Experimental investigation on environmental control of a 50-person mine refuge chamber

Air quality and thermal environment of mine refuge chamber (MRC) are very important to determine the physical safety of refugees. Accurately assessing the environmental load and taking reasonable measures are critical to achieve the environmental control goals of MRC. In order to evaluate the metabolic parameters of occupants and the effectiveness of environmental control measures in a MRC, in this research, 50 adult men entered a MRC laboratory for an 8-h test. During the test, the compressed O2 cylinders and air purification devices were used to ensure the indoor air quality. The possibility of using chemical adsorbents to passively scrub CO2 and the performance of dehumidification by mine compressed air (MCA) were also investigated by simulation experiments. The results indicated that: (1) The per capita metabolic rates of O2, CO2 and heat during the refuge process are 0.34-0.37 L/min, 0.34 L/min and 117-128 W, respectively. (2) When Ca(OH)2 particles are used as CO2 adsorbent, the air purification device has both dehumidification and CO2 scrubbing functions, and three air purification devices could make the CO2 concentration below 0.8% with the relative humidity below 76%. When Ca(OH)2 particles are packaged to passively scrub CO2, the amount of adsorbent may increase significantly. (3) When MCA is used for dehumidification in a MRC, the air volume of 0.15 m3/min per capita could maintain the relative humidity close to 60%. (4) In the early stage of disaster avoidance, the indoor ambient temperature rises rapidly within 1 h followed by a slight increase.