For continuous chemical processs, security and economy are threatened by the process transition. Considering the limitations of conventional control, dynamic optimization is a potential strategy for large-range process transition. To avoid dimension problems caused by full discretization, the dynamic optimization problem is transformed into the mixed integer nonlinear programming problem by control vector parameterization. In detail, the control variables are discretized as real parameters, whereas the time grid for discretization is determined by integer parameters. The strategy is verified by the case study of a throughput-fluctuating ethylene column. By simulation, two scenes are discussed. For small-range transition, conventional strategy is adequate. For large-range transition, the dynamic optimization is employed. Compared with the experiential operation, the equal time-interval dynamic optimization decreases the deviation and shortens the duration of process transition. Furthermore, the unbalancing of fluctuation is eliminated by the varied time-interval approach.

中文翻译：

---

基于动态优化的产量波动型乙烯塔工艺过渡

对于连续的化学过程，过程过渡会威胁到安全性和经济性。考虑到常规控制的局限性，动态优化是大范围过程转换的潜在策略。为了避免完全离散化引起的尺寸问题，通过控制矢量参数化将动态优化问题转换为混合整数非线性规划问题。详细地，将控制变量离散化为实参，而离散化的时间网格则由整数参数确定。通过产量波动的乙烯塔的案例研究验证了该策略。通过仿真，讨论了两个场景。对于小范围过渡，常规策略就足够了。对于大范围过渡，采用动态优化。与经验操作相比，等时间隔动态优化可减少偏差并缩短过程过渡的持续时间。此外，通过变化的时间间隔方法可以消除波动的不平衡。