Improving the Single-Slope Solar Still Performance Using Solar Air Heater with Phase Change Materials

Abstract

This communication discusses the energy, exergy, and economic feasibility of novel heat storage based on a single-slope solar still coupled with a solar air heater (SAH). The analysis was conducted on three different solar stills, i.e., a single-slope solar still (SSSS), single-slope solar still with latent heat storage, and a single-slope solar still with latent heat storage coupled with a solar air heater. The performance evaluation of all types of solar still has been compared to evaluate the best-performing solar still. Paraffin wax as a phase change material (PCM) has been used at the bottom of the solar still to provide proper thermal storage. The experiments were conducted on different depths, i.e., 3 cm, 6 cm, 9 cm, 12 cm, and 15 cm. The efficiency of a single-slope solar still with PCM and SAH was 65.58% higher than a conventional solar still. The average exergy efficiency of a single-slope solar still with latent heat storage coupled with a solar air heater is 83.19% higher than a traditional solar still. Additionally, the maximum hourly output was found to be 735 mL/m2 h for the solar still customized with PCM and solar heater for a depth of 3 cm. This shows that the still (single-slope solar still with latent heat storage coupled with a solar air heater) has higher thermal performance than the other two solar stills. Therefore, the proposed solar still is very suitable for desalination.