Productivity enhancement of solar still using water heater and cooling fan

In the present work, an attempt is made to enhance the productivity of a double slope solar still by using an immersion type water heater. The effect of using an external fan to cool the glass surface is also examined. Experiments were carried out for winter season in Saudi Arabian climatic conditions at latitude 26 deg N. A solar still with 35 deg glass slope angle is chosen in our study. Since the yield of a solar still is more for low water depths, the water level in the base tank was maintained at 1 cm. The experimental results showed that the productivity increased by a significant 370% when two water heaters each having 500 W capacities was used. When external cooling fan was used the productivity was found to decrease by 4% and 8% for wind speeds of 7 m/s and 9 m/s, respectively. Thermal modeling was also done using the heat and mass transfer relations, and then, numerical simulations were carried out to validate with the experimental results. A good agreement between experimental and numerical results was found. The present study is partial implementation of two patents submitted in this field.