| 摘要 |
PURPOSE:To prevent lack of hydrogen, remove adsorbed oxygen and prevent performance being worsened while power generation is stopped by supplying inert gas and hydrogen gas to an oxidant electrode and a fuel electrode respectively and turning a resistor on/off in accordance with a detected value of hydrogen concentration at an outlet of the oxidant. CONSTITUTION:In a process in which power generation of a fuel cell is stopped, supplying oxidant to an oxidant electrode 1b is stopped, to which inert gas is supplied from an inert gas supplying system 4 to purge oxygen remained thereof. On the other hand, with starting stop operation, a resistor 7 provided at a direct current output is turned on to energize the fuel cell. This causes that adsorbed oxygen is consumed and removed due to reaction of the oxygen adsorbed to the oxidant electrode 1b and hydrogen supplied to a fuel electrode 1a. In this case, when a voltage detected by a voltage detector 6 is high, a control device 8 selects a tap so as to minimize a value of the resistor 7. With procceding removal of the adsorbed oxygen, the oxygen is removed which reacts with the hydrogen and a current flows between the electrodes in accordance with electromotive force of a concentration cell due to concentration difference of the hydrogen. Then, the resistor 7 is turned off. |
