Coal mine fires,which can cause heavy casualties,environmental damages and a waste of coal resources,have become a worldwide problem.Aiming at overcoming the drawbacks,such as a low analysis efficiency,poor stability ...Coal mine fires,which can cause heavy casualties,environmental damages and a waste of coal resources,have become a worldwide problem.Aiming at overcoming the drawbacks,such as a low analysis efficiency,poor stability and large monitoring error,of the existing underground coal fire monitoring technology,a novel monitoring system based on non-dispersive infrared(NDIR)spectroscopy is developed.In this study,first,the measurement principle of NDIR sensor,the gas concentration calculation and its temperature compensation algorithms were expounded.Next,taking CO and CH_(4) as examples,the liner correlation coefficients of absorbance and the temperature correction factors of the two indicator gases were calculated,and then the errors of concentration measurement for CO,CO_(2),CH_(4) and C_(2)H_(4) were further analyzed.The results disclose that the designed NDIR sensors can satisfy the requirements of industrial standards for monitoring the indicator gases for coal fire hazards.For the established NDIR-based monitoring system,the NDIRbased spectrum analyzer and its auxiliary equipment boast intrinsically safe and explosion-proof performances and can achieve real-time and in-situ detection of indicator gases when installed close to the coal fire risk area underground.Furthermore,a field application of the NDIR-based monitoring system in a coal mine shows that the NDIR-based spectrum analyzer has a permissible difference from the chromatography in measuring the concentrations of various indicator gases.Besides,the advantages of high accuracy,quick analysis and excellent security of the NDIR-based monitoring system have promoted its application in many coal mines.展开更多
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, m...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, multi-field 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 simul-(ation) model was checked by the parameters measured in an operating boiler, (DG130-9.8/540.) 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.展开更多
随着自动驾驶技术的快速发展,4D毫米波雷达因其全天候适应性和抗干扰能力,成为同步定位与地图构建(Simultaneous Localization and Mapping,SLAM)的关键传感器。然而在隧道等封闭环境中,多径效应引发的虚警点云严重影响了雷达SLAM系统...随着自动驾驶技术的快速发展,4D毫米波雷达因其全天候适应性和抗干扰能力,成为同步定位与地图构建(Simultaneous Localization and Mapping,SLAM)的关键传感器。然而在隧道等封闭环境中,多径效应引发的虚警点云严重影响了雷达SLAM系统的定位精度与建图效果。针对这一问题,本文基于对隧道中的毫米波雷达点云数据特性和散射角特征的规律分析提出了一种全新的滑窗动态滤波算法。该方法结合了点云的空间统计特性与邻域密度检测方法剔除离群噪声点云,利用雷达点云粗配准获得先验估计位姿,结合雷达点云俯仰向和方位向的三维散射角特征,实现对真实目标点云数据的区分和聚类。随后使用随机采样一致性算法(Random Sample Consensus,RANSAC)拟合隧道墙壁平面并构建隧道墙面模型。通过引入动态滑窗更新策略,利用拟合的隧道墙面模型与先验估计位姿实时更新当前姿态节点到墙面边界距离阈值,使用距离阈值进一步消除隧道空间以外的虚警点云和噪声点云,并在因子图优化框架下完成全局位姿修正与局部地图更新。本研究在真实的隧道环境中采集多个不同场景的数据进行实验验证,实验结果证明本研究提出的方法在有效降低虚警点云干扰的同时,显著提高了定位精度和建图质量,且能在复杂环境中保持较高的稳定性。本研究为提高4D毫米波雷达SLAM在封闭环境中的鲁棒性提供了新的技术思路和实现路径。展开更多
煤矿甲烷排放遥感监测已经成为世界各国监测温室气体排放的主要研究内容之一。为系统总结以往研究,分析研究趋势和发现当今研究热点,首先利用Web of Science与中国知网(CNKI)数据库和关键词检索,筛选了2000—2024年煤矿甲烷排放遥感监...煤矿甲烷排放遥感监测已经成为世界各国监测温室气体排放的主要研究内容之一。为系统总结以往研究,分析研究趋势和发现当今研究热点,首先利用Web of Science与中国知网(CNKI)数据库和关键词检索,筛选了2000—2024年煤矿甲烷排放遥感监测领域的国内外文献;然后,采用CiteSpace文献计量工具进行文献计量和可视化分析。结果表明:煤矿甲烷遥感监测领域文献呈显著增长态势,年均增幅达20%;发文量排名靠前的国家为美国(181篇)和中国(98篇),德国、加拿大等国家紧随其后;美国国家航空航天局(NASA)以66篇发文量居机构首位,中国科学院位列全球第6;研究热点主要集中于卫星遥感监测、甲烷浓度反演、甲烷量化估算以及数据智能处理;国外研究更多聚焦于全球甲烷排放的监测及政策驱动下的技术创新,我国则在煤矿甲烷排放监测和智能化管理方面表现突出;根据文献共被引分析,高分辨率遥感与反演技术的发展显著提升了甲烷排放监测的时空精度,遥感监测精度和效率、数据智能化处理与算法、多平台集成与融合、国际合作和数据共享等为未来研究方向。展开更多
基金Project(2021MD703848) supported by the China Postdoctoral Science FoundationProjects(52174229, 52174230)supported by the National Natural Science Foundation of China+1 种基金Project(2021-KF-23-04) supported by the Natural Science Foundation of Liaoning Province,ChinaProject(2020CXNL10) supported by the Fundamental Research Funds for the Central Universities,China。
文摘Coal mine fires,which can cause heavy casualties,environmental damages and a waste of coal resources,have become a worldwide problem.Aiming at overcoming the drawbacks,such as a low analysis efficiency,poor stability and large monitoring error,of the existing underground coal fire monitoring technology,a novel monitoring system based on non-dispersive infrared(NDIR)spectroscopy is developed.In this study,first,the measurement principle of NDIR sensor,the gas concentration calculation and its temperature compensation algorithms were expounded.Next,taking CO and CH_(4) as examples,the liner correlation coefficients of absorbance and the temperature correction factors of the two indicator gases were calculated,and then the errors of concentration measurement for CO,CO_(2),CH_(4) and C_(2)H_(4) were further analyzed.The results disclose that the designed NDIR sensors can satisfy the requirements of industrial standards for monitoring the indicator gases for coal fire hazards.For the established NDIR-based monitoring system,the NDIRbased spectrum analyzer and its auxiliary equipment boast intrinsically safe and explosion-proof performances and can achieve real-time and in-situ detection of indicator gases when installed close to the coal fire risk area underground.Furthermore,a field application of the NDIR-based monitoring system in a coal mine shows that the NDIR-based spectrum analyzer has a permissible difference from the chromatography in measuring the concentrations of various indicator gases.Besides,the advantages of high accuracy,quick analysis and excellent security of the NDIR-based monitoring system have promoted its application in many coal mines.
文摘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, multi-field 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 simul-(ation) model was checked by the parameters measured in an operating boiler, (DG130-9.8/540.) 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.
文摘煤矿甲烷排放遥感监测已经成为世界各国监测温室气体排放的主要研究内容之一。为系统总结以往研究,分析研究趋势和发现当今研究热点,首先利用Web of Science与中国知网(CNKI)数据库和关键词检索,筛选了2000—2024年煤矿甲烷排放遥感监测领域的国内外文献;然后,采用CiteSpace文献计量工具进行文献计量和可视化分析。结果表明:煤矿甲烷遥感监测领域文献呈显著增长态势,年均增幅达20%;发文量排名靠前的国家为美国(181篇)和中国(98篇),德国、加拿大等国家紧随其后;美国国家航空航天局(NASA)以66篇发文量居机构首位,中国科学院位列全球第6;研究热点主要集中于卫星遥感监测、甲烷浓度反演、甲烷量化估算以及数据智能处理;国外研究更多聚焦于全球甲烷排放的监测及政策驱动下的技术创新,我国则在煤矿甲烷排放监测和智能化管理方面表现突出;根据文献共被引分析,高分辨率遥感与反演技术的发展显著提升了甲烷排放监测的时空精度,遥感监测精度和效率、数据智能化处理与算法、多平台集成与融合、国际合作和数据共享等为未来研究方向。
