摘要
确定重力流输水管道最合理的关阀时间需要考虑如下因素:一是管道的水锤压力不要过高,防止管道破裂;二是水锤压力不要过低,严禁管道沿线出现断流弥合水锤,防止出现负压压瘪管道;三是要有利于操作方便、保护设备。以北京市某南水北调配套工程为例,选择HAMMER软件模拟管道瞬变流,分析重力流输水管道关阀过程中的水锤现象。结果表明:关阀时间越长,管道最大压力越小,最小压力越大,水流条件越好。蝶阀关闭时间为50 s时管道最大压力达169.27 m,关闭时间为500 s时管道最大压力为65.18 m。在线性关阀时间不小于200 s时,管道沿线不产生负压,且最大压力小于管道的设计压力。综合考虑保护管道、操作方便、便于管理、保护设备等因素,确定蝶阀线性关闭时间为300 s。研究成果对重力流输水管道阀门管理和保护具有参考价值。
For determining the most reasonable valve closing time of gravity flow water conveyance pipeline,the following factors are necessary to be taken into account： Firstly,the water hammer pressure in the pipeline must not be too high to prevent pipe rupture; secondly,the water hammer pressure in the pipeline must not be too low and the occurrence of water hammer of cavities collapsing along pipeline is strictly avoided,so as to prevent the pipeline from being squished by negative pressure; thirdly,it must be favorable for convenient operation and equipment protection. By taking an ancillary works for the South-to-North Water Transfer Project in Beijing as the study case,the transient flow in the pipeline is simulated with the software—HAMMER,and then the water hammer phenomenon during the valve closing process of the gravity flow water conveyance pipeline is analyzed herein. The result shows that the longer the valve closing time is,the smaller the maximum pressure in the pipeline is to be,while the larger the minimum pressure is,the better the flow condition is to be as well. When the closing time of the butterfly valve is 50 s,the maximum pressure in the pipeline reaches to 169. 27 m and when the closing time is 500 s,the maximum pressure in the pipeline is to be 65. 18 m. When the linear valve closing time is less than 200 s,no negative pressure is to be there along pipeline,moreover,the maximum pressure is to be less than the design pressure. Under a comprehensive consideration of the factors,such as pipeline protection,convenient operation,easy management and equipment protection,etc.,the linear valve closing time is determined to be 300 s. The study result has reference value for both the protection and management of gravity flow water conveyance pipeline.
出处
《水利水电技术》
CSCD
北大核心
2017年第5期95-96,127,共3页
Water Resources and Hydropower Engineering
基金
基金项目:南水北调来水调入密云水库调蓄工程(NSBD-PT-MYTX-KS)
