Research On Optimal Operation And Safe Operation Of Pumping Station In Complex Water Supply System

Water resources in China are not evenly distributed in time and space.,and the contradiction between industrial water and agricultural irrigation water is becoming more and more serious.Therefore,how to make the rational use of water resources,to solve the regional differences in the distribution of water resources and alleviate the contradiction between supply and demand of water resources has become a hot issue.Water diversion project is an effective way to solve these problems.With the construction of water diversion project,the traditional water supply engineering has become complicated.The complex water supply system refers to the construction of water resources optimal allocation of inter basin coordination,multi sources and multi objectives,multi user water diversion project.The system is generally composed of water source engineering,pumping station engineering and water conveyance project.It has many characteristics,such as many water sources,wide cross regions,many pumping stations,long distance from single stage pumping stations,high water head and large flow volume.At the same time,the complex level of water conveyance system in the operation of the relationship between stations,traffic has strict requirements,often due to pumping station on the lower level betweenthe flow mismatch occurred or abandoned water cut-off,may lead to running disorder,energy waste,and water hammer accident,cause economic losses.Because the cascade pumping station water supply project has strong representativeness and many operation theory and technology problems in the complex water supply system,so the paper takes cascade pumping station complex water supply system as the research object,mainly studies the optimal operation and safety operation of complex water supply system.On the basis of previous research results,based on the theory of pump similarity,a theoretical calculation and analysis of various matching conditions of start-up stations for variable speed regulation of cascade pumping stations is carried out.By establishing the mathematical model of water hammer calculation,the hydraulic transient process of pumping stations is calculated,and the protection measures for water hammer are put forward.Combined with the water supply system of Zhang Feng reservoir in Shanxi Province,the research on optimal operation and safe operation of complex water supply system is carried out.The main contents are as follows:(1)The same type of pump speed,the same type of pump variable speed pump operating point,pump efficiency solution.(2)According to the running characteristics of the water supply system,the method of variable speed adjustment is adopted to achieve the balance matching of the flow of the cascade pumping stations.Aiming at the highest efficiency of the water supply system in the cascade pumping station,the optimal dispatching measures for the water supply system of the Zhang Feng reservoir are put forward.(3)The establishment of mathematical model of hydraulic transient process under different boundary conditions,and the model solution.(4)According to the established steady state mathematical model of pump,the mathematical model of pump speed regulation and the mathematical modelof hydraulic transients,the programming language and database are applied to develop the water supply system dispatching analysis and calculation software.(5)Taking the Zhang Feng reservoir water supply system as an example,the numerical simulation of pump station steady state and cascade pumping station complex conditions(the combination of different start-up numbers and frequency conversion units)is carried out,and the hydraulic transient process of pumping station is simulated.It provides technical support for the optimal scheduling and safe operation of the system.