垂直管内蒸汽射流凝结流型研究

Investigation on Steam Jet Condensation Regime in Water Flow in a Vertical Pipe System

本文实验研究了垂直管内蒸汽射流凝结流型,通过安装在管道壁面的高频压力传感器获取蒸汽在流动水中凝结诱导形成的压力波动信号,统计提取能清晰表征不同蒸汽射流凝结流型的压力振荡特征。基于不同蒸汽射流凝结流动工况下压力信号的绝对值方差变化规律,对不稳定间歇振荡、不稳定界面振荡、不稳定气泡振荡/稳定凝结流型进行划分。再根据不稳定气泡振荡凝结流型所对应压力振荡信号的绝对值方差明显大于稳定凝结流型,将不稳定气泡振荡凝结流型从不稳定气泡振荡/稳定凝结流型中区分。通过本文建立的管内蒸汽射流凝结流型图,可以应用低系统压力下的流型变化来预测较高系统压力下的流型分布。

The steam jet condensation regime in water flow in a vertical pipe system was investigated experimentally. The pressure wave induced by steam jet condensation was captured by several pressure transducers with high frequency, which are mounted on the wall of the vertical pipe. The statistical features of condensation pressure oscillation which is highly correlated to different jet condensation regimes were obtained. The absolute variance of pressure oscillation could be applied to quantitatively categorize different jet condensation regimes including Chugging, Oscillation condensation Ⅰ, ＂Oscillation condensation Ⅱ/Stable＂ regimes. After that, Oscillation condensation II regime could be simply isolated from the ＂Oscillation condensation Ⅱ/Stable＂ via comparison of the the absolute variance of pressure oscillation in these two regimes. The condensation regime diagram obtained from low ambient pressure can be applied to predict regimes classification at elevated ambient pressure.