Patent ID: 7291411

Claim:
A method of purging a fuel cell system, said method comprising: configuring said system to include: at least one fuel cell comprising an anode, a cathode and a membrane disposed between said anode and cathode; an anode flowpath configured to couple said anode to a source of a first reactant; a cathode flowpath configured to couple said cathode to a second reactant source; a combustor in selective fluid communication with both of said flowpaths, said combustor comprising a reaction chamber configured to promote staged mixing of said first reactant and said second reactant; and a plurality of valves, at least one of which is configured to establish said selective fluid communication between said combustor and at least one of said flowpaths, said plurality of valves comprising: an inerting valve configured to selectively introduce one of said first or second reactants into said combustor; and a run valve configured to selectively introduce said first reactant into at least one of said combustor or said anode; adjusting at least one of said inerting valve or said run valve to obtain a substantially stoichiometric mixture of said first and second reactants in said combustor; reacting said substantially stoichiometric mixture such that a substantially inert fluid is produced; introducing said substantially inert fluid into at least one of said anode or cathode such that any fluid previously resident therein is substantially displaced therefrom; and adjusting at least one of said inerting valve or said run valve to stabilize said system.