旋流快分器内气相流场的实验与数值模拟研究

用智能型五孔探针对催化裂化沉降器带筒状物的旋流快分系统(在旋流头上插入了一个筒状物)内的气体流场进行了测试。应用CFX软件,采用应力输运方程模型对系统内气相流场进行了三维数值模拟,以考察适合该旋流快分系统内流场模拟的湍流模型。结果表明,模拟结果与实验数据吻合较好,应力输运方程模型适用于带筒状物的旋流快分器内三维流场的数值模拟。系统内流场为三维湍流场,内插一个筒状物后,消除了旋流头喷出口附近的短路流,更有利于提高旋流快分器的分离效率,但在内插筒状物的底部附近还存在短路流现象。

Experiment and numerical simulation of gas flow field in new vortex quick separation system

The gas flow field in the vortex quick separation system with a inner cylinder for fluid catalytic cracking gas disengaging was measured by an intelligent five-hole probe. To study the turbulent model for flow fields in the vortex quick separator with a inner cylinder, three-dimensional gas flow field was simulated based on the differential stress model(DSM)provided by CFX software. The results show that predictions by the DSM agree well with experimental results, and DSM is suitable for simulating three-dimensional flow field in the vortex quick separator. Both numerical calculation and the experimental results show that three-dimensional turbulent flow field in the vortex quick separator with a inner cylinder is symmetric, which eliminates the short-circuit flow near the outlet. This inner cylinder benefits improving the separation efficiency of the vortex quick separator, but there is still a short-circuit flow near the bottom of the inner cylinder, which has negative effect on the particle separation.