Study On The Influence Of High Head Water Pipe Hydraulic Transients Calculation By The Numeralization Methods Of Fully Characteristic Curve Of Pump

In recently years, in order to improve resources shortage and uneven distribution in ourcountry, a large number of long-distance water delivery projects are in construction constantly.Most of the long-distance water delivery projects are with characteristics of large flow, longpipelines, high level difference and multi-undulate pipelines, especially for the high head andlong distance ones. No matter in trial or stable operation stage, the actual water deliveryprojects may suddenly have accident for various reasons, the most common and harmful onesare pipe explosion accidents caused by the sudden pump-stopping.Therefore, the moreaccurate and reliable pump-stopping water hammer calculation is the important theory basisof ensuring the safety of long-distance water delivery projects.The most important part inpump-stopping water hammer calculation is the analysis of fully characteristic curve ofpump,because accurate fully characteristic curve could describe the pump running conditionsand the pump with different specific speed has different fully characteristic curve. In thispaper, based on the theory of fully characteristic curve of pump, the different numeralizationmethods and comparison between them which is used for the pump-stopping water hammercalculation of the pump with specific speed lack of fully characteristic curve data isintroduced, and the influence of high head water pipe is focused on.1、The numeralization innovation methods of fully characteristic curve of pump and how toacquire discrete data WH、WM from the fully characteristic curve by the methods isintroduced;2、The principle of approximate calculation method, general formula method andclassification cubic polynomial method is introduced,and the coefficient in formula iscomputed.In actual calculation, we just need to plug the calculated specific speed data Ns ofthe pump into formulas;3、Combined with the three high head and long-distance water delivery project examples, byusing the three methods to have pump-stopping water hammer calculation,we studied theimpact of different numeralization methods on water hammer rising pressure in high head andlong-distance water delivery projects. Came to the conclusion, the discrete data WH、 WM calculated by differentnumeralization methods differs large,so the impact of different numeralization methods onthe highest pressure of water hammer is great.Therefore,we could use the classification cubicpolynomial method, general formula method to acquire the data in pump-stopping waterhammer calculation.