煤绝热氧化动力学特征参数与变质程度的关系

为分析不同变质程度煤自然发火难易程度差异的氧化动力学原因,基于煤绝热氧化自热升温过程的基本假设,结合Arrhenius方程对该过程的反应特征进行了氧化动力学分析,然后研究得出绝热过程表观活化能(Ec)、绝热过程临界温度(Tc)和阶段内平均升温速率(Rhm和Rjs)4个特征参数,最后对各特征参数与煤质等级的关系进行数值拟合。结果表明:Ec,Tc,Rhm和Rjs四个特征参数,分别从煤自燃反应难易(Ec),控制难易(Tc)以及升温快慢(Rhm和Rjs)3方面表征其氧化动力学特征;随着煤的变质程度的升高,Ec与煤质等级成对数关系,Tc与其成线性关系,而Rhm和Rjs与之呈负指数关系。从氧化动力学角度对不同变质程度煤的自燃差异性进行分析,为自燃防治提供参考。

The relationship between oxidation kinetics characteristic parameters of coal adiabatic progress and metamorphic degree

To analyze the oxidation kinetics reason that self- ignition tendency of coal with different metamorphic degree are different，based on the basic assumptions of coal adiabatic self- heating process，a oxidation kinetics analysis on the reaction characteristics of the process was made combined with the Arrhenius equation，then this paper studied four feature parameters：adiabatic process apparent activation energy(Ec)，the critical temperature(Tc)and the average heating rates each stages of the adiabatic process，(Rhm，Rjs)，finally，the relationship between each characteristic parameter and coal metamorphic level was made by numerical fitting.It is show that the oxidation kinetics characteristics are characterized by the four parameters(Ec，Tc，Rhm and Rjs)in the difficulty degree of coal self- ignition reaction(Ec)，the difficulty degree of control(Tc)and the heating speed(Rhm and Rjs)；with the increase of coal metamorphic grade，Ec has a logarithmic relation with it，Tc has a linear relation，however，Rhm and Rjs have a negative exponent relation.The difference of self- ignition tendency of coal with different metamorphic degree is studied on oxidation kinetics，and it is of great significance to self- ignition control.