Machine learning predictions for enhancing solar parabolic trough collector efficiency with corrugated tube receivers

This work introduces an innovative methodology to enhance the efficiency of solar Parabolic Trough Collectors by integrating corrugated tube receivers accompanied by conical strip inserts. Conventional optimization techniques involving adjustments in size, material composition, and insert configurations often necessitate supplementary energy input. A concept centered around augmenting turbulence was introduced, employing corrugated tube receivers to address this challenge. The study encompassed empirical investigations employing three corrugated copper tube receivers, each possessing distinct pitches (8 mm, 10 mm, and 12 mm) while maintaining uniform corrugation heights (2 mm). These experiments were conducted within a regime of laminar flow conditions characterized by Reynolds numbers spanning from 700 to 2000. The primary objective was to identify the most favorable absorber geometry, subsequently coupled with three varying pitches of conical strip inserts (20 mm, 30 mm and 50 mm) to intensify heat transference. The findings unveiled that the corrugated tube with an 8 mm pitch and 2 mm corrugation height, combined with a conical strip insert possessing a pitch of 20 mm, exhibited promising results. This specific amalgamation yielded remarkable enhancements in the augmented Nusselt number (132%), friction factor (38%), and thermal efficiency (9%) in contrast to the unadorned tube operating under analogous conditions. These outcomes underscore the substantial potential of this pioneering approach in significantly elevating the overall performance of solar parabolic trough collectors.