热轧工作辊换热系数的遗传算法优化模型

边界热交换系数的确定是热轧工作辊高精度温度场计算的关键参数.分析了热轧工作辊的热边界条件,建立了实用的轧辊温度场模型,采用改进的遗传算法--新的适应值标定方法对工作辊关键换热参数进行优化.仿真和实验结果表明,该优化模型实用可靠,可用于生产实践中工作辊换热系数的确定.     

自适应阈值估计的MS模型仿真建模

提出了一种改进的模拟电路多信号模型(MS模型)的仿真建模方法.采用Monte-Carlo方法实现电路的仿真,以获取电路特征的统计数据,利用经验公式法确定Monte-Carlo仿真的分析次数,可以减少仿真时间开销;同时,根据统计数据检验该特征的统计分布情况,再以此为依据采用自适应方法确定该特征的阈值估计区间,从而提高模型精度.最后进行了实例分析,验证了该建模方法的有效性;并从仿真时间与建模精度两个方面进行了性能比对,说明其具有的优势.     

湿法冶金下游流程的分层优化及全流程优化仿真算法分析研究

为了优化控制湿法冶金过程，通过机制建模，并结合专家知识建立了一种湿法冶金全流程过程模型。采用基于最小消耗模型的区间分层优化方法，对湿法冶金下游流程及全流程分别进行优化求解，建立最优模式库，并对湿法冶金生产过程进行仿真分析和对比，验证了区间分层方法的正确性及有效性。结果表明，该方法比传统的优化方法更优越有效。     

基于lingo算法的货位优化研究

以自动化仓库货位优化问题为目标,在分析了现行货位优化方法及思路的基础上,提出了一种新的货位优化方法,并建立了货位优化问题解析模型,同时基于lingo优化工具进行了仿真分析。仿真分析结果表明,所提出的货位优化方案极大地提高了仓库的存储效率及存储利用率,显示了货位优化方法的有效性。     

热连轧窄带钢自适应控制在线确定增益系数的研究

对热连思窄带钢热轧制过程中自适应增益系数α的确定进行探讨，以４５０ｍｍ热连轧机为仿真对象，分析各种影响α的因素，胜数理统计中未知方差σ＾２的参数区间估计方法确定实测数据的置信概率，用参数寻优法建立了α和实测数据置信概率之间的定量关系，为在线确定α值提供了依据。     

绝热层结构等效有限元模型的研究及应用

为了简化绝热层的有限元计算模型,提出了等效换热系数的概念,将绝热层和热交换介质的传热过程简化成等效热交换,并由此给出了平壁和圆筒壁传热的等效换热系数计算公式。该方法不仅极大地简化了热力学中的有限元模型,而且顺利解决了一些由于模型过大导致的问题。仿真结果表明:该方法准确可信,将其应用于鼓风站管道的有限元计算中,取得了令人满意的结果。     

混合时变时滞神经网络的状态估计器设计

研究了混合时变时滞(离散时滞和分布时滞)神经网络的状态估计问题.离散时滞在一个区间上变化,区间下界不一定为零.通过构造一个新的Lyapunov泛函,结合Jensen积分不等式,可以得到一个时滞相关状态估计器设计方法,使得误差系统是全局渐近稳定的,所得结果由线性矩阵不等式形式给出.数值算例证明了本文方法的有效性和优越性.      

区间时滞系统的非脆弱鲁棒H∞控制

针对一类时滞是时变的且属于一个已知区间的线性系统,提出了一种新的Lyapunov-Krasovskii函数分析方法,分析区间时滞线性系统的稳定性,并设计了非脆弱鲁棒H∞控制器.设计的非脆弱鲁棒H∞控制器不仅可以保证时滞系统是渐近稳定的,同时可以满足所给定的H∞性能指标.非脆弱鲁棒H∞控制器可以通过线性矩阵不等式方法获得.仿真例子验证了该方法的有效性.     

基于ELM和MCSCKF的锂离子电池SOC估计

为了减少噪声对锂离子电池荷电状态估计的影响,本文提出一种新颖的基于极限学习机和最大相关熵平方根容积卡尔曼滤波的SOC估计方法。首先,利用泛化性好、运行速度快的极限学习机作为卡尔曼滤波的测量方程;其次,基于灰狼优化算法,极限学习机的超参数被优化以提高电池荷电状态的估计精度;最后,基于最大相关熵平方根容积卡尔曼滤波,极限学习机的测量噪声被进一步减弱。所提方法可以简化极限学习机繁琐的调参过程,且为闭环的SOC估计方法。所提方法在多工况和宽温度范围内被测试以验证其泛化性能。测试结果显示,所提方法明显地提高了锂离子电池的荷电状态估计精度。同时,对比其他算法,所提方法的平均运行时间仅仅为长短时序列和循环门控单元网络的三分之一。当行驶工况复杂、温度变化区间较大时,所提方法的均方根误差小于1%,最大误差小于3%。当存在初始误差与环境噪声时,所提方法显示出了优越的鲁棒性。      

回转窑内气流与设备结构的分析研究

通过对回转窑内各区域气流情况的分析，结合目前设备状况，研究优化窑内热交换的途径，提出了进一步提高回转窑产能的设备本体改进方案。     

铝电解槽侧壁换热体系的计算建模与应用

以商业软件ANSYS为平台,建立了400 kA预焙阳极铝电解槽侧壁换热体系的的三维仿真模型,并进行了具体的数值模拟计算。结果表明:在设定的工况条件下,熔体区侧壁最高温度为112℃,与常规的自然冷却相比,降低150℃以上,侧壁单组换热器的换热量为2 342 W。炉帮形状比较规整,炉帮厚度为16.8 cm左右。研究成果可为铝电解槽侧壁换热体系的设计提供参考。     

高炉炉衬测温传感器热传输规律分析

摘要： 高炉冶炼过程中炉腰位置容易出现倒V型软熔带，存在固液两相的复杂流动过程。针对此恶劣环境，提出一种基于一维导热的炉温在线检测传感器，传感器不同位置埋设有测温探头，建立了其导热过程的数学模型。以数值模拟为基础并通过控温试验进行验证，分析了传感器不同位置温度分布规律。得到了高温端温度与低温区域温度的理论关系，从而能够实现由低温区温度推算高温区温度的目的，克服高温端不能直接测温的困难。试验与数值模拟对应较吻合，在线检测传感器能够为高炉智能化、自动化检测提供新的方法。     

计算机模拟仿真在过程冶金中的地位和应用

计算机模拟仿真作为一种研究流动，传热和化学反应过程的方法，目前已在冶金等领域得到广泛应用并显示出良好的应用前景，结合冶金过程的一些特点概述数值模拟仿真的基本原理，区域离散化方法，求解技术及应用实例。     

关于大量喷煤高炉的某些理论问题的思考

讨论了与高炉大量喷煤有关的某些理论问题,主要是高炉下部透气性和原料质量、热补偿和理论燃烧温度等。考虑到风口区煤粉的燃烧率及实际发生的化学反应,提出了计算理论燃烧温度的一种新方法。从保证未燃煤粉在高炉内完全消耗的角度提出了高炉的喷煤极限。     

焊接热循环对07MnCrMoVR钢热影响区组织及韧性的影响

为深入分析07MnCrMoVR钢热影响区的脆化问题,采用热模拟技术和显微观察技术,对该钢热影响区的组织和性能进行了深入研究.研究结果表明:单次热循环时,粗晶区(CGHAZ)和临界区(ICHAZ)韧性恶化严重,晶粒长大及粒状贝氏体、M-A组元等非平衡组织的形成是粗晶区韧性恶化的主要原因.随着t8/5的增加,粗晶区冲击韧性...     

Heat transfer-solidification kinetics modeling of solidification of castings

A close examination of the recent developments in the field of computer simulation of solidification process reveals that a combination of both macroscopic and microscopic models is necessary in order to accurately describe the solidification of castings. Currently available macroscopic models include models that describe heat transfer from metal to mold, fluid flow of liquid metal during mold filling, and stress field in the casting. At the microscopic level, the models should include more intricate issues such as solidification kinetics and fluid flow in the mushy zone. Although significant progress has been accomplished over the years in each field, the task of including all of these models into a comprehensive package is far from being complete. This paper describes the state of the art on coupling the macroscopic heat transfer (HT) and microscopic solidification kinetics (SK) models and introduces thelatent heat method as a more accurate method for solving the heat source term in the heat conduction equation. A new method for calculation of fraction of solid evolved during solidification based on computer-aided cooling curve analysis (CA-CCA), as well as a method based on nucleation and growth kinetics laws, is discussed. A new nucleation model based on the concept of instantaneous nucleation, which is used to describe equiaxed eutectic solidification of commercial alloys, has been introduced. It is demonstrated that the instantaneous nucleation model agrees well with the experimental results in terms of cooling curves and of evolution of the fraction of solid during solidification. Validation results are also shown for SK models that are based on CA-CCA coupled with HT models for eutectic Al-Si and gray cast iron alloys.     

Numerical Simulation of Batch Settling Process

The batch settling process was simulated numerically using a dynamic model for zone settling and compression. The simulation can provide the height variation of the supernatant-suspension interface with time as well as the vertical solids profile at different times. The simulation results were compared with experimental batch settling data in the literature for various types of suspended materials with different initial suspended solids concentrations. Generally good agreement between the simulations and experimental measurements was obtained. The method presented here has several advantages for the simulation of the batch settling process compared with the methods found in the literature; it is simple, requires only four parameters, and provides good results for both zone and compression settling. Also presented is a technique for quantifying all four required parameters, in particular, the two describing the compression characteristics of a suspension from batch settling tests. These compression parameters are needed to estimate the depth requirement of steady-state gravity thickeners. This method also will be useful for environmental engineering processes that use batch settling for solids-liquid separation, such as sequencing batch reactors.     

Effect of Nb on Mechanical Properties of HAZ for High-Nb X80 Pipeline Steels

The mechanical properties of heat affected zone (HAZ) of two commercial high-Nb X80 grade pipeline steels with different alloy elements were investigated using thermal simulation performed on a Gleeble-3500 thermal simulator. The results showed that the high-Nb steels have excellent weldability. Embrittlement regions appear in coarse grain heat affected zone (CGHAZ) and intercritically heat affected zone (ICHAZ); Softening region appears in fine-grain heat affected zone (FGHAZ), and the strength here was even lower than 555 MPa as required in the standard. Meanwhile, with the increase of heat input, the strength and the toughness of HAZ of steel with high Nb, C and lower alloy decrease notably. Therefore, take into account the welding procedure during manufacture of weld pipe, suitable amount of alloy elements, such as Cr, Ni, Cu, Mo and so on, is necessary for high Nb X80 heavy-thick steel plate.     

Laboratory development of high performance steel plates with excellent HAZ toughness at large heat inputs

Presented in this study is the result of steel plates developed at laboratory by using the technique of chemistry design based on microstructure evolution.It has been shown that the produced 50mm thickness steel plates with yield and tensile strength being 420 MPa and 530 MPa respectively exhibit excellent large heat input weldability:the Charpy impact tests in the whole range of heat affected zone(HAZ) including the fusion line at the welded joint with large heat input of 100 -300 kJ/cm showed uniform impact toughness of above 140 J at -40℃.Welding simulations were also performed for heat inputs of 200-600 kJ/cm,which showed far better toughness at -20℃.Analysis on the results of the simulations and the practical welding tests were done and the microstructure evolution mechanisms were proposed.Finally suggestions were given to improve the simulation processes as well as chemistry modification.     

硫酸转化系统中新型换热器的强化传热研究

针对硫酸转化系统中气体换热器的特点,提出并分析了一种新型的传热强化元件——旋流片作为管束间支撑物的流动与传热特性。在实验研究基础上,应用周期性单元流道模型,数值模拟了空心环和旋流片支撑时的湍流流动和传热性能。结果表明,空心环和旋流片均增强了换热,旋流片能迫使流体做强烈的三维螺旋运动,增强湍流度,同时使流体冲刷壁面,减薄边界层,所以换热效果优于空心环。旋流片产生的自旋流具有低阻高效的优势,其传热强化因子大于空心环。