Linear Fresnel Ray Tracing Analysis: Southern Italy Plant Optimization Through FresnelSim Algorithm

The goal of maximizing the optical efficiency of a Linear Fresnel Collector is typically addressed through Monte Carlo Ray Tracing simulations. This study introduces FresnelSim, a 3D ray tracing software developed at the University of Genoa, Italy, for the optical analysis of Linear Fresnel Collectors. FresnelSim has been herein used to examine key geometric factors and their impact on a reference plant's producibility, allowing to almost triple the irradiance at the secondary concentrator with respect to a reference base configuration. Through a series of fast parametric simulations, an optimized geometry for such a system is proposed, highlighting to which extent different efficiency indicators are dependent on mirrors’ gap, field length and mirrors’ radius of curvature. Then, an assessment of the effect of the plant’s azimuthal orientation in the range from 0° to 45° is presented, showing that the site’s yearly average producibility is reduced up to 3.3% as an effect of primary mirror alignment. Finally, an analysis of the Compound Parabolic Collector is presented in terms of sub hourly opto-energy efficiency for 3 reference days, resulting in values ranging from 80.9% to 87.4%. Energy flux circumferential uniformity at the absorber tube is evaluated under 6 different incidence angles, highlighting that irradiance uniformity could be further enhanced by a properly defined mirrors’ motion law.