Analyzing Complete Characteristic Curves Of Pump And Studying Of The Impact On The Hydraulic Transient Of Long-Distance, Large-Diameter, High-Lift Water-Delivery Pipelines

China's water resources are unevenly distributed in time and space, so regional water shortage is very serious.With the social and economic development, a small area of the water-transfer has been difficult to meet some regions water demand, an urgent need to build a number of long-distance water transfer projects to address regional water resources uneven distribution problem, such projects often adopted a large-diameter and high-lift water-transfer pipelines.The main objective of such distribution system to address serious regional imbalance in water distribution, in order to achieve the optimal allocation of water resources.Pumping accidents, if there is no reasonable and reliable water hammer protection, water supply system is likely to occur such destructive water hammer incidents. Pumping accidents by simulating the system of hydraulic transient, step-up to predict the water hammer can choose to provide evidence of water hammer protection. At present, the hydraulic transition process of pump usually using transformed by computer simulation of the compete characteristic curve. The compete characteristic curve of pump is to describe the hydraulic whole transition process of the pump operating condition of the important parameters, but all the known pump curve is relatively limited, for water hammer calculations have to apply the pump specific speed is similar to the whole characteristic curve. This will undoubtedly bring results of the error.In this paper, in northern Shaanxi, a large-diameter,long-distance and high-lift water transfer project as a example, using C++ language computer program to calculate water hammer analysis. Mainly analyzes the specific speed (Ns=128,80,530,950)complete characteristic curves of pump impacting on water hammer calculation results.Through this analysis shows that, in the absence of the selected compete characteristic curve of pump all cases, apply the specific speed pump the whole series of similar characteristics with the water hammer curve calculation, the error can be within the control of the calculated results can be used as a basis of selecting water hammer protection. Conversely, if applied to a larger difference than the rotation of different series of pump characteristic curves are all calculated on the greater impact of water hammer. Meanwhile, if the system occurs water hammer of cavities collapsing, apply different complete characteristic curve of the whole water pump water hammer calculations, will be completely different results.