气相法聚乙烯牌号过渡优化策略

The optimization tactic for grade changeover of gas phase polyethylene

介绍了气相法聚乙烯工艺以熔体流动指数和密度为状态变量,以氢气和共聚单体的进料速率、反应温度、系统排放量、催化剂加料速率及床层料位为控制变量的产品过渡优化模型,讨论了利用该模型在最短的切换时间内生产最少数量不合格品的策略,以实现多牌号生产中经济效益的最大化。

This paper introduced a kinetics model for economically optimizing the changeover between the product grades in the gas phase polyethylene process. In the model, the melt flow index and melt density were taken as state functions and the feeding rate of hydrogen and comonomer, reaction temperature, discharge from system, feeding rate of catalyst and the fluidized bed level were set as control variables. The tactic for using the model for minimizing the undesired product within the shortest period of changeover was discussed on the purpose of realizing maximization of the economic profit in the muLti - grade production.