基于受控混杂Petri网的事件逻辑驱动的炼油厂动态调度建模方法

将受控混杂Petri网同事件逻辑网和数学规划相结合提出了一种适用于炼油等流程工业生产调度的动态建模方法.作为事件逻辑网和数学规划模型之间连接的桥梁,受控混杂Petri网将离散变量和连续变量统一在一个模型中.用受控混杂Petri网建立整个生产流程的仿真模型,事件逻辑网响应生产过程中的突发事件并结合经验规则做出逻辑判断,产生新的调度指令.生产过程重新调整后,上层数学规划模型进行相应更新,产生的优化结果作为设备新的运行参数.该模型既可以响应突发事件,又能及时进行优化,具有更好的动态优化特性.     

煤化工产品加工流程模拟系统CCPS的设计与实现

结合煤化工产品工艺特点,建立了此过程的热力学计算方法和单元设备数学模型,开发了煤化工产品加工流程模拟软件ＣＣＰＳ,并对焦油闪蒸及初馏生产工艺流程进行了模拟运算,计算结果与现场数据吻合。     

Ganzheitliche Verfahrensentwicklung und ‐optimierung aus industrieller Sicht

This paper describes the way in which processes are currently developed and optimized within a chemical firm, paying attention to all aspects of the production process. The use of mathematical models and simulation alongside laboratory and plant experiments has proved successful for well understood processes. For new processes that are not as well understood, knowledge‐based process synthesis tools offer advantages over optimization‐based synthesis methods, which select particular designs from a predefined superstructure. Methods of mathematical programming are used in production logistics.     

Designing the optimal structure of the petrochemical industry for minimum cost and least gross toxicity of chemical production

The factor of toxicity associated with chemical production is incorporated into the simulation of the industrial development of the petrochemical industry which was previously studied for production economics. Choosing threshold limit value as chemical toxicity index, a toxicity model is formulated capable of structuring the industry for the least amount of toxicity resulting from the emission of organic pollutants. The optimal industry also points out the industrial sectors which contribute more to the industry-wide toxicity of chemical production.The industrial structure corresponding to the least gross toxicity is observed to be in conflict with that of the minimum production cost in terms of process selection. Using the theory of multiobjective programming this conflict is then explicitly displayed as a noninferior solution set which comprises a host of optimal structures each representing a particular value judgment between the cost of chemical production and its associated toxicity. Further, based on a balanced view on the two objectives, a small solution set is proposed as the best compromise. Within this solution region, the industrial structures corresponding to both design objectives are observed to be practically identical. This can be seen as a flexible as well as a reasonable compromise solution to the dual-objective industrial problem.     

Classical and alternative fuel mix optimization in cement production using mathematical programming

In this paper a systematic methodology is presented for the simultaneous optimal selection of raw materials, fossil fuels and alternative fuels in cement production. The aim is to offer a generic mathematical formulation that can be used as the basis for developing case specific mathematical formulations that can assist the strategic decision-making process. The mathematical model presented takes into consideration the essential elements of a cement plant operation. The final formulation is a mixed integer linear programming problem that aims at minimizing the overall operating cost. A realistic case study is presented which demonstrates the usefulness of the proposed mathematical programming methodology.     

等离子体裂解煤工艺过程的三维仿真与可视化监控系统

将等离子体裂解煤的新工艺过程,利用三维仿真可视化技术建立了全流程的监控系统,通过采集生产实时数据,可以对生产过程进行三维可视化监控。该工艺过程监控系统的三个组成部分,包括三维建模环境、过程集成仿真系统与可视化监控平台,并且针对具体的工艺流程,详细说明了每个部分的原理与实现过程。该系统通过生产过程与数据的可视化呈现以及现场应用实例,可以为等离子体裂解煤工艺过程的流程模拟仿真培训与三维可视化的实时过程监控提供有效的支持。     

MODELING, SIMULATION AND DESIGN OF CONVECTIVE INDUSTRIAL DRYERS

The use of computers to perform simulations of chemical engineering processes has lead to the development of software tools that perform most tedious computations in the field of process analysis, mathematical modeling and design. In the case of dryers, these mathematical programming aspects can be dealt in a straightforward way. The mathematical models of all popular convective dryers are presented and analysed. The transport and thermophysical properties of materials and air involved in the developed mathematical models are briefly discussed. The simulation of convective drying processes facilitated by modern computer technology is outlined and discussed. Design of convective industrial dryers is described and performed through the simulation tools developed. Short-cut design techniques are introduced allowing concentrated information on design results for various levels of process parameters and variables to be integrated in generalized design curves that produce values of optimal dryer structures and operating conditions related to cost     

醋酸生产的仿真研究(Ⅲ)--分离系统的仿真

在MATLAB的SIMULINK环境中对醋酸生产的分离系统进行动态仿真。建立醋酸蒸发器的数学模型，根据实际流程并结合数学模型建立相应的SIMULINK方框图，进行实际生产的动态仿真；建立精馏塔的通用动态数学模型，在SIMULINK中以S-函数的方式进行实现，相平衡计算采用严格的热力学模型，针对醋酸分离流程中的低沸点塔按两种开工情况进行仿真。     

探究支持向量机算法在化学化工中的应用

计算机技术的快速发展,给化学化工数据的处理带来极大便利。通过机器学习算法,可以总结化学化工实验规律,控制化工生产过程。原有的机器算法虽能为化学化工带来很大便利,但是它本身就存在缺陷。机器学习算法的核心是数学中的渐近理论,这项理论的适用情景是必须有大量的样本,而实际的化学化工工作中样本有限,这就可能导致计算中的过拟合。为了解决这一弊病,我们采用了向量机算法取代原有的机器算法,目前使用支持向量机算法(SVM)建立数学模型已经得到国内外的广泛关注。笔者通过调查化学化工行业中SVM的使用情况,阐述了向量机算法的优势,分析了它在食品检验、化工生产等多项领域的应用。     

NOx废气吸收的板式塔模型

化学工业中产生的NOx废气是一种大气污染源,对人类和生态环境具有极大的危害,用水或稀硝酸溶液吸收氮氧化物可以回收硝酸,是化学工业中应用较为广泛的氮氧化物废气治理方法之一。文章通过对氮氧化物气体吸收过程中的气液相反应平衡和传质机理进行研究,结合板式塔吸收的特点,建立了水或稀硝酸在板式塔内吸收NOx废气的数学模型,并进行了实验验证,模拟结果和实验结果吻合良好。模型计算分析结果表明,氮氧化物的吸收效果随着温度的升高而降低,随着压力的增加而增加,而且压力对氮氧化物吸收效果的影响比温度对氮氧化物吸收效果的影响显著,随着停留时间的延长,起初氮氧化物的吸收效果迅速增强,当停留时间达到10 s时,氮氧化物的吸收效果的增强不再明显。     

基于Matlab的精馏塔模拟计算

通过计算机编程软件,运用三对角矩阵法的严格算法对醋酸乙烯精馏过程中的精馏塔进行模拟计算。而模拟的结果与实际情况符合,由此可以实现计算机模拟化工过程的可能,并能将其应用到真实的化工生产中。     

平衡分解率模拟分解炉工艺特性

应用高温、悬浮态气固反应试验台测得的碳酸钙平衡分解率，建立了分解炉的数学模型，并针对某水泥厂的物料及工艺参数进行了分解炉工艺特性模拟实验，提出了用平衡因子评价实际分解炉状态的概念，其模拟结果与实际情况有很好的可比性。这种模型可用于各种类型分解炉的工艺特性研究、工业设计和生产控制。     

Process systems engineering studies for the synthesis of catalytic biomass-to-fuels strategies

The goal of this paper is to show how chemical process synthesis and analysis studies can be coupled with experimental heterogeneous catalysis studies to identify promising research directions for the development of strategies for the production of renewable fuels. We study five catalytic biomass-to-fuels strategies that rely on production of platform chemicals, such as levulinic acid and fermentable sugars. We first integrate catalytic conversion subsystems with separation subsystems to generate complete conversion strategies, and we then develop the corresponding process simulation models based on experimental results. Our analyses suggest that catalytic biomass-to-fuel conversion strategies could become economically competitive alternatives to current biofuel production approaches as a result of iterative experimental and computational efforts.     

A rigorous targeting algorithm for resource allocation networks

Techniques of process integration can be applied to conserve resources such as energy, freshwater, cooling water, hydrogen, solvent, etc. Process integration methodologies are broadly classified into two categories: methodologies based on the mathematical optimization techniques and methodologies based on the conceptual approaches of pinch analysis. In this paper, a mathematically rigorous methodology is proposed to minimize the requirement of a natural resource in a chemical process industry. The proposed methodology combines the simplicity of the pinch analysis with the mathematical rigor of mathematical optimization techniques. Conservation of resource in a chemical process industry is posed as a network flow optimization problem and a simple algebraic methodology is proposed to solve the optimization problem. The proposed algebraic methodology is mathematically proved in this paper. The proposed algorithm is numerically faster than the general mathematical optimization methods used for solving optimal resource allocation problems.     

Consequence Identification for Maloperation in Batch Process

Batch processes are important in chemical industry, in which operators usually play a major role and hazards may arise by their inadvertent acts. In this paper, based on hazard and operability study and concept of qualitative simulation, an automatic method for adverse consequence identification for potential maloperation is proposed. The qualitative model for production process is expressed by a novel directed graph. Possible operation deviations from normal operating procedure are identified systematically by using a group of guidewords. The proposed algorithm is used for qualitative simulation of batch processes to identify the effects of maloperations. The method is illustrated with a simple batch process and a batch reaction process. The results show that batch processes can be simulated qualitatively and hazards can be identified for operating procedures including maloperations. After analysis for possible plant maloperations, some measures can be taken to avoid maloperations or reduce losses resulted from maloperations.     

MPEC problem formulations and solution strategies with chemical engineering applications

With the development and widespread use of large-scale nonlinear programming (NLP) tools for process optimization, there has been an associated application of NLP formulations with complementarity constraints in order to represent discrete decisions. Also known as mathematical programs with equilibrium constraints (MPECs), these formulations can be used to model certain classes of discrete events and can be more efficient than a mixed integer formulation. However, MPEC formulations and solution strategies are not yet fully developed in process engineering. In this study, we discuss MPEC properties, including concepts of stationarity and linear independence that are essential for well-defined NLP formulations. Nonlinear programming based solution strategies for MPECs are then reviewed and examples of complementarity drawn from chemical engineering applications are presented to illustrate the effectiveness of these formulations.     

考虑本质安全的换热网络多目标优化

由于国内外重大化工事故的频发及化工行业节能降耗的需求日益迫切,研究本质更安全的换热网络多目标优化具有重要意义。采用评价指数的方法,对换热网络的本质安全易爆性、毒性、存量进行量化表征。采用数学规划法分别建立换热网络经济与本质安全易爆性、毒性、存量同步优化数学模型。采用归一化法构建经济和安全的目标函数。通过算例研究发现,考虑易爆性,倾向于不易爆流股间换热,减少易爆流股换热次数;考虑毒性,倾向于减少有毒流股流经换热器的次数;考虑存量倾向于减少换热网络的总存量。最后综合考虑易爆性、毒性、存量作为安全指标与经济同步优化,通过算例研究表明,多目标优化的最优换热网络在很大程度上取决于经济权重的选取。     

Multisite facility network integration design and coordination: An application to the refining industry

This paper addresses the design and analysis of multisite integration and coordination strategies within a network of petroleum refineries using different crude combination alternatives. In addition, production capacity expansion requirements are also accounted for. The main feature of the paper is the development of a methodology for simultaneous analysis of process network integration alternatives in a multisite refining system through a mixed-integer linear program (MILP) with the overall objective of minimizing total annualized cost. The State Equipment Network (SEN) representation was used for modeling the network as it provides a consistent modeling strategy and proper handling of units that operate under different operating modes, which is common in the refining industry. The integrated network design specifically addresses intermediate material transfer between processing units at each site. The performance of the proposed model was tested on several industrial-scale examples to illustrate the economic potential and trade-offs involved in the optimization of the network. The use of mathematical programming models on an enterprise-wide scale to address strategic decisions considering various process integration alternatives yielded substantial benefits. These benefits not only materialize in terms of economic considerations, but also in terms of process flexibility and improvements in the understanding of the process interactions and systems limitations. Although the methodology was applied on a network of refineries, it can be readily extended to cover any network of continuous chemical processes.     

动态模拟技术与化学工程

介绍了化工过程动态模拟技术及相应软件的发展与应用状况 ,总结了动态模拟技术的最新进展。指出动态模拟技术应当与动态优化技术相结合 ,动态计算机网络管理将实现石油化工过程的连续实时优化 ,动态模拟技术将向工艺流程和生产方案的合成、能量系统集成、结合生态工业园区实例进行动态流程模拟等方向发展