Experimental assessment of a heavy-duty fuel cell system in relevant operating conditions

During the past few years, the research interest in fuel cell systems (FCS) has increased significantly. Thus, this kind of powertrain is now at high Technology Readiness Levels (TRLs) and even starting to be commercialized. However, the currently available technology still has room for optimization. The existing bibliography shows studies mainly related to stack-level characterization or FCS studies with a poor level of detail. The present paper focuses on producing a detailed database about the performance of a specific FCS designed for heavy-duty vehicle (HDV) applications. The obtained dataset provides information about the influence of ambient conditions on the performance of the system, plus information about the anode and cathode circuits. These factors represent an important novelty with respect to other pieces of literature present in the actual research framework. Additionally, the obtained data regarding the performance of an FCS is highly significant for HDV manufacturers in the transportation sector and eases the pathway to the optimization of these technologies. The written piece of research proves the importance of studying the ambient conditions. The experimental campaign has shown that increasing relative humidity can improve the performance of the membrane up to a 2% for a 25% change in the humidity level. Additionally, the study shows the importance of implementing an appropriate supply gas strategy, both for anode and cathode, and designing the right purging mechanisms for H2 at the anode inlet. The obtained results show how there exist a relation between the optimal efficiency operating point and a H2 excess from the supply strategy.