| 摘要 |
PURPOSE:To increase fuel utilization by specifying flow rate per electrode unit area of fuel when fuel concentration supplied to a fuel chamber is constant. CONSTITUTION:A fuel cell 1 consists of a fuel electrode 2, an oxidizing agent electrode 3, an electrolyte chamber 4, a fuel chamber 5, an oxidizing agent 6, and a matrix 41 or an ion-exchange membrane 42. When fuel 7 is supplied to the fuel chamber 5, part of fuel is converted into electric energy with the fuel electrode. The rest of fuel is returned from the fuel chamber 5 as fuel M12 and moves toward the oxidizing agent electrode 3 through the chamber 4 as fuel M2. When fuel concentration CM1 supplied to the fuel chamber 5 is constant, flow rate per electrode unit area QM(l/min.cm<2>.cell) is limited to 4X10<-3>d1J/CM1 or more within a range whose lower limit is 15d1K2(l/min.cm<2>.cell). Where K2 is a fuel transmission factor (mol/min.cm<2>.mol/l) of the membrane 41 or 42, d1 is thickness (cm) of the electrode 2, J is current density A/cm<2>, CM1 is fuel concentration mol/l of the chamber. Thereby, fuel consumption is decreased. |
