Building a 5D Database of Heliostats Flux Distributions: Toward High Flexibility High Accuracy Flux Control for Odeillo's Big Solar Furnace

Abstract

In order to increase the flexibility and the control of the concentrated solar flux provided to test processes and materials at the big solar furnace in Odeillo (up to 1000 kW and 10000 KW/m2), extensive and accurate knowledge of the individual contribution of each of the heliostats is required, for all their aiming points. For a solar furnace, with double mirror reflection and heavily changing shadow of the solar beams, this would require too much experimental time to record this behaviour systematically, either directly (flux measurements of all the configurations) or indirectly (simulation by ray tracing based on the real optical configuration measured, both at macroscopic and microscopic scale). This work here presents a trade-off method based on real flux measurement, but at sampled configurations, then interpolated to fill in missing data. 5 dimensions have been sampled: heliostats (1D) + aiming directions (2D) + flux distributions (2D). An evaluation of the method is presented based on actual experimental data, with a discussion of the experience.