PTFE间歇聚合反应过程变周期动态经济优化控制

聚四氟乙烯(PTFE)间歇聚合生产模式可满足小批量、多用途以及高质量产品的市场需求。针对PTFE聚合过程存在强非线性和大时滞特性，提出了一种基于自由终端的动态经济优化控制方法。首先，将生产周期作为一个自由度纳入优化变量建立动态经济优化问题，采用改进控制变量参数化方法，控制输入被离散为可变长度的片状序列，便可将动态经济优化问题转换为非线性规划(NLP)问题；然后，采用基于梯度下降的内点罚函数法求解NLP问题，通过变周期预测时域的滚动优化控制方法优化控制输入和终端时间；最后将提出的变周期动态经济优化控制与传统PI控制、非线性模型预测控制进行对比测试分析，仿真结果表明本方法单位经济效益更高，生产周期更短，突显了间歇生产的灵活性。

Dynamic economic optimal control for PTFE batch polymerization process with free terminal

Polytetrafluoroethylene (PTFE) batch polymerization production mode can meet the market demand of small batch, multi-purpose and high quality products. Aiming at the strong nonlinearity and large time delay in the PTFE polymerization process, a dynamic economic optimization control method based on free terminal is proposed in this paper. Firstly, the dynamic economic optimization problem is established by integrating the production cycle as a degree of freedom into the optimization variable. The control inputs are discretized into piece-wise sequences by using improved control variable parameterization method, and the dynamic economic optimization problem can be transformed into a nonlinear programming (NLP) problem. Then, the NLP problem is solved based on the penalty function method of gradient descent, and the rolling optimization control method in the free prediction time domain is used to optimize the control input and terminal time. Finally, compared with PI control and nonlinear model predictive control, the simulation results show that free terminal dynamic economic optimization control method has higher economic benefit and shorter production cycle, which highlights the flexibility of batch production.