变压吸附制氮气的数值模拟
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。
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.
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。
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.
引文
[1]叶振华.化工吸附分离过程[M].北京:中国石化出版社,1992:38-39.
[2] Skarstrom C W. Method and apparatus for fractionating gaseous mixtures by adsorption [P].U.S.A.No. 2944627,1960.
[3] Chan Y N I., Hill F B, Y W. Equilibrium theory of a pressure swing adsorption progress [J].Chem. Eng. Sci.1981, 36:243-251
[4] Ruthven D M, Farooq S, Knaebel K S. Pressure Swing Adsorption [M]. USA: VCHPublishers, Inc., 1993.
[5]陈健,古共伟,郜豫川.我国变压吸附技术的工业应用现状及展望.化工进展.成都:1998(1).
[6]顾福民.国内变压吸附技术的发展及动态.杭州制氧机研究所行业情报室,浙江杭州2002.6
[7]吴明铂,郑经堂,王茂章.碳分子筛概述[J].炭素技术1997,6:19-24.
[8]徐如人等,分子筛与多孔材料化学[M].北京:科学出版社,2004:138-150
[9]宋伟杰,张永春,张健.变压吸附空分富氧吸附剂进展[J].低温与特气,2001,(19):1-5.
[10] Kawai M, Kaneko T.日本变压吸附分离空气的现状[J].低温与特气,1991.(1):8-13.
[11] http://www.00442.com/tradeinfo/offerdetail/info.asp?info_id=41383.
[12] http://www.jinze.net/user1/312/17/20169.shtml.
[13]吕晓云.安为民.制氧机空分装置切换系统的PLC控制.冶金自动化,1995,19(3):186-187.
[14]戴先知.刘应书.变压吸附过程数学模型及其应用[J].低温与特气,2006,2(1):37-41.
[15] Doong S J, Yang R T. The role of pressure drop in pressure swing adsorption[J].AIChE. Symp. Ser.,1988,264(84): 145-154.
[16] Shin H S, Knaebel K S. An experimental study of diffusion-induced separation of gas mixtures by pressure swing adsorption [J].AIChE, 1988,34(9): 1409-1416.
[17] Shin H S, Kim D H, Koo K K, et al. Performance of a two-bed pressure swing adsorption process with incomplete pressure equalization [J]. Adsorption, 2000, (6): 233-240.
[18]杨春育,马宁宁,焦玉海等.变压吸附空气分离过程中变压步骤的数学模拟[J].石油化工,1998,27(5): 335-340.
[19]崔红社,刘应书,乐恺,赵治.小型变压吸附制氧过程的数值模拟[P].深冷技术,2004,(1):20-23.
[20]崔红社.两级变压吸附制高浓度氧实验研究及数值模拟[D].北京科技大学,2004.
[21] Jee J G, Lee J S, Lee Ch H. Air separation by a small-scale two-bed Medical oxygen pressure swing adsorption. Ind.Eng.Chem.Res. 2001, 40 :3647.
[22] Glueckauf E,Coates LL Theory of chromatography: V. the influence of incomplete equilibrium on the front boundary of chromatograms and an efectiveness of separation [J].Journal of Chemical Society,1947,(1), 1315- 1329.
[23] Ruthven D M, Farooq S, Knaebel K S. Pressure Swing Adsorption [M]. USA: VCH Publishers, Inc., 1993:76-84
[24] Fernandez G F, Kenny C. N. Modeling of the pressure swing air separation [J]. Chem.Eng. SO., 1983, 38(6): 827-834.
[25]龚建英,张玉文.PSA空气分离吸附过程中的压降特性研究,低温工程, 2002(4):20-23.
[26]周汉涛.马正吃,姚虎卿.变压吸附空分制氧非等温过程模拟.南京工业大学学报:白然科学版,2003,25(3):39-44.
[27] GlueckaufE,Coates LL Theory of chromatography: V. the influence of incomplete equilibrium on the front boundary of chromatograms and an efectiveness of separation [J].Journal of Chemical Society, 1947, 1315- 1329.
[28] Richard S Todd, Paul A Webley. Limitations of the LDF/Equimolar counter diffusion assumption for mass transport within porous adsorbent Pelets [J]. Chem. Eng. Sci., 2002, 57:4227-4242.
[29]朱大方.氨厂弛放气提氢吸附过程的平衡模型[J].天然气化工,1994.19(3): 22-27.
[30] Farooq S, Ruthven D M, Boniface H.A Numerical simulation of a pressure swing adsorption oxygen unit [J]. Chem. Eng. Sci.,1989, 44: 2809-2816.
[31] Raghavan N S, Hassan M M, Ruthven D M. Numerical simulation of a pressure swing air separation system-a comparative study of finite diference and colocation methods.The Canadian Journal of Chem. Eng.,1987, 65: 512-516.
[32] Farooq S., Ruthven D M. Numerical simulation of a kinetically controlled pressure swing adsorption bulk separation process based on a diffusion model [J]. Chem. Eng. Sci.,1991,46(9): 2213-2224.
[33] Narasimhan Sundaram, Yang R T. Efects of main and cross term diffusivities on kinetic separation by pressure swing adsorption [J]. CES,1998,53(10): 1901-1912.
[34] Ling Jiang, Lorenz T Biegler, Fox V Grant. Design and optimization of pressure swing adsorption systems with parallel implementation [J]. Computers&Chemical Engineering,2005,29: 393-399.
[35] Alpay E, Scot D M. The linear driving force model for fast-cyclic adsorption and desorption in a spherical particlep.Chem. Eng. Sci,1992, 47(2):499-502
[36]袁一.化学工程师手册[M].北京:机械工业出版社.2001:492.
[37] Sun L’M and Levan L D.Numerical solution of diffusion equation by the finite Difference method: efficiency improvement by iso-volumetric spatial discretization. Chem Eng Sci,1995,50(1):163-166
[38]张国亮,张凤宝,王绍亭,陈元勇.用正交配置法求解血液透析超过滤的传质动力模型.化工学报.1993,44(5):609-616
[39] Villadsen J V and Stewart W E.Solution of boundary-value problems by Orthogonal collocation. Chem Eng Sci.1967,22:1843-1501
[40]李喜载,王中来,李志福,叶长森.用正交配置法求解搅拌槽液相吸附动力学模型[J].计算机与应用化学,1997,14(4):273-280
[41]李红.数值分析[M].武汉:华中科技大学出版社,2003:96-100
[2] Skarstrom C W. Method and apparatus for fractionating gaseous mixtures by adsorption [P].U.S.A.No. 2944627,1960.
[3] Chan Y N I., Hill F B, Y W. Equilibrium theory of a pressure swing adsorption progress [J].Chem. Eng. Sci.1981, 36:243-251
[4] Ruthven D M, Farooq S, Knaebel K S. Pressure Swing Adsorption [M]. USA: VCHPublishers, Inc., 1993.
[5]陈健,古共伟,郜豫川.我国变压吸附技术的工业应用现状及展望.化工进展.成都:1998(1).
[6]顾福民.国内变压吸附技术的发展及动态.杭州制氧机研究所行业情报室,浙江杭州2002.6
[7]吴明铂,郑经堂,王茂章.碳分子筛概述[J].炭素技术1997,6:19-24.
[8]徐如人等,分子筛与多孔材料化学[M].北京:科学出版社,2004:138-150
[9]宋伟杰,张永春,张健.变压吸附空分富氧吸附剂进展[J].低温与特气,2001,(19):1-5.
[10] Kawai M, Kaneko T.日本变压吸附分离空气的现状[J].低温与特气,1991.(1):8-13.
[11] http://www.00442.com/tradeinfo/offerdetail/info.asp?info_id=41383.
[12] http://www.jinze.net/user1/312/17/20169.shtml.
[13]吕晓云.安为民.制氧机空分装置切换系统的PLC控制.冶金自动化,1995,19(3):186-187.
[14]戴先知.刘应书.变压吸附过程数学模型及其应用[J].低温与特气,2006,2(1):37-41.
[15] Doong S J, Yang R T. The role of pressure drop in pressure swing adsorption[J].AIChE. Symp. Ser.,1988,264(84): 145-154.
[16] Shin H S, Knaebel K S. An experimental study of diffusion-induced separation of gas mixtures by pressure swing adsorption [J].AIChE, 1988,34(9): 1409-1416.
[17] Shin H S, Kim D H, Koo K K, et al. Performance of a two-bed pressure swing adsorption process with incomplete pressure equalization [J]. Adsorption, 2000, (6): 233-240.
[18]杨春育,马宁宁,焦玉海等.变压吸附空气分离过程中变压步骤的数学模拟[J].石油化工,1998,27(5): 335-340.
[19]崔红社,刘应书,乐恺,赵治.小型变压吸附制氧过程的数值模拟[P].深冷技术,2004,(1):20-23.
[20]崔红社.两级变压吸附制高浓度氧实验研究及数值模拟[D].北京科技大学,2004.
[21] Jee J G, Lee J S, Lee Ch H. Air separation by a small-scale two-bed Medical oxygen pressure swing adsorption. Ind.Eng.Chem.Res. 2001, 40 :3647.
[22] Glueckauf E,Coates LL Theory of chromatography: V. the influence of incomplete equilibrium on the front boundary of chromatograms and an efectiveness of separation [J].Journal of Chemical Society,1947,(1), 1315- 1329.
[23] Ruthven D M, Farooq S, Knaebel K S. Pressure Swing Adsorption [M]. USA: VCH Publishers, Inc., 1993:76-84
[24] Fernandez G F, Kenny C. N. Modeling of the pressure swing air separation [J]. Chem.Eng. SO., 1983, 38(6): 827-834.
[25]龚建英,张玉文.PSA空气分离吸附过程中的压降特性研究,低温工程, 2002(4):20-23.
[26]周汉涛.马正吃,姚虎卿.变压吸附空分制氧非等温过程模拟.南京工业大学学报:白然科学版,2003,25(3):39-44.
[27] GlueckaufE,Coates LL Theory of chromatography: V. the influence of incomplete equilibrium on the front boundary of chromatograms and an efectiveness of separation [J].Journal of Chemical Society, 1947, 1315- 1329.
[28] Richard S Todd, Paul A Webley. Limitations of the LDF/Equimolar counter diffusion assumption for mass transport within porous adsorbent Pelets [J]. Chem. Eng. Sci., 2002, 57:4227-4242.
[29]朱大方.氨厂弛放气提氢吸附过程的平衡模型[J].天然气化工,1994.19(3): 22-27.
[30] Farooq S, Ruthven D M, Boniface H.A Numerical simulation of a pressure swing adsorption oxygen unit [J]. Chem. Eng. Sci.,1989, 44: 2809-2816.
[31] Raghavan N S, Hassan M M, Ruthven D M. Numerical simulation of a pressure swing air separation system-a comparative study of finite diference and colocation methods.The Canadian Journal of Chem. Eng.,1987, 65: 512-516.
[32] Farooq S., Ruthven D M. Numerical simulation of a kinetically controlled pressure swing adsorption bulk separation process based on a diffusion model [J]. Chem. Eng. Sci.,1991,46(9): 2213-2224.
[33] Narasimhan Sundaram, Yang R T. Efects of main and cross term diffusivities on kinetic separation by pressure swing adsorption [J]. CES,1998,53(10): 1901-1912.
[34] Ling Jiang, Lorenz T Biegler, Fox V Grant. Design and optimization of pressure swing adsorption systems with parallel implementation [J]. Computers&Chemical Engineering,2005,29: 393-399.
[35] Alpay E, Scot D M. The linear driving force model for fast-cyclic adsorption and desorption in a spherical particlep.Chem. Eng. Sci,1992, 47(2):499-502
[36]袁一.化学工程师手册[M].北京:机械工业出版社.2001:492.
[37] Sun L’M and Levan L D.Numerical solution of diffusion equation by the finite Difference method: efficiency improvement by iso-volumetric spatial discretization. Chem Eng Sci,1995,50(1):163-166
[38]张国亮,张凤宝,王绍亭,陈元勇.用正交配置法求解血液透析超过滤的传质动力模型.化工学报.1993,44(5):609-616
[39] Villadsen J V and Stewart W E.Solution of boundary-value problems by Orthogonal collocation. Chem Eng Sci.1967,22:1843-1501
[40]李喜载,王中来,李志福,叶长森.用正交配置法求解搅拌槽液相吸附动力学模型[J].计算机与应用化学,1997,14(4):273-280
[41]李红.数值分析[M].武汉:华中科技大学出版社,2003:96-100