Study On Technology Of The Water Hammer Protection Of Large Elevation Difference And Long Distance Water Gravitational Transportation Pipeline

Since entering the new century,with the continuous development of social economy,theurban scale expands unceasingly,as the city of the growing demand for water.But most of thearea of surface water are pollution and ground water levels are fall increasingly serious inurban water shortage,in order to meet the needs of population growth and urban developmenton consumption water,long distance water transportation project became a lifeline of theurban people’s livelihood project,it has become an important measure to solve the problem ofurban water shortage.As time goes by,the water transportation project are more and morecomplex,capacity is more and more big,long-distance water transportation is longer andlonger,Such as the project have been completed or under construction in China:Dongshenwater supply project,Yin luan ru jin engineering, the Yellow River to Wanjiazhai,Xi ’an heihewater project,the Yellow River to Qingdao,The eastern route of south-to-north water diversionproject.In the foreign country,High plain water project in American,Lenin the karakum canalin the former Soviet union,Snowy mountains engineering in Australia,And the planed project,Yin han ji wei water in Xi ’an,The middle and westen line of the south-to-north water transferproject,Bailong river water transfer project in Gansu province,Lake Baikal water transferproject between Russia and China,etc.However long distance water transportation projectinfluenced by various factors,in order to meet the requirements of water,most of the longdistance water transportation project of interbasin Water diversion,and great gradientvariation,and it is likely to occur such water hammer incidents.When it happens,the waterpipe of the water hammer pressure will drop,the local position possible breathe air in pipeline,release air to pipeline,so that liquid water will occur gasification phenomenon and cut-off andclosing water,When the water hammer pressure may also occur high pressure cut-off andclosing water hammer,water hammer accident makes the piping system can’t normal running,the water pipe burst accident is likely to produce in long distance water transportation project,this accident will cause huge social and economic losses,and influence to regional watersecurity and steady social and economic development.In order to reduce transportation cost ofwater in the long distance water transportation project,when conditions the limited of the locallandform,the gravity flow water transportation project are more and more.So study ontechnology of the water hammer protection of large elevation difference and long distancewater gravitational transportation pipeline has become an important hot topic in the field ofwater transportation pipeline system nowadays. This article comprehensively describes the general situation of water hammer problemsresearch both at home and abroad,the basic principle of numerical calculation of waterhammer and the method of computer analysis of gravity water hammer protection technology,and booster of air movement in pipe is do brief explanation,harm and exhaust pipe,throughthe water pipe hydraulic transition under each state conditions were analyzed,and establish agravity flow multiple boundary conditions,a mathematical model of water hammer in thesystem to list the large elevation difference distance gravity flow water transportation pipelinewater hammer protection boundary conditions.Through three different types of large elevationdifference distance calculation of gravity flow water transportation project analysis.Arrivingat the effective measures of large elevation difference and long distance gravitational flowpipeline water hammer protection.This paper figure the city industrial park water supply project in Atushi,Yangling watersupply project in Shaanxi province,Yin Shi Ru Bai water supply project as an example,itconducted under a variety of combination plan of the water hammer calculation,and usingC++language to write the program code and using the computer run results,the output usingthe Excel spreadsheet visual representation,according to the solutions of the water hammerpressure is analyzed and calculated results and the valve control time,it demonstrated to thewhole water supply pipeline water hammer happened situation,and comprehensive putforward reasonable water hammer protective shut valve open valve, inlet exhaust valvecontrol time setting advice,pipes,water hammer protective equipment and parameters such aslocation,project final summary recommendations are drawn.To three practical engineering haspractical guidance to the safe and stable operation,also for construct the similar projects underthe condition of other large elevation difference and long distance gravity flow watertransportation pipeline water hammer protection research has certain reference value in thefuture.