Closed loop type fuel cell system

A closed loop type fuel cell system comprising:

• a main fuel cell that generates electricity by receiving fuel and oxygen;
• a supply unit that supplies gas containing fuel and oxygen to the main fuel cell;
• a recirculating unit that recirculates the gas containing hydrogen and oxygen discharged from the main fuel cell;
• a sensing unit that senses the voltages of a plurality of cells in the main fuel cell;
• a reproducing unit that selectively communicates with a side of the main fuel cell and removes water and impurities in the main fuel cell;
• and
• a control unit that controls the operations of the supply unit, the recirculating unit, the sensing unit, and the reproducing unit,
• wherein the reproducing unit includes:
• a reproducing pipe that guides the flow direction of the gas containing hydrogen and oxygen passing through the recirculating unit;
• a reproducing valve that selectively blocks the reproducing pipe;
• a sacrifice fuel cell that produces water by reacting the gas containing hydrogen and oxygen supplied from the reproducing pipe with air;
• and
• a collecting unit that collects water produced in the sacrifice fuel cell.