Temperature Rise Within a Mobile Refuge Alternative—Experimental Investigation and Model Validation

Abstract

Mine Safety and Health Administration (MSHA) regulations require underground coal mines to install refuge alternatives (RAs). In the event of a disaster, RAs must be able to provide a breathable air environment for 96 h. The interior environment of an occupied RA, however, may become hot and humid during the 96 h due to miners’ metabolic heat and carbon dioxide scrubbing system heat. The internal heat and humidity may result in miners suffering heat stress or even death. To investigate heat and humidity buildup with an occupied RA, the National Institute for Occupational Safety and Health (NIOSH) conducted testing on a training ten-person, tent-type RA in its Safety Research Coal Mine (SRCM) in a test area that was isolated from the mine ventilation system. The test results showed that the average measured air temperature within the RA increased by 11.4°C (20.5 °F) and the relative humidity approached 90% RH. The test results were used to benchmark a thermal simulation model of the tested RA. The validated thermal simulation model predicted the average air temperature inside the RA at the end of 96 h to within 0.6 °C (1.1 °F) of the measured average air temperature.

A test method for evaluating the thermal environment of underground coal mine refuge alternatives

“…In addition, thermal simulation models could be used to examine the maximum RA occupancy so that the AT limit is satisfied across a broad range of mine ambient temperatures, strata properties, and dimensions. NIOSH RA heat/humidity test data has been used to develop and validate several thermal simulation models [ 9 , 11 , 17 ] and a thermal simulation software tool [ 18 ]. The RA thermal simulation models have been used to examine a variety of aspects related to RA heat/humidity, including heat loss mechanisms for occupied RAs [ 19 ], the effect of mine strata thermal behavior and initial mine temperatures [ 14 ], and the effect of seasonal temperatures on RA heat/humidity and occupancy [ 20 ].…”