电厂烟气对采空区防火效果实验研究

Experiment study on fire prevention effect of power plant flue gas in goaf

为考察电厂烟气对采空区防灭火效果的影响,采用吸附实验装置和热重分析仪开展了不同气体氛围下煤吸附O2的实验研究,研究了不同气氛下煤的着火活化能。结果表明:将惰性气体N2和烟气注入井下,均可有效地减小常温常压下煤对氧气的吸附量,即具有抑制煤自燃氧化反应的作用。其中,烟气对减小煤吸附氧气量的效果优于N2,使同忻矿和高海矿煤样吸附氧气量分别减少了27%和35%。TG实验数据表明,煤样在烟气氛围下燃烧时低温氧化阶段的增重率略小于在空气氛围下燃烧时的增重率,而其着火点大于在空气氛围下燃烧时的着火点。同时,发现煤样在烟气中燃烧时的着火活化能大于在空气中燃烧时的着火活化能,说明煤在烟气氛围下燃烧时对O2的吸附量变小,活化能增大,增加了煤自燃的困难程度。

In order to investigate the fire prevention effect of power plant flue gas in goaf,the experimental study on adsorption of oxygen by coal under different gas atmosphere was carried out by using the adsorption experimental device and thermal gravimetric analyzer,and the ignition activation energy of coal under different gas atmosphere was studied. The results showed that the amount of oxygen adsorption by coal at normal temperature and pressure can be effectively reduced both by ejecting inert gas nitrogen and flue gas into underground,namely they have the effect of inhibiting the spontaneous combustion and oxidation reaction of coal. The effect of reducing the amount of oxygen adsorption by coal using flue gas is better than that using nitrogen,which make the amount of oxygen adsorption by Tongxin coal and Gaohai coal reduce by 27% and 35% respectively. The TG experimental data showed that the weight gain rate of coal sample at low temperature oxidation stage when combusting under the flue gas atmosphere is slightly less than that when combusting under air atmosphere,while the ignition point is larger. Meanwhile,the ignition activation energy of coal sample when combusting in flue gas is larger than that when combusting in air,which showed that when combusting under the flue gas atmosphere,the amount of oxygen adsorption by coal reduces and the activation energy increases,which increase the difficulty of coal spontaneous combustion.