Leakage Components Research Of The City Water Supply System Based On Analysis

It is pay more attention to the leakage management with the expansion of the scale of urban water distribution system, as well as the safety of water supply and the increasing of economic requirements. Combination of the revision of water loss assessment standard of urban water supply system, it is very important to study the constituents of the leakage determination method of each part. Thus, it has very important practical significance that the technology is provided for water supply enterprises to carry out the water loss assessment and control.At present, there is still a wide gap about the leakage control level in domestic with the international advanced level. The International Water Association put forward a series of relevant methods and strategies about leakage control, and recommended standard water balance sheet as the master tool of leakage analysis. The corresponding specific measures were formulated by the calculating of water balance, the leakage of water was clarified, and the priority control objectives were found out. In domestic, it has become the industry consensus about the application of water balance, but it is one of the main problems how to combine the characteristics of China's water industry technology and management for application that needs to be solved. Meanwhile, it is also very important how to improve management and improve the system aimed at the problems found during the application process. In the study, the form of water losses was analyzed, respectively, by the revised water balance sheet using domestic water supply enterprises data. The current data of most companies cannot support the needed analysis, and it is difficult to achieve accurate leakage component analysis. Therefore, a need to guide and regulate the new industry standard is urgent.The water losses of water supply system can be decomposed into real losses, metering losses, and other losses. In which, real losses is caused by different forms of bursts, including reported leakage, unreported leakage and background leakage. The calculation method of reported leakage is more clear and uniform, and the influence weight of background leakage is very small. While, because of influencing factors are very much and estimation methods are different and lack of comparability, so the analysis of unreported leakage is much difficulty. In this study, six kinds of methods commonly used in estimating the unreported leakage are selected based on unreported leakages' morphological characteristics and influencing factors, and its applicability is analyzed separately from the theoretical and practical application. At the same time the flow rate estimation formula applicable to common porous leakage points was proposed referring to the foreign experience. Generally, water supply pipes buried in the soil that influenced by many environmental factors. The pressure and velocity is difficult to measure under experimental conditions around bursts. The study also use the FLUENT software analogue simulate the changes of velocity and pressure field characteristics, which can provide references to determine the parameters of the formula estimated reported bursts flow.Metering losses includes metering error losses of measuring appliances and measurement error resulting losses of water transfer. According to the measurement system characteristics of the water supply system, the metering losses of large water users(non-residential customers) have a large proportion of total losses, and the impact is also the greatest on the economic efficiency. In addition, with the increase of the rate of households look-up table, the total sub-metering losses of residential customers cannot be ignored, which also is the focus of leakage control. There are two types of field experiments designed in the actual water supply pipe network which includes situation meter series experiments with high-precision meter of large water users and total sub-metering error detection experiments of area residents, Through those two experiments, the meter error rate of non-residential customers and the total-branch meter error rate of residential customers were analyzed and calculated, respectively. The results provided test basis to determine the meter losses in water balance analysis.