EXPERIMENTAL CHARACTERIZATION OF THE HEAT-TRANSFER IN A FREE-FALLING-PARTICLE RECEIVER

This paper describes the measurements performed on a Free Falling curtain of spherical beads being irradiated in a high-flux solar furnace. The curtain of spherical beads is part of a direct absorption solar receiver concept, which replaces the conventional water and steam receiver (DAR) and is potentially more efficient and less expensive than a conventional receiver. To adequately describe a DAR a series of experiments have been designed and implemented to measure radiative heat flux and particle temperatures. The extinction coefficient for the DAR bead curtain has also been measured. These data and results along with a new method for measuring bulk bead temperature will be discussed. A method is also described which uses the angular distribution of incoming radiative heat flux to estimate the incoming intensity field.