Purging control of fuel cell anode effluent

A fuel cell power plant comprising:

• a fuel cell stack for performing power generation by means of an electrochemical reaction between hydrogen contained in hydrogen-rich gas which is supplied to an anode and oxygen which is supplied to a cathode, the fuel cell stack comprising a stacked body of a plurality of fuel cells each of which outputs an electrical current in accordance with an electrochemical reaction amount;
• means for adjusting one of a flow rate of the hydrogen-rich gas supplied to the anode and an output current of the fuel cell stack;
• means for detecting a concentration of impurity gas contained in the hydrogen-rich gas;
• means for determining if a concentration of the impurity gas has reached a predetermined concentration;
• and
• means for controlling the adjusting means to cause an entire amount of the hydrogen supplied to the anode to be expended in power generation by the fuel cell stack, when the concentration of the impurity gas has reached the predetermined concentration.

A control method of a fuel cell power plant comprising a fuel cell stack for performing power generation by means of an electrochemical reaction between hydrogen contained in hydrogen-rich gas which is supplied to an anode and oxygen which is supplied to a cathode, and an adjustment mechanism which adjusts one of a flow rate of the hydrogen-rich gas supplied to the anode and an output current of the fuel cell stack, the fuel cell stack comprising a stacked body of a plurality of fuel cells each of which outputs an electrical current in accordance with an electrochemical reaction amount, the method comprising:

• detecting a concentration of impurity gas contained in the hydrogen-rich gas;
• determining if a concentration of the impurity gas has reached a predetermined concentration;
• and
• controlling the adjustment mechanisms to cause an entire amount of the hydrogen supplied to the anode to be expended in power generation by the fuel cell stack, when the concentration of the impurity gas has reached the predetermined concentration.