Numerical Analysis of Natural Convection Induced Oxygen Transport in Liquid Lead Bismuth Eutectic

Abstract

Liquid lead bismuth eutectic (LBE) is very corrosive to steels. To mitigate structural corrosion of LBE systems, active oxygen control technique is developed. To enhance the speed of oxygen transport in liquid LBE, natural convection has been proposed. This paper numerically analyzes the oxygen transport in a natural convection induced LBE enclosure. Different temperature boundary conditions are added to the container. Both laminar and turbulent LBE flows which are distinguished by strength of flow measured are analyzed. Three laminar cases: (a) heated from the bottom and cooled from the top of the container; (b) heated from the sidewalls and cooled from the top of the container; (c) one sidewall heated and the opposite wall cooled, and one fully turbulent case with one sidewall heated and the opposite sidewall cooled are chosen. Oxidization in near wall areas and formation of oxide layers on container surfaces are considered. In each case, the characteristic velocity and oxygen diffusion time are estimated, the change of oxygen distribution with time are obtained, and the bulk concentration of oxygen and the efficiency of oxide layer formation on different liquid-solid interfaces are calculated. To obtain more information of oxygen transportation and distribution, three-dimension analysis of the laminar flow is done. Based on the analysis, several conclusions are finally obtained.