褐煤自燃过程中自热特性的试验研究

Study on Self-heating Characteristics of Lignite During Spontaneous Combustion

系统研究了褐煤自燃过程并分析该过程的自热特征;结合气体氧化产物的生成,研究煤质量、粒径、气流速率、水分对褐煤自燃过程中自热特征的影响。煤样自燃过程中经历的交叉点温度(CPT)、燃烧温度(CT1、CT2)等特征温度反映出褐煤自燃过程中的自热特征。研究表明:较小质量的煤样特征温度均偏高;粒径较小的煤样自燃所需时间缩短,CO2生成速率加快;随着气流速率升高,褐煤在CT1点后的温度逐渐升高,CO2生成速率逐渐加快;不同含水量褐煤的自燃时间不同,这可能是水分脱除过程孔结构坍塌所致。

Spontaneous combustion process of lignite is studied systematically to analyze its self- heating characteristics. The effect of coal quality,particle size,air flow rate and moisture content on the self- heating characteristics is researched by combining with gaseous oxidation products. The characteristic temperature such as cross point temperature（ CPT） and combustion temperature（ CT1,CT2） reflects the self- heating characteristics of lignite in the process of spontaneous combustion. The results show that characteristic temperature of smaller quality coal sample tends to be high. The small particle size shortens the time of spontaneous combustion and accelerates CO2 generation rate. After CT1,coal temperature and CO2 generation rate goes up with the increase of gas flow rate. With the increase of moisture content,spontaneous combustion time of lignite with different water content is different,which may be ＂ pore collapse＂ occuring at the drying process.