Design Of Heat Integrated Water Networks Considering Non-isothermal Mixing

Water and energy are important resources to the survival of human. Shortage of water and energy has caused widespread concern all over the world recently. Energy-saving emission must be carried out to solve such problem. Design of water network and heat exchanger network synthesis method has made considerable development. But study of heat integrated water network is defective. Based on the research background, this paper has finished the following research work.Based on analysis and modeling of multiple-contaminants water network, solving strategies with improved particle swarm optimization (PSO) is put forward. The minimum quantity of fresh water is taken as the optimization goal which is solved by using inlet-outlet concentration constraints and penalty function. The results of two examples showed that the proposed methodology has the applicability of attaining ideal effects in the design of water network.Based on analysis of stage-wise superstructure of heat exchanger network proposed by Yee and Grossmann, split and non-isothermal mixing of streams is considered to make the problem realistic. An improved simultaneous synthesis model of heat exchanger network containing more feasible structures is proposed. An improved PSO optimization is proposed for optimizing such system. The results of two typical cases show that the proposed methodology has the applicability of attaining ideal effects in heat exchanger network. In addition, the superstructure adopted by this paper contains situation without split to guarantee the optimal solution.A new integrated optimization method for the minimization of energy and water in multiple-contaminants system is proposed in this paper based on design of water network and heat exchanger network. Non-isothermal mixing inside unit operations between freshwater and reuse water is considered. The mathematical model of multiple-contaminants water network is improved. An improved PSO optimization is proposed for optimizing an example. Comparison of consequences shows that the optimized network is simpler and2.4%of annual cost can be saved, indicating the feasibility and effectiveness of the above method.