封闭火区注惰下瓦斯气体分布规律的探讨

The methane distribution law of closed fire zone when pumping inert gas

为研究煤矿封闭火区注入惰气抑制火灾情形下火区瓦斯气体分布规律,利用CFD流体软件Fluent建立数学模型并进行数值模拟;在试验巷道中进行了不同流量惰气注入试验,建立了相关的数学模型并对N2和CO2不同情形的安全、有效的注入速度进行了计算。结果表明,注惰速度对火区瓦斯分布影响较大,是诱发注惰过程中次生瓦斯事故的主要因素之一;注惰速度较小时,惰气和瓦斯混合缓慢,封闭火区巷道前方易形成危险性瓦斯气体层;注惰速度较大时,惰气和瓦斯迅速混合而起到稀释和惰化作用,紊流作用明显,整个巷道内瓦斯浓度均处于安全范围内。

The distribution law of methane when pumping inert gas to closed fire zone were studied through numerical simulation, experiments and relating analysis. Using CFD software Fluent to do numerical simulation, simulated experiments were carried out in an experimental laneway, and the minimum safety and effective pumping velocities of nitrogen and carbon dioxide were calculated based on one math model. Pumping velocity has great effect on methane distribution,it＇ s also one of the main factors to cause methane accident such as fire or explosion. Inert gas and methane blend slowly when pumping velocity is small, there is a dangerous high concentration methane layer which is possible to cause fire or explosion accident in the front of laneway ; inert gas can blend quickly with methane when pumping velocity is large, and the effect of dilution and inerting is observably. The methane concentration of the whole laneway is safe.