MODELLING AND CONTROL OF pH IN A CONTINUOUS STIRRED TANK REACTOR (CSTR)

摘要

Obtaining a model for Continuous stirred tank reactors (CSTR) is an important engineering problem. The CSTR has various uncertainties and a nonlinear characteristic hence designing a model that captures the varying dynamics of the system is necessary. In wastewater treatment applications the important process variable to be controlled is pH and it is necessary to design an efficient controller to maintain the pH at its desired levels. The present work uses the Auto Regressive with Exogenous inputs (ARX), Non Linear ARX (NLARX), and Non Linear Hammerstein Weiner (NLHW) modelling to capture the dynamics of the system. Among the designed models the one that has the best fit and least MSE is used to design controller for CSTR. The controller design that is used to for this process is the MPC and its tracking performance is analysed.