Numerical analysis of laminar flow and heat transfer in a high temperature electrolyzer

This paper presents a numerical analysis of convective heat transfer in an annular high temperature electrolyzer. High temperature electrolysis is a prospective method to commercially produce hydrogen fuel. The high operating temperature of the electrolyzer reduces the electrical energy requirement for dissociation and improves the specific electric power requirements. This preliminary analysis assumes constant fluid properties to keep the problem simple, solvable, and explainable in physical terms. The results show that the energy transport in the electrolyzer is elliptic due to low speed of the flowing steam. Radiation plays an important role and the electrolysis cell surface temperature can be controlled by adjusting the emissivities of the participating surfaces. The thermal gradient, which affects the fatigue life, on the electrolysis cell can be reduced by decreasing the reaction intensity (by decreasing current density) and increasing the electrolysis cell's radiation emissivity. (C) 1997 International Association for Hydrogen Energy.