TY - JOUR AU - Cieśliński, Janusz T. AU - Kaczmarczyk, Tomasz AU - Dawidowicz, Bartosz PY - 2017 TI - Performance of the PEM fuel cell module. Part 2. Effect of excess ratio and stack temperature JF - Journal of Power Technologies; Vol 97 No 3 (2017) KW - N2 - The paper describes a fuel cell based system performance under different thermal conditions. The system could be fed with bottled hydrogen or with very high purity hydrogen obtained from reforming of methanol. The system is based on two fuel cell units (1.2 kW each, produced by Ballard Power Systems Inc. and called Nexa), DC/DC converter, DC/AC inverter, microprocessor control unit, load unit, bottled hydrogen supply system and a set of measurement instruments. In this study steady-state operation of the PEM fuel cell system at different values of air excess ratio and different stack temperature was investigated. The load of the system was provided with the aid of a set of resistors. The results obtained show that the net power of the system does not depend on the air excess ratio within the range of O2 from 1.9 to 5.0. The polarization curves of the fuel cell module showed that the fuel cell performance was improved with increased stack temperature within the range of 30C to 65C. It was established that the total efficiency of the tested system depends on the hydrogen source and is higher when using bottled hydrogen of about 30% and 16%, for minimum and maximum load, respectively. UR - https://papers.itc.pw.edu.pl/index.php/JPT/article/view/601