A wind turbine driven hybrid HDH-MED-MVC desalination system towards minimal liquid discharge

Abstract

Global issues arising from water and electricity shortages have notoriously affected social life over the last decades. In this regard, using renewable energy sources like waste heat of wind turbines (WTs) to drive desalination systems can be a promising solution. However, high specific work consumption (SWC) for desalinating seawater from the waste heat of the wind turbine generator can hinder the application of this new emerging technology. To address this problem, a multi-effect distillation mechanical-vapor compression (MED-MVC) desalination unit is used to recover the brine rejected from a humidification-dehumidification (HDH) desalination unit operating by the waste heat of the generator of a wind turbine. To reduce the rejected brine, 90% of the rejected brine is added to the mainstream of the HDH desalination system. The devised system is evaluated in terms of the first and second laws of thermodynamics using engineering equation solver (EES) software. The proposed cycle with a seven-effect MED-MVC unit has a lower SWC than the same cycle with a reverse osmosis (RO) unit. It is noteworthy the freshwater rate increases by 18% at all wind speeds. Parametric study shows the SWC decreases from 33.41 to 21.27 kWh/m3 by enhancing the wind speed.

Keywords

• Waste heat
• Wind turbines
• Desalination
• HDH-MED-MVC
• Energy analysis
• Exergy analysis