| 摘要 |
PROBLEM TO BE SOLVED: To accelerate reaction and increasing the battery cell output by successively relatively raising the operation temperature of cell stacks connected in series in the flow direction of reaction gas, and moistening the reaction gas according to the operating temperature of the cell stack flowing at first, then supplying the moistened reaction gas. SOLUTION: A fuel cell system is constituted with cell stacks 11a, 11b, 11c for operating at low, middle, and high temperatures, fuel gas and oxidizing agent gas let continuously flow from the low temperature side to the high temperature side. The fuel gas and the oxidizing agent gas are previously moistened by adding water vapor, and the temperature of a reaction gas is raised so as to correspond to the operation temperature of each cell stack. Even if the non-reacted part of the reaction gas is increased in the cell stack 11a for operating at low temperature, the non-reacted gas is reacted and completely consumed in the cell stacks 11b, 11c for operating at the intermediate and high temperatures. Even if condensed water generating on a carbon electrode side of the cell stack 11a is increased, the water is evaporated in the cell stacks 11b, 11c, and the reaction of the oxidizing agent gas is conducted smoothly. |
