摘要
为了准确预测室外高温环境下作业人员的热应激水平,研究了作业人员核心温度和最大允许暴露时长的影响.基于平均辐射温度和代谢率的计算方法对预测热应激(Predicted Heat Strain,PHS)模型进行改进,研究不同平均辐射温度和代谢率对作业人员的核心温度的影响,并分析了直肠温度和出汗量确定的最大允许暴露时长的变化规律.结果显示:人体核心温度随平均辐射温度和代谢率的增加而增大,当代谢率≥419 W/m2时,人体核心温度随作业时间快速上升并达到阈值;代谢率和平均辐射温度对出汗量确定的最大允许暴露时长影响较小,直肠温度确定的最大允许暴露时长随着代谢率的增加而显著降低.研究结果可为室外高温作业人员热安全评估提供指导.
Abstract
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.
维普
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