Fuel cell system having fuel and water controlling means

A fuel cell system comprising:

• a fuel cell including a cell that comprises a polymer electrolyte membrane sandwiched between an anode and a cathode;
• means for supplying an oxidant gas to the cathode of said fuel cell;
• a dilute tank that stores an aqueous solution of liquid fuel and supplies said aqueous solution to the anode of said fuel cell;
• a fuel tank connected to said dilute tank via a first controlling section;
• a water tank connected to said dilute tank via a second controlling section;
• a gas detector that measures a component of a gas discharged from the cathode of said fuel cell and outputs a measured result;
• a current detector that measures the amount of power generated by said fuel cell and outputs a measured result;
• an unspent methanol fuel detector that measures unspent fuel discharged from the anode of said fuel cell and outputs a measured result;
• and
• a controller that controls said first controlling section and said second controlling section based on the results outputted by said gas detector, said current detector, and said unspent fuel detector.

A fuel cell system comprising:

• a fuel cell including a cell that comprises a polymer electrolyte membrane sandwiched between an anode and a cathode;
• means for supplying an oxidant gas to the cathode of said fuel cell;
• a dilute tank that stores an aqueous solution of liquid fuel and supplies said aqueous solution to the anode of said fuel cell;
• a fuel tank connected to said dilute tank via a first controlling section;
• a water tank connected to said dilute tank via a second controlling section;
• and
• controlling means comprising a current detector which measures the amount of the fuel consumed by said fuel cell from the amount of power generated by said fuel cell, said controlling means controlling said first controlling section based on the measured amount of fuel consumption, said controlling means further comprising correcting means for measuring a component of a gas discharged from the cathode of said fuel cell, calculating the amount of the fuel which has crossed over from the anode to the cathode based on the measured component, and correcting the measured amount of fuel consumption based on the calculated amount of the fuel which has crossed over,
• wherein the gas detector is capable of determining the amount of liquid fuel which has crossed over the polymer electrolyte membrane from the anode to the cathode based on the measured result of gas discharged, and
• wherein the liquid fuel is comprised of methanol, and the gas discharged from the cathode is carbon dioxide.