采场自燃发火危险预测方法与控制原理研究

PREDICTION AND CONTROL OF SPONTANEOUS COMBUSTION IN WORKING FACES

根据综采放顶煤工作面的通风阻力及其通风网络等势图 ,采用释放示踪气体SF6技术 ,确定了综放面进风隅角采空区的漏风风速和采场漏风量及其分布状态。测定了采空区气体浓度和温度的分布状况 ,划分了采空区煤炭氧化三带范围。煤炭氧化自燃模拟试验证明 :常温下煤氧复合的自由基反应生成大量的CO、CO2 气体 ,所产生的热量使采空区煤岩温度升高 10℃。保证采空区流体动力相似 ,便可满足采空区注氮模拟条件。对 2 0 0m长的综放面采空区注氮 ,难以取得有效的惰化效果。综放面无煤柱开采的邻近老空区漏风及自燃发火危险大 ,应在漏风源处注氮 ,配合堵漏和均压措施 。

Measured ventilation resistance and isobar in mining areas,the leakage rate in intake goaf and the distribution of air leakage in mining areas were determined by instantaneous and steady liberation of trace gas SF 6.Gas concentration and temperature are measured and three oxidation areas in goaf are determined.According to oxidation experiment of coal and in situ measurements,the CO and CO 2 can be produced largely by coal and oxygen combination at ambient temperature and the temperature of coal and rock in goaf can rise 10℃ due to heat produced by coal and oxygen combination.The analysis shows that the conditions of the nitrogen injection modeling can be well satisfied if hydrodynamic similarity is pledged to the model.The research shows that nitrogen injection is noneffective for a 200 m long goaf and that there is a great danger of spontaneous combustion because of air leakage for pillarless mining.It is very important to inject nitrogen at the location of air leakage and to take the measures of blocking leakage and eliminating pressure difference.