Fast Optical Receiver Surface Characterization

Application on Cylindrical Solar Tower Receivers

Abstract

This paper presents an extension of the "Maximum Front Method" for assessing the spatially varying Bidirectional Reflectance Distribution Function on curved surfaces, specifically the receiver of a Solar Tower. The receiver, which links the solar field and the thermal cycle of a ST, operates under high solar concentrations and temperatures. This method is vital for efficient plant operations, enabling regular assessment of the receiver coating quality, early detection of degradation, and facilitating other measurement techniques. The paper discusses the challenges faced with the far field SVBRDF measurement when dealing with complex surfaces, including the trajectory of the light spot, and dealing with distance dependant reference intensity values. These challenges were addressed through a geometric approach and simulations were carried out using blender® to validate the method, showing its effectiveness on cylindrical and structured surfaces. However, accurately determining each component's spatial position was a persistent challenge for the practical demonstration. The paper suggests future research could consider line overlaps to maintain the evaluated area and develop methods to determine pipe positions directly from captured images. In conclusion, this method provides a foundation for solar tower receiver applications to monitor receiver state and improve robustness and efficiency in solar tower operation.