Optimization Design of Heliostat Field Arrangement Based on Objective Optimization Model

Tower solar energy achieves high efficiency solar heat conversion by virtue of the advantages of concentrating light and collecting heat. In this paper, a spatial model of the sun's incident light collection and the mirror's reflected light collection is established. The sun's orientation at different times is investigated and the optical efficiency of each heliostat is obtained. The average of the optical efficiency of the heliostat field in the case of the collection of incoming solar rays is obtained as the optical efficiency of the heliostat field under the irradiation of the sun cone. Firstly, based on the latitude and longitude of the heliostat field, the altitude Angle and azimuth Angle of the sun at different times are calculated. Secondly, according to the position coordinates of heliostatic center and absorption tower in geodetic coordinate system, the normal direct radiation irradiance DNI and atmospheric transmittance of all heliostatic fields are determined . Subsequently, a number of mirror coordinate systems are established to calculate the direction vector of the sun incident light and the direction vector of the mirror center pointing to the collector center, and obtain the incidence Angle, mirror normal vector, helioscope pitch Angle, helioscope azimuth Angle and cosine efficiency of each helioscope. According to this, the ray tracing method is used to calculate the shadow blocking efficiency of the mirror. Finally, the HFLCAL model is used to calculate the collector truncation efficiency , and the average annual optical efficiency of the heliostat field is 0.313067, the average annual output work and heat rate is 19.266981MW and the average annual output power per unit mirror area is 0.306701kw/m2.