초록 ▼

The CO-concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and voltage behavior patterns from an auxiliary cell attached to the end of the stack. The auxiliary cell is connected to the same oxygen and hydrogen feed manifolds that supply the stack, and

The CO-concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and voltage behavior patterns from an auxiliary cell attached to the end of the stack. The auxiliary cell is connected to the same oxygen and hydrogen feed manifolds that supply the stack, and discharges through a constant load. Pattern recognition software compares the current and voltage patterns from the auxiliary cell to current and voltage signature determined from a reference cell similar to the auxiliary cell and operated under controlled conditions over a wide range of CO-concentrations in the H.sub.2 fuel stream.

대표청구항 ▼

[ I claim:] [8.] A method for monitoring the performance of a stack of H.sub.2 --O.sub.2 PEM fuel cells and initiating corrective action when operating conditions indicate the need for said action, said stack having an oxygen-feed manifold and a hydrogen-feed manifold supplying oxygen and hydrogen r

[ I claim:] [8.] A method for monitoring the performance of a stack of H.sub.2 --O.sub.2 PEM fuel cells and initiating corrective action when operating conditions indicate the need for said action, said stack having an oxygen-feed manifold and a hydrogen-feed manifold supplying oxygen and hydrogen respectively to said cells, said manifolds being coupled to an auxiliary H.sub.2 --O.sub.2 PEM fuel cell so as to supply said auxiliary fuel cell with oxygen and hydrogen at the same temperature, pressure, CO-concentration, and humidity as said oxygen and hydrogen are supplied to said fuel cells in said stack, comprising the steps of:(i) discharging said auxiliary fuel cell through a constant electrical load;(ii) sensing voltage fluctuations across said constant load over a time interval during said discharge, and generating a voltage signal having a voltage behavior pattern indicative of said voltage fluctuations;(iii) sensing current fluctuations through said load over a time interval during said discharge, and generating a current signal having a current behavior pattern indicative of said current fluctuations;(iv) converting said signals to a digital data stream;(v) from a reference fuel cell similar to said auxiliary fuel cell and discharging through a test load having the same resistance as said constant electrical load, determining a plurality of reference voltage and current signatures which are correlated to specific known operating conditions of the reference fuel cell;(vi) storing said reference voltage and current signatures in readable memory;(vii) comparing the voltage behavior patterns from said auxiliary fuel cell to the voltage signatures of said reference fuel cell to identify at least one of said voltage signatures that is substantially similar to the voltage behavior pattern being compared;(viii) comparing the current behavior patterns from said auxiliary fuel cell to the current signatures of the reference fuel cell to identify at least one of said current signatures that is substantially similar to the current behavior pattern being compared; and(ix) automatically initiating corrective action to protect said stack if a said behavior pattern is substantially similar to a said signature that is indicative of an operating condition that is detrimental to the stack.