Methods and Systems For Detecting A Leak In A Fuel-Cell System

A control device comprising:

• a first control device section for receiving a hydrogen signal from a hydrogen sensor;
• a second control device section for transmitting a diagnosis signal;
• a third control device section for determining that a membrane or a flushing valve is at least partially leaky;
• and
• a fourth control device section for transmitting a control signal;
• the control device operable to detect a leak in a fuel-cell system with an exhaust system by:
• receiving a hydrogen signal from a hydrogen sensor arranged in the exhaust system, wherein the hydrogen signal represents a hydrogen concentration in a gas mixture present in the exhaust system;
• transmitting a diagnosis signal prompting the fuel-cell system to change into a diagnostic operating mode, if the received hydrogen signal indicates a hydrogen concentration value in the exhaust system exceeding a predetermined hydrogen concentration threshold value;
• determining a member of a fuel cell of the fuel-cell system is at least partially leaky if the hydrogel signal received during the diagnostic operation of the fuel-cell system is essentially decreasing, or a flushing valve arranged in the anode line system is at least partially leaky if the hydrogen signal received during the diagnostic operation of the fuel-cell system is not essentially decreasing;
• and
• transmitting a control signal indicating which of the membrane or the flushing valve is at least partially leaky.