Integrated simple design wind tower and enhanced solar still for hot and arid climate

ABSTRACT

The present work deals with a novel system in which a wind tower having evaporative cooling channel made of flat cotton ropes is integrated with solar still to fulfill the need of thermal comfort and potable water both. In proposed system, cooled water obtained in wind tower has been utilized for increasing the yield of solar still. Additionally, floating pieces of flat cotton rope are provided in still to enhance evaporation rate. The performance of proposed integrated unit has been analyzed mathematically for hot and dry climate of Jaisalmer, Rajasthan (India). The proposed wind tower has resulted average drop in air temperature of 12.5°C and increase in relative humidity of 45.5%, whereas air velocity is found to be in range of 1.2 m/s–1.8 m/s. The maximum reduction in temperature of water in basin of integrated solar still is about 21°C, whereas the same for glass temperature is about 34°C in summer. In winter season these reductions are about 20°C and 15°C, respectively. About 44%–49% additional yield has been found by proposed solar still compared to conventional when mass flow rate of water varies from 0.01 kg/s–0.08 kg/s. The proposed system resulted 45.5% more yield in summer and 40.1% in winter for constant 0.07 kg/s flow rate of water. The cost of potable water and payback period for the proposed system is US $ 0.036 /liter and 0.61 years, respectively.

KEYWORDS:

• Desalination
• evaporative cooling
• solar still
• thermal comfort
• wind tower

Nomenclature

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Disclosure statement

No potential conflict of interest was reported by the author(s).