关键词: 乙烯, 调度, P-graph, 优化, SGBP算法, 系统工程, 过程系统

Abstract:

There are differences in equipment and technology between different cracking devices in the ethylene industry. There is also a difference in the yield and energy consumption of ethylene products from cracking devices of different furnace types or processes in each ethylene feedstock plant. With the commissioning and starting of the new ethylene plant, it is necessary to simultaneously operate a large number of differential cracking devices, thereby providing space for the optimization of ethylene cracking raw materials to achieve improved material efficiency and lower energy consumption. This paper proposes a modeling and optimization method based on P-graph for the scheduling of raw materials and energy optimization among such plants(SGBP). This algorithm extracts the structural information of the process by P-graph itself, and preserves the suboptimal solution set while accelerating the solution. Afterwards, using a certain ethylene plant as an example, the proposed method was applied to achieve the modeling and optimization of raw material scheduling. The advantages of the proposed method has been verified via comparing with MINLP and one kind of intelligent optimization algorithm. It can provide simultaneously more abundant optimal solution and suboptimal solution. The optimal result of the proposed method is equivalent to the optimization effect of MINLP. The overall energy consumption after optimization is significantly reduced, and a variety of alternative operation options can be provided for the production plan personnel to choose flexible raw material deployment plans.

Key words: ethylene, scheduling, P-graph, optimization, SGBP, systems engineering, process systems