An anode utilization control system (10) for a fuel cell (12) power plant for generating electrical current from an oxidant stream and a hydrogen-rich fuel stream, the system (10) comprising:
- a. at least one fuel cell (12) including an anode catalyst (14) and a cathode catalyst (16) secured to opposed sides of an electrolyte (18), an anode flow field (20) defined in fluid communication with the anode catalyst (14) and with a fuel inlet line (22) for directing flow of the hydrogen-rich fuel stream from the fuel inlet line (22) adjacent the anode catalyst (14) and out of the anode flow field (20) through an anode exhaust (24) as an anode exhaust stream, a cathode flow field (26) defined in fluid communication with the cathode catalyst (16) and with a source of the oxidant (28) for directing flow of the oxidant stream from an oxidant inlet line (30) adjacent the cathode catalyst (16) and out of the cathode flow field (26);
- b. a fuel processing system (10) for generating the hydrogen-rich fuel stream from a fuel feedstock (42), the fuel processing system (10) including a burner device (44) secured in fluid communication with the anode exhaust (24) and secured in heat transfer relationship with an endothermic reacting reformer (48), the burner device (44) being configured to transmit heat to the reformer (48) by one of transmitting heat directly into the reformer (48) through conduction and convection through a heat transfer line (46) secured in fluid communication with the anode exhaust stream burned within the burner device (44), or by burning the anode exhaust stream within the burner device (44) to generate steam within a boiler (45) secured adjacent the burner device (44) and directing the steam through a steam transfer line (49) into the reformer (48) that is secured in fluid communication with the heat transfer line (46) or the steam transfer line (49), the reformer (48) also being secured in fluid communication with a fuel feedstock inlet line (54) for directing the fuel feedstock (42) into the reformer (48) to be reformed into the hydrogen-rich fuel stream, the reformer (48) also being secured in fluid communication with the fuel inlet line (22) for directing the reformed hydrogen-rich fuel stream through the fuel inlet line (22) into the fuel cell (12);
- c. a burner feed line (62) secured in fluid communication between the burner device (44) and the anode exhaust (24) for directing the anode exhaust stream into the burner device (44) to be burned and out of the burner device (44) through a burner exhaust (66);
- d. an oxygen sensor (28) secured in fluid communication with the burner exhaust (66) for sensing a concentration of oxygen within the burned anode exhaust stream passing out of the burner device (44) through the burner exhaust (66);
- and,
- e. an oxygen sensor controller (80) secured in communication between the oxygen sensor (78) and a fuel flow control device (55, 56) secured in fluid communication with the fuel feedstock inlet line (54), the oxygen sensor controller (80) configured to selectively control flow of the fuel feedstock (42) through the flow control device (55, 56) into the reformer (48) in response to sensed oxygen concentrations within the burned anode exhaust stream.