Finite Element Modeling of Parabolic Trough Mirror Shape in Different Mirror Angles

Abstract

Deviations from the ideal shape of reflector panels for parabolic trough solar power plants have relevant impact o field efficiency and thus on the performance of the whole power plant. Analyzing the gravity-induced deformation of mirror shape for different mirror angles is relevant for performance calculation of soar parabolic torugh collectors and identifying optimizatio potetial of the mirror panels. Two mirror model versions (stiff and elastic supports) are evaluatioed in four angles: in horizontal laboratory angle (mirrors facing upward with mounting points horizontally aligned), and in 0°, 45° and 90° collector angle. The resulting slope maps are calculated in a separate post-processing. In order to evaluate the effect of gravity load on mirror shape, the deformed mirror in each evaluated angle is compared to the non-deformed mirror shape, and to the shapes in 0° (zenith( collector angle, respectively. the resulting slope deviation maps show the mirror deformation in different mirror angles. Stiffness of themounting to the support structure has a relevant impact. Mirror deforamtion on elastic brackets. (SDx up to 1.6 mrad) is much more pronounced than on an ideal stiff support structure (SDx up to 1.0 mrad).