Tuning and activation of a PI controller during start-up of a non -isothermal CSTR

Abstract

Continuous processes show dynamic behavior during start-up, shutdown, and when upsets occur during steady state operation. Mathematical modeling, simulation, and control of these processes is relatively difficult, because of the nonlinear nature of these processes and the activation and tuning difficulties of the controllers. This paper applies proportional plus integral (PI) control to start-up a non-isothermal CSTR. PI eliminates offsets and maintains acceptable speed of response. Simple and straightforward schemes of activation are tried to startup the CSTR smoothly and to get the maximum attainable conversion. The importance of this control problem lies in the difficulty of triggering the controller and the re-tuning of the PI settings.