Patent ID: 8338040

Claim:
A fuel cell system including a fuel cell having a cell stack formed by stacking a plurality of unit cells each having an anode electrode, a cathode electrode, an electrolyte membrane located between the anode electrode and the cathode electrode, and a reaction gas flow channel, the fuel cell system further having: an estimation unit that estimates a water vapor amount and a nitrogen gas amount at a plurality of predetermined positions inside the electrolyte membrane and the reaction gas flow channel of at least one unit cell; wherein the water vapor amount is estimated by determining a residual water amount distribution in the reaction gas flow channel and a water content distribution in the electrolyte membrane in a cell plane of the unit cell with consideration for water transfer performed between the anode electrode and the cathode electrode via the electrolyte membrane; wherein the nitrogen gas amount is estimated by determining a nitrogen gas distribution in the reaction gas flow channel in the cell plane of the unit cell with consideration for nitrogen gas transfer performed between the anode electrode and the cathode electrode via the electrolyte membrane; and an operation control unit that: compares, during an operation stop of intermittent operation, at least either of the water vapor amount or the nitrogen gas amount at each of the predetermined positions that has been estimated by the estimation unit with a threshold for each of the predetermined positions that has been set with consideration for a stacking direction of the unit cells and a flow channel direction of the reaction gas flow channel, and supplies a gas including hydrogen gas to the reaction gas flow channel and discharges water vapor and nitrogen gas from inside the fuel cell, when at least either of the water vapor amount and the nitrogen gas amount exceeds the threshold at at least one of the positions.