411-336 Process Dynamics and Control

431-202 Engineering Analysis B (prior to 2001, 421-205 Engineering Analysis B) or equivalent

Students successfully completing the subject should understand the factors influencing the dynamic response of chemical processes and be able to analyse and implement process control strategies.

Content: Process Dynamics: Examples of controlled and manipulated variables and control schemes in chemical plants. Time domain, Laplace and frequency domain analyses of process dynamics modelled by linear ordinary differential equations. Transfer functions, amplitude ratio and phase angle, Bode plots. Modelling of complex chemical plants by a series of first, second order and dead time processes. Process identification by step response and frequency response, pulse testing. Step response vector and dynamic matrix.

Process Control: Transfer function of PID controller, closed loop transfer function. Effects of varying proportional gain, derivative and integral times. Effects of measurement lag. Routh stability analysis, Bode stability criterion, gain and phase margins, Ziegler-Nichols tuning. Cascade control and improvements arising from cascade control. Dead time compensation and other and model-based process control. Feedforward compensation, steady-state and lead-lag feedforward. Interactions in multiple-input multiple-out processes, Bristol relative gain array, decoupling. Introduction to dynamic matrix control. Computer-based process control, sampling interval, Shannon sampling theorem and computer implementation of process control.

An examination not exceeding three hours.