采煤工作面瓦斯重大危险源风险评估

Risk assessment of major gas hazard in coal mining face

为准确评估煤矿瓦斯爆炸危险源的危险程度,针对不同瓦斯矿井工作面及采空区,运用CFD软件模拟瓦斯危险源的失控状态,以瓦斯危险源辨识为主要依据,结合事故案例,对瓦斯爆炸危险性进行定量风险评价。结果表明：低瓦斯矿井工作面无风或风量不足时,上隅角瓦斯体积分数达到10%~22%,工作面沿回风巷方向瓦斯体积分数逐渐升高,回风巷内瓦斯体积分数在7%~15%,其中工作面瓦斯爆炸危险性系数最高,风排瓦斯并未解决上隅角瓦斯超限问题。高瓦斯矿井工作面无风或风排瓦斯时,工作面、上隅角瓦斯体积分数在5%~17%,极易发生瓦斯爆炸,若仅井下综合抽采,上隅角瓦斯体积分数在4%~10%,仍存在安全隐患。该研究通过对工作面采空区的瓦斯重大危险源进行风险评估可为预防瓦斯爆炸提供理论指导。

This paper aims to accurately identify the dangerous degree to which coal mine gas explosions occur. The identification is performed by the simulation of an out of control state of gas hazards occurring in different gas mine working face and goaf using the CFD software; and the quantitative risk assessment of gas explosion hazard, based mainly on the identification of gas hazard sources and combined with the accident case. The research demonstrates that the occurrence of little or insufficient wind or air in low gas coal mine working face is associated with： upper comer gas concentration of up to 10%- 22% ; a gradually increased gas concentration in return air lane direction in working face; gas concentration of 7% - 15% in return air lane, putting the working surface at the highest gas explosion haz- ard, thus rendering it impossible for exhaust gas to solve the problem of upper corner gas gauge ; the presence of little or insufficient wind or air in gas drainage in high gas mine working face is accompanied by the upper corner gas concentration of 5% - 17%, contributing to a higher likelihood for gas explosion, which indicates that there stilI occurs a potential safety hazard, if only underground comprehensive extraction is performed, leaving the concentration of gas in upper corner in 4% - 10%. The study may provide a theoretical guidance for prevention of gas explosion by a risk assessment of major hazard sources of goaf in working face.