悬挂式降液管液流孔气液流动状态研究

悬挂式降液管液流孔存在3种气液流动状态:只有液体流过液流孔(称走液态),只有气体流过液流孔(称走气态),气液二相都不流动(称气液堵塞态)。实验在长300 mm和宽200 mm的有机玻璃塔中进行,物系是空气-水。使用多路电导仪测试,在每个测试点都巧妙地布置3个电导探针,3种气液流动状态都被测出。结果表明,气液堵塞态确实存在,其面积分率是走气态面积分率的0.4—1.8倍。因此,悬挂式降液管液自封标准既应限制漏气量,还应限制气液堵塞。

Study on vapor-liquid flow states of hanging downcomer bottom-orifices

At hanging downcomer bottom-orifices,there exist three fluid flow states: only liquid flowing downwards through orifices(called "descending");only vapor flowing upwards through orifices(called "bubbling");neither of vapor-liquid phases flowing through orifices(called "bridging").The experiment was carried out in a(300 mm×)200 mm simulator of organic glass in air-water system.Using a multi-path conductometer,the three types of fluid flow states were successfully measured with ingenious layout of conductometric probes.The results indicate that the bridging exists really,its area fraction is 0.4-1.8 times bubbling area fraction.Hence,not only bubbling but also bridging shall be restricted for the seal criterion of hanging downcomer.