低阶煤高温燃烧特性参数实验研究

Experimental study on high temperature combustion characteristic parameters of low rank coal

为了研究低阶煤在高温氧化过程中的燃烧特性,采用锥形量热仪测试了3种低阶煤样的点燃时间、热释放速率、总热释放量、质量损失速率、总质量损失量、CO释放量等参数,通过计算得到各煤样的燃烧效率,进而分析煤样的变质程度与燃烧特性参数之间的关系。结果表明:煤样的点燃时间随变质程度的加深而增加;煤样的热释放速率和总热释放量随变质程度的加深而增加,其热释放速率峰值也随之增加,分别为48.27、98.98、108.91 kW/m^(2);煤样的质量损失速率和总质量损失量随变质程度的加深而呈减少趋势,其质量损失速率峰值也随之减小,分别为0.052、0.049、0.044 g/s;煤样的CO释放量最大值随变质程度的加深而增大,在燃烧初期,长焰煤的CO释放量大于气煤和1/3焦煤,在燃烧后期,长焰煤的CO释放量小于气煤和1/3焦煤;煤样的变质程度越高,燃烧效率就越高。

In order to study the combustion characteristics of low-order coal in high temperature oxidation process,the cone calorimeter was used to test the ignition time,heat release rate,total heat release,mass loss rate,total mass loss,CO release and other parameters of three low-order metamorphic coal samples.The combustion efficiency of each coal sample was calculated,and then the relationship between the metamorphic degree of coal samples and combustion characteristic parameters was analyzed.The experimental results show that the ignition time of coal samples increase with the deepening of metamorphism degree,the heat release rate and total heat release amount of coal samples increase with the deepening of metamorphism degree,and their peak heat release rates also increase,which are 48.27,98.98 and 108.91 kW/m~2,respectively.The mass loss rate and total mass loss of coal samples decrease with the deepening of metamorphism degree,and the peak value of mass loss rate also decreases,which are0.052,0.049 and 0.044 g/s respectively.The maximum CO release amount of coal samples increase with the deepening of metamorphism degree.In the early stage of combustion,the CO release amount of long-flame coal is larger than that of gas coal and 1/3 coking coal,but in the late stage of combustion,the CO release amount of long-flame coal is smaller than that of gas coal and 1/3 coking coal.The higher the metamorphic degree of the coal sample is,the higher the combustion efficiency is.