Operational experience of a 1 kW PAFC stack

A 1 kW phosphoric acid fuel-cell (PAFC) stack with 30 cells, was designed, fabricated, assembled with "in-house" developed components at ERI, KACST, and successfully operated for 250 h. The stack was operated at 180 degrees C, 1 bar, using commercial H-2/CO2 gas and air. The electrical output power generated by the stack was similar to 1 kW (20.5x50 A), with a current density of 125 mA/cm(2) at an average cell voltage of 0.7 V. From the results of the successful operation of the stack, it was found that the stack was stable during the operation and the heat generated in the stack was sufficient to retain the temperature at 175 to 180 degrees C without any external heating. To cool the stack, three cooling plates were used in the stack. Insulation was applied to the stack to get a more uniform temperature. The water formed in the stack was collected through the H-2 gas outlets and air manifolds during the operation of the stack. As the temperature of the stack at the centre was slightly high, it is recommended introducing two more cooling-plates to achieve a more uniform temperature and better stack performance. (C) 1999 Elsevier Science Ltd. All rights reserved.