Efficient Water Recycling Through Solar Distillation

The supply of clean water that can be used to meet human demands is very limited, where only less than one percent is available. Water scarcity faced by several countries in the world such as in Saudi Arabia, African countries and India has become worse each year due to the impacts of global warming thus limiting the clean water supply for their domestic use. The use of oil/diesel generators to purify and recycle used water or brackish water is very expensive and non-environment friendly; hence a need of developing a renewable energy water recycling method is to be addressed, as such provided by this project.
A pyramid shape cascade solar still model is chosen from the several conceptual designs proposed. This model is the result of improvement of the previous designs to create a better efficiency model. In this project, experiments and CFD simulations are conducted to determine the highest rate of fresh water production yielded by the solar still. The experiment is conducted by using pre-heated tap water via solar heaters to increase the inlet water temperature that promotes efficiency of fresh water production from the solar still.
From the experiment, a maximum rate of fresh water production of 0.47 kg/m2.hr is yielded which results a significant 57% increase in productivity when compared to a single slope cascade solar still model and 27% increase compared with an inclined solar still model. From the CFD simulation, the maximum rate of fresh water production predicted is 0.51 kg/m2.hr. The CFD simulation predictions and the experimental results are agreeable with a percentage deviation ranging from 7.8% – 15.7% by comparing the rate of fresh water production from both types of analysis.