Impact of Secondary Loop Time Delay on Cascade Temperature Control Systems in Polyethylene Fluidized Bed Reactors
HAN Guodong1, ZHANG Mengdi2, HONG Xiaodong2
1. SINOPEC Ineos (Tianjin) Petrochemical Company Limited, Tianjin 300450, China;
2. College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, China
Abstract：To clarify the influence of time delay in the secondary control loop on the control performance of both the primary and secondary loops in a cascade temperature control system for a polyethylene fluidized-bed reactor, a dynamic simulation model was established in this study. The system response characteristics under different dead times and their effects on key control performance indicators, including the integral absolute error (IAE), were then quantitatively analyzed. The results indicated that, as the dead time increased, the control performance of the secondary loop deteriorates and obvious overshoot occurs. PID parameter tuning was found to effectively reduce the adverse influence of the delay on the secondary-loop control performance, thereby improving the secondary-loop response and enhancing the temperature control performance of the fluidized bed. This study provides theoretical guidance for the optimal design of fluidized-bed cascade control systems and is of practical significance for improving the control performance of industrial units.
HAN Guodong,ZHANG Mengdi,HONG Xiaodong. Impact of Secondary Loop Time Delay on Cascade Temperature Control Systems in Polyethylene Fluidized Bed Reactors[J]. Chemical Reaction Engineering and Technology, 2026, 42(3): 236-243.
