Wind Load Effect Study on Large-Aperture Parabolic Trough Collector Mirror Fields

Abstract

Large-aperture parabolic trough collectors (LPTCs) are recognized as one of the most promising next-generation linear-focus concentrating solar power (CSP) technologies. However, large apertures inevitably introduce higher wind loads and stronger inter-row interactions. In the present study, a multi-physics-coupled model is established to study the wind load effect on multiple rows of LPTCs. First, it is found that wind load fluctuates significantly in the first four rows and then decreases gradually. The first and second rows suffer the most and least damage, respectively. Because wind load effect is highly dependent on the row number, it is recommended to build wind fences and reinforce the strength of collectors according to their positions in the solar field. Second, the wind load reduction effectiveness of the varied focal length design, incorporated in the LPTC, is numerically validated so that the stress and optical efficiency loss can be reduced by 29.1% and 58.9%, respectively. Finally, the optical efficiency loss is first introduced to evaluate the wind load reduction performance of different mirror gap sizes. The optimal mirror gap size is found to be dependent on the weight coefficient between the wind load reduction and the optical efficiency, which should be determined by the actual scenario. For weight coefficients of 1:1, 1:2, and 2:1, optimal mirror gap sizes of 90 mm, 30 mm, and 120 mm, respectively, are recommended for reference.