Method for regulating anode pressure in a fuel cell system, fuel cell system, vehicle, computer program product and storage medium

Abstract

The technology disclosed herein pertains to a method for regulating an anode pressure in a fuel cell system (10), wherein the fuel cell system (10) comprises a fuel cell (11) having an anode (12) and a cathode (13), a pressure sensor (21, 22) and a fuel sensor (24, 25), and the method has the steps of ascertaining an anode pressure by means of the pressure sensor (21, 22), ascertaining a fuel concentration in and / or on the anode (12) by means of the fuel sensor (24, 25), and regulating the anode pressure on the basis of the ascertained fuel concentration. The technology also pertains to a fuel cell system (10), a vehicle (100), a computer program product (30) for implementing the method, and a computer-readable storage medium (40) having the computer program product (30) stored thereon.

Description

Technical Field

[0001] The technology disclosed herein relates to a method for regulating anode pressure in a fuel cell system. This technology also relates to a fuel cell system, a vehicle, and a computer program product for performing the method. Furthermore, the present invention relates to a computer-readable storage medium on which a computer program product for performing the method is stored. Background Technology

[0002] Fuel cell systems for mobile applications are known in the prior art. In vehicles, fuel cell systems are configured to provide electrical power to the vehicle's drive motor. Similar fuel cell systems have fuel cell stacks. These stacks typically contain multiple fuel cells, each having an anode, a cathode, and a membrane arrangement disposed between the two electrodes. Within the fuel cell stack, fuel can react with oxygen in a reverse electrolysis process, thereby generating an electric current. The fuel can be supplied to the fuel cell stack from one or more pressure vessels within the vehicle. Oxygen is typically extracted from ambient air.

[0003] Known fuel cell systems incorporate pressure sensors to regulate the anode gas pressure at and / or on the anode. When a pressure sensor fails, an emergency sensor must be activated. If the emergency sensor is not present, the fuel cell system cannot start or continue operating for safety reasons. Pressure sensors can fail, for example, at temperatures below freezing, where moisture within the sensor may freeze. Furthermore, it is possible for a faulty pressure sensor to provide erroneous measurements that cannot be identified. This can lead to malfunctions in the fuel cell system, damage to the fuel cell system, and / or damage to peripheral equipment of the fuel cell system. Summary of the Invention

[0004] The objective of this invention is to improve the operational safety of fuel cell systems.

[0005] The aforementioned task is addressed by the claims. In particular, the aforementioned task is addressed by the method according to claim 1 and by the fuel cell system, vehicle, computer program product, and computer-readable storage medium according to the co-claims. Other advantages of the disclosed technology are apparent from the dependent claims, the specification, and the drawings. Herein, the features described in connection with the method also apply to the fuel cell system, vehicle, computer program product, and storage medium, and vice versa, so that the disclosures with respect to each aspect are always cross-referenced.

[0006] According to a first aspect of the present invention, a method for regulating the anode pressure in a fuel cell system is provided. The fuel cell system includes a fuel cell having an anode and a cathode, a pressure sensor, and a fuel sensor. The method comprises the following steps: - The anode pressure is determined by means of the pressure sensor; - The fuel concentration in and / or on the anode is determined by means of the fuel sensor; and - Adjust the anode pressure based on the identified fuel concentration.

[0007] The anode pressure can be increased by increasing the fuel partial pressure. If, for example, fuel and / or pure fuel (such as hydrogen) are directed to the anode via an injector in a fuel cell system, the fuel forms the dominant gas flow to the anode. For example, the diffusion process of nitrogen from the cathode to the anode is slower than the overall pressure dynamics and can be ignored, at least for short-term observation. Within the scope of this technology, it is now recognized that an increase in anode pressure caused by fuel supply can be identified by means of a fuel sensor. More precisely, the fuel concentration can be identified by the fuel sensor, and the fuel partial pressure can be inferred from the fuel concentration. The anode pressure can be inferred from the adjusted and / or changed fuel partial pressure. Therefore, it is possible to correct and / or verify the anode pressure based on the identified fuel concentration, or, in the short term, replace the anode pressure as an adjustment parameter. That is, the anode pressure value identified by the pressure sensor can be corrected and / or verified based on the identified fuel concentration, or, in the short term, replace the anode pressure as an adjustment parameter. This allows for particularly reliable and / or precise regulation of the anode pressure. This, in turn, enables high operational safety for the fuel cell system. The correction can be achieved using an observer, such as a Lundberg observer or a Kalman filter. Furthermore, it is possible, at least in the short term, to regulate the anode pressure without using a pressure sensor. That is, the proposed method allows for the complete replacement of the pressure sensor with a fuel sensor, at least in the short term.

[0008] Anode pressure can be adjusted based on the identified and / or determined correlation between fuel concentration and anode pressure. The faster and more accurate the fuel sensor operates, the more accurate the surrogate measurement of anode pressure will be.

[0009] The regulation of anode pressure can be understood as actively changing the anode pressure or consciously maintaining the anode pressure. That is, the anode pressure can be adjusted from the currently determined anode pressure to another anode pressure or consciously kept constant. Regulating anode pressure based on the determined fuel concentration can be understood as further regulating the anode pressure based on the determined fuel concentration. For example, the anode pressure can be adjusted based on the anode pressure value measured by a pressure sensor and based on the fuel concentration.

[0010] To simplify the method, it can be assumed that the anode subsystem of the fuel cell system contains only fuel, specifically hydrogen, and possibly nitrogen as gaseous components. This assumption can be sufficiently accurate, especially at ambient temperatures below freezing. Nitrogen diffusion can be described and / or identified with sufficient precision. However, nitrogen diffusion is so slow that it can be ignored, at least in the short term.

[0011] Furthermore, it is possible that, at least in the presence of an initial anode pressure or a corresponding anode pressure value, the anode pressure is adjusted solely based on the determined fuel concentration. The anode pressure can be understood as the anode pressure value changing over time. That is, determining the anode pressure can be understood as determining the anode pressure value changing over time. Determining the fuel concentration can be understood as determining the fuel concentration value changing over time.

[0012] Adjusting the anode pressure can be understood as regulating the anode pressure. Regulating the anode pressure can be understood as open-loop control (Steuern) and / or closed-loop control (Regeln) of the anode pressure. The anode pressure can be understood as the anode gas pressure in and / or on the anode. To regulate the anode pressure, the fuel cell system may have a controller. The controller may be signal-connected to the at least one pressure sensor, the at least one fuel sensor, and a suitable actuator for regulating the anode pressure.

[0013] Determining anode pressure using a pressure sensor can be understood as meaning that anode pressure can also be determined using a pressure sensor. That is, in order to determine anode pressure, other auxiliary devices and / or models can be used besides a pressure sensor. A similar approach applies to determining fuel concentration using a fuel sensor.

[0014] The anode pressure can be determined using at least one pressure sensor. The anode pressure can be determined using a pressure sensor located downstream of the injector / jeterator and upstream of the anode in the anode gas path. Additionally, the anode pressure can be determined using a separate pressure sensor located downstream of the anode and upstream of the injector / jeterator in the recirculation path.

[0015] Fuel concentration can be determined using at least one fuel sensor. The fuel concentration can be determined using a fuel sensor located downstream of the injector and upstream of the anode in the anolyte gas path. Additionally, a separate fuel sensor can be used to determine the fuel concentration in the recirculation path downstream of the anode and upstream of the injector. This fuel sensor can be understood as a hydrogen sensor. The hydrogen sensor can be configured as an electrochemical hydrogen sensor or a semiconductor hydrogen sensor. Hydrogen concentration can be determined, for example, using the omega-3 method.

[0016] The fuel cell system may have a purge valve for purging process fluids from the fuel cell system, wherein the purge valve preferably remains closed during fuel concentration determination and / or anode pressure regulation. In this manner, the fuel concentration can be determined particularly accurately, and the anode pressure can be regulated accordingly precisely. Here, the purge valve can be understood as a discharge and / or purging valve, which can be configured to purge liquids, such as water, from the fuel cell system and / or to vent process gases from the fuel cell system.

[0017] According to another embodiment of this technology, it is possible to correct and / or verify the determined anode pressure based on the determined fuel concentration using a lookup table. In this way, the correlation between the determined anode pressure and the determined fuel concentration can be determined particularly simply and reliably. The lookup table can be created and / or generated based on the location of the fuel sensor. The lookup table can be read from and / or provided accordingly as a predefined lookup table from a computer-readable storage medium. Furthermore, it is possible to correct and / or verify the determined anode pressure based on a model using the determined fuel concentration. In this way, the correlation between the determined anode pressure and the determined fuel concentration can be determined particularly quickly and dynamically. The lookup table can also use reference values ​​as input parameters. If, for example, the pressure sensor is no longer in use, the last valid pressure value and the fuel concentration measured at that time can be used as input parameters for the lookup table.

[0018] Another possibility is that the nitrogen diffusion in the fuel cell can be identified in the method proposed herein, and the anode pressure can be adjusted based on the identified nitrogen diffusion. This allows for particularly precise adjustment of the anode pressure. Within the scope of this research, it has been recognized that nitrogen diffusion in the fuel cell can theoretically be neglected during the proposed method. This is particularly applicable to highly dynamic effects and / or regulation processes. It is also possible, for example, to identify nitrogen diffusion based on a model and compensate for and / or subtract the resulting pressure changes. That is, the anode pressure adjustment can be additionally implemented based on the identified nitrogen diffusion. Specifically, the anode pressure can be adjusted not only based on the identified anode pressure or based on pressure sensor values ​​and subsequently based on fuel concentration, but also additionally based on nitrogen diffusion.

[0019] According to another aspect of the present technology, a fuel cell system with a controller is proposed, wherein the controller is configured to perform the method described above. The fuel cell system thus provides the same advantages as described in detail with reference to the method. The controller can be understood as an ECU, a controller, and / or a computer. The fuel cell system may also include a fuel cell comprising an anode and a cathode, at least one pressure sensor, and at least one fuel sensor.

[0020] The fuel cell system is preferably configured for mobility applications such as vehicles. The fuel cell system can be configured to provide energy to at least one drive unit of the vehicle to propel it forward. The fuel cell can be understood as a fuel cell stack having multiple fuel cells. In its simplest form, a fuel cell is an electrochemical energy converter that converts fuel and oxidant into reaction products, thereby generating electricity and heat. The anode and cathode can be separated from each other by an isolator that is selective for ions or allows ions to pass through.

[0021] The fuel cell system may have an anode gas path for guiding anode gas into the anode and a process gas discharge path for guiding process gas from the anode, wherein the fuel sensor, or at least one fuel sensor, is configured to determine the fuel concentration in the anode, in the anode gas path, and / or in the process gas discharge path. At these locations, the anode pressure and / or fuel concentration can be determined particularly accurately and reliably. According to a preferred embodiment, unlike conventional structures, only one pressure sensor is provided in the process gas discharge path, particularly immediately downstream of the anode, and only one fuel sensor is provided in the anode gas path, particularly immediately upstream of the anode. It has been shown that the anode pressure in the process gas discharge path can be determined particularly accurately and reliably, and the fuel concentration in the anode gas path can be determined particularly accurately and reliably. Therefore, with the proposed sensor arrangement, the anode pressure can be regulated not only particularly accurately and reliably, but also particularly efficiently.

[0022] Another aspect of this technology relates to a vehicle having a fuel cell system as described above, wherein the fuel cell system is configured to generate electricity in the vehicle. The vehicle may have at least one electric motor for driving the vehicle, wherein the fuel cell system may be configured to supply power to the at least one electric motor. Thus, the vehicle thereby provides the same advantages as described in the detailed description with reference to the fuel cell system. The vehicle can be understood as a motor vehicle, such as a motor-driven two-wheeled vehicle, a car, or a truck. The vehicle can also be understood as a road vehicle, an air vehicle, a water vehicle, a rail vehicle, a space vehicle, and a robot. The vehicle can also be understood to include pure electric vehicles and hybrid vehicles, wherein the hybrid vehicle has an internal combustion engine attached to the at least one electric motor for driving the vehicle. The vehicle can be understood as a so-called FCEV (Fuel Cell Electric Vehicle).

[0023] Furthermore, the technology disclosed herein includes a computer program product and a computer-readable storage medium, particularly a non-volatile storage medium, on which the computer program product is stored. The computer program product and the computer-readable storage medium also provide the aforementioned advantages. The computer program product may include instructions that, when executed by a computer, cause the computer to perform the proposed method in the aforementioned fuel cell system and / or vehicle. The computer can be understood as the computer of the vehicle's controller.

[0024] The computer program product can be computer-readable command code written in any suitable programming language and / or machine language (e.g., JAVA, C++, C#, and / or Python). The computer program product can be stored on a computer-readable storage medium, such as a data disk, removable drive, volatile or non-volatile memory, or built-in memory / processor. The command code can program a computer and other programmable devices (such as controllers) to perform desired functions. Furthermore, the computer program product is available and / or has been provided on a network, such as the Internet, from which users can download it on demand. The computer program product can be implemented and / or has been implemented not only by means of software but also by means of one or more dedicated electronic circuits, i.e., in hardware or in any hybrid form, i.e., by means of software components and hardware components.

[0025] Other measures are derived from the following description of different embodiments, which are schematically illustrated in the accompanying drawings. It is important that all features and / or advantages (including structural details and spatial arrangement structures) derived from the claims, description, or drawings are not only individual but also in different combinations. Attached Figure Description

[0026] The following are schematically illustrated: Figure 1 A fuel cell system according to a first embodiment of the present technology is shown; Figure 2 A fuel cell system according to a second embodiment of the present technology is shown; Figure 3 A flowchart illustrating a method according to one embodiment of the present technology is shown; Figure 4 A computer-readable storage medium is shown, the computer-readable storage medium having a computer program product according to an embodiment of the present technology stored thereon; Figure 5 A vehicle having a fuel cell system according to one embodiment of the present technology is shown.

[0027] Specific implementation form

[0028] In the accompanying drawings, elements with the same function and purpose are respectively assigned the same reference numerals.

[0029] Figure 1 A fuel cell system 10 according to one possible embodiment is shown. The fuel cell system 10 shown has a fuel cell 11 including an anode 12 and a cathode 13. The fuel cell system 10 also includes an anode gas path 14 for supplying fuel and recirculated process gas to the anode 12 and a process gas discharge path 15 for guiding process gas from the anode 12. Furthermore, the fuel cell system 10 has a water separator 17 and a syringe / injector 23, which are interconnected via a recirculation path 16. Additionally, the fuel cell system 10 has an exhaust path 19, within which a purge valve 18 is positioned. Pressure sensors 21 and 22 are provided in the anode gas path 14 and the recirculation path 16, respectively. Furthermore, the fuel cell system 10 has fuel sensors 24 and 25 in the anode gas path 14 and the process gas discharge path 15, respectively. Fuel sensors 24 and 25 are configured as hydrogen sensors. The fuel cell system 10 also has a controller 20 in the form of an ECU. The controller 20 is signal-connected to pressure sensors 21 and 22, fuel sensors 24 and 25, injector / jet injector 23, and purge valve 18.

[0030] Figure 2 A fuel cell system 10 according to a second embodiment is shown. Compared to the first embodiment, Figure 2 The fuel cell system 10 shown omits the pressure sensor 21 in the anode gas path 14 and the fuel sensor 25 in the process gas exhaust path 15. In other words, only the pressure sensor 21 is used, or no other pressure sensor is used, and only the fuel sensor 25 is used, or no other fuel sensor is used.

[0031] Next refer to Figure 3A method for adjusting the anode pressure in a fuel cell system 10 according to a second embodiment is described. In a first step S1, the initial anode pressure is first determined by means of a pressure sensor 22. In a second step S2, the fuel concentration in the anode gas path 14 is determined by means of a fuel sensor 24. This fuel concentration corresponds to the fuel concentration on the anode 12. In a third step S3, the determined anode pressure is corrected or verified based on the determined fuel concentration and without using the pressure value of the pressure sensor (i.e., without using the pressure value). The corresponding correlation between the determined anode pressure and the determined fuel concentration is determined based on a model and / or by means of a lookup table. Nitrogen diffusion in the fuel cell 11 is ignored. In a fourth step S4, the anode pressure is adjusted based on the determined fuel concentration or based on the anode pressure that has been corrected or verified based on the determined fuel concentration. More precisely, the adjustment is further implemented based on the determined fuel concentration.

[0032] In terms of formula, the relationship between the determined anode pressure and the determined fuel concentration can be expressed as follows:

[0033] in,

[0034] and

[0035] Under the assumed conditions .

[0036] Figure 4 A computer-readable and non-volatile storage medium 40 is shown, on which a computer program product 30 is stored. The storage medium 40 is configured in the form of a flash drive. The computer program product 30 includes instructions that, when executed by a computer, cause the computer to perform the described methods in the illustrated fuel cell system 10. The computer can be understood as part of the aforementioned controller 20 and / or controller 20.

[0037] Figure 5 A vehicle 100 in the form of a sedan is shown. The vehicle 100 has a fuel cell system 10 as described above. The vehicle 100 also has two electric motors 50 for driving the vehicle 100, wherein the fuel cell system 10 is configured to supply power to the electric motors 50. The vehicle 100 further has a pressure vessel 60 filled with fuel for supplying fuel to the fuel cell system 10. Additionally, the vehicle 100 has a controller 20 configured to perform the aforementioned methods.

[0038] The technology disclosed herein allows for other design principles besides those shown. That is, this technology should not be considered limited to the embodiments illustrated with reference to the accompanying drawings. For example, it is possible to determine nitrogen diffusion in fuel cell 11 and, additionally, adjust the anode pressure based on the determined nitrogen diffusion. In other words, in this case, the anode gas pressure is adjusted not only based on the determined fuel concentration but also, additionally, based on the determined nitrogen diffusion. In other words, the anode pressure can be corrected, verified, or fully determined based on the determined fuel concentration and the determined nitrogen diffusion.

[0039] List of reference numerals

[0040] 10 Fuel Cell System

[0041] 11 fuel cells

[0042] 12 anodes

[0043] 13 cathodes

[0044] 14 Anode Gas Path

[0045] 15 Process Gas Exhaust Path

[0046] 16 Recycle Paths

[0047] 17 Water Separator

[0048] 18 purge valve

[0049] 19 Exhaust Path

[0050] 20 controllers

[0051] 21 pressure sensors

[0052] 22 pressure sensors

[0053] 23 Syringe / Injector

[0054] 24 fuel sensors

[0055] 25 Fuel Sensor

[0056] 30 Computer Program Products

[0057] 40 storage media

[0058] 50 motor

[0059] 60 pressure vessel

[0060] 100 vehicles

Claims

1. A method for regulating the anode pressure in a fuel cell system (10), wherein, The fuel cell system (10) includes a fuel cell (11) having an anode (12) and a cathode (13), pressure sensors (21, 22), and fuel sensors (24, 25), and the method comprises: - The anode pressure is determined by means of the pressure sensors (21, 22); - The fuel concentration in and / or on the anode (12) is determined by means of the fuel sensors (24, 25); and - Adjust the anode pressure based on the identified fuel concentration.

2. The method according to claim 1, wherein, The anode pressure is adjusted based on the identified fuel concentration and / or verified anode pressure.

3. The method according to claim 2, wherein, The determined anode pressure is corrected and / or verified using a lookup table based on the determined fuel concentration.

4. The method according to any one of claims 2 to 3, wherein, The identified anode pressure is model-based to correct and / or validate the identified fuel concentration.

5. The method according to any one of the preceding claims, wherein, The nitrogen diffusion in the fuel cell (11) was identified, and the anode pressure was adjusted based on the identified nitrogen diffusion.

6. A fuel cell system (10) comprising a fuel cell (11) including an anode (12) and a cathode (13), pressure sensors (21, 22), fuel sensors (24, 25), and a controller (20), wherein, The controller (20) is configured to perform the method according to any one of the preceding claims.

7. The fuel cell system (10) according to claim 6, wherein the fuel cell system has an anode gas path (14) for guiding anode gas into the anode (12) and a process gas discharge path (15) for guiding process gas from the anode (12), wherein, At least one fuel sensor (24, 25) is configured to determine the fuel concentration in the anode (12), in the anode gas path (14), and / or in the process gas discharge path (15).

8. A vehicle (100) comprising a fuel cell system (10) according to any one of claims 6 to 7, wherein, The fuel cell system (10) is configured to generate current in the vehicle (100).

9. A computer program product (30) comprising instructions that, when executed by a computer, cause the computer to perform the method according to any one of claims 1 to 5 in a fuel cell system (10) according to any one of claims 6 to 7.

10. A computer-readable storage medium (40) having a computer program product (30) according to claim 9 stored thereon.

Images