| This study is based on8104fully mechanized top coal caving face of Tashan coal mine with large gas emission and corner gas overrun. With the research on the law of goaf gas emission and analysis of gas extraction feasibility and necessity, to set up comprehensive gas extraction system and carry on the extraction effect evaluation.Then, to solve the security risks caused by the gas effectively.First, analyzing the gas emission of8104fully mechanized top coal caving face. With calculation, goaf gas emission is in the proportion83%of all gas emission. And the key to solve gas overrun problem is to governance goaf gas emission. With numerical simulation method, research on air flow field pressure and velocity distribution in goaf and their affect to gas emission. Analyzing the distribution of gas in goaf and emission characteristics. Then, with the analysis of gas extraction feasibility and necessity, to draw up comprehensive extraction technical solutions include high drilling extraction, the upper corner pipe extraction and high roadway extraction. Setting up comprehensive gas extraction system and evaluating the comprehensive gas extraction effect. With high drilling extraction in the case of high negative pressure, goaf gas is extracted in the quantity of6m3/min. It has certain effect to the reduction of goaf gas emission. With the upper corner pipe extraction, goaf gas is extracted in the quantity of24m3/min and maintain the gas concentration between4～8%, effectively intercept the goaf gas emission. With high roadway natural emissions, goaf gas is let off in the quantity of35m3/min and maintain the gas concentration between3～8%, exist security risks. With high roadway extraction, goaf gas is extracted relatively stable in the quantity of50m3/min and effectively governance the problem of gas overrun. |
PDF Full Text Request