1. College of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo　 454003,China; 2. State Key Laboratory Cultivation Base for Gas Geolo- gy and Gas Control,Henan Polytechnic University,Jiaozuo　 454003,China; 3. Collaborative Innovation Center of Coal Safety Production of Henan Province, Jiaozuo　 454003,China

煤炭开采过程中,由煤自燃引起的矿井火灾是煤矿主要灾害之一。交叉点温度法(CPT)是测试煤自燃倾向性指标及温升特性参数的一种实验方法。基于交叉点温度法,通过程序升温测试系统对0.45~0.60 mm粒径的烟煤在氧体积分数分别为20.65%,17.80%,13.62%,10.49%,5.00%和3.00%的贫氧环境中分别进行了升温测试。通过煤体温升速率、炉温与煤温温差特性以及耗氧规律进行分析,结合程序升温过程煤样产热速率特性曲线,将煤自燃低温氧化过程划分为4个阶段:阶段Ⅰ-无反应阶段,阶段II-吸热阶段,阶段Ⅲ-快速放热阶段,阶段Ⅳ-稳定放热阶段。同时通过对煤自燃升温过程能量守恒公式进行归一化处理,加热炉体与煤体温差在阶段Ⅰ和阶段Ⅳ分别为由ατ和(B-1)ατ决定,而在阶段Ⅲ出现交叉点温度必须满足B>1这一条件,经对比实验数据契合理论推导结论。

Coalmine fire caused by coal spontaneous combustion is one of the main disasters in coalmines. The cross- ing-point temperature (CPT) method is an experimental technique to test the propensity of coal to spontaneous com- bustion and the characteristic parameters of temperature increase. A Temperature-Programmed System ( TPS) was used to develop the oxidation tests of the bituminous coal under various flow and oxidation conditions for temperatures at low temperatures (such as the volume fraction of oxygen in air at inlet are 20. 65% ,17. 80% ,13. 62% ,10. 49% , 5. 00% and 3. 00% respectively). Based on the present analysis of temperature increase rate of coal,the temperature differences between oven and coal,and the characteristics of oxygen consumption,furthermore,considering the heat generation rate of coal during the procedure of the Temperature-Programmed tests,the four stages of coal oxidation at low temperature were identified:(I) initial heating with no reaction,(II) a endothermic period,(III) an unsteady ex- othermic period and (IV) a steady period. Moreover,according to the normalization of the energy conservation equation of the coal spontaneous combustion during the tests,the temperature differences of the oven and the coal samples were dominated by the parameters of ατ and (B-1)ατ separately at the stages I & IV. Also,there must be parameter B larger than 1 as the CPTs occur at stage III. The theoretical results remains the same as the experimental ones.

国家自然科学基金资助项目(51304073；51304071；U1361205)；

Xu Yongliang,Wang Lanyun,Song Zhipeng,et al. Characteristics and critical parameters of coal spontaneous combustion at low temperature stage based on CPT method[J]. Journal of China Coal Society,2017,42(4):935-941.