Multi-Objective Optimization Design Of Urban Water Distribution Networks

The optimal design is a significant task of urban water supply engineering, playing an important role in economic development and improving living standards of people. It has great economic and social benefit to seek the optimal design programme that has the minimum cost, the highest reliability and the maxmum entropy to reduce investment and energy consumption of the water distribution networks under the limited project investment. Therefore the multi-objective genetic algorithm is applied to research the optimization design of urban water distribution networks.Firsltly, the present situation, background about the optimal design of water distribution svstems are introduced. The optimal design theory and optimal distribution systems are discussed, and the optimal model which is adopted in this thesis is tintroduced. The multi-objective optimization design model pointed out in this paper is consited of three objective functions, the minimum total converted cost of urban water distribution system, the maximum reliability and entropy of system. Based on the nodal available flow, from perspective of users to describe the reliability of the network, and analyzing the uniformity coefficient of water distribution by the entropy index.Then, the Nodomination Sorting Genetic Algorithms(NSGA) is discussed, and several fundamental conceptions of the Multiobjective Optimization is listed. NSGA algorithm is proved to be suitable and practical for the Multiobjective Optimization. Based on some problems, which discussed in the paper . According to problems, this paper solves the multibojective optimization model based on the interger encoding, random tournament selection, uniform Crossover and uniform mutation algorithms, after that, a method for selecting the solution set is presented. This paper gives some calculation and the process of collecting circuits with this method and the rationality and validity of the model is examined by an example.At last, Based on the optimal model theories and NSGA algorithm, a optimal design software called WDN_Analysis1.0 is developed. The optimal software has...