Self-cleaning of a fuel cell system with fluid circuit

摘要

The method comprises reducing the fluid quantity in a fluid circuit of a fuel cell system by discharging a part of the fluid, and increasing the fluid quantity in the fluid circuit. The reducing step takes place before the increasing step and the increase of the fluid quantity takes place so long until the fluid quantity discharged in the reducing step is supplied again. The increasing step takes place before the reducing step and the reduction of the fluid quantity takes place so long until the fluid quantity increased in the increasing step is discharged again. The method comprises reducing the fluid quantity in a fluid circuit of a fuel cell system by discharging a part of the fluid, and increasing the fluid quantity in the fluid circuit. The reducing step takes place before the increasing step and the increase of the fluid quantity takes place so long until the fluid quantity discharged in the reducing step is supplied again. The increasing step takes place before the reducing step and the reduction of the fluid quantity takes place so long until the fluid quantity increased in the increasing step is discharged again. The reducing step and the increasing step are simultaneously or partially simultaneously carried out. The fluid circuit comprises anode circuit and the reduction step comprises discharging the part of the fluid from the anode circuit. The water quantity in the fluid circuit of the fuel cell system is regulated by discharging water vapor from the fuel cell system, where the increase of the fluid quantity in the fluid circuit comprises reducing the water vapor discharge, and supplying water into the fluid circuit. The fluid comprises a mixture of water and methanol. The increasing step comprises supplying methanol, so that the mixture ratio of water and methanol in the anode circuit is equal before and after carrying out the increasing step. The increasing step and the reducing step or one of the increasing step and the reducing step are periodically carried out in a repeated manner. The increasing step and the reducing step are coordinated to each other, so that the fluid quantity in the fluid circuit is equal during carrying out the process. An independent claim is included for a fuel cell system.