惰化降温耦合作用下的采空区低温CO2注入流量与温度研究

为了更好地使用LCO_2预防采空区煤自燃安全事故,结合宣东二号煤矿Ⅲ3煤层209工作面的实际条件,利用FLUENT数值模拟的方法,分别研究了低温CO_2的不同注入流量与温度对采空区氧化带内最高点温度、氧化带宽度和最大高温区域温度的影响。发现随着注入流量的增大,氧化带宽度与温度先逐渐下降后趋于平缓,注入温度的下降对回风侧高温点影响不大,而能将入风侧采空区最大高温区域温度降低。研究表明,注入流量增大到一定程度后对缩小采空区氧化带宽度的作用变小,而注入温度的下降对回风侧存在高温发火危险的采空区降温效果不佳。

Study on CO2 injection effect on flow rate and temperature based on coupling effect of inerting and cooling

This paper studies the use of LCO2 in the prevention of gob coal spontaneous combustion accidents, for the 209 working face of coal seam III3 in the Xuandong No. 2 Coal Mine. Numerical simulation by FLUENT is used to study the influence of low temperature CO2 injection volume and temperature in goaf on the highest temperature in oxidation zone, the oxidation zone width and maximum temperature in the high temperature region. It is found that with the increase of the injection flow rate, oxidation zone width and temperature first decrease and then tend to be almost constant. The injection temperature drop has little effect on the hot spots of the return air side, while the maximum temperature zone temperature can be reduced in inlet side of goaf. Research shows that when the injection rate increases to a certain extent, the effect of reducing the goaf oxidation zone width becomes small while the injection temperature drop has minor effect on the cooling of high-temperature combustion dangerous region.