熔池熔炼炉烟气中单体硫的治理方法探讨

基于单体硫形成原因和危害机理的分析，通过冷态－模拟试验，研究了加料方式、二次风、烟道结构等对减少物料夹带、加强烟气混合、加速烟尘粘结物沉降的作用，并由此得到了熔池熔炼炉烟气中单体硫的治理方案。     

水泥回转窑二次风温测量误差分析

回转窑的气流温度是非常重要的热工参数。本文以二次风温为例 ,应用传热学原理研究了抽气热电偶的静态测温误差和动态响应特性。此研究结果不仅可用于热电偶信号的校正 ,也可为回转窑热工参数的在线控制提供科学依据。研究成果已成功应用于多家水泥厂回转窑 ,并取得良好的效果     

Numerical simulation of aluminum holding furnace with fluid-solid coupled heat transfer

To predict three-dimensional temperature distribution of molten aluminum and its influencing factors inside an industrial aluminum holding furnace, a fluid-solid coupled method was presented. The fluid-solid coupled mathematics models of aluminum holding furnace in the premixed combustion processing were established based on mass conservation, moment conservation, momentum conservation, energy conservation and chemistry species conservation. Computational results agree well with the test data of the typical condition. The maximum combustion temperature is 1 850 K. The average temperature of the molten aluminum is 1 158 K, and the maximum temperature difference is about 240 K. The average temperature increases 0.3 °C while the temperature of combustion air increases 1 °C. The optimal excess air ratio is 1.25–1.30.     

基于单片机技术的火花塞离子电流检测系统研究

基于离子电流的诊断方法,设计了一套以火花塞为传感器,以MC9S12XS128单片机为核心的离子电流检测系统.该系统应用单片机技术以及离子电流回路检测发动机工作时的燃烧信号,通过高压硅堆以及小波降噪技术自动隔离高压、高频信号,然后对火花塞离子电流信号进行在线采集并通过界面显示,有效提取特征参数;对发动机运行过程中离子电流信号进行试验研究,采集1 000个点耗时约20 259μs,离子电流两个峰值之间的时间间隔大约为5 ms,此离子电流的峰值延迟时刻大约是42°,与实际气缸的燃烧情况基本一致;通过与数字示波器采集信号对比,验证了本系统对离子电流信号采集的准确性.     

基于小波包变换预处理的铝电解槽针振信息元分析与诊断

简述了小波包变换的基本原理及利用小波包对电压信号进行分解的方法。针对铝电解槽电压波动信号的频谱特点。采用小波包分析方法提取了电压信号的特征向量。将信号分解到8个频段内。进行预处理得到频段能量特征向量。应用BP神经网络建立了特征向量到振针信息元之间的映射。仿真结果表明，小波包分析能够有效地将隐藏在正常电压信号之中的早期弱故障信号提取出来，从而发现槽子的早期不良症状。     

三种湍流模型对Al电解槽内Al液流场预测的比较及其工业测试

应用标准k-Е双方程、低Reynolds数Jones-Launder k-Е模型与RNG k-Е模型分别对三种不同进电方式(四点进电的200kA槽、两点进电的160kA槽以及三点进电的80kA槽)的预焙阳极Al电解槽内的Al液流场进行了数值仿真，并且应用铁棒溶蚀法对相应工况下的Al液流场进行了工业测试。通过对计算结果和测试结果的比较与分析，可以得出：与标准k-Е模型相比较，低Reynolds数模型具有较小的湍流粘度；标准k-Е模型与RNG模型用于Al液流场的数值仿真时，其计算结果均有较高的可靠性。并初步得出在电流强度大于80kA的Al电解槽中，Al液流动的计算不适宜应用低Reynolds数模型。     

不同进电方式与槽膛内形的铝电解槽内流场的数值模拟

采用k-ε双方程模型封闭的Navier-stokes方程描述铝电解槽内熔体的湍流流动。对于200kA、160kA与80kA三种不同进电方式的铝电解槽以及具有不同槽膛内形的160kA槽，在磁场、热场解析的基础上，计算出相应工况下动量方程中的源项，即洛仑兹力，并对稳定状态下熔体的三维流场进行了数值计算。计算结果表明，在模拟工况条件下，铝液流动在200kA槽内呈现出四个旋涡，在160kA与80kA槽内呈现出两个旋涡；不同的进电方式与槽膛内形对熔体的运动方式均有显著影响。     

Combustion and energy balance of aluminum holding furnace with bottom porous brick purging system

For acquiring the details in aluminum holding furnace with bottom porous brick purging system, efforts were performed to try to find out the potential optimal operation schemes. By adopting transient analysis scheme and constant boundary temperature, combustion in the furnace was investigated numerically using computational fluid dynamics (CFD). The predicted gas temperature shows good agreement with the measured results, and the predicted energy distribution of the furnace is consistent with that obtained from energy balance experiment, which confirms the reliability of the numerical solution. The results show that as the fuel-air mixture temperature rises up from 300 K to 500 K, the energy utilization of the furnace could increase from 34.55% to 37.14%. However, as the excess air coefficient increases from 1.0 to 1.4, energy utilization drops from 34.55% to 29.56%. Increasing the combustion temperature is the most effective way to improve the energy efficiency of the furnace. High reactant temperature and medium excess air coefficient are recommended for high operation performance, and keeping the furnace jamb sealed well for avoiding leakage has to be emphasized.     

基于模型汽油发动机的空燃比控制器仿真研究

建立了合理的四缸四冲程汽油发动机数学模型,对模型发动机进行仿真标定实验,获得其喷油MAP图.根据发动机运行特点及控制要求,在均值模型的基础上,建立了稳态部分负荷、瞬态、怠速3种主要运行工况下的控制器模型,并给出了以上模型在Matlab/Simulink环境下的结构框图和综合仿真过程.仿真结果表明:控制器能够判断不同工况,并自动切换到相应的控制模块,使空燃比达到预期要求,具有良好的控制性能、控制策略与控制算法可行.     

Two-stage numerical simulation for temperature profile in furnace of tangentially fired pulverized coal boiler

Considering the fact that the temperature distribution in furnace of a tangential fired pulverized coal boiler is difficult to be measured and monitored, two-stage numerical simulation method was put forward. First, multifield coupling simulation in typical work conditions was carried out off-line with the software CFX-4.3, and then the expression of temperature profile varying with operating parameter was obtained. According to real-time operating parameters, the temperature at arbitrary point of the furnace can be calculated by using this expression. Thus the temperature profile can be shown on-line and monitoring for combustion state in the furnace is realized. The simulation model was checked by the parameters measured in an operating boiler, DO130-9. 8/540. The maximum of relative error is less than 12% and the absolute error is less than 120℃, which shows that the proposed two-stage simulation method is reliable and able to satisfy the requirement of industrial application.