Burden Distribution for Bell-Less Top With Two Parallel Hoppers

The circumferential burden distribution of bell-less top with two parallel hoppers was analyzed to obtain the expressions of burden flux and uneven ratio. The four-batch feeding spirally with two parallel hoppers was proposed to realize even burden distribution by uneven flux, ensuring reasonable distribution of BF gas and effective usage of heat energy and chemical energy of gas as well as stable BF production with higher quality and lower consumption.

Multi-Model Based PSO Method for Burden Distribution Matrix Optimization With Expected Burden Distribution Output Behaviors

Burden distribution is one of the most important operations, and also an important upper regulation in blast furnace(BF) iron-making process. Burden distribution output behaviors(BDOB) at the throat of BF is a 3-dimensional spatial distribution produced by burden distribution matrix(BDM),including burden surface output shape(BSOS) and material layer initial thickness distribution(MLITD). Due to the lack of effective model to describe the complex input-output relations,BDM optimization and adjustment is carried out by experienced foremen. Focusing on this practical challenge, this work studies complex burden distribution input-output relations, and gives a description of expected MLITD under specific integral constraint on the basis of engineering practice. Furthermore, according to the decision variables in different number fields, this work studies optimization of BDM with expected MLITD, and proposes a multi-mode based particle swarm optimization(PSO) procedure for optimization of decision variables. Finally, experiments using industrial data show that the proposed model is effective, and optimized BDM calculated by this multi-model based PSO method can be used for expected distribution tracking.

DPM-CFD simulation of powder motion in the burden distribution process of COREX shaft furnace

Single off-gas outlet devised by one-step COREX shaft furnace will ultimately lead gas distribution to segregate,furthermore the distribution of powder on charge level is non-uniformity.DPM-CFD model was employed to simulate the pellet minus sieve powder motion in the burden distribution process,in order to quantitative description the non-uniformity distribution.The results showed that,the non-uniformity distribution is increasing with the melting rate increased.The powder segregates to the fourth quadrant where off-gas outlet lies is 2.4 or 2.5 fold of any other quadrant,while the melting rate is 130 t/h or 180 t/h.The best method to resolved the problem adds an symmetry off-gas outlet.

Mathematical simulation of burden distribution in COREX 3000 shaft by discrete element method

The distribution of reducing gas in a shaft furnace dominates the temperature profile,gas utilization ratio,metallization degree and is the overwhelming factor for stable,high productivities and low-energy-consumption operation.At the same time,the distribution of gas flow is mainly determined by the position of gas inlet,the packed bed porosity distribution as well as its change due to the difference on the mode of top charge and bottom discharge.When injecting position of the process is fixed,the charge mode is the only means for regulating the gas flow distribution.In this paper,a numerical simulation model of burden distribution in the shaft furnace of COREX 3000 has been developed to analyze the porosity distribution under the different charge modes by means of Discrete Element Method(DEM).The effects of the particle size and its distribution under conditions of different charge batches,chute angle,stoke line on the burden surface shape and burden bed particle size distribution and segregation were investigated,and then the porosity distribution in the shaft of corresponding charging pattern was quantitatively accessed.Therefore,the results can be used to optimize the charge patterns base on required gas distribution.

论环境民事公益诉讼中因果关系要件的证明

当前,环境民事公益诉讼中因果关系要件的证明责任如何分配及其证明标准如何设定,对此理论界和实务界仍有很大争议。在证明责任分配问题上,解决路径在于参照适用《民法典》第一千二百三十条的规定,由被告承担环境民事公益诉讼中因果关系要件的客观证明责任。与此同时,原告需提供能够证明关联性事实的初步证据。这一规则应当理解为因果关系的法律推定。将因果关系法律推定规则引入环境民事公益诉讼中具有合理性基础,如纠正人们对环境侵权因果关系要件“证明责任倒置”的错误认识、防止原告滥用诉权、平衡原被告双方的举证负担。在证明标准问题上,环境民事公益诉讼中因果关系要件的证明标准应因事后救济性环境民事公益诉讼和预防性环境民事公益诉讼的类型划分而有所区别,且受关联性事实认定标准的影响。

Improve the System of Medical Damage Identification to Balance the Burden of Proof between Medical Institutions and Patients

With the development of the theory of identification "duality" in medical tort lawsuit,the burden distribution system of proof of medical tort also gradually developed.So-called links are universal,state institutions are often"one change makes all change".In medical tort cases,the judges replace the trial results with expert opinion let alone tend to rely on expert opinion to determine the truth while he can't verify the case facts.The another thing,after the newly revised Civil Procedure Law revised in 2012,it defined the parties of basic rights or interests protected in the case of the cross-examination of medical damage expert opinion.But due to patient lack of medical expertise and expert refuse to appear in court,no right of cross examination could happen.A part of the medical cases are used in expert auxiliary system to solve the above difficulties,but procedures of expert assistant system have not been unified.Many problems and doubts are still in implementation for judges,lawyers,parties concerned.Analyzing the disadvantages of the present the appraisal system of medical lawsuits and working on the improvement of expert assistant system,and expect to the analysis and explanation for the medical tort lawsuit contribute to subsequent researchers and juridical practice.

料斗倾角对气基竖炉布料过程中物料流动及分布的影响

球团矿离开料斗时的颗粒偏析会影响其在气基竖炉内的分布,分布不合理将影响还原气的利用率建立20°~70°倾角的料斗、导料管、溜槽、气基竖炉三维模型,基于离散元法研究物料从料斗到气基竖炉布料过程中的流动和分布结果表明:排料时,20°~25°倾角的料斗内炉料流型均为整体流,30°~55°倾角的料斗内炉料流型均为混合流,60°~70°倾角的料斗内炉料流型均为漏斗流漏斗流促使料层形成快速流动的中心通道,大颗粒会更早地离开料斗进入炉内,在落点区域堆积,导致料斗内大颗粒负偏析、竖炉内落点区域大颗粒正偏析20°~35°倾角的料斗布料后,炉内孔隙率偏差分布在000383~000468,倾角增大,孔隙率偏差增大改变炉料-料斗静摩擦系数、炉料批重、料斗半径等参数,发现料斗倾角是影响布料过程和结果的主要因素,孔隙率偏差仍随料斗倾角的增大而增大。

Improving mathematical model of burden distribution and correcting chute angle to cope with fluctuation of stock line

Accurate evaluations of the burden distribution are of critical importance to stabilize the operation of blast furnace.The mathematical model and discrete element method(DEM)are two attractive methods for predicting burden distribution.Based on DEM,the initial velocities of the pellet,sinter,and coke were calculated,and the velocity attenuations of the above three particles between the burden and the chute were analyzed.The initial velocity and velocity attenuation were applied to a mathematical model for improving the accuracy.Additionally,based on the improved model,a scheme for rectifying the chute angles was proposed to address the fluctuation of the stock line and maintain a stable burden distribution.The validity of the scheme was confirmed via a stable burden distribution under different stock lines.The mathematical model has been successfully applied to evaluate the online burden distribution and cope with the fluctuation of the stock line.

论证明责任分配对企业合规的激励功能

证明责任理论不仅决定着企业合规免责的正当性证成,同时也激励着企业积极主动开展合规建设。审判程序中企业合规免责分为两种模式,在主观过错免除模式中,基于企业独立意志理论与司法实践存在的主观过错推定,应由控方就入罪事实承担行为责任及相应的结果责任,由被诉企业就其内部合规事实承担行为责任及相应的结果责任;在法定管理义务履行模式中,基于该模式的特殊适用范围,应由控方就入罪事实承担行为责任和相应的结果责任,被诉企业并不承担证明责任。

邯宝3200m^(3)高炉原燃料质量下降后的提产降耗措施

邯宝3200m^(3)高炉原燃料质量下降后,中心气流不畅通,边沿气流不稳定,炉况顺行变差,高炉主要技术经济指标退步较多,生产成本大幅升高。通过采取提高原燃料质量、调整布料制度、优化下部操作制度、优化造渣制度及改进修复风操作等措施,高炉炉况顺行程度得到明显改善,风氧量水平大幅度提高,高炉稳定性和抗干扰能力增强,主要技术经济指标有较大的进步。2022年11月,高炉日产量达到8705t/d,燃料比降低至507.3kg/t,生产成本大幅降低。

马钢A高炉低风温条件下的布料矩阵转换探索

通过对A高炉炉缸活性不足条件下的两次布料矩阵转换探索,经过技术攻关,结合布料落点计算分析以及全铸铁冷却壁操作炉型的制度、参数匹配性摸索,得到了合理的布料矩阵,优化了两道煤气流分布,实现了低风温冶炼条件下的高产低耗生产。

数字化背景下配网业务流程自动化的应用研究

文章分析了目前配电网数字化转型的现状和存在的问题,提出通过自动化流程工具替代人工执行基本业务的方法,对不同的自动化流程工具进行了研究和应用,以高效解决重复、复杂的流程,同时实现不同系统之间的数据连通,进一步挖掘现有系统的数据潜力,探索自下而上的数字化建设模式。

COREX竖炉布料规律的数学模型

通过建立布料过程的数学模型研究了COREX竖炉的布料规律,改进了空区料流轨迹模型使其可以考虑溜槽内料流厚度和宽度分布及炉料粒度的影响,并用多条线段联合描述料面形状.研究表明:炉料在溜槽末端出口处的料层厚度和炉料的粒度分布决定了炉料在空区的料流轨迹;炉料离开溜槽末端速度与溜槽倾角成反比关系,与溜槽转速成正比关系;炉料在炉喉的落点位置离炉喉中心距离与溜槽倾角、溜槽转速成正比关系.利用该模型可计算出不同布料模式和布置不同炉料时料堆长大过程和形成的料面形状.

医生工作负荷、工作满意度及人力配置认知意向调查

目的:医生对工作负荷、人力配置、工作压力和满意度的自我认识与评价;年龄、学历、工作年限等个人特征对工作负荷、工作压力和工作满意度认知的影响。方法:分层整群抽样方法,对两所三级医院按科室分布抽取科室,对所选科室的所有在编医生进行问卷调查。结果:60.3%的医生认为工作负荷重,69.3%报告工作压力大,医生工作平均满意度为3.3%,收入满意度2.6%。有一半以上的医生认为现有人力配置数量、结构不适宜。工作负荷重的原因主要是医生缺乏。工作压力大的原因主要是医疗工作风险大、工作负荷重、急危重病人多。结论:医生工作负荷重、工作压力大、工作满意度不高。调查结果对医院管理人员制定医院医疗人力资源管理对策,合理配备与使用医生,减轻医生工作负荷与压力,提高其工作满意度有着重要的现实意义。

无料钟高炉布料模型的研究与应用

针对高炉炉内料面的分布特征,通过分析和考虑无料钟高炉布料的影响因素及其特点,结合数学知识和计算机技术,建立了无料钟高炉布料模型。该模型在某钢铁企业的450 m3小型高炉中得到了实际应用,实现了无料钟高炉布料过程的实时监视,指导操作工对炉料分布进行合理调整,从而提高了料柱的透气性指数,降低了焦比,改善了高炉冶炼状况。这对实时了解高炉炉内料面的分布情况,指导高炉的优化操作具有十分重要的意义。

高炉无料钟炉顶布料规律探索与实践

济钢1 750 m3高炉采用串罐无料钟炉顶布料系统。建立了布料模型,并在高炉生产中不断验证,逐步消化和掌握了无料钟技术,摸索出一系列无料钟炉顶布料的相关规律;建立了布料矩阵调节的基本准则,以“稳”为前提,以“平台漏斗”理论为依据,充分发挥了布料矩阵技术优势,确保高炉稳定顺行。研究结果表明:焦平台一旦确定,靠微调矿石矩阵可以调整煤气流的合理分布,达到维持矿焦比合理分布的控制目标。通过布料矩阵的不断优化,使高炉的顺行状况改善,高炉的利用系数达到2.35 t/(m3.d)。

高炉无钟炉顶布料模拟实验与应用

对无料钟布料公式进行修正,得到修正公式n={l20cos2β+2l0cosβLx+[1+(4π2ωl20/C21)L2x]}1/2-0.38.运用1:7模拟试验装置模拟南钢1号高炉布料规律.提出适合南钢1号高炉的布料制度C32C30C30C28.针对南钢亏料线及中心不活跃炉况计算出不同亏料线深度时溜槽角度的变化及中心加焦制度方案,中心加焦时α大约为17o.

高炉布料数学模型的开发及应用

为研究炉料在炉内的分布,对武钢1号高炉在开炉前进行了料面测量,在获得的炉料堆积规律的基础上开发了高炉布料数学模型,利用开发的数学模型模拟炉料下落的轨迹,求解料面形状,计算炉料的O/C比分布,利用模型计算结果对不同布料矩阵的布料效果实行量化评估,结合高炉专家系统中有关煤气流分布的信息,可以及时对布料矩阵作出调整。

高炉布料设定值优化控制

高炉炼铁是钢铁生产中的重要能耗因素.为了实现生产的节能降耗,布料策略显得极为重要.本文针对某钢铁厂高炉的无料钟布料系统,基于现场采集的数据,建立了以铁水质量和经济效益为变量的指标效益评价函数,给出了最优设定料面的推理机制.针对不同运行环境,建立不同的料面优化设定值,构成多模型集合.当工况环境发生大的变化时,采用切换机制,对比多模型集合,选择最优料面设定值,并在此基础上对布料进行自适应控制,计算布料矩阵,提高布料过程的快速性和准确性.最后对整个高炉动态优化控制系统做了总体分析,基于现场数据,对高炉布料模型进行了仿真和验证.

烧结环冷机分层布料的数值模拟与优化

基于局部非热平衡换热理论,建立多孔介质内气体-颗粒两相非平衡换热的能量双方程模型,并通过计算流体动力学软件(FLUENT)和自编程序的结合,对三维环冷机内的换热过程进行仿真计算,研究环冷机内各层物料粒径对换热的影响。研究结果表明,采用分层布料工艺,将大粒径物料分布于环冷机底层,小粒径物料分布于中层,可以增加约14%的余热利用量,且有助于实现环冷机内温度场分布的均匀性,研究结果对环冷机分层布料以及余热利用具有参考作用。