PERFORMANCE OF SERPENTINE PASSAGES IN THE COOLING SYSTEM OF A PHOSPHORIC-ACID FUEL-CELL STACK

An experimental rig was designed and constructed to simulate the operating conditions prevailing in a phosphoric acid fuel cell stack. The rig measures the heat transfer coefficient, the thermal contact resistance, and the fuel cell plate temperature. A serpentine cooling plate configuration was used to investigate cooling system performance and efficiency. Oil and water were used as cooling media. Measurements for coolant flow rates ranging from 16 to 88 kg/h and stack clamping pressures (interface pressures) from 0 to 3445 kPa were investigated. The experimental results were used to derive mathematical relations for the overall heat transfer coefficient as a function of the stack clamping pressure and Reynolds number for the two coolants. These relations were incorporated into a previously developed computer program to predict fuel cell plate temperature distributions and performance of the stack cooling system. The experimental results showed good agreement with the computer simulation.