Study On Hydraulic Model Calibration And Fire Water Supply Capacity Evaluation Of Municipal Water Supply Pipeline Network

Municipal water supply network system is an important infrastructure of the city.It is known as one of the lifeline projects of the city.It not only provides water for people's daily life and production,but also undertakes the task of fire protection.The hydraulic model of municipal water supply network can monitor the information management and operation status of municipal water supply network.It is a direct and effective technical means for municipal water supply network design planning,operation management,optimal dispatch,risk prediction and fire assessment.The evaluation of municipal fire water supply capacity based on the hydraulic mo del of municipal water supply network is an extension of the research on the hydraulic model of water supply network.At present,our country is in a period of rapid economic development,building with different risk levels is constantly newly built,fire risk is constantly increasing,and the demand for fire safety is also increasing day by day.Therefore,strengthening the evaluation of the fire and water supply capacity of municipal pipeline network can not only protect the safety of urban production and life,promote the development of social and economic construction,but also lay a solid theoretical foundation for the future reconstruction and expansion of municipal pipeline network.The research direction of this paper is the construction of hydraulic model of urban water supply network,the verification of hydraulic model of pipeline network and the evaluation of fire water supply capacity of pipeline network based on hydraulic model.The main contents include:(1)Hydraulic model construction of municipal water supply network.The hydraulic model of municipal pipeline network is composed of five basic system components: nodes,pipelines,pumps,valves,reservoirs and towers.Modeling commonly used refers to the process of transforming practical engine ering problems into mathematical problems according to the basic theory of hydraulics and establishing equations to solve them.This part elaborates the hydraulic theory knowledge involved in the modeling process in detail,then compares and analyses several commonly used modeling software,and finally chooses WaterGEMS to build the hydraulic model of L municipal pipeline network,and makes a detailed analysis of the problems encountered in the modeling process and gives specific solutions.(2)Study on hydraulic model checking of municipal water supply network.Combining with the introduction,the advantages and disadvantages of current checking methods and intelligent algorithms are compared.Finally,the recessive checking method of node flow parameters based on genetic algorithm and MATLAB software programming are used to check the municipal pipeline network of L City.The results show that the checking method adopted in this paper solves the time-consuming and manual checking problems in large-scale municipal pipeline network.The disadvantage of inaccuracy and the reliability of checking results will lay a foundation for the application of the model in the evaluation of fire water supply capacity in the next step.(3)Study on the method of evaluating the fire water supply capacity of municipal pipeline network.This part introduces in detail the existing evaluation methods of fire water supply capacity of municipal pipeline network,including NFPA method,trial algorithm based on hydraulic model and Boulos method,and analyses the advantages and disadvantages of each method.The calculation of NFPA method is simple,but it needs a lot of manpower and material resources to ensure the accuracy,and may affect the normal operation of the pipeline network;the trial algorithm based on hydraulic model also has the problem of cumbersome and time-consuming calculation process;the Boulos method of index method has the problem of many iterations and limited application scope of commercial software;the index metho d can not evaluate the fire supply of specific hydrant joints.Water capacity has some limitations in application.Based on the above problems,this paper proposes a new method for evaluating the fire water supply capacity of municipal pipeline network bas ed on Newton iteration.This method converts the evaluation of the water supply capacity of municipal pipeline network into an optimization problem,and uses Newton iteration to solve the problem.It involves fewer parameters and has higher calculation efficiency.Taking the hydraulic model of Mianyang municipal water supply network as an example,the Boulos method is compared with the Newton iteration method proposed in this paper.The results show that the Newton iteration method proposed in this paper can more effectively evaluate the fire water supply capacity of the pipeline network.(4)Evaluate the fire water supply capacity of L municipal water supply network.Firstly,the basic principle,operation steps and setting of relevant parameters of WaterGEMS fire fighting water supply capacity assessment are discussed in detail.Then,taking L municipal water supply network in Yunnan Province as an example,the requirements of fire fighting regulations in China are introduced(the discharge of the most disadvantageous hydraulic municipal fire hydrant should not be less than 15L/s,and the water supply pressure should not be less than 0.1MPa from the ground)and relevant evaluation criteria.Secondly,all fire hydrant nodes of L municipal pipeline network are evaluated based on WaterGEMS software and Newton iteration method respectively,and the results show that the evaluation results of the two methods are similar.Finally,for the six areas where the evaluation results are poor,this paper presents the evaluation results of the two methods.This paper puts forward the corresponding solutions,which can provide reference for the future reconstruction and expansion of pipeline network and fire safety management.In summary,the research content of this subject has the characteristics of combination of theory and practicality,and provides new ideas for future research in the field of urban pipe network transformation and engineering design in small and medium-sized cities and towns.