CFD Analysis for the Hydrodynamics and Heat Transfer in Packed Pebble Bed.

Lithium titanate (Li2TiO3) and lithium orthosilicate (Li4SiO4) are the promising solid breeder materials for the fusion reactors. Packed bed of Li2TiO3or Li4SiO4pebbles is considered in the fusion reactor blanket for in situ production of tritium and for this a good effective thermal conductivity of the pebble bed is necessary. In recent past, Mandalet al.[26] studied the hydrodynamics and heat transfer properties of bed of lithium titanate pebbles at different operating conditions viz., gas flow rates, pebble sizes, bed wall temperatures, etc. In the present study laminar,k – εand low Reynoldsk – εmodel have been used to simulate the hydrodynamics and heat transfer data of Li2TiO3pebble bed. The computational fluid dynamics (CFD)-simulated hydrodynamics results have been compared with hydrodynamics and heat transfer results of bed of Li2TiO3pebbles reported by Mandal et al. [26] and others. It was found thatk – εand low Reynolds numberk – εmodel shows better agreement with experimental results. The CFD study were carried out using low Reynoldsk – εmodel for pebble bed of different materials viz. Li2TiO3, Li4SiO4and alumina (Al2O3). The effect of flow rate, pebble size, wall temperature, solid properties viz. thermal conductivity and specific heat on effective thermal conductivity and overall heat transfer coefficient has been discussed in this paper. [ABSTRACT FROM AUTHOR]