On the control of large highly interconnected chemical plants.

摘要

arge chemical plants are usually designed by combining several individually well controlled process units into a whole. This practice produces satisfactory, controlled response if the dynamic interactions are "weak". However, high material and energy costs and increased market competition have driven chemical plants towards a higher degree of energy integration and material recycle. These "modern" plants become difficult to operate and control because strong interconnections generally degrade the performance of the individual units, and in some cases the total response for the plant may be unstable.;Our study focuses on modifying the plant design and improving control configurations to regain stability and to obtain the original output trajectories of the units as closely as possible. Via a sequential procedure, we represent the plant by a hierarchical set of self-similar modules, in which the top level represents the entire plant. The analysis of the synthesis procedures depends on a proposed measure of interaction,