| 摘要 |
PURPOSE:To adequeately heat a fuel cell to retain high cell performance for a long time and to lengthen the life by computing the optimum amount of water vapor based on output current from a fuel cell, and controlling the water vapor amount to be added to fuel and oxidizing agent gas supplied to a fuel cell. CONSTITUTION:A water vapor adding amount controller 13 computes the am ount of water producing on the surface of a catalyst layer in a fuel cell 6 based on output current supplied to a load from the fuel cell. Based on the data obtained, a fuel gas line water vapor control valve 10F and an oxidizing agent gas line water vapor control valve 10A are controlled so that the amount of water vapor required to keep the volume of phosphoric acid electrolyte constant is supplied to fuel gas F and oxidizing agent gas A. Since the amount of water vapor supplied to the electrolyte is kept optimum, the volume of electrolyte in the fuel cell is kept constant. Therefore, deterioration in cell performance caused by crossover and decrease in the life can be prevented, steady cell perfor mance is retained over a long period of time, and the life is increased. |
