Research And Application On Optimal Operation Of D City's Multi-Source Water Distribution System When Source Accident

The urban water distribution system(WDS) is an important city infrastructure,which plays an irreplaceable role in people's lives and social production. With the economic and social development,the safety of water supply is given more attention. However, the growing conditions of water pollution and many other uncertainties, lead to sudden water source pollution accidents occurred frequently, which has posed a severe challenge to the safety and reliability of water supply system. To improve the safety and reliability of water supplying,using muti-source water distribution systems become a trend. For sudden water source pollution accidents, many districts developed a number of contingency plans of measures. Among them, The active optimal operation of muti-source wter distribution system with water source sudden polluted is an important measure.In the traditional water supply network hydraulic model, the water flow of nodes is given by water demand,and is constant,so the traditional hydraulic model is difficult to simulate the water shortage conditions with water source polluted. For the shortcomings of the traditional hydraulic model,from the view of water flow of nodes, the water flow of nodes is divided into two parts of water actual consumption and leakage.Then the two parts are established with the relation of water pressure of nodes,and then the water supply network hydraulic model is constructed,which could simulate the conditions of water shortage condition. Combined the model, the expression of water supply meet rate is given under water source polluted, and the evaluation of water distribution system failure degree is developed using the comprehensive evaluation method. Though sollution analysis of an example network, it was found that this water supply network hydraulic model not only simulate the normal operation conditions accurately,but also is well capable of simulating the water inadequation condition with one water source polluted.For optimal scheduling of water distribution system with water source sudden polluted, three scheduling objectives proposed: (1)increasing the water supply meet rate of the key users in key periods, (2) reducing the leakage and increasing water consumption in the pipe network,(3) reducing pump operating costs. Taking the open state and the speed ratio of pump in each period as decision variables,the optimal scheduling model of water distribution system with water source polluted is constructed,and the model is solved by non-dominated sorting genetic algorithm.With the status of muti-source water distribution system of D city in North China, the water network hydraulic model was established at normal operating condition,which could simulate the water inadequation condition. After model calibration,the pressure and flow of nodes has high agreement with the monitoring data of actua l pipe network. On this basis, by assuming a sudden accident of one source pollution, the optimal allocation is solved under the accident. The result can provide guidance on scheduling decisions of the multi-source water distribution system with one source polluted accident.