Process Control: Modeling, Design, and Simulation

M8.7. Summary

Exothermic CSTRs can exhibit interesting, and challenging, nonlinear behavior. Even a simple two-state model, with jacket temperature manipulated and the reactor temperature as the (controlled) output variable, can have multiple steady-state behavior. For reactors with three steady states, the intermediate steady-state is unstable, requiring a feedback controller for stable operation.

CSTRs often have recirculating jacket fluid heat-transfer systems to improve the heat removal capability. For tighter control, and particularly for start-up and transition control, it is important to incorporate a split-range strategy; here, the jacket temperature controller output manipulates either a hot fluid valve or a cold fluid valve, depending ...