Model Software Package Development for Laminar Cooling Process in a Hot Mill

 The use of computer simulation techniques in the control system design of the laminar cooling process in a hot mill can significantly reduce the development cost while ensuring maximum production safety. The case-based modelling strategy that the authors proposed was implemented in a software package. The functional structure of the software package was discussed in detail. The interfaces and functions of the software package were introduced. The results of industrial experiments can be directly visualized in the software package, allowing accurate and instant comparison of the model predictions with real measurements. The software package provides the simulation platform for research into advanced modelling and control strategies of the laminar cooling process in a hot rolling mill.     

济钢1700热轧层流冷却过程控制系统的开发与应用

针对济钢1700 mm热连轧生产线原层流冷却卷取温度控制系统中,存在的不足和弊端,分析影响卷取温度的各种因素,对原系统进行了升级和改造,由原来简单的一级控制改为二级模型过程控制,并且取得了不错的效果.     

层流冷却的前馈控制

为提高热轧带钢层流冷却卷取目标温度的控制精度,根据冷却过程的传热机理,分析了带钢层流冷却的传热过程.在此基础上,给出了冷却控制的空冷和水冷预测数学模型,分析并阐述了层流冷却控制系统的前馈控制算法及其在实际控制中的应用.本前馈控制的使用效果良好,具有较高的目标卷取温度控制精度,能满足生产的需要.     

带钢厂热轧机组层流冷却数学模型

对带钢层流冷却的传热过程进行了分析,以此作为层流冷却控制的传热模型和自学习模型的理论依据,给出了带钢厂热轧机组层流冷却在线控制的传热和自学习模型的算法,从数学模型的角度对控制模型的实际运行结果进行了分析.     

Hot Strip Laminar Cooling Control Model

The control model of laminar cooling system for hot strip, including air-cooling model, water-cooling model, temperature distribution model along thickness direction, feedforward control model, feedback control model and self-learning model, was introduced. PID arithmetic and Smith predictor controller were applied to feedback control. The sample of model parameter classification was given. The calculation process was shown by flow chart. The model has been proved to be simple, effective and of high precision.     

热轧带钢层流冷却自动控制系统开发与应用

结合现场情况介绍了热轧带钢层流冷却自动控制系统的设备及硬件配置,并从过程自动化和基础自动化两个方面介绍了该系统的功能和数学模型,其中数学模型主要包括空冷模型、水冷模型、自学习模型和前馈控制模型以及反馈控制模型。现场实际应用表明,带钢全长的95.93%的卷取温度可控制在目标值的±15 ℃之内。     

层流冷却过程中带钢温度场数值模拟

分析了带钢层流冷却过程中的传热，并利用有限元法对层流冷却过程中带钢温度场进行了模拟计算。结果表明：随着轧件厚度的减薄，在带钢厚度方向上的温差逐渐减小；冷却速度不同时，带钢表面温度和中心温度的变化趋势以及波动幅度相应发生变化。在进行模型计算时，应合理考虑带钢厚度及内部热传导的影响。这对提高数学模型的精度，控制卷取温度，提高产品质量以及指导生产具有重要意义。     

热轧带钢层流冷却过程的温度预测模型

通过分析热轧带钢在层流冷却过程中的能量变化,利用焓法模型建立了热轧带钢通过层流冷却段的能量平衡方程。然后利用相变热力学和相变动力学模型得到热焓,最后采用有限差分求解能量平衡方程,得到层流冷却过程中带钢的温度场和热焓场,该模型的计算结果与实测值符合良好,能够准确地预测带钢冷却后的温度分布,同时明确了冷却过程实际上是带钢能量传递给周围环境的过程,并非温度不断下降的过程。     

济钢1700mm热轧层流冷却系统改造

针对济钢1700mm热连轧生产线原层流冷却卷取温度控制系统中存在的不足和弊端,通过采用数学模型,开发多种冷却策略,修正带钢速度变化,抛钢后处理,采用反馈控制,开发模型维护工具等措施对层流冷去系统进行改造。系统改造后稳定可靠,卷取温度命中率有了较大幅度的提高。     

层流冷却工艺在鞍钢1580 mm机组的应用

介绍了鞍钢1580 mm机组带钢轧后层流冷却控制系统工艺设备与数学模型在检测仪表、集管组及侧喷等方面的布置及改进优化。细化卷取目标温度、钢种及厚度层别,引入实际水温变量,优化冷却模式。实践表明,鞍钢自主研发的热轧带钢层流冷却控制系统具有较高的卷取温度控制精度,满足复杂的品种冷却工艺需求。     

Cooling Efficiency of Laminar Cooling System for Plate Mill

Heat transfer was researched from a perspective of the industry application. On the basis of the first law of thermodynamics, the cooling efficiency was deduced from the change of enthalpy inside hot plate. The relationship between the cooling efficiency and its influencing parameters was regressed from plenty of data collected from the worksite and discussed in detail. The temperature profiles resulting from the online model and the model modified by regressed formulas were presented and compared. The results indicated that the control accuracy of the modified model was increased obviously.     

热轧带钢层流冷却计算机控制系统

从基础自动化、系统服务、过程自动化3个方面介绍了攀钢热轧带钢厂层流冷却计算机控制系统的设计，着重介绍了过程自动化中的样本微跟踪和一种改进的层冷热流密度参数回归求解方法以及系统模型调优。实际运行结果表明，国内自主开发的热轧带钢层流冷却计算机控制系统完全达到并超过了设计要求，具有较高的卷取温度控制精度。     

Optimization and Model of Laminar Cooling Control System for Hot Strip Mills

The microstructure and mechanical propertiesof hot rolled strips are determined by the tempera-ture drop fromthe exit of finishing stand to the coi-ler .Laminar coolingis an effective way to make theproducts with ideal microstructure and mechanicalproperties and the coiling temperature must be con-trolled properly[1 -4]. The traditional models cannot meet the require-ment for high precision of coiling temperature . Theai m of present work was to develop a newlaminarcooling system with satisfac…     

Self-Learning and Its Application to Laminar Cooling Model of Hot Rolled Strip

The mathematical model for online controlling hot rolled steel cooling on run-out table （ROT for abbreviation） was analyzed, and water cooling is found to be the main cooling mode for hot rolled steel. The calculation of the drop in strip temperature by both water cooling and air cooling is summed up to obtain the change of heat transfer coefficient. It is found that the learning coefficient of heat transfer coefficient is the kernel coefficient of coiler temperature control （CTC） model tuning. To decrease the deviation between the calculated steel temperature and the measured one at coiler entrance, a laminar cooling control self-learning strategy is used. Using the data acquired in the field, the results of the self-learning model used in the field were analyzed. The analyzed results show that the self-learning function is effective.     

热轧带钢层流冷却的控制策略及其应用

阐述了热轧带钢层流冷却常用的7个控制策略，即前馈控制、反馈控制、自适应控制、带钢头尾冷却控制、带钢边部冷却控制和对带钢厚度的适应性冷却控制以及对升速轧制的适应性冷却控制的内容及其发展，同时还简单地介绍了这些控制策略在国内某些热轧板厂的实际应用情况。     

Algorithm Design and Application of Laminar Cooling Feedback Control in Hot Strip Mill

 Abstract： Feedback control is one of the most important ways to improve coiling temperature control precision during laminar cooling process. Laminar cooling equipments of a hot strip mill and structure of the control system were introduced. Feedback control algorithm based on PI controller and that based on Smith predictor were designed and tested in a hot strip mill respectively. Practical application shows that the feedback control system based on PI controller plays a limited role in improving coiling temperature control precision. The feedback control system based on Smith predictor runs stable and reliable. When the measured coiling temperature deviates from the target value, it can be adjusted to the required range quickly and steadily by Smith predictor feedback control, which improves the coiling temperature control precision greatly, and qualities of hot rolled strips are improved significantly.     

Element Tracking Strategies for Hot Strip Laminar Cooling Control

Coilingtemperaturecontrolinhotstripmill playsaveryimportantroleindeterminingtheme chanicalpropertiesofthefinishedproduct[1].The earlypracticeofrunouttablecoolinginvolvedpre settingthewaterjetflowratebasedonexperience.Thisexperientialapproachwassufficientf…     

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In order to solve the problems of time-consuming and intense vibration during the calculation process of inverse heat conducting problem (IHCP) with conjugate gradient method (CGM), a non-iterative model was developed based on finite element method (FEM) and related program code was compiled with Fortran. This non-iterative method was then applied to IHCP of laminar cooling process of hot rolled steel plate to calculate the convective heat transfer coefficient in the boundary. Through comparison of the convective heat transfer coefficient obtained by both CGM and the non-iterative method, the results were shown to be consistent with each method. Furthermore, the computing result of the non-iterative method were more stable, and had an obviously faster speed, which eventually cut down the whole computing by 76%. The new method could retain high sparsity of the matrix, which is more concise than the exiting non-iterative method. Besides, the new non-iterative method could also be an efficient way to calculate the heat flux and wall temperature at the same time, which made it possible for real-time output of boundary conditions during laminar cooling process of hot rolled steel plate.     

中厚板轧后高密度管层流快冷控制模型

根据鞍钢厚板厂投产的国内第一套中厚板轧后高密度管层流控冷装置的特点,结合理论分析,建立了一套适用于中厚板轧后快冷的控制用数学模型.该模型由层流冷却预设定冷却模式、各预设定冷却模式下终冷返红温度预报模型、终冷返红温度修正模型、自学习模型等组成,且该套模型已在鞍钢厚板厂投入使用.