Spheripol-Ⅱ双环管聚丙烯装置动态建模

Dynamic modeling of Spheripol-Ⅱpropylene polymerization in dual-loop reactor

针对工业实际装置Spheripol-Ⅱ液相双环管聚丙烯反应器,从丙烯聚合反应动力学出发,根据物料平衡和能量平衡原理建立了反应器动态数学模型,并采用机理建模和经验建模相结合的方法得到熔融指数预报模型。考虑到装置是双环管串联的结构,给出聚合速率系数和夹套水换热系数的估计方法,并利用现场操作数据确定出上述模型参数。使用建立的模型对反应器进行仿真研究,分析主要操作条件的变化对浆液密度、反应温度和熔融指数等产生的影响。仿真结果表明所建模型能较好地反映双环管反应器的动态性能,对进一步先进控制策略的实施具有一定的指导意义。

A dynamic model of propylene polymerization was developed based on the kinetics of polymerization. The melt index inferential model＇s structure was derived from first principle method, while the model＇s unknown parameters were validated by process data. Considering the particular structure of dual-loop reactor, an approach based on the temperature and density of the two reactors was given to regulate the polymerization rate and jacket exchanged rate, after that the industry practical data was used to estimate these unknown parameters. The proposed model was applied to investigate the effects of the step changes in feed flow rate of materials, including propylene, catalyst and hydrogen, the simulation results confirm the validity of the proposed model.