Movable refuge chambers are a new kind of rescue device for underground mining, which is believed to have a potential positive impact on reducing the rate of fatalities. It is likely to be hot and humid inside a movable refuge chamber due to the metabolism of trapped miners, heat generated by equipment and heat transferred from outside. To investigate the heat stress experienced by miners trapped in a movable refuge chamber, the predicted heat strain (PHS) model was used to simulate the heat transfer process between the person and the thermal environment. The variations of heat stress with the temperature and humidity inside the refuge chamber were analyzed. The effects of air temperature outside the refuge chamber and the overall heat transfer coefficient of the refuge chamber shell on the heat stress inside the refuge chamber was also investigated. The relationship between the limit of exposure duration and the air temperature and humidity was numerically analyzed to determine the upper limits of temperature and humidity inside a refuge chamber. Air temperature of 32 °C and relative humidity of 70% are recommended as the design standard for internal thermal environment control of movable refuge chambers.

In order to study the influence of clothing materials on the cooling effect of mine ventilation clothing, the temperatures of human skin and micro-environment under clothing were used as reflection indexes of the cooling effect, and numerical simulations were carried out using fluent software to compare and analyze the temperature changes of human skin and micro-environment under the influence of mine ventilation clothing made of different clothing materials. The results regarding the human skin temperature showed that the modal fiber type resulted in a 0.4 °C lower temperature than the pure cotton type and that the pure cotton type resulted in a 0.6 °C lower temperature than the silica gel type. The temperature comparison of the micro-environment under clothing showed that the modal fiber type resulted in a lower value than the pure cotton type and that the pure cotton type resulted in a lower value than the silicone type; the cooling effect of the three kinds of mine ventilation clothing was modal fiber type > cotton type > silica gel type. In summary, fabric with good permeability and moisture permeability was helpful in improving the cooling effect of mine ventilation clothing.

In this study, a novel air-ring flow regulating valve was proposed to reduce the flow resistance caused by valve structural pressure drop in fluid transportation pipeline system. The regulating characteristics at different valve openings were analyzed by numerical method and the results were compared with the center butterfly valve which is most widely applied in fluid transportation pipeline system. Besides, an experimental system was designed to validate the numerical model in the present study. The results indicated that the simulation results agree well with experimental data. The resistance coefficient of the air-ring flow regulating valve is smaller than that of the center butterfly valve when the valve opening is greater than 67%, and the resistance coefficient is reduced by up to 100% as the valve is fully opened. Both valves maintain approximately equal percentage flow characteristics, the deviation in relative flow coefficient is small. In addition, the wall shear stress of the air-ring flow regulating valve is much smaller than that of the center butterfly valve at the same valve opening, and the maximum velocity in the pipeline system is always smaller than that of the center butterfly valve, which significantly reduces valve surface abrasive erosion and thus prolongs its service life.

It was significant for energy save and environment protection that heat recovering high temperature and high humidity air directly discharged into the atmosphere. Based on high temperature and high humidity mine retention tower and return air fluid, the air heat recovery simulation experiment device was designed, and air heat recovery experiment was researched by using spray heat exchanger. Heat exchange efficiency was tested by experiment with certain water spray coefficient and different nozzle number, and experiment result that was error analysis and data correction through compared with theoretical analysis results. Result showed that the air heat recovery simulation device can recycle heat of air fluid stably, and rise temperature of spray cold water to about 15°C. The heat exchange efficiency would be 90% with certain water spray coefficient, which is basically identical with theoretical analysis. Energy saving effect of this device was remarkable with high heat exchange efficiency.