Patent ID: 7740964
Filing Date: 2010-06-22
Classification: H01M,Y02E

Abstract:
1. A method for controlling the concentration of nitrogen in a fuel cell stack, comprising: providing a fuel cell stack with cathode passages and anode passages including a valve in communication with the anode passages and a permeable membrane having a first face adjacent to the cathode passages and a second face adjacent to the anode passages; calculating an actual amount of nitrogen in the fuel cell stack; comparing a predetermined maximum desired amount of nitrogen in the fuel cell stack to the actual amount of nitrogen in the fuel cell stack; and opening the valve if the actual amount of nitrogen in the fuel cell stack is greater than the maximum desired amount of nitrogen in the fuel cell stack, wherein calculating the actual amount of the nitrogen in the fuel cell stack includes: determining an amount of nitrogen that enters the anode passages due to an age of the fuel cell stack; determining a permeation coefficient of the permeable membrane; and determining a bleed rate correction factor associated with the rate of increase of nitrogen into the anode passages.