Study On The Water Hammer Protection Measure Of Long Distance Water Gravitational Transportation Pipeline System

China is a country which has a serious problem of water shortage, and the water resourcesdistribution is extremely unbalanced, which means a little more from southern China to thenorthern. In order to avoid the limit of the locality economic development caused by theshortage of water resources, We has built20large scale and long distance water transferprojects since the reform and opening-up policy had published, such as the River Water ToNorth Diversion Project of Jiangsu, Yellow River diversion water transfer project ofShandong. With the number of inter-basin long distance water transfer project increasing bydegrees, the safety problem of pipelines stands out with each passing day, and the research ofpipeline safety protection in long distance water delivery projects come to be of great urgencydue to the frequently occur of domestic pipe explosion accident in recent years. Moreover, asa kind of efficient and energy-saving method of water transportation, the gravity flow shouldbe highly concerned.This paper first introduces the basic theory of water hammer and the currentcharacteristic line equation method of water hammer calculation, and on that basis, analyzesthe various flow regime and transformation in gravity flow pressure pipe, and goes into thecause for pipeline gas, the damage to pipeline from air sac movement and the best way toexclude the pressure gas in pipeline. In summing up of the characteristics of gravity flow, itexpounds different water hammer protect measures and its boundary conditions for gravityflow in detail at the same time. Meanwhile, it also put forward the viewpoint that it is moreclose to the engineering practice to calculate cutoff water hammer model than uncutout modelusing gravity water hammer definitely.Finally, taking the water hammer protect calculation of Baiyang river water diversionproject in Xinjiang Tacheng as an example, the paper makes a calculation of water hammerprotection to the gravity flow conduit of long distance, large diameter and multipleundulations, especially a necessary analysis and discussion on that whether the long distancegravity flow conduit needs a pressure-reduction pool to grading the pipeline pressure. In thelast place, it makes an arrangement on the water hammer protection measures which thegravity flow conduits of long distance, large diameter and multiple undulations generally take,according to the important degree. The research findings not only are instructive andmeaningful to this project, but also have a certain reference value of the selection of waterhammer protection measures in all this kind of projects.