Experimental Study to Obtain the Optimal Performance of the Solar Still With Different Shapes Conducting Nano‐Phase Change Materials as Evaporation Enhancers

ABSTRACT The limited access to potable water is also a critical issue, especially in remote desert areas where the use of advanced treatment methods is not a possibility. Since such regions have high solar availability, the research provides an experimental assessment and performance improvement of two solar distillation systems, a single‐slope (inclined) still and a pyramidal still. Paraffin wax is used as a phase change material (PCM) and nano‐enhanced PCM with 0.3% mass fraction of aluminum oxide. Also, a corrugated absorber plate is used to enhance the heat transfer characteristics. The experiments have been conducted in winter in Iraq, Najaf. The modified system exhibited a significant performance improvement. The cumulative fresh water yield of 2168 L/m 2 ·day realized in contrast to 906 L/m 2 ·day of the inclined conventional unit and (1091–2735 L/m 2 ) for the pyramidal solar still, and this represents a productivity improvement of 139.2% for the inclined solar still and 125.7% for the pyramidal solar still. The daily thermal efficiency rates reached were 40.3% for the inclined solar still and 50.9% for the pyramidal solar still. Out of all the results that were obtained, the nano‐enhanced PCM configuration showed the highest thermal stability and productivity. The results validate that combining geometric modification with nano‐enhanced latent heat storage greatly enhance the desalination performance in the conditions of low solar radiation the nano‐enhanced latent heat storage possibility that greatly enhance the desalination performance in the conditions of low solar radiation.