Critical heat flux analysis of divertor cooling flow channel in fusion reactor with CFD method

Abstract

Situated at the bottom of the vacuum vessel, the divertor extracts heat and ash produced by the fusion reaction, minimizes plasma contamination, and protects the surrounding walls from thermal and neutronic loads. The vertical targets of divertor are designed to be able for up to 20 MW/m2 high heat flux. It is a great ordeal for both the material performance and the cooling ability. Critical heat flux margin is very crucial during the design of divertor. The ANSYS FLUENT is used in this paper to predict the critical heat flux on a monoblock structure with a twisted tape inside the tube. Numerical results are validated with the corresponding sets of experimental results. In this paper, CFD method used to predict critical heat flux of divertor cooling channel was first introduced. On the other hand, influence of inlet subcooling on critical heat flux is studied in detail. The inlet subcooling affect the critical heat flux much complicated for the single-side heated and swirl flow channel. Whether the influencing trend or the locations of critical heat flux occurrence are different under different inlet sub-cooling. The derivations between the simulation and experimental results were no more than 32%. This study proves the CFD tools can provide efficient help on the understanding of the critical heat flux phenomenon of complex construction.