多产品空分供气网络生产调度

Production scheduling for multi-product air separation gas supply network

针对多产品空分供气网络的生产调度问题,依据进料空气量与氧、氮、氩气体和液体产品的代理模型和空压机设备负荷-能耗的非线性关系,提出一种基于原料空间划分空分装置(ASU)生产模态的策略,减少了模态数量,避免了调度决策变量增长引发的计算复杂度问题。在变压吸附(PSA)、液化器、气化器、氧压机、氮压机等设备的调度模型基础上,结合氧氮氩管网的物料平衡,构建最大化利润为目标的多产品联合调度混合整数规划命题。在调度模型中,采用氮压机复用策略,拓展了系统应对氧氮需求比例失调的能力。针对某钢铁集团的实际供气网络,开发了一个短期调度系统,能够以气体需求的实时预测触发求解调度模型,优化空分供气网络中设备启停和负荷变化决策,工业实例分析表明该系统可在多产品生产能力约束下获得整体优化的调度方案。

A surrogate model of inlet air,gaseous and liquid products of oxygen,nitrogen and argon was first built to accurately depict the characteristics of the units,and the nonlinear relationship between air compressor load and energy consumption was analyzed.Then a strategy for partitioning production modes of air separation plants based on the raw material space was proposed to avoid the computational complexity caused by the growth of scheduling decision variable.Combining the established scheduling models of PSA,liquefier,vaporizer,oxygen compressor,and nitrogen compressor and the mass balance of oxygen,nitrogen,and argon pipe network,a mixed integer programming of multi-product integrated scheduling was constructed to optimize the total profit.In the scheduling model,the multiplexing mode of the nitrogen compressor was adopted to expand the ability to deal with the imbalance of oxygen and nitrogen demand.A short-term scheduling system was also developed to handle a real gas supply network of an iron and steel group.The system could solve the scheduling problem triggered by the real-time prediction of gas demand,and optimize the decision-making of the overall equipment startup,shutdown and load change in the air separation gas supply network.The industrial test demonstrates that the system can obtain the overall optimal scheduling scheme under the constraint of multi-product production capacity.