Research On Failure Forecast And Application In Water Supply System

Water distribution system is one major infrastructure of cities, and water network is an important part of the system. So it is an important subject that improving the security, cutting down the rate of accident and shorting the repairing periods of water network.Here, conducting an assessment of the threat of its system using markov latent effects (MLE) modeling from the point of system security. Threat assessments were to serve as a guide to the water utility by providing a prioritized plan for security upgrades, modification of operational procedures, and policy changes to mitigate risks. The process was intended to be a dynamic one in which the utilities review their vulnerability assessments periodically to account for changing threats or changes to the water system.We have obtained that the relationship between the failure rate of the network and pipe diameter is multinomial from the optimization of the design point, which overcome the disfigurement of the the qualitative analysis for reliability in optimizing design in the past, so that the factors relatived to the objective function may be considered more completely, the optimization results of the water distribution system may be more veracity. Giving one criterion about the pipe replacement from the pipe newel point, that is threshold break rate. Optimal replacement times are obtained by equaling the threshold break rate and the rate of occurrence of failure (ROCOF) and the hazard rate functions. The water utilities can replace the pipes according to this time. We also have one study on the rechlorination and on-line monitoring combining with the contamination event of songhua river.This study must be one strength power for the safeguard of the water in water distribution system. The level of management of the water utilities can be improved to be one new period.