Effect of nanofluid on the performance of humidification-dehumidification (HDH) desalination system

The small-scale desalination system known as humidification-dehumidification (HDH) operates on the principles of low-grade energy compatibility and simple design. The air in a bubble column becomes more humidified due to a combination of factors such as the liquid's height, thermophysical properties, air mass flow, and flow characteristics like bubble size. The designed HDH unit can be utilized to provide cooling water with low conductivity to reactors. An experimental setup and a theoretical model are developed to study the Humidification-Dehumidification (HDH) system's performance in a co-current direct-contact condenser spray column (CDCC). The designed HDH unit in the present study can be utilized to provide cooling water to the reactors. A novel use of nanofluid is introduced for enhancing the humidification of air in bubble columns. The addition of copper oxide nanoparticles to water-base fluid to form nanofluid in the bubble column humidification can increase the thermal conductivity and the viscosity of the suspensions. The impact of copper oxide nanofluid (CuO, 99%, 40 nm) in the bubbling column and air temperature were studied. The experiment's findings indicate that, at a humid air temperature of 45 °C, the condensate flow rates are nearly twice as high when utilizing CuO-water nanofluid as when using water. With nanofluid, the average product from HDH is higher than with water, around 34% in theory and 29% in experiment. The inlet temperature of hot humid air has a significant effect on the condensate product. When the temperature of humid air rises from 45 to 70 °C, the product increases more than four times at constant mass fluxes of cooled spray water and hot humid air. Results show that, for various humid air outlet temperatures, the nanofluid raises the absolute humidity of the humid air in the bubbling column filled with CuO-water nanofluid. When using nanofluids instead of water, the HDH system's effectiveness is improved by 4% in humidifiers and 8% in dehumidifiers. There is good agreement between experimental measurements and theoretical predictions for the HDH system.