不同掘进工艺煤与瓦斯流固耦合数值模拟研究

梁　冰,李　野(,123000):井下瓦斯事故严重威胁着煤矿的安全,研究煤与瓦斯耦合作用规律并采取相应措施可以有效地防止事故发生。考虑瓦斯气体的可压缩性和吸附、解吸特性,假设瓦斯气体在煤体孔隙中的流动遵循Darcy定律,建立了考虑爆破因素的煤与瓦斯流固耦合数学模型,并利用comsol对其求解。结果表明:炮掘对煤体的破坏能力大于机掘;炮掘工艺下,爆破应力对煤体应力、位移的作用大于应力耦合的作用,机掘工艺应该考虑应力耦合的作用;煤层瓦斯压力随着煤壁暴露时间的增加而发生改变,整个巷道附近的瓦斯压力有降低的趋势,呈现漏斗状分布;煤层上表面煤体竖向位移边界呈以巷道顶端为中心的“O”型分布,且以“O”型中心处的位移值最大。:;;;;:TD712:A:1672-2132(2011)02-0180-05,,,,[1],,[2,3]2,,comsol,,1,,:;;,,;;;;1.1,,[4-6]:ij=ij-pij(1)p,MPa;;ij,MPa;ij:ij=2Gij+2G1-2vkkij-apij(2)G,Pa;;abiot:ij=12(i,j+j,i)(3):ij,j+Fi=0(4)(1)(3)(4),31220114JournalofDisasterPreventionandMitigationEngineeringVol.31No.2Apr.2011:2010-03-09;:2010-11-02:973(2005CB221503-05):(1962-),,,Email:[e-mail]:Gui,jj+G1-2vuj,ij-ap,i+Fi=0(5),Gui,jj+G1-2vuj,ij-ap,i+Fi=vit(6)vi(m/s);(kg/m3)1.2,,,,,Langmuir:m=Cf+Ca=g+VLPLP1+PLPgas(7)m(kg/m3);;g(kg/m3);ga(kg/m3),ga=Pa,Pa;s(kg/m3);P(Pa);VLLangmuir(m3/kg);PLLangmuir(1/Pa)Darcy:qg=-kggp(8)qgDarcy(m/s);kg(m2);g(Pas):g=P(9)g(kg/m3);P(Pa);(kgm3P-1a),=Mg/RT,Mg(kg/kmol),R(Jkmol-1K-1),T(K),:mt+(gqg)=0(10)m(kg/m3);g(kg/m3);qgDarcy(m/s);t(s):2+2VLPLPas(1+PLp)2pt+2pt-kggp2=0(11)t=1-kksvt+1-kspt:2pvt+2+2(1-)ksp+2VLPLPas(1+PLp)2pt-kggp2=0(12)1.3(1):pt=0=p0,p0(Pa);p=pi,pi(Pa)(2):t=0=0;W=Wiijnj=Ti,Wi(m),Ti(Pa)W=Win=2Cpvns=2Csvs,n,s(m/s),(kg/m3),C(m/s)2,,PDE,Generalform,,1812:PDEDarcy,,ComsolMultiphysicsPDEup,subdomainsetting,2.1()11-2comsol(xyz)=15m15m5m,(xyz)=10m2m2m,1.7MPa1m2m12,,111Fig.1Geometricmodelofexcavatedsection1Table1Parametersofcoalpetrography0.0266MPa-130%1.70gcm-32.1610-3m2d-11.28gm-31.0910-5Pas7.46MPa28.87m3t-11.87MPa0.1MPa1.7MPa2.22.2.1瓦斯吸附解析影响因素对比分析2,,,;5m,2,2Fig.2Distributionofgaspressurealongtunnellingdi-rectionunderdesorptionandnon-desorption2.2.2炮采掘进工艺耦合效应研究34,12,3Fig.3Changeoftotaldisplacementatmonitoringpointsunderstresswaveactionfromblastexcavation4Fig.4Changeoffirstprincipalstressatmonitoringpointsunderstresswaveactionfromblastexca-vation18231,,,;,,,,,2.2.3机采掘进工艺耦合效应研究56,12,,,,,,,,5Fig.5Changeoftotaldisplacementatmonitoringpointsunderactionofmechanicalexcavation6Fig.6Changeoffirstprincipalstressatmonitoringpointsunderactionofmechanicalexcavation2.2.4不同掘进工艺下瓦斯耦合效应对比712,,;,,,7Fig.7Totaldisplacementatmonitoringpointsinpro-cessofblastingandmechanicalexcavations812,,;,,,8Fig.8Firstprincipalstressatmonitoringpointsinpro-cessofblastingandmechanicalexcavations2.2.5炮掘开采方式煤岩瓦斯流固耦合分析911,,1832:91Fig.9Nephogramofgaspressuredistributiononfirstday1015ig.10Nephogramofgaspressuredistributionon15thday11360Fig.11Nephogramofgaspressuredistributionon360thday,1230z,1230zFig.12Nephogramofdisplacementdistribationinz-di-rectionon30thdayO,O,14mm3,11-2,,,:(1),,;,,,,,,,,(2),,(3)O,O,14mm:[1],.[J].,2004,14(7):101-104.LiXL,LiuJZ.Newachievementsofgascontroltechnology[J].ChinaSafetyScienceJournal,2004,14(7):101-104.[2],.[M].:,1999.ZhouSN,LinBQ.TheoryofGasFlowandStorageinCoalSeams[M].Beijing:ChinaCoalIndustryPub-lishingHouse,1999.[3],.[J].,2005,24(10):1674-1678.WuSY,ZhaoW.Analysisofeffectivestressinad-sorbedmethane-coalsystem[J].ChineseJournalofRockMechanicsandEngineering,2005,24(10):1674-1678.(195)18431averageofthelargevalues,whilethethree-dimensionalfiniteelementmethodshouldselecttheaverageofthesmallvalues.Finally,thepreventionmeasuresofcuttingslopeandpressingfootarepresentedonthebasisofthree-dimensionalfiniteelementsimulation.Keywords:landslide;limitequilibriummethod;finiteelementmethod;choiceofparameters(184)[4],,.[J].,2003,18(4):420-426.LiPC,KongXY,LuDT.Mathematicalmodelingofflowinsaturatedporousmediaonaccountoffluid-structurecouplingeffect[J].JournalofHydrodyna-mics,2003,18(4):420-426.[5],,.[J].,2001,23(4):42-45.XuXZ,LiPC,LiCL.Principleofeffectivestressbasedonporousmedium[J].MechanicsandPractice,2001,23(4):42-45.[6],,,.[J].,1999,21(5):288-291.LiCL,KongXY,XuXZ,etal.Doubleeffectivestressesofporousmedia[J].ZiranZazhi,1999,21(5):288-291.NumericalSimulationofFluid-solidCouplingofGasinCoalFaceunderDifferentTunnelingTechnicsLIANGBing,LIYe(DepartmentofMechanicsandEngineeringSciences,LiaoningTechnicalUniversity,Fuxin123000,China)Abstract:Theaccidentofcoalmethanegasisalwaystothreatenthesafetyincoalproduction.Researchingtheinteractionlawbetweencoalandgascanpreventoccurranceofaccidenteffectively.Consideringcom-pressibility,adsorptionanddesorptionofgas,andsupposingthatthegasflowinporeofcoalfollowsDar-cylow,webuiltupagas-solidcouplingmathematicalmodelwithconsiderationofblastingfactors.Resultssolvedbycomsolshowthatcoaliseasilydestroyedbyblastingexcavationthanmachnicalexcavation;con-trastingtostresscouplingblastingloadaction,coalstressesanddisplacementsislargeandcouplingeffectsshouldnotbeneglectedinmechancalmining;gaspressurechangeswithtimeincreaseofcoalrakeexpo-sureandhasadecreasetrendneartunnel,itlookslikeafunneldistribution;thecontourofdisplacementontopofthetunnelassumesanOtypedistributionandthemaximumdisplacementisthecentreoftheOtypedistribution.Keywords:excavatedsection;coalrake;gas;fluid-solidcoupling;numericalsimulation1952: