Heat and Mass Transfer Analysis of a Water and Solute Separation System: Using Solar Thermal Energy for Water Desalination

Abstract

A concept and the associated device of thermal-driven water treatment to fully separate water and solute have been proposed. The device is integrated to a conventional multi-effect-distillation water treatment system to achieve high energy efficiency and 100% water extraction using high temperature thermal energy. In the water treatment system, water for reclamation is sprayed into droplets which fall into hot, dry air and creates very effective convective heat transfer between water droplets and hot airflow. During the heat transfer process, water is vaporized for pure water collection while the crystallized solute from the reclamation water settles down to the bottom for collection. The current study investigates the energy consumption versus water treatment in the system, the correlation of the size of droplets and the temperature of hot air, and the mass heat distribution in subsystems or devices. Results from the study provide important guidance to the design of such a water treatment system.