Calculation And Study On The Transition Process Of Chuhe Quaternary Station Water Conveyance System In Simashan

The Chuhe fourth pumping station main canal project in simashan is one of 150 major water conservancy projects to be promoted by The State Council from 2020 to 2022,its total investment is 2.24 billion yuan.The project’s beginning is the outlet of the Chuhe 4th pumping station in simashan and the end is the inlet pond of Jiangzhuang pumping station.Its purpose is to divert river water into Jiangxiang reservoir,meet the irrigation water of farmland along the line,and at the same time provide production and living water for Dingyuan County.In order to ensure the safety and stability of the project operation,this paper establishes a mathematical model,calculates the transition process of the system,and obtains the water parameters under various operating conditions of the system,which has certain research significance for ensuring the safety of long-distance pressurized pipeline water delivery system of the cascade pump station.In this paper,1D characteristic line method is used to calculate the pipeline water hammer and the pressure inside the pipeline.Based on the characteristic line equation calculated by the water hammer and the basic equation of unsteady flow,instantaneous working conditions are calculated and analyzed to obtain the pressure along the pipeline and other data.The water level information was obtained by calculating the free surface and water level of each part of the system using 3D OpenFOAM.The 3D calculation was based on the Navier-Stokes equations.The fluid volume method(VOF)was used for free interface problems and the finite volume method(FVM)was used for spatial discretions.In the calculation,it is necessary to calculate the result of constant flow first as the initial value and then carry on the calculation of transient flow.In this paper,1D and 3D mathematical models are established,and the structure and construction of the model are elaborated.In the calculation,the results of the 3D calculation of the free surface water level are sorted out and used as the condition basis of the 1D calculation,and the 3D calculation can calculate the transition situation of bright full flow.Therefore,the two algorithms complement each other and jointly calculate the data of the system transition process.The results show that the method is feasible and can calculate the transition process well.In this paper,the numerical simulation calculation of the main canal project of the quaternary station of the Chuhe River in Chaisan Mountain is carried out.Because of the long whole course of the pressurized pipeline,the large conveying flow,and the upstream and downstream pump stations,the normal opening and shutdown of the pumping station units in the calculation will cause the change of hydraulic parameters such as the water pressure in the pipeline,which will seriously affect the safety of the pressurized pipeline.At present,there are few researches on long-distance pressurized water delivery in cascade pump station,and the protection of water hammer in this project mainly depends on the existing regulation well and the opening and closing rule of gate.Therefore,through the calculation of this paper,the combination of different opening and closing rules of the gate is compared,and the opening and closing rules of the gate are given to make the system operate safely under different operating conditions,and each free liquid level is monitored to prevent overflow accidents.The model calculation method established in this paper has certain research significance to ensure the safety of long-distance pressurized pipeline water delivery system in step pump station.