矿井反风时期网域系统瓦斯运移仿真

为了解矿井反风时期矿井系统网域中瓦斯运移及其体积分数分布的变动,以九里山矿井为实例,运用TF1M3D进行仿真分析。根据反风时采空区瓦斯分布换向变化和涌出处在最低值期的特征,指出反风后系统瓦斯涌出源主要来自采煤工作面。模拟得到反风时期工作面瓦斯体积分数的变化规律是,在实施全矿反风后,工作面回风道的瓦斯重新回流至工作面,与工作面内涌出的瓦斯重复叠加形成体积分数高峰瓦斯风流,致使反风后原来进风巷中回风流瓦斯体积分数增高;反风刚开始时瓦斯体积分数陡增,待峰值过后,瓦斯体积分数逐渐呈阶梯式降低。模拟结果反映出反风时采煤工作面中回流瓦斯与涌出瓦斯形成二次叠加的存在性,而所产生的瓦斯体积分数高峰值与矿井回风网络系统的结构有关。高峰瓦斯风流影响矿井反风过程的安全性,因此不但应连续检测工作面的瓦斯体积分数变化,更应提前做好应对措施和技术预案。

Simulation on gas migration and concentration distribution in the ventilation network in the mine in reverse ventilation process

The paper has managed to simulate and analyze the changing process with the TF1 M3D method by taking the Jiulishan coal mine as a case study sample in hoping to investigate and clarify the changing process of the gas migration and the concentration distribution in the ventilation network system during the period of the mining reverse ventilation.As a result of our simulated study,we have found that the gas emission in the mining system mainly comes from the working face of the goaf due to the reverse ventilation,and,in turn,the gas distribution and the characteristic features of the mine are mainly dependent on the gas emission amount atthe minimum level of the said process.Therefore,our simulation and analysis results are helpful for disclosing the regularity of the gas concentration change in the panel in the reverse ventilation period,that is,the gas tends to return to the airway of the panel through the reverse ventilation and pile up with the would-be-emitted gas from the panel,repeatedly,hence leading to the gas concentration pile-up and affecting the gas return airflow in the initial inlet airway.Moreover,due to the abrupt increase of the gas concentration at the beginning end of the reverse ventilation,the gas concentration would decrease gradually bit by bit after reaching the peak ventilation point.The simulation results have also proven that there exists a superlative position between the reflux gas and the emission gas in the panel during the reverse ventilation period.In addition,the peak point of the gas concentration piling-up must have been related with the reverse ventilation system structure of the mine.More exactly speaking,the safety of the reverse ventilation of the mine tends to be affected by the peak gas concentration airflow,which is of the actual continuous need of supervision and the monitoring activities for the gas concentration changing rate in the panel on the one hand,and the countermeasures and technological regularity facilities for the coal production should be well made to the point in advance on the other.