The Application Of PGA On A New Optimal Design Of Water Supply Networks

The optimal design of water supply networks is an important task of town water supply engineering. It has been broadly and deeply studied by many domestic and foreign scholars and many representative optimal theories and design methods have been advanced such as enumerating method, liner programming method, dynamic programming method, genetic algorithms(GA) and simulated annealing (SA) and so on.Firstly, the status quo, content and sense about the optimal design of water supply networks are introduced. Hydraulic theory of water supply networks and the theory and flow of optimization methods-GA are discussed.Then some optimal models of water supply networks are enumerated and some factors which can influence the optimal results are analyzed such as the efficiency of pump station, the temporal value of fund, the curve of water consumption and the coefficient of water supply energy and so on. Considering the electrovalence, the curve of water consumption and the reliability of water supply, this paper respectively sets up the model based on the maximal flux and the model based on the expectation flux. It takes yearly expenditure converting value and yearly cistern converting value as target function and takes continuity equation, velocity of flow and compression resistance of cast iron pipeline as restrictions and sets up the PGA model on optimal design of water supply networks. The whole colony is divided into some colonies and they have evolution independently. Selection operator, crossing operator, mutation operator and some parameters setting are advanced.Finally, the PGA model and the expectation flux are verified by application on engineering project. The model based on the expectation flux is more economical, and it can ensure the reliability as the maximal flux.