Improvement in Spiral Heliostat Field Layout Thermo-Economic Performance by Field Zoning Implementation

Abstract

Arguably, the most complicated and problematic mathematical formulation for solar collectors belongs to the heliostat field collectors. Consequently, extensive researches are carried out in order to develop several codes capable of providing heliostat field analysis and optimization. Noting that most of the aforementioned heliostat field codes are developed based on the radial-staggered field layout which is arguably the most popular and widely implemented heliostat field configuration in the literature. Nevertheless, a ground-breaking heliostat field layout based on the spiral patterns of phyllotaxis discs is recently proposed. It was argued that the transition between the areas with high and low heliostat field density is not continuous in radial-staggered configuration. In a study by the authors, the spiral and radial-staggered field layouts thermo-economic analyses are compared and the results points to the superiority of the radial-staggered layout. Nevertheless, it is believed that utilizing two design variables might be only sufficient for small number of mirrors. Therefore, more design variables must be implemented to fully control different areas of the field for larger capacity heliostat fields. In this paper, spiral field zoning is proposed and its impact on the spiral heliostat field layout performance is assessed. By dividing the heliostat field into multiple zones, each zone is designed with a set of design variables (two design variables: a and b). Consequently, the impacts heliostat field zoning might have on the field thermo-economic performance are investigated.