精馏惰气升压冷却方式的模拟与基础试验研究

Simulation and Basic Experimental Study on the Increasing Pressure and Cooling Mode Using Inert Gas in Distillation

针对普通精馏塔塔顶冷凝系统的缺点与不足,在节能环保的前提下对原有操作方式进行了改进:利用惰性气体作为压缩介质将塔顶高温气体加压升温后,在换热器中进行热交换,合理利用凝冷潜热的同时达到了冷却塔顶蒸汽的目的。该方式降低了精馏系统中冷凝器的热负荷,同时避免了冷凝系统中冷冻盐水的高成本及腐蚀性。首先应用Aspen Plus软件对该新工艺流程进行了模拟计算,以SRK方程为热力学模型,通过灵敏度分析模块考察了混合气体压缩比、氮气初始温度、混合气体物质的量之比等因素对该过程的影响。之后进行了该过程的小试试验,试验结果与模拟结果符合良好。

An improvement on the intrinsic operation mode was proposed,based on the deficiency of ordinary cooling system in the distillation column,aiming at energy saving and environmental protection.The pressure and temperature of the high-temp vapor on the top of the column were elevated with the use of inert gas as compressed media,and heat exchange occurred in the heat exchanger.The latent heat of the condensate was fully utilized,and the purpose of cooling the top vapor was achieved at the same time.In this mode,the heat duty of the condenser in distillation system was reduced,at the meantime,the high cost and corrosivity of brine water in cooling system were avoided.In this work,Aspen Plus software was used to simulate the new process,with SRK equation as the thermodynamic model.The influence of compression ratio of the mixed gases,initial temperature of nitrogen and molar ratio of the mixed gases were investigated using the sensitivity analysis module in Aspen Plus.After that,the laboratory experiments were carried out,and the experimental results agreed well with simulation.