Study On The Effect Of Wind Speed On Human Physiological Stress In Hot And Humid Mine

The hot and humid environment of the mine refers to the special mine thermal environment that exhibits the characteristics of high temperature and high humidity,as one of the main occupational harmful factors in the mine production environment,high temperature and high humidity widely exist in deep mines,which has a great impact on the safety and health of miners working underground.In order to explore the impact of wind speed on human physiological stress in the hot and humid environment of mines,this paper uses bioclimatic research methods to establish 24 different mine simulation environments in the artificial climate room,with temperatures set to 32?,36?,40?,and relative humidity.Set to 70%,90%,and set the wind speed to static wind(<0.2m/s),lm/s,2.5m/s,4m/s.Taking five mine workers with underground operation experience as the test personnel,while recording the experimental time,six physiological indicators(core temperature,eardrum temperature,average skin temperature,heart rate,blood pressure,respiratory rate)and subjective thermal sensory evaluation in the three major human systems of human body thermoregulation,cardiovascular and breathing were measured.First,analyze the six physiological indicators,and the results show that core temperature,eardrum temperature,average skin temperature,heart rate and breathing rate generally increase with the increase of working hours,diastolic blood pressure decreases with the increase of working hours,and systolic blood pressure showed a trend of first rising and then falling with the increase of working hours.In a lower environmental intensity,the wind speed has significant differences in the degree of influence of the core temperature,eardrum temperature,average skin temperature,heart rate,and blood pressure.However,regardless of the environmental intensity,There is no significant difference in the degree of influence of wind speed on the change trend of respiratory frequency.The existing PSI index is improved by the eardrum temperature to obtain an RPSI that is easier to use on site.Then through the analysis of subjective thermal sensation,it is found that thermal sensation generally increases with the increase of average skin temperature.In the warmer state(2<TSV<3),skin temperature changes have a significant impact on thermal sensation,and in extreme states(When TSV>3),the sensitivity of thermal sensation to skin temperature is weak.It is clear that the PMV model cannot accurately predict the thermal sensation of the human body in the high-temperature and high-humidity environment of the mine,but there is a certain linear relationship between the thermal sensation of the human body and PMV under different wind speed conditions,A calculation and prediction program for thermal sensation of damp and hot mine operators has also been developed.Finally,the Cox regression analysis is used to explore the degree of influence of temperature,relative humidity and wind speed on the safe working limit time,and an environmental risk model for working in damp and hot mines is established.The order of the degree of influence of each factor on the safe working limit time is found:temperature>Wind speed>Relative humidity.Among the four wind speed types,the order of survival rate decline rate is:static wind(<0.2 m/s)>low speed wind(1 m/s)>medium speed wind(2.5 m/s)>For high-speed wind(4 m/s),increasing the wind speed can effectively increase the safe working limit time value,but when the wind speed reaches 2.5 m/s,increasing the wind speed will not have a good effect on increasing the safe working limit time value.This paper also gives the recommended value of safe working limit time under the coupling effect of wind-induced effect,temperature-induced effect and moisture-induced effect,and uses multiple regression analysis to establish a prediction model of safe working limit time for wind speed in the damp and hot mine environment,In order to provide effective theoretical support for the safety and health of workers in high-temperature and high-humidity mines.