堆放方式对煤堆自燃升温过程的影响分析

1.河南工程学院 安全工程系,河南 郑州 451191; 2.中原工学院 能源与环境学院,河南 郑州 451191

煤堆; 堆放方式; 漏风; 氧气; 温度

Effect of stacking mode on coal pilespontaneous combustion heating up process
LIU Xing-kui1,QU Li-na2,CHANG Xu-hua1

(1.Safety Engineering Department,Henan Institute of Engineering,Zhengzhou 451191,China; 2.School of Energy and Environment,Zhongyuan University of Technology,Zhengzhou 451191,China)

coal pile; stacking mode; air leakage; oxygen; temperature

DOI: 10.13800/j.cnki.xakjdxxb.2017.0107

备注

为了研究露天煤堆自燃过程中温度的变化特征及其影响因素,在考虑风压、热压和质量扩散等驱动力的情况下建立了二维干燥煤堆传热传质数学模型,利用FLUENT软件对煤堆内部各类场信息进行分析。结果 表明:干燥煤堆升温过程大致符合指数特征,在文中设置的边界条件下,高温点位于煤堆中下部,距迎风面大致3 m; 煤堆高度越高,内部升温速率越快,其对升温速率的激励影响主要体现在自燃后期; 放缓迎风角能降低升温速率,使高温区向迎风面移动; 分粒径堆放可显著减缓煤堆升温速率。根据结论,煤堆放置应根据实际条件尽量降低煤堆高度,放缓坡迎风倾角,并将粗细粒径分区堆放,以延长安全存放时间。

In order to study temperature change feature and its influential factors during coal pile heating up process,a 2D heat and mass transfer mathematical model of coal pile was established under the condition of driving force of air pressure,thermal pressure and mass diffusion.Then the Fluent software was used to analyze some field information such as air leakage,oxygen concentration and temperature.The results showed that heating up process presents exponent feature,and high temperature region always lies in the middle and lower segments of coal pile, which is about 3 m from windward slope.The effect of coal pile height on heating up rate does not mainly focus on early period but later,the higher coal pile,the higher heating up rate.The rate decreases and high temperature region moves torward windward when the windward angle decreases.Lastly,correct separate particle size stacking could bring down heating up rate dramatically.According to research conclusion,low coal pile height,small slope angle and correct separate particle size stacking should be chosen to prolong storing time.