甲醇催化重整制氢反应器的二维模拟及管径的选取

以甲醇裂解和甲醇水蒸气重整制氢作为平行的独立反应,CO、CO2为关键组分,建立了甲醇催化重整制氢反应器的二维数学模型,用正交配置法计算了催化床内各组分浓度及床层温度随径向和轴向的分布。考察了反应管管径变化对反应器性能的影响。在整个床层催化剂装填量及反应操作条件均不变的情况下,反应管管径增加,催化床层的出口温度降低,径向温差加大,氢气的时空产率略有降低,但所需的反应管根数迅速减少。     

关于证券组合最优结构的数学模拟

研究了降低经济风险方法之一的多样化问题，指出了传统的证券组合理论所利用的各种假设不一定总能成立，提出了若干表示证券组合最优结构的数学模型。     

A new compressibility modification <Emphasis Type="Italic">k</Emphasis>-ε turbulence model with shock unsteadiness effect

A new compressibility modification k-ε model, including shock unsteadiness effect and the previous compressibility modification of pressure dilatation and dilatational dissipation rate, was developed with a simple formulation for numerical simulation in supersonic complex turbulent flows. The shock unsteadiness effect was modeled by inhibiting turbulent kinetic energy production in the governing equations of turbulent kinetic energy and the turbulent kinetic energy dissipation rate. Sarkar＇s correction models were employed accounting for the dilatational compressibility effects in the new model. Two types of flows, the free supersonic mixing layers and complex supersonic flow with transverse injection were simulated with different flow conditions. Comparisons with experimental data of the free supersonic mixing layers showed that the new compressibility modification k-ε model significantly inhibited the excessive growth of turbulent kinetic energy and improved predictions. On the supersonic mixing layer flows, prediction results with the new model were in close agreement with experimental data, accurately predicting the decreasing trend of the mixing layer spreading rate with the increase of the convective Mach number. Due to the complicated flow field with flow separation, shock unsteadi- ness modification inhibited excessive growth of the turbulent kinetic energy in shock regions and wider shock regions are predicted, thereby significantly improving results of the flow with a strong separation forecast. The flow separation was stronger, which was the primary modification effect of the new model. Predictions accord with experimental results even in strong separation flows.     

矿用圆环链闪光对焊机送进凸轮曲线的数学模拟

建立送进凸轮曲线的数学模拟模型和曲线方程,编制程序,改进沿用的凸轮制造工艺。采用程序控制机床加工,保证设计精度。     

甲醇合成流程模拟策略

以Rosen提出的联立模块法的分层计算思想为基础,针对具有两层嵌套反馈回路的流程,提出了一种流程模拟的三层策略。将该模拟策略成功地应用于具有二层嵌套反馈回路的甲醇合成流程的模拟,并与二层的联立模块法相比。不仅能大大地缩短流程模拟的计算机时间,还能大幅度地降低流程模拟系统对初始估计值的要求。建立的甲醇合成流程模拟系统能较好地描述工业原型,并对甲醇的生产操作和优化有一定的指导作用。     

再沸吸收脱乙烷塔的计算机模拟与优化

应用工程化学模拟软件ＥＣＳＳ对再沸吸收脱乙烷塔进行了全面的模拟分析，在此基础上，将正交设计的方法引入到化工过程的参数优化之中。通过对几个主要影响因素进行了综合分析与优化，提出了一组最佳组合的操作参数。本研究对现有装置的改造的新装置的设计开发具有一定的指导意义。     

径向流动反应器的数学模拟——Ⅰ.Ⅱ型径向反应器流体力学计算

本文根据描述流体变质量流动的动量微分方程,建立了表征Ⅱ型径向流动反应器内流体流动规律的数学模型。该模型为一特殊的二阶微分方程的边值问题:Au′u″ Bu′u Cu~2=0(?)其边界条件为:y=0,u=1;y=1,u=0。式中模型参数A、B、C决定于径向流动反应器分布流道的几何尺寸、侧流穿孔阻力系数和床层空隙率等参数。本文推荐一种解析求解上述边值问题的方法。该模型应用于径向氨氧化炉操作工况的模拟,获得了预期的效果。