This work introduces a polydisperse aerosol testing system for respirable dust virtual impactor evaluation for the first time, and characterizes its performance. The aerosol in the dust chamber diluted and mixed completely, its diameter distribution follows a lognormal distribution. Although the aerosol concentration increased from top to bottom in the chamber, the particle distribution in the same measurement plane was relatively uniform. The sample flow rate of the test system is stable, and the change of temperature on the flow rate is negligible. The most common virtual impactor with the operating point flow rate of 4 L/min was selected as the subject, and its separation performance, flow variation and load characteristics were evaluated by this test system. The results show that the cutoff diameter deviation is − 2.8

In order to increase the detection accuracy of coal dust and reduce the maintenance of the coal dust concentration sensor, in this paper, the electrostatic sensor of the plate-ring detection electrode was developed for the detection of coal dust concentration. Through the establishment of the three-dimensional finite element model of the plate-ring detection electrode and the simulation results of COMSOL, the superiority of the plate-ring detection electrode was demonstrated, and the basis for the structure design of the plate-ring detection electrode was provided. The plate-ring detection electrode and the processing circuit of the tiny electrostatic induction signal were designed. Electrostatic induction dust concentration sensor with plate-ring detection electrode was developed. Experiments and data analysis proved that the 1.5-order central moment of the electrostatic induction signal had a high degree of fit with the dust concentration value. The mathematical relationship between the electrostatic induction signal and the dust concentration was determined. The detection error of coal mine dust concentration sensor based on plate-ring detection electrode did not exceed 10%.

To reduce the error caused by optical device pollution and background value drift in the measurement process of ultra-low emission particulate concentration by light scattering method, an on-line calibration method which can realize self-check and full-range calibration was put forward. The single light source spectral method was used to set up calibration light path, through a strong emphasis on technology achieving light signal extraction. The calibration effect was evaluated based on the dust tunnel system. The results show that the light intensity-modulated technique can significantly improve the measurement accuracy of low concentration particles compared with the constant light intensity technology. When the concentration of particles to be measured is higher than 500 mu g/m(3), the relative error between the measurement results of the experimental prototype and those of the filter membrane weighing method is less than 10 %. The optimal calibration period of the measuring instrument is 3 hours. When the variation deviation from the calibration light intensity of light intensity modulation is less than 2 %, the relative error between the particle concentration measurement result and the filter membrane weighing method is less than 10 %.

呼吸性粉尘连续分离技术是实现其在线监测和尘肺病预警的基础及关键.为了解决常见的旋风分离、水平陶析及平板冲击等分离方式易积尘、过载、堵塞等弊端,提出一种基于虚拟冲击原理的呼吸性粉尘连续分离技术.基于虚拟冲击理论,建立呼吸性粉尘虚拟分离三维模型,仿真分析其速度场和压力场的分布,通过分域法阐释虚拟冲击的分离机理,并构建分离效能和分离时效一体化测试系统,对设计的虚拟冲击器进行验证.研究结果表明:分离效能模拟曲线随着喷嘴与收集腔间距和收集腔直径增大而上移,而收集腔直径对分离效能的影响作用强于喷嘴与收集腔间距的影响.当喷嘴与收集腔间距为4.0 mm、收集腔直径为3.0 mm时,各个粒径点的分离效率与BMRC曲线的偏差在±5％以内.在工作点流量为4 L/min、弱流比为0.1条件下,分离器的分离效能曲线与BMRC曲线相比,整体呈负偏差,最大偏差为?4.7％.在质量浓度为35～40 mg/m3的粉尘浓度环境下,传统旋风分离器容易出现排灰口和排气口堵塞,测试结果偏差较大,连续运行1 d后已不能满足连续分离要求,而虚拟冲击式分离器内部颗粒损失及截留较少,可实现15 d以上的连续运行而无需人工清理,连续分离时效提升了10倍以上,验证了本文方法的可行性及优越性,满足呼吸性粉尘浓度在线测量对粉尘连续分离的分离效能及分离时效要求.

In the ultra-low emission facilities of coal-fired power plants, in order to explore the cause of different PM10/PM2.5 measurement results from the particle samplers adopted with different principles, the correlation and stability of the sampling results of the cyclone separator and virtual impactor were tested and compared. In addition, the influence of humidity on the two sampling methods was verified and analyzed, which were all based on particle sampling experiment verification simulation system and automatic filter membrane batch weighing system in the mass concentration environment of 0~6 mg/m3. The results show that the test results of the two sampling methods of cyclone separator and virtual impactor are highly correlated. The stability and reproducibility of the cyclone separator in dry environment is better than that of the virtual impactor. However, the humidity shows stronger effect on the cyclone separator than the virtual impactor. Particularly in the case of PM10/PM2.5 detection in ultra-low emission power plants, appropriate sampling methods should be selected in consideration of environmental differences.

采用主成分分析法探究环境温度、湿度、动态加热温度、采样流量、分离器切割性能、走纸精度、本底值分析时间、采样时间等8项因素对β射线法PM2.5测量准确度的影响,定量分析各影响因素的贡献率并提出主要影响因素的影响程度、控制范围及方法.结果表明:走纸精度、动态加热温度及采样流量的贡献率之和为54.2％,对β射线法PM2.5测量结果影响较为明显.为使测量结果误差<5％,滤带定位误差应不超过1.3 mm,动态加热温度控制在45℃ ～50℃范围内,采样流量偏离在±0.8 L/min以内.

Pneumoconiosis is the most important occupational disease in China, and respiratory respirable dust is the main cause of pneumoconiosis. It can effectively reduce the incidence of pneumoconiosis by improving the monitoring and supervision level of respiratory dust concentration in the workplace. In order to solve the shortcomings of obtaining the concentration of respirable dust in mines by methods such as sampling by respirable dust samplers and numerical simulation experiments, an artificial neural network is proposed to predict the concentration of respirable dust. The factors affecting the concentration of respirable dust in coal mining face were analyzed, and the neural network structure for predicting respirable dust was established in this paper. Through training by selecting measured data, it was found that the error between the predicted result and the measured concentration was less than 15%, which was better than the error of regulations of dust measuring instruments. The results of the study have a certain reference effect on the prediction and prevention of respiratory dust in coal mines and the reduction of the incidence of pneumoconiosis.

Fully mechanized face is one of the main dust production points in mines. Air duct ventilation is an important measure to reduce dust damage. In order to grasp the dust distribution of the fully mechanized excavation surface under the condition of the indented double air duct, this paper comprehensively uses the field measurement and numerical simulation method to study the migration and deposition law of the fine dust. Firstly, the dispersion of flour dust and the concentration along the road in a mine in Shanxi were measured. Secondly, considering the influence of the comprehensive excavation machine and coal conveyor belt, the high simulation degree collection model of the double-drum comprehensive face was established and solved by FLUENT. Finally, the amount of air distribution in the front and rear air ducts was changed, and the distribution of dust particles, wall sedimentation fraction and dust concentration on the side wall of the sidewalk were obtained under three different conditions. The results show that the number of dust particles along the path decreases with the distance from the head-on distance; the air distribution has a great influence on the migration and deposition of dust, and the dust deposition basically conforms to the bottom wall, the side wall of the pedestrian side, the coal wall of the wind tube, and the roof. The law of decreasing the number of winds is constant. With the same amount of air supply,and the same air distribution of before and after air duct,the concentration of dust along the heading face is relatively low. Auxiliary dust removal facilities should be arranged away from 5~20m of the heading face.

为加强对储煤场扬尘的有效监测,提出了一种多参数一体化扬尘监测系统.该系统以光散射法为基础,通过小流量旋风切割器实现PM10及PM2.5的分离.该系统不但可以检测颗粒物质量浓度,而且可以监测温度、湿度、噪声、风速及风向等,监测数据可通过4G网络传输至监管中心.通过与蔡家环境监测站颗粒物质量分数监测结果对比,PM2.5监测值与公布值相关系数为0.97,一致性较高.该系统集成度高,可实现颗粒物质量浓度检测的自动标定,并可以与抑尘、降尘设备联动,可以为储煤场的扬尘监管提供有效依据.

为解决湿度过大造成的矿山呼吸性粉尘浓度检测结果偏大甚至检测设备损坏等问题,提出了一种矿山呼吸性粉尘浓度检测除湿系统.该系统以半导体制冷为原理,选择XH-C1210作为制冷器件,设计了散热方式及排水系统,给出了系统的软件流程.系统采用水冷法提高热交换效率,通过除湿后净气对高湿含尘气流进行稀释干燥减少颗粒损失.实验结果显示,对高湿度的含尘气流,当气流温度在24℃以下时,均可使湿度降至60％RH以下,入口温度越低,除湿效果越明显.使用激光粉尘浓度仪进行测试发现,使用该除湿系统可有效避免高湿环境下粉尘浓度测试结果偏大的情况.

针对常用大气颗粒物监测系统稳定性差,集成度低,测试耗时,TSP、PM10及PM2.5数据"倒挂"等问题,提出一种基于P LC的三通道β射线大气颗粒物连续自动监测系统.系统以β射线吸收原理为基础,采用PLC控制技术,以HMI为人机界面,实现了TSP/PM10及PM2.53种颗粒物质量浓度同时检测.监测系统三通道共用动态加热系统,减少了高湿度差异情况下的数据"倒挂"现象.使用称重法作为参比方法对样机进行比对测试,TSP、PM10及PM2.5质量浓度与称重法质量浓度的相关系数均大于0.95,能够准确地反映测试环境的颗粒物实际水平.

为解决燃煤电厂超低排放颗粒物浓度监测中存在的集成度低、标定繁琐、不便远程管理等问题,提出了一种基于组态王的颗粒物浓度监测系统.系统融合激光散射法及β射线法,通过PLC实现数据采集与运动控制,采用组态王软件作为上位机开发颗粒物浓度远程监控及Web发布功能.研究结果表明,该监控系统可以远程实时监测和记录颗粒物浓度变化,并适时对监测数据进行校准,提高了监测效率及系统适应性,可以更好地满足燃煤电厂超低排放监管要求.

为了有效地对煤矿井下防尘设备进行监控,设计了一种煤矿防尘设备在线监控系统.提出了系统的总体设计方案,阐述了系统重要组成部分中继通信站的核心单元、数据通信控制技术、数据采集技术和本安电路等关键技术设计方案,介绍了地面监控平台的设计方法及功能.该系统通过中继通信站连接地面监控中心和井下防尘设备,实现了煤矿井下防尘设备的在线监控.

In order to study the respirable dust cyclone separator,that meet the BMRC curve,the inner flow fields of cyclone separators with various geometries were simulated by commercial computational fluid dynamics( CFD) software Fluent 6. 3. Based on the response surface methodology and using the statistical software Design-Expert,the quadratic polynomial prediction model of cyclone sampling efficiency was obtained. The results show that the tube length,vortex finder diameter and vortex finder height have significant effect on the cyclone performance. The sample cyclone separator was made based on prediction model and tested,it was found that the standard deviations of cyclone separator designed by RSM and BMRC curve was 3. 16% which was less than 5%. The study shows that RSM not only improves work efficiency,but also ensures the reliability of calculation model,at the same time,provides a reference for the design of separator to meet the requirements of EN481,PM10 and PM2. 5.

In order to research and develop the respirable dust separator satisfied the sample specification of BMRC curve. Various geometries were performed to study inner flow field by commercial computational fluid dynamics(CFD) code Fluent 6. 3. Moreover a quadratic regression model for sampling efficiency was established by regression design technique. Through comparing the prediction model with numerical simulations,it was found that regression design can ensure reliability of calculation model,and significantly raise work efficiency.

To improve the safety management level of overhead travelling crane in modern urban construction and industrial production,the paper proposes the concept of applying the GPRS technology and virtual instrumentation to the network management system of overhead travelling crane group.The paper details the general design scheme for such system,and presents the system structure,function and implementation method.The result shows that such Labview-based network management system of overhead travelling crane group provides guidance to efficient management of decentralized heavy duty crane such as overhead travelling cranes.