乙烯淤浆聚合动态分子量分布模拟计算

Dynamic simulation of molecular weight distribution of ethylene slurry polymerization

以乙烯淤浆聚合反应过程为研究对象,提出动态分子量分布的严格模型的数值计算方法。将动态分子量分布的大规模微分代数混合模型解耦为小规模微分代数方程组动态矩模型与大规模常微分方程组粒数衡算模型,然后通过变量解耦的方法进一步将大规模粒数衡算方程组转换为序贯差分方程组,实现了乙烯动态分子量分布严格模型的数值模拟计算。动态模拟乙烯聚合反应从一个稳态切换到另一个稳态,通过在切换后稳态的分子量分布计算结果与Flory分布计算方法进行比较,两者得到的分子量分布曲线吻合很好,证实了本文提出的动态模拟计算方法的精度和准确度都获得良好的保障。

Based on the dynamic model of ethylene slurry polymerization,a decoupling method was proposed for rigorous model calculation of molecular weight distribution（MWD）.The MWD model in large scale differential-algebraic equations（DAEs）was decoupled to a moment model in small scale DAEs and chain length based MWD in large scale ordinary differential equations（ODEs）.The variable decoupling method was further proposed to solve the large scale ODEs through numerical computation.Comparison of the MWD curves with Flory distribution calculation was also presented and discussed.