Structural analysis of mirror bent strips and connection elements for heliostat with drive rims

Abstract

Heliostat is considered the component with the greatest impact on the costs of a CSP plant with a central tower and the use of the appropriate heliostat can generate reductions of up to 40% in energy losses. In this sense, it is necessary to nationalize the structural and optical components of the same as a cost mitigation measure, with solutions that favor the introduction of technology in the Brazilian agroindustry. In addition, there is a need for studies so that CSP technology adapts to tropical latitudes, which require shorter focal length and, therefore, the use of narrower heliostat fields than at latitudes such as Europe and the United States, places where CSP technology is already commercially established. The solution proposed in this study requires the use of a mirror with a curved surface in order to achieve the required concentration using a low number of heliostats, reduce spill losses and increase the amount of energy absorbed and, consequently, the performance of the solar plant. A reflective surface configuration was proposed, consisting of six horizontal mirror strips that were designed using the Autodesk Inventor program and submitted to structural analysis by the Finite Element Method (FEM) with the ANSYS Workbench program. In the simulations, a wind load that can occur in São Paulo was applied and the results of stress and deformation in the mirrors were analyzed. In order to optimize the use of material in the mirror, two thicknesses were proposed: 4 and 7 mm. The 4 mm thick mirror can become a solution, although it has been shown to be susceptible to tension caused by the wind, near the central connecting elements positioned next to the support of the drive system. In addition, an option to connect the mirrors to the frame via an L-shaped angle bracket is presented as a solution.

DOI:https://doi.org/10.56238/uniknowindevolp-056