Advanced surface reconstruction method for solar reflective concentrators by flux mapping
A. Martínez-Hernández, Ricardo Conceição, Charles-Alexis Asselineau, Manuel Romero, José González‐Aguilar
Abstract
Accurate determination of curvature and surface distortions on solar reflective concentrators is crucial, since flux distribution on the receiver depends on it. Here, a new optical characterization technique able to determine the shape of a solar concentrator from a single flux map measurement is presented. With this technique, the shape of a model heliostat is iteratively varied until the Pearson correlation coefficient between the simulated and the measured flux maps is maximised. The use of a single flux map is made possible through discretisation of the heliostat and target surfaces into two-dimension meshes and a careful choice of heliostat-target distance in the experiment, that must be much shorter than the heliostat focal length. Employing a mesh density of 1 normal vector per 4 cm2, yields correlations higher than 0.99999 with a root mean square slope deviation uncertainty around 0.25 mrad for heliostats of 1.6 m × 1.9 m.