自由基聚合反应器中多尺度流场的模拟进展

doi:10.16085/j.issn.1000-6613.2018-1050

摘要/Abstract

摘要：

自由基聚合过程中，由于混合、传递及聚合反应的相互作用使得反应器内部存在复杂的多尺度流场，例如宏观尺度的速度、浓度、温度分布，介观尺度的液滴粒径分布，微观尺度的聚合反应速率、聚合物分子量和多分散性指数分布。这些复杂的多尺度流场分布使得聚合反应器的模型化研究成为难题。本文较为系统地介绍了自由基聚合反应器中存在的多尺度现象；简述了微观尺度聚合物性质流场分布的模型化与模拟研究方法；从悬浮聚合和乳液聚合两个方面介绍了介观尺度液滴粒径分布的模拟研究进展；从非理想混合的角度阐述了宏观尺度多相流流场分布的研究进展。最后，本文分析了多尺度模型的耦合求解方法。本综述也有本文作者对这个领域的初步观点，可为聚合反应器的设计、优化和放大提供参考。

关键词: 聚合, 反应器, 多尺度, 计算流体力学, 数值模拟

Abstract:

During the free radical polymerization process, due to the interactions of mixing, transfer and polymerization, the complex multiscale flow fields, such as the macroscopic velocity, concentration and temperature distributions, the mesoscopic droplet size distribution, the microscopic polymerization rate, polymer molecular weight and polydispersity index distributions, exist within the reactor，thus making the modeling of polymerization reactors be a difficult issue. In this paper, the multiscale phenomena existing in the free radical polymerization reactors were systematically introduced. Modeling and simulation methods of flow field distributions of microscopic polymer properties were briefly described. The simulation research progress of mesoscopic droplet size distributions were introduced from two aspects of suspension polymerization and emulsion polymerization. At macroscopic scale, the research progress of multiphase flow field distributions were expounded from the perspective of non-ideal mixing. Finally, the coupled solution methods of multiscale models were analyzed. This review is our preliminary views, which can be used as a reference for the design, optimization and scale-up of polymerization reactors.

Key words: polymerization, reactor, multiscale, computational fluid dynamics(CFD), numerical simulation

中图分类号:

TQ315

谢乐, 罗正鸿. 自由基聚合反应器中多尺度流场的模拟进展[J]. 化工进展, 2019, 38(01): 72-79.

Le XIE, Zhenghong LUO. Progress in simulation of the multiscale flow field in free radical polymerization reactors[J]. Chemical Industry and Engineering Progress, 2019, 38(01): 72-79.

图/表 3

图1 聚合过程中的多尺度现象

表1 自由基聚合机理和反应动力学方程

反应类型	反应机理
链引发	$I → f k d 2 R ?$
链增长	$R ? + M → k i n P 1 ?$
链增长	$P n ? + M → k p P n + 1 ?$
链转移	$P n ? + M → k t r P n + P 1 ?$
链终止	$P m ? + P n ? → k t c P n + m$ $P m ? + P n ? → k t d P m + P n$ $R ? + R ? → k t R R R$

表1 自由基聚合机理和反应动力学方程

反应类型	反应机理
链引发	$I → f k d 2 R ?$
链增长	$R ? + M → k i n P 1 ?$
链增长	$P n ? + M → k p P n + 1 ?$
链转移	$P n ? + M → k t r P n + P 1 ?$
链终止	$P m ? + P n ? → k t c P n + m$ $P m ? + P n ? → k t d P m + P n$ $R ? + R ? → k t R R R$

图2 多尺度模型的耦合机理和求解过程

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