沙柳半焦与煤共燃烧特性及动力学实验研究

Experimental Study on Co-combustion Characteristics and Co-combustion Kinetics of Salix psammophila Charcoal and Coal

在空气气氛下利用热重微差分析天平对沙柳半焦与煤单独燃烧和混合燃烧时的特性进行研究。结果表明:沙柳半焦和煤单独燃烧的热重曲线相似;将沙柳半焦与煤进行混合后,可以改善煤的燃烧特性;而且随着沙柳在煤中占比的不断增加,相比于单煤,沙柳半焦与煤混合燃烧的着火温度、燃尽温度表现出一致的减少。沙柳半焦与煤混合的实际转化率远远大于其相应的理论转化率,表明沙柳半焦对煤的燃烧起到明显的促进作用;通过Coast-Redfern积分法对沙柳半焦和煤单独燃烧和混合燃烧时所得热力学数据进行拟合,其符合一级反应动力学模型,当煤中掺和沙柳半焦后,两者共燃烧的活化能与频率因子均明显增大,且随着沙柳半焦掺和比例的增加,混合燃烧的活化能及指前因子进一步递增,进一步说明沙柳的加入对煤的燃烧过程产生了明显的协同作用。

The single combustion and the mixed combustion characteristics of Salix psammophila charcoal and coal were investigated by using the thermo-gravimetric apparatus in air atmosphere.The experimental results showed that the TG-DTG curve of Salix psammophila charcoal and coal is similarity.The mixing of Salix psammophila charcoal and coal is favor to improve combustion characteristic.As the blending ratio increased,the ignition temperature and burnout temperature show consistent reduction.At the same time,the calculated conversion rate is greater than the experimental conversion rate,which show that Salix psammophila charcoal plays a significant role in promoting the combustion of the coal.By the Coast-Redfern integral method,the data of combustion were analyzed.It conforms to the first order reaction kinetics model.The results of kinetic analysis showed that the activation energy and exponent factor of co-combustion increased obviously with the addition of Salix psammophila charcoal,and the activation energy and exponent factor of co-combustion increased further with the increasing of the proportion of Salix psammophila charcoal.It is shown that there is a cooperative effect in co-combustion.