Patent ID: 7479338

Claim:
A fuel cell system comprising: one or more fuel cells, each of the fuel cells having an anode and a cathode; a mixing tank supplying a fuel to the anode; a discharging flow path connected to the fuel cells, the discharging flow path conducting an exhaust from the fuel cells to the mixing tank; a radiator installed on the discharging flow path, the radiator cooling the exhaust to a controlled temperature so as to condense a controlled amount of water meeting a demand in the fuel cells; a ventilator controllably feeding air to the radiator; and a controller unit controlling the ventilator so as to control cooling the exhaust to the controlled temperature, wherein the controller unit calculates the controlled temperature in accordance with an equation of P H 2 ⁢ O sat ⁡ ( T fin_cathode ) = N ⁡ ( 2 ⁢ I op 6 ⁢ F + 2 ⁢ I c . o . 6 ⁢ F ) F cathode_out ⁢ P , in which T fin — cathode is the controlled temperature, I op is a current generated by the fuel cells,I c.o. is a proton current converted from a quantity of a crossover methanol through the fuel cells, F is the Faraday constant, F cathode — out is a flow rate of gas exhausted from the cathodes, N is a number of the fuel cells, and P is gas pressure in the radiator.