Gradient Optimization Algorithm for Structural Optimization and Performance Analysis of the Solar Air Collector

The solar air collector (SAC) is one of the key technologies for space heating, with various designs proposed to enhance heat collection, but increasing design complexity makes determining the optimal structure more challenging. In this paper, a gradient optimization method, based on heat transfer and optical models, is established for the structural optimization of SAC and applied to the triangular solar air collector (TSAC). With maximum heat collection during the heating season as the objective function, the TSAC side material and the absorber angles are optimized. The performance improvement of the TSAC before and after optimization is analyzed, and the applicability of the optimized TSAC is compared with traditional flat-plate solar air collectors (FSACs) in different climate and solar resource zones. The results indicate that the heat collection of the TSAC increased by 19.2% and the operating time increased by 106 h after optimization. In various zones, the heat collection of TSAC is superior to that of FSAC, with an average increase of 18.1%.