EFFECT OF HYDROGEN FEEDING SUBSYSTEM ON EFFICIENCY AND DURABILITY OF PEM FUEL CELL SYSTEMS

The hydrogen feeding sub-system is one of balance of plants (BOP) components necessary for the correct operation of a fuel cell system (FCS). In this paper the performance of a 6 kW PEM (Proton Exchange Membrane) FCS, able to work with two fuel feeding procedures (dead-end or flow-through with recirculation), was experimentally analyzed with the aim to verify the effect of the anode operation mode. The FCS operated at low reactant pressure (< 1.5 bara), without external humidification. The experiments were performed in both steady state and dynamic conditions, typical of automotive applications. The results were analysed in terms of total available power, individual cell voltage distribution and efficiency. The performance worsening observed without fuel recirculation in dynamic conditions evidenced the correlation between the fuel feeding method and cell voltage uniformity