炼钢生产物流系统仿真的细胞自动机模型

基于细胞自动机建模思想提出了炼钢生产物流系统仿真的细胞自动机方法,并建立了相应的模型,用工位、作业以及作业规则来描述物流系统,以工位作为细胞自动机仿真模型的网络格点;按炼钢物流特点设定格点的属性值并抽象出模型的自组织演化机制。针对攀钢炼钢生产的建模与仿真实验表明：根据微观动力学局域作用机制和自组织演化思想建立的细胞自动机动态仿真模型是有效的,模型的建立为复杂制造流程的系统仿真提供了新的手段。     

基于Petri网的钢铁生产复杂物流系统建模

针对钢铁生产过程中物流系统结构复杂和实体间交互关系难以表达以及有效精确建模等问题,把钢铁生产复杂物流系统抽象定义为多智能体（Agent）系统,提出对基本Petri网进行颜色和时间的扩展及与多Agent技术相结合的建模方法。以智能体为基本建模元素,利用时间着色Petri网来描述Agent内部行为规则及其之间的交互过程,基于分层建模思想,结合某钢铁企业炼钢生产工艺和设备参数,在AnyLogic仿真平台上实现了钢铁生产复杂物流多智能体系统建模。仿真结果表明,该建模方法能够真实有效地反映炼钢生产过程复杂物流系统的特性。     

一种可应用于分布式仿真的连铸物流仿真系统

介绍了一种可应用于分布式仿真的连铸物流仿真系统,该系统通过模拟连铸各个生产环节、内嵌与物流相关的模型、搭建连铸生产环境,实现了对连铸物流的仿真.还介绍了系统通用性、可作为分布式仿真节点的特点及实现方法,及其在生产过程管理方面的作用.     

中冶赛迪自主研发的炼钢物流系统仿真平台

中冶赛迪自主研发的炼钢物流系统仿真平台作为实际系统的预测器,为方案决策和优化提供准确而详细的数据,成功实现了对炼钢生产过程的有效的流程仿真,具有快速建模、虚拟现实的现实和分析、仿真与优化算法相结合等功能特点。该平台现已广泛应用于多个国内外炼钢工程项目的规划和设计。     

基于时间影响网络的铁水运输系统时间Petri网建模

针对铁水运输系统流动途径网络化和动态复杂性等特点,考虑到运输系统对整个企业有序运行和产品质量及成本控制至关重要的影响作用,基于铁水运输时间约束条件的复杂多样性和不确定性,利用时间Petri网与时间影响网络相结合的建模理论和方法,构建钢铁企业铁水运输复杂物流系统模型。在Extendsim仿真平台基础上,通过算法优化和二次开发,实现某炼钢厂铁水运输复杂物流系统的模拟仿真,为铁水物流路径网络动态优化和改进、提高钢铁生产物流过程运行效率、实现节能减排目标提供指导和帮助。     

物流仿真技术在炼钢连铸调度计划中的应用

物流仿真技术的应用研究是国内外研究的一个热点.首先简要介绍了炼钢连铸物流研究中的一些理论和方法,分析了炼钢连铸生产计划与调度的过程、工艺和特征等.然后针对炼钢连铸调度的复杂混合系统的特性,建立了各物理对象的Petri模型,进一步根据炼钢连铸的调度目的,开发了基于组件技术及其体系架构的炼钢连铸物流仿真系统.最后给出了一个调度计划的实例,说明了物流仿真系统的应用效果.     

中厚板热轧生产线物流仿真关键技术研究

物流仿真技术是分析中厚板热轧生产线生产节奏、生产瓶颈、在制品库存、生产周期、产出率等,并实现生产过程的可视化演示的重要手段。首先介绍了中厚板热轧生产线的主要工艺过程,然后指明了应用物流仿真研究该问题的目的,并重点介绍了系统开发过程中的多项关键技术,如轧机轧制过程处理方法、冷床作业过程,冷却模型的集成方法、热分切定尺剪过程方法等。最后给出了一个中厚板物流仿真系统的应用实例。     

宝钢炼钢连铸物流仿真器的建模方法

宝钢炼钢连铸物流系统是一个典型的混杂系统,使用Petri Net可以很好地描述其特征,因此Petri Net是炼钢连铸物流研究的重要方法之一。介绍了Petri Net、COM等技术的基本概念和方法,并根据宝钢炼钢连铸物流的特点,提出了基于面向对象技术和Petri Net技术相结合的炼钢连铸物流仿真方法。构建了宝钢炼钢连铸物流仿真器的Petri Net模型、组件模型等,并对其组态技术及其实现进行了详细介绍,进一步给出了组态环境的实现界面。     

仿真技术 CISDI-联合钢铁企业物流仿真

正炼钢系统仿真炼钢系统仿真多方案多工况分析优化了天车任务调度,减少天车冲突次数10%以上,优化了罐周转数目。铁水铁路系统仿真铁水铁路系统仿真论证了平交道口的通行能力满足需要,取消经四路立交桥的总图布置方案,节约投资2000多万。全厂道路系统仿真全厂道路系统仿真验证了道路系统是否匹配生产系统产能需求。通过优化组织调度每年可节约物流成本500万左右(包含时间浪费成本、运营成本)。     

汽车尾气热能回收系统建模仿真分析

介绍了一种汽车尾气热能回收系统,利用Solidworks进行了建模仿真分析,并利用Fluent软件对汽车尾气管出口处的速度场、压力场和温度场进行了定性的仿真分析。     

Mathematical modeling of pharmacy systems

Mathematical modeling and its potential applications in pharmacy are discussed. A model is a simplified representation of the real world. As an experimental approach, modeling minimizes expense, risk, and disruption, but its validity can be hard to ascertain. Mathematical models describe numerically the relationships among elements of a system and are a powerful tool in making decisions affecting that system. There are two types of mathematical models: analytical models, which directly describe the relationships between system inputs and outputs using mathematical equations (such as pharmacokinetic models), and simulation models, which involve the replication, usually with a computer, of events as they occur in the real world. Analytical models are easier to develop but are not appropriate for describing highly complex systems. In continuous-time simulation, the system is represented as an uninterrupted flow of material; in discrete-event simulation, it is assumed that events occur only at distinct times. Various simulation programs are commercially available. The stages of a mathematical modeling study are (1) formulate the problem, (2) determine the model's structure, (3) collect and analyze initial data, (4) develop the model further, (5) validate the model, (6) experiment using the model, and (7) use the results. There have been many applications of modeling in health care, but relatively few have involved the study of pharmacy systems. Mathematical modeling offers pharmacists a low-risk, low-cost tool for aiding decisions about pharmacy systems by predicting alternative futures.     

Integrated Hydrodynamic and Water Quality Modeling System to Support Nutrient Total Maximum Daily Load Development for Wissahickon Creek, Pennsylvania

This paper presents a hydrodynamic and water quality modeling system for Wissahickon Creek, Pa. Past data show that high nutrient levels in Wissahickon Creek were linked to large diurnal fluctuations in oxygen concentration, which combining with the deoxygenation effect of carbonaceous biological oxygen demand (CBOD) causes violations of dissolved oxygen (DO) standards. To obtain quantitative knowledge about the cause of the DO impairment, an integrated modeling system was developed based on a linked environmental fluid dynamics code (EFDC) and water quality simulation program for eutrophication (WASP/EUTRO5) modeling framework. The EFDC was used to simulate hydrodynamic and temperature in the stream, and the resulting flow information were incorporated into the WASP/EUTRO5 to simulate the fate and transport of nutrients, CBOD, algae, and DO. The standard WASP/EUTRO5 model was enhanced to include a periphyton dynamics module and a diurnal DO simulation module to better represent the prototype. The integrated modeling framework was applied to simulate the creek for a low flow period when monitoring data are available, and the results indicate that the model is a reasonable numerical representation of the prototype.     

Numerical Simulation and Cold Modeling experiments on Centrifugal Casting

In a centrifugal casting process, the fluid flow eventually determines the quality and characteristics of the final product. It is difficult to study the fluid behavior here because of the opaque nature of melt and mold. In the current investigation, numerical simulations of the flow field and visualization experiments on cold models have been carried out for a centrifugal casting system using horizontal molds and fluids of different viscosities to study the effect of different process variables on the flow pattern. The effects of the thickness of the cylindrical fluid annulus formed inside the mold and the effects of fluid viscosity, diameter, and rotational speed of the mold on the hollow fluid cylinder formation process have been investigated. The numerical simulation results are compared with corresponding data obtained from the cold modeling experiments. The influence of rotational speed in a real-life centrifugal casting system has also been studied using an aluminum-silicon alloy. Cylinders of different thicknesses are cast at different rotational speeds, and the flow patterns observed visually in the actual castings are found to be similar to those recorded in the corresponding cold modeling experiments. Reasonable agreement is observed between the results of numerical simulation and the results of cold modeling experiments with different fluids. The visualization study on the hollow cylinders produced in an actual centrifugal casting process also confirm the conclusions arrived at from the cold modeling experiments and numerical simulation in a qualitative sense.     

基于MIND方法的钢铁企业能源系统集成优化

钢铁企业生产系统结构复杂,含铁物质流和含碳能量流相互交错,形成庞大的物质流、能量流网络,能源系统涉及参数多,错综复杂,节能减排工作面临较大难度。MIND方法是一种面向企业级能源系统建模和优化的方法,是从系统的角度考虑节能方法。以钢铁企业物质流、能量流数据为基础,通过MIND建模方法,构建了某钢铁企业能源系统集成优化模型,通过CPLEX进行求解,并对结果进行了分析。研究结果表明：所建立的能源系统优化模型符合企业实际,误差小于1.5%;通过提高能源转换水平、主生产能力和外加含铁物流用量等参数,得到了生产优化方案,降低了能源消耗。     

Debris Flow Simulation-Oriented Three-Dimensional Scenery Modeling and Rendering

3D (three-dimensional) process simulation is currently one of the most challenging fields of research on debris flow.Large scale terrain rendering is the most basic task of 3D scenery construction in debris flow simulation. As the major trigger for debris flow, rainfall will substantially enhance the realistic sense. Terrain and rainfall rendering in 3D debris flow simulations poses great challenges for numerical computation and graphical processing capability. In this paper, we propose to integrate GPU technology, LoD algorithms, and particle systems to realize 3D scenery modeling and rendering. The real-time LoD-based terrain modeling and rendering algorithm is presented first, and then a particle systcm-basext rainfall scenery rendering method is implemented. Experimental results demonstrate that the 3D scenery rendered with the proposed approach exhibits sound performance and fair visual effects, which lays a solid foundation for the whole process simulation of debris flow disasters.     

基于系统动力学的烧结工序铁素流动态特性分析

运用系统动力学原理,采用因果关系和存量流量分析方法,在相对宏观的层面构建了钢铁生产过程烧结工序的铁素流动态模型。仿真结果准确,验证了系统动力学原理应用于钢铁生产流程研究的适用性及建模仿真的有效性。计算表明:烧结矿铁素流随时间的增加而不断增大,然后逐渐趋于稳定,且烧结矿铁素流在烧结初始时段增加速度最快;返回铁素流波动越大,烧结矿铁素流、损失铁素流和烧结机铁素重新达到输出稳定状态所需时间越长。     

Continuum Modeling and Discrete Element Simulations of Elastic-Quasi-Static Granular Flow in a Compressing Slot

The stress generated by the horizontal compression of a vertical column of granular material is investigated. The column is open at the top so that the material is free to flow upward in the slot as it is compressed. This simple geometry has interesting mechanics because both elastic and frictional regimes coexist, and it is also relevant to problems involving the insulating material in cryogenic storage tanks. Two methods are used to investigate this problem: traditional continuum modeling and discrete element simulation. The continuum model assumes that the column consists of a frictional region near the top of the column and a linearly elastic region near the bottom. Analytic solutions are obtained for each region and predictions for the location of the transition are made based on intersections of the two solutions. A discrete element simulation of the same geometry is performed to compare with the results from the continuum model. Various conditions of wall friction and particle stiffness are simulated. Based on the outcome of this comparison, we verify that in a compressing slot there are essentially two distinct regions: a frictional flow region near the top of the column that results in an exponential increase in stress with depth. This eventually saturates leading to a linear-elastic plane strain region. The location of the transition between these two regions depends on the material properties and the state of the compression.     

3D Shape Characterization and Image-Based DEM Simulation of the Lunar Soil Simulant FJS-1

This paper describes a procedure used to characterize the three-dimensional (3D) grain shape of lunar soil and undertake simulations of lunar soil by image-based discrete element method (DEM). Given that detailed 3D grain-shape information is unavailable for real lunar soil, a simulant material, FJS-1, is used in this study. We use the high-resolution micro X-ray CT system at SPring-8, a synchrotron radiation facility in Japan, to visualize precise 3D images of the granular assembly of FJS-1. A newly developed image-analysis procedure is then applied to identify individual grains. Using the obtained grain-shape data, a sufficient number of FJS-1 grains are directly modeled for DEM simulation using an efficient modeling scheme. A series of particle flow simulations are then performed with the modeled grains. The resulting slope angles are in good agreement with experimental results. We discuss the effect on the slope angle of grain parameters such as contact stiffness, restitution coefficient, and interparticle friction.     

Modeling of Multilayer Composite Fabrics for Gas Turbine Engine Containment Systems

An experimental and modeling system for the modeling of multilayer composite fabrics used in a gas turbine engine containment system is developed. Specifically, Kevlar 49 (17×17) and Zylon AS (35×35) fabrics are used in the study. The experimental setup is first used to obtain the material properties of these fabrics. Later, one or more layers of these fabrics is tightly wrapped around a steel cylinder that simulates an engine containment housing. A steel penerator (or a blunt nose) is used in a static test by slowly pushing against the fabric. The resulting load-deflection data are used to compute a variety of parameters, including the energy absorption capacity. The material behavior obtained from the experimental study is then used as the constitutive model in a finite element simulation of the static test. The objective is to develop a procedure for understanding the relative strengths and weaknesses of different fabrics and to aid in the development of finite element modeling of actual fan blade-out events.     

钢铁企业能源系统网络模型仿真及组态的研究与实现

以钢铁企业为研究对象,以各工序及设备间的物质流、能量流及其产消转换关系为基础,把整个钢铁企业划分为五个子系统：生产系统、能源转换系统、回收系统、库存系统、连接系统,分别建立了能源产消单元模型,接着建立了整个企业的能源系统网络模型,并定义了其形式化模型,然后设计开发了用于钢铁企业能源仿真的工厂组态软件。针对某钢铁企业能源系统的现状,利用所开发的组态软件,设计出能源系统的组态模型,通过仿真计算,对仿真模型和组态软件进行了验证,仿真数据与实际数据误差较小,能够反映企业能源产消现状。