MODELLING OF POLYMER ELECTROLYTE MEMBRANE ELECTROLYSIS CELL

Abstract

Hydrogen is a vital energy source that may be obtained from several sources and has important applications in sustainable energy. Although water electrolyzers have great potential, just 4 percent of the world's current hydrogen generation comes from them, primarily because of cost issues. In dealing with this issue. Anode and cathode chambers, two electrode catalyst surfaces, and a proton exchange membrane (PEM) make up a PEM electrolyzer cell. The bipolar plate (BPP), which is essential to carrying out several tasks inside the PEM electrolyzer, is examined in this thesis. Various bipolar plate types and their importance in maximizing PEM electrolyzer performance are presented in the report. Additionally, the study includes a simulation of a single flow channel, counterflow PEM electrolyzer. The results offer in-depth understanding of pressure, hydrogen distribution, and current density contours using Solidworks for geometry development and Ansys Fluent for simulation. This research examines the precise impacts of operating parameters on proton exchange membrane electrolyzer cell (PEMEC) performance, including temperature, pressure, and intake velocity. A finite volume method based on a completely three-dimensional model with ten flow channels is used to perform a computational fluid dynamic (CFD) analysis. The realistic impacts of different operating conditions are taken into consideration, and the model is validated against experimental data. The results indicate that an increase of temperature from 333K to 353K at a cell voltage of 1.6 V leads to an increase of current density from 0.12 to 0.21 A/cm2, respectively. Because of the buildup of water beneath the channel's ribs, which raises the electrochemical rate, the temperature and hydrogen concentration there are comparatively higher. Moreover, the impact of pressure is more pronounced at higher current densities, as noted at 1.6 V, increasing the cathode pressure from 1 to 3 atm reduces the current density from 0.45A/cm² to 0.25 A/cm², indicating a decline in cell performance with increased pressure. The findings demonstrated that a higher water velocity decreased polarization and enhanced the electrolysis cell's electrochemical performance. Moderate increases in inlet velocity improve PEM electrolyzer performance and allow operation at higher current densities by optimizing mass transport and minimizing reactant depletion. However, there is a trade-off, as very high velocities can lead to energy inefficiencies and mechanical challenges, necessitating careful optimization.