Remedial start method in a fuel cell

A remedial method for starting a fuel cell system comprising:

• determining if the remedial method is required;
• providing air to an exhaust of a fuel cell stack;
• setting a hydrogen flow rate to an anode side of the fuel cell stack using the following equations:
• n
• .
• H
• 2
• Vlv
• =
• Y
• H
• 2
• Exh
• 
• n
• .
• Air
• Exh
• 1
• -
• Y
• H
• 2
• Exh
• where,
• {dot over (n)}H2Vlv is desired hydrogen flow through valve
• YH2Exh is the target exhaust concentration
• {dot over (n)}AirExh is the available air flow for dilution in the exhaust
• P
• An
• =
• [
• (
• n
• .
• H
• 2
• Vlv
• *
• 4.633
• K
• v
• )
• 2
• *
• MW
• *
• T
• +
• P
• Exh
• 2
• ]
• where,
• PAn is the anode pressure set point
• {dot over (n)}H2Vlv is the desired hydrogen flow as previously calculated
• Kv is the equivalent valve flow coefficient
• MW is the molecular weight of hydrogen
• T is the gas temperature
• PExh is the exhaust (downstream) pressure;
• providing a predetermined volume of hydrogen to the anode side of the fuel cell at the hydrogen flow rate;
• providing a predetermined volume of air to a cathode side of the fuel cell stack after the predetermined volume of hydrogen has been provided to the anode side while continuing to provide air to the exhaust of the fuel cell stack and hydrogen to the anode side of the fuel cell stack;
• determining if the stack voltage is stable after the predetermined volume of air has been provided to the cathode side;
• and
• closing the anode outlet valve after the stack voltage is stable.