不同颗粒属性下旋流阀固液两相管道流动特性

采用欧拉-拉格朗日方法,对自行设计的旋流阀进行三维数值模拟,重点分析小颗粒粒径(10 μm)和大颗粒粒径(200 μm)2种颗粒共存时,不同颗粒密度(1 900,2 300,2 650 kg/m³)下,旋流阀内部的流动特性、管道出口流量和压力损失系数. 结果表明:旋流阀内部流场会产生偏离基圆中心的偏心旋流速度场和压力场,在偏心压力场中心会形成局部低压.由于压力能的减小,使得流体速度增加,产生了旋流加速.旋流阀的存在,使得管路中产生了大小不同的涡旋,在旋流阀出口,涡旋的延伸区域中,颗粒的含量减少. 小粒径颗粒从流体获得的速度较大;颗粒密度越大,阻力系数越大,能量损失越大. 较高的旋流速度,降低了颗粒在管路中的含量,有助于管道颗粒物迁移. 通过试验测试可以发现,由于旋流阀的存在,在其内部形成了旋流气柱;在旋流阀及其系统中,含有的杂质会在旋流的作用下旋转起来; 这在一定程度上验证了数值模拟中旋流阀的低压分布和旋流加速特性.

Flow characteristics of solid-liquid two-phase pipes with swirl valve under different particle properties

The Euler-Lagrangian method was used to carry out three-dimensional numerical simulation of the self-designed swirl valve, and the analysis was focused on the flow characteristics inside the swirl valve, the outlet flow of the pipeline and the pressure loss coefficient at different particle densities(1 900, 2 300, 2 650 kg/m³)when two kinds of small particles(10 μm)and large particles(200 μm)coexisted. The results show that the flow field inside the swirl valve will generate an eccentric swirl velocity field and a pressure field that deviate from the center of the base circle, and a local low pressure will form at the center of the eccentric pressure field. As the pressure energy decreases, the velocity of the fluid increases, resulting in swirling acceleration. The existence of the swirl valve causes vortexes of different sizes to be generated in the entire pipeline. At the exit of the swirl valve and the extension area of the swirl vortex, the content of particles is reduced. The smaller the particle size, the greater the speed at which particles are obtained from the fluid; the greater the particle density, the greater the drag coefficient, and the greater the energy loss. The higher swirl speed reduces the content of particles in the pipeline and helps the pipeline particle migration. Through experimental tests, we found that due to the existence of the swirl valve, a swirl gas column was formed in the interior; in the swirl valve and its system, the impurities contained in the swirl valve would rotate under the action of the swirl; this verifies the low pressure distribution and the swirl acceleration cha-racteristics of cyclone valve in the numerical simulation to a certain extent.