新型高气液比混合器携气机理研究

Theoretical Research on Gas Holding of A New Kind Mixer with High Gas-liquid Ratio

新型高气液比混合器能解决电潜泵系统在高含气井中的气锁问题,为探究其工作机理,采用欧拉模型和气泡数平衡模型对混合器内气液两相流动进行了数值模拟,模拟了混合器内气泡的直径及流场压力和含气率的分布。模拟结果表明:叶轮出口高压液体通过混合器轮盘圆孔,回流至叶片非工作面最低压力区,与叶轮流道内正常流动流体形成交叉流,从而在该区域产生较为强烈的剪切摩擦,撕碎此处聚集的大尺度气泡;高气液比介质经过混合器多级混合后,气泡直径逐级减小,气相分布逐渐趋于均匀。研究结果可为后续建立混合器设计理论提供依据。

The new type mixer with high gas-liquid ratio can deal with the air lock problem ol the electric sub-mersible pump system operating in the well with high gas content. In order to find out its working mechanism, the motion ol the gas and the liquid in the mixer was simulated by using the Euler model and the bubble number balance model. The bubble diameter in the mixer, the flow field pressure and the distribution of gas ratio were obtained through simulation. The simulation results showed that the high pressure liquid at impeller outlet would return to the zone on the blade non-working surface with the minimum pressure through the round hole on the mixer disc, and form cross flow with fluid in normal flowing inside the impeller passage to produce strong shear friction inside the area and burst a large amount of bubbles accumulated in the area. After the media with high gas-liquid ratio was mixed by the multi-stage mixer, diameter of bubbles diminished and phase distribution became gradually even. The research result could be the basis of theory in later design of mixers.