大气压力变化对锁风启封火区气体积聚的影响规律
Influence of Atmospheric Pressure Change on Gas Accumulation in Unsealing of Coal Mine Fire Zone
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摘要: 为研究大气压力变化对锁风启封火区内气体积聚的影响,探索合理的启封时机,降低火区启封工作中的危险性。在大气压力对火区内气体运移作用机理的基础上,运用Fluent软件对锁风启封前、启封后的封闭火区内的气体状态进行计算,对各个启封时期封闭区内的气体状态进行理论分析。研究结果表明:大气压力变化平缓时启封火区危险性较小;锁风启封火区过程中,由于外界新鲜空气不断漏入封闭区内,当密闭距离越接近着火带时,着火带附近的氧浓度越高;瓦斯主要积聚在着火带下风侧,随着漏入火区氧量的增大其瓦斯浓度也相应地降低。在实际启封工作中,应根据矿区实际情况合理选择启封时机,时刻监视火区内气体状态,提高煤矿火区启封的安全性。Abstract: In order to study the influence of the variation of atmospheric pressure change on the gas accumulation in the unsealing coal mine fire zone, to explore a reasonable time to unseal and reduce the risk of it, the state of gas in the closed fire area was calculated by Fluent software based on the mechanism of atmospheric pressure on gas migration in fire area, which was in the process before opening coal mine fire zone and after opening coal mine fire zone, and the state of gas in each period of unsealing of coal mine was analyzed. The results show that when the atmospheric pressure changes slowly, the risk of unsealing of fire zone is in low level. During the process of unsealing of fire zone, the oxygen concentration near the fire zone is higher when the airtight distance is closer to the fire zone because of the continuous leakage of fresh air from outside into the closed zone. Gas accumulation mainly at the downwind side of the ignition zone, and the gas concentration decreases with the increase of oxygen leakage into the fire zone. In practice, according to the actual situation of the mining area, the unsealing time should be selected reasonably; the gas state in the fire area should be monitored at all times, so as to improve the safety of the unsealing of coal mine fire area.