Analysis On The Hydraulic Transients In The Pumping Stations Of Hongsibao Irrigation Area

In pressure pipeline of pumping water supply system, hydraulic dash (namely , water hammer) occurs frequently because of sharp variation of velocity of flow, which often destroy the structure and property of the system, and make it impossible to work normally, even cause serious project accidents.Carry on analytical researches to the hydraulic transients in the water-carriage systems of pumping stations , their purposes are for discovering the hydraulic and mechanical characteristics in the water-carriage systems of pumping stations when various hydraulic transition processes occur probably, and looking for the reasonable control methods and the technical measures of improving these dynamic characteristics in order to improve pumping stations technical and economic level and circulating stability.For this, this paper researches and computes the hydraulic transients in pumping stations which is combined with pumping stations of Hongsibao irrigation engineering in Ningxia , the main inside are as follows:The fundamental water hammer theories are described in detail in the paper. Adopting method of characteristics accomplishes the numerical calculation on water hammer. Boundary condition of single water pump, identical or different type water pumps in parallel and butterfly valves of two staged closure procedure, air valves one-way surge-chambers are separately established. And the solutions of all the boundary conditions are studied, then programming the corresponding fortran computer programs, the butterfly valves application scopes , the excellent closure process are also researched .The combination of butterfly valves and inertial flywheel or surge-chambers is an effective method to control suction press problem in pipes, segmentation of head conduit is discussed. then improving the method of adjusted wave speed.Finally, analysis and calculation on hydraulic transients in the five pumping stations of Hongsibao irrigated area in Ningxia are performed, then the credible and safe, economic and reasonable water hammer protection measures are achieved in order to ensure pumping station system in safe operation. Law of similarity of water pumps is analyzed and examined through experiments.when the rotationl speed declines to the 26% of rated rotationl speed , the varieties of the discharge and the head still matches the Law of similarity that extends the scope of application of the Law of similarity.then,putting forward further researched problems in hydraulic transient in pumping stations.