Ahmed Mohammed - Department of Mechanical Engineering, Faculty of Engineering, South Valley University, P. O. Box: ۸۳۵۲, Qena , Egypt.
Ahmed Shmroukh - Department of Mechanical Engineering, Faculty of Engineering, South Valley University, P. O. Box: ۸۳۵۲, Qena , Egypt.
Nouby Ghazaly - Department of Mechanical Engineering, Faculty of Engineering, South Valley University, P. O. Box: ۸۳۵۲, Qena , Egypt.a Department of Mechanical Engineering, Faculty of Engineering, South Valley University, P. O. Box: ۸۳۵۲, Qena , Egypt.
Abd Elnaby Kabeel - Department of Mechanical Power Engineering, Faculty of Engineering, Tanta University, P. O. Box: ۳۱۵۲۱, Tanta, Egypt.

In the present study, a modified pyramid-solar-still (MPSS) with new multiple stepped basin areas was investigated in the weather conditions of Qena, Egypt, at a location of (Latitude: ۲۶.۱۶°, Longitude: ۳۲.۷۱°). Boosting the output of the pyramid solar still is the primary focus of the proposed strategy. To achieve this, four basins were built and integrated into the pyramid solar still, with their size increasing in proportion to the surface area of the condensing glass. A ۲۵% increase in basin area per square meter of solar still was achieved compared to conventional pyramid solar still (CPSS) with the same condensing cover area. The thermal performance and productivity of the suggested solar still were demonstrated by developing energy balance equations for temperature components and then analytically computing their solutions. The results showed compatibility between theoretical and experimental results. The highest yields for CPSS were ۲۵۲۴ mL/m۲, and for MPSS, they were ۳۴۱۵ mL/m۲. The stepped area enhanced the yield by ۳۵.۳% compared with CPSS. Moreover, the efficiency of CPSS and MPSS was recorded as ۲۳.۵% and ۳۱.۷%, respectively. Furthermore, the maximum yield of freshwater was obtained for the northern condensing cover, with the recorded value reaching ۱۱۷۴ mL/m۲. Distilled water under the proposed system would cost ۰.۰۱۷۹ per liter. Finally, the TDS and pH levels are in accordance with WHO recommendations for the quality of drinking water.

pyramid solar still, stepped basins, Yield, Efficiency, Cost analysis