Patent ID: 7141324

Claim:
A method of shutting down a fuel cell power plant ( 10 ), the power plant comprising at least one fuel cell ( 12 ) for generating electrical current from hydrogen containing reducing fluid fuel and oxygen containing oxidant reactant streams, the fuel cell ( 12 ) including an anode catalyst ( 14 ) and a cathode catalyst ( 16 ) on opposed sides of an electrolyte ( 18 ), an anode flow path ( 24 ) in fluid communication with the anode catalyst ( 14 ) for directing the hydrogen fuel to flow through the fuel cell ( 12 ) and adjacent the anode catalyst ( 14 ), and a cathode flow path ( 38 ) in fluid communication with the cathode catalyst ( 16 ) for directing the oxidant stream to flow through the fuel cell ( 12 ) and adjacent the cathode catalyst ( 14 ), the method comprising the steps of: a. disconnecting a primary load ( 90 ) from the fuel cell ( 12 ); b. terminating flow of the oxidant into the cathode flow path ( 24 ) from an oxidant source ( 58 ); c. connecting an auxiliary load ( 94 ) to the fuel cell ( 12 ); d. permitting transfer of the hydrogen fuel from the anode flow path ( 24 ) into the cathode flow path ( 38 ); e. terminating flow of the hydrogen fuel into the anode flow path ( 24 ) from a hydrogen fuel source ( 54 ) whenever the anode flow path ( 24 ) and cathode flow path ( 38 ) are filled with a hydrogen concentration of greater than ninety percent hydrogen; and, f. permitting release into the anode flow path ( 24 ) and into the cathode flow path ( 38 ) of hydrogen stored within a hydrogen reservoir means for storing hydrogen secured in fluid communication with the anode flow path ( 24 ).