Influence of low oxygen in return air corner on optical interference methane detector and its correction method research
In view of the inconsistent monitoring results of various methane monitoring equipment in the return air corner of the mining working face,laboratory and field tests were carried out from the aspects of the equipment itself and oxygen concentration.The results show that the portable methane detector and the online methane detector have consistent measurement data and are not affected by chan-ges in oxygen concentration.As the oxygen concentration decreases,the methane concentration value displayed by the optical interfer-ence methane detector shows a continuous upward trend.Based on laboratory data,the calibration formula for the optical interference methane detector under low oxygen conditions was obtained,and the calibration formula was verified on site.An analysis was conducted on the occurrence and mining situation of coal seams in Jinda Coal Industry,and the reason for the decrease in oxygen concentration at the return air corner was obtained.That is,the return air corner of the No.10 coal seam working face was comprehensively affected by the return air from the goaf of this coal seam and adjacent layers,the spontaneous combustion of residual coal in the goaf,and the nitro-gen injection fire prevention measures.Based on this,measures were proposed to strengthen the ventilation management of the return air corner and correct the readings of the light interference methane detector,in order to reduce the impact of oxygen concentration on the measurement of the light interference methane detector.This provides a reference for solving such problems and improving gas safety monitoring in the working face.
return air cornerlow oxygenmethane detectoroxygen concentration
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