초록 ▼

A system and method for regulating the total oxygen content entering the cathode side of a fuel cell stack at less than full power depends on measurement of: oxygen partial pressure in the cathode exhaust stream; total flow entering the cathode; and current produced by the stack. During partial powe

A system and method for regulating the total oxygen content entering the cathode side of a fuel cell stack at less than full power depends on measurement of: oxygen partial pressure in the cathode exhaust stream; total flow entering the cathode; and current produced by the stack. During partial power operation of the stack, it is desirable to limit the cathode potential, or voltage, by recycling cathode exhaust and mixing it with incoming fresh air fed into the cathodes. This system ensures that the total oxygen flow to the cathodes remains constant at any given current by reducing the amount of fresh air flowing to the cathodes as the recycled cathode exhaust flow is increased.

대표청구항 ▼

A cathode air flow control system for use in a fuel cell power plant to minimize oxygen starvation of fuel cells in the power plant, said system comprising: (a) means forming a fresh air inlet for admitting air into the cathodes of the fuel cells in the power plant; (b) means in said fresh air inlet

A cathode air flow control system for use in a fuel cell power plant to minimize oxygen starvation of fuel cells in the power plant, said system comprising: (a) means forming a fresh air inlet for admitting air into the cathodes of the fuel cells in the power plant; (b) means in said fresh air inlet for varying the amount of fresh air admitted to said cathodes; (c) means forming an exhaust outlet for exhausting oxygen-depleted gas from said cathodes; (d) sensor means in said exhaust outlet for measuring the oxygen content of the oxygen-depleted gas therein; (e) means forming a recirculating loop for recirculating oxygen-depleted gas from said exhaust outlet to said air inlet; (f) monitoring means in said air inlet to measure the combined flow of incoming air and recirculated oxygen-depleted gas in said air inlet so as to effectively measure the total amount of flow conveying oxygen to the cathodes; (g) means for continuously measuring the electrical current output of the power plant; and (h) control means operably connected to said means for varying, to said sensor means, to said monitoring means, and to said means for continuously measuring, said control means being operable to calculate oxygen utilization in said cathodes and cause said means for varying to increase or decrease the amount of air in said air inlet in response to changes in the total measured oxygen utilization.