Research on gas migration law and gas drainage parameters optimization in goaf of fully mechanized caving face in Buertai Coal Mine

Gasemissionfromthegoafisoneoftheimportantsourcesofgasintheworkingfaceanda reasonable goaf drainage scheme can effectively solve the problem of gas overrun in working face.Combinedwithnumericalsimulationandfieldapplication,thegasintubationextractionsystemin thegobofthefullymechanizedcavingfacein42-topcoalseamofBuertaiCoalMineisoptimizedin thispaper.Firstly,theFLUENTfluidsimulationsoftwareisutilizedtosimulatethecharacteristicsofgas migrationinthestope,consideringthedesorptionoftheremainingcoalinthegoafandthegasemission fromtheupperadjacentlayer.Thedistributionlawsofgasconcentrationinthegoafarerevealed,and theinfluenceofthedistancebetweentheextractionoutletandtheair-returncorner,drainagenegative pressureandairsupplyratioontheextractioneffectareanalyzed,theoptimizedschemeofextractionis proposedaccordingly.Thentheoptimizationschemeisappliedonthespot,focusingonthedistancebetweentheextractionoutletandtheair-returncornerandnegativepressure.Itisconcludedthatwhenthe intubationdistanceis70mandnegativepressureis12~18kPa,theextractioneffectisbetter.Theresearchresultshavetheoreticalandpracticalsignificancefortheoptimizationofgasdrainageschemein goafofhighyield,highefficiencyandlowgasmines.