高温户外环境电网作业人员热应激预测评价*

为了预测分析户外高温环境下电网作业人员热安全风险，采用预测热应激（Predicted Heat Strain,PHS）模型，考虑人体基础代谢率个体差异性和人体移动与风速对服装热阻和湿阻的影响，应用改进后的预测热应激模型对多种户外高温作业环境工况和不同劳动强度下电网作业人员的核心体温、出汗量等生理参数和最大允许暴露时长进行计算分析。结果表明:在户外高温环境中，随着环境温度、相对湿度和新陈代谢率的升高，电网作业人员的核心体温也随之升高，湿热环境中风速的增加会加剧电网作业人员的热应激；当电网作业人员从事代谢率为240 W/m2高劳动强度工作时，可接受的最大工作时长相比代谢率为190 W/m2中度劳动强度工作时长减小50%以上。研究结果可为电网公司夏季户外工作组织策略制定和作业人员热安全防护提供参考支持。

Prediction and evaluation on heat strain of power grid workers in high-temperature outdoor environment

In order to predict and analyze the thermal safety risk of power grid workers in the outdoor high-temperature environment,the Predicted Heat Strain (PHS) model was employed with taking into account the individual difference of human basic metabolic rate and the influence of human movement and wind speed on the thermal resistance and moisture resistance of clothing,and an improved PHS model was used to calculate and analyze the physiological parameters such as core body temperature and sweating amount and the maximum allowable exposure time of power grid workers under various outdoor high-temperature operating conditions and different labor intensities.The results showed that in the outdoor high-temperature environment,the core body temperature of power grid workers increased with the increase of ambient temperature,relative humidity and metabolic rate,and the increase of wind speed in the hot and humid environment aggravated the heat strain of power grid workers.When the power grid workers were engaged in high labor intensity work with the metabolic rate of 240 W/m2,the maximum acceptable working time was reduced by more than 50% compared with the moderate labor intensity work with metabolic rate of 190 W/m2.The results can provide reference support for the power grid companies to make the summer outdoor work organization strategy and thermal safety protection of workers.