Abstract: The present invention relates to a fuel cell system (100) for converting energy. The fuel cell system (100) comprises: a fuel cell stack (101) which comprises a cathode subsystem (103) and an anode subsystem (105), a pressure sensor (107) which is arranged in the anode subsystem (105), a flush valve (109) for purging the anode subsystem (105), a computing unit (111), the computing unit (111) being configured to determine a composition of a gas which is flowing through the anode subsystem (105) by means of measured values acquired by the pressure sensor (107) and to control the flush valve (109) according to the determined composition.

Abstract: The present invention relates to a method for operating a fuel cell (1) of a fuel cell system (2) for a vehicle. According to the method, a predetermined load reduction is implemented in stages so that, combined with cooling of the fuel cell (1), unacceptable operating conditions, which can, for example, lead to increased wear of the fuel cell (1), are avoided. The invention also relates to a fuel cell system (2) for a vehicle.

Abstract: A method for drying a fuel cell (10) for generating electrical energy for a consumer (20), in particular for a vehicle (20), in which an anode gas having a first reactant is supplied to an anode (200), and a cathode gas having a second reactant is supplied to a cathode (100), and the reactants are converted into electricity along a flow path (300) in the fuel cell (10) by means of an electrochemical reaction, the method having the following steps: a) flushing (2) the cathode (100) with the cathode gas; b) operating (4) the fuel cell (10) with so little cathode gas that the second reactant is substantially consumed along the flow path (300) by the electrochemical reaction for conversion to electricity, an electric current density of the fuel cell (10) being less than 20% of a maximum achievable electric current density of the fuel cell (10).

Abstract: The invention relates to a method for cooling a fuel cell system by operating a cooling system, comprising a coolant pump, a cooler through which coolant can flow, a bypass with a bypass valve for selectively, at least partially bridging the cooler, and a coolant passage of a fuel cell stack thermally coupled to the fuel cell system, said method comprising the following steps: determining a flooding risk of the fuel cell system at least once according to current operating conditions of the fuel cell system; determining a maximum permissible temperature gradient based on the determined flooding risk; operating the coolant pump such that it conveys a volumetric flow of a coolant through the coolant passages of the stack and the cooler; actuating the bypass valve such that it divides the volumetric flow through the bypass and the cooler; and limiting a cooling output by limiting the volumetric flow and a status of the bypass valve in order to limit the temperature gradient to the determined maximum permissible t

Abstract: The invention relates to a method for operating a fuel cell system (100) comprising at least one stack (101) when starting the fuel cell system (100), in particular when during a cold start of the fuel cell system and/or start of the fuel cell system (100) under freezing conditions, in order to bring, in particular to adjust, a coolant temperature (TCoolIn) at the entry point into the stack (101) to a desired stagnation temperature (Ts), the method comprising the following steps: predicting the stagnation temperature (Ts) of the coolant (KM) for various rotational speeds (N) of a coolant pump (31), adjusting the rotational speed (N) of the coolant pump (31) so that the stagnation temperature (Ts) is above the desired value (Ts).