Optimization of a Single Effect, Multi-Stage Flash Distillation Desalination System

摘要

Due to the necessity for chemically pretreating the saline input flow to a desalination plant, it is advantageous to recycle through the condensers a fraction of the brine leaving the plant to reduce the required saline input flow and thereby reduce pretreatment costs. Such a system is referred to as single effect or multieffect depending upon whether it has one or multiple recycle loops each in series configuration. The model for the present analysis is of the single effect type. It is the purpose of the analysis to develop a reliable mathematical model for the process and to present it in a form compatible with optimization via dynamic programming. It is felt that such an approach has the advantage that given a certain demand on the system the designer can optimize his cost performance index without having to fix the number of flashing stages or the amount of product flashed in each stage. To test the model and the optimization of that model a 50 million gallon per day system has been chosen. (Author)