Calculation Method and Simulation Study of Optical Efficiency of Fixed-Heaven Mirror Field

Abstract

Tower solar thermal power generation is an environmentally friendly new clean energy technology. This paper lays the foundation for constructing a heliostat mirror field with optimal annual average thermal power per unit mirror area by solving the annual average optical efficiency, annual average output thermal power and annual average output thermal power per unit cross-section area for a specific heliostat mirror field. This paper begins with calculating the solar altitude angle and azimuth angle at different times, and derive the normal equation of each heliostat. The specular reflection is studied by taking 100 uniform discrete points on a specular surface and establishing a specular coordinate system, which is used to calculate the ratio of the blocked light to the total light of a single specular surface to indicate the shadow blocking efficiency. The dispersion of light in a single light cone is simulated by establishing a light cone coordinate system for the reflected light, and the ratio of the number of light captured by the collector to the total light is calculated to indicate the truncation efficiency; then the cosine efficiency is calculated by the angle of incidence, and the average annual optical efficiency, average annual output thermal power, and average output thermal power per unit of mirror area are finally derived from the formulas in the relevant literature, and the results are 0.5408, 16.2327 MW, and 0.2584 kW/m², respectively.