Effect of Geometric Configurations of Molten-Salt Risers on Its Hydraulic and Structural Behavior in Tower-Based Concentrated Solar Power Station

Geometric configuration influences the hydraulic performance, structural response, and material requirements of molten-salt risers in tower-based concentrated solar power plants. However, the effects of the principal geometric parameters on the hydraulic and structural responses of a complete riser system have not been sufficiently clarified. In this study, a full-scale molten-salt riser model was established under fixed total-height and lateral-space constraints. Thirteen configurations were generated using a single-factor parametric design, and computational fluid dynamics and structural finite-element simulations were employed to investigate the effects of the inclined-segment length-to-diameter ratio Ls/Di, elbow curvature ratio R/Di, and inclined-segment angle θ. The results show that increasing Ls/Di increases the overall system resistance coefficient but reduces the maximum von Mises equivalent stress under the combined load case by up to 17.12%. Increasing R/Di reduces both the overall system resistance coefficient and the combined-load maximum stress, while the maximum total deformation and pipe mass change only slightly. Increasing θ increases the overall system resistance coefficient but decreases the combined-load maximum total deformation, whereas the combined-load maximum stress varies nonmonotonically and reaches a minimum of 194.95 MPa at θ = 75°. These results clarify the distinct hydraulic and structural response trends associated with the three geometric parameters. Among the investigated configurations, the 45° configuration demonstrates a degree of coordination among hydraulic performance, structural response, and pipe material usage. The findings provide a numerical basis for the configuration design and parameter selection of molten-salt risers in tower-based concentrated solar power plants.