Impacts of geometrical characteristics on MHD flow and mechanical behaviors of FCI in blanket modules

Abstract

Flow channel insert (FCI) serves as thermal and electrical insulator in the blanket module in the international thermonuclear experimental reactor (ITER). The geometrical characteristics of FCI greatly affect magneto-hydrodynamics (MHD) features, heat transfer and structural safety of the system. In this paper, the MHD flow and heat transfer in blanket modules with different FCI thicknesses and gap widths are investigated. Finite element method and finite volume method with a consistent and conservative scheme are used to deal with the magneto-thermo-fluid-mechanical fields. The detailed flow behaviors of metal fluid, thermal and mechanical behaviors in coupled field are investigated. A dimensionless parameter is introduced to evaluate the heat transfer efficiency. Results indicate the complicated effects of FCI thickness and gap width on heat transfer efficiency, pressure drop, first wall temperature and FCI thermal stress. The nonlinear and non-monotonous influences of geometrical characteristics on structural behavior and heat transfer efficiency are presented. The correlation between pressure drops and gap width is presented. After detailed analysis, a most promising design is recommended by evaluating heat transfer efficiency, fluid pressure drop, first wall temperature and structural stress. This work can be regarded as a foundation of future design and optimization of blanket modules.