Thermal performance of a mine refuge chamber with human body heat sources under ventilation

Highlights: • Sensitivity analysis is carried out regarding rock thermal parameters, heating rate, ventilation and wall area. • Air temperature rises linearly with the square root of time during slow increase of the air temperature. • Temperature rise rate in a Mine Refuge Chamber (MRC) is proportional to the heat generation rate. • An empirical correlation for the MRC average air temperature under ventilation is developed. • Cooling is not needed when MRC built in sandstone with initial rock temperature less than 27 °C under ventilation. -- Abstract: This paper investigated the dynamic coupling heat transfer characteristics of rock and air in a Mine Refuge Chamber (MRC) under ventilation. In the current work, a comprehensive fifty-person MRC model combining human-body heat sources and ventilation is established, the proposed model is validated against available experimental data with deviation less than 4%. Furthermore, sensitivity analysis is performed to investigate the influence of several control parameters such as heating rate, ventilation and wall area in a MRC through using numerical simulation. Results indicated that: (i) the heat transfer process in a MRC will reach a stage of air temperature slow increase (ATSI) in less than 0.5 h. The air temperature rises linearly with the square root of time during the ATSI stage; (ii) for a MRC built in a sandstone seam with an initial rock temperature of less than 27 °C, the average air temperature will not exceed 35 °C in 96 h when the ventilation volume rate is 0.3 m³/min per person; (iii) the rate of temperature rise in MRC is proportional to the rate of heat generation, but it is inversely proportional to the thermal conductivity, density and thermal capacity of the rock, as well as the ventilation volume rate and the wall area; (iv) an empirical correlation for the MRC average air temperature is developed while the supply air temperature equals to the initial rock temperature.