内压缩流程空分设备中氮气获取方式对能耗的影响

内压缩流程空分设备中,获得高压氮气有三种方式:液氮泵内压缩、上塔抽取低压氮气外压缩和下塔抽取压力氮气外压缩。利用UNISIM软件建立模型,模拟空分精馏过程,比较上塔抽取低压氮气外压缩和下塔抽取压力氮气外压缩两种获得方式对能耗的影响。在不同的下塔氮气流量与氧气流量比下选出合适的氮气获取方式,以实现能耗最低的目标。

The impact of gaseous nitrogen obtaining mode on the energy consumption of inner compression process air separation plant

For inner compression process air separation plant, three methods are available to obtain high-pressure gaseous nitrogen ： inner compression with liquefied nitrogen pump, extraction of low-pressure gaseous nitrogen from upper tower and external compression, and extraction of pressurized gaseous nitrogen from lower tower and external compression. The model is established with UNISIM software, the air separation rectification process is simulated, the impact on the energy consumption by two gaseous nitrogen obtaining modes （extraction of low-pressure gaseous nitrogen from upper tower and external compression, and extraction of pressurized gaseous nitrogen from lower tower and external compression ） are compared, and an adequate gaseous nitrogen obtaining mode is obtained under different flow rate ratio of gaseous nitrogen over the gaseous oxygen in the lower tower to minimize the energy consumption.