基于煤自燃防治视角的升温速率对煤低温预氧化热流变化特性的影响研究

Impact of Heating Rate during Low Temperature Pre-oxidation of Coal on Heat Flow Characteristics Based on Preventing Spontaneous Combustion of Coal

为研究煤在低温预氧化过程中热流变化的特性,利用差示扫描量热仪对3种煤样(长焰煤、焦煤、无烟煤)进行了循环升温试验,得到煤样在不同升温速率下两次预氧化程序升温过程中的DSC曲线。结果表明:煤在低温预氧化过程中,前后两次升温过程对煤热流变化的作用存在明显差异,即第一次预氧化升温过程中,3种煤样随着升温速率的增加,吸热峰向高温侧偏移,吸热量增大,热流变化的规律性明显,第二次预氧化升温过程中,煤样的热流变化较小,没有出现明显的吸热峰,表明第一次预氧化升温过程对煤热流变化的影响较大。

To study heat flow characteristics of the low temperature pre-oxidation of coal,this paper uses differential scanning calorimetry to conduct cyclic heating experiments of three coal samples（long-flame coal,coke,anthracite）,and obtains the heating DSC curves of the samples under two different heating rates.The results show that in low-temperature coal pre-oxidation process,there are two significant differences before and after the heating process.During the first pre-oxidation heating process,the heat flow varies significantly,and the endothermic peaks shift to higher temperature side with the heating rate increasing.During the second oxidation heating process,the heat flow varies slightly with no noticeable endothermic peaks,indicating that the first pre-oxidation heating has a greater impact on change of coal heat flow.