Thermal hydraulic characteristics of spiral cross rod bundles in a lead–bismuth-cooled fast reactor

Abstract

The flow and heat transfer behavior of self-structured spiral cross rod bundles in lead–bismuth-cooled fast reactor is analyzed with CFD methods. A computational model of spiral-cross-section fuel rod was established, and the velocity and temperature fields in the triangular arrangement of the fuel rod were numerically simulated. Uniform circumferential distribution in the velocity and temperature contours of the coolant was observed, which was resulted from the strong mixing effect in the spiral structure. Such a structure could replace the function of the wrapping wire. The Reynolds number had an obviously effect to the velocity and temperature, while the contribution of heat flux is negligible. It was also found that the heat transfer characteristics of the fluid flow can be affected by the shape of the cross section and the pitch of the spiral cross rod, etc.