College of Safety Science and Engineering, Liaoning Technical University, Fuxin, Liaoning, China.
Key Laboratory of Mine Thermodynamic Disaster & Control of Ministry of Education, Liaoning Technical University, Huludao, Liaoning, China.
PLoS One. 2022 Apr 27;17(4):e0267479. doi: 10.1371/journal.pone.0267479. eCollection 2022.
Investigating the division of coal spontaneous combustion stages and the selection of indicator gases is significant to the safe production of coal mines. In this study, the characteristic temperature of coal spontaneous combustion, the generation law of indicator gases, the combustion process, and the division of the combustion stages of coal samples taken from Hongqingliang (HQL) and Dayan (DY) mines were investigated using thermogravimetric analysis experiment, indicator gas detection experiment, and coal oxidation spontaneous combustion experiment. The results of the thermogravimetric analysis experiment showed that the pyrolysis temperatures of the HQL and DY coals were 115.76°C and 131.80°C, and the ignition temperatures were 337.74°C and 360.18°C, respectively. The indicator gas detection results showed that the first-appearance temperature of C2H4 was 85°C for the HQL and DY coals, whereas the first-appearance temperature of C2H6 varied: 115°C for the HQL coal and 130°C for the DY coal. The first-appearance temperatures of C2H2 were 180°C and 195°C for the HQL and DY coals, respectively. The experiments on coal oxidation spontaneous combustion showed that the spontaneous combustion period of the HQL and DY coals were 35.45 and 42.3 days, respectively. The heating process during combustion could be divided into four stages: a latent period of spontaneous combustion, a slow spontaneous heating period, an accelerated spontaneous heating period, and a period of combustion. The critical temperature of each stage showed a good correlation with the incipient temperature of the indicator gases, namely C2H2, C2H4, and C2H6, and the appearance of the above gases can be used to characterize the degree of spontaneous combustion of coal.
研究煤自燃阶段的划分和指标气体的选择对煤矿的安全生产具有重要意义。本研究采用热重分析实验、指标气体检测实验和煤氧化自燃实验，对取自红梁（HQL）和大雁（DY）煤矿的煤样的特征温度、指标气体生成规律、燃烧过程和燃烧阶段的划分进行了研究。热重分析实验结果表明，HQL 和 DY 煤的热解温度分别为 115.76°C 和 131.80°C，着火温度分别为 337.74°C 和 360.18°C。指标气体检测结果表明，HQL 和 DY 煤的 C2H4 首次出现温度分别为 85°C 和 115°C，而 C2H6 的首次出现温度则分别为 115°C 和 130°C。HQL 和 DY 煤的 C2H2 首次出现温度分别为 180°C 和 195°C。煤氧化自燃实验表明，HQL 和 DY 煤的自燃期分别为 35.45 天和 42.3 天。燃烧过程中的加热过程可分为四个阶段：自燃潜伏期、缓慢自燃升温期、加速自燃升温期和燃烧期。各阶段的临界温度与指标气体 C2H2、C2H4 和 C2H6 的起始温度呈良好的相关性，上述气体的出现可用于表征煤自燃的程度。
