Fuel cell system using evaporative cooling and method of cooling fuel cell system

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;
• and
• an air compression means provided at the rear of the fuel cell stack and connected to a discharge line coupled to an outlet side of the cooling channel to provide a suction force to the cooling channel and to compress a mixture of air and water vapor sucked from the cooling channel,
• 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 a negative pressure by the suction force of the air compression means 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.