Reliable Performance Evaluation of Single Cells Through an Effective Experimental Test Rig and Measure Chain

Fuel cells are known to be efficient and environmental friendly electricity generation devices. Great expectations are put on their contribution for future ultra-clean energy production. Nevertheless, the requests from deregulated energy market prompt fast commercialization of systems that are not yet fully optimized. Low efficiencies of first generation commercial fuel cell plants could result in failure when satisfying end users’ requirements thus creating an obstacle for subsequent market penetration. In this context, the availability of reliable data on fuel cells, necessary for their correct integration in full energy systems for plant optimization and feasibility assessment constitutes a priority. On the other hand, while measuring fuel cells performance is a difficult task nevertheless within reach for most research departments; the challenge for the scientific community is to reliably assess performance dependence on all the most relevant input parameters. As a result, most of the experimental data find on literature on fuel cells performances refer to voltage measures at increasing currents for fixed gas compositions and flow rates. In this work an experimental facility has been set up, test rigs have been designed and constructed both for fuel cells and reforming section testing; the main aim was to allow great operational flexibility. Great attention has been paid on test procedures and on input parameterisation as well on reliable advanced control systems. Dependence on the most relevant input parameters, i.e. current density, operating temperature, fuel and oxidant utilization factor, fuel humidification and dilution has been deeply analysed. Performances have been analysed both in terms of output voltage and efficiency and in terms of time degradation and expected total lifetime. The contribution of the work done consist in defining adimensional parameters which, thanks to their direct relation with the theoretical equations which govern a fuel cell, can greatly improve performance evaluation capability of experimental tests. Moreover those parameters can represent a way to standardize test procedures and constitute a means for comparing and exchanging results in a easier and effective way. A second contribution consist in designing and developing a unique control system that can improve test reliability thanks to the feature that allows to change single parameters while keeping the others constant and greatly enhance the number of experimental points that can be obtained in a test.Copyright © 2002 by ASME