COMPUTER AIDED FUEL CELL DESIGN AND SCALE UP - FIRST EXPERIMENTAL RESULTS

The gas flow distribution in fuel cells has great influence on both the power density and efficiency of the fuel cell system. In these devices gas distribution take places by channels realised in the shell plates, that supply gas to the backing of the porous electrodes. Consequently, the gas flow incoming into the fuel cell can be divided in two components the first through the flow field channels in the shell plates, the second one through the porous electrode, and their ratio depends on the interaction between flow field geometry and gas diffusion electrode characteristics. Because of the fuel cell design and its optimisation are generally carried out in small scale cell, when a scale up was made the reactant distribution complexity renders more difficult the performance maintenance. To solve the scaling up problems a computer aided selection method was evolved for a serpentine flow field. The algorithm generates and selects the flow channels design that matches the requested geometrical and fluid dynamics constrains, successively the scaled flow field can be realised and tested. In order to validate the scaling procedure, the method was applied to a cell with a scaling up from 5 cm2 to 50cm2 of active area with two different constrains. Experimental tests were carried out and the obtained experimental data were compared with calculated values to verify the validity of the used model.