A comparative assessment of innovative hemispherical solar distillers with cylindrical and conical fins: an experimental approach
Mohammed El Hadi Attia, A.E. Kabeel, Mohamed Abdelgaied, K.M. Almohammadi, Moataz M. Abdel‐Aziz
Abstract
The present study aims to reach the best design of the fins installed on the basin absorber surface that achieves the highest performance of the hemispherical solar distillers. The fins represent one of the most important improvement techniques utilized to increase the evaporation rates inside the solar distillers, by increasing the heat transfer area between the absorption surface and the basin water. However, some designs of the fins have negative effects due to the shading problem, which causes a reduction of the absorption rates of solar rays. Therefore, the current study aims to find the best design of the fins that achieve the least shading effects and the highest performance of hemispherical solar distillers. To achieve this idea, two types of fins (cylindrical and conical) with a diameter of 1.5 cm and a height of 3 cm, with different gap distances of 3, 3.75, and 4.5 cm were studied. To achieve these, three hemispherical solar stills were tested under the same weather conditions, first is a conventional hemispherical still without fins (CHSWF) which is the reference distiller. The second is the hemispherical distiller with cylindrical fins (CyFHS), and the third is the hemispherical distiller with conical fins (CoFHS). The results show that the hemispherical distiller with cylindrical fins (CyFHS) productivity values are 5.55, 6.00, and 6.70 kg/m2, respectively, while the hemispherical distiller with conical fins (CoFHS) productivity values are 6.20, 6.65, and 7.15 kg/m2 at the gap distances of 3, 3.75, and 4.5 cm, respectively, compared to 4.20 kg/m2 produced by CHSWF. The results showed that the use of conical fins with a gap distance of 4.5 cm represents the optimal fin design that achieves the least shading and the highest performance of hemispherical solar distillers, with improvement rates of 70.24% compared to reference distiller (CHSWF).