不同粒径焦煤高温燃烧特性参数研究

Study on high temperature combustion characteristic parameters of coking coal with different particle sizes

为研究不同粒径煤样在高温条件下的燃烧特性,利用锥形量热仪对粒径为0.200~0.450、0.125~0.200、0.097~0.125 mm的焦煤及其混合煤样的燃烧特性参数进行测试,并计算燃烧效率参数,分析其与煤样粒径之间的关系。结果表明:随着粒径的减小,点燃时间逐渐缩短,表明粒径越小越易燃烧;达到热释放速率峰值所需时间及峰值高低随粒径的减小而减小,其中混合煤样的峰值最低;当热释放速率曲线趋于平稳后,随着粒径的减小,热释放速率及总热释放量均呈增大趋势,且关系均为0.097~0.125 mm>0.125~0.200 mm>混合煤样>0.200~0.450 mm;质量损失速率峰值及稳定后的质量损失速率随粒径的减小而增大,总质量损失也随之增多,且关系均为0.097~0.125 mm>0.125~0.200 mm>混合煤样>0.200~0.450 mm;CO释放量随着粒径的减小呈减小趋势;随着粒径的减小,火灾性能指数逐渐减小,而火灾蔓延指数逐渐增大,其中混合煤样火灾性能指数最大,火灾蔓延指数略高于0.200~0.450 mm煤样;煤样粒径越小火灾危险性越大,混合煤样火灾危险性较低。

In order to study the combustion characteristics of coal samples with different particle sizes under high temperature conditions,the combustion characteristic parameters of coking coal and its mixed coal samples with particle sizes of 0.200-0.450 mm,0.125-0.200 mm and 0.097-0.125 mm were tested by cone calorimeter.The combustion efficiency parameters were calculated and the relationship between combustion efficiency parameters and the particle size of coal samples was analyzed.The results show that with the decrease of particle size,the ignition time becomes shorter,indicating that the smaller the particle size of the coal sample,the easier it is to burn;the time required to reach the peak value of heat release rate and the peak value decrease with the decrease of particle size,and the peak value of mixed coal sample is the lowest.When the heat release rate curve tends to be stable,the heat release rate and total heat release increase with the decrease of particle size,and the relationship is 0.097-0.125 mm>0.125-0.200 mm>mixed coal sample>0.2000-0.450 mm;the peak value of mass loss rate and the stable mass loss rate increase with the decrease of particle size,and the total mass loss also increases,and the relationship is 0.097-0.125 mm>0.125-0.200 mm>mixed coal sample>0.200-0.450 mm.The CO release decreases with the decrease of particle size.With the decrease of particle size,the fire performance index decreases,while the fire spread index increases.The fire performance index of mixed coal sample is the largest,and the fire spread index is slightly higher than that of 0.200-0.450 mm coal sample;the fire risk increases with the decrease of coal particle size,and the fire risk of mixed coal sample is low.