Temperature distribution and dynamic control of secondary cooling in slab continuous casting

To predict and optimize the temperature distribution of slab continuous casting in steady operational state, a three-dimensional model (named offline model) based on the heat transfer and solidification theories was developed. Both heat transfer and flux distribution characteristics of the nozzle sprays on the slab were considered, and the complicated boundary condi-tions, such as spray cooling, natural convection, thermal radiation as well as contact cooling of individual rolls were involved in the model. ...     

Effects of main factors on remedying northern landscaping water by hybrid ecological filter

Natural zeolite and coal cinder were layered as main packing medium of the ecological filter instead of traditional filling to remedy the static lake water in Northern China.The ecological filter was running in a combined upward and downward flow mode.Dynamic experiments were carried out to study the effects of retention time and ambient temperature on pollutants’ removal efficiency of the hybrid ecological filter.The function of plant was also studied by contrast test.It is showed that the removal efficiencies of NH4+-N and TP are increased when the retention time is changed from 1 h to 2 h and 4 h,but the removal efficiency of TN is decreased,the removal efficiency of NH4+-N is increased from 91.5% to 98% and that of TP is increased from 31.8% to 52.5%.When the temperature declines,the temporal removal efficiency of NH4+-N is reduced,but the removal efficiency of 24 h and 48 h is remained.The removal efficiency of TP after 24 h and 48 h is decreased when the temperature declines evidently.The retention time plays an important role in NH4+-N and TP removal,and the ambient temperature is significant for TP removal.The plant favors for TP and organic matter removal but has little effect on TN removal.     

火电机组过热汽温神经网络控制的研究

研究了单神经元PID控制器和BP神经网络PID控制器在火电机组过热汽温的应用．实验结果表明,神经网络PID控制结构简单,有较强的鲁棒性,取得了较好的控制效果．     

压型钢板—混凝土组合楼板瞬态温度场有限元分析

要对压型钢板—混凝土组合楼板进行抗火性能的研究,首先要研究组合楼板在受火情况下板内温度场的分布情况.用大型通用有限元分析软件ANSYS对青岛理工大学韩金生所进行的组合楼板抗火试验进行数值分析,并与试验结果进行对比,验证所建立的模型的正确性,并为以后进一步对组合楼板抗火性能研究提供基础性的研究成果.     

木枣低温贮藏过程中品质变化规律的研究

研究了木枣在4℃、相对湿度95%的低温条件下贮藏期间贮藏品质的变化.实验结果表明木枣在贮藏60d软果率达到46.5%,有机酸含量较鲜枣上升了14.3%,总糖含量由22.4%下降至18.05%,Vc含量为298.56mg/100g,而乙醇含量则达到0.24%.     

自源无线温度检测技术的研究与应用

基于温差模块、DS18B20和红外技术的自源无线温度检测技术,利用故障发热部位与环境的温度差发电自给,解决高压现场内难以获得低压电源的问题;利用红外线传输信号,避免在高压变电站中布线和信号受高压现场的强电磁干扰.实验结果表明,半导体温差模块输出电压与温差在一定范围内呈线性关系,温差越大,输出电压越大.采用带有超低压启动器的DC/DC电压提升电路进行电压提升,解决实际应用中由于温差过小而导致的半导体温差模块输出电压过低,不足以提供所需的电压问题.     

无限长圆柱非稳态导热集总参数法应用

圆柱体进行非稳态导热时,集总参数法只适用于Bi〈1的情况,Bi〉1时一般采用根据解析解绘制的Heisler图线．由于前者适用范围窄,后者误差大,探讨一个非稳态导热的实用便捷公式具有重要意义．以无限长圆柱为例,研究在0〈Bi〈∞条件下非稳态导热平均温度集总参数分析方法,定义必要的参数,建立了平均温度瞬态响应关系式．拓展了传统的非稳态导热集总参数法应用范围．数值分析给出了计算关系式的辅助参数表．通过推导出的公式,结合参数表来计算工程实际问题,比通用的Heisler图解法更为简洁方便．     

真空烧结温度对多孔钛影响的研究

以碳酸氢铵做造孔剂,采用真空烧结法制备出生物多孔钛．研究了烧结温度对多孔钛显微形貌、显气孔率、抗压强度的影响．研究表明,提高烧结温度,有利于Ti晶体的发育,并提高制品抗压强度．     

局域畸变结构对铁电薄膜极化性质的影响

引入描述薄膜内部极化强度的分布函数,采用GLD（Ginzburg-Landau-Devonshire）唯象理论,研究非铁电性局域畸变结构对铁电薄膜极化性质的影响.研究结果表明,非铁电性局域畸变结构的存在降低了铁电薄膜的极化强度和相变温度,并破坏了极化强度在薄膜内部的均匀分布.薄膜内部局域畸变结构厚度的增加及铁电性结构区域至非铁电性结构区域过渡层厚度的增加,都会导致薄膜极化强度的降低.     

水温差及热负荷在线检测技术在包钢高炉上的应用

简介了水温差及热负荷在线检测系统功能、系统组成和特点,以及如何利用它分析、判断、执行高炉冷却制度,该系统还可用于预测煤气流的分布和冷却壁的漏水情况.