The supercritical carbon dioxide cOoled lithium-lead (COOL) blanket is one of the candidate blankets for Chinese Fusion Engineering and Test Reactor. The lead-lithium (PbLi) is used as neutron multiplier and tritium breeder, as well as the coolant to bring the volumetric nuclear heat out of the blanket. There are 4 (toroidal) × 3 (radial) channels for PbLi flowing, and the flow velocity is reduced along the radial direction to match the spacial variation of the nuclear heat. However, due to incomplete insulation of the channel wall, the magnetohydrodynamic (MHD) coupling effect between adjacent channels becomes significant. In this study, numerical simulations are performed to clarify the influence of the differences in flow velocity between adjacent channels on the MHD coupling channel flow states. It is discovered that a reverse jet zone appears in the low-velocity channel, and its velocity increases as the velocity ratio of adjacent channels increases. This phenomenon is explained through an analysis of the potential and current distribution inside the flow channels. Based on this analysis, research is conducted on the MHD coupling flow of the geometric model of the COOL blanket. Typical units in the COOL blanket sector are selected for research, and periodic boundary conditions are adopted along the flow direction to eliminate interference caused by insufficient flow development on the results. Calculations are conducted separately for cases with and without flow channel insert (FCI) made by SiCf/SiC to explore the weakening effect of FCI on MHD coupling effects. Finally, the flow velocity, pressure, and current distribution inside the blanket are obtained in the presence of MHD coupling effects. Additionally, the impact of FCI conductivity on the flow velocity distribution, pressure drop, and pressure deviation between channels of the blanket was determined. The study provides a computational basis for the design and optimization of the COOL blanket.
This paper investigates the magnetohydrodynamic (MHD) coupling effect in the supercritical carbon dioxide cooled lithium-lead (COOL) blanket for the Chinese Fusion Engineering and Test Reactor (CFETR). The study uses numerical simulations to understand how differences in flow velocity between adjacent channels affect the MHD coupling, leading to a reverse jet zone in the low-velocity channel. The impact of flow channel inserts (FCI) made of SiCf/SiC on mitigating the MHD coupling effect is also explored.