| 主权项 |
1. A fuel cell comprising:
a stacked membrane electrode assembly and separators, the membrane electrode assembly including a pair of electrodes and an electrolyte membrane interposed between the electrodes, a reactant gas flow field supplying a reactant gas along an electrode surface, the reactant gas flow field including a plurality of flow grooves, an inlet buffer being connected to inlets of the flow grooves in the reactant gas flow field, the inlet buffer uniformly distributing the reactant gas to the flow grooves in the reactant gas flow field, and an outlet buffer being connected to outlets of the flow grooves in the reactant gas flow field, the outlet buffer discharging the reactant gas from the flow grooves so that the reactant gas is merged uniformly into a reactant gas discharge passage, the widths of the inlet buffer, the outlet buffer and the reactant gas flow field being substantially the same in a direction along which the inlets and outlets of the flow grooves are aligned, wherein cross-sectional areas of the inlets and the outlets of the flow grooves in the reactant gas flow field are substantially identical to each other, wherein the flow grooves in the reactant gas flow field have a constant depth from the inlets to the outlets of the grooves, and wherein at least part of the inlet buffer is deeper than at least part of the outlet buffer such that the pressure loss of the reactant gas in the inlet buffer before being subjected to power generation becomes equal to the pressure loss of the reactant gas in the outlet buffer after being subjected to the power generation, a depth H1 in the at least part of the inlet buffer and a depth H2 in the at least part of the outlet buffer being determined based on a relationship of H1/H2=3√(Q1/Q2) where Q1 is a flow rate at an inlet of the reactant gas flow field and Q2 is a flow rate at an outlet of the reactant gas flow field. |
