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Chinese Journal of Chemical Engineering 2020年第1期28卷 23-32页

作者： Weishu wang Yihan Liao Youzhi Yan Bingchao Zhao Tao wang Shanshan Shangguan North China University of Water Resources and Electric Power Zhengzhou 450045China

To develop an appropriate falling film evaporation device for organic fluid cogeneration, a numerical study on the gas–liquid two-phase counter-current flow characteristics of R113 inside a vertical tube under different structural conditions was conducted using the Fluent software. The effects of the tube length, tube diameter, and annular gap on the falling film flow characteristics were determined, respectively. The results indicated that under a certain spray density, the falling film thickness in the region of the steady section was almost constant with different structural parameters for the tube diameter, tube length, and annular gap. In addition, a smaller tube diameter resulted in a steadier film flow. When the tube diameter decreased to a specific value, the film thickness showed a uniform distribution along the wall surface. This indicated that a best falling tube diameter exists. Meanwhile, the film fluctuation was enhanced with an increase in the tube length. When the tube length was greater than 1.2 m, the falling film splashed and could not completely wet the wall surface. The film fluctuation was enhanced by decreasing the annular gap, and the film could not be formed when the annular gap was smaller than 1.2 mm.

关键词： Falling film Numerical simulation R113

Sulfur evolution in chemical looping combustion of coal with MnFe_2O_4 oxygen carrier

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Journal of Environmental Sciences 2014年第5期26卷 1062-1070页

作者： Baowen wang Chuchang Gao Weishu wang Haibo Zhao Chuguang Zheng College of Electric Power North China University of Water Conservancy and Hydroelectric Power State Key Laboratory of Coal Combustion Huazhong University of Science and Technology

Chemical looping combustion （CLC） of coal has gained increasing attention as a novel combustion technology for its advantages in CO2 capture. Sulfur evolution from coal causes great harm from either the CLC operational or environmental perspective. In this research, a combined MnFe2O4 oxygen carrier （OC） was synthesized and its reaction with a typical Chinese high sulfur coal, Liuzhi （LZ） bituminous coal, was performed in a thermogravimetric analyzer （TGA）-Fourier transform infrared （FT-IR） spectrometer. Evolution of sulfur species during reaction of LZ coal with MnFeaO40C was systematically investigated through experimental means combined with thermodynamic simulation. TGA-FTIR analysis of the LZ reaction with MnFe2O4 indicated MnFe2O4 exhibited the desired superior reactivity compared to the single reference oxides Mn304 or Fe203, and SO2 produced was mainly related to oxidization of H2S by MnFe2O4. Experimental analysis of the LZ coal reaction with MnFe2O4, including X-ray diffraction and X-ray photoelectron spectroscopy analysis, verified that the main reduced counterparts of MnFe2O4 were Fe304 and MnO, in good agreement with the related thermodynamic simulation. The obtained MnO was beneficial to stabilize the reduced MnFe2O4 and avoid serious sintering, although the oxygen in MnO was not fully utilized. Meanwhile, most sulfur present in LZ coal was converted to solid MnS during LZ reaction with MnFe2O4, which was further oxidized to MnSO4. Finally, the formation of both MnS and such manganese silicates as Mn2SiO4 and MnSiO3 should be addressed to ensure the full regeneration of the reduced MnFe2O4.

关键词： CO2 capture chemical looping combustion MnFe2O4

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有机复合绝缘干式高压电流互感器及其发展

高压电器 2022年第1期58卷 175-181页

作者：王如璋黄维枢中国电力科学研究院北京100085

文中介绍了笔者研发的一种具有自主知识产权并在国内外应用超过20年的,以涂覆硅油的聚四氟乙烯薄膜等复合材料为主要绝缘的干式高压电流互感器。该产品较油纸绝缘和SF;气体绝缘高压电流互感器,在安全性、可靠性、重量、制造成本、生产... 详细信息

文中介绍了笔者研发的一种具有自主知识产权并在国内外应用超过20年的,以涂覆硅油的聚四氟乙烯薄膜等复合材料为主要绝缘的干式高压电流互感器。该产品较油纸绝缘和SF;气体绝缘高压电流互感器,在安全性、可靠性、重量、制造成本、生产效率和许多技术参数如极低的局部放电量和介质损耗因数等方面具有较大的优势。文中还介绍了这种电流互感器额定电压已从低到高、类型从单一到成系列、以及从国内到国外的发展情况。目前该技术已臻于成熟,已应用于国内和30多个国家,产品运行安全可靠,在高压电器行业中独树一帜。

关键词：高压电流互感器有机复合绝缘聚四氟乙烯薄膜干式低负载容量电流电压互感器串级式

Numerical Simulation and Optimization of Staged Combustion and NO_x Release Characteristics in Precalciner

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Journal of Thermal Science 2019年第5期28卷 1024-1034页

作者： wang weishu LIAO Yihan LIU Jun HUANG Zhihao TIAN Miao Thermal Engineering Research Centre North China University of Water Resources and Electric Power

In order to study the combustion characteristics in a precalciner, the temperature and composition field in a typical Trinal-sprayed calciner were numerically analysed. The results obtained by simulation were compared to actual measurements and the simulated results were in good agreement with the measured ones. The results indicated that the aerodynamic flow field in the precalciner is satisfactory, and a symmetrical reflux occurs in the shrinkage zone of the precalciner because of air staging, which can increase the residence time of the solid particles. The temperature distribution in the furnace is uniform, and the average temperature is greater than 1200 K, which can satisfy the conditions for the pulverised coal combustion and raw material decomposition. The mass fraction distribution of oxygen, carbon monoxide, and carbon dioxide in the precalciner is closely related to the temperature distribution. The concentration of nitrogen oxides(NO_x) exhibits a trend of increasing, decreasing and then increasing, and finally tending to a stable level. Within a certain velocity range, the average temperature in the precalciner and the decomposition efficiency of the raw material increase as the flue gas velocity increases. When the flue gas velocity is 24 m/s, the overall performance of the precalciner is optimal.

关键词： TTF precalciner staged combustion NOx emission characteristics optimization

基于局部离群因子的列车卫星定位故障检测方法

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铁道科学与工程学报 2023年第10期20卷 4021-4030页

作者：王韦舒上官伟刘江姜维北京交通大学电子信息工程学院北京100044 北京市轨道交通电磁兼容与卫星导航工程技术研究中心北京100044

基于卫星导航系统的定位技术已成为我国下一代列车运行控制系统中自主定位的重要方式。卫星信号在传播过程中易受到环境多源噪声的影响而导致定位解算性能下降,需要对潜在发生的故障进行检测以保证定位性能。针对一致性假设检验中观测... 详细信息

基于卫星导航系统的定位技术已成为我国下一代列车运行控制系统中自主定位的重要方式。卫星信号在传播过程中易受到环境多源噪声的影响而导致定位解算性能下降,需要对潜在发生的故障进行检测以保证定位性能。针对一致性假设检验中观测新息不再服从先验高斯分布问题,提出一种基于局部离群因子的卫星定位故障检测方法。首先,基于正常运行环境中的滤波新息构建历史数据集,采用核密度估计方法获取检验阈值。在此基础上,根据特定的邻域值计算当前时刻观测新息的局部离群因子,通过度量其与历史数据集中邻域数据之间的局部密度进而判别是否发生故障。最后,采用西部铁路实测数据对所提算法进行实验验证。研究结果表明,在不同偏差阶跃故障和不同速率斜坡故障场景下,所提出方法的故障检测性能优于滤波新息故障检测和自主完好性监测外推法。在15m阶跃故障场景中,所提出的算法故障检测率分别提高了100%和62%,故障期间水平位置均方根误差降低了36.1%和18.5%。在0.5m/s斜坡故障场景中,故障检测时延分别缩短了20s和11s,故障检测率提高了40%和20%,水平位置均方根误差降低了28.6%和9%。基于局部离群因子的故障检测方法具有高检测、低时延的显著优势,打破了先验特定分布假设对于故障检测性能的约束,有效提高了定位系统的定位精度和可靠性。

关键词：列车运行控制系统列车定位卫星定位故障检测局部离群因子