Advanced Optical Efficiency Analysis of Tower Solar Heliostat Fields based on Monte Carlo Ray Tracing and Analytic Geometry method

Abstract

Solar thermal tower power is an innovative technology that uses a field of heliostats to convert solar energy into electricity. The ability to accurately compute the optical efficiency and thermal power output is a crucial aspect of effectively employing this technology, subsequently enhancing power generation efficiency through strategies such as optimizing the distribution of the heliostat field. An innovative approach for calculating the annual mean optical efficiency, annual mean output thermal power will be presented in this paper. To calculate the related parameters, a spatial Cartesian coordinate system will be established in this paper by utilizing conventional analytical geometry techniques. This methodology explicitly provides the trigonometric functions for diverse angles, thereby eliminating inaccuracies linked to approximations, guaranteeing that subsequent algorithms deal with the minimal number of variables necessary to achieve a more precise fitting outcome. Regarding the shadow occlusion efficiency, basic analytical geometry will be adopted to simulate the positional relationships and solar reflection angles of the heliostats. This method enables us to compute an annual mean shadow occlusion efficiency of approximately 0.8412. As for the collector truncation efficiency, this paper has developed a ray tracing model based on Monte Carlo random sampling. This model decomposes the solar light cone into discrete rays, which allows us to use the simulation model to assess whether the rays impact the collector. By integrating the energy carried by rays that meet the requirements, this paper quantifies the energy received by the collector, resulting in an annual mean truncation efficiency of 0.8723.