Patent ID: 8697303
Filing Date: 2014-04-15
Classification: H01M,Y02E,Y02T

Abstract:
1. A method for determining the position of a cathode by-pass valve in a fuel cell system that allows cathode air to by-pass a fuel cell stack, said method comprising: determining a concentration of hydrogen in a cathode side of the fuel cell stack; determining a volumetric flow rate through a compressor that delivers air to the cathode side of the fuel cell stack; determining a volumetric flow rate through the cathode side of the fuel cell stack; determining a fraction of volumetric flow rate through the cathode side to a total flow through the compressor using the volumetric flow rate through the compressor and the volumetric flow rate through the cathode side; determining a modeled hydrogen outlet concentration from the fuel cell stack based on the volumetric flow rate through the compressor, the fraction of volumetric flow rate through the cathode side to the total flow through the compressor and the concentration of hydrogen in the cathode side; determining a desired fraction of volumetric flow rate through the cathode side to the total flow through the compressor using a desired maximum cathode side outlet emission and the modeled hydrogen outlet concentration; and using the desired fraction of volumetric flow rate through the cathode side and the total flow through the compressor to determine the position of the by-pass valve.