Performance assessment of a passive solar still integrated with thermal energy storage and nanoparticle stored in copper cylinders

In the present study, nanoparticle (CuO) has been dispersed in paraffin wax and stored in a copper cylinder to enhance the thermal conductivity and increase the total daily production of the solar distillation unit. Experiments have been performed for comparison between simple solar still (SSS), solar still with phase change material (SSPCM), and solar still with phase change material doped with nanoparticle (SSNPCM). The mixing of nanoparticle causes a paradigm shift of the thermophysical properties of phase change material (PCM). Nanoparticle and copper cylinder enhance the heat transfer rate with decreased duration of sensible heating, melting and solidification of PCM. Thermal analysis reveals that the evaporative mode of heat transfer has dominated heat transfer between glass cover and water. The maximum and average temperature for water basin and NPCM has been increased significantly for SSNPCM. The daily productivity of SSPCM and SSNPCM has been increased by 40.5% and 94.19% as compared to SSS. Based on the heat transfer rate, thermal conductivity, and daily productivity, SSNPCM can be considered not only as a better performing system as compared to SSS and SSPCM but also as a low cost disruptive technology in resource-constrained settings where drinking water is really scarce.