Abstract: When using superstructure modeling method to optimize the waste hydrogen stream recovery network, it is often difficult to solve the model, or even unable to get the optimal solution. In this paper, the components in the waste hydrogen stream are characterized as hydrogen, condensable light hydrocarbons and fuel gas. The triangular coordinate characterization is established, and the resource recovery optimization method is discussed, so as to form the corresponding constraints on the material balance and stream flow direction. Combined with mathematical constructions, an improved superstructure optimization model is established. The model is verified with a case from a refinery. The results show that under the same calculation conditions, the conventional modeling method and the improved modeling method obtain calculation results after 5.3 seconds and 1.6 seconds respectively. The former does not achieve the optimal solution for some streams, only obtains the suboptimal solution, while the improved method is faster and obtains the best matching network. The annual economic benefits of the two are 10.63 million yuan and 21.44 million yuan respectively, and the latter gains 10.81 million yuan per year more than the former.    

Key words: refinery, hydrogen network, superstructure optimization, waste hydrogen stream, objective function, constraint condition

摘要： 在用超结构建模方法优化废氢流股回收网络时,往往会遇到模型求解难度大,甚至无法得到最优解的情况。将废氢流股中组分表征为氢气、可凝轻烃和燃料气3种资源,建立三角坐标表征,探讨资源回收优化方法,由此形成物料平衡及流股走向的相应约束,并结合数学建模方法建立了一种改进的超结构优化模型。用某炼油厂案例对该模型进行验证,结果表明:同等计算条件下,常规建模方法和改进建模方法分别运算5.3 s和1.6 s后获得计算结果;前者对部分流股的去向优化并未达到最优,获得了次优解,而改进方法计算速度更快,并获得最佳匹配网络;两者的经济效益分别为1 063,2 144万元/a,后者较前者获得了1 081万元/a的超额收益。

关键词: 炼油厂, 氢网络, 超结构优化, 废氢流股, 目标函数, 约束条件