2026-01-01 INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW 2026 117(卷), null(期), (null页)
Water scarcity in remote and arid regions necessitates efficient solar desalination technologies. While pyramid solar stills (PSS) offer promise, their low productivity remains a critical limitation. This study experimentally investigates the integration of horizontal cylindrical tubes into PSS to enhance thermal, energy, and exergy efficiencies. Conventional and modified PSS configurations (3, 5, 9, and 12 tubes) were compared under identical environmental conditions. Results demonstrate that cylindrical tubes significantly improve performance, with the 9-tube configuration achieving peak energy efficiency (28.49%, 65.93% higher than conventional PSS) and exergy efficiency (100.78% increase). Evaporation dominated heat transfer, and diminishing returns were observed beyond nine tubes. The study provides actionable insights for optimizing solar still designs to address global water scarcity sustainably.