不锈钢氩氧脱碳精炼过程的物理和数学模型

The available studies in the literature on physical and mathematical modeling of the argon-oxygen decarburization(AOD) process of stainless ssteel have briefly been reviewed.The latest advances made by the author with his research group have been summarized.Water modeling was used to investigate the fluid flow and mixing characteristics in the bath of an 18t AOD vessel,as well as the “back-attack” action of gas jfets and its effects on the erosion and wear of the refractory lining,with sufficiently full kinematic similarity.The non-rotating and rotating gas jets blown through two annular tuyeres,respectively of straight-tube and spiral-flat tube type.Were employed in the experiments.The geometric similarity ratio between the model and its prototype(including the straighttube type tuyeres)was 1:3 ,The influences of the gas flow rate,the angle included between the two tuyeres and other operating parameters,and the suitability of the spiral tuyere as a practical application,were examined.These latest studies have clearly and successfully brought to light the fluid flow and mixing characteristics in the bath and the overall features of the back-attack phenomena of gas jfets during the blowing.nd have offered a better understanding of the refining process.Besides,mathematical modeling for the refining process of stainless steel was carried out and a new mathematical model of the process was proposed and developed.The model performs the rate calculations of the refining and the mass and heat balances of the system.Also,the effects of the operating factors,including adding the salg materials.crop ends,and scrap,and alloy agents;the non-isothermal conditions;the changes in the amounts of metal and slag materials,crop ends,and scrap,and alloy agents;the non-isothermal conditions;the changes in the amounts of metal and slag during the refining;and other factors were all considered.The model was used to deal with and analyze the austenitic stainless steel making (including ultra-low carbon steel) and was tested on data of 32 heats obtained in producing 304 grade steel in an 18t AOD vessel.The changes in the bath compostion and temperature during the refining process with time can be accurately predicted using this model.The model can provide some very useful information and a reliable basis for optimizing the process practice of the refining of stainless steel and control of the process in real-time and online.     

Foundation of three-dimensional mathematical models for glass furnace regenerator

This paper presents a practical three-dimensional mathematical model of circulation and heat transfer in generator of glass melting furnaces. The model was based on the heat transfer between the smoke flow and the lattice units, and between the air flow and the lattice units. This model not only bypassed the difficulty of complicated computation of the heat transfer process in the regenerator of glass furnaces, but also avoided the irrationality of fixing the temperature distribution on the surfaces. Use of the model yielded very important data and also the method for the design of the regenerator of glass furnaces in practical production.     

On the hydrodynamic stability of a particle-laden flow in growing flat plate boundary layer

INTRODUCTION Turbulent particulate flows occur in many in-dustrial applications, such as in pneumatic transportof particulates, cyclone separators and chemical re-actors. The particles suspended in fluid play a role inthe turbulence modulation, which has been known forseveral years. The observation that adding dust to airflowing in turbulent motion through a pipe can ap-preciably reduce the resistance coefficient was re-ported by Sproull (1961). The observation can beexpressed as saying …     

气液两相搅拌槽内气泡直径的数值模拟

搅拌槽内气泡直径是一个很重要的参数.本文对搅拌槽内气泡直径进行了数值模拟,模拟结果表明,在搅拌槽内排出流区和循环区内模拟值同实验值的吻合情况都比较好.在模拟过程中仅考虑了湍流动能耗散率对气泡大小的影响,没有考虑到气泡本身凝并和循环过程,所以在循环区中模拟值要比实验值稍大.     

一种改进的交通流元胞自动机模型

A modified cellular automaton model for traffic flow was proposed. A novel concept about the changeable security gap was introduced and a parameter related to the variable security gap was determined. The fundamental diagram obtained by simulation shows that the maximum flow more approaches to the observed data than that of the NaSch model, indicating that the presented model is more reasonable and realistic.     

Performance of simultaneous nitrification and denitrification in lateral flow biological aerated filter

1 Introduction a Water eutrophication becomes increasingly serious owing to untreated or illegally discharged domestic as well as industrial wastewater. Hopefully, more strict requirements for nitrogen and phosphorus removal have been set in new wastewate…     

流动注射光度法测定药物中的磺胺嘧啶

在盐酸介质中，利用磺胺嘧啶-亚硝酸钠-α-萘胺的重氮化-偶合反应，建立了流动注射光度法测定磺胺嘧啶的新方法.利用控制加权形心单纯形优化法选择最佳实验条件，测定的线性范围为0.2-20μg/mL，检出限为0.06μg/mL，进样频率为130次/h.该法已用于药物中磺胺嘧啶含量的测定.     

影响Cu-Zn合金锯齿屈服现象的因素

研究了Cu-Zn合金动态应变时效的现象,发现在4.76×10-4s-1的应变速率下,H68黄铜和H58黄铜在一定的温度范围内均会出现锯齿屈服现象;随着Zn含量的增加,锯齿屈服的温区向低温方向移动。在出现动态应变时效的温区形变时,两种合金的屈服强度与温度的关系表现为应力平台。对于H68黄铜,随着晶粒尺寸的增大,出现锯齿屈服的临界应变量增大,锯齿波的最大应力振幅减小。     

EVA based model to estimate the Chinese listed company＇s intrinsic value

This article is based on traditionally intrinsic value assessment model. We employed the assumption on the differences in future increase rates of companies, taking into account of the expected Economic Value Added （EVA） discount and the capital investment, to establish a high increase model, a two-stage EVA discount model and a three-stage EVA discount model for the intrinsic value assessment. Those models eliminate the great fluctuation of free cash flow in calculating the capital expenditure by setting aside the cash flow of the company＇s investment in the year and considering only the capital cost. This method needs only to assess the EVA flow in different year in probing the intrinsic value of a company, thus give more consistent conclusion than conventional methods.     

投资评价的净现值法分析研究

本文对投资主要评价指标--净现值指标进行了分析研究,针对指标由于现金流量估计的不准确等问题提出了一些解决办法.同时文中用实物期权法对投资项目进行了评价,并以此对净现值法的缺陷作一弥补.