Nonlinear Model Reduction and Control for Integrated Process Systems

研究：该项目涉及综合过程系统的非线性模型还原和控制方法的开发和评估，特别是具有大量材料和/或能量回收的反应和分离单元网络。与单个单元的动态相比，这种网络通常表现出由循环引起的强烈非线性动力学，并且在较慢的时间尺度（较长的时间范围）中演化。这种时间尺度的分离自然地使其成为一种控制范式：区分单个过程单元的“分布式”控制目标（快速时间尺度）和整个网络的“监督”控制目标（慢时间尺度），并规定补偿由监督控制级别的循环引起的非线性。在此框架内，主要的技术任务将是推导由循环结构引起的核心网络动力学的低阶非线性模型，并在这些模型的基础上设计非线性监控控制器。待开发的方法将：(i)加强对高度集成过程系统的动力学和控制的基本理解，（ii）通过设计有效的监督控制方案来改善其操作，（iii）补充现有的全厂控制方法，并促进实时优化和监督控制的更有效集成。影响：这项工作可使化工厂的运作更有效率，因而在商业上更可行。可以从这项工作的结果中受益的过程系统包括反应分离网络和具有“内部”材料回收和/或热集成的单个多阶段过程，例如高纯度和反应精馏塔。该项目还涉及开发软件工具和一个专门的网站，这将进一步加强成果的传播以及研究和教育的基础设施。

Research:This project involves the development and evaluation of nonlinear model reduction and control methods for integrated process systems, specifically, networks of reaction and separation units with large material and/or energy recycle. Such networks typically exhibit strongly nonlinear dynamics which is induced by the recycle and evolves in a slower time scale (longer time horizon) compared to the dynamics of the individual units. This time scale separation lends itself naturally to a control paradigm which:Distinguishes between "distributed" control objectives for individual process units (fast time scale) and "supervisory" control objectives for the overall network (slow time scale), andDictates compensating for the nonlinearities induced by recycle at the supervisory control level.Within this framework, the main technical tasks will be the derivation of low-order nonlinear models of the core network dynamics induced by recycle structures and the design of nonlinear supervisory controllers on the basis of these models.The methods to be developed will: (i) enhance fundamental understanding of the dynamics and control of highly integrated process systems, (ii) enable improving their operation via the design of effective supervisory control schemes, and (iii) complement existing plant-wide control methodologies and facilitate a more efficient integration of real-time optimization and supervisory control.Impact:This work could result in more efficient and hence more commercially viable operation of chemical plants. Process systems that could benefit from the results of this work include reaction-separation networks and individual multi-stage processes with "internal" material recycle and/or heat integration, such as high purity and reactive distillation columns. The project also involves the development of software tools and a dedicated web site which should further enhance the dissemination of the results and the infrastructure for research and education.