Numerical simulation of the change process of field variables distribution in goaf caused by air reversing in working faces
-
摘要: 結合華興煤礦1318炮放面實例,運用數值模擬手段,描繪了工作面反風時采空區流場內漏風流,氧、CO和瓦斯各組分氣體,以及溫度等的分布變動過程,給出了反風時沿工作面邊界各組分氣體涌出量的變化規律.模擬在反風后,場內各組分氣體含量分布重心發生倒置,原上游高溫區被冷卻,下游低溫區逐漸轉變為新的高溫區,使采空區的溫度上升過程重新回到一個相對較低的溫度起點,使自燃升溫得到一定的延緩.反風后,場內CO氣體涌出量經歷突降—回跳上升—緩慢衰減—再逐漸增加的跳動過程,瓦斯涌出量在經歷大幅度突降和回跳后,其增幅度不大.用埋管抽放的辦法能夠防止因反風導致工作面內有害氣體超限,同時給出了反風的實施條件,即必須確保采空區無明火.Abstract: Based on No.1318 shooting case in Huaxing Coal Mine,the changing process of air leakage flow,components (oxygen,CO and methane),and temperature in the flow field of goaf during air reversing were solved and described,and the changing rule of gas emission volume of different components along the boundaries of the working face while air reversing was given.It is simulated that after air reversing the content distribution centers of different components are reversed,the upper high temperature area is cooled down while the lower area with low temperature becomes a new high temperature area,making the temperature rising process in goaf at a low start point,which is favorable for slowing down the rising velocity of temperature and thus preventing spontaneous combustion of coal from taking place.During air reversing,the emission volume of CO has a jumping process of sudden decrease→increase→slow attenuation→gradual increase.After this process,the increase range of gas emission volume becomes slowed.By burying pipes to extract gas,harmful gases within the working face could be prevented from exceeding limit during air reversing.At the same time,the condition to realize air reversing is given,namely there is no naked flame in goaf.
-
Key words:
- goaf /
- gas distribution /
- temperature field /
- spontaneous combustion /
- ventilation /
- numerical simulation
-

計量
- 文章訪問數: 236
- HTML全文瀏覽量: 77
- PDF下載量: 8
- 被引次數: 0