On-sun experiments on various particulate materials flowing through obstructed particle heating receiver for solar power tower systems.

The usage of solid particles as solar thermal energy absorption/storage medium requires particle heating receiver to be developed. King Saud University and Georgia Institute of Technology have been collaborating in designing and testing obstructed particle heating receiver. Size of the receiver is 1.2 m x 1.2 m; the base of it is made of duraboard on which chevron-shaped meshes, made of Inconel 601, are installed as the obstructions in a staggered arrangement. The receiver is employed in the particle-based solar power tower experimental facility at King Saud University. To evaluate performance of the receiver, on-sun tests were conducted on two types of particle material, i.e., red sand and CARBOBEAD. Results show that CARBOBEAD absorbed more solar thermal energy and achieved higher temperature rise across the receiver compared to red sand, which is, most likely, due to a higher radiation absorptivity. It was also found that red sand tended to agglomerate at the tip of the chevron mesh during the test, blocking the concentrated sunlight. Moreover, as these agglomerates crumbled, they created many smaller agglomerates that can block the filter downstream, which will, consequently, block the particle flow path. Mesh material also needs to be analyzed further to avoid particle agglomeration, because it is expected that it has a significant role in this matter. [ABSTRACT FROM AUTHOR]