丙烯改进型差压热耦合精馏系统优化与控制

Dynamic simulation and control of improved differential pressure thermally coupled distillation system for separation of propylene/propane mixture

以炼厂气体分馏装置丙烯精馏为例,利用Aspen Plus建立不同工况下改进型差压热耦合精馏稳态模拟,在此基础上运用Aspen Dynamics对RR-BR控制方案和D-B控制方案的动态特性进行研究,并与传统的差压热耦合精馏进行比较。结果表明,辅助冷凝器和中间冷却器冷却负荷分配不同,高低压塔的分离负荷不同,节能效果也不同,也是动态性能差异的主要原因。选择部分耦合流程可以使流程更加灵活,通过优化冷却负荷分配比,可以使改进型流程比传统流程具有更好的控制效果。

Taking the propylene distillation unit in gas fractionation facility of refinery as an example,Aspen Plus is utilized to establish a steady-state simulation for the improved differential pressure thermally-coupled distillation under different working conditions.Based on this,Aspen Dynamics is employed to study the dynamic characteristics of RR-BR control scheme and D-B control scheme,which are compared with that of conventional differential pressure thermally coupled distillation scheme.It is shown that there are differences in cooling load distribution between auxiliary condenser and intercooler,there are differences in separation load between high and low pressure tower,and there are also differences in energy saving effect,all contributing to the difference in dynamic performance.Selecting a partial coupling process can make the process more flexible. By optimizing the cooling load distribution ratio,the improved process can have better control effects than traditional one.