Chinese Journal of Chemical Engineering, Vol.13, No.3, 380-387, 2005
Constraints adjustment and objectives coordination of satisfying optimal control applied to heavy oil fractionators
In this paper, the feasibility and objectives coordination of real-time optimization (RTO) are systemically investigated under soft constraints. The reason for requiring soft constraints adjustment and objective relaxation simultaneously is that the result is not satisfactory when the feasible region is apart from the desired working point or the optimization problem is infeasible, The mixed logic method is introduced to describe the priority of the constraints and objectives, thereby the soft constraints adjustment and objectives coordination are solved together in RTO. A case study on the Shell heavy oil fractionators benchmark problem illustrating the method is finally presented.
Keywords:satisfactory control;real-time dynamic optimization;constraint priority;objective priority;soft constraint;mixed logic