Method for diagnosing a tank system comprising a plurality of tanks for storing hydrogen

Abstract

The invention relates to a method (100) for diagnosing a tank system (200) comprising a plurality of tanks (201) for storing hydrogen. The method (100) comprises: - outputting (101) a command for closing tank valves (203) of the tanks (201), - determining (103) a first pressure in a collecting line (207) supplied with hydrogen by the tanks (201), - removing (105) hydrogen from the collecting line (207), - determining (107) a second pressure in the collecting line (207), after the first pressure has been determined and after the command for closing the tank valves (203) has been carried out, - comparing (109) the first pressure with the second pressure, and, in the event that a difference between the first pressure and the second pressure is smaller than a predefined diagnosis threshold value: - determining (111) a state value for a respective tank (201) by measuring a specific state of the tank (201), - comparing (113) the state value with a reference value, - outputting (115) a warning message for the tank (201) in the event that its state value deviates from the reference value.

Description

[0001] R.417207

[0002] - 1 -

[0003] Description

[0004] title

[0005] Method for diagnosing a tank system comprising a multitude of tanks for storing hydrogen

[0006] The presented invention relates to a method for diagnosing a tank system comprising a plurality of tanks for storing hydrogen, a tank system for storing hydrogen and an energy converter.

[0007] State of the art

[0008] Known methods for detecting faulty tank valves in multi-tank systems can only determine that a faulty tank valve is present, but cannot assign the faulty tank valve to a specific tank. Consequently, complex tests are required to identify the tank whose tank valve is faulty.

[0009] Disclosure of the invention

[0010] Within the scope of the presented invention, a method for diagnosing a tank system comprising a plurality of tanks, a tank system for storing hydrogen, and an energy converter are presented.

[0011] Further features and details of the invention will become apparent from the respective dependent claims, the description, and the drawings. Features and details described in connection with the tank system according to the invention naturally also apply in connection with the method according to the invention or the energy converter according to the invention, and vice versa, so that with regard to the disclosure to R.417207

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[0013] The individual aspects of the invention are always, or can always be, mutually referenced.

[0014] The invention presented here serves in particular to provide a means for the safe operation of a tank system with a multitude of tanks for storing hydrogen.

[0015] Thus, according to a first aspect of the presented invention, a method for diagnosing a tank system comprising a plurality of tanks for storing hydrogen is presented.

[0016] The presented method comprises issuing a command to close the tank valves of the tanks, determining a first pressure in a collection line supplied with hydrogen by the tanks, withdrawing hydrogen from the collection line, determining a second pressure in the collection line after the first pressure has been determined and after the command to close the tank valves has been executed, and comparing the first pressure with the second pressure.

[0017] Furthermore, the presented procedure includes, in the case where the difference between the first pressure and the second pressure is less than a predetermined diagnostic threshold, determining a state value for a given tank by measuring a specific state of the tank, comparing the state value with a reference value, and issuing a warning message for the tank if its state value deviates from the reference value.

[0018] In the context of the presented invention, issuing a warning message means a process in which the warning message is displayed on an output unit and / or transferred to a memory, in particular an error memory, and / or transferred to a function for controlling the tank system.

[0019] In the context of the presented invention, determining a state value for the respective tank particularly means determining the state of the tank, R.417207

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[0021] For example, its fill level over the following period, especially after the tank valves are closed. This can occur multiple times, particularly continuously.

[0022] The presented invention is based on the principle that if a leak is detected by a faulty tank valve (i.e., if the pressure in the manifold does not decrease after all tank valves are closed, despite hydrogen being withdrawn from the manifold), a specific tank valve responsible for the leak can be identified. For this purpose, a status value is determined for each tank by measuring its specific condition. The resulting status values ​​are individually compared with a reference value. If a specific status value for a particular tank deviates from the reference value, it can be assumed that the tank valve of that tank is faulty or leaking. Accordingly, a warning message can be automatically issued for the respective tank or its corresponding tank valve.

[0023] Accordingly, the warning message provided according to the invention can include an identifier that specifically characterizes each defective tank or its tank valve. The identifier can, for example, include a number assigned to the defective tank or a location assigned to the defective tank. For this purpose, an assignment scheme can be specified that assigns a respective identifier to each tank in the tank system.

[0024] The manifold can be coupled to the tanks directly or indirectly, e.g. via at least one intermediate element, so that all tanks supply the manifold with hydrogen when their tank valves are open at the same time.

[0025] It may also be provided that the state value is determined based on a pressure measured by a pressure sensor in a respective tank. R.417207

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[0027] Since hydrogen escapes from a leaking tank valve, the pressure inside the tank changes, whereas the pressure in tanks with functioning valves remains constant. Therefore, a changing pressure in a tank indicates that a tank valve is faulty or leaking.

[0028] It may also be provided that the state value is determined based on a temperature measured by a temperature sensor in a respective tank.

[0029] Since a leaking tank valve allows hydrogen to escape from the tank, the pressure inside the tank changes, and consequently, so does the temperature inside and on the tank's surface. In contrast, the temperature in and around tanks with functioning valves remains constant. Therefore, a changing temperature inside and / or around a tank can indicate that a tank valve is faulty or leaking.

[0030] To measure the temperature of a tank, a temperature sensor can be used, which is placed inside the tank or detects a surface of the tank, such as a thermal camera.

[0031] It may also be provided that the condition value is determined by repeatedly measuring the specific condition of the tank.

[0032] By repeatedly, and especially continuously, determining the state value over a specified period, any leakage that may be present accumulates, resulting in correspondingly large differences from the reference value and reliably detecting an open valve. In particular, by repeatedly comparing the respective state values ​​determined over time with the reference value, a leakage of the respective tank or tank valve can be considered in an integrated manner over time. R.417207

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[0034] It may also be provided that the reference value for a selected tank is a state value of the selected tank that was determined prior to the state value to be compared with the reference value.

[0035] By using a reference value, which is a state value of the selected tank determined before the state value to be compared with the reference value, each tank can serve as a reference for itself, so that a change in the state of the tank directly leads to the issuance of a warning message.

[0036] It may also be provided that the reference value for a selected tank is a state value of the selected tank, which was determined at the time the tank valve of the respective tank was closed.

[0037] The time of closing the tank valve of a given tank is a particularly advantageous, easily determinable point in time for carrying out the presented method, especially when the command to close the tank valve is issued.

[0038] It may also be provided that the extraction of hydrogen from the collection line continues until the state value of at least one tank deviates from the reference value by a value greater than a predetermined warning threshold.

[0039] To minimize the probability of a false positive message, i.e., issuing a warning message without an actually faulty tank valve, a warning threshold can be provided which must be reached by at least one deviation between the state value and the reference value before a warning message is issued.

[0040] The warning threshold can be predefined or determined dynamically, e.g. based on a threefold standard deviation of the determined state values.

[0041] It may also be stipulated that, after the warning message has been issued, the tank valves of all tanks in the tank system are opened. R.417207

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[0043] Opening all tank valves of the tank system after a warning message has been issued ensures a uniform tank emptying during further operation.

[0044] It may also be provided that the hydrogen is withdrawn from the collection line by a consumer supplied with hydrogen from the tank system or by opening a drain valve.

[0045] The hydrogen from the manifold can be automatically extracted by a consumer connected to the manifold, such as a power converter. Alternatively, for example, if the consumer's control logic prevents operation with closed tank valves, a drain valve, such as a so-called "defueling port" of the tank system, located in the manifold or downstream of the manifold, can be opened.

[0046] According to a second aspect, the presented invention relates to a tank system for storing hydrogen.

[0047] The presented tank system comprises a multitude of tanks, a number of sensors for measuring the condition of the respective tanks, a multitude of tank valves for controlling a mass flow from the tanks, a collecting line coupled to all tanks, and a computing unit, the computing unit being configured to carry out one possible embodiment of the presented method.

[0048] In the context of the presented invention, a computing unit is understood to be a computer, in particular a cloud computer, a processor, a control unit or any other programmable circuit.

[0049] The presented method serves in particular to identify a specific tank among the multitude of tanks in the presented tank system that is defective, especially exhibiting a leak. R.417207

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[0051] According to a third aspect, the presented invention relates to an energy converter for converting energy.

[0052] The presented energy converter comprises an energy unit and a possible configuration of the presented tank system, wherein the energy unit is a fuel cell system or a hydrogen engine.

[0053] Based on the presented method, a diagnosis of the tank system of the presented energy converter can be carried out fully automatically, so that in case of a fault, a user can determine which tank whose tank valve is faulty.

[0054] Advantages described in detail for the method of diagnosing the condition of a tank system according to the first aspect of the invention apply equally to the tank system according to the second aspect of the presented invention and to the energy converter according to the third aspect of the presented invention, and vice versa.

[0055] Further advantages, features, and details of the presented invention will become apparent from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination.

[0056] Brief description of the drawing

[0057] They each show schematically:

[0058] Figure 1 shows a possible embodiment of the presented method,

[0059] Figure 2 shows a detailed representation of a tank system during the process according to Figure 1 and R.417207.

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[0061] Figure 3 shows a possible embodiment of the presented energy converter with a possible embodiment of the presented tank system.

[0062] Description of the exemplary implementations

[0063] Fig. 1 shows a method 100 for diagnosing a tank system 200, such as that shown in Fig. 2, which comprises a plurality of tanks 201.

[0064] Procedure 100 comprises a first output step 101, in which a command to close all tank valves 203 of the tanks 201 is issued. Accordingly, the tank valves 203 are, for example, switched to a de-energized state.

[0065] Furthermore, the procedure 100 comprises a first determination step 103, in which an initial pressure is determined in a collecting line 207 supplied with hydrogen by the tanks 201, a withdrawal step 105, in which hydrogen is withdrawn from the collecting line 207, a

[0066] second determination step 107, in which a second pressure in the collecting line 207 is determined after the first pressure has been determined and after the command to close the tank valves has been executed, i.e., e.g., the tank valves have been de-energized, and a balancing step 109, in which the first pressure is balanced with the second pressure.

[0067] Furthermore, the procedure 100 includes, in the case that a difference between the first pressure and the second pressure is less than a specified diagnostic threshold, a third determination step 111 in which a state value for a respective tank is determined by measuring a specific state of the tank, a comparison step 113 in which the state value is compared with a reference value, and a

[0068] Second output step 115, in which a warning message is issued for the tank if its status value deviates from the reference value. R.417207

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[0070] Figure 2 shows a tank system 200 for storing hydrogen.

[0071] The tank system 200 comprises a plurality of tanks 201, a plurality of tank valves 203 for controlling a mass flow from the tanks 201, a number of sensors 205 for measuring a condition of the respective tanks 201, a manifold 207 which is supplied with hydrogen by all tanks 201 or is coupled to the tanks 201, and a computing unit 209 which is configured to carry out the process 100 e.g. according to Fig. 1.

[0072] Figure 3 shows an energy converter 300 for converting energy.

[0073] The energy converter 300 comprises an energy unit 301, such as a hydrogen engine or a fuel cell system, and the tank system 200, for example, according to Fig. 2.

Claims

R.417207 - 10 - Claims 1. Method (100) for diagnosing a tank system (200) comprising several tanks (201) for storing hydrogen, the procedure (100) comprises: Issuing (101) a command to close tank valves (203) of the tanks (201), Determining (103) an initial pressure in a collecting line (207) supplied with hydrogen through the tanks (201), Extraction (105) of hydrogen from the collection line (207), determination (107) of a second pressure in the collection line (207) after the first pressure has been determined and after the command to close the tank valves (203) has been executed, Comparing (109) the first pressure with the second pressure and, in the event that a difference between the first pressure and the second pressure is less than a specified diagnostic threshold: Determining (111) a state value for a respective tank (201) by measuring a specific state of the tank (201), comparing (113) the state value with a reference value, issuing (115) a warning message for the tank (201) in the event that its state value deviates from the reference value.

2. Method (100) according to claim 1, characterized by that the state value is determined based on a pressure measured by means of a pressure sensor (205) in a respective tank (201).

3. Method (100) according to claim 1 or 2, characterized by that the state value is determined based on a temperature measured by a temperature sensor (205) in a respective tank (201). R.417207 - 11 - 4. Method (100) according to one of the preceding claims, characterized in that that the state value is determined by repeatedly measuring the specific state of the tank (201).

5. Method (100) according to one of the preceding claims, characterized in that that the reference value for a selected tank (201) is a state value of the selected tank (201) that was determined prior to the state value to be compared with the reference value.

6. Method (100) according to one of the preceding claims, characterized in that that the reference value for a selected tank (201) is a state value of the selected tank (201) that was determined at the time of closing the tank valve (203) of the respective tank (201).

7. Method (100) according to one of the preceding claims, characterized in that that the extraction of hydrogen from the collection line (207) continues until the state value of at least one tank (201) deviates from the reference value by a value greater than a specified warning threshold.

8. Method (100) according to one of the preceding claims, characterized in that that, after the warning message was issued, the The tank valves (203) of all tanks of the tank system (200) are opened.

9. Method (100) according to one of the preceding claims, characterized in that R.417207 - 12 - that the hydrogen is withdrawn from the collection line (207) by a consumer supplied with hydrogen from the tank system (200) or by opening a drain valve.

10. Tank system (200) for storing hydrogen, the tank system (200) includes: - a large number of tanks (201), - a number of sensors (205) for measuring the condition of the respective tanks (201), - a large number of tank valves (203) for controlling a mass flow from the tanks (201), - a collecting line (207) that is coupled to all tanks (201), and - a computing unit (209), wherein the computing unit (209) is configured to perform a method (100) according to any one of claims 1 to 9.

11. Energy converter (300) for converting energy, the energy converter (300) comprises: - one energy unit (301) and - a tank system (200) according to claim 10, where the energy unit (301) is a fuel cell system or a hydrogen engine.

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