不同通风速率下水浸煤燃烧特性及氧化动力学研究

Study on combustion characteristics and oxidation kinetics of water-immersed coal under different ventilation rates

煤样在长期的浸水过程中突然风干会增加煤自燃风险,进而发生煤自燃现象。通风速率是影响煤自燃的一个关键因素,但它对水浸煤自燃的影响尚不清楚。为了研究通风速率对水浸煤燃烧特性的影响,先利用程序升温系统测试了煤样在低温氧化过程中的交叉点温度和CO与CO_(2)释放规律,然后利用同步热分析仪对水浸煤的燃烧特性进行了测试,最后利用红外光谱测试了水浸煤的官能团含量。结果表明:通风速率为60 mL/min时煤样的交叉点温度最低,但是CO与CO_(2)释放量随着通风速率的增加而增加;煤燃烧过程中存在最佳通风速率,此时煤的活化能最小,煤更容易燃烧,释放出的热量也更多;通风速率越高,煤中含有越多的羰基和羧基等含氧官能团,为煤氧化提供了足够的能量来源。

The sudden air drying of coal samples during long-term immersion in water will increase the risk of coal spontaneous combustion,and then coal spontaneous combustion will occur.Ventilation rate is a key factor affecting coal spontaneous combustion,but its effect on spontaneous combustion of water-immersed coal is not clear.In order to investigate the effect of ventilation rate on the combustion characteristics of water-immersed coal,this paper first tested the cross-point temperature and CO and CO_(2) release patterns of coal samples during low-temperature oxidation using a programmed heating system,then tested the combustion characteristics of water-immersed coal using a simultaneous thermal analyzer,and finally tested the functional group content of water-immersed coal using infrared spectroscopy.The study showed that:the cross-point temperature of the coal sample was the lowest when the ventilation rate was 60 mL/min,but the release of CO and CO_(2) increased with the increase of ventilation rate;the optimal ventilation rate existed in the coal combustion process,when the activation energy of the coal was the smallest,and the coal burned more easily and released more heat;the higher the ventilation rate,the more oxygen-containing functional groups such as carbonyl and carboxyl groups were contained in the coal,which provided the coal oxidation sufficient energy source for coal oxidation.