(64g) Characteristics of Flow and Heat Transport in a Packed Pebble-Bed Reactor

Despite the recent interests in two-phase flow catalytic hydro-processing of heavy oil and the packed pebble-bed reactors (PBRs) for the next generation nuclear energy, there is still lack of understanding of the complex gas flow structure, mixing, and heat transport phenomena. Therefore, this work uses an advanced gaseous tracer technique and sophisticated fast-response heat transfer probe of spherical-type to measure in a cold-flow randomly packed pebble-bed unit both the residence time distribution (RTD) of coolant gas and solid-gas convective heat transfer coefficient, respectively. The degree of axial mixing and the convective heat transport have been quantified in terms of Peclet numbers and Nusselt numbers, respectively, over a wide range of Reynolds numbers which cover both laminar and turbulent flow conditions in the studied packed-bed. The present work provides insight and advancing the knowledge of the extent of mixing and the heat transport phenomena in the studies bed using advanced and fast-response measuring techniques.