Patent ID: 8323841
Filing Date: 2012-12-04
Classification: H01M,Y02E

Abstract:
1. A method for determining the concentration of hydrogen in an anode recirculation loop of a fuel cell stack, said method comprising: measuring the pressure drop across a recirculation pump; measuring the temperature of the anode recirculation gas flowing through the recirculation loop; setting an arbitrary value for the percentage of hydrogen in the recirculation gas; calculating the pressure drop across the anode side of the stack; calculating the volume flow of the recirculation gas flowing through the anode side of the stack as a function of the calculated pressure drop across the anode side of the stack, the percentage of hydrogen in the recirculation gas, the measured temperature and the measured pressure drop; calculating the density of the recirculation gas flowing through the recirculation loop using the calculated volume flow, the measured pressure drop and the speed of the recirculation pump; and using the calculated density, the measured temperature and the measured pressure drop to calculate a new percentage of hydrogen in the recirculation gas.