Patent ID: 8216736

Claim:
A fuel cell system using evaporative cooling that generates electricity by reacting hydrogen as a fuel and air as an oxidant, the system comprising: a fuel cell stack including a cooling channel provided on a bipolar plate separately from an air channel and a hydrogen channel; an air inlet line connected to an inlet side of the cooling channel of the fuel cell stack; a water injection means provided at the inlet side of the cooling channel to inject water into air introduced to the cooling channel through the air inlet line; an air outlet line connected to an outlet side of the cooling channel; an air compression means disposed within the air outlet line to receive a mixture of air and water vapor discharged from the cooling channel of the fuel cell stack and to provide a suction force to the cooling channel and to control a negative pressure in the cooling channel to compress the mixture of air and water vapor sucked from the cooling channel; a heat dissipation unit connected to the air compression means to receive the mixture of air and water vapor compressed by the air compression means to cool and humidify the air and water vapor before reintroducing the air and water vapor to an inlet of an air channel in the fuel cell stack; an air supply line disposed between and directly connecting an outlet side of the heat dissipation means and the inlet of the air channel of a cathode of the fuel cell stack to supply the compressed and humidified air and water vapor discharged from the heat dissipation means to the inlet of the air channel of the fuel stack to be used as an oxidant for a fuel cell reaction, and wherein water is evaporated while air and water pass through the cooling channel in a state where an internal pressure of the cooling channel is maintained at the negative pressure by the suction force of the air compression means to increase the absolute humidity of the air in the cooling channel and, at the same time, heat generated from the fuel cell stack is absorbed by latent heat of evaporation, thus cooling the fuel cell stack.