Enhancing rotating wick solar still performance with various porous breathable belt designs and nanofluid

• Published in: Case studies in thermal engineering Vol. 49; p. 103205
• Main Authors: Abdullah, A.S., Hadj-Taieb, L., Aljaghtham, Mutabe, Omara, Z.M., Essa, Fadl A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-09-2023; Elsevier
• Subjects: Nanofluids; Rotating wick; Solar desalination; Wick solar still; Wick solar still; Solar desalination; Rotating wick; Nanofluids
• ISSN: 2214-157X; 2214-157X
• DOI: 10.1016/j.csite.2023.103205

The freshwater shortage problem is increasing day after day. Solar stills are suitable devices to overcome this problem for small families and remote areas. However, these devices suffer from their low productivity. Two different modified designs for spinning wick solar stills were tested here. One distiller contained a rotating wick belt with a path of “LC” character shape (LC-RWSS), and the other with a path of “L” shape (L-RWSS). Additionally, the wick type was studied for black cotton and jute wicks. Moreover, the influence of belt-rotation direction (counterclockwise and clockwise) on the performance of solar still has been investigated. The period of wick belt rotation was tested (ON = 5 min and different OFF times = zero, 10, 20, 30, 40, 50, and 60 min). Also, the impact of utilizing graphene quantum dots nanofluid on the performance of LC-RWSS was considered. In addition, the effects of external reflectors and exhaust fan were examined. Results indicated that the jute wick provided more distillate than the cotton cloth. Furthermore, the productivity of LC-RWSS with counterclockwise movement of wick belt was always larger than that with clockwise direction under all different OFF times. In addition, the best output yield of LC-RWSS (at 0.1 rpm with jute wick-counterclockwise) was achieved when operating the wick belt under 30 min OFF and 5 min ON times, the LC still had a daily distillate more than L still by 17%. The thermal efficiency of L still and LC still was 82% and 86%, under 30 min OFF period of belt. With reflectors, exhaust fan and nano, the best output yield of LC-RWSS was provided when operating the belt under 10 min OFF and 5 min ON times. The LC still had a total yield more than that of the L still by 28% with 87% thermal efficiency. Also, the cost of freshwater obtained is 0.016 for LC still with reflectors, fan and nanofluids.