中文摘要：

对一种催化裂化（FCC）沉降器内的流动状况进行全尺寸数值模拟,考察粗旋与顶旋采用不同连接方式时沉降器内的油气流动规律,应用雷诺应力模型模拟单个旋风分离器内的气相流场。通过标量输运方程计算简单圆管内气体的停留时间,并与经验公式进行比较,验证采用标量输运方程计算停留时间的可靠性。在此基础上,考察粗旋与顶旋的两种连接结构对沉降器内流动状况以及油气停留时间的影响。结果表明：计算结果与实验数据吻合较好,雷诺应力模型可以用于FCC沉降器内气相流动研究;改进粗旋出口与顶旋入口的相对位置,绝大部分油气直接进入顶旋,可以减少进入沉降器空间的油气量,降低油气结焦的几率。

英文摘要：

A full-scale numerical simulation was carried out to investigate gas flow behavior in FCC disengager,especially the flow under different linkage types between primary and secondary cyclone.Reynolds stress model（RSM） was applied to simulate gas flow field in a single cyclone.Moreover,a scalar transport equation was adopted to calculate residence time distribution（RTD） of gas in a simple tube.The RTD curves obtained by simulation agree well with the results from the empirical formula,which verifies the reliability of the scalar transport equation.On the basis,the numerical simulation of flow in FCC disengager was carried out,and flow condition as well as gas residence time under different linkage types was analyzed.The results show that gas flow behavior and residence time distribution are significantly affected by relative position of primary cyclones outlet to secondary cyclones inlet.The optimized structure makes the majority of gas directly into secondary cyclone,which reduces the gas quantity into disengager and effectively lowers the chances of coke generation.