Study For The Influence Of Pump Full Characteristic Curve Error On High Lift Water Transmission Pipeline

Along with the increase of high lift water transmission pipeline projects in our country,using the computer to carry on the dynamic simulation of pipeline operation condition,determining the risks of pump-stopping water hammer and proposing effective water hammerprotection measures have become an important content of guaranteeing the safe operation ofwater transmission pipeline system. Reliable numerical data of pump full characteristic curveis a crucial premise to accurate calculation of pump-stopping water hammer. Therefore, on thebase of simply introducing pump-stopping water hammer calculation theory, considered theengineering example and pipeline model, the influence of pump full characteristic curve erroron high lift water transmission pipeline was studied in this thesis, by the way of using analysiscalculation and making out of pump-stopping water hammer computer program withMicrosoft Visual C++.(1) Pump full characteristic curve is an important parameter to describe the pumpoperation condition. Because of the influence of friction, head loss and measuring factors,there will be error in the process of practical measurement and the numerical transformation.The theoretical, the maximum and the minimum value of full characteristic curve of the pumpwith80and127specific speed (Ns) were obtained by reading the pump full characteristiccurve picture and numerical transformation, and the maximum error range was determined bythe error analysis calculation of the three groups of discrete data.(2) Taking a high lift water diversion project in Shaanxi Yanchuan for example,pump-stopping water hammer was calculated by using the three groups of discrete data of thepump full characteristic curve numerical transformation. At the same time, the highest andlowest head envelope curves were analyzed to calculate the protection of pump station waterhammer and propose the best water hammer protection measures.(3) On the foundation of the fifth pump station in the water transmission pipeline projectbetween the Yellow River water intake and Yaodian water plant, two pipeline models wereproposed, which are showed respectively as follows: pipeline model with the water columnseparation and pipeline model without the water column separation. Pump-stopping water hammer was calculated by using the three groups of discrete data of the pump fullcharacteristic curve numerical transformation. Meanwhile, the different influence of pumpfull characteristic curve error on high lift water transmission pipeline between pipeline withthe water column separation and pipeline without the water column separation situation wasanalyzed.In the actual high lift water transmission pipeline projects, because of the complex andvaried terrain, water hammer due to cavities collapsing with water column separation is likelyto happen in water transmission pipeline. Then the pump full characteristic curve error willhave a great effect on the water transmission pipeline system. In order to guarantee the safetyof high lift water transmission pipeline projects, we should use the theoretical value of pumpfull characteristic curve in the pump-stopping water hammer calculation and take effectivewater hammer protection measures.