Coal spontaneous combustion is one of the main potential hazards in the process of mining. To study the spatial and temporal variations of higher-temperature area and indicator gases, an adiabatic oxidation testing system was developed to simulate the whole process of coal spontaneous combustion. The experimental results show that the entire process of coal spontaneous combustion could be divided into three stages: slow-oxidation, accelerated-oxidation and combustion stages. In the slow-oxidation stage, the higher-temperature area shifted slowly from the bottom to the top and then stayed at the top until accelerated-oxidation stage was reached; CO and CO 2 concentration remained more or less constant as well as the oxygen concentration. In accelerated-oxidation stage, the higher-temperature area moved to the bottom rapidly and subsequently stayed approximately in the center of the coal; CO , CO 2 concentration and oxygen consumption increased sharply. In addition, the occurrence of higher-temperature area is accompanied by higher oxygen consumption. The obtained results show that higher air supply rate could shorten spontaneous combustion period and there exists a hyperbolic relationship between the temperature and time.

中文翻译：

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煤自燃过程中温度和指示气体时空变化的试验研究

煤炭自燃是开采过程中的主要潜在危害之一。为了研究高温区和指示气体的时空变化，开发了绝热氧化测试系统来模拟煤自燃全过程。实验结果表明，煤自燃的整​​个过程可分为三个阶段：慢氧化阶段、加速氧化阶段和燃烧阶段。在慢氧化阶段，高温区从底部缓慢移动到顶部，然后停留在顶部，直到达到加速氧化阶段；CO和CO 2 浓度以及氧浓度或多或少保持恒定。在加速氧化阶段，高温区迅速向底部移动，随后大致停留在煤的中心；CO 、CO 2 浓度和耗氧量急剧增加。此外，高温区的出现伴随着更高的耗氧量。结果表明，较高的送风量可以缩短自燃时间，温度与时间之间存在双曲线关系。