Optimization of a wavy-channel compact solar receiver with supercritical carbon dioxide

The compact solar receiver stands out as a promising solar absorber for the direct supercritical carbon dioxide cycle, and the wavy channel exhibits notable comprehensive performance owing to its excellent heat transfer capabilities and relatively low flow resistance. However, there exists considerable room for improvement in performance through the optimization of geometric parameters in wavy channels. In this paper, the amplitude and the period of the wavy channel are optimized by a coupled response surface method with multi-objective genetic algorithm, with objectives of maximizing the heat transfer coefficient and minimizing the friction factor. Results indicated that smaller period or larger amplitude enhances heat transfer but also increases flow resistance. Through the non-dominated sorting genetic algorithm and k-means clustering method, five representative optimal solutions were identified. The optimal result, characterized by a period of 15.07 mm and an amplitude of 1.73 mm, was selected based on the highest comprehensive heat transfer factor under identical pump power, reaching 1.213. This solution demonstrated high comprehensive performance across a wide range of working conditions. The optimization results are not only valuable for the design of compact solar receivers but also hold significant potential for application in other compact heat exchangers, such as printed circuit heat exchangers.