Numerical Simulation Research On Thermal-hydraulic In Helium Cooled Solid Blanket Of Nuclear Fusion Reactor

It has been intensified the importance of nuclear energy, which has been a criticalsource of energy and utilized by nuclear power, by the energy crisis of contemporarysociety. The fusion blanket is one of the core components of fusion reactor, which iscomposed of the first wall, helium tank, sub-module and other related accessories. The firstwall (FW) is one of the most important components of any fusion blanket design in that itis directly faced with the plasma. China has developed two concept of breeding blanket forITER, which are dual-functional liquid lithium lead blanket (DFLL) and helium-cooledsolid blanket (HCSB). Both blankets have similar first wall structure, and cooled by the8MPa helium coolant.A3D analytical thermal–hydraulic simulation studies using computational fluiddynamics software Fluent has been performed based on the original HCSB-DEMO TBMconcept to confirm the heat removal and structural integrity under various conditionsincluding different inlet mass flow rate of helium. The results showed that the maximumtemperature（829.2K） of the structural material occurred at the outer side of the fillet inthe HCSB-DEMO blanket design, which leaded that the maximum allowable temperaturehas been exceeded. By reducing the corresponding cross-sectional area of the flow channel,the local convective heat transfer coefficient can be increased, which resulted in thereducing of the temperature of structural materials, while the pressure loss can becontrolled in a reasonable range. Various width of the part of channel studies with Fluentare conducted in the paper and the results show that the channel with15.0mm width hasthe best thermal and hydraulic performance.Meanwhile, this paper discusses the accuracy of numerical simulation methods. Theaccuracy of the calculation cases are analyzed, the results shows the max deviation of theoutlet temperature of helium, heat transfer coefficient and other parameter is less than5%,and the reliability of the results are verified by comparing with the theoretical analysis. Thesetting of boundary conditions are analyzed for the accuracy of results. The real resultshould be between the adiabatic boundary conditions of the top and bottom of the blanketand periodic boundary conditions. It is conducted that the influence of the channel filletand material parameters to the heat transfer performance of the first wall, which provides a reference for the further heat transfer enhancement work.