Natural Intelligence Principle of Supervisory-Level Control for Condensed-Mode Polyethylene Fluidized Bed Reactors: A Proportional-Integral-Derivative Perspective

Abstract Manual distributed control system (DCS)-assisted regulation of critical proportional–integral–derivative (PID) loops is essential for the stable operation of condensed-mode polyethylene fluidized bed reactors. This study evaluates the individual and combined effects of PID actions using a position-based parallel PID controller; the mechanisms underlying effective supervisory assistance from a control-theory perspective were examined. Industrial case studies were performed. A key principle of supervisory-level control was identified: alignment of a target-yield-driven, asymmetric thermal equilibrium between dual thermopairs, governed by optimal kinetic adjustments that accelerate convergence to the desired state. Case studies demonstrated that manual DCS compensation, interpreted through PID logic, introduces nonlinear modulation that expands the operating range of conventional linear PID cascade control systems. These results provide industrial-scale evidence and a theoretical foundation for developing and training advanced supervisory control strategies for complex polymerization systems.