窄隙流道自然对流沸腾流动不稳定性实验研究

Flow instability in vertical narrow annuli with both subcooled and saturated boilings

以水为工质,分别在过冷和饱和条件下对竖直窄环隙流道进行了自然对流沸腾流动不稳定性实验,观测到了窄隙流道饱和沸腾时所特有的蒸干型流动不稳定性。分析了流道进出口过冷度、加热负荷、温度分布、汽化核心、几何尺寸等因素对低千度流动不稳定性的影响,划分了饱和沸腾时各类流动不稳定性的发生区域,并给出了用于预计不稳定性界限值的经验公式。

Experimental study was performed using water as working medium to investigate the flow instability in a vertical narrow annuli with both subcooled and saturated boilings. The effects of inlet/outlet subcooling, heat flux, temperature distribution, nucleation sits and channel sizes on low quality flow instability were analyzed. The flow regions where different kinds of instability occurred during saturated boiling were defined and empirical formula were given for definition of flow region boundary. Dryout flow instability that is peculiar to saturated boiling in narrow channels was observed.