煤自然发火过程温度、氧浓度的时空演化规律

1.西安科技大学 安全科学与工程学院,陕西 西安 710054; 2.陕西省煤火灾害防治重点实验室,陕西 西安 710054

自然发火; 高温点; 氧浓度分布; 温度分布; 耦合作用

Spatial-temporal variation of temperature and oxygen concentration in coal spontaneous combustion process
LIU Wen-yong1,2,WEN Hu1,2,YAN Xu-bin1,2

(1.College of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.Shaanxi Key Laboratory of Prevention and Control of Coal Fire,Xi'an 710054,China)

spontaneous combustion; high temperature point; oxygen concentration distribution; temperature distribution; coupling effect

DOI: 10.13800/j.cnki.xakjdxxb.2017.0506

备注

为研究煤自然发火过程不同区域的动态发展规律,使用大型煤自然发火实验台测试松散煤体在恒风量条件下从常温至140 ℃的氧化过程,分析了温度、氧浓度在时间及空间上的变化规律。结果 表明:松散煤体自燃过程温度随煤体高度的变化在不同温度阶段趋势差异较大,高温点由煤体中部位置向着进风侧方向移动; 不同煤体高度温度与时间呈现指数增长,70 ℃前后煤体呈现缓慢和快速增长分阶段特性; 松散煤体进风口和出气口两侧氧体积分数18%以上,温度超过70 ℃后,不同煤体高度的氧浓度随时间增长逐渐下降。

In order to study the dynamic development law of coal spontaneous combustion process in different regions,large-scale coal spontaneous combustion experiment was used to test oxidation process of loose coal under the condition of constant air volume from room temperature to 140 ℃.The changes of temperature and oxygen concentration in time and space were analyzed.The temperature varied greatly with the change of coal height at different temperature phase of loose coal spontaneous combustion process.High temperature point moves from middle part of the coal body to the inlet side.In different coal height the temperature and time increased exponentially.When the maximum temperature reaches 70 ℃,loose coal showed slow and rapid growth phase characteristics.The oxygen volume fraction of loose coal from the air inlet and outlet sides is above 18%,after the temperature exceeds 70 ℃,the oxygen volume fraction of different coal height decreases with the increase of time.