A Continuous-time Formulation for Refinery Production Scheduling Problems Involving Operational Transitions in Mode Switching

CATEGORY: REFINERY PRODUCTION SCHEDULING 
A Continuous-time Formulation for Refinery Production Scheduling Problems Involving Operational Transitions in Mode Switching

Type	Journal Article
Author	Lei Shi
Author	Yongheng Jiang
URL	http://www.sciencedirect.com/science/article/pii/S1004954116303743
Publication	Chinese Journal of Chemical Engineering
Date	2016
Abstract	In refinery scheduling, operational transitions in mode switching are important in formulating dynamic nature of production and obtain efficient schedules. The discrete-time formulation meets two main challenges in modeling: discrete approximation of time and large size of mixed-integer linear problem (MILP). Authors present a continuous-time refinery scheduling model, involving transitions of mode switching. To reduce the difficulty in solving large scale MILPs resulting from the sequencing constraints, the global event-based formulation is used. Both transition constraints and production transitions are introduced and the numbers of key variables and constraints in both of the discrete-time and continuous-time formulations are analyzed and compared. Three cases with different lengths of time horizons and different numbers of orders are presented to illustrate the efficiency of the model.