Study On The Optimization Of Sewage Pipe Network In Jinan City

Water is a necessary condition for human life,and through human life,production forms a waste water discharge.Sewage network system is used to collect,transport sewage urban infrastructure,drainage system is an important part of the urban sewage treatment has an extremely important role and status.Sewage pipe network is a city underground artery,sewer system design is directly related to the effectiveness of urban water pollution control,affecting the urban ecological environment and living environment.Moreover,the construction of urban sewer network accounts for a large proportion of investment in construction of drainage projects,and the cost of sewer network accounts for 70% of the total drainage works.Therefore,it is very necessary for the sewage pipe network system to be optimized reasonably,which has good social,environmental and economic benefits.Jinan is also called "Spring City".Spring water plays an extremely important role in the historical development of Jinan.In the process of urban development,Jinan also faces the problem of sluggish construction of sewage pipe network facilities and destruction of aquatic ecological environment.The prevalence of urban sewage pipe network investment insufficient,design flaws,sewage collection rate is low and so on,resulting in a large number of sewage discharged into the river,the formation of black and smelly water body.This situation led to the further deterioration of urban water environment,Xiaoqing River,a serious pollution of ammonia nitrogen continues to exceed the standard,Jinan City,urban sewage pipe network system needs to be optimized.In this paper,based on the water pollution in Xiaoqing River Basin,and based on the solution of urban sewage network system in Jinan,the paper studies the urban sewage network optimization.First of all,through the detailed investigation of the status quo of the urban sewage network in Jinan,the problems existing in the sewage pipe network system in Jinan are analyzed.Based on the advantages and disadvantages of the drainage system and the actual conditions in Jinan City,it is determined that the rainwater and sewage diversion and drainage system will be adopted in the newly rebuilt areas of Jinan City and the old urban areas will be gradually transformed into the complete diversion system in combination with the renovation of the old city.After confirming the drainage system and drainage division,the plan of the sewage pipe network system layout of each sewage sub-district has been determined through the prediction of wastewater volume and the hydraulic calculation of flow rate..After confirming the drainage system and layout of sewerage network system in urban area of Jinan City,the direct optimization method was used to optimize the hydraulic parameters of sewer network.By setting objective function,constraints and design variables,a mathematical model of sewer network is established.In the optimization process of the sewer network model,the method of controlling the gradient and the flow rate is adopted,and the fullness is approximated by the dichotomy approximation of the flow velocity and the dichotomy approach gradient.The model design parameters are optimized and solved,Excellent layout design parameters.Through the analysis and verification of the optimization method,it can be concluded that the optimal design of the hydraulic network in the flow rate,slope,fullness and other hydraulic parameters after the optimization method is adopted can reduce the overall cost of the project by 4.21%.Based on the research results of the direct optimization of sewage pipe network,the first and third factory pipelines of Sewage Treatment Plant in Jinan were implemented.The design parameters of sewer network were optimized and adjusted by the direct optimization method.Through the economic comparison of the optimized project before and after,we can see that the cost of the optimized project is reduced by about 7.7%.After the implementation of the project,the pipeline runs safely and steadily,and the effect of pipeline water diversion is obvious.Every day,about 30,000 m~3 of sewage is transferred from one plant to the third plant,easing the sewage overflow in Xiaoqing River.Through the engineering example,the effect of the optimal design of sewage pipe network is confirmed,and the direct optimization method is easy to apply.The superiority in the optimal design of the sewage pipe network is reflected,which has good social and economic benefits.