Design and optimization of an electrostatic fog collection system for water harvesting: Modeling and experimental investigation

Abstract

Electrostatic fog collection presents a promising solution for addressing water scarcity by recovering water from fog. This study proposed a multi-channel electrostatic fog collector that utilizes multiwire-to-plate electrodes. Through numerical simulations, the charging and migration mechanisms of fog droplets were revealed. Additionally, the influence of electrode structure parameters on the electrostatic fog collection process was analyzed. Results show that during the charging process, droplet charge rapidly approaches saturation near the wire electrodes. Moreover, the fog collection efficiency increases with an increase in working voltage, but the growth rate decreases gradually at high voltage. The wire interval and wire-plate gap determine the electric field distribution, which in turn affects the collection efficiency. The effect of wire interval and wire-plate gap on the electric field distribution could be categorized into three zones: the insensitive region, the weak influence region, and the strong influence region. The simulation results show that the optimal range of the dimensionless wire interval falls in the weak influence region, specifically in the range of 0.8 ≤ S/G ≤ 1.6, where S/G represents the ratio of wire interval to wire-plate gap. The experimental results demonstrate that the electrostatic fog collector within this range can achieve a water collection rate of 123.7 g/min at 20 kV. The corresponding performance coefficient is 388.7 kg/kWh, which exceeds the 200–333.3 kg/kWh performance coefficient of commonly used commercial reverse osmosis desalination technology. These findings provide direction for the practical application of electrostatic fog collection technology.