催化裂化沉降器旋流快分系统内气相流场的数值模拟与分析

为进一步提高催化裂化沉降器旋流快分系统的分离效率，首先对系统内气相流场进行了研究和分析.采用CFX5软件和应力输运方程模型（DSM）对其气相流场进行了三维数值模拟.将计算结果与用五孔探针测试的流场实验结果对比发现，计算结果与实验结果吻合较好，证明了应力输运方程模型适合用于旋流快分系统内三维流场的数值模拟.模拟结果表明：旋流快分系统内的流场为三维湍流场，在旋流头喷出口附近区域存在多个纵向旋涡，存在短路流现象，这是导致分离效率不易提高的主要原因.旋流快分头的S值和倾斜角对气流切向速度都有一定的影响，应优化确定.加入汽提气后，对旋流快分系统内的流场影响不大，但对气体的快速引出有利.

Numerical simulation and analysis of gas flow field in vortex quick separation system of FCC disengager

Three-dimensional flow field in the vortex quick separation system of FCC disengager is simulated based on the Differential Stress Model（DSM）provided by CFX5,is studied firstly to improve the separation efficiency.Predictions with the Differential Stress Model are in reasonable agreement with experimental results measured by intelligent five-hole probe, attesting to the suitability of Differential Stress Model for simulating flow field in the vortex quick separator. Both the numerical calculation and the experimental results show that turbulent flow field in the vortex quick separator is symmetric.There is a short-circuit flow near the outlet of the vortex quick separator, which has negative effect on the particle separation and is a key factor to decrease the separation efficiency.The configuration dimensions (S) and the characteristic angle (α) of the vortex head have influences on the tangential velocities in the vortex quick separation system, so they should be optimized. The stripping gas has a little effect on the gas-solid separation efficiency and can be beneficial for discharging the gas.