Analysis of water management in PEM fuel cell stack at dead-end mode using direct visualization

Abstract

Abstract Polymer electrolyte membrane fuel cells (PEMFC) have the ability to be operated with open-end and dead-end modes. At the open-end mode the extra reactants are essential for obtaining the specified current density. The removal of impurities from channels at the dead-end mode at a specific period of time is a very important issue. Water accumulation leads to the non-uniform distribution of reactant flow in individual fuel cell plate and within the fuel cell assembly, which can result in the voltage instabilities and electrodes degradation. In this work, a transparent PEMFC stack has been suggested and designed to explore water flow within the cell through direct visualization as the simplest and most reliable tool for water management studies. Design steps are explained in details within the manuscript and the performance of PEMFC stack at open-end and dead-end modes is compared. The effect of liquid water flow regime on voltage and pressure variation is investigated. The different losses at stack and single cell are compared and analyzed. In addition, an empirical correlation has been extracted for setting the purge parameters in PEM fuel cell stacks at dead-end mode which can be useful for further research works in the field of dead-end PEMFC.