摘要
为解决新疆克拉玛依市大型灌溉管网关阀过程中的水锤和灌溉出流流量不均匀等问题,基于一维特征线法,利用Flowmaster软件建立管网水力模型,研究管网在不同阀门关闭规律下的瞬变流特性以及阀门开度扰动对管网流量均匀性的影响.研究结果表明:模型预测的相关水力特性与管网设计参数对比误差不超过8%,验证了模型的准确性.针对管网运行的瞬变水力特性,总阀采用20至60 min的不同总历时一阶段线性关闭规律,即使关阀时间长达60 min,管网管段仍发生空化现象;开展关阀总历时30 min和快关10 min、快关开度分别为65%,75%,85%等不同组合的先快后慢两段关闭规律,其中快关85%、慢关15%的关闭规律下,管网管段不会产生空化,且管道内最大水锤压力小于管道设计压力.针对管网压力波动引起的流量均匀性变化,通过阀门开度扰动仿真压力波动,阀门开度由100%到90%调节后,各支管流量下降比例平均值为0.079%,流量波动较小;各出水桩流量下降比例平均值为0.074%,克里斯琴森系数为0.9899,灌溉均匀性较好.研究结果可为大型灌溉管网的水锤防护及阀门开度扰动对管网流量均匀性分析提供一定的指导.
In order to solve the problems of water hammer and uneven irrigation outflow during valve closing of large-scale irrigation pipe network in Kelamayi City,Xinjiang,based on the one-dimensio-nal method of characteristics,a hydraulic model of pipeline network was established by using Flowmaster software to study the transient flow characteristics of pipeline network under different valve-closing laws and the influence of valve-opening disturbance on pipeline network flow uniformity.The research results show that the comparison error between the predicted hydraulic characteristics of the model and the design parameters of the pipeline network does not exceed 8%,which verifies the accuracy of the model.For the transient hydraulic characteristics of the pipeline network operation,one-stage linear closing laws with different total durations ranging from 20 to 60 min were adopted to control the closing process of the main valve in the pipeline network system.Even if the valve is closed for up to 60 minutes,cavitation phenomenon still occurs in the pipeline section of the pipeline network.Two-stage valve-closing law of fast closing followed by slow closing with the total valve closing duration of 30 min was studied,and the fast closing time is 10 min when the opening degrees of fast closing are 65%,75%and 85%,respectively.Under the fast closing opening degree of 85%and slow closing opening degree of 15%,there is no cavitation in the pipeline section,and the maximum water hammer pressure in the pipeline is less than the design pressure of the pipeline.For the flow-rate uniformity caused by pressure fluctuation of the pipe network,the pressure fluctuation was simulated by valve-opening disturbance.When the valve-opening is adjusted from 100%to 90%,the average reduction rate of the flow rate at the head end of each branch pipe is 0.079%with small flow rate fluctuation.The average decrease in flow rate at each outlet pile is 0.074%and the Christensen coefficient is 0.9899,indicating good irrigation uniformity.The research results can provide guidance for the analyses of water hammer protection and valve-opening disturbance on the flow uniformity of large irrigation pipelines.
作者
杨国苗
李小芹
唐学林
崔春亮
彭致功
张兴峰
封顶梁
YANG Guomiao;LI Xiaoqin;TANG Xuelin;CUI Chunliang;PENG Zhigong;ZHANG Xingfeng;FENG Dingliang(College of Water Conservancy and Civil Engineering,China Agricultural University,Beijing 100083,China;Beijing Water Supply Pipeline Network System Safety and Energy Conservation Engineering Technology Research Center,China Agricultural University,Beijing 100083,China;Xinjiang Institute of Water Resources and Hydropower Science,Urumqi,Xinjiang 830049,China;China Institute of Water Resources and Hydropower Research,Beijing 100038,China)
出处
《排灌机械工程学报》
北大核心
2025年第1期101-108,共8页
Journal of Drainage and Irrigation Machinery Engineering
基金
新疆维吾尔自治区重大科技专项项目(2020A01003-1)
国家自然科学基金资助项目(52079140)。
关键词
灌溉管网
特征线法
水锤
关阀规律
瞬变特性
灌溉均匀性
irrigation pipeline network
method of characteristics
water hammer
valve-closing law
transient characteristics
uniformity of irrigation
