【作者】 高倩；

【导师】 苏宏业； 褚健；

【作者基本信息】 浙江大学 ， 控制科学与工程， 2003， 硕士

【摘要】 丙烯在非均相催化剂上的聚合属阴离子配位聚合，其反应机理非常复杂，至今无法完全分析清楚，而且聚丙烯生产工艺多种多样，如何准确表述丙烯聚合的动力学行为，并实现聚合过程的计算机仿真与模拟是进行反应器优化设计和控制的基础。 本文针对聚丙烯实际生产中存在的问题，建立了聚合反应器稳态和动态模型，并根据实际操作条件计算出聚合率、浆液浓度、液相氢气浓度、催化剂残留量，出料组成等重要变量以及这些变量随聚合时间的变化规律。本文还从聚合反应机理出发，建立了聚丙烯树脂的分子量及其分布的动态数学模型，为聚丙烯流程模拟系统的开发，以及聚合工艺先进控制策略的实施提供了良好的模型基础。 聚丙烯反应器的稳态模拟以连续搅拌釜反应器为主要研究对象，根据物料和能量衡算方程式，建立连续搅拌反应釜的稳态模型，模拟计算出浆液浓度、液相氢气含量、产率等重要控制参数，并从反应器的热量衡算入手，分析了反应器的操作性能，指出聚合反应器是以不稳定的定态点为操作点，为釜温的优化控制提供了参考。动力学参数采用文献发表的数据，并在实际计算过程中加入一可调参数对模型进行修正，因催化剂和操作条件不同带来的误差也并入该参数以参与调整。实际计算结果表明，该算法可以有效消除计算中的累计误差，具有可行性和有效性。 聚丙烯连续搅拌釜反应器的动态模型主要由物料衡算、能量衡算及动力学方程组成，计算出关键过程变量随聚合时间的变化规律，并分析主要操作条件对浆液固含率、催化剂残留量等关键指标的影响，为丙烯聚合过程的先进控制和牌号切换优化控制奠定了基础。 本文还从微观聚合机理出发，建立了聚丙烯分子量及其分布的动态模型，计算出数均分子量、重均分子量和分散度指数，分析了液相氢含量对聚丙烯分子量的影响，为聚丙烯过程的质量控制奠定了基础。更多还原

【Abstract】 Propylene polymerization on heterogeneous catalyst belongs to anion coordination polymerization, which kinetic mechanism is very complex and have not been made clear completely yet. As the polymerization processes are various and the used catalysts are different, it is important to build mathematical models and conduct simulation on computer, which can provide basis for the design of optimization and control system of polymerization reactors.A steady model of industry polypropylene reactors is developed, which comprises mass balance equations, energy balance equations, vapor-liquid phase balance equations and reaction kinetic equations, can predict the important process variable, such as productivity, slurry density, liquid hydrogen concentration, the fraction of catalyst in macroparticle. Not only the key results are computed, but also the steady-state behavior of the reactor is interpreted and analyzed theoretically through the energy balance. The kinetic parameters come from the articles and are corrected in the calculation.The dynamic model is also based on mass balance, energy balance and vapor-liquid phase balance. By computer simulation, the change trend of the key process variables against the reactive time is calculated and the influence on the slurry density of continuous stirred tank reactor imposed by operational variables is ’Studied, which laid basis for the optimal design of advanced control system and grade transition process.This paper also develops a dynamic model of polypropylene molecular weight distribution and predicts the mean number average molecular weight, mean weight average molecular weight and disperse index. By computer simulation, the influence on the molecular weight of polypropylene by various process parameters is analyzed, which provides basis for the design of qualities control system for Propylene polymerization.更多还原