An Experimental Study on Two-Phase Flow and Coolability of Particulate Beds Packed with Multi-Size Particles

Abstract

This paper presents the results of an experimental study on the friction laws of two-phase flow and coolability in a volumetrically heated particulate bed packed with multi-size particles. The pressure gradients and dryout heat fluxes of the bed are measured for both top-flooding and bottom-fed schemes. The bottom-fed scheme is driven by forced injection of water from the bottom of the bed. Moreover, a varied configuration of the bed with a downcomer is employed to investigate the effectiveness of natural circulation-driven coolability (NCDC). The results show that at top-flooding conditions, both the pressure gradient and the dryout heat flux of the bed can be predicted by the Reed model. The coolability is enhanced by the bottom-injection and the downcomer, and the dryout heat flux rises significantly with increasing water velocity of bottom- injection.