Heat-Carrying Effect of Goaf Air Leakage: Working Face Speed-Inlet Velocity Coupling

To address mine thermal hazards in coal mining operations, this study focuses on the 8701 fully mechanized mining face of Huoshizui Coal Mine. Computational Fluid Dynamics (CFD) numerical simulation was employed to analyze how heat carried by goaf air leakage impacts the mining face temperature. A porous medium model and a temperature field model for the goaf were constructed, with particular emphasis on investigating the effects of working face advance speed and inlet air velocity.Key findings reveal that a slower advance speed leads to a larger high-temperature zone and higher temperature in the goaf, with 3 meters per day (m/d) identified as the reasonable advance speed. A faster inlet air velocity results in increased goaf air leakage and a more significant impact from residual coal oxidation heat release, leading to the selection of 2 meters per second (m/s) as the optimal inlet air velocity. Additionally, higher inlet air temperatures cause more pronounced temperature rises on the mining face’s return air side, prompting the selection of 292.15 Kelvin (K) as the inlet air temperature for the transport gateway. This research provides a reference for coal mines to regulate the mining face thermal environment and reduce the risk of coal spontaneous combustion.