An experimental apparatus was custom-designed to scrutinize the evolution of temperature and methane pressure during the freezing process in both soft and hard coal samples. Additionally, a thermal–hydrological–mechanical coupling theoretical model was developed, and temperature and methane pressure evolutions were simulated using COMSOL software. It was observed that methane pressure and temperature within the coal samples underwent two distinct phases during the freezing process: an initial rapid decline followed by a more gradual reduction. An exponential function was found to describe aptly the correlation of methane pressure or temperature in the coal samples with both freezing time and radial direction. Moreover, it was discerned that the thermal conductivity of soft coal is inferior to that of hard coal, and the radial decay coefficient of methane pressure or temperature in both types of coal is inversely proportional to freezing time. Significantly, it was revealed that, in post-freezing treatment, ethane pressure in both soft and hard coal could be reduced to 0.74 MPa. This finding elucidates the potential applicability of cryogenic methods for the theoretical elimination of coal seam outbursts. The results furnish a vital understanding of the physical properties of coal under cryogenic conditions, and they can inform the optimization of cryogenic treatment procedures for industrial applications.

定制设计了一个实验装置，用于检查软煤和硬煤样品在冷冻过程中温度和甲烷压力的变化。此外，还开发了热-水文-机械耦合理论模型，并使用 COMSOL 软件模拟了温度和甲烷压力的演变。据观察，煤样内的甲烷压力和温度在冻结过程中经历了两个不同的阶段：最初快速下降，随后逐渐降低。发现指数函数可以恰当地描述煤样中甲烷压力或温度与冻结时间和径向的相关性。此外，人们发现，烟煤的导热系数比硬煤差，并且两种煤的甲烷压力或温度的径向衰减系数都与冻结时间成反比。值得注意的是，研究表明，在冷冻后处理中，软煤和硬煤中的乙烷压力均可降低至 0.74 MPa。这一发现阐明了低温方法在理论上消除煤层突出的潜在适用性。研究结果提供了对低温条件下煤的物理性质的重要了解，并且可以为工业应用的低温处理程序的优化提供信息。