【作者】 田春刚；

【导师】 叶春生；

【作者基本信息】 华中科技大学 ， 材料加工工程， 2007， 硕士

【摘要】 本文主要研究的对象是PSA制氮,本文根据变压吸附工艺过程的基本原理,确定其传质机理和传质模型。在此基础上建立了常温下PSA法制氮的数学模型,该模型包括:流动气象组分质量守恒,流动气相总量变化引起流速变化,线性推动力模型表示气固相间的传质。该模型涉及的参数繁多,PSA制氮通过试验确定最佳参数研究具有一定的困难和局限,且单纯依靠试验方法很难获得过程的内在机理。所以本文采用数值模拟,分析其内部机理,优化结构和过程工艺参数,从而有效降低成本和投资规模。本文中的数学模型采用正交配置法求解数学模型,正交配置法中正交矩阵的配置是往往得花费大量的时间,这里介绍权函数为w( x ) = 1? x2的具体配置方法,配置过程中简化传统公式,采用matlab编写程序,输出的正交配置矩阵可以在后续求解中直接被调用,特别是矩阵较大时可以减少工程人员的工作量和准确率。采用正交配置法离散化模型微分方程,在matlab中编写程序完成模型的动态模拟过程,主要分析了吸附床层长度,吸附时间,吸附压力等参数对氮气纯度及实际浓度的影响。本文提出将数值模拟过程制作成用户交互界面模式,可以使工作人员任意修改参数令结果达到最佳状态,从而作实验验证和指导试验,为实验的过程优化设计作指导,本文同时提出将数值模拟采用matlab和.net完成用户试验数据的处理,以便用户比较试验数据和模拟结果。更多还原

【Abstract】 The application of PSA to produce nitrogen was the main researching object in this thesis. Base on the fundamental principle of PSA procedure, the author ascertained the mass transfer mechanism and the mass transfer model. By analyzing the procedure of PSA, the mathematical model had been found. This model included: mass conversation of the flow gaseous phase, the overall material balance equation causing the variation of the fluid velocity though the column and using the linear driving force model to describe the mass transfer between the fluid and the absorption substance. This model referred to various parameters, so it was hard to obtain the optimization combination of all parameters and explain the mechanism of the PSA by experiment. In order to reduce the cost and investment scale, so in this thesis, the author deployed mathematical model to simulate the PSA procedure, analyze the inner mechanism and optimize the technology parameters.In this text, the mathematical model had been solved by applying the orthogonal collocation. But to allocate the orthogonal matrix requests massive time and energy. The specific collocation had been displayed by using w( x ) = 1? x2 as weight function. During the procedure of allocating the orthogonal matrix, the author simplified the tradition formula. The m-function of Matlab was used to design calculating program. The exporting orthogonal matrix could be used in the continued solution directly. When the collocation points were multitude, this function could reduce the workload and increase the accuracy.The dynamic simulating procedure had shown the affection to the nitrogen purity cause by the length of absorption bed, absorption time and absorption pressure and so on.In this thesis, the simulating procedure being made to GUI mode had been propounded. In the GUI mode, the staff could modify parameters to obtain the best outcome. The parameters gotten from the GUI mode could be used to guide the experiment.更多还原