超低浓度煤层气由于甲烷含量低、浓度变化大而较难加以利用。采用实验和数值模拟的方法，研究了超低浓度煤层气在流化床中的燃烧，分析了床层温度、甲烷体积浓度，流化风速对甲烷燃烧效率的影响，并用数学模型预测了甲烷沿床层高度方向的分布。研究表明，数学模型和实验数据吻合较好。床层温度是煤层气燃烧反应的关键因素，甲烷的转化率随着床层温度的升高而增加。燃烧反应主要发生在乳化相，且主要集中在床层的下部。甲烷的转化率随着流化风速和煤层气中甲烷浓度的增加而减少。在床层温度为650℃时，甲烷浓度低于1％的煤层气的甲烷转化率均大于93％。增加床层高度可使甲烷完全转化。
The ultra-low concentration coal bed methane is difficult to utilize due to its low methane content and fluctuated concentration. Coal bed methane combustion in a fluidized bed was studied experimentally and numerically. The effects of bed temperature, methane volumetric concentration and fluidized velocity on methane conversion were analyzed. The methane profile along bed height was predicted with the mathematical model. The results show that the model compares reasonably well with experimental data. Bed temperature is a major factor on combustion. And the methane conversion increases with the rising bed temperature. The combustion reaction is mainly occurred in the emulsion phase and at lower part of the bed. The methane conversion decreases with the increasing fluidized velocity and inlet methane concentration. When the bed temperature is 650℃ and methane concentration is less than 1%, the conversion is greater than 93%. More methane can be consumed when the bed height is increasing.
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