Measurements of the effective thermal conductivity of a non-compressed Li4SiO4 pebble bed

Abstract

Li4SiO4 is a tritium breeder material for helium cooled solid breeder blanket concept. The thermal properties of ceramic pebble beds provide important support for designing the solid breeder test blanket module (TBM). A new apparatus was developed to measure the effective thermal conductivity of a packed ceramic pebble bed by steady state method. Accordingly, the effective thermal conductivity of a non-compressed Li4SiO4 pebble bed at temperatures ranging from 300°C to 640°C was measured as well in this study. The packing factor was about 59.7% for the single size pebble bed and helium at atmospheric pressure was used as a filling gas. The experimental results show that the effective thermal conductivity increased with increasing the average bed temperature.