分层填料对旋转填料床气相流场影响的数值模拟

通过设计简化的分层填料旋转床(SP-RPB)模型，采用计算流体力学方法(CFD)对比同尺寸旋转填料床(RPB)的稳态气相流场。分析转速和进料速度对气相压力、相对速度及湍动能分布的影响，同时还考察了单位丝网圈上的压降情况。结果表明，在气体进入各级填料位置的相对速度出现峰值，湍动能分布与之相同，各峰的出现位置仅由填料位置决定，两者共同表明SP-RPB具有多个端效应区域。转速增加对相对速度峰值大小有更明显的提升，较大的进料速度使填料内气体的速度波动更大，也使湍动能的峰值有所增加。由于SP-RPB内填料厚度较RPB变薄，从整个设备范围上看，SP-RPB表现出更低的压降。进气速度提高和转速降低使SP-RPB两层填料间的高压范围变窄，但SP-RPB的单位丝网圈数压降更大。

Numerical simulation of the effect of split packing on gas flow field for rotation packed bed

A simplified split packing rotation packed bed (SP-RPB) model was designed, and the computational fluid dynamics (CFD) method was used to simulate the steady-state gas flow field compared with the same size general rotation packed bed (RPB). The influence of different rotation speed and feed rate on gas phase pressure, relative velocity and turbulent kinetic energy distribution were compared and analyzed. The pressure drop across each mesh lap was examined as well. Counters of gas velocity and pressure of RPB and SP-RPB in steady state had been obtained, in order to understand the hydrodynamic and flow patterns deeply. The plots of different rotation speed or feed rate attribute to pressure, relative velocity and turbulent kinetic energy also were investigated. They pointed out that the relative velocity of the gas entering each packing rings was the highest in the vicinity, and the distribution of turbulent kinetic energy was the same. And the appearance of each peak was determined solely by the arrangement of the packing ring. Both results of them indicated that SP-RPB could have multiple end effect regions located at packing ring edge. The increase in rotation speed had a more pronounced effect on the peak level than the feed rate. And the larger feed rate caused the velocity of the gas in the filler fluctuate more intensively, the peak value of the turbulent kinetic energy increased. Due to the thinner thickness of the packing in SP-RPB compared with the same size of RPB, the SP-RPB exhibited a lower pressure drop over the entire equipment range. By increasing the feed rate and reducing the rotation speed, the high pressure in the RPB range between the two packing layers of SP-RPB could be reduced. In addition, the pressure drop of SP-RPB on unit mesh lap was larger than PRB with the same size.