Innovative enhancements in solar still performance: A comprehensive study on wick-absorber configurations

• Published in: Case studies in thermal engineering 2024-11, Vol.63, p.105273, Article 105273
• Main Authors: Abdelrehim, Osama, Awad, A.M., Hegazi, A.A., El-Said, Emad M.S., Khater, Asmaa
• Format: Article
• Language: English
• Subjects: Cotton-wick; Exergy efficiency; Heat and mass transfer; solar desalination; Thermal efficiency; Water productivity
• ISSN: 2214-157X; 2214-157X
• DOI: 10.1016/j.csite.2024.105273

This study introduces a new thermo-fluid analysis of using wick-absorbers to enhance solar still performance. Three configurations of wick absorbers were tested in a conventional single-slope solar still: (i) Case I: individual wick balls, (ii) Case II: zig-zag wick pattern, and (iii) Case III: rectangular wick array (grid-like pattern). The study evaluates multiple parameters, including saline water temperature, daily water productivity, Nusselt number, Sherwood number, thermal and exergy efficiencies, water cost, and payback period. The addition of an absorbing plate with an insulation layer led to lower saline water temperatures and shifted peak values. Compared to a traditional still, wick utilization enhanced water productivity by 45.8 %, 84.5 %, and 86 % for Cases I, II, and III, respectively, due to increased evaporation rates. This resulted in a relative enhancement in daily thermal efficiency by 64 %, 76 %, and 97.5 %, respectively. Additionally, four correlations were developed to describe Nusselt and Sherwood numbers, with a maximum deviation of 25 %. Economic analysis demonstrated cost-effectiveness, significantly reducing water cost and the payback period by 37 %, 39 %, and 44 % for Cases I, II, and III, respectively, compared to the conventional system.