Improving the performance of hemispherical solar stills using four axial magnetic cylindrical magnets: Innovative configurations for optimizing magnetic field distribution

Abstract

The present research aims to improve the design of solar stills by introducing efficient and economical technology to address their low productivity and scarcity of drinking water in rural areas. This is achieved by using innovative and low-cost axial magnetic cylindrical magnets in basins of hemispherical solar stills. The resulting magnetic field reduces the surface tension between water molecules and salts, which helps to increase evaporation rates and hence productivity. In addition, the ceramic cylindrical magnets act as thermal storage materials. To determine the optimal magnetic field distribution within the water basins that achieve maximum productivity, four configurations of the cylindrical magnets were developed and tested. The configurations include in-line (HSD-ICM), circular (HSD-CCM), zigzag (HSD-ZCM), and parallel (HSD-PCM) cylindrical magnets. Three identical hemispherical distillation devices were constructed and tested with the proposed cylindrical magnets incorporated into the basins over two consecutive days on October 2 and 3, 2024. The outcomes from the proposed configurations were compared to standard hemispherical still. The results showed that the use of cylindrical magnets inside the basins significantly improved production by about 88.71, 64.24, 76.94, and 50.82 %, respectively, for HSD-ICM, HSD-CCM, HSD-ZCM, and HSD-PCM. In addition, the use of cylindrical magnets with different configurations improved the energy efficiency of HSD-ICM, HSD-CCM, HSD-ZCM, and HSD-PCM by 87.27, 63.60, 75.93, and 50.54 %, respectively. It also reduced the freshwater cost and recovery time by 20.44–36.41 % and 39.13–73.91 %, respectively. The results of the obtained study confirm the novelty and importance of the current study in the possibility of using axial magnetic cylindrical magnets with different configurations to improve the performance and reduce the production cost of hemispherical solar stills.