金属镁还原罐径向传热强化器的研究

皮江法是镁还原工艺中采用最为广泛的一种热法炼镁工艺。通过采用CFX软件对皮江法镁还原炉内的换热进行了数学建模和仿真计算,研究开发了一种安装在还原罐中强化罐内径向传热的装置,这种装置在缩短镁还原周期近30％的同时,实现了金属镁还原炉的机械化装出料。     

硅热法炼镁节能还原炉研究

自行设计安装一台小型内电阻加热硅热法镁还原试验炉,加入工业用皮江法炼镁球团进行镁还原试验,得到能耗小于9kWh/kg-Mg、镁收率大于90%、还原反应周期小于180min的技术指标。与传统外加热的皮江法相比,内电阻加热硅热法炼镁在还原阶段的热效率提高4倍,反应周期大大缩短。     

皮江法炼镁节能技术探讨

针对我国皮江法炼镁生产工艺现状,提出优化原料质量、改进煅烧炉窑设备、开发高效还原装置、应用经济型清洁能源、系统能量分级利用等措施来降低皮江法炼镁过程中的能量损耗,以提高单位吨镁的经济效益,促进我国由镁生产大国向镁生产强国迈进。     

新型蓄热式镁还原炉内流场的数值模拟

用大型软件fluent,采用-双方程模型对新型炼镁炉内湍流流场进行数值模拟,分析了炉内气体扩散过程、流场分布以及炉内流场对燃烧过程的影响。结果表明,这种新型的镁还原炉可以获得很好的流场来满足镁还原工作要求。     

水化白云石真空热还原提炼金属镁的实验研究

实验采用来自罗马尼亚的水化白云石作为原料,通过真空热还原法提炼出金属镁.对原料和还原渣进行了X射线衍射分析,并进行了热力学计算.通过和白云石在相同条件下进行还原作对比,认为这种水化白云石和国内某地出产的高质量白云石的还原效果十分接近,可以作为热法炼镁的理想原料.     

炼钢渣罐用新型防粘渣剂的开发与应用

介绍了利用机械力激发矿物活性的工艺,将炼钢厂鱼雷罐使用后的铝-碳化硅-碳质砖和钢包使用的镁碳砖,进行机械破碎、磨粉以后,激发其反应活性,然后添加胶凝性原料,制作成为炼钢渣罐用防粘渣剂,应用于120 t转炉生产线的11 m3渣罐的内壁喷涂作业,能够有效地隔离高温钢渣直接与渣罐的铸钢件内壁直接接触,降解渣中氧化铁含量明显,翻罐率达到99.5%以上。     

冰蓄冷系统的控制

部分负荷方案的结果 在部分负荷方案中,同时采用制冷机组和蓄冰罐来满足供冷负荷,而且制冷机组在无供冷负荷时对蓄冰罐进行蓄冰操作。因此,对蓄冰和供冷两个阶段都必须加以分析。 蓄冰罐和制冷机组的容量是按照与采用全负荷方案时同样的负荷值,应用模拟研究的方法来确定的。该模拟计算为一迭代过程,即先选定一个制冷机组的容量值,然后再确定蓄冰罐的最小尺寸。 影响蓄冰罐容量的关键因素是在最小负荷下的供冷率。制冷机组的容量等于为满足蓄冰罐蓄冰所需求的冷量。为了消除蓄冰罐蓄冰过程初始阶段的影响,进行了一次持续三天的模拟研究。 对于每一种负荷分布情况,有可能采用不同的蓄冰罐和制冷机组容量的组合。制冷机组必须具有的最小容量应该满足能在整个12小时夜间时间内,以满负荷运行的方式完成蓄冰过程。如果制冷机容量小于该最小值,则其无法为蓄冰罐提供足够的冷量,蓄冰罐则无法完成第二天的供冷任务。 制冷机组的实际最大容量等于在毫无蓄冷量的情况下,为了满足最大供冷负荷所需要的容量值。这些制冷机组容量的限定值也就限定了所需蓄冰罐的大小。 图3给出了对于16℃的供冷空气出口温度,差异因数值等于0.83的建筑物供冷负荷在不同的蓄冰罐和制冷机组容量情况下的特性。该图中也绘出了制     

复合喷吹铁水脱硫喷吹系统稳定性研究

结合国内某钢厂120 t复合喷吹脱硫改造项目,对复合喷吹铁水脱硫喷吹系统的稳定性进行了研究。根据现场调试及生产数据,对喷吹罐压力控制方式、粉末流量调节阀控制逻辑、喷吹罐下流化气体流量、助吹气体流量对喷吹稳定性产生影响的因素进行了研究。研究表明,喷吹罐采用恒压控制可以实现喷吹罐与喷吹管道间压差的稳定控制,有利于喷吹速度的稳定控制;粉末流量调节阀采用实时动态调整控制逻辑,能有效提高喷吹速度控制的精度;粉气比控制在32左右,喷吹过程连续稳定,管道及喷枪无堵塞现象,铁水喷溅小。     

以液态钙为还原剂的金属镁生产新工艺的热力学分析

为了从根本上改进现行的硅热法炼镁工艺,从新的还原剂——液态钙着手,研究了用液态钙为还原剂的金属镁还原新工艺的可行性。结果表明,以液态钙为还原剂的还原工艺是可行的。     

超临界压缩空气堆积床蓄冷罐循环性能分析

基于二维多孔介质热平衡模型对堆积床蓄冷罐的储释冷循环过程进行了计算,分析了循环过程中储释冷截断温度、储释冷质量流量和蓄冷罐工作压力对蓄冷罐循环热性能的影响.结果 表明:随着储释冷截断因子增大,斜温层厚度减小,储释冷时间及循环时间变长,蓄冷罐的有效容量比逐渐上升;随着储释冷质量流量的增大,储释冷时间及总时间显著缩短,但是储释冷截止时刻蓄冷罐温度和有效容量比变化较小;蓄冷罐工作压力的增大对储冷过程中蓄冷罐温度的影响很小,但是会明显缩短释冷时间并延长释冷过程中低温出口段的时间.     

小型锅炉烟尘测试时锅炉出力的计算

锅炉烟尘测试时,必须对锅炉出力进行测试。但监测中,许多小型锅炉往往不具备相关的计量装置和仪表,为解决这一问题,文章提出了用烟气量和空气过剩系数来计算锅炉的出力的公式,在实际使用中,该方法简单易行,其结果和实测值具有很好的一致怀。     

Unerroric of control of mutual compliance of the efficiency of hydrogen engines of unmanned vehicles in the conditions of mass production

The issues related to the reliability of hydrogen engines of unmanned vehicles and increasing the efficiency of using hydrogen as fuel when using the method of its production during the decomposition of hydrogen-containing molecules of liquid-phase organic compounds in a plasma discharge under the action of intense ultrasonic exposure are considered. Experiments have shown that as a result of decomposition in the acoustoplasma discharge of liquid hydrocarbons, solid-phase carbon-containing products are formed, chemical transformations occur in the liquid phase and hydrogen-containing combustible gas is formed. Hydrogen-containing gas can be used as fuel immediately after synthesis, i.e. it does not require separation, since in addition to hydrogen it contains only impurities of CO₂ and water vapor. The purpose of the study is to formalize the basic conditions for tightening the control of mutual compliance with the efficiency of hydrogen engines of the same series in the conditions of their mass production. Methods of mathematical statistics and hardware-software modeling were used in the study. The term “unerroric of quality mutual compliance control” is introduced to describe a set of hardware and software tools for such control. The principle of in-depth testing of the technical condition of such engines of one series is described in a multidimensional formulation of the quality control problem for three of their operating parameters at once. The conditions for increasing the mutual correspondence of the measured values of such parameters in the conditions of serial production of hydrogen engines are formalized.     

中国煤炭地下气化技术的发展

本文综述了煤炭地下汽化技术的国内外发展现状,对我国“长通道、大断面”煤炭地下气化新工艺给予了技术经济评述,并提出了发展煤炭地下汽化技术的政策建议。     

Review of theory of distortion and disintegration of liquid streams

Linear and nonlinear analyses of the instabilities and distortion of liquid streams injected into a gaseous media are discussed. The various fundamental mechanisms and the predictive capabilities for the distortions are emphasized. Round jets, planar sheets, annular sheets, and conical sheets are discussed in detail. The balance between capillary and inertial forces is primarily examined. The method for simplifying the analyses in the case of thin liquid sheets is discussed. The capabilities for representing the droplet size distribution that follows the stream disintegration are outlined.     

机车车轮多轴疲劳强度安全评定的研究

使用ANSYS8.0软件对高速列车车轮进行了三维有限元分析,计算出车轮在直线、曲线和道岔条件下牵引、制动共6种工况时孔边薄弱部位的应力,分别通过Mises等效平均应力方法、Sines平均主应力方法和应力分量中考虑平均应力方法计算出应力在极值位置时的等效应力幅、等效平均应力,从而进一步算出车轮的安全系数,对其疲劳强度进行评定,并对3种方法进行了比较研究。     

Constructal optimization of the geometry of an array of micro-channels

This paper documents the geometric optimization of an array of circular and non-circular ducts. The optimization was carried out numerically using finite volume method. As optimal dimensions were independent of the array configuration, the numerical simulation was performed on a unit cell. Numerical optimization for circular, square and isosceles right triangle cross-sections of channels was performed. Based on the results of this investigation, some correlations were proposed to predict the optimal hydraulic diameter and dimensionless heat transfer per unit volume. In addition to examining the effect of pressure drop on these parameters, it was showed that among the different geometries of this study, square cross-section has the most efficiency for a given volume. The numerical results of the present study were compared with approximate results reported in the literature which a good agreement was observed.     

固体热辐射Yong性能分析

本文对漫灰均温物体在常物性条件下对外辐射传热的Ｙｏｎｇ值计算建立了数学模型。通过与物体内能Ｙｏｎｇ公式的数值计算比较,得出了辐射能量的Ｙｏｎｇ值不大于内能Ｙｏｎｇ值的结论。从初步的热射Ｙｏｎｇ值计算公式发现。Ｙｏｎｇ与物体表面辐射率有关。     

MgO膨胀剂细度对MgO水化和水泥浆体膨胀的影响

基于《水工混凝土掺用氧化镁技术规范》中的Ⅰ型氧化镁（MgO）,研究了该型MgO膨胀剂（MEA）细度对掺粉煤灰水泥浆体膨胀性能的影响。即采用X射线衍射分析(XRD)及同步热分析（TG DSC）分析了掺MEA水泥浆体中MgO的水化性。结果表明,养护温度相同时,MEA的细度对水泥浆体内MEA中MgO的水化和水泥浆体的膨胀无显著影响,产生的膨胀均能补偿水泥浆体的收缩;MEA的细度可从试验设计采用的45 μm筛筛余15%左右增加到30%左右,这将有利于MEA生产企业的节能降耗。     

Measurements of concentration distribution of hydrogen jet using deflection of center of the laser spot

The main purpose of this work is to propose a new method to evaluate the concentration distribution of the hydrogen jet by using a He–Ne laser through the jet. This research attempts to apply the expression of concentration Gaussian distribution, the refraction formula of inhomogeneous refractive index medium, and the concentration inversion function to disclose the displacement of the center of the laser spot at different heights in the gas jet. The spot images of the laser beam passing through the gas jet at three vertical heights z = 10d, 20d, 30d, and different radial positions are obtained. The radial spatial asymmetry of the gas jet is also found in the experiment. Finally, the calculated concentration distribution curve and the fluent simulation curve, it is found that the two results are very similar. Our findings show that the error between the concentration distribution of this method and the simulated concentration distribution reaches 2.43%.     

汽轮机零件防锈性能的改善

介绍了汽轮机零件的封存特点、防锈要求及防锈油性能对比试验的方法,通过对试验结果的对比分析,客观验证了各种防锈油的性能。试验表明,只有选择了合适的防锈油,才能保证汽轮机零件长期封存的质量。