Research On CO Poisoning Risk Prediction And Ventilation Control In A Mine Tunnel In Yunna

There is a bottleneck problem of small section,long distance ventilation and high concentration of toxic and harmful gas after blasting in a mine roadway in Yunnan.Based on this,this paper adopts the research methods of field experiment,theoretical analysis and numerical simulation to study the spatial and temporal migration and concentration distribution characteristics of CO in the roadway stope,the spatial and temporal variation law of average concentration of CO,and the risk factors and factor combinations that have the greatest impact on CO poisoning accidents in the roadway stope.The following main conclusions are formed:（1）The main component of toxic and harmful gas in blasting fume after blasting in roadway stope is CO.The average concentration of CO decreases exponentially with time and finally tends to a constant value.With the increase of the distance from the tunnel face,the average concentration of CO in each detection section shows a negative x² attenuation.（2）The combination of basic risk factors that have the greatest impact on the occurrence of CO poisoning accidents in roadway stope is determined,that is,the local ventilation mode,the wind speed of the stope,the selection of the diameter of the air duct and the air volume of the local fan are unreasonable.（3）Through the optimization of the scheme,it is determined that the best ventilation mode of the roadway stope is long pumping and short pressing,the air volume of the local fan is 2.62m³/s and 3.18m³/s respectively,and the diameter of the air duct is 400mm.The attenuation equation of the average concentration of CO in the optimized roadway stope with time is:y=99.106e^-0.058t,and the attenuation equation of the average concentration of CO with the increase of the distance from the face is:y=-1.5696x²+2.6389x+55.77.In this paper,through the study of CO poisoning risk prediction and ventilation control in roadway stope,the CO concentration control scheme of roadway stope is proposed,which has the characteristics of practice and theory integration.The research results can provide the basis for CO control in roadway stope after blasting.At the same time,this paper applies the dynamic Bayesian network to the risk analysis and prediction of CO poisoning accidents in roadway stope for the first time,which provides a new idea for the quantitative analysis of CO poisoning accidents in roadway stope.