Space-Time Evolution Law of the Temperature Field in Coal Gangue Dump Under Different Heat Pipe Arrangement Strategies

Coal gangue is prone to exothermic oxidation reaction and spontaneous combustion in the process of stockpiling, which constitutes a serious ecological and safety hazard. In order to achieve efficient management of the high-temperature risk of coal gangue dump, this study constructs a multi-physical field coupling numerical model with the coal gangue dump in Daonao Liang, Shanxi Province, as the research object. The model is verified by on-site measured temperature data, and the maximum relative error is no more than 20%. And the influence of the law of heat pipe (HP) insertion depth, spacing, and arrangement on the temperature field was systematically analyzed. The results show that HP can make the coal gangue dump in a short period of time to form a significant cooling core area, with a cooling amplitude of up to 27°C; inserted into the depth of the coal gangue dump closer to the high-temperature core area, the cooling effect is more significant, the deeper the coal gangue heat extraction ability to enhance; smaller spacing (S = 2 m) favors rapid cooling of the coal gangue dump but limited coverage; the S = 3 m arrangement provides an optimal balance between cooling efficiency and space coverage; and the triangular arrangement is more effective than the square arrangement in cooling the high-temperature control area of the coal gangue dump. The research results can provide theoretical support and arrangement strategies for the accurate management of heat-affected coal gangue dump.