激波诱导瓦斯爆炸的动力学特性及影响因素

通过修改化学动力学计算软件CHEMKIN Ⅲ中的SHOCK 程序包,建立了激波管中激波诱导瓦斯爆炸过程的计算模型,化学反应采用了详细反应机理(包括53种组分、325个反应)。对激波诱导瓦斯爆炸过程中混合气温度、冲击波传播速度、反应物(甲烷、氧气)摩尔分数、活化中心(O、H)摩尔分数、部分致灾性气体(CO、CO2、NO、NO2)摩尔分数的变化趋势进行了详细分析。同时,分析了瓦斯爆炸前混合气初始压力及初始混合气组成对激波诱导瓦斯爆炸动力学特性的影响。结果表明:瓦斯爆炸后CO 的摩尔分数达到0.07左右,CO2 的摩尔分数为0.02左右,NO 的摩尔分数为0.001左右,NO2 的摩尔分数则在10-6左右;随着瓦斯爆炸前混合气初始压力的提高以及混合气中甲烷体积分数的降低,瓦斯引爆时间将缩短,爆炸后温度将降低,但压力将升高,同时,爆炸后CO 的摩尔分数将降低,NO 的摩尔分数将提高。

Kinetic characteristics and influencing factors of gas explosion induced by shock wave

ByamendingtheSHOCKcodeintheFortranchemicalkineticspackage,CHEMKIN Ⅲ,acomputationalmodelwasbuiltfortheshockwave-inducedgasexplosioninashocktube.And,thedetailedreactionmechanismsinvolving53speciesand325reactionswereadoptedinthemodelabove.Thebuiltcomputationalmodelwasusedtoanalyzetheevolvementsofthefollowingparameters:mixedgastemperature,shockwavevelocity,themolefractionsofreactants(CH4andO2),themolefractionsofactivecenters(O,H),andthemolefractionsofcatastrophicgases(CO,CO2,NOandNO2)intheprocessofgasexplosioninducedbyshockwave.Furthermore,theeffectsoftheinitialpressureandthemixedgascompositionbeforegasexplosiononthekineticcharacteristicsofgasexplosioninducedbyshockwavewerediscussed.TheresultsshowthatthemolefractionsofCO,CO2,NOandNO2areabout0.07,0.02,0.001and10-6,respectively,aftergasexplosion.WiththeincreaseoftheinitialpressureandthedecreaseoftheCH4fractioninthemixedgas,thedetonationtimeofgasexplosionshortens,thetemperaturedecreases,butthepressureincreasesaftergasexplosion.Meanwhile,themolefractionofCOdecreases,themolefractionofNOincreases.