet arrangement (16) with an outlet means (17, 18, 19) for each fuel tank (12, 13, 14) for the controlled conduction of. Fuel from the fuel tanks (12, 13, 14) through the fuel line arrangement (15), characterized by: - a determination unit (21) for determining a transition from an increased operation to a reduced operation of the tank system (11) with a reduced fuel mass flow from the fuel tanks (12, 13, 14) and for determining a pressure build-up gradient in the fuel line arrangement (15) during the reduced operation after a defined time after the determined transition to the reduced operation, and - a computing unit (22) for performing a comparison between the determined pressure buildup gradient during reduced operation and the provided target pressure buildup gradient, and for detecting a malfunction of the fuel outlet arrangement (16) based on the comparison. Tank system (11) according to claim 7, which is configured and designed to carry out a method according to one of claims 1 to 6. A computer program product (23) comprising instructions that cause the method steps according to one of claims 1 to 6 to be executed in the tank system (11) according to one of claims 7 to 8. A computer-readable storage medium (24) having a computer program product according to claim 9 stored thereon.

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