FUEL CELL SYSTEM COMPRISING A METERING UNIT

摘要

The invention relates to a fuel cell system comprising a fuel cell unit (1) and a metering unit for metering a quantity of a substance for at least one electrode (3, 5), said metering unit comprising at least two metering elements (16, 17) that are connected in parallel. Said system simplifies the control of the substance quantity to be metered and permits in particular a comparatively sensitive and/or relatively rapid control of the substance quantity to be metered or has the lowest possible internal consumption. The system should also be capable of diagnosing faults, i.e. should recognise a development of pressure ratios that could damage the system. To achieve this, the first metering element (16) is configured as a control element for controlling the flow cross-section of the second metering element (17) by means of a pneumatic coupling.