Research On Real-time Monitoring Method Of Temporal-spatial Field Of Respirable Dust Concentration In Fully Mechanized Excavation Face And Accumulative Dust Exposure Of Workers

Accumulated dust exposure is an important factor in causing pneumoconiosis.The current common test method is the work shift sampling method.However,the work shift sampling method will further increase the workload of the workers,and it cannot monitor the cumulative dust exposure of the workers in real time,and the real-time warning of pneumoconiosis is poor.The real-time monitoring technology of cumulative dust exposure can monitor the cumulative dust exposure of workers in real time and help to give real-time early warning of pneumoconiosis.However,the real-time monitoring technology of cumulative dust exposure of workers is still blank at home and abroad.This article has been funded by the National Key Research and Development Program "Key technologies and equipment for cccupational hazard prevention and control in mines"(Project No.2017YFC0805200)Project 8 "Mine occupational hazard warning information database and third-party support platform for monitoring and supervision"(Project No.2017YFC0805208).Taking the monitoring of cumulative dust exposure of workers on fully mechanized excavation face in coal mines as the research object,a combination of theoretical analysis,numerical simulation,experimental test,field test and application methods is adopted.Research on the spatiotemporal field of respirable dust concentration in fully mechanized excavation face,spatiotemporal data acquisition technology for real-time monitoring of cumulative dust exposure of fully mechanized excavation face workers,and multi-source spatiotemporal data coupling for the real-time monitoring method and verification of accumulated dust exposure of fully mechanized excavation face workers are carried out.Exploring a new method for real-time monitoring of accumulated dust exposure of fully mechanized excavation workers,laying a theoretical foundation and providing data support for the early warning of pneumoconiosis among coal mine workers.The main achievements of this paper include:1.Study on spatiotemporal field of respirable dust concentration in fully mechanized excavation face.Based on the theory of particle kinematics,the movement process of respirable dust on the fully mechanized excavation face is analyzed,a respirable dust movement model is established,and the diffusion concentration distribution solution of respirable dust is obtained.Using numerical simulation and field measurement comparison methods,the multi-factor influence law and the distribution law of respirable dust on the fully mechanized excavation face are studied.Based on the former,a multi-factor influencing model of respirable dust distribution is established;on the basis of the latter,respirable dust concentration sensors are arranged at key points.Collecting real-time respirable dust concentration data from sensors at key monitoring points,and introducing the time and space dimensions of concentration changes into the semivariogram,combined with the multi-factor influence model,the spatiotemporal field algorithm of respirable dust in the fully mechanized excavation face is obtained,and the spatiotemporal field function model of the concentration of respirable dust in the fully mechanized excavation face is established.Laboratory comparison experiments with distance weighted inverse proportional method and kriging model are carried out,it is proved that the calculation error of the spatiotemporal field function model of respirable dust concentration proposed in this paper is ±14.8 %,which is±10.8 % smaller than that of kriging method and ±23.0 % smaller than that of distance-weighted inverse method.2.Spatiotemporal data acquisition technology for real-time monitoring of cumulative dust exposure of workers in fully mechanized excavation face.On the basis of analyzing the sources and characteristics of the spatiotemporal data(real-time respirable dust concentration,spatiotemporal field function model correction coefficient of respirable dust concentration,and operator location information)of real-time monitoring of cumulative dust exposure,the idea of multi-source real-time and parallel accumulation of time-space data collection of dust exposure is proposed,the first optimal fusion sensor for respirable dust concentration is developed,and the monitoring algorithm of the direct-reading instrument for respirable dust is improved,error analysis of individual respirable dust monitor and personnel positioning system.Based on the above research,the spatiotemporal data collection technology of cumulative dust exposure of workers is proposed,which can meet the performance of quickly and accurately distinguishing the changes of workers’ walking and breathing dust concentration changes.3.A real-time monitoring method for cumulative dust exposure of workers in fully mechanized excavation face with multi-source spatiotemporal data coupling.Collect the real-time concentration of the respirable dust concentration sensor at key monitoring points in the fully mechanized excavation face and integrate it into the spatiotemporal field function model of the fully mechanized excavation face.Select one worker to wear a personal respiratory dust monitor,and obtain the correction coefficient of the spatiotemporal field function model of the concentration of respirable dust by comparing the measured value of the personal monitor with the calculated value of the spatiotemporal field function model,and make real-time corrections to the concentration spatiotemporal field function model.Then calculate the real-time respirable dust concentration of the operator’s location.Based on this idea,the coupling mechanism of multi-source spatiotemporal data is revealed.Based on the coupling algorithm,a real-time monitoring error model of cumulative dust exposure is deduced and established.The real-time monitoring method of cumulative dust exposure is verified and laboratory tests are carried out,and it is verified that this method can realize real-time monitoring of cumulative dust exposure of workers in fully mechanized excavation face,and the relative error after multiple corrections in the laboratory is ±15.3%.4.Industrial field application and analysis of real-time monitoring method for cumulative dust exposure of fully mechanized excavation workers.The real-time monitoring method of cumulative dust exposure of workers in fully mechanized excavation face is applied in industrial field.It is proved by practice that the real-time monitoring method of cumulative dust exposure can be applied to the monitoring of cumulative dust exposure of workers in fully mechanized excavation face industrial site.The relative error of monitoring is ±18.6 %.