NUMERICAL MODELING OF TWO-PHASE FLOW IN A BIPOLAR PLATE OF A PEM ELECTROLYZER CELL

摘要

Optimization of electrolysis cell for producing hydrogen is dependent of a set of complex physical and chemical processes simultaneously occurring within the electrolysis cell. Similar to fuel cells, it has been demonstrated that these processes are strongly dependent on the fluid dynamics inside the electrolysis & fuel cell. Bipolar plates are important components of PEM electrolysis cells because they are the first stage of the flow distribution system. Numerical simulations were performed for three-dimensional two-phase water/oxygen flow in the anode side of a bipolar plate with a diagonal flow design. The water flowrate was maintained as constant of 260 ml/min, while the oxygen bubble generation rate was assumed to change from 0 -0.014 g/s. Numerical results reveal that a minimum of the peak values of mainstream velocity component in the channels develops in the middle of the plate. Pressure drop and volume fraction of oxygen at the exit become higher as the oxygen bubble generation flowrate increases. The irregular velocity profile (locally low velocity magnitude near the exit port section) is not observed when the oxygen bubble flowrate is relatively low.