流化床中床体宽度对气固流动特性的影响

Effect of bed width on gas-solid flow characteristics in fluidized beds

由于流化床具有良好的传热传质特性,被广泛应用在能源化工行业、而流化床床体结构对流化床内部气固两相流动特性影响显著.通过数值模拟的方法对4种不同床体宽度的准二维流化床进行研究、结果表明,随着床体宽度增加,流化床内部气泡的数量会变多,同时由于小气泡的合并导致气泡尺寸增大,并且床层中的压降也随着床体宽度的增大而更加均匀,从气相流线图分布来看,沿着流化床垂直方向流化床内部漩涡的纵横比也逐渐减小,从而更加有利于气固两相在床体内部的混合。

Due to the good heat and mass transfer characteristics of fluidized beds, they are widely used in energy and chemical industries.The fluidized bed structure has a significant influence on the internal gas-solid two-phase flow characteristics inside the fluidized bed.Four quasi-two-dimensional fluidized beds with different bed widths are studied by numerical simulation.The results show that as the bed width increases,the number of bubbles inside the fluidized bed becomes larger,and the bubble size increases due to the merging of small bubble pairs,and the pressure drop in the bed also becomes more uniform with the increase of the bed width,and from the distribution of gas-phase streamlines,the aspect ratio of vortices inside the fluidized bed decreases along the vertical direction of the fluidized bed,which is more favorable to the mixing of gas-solid phases inside the bed.