Heating-up control with delay-free output prediction for industrial jacketed reactors based on step response...

Area of Science:

• Chemical Engineering
• Process Control
• Automation

Background:

• Industrial jacketed reactors often exhibit long input delays, complicating precise temperature control during heating-up phases.
• Existing control methods struggle to maintain optimal performance under these challenging dynamic conditions.

Purpose of the Study:

• To propose a novel predictor-based two-degree-of-freedom (2DOF) control scheme for enhancing heating-up control performance in industrial jacketed reactors.
• To develop a robust model identification method for accurately characterizing the reactor's thermal dynamics, including time delays.

Main Methods:

• A simple step response test was conducted to identify a transfer function model, representing an integrating process with time delay.
• A predictor-based 2DOF control structure was designed, utilizing two filters for delay-free output prediction.
• Controllers were analytically derived for set-point tracking and load disturbance rejection, featuring a single tunable parameter for performance optimization.

Main Results:

• The proposed identification method successfully established an accurate process model for the heating-up dynamics.
• The predictor-based 2DOF control scheme demonstrated effective temperature regulation and disturbance rejection capabilities.
• Validation through illustrative examples and a practical application on a 4-liter jacketed reactor confirmed the method's effectiveness.

Conclusions:

• The predictor-based 2DOF control strategy offers a significant improvement over existing methods for heating-up control in industrial reactors with long delays.
• The developed model identification and control design provide a tunable and effective solution for pharmaceutical crystallization and similar processes.