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燃烧特性,得到燃烧产物的轴向分布规律,分析了进气浓度、床层温度、流化风速等因素对甲烷浓度轴向分布的影响。研究结果表明:随着床层高度的增加,无量纲甲烷浓度逐渐减小,在床层表面达到最小值,然后突然增加,随后达到稳定。实验范围内,CO浓度均小于20mL/m~3减小进气浓度、增加床层温度、降低流化风速部会使相同床层高度处的无量纲甲烷浓度减小。燃烧反应主要发生在密相区,随着进气浓度的减小、床层温度的增加、流化风速的降低,反应区域逐渐向床层下部移动。 Ultra-low concentrations of CBM are difficult to exploit because of low methane content and large concentration variations. Experimental and numerical simulation methods were used to study the combustion characteristics of ultra-low concentration CBM in a fluidized bed. The axial distribution of combustion products was obtained. Factors such as inlet concentration, bed temperature and fluidization velocity were analyzed. Effect of axial distribution. The results show that with the increase of bed height, the dimensionless methane concentration gradually decreases and reaches a minimum value on the surface of the bed, then suddenly increases and then reaches a steady state. In the experimental range, the concentration of CO is less than 20mL / m ~ 3 to reduce the inlet concentration, increasing the bed temperature, and reducing the velocity of the fluidized bed will reduce the dimensionless methane concentration at the same bed height. The combustion reaction mainly occurs in the dense zone. With the decrease of the inlet gas concentration, the increase of the bed temperature and the decrease of the fluidized air velocity, the reaction zone gradually moves to the lower part of the bed.