Experimental characterization of the spatial flux distribution in a point-focus solar concentrator

The input power and spatial flux distribution are critical parameters for the efficiency of solar thermochemical processes and the thermal performance of receivers in point-focus concentrating solar power (CSP) systems, such as solar towers and solar furnaces. While current research primarily focuses on flux measurements at the focal plane, a significant knowledge gap exists regarding the three-dimensional (3D) flux distribution in the near-focal region, which is crucial for the design and operation of novel reactors and the dynamic performance evaluation of receivers under realistic operating conditions. To address this gap, this study presents a novel method for 3D flux characterization, extending conventional 2D plane measurements. A comprehensive 3D flux measurement was conducted on a 30 kWth point-focus solar concentrator (a solar furnace). The methodology used a dual-axis rail system to traverse an array of radiometers, scanning multiple planes parallel to the focal plane. The captured spatial flux data were then processed using interpolation to reconstruct the complete 3D distribution. This study demonstrates the effectiveness of 3D flux characterization. The invaluable data and adaptable methodology provided can optimize reactor or receiver design, support performance testing, and inform future standards for concentrating CSP systems.