Intelligent optimization of structural parameters of solar dish concentrator for annual comprehensive optical performance under service loads

Solar dish concentrator is an optical-mechanical integrated device where structural design directly determines optical accuracy and manufacturing cost. This paper proposes an intelligent optimization method for geometric parameters of dish concentrator structures, aiming to achieve comprehensive annual service optical accuracy. By optical-mechanical integrated method, surrogate modeling, and intelligent optimization algorithms, it addresses the challenge of co-optimizing optical accuracy, structural mechanical performance, and structural lightweighting, thereby enhancing its techno-economic competitiveness. First, the optimal Latin hypercube sampling method is employed to sample the geometric parameters of the concentrator structure. An optical-mechanical integrated analysis is then performed to determine the optical error Stotal and the maximum structural stress across all wind conditions for each geometric parameter set. Secondly, a comprehensive optical error index Sst is proposed, which fully accounts for wind direction angle, annual elevation angles, and annual collected energy. This index transforms the complex multi-condition optical error indicators into a unified composite index. Subsequently, a high-precision surrogate model is established using GA-BP intelligent algorithm, and the intelligent optimization of the concentrator's structural parameters is achieved by integrating this surrogate model and MIGA algorithm. Using a large 17.7 m diameter dish concentrator with wind speed of 17.1 m/s as a case study, this paper fully demonstrates the effectiveness of the intelligent optimization method and the optimized concentrator. The Sst for the original concentrator and two optimized concentrator are 1.374 mrad, 1.864 mrad, and 2.431 mrad, respectively. These optimizations yield significant steel savings of 3613 kg and 4277 kg, corresponding to substantial weight reduction rates of 36.58% and 43.32%. Under the most unfavorable condition 45°-0°, the Stotal for the original concentrator and two optimized concentrators are only 2.48 mrad, 3.52 mrad, and 4.91 mrad, respectively. When β = 90°, the Stotal of both optimized concentrators remains below 1.6 mrad. For a cavity receiver with an aperture radius of 200 mm, the intercept efficiency exceeds 92.64%, and the optical efficiency of the concentrating system is greater than 82.11%, confirming exceptional service optical performance.