A comprehensive methodology for the design of solar tower external receivers

The design optimization of external cylindrical receivers for solar tower plants is a complex task that involves several interrelated factors such as optical performance, thermal losses, pressure drops, mechanical integrity, and capital and operating costs. This work describes a comprehensive parametric methodology for the techno-economic optimization of external receivers design. The methodology is based on Levelized Cost of Heat minimization, relies on SolarPILOT for the optical analysis, and involves (i) three-dimensional steady state receiver thermal model, (ii) creep-fatigue lifetime assessment model, (iii) yearly performance assessment on hourly basis, and (iv) economic analysis. To ensure manageable computational efforts, some simplifying assumptions are introduced and successfully validated against more detailed approaches, thus allowing a more refined parametric analysis of design choices. The developed methodology is applied to optimize the receiver design of a Crescent Dunes-like plant comparing three different materials: Alloy 740H, Haynes 230, and Alloy 800H. Results show that the optimized peak heat flux is 1288 kW/m2 with 740H, 1245 kW/m2 with H230, and 868 kW/m2 with 800H. Moreover, the optimized receiver aspect ratio (height/diameter) is 1 for 740H, 1.25 for H230, and 1.5 for 800H. This highlights how the receiver material thermomechanical properties represent a crucial aspect for an accurate optimization of external receiver design. The developed methodology can be applied with any HTF, temperature range, solar field, tower height, and plant location. The flexibility of the proposed methodology, along with its limited computational demand, make it a powerful tool for the CSP industry and scientific research.