Human thermal comfort for mine environment

By the analysis of miners' mean skin temperature, sweating rate, skin wettedness and upper limit of working time that were the subjective thermal stress indexes in the heat equilibrium condition, it is found that the upper limit of dry-bulb temperature can be extended to 28°C if some humidity conditions are satisfied. Furthermore, the concept of thermal zone diagram was represented by combining the human heat balance equation with measured data, which was comprised of subjective and objective indexes. When human heat balance conditions and sweating rate were satisfied, the thermal zone diagram was divided into non-working zone, comfort zone and prohibitory zone by miners' mean skin temperature curves with different working intensities. The validities of the new upper limit of dry-bulb temperature of 28°C and the thermal zone diagram are approved with the help of the measured data and simulated results of flow field and temperature field in the stope of Dongtan Coal Mine in Yanzhou.