支管管径变化对枝状管网水锤压力的影响  

Influence of Branch Pipe Diameter on Water Hammer Pressure ofBranched Pipe Network

作　　者：石喜[1] 陶虎[1] 柴媛媛 李露 SHI Xi;TAO Hu;CHAI Yuan-yuan;LI Lu(College of Civil Engineering,Lanzhou Jiaotong University, Lanzhou 730070, China;Gansu Institute of Soil & Water Conservation Sciences, Lanzhou 730020,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]甘肃省水土保持科学研究所,兰州730020

出　　处：《长江科学院院报》2020年第10期76-81,共6页Journal of Changjiang River Scientific Research Institute

基　　金：国家自然科学基金项目(51469012);兰州交通大学青年科学基金项目(2016018)。

摘　　要：随着节水管网技术的大力推广,管网水锤问题变得日益突出。为了探讨管网中支管管径变化对管网水锤压力的影响,采用Pipenet软件对带有一个分支管的枝状管网在支管球阀突然关闭(工况1)和直管球阀关闭(工况2)2种操作工况下的水锤压力波动进行了数值计算,支管型号分别取DN110、DN90、DN75、DN63和DN50共5种;并采用理论方法分析了2种工况下最大水锤压力的变化规律。结果表明:随着支管管径的减小,2种工况下各自阀门处产生的最大水锤压力和管网水锤压力均呈增大的趋势,相比之下支管管径减小对工况1时的影响更大。理论分析表明工况1时最大水锤压力随支管管径减小而增大的主要原因是支管流速的增大;工况2时最大水锤压力随支管管径减小而增大的主要原因是反射回的降压波逐渐减小。研究成果可以为管网设计提供参考。The water hammer effect in pipeline has become increasingly acute with the development of water-saving pipe network technology.To investigate the influence of branch pipe diameter on water hammer pressure of pipe network,the fluctuation of water hammer pressure was examined via numerical computation using Pipenet software.Two working conditions were designed.One is to close suddenly the branch pipe valve(working condition one),and the other is to close the main pipe valve(working condition two).In both conditions,there is only one branch in the pipe network.Five pipe types(DN110,DN90,DN75,DN63 and DN50)were selected in the study.Moreover,the variation law of maximum water hammer pressure under the two working conditions was analyzed by theoretical method.Results revealed that the maximum water hammer pressure at each valve and the water hammer pressure on pipe both increased with the reduction of branch pipe diameter under the two working conditions;reducing the branch pipe diameter had greater impact on working condition one in comparison.Theoretical analysis showed that the main reason for the rise of water hammer pressure along with the recession of branch pipe diameter lies in the increment of flow velocity in branch pipe in working condition one,and the reduction of the reflected buck wave in working condition two.

关 键 词：支管管径 枝状管网 水锤压力 数值计算 理论分析 

分 类 号：S277.9[农业科学—农业水土工程]