Description
A new configuration of a solar still desalination system that uses a Fresnel lens as a solar energy collector was developed. The system consists of mainly a Fresnel lens to capture solar energy and a 4 L reactor for water evaporation. Water vapor condensation was designed to happen externally, and characteristics of condensed water were analyzed. The study was conducted in San Diego, California, United States, and seawater was collected from Coronado ferry land, CA. The aim of this experimental study was to investigate the feasibility of seawater desalination with Fresnel lens and enhance the efficiency of the system. The effect of following variables on the efficiency of the system and water evaporation were studied: 1) varying the volume of feedwater in the reactor, 2) using different doses of activated carbon and a steel plate in feedwater, separately as solar energy absorbers, 3) the effect of diluting the feedwater on evaporation, and 4) the effect of time on the evaporation rate. The best performance of the system was achieved when 8 g/L activated carbon was added to the feedwater. The results show an increase in the water's evaporation and efficiency of the system by 25.5% and 10.4%, respectively. Moreover, it was observed a 31.7% enhancement in the efficiency of the system, using 2.5 L of feedwater. Having more total dissolved solid (TDS) in the feedwater results in more evaporation due to the ability of the particles to absorb solar energy and transfer it to water. Lastly, the time-evaporation graph was linear, meaning the evaporation rate of feedwater remained constant in an experiment with a duration of 195 minutes. The results of this study show that the proposed system is reliable for desalinating seawater to produce freshwater.
