Study on heat stress of outdoor workers considering mean radiant temperature
To enhance the precision of heat strain level predictions for outdoor workers in high-temperature environments,this study investigated the influence of workers'core temperature and maximum exposure duration.The Predicted Heat Strain(PHS)model underwent refinement by incorporating the calculation methodology for mean radiant temperature and metabolic rate.The mean radiant temperature is determined using meteorological data and a globe temperature model,while the metabolic rate considers individual variations in age,gender,weight,and the effects of work intensity.A modified Predicted Heat Strain(PHS)model was employed to investigate the impact of varying mean radiant temperatures and metabolic rates on workers'core temperature.By utilizing this model,alterations in the maximum permissible exposure duration were assessed based on rectal temperature and sweat volume.The findings indicate that as both the mean radiant temperature and metabolic rate escalate,there is a corresponding rise in the body's core temperature.At a metabolic rate of 210 W/m2,an incremental duration of work leads to a gradual and moderate rise in the human body's core temperature,without surpassing the threshold.Contrastingly,when a metabolic rate is greater than or equal to 419 W/m2,there is a swift escalation in core body temperature with prolonged work time,culminating in reaching the specified threshold.Moreover,it was observed that while metabolic rate and mean radiant temperature exert subtle influences,they have minimal impact on determining the maximum allowable exposure time dictated by sweating.With an escalation in the metabolic rate,there is a corresponding reduction in the maximum allowable exposure time determined by rectal temperature.Notably,when the metabolic rate surpasses 279 W/m2,there is a substantial decrease in the maximum allowable exposure time determined by rectal temperature.At a metabolic rate of 210 W/m2,the maximum allowable exposure time determined by sweating offers a safer working condition for workers.Conversely,when the metabolic rate exceeds 279 W/m2,the maximum allowable exposure time determined by rectal temperature presents a safer working environment for workers.These research findings offer valuable insights for guiding thermal safety assessments of individuals engaged in outdoor work under high-temperature conditions.
safety and hygiene engineering technologyhigh temperature environmentPredictive Heat Strain modelmean radiant temperaturemetabolic rate
万方数据
维普
