Dynamic analysis of internal reactants and water content distribution during anode purge in a proton‐exchange membrane fuel cell

Abstract

For proton-exchange membrane fuel cell, anode purge is a commonly used method to increase utilization rate of hydrogen and proton-exchange membrane fuel cell durability. Limited by experiment condition, it is hard to analyze reactants and water content distribution in fuel cell during purge. This article uses transient simulation to dynamic analyze distribution of reactants and water content in a full flow field fuel cell (active area 82.14 cm2) with serpentine flow field during purge. From simulation result, it is found that corresponding structures relationship of anode and cathode flow channel causes reactants fluctuating greatly. The direction of water transport across membrane is not fixed. The transmission direction is also affected by local water content of anode and cathode. Dynamic analysis of purge is divided into three stages: purge interval, purging and after purge. During purge interval, water content increases with time. During purging, water content decreases with time in inlet and outlet sections, but in serpentine section water content still increases with time. During after purge, water content increases with time, except inlet section. After multiple purge, purge has little influence on hydrogen distribution in anode flow channel, but value of hydrogen mass fraction increases and increase magnitude gradually decreases, finally reach dynamic equilibrium.