Fuel cell system

Abstract

A fuel cell system can be initiated in shorter time while minimizing the deterioration of a fuel cell. The fuel cell system includes a fuel cell stack having a fuel electrode, an oxidizer electrode and an electrolyte membrane disposed there between, the fuel cell producing electricity by an electrochemical reaction of a fuel gas and an oxidizer gas, which are supplied to the fuel electrode and the oxidizer electrode, respectively; a fuel gas supplying device for supplying the fuel gas to the fuel cell stack; an oxidizer gas supplying device for supplying the oxidizer gas to the fuel cell stack; a current controlling device for extracting a current from the fuel cell stack; and a voltage sensor disposed in at least two of the fuel cell stacks. A controller controls the current controlling device such that a minimum voltage, which is obtained from the voltage sensor after a fuel gas is supplied to the fuel electrode without supplying the oxidizer gas to the oxidizer electrode at the time of initiating, becomes zero volts or more. Then, the oxidizer gas is supplied to the oxidizer to start producing electricity.

1 - 33 . (canceled) 
     
     
         34 . A fuel cell system including a fuel cell stack, a fuel gas supplying unit for supplying fuel gas to the fuel cell stack, and an oxidizer gas supplying unit for supplying oxidizer gas to the fuel cell stack, wherein the fuel cell stack includes a plurality of stacked cells each formed by interposing an electrolyte membrane between a fuel electrode supplied with the fuel gas and an oxidizer electrode supplied with the oxidizer gas; the fuel cell system comprising:
 current extracting means for extracting a current from the fuel cell stack;   voltage measuring means for measuring voltages from a plurality of different cells of the fuel cell stack; and   a control means for supplying only the fuel gas to initiate the fuel cell stack and extracting the current to make the voltages a predetermined value or below that does not deteriorate the fuel cell stack.   
     
     
         35 . A method of operating a fuel cell system including a fuel cell stack, a fuel gas supplying unit for supplying fuel gas to the fuel cell stack, and an oxidizer gas supplying unit for supplying oxidizer gas to the fuel cell stack, wherein the fuel cell stack includes a plurality of stacked cells each formed by interposing an electrolyte membrane between a fuel electrode supplied with the fuel gas and an oxidizer electrode supplied with the oxidizer gas; the method comprising:
 extracting a current from the fuel cell stack;   measuring voltages from a plurality of different cells of the fuel cell stack; and   initiating operation of the fuel cell stack by supplying the fuel gas to the fuel electrode without supplying the oxidizer gas to the oxidizer electrode;   producing electricity occurs after a minimum value detected by the voltage sensor becomes zero volts or more, whereupon the oxidizer gas is supplied to the oxidizer electrode.