空气罐与超压泄压阀联合水锤防护特性  

Water hammer protection characteristic of combined air vessel and overpressure relief valve

作　　者：李楠 张健[1] 石林 陈旭云 张小莹[2] LI Nan;ZHANG Jian;SHI Lin;CHEN Xuyun;ZHANG Xiaoying(College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing,Jiangsu 210098,China;College of Hydraulic and Civil Engineering,Xinjiang Agricultural University,Urumqi,Xinjiang 830052,China)

机构地区：[1]河海大学水利水电学院,江苏南京210098 [2]新疆农业大学水利与土木工程学院,新疆乌鲁木齐830052

出　　处：《排灌机械工程学报》2020年第3期254-260,共7页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家重点研发计划项目(2016YFC0401810);江苏省研究生科研与实践创新计划项目(SJCX180175)。

摘　　要：提出了一种空气罐与超压泄压阀联合设置的停泵水锤防护方案,并基于瞬变流计算的特征线法建立了空气罐、液控蝶阀、超压泄压阀等边界条件的数学模型,模拟了停泵工况下系统的压力变化过程.结合工程实例,对比分析了空气罐单独防护、空气罐与两阶段关闭泵后液控蝶阀联合防护以及空气罐与超压泄压阀联合防护对停泵水锤的影响.在空气罐体型一定时,对超压泄压阀的启闭规律进行了敏感性分析.计算结果表明,空气罐与两阶段关闭泵后液控蝶阀联合防护方案对输水系统正负水锤防护均不利;而空气罐与超压泄压阀联合防护方案对输水系统正负水锤均有较好的防护效果,与空气罐单独防护方案相比,泵后高压管段最高压应力由1.343 MPa降至1.087 MPa,在满足承压标准1.2 MPa的基础上安全裕度提高了9.4%,空气罐体型也由200 m 3缩减至160 m 3.超压泄压阀应在5 s内开启至全开度,且开启后持续时间应接近1个相长.A water hammer protection scheme,i.e.combined air vessel and overpressure relief valve installation,was proposed,then the mathematical model for the whole system including air vessel,hydraulic control butterfly valve and overpressure relief valve was established based on the method of characteristics to simulate the transient pressure variation process in the system during pump stopping period.Based on a specific water supply project,three protection measures,such as single air vessel scheme,combined air vessel and hydraulic control butterfly valve scheme and combined air vessel and overpressure relief valve scheme,were assessed in terms of water hammer effect during pump stopping period.Specially,a sensitivity analysis was carried out on the opening and closing rules of the pressure relief valve as the shape parameters of the air vessel volume were fixed.The results show that the combined air vessel and hydraulic control butterfly valve scheme is unfavorable to positive and negative water hammer protection,and the combined air vessel and overpressure relief valve scheme has a good effect on both positive and negative water hammer protection.Compared with single air vessel protection scheme,the maximum stress in the high-pressure pipe wall is decreased from 1.343 MPa to 1.087 MPa,and the safety margin is increased by 9.4%.The volume of air vessel is reduced from 200 m 3 to 160 m 3.The overpressure relief valve should be opened fully within 5 seconds,and the duration after opening should be close to one phase length(the time for traveling one wavelength).

关 键 词：长距离供水工程 停泵水锤 空气罐 正水锤防护 超压泄压阀 液控蝶阀 

分 类 号：S277.9[农业科学—农业水土工程] TV674[农业科学—农业工程]