Study on the Optical Properties of the Point-Focus Fresnel System

Abstract

The characteristic analysis of the flux formed by the heliostat in the optical system is the basis in design and optimization of the whole system. In this paper, our research subject is a pilot installation of the point-focus Fresnel system, which is a new optical design between the tower system and the dish system. For the optical system, it is very important to accurately calculate the solar flux density distribution on the receiver plane. Aiming at the case that the focal length of the heliostat is not equal to the distance from the center of the heliostat to the center of the receiver plane, based on the projection, an approximate calculation method is proposed. Using the method to calculate the solar flux density distribution of the point-focus Fresnel system, and the results are compared with that calculated by SolTrace code, it is found that the solar flux density distribution of both is relatively consistent in shape and numerical value, which verifies the accuracy of the method and it can be used for design and optimization of the point-focus Fresnel system.