几种燃烧炉炉膛测温装置的使用与改进

铅锌冶炼企业燃烧炉、冶炼炉种类较多。测温装置对炉子的安全、平稳运行起着至关重要的作用,本文结合企业的生产实践,对测温装置的使用和改进进行了总结,提出了不同燃烧炉测温装置的选择要点。     

煤中全硫测定方法的探讨

煤炭中全硫的分析，采用高温燃烧中和法进行测定，其中所用氧气采用纯氧瓶来供氧。因此，在试验中有很多不便。本文通过大量试验，从理论和实践中提出了直接以空气中氧来代替目前所用氧气钢瓶是完全可行的。     

数字化加热炉在石钢的应用

介绍了数字化加热炉的特点及优点,并和传统比例加热炉作了比较.     

Combustion of Ti+0.5C and Ti+C mixtures of bulk density in inert gas coflow

The combustion of Ti-C mixtures of bulk density under inert gas blowing conditions produced by evacuation of one end of the reaction cell was studied for the first time. The experiments showed that the tested mixtures in quartz cups were not ignited and did not burn without the inert gas (argon) flow. Increasing the rate of gas evacuation from the sample increased the rate of steady-state combustion of the mixture of titanium with carbon black, and for the mixture of titanium with graphite, stabilization of the flat combustion front was observed. It is shown that the presence of small pressure difference (up to 105 Pa) allows control of the combustion process and confirms the basic postulates of the convective-conductive theory of combustion for heterogeneous condensed systems. __________ Translated from Fizika Goreniya i Vzryva, Vol. 45, No. 1, pp. 30–37, January–February, 2009.     

Effect of alumina nanoparticles in the fluid on heat transfer in double-pipe heat exchanger system

This study was performed to investigate the convective heat transfer coefficient of nanofluids made of several alumina nanoparticles and transformer oil which flow through a double pipe heat exchanger system in the laminar flow regime. The nanofluids exhibited a considerable increase of heat transfer coefficients. Although the thermal conductivity of alumina is not high, it is much higher than that of the base fluids. The nanofluids tested displayed good thermal properties. One of the possible reasons for the enhancement on heat transfer of nanofluids can be explained by the high concentration of nanoparticles in the thermal boundary layer at the wall side through the migration of nanoparticles. To understand the enhancement of heat transfer of nanofluid, an experimental correlation was proposed for an alumina-transformer oil nanofluid system.     

烧成制度对BaTiO3介电性能的影响

烧成制度对BaTiO3质PTC陶瓷的介电性能有重要影响,详细讨论了烧成温度、保温时间、冷却速度以及烧结气氛等因素对BaTiO3质陶瓷室温电阻和PTC效应的影响,并对其影响机制给出了合理解释。研究结果表明,陶瓷的半导化与烧成温度密切相关,适当保温对传质有很大影响,冷却速度和烧结气氛对室温电阻和PTC效应有一定影响。     

列车车轮踏面缺陷的图像区域提取

建立了基于机器视觉的踏面缺陷检测系统,研究了该系统的踏面缺陷图像区域提取技术.采用基于平稳小波自适应阈值算法提取踏面区域;然后,根据踏面剥离缺陷图像特征,利用基于分块思想的粗定位和精定位组合的方法提取剥离图像区域;最后,根据踏面擦伤缺陷图像特征,利用基于踏面边缘线扫描搜索擦伤区域的方法提取擦伤图像区域.用两个实例验证了提出方法的有效性,实验结果表明:系统对剥离和擦伤两种缺陷的漏识率分别为8.3%和5.3%,误识率为5.1%,从而为后续特征提取和缺陷识别奠定了基础.     

喷嘴型面对膏体火箭内弹道的影响

为研究燃面变化对膏体火箭发动机内弹道调节精度的影响,根据膏体火箭发动机的工作原理,分别推导了直圆管喷嘴和锥形扩张喷嘴型面下的膏体推进剂燃面方程,建立了膏体火箭发动机零维内弹道模型,分析了喷嘴型面对发动机内弹道性能的影响,并进行了直圆管喷嘴发动机试验.结果表明,直圆管喷嘴下计算的点火时间比试验结果短,但平衡时间及平衡压强与试验结果基本吻合,喷嘴型面变化对发动机平衡时间影响很大.     

传热传质对膨胀阻燃聚丙烯裂解燃烧行为的影响

通过对膨胀阻燃聚丙烯材料在锥形量热仪实验条件下燃烧的分析和研究,建立了能够描述膨胀阻燃材料升温、燃烧过程的传热传质数学模型,分析了传热传质对材料裂解行为的影响.实验中测量了纯聚丙烯及膨胀阻燃聚丙烯在膨胀燃烧过程中的样品质量损失、质量损失速率、热释放速率和内部温度随时间变化规律.通过理论分析及实验比较发现,不同的传热传质过程,对样品裂解、燃烧及热化学行为的影响非常大.膨胀阻燃聚丙烯的传热传质过程可减缓裂解、燃烧行为.DSC的分析结果表明,炭层对传热传质的阻隔作用使膨胀阻燃聚丙烯的热稳定性增强,放热峰值降低.