The Proton Exchange Membrane Fuel Cell Performance Impact Studies

In this article, basing on the electrochemical thermodynamics and dynamics,it mainlyanalyzes the ideal state and actual work state of PEMFC, deduces the related formula ofgas flows and the current.To research the performance of PEMFC,the test station forPEMFC was designed and built,and how each cell system impacts the whole system ofPEMFC was analyzed.By assemblying graphite bioploar plate stack and graphitecompound bioploar plate stack,and through leak tests, the activation and performance ofthe two stack was analyzed basing on the activation parameter values computed,getting theconclutions: that the graphite compound bioploar plate' resistance a little higher than theother one,impacts only the export power and total voltage,and has no effects on thestability and uniformity of fuel cells. When the current is 35A,the power discrepancy is34W.The total voltage standard deviations are 0.1213V and 0.1101V, cells voltagecollectivity standard deviations are 0.042167V and 0.043416V.For the industrialization ofPEMFC, the graphite compound bioploar plate has more advatages in costs and processtechnologies for its lower cost.How the temperature,pressure and air flow impacts the run of graphite compoundbioploar plate PEMFC was researched through the electrochemistry model and fuel stackmodel,coming into the conclusions,(1) With the humidification on both electrodes,increasing the temperature of thestack, turning up the stoichiometric coefficient of air, the performace of the stack getsbetter.After 70℃, the performace of the stack gets worse.The proper temperature for stackrun is 65℃-70℃.When the stoichiometric coefficient exceeds 3.0, the performace of thestack changes little.The appropriate stoichiometric coefficient should be about 2.5-3.0.Forthe ambient pressure PEMFC,the changes of the pressure of H₂ in a little higher than 1atm impacts the performance of the stack little.(2) Basing on the simulation result of Fluent and the run result of the stack,thelayout of the bipolar plate flow-field has little impacts on the uniformity of the air flow intoeach fuel cell.In the higher currents of the stack,the main impact factors should be the heatdistribution and water management in the stack.