Exergy Analysis and Optimization of Multi-effect Distillation with Thermal Vapor Compression System of Bandar Abbas Thermal Power Plant Using Genetic Algorithm

Abstract

Multi-effect distillation desalination system with thermal vapor compression is one of the systems of producing fresh water based on distillation desalination. This type of desalination system is one of the most appropriate and economic types of desalination systems for low to high capacities of seawater and brackish water in which evaporation and distillation have occurred in a vacuum and in temperature below 70 °C. This research provides a mathematical model in the steady-state conditions for multi-effect distillation desalination system with thermal vapor compression in Bandar Abbas thermal power plant in south of Iran. The genetic algorithm is used for maximizing the produced fresh water and minimizing total exergy destruction rate. Exergy analysis shows that the thermo-compressor and effects are the main sources of exergy destruction in the system (more than 80%). The actual operating data in summer and winter were used for the exergy destruction study. The results show that the exergy destruction in winter is more than summer. Parametric analysis for studying the effects of key parameters shows that increasing the top brine temperature leads to increase in the total exergy destruction of the system. The optimization of the system with two-target genetic algorithm causes distillate production to increase by 16.62%, and the total exergy destruction rate decreases by 3.58%.