Feasibility analysis and parameter optimization of organic steam to drive a MED system dealing with high salinity waste water

Abstract

It is important to select suitable heat resources to drive multi-effect distillation (MED) systems to process high salinity water. In this paper, a MED system driven by organic steam was studied. The feasibility of organic steam as a heat resource was firstly studied. The results indicated that the heating steam utilization (HSU) of a MED system driven by R123 and R600a was higher than that of a MED system driven by water steam. Additionally, key parameters of the MED system (including the effect number, the temperature of the organic steam and the temperature difference in the last effect) were optimized. The results showed that the mass of feed steam decreased as the effect number increased, which results in a higher HSU. In the MED systems with the same effect numbers, a lower mass of feed steam was needed when the temperature of the feed steam was higher. Lastly, the mass of the feed steam decreased gradually with the increase of the temperature difference in the last effect. Furthermore, the gas-water ratio (GWR) and HSU in the MED system with a higher temperature difference were higher than those when the temperature difference was lower.