用系统工程方法定量估计二氧化硫转化器的设计裕量

本文建立了二氧化硫多段间接换热催化转化器的数学模型，应用变分法求解各段最优入口温度，对转化器的设计参数系统进行灵敏度分析，由此定量估计转化器催化床高度的设计裕量。     

酸性气湿法制酸工艺中SO_2转化器数学模拟

根据工业设计与生产操作条件,建立了酸性气湿法直接制酸工艺中SO2转化器的数学模型,用此模型对转化器进行模拟,结果与工业设计和生产数据相吻合。利用此模型分析了转化器进口条件对SO2转化率的影响,对SO2转化器几种操作工况进行了优化,结果表明提高一、二段催化床进口温度、降低第三段催化床进口温度、增大进口气体中O2与SO2摩尔比有利于SO2的转化。在给定的生产工况条件下,SO2最优转化率可达99.01%、酸性气体中SO2质量分数可降至0.06%。     

整装催化转化器数学模型研究进展

对用于控制汽车尾气排放的整装催化转化器的模型研究进行了论述。讨论了催化转化器中主要的物理和化学过程,包括传热传质、气流分布、化学动力学、储氧和催化剂中毒。对已有的一些模型作了描述和分析。最后分析了转化器模型的应用。     

汽车排气催化转化器中的现象分析

催化转化器己广泛用于汽车排放控制,深入了解其中发生的现象对改进催化剂和转化器的设计以及建立合理的转化器模型都具有重要意义。本文分析了整装催化转化器中发生的现象,其中主要物理、化学过程包括传热、传质、气流分布、化学动力学过程、储放氧和催化剂中毒等。     

催化精馏塔通用数学模型及其求解方法

建立了醋酸甲酯水解反应精馏实验流程,并探讨了反应精馏的工艺特点和可行性。建立了催化精馏塔通用数学模型,并给出了求解方法。该模型对于化学反应和精馏分离同时进行及交替进行两种形式的催化精馏塔均能适用,且可用于催化精馏塔的动态分析。     

氯乙烯合成转化器数学模型及优化操作指导系统的研究

以化工厂聚氯乙烯生产流程中转化器为背景，考虑了催化剂随时间和温度变化的失活机理，采用一维均相模型对氯乙烯合成转化器进行建模及仿真。结果证明，采用本文建立的数学模型对反应器的轴向温度及转化率模拟具有一定的准确性，对优化操作有一定的指导意义，具有工业实用价值。     

催化精馏塔通用数学模型及其求解方法

建立了醋酸甲酯水解反应精馏实验流程,并探讨了反应精馏的工艺特点和可行性。建立了催化精馏塔通用数学模型,并给出了求解方法。该模型对于化学反应和精馏分离同时进行及交替进行两种形式的催化精馏塔均能适用,且可用于催化精馏塔的动态分析。     

国内专利精选

一种无汞催化合成氯乙烯的工艺装置及方法:CN110790630A//宁小钢(陕西北元化工集团股份有限公司),公开日期:2020-02-14公开了一种无汞催化合成氯乙烯的工艺装置,包括原料混合器和热水泵。其中,原料混合器连接有混合气预热器,混合气预热器分别与前台转化器和后台转化器的物料进口连接,前台转化器和后台转化器的物料出口互连后连接在吸附装置上。     

汽车催化转化器数学模型的修正

催化转化器涂层和孔道之间存在着质量传递,由于涂层和孔道中物质的能量不同,在质量传递的同时必然伴随着能量传递。首先对这种伴随质量传递的能量传递进行分析,从理论上研究了这部分能量交换对计算结果的影响,得出这部分能量交换不可忽视的结论,据此对当前应用的催化转化器模型进行了改进,使计算模型在理论上更加完善,又结合试验对模型改进前后的预测结果进行了分析,验证了改进模型的有效性。     

国内专利精选

正一种无汞催化合成氯乙烯的工艺装置及方法:CN110790630A∥宁小钢(陕西北元化工集团股份有限公司),公开日期:2020-02-14公开了一种无汞催化合成氯乙烯的工艺装置,包括原料混合器和热水泵。其中,原料混合器连接有混合气预热器,混合气预热器分别与前台转化器和后台转化器的物料进口连接,前台转化器和后台转化器的物料出口互连后连接在吸附装置上。此外,还公开了一种无汞催化合成氯乙烯的方法:乙炔与氯化氢在经原料混合器混合后进入混合气预热器,预热后温度升至80～100℃;升温后的混合气进入前/后台转化器进行催化反应。前/后台转化器可根据工艺要求实     

间歇精馏模拟及操作方式的研究进展

综述了间歇精馏模拟研究常用的数学模型,主要介绍了严格模型和简捷模型,简要讨论了各个模型的特点.较详细地介绍了国内外间歇精馏操作方式的研究进展,讨论了动态累积间歇精馏塔、反向间歇精馏塔、中间罐间歇精馏塔、多罐间歇精馏塔等新塔型的操作.     

3种离子交换相平衡模型在Tau/OH~-体系中的比较

在牛磺酸/氢氧根相平衡体系下,对计量置换模型、异质作用模型和改进的Langmuir模型的计算精度等特性进行了比较。采用静态法进行牛磺酸/氢氧根体系的离子交换平衡实验,测定30℃下的离子交换等温线;分别使用计量置换模型、异质作用模型和改进的Langmuir模型方程对相平衡数据进行拟合得到相关模型参数。结果表明:改进的Langmuir模型在一定牛磺酸浓度范围内可以正确地描述Tau/OH-体系的相平衡,拟合结果优于计量置换模型和异质作用模型。     

Derivation of a control oriented low order model of the dynamics of an infrared oven for the continuous drying of a thin sheet of material

A model consisting of three partial non-linear differential equations for describing the humidity and temperature of a thin sheet of material and of the temperature of the air flow as a function of time and position in an infrared dryer was reduced to a model more adaptable to direct digital control. To begin with the original model was discretized along the length of the dryer and then linearized. Models of orders ranging from 12 to 72 were analyzed for controllability and observability. Using Moore's method, the models thus obtained were further reduced to a controllable state space model of order 5 that produced satisfactory results and for which stability was preserved. Simulated open loop responses of the reduced model to discrete perturbations in emitter electrical power, inlet humidity and velocity of the web, produced satisfactory dynamic and steady-state responses when compared to responses of the original model subjected to similar perturbations. The steady-state responses showed absolute errors for humidity and temperature of the web less than 1.3% [g water/100 g] and 2.2°C, respectively.     

Modeling of Mass Transfer in an Internal Loop Airlift Reactor

A complete mass transfer model was established for an internal loop airlift reactor. All sections of the reactor, including bottom, riser, top, and downcomer, were taken into account. A numerical method was developed to solve the mass transfer model. The effectiveness of the model was validated by experimental measurements. Based on numerical results of the model, the dynamical mass transfer process in the reactor was analyzed in detail. Some mass transfer characteristics of the airlift reactor were revealed. The results indicated that the proposed model well predicted the mass transfer in the internal loop airlift reactor.     

水华预警模型研究进展

对水华进行及时与准确的预测具有重要意义,水华预警模型是研究水华变化过程较为有利的工具.文章着重介绍了三类水华预警模型：机理模型、数据驱动模型、遥感预警模型.对这三类模型的建立思路和应用实例进行了概况和描述,总结对比各类模型的优缺点,分析现有水华模型的不足,并对水华模型的发展方向做出展望.     

Hybrid model for the diffusion of simple and complex penetrants in polymers

A hybrid model, which combines the characteristic features of the Pace–Datyner molecular model with those of the Kulkarni–Stern free‐volume model, was developed to assess the effect of temperature, penetrant concentration, and polymer crystallinity on penetrant diffusivity. The predictive capabilities of the proposed model were tested by a direct comparison with experimental data. The diffusivity of ethylene and propylene vapors in semicrystalline polyethylene and isotactic polypropylene was experimentally measured using a magnetic suspension microbalance. Sorption kinetic measurements were carried out at temperatures up to 80°C and pressures up to 80 atm. The diffusivity was found to increase with temperature and penetrant concentration. Apparently, there was a very good agreement between the theoretical values predicted by the new hybrid diffusion model and the experimentally determined diffusivities. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

PREDICTION OF THE ASYMMETRIC PEAK PROFILE USING A MATHEMATICAL METHOD WITH A COMPETITIVE LANGMUIR ISOTHERM

The adsorption characteristics of a single component and a binary component in the stationary phase using preparative chromatography were investigated with a six-adsorption isotherm model. These analyses were based on the Langmuir model. Each parameter of the adsorption isotherm was obtained with the adsorption raw data that was calculated by frontal analysis (FA). The experimental data and the values calculated using the adsorption isotherm model were compared. The bi-Langmuir model showed good agreement for phenol while the tri-Langmuir model showed good agreement for caffeine. Each characteristic of adsorption was obtained from these results. The effect of competitive adsorption was investigated using the parameters of the adsorption isotherm model with a single component. There was good agreement between the experimental data and the calculated values.     

Modeling of high-temperature catalytic combustors: Comparison between theory and experimental data

The objective of this work was to model experimental results using the simplest possible mathematical model. Here we report on preliminary results obtained with a one-dimensional model used for parameter-fitting of experimental combustion data with an inlet temperature ramp. It was possible to fit our one-dimensional model with simple power law kinetics to an experimental curve. It was also possible to use a quasi-steady state model with a computing time about a hundred times shorter than for a corresponding transient model.     

PREDICTION OF THE ASYMMETRIC PEAK PROFILE USING A MATHEMATICAL METHOD WITH A COMPETITIVE LANGMUIR ISOTHERM

The adsorption characteristics of a single component and a binary component in the stationary phase using preparative chromatography were investigated with a six-adsorption isotherm model. These analyses were based on the Langmuir model. Each parameter of the adsorption isotherm was obtained with the adsorption raw data that was calculated by frontal analysis (FA). The experimental data and the values calculated using the adsorption isotherm model were compared. The bi-Langmuir model showed good agreement for phenol while the tri-Langmuir model showed good agreement for caffeine. Each characteristic of adsorption was obtained from these results. The effect of competitive adsorption was investigated using the parameters of the adsorption isotherm model with a single component. There was good agreement between the experimental data and the calculated values.     

蜡沉积厚度随时间变化规律的模型研究

在分析蜡沉积过程的基础上, 基于一定的假设条件, 建立了蜡沉积厚度随时间变化的模型。通过提取蜡沉积厚度随时间变化曲线的数据, 拟合了模型中的待求常数, 并对模型计算值和实验值的吻合程度进行了分析。结果表明:对数模型、指数模型及动平衡模型均能反映蜡沉积厚度随时间的变化趋势, 对数模型与实验值的吻合程度最好;指数模型和动平衡模型所得的结果与实验结果的吻合程度相当, 在沉积初期, 指数模型的吻合程度高于动平衡模型, 但当沉积时间接近实验规定时间时, 动平衡模型的吻合程度高于指数模型;所建立的模型简单实用, 能够反映沉积厚度随时间变化的增长快慢趋势, 不同实验数据应用时仍需对各模型的计算精度进一步验证, 从而使得选用模型能更好地符合实际。