Study On Leakage Hydraulic Characteristics Of Municipal Water Supply Network

In this paper, the hydraulic characteristics of pipe flow with leakage were systematic studied. A simulated lab-scale environment, pipe section experiments and water distribution system experiments, were set up. By parallel experiments under normal and leakage they were systematic studied and a leakage hydraulic model of water distribution system was established, which provided theory for the leakage detection and control.Firstly, the relation between leakage area ratio and leakage was validated with Exponent Model. For the function characteristics of pipe, the leakage area ratio was used for characterizing the level of leakage first, and the relation between leakage area ratio and leakage was analyzed in addition. Pressure and leakage area ratio were the most important factors in leakage quantification, in comparison with pipe flow quantity, and the way of outflow. A"S"Model was established innovative in this paper, which embody both pressure and leakage area ratio by synthesis, and the physics meanings and the law of its change of the parameters were analyzed.Secondly, based on the hydraulics of pipelines, a new concept"leakage head loss"was proposed, and a hydraulic model of water supply network was established. With this model, it is expected that the mathematic representation and the law of pressure change can be find with leakage. Farther the validity and localization of the pressure data as the criterion of leakage detection were analyzed. By pipe section experiments and water distribution system experiments, the hydraulic characteristic of pipe flow was analyzed from flow and pressure tow points of view. The experiment and simulation results showed that"leakage head loss"model surpassed traditional hydraulic analysis.Finally, according to similarity theory of pressure flow, a pipe network distorted hydraulic model was done, then the two states (with or without leakage) were analyzed respectively. The feasibility and applicability of normal and distorted similitude were confirmed by simulation tests. The specific method and advised value of simulate ratio of pipe network model was commended by inverse analysis.