氧气体积分数与升温速率对弱黏煤燃烧特性的影响

Effects of oxygen concentration and heating rate on the characteristics of bituminous coal combustion

采用热重实验研究氧气体积分数和升温速率对弱黏煤燃烧特性的影响,通过分析TG/DTG曲线得出样品的特征温度和反应速率,基于样品的特征温度和反应速率计算得到样品的燃烧特性参数。研究结果表明,改变氧气体积分数和升温速率对煤的着火温度影响不大,主要对煤的燃烧阶段产生影响。提高升温速率会延长煤的氧化反应历程,使煤各特征温度升高,并且增大煤的氧化反应速率;提高氧气体积分数会缩短煤的氧化反应历程,使煤各特征温度降低,并增大煤的氧化反应速率。在煤的氧化过程中,改变氧气体积分数和升温速率都能对煤的特征温度和燃烧特性参数造成影响,但氧气体积分数对他们的影响要大于升温速率造成的影响。

Thermogravimetric analysis method was used to investigate the effects of oxygen concentration and heating rate on the characteristics of coal combustion.According to the TG-DTG graphs,characteristic temperatures and reaction rates were obtained.Furthermore,three combustion characteristic indexes were obtained on the basis of characteristic temperatures and the reaction rate.Experimental results indicate that the change of oxygen concentration and heating rate has little effect on the ignition of coal,which mainly affects the combustion stage of coal.With the increase of the heating rate,the oxidation reaction process of coal become longer,the characteristic temperature increased and the reaction rate of coal oxidation also increased.With the increase of oxygen concentration,the oxidation reaction process of coal become shorter,the characteristic temperature decreased and the reaction rate of coal oxidation also increased.In the process of coal oxidation,the changes of oxygen concentration and heating rate can affect the characteristic temperature and combustible parameter of coal,but the effect of oxygen concentration on them is greater than the effect of heating rate.