为探索煤炭地下气化技术对贫瘦煤的适用性,在地下煤层模型试验平台上研究了贫瘦煤层的气化特性。结果表明:贫瘦煤层在空气气化下的煤气热值能达到3 404 MJ/m3,优于地下褐煤空气气化所生成煤气的热值;贫瘦煤层在富氧水蒸气气化下,煤气的有效组分和热值随气化剂中氧浓度的增加而增加,氧气体积分数在40%~50%时产生的煤气比较适合用于燃气发电;污染物分析说明煤气冷凝水中部分污染物含量超标。通过对燃空区三维形状及模拟煤层顶板的分析,发现燃空区沿气化通道稳步推进,横向扩展宽度自点火点处的0.86 m缩小至终点的0.43 m;模拟煤层的表土下沉量约占总厚度的6.5%,下沉面积约占煤层总表面积的6.1%左右。

In order to seek the suitability of the coal underground gasification technology to lean coal, the gasification features of the lean coal seam was studied 0 n the underground seam model experiment platform.The results showed that the calorific value of the coal gas from the lean coal seam under the air gasification conditi on would be 3 404 MJ/m3 and would be better than the calorific value of coal gas from the underground lignite seam under the air gasification.Under the rich oxygen an d steam gasification of the lean seam, the effective components and calorific value of the coal gas would be increased with the oxygen concentration in the gasification agent increased and the coal gas produced with the oxygen volume fraction of 40%%0% would be suitable for the gas-fired power generation. The pollutant analysis sho wed that the partial pollutant content of the coal gas cooling water would be over the limits.The analysis on 3D shape of cavity and coal seam roof, the cavity would be steadily forward along with the coal gasification channel and the lateral expansion width would be reduced from the ignition location of 0.86 m to the terminal location of 0.43 m.The overburden subsidence depth above the simulated seam would be 6.5% of the total thickness and the subsidence area would be about 6.1% of the total surf ace area.

国际科技合作资助项目(2009DFR60180；2010DFR60610)；