烟煤与无烟煤混合煤粉燃烧过程的动力学研究

Combustion kinetics of mixed coal blending bituminous coal with anthracite

利用热重分析(TGA)方法系统研究了配加烟煤对无烟煤燃烧特性的影响。结果表明:煤粉燃烧主要由3个阶段组成,烟煤配加量和升温速率对燃烧过程有重要影响,随着烟煤配加量的增加,燃烧DTG曲线向低温区移动;实验所用煤种中的主要矿物元素是Si,Ca,Al,Fe,S,P,其中Mg,Zn,K,Na,Cl等含量较低,这些元素主要以氧化物、硅酸盐、碳酸盐、硫酸盐、氯化物和磷酸盐等形态存在,在低温燃烧过程中,矿物质挥发损失量对煤粉燃烧率的影响较小。采用非等温模型Flynn-Wall-Ozawa(FWO)对主要燃烧过程进行动力学分析,当烟煤配加量从0增加到100%时,煤粉燃烧活化能从133.94 kJ/mol降低到78.03 kJ/mol,且烟煤的配加量低于60%时,能够显著降低煤粉燃烧的活化能。

The influence of additive amount of bituminous coal on anthracite combustion is systematically analyzed with thermogravimetric analysis （TGA）. The results show that, the combustion process is composed of three stages, which are strongly influenced by the additive amount of bituminous coal and heating rate. The increase of bituminous coal makes DTG curves towards low temperature area. The Si, Ca, A1, Fe, S, P are the essential mineral of experimental coal, while the content of Mg, Zn, K, Na, C1 are lower. All thses mineral exist as oxide, silicate, carbonate, sulfate, chlorid and phosphate and so on. During low temperature combustion, the volatilization of mineral has little influence on combustion ratio of mixed coal. The iso-conversional method involving Flynn-Wall-Ozawa （FWO） methods is used for the kinetic analysis of the main combustion process. The results show that, when the additive amount of bituminous varies from 0 to 100 percent, the value of activation energy, which would sharply reduce if the additive amount of bituminous is under 60 percent,increases from 133.94 kJ/mol to 78.03 kJ/mol.