煤与瓦斯突出过程煤体层裂演化与煤粉运移模拟实验研究

煤与瓦斯突出过程煤体层裂演化与煤粉运移模拟实验研究摘要：

煤与瓦斯突出事故是煤矿井下常见的一种危险现象，煤体层裂演化与煤粉运移是煤与瓦斯突出过程中的两个重要因素。针对这两个因素，本文开展了一系列模拟实验研究。首先，利用煤体切割机对煤体进行了层裂处理，模拟不同程度的煤体层裂演化过程，分析了煤体层裂对煤与瓦斯突出的影响。其次，通过粉尘颗粒跟踪技术，对煤粉运移规律进行了研究，探究了煤粉在不同速度和方向下的运动规律。最后，基于分子动力学模型，模拟了煤与瓦斯突出过程中煤粉颗粒的运动情况，得到了煤粉颗粒在层间隙中的碰撞频率和煤粉流动的速度分布规律。研究结果表明，层裂会导致煤体排气能力降低，增加煤与瓦斯突出的风险；煤粉的运移规律与煤体层裂程度、速度和方向有关，需要综合考虑多个因素，才能准确预测并控制煤与瓦斯突出过程。

关键词：煤与瓦斯突出；煤体层裂演化；煤粉运移；模拟实验；分子动力学模型

Abstract:

Coalandgasoutburstisacommondangerinundergroundcoalmines.Coalfracturingevolutionandcoalpowdertransportationaretwoimportantfactorsinthecoalandgasoutburstprocess.Inthispaper,aseriesofsimulationexperimentswerecarriedouttostudythesetwofactors.Firstly,thecoalwastreatedwithfracturingbyacoalcuttingmachinetosimulatedifferentdegreesofcoalfracturingevolution,andtheinfluenceofcoalfracturingoncoalandgasoutburstwasanalyzed.Secondly,theparticletrackingtechnologywasusedtostudythetransportationlawofcoalpowder,andthemovementlawofcoalpowderunderdifferentspeedsanddirectionswasexplored.Finally,basedonthemoleculardynamicsmodel,themovementofcoalpowderparticlesduringthecoalandgasoutburstprocesswassimulated,andthecollisionfrequencyofcoalpowderparticlesintheinterlayerandthevelocitydistributionlawofcoalpowderflowwereobtained.Theresultsshowthatfracturingreducesthegasdrainagecapacityofcoal,increasingtheriskofcoalandgasoutburst.Thetransportationlawofcoalpowderisrelatedtothedegree,speed,anddirectionofcoalfracturing,andmultiplefactorsneedtobeconsideredtoaccuratelypredictandcontrolthecoalandgasoutburstprocess.

Keywords:Coalandgasoutburst;Coalfracturingevolution;Coalpowdertransportation;Simulationexperiment;MoleculardynamicsmodelCoalandgasoutburstshavebeenasignificantsafetyconcernincoalmines,especiallyinChina,causingnumerousfatalitiesandinjuries.Themulti-factorcomplexnatureofcoalandgasoutburstmakesitdifficulttopredictandcontrol.Inthisstudy,aseriesofsimulationexperimentswereconductedtoinvestigatethecoalfracturingevolutionandcoalpowdertransportationinthecoalandgasoutburstprocess.

Theresultsoftheseexperimentsshowthatthedegree,speed,anddirectionofcoalfracturingarecrucialincontrollingthetransportationofcoalpowder,whichultimatelyaffectstheoccurrenceofcoalandgasoutburst.Fracturingreducesthegasdrainagecapacityofcoal,leadingtoanincreaseintheriskofcoalandgasoutburst.

Thesimulationexperimentswerealsousedtodevelopamoleculardynamicsmodelofcoalpowdertransportation,whichcanpredictthebehaviorofcoalparticlesduringtransportation.Themodelconsidersseveralfactors,suchasgaspressure,stressdistribution,andtheshapeofcoalparticles.Theaccuracyofthemodelwasverifiedbycomparingtheresultsofthesimulationexperiments,whichshowedagoodcorrelation.

Inconclusion,thisstudyprovidesinsightintotheevolutionofcoalfracturingandthetransportationofcoalpowderduringcoalandgasoutburst.Thefindingshighlighttheimportanceofconsideringmultiplefactorstoaccuratelypredictandcontrolthecoalandgasoutburstprocess,reducingtheriskofaccidentsincoalminesCoalandgasoutburstisasignificantsafetyhazardthatcancauseseveredamagetocoalminesandendangerthelivesofworkers.Theexplosivenessofcoalandgasoutburstarisesfromthesuddenreleaseofgasandcoalpowderunderhighpressure.Theprecisefactorsresponsibleforcoalandgasoutburstarenotyetfullyunderstood,andseveralmodelshavebeenproposedtoexplainthephenomenon.

Onesuchmodelistherockbursttheory,whichsuggeststhattheoutburstiscausedbythesuddenreleaseofelasticenergystoredinthecoalseam,leadingtothedisintegrationoftherocksurroundingthecoalseam.Thistheoryemphasizestheroleofstructuralchangesanddynamicstressinginthecoalseamincausingoutburst.

Anothermodelisthegasflowtheory,whichsuggeststhattheoutburstiscausedbytheflowofgasthroughthecoalseam.Accordingtothistheory,thegaspressureinthecoalseamincreasesduetothedesorptionofgasfromthecoal.Asthegaspressurereachesacriticallevel,thereisasuddenreleaseofgas,causingtheoutburst.

Inrecentyears,researchershavealsostartedstudyingtheroleofcoalparticlesizedistributionandshapeinthecoalandgasoutburst.Ithasbeenobservedthatthesizeandshapeofcoalparticlescanplayacrucialroleintheoutburstprocess,affectingthetransportandreleaseofgasandcoalpowder.

Thestudyofcoalparticlesizedistributionhasshownthatfinerparticleshaveahigherexplosionvelocityandaremorepronetodustexplosionthanlargerparticles.Additionally,theshapeofcoalparticlescanaffecttheslidingfriction,whichcaninfluencethetransportofcoalpowderwithinthecoalmine.

Overall,itiscrucialtounderstandthevariousfactorsthatcancontributetocoalandgasoutbursttodevelopeffectivestrategiesforpreventingandcontrollingsuchincidents.Themodelsproposedtoexplaincoalandgasoutburstprovideausefulframeworkforunderstandingthephenomenon,butmoreempiricalstudiesareneededtovalidatethesemodelsandimproveourunderstandingoftheoutburstprocess.

Insummary,coalandgasoutburstisasignificantsafetyhazardincoalminesthatcancauseseveredamageandendangerthelivesofworkers.Understandingthevariousfactorsresponsibleforcoalandgasoutburst,suchasthesizeandshapeofcoalparticles,canhelppreventandcontrolsuchincidents.FurtherresearchisneededtorefineexistingmodelsanddevelopmoreeffectivestrategiesforpreventingcoalandgasoutburstApartfromunderstandingthefactorsresponsibleforcoalandgasoutburst,itisequallyimportanttodevelopeffectivestrategiesforpreventingandcontrollingsuchincidents.Inthisregard,variousapproacheshavebeenproposedandimplementedincoalminesworldwide.

Onesuchapproachistheuseofrockburst-resistantsupportsystemsthatcanwithstandhighstressandstraincausedbycoalandgasoutbursts.Thesesupportsystemsaredesignedtoreducetheenergyreleasedduringanoutburstandminimizethedamagecausedtothemineinfrastructureandworkers.Theuseofsuchsupportsystemshasbeenshowntobeeffectiveinreducingthefrequencyandseverityofcoalandgasoutbursts.

Anotherapproachistheimplementationofreal-timemonitoringandearlywarningsystemstodetecttheprecursoreventsthatleadtocoalandgasoutbursts.Thesesystemsusevarioussensorsandmonitoringdevicestomeasurethestress,strain,andgaslevelsinthemine,andprovidereal-timealertstominersifanyabnormalactivityisdetected.Thisallowsminerstotakeappropriatepreventivemeasuresbeforeanoutburstoccurs.

Theuseofmodernminingtechniques,suchaslongwallmining,canalsohelppreventandcontrolcoalandgasoutbursts.Longwallmininginvolvestheuseofashearermachinethatextractscoalinlargepanels,leavingbehindastablerockmassthatislesspronetooutbursts.Thismethodhasbeensuccessfullyimplementedincoalminesworldwide,resultinginasignificantreductioninthefrequencyandseverityofcoalandgasoutbursts.

Inadditiontotheseapproaches,itisalsoimportanttoprovideadequatetrainingtominersandotherpersonnelworkingincoalmines.Thisincludestrainingonhazardrecognition,emergencyresponse,andtheproperu