提升管CSVQS环流预汽提器的CFD优化

CFD Optimization of the Central Flow Pre Stripper in the Riser CSVQS

针对原结构尺寸的环流预汽提器实现中心气升式环流时颗粒分布不均匀,环流效果较差,基于欧拉-欧拉双流体模型,应用CFD软件,对提升管CSVQS的环流预汽提器的结构进行了优化。结果表明,随着径高比D/H的增加,导流筒区与环隙区的固含率呈增加趋势;但若D/H过大,却不利于环流,取D/H=0.65~0.69。与原结构相比,当环隙区面积与导流筒区面积比S1/S2=0.97时,颗粒分布明显均匀,环流效果较好,有利于环流床内的气固充分混合接触,取S1/S2=0.95~0.99。与导流筒径高比和环隙区面积与导流筒区面积比相比,导流筒下端距莲蓬式气体分布器的距离H1对颗粒分布的影响较小,但当H1=120mm时,导流筒区和环隙区的颗粒分布更接近静床层时的颗粒分布,取H1=115~125mm。

Based on Euler-Euler two-fluid model, optimize the structure of circulation stripper in the riser CSVQS quick separation system by CFD. The results show that： the circulation stripper original structure can achieve the central circula- tion, but the particle distribution is not uniform, and the circulation effect is not very ideal. Therefore, it is necessary to op- timize the original structure. The larger D/H, the higher solid-phrase percentage of the draft tube region. However, if D/ H is too large, it is not conducive to the circulation, and it is suggested that D/H values are in 0.65-0.69. When the ratio of S1/S2 is 0.97, the effect of the pre stripper could be satisfied. Compared with the original structure, the particle distribu- tion is uniform, and the circulation effect is better. It is beneficial to the fully mixed contact of gas and solid in the circula- tion, and it is suggested that the ratio of S1/S2 is 0.95-0.99. Compared with the optimization of D/H and S1/S2, it has lit- tle influence on the particle distribution by changing the distance between the lower end face of draft tube and the lotus type gas distributor. The particle distribution of draft tube region and the annulus region is close to the static bed relatively when Hx =120 mm, and it is suggested that H1 values are in 115-125 mm.