Dryout heat flux in a debris bed with forced coolant flow from below

The objective of the present study is to experimentally investigate the enhancement of dryout heat flux in debris beds with coolant flow from below. The experimental facility consists mainly of an induction heater (40 kW, 35 kHz), a double-wall quartz-tube test section containing steel-particle bed and coolant injection and recovery condensing loop. A fairly uniform heating of particle bed was achieved by induction heating. This paper reports the experimental data for 5 mm particle bed and 300 mm bed height. The dryout heat rate data were obtained of both top-flooding case and forced coolant injection from below with the injection mass flux up to 1.5 kg/m2s. For the top-flooded case, the volumetric dryout heat rate was about 4 MW/m3 and it increased as the rate of coolant injection from below was increased. At the coolant injection mass flux of 1.5 kg/m2s, the volumetric dryout heat rate was about 10 MW/m3, the enhancement factor was more than two. (author)