Study On The Economical And Safe Operation Mode Of The Dongkuo Water Supply System Of Yumenkou

In recent years,with the gradual transformation of the social economy into high-quality development,the contradiction between supply and demand of water resources has become more and more prominent,and a large number of complex water supply systems have been built successively.Such projects often have the characteristics of large flow,high head,long pipeline distance and large fluctuation along the road.Due to the complexity of the water supply system,it also faces many technical problems in the process of operation.In practice,improper decision-making often results in waste of water and electricity,which makes it difficult to achieve the goal of economic operation and safe operation.Aiming at the technical problems of water supply system,focusing on the connotation of economic operation and safe operation,the main research contents are as follows:(1)Based on the characteristics of centrifugal pump and pump station head unit demand curve,and establish a single pump and centrifugal pump in parallel,the mathematical model of variable frequency pump working point,adopt the method of numerical simulation,study the steady state operation mode of the water supply system,to determine the pump power frequency and frequency of the pump parallel operation,such as working point,the study of economic operation mode for water supply.(2)Based on the determination of the working point of the pumping station,the efficient operation interval of a single pump and the efficient operation interval of the pumping station were proposed,and the optimal operation of the minimum power was studied.The economic operation model of the pumping station based on the minimum power was established,and the economic operation scheme of the pumping station was finally obtained.(3)In view of the shortcomings of the hydraulic calculation model of air valve,the concept of dynamic inlet and exhaust coefficient is put forward,and the function relationship between the inlet and exhaust coefficient and the pressure difference inside and outside the pipe is established.This paper studies the influence of multi-index value on inlet and exhaust coefficient and inlet and exhaust flow,makes up for the deficiency of air valve model calculation and practical application,and ensures the safe operation of water supply system.(4)In view of the safe operation of the water supply system of complex pipelines,based on the establishment of the boundary condition equation of water hammer calculation,the method of solving the characteristic line is used to provide a theoretical basis for the safe operation of the water supply system.(5)Combined with the engineering practice of the Dongkuo Water Supply System of Yumenkou,the working points of each station are determined,the economic operation scheme of the project is put forward,and the transition process of the water hammer in the accident shutdown of the project is checked by the dynamic inlet and exhaust coefficient of the air valve.The main conclusions are as follows:(1)The economic operation mode of the Dongkuo Water Supply System of Yumenkou is put forward,and the pump station power and unit water supply power corresponding to the water supply flow are obtained.(2)The function relation of dynamic inlet and exhaust coefficient is established,and the calculation result of the model is optimal when the multi-party index is 1.20.The improved hydraulic calculation model of air valve provides a theoretical basis for its further application.(3)Check the safety of the project under economic operation conditions,that is,the calculation of the water hammer transition process when the pump is stopped.