Patent ID: 9564647
Date: 2017-02-07
CPC Classifications: B60K,H01M,Y02E,Y02T

Claim:
1. A fuel cell system including a fuel cell stack and a mounting section, the fuel cell stack being formed by stacking a plurality of fuel cells, the fuel cells each including a membrane electrode assembly and a pair of separators sandwiching the membrane electrode assembly, the membrane electrode assembly including a pair of electrodes and an electrolyte membrane interposed between the electrodes, a fuel gas flow field being formed between one of the electrodes and one of the separators for supplying a fuel gas along an electrode surface, an oxygen-containing gas flow field being formed between the other of the electrodes and the other of the separators for supplying an oxygen-containing gas along an electrode surface, the fuel gas in the fuel gas flow field and the oxygen-containing gas in the oxygen-containing gas flow field flowing in a counterflow manner, the mounting section being provided in a front box of a vehicle for mounting the fuel cell stack in a state where an inlet side of the fuel gas flow field is positioned above an outlet side of the fuel gas flow field with respect to a fuel gas flow direction such that the fuel cell stack is inclined downward in the direction of the fuel gas flow toward a back of the vehicle in a vehicle length direction, wherein: the fuel gas flows in the fuel gas flow field from the inlet side to the outlet side, in only one direction without any turnover, and an inlet side of the oxygen-containing gas flow field is positioned below an outlet side of the oxygen-containing gas flow field with respect to the direction of the fuel gas flow when the fuel cell system is mounted in the vehicle, and wherein a water drainage passage extends through the inlet side of the oxygen-containing gas flow field in the stacking direction of the fuel cells, wherein the water drainage passage is connected to a drainage pipe extending to an outside of the fuel cell stack, and wherein the water drainage passage is separate and distinct from an oxygen-containing gas supply passage that extends through the separators for supplying the oxygen-containing gas and from a fuel gas discharge passage extending through the separators for discharging the fuel gas, wherein an inlet buffer region is formed at an inlet of the oxygen-containing gas flow field, and wherein the water drainage passage is formed in the inlet buffer region.