水力聚结器内油滴聚结特性及运动行为分析  

Analysis on Coalescence Characteristics and Migration Behaviors of Oil Droplet in Hydraulic Coalescer

作　　者：邢雷[1,2] 李金煜 蒋明虎 赵立新[1,2] 关帅 Xing Lei;Li Jinyu;Jiang Minghu;Zhao Lixin;Guan Shuai(School of Mechanical Science and Engineering,Northeast Petroleum University;Heilongjiang Key Laboratory of Petroleum and Petrochemical Multiphase Treatment and Pollution Prevention)

机构地区：[1]东北石油大学机械科学与工程学院 [2]黑龙江省石油石化多相介质处理及污染防治重点实验室

出　　处：《石油机械》2022年第8期81-88,共8页China Petroleum Machinery

基　　金：国家自然科学基金区域创新发展联合基金重点支持项目“同井注采井筒内关键湍流场域离散相运聚机理及动力学行为研究”(U21A20104);东北石油大学“国家基金”培育基金项目“超重力场作用下水中油滴碰撞聚结机理及后续运动行为研究”(2021GPL-10);大庆市指导性科技计划项目“聚结-旋流多场耦合强化油水高效分离技术研究”(zd-2021-38)。

摘　　要：为了分析离散相油滴在水力聚结器内的运移轨迹以及聚结器流场特性对油滴聚结的影响,采用PBM-DPM耦合数值模拟方法获得了聚结器内速度场及油相体积分数的分布规律,掌握了聚结器旋流腔为油滴碰撞聚结的主要发生区域,但在螺旋流道及聚结内芯的近壁区域受较大时均速度梯度影响油滴出现明显的破碎现象。数值模拟结果表明:聚结器内部流场呈外部为准自由涡、内部为强制涡的复合涡旋流场特性,且沿内涡区流出的油滴较外涡区运动的油滴在聚结器内的停留时间更长,时间差值约为0.029 s;内涡区含油体积分数较高,增大了油滴间的碰撞概率,因此内涡区的油滴粒径较大,同时也受到更高的流场阻力,致使在油滴运动过程中速度衰减明显高于外涡区油滴。针对水力聚结器试验样机开展了聚结性能试验,对比了聚结器出口及入口的粒度分布,得出试验工况下聚结器可将入口处平均粒径为92μm的油滴增大到298μm。研究结果可为进一步揭示旋流聚结机理及设计出通过多场耦合作用来提高油水分离性能的新型设备与方法提供思路。In order to analyze the migration trajectory of discrete oil droplets in coalescer and the influence of coalescer flow field characteristics on oil droplet coalescence,PBM-DPM coupled numerical simulation method was used to obtain the distribution law of velocity field and concentration field in the coalescer.It was found that the swirl chamber of coalescer is the main area where oil droplets collide and coalesce,while the oil droplets are obviously broken near the wall of the spiral channel and the coalescer core due to the large time-average velocity gradient.The numerical simulation results show that the flow field inside the coalescer is a compound vortex flow field with the outer quasi-free vortex and the inner forced vortex.The oil droplets flowing out of the inner vortex region stay in the coalescer longer than those moving in the outer vortex region,with a time difference of about 0.029 s.The high volume fraction of oil in the inner vortex region increases the collision probability among oil droplets.So the oil droplets in the inner vortex region have a larger particle size and they are subject to higher resistance of the flow field,resulting in the velocity attenuation of oil droplets in the migration much higher than that in the outer vortex region.The experimental prototype of hydraulic coalescer was used to perform the coalescence performance test and the particle size distribution at the outlet and inlet of coalescer was compared.It was concluded that the coalescer could increase the average particle size of oil droplets at the inlet from 92μm to 298μm under the experimental conditions.The research results provide ideas for further revealing the mechanism of swirling coalescence and designing new equipment and methods to improve oil-water separation performance by means of multi-field coupling.

关 键 词：水力聚结器 停留时间 运动特性 油滴粒径 聚结性能 数值模拟 

分 类 号：TE99[石油与天然气工程—石油机械设备]