Patent ID: 7569296

Claim:
A method for operating a vehicle-mounted fuel cell stack, said vehicle-mounted fuel cell stack comprising: (a) a plurality of power generating cells each of which is generally in a shape of a flat plate and includes a solid polymer electrolyte membrane sandwiched between an anode electrode and a cathode electrode, each of said power generating cells generating electric power through reaction, via the solid polymer electrolyte membrane, between fuel gas and reacting air supplied to the anode electrode and cathode electrode, respectively, each of said power generating cells having, a reacting-air introduction opening for introducing the reacting air into said power generating cell; (b) one or more cooling cells stacked alternately with said power generating cells, each of said cooling cells including two opposed flat plates for passage therebetween of cooling air and having a cooling-air introduction opening for introducing the cooling air between the opposed flat plates; and (c) an air allocation mechanism for allocating traveling wind or a stream of air, produced via a fan, to the reacting-air introduction openings and to the cooling-air introduction openings as the reacting air and cooling air, respectively, said air allocation mechanism being capable of adjusting an allocation ratio between the reacting air and the cooling air, said method comprising: measuring electric power consumed by a traveling motor for causing the vehicle to travel; measuring a traveling velocity of the vehicle; determining standard electric power that corresponds to the measured consumed electric power, said standard electric power representing a level of electric power that would be consumed by said traveling motor if the vehicle travels on flat land at the measured traveling velocity; determining that the measured consumed electric power is greater than the standard electric power; determining that the vehicle velocity has not increased: determining that a temperature of the power generating cells increases beyond a; placing said fan in an activated state for rotation; and operating the air allocation mechanism to increase an allocated amount of the cooling air and to prevent the temperature of the power generating cells from increasing further; wherein the air allocation mechanism comprises an opening/closing drive source, a link mechanism coupled to the opening/closing drive source and a valve driven via the link mechanism, wherein the step of operating the air allocation mechanism further comprises: operating the link mechanism to increase a distance between the cooling-air introduction opening and the air allocation mechanism; placing the air allocation mechanism in a retreat limit position where the air allocation mechanism is opened; introducing a portion of the traveling wind or the stream of air, produced via the fan, as the reacting air; and introducing a remaining portion of the traveling wind or a stream of air, produced via the fan, as the cooling air through the cooling-air introduction opening.