Numerical analysis of evaporation process in the heating column of a solar water desalination plant under various geometries, ambient conditions, solar radiations, and time steps

Solar-powered desalination offers a promising and sustainable method for producing potable water. In this study, the heating column of a solar desalination powerplant is numerically investigated under different novel geometric/structure scenarios, various solar/ambient conditions and different seawater salinity through different time steps. The primary objective is to identify the optimal configuration that maximizes water evaporation within the heating cylinder which has not been carried out before. Initially, four distinct heating cylinder configurations are examined under a fixed time step. The most promising configuration is then selected and evaluated under a broader range of ambient conditions and the same time step. The influence of solar radiation throughout the day is also analyzed. Finally, the evaporation process is simulated for the selected geometrical and environmental conditions across different time steps ranging from 60 to 300 s. The findings reveal that incorporating fins alone, a glass cover alone, and a combination of both fins and a glass cover could enhance the volume fraction of vapor by approximately 8 %, 33.3 % and 10.6 %, respectively, compared to the baseline configuration without fins or a glass cover. However, the evaporation rate for the glass cover configuration increased with rising ambient air temperature. Additionally, the highest evaporation is observed at 15:00 p.m., corresponding to the peak solar radiation intensity. Under optimal conditions, the heating cylinder achieved a promising vapor volume fraction of approximately 78.2 % after 300 s. These findings offer valuable insights for optimizing solar desalination system design. By increasing the salinity of the water from 0 to 75 %, the value of steam volume fraction is reduced from 77 % to 60 % for a given time step. [Display omitted] •Solar heating column of a vacuum-based water desalination plant is simulated.•Four different geometric scenarios are investigated.•Various ambient conditions are simulated for the best selected geometry.•The simulation is performed along different time of the day (solar intensity).•Different time steps are evaluated and optimum conditions are introduced.