Study On The Threshold Definition Of The Pipe-broken And The Layout Optimization Of The Pressure Measuring Point For The Urban Water Supply Pipe Network

As the principle infrastructure,being used to provide residents with basic things needed for life and ensure industrial production,the supply pipe's safety and reliability are the precondition for the whole system to operate smoothly.However,some safety accidents,such as tube explosion happening frequently,result in lowering water efficiency,blocking production living and causing huge loss of property.And what cause those problems are leaks,rough judgment method and tube explosion not being detected in time.The paper has taken downtown area of Shanghai city as an example,proposing a judgment way of the pressure drop and the pressure of measuring point based on the statistics and optimizing some influencing factors,such as holidays,comprehensive risk of pipe network,temporary hydraulic facilities works and the temperature.After calculating and analyzing those statistics with that method,it can be found that pressure measuring points' unreasonable layout location of a city has a great impact on leak accidents and detection efficiency.Therefore,under this situation,through optimization of location and layout of pressure point based on genetic algorithm and clustering partition,provides an accurate and efficient determination method for the leakage detection of the water supply system.From a very start of the leak and tube explosion accidents' records in Shanghai city since 2011,this paper has calculated and analyzed the regularities and relevance within those factors.Because there is not much of the data samples of large-scale tube explosion,the paper has used old data of each pressure measuring point to calculate threshold based on the statistics.Also it has ensured the threshold criteria of leaks and tube explosion.Meanwhile,considering some elements,such as the holiday,comprehensive risk of pipe network,temporary hydraulic facilities works and the temperature,it has adopted the way of AHP analytic hierarchy process and BP neural network to analyze it.On this basis,it has updated the scope of pressure threshold to make the judgmental condition of leaks and tube explosion much more refined.Among the offline analyze of leaks and explosion of Shanghai city in 2016,there were 182 production accidents,within which there were 121 accidents not being reflected by the pressure data and most of which being difficult to be judged.Besides partial leak accidents,an insufficient number of pressure measuring point and the unreasonable layout location are also significant reasons leading to the lack of the water pressure fluctuation when leaking and tube explosion happens.Based on this,the distribution of water supply network and pressure measuring point layout in Hongkou District of Shanghai city has been analyzed and optimized.On the basis of simulation model of Hardy cross hydraulic pipe network,use improving genetic algorithm whose objective function are number of associated nodes and total flow rate to execute iterative optimization,and select different number of pressure points to test algorithm results,considering the existing pressure measuring points layout and economy principal,this paper has taken the Hongkou district as an example and has proposed a feasible scheme of the allocation and adjustment of pressure measuring point.Finally,using the K-means and DBSCAN basing on the water pressure association to make a smart partition and improve the economy and reliability of water supply network.In the end,it can provide a division of the neutron region in the target region to access to a higher pressure's association and a closer location in each neutron region,which are convenient to manage by people,then managers can find a region being roughly affected by an emergency immediately and arrange the follow-up work.