Leakage Analysis And Control Of Urban Water Supply System

Water supply network is the"lifeline"to ensure the normal operation and healthy development of the city,and plays an important role in urban construction.However,there is usually a difference between the total water supplied by the water purification plant or water distribution plant and the total water intake of urban water users,which is called leakage.At present,according to statistical data,the total leakage of water supply network in China in 2017exceeded 7.3×10~9 m~3,of which,the leakage rate of water supply network in 27 provinces and cities exceeded 12%of the national standard,and the leakage rate in 4 provinces and cities exceeded 20%.With the aging of urban water supply network,the leakage of water supply network is increasing.The leakage components of the pipe network include real leakage and apparent leakage.At present,a set of mature real leakage control strategies has been formed internationally,and the apparent leakage mainly occurs in the client.Because of its concealment and not easy to be found,the economic loss caused by the apparent leakage is far greater than the real leakage,which brings great trouble to the actual operation of the water supply enterprises.Therefore,it is necessary to strengthen the apparent leakage The study of leakage is of great practical significance.Because there are many reasons for the apparent leakage,this paper reveals the causes of the apparent leakage from many angles and all-round,and establishes the corresponding solutions to prevent and control the appearance of the leakage.The main results are as follows:(1)Measurement error is the main cause of apparent leakage.The control of water meter measurement error should start from the selection of water meter,including the accuracy of water meter,flow matching,installation and maintenance,online monitoring management and other aspects.The main control technologies include:1)the water meter should be selected reasonably,matched one by one according to the characteristics of the user’s flow;the error of water meter should be measured under the static flow,and the user should be combined with the processing software The dynamic error of water meter is analyzed by water consumption model,the characteristics of water meter are verified and analyzed,and the apparent leakage is reduced according to the quantitative data.2)The performance evaluation of water meter shall be carried out regularly to check the water meter that does not match the flow,so as to avoid the measurement error caused by too small or too large water meter caliber.The selection of water meter caliber shall be based on the size of water consumption,and the priority of replacing water meter shall be formulated gradually.(2)Water balance table can be used to quantify the amount of water leakage in the pipe network,which is an important means to analyze the pipe network leakage.In the process of making water balance table,the leakage links in the process of water delivery and supply are analyzed comprehensively,and the calculation method and evaluation index of the real and apparent leakage are obtained,and the DMA(District Metering Area)method is used to quantify the components of pipeline network leakage and calculate the apparent leakage water.(3)Illegal water use is an important part of apparent leakage.Illegal modification of water meter,illegal connection of pipe network,private connection of bypass,water stealing of fire hydrant and other illegal water use behaviors are important factors leading to the increase of apparent leakage.The calculation method of apparent leakage caused by illegal water use mainly starts from the causes of apparent leakage,analyzes the characteristics of each component and the corresponding methods,and analyzes the leakage in the whole region regularly and quantitatively by establishing different management areas.In view of all kinds of illegal water use,the corresponding control measures are proposed.It mainly includes:strengthen supervision and enterprise management,carry out staff business training;set up automatic alarm device;reduce data processing error;adopt online transmission technology,etc.(4)Through case analysis,it is found that timely modification and replacement of water meters,and elimination of illegal water use behaviors such as private connection of pipe network and fire hydrant stealing can reduce a large number of apparent leakage and economic losses of water supply enterprises.Therefore,the premise of managing and controlling the leakage of pipe network is to establish and improve the corresponding management methods and objectives,determine the key points of managing and controlling the leakage,formulate the management and control objectives and methods,adjust measures to local conditions,manage the apparent leakage in different regions according to the water use habits of different regions,so as to promote the relevant measures in a long-term and sustainable way,achieve the effectiveness and economy of the management and control,and provide the water supply enterprises with the prevention and control of the apparent leakage reference.