吸收塔动态模型的建立及应用研究

Research on Establishment and Application of Dynamic Model for Absorption Towers

气体吸收是非常重要的化工单元操作,实现这一过程的设备称为吸收塔。吸收塔的计算涉及物料衡算、填料高度、操作线方程的计算等。静态模型不能满足对于工业流程中动态模拟仿真的需求。本文基于将吸收塔的气相流道及液相流道分割为多个小单元,对单元之间传质时浓度随时间的变化建立了模型,并对单元块的平推流建立了模型,结合这两个模型,建立了吸收塔的动态模型。应用此模型对吸收塔的冷态开车及操作条件波动进行了动态模拟。模拟结果显示,此方法能较好地对吸收塔的动态特性进行模拟,可以将该模型应用于DCS仿真系统的开发及吸收塔动态特性的分析。

Gas absorption is a very important chemical unit operation. The device that implements this process is called as absorption tower. The calculation of absorption tower involves the calculation of material balance, packing height and operating line equation, etc. The static model does not meet the requirements for dynamic simulation in industrial processes. In this paper, a dynamic model of the absorption tower was built to simulate the absorption tower in the actual production, and to provide dynamic characteristics of the tower. Based on dividing the gas flow and liquid flow channel into multiple small unit, the unit mass transfer model between the units was established. The cell block plug flow model was also established. By combination of these two models, the dynamic model of the absorption tower was established. This model was used to simulate the cold starting and operating conditions change of the absorption tower. The simulation results showed that this method could simulate the dynamic characteristics of the absorber, and could be applied in the development of DCS simulation system and the analysis of its dynamic characteristics.