ABSTRACT
The solar still utilizes solar energy to produce potable water from brackish water, which may support agricultural and industrial sectors as well as the life of humans and animals. A conventional solar still normally distills an average freshwater of 2 L/m2/day which is not sufficient to meet individual daily demand. As a motivation for productivity enhancement, a new model of solar water distiller has been experimented with under Thailand climatic conditions. Its structure is not like a typical solar still, the low-temperature brackish water was supplied from the water tank to the condenser tubes for condensation rate improvement. After making a turn, the brackish water was heated up in blackened receiver tubes by absorbing solar radiation, which leads to a temperature growth of the feed water. The high temperature of outlet water in the receiver tubes plays a role as an additional heat for brackish water in the basin, which will enhance the temperature of basin water along with the evaporation rate. Various water feed rates and a variety of water depths were studied for their effect on the performance of the proposed solar still. The experimental conditions consisted of 0.5 cm, 1 cm, and 2 cm of water levels and 0.5 L/h and 1 L/h of mass flow rates. As the water level decreased from 2 cm to 0.5 cm, the daily productivity was improved by 34%. Additionally, there is a 28% growth in output as the mass flow rate of feed water declined from 1 L/h to 0.5 L/h. Further remarkably, in comparison with a conventional solar still under the same level of water depth, the daily distillate yield of the proposed model improved double and 58.5% at a water depth of 0.5 cm and 1 cm, respectively.
Acknowledgments
This research was sponsored by the SUT Research and Development Fund of Suranaree University of Technology (SUT), Thailand.