空气阀气液两相动态特性研究综述

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。

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

Air v alv es ar e important aux iliary elements in w ater div ersio n pr ojects, and ar e usually used to remov e the addit ional entr apped a ir in pipelines, mitig ate w ater hammer pressur e peaks, and admit air into pipes t o co unter sub2atmo spheric condi2 tions. The air release/ intake pro cesses of air valves invo lve complicated g as2liquid t ransient f low . T he dynamic behavio rs of the air v alv e ( such as t he air v alve dischar ge co efficient, the r esidual g as vo lume in the v alve chamber, the air valve closing time length, and the air valve opening and closing time) hav e dir ect effects o n the w ater hammer pressur e peaks. This paper critically reviews the curr ent desig ns, lay outs, physical model tests, and numerical simulations of air v alv es. It arg ues that there is a press2 ing need for a comprehensiv e, systematic and lar ge2scale test study on the dy namic behav iors of air valv es under the conditio n of gas2liquid transient flow , which will impro ve the current mathemat ical model and prov ide a theoret ical basis for the design, de2 tectio n, selectio n, and la yout of a ir v alves.