带钢连续退火炉加热室传热计算方法

对带钢连续退火组(CAPL)退火炉加热室传热进行了分析,提出了一种简化辐射管辐射的方法,并利用该法建立了带钢加热数学模型。用此模型,对某厂的CAPL加热室仿真计算结果与现场实测数据吻合较好。     

宝钢热轧4号加热炉传热模型的参数确定

根据宝钢热轧4号加热炉数模调试阶段的经验,总结了板坯传热模型参数确定的过程和方法。埋偶实验是整个模型参数确定的基础,它收集了模型参数确定的必要实际现场数据;板坯传热模型中的炉内温度模式确定了炉内的温度分布情况;热吸收系数φcg的值是进行板坯加热计算升温的最重要参数,它主要由加热炉的炉型和炉况决定,而水印温度的计算和控制可以更好地跟踪和控制加热质量。     

硅钢连退机组辐射管加热段数值模拟

文章以国内某公司硅钢厂连续退火机组1号辐射管加热段为研究对象,分析炉内传热机理,建立并开发了辐射管加热段的传热模型.采用生产实际数据对模型进行了验证,以总燃料消耗量最小为目标,得出该炉段长度方向上燃料的最佳分配机制.所得结论为该公司连续退火机组节能控制提供理论依据.     

宝钢HPH全氢罩式退火炉钢卷加热时间的研究

控制全氢罩式退火炉钢卷的加热时间,对提高生产效率,改善产品质量有重大意义。本文在宝钢生产条件下建立并验证了钢卷传热模型,然后以此为基础分析了钢卷的径向等效导热系数,钢卷外径、高度,炉内循环气体的流量、温度对钢卷加热时间的影响。研究表明,钢卷径向等效导热系数增加8W/(m℃)时,退火加热时间缩短3.3h;钢卷外径增加0.8m时,退火加热时间延长3.9h;钢卷高度增加0.6m时,退火加热时间延长5.9h;循环气体流量增加6000m3/h时,退火加热时间缩短了0.50h;循环气体温度提高40℃,退火加热时间缩短了2.8h。     

步进式加热炉加热时间预测优化

主要研究在热轧步进式加热炉过程控制计算机系统中，如何准确预测板坯在炉加热时间。通过分析时间预测计算的相关因素，给出了针对板坯抽出节奏、最小在炉时间和待轧策略等相关因素的时间预测优化手段。其中优化手段主要包括预测策略的改进，采用理论公式计算值替代经验常数，通过实际数据回归修正公式系数等。最后采用离线模拟试验，通过验证结果数据展现了优化效果。整个时间预测优化提高了炉内板坯在炉时间的预测精度，为加热炉自动燃烧控制模型提供了可靠的计算前提条件。同时准确的时间预测既保证了轧线对板坯产量的需求，又保证了板坯有较好的加热质量和较低的燃耗。     

冷轧全氢罩式炉退火工艺优化实践

通过冷轧全氢罩式炉退火过程的传热过程分析,建立全氢罩式炉退火过程数字化仿真平台。再利用现场插片实测数据对修正系数进行校正,得到与现场实际生产情况匹配的仿真平台。用仿真平台对现行全氢罩式炉退火工艺的加热制度、冷却制度、出炉温度进行优化。达到了降低全氢罩式炉能耗、提高炉台作业率及产品质量的目的。     

基于模糊聚类和最小二乘回归的罩式退火炉冷却时间预报及其应用

按照退火计划内各钢卷的钢种和厚度对退火中的冷却工艺进行分类 ,将罩式退火炉冷却时间预报的多入单出建模问题化为一组单入单出建模问题。采用模糊C均值聚类方法对退火生产数据进行处理 ,再基于得到的聚类数据点进行指数最小二乘回归。现场应用表明 ,该方法能够较为准确地实现退火炉冷却时间预报 ,满足了现场要求。     

基于Matlab环境的全氢罩式炉退火过程模拟研究

模拟退火钢卷温度场,预测退火时间,对于全氢罩式炉生产现场操作人员控制退火过程,减少退火时间和产品粘结率具有指导意义.在Matlab平台上,开发了界面友好,功能强大,方便使用的罩式炉钢卷温度场计算软件和退火加热时间预测软件.软件已作为离线预测工具应用于宝钢,为操作人员提供了决策支持,收到良好的效果.     

连续退火线辐射管炉内传热过程模型

建立连续退火辐射管加热炉内传热的数学模型,推导了模型的解析式,并给出了无量纲解的图像.引入当量灰平面法来简化带钢与辐射管之间的辐射换热计算,讨论了辐射管布置对系统黑度和机组长度的影响.计算表明,辐射管的间距直径比增加,系统黑度降低,机组长度增加.采用实际生产数据,分析了机组带钢厚度与机组速度的乘积(TV值)变化对带钢加热温度的影响.     

电接触加热时间的计算

本文根据电热原理和传热学理推导出了电接触加热时间的计算公式，并通过实验进行了验证。实验结果表明，该计算公式计算准确，可以指导实际生产和设计。     

Modeling of Strip Heating Process in Vertical Continuous Annealing Furnace

 The mechanism for heat transfer of radiation is usually adopted to heat strip in vertical continuous annealing furnace. The rate of heat transfer among strip and other objects can be hugely affected by the parameters of strip speed, geometry factors and radiating characteristic of surfaces of strip, radiating tubes and walls of furnace. A model including all parameters is proposed for calculating the heat transfer coefficient, predicting the strip temperature and boundary temperature of strip through analyzing these parameters. The boundary temperature is a important datum and different from average arithmetic value of temperature of strip and temperature in furnace. Also, the model can be used to analyze the relation for temperature of strip and heat transfer coefficient, total heat transfer quantity and heating time. The model is built by using the radiating heat transfer rate, the Newton′s law of cooling, and lumped system analysis. The results of calculation are compared to the data from production line. The comparisons indicate that the model can well predict the heating process. The model is already applied for process control in production line. Also, this research will provide a new method for analyzing the radiation heat transfer.     

环形加热炉管坯三维传热数学模型的研究

针对某公司环形加热炉的实际生产情况,建立了管坯加热过程的三维传热数学模型。采用交替隐式格式的TDMA（三对角矩阵）数值计算方法,开发了环形加热炉管坯加热过程三维传热数学模型计算机数值仿真系统。利用管坯内部温度黑匣子实验对所建立的数学模型进行了验证。结果表明：所建模型正确可信,同时也证明了利用管坯二维传热过程数学模型实现在线计算机优化控制的可行性。所做工作为某公司即将开展的管坯加热过程计算机优化控制奠定了坚实的理论基础。     

焦炉加热复合智能控制系统的研究与应用

 焦炉是具有大时滞、强非线性、多变量耦合、变参数的复杂对象。直行温度受多种因素的影响,传统的控制方法难以满足焦炉加热控制的要求。提出了间歇加热控制与加热煤气流量调节相结合的控制原理,利用模糊控制、神经网络等智能控制方法建立了焦炉加热的智能控制策略和模型。该控制策略采用一前馈、二反馈和智能控制相结合。根据焦化机理建立焦炉供热量前馈模型,并提出结焦指数CI反馈模型控制焦炉的炼焦过程。基于线性回归和RBF神经网络构建火道软测量模型,为控制建立温度反馈环节。智能控制方法用于调节停止加热时间和加热煤气流量。最后研究开发了焦炉加热的复合智能控制系统。实际运行结果表明：该系统能够实现焦炉加热的智能控制,稳定了焦炉生产,有效地提高了焦炭质量和降低了能耗,具有很好的实用价值。     

Thermal performance of annealing line heating furnace

Abstract

In the present study, a stepwise model based on the enclosure concept has been applied to an annealing line heating furnace. The model has been satisfactorily tested using three industrial manufacturing data sets. As temperature measurement inside the furnace is difficult, the model could be used to improve control and to obtain the outlet temperature of the steel strip, the heat transfer rate loss and the strip heat transfer rate throughout the length of the furnace. Variations in the thermodynamic properties included in the model and in the operational conditions, which cannot be accurately known, have been tested to ascertain their effects on the evolution of the strip temperature. It is found that precise knowledge of the heat capacity and heating power introduced in the furnace are important to obtain good results in application of the model.     

1800mm连退加热炉CPU板温控制及实践

冷轧板连续退火过程加热温度的控制是产品性能合格的重要保证,通常加热炉的温度控制方式有DCS炉温控制和CPU板温控制两种,CPU板温控制方式因模型中的控制对象直接是带温,所以控制精度较高,也较为科学.1800mm连退加热炉的CPU板温控制在原来基础上增加了动态速度控制和预加热控制两个功能,实践证明,CPU板温控制是正常生产中理想的控制方式.     

Mathematical model of metallurgical thermal processes and application

There are lots of physical changes and chemical reactions in the processes of iron and steel making, these processes are quite complex in the aspect of heat transfer.The processes of iron and steel making can be approximately divided into three kinds.The first kinds are the processes of fusion metallurgy which involve enormous chemical reactions,such as blast furnace,converter,electric furnace and coke oven.The second kinds are the processes of heating and cooling which are mainly the physical changes,such as walking-beam reheating furnace,annular heating furnace and car-type furnace.The third kinds are the processes of heat treatment which mainly adjust metallurgical structure of metal,such as roller hearth heat treatment furnace, strip continuous heat treatment vertical/horizontal furnace and HPH bell-type annealing furnace.Every process can only be finished in particular thermal equipment.And all the physical and chemical processes mentioned above must obey first principles of engineering thermodynamics,heat & mass transfer,hydromechanics, combustion,metallurgy physical chemistry etc,and which can be summarized as principle of heat transfer,mass transfer,momentum transfer and chemistry reaction.In this paper,based on first principle of heat and mass transfer in iron and steel making processes,a series of mathematical models of thermal equipments and processes are presented.Such as the model of hot-blast stoves,coke oven,CDQ-boiler system,sintering, reheating furnace,soaking furnace,annular heating furnace,roller hearth heat treatment furnace,strip continuous heat treatment vertical/horizontal furnace,HPH bell-type annealing furnace,control cooling of medium plate,burner,heat exchanger and regenerative burner etc.The on-line application of the model is based on experimental certification of the mathematical model.And finally the computer optimization system of metallurgical thermal process is obtained.     

钛/钢复合板天然气炉退火处理的可行性研究

钛/钢复合板经爆炸复合后,存在较大的残余应力,因此,在生产过程中需进行消应力退火处理。天然气炉加热速度快,保温时间短,单炉承载吨位大,成本低,可用于热处理。但是由于钛/钢复合板中的钛易吸氢,易氧化,为此进行了钛/钢复合板在天然气炉中消应力退火的可行性研究。研究结果表明,在天然气炉中对钛/钢复合板进行消应力退火后,钛覆层表面无烧伤;氧含量无变化;氢含量增加0.001%～0.002%,满足氢含量<0.006%的要求;力学性能和耐蚀性均与箱式电阻炉退火的相当;钛/钢复合板整体的剪切性能也与箱式电阻炉退火的相当。西安天力金属复合材料有限公司两年来的生产实践也进一步证明,使用天然气炉对钛/钢复合板进行消应力退火,对其使用性能几乎没有影响,未出现不合格产品,而且缩短了生产工期,大幅度提高了生产效率,是完全可行的。     

连退炉辐射管时序脉冲燃烧控制方式的应用和分析

针对连续退火炉原有燃烧控制系统目前存在的问题,对辐射管加热段进行优化。利用横河的DCS集散控制系统,分析空气和煤气的配比,及其他影响因素,建立控制参量之间的关系,推出退火炉燃烧系统的传递函数。并运用时序脉冲燃烧控制的方法对辐射管加热段进行优化控制,提高了控制精度,减少了带钢表面氧化,同时提高加热效率,节能环保效果显著。     

Analysis and calculating for preheat temperature and average convection heat change coefficient in the continue annealing furnace

The aim of the thesis is to utilize essential theory of heat transfer,to use correlative expressions to calculate average convection heat change coefficient and heating temperature of strip in Jet Preheat Furnace （JPF）,make the calculating results accordant with production data,and make the calculation to be used the process of production.The method is to collect:entry temperature and speed of strip,temperature and speed of N₂ - H₂,to analyse heat transfer according to length and thickness of strip,jet hole and mutual position of jet piping in JPF,to analyse heat transfer and built the physical model.In mathematic model, Martin correlative expressions are tried to calculate using the data from production,and are modified in part properly.At the same time,heat boundary condition is analysed with theory of impact jet and production data.The conclusion is obtained that boundary condition is rarely average numerical value of temperature of strip and N₂ - H₂ with impact jet condition,instead of a relation of function of temperature of strip, temperature and speed of N₂- H₂,array of jet holes,diameter of hole,distance between hole and strip,and acquired a calculating expression.In calculation of examples,the thesis collected and calculated 15 kinds of strips.The thickness of strips are 2=0.51¹.41 mm,material DQ - IF、DDQ,EDDQ,SEDDQ and 340DDQ.Main assess numerical value is temperature value after strip is heated with certain speed and within section of time.Maximum error in 9 groups of numerical value in the thesis is 3.36%comparing with production data.The correlative expressions can be used in production to adjust temperature of strip through changing speed and temperature of N₂ - H₂ and speed of strip.The correlative expressions are compiled computer process.The process can be applied in on line control of production by rapid calculating speed.     

Modeling of Strip Temperature in Rapid Cooling Section of Vertical Continuous Annealing Furnace

 The strip temperature is affected by many factors in rapid cooling section (RCS) of the vertical continuous annealing furnace (VCAF). They can be divided into four types: the physical properties of cooling gas, the geometry characteristics of configuration of cooling equipment, the heat transfer between the strip and the cooling gas, and the conductivity of the strip. It aims to model the strip temperature in the cooling section based on the fundamental heat transfer theory and the four aspects factors. The model for transient Nusselt number is obtained by considering Reynolds number, Prandtl number and geometry characteristics of RCS. Then cooling model of the strip transient temperature is built by Nusselt number, heat transfer coefficient and heat conductivity of the strip. The results are compared with the data from production line. The comparisons indicate that the model can well predict cooling temperature of the strip. It is hoped that the proposed model can be used for design and control of the vertical continuous annealing furnace.