Numerical Two-Phase Simulations of Alkaline Water Electrolyzers

Abstract

This study presents a computational simulation of a zero-gap alkaline water electrolysis cell. The model employed is a three-dimensional, steady-state, non-isothermal, two-phase-flow computational fluid dynamics approach, which has been implemented by means of the OpenFOAM software library. This integration expands the capabilities of the existing libraries within the open-source framework, openFuelCell2, by introducing novel surface and volumetric coupling strategies to connect the dependent quantities over the existing interfaces and different regions. Additionally, the Nernst–Planck equation is incorporated into the two-phase Eulerian–Eulerian framework to describe the behavior of the liquid electrolyte within the cell.The model’s validation in this study is based on experimentally-determined polarization curves for various temperatures and volumetric flow rates. The results obtained show good agreement with the experimentally-acquired data. The implemented model has demonstrated its ability to accurately predict the transport of ions within the electrolyte and assess the influence of the generated gas phase on the local distribution of current density.