Research On The Influence Of Pipeline Tructure On Microclimate Of Mining Ventilation Suit And Human Thermophysiology

Working for a long time in the harsh environment of high temperature and high humidity will produce thermal damage to the human body,causing abnormal physiological reactions,which will affect physical functions,reduce work efficiency,and seriously lead to safety accidents.For the problem of heat damage protection,non-mechanical refrigeration cooling,mechanical refrigeration cooling technology due to a variety of objective conditions and limitations of the application,resulting in not completely solve the problem of heat damage to all human beings underground,while individual protection technology has the advantages of targeted,relatively simple overall structure,low cost and obvious cooling effect,can effectively reduce the heat damage suffered by the human body in a hostile environment.As a way of individual protection,mining ventilation suits are mainly used to change the micro-environment of human near body surface and then reduce the harm to human body.In this paper,numerical simulation is used to study the changes of microclimate parameters and the cooling effect on human body for three different pipeline structures of mining ventilation suits,and the reliability of the simulation is verified by real-life dressing experiments.According to the human thermal physiological parameters measured by the experiment,the relationship between different influencing factors and human thermal physiology is analyzed by using spss software,which provides a certain reference value for the research of improving human thermal physiology.The main research contents of this paper are as follows.(1)This paper describes the cooling mechanism of mining ventilation suits,introduces the theory of human body heat balance,analyzes the heat transfer mode of mining ventilation suits,establishes three-dimensional physical models of mining ventilation suits with three pipeline structures,and studies the heat transfer characteristics of the space inside the mining ventilation suit under different working conditions and its local cooling effect on the human body by means of numerical simulation,which provides feasibility for subsequent research.(2)The physicalization of the mining ventilation suit was carried out,and the changes of microclimate parameters and the effects on human skin temperature of three types of pipeline structure mining ventilation suits under different working conditions were studied through real-life dressing experiments to verify the reliability of the numerical simulation,while the correlation between different influencing factors and human thermal physiology was analyzed based on the human thermal physiological parameters obtained from the experiments.(3)The simulation and experimental results both show that the skin temperature is influenced by the structure of the pipeline and the location of the vent entrance,ambient temperature,human labor intensity and ventilation volume,and there are differences in the skin temperature of each torso position;the overall human skin temperature after wearing vertical and hybrid ventilation clothing shows a "low left and high right" change pattern,and the skin temperature after wearing horizontal ventilation clothing shows a "high left and low right" change pattern.The skin temperature of the human body is "high at the front and low at the back",with a stepped distribution.The micro space temperature increases with the increase of ambient temperature and labor intensity,and is negatively correlated with the air volume;the micro space wind speed is positively correlated with the inlet air volume;under the same working condition,the average micro space temperature of three types of pipeline structure mining ventilation suits is the largest for the horizontal type,the second for the mixed type,and the smallest for the vertical type.(4)Simulation and experimental results were compared and analyzed,and the difference between the two micro space wind speeds was large,which was due to the fact that the simulation results were the result of the ideal state,without considering the human motion state,while the experiment was affected by multiple factors;the difference between skin temperature and micro space temperature was within 1.2 ℃,which was in the acceptable range of error.Overall,the two have good agreement.(5)The correlation between human thermophysiological parameters,labor intensity,ambient temperature and ventilation was analyzed by using spss software,and the results showed that: human average skin temperature,heart rate and human sweating were significantly positively correlated with ambient temperature and labor intensity and negatively correlated with ventilation;systolic blood pressure was positively correlated with labor intensity and negatively correlated with ambient temperature and ventilation;diastolic blood pressure was not significantly correlated with labor intensity and negatively correlated with ambient temperature and ventilation.The correlation between diastolic blood pressure and labor intensity was not significant,and was negatively correlated with ambient temperature and ventilation.Under the same working conditions,the three types of pipeline structure mining ventilation clothing have different effects on improving the thermal physiological response of human body,and the results are that the horizontal type is the best,the mixed type is the second,and the vertical type is the worst.