AP1000中ADS-4液体夹带实验研究

以AP1000核电厂中自动泄压管线(ADS-4)与热管段形成的T型结构为研究对象,开展缩小比例的T型管夹带实验。实验结果表明:大尺寸支管的夹带与小尺寸支管的夹带有明显差别。分层流情况下的夹带研究中发现两种夹带机理;在较低气相Froude数及较低气腔高度时,容易产生间歇流夹带;在较高气相Froude数情况下,往往出现环状流夹带。此外,实验研究发现,大尺寸支管中回流现象显著。支管形状对起始夹带有重要影响,而液体横流似乎并不影响起始夹带。

Experimental Research of Liquid Entrainment through ADS-4 in AP1000

With the T-junction formed by the fourth stage automatic depressurization system (ADS-4) and hot leg in AP1000 nuclear power plant as object of study, a small-scale experiment research on entrainment at T-junction was performed. The visualization research indicates that the entrainment phenomena through a large size branch are apparently different from those through a small branch. Two entrainment mechanisms could be found in the stratified flow entrainment area. Intermittent flow entrainment tends to occur at a lower Froude number and a lower gas chamber height. Annular flow entrainment always arises at a higher Froude number. Also, the experimental research shows that the reverse flow is observable in a large size branch inlet. The geometry of the branch has an important effect on the onset entrainment. In addition, liquid crossflow does not seem to affect the onset entrainment.