卧式紧凑型旋流气浮装置旋流筒结构优化数值模拟研究

Numerical simulation study on the structure optimization of cyclone tube of horizontal compact cyclone air flotation device

由于油田开发采出液含水率上升和海上平台空间的限制,亟需紧凑型污水处理设备用于对海上油田含油污水处理。对此设计了卧式紧凑型旋流气浮装置,通过Fluent数值模拟方法对该装置旋流筒区域的流场分布及油水分离性能开展了系统研究,探究了旋流筒结构、入口管径、含油污水入口速度和入口含油率等因素对油水分离效果的影响。结果表明,在入口管径为20 mm,含油污水入口速度为2 m/s时,采用导流叶片的旋流筒结构能获得较好的流场分布;含油污水入口速度越大切向速度衰减越严重;旋流筒在高度为100~300 mm时切向速度衰减较大,在高度为300~650 mm内衰减较小;相同含油污水入口速度下,增大入口管径能使旋流筒内油相体积分数增大;增大含油污水入口速度反而会导致旋流筒内油相体积分数减小;旋流筒内油相体积分数呈“U”型分布,且随入口含油率增大而增大,与入口含油率成正比。

Due to the increase of the water content in the produced fluid from oilfield development and the limita-tion of space on offshore platforms,compact wastewater treatment equipment is urgently needed to treat oily waste-water.In this regard,a horizontal compact cyclone air flotation device was designed,and the flow field distribution and oil-water separation performance of the cyclone cylinder area of the device were systematically studied by the Fluent numerical simulation method.The effects of cyclone cylinder structure,inlet pipe diameter,oily sewage inlet velocity and inlet oil content on oil-water separation were explored.The results showed that when the inlet pipe di-ameter was 20 mm and the oily sewage inlet velocity was 2 m/s,the swirl tube structure using the guide vane could obtain a better flow field distribution.The larger the oily sewage inlet velocity,the more serious the attenuation of tangential velocity.When the height of the swirl cylinder was 100-300 mm,the tangential velocity attenuation was larger,and the attenuation was small within the height of 300-650 mm.Under the same oily sewage inlet velocity,increasing the inlet pipe diameter could increase the volume fraction of the oil phase in the cyclone tube.Increasing the oily sewage inlet velocity would lead to a decrease in the volume fraction of the oil phase.The volume fraction of oil phase in the cyclone tube was distributed in a“U”shape,and increased with the increase of inlet oil content,which was directly proportional to the inlet oil content.