Dynamic optimization of batch free radical polymerization with conditional modeling formulation through the adaptive smoothing strategy
Dynamic optimization of batch free radical polymerization with conditional modeling formulation through the adaptive smoothing strategy
复制标题
通过自适应平滑策略使用条件建模公式动态优化间歇自由基聚合
DOI：
10.1016/j.compchemeng.2018.09.023
复制
发表时间：
2019-01-05
影响因子：
4.3
通讯作者：
Chen, Xi
中科院分区：
文献类型：
--
作者：
Kong, Jing;Chen, Xi
随着转化率和粘度的增加，分批自由基聚合（FRP）可能会遇到复杂的现象，包括凝胶效应、玻璃效应和笼效应。这些影响通常导致由一组微分代数方程（DAEs）描述的条件建模公式。由于效应的发生而引发的模型切换处存在不连续梯度，给批量过程的动态优化带来困难。为了处理这种不连续性，提出了内点光滑近似来描述在影响发生时的模型切换。针对动态优化问题，提出了一种能够有效平衡优化效率和逼近模型精度的自适应平滑策略。为了证明这种平滑策略的有效性，对甲基丙烯酸甲酯聚合过程中的最佳操作剖面进行了案例研究。该策略取得了良好的计算性能。(C) 2018 Elsevier Ltd.版权所有。
With the increase of conversion and viscosity, a batch free radical polymerization (FRP) may encounter complicated phenomena, including the gel, glass, and cage effects. These effects normally lead to a conditional modeling formulation described by a set of differential-algebraic equations (DAEs). Discontinuous gradient exists at model switches triggered by occurrence of the effects, which cause difficulty for dynamic optimization on the batch process. To deal with the discontinuity, interior-point smooth approximations are proposed to describe the model switches at the occurrence of the effects. An adaptive smoothing strategy, which can efficiently balance the efficiency of optimization and the accuracy of the approximated model, is proposed for the dynamic optimization. To show the effectiveness of this smoothing strategy, case studies for optimal operating profiles in a polymerization process of methyl methacrylate are conducted. Good computational performance is achieved with the proposed strategy. (C) 2018 Elsevier Ltd. All rights reserved.