Comparative performance analysis of pyramid-shaped solar distiller augmented with phase change materials enriched with graphite nanoparticles: experimental study

The present work introduces a comparative investigation on the use of paraffin wax enriched with graphite nanoparticles in the basin of a pyramidal solar distiller as a nano-composite energy storage medium to augment the distillation yield. Four diversified nanoparticle concentrations of 0%, 10%, 15%, and 20% are investigated and compared to the traditional pyramidal solar distillatory (TPSD) under the same conditions. The present findings indicated that the utilization of paraffin wax/graphite nano-composite with a graphite nanoparticles concentration of 20% represents the optimum concentration that maximizes the performance of pyramidal distillers. The daily freshwater yield of the TPSD reached 4.8 L/day.m², whereas the integration of paraffin wax/graphite nano-composite with a concentration of 20 wt.% augmented the distilled yield to 8.72 L/day.m² with an 81.70% improvement in the freshwater yield. Moreover, the daily energetic efficiency and exegetic efficiency of the TPSD reached 41.72% and 1.81%, respectively, while they improved to 75.55% and 4.46% with using 20 wt.% paraffin wax/graphite nano-composite, achieving an 81.08% and 146.4% enhancement in the daily energy and exergy efficiencies, respectively. Additionally, the pyramidal distiller with a 20 wt.% paraffin wax/graphite nano-composite yielded a 31.2% reduction in the cost of 1.0 L of distilled water than the TPSD.