Research Of Key Technology On Gas Treatment At Upper Corner In Fully Caving Face

Due to high productivity and concentrated production as well as faster promoting infully mechanized caving face, the quantity of residual coals has increased and also a largespace in the goaf has formed, which would lead to a spontaneous combustion and gasemissions in the goaf. This situation will contribute to quite severe impacts on coal mines’safety production. Numerous studies have shown that overlying strata based on the rules ofgas seepage and gas drainage design theory are rational and efficient to treat the gas issuesat upper corner in fully mechanized caving face. Therefore, it is necessary to combine theactual situation with the FLUENT software and to compare with the U-type, U+L-type andY-type ventilation because they can show the advantages and disadvantages to control thegas management problems at upper corner.Since there is a large amount of gas emissions in the process of production, it ispractical to come up with some solutions depending on the source of gas developinggovernance programs. Gas emissions of coal wall are9m3/min; gas emissions of goafare30m3/min, which cover76%in caving working face. Most of airflow flowsinto the face in traditional u-shaped ventilation, but part of air flows into mine area becauseof air leakage, and this part of air flows out from the upper corner, joining the main airflowand then it goes back into the air. Air flow at the upper corner of working face is less thanany other places including the whole process of air return loop; there is a vortexat upper corner, which becomes a major area of gas accumulation.This paper has summed up main methods to deal with the gas at upper corner inmodern times. Meanwhile, it also discussed some other topics, such as methods of burringpipes in upper corner, introduction about gas from the alley and high lane in details; what’smore important is this paper gives priorities to gas control at upper corner by changingventilation pattern. The paper not only defines a line between horizontal and verticalaspects respectively but also summarizes gas migration law in goaf and provides atheoretical basis for the study of the mechanism in working face. The thesis combines the Fluent numerical simulation with the site monitoringexperiments in Bao De mine in order to compare gas distribution and air leakage on thecondition of different ventilation. It turns out that U-type and Y-type have distinguishedadvantages to solve the gas problems at the upper corner. The simulation parameters asreferred can be developed to mines on similar conditions and this solution has a very highvalue of application.