The effect of geometric parameters of PTL on oxygen transport in PEM electrolysis cell

In this study, two-phase flow of oxygen-water is studied by using numerical simulation in the Porous Transport Layer (PTL) of the Polymer Electrolyte Membrane Electrolysis Cell (PEMEC). The effect of thickness, porosity and multi-layer arrangement of PTL on the oxygen flow pattern and its removal from the PTL is investigated. The results showed the increase in the PTL thickness causes to increase the growth of the lateral paths from the inlet to the channel, which leads to increase the oxygen saturation in the PTL. It is also obtained that for PTL with different porosity, number and volume of occupied pores by oxygen in the PTL are the two main factors affecting the oxygen saturation and trade-off between them indicate the proper porosity to be used in different operating conditions. Furthermore, studies showed the use of two-layer PTL instead of single-layer can cause reduction in oxygen saturation in the proximity of reaction sites leading to a better operation of the electrolyzer.