Study On Control Technology Of Physical And Apparent Leakage In Jiujiang Water Supply Pipe Network

As one of the important municipal infrastructure,urban water supply network is indispensable in the modern city construction as well as social stability and development.Due to the corrosion,deformation and aging of urban water supply network,its leakage problems become more and more serious,which have already got widely concerns from water supply enterprises,government departments,the scientific communities and all sectors of society.So it is urgent to strengthen the control and research work of pipe network leakage.The present work chose the water supply network of Jiujiang City as the research object,and carried out some studies on the leakage monitoring,evaluation,control and management in order to establish a scientific supervision system for urban water supply network leakage in Jiujiang City,thus promoting the improvement of enterprise's benefits and the effective utilization of water resource.To figure out the main leakage composition and control direction during the process of traditional leakage assessment,the leakage current situation in Jiujiang city was estimated by water balance test method using the leakage rate as a technical indicator.The results indicated that in 2013 the leakage rate was 29.13%,of which the apparent leakage rate was 1.65%and the physical leakage rate was 27.48%,and the actual leakage amount reached 24.61 million m~3 per year.The control strategy for leakage was therefore identified as the physical leakage rate being primary and the apparent leakage rate being auxiliary.For the physical leakage control,the DMA community management mode was employed in this work.Based on this,the paper presented some management measures,including dividing water supply areas,installing electromagnetic and ultrasonic flowmeters,updating construction standards of valve well and water meter basin,and establishing the corresponding DMA management software system to monitor the minimum night flow,water supply pressure,and monthly water consumption,which could evaluate the network leakage accurately in water supply areas.In addition,combining with some other measures such as strengthen the leakage detection and network transformation as well as affiliated facilities management,the multi-layered supervision system was established to coordinately reduce the physical leakage.With respect to the apparent leakage control,according to the results of investigation on the measurement errors and metering efficiencies of all the water-meters in use in Jiujiang City,the water-meters with different dimensions were upgraded by various ways including elimination,periodic replacement and reselection so as to improve the measuring accuracy and stability.Also,by building a table management system for the full life cycle of each water-meter and developing the meter reading management system,the apparent leakage could be further controlled stably and orderly.By taking the above measures,the leakage rate in 2016 decreased to 24.44%,of which the apparent leakage rate was 1.27%and the physical leakage rate was 23.17%,and the actual leakage amount reduced to 20.17 million m~3 per year,exhibiting significant leakage control effect.