摘要
普通水力旋流器在分离天然气水合物泥砂混合浆体的过程中,外界不稳定工况易导致天然气水合物浆体分解出天然气气体,加之其与外界环境中的空气结合更易产生空气柱,而空气柱会影响旋流器的分离效率和分离精度。鉴于此,设计了内置扭带水力旋流器。采用Solidworks 2018对水力旋流器进行三维建模,利用ICEM CFD对模型进行结构化网格划分,采用有限体积数值模拟方法研究了不同长度的扭带与水力旋流器组合,来对比分析该设备中内部流场的变化对分离除砂效率及分离精度的影响。研究结果表明:扭带的放置消除了空气柱对沉砂口排出砂的阻碍,增强了内旋流效果并提高了分离效率及分离精度;内旋流增强及稳定性提高使未被完全分离的天然气水合物泥砂混合浆体在内旋流区停滞时间延长,将泥砂与水合物进行二次分离,提高了水合物浆体纯度,使得溢流口的水合物含量激增并出现突兀的波峰;200 mm非变径扭带与水力旋流器组合对天然气水合物的分离效果最好。研究结果可为分离器性能的深入研究提供参考。
In the process of separating natural gas hydrate silt mixed slurry,the unstable external conditions often result in the decomposition of natural gas from hydrate slurry in conventional hydrocyclone.Combined with the air in the external environment,it is more likely to generate air column to hinder the separation efficiency and separation accuracy.To address the problem,a hydrocyclone with a built-in twist band is designed.The hydrocyclone is modeled in three dimensions by using Solidworks 2018.The model is meshed by using ICEM CFD.The finite volume numerical simulation method is used to study the combination of twisted band with different lengths and hydrocyclone.The resulted internal flow field effects on the separation efficiency and separation accuracy are analyzed and compared.The results show that the twisted band eliminates the obstruction of the air column to the sand discharge from the outlet,enhances the internal swirling effect and improves the separation efficiency and separation accuracy.The internal swirling enhancement and stability increase make the natural gas hydrate silt slurry not completely separated has a longer stagnation time in the inner swirl zone.The resulted secondary separation of silt and hydrate improves the purity of the hydrate slurry,leading to a sharp increase of hydrate content of the overflow port and a sudden peak.The combination of diameter-constant 200 mm twist band and hydrocyclone has the best separation effect on natural gas hydrate.The study results can provide a reference for the in-depth study of separator performance.
作者
孙毅
饶永超
李立军
王树立
王子文
丁博洋
Sun Yi;Rao Yongchao;Li Lijun;Wang Shuli;Wang Ziwen;Ding Boyang(School of Petroleum Engineering,Changzhou University)
出处
《石油机械》
北大核心
2019年第11期66-73,共8页
China Petroleum Machinery
基金
国家自然科学基金项目“基于螺旋流的天然气管道水合物堵塞风险边界拓展机制研究”(51574045)
江苏省研究生科研创新计划项目“螺旋流管道水合物生成动力学研究”(KYCX18_2629)
关键词
内置扭带
水力旋流器
天然气水合物
分离效率
数值模拟
分离精度
built-in twisted band
hydrocyclone
natural gas hydrate
separation efficiency
numerical simulation
separation accuracy
