Petri Net-Based Heuristic Algorithm For Short-term Scheduling Of Crude Oil Operations And Implementation

Short-term planning and scheduling take an important part in automation in oil refinery. Because of the hybrid characters of the oil refining process, it is very difficult to optimize short-term planning and scheduling. As an effective modeling and analysis tool of discrete event dynamic system, Petri nets have not only a terse graphic representation, but also have a solid mathematical background, so it is very suitable to describe and analyze the asynchronous concurrent system with parallelism, synchronization and resource sharing. In this paper, by using hybrid Petri nets as modeling and analysis tool, issues such as modeling and analysis technology for charging tanks assignment, crude oil transportation and crude oil discharge in crude oil operations are studied. Based on this PN model, a heuristic algorithm is introduced, in which the following works are included:Firstly, taking Petri nets to model and analyze crude oil operations.Secondly, based on the analysis, a low boundary with correlative proof is brought forward to show how a feasible schedule can be obtained, so some result and rules are deduced. With these results and the PN model, a heuristic algorithm is introduced to obtain a feasible short-term schedule in crude oil operations.Lastly, this heuristic algorithm is implemented by using object oriented technology, a prototype system is developed. This system is tested by using a real case problem from the industry. The result shows that, in normal situation, it is consistent with the real industry production..