This study aimed to investigate the thermal responses of acclimated workers exposed to heat stress in a real work environment. The physiological indices and subjective thermal perception of the 14 acclimated workers were measured in an industrial plant. The effects of wet bulb globe temperature (WBGT) on physiological indices and subjective thermal perception were studied. The differences in thermal responses between the acclimated workers and unacclimated college students exposed to heat stress were compared and analyzed. The relationship between the mean skin temperature and the thermal sensation was revealed. The results show that the mean skin temperature, oral temperature, and heart rate of the acclimated workers increase with WBGT, while the blood pressure decreases with WBGT. Compared with the unacclimated college students, the acclimated workers felt more comfortable and tolerant under the same heat stress. The thermal neutral mean skin temperature of the acclimated workers is 32.3 °C, which is approximately 1.0 °C lower than that of the unacclimated college students. The results of this study can help ensure the occupational safety and health of heat stress-exposed workers.

Hot working environment not only affects work efficiency, but also poses a potential threat to the physical and mental health of staff. The current common method for dealing with high temperatures is spray-only or ventilation-only. To investigate the impact of different spray and ventilation modes on indoor high-temperature environments, this study examined their effects on indoor environmental parameters, average skin temperature, and psychological indicators. By establishing an experimental platform for high-temperature thermal environments, a spray ventilation cooling system was implemented, and its cooling efficacy in the indoor thermal environment was analyzed. The environmental classification of the high-temperature working environment under experimental conditions is provided based on the experimental data. A comparison and analysis of environmental parameters and physiological and psychological indicators between moderate and high-temperature environments were conducted. The combination of spray and ventilation modes resulted in a 5.3 °C reduction in air temperature, a 24.1% increase in average relative humidity, and a 3.3 °C reduction in average Wet-bulb Globe Temperature (WBGT). The cooling effect was increased by 2.3 °C and the average relative humidity was increased by 10.8% compared to spray-only and ventilation-only modes. In spray and ventilation mode, when the spray volume is increased by 15 mL/min, the air temperature is reduced by 8.2 °C, the average relative humidity is increased by 31.9%, and the average WBGT is reduced by 5.1 °C. This study has guiding significance for finding a reasonable cooling scheme to cope with indoor high-temperature environments.

The airflow within industrial buildings under natural ventilation is influenced by both internal conditions and external environments. Multi-layer vertically connected plants include a vertically connected space and multiple heat sources distributed on different floors. Due to its complex internal conditions, airflow patterns under natural ventilation in this type of plant are not clear. In this work, we numerically investigate the influence of outdoor wind and thermal pressure on the airflow patterns within this type of plant. The findings indicate that with no outdoor thermal and wind pressure, the airflow crosses the layers from the bottom to the top, while intermediate layers tend to present independent airflows. As the ratio of the Grashof numbers of outdoor thermal pressure and indoor heat source (Gr_i−o/Gr_s) increases from 0 to 0.2, the airflow in the plant changes pattern from a middle layer alone type to the pattern of each layer mixed. Furthermore, when the ratio of the natural ventilation Reynolds number to the indoor heat source Grashof number (Re_o/Gr_s) rises from 0 to 9.7 × 10⁻⁸, the airflow pattern in the plant radically changes from a middle layer alone type to straight through flow. This study provides an important reference for optimizing the natural ventilation environment in such plants.