Thermal-hydraulic analysis of LBE flow in rod bundles with wire spacers based on heat transfer framework of OpenFOAM

Abstract

The wire spacer allows for a compact layout in the core of lead-cooled fast reactor (LFR). However, it also introduces complexity to the flow and heat transfer of the coolant, lead-bismuth eutectic (LBE). This paper aims to analyze the effect of wire spacer in rod bundle and the applicability of heat transfer framework to LBE flow. Three Reynolds-Averaged Navier–Stokes (RANS) turbulence models with two representative turbulent Prandtl number (Prt) 1.5 and 2.0 are employed within the framework of OpenFOAM. The sensitivity of the models is examined based on turbulent heat transfer in tube flow. The simulations considered with an extensive mesh sensitivity study were analyzed. The buoyantSimpleFoam solver is compared with direct numerical simulation (DNS) data. Thermal-hydraulic analysis are conducted, considering temperature, velocity distribution, and local Nusselt (Nu) number, and pressure drop based on 7-rod and 19-rod bundle with wire spacers. The influence of wire initial starting angles from 0°, 10°, 20°, 30°, 40°, 50° on heat transfer is carried out. The study reveals that an optimum angle range from 20° to 40° exists in the sub-channels. This work validates the basic heat transfer solver for LBE using OpenFOAM.