Abstract
A fuel cell vehicle using a polymer electrolyte membrane fuel cell (PEM FC) as power source produces electric power by consuming the fuel, hydrogen. The unconsumed hydrogen is recirculated and reused to gain higer stack efficiency and to maintain the humidity in the anode side of the stack. So it is needed considering fuel efficiency to recirculated hydrogen. In this study, the indirect hydrogen recirculation flow rate measurement method for fuel cell vehicle is presented. By modeling of a convergent nozzle ejector and a hydrogen recirculation blower for the hydrogen recirculation of a PEM FC, the hydrogen recirculation flow rate was calculated by means of the mass balance and heat balance at Anode In/Outlet.