Parquetting the Surface of a Parabolic Concentrator of a Solar Photovoltaic Thermal Module According to Given Differential- Geometric Requirements

Abstract

The article discusses the geometric aspects of the design and creation of parabolic-type solar radiation concentrators. Practical methods of geometric design and manufacturing of concentrators of this kind are presented. Parabolic type concentrator is the main part of the solar photovoltaic thermal installation. Its effectiveness depends on the quality factors of the geometric shaping of the working surface, composed of a set of parquet components, linked to each other on the basis of differential geometric requirements. The distribution of illumination in the focal spot of such a concentrator, made by parquet based on the constructive connection of individual elements, makes it possible to obtain acceptable results. However, there is considerable potential for improving performance by providing a smoother and more uniform illumination of the photodetector. To ensure the specified accuracy and smoothness of the rim of the surface at the stages of designing and manufacturing the device, two methods are proposed: orthogonal and fan-shaped geometric parquetting of the surface of a parabolic concentrator with the ability to pre-set the required shape accuracy for given rim geometrical characteristics. Parquetting with given differential requirements for the surface, in turn, provides for two methods for calculating parquet elements: first, by the minimum number of curvilinear elements followed by stitching, taking into account the differential conditions; the second is based on the maximum number of flat elements, the multiplicity of which provides acceptable smooth surface properties. In this paper, we consider the first method for cases of orthogonal and fan parquet. On the example of a parabolic concentrator, the implementation of the considered method is presented, which provides for the possibility of controlling the geometric smoothness of the concentrator surface in order to ensure optimal distribution of concentrated solar radiation in the focal region. The output characteristics of photovoltaic and thermal converters of solar energy, which are in the focus of such a concentrator, become optimal, and the installation itself will operate in nominal mode.