【作者】 张鹏；

【导师】 方赵嵩；

【作者基本信息】 广州大学 ， 人工环境工程（含供热、通风及空调等）（专业学位）， 2024， 硕士

【摘要】 近年来,全球气候变化逐渐加剧,城市热岛效应趋于严重。室外作业人员面临严重的高温暴露热安全风险。为此,研究处于高温作业环境中不同劳动强度下人体的热响应特征有着显著的必要性,在此基础上结合不同的改善措施对降低作业人员的健康风险有着重要意义。本文主要研究高温作业环境中不同劳动强度下人体的主观和生理反应特性,同时结合不同的改善措施对热舒适的影响效果,明确有效的热安全改善措施。这为改善高温环境下工作人员的热舒适,降低高温暴露的健康风险提供一定的参考。本文采用实地调研与人工气候室模拟实验相结合的研究方法。于2023年7月在广州建筑工地进行了人体热舒适主观问卷调研和现场热环境测试,收集了有效问卷600份。调研期间工地的平均相对湿度为67%,工作时间段平均空气温度为37.3℃;工人的劳动强度基本维持在4.0met左右。主观问卷显示超过75%的工人出现了“大量出汗”或“出汗过多”的现象。近90%的工人感到“热”(42.6%)或“非常热”(46.3%)。基于现场调研结果确定人工气候室试验工况:运动速度(1.1m/s、1.5m/s、1.9m/s)分别模拟2.4met、3.2met、4.0met的劳动强度;空气温度(31℃、34℃、37℃)和相对湿度为70%,同时考虑到实际降温的情况,采用了冷却背心和空调服两种降温措施,共27个工况。每一个实验工况邀请24名受试者参与实验,共648人次,在实验过程中按照一定的间隔时间收集受试者的生理参数和主观问卷,整个实验周期持续8周。首先对实验中收集的受试者生理数据进行了分析,结果表明:生理参数随着温度和运动速度的增加先增加后趋于稳定,并且温度越高、运动速度越快生理参数达到最大值的时间越短。例如受试者心率在31℃、1.1m/s工况下达到最大值,时间为运动20分钟后;在34℃、1.5m/s工况下其时间为15分钟左右;在37℃、1.9m/s工况下其时间为10分钟左右。其次,通过比较不同降温措施的实验结果,发现在运动前,冷却背心和空调服均具有改善作用,且空调服的改善较为明显。运动阶段:在31℃和34℃、1.1m/s工况下,冷却背心和空调服均具有改善作用,然而在34℃、1.9m/s和37℃的工况下冷却背心却加重了受试者的热感觉。空调服仍然具有改善效果,其效果随着温度和速度的增加逐渐减弱。通过受试者的热症状分析,结果表明:受试者主要出现的症状为面部闷热(28.33%)、剧烈出汗(17.00%)以及心跳加速(9.59%)。最后分析了受试者的疲劳值,结果表明:冷却背心和空调服在温度较低和运动强度较低的时候具有改善效果;温度超过34℃,且运动速度高于1.5m/s时,穿戴冷却背心会增加受试者的疲劳感,而空调服仍具有改善效果,两者疲劳值相差4~6。基于上述分析,本论文最后提出了室外作业人员穿戴不同降温措施的疲劳值评价模型,明确了其与作业强度、作业时长和环境参数的关系。这对指导作业人员在室外高温环境下科学作业,减少高温暴露热安全风险有着重要意义。更多还原

【Abstract】 In recent years,global climate change has gradually intensified and the urban heat island effect has become more severe.Outdoor workers are exposed to serious thermal safety risks due to high temperature exposure.Therefore,it is necessary to study the thermal response characteristics of the human body under different exercise intensities in a high-temperature working environment,and based on this,it is important to combine different improvement measures to reduce the health risks of the workers.This paper focuses on the subjective and physiological response characteristics of the human body under different labour intensities in high temperature working environments,and at the same time combines the effects of different improvement measures on thermal comfort to clarify effective thermal safety improvement measures.This provides a certain reference for improving the thermal comfort of workers in high-temperature environments and reducing the health risks of high-temperature exposure.This paper adopts a research method combining field research and artificial climate chamber simulation experiment.The subjective human thermal comfort questionnaire research and on-site thermal environment test were conducted in Guangzhou construction site in July 2023,and 600 valid questionnaires were collected.The average relative humidity of the construction site during the research period was 67%,and the average air temperature during working hours was 37.3°C;the labour intensity of the workers was basically maintained at about 4.0 met.The subjective questionnaire showed that more than 75% of the workers experienced the phenomenon of "heavy sweating" or "excessive sweating".Nearly 90 percent of the workers felt "hot"(42.6 percent)or "very hot"(46.3 percent).Based on the results of the on-site research to determine the artificial climate chamber test conditions: movement speed(1.1m/s,1.5m/s,1.9m/s)to simulate the labour intensity of2.4met,3.2met,4.0met,respectively;the air temperature(31 ℃,34 ℃,37 ℃)and the relative humidity of 70%,while taking into account the actual cooling,the cooling vests and air-conditioning suits are used in the two kinds of cooling measures,with a total of 27 working conditions.For each working condition,24 subjects were invited to participate in the experiment,a total of 648 people,and physiological parameters and subjective questionnaires were collected at certain intervals during the experiment,and the whole experimental cycle lasted for 8 weeks.Firstly,the physiological data collected from the subjects in the experiment were analysed,and the results showed that the physiological parameters first increased and then stabilized with the increase of temperature and exercise speed,and the higher the temperature and the faster the exercise speed,the shorter the time for the physiological parameters to reach the maximum value.For example,the heart rate of the subjects reached the maximum value at31℃ and 1.1m/s for 20 minutes after exercise;at 34℃ and 1.5m/s for about 15 minutes;and at 37℃ and 1.9m/s for about 10 minutes.Secondly,by comparing the experimental results of different cooling measures,it was found that both cooling vests and air-conditioned suits had an improvement effect before exercise,and the improvement of air-conditioned suits was more obvious.In the exercise phase,both cooling vests and air-conditioning suits had an improving effect at 31℃ and 34℃and 1.1m/s,however,the cooling vests aggravated the thermal sensation of the subjects at34℃,1.9m/s and 37℃.The air-conditioning suit still had an ameliorating effect,and its effect gradually diminished with increasing temperature and speed.The analysis of the thermal symptoms of the subjects showed that the main symptoms experienced by the subjects were facial stuffiness(28.33%),intense sweating(17.00%)and rapid heartbeat(9.59%).Finally,the fatigue values of the subjects were analysed,and the results showed that the cooling vest and the air-conditioned suit had an improvement effect at lower temperatures and lower exercise intensities;when the temperature exceeded 34℃ and the exercise speed was higher than 1.5m/s,wearing the cooling vest increased the fatigue feeling of the subjects,whereas the air-conditioned suit still had an improvement effect,and the fatigue values of the two differed by 4 to 6.Based on the above analyses,this thesis finally proposes a fatigue value evaluation model for outdoor operators wearing different cooling measures,and clarifies its relationship with the intensity of operation,the duration of operation and environmental parameters.This is of great significance in guiding operators to work scientifically in outdoor high temperature environments and reducing the thermal safety risk of high temperature exposure.更多还原