FINITE ELEMENT MODELING OF CONCENTRATING SOLAR COLLECTORS FOR EVALUATION OF GRAVITY LOADS, BENDING, AND OPTICAL CHARACTERIZATION

Understanding the effects of gravity and wind loads on concentrating solar power (CSP) collectors is critical for performance calculations and developing more accurate alignment procedures and techniques. This paper presents a rigorous finite-element model of a parabolic trough collector that is used to determine the impact of gravity loads on bending and displacements of the mirror facets and support structure. The geometry of the LUZ LS-2 parabolic trough collector was modeled using SolidWorks, and gravity-induced loading and displacements were simulated in SolidWorks Simulation. The model of the trough collector was evaluated in two positions: the 90 degrees position (mirrors facing upward) and the 0 degrees position (mirrors facing horizontally) The slope errors of the mirror facet reflective surfaces were found by evaluating simulated angular displacements of node-connected segments along the mirror surface The ideal (undeformed) shape of the mirror was compared to the shape of the deformed mirror after gravity loading Also, slope errors were obtained by comparing the deformed shapes between the 90 degrees and 0 degrees positions. The slope errors resulting from comparison between the deformed vs undeformed shape were as high as similar to 2 mrad, depending on the location of the mirror facet on the collector. The slope errors resulting from a change in orientation of the trough from the 90 degrees position to the 0 degrees position with gravity loading were as high as similar to 3 mrad, depending on the location of the facet.