6E evaluation of an innovative humidification dehumidification solar distiller unit: An experimental investigation

This work aims to enhance the productivity, efficiency, energy utilization, feasibility, and environmental outcomes of solar desalination systems via representing an innovative humidification dehumidification solar distillation unit coupled with a built-in air solar heater and photovoltaic thermal unit. The air solar heater was further improved by the incorporation of copper chips as thermal energy-storing materials for extending the desalination process during the sun's hours. Three distinct humidifier beds, including plastic waste (case A), wick materials (case B), and cellulose paper (case C) were tested and compared regarding system temperatures and hourly and daily drinkable water yield. Additionally, a 6E analysis was assessed and evaluated in terms of energy, exergy, economic, exergoeconomic, exergoenvironmental, and exergoenviroeconomic analysis for all the cases. According to the outcomes, the humidification dehumidification solar distiller with cellulose paper yielded the highest productivity and 6E outcomes where the daily drinkable water, thermal efficiency, and exergy efficiency were estimated as 7.78 L/m², 73.45 %, and 5.3 %, outperforming the CSD by nearly 142.59 %, 144.02 %, and 229.19 %, respectively. Moreover, the price of drinkable water and the payback time decreased to 0.0099 $/L and 0.12 years, which represents a reduction of 68.27 % and 69.23 %, respectively, at an exergoeconomic factor of 4.19 kWh/$. Furthermore, the amount of CO₂ reduced was increased to 3.92 tons, which is associated with earned credits of carbon of 56.78$. Finally, for this case, the HDH humidifier efficiency, dehumidifier effectiveness, and gain output ratio maximum and mean values were 96.66 and 84.5 %, 85.61 and 78.96 %, and 1.86 and 1.08, respectively.