大变幅流量下重力流系统末端调流阀流量特性选型研究  

Study on flow Characteristics Selection of the End Control Valve of gravity flow System with Wide-range Variation flow

作　　者：童保林 李直权 李玲玲 阳雯 顾世祥 刘志勇[3] TONG Bao-Lin;LI Zhi-quan;LI Ling-ling;YANG Wen;GU Shi-xiang;LIU Zhi-yong(Yunnan Institute of Water&Hydropower Engineering Investigation,Design and Research,Kunming 650021,Yunnan Province,China;Yunnan Water Conservancy and Hydropower Engineering Technical Evaluation Center,Kunming 650021,Yunnan Province,China;School of Power and Mechanical Engineering,Wuhan University,Wuhan 430072,Hubei Province,China)

机构地区：[1]云南省水利水电勘测设计研究院,云南昆明650021 [2]云南省水利水电工程技术评审中心,云南昆明650021 [3]武汉大学动力与机械学院,湖北武汉430072

出　　处：《中国农村水利水电》2024年第10期188-192,199,共6页China Rural Water and Hydropower

基　　金：国家重点研发计划项目(2021YFC3000205-06);云南省高层次人才及创新团队专项(2018HC024)。

摘　　要：针对大变幅流量下重力流系统末端调流阀流量特性的选型问题,基于一维水锤理论,采用数值模拟方法,结合工程实例,从调流阀流量特性对稳态运行开度的影响、调流阀关阀水锤最不利流量工况确定、调流阀流量特性对关阀水锤的影响等3个方面,对线性型、抛物线型和等百分比型等3种流量特性进行比较研究。结果表明:①等百分比型流量特性更有利于调流阀在小流量工况的稳定运行。该工况下,等百分比型调流阀的稳态运行开度更大,可避免因开度过小导致的汽蚀和振动。②关阀水锤的最不利流量工况应考虑初始流量最小工况。该工况的调流阀前初始压力最大,关阀历时最短,阀前最大水锤压力往往最大。③等百分比型流量特性更有利于减小调流阀的关阀水锤压力。在相同的初始流量和关阀速率下,等百分比型调流阀的初始开度更大,实际关阀历时更长,在小开度区域的流量系数变化梯度更小,因而关阀水锤压力更小,更有利于管道安全。Based on one-dimensional water hammer theory and combined with an engineering example,the selection of the flow characteristics of the end control valve of gravity flow system with wide-range flow variation is numerically studied from three aspects:the influence of flow characteristics of control valve on its steady-state opening-degree,the determination of the most unfavorable flow conditions of valveclosing water hammer,and the influence of flow characteristics of contrive valve on valve-closing water hammer.And the flow characteristics of linear type,parabola type and equal percentage type are compared.The results show that:①The equal percentage flow characteristic ismore conducive to the stable operation of the control valve under the low flow condition.Under this condition,the steady-state opening-degree of the equal percentage type control valve is larger,which can avoid cavitation and vibration caused by too small opening.②The most unfavorable flow condition of the valve-closing water hammer should consider the minimum initial flow condition,under which the water hammer pressure of the input point of the control valve is largest because of the largest initial pressure and the shortest closing time.③The equal percentage flow characteristic is more conducive to reducing the control valve-closing water hammer pressure.Under the same initial flow rate and valve closing rate,the control valve with equal percentage type flow characteristics has a larger initial opening-degree,a longer actual closing time,and a smaller change gradient of flow coefficient in the small opening-degree range,so the extreme value of the valveclosing water hammer pressure is smaller,which is more conducive to pipeline safety.

关 键 词：调流阀 流量特性 稳态开度 关阀水锤 大变幅流量 重力流输水系统 

分 类 号：TV675[水利工程—水利水电工程]