Optical and radiation considerations in bladed receiver designs for central tower systems

The bladed receiver is a promising concept for improving performance of traditional external receivers in commercial-scale central tower systems due to its light-trapping benefits for reducing reflections and thermal emission. This study reviews the optical and thermal radiation considerations in its design. Adding blades on an existing external receiver would increase surface area thus cause the risk of increasing thermal losses. If the surface area is kept constant, the aperture of the bladed receiver would be smaller, but this would cause more spillage losses, while exceeding peak flux limitations by high concentration ratios. In this study, trade-offs between spillage losses, aiming strategies and thermal losses are investigated under peak flux constraints for molten salt applications. The total efficiency is decomposed to three variables: effective absorptance, spillage and thermal losses, to build a whole picture of the performance of receivers.