考虑降液管影响的多元精馏塔动态机理建模 II . 模型求解与仿真分析

 结合动态机理模型的特点，将泡点方程的求解问题转化为微分方程的求解问题，以便于机理模型的应用。以某乙烯生产装置中具有127层塔板、中间再沸器、侧线抽出的，四组分混合物为原料的乙烯精馏塔作为研究对象，建立其动态机理模型。通过对模型中微分方程的刚性分析，选取了基于隐式Runge-Kutta法（TR-BDF2）的积分方法对模型进行求解，大大提高了模型的求解效率。通过仿真对比表明，降液管对多元精馏塔的分离计算具有较大的影响，考虑降液管的影响将更加符合实际工况。

DYNAMIC MECHANISM MODELLING OF MULTICOMPONENT DISTILLATION COLUMN CONSIDERING INFLUENCE OF DOWNCOMER Ⅱ. Resolution of Model and Simulation Analysis

According to the characteristics of dynamic mechanism model, the problem of solving bubble point equations can be translated to the question of solving differential equations, which make the use of mechanism model convenient. Based on an ethylene distillation column with 127 trays, intermediate reboilers, side-draw trays and the mixture of four components as raw material, its dynamic mechanism model was founded. Through the rigidity analysis of the differential equations in the model, the model can be solved by the integral method depending on the implicit Runge-Kutta algorithm, which obviously improved the solving efficiency. By the simulation comparison it is clear that the downcomer greatly affected the severing calculation of multicomponent distillation columns, therefore it is more reasonable to consider the effect of downcomers.