Research and Calculation of Heliostat Field Efficiency Based on Solar Ray Reflection Modeling

Tower solar photovoltaic power generation is a low-carbon and environmentally friendly energy technology, and heliostat mirrors, as an important part of tower solar power stations, are therefore modeled in this paper as the annual average optical efficiency, annual average output thermal efficiency, and annual average output thermal power per unit mirror area of the heliostat field. First, we establish the heliostat field coordinate system and the heliostat mirror coordinate system, introduce the rotation matrix to obtain the rotation of the heliostat mirror, so that the light emitted from the center point of the sun is reflected by the center of the heliostat mirror and then pointed to the center of the collector; we introduce the transformation matrix to achieve the transformation of the coordinates between the two coordinate systems. We establish mathematical models for each of the three indicators to be calculated. In the optical efficiency model, we use geometric analysis to establish the reflection model of solar rays and calculate the cosine efficiency; we use the geometric projection method to calculate the shading loss and introduce the microelement method to optimize the process of calculating the shading loss; in the calculation of the truncation efficiency, we take into account the fact that the solar rays propagate in the form of light cones, and the spot reflected to the collector conforms to the Gaussian distribution, which is calculated by combining with the light spot equation to obtain the truncation efficiency.