Enhancing pyramid solar still performance using suspended v-steps, reflectors, Peltier cooling, forced condensation, and thermal storing materials
Ali Alshamrani
Abstract
This work aims at enhancing the thermal efficiency of pyramid distiller solar still (PDSS). A modified version (MPDSS) was developed, featuring suspended v-steps on the vertical walls of the distiller. Additionally, the MPDSS was equipped with external reflectors (MPDSS-R) designed to concentrate solar energy, thereby potentially increasing evaporation rates. To further boost the condensation rate, three different methods were implemented and evaluated independently: an external condensation unit integrated with the MPDSS (MPDSS-C), a fixed nano-enhanced thermal storing material (NTSM) within the MPDSS (MPDSS-NTSM), and an installed Peltier device (MPDSS-P). The results indicated that the MPDSS with suspended steps achieved a significant improvement, with a 40 % increase in distillate yield over PDSS. MPDSS with reflectors resulted in a 96 % increase in yield. Moreover, integrating a Peltier device with the MPDSS led to a 148 % boost in distillate yield, while the yields increased by 139 % and 143 % when utilizing the NTSM and the condenser, respectively. Consequently, the optimal performance for the MPDSS was achieved with the combination of reflectors and the Peltier device, attaining a thermal efficiency of 53.96 % and a 148 % improvement in distillate yield. Also, the thermal efficiency of PDSS, MPDSS, MPDSS-R, MPDSS-C, MPDSS-NTSM, and MPDSS-P was 35.46 %, 42.23 %, 46.77 %, 50.89 %, 48.33 %, and 54.67 %, respectively. While the exergy efficiencies ranged from 3.44 % for the PDSS configuration to 4.87 % for the MPDSS-P configuration. Interestingly, the MPDSS-C configuration achieved an exergy efficiency of 4.64 %. The emissions for MPDSS, MPDSS-R, MPDSS-C, MPDSS-NTSM, and MPDSS-P are estimated at 15.03, 14.62, 14.09, 14.30, and 13.79 tons a year, severally. The enviroeconomic parameters were 218, 212, 204, 207, and 200 a year for MPDSS, MPDSS-R, MPDSS-C, MPDSS-NTSM, and MPDSS-P, respectively. Finally, the water expenses are as follows: $0.343/L for the PDSS, $0.292/L for the MPDSS, $0.220/L for the MPDSS-R, $0.082/L for MPDSS-P, $0.105/L for the MPDSS-C, and $0.114/L for the MPDSS-NTSM.