A comprehensive 4E (energy, exergy, economic, environmental) analysis of novel pyramid solar still coupled with pulsating heat pipe: An experimental study

Remote regions and poor communities often suffer the most from the shortage of fresh water. Providing a sustainable supply of fresh water and improving the quality of life for millions of people worldwide is crucial. In the present study, two experimental setups, namely (i) a modified pyramid solar still (MPSS) coupled with pulsating heat pipe and (ii) the conventional pyramid solar still (CPSS), were designed, constructed, and investigated under the same ambient conditions of Surat City, India. The MPSS and CPSS were compared for freshwater yield, energy, exergy, and economic analysis at four different depths. The experimental results demonstrate that the accumulated distillate yield for the MPSS was higher than that of the CPSS. The maximum freshwater yield obtained for MPSS and CPSS was approximately 4.10 L/m 2 -day and 3.05 L/m 2 -day at 2 cm depth. During the experiment, improvement in the yield of MPSS due to the attachment of PHP was 34.42%, 37.13%, 31.87%, and 29.62 % as compared to CPSS for 2 cm, 3 cm, 4 cm, and 5 cm, respectively. Moreover, the energy and exergy efficiency of MPSS was higher than CPSS. The maximum enhancement for average energy and average exergy efficiency obtained in MPSS was 25.51% and 29.31% compared to CPSS at 2 cm water depth. The economic analysis exhibits that the cost per liter of fresh water was decreased by up to 13.33% compared with CPSS at 2 cm depth. Based on the environmental assessment, the MPSS ' s most significant environmental parameter (CO2 mitigation) at 2 cm of water depth was 18.79 tons. The present study ' s advantage is using a pulsating heat pipe and passively transferring the additional heat energy into the basin.