基于DEM-CFD水力旋流器的水合物浆体分离规律研究

采用离散元素法和计算流体力学耦合仿真的方法，研究不同入口速度下的水力旋流器分离效率.以较佳入口速度的分离效率工况为例，研究不同入口区域的水合物颗粒的力学行为与特征.结果表明：由入口上侧和入口内侧进入的水合物颗粒具有短路流特征.由入口下侧和入口中心进入的水合物颗粒以螺旋轨迹线向下运动.同时在离心浮力与离心惯性力的差值作用下，沿半径向中心运动.进入内旋流场后，水合物颗粒则改变方向，以螺旋轨迹向上运动，直至从溢流管被排出.这是典型的水合物颗粒分离运动轨迹.由入口外侧进入的水合物颗粒中大多数也具有这一特征，只有少部分水合物颗粒紧贴水力旋流器的内壁，沿边界层或在边界层附近，以螺旋轨迹一直向下运动，最终从底流口排出.这一部分水合物颗粒对总体分离效率影响最大.
Abstract: The separation efficiency of hydrocyclone at different inlet velocities was investigated by using the discrete element method and computational fluid dynamics coupling simulation method. Taking the optimum separation efficiency as an example, the mechanical behavior and characteristics of hydrate particles at different entrance regions were studied. Results show that the hydrate particles entering from upside and inside of the inlet have short circuit flow characteristics. The hydrate particles entering from underside and center of the inlet move downward with a spiral path, which at the same time move toward the center along the radius under the action of the buoyancy and the centrifugal force. The hydrate particles change direction into the swirling and move upward with the spiral path until discharged from the overflow pipe. This is the typical separation trajectory of hydrate particles. Most hydrate particles entering from outside of the inlet also has this feature. Only few of hydrate particles are close to the inner wall of hydrocyclone and move downward with a spiral path along the boundary layer, or near the boundary layer finally discharged from the underflow. This hydrate particle has the greatest influence on the overall separation efficiency.