低温甲醇洗净化工艺模拟与改造研究

应用PROII软件,采用修正的SRK热力学模型,完成了对原装置工艺流程的模拟,针对装置技改后出现的CO2、H2S浓度变大问题,提出了改造方案,并对改造方案进行了模拟。     

低温甲醇洗吸收塔的计算机模拟

应用PRO/II工程模拟软件对某60万t/a煤气化制甲醇项目低温甲醇洗酸性气体吸收塔进行了模拟,通过对比不同热力学模型的模拟结果,明确了H2-CO2-CH3OH三元体系偏离高压和低温条件下的气液平衡是模拟误差较大的原因.将修正后的SRK-SIMSCI热力学模型用于吸收塔的计算,结果表明,该模型能够较好地反映该工艺装置的实际操作状况.     

PX芳烃联合装置的计算机模拟

简单介绍了我国PX工业生产和市场前景,同时介绍了商用软件在计算PX芳烃装置过程中热力学模型选取方法。运用PROII模拟软件对PX芳烃装置的主要设备进行模拟,并与国际先进的70万t/a PX工艺包进行比对,模拟结果与设计值基本吻合,从而可以建立一套PX装置的流程模拟模型,为同类装置的设计提供物料、能量平衡计算的标准。     

二甲苯精馏装置的流程模拟

应用Pro/II流程模拟软件,对年产1014.3 kt二甲苯精馏装置进行流程模拟.选择合理的热力学模型,模拟分析了精馏的温度和浓度分布以及理论板敷,回流比和能耗的关系.模拟结果与实际操作数据吻合较好,说明该软件在二甲苯精馏装置中的应用是可行的,可用于指导生产和设计.     

苯乙烯装置流程模拟

利用PROCESS过程模拟软件对苯乙烯装置进行模拟计算。采用NRTL,SRK,BK10等热力学方法,选择合适的模型参数。计算结果与国外设计吻合,可应用于国产化设计。     

制氢装置建模分析与优化研究

烃类蒸汽转化制氢装置是炼化企业重要的供氢装置。应用化工流程模拟软件Aspen Plus开发了天然气水蒸汽重整转化制氢生产工艺数学模型,并以某炼厂实际装置为研究对象,考察了模型计算的准确性,模拟结果与生产实际数据吻合较好,说明所建流程模拟模型及热力学物性方程选择正确。考察了水碳比、转化温度、转化压力、制氢原料等因素变化对装置生产的影响,为装置生产操作调优提供技术指导。     

液氮洗工艺模拟分析与改造研究

应用ASPENPLUS模拟软件，采用具有预测性的RK-ASPEN热力学模型，在成功完成某厂液氮洗装置设计工况模拟分析的基础上，针对原料气发生较大变化情况进行了原工艺流程可行性研究。提出2种改造方案，为工厂改造提供了必要的技术支持和理论指导，同时对各类装置改造也具有借鉴意义。     

用人工神经网络预测二元气液平衡数据

提出应用人工神经网络对溶液热力学模型进行模拟的思路，举DMF（二甲基甲酰胺）＋water体系的溶液热力学模型为例进行模拟，预测特定条件下气相组成并与实验测定结果比较。结果表明，本文所提出的人工神经网络能够很好的模拟溶液热力学模型，对相关数据具有很强的预测能力，精度能满足应用要求。     

多晶硅精馏装置节能改造设计

本文首先根据文献中考查氯硅烷体系的热力学模型的适用型,并将Aspen软件模拟的工艺数据与现场工艺装置操作数据对比,选择NRTL模型作为本文模拟计算的物性方法。其次本文使用Aspen Plus软件对装置进行了的工艺及水力学模拟计算,还对双效精馏节能的影响因素进行初步分析,根据装置原有设备规格,重新设计了工艺方案。最终给出了对原装置中的设备改动最小,节能最佳的改造方案。     

NHD脱硫系统模拟与优化

以实际脱硫装置的运行数据为基础,应用VMGSim软件,采用软件特有的Physical Solvents热力学模型,对NHD脱硫系统进行模拟,模拟结果与实际结果比较吻合。以再生塔年度化费用最小化为目标,提出了优化改造方案。改造后,年度运行费用可以节约230万元。     

气体水合物生成机理和热力学模型的建立

提出了一个双过程水合物成核动力学机理模型 :(1 )拟化学过程生成基础水合物 ;(2 )小分子气体在基础水合物中的拟Langmuir吸附形成化学组成不恒定的水合物 .以此机理模型为基础建立了水合物热力学模型 .大量检验结果表明 ,新模型在预测气体水合物 (特别是由很复杂的天然气、凝析气和原油生成的水合物 )生成条件方面优于传统的vanderWaals -Platteeuw(vdW -P)模型及其改进型 ,且计算方法更简单 .     

A NEW MECHANISM FOR HYDRATE FORMATION AND DEVELOPMENT OF THERMODYNAMIC MODEL

提出了一个双过程水合物成核动力学机理模型 :(1 )拟化学过程生成基础水合物 ;(2 )小分子气体在基础水合物中的拟Langmuir吸附形成化学组成不恒定的水合物 .以此机理模型为基础建立了水合物热力学模型 .大量检验结果表明 ,新模型在预测气体水合物 (特别是由很复杂的天然气、凝析气和原油生成的水合物 )生成条件方面优于传统的vanderWaals -Platteeuw(vdW -P)模型及其改进型 ,且计算方法更简单 .     

煤加氢气化的化学热力学模型预测

综合运用化学平衡和热力学平衡对于给定煤种的加氢气化反应建立了通用的热力学数学模型。用于预测气化炉出口的煤气成分、产量等。并利用该模型计算分析了煤加氢气化直接生成CH4的过程,主要分析了反应温度及压力对加氢气化反应的平衡常数和平衡转化率的影响。用化学动力学方法建立数学模型,通过计算获得主要气体产物与反应温度和压力之间的关系,以及气化过程中氢气系数对最终气体产物的影响。     

一种新型天然气锅炉烟气余热回收系统

引言随着城市生活水平的提高,空气质量逐渐成为人们关注热点,清洁能源得到越来越广泛的应用。天然气的大量开采,使得天然气锅炉凭借其节能环保的优势在城市供暖中逐渐占据主导地位。然而,天然气锅炉同样存在排烟温度高引起的一次能源浪费问题。目前大多数热水锅炉的排烟温度为140~200℃,一些蒸汽锅炉则高达250℃。同时,由于     

Multilevel surrogate modeling of an amine scrubbing process for CO2capture

Surrogate models provide a powerful method for simplifying calculations within complex simulations. While surrogate models are broadly applied within chemical engineering, little research exists investigating the level of surrogacy's impact on a simplified process model. In this work, artificial neural networks (ANN) and Kriging models are used as surrogate models at the process, process unit, and thermodynamic levels for a CO₂ amine scrubbing process. The surrogated models are evaluated against an Aspen Plus simulation for accuracy, convergence behavior, computational cost, and ability to extrapolate. The thermodynamic and process unit models can better handle discontinuous, non-smooth behavior, and convergence issues in the surrogated truth model, but poor conditioning in the final system of equations results in a lower accuracy and convergence rate than the process level surrogate. Beyond model accuracy, availability of diverse data, intended re-usability, and the desired outputs must be considered when selecting a level of abstraction.     

Integrated ionic liquid and rate-based absorption process design for gas separation: Global optimization using hybrid models

A new method for integrated ionic liquid (IL) and absorption process design is proposed where a rigorous rate-based process model is used to incorporate absorption thermodynamics and kinetics. Different types of models including group contribution models and thermodynamic models are employed to predict the process-relevant physical, kinetic, and thermodynamic (gas solubility) properties of ILs. Combining the property models with process models, the integrated IL and process design problem is formulated as an MINLP optimization problem. Unfortunately, due to the model complexity, the problem is prone to convergence failure. To lower the computational difficulty, tractable surrogate models are used to replace the complex thermodynamic models while maintaining the prediction accuracy. This provides an opportunity to find the global optimum for the integrated design problem. A pre-combustion carbon capture case study is provided to demonstrate the applicability of the method. The obtained global optimum saves 14.8% cost compared with the Selexol process.     

Dynamic modeling of a gas pressure control system for a gas‐assisted injection molding process

This study presents the development of dynamic models for gas injection pressure that may be implemented in the design of control systems for gas‐injection units. A nonlinear dynamic model was first derived and then verified by experimental measurements. This was done by using a laboratory‐built, gas‐assisted injection unit. The agreement between the prediction and measurement indicates that the present nonlinear dynamic model adequately predicts the dynamic behavior of gas injection pressure during the process. Although the resulting model is useful for understanding the behavior of the process and the effects of different process variables, its complexity may cause difficulties in a real control application. Therefore, a second‐order model based on the basic characteristics of the nonlinear model was proposed to approximate the gas injection pressure. In order to determine the model parameters, the algorithm of recursive least‐square system identification was employed. A comparison of simulated results of an identified model with experimental data showed that the model accurately predicted the transient behavior of gas injection pressure. Consequently, this low‐order model can be easily implemented into the control system design of a gas‐injection unit.     

Modeling of the Off‐Gas Cooling System for an Electric Arc Furnace and Evaluation of the Heat Recovery Potential

The prerequisite for the optimization and control of many industrial processes is having a model. It should be accurate and fast to prepare an appropriate estimation of the process. The exhaust system plays a significant role in the electric arc furnace process and, therefore, its optimization is investigated in this work. An unsteady and nonlinear model of the fluctuating off‐gas flow through the exhaust system is presented based on the mass and energy conservation laws. The thermodynamic calculations are facilitated by modular based modeling and also the model is implemented equipmentwise to cover all possible arrangements in the dedusting system. A Sankey diagram of the whole system is illustrated to examine the heat recovery potential of the off‐gas cooling system.     

集成NGL回收的新型天然气液化系统AP-XTM的概念设计与模拟分析

为提高液化天然气能量集成与设备共用水平,提出了一种基于大型AP-X^TM液化流程，综合气体过冷技术（GSP）的集成NGL（天然气凝液）回收工艺的天然气液化系统的概念设计。基于化工流程模拟软件Aspen HYSYS进行模拟和分析，将集成工艺多流股换热器性能、全流程的单位功耗和乙烷回收率作为衡量系统性能的三项指标。模拟和分析的结果表明，集成NGL回收的AP-X^TM液化工艺单位功耗降低至0.45 kW·h·(kg LNG)^-1，较单产系统能耗降低了6%，同时乙烷回收率达到93%，实现了NGL的高效分离。通过热力学分析、?分析和经济性分析得出本设计流程具有较高的性能和经济价值，可为天然气液化工艺的集成设计和技术改造提供指导借鉴。