NUMERICAL-ANALYSIS OF LAMINAR-FLOW AND HEAT-TRANSFER IN A HIGH-TEMPERATURE ELECTROLYZER

This paper presents a numerical analysis of convective heat transfer i n an annular high temperature electrolyzer. High temperature electroly sis 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 electri c power requirements. This preliminary analysis assumes constant fluid properties to keep the problem simple, solvable, and explainable in p hysical terms. The results show that the energy transport in the elect rolyzer is elliptic due to low speed of the flowing steam. Radiation p lays an important role and the electrolysis cell surface temperature c an be controlled by adjusting the emissivities of the participating su rfaces. The thermal gradient, which affects the fatigue life, on the e lectrolysis 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.