Volumetric direct solar receivers have been proposed in
Concentrated Solar Power (CSP) applications since they present
higher efficiencies than standard surface receivers do. Silicon
dioxide sand has been proposed as heat transfer and thermal
storage material in Concentrated Solar Power (CSP)
applications. Fluidized sand can be used in volumetric direct
solar receivers; however, in this case, sand should be colored in
order to improve its optical absorption properties in the solar
spectrum. In this work, two methods are proposed and compared
to colour the sand: Carbon Black (CB) nanoparticle coating and
glucose degradation. The optical absorption is characterized
using a double-beam UV-VIS spectrophotometer
(Spectrophotometer Cary 500) before and after the fluidization.
Moreover, colored sand shows no change in optical properties
after 24 hours of fluidization, showing the practical applicability
of this approach.
Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .