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精馏过程的模型化与仿真在化工操作和工艺设计中具有重要的意义。对精馏塔进行动态数学模型的建立与仿真,不仅可以研究精馏过程在不同工况下的变化情况,而且还可以用于精馏塔的优化控制,进而提高精馏过程的生产效益。本文针对精馏塔操作过程,建立了基于平衡级假设和非平衡级假设的精馏过程动态机理数学模型,并对平衡级假设的模型进行了动态模拟。该模型从机理分析入手,进行合理的简化,模型的计算时间大大的缩短,从而使模型具有比较广泛的实用性。该模型采用的动态数学模型为METSH(质量平衡方程、相平衡方程、塔板效率方程、摩尔分数归一化方程、能量平衡方程)方程,通过计算METSH方程,可以模拟出精馏塔内温度、汽相流量、液相流量、汽相组分以及液相组分的变化趋势。通过仿真结果可以看到,该模型比较准确的预测了精馏塔中各个操作参数的动态趋势,与实际情况基本一致,其稳态结果与实际情况也基本吻合。该模型对于仿真培训及精馏过程的控制分析具有较高的理论研究意义和实际应用价值。
Distillation process modeling and simulation in chemical operations and process design is of great significance. The establishment and simulation of the dynamic mathematical model of the rectification column can not only study the changes of the distillation process under different working conditions, but also can be used for the optimal control of the distillation column, thereby improving the production efficiency of the distillation process. In this paper, the mathematical model of the dynamic mechanism of the distillation process based on the equilibrium level assumption and the non-equilibrium level assumption is established for the rectification tower operation. The model of the equilibrium level hypothesis is simulated dynamically. The model starts with the mechanism analysis, simplifies reasonably, and the calculation time of the model is greatly shortened, so that the model has a wide range of practicality. The dynamic mathematical model used in this model is METSH (Mass Balance Equation, Phase Equilibrium Equation, Tray Efficiency Equation, Molar Fractional Normalization Equation, Energy Balance Equation) equation. By calculating the METSH equation, the temperature inside the distillation column can be simulated, Vapor phase flow rate, liquid phase flow rate, vapor phase component and liquid phase component trend. The simulation results show that the model predicts the dynamic trend of various operating parameters in the rectification tower more accurately, which is in good agreement with the actual situation. The steady-state result is in good agreement with the actual situation. The model for simulation training and distillation process control analysis has a high theoretical significance and practical value.