空气阀气液两相动态特性研究综述

A literature review on the dynamic behaviors of air valves during gas-liquid transients

空气阀用于解决管道输配水工程中存气、补气问题,并预防断流弥合水锤的重要辅助设备。空气阀的进/排气过程是一个复杂的气液两相瞬变过程,其动态特性参数(包括进/排气流量系数、阀室内剩余气体体积、阀门关闭时长、阀门启闭时间等)直接影响系统的水锤防护效果。通过对空气阀动态特性相关的选型和布置、模型试验和数值模拟等方面的研究成果进行回顾综述,指出当前研究对空气阀动态特性参数的响应机理和临界阈值尚不明确,有必要在大比尺系统试验分析的基础上,明确空气阀结构特性及动态参数对两相瞬变过程的响应机理,完善现有的数学模型,进而给出空气阀设计、检测、选型、优化布置等的理论依据。

Air valves are important auxiliary elements in water diversion projects,and are usually used to remove the additional entrapped air in pipelines,mitigate water hammer pressure peaks,and admit air into pipes to counter sub-atmospheric conditions.The air release/intake processes of air valves involve complicated gas-liquid transient flow.The dynamic behaviors of the air valve(such as the air valve discharge coefficient,the residual gas volume in the valve chamber,the air valve closing time length,and the air valve opening and closing time)have direct effects on the water hammer pressure peaks.This paper critically reviews the current designs,layouts,physical model tests,and numerical simulations of air valves.It argues that there is a pressing need for a comprehensive,systematic and large-scale test study on the dynamic behaviors of air valves under the condition of gas-liquid transient flow,which will improve the current mathematical model and provide a theoretical basis for the design,detection,selection,and layout of air valves.