Numerical Study of Liquid Metal Turbulent Heat Transfer in Cross-Flow Tube Banks

Abstract

Heavy liquid metals (HLM) are attractive coolants for nuclear fission and fusion applications due to their excellent thermal properties. In these reactors, a high coolant flow rate must be processed in compact heat exchangers, and as such, it may be convenient to have the HLM flowing on the shell side of a helical coil steam generator. Technical knowledge about HLM turbulent heat transfer in cross-flow tube bundles is rather limited, and this paper aims to investigate the suitability of Reynolds Average Navier–Stokes (RANS) models for the simulation of this problem. Staggered and in-line finite tube bundles are considered for compact ((Formula presented.)), medium ((Formula presented.)), and wide ((Formula presented.)) pitch ratios. The lead bismuth eutectic alloy with (Formula presented.) is considered as the working fluid. A 2D computational domain is used relying on the (Formula presented.) Shear Stress Transport (SST) for the turbulent momentum flux and the (Formula presented.) concept for the turbulent heat flux prediction. The effect of uniform and spatially varying (Formula presented.) assumptions has been investigated. For the in-line bundle, unsteady (Formula presented.) SST/ (Formula presented.) has been found to significantly underpredict the integral heat transfer with regard to theory, featuring a good to acceptable agreement for wide bundles and (Formula presented.). For the staggered tube bank, steady (Formula presented.) SST and a spatially varying (Formula presented.) has been the best modeling strategy featuring a good to excellent agreement for medium and wide bundles. A poor agreement for compact bundles has been observed for all the models considered.