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DE-102024210845-A1 - Method for determining the hydrogen concentration in a fuel cell system

DE102024210845A1DE 102024210845 A1DE102024210845 A1DE 102024210845A1DE-102024210845-A1

Abstract

The presented invention relates to a method (100) for determining a hydrogen concentration in a fuel cell system (200) comprising several fuel cell stacks (203, 207) and several anode subsystems, wherein the method (100) comprises: - Measuring (101) a hydrogen concentration in a collecting line into which respective anode subsystems deposit fluid flushed out during a purging process, - Assigning (103) respective measured values to a respective fuel cell stack (203, 207), wherein the assignment (103) of the measured values to a respective fuel cell stack (203, 207) is carried out on the basis of a position of all purge valves of the fuel cell system (200).

Inventors

  • Helerson Kemmer
  • Mark Hellmann

Assignees

  • Robert Bosch Gesellschaft mit beschränkter Haftung

Dates

Publication Date
20260513
Application Date
20241112

Claims (10)

  1. Method (100) for determining a hydrogen concentration in a fuel cell system (200) comprising several fuel cell stacks (203, 207) and several anode subsystems, the method (100) comprising: - measuring (101) a hydrogen concentration in a collection line into which respective anode subsystems deposit fluid purged during a purging process, - assigning (103) respective measured values to a respective fuel cell stack (203, 207), the assignment (103) of the measured values to a respective fuel cell stack (203, 207) is carried out based on the position of all purging valves of the fuel cell system (200).
  2. Procedure (100) according to Claim 1 , characterized in that , in the event that all anode subsystems of the fuel cell system (200) can be connected to the manifold via a multi-way purge valve, a target position of the multi-way purge valve is determined, and the measured values are assigned to a fuel cell stack (203, 207) which is supplied with fuel by an anode subsystem which is connected to the manifold by the target position of the multi-way purge valve.
  3. Procedure (100) according to Claim 1 , characterized in that , in the event that all anode subsystems of the fuel cell system (200) are connectable to the manifold via a multi-way purge valve which provides position feedback, an actual position of the multi-way purge valve is determined on the basis of a current position feedback, and the measured values are assigned to a fuel cell stack (203, 207) which is supplied with fuel by an anode subsystem which is connected to the manifold by the actual position of the multi-way purge valve.
  4. Procedure (100) according to Claim 1 , characterized in that each fuel cell stack (203, 207) of the fuel cell system (200) is assigned a time range for carrying out a purging process in a time grid and measured values determined in a respective time range are assigned to a respective fuel cell stack (203, 207) assigned to the respective time range.
  5. Procedure (100) according to Claim 1 , characterized in that each flushing operation of each flushing valve is planned and registered with a coordination instance (201), and the coordination instance releases only one flushing operation of a single flushing valve in a given time range.
  6. Method (100) according to one of the preceding claims, characterized in that measured values assigned to a respective fuel cell stack (203, 207) are assigned by means of a machine learner to a first class that indicates a purging process or to a second class that does not indicate a purging process.
  7. Procedure (100) according to Claim 6 , characterized in that measured values are supplied to the machine learner in a given time range before and after an increase in the measured values above a given threshold.
  8. Method (100) according to one of the preceding claims, characterized in that when assigning (103) the measured values to a respective fuel cell stack (203, 207) a geometry of lines for the discharge of fluid during a rinsing process is taken into account.
  9. Method (100) according to one of the preceding claims, characterized in that when assigning the measured values to a respective fuel cell stack (203, 207) an operating state of the fuel cell system (200) is taken into account.
  10. Fuel cell system (200) for converting energy, wherein the fuel cell system (200) comprises: - a plurality of fuel cell stacks (203, 297), wherein each fuel cell stack (203, 207) of the plurality of fuel cell stacks (203, 207) comprises a respective anode subsystem with a purge valve, and all anode subsystems are connected to a manifold for discharging fluid discharged during a purge process through a respective purge valve, - a hydrogen concentration sensor arranged in the manifold - a computing unit (209), wherein the computing unit is configured to execute a method (100) according to one of the Claims 1 until 9 to carry out.

Description

The presented invention relates to a method for determining a hydrogen concentration in a fuel cell system comprising several fuel cell stacks and several anode subsystems and a fuel cell system. State of the art Fuel cells convert hydrogen and oxygen into water, generating electricity that can be supplied to a consumer, such as an electric motor, to power it. Particularly in the field of large vehicles, such as trucks or ships, fuel cell systems are known that comprise a large number of fuel cell stacks supplied with air by a single central or shared air system. Each fuel cell stack within the large number of stacks is supplied with fuel by a specific anode subsystem, allowing each stack to operate independently of the other fuel cell stacks in the system. To flush each fuel cell stack, a flushing valve or so-called "purge valve" is arranged in each anode subsystem of such a fuel cell system, through which fluid from the anode subsystem can be flushed into a collecting line and finally discharged into an environment. A single or shared hydrogen concentration sensor is arranged in the collecting line, by means of which a hydrogen concentration in the collecting line can be determined. Disclosure of the invention Within the scope of the presented invention, a method for determining a hydrogen concentration in a fuel cell system comprising multiple fuel cell stacks and multiple anode subsystems, and a fuel cell system itself, are presented. 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 method according to the invention naturally also apply in connection with the fuel cell system according to the invention, and vice versa, so that the disclosure regarding the individual aspects of the invention is always, or can always be, mutually referenced. The invention presented here serves in particular to provide a means of determining a hydrogen concentration in a fuel cell system comprising several fuel cell stacks and several anode subsystems. Thus, according to a first aspect of the presented invention, a method for determining a hydrogen concentration in a fuel cell system comprising several fuel cell stacks and several anode subsystems is presented. The presented method comprises measuring a hydrogen concentration in a collecting line into which respective anode subsystems deposit flushed fluid during a purging process and assigning respective measured values to a respective fuel cell stack, whereby the assignment of measured values to a respective fuel cell stack is carried out based on the position of all purging valves of the fuel cell system. The presented invention is based on an assignment of measured values, which were measured by means of a single or common hydrogen concentration sensor, to a respective fuel cell stack of a plurality of fuel cell stacks or its anode subsystem. Accordingly, the hydrogen concentration in a respective anode subsystem of a fuel cell stack with multiple fuel cell stacks can be determined using the presented method. To assign specific measured values to a particular fuel cell stack, the position of each purge valve in the fuel cell system is evaluated. The position of the purge valves can be evaluated as either the target position (i.e., the position planned for the future) or the actual position (i.e., the position already set). Once individual measured values are assigned to a specific fuel cell stack or its anode subsystem, the hydrogen concentration in the anode subsystem of the fuel cell stack can be determined based on these measurements. This can be achieved, for example, using a predefined mathematical relationship, a mathematical model of the fuel cell system that incorporates, for instance, an operating state of the fuel cell system, in particular a pressure and/or a temperature and/or a flow rate in or through the respective lines of the fuel cell system, or a machine learner. It may be provided that, in the event that all anode subsystems of the fuel cell system can be connected to the manifold via a multi-way purge valve, a target position of the multi-way purge valve is determined, and the measured values are assigned to a fuel cell stack that is supplied with fuel by an anode subsystem that is connected to the manifold by the target position of the multi-way purge valve. To determine the target position of a flushing valve, especially a multi-way flushing valve, a corresponding request can be sent to a control unit configured to control the flushing valve. Alternatively, a control unit configured to control the flushing valve can report a planned target position of the flushing valve before each change of a flushing valve, i.e., transmit it, for example, to a computing unit executing the presented procedure. For example, an assignment scheme can be specified that assigns a respective fuel cell stack to each position of