Study Of Human Thermal Sensation In Different Metabolic Levels Under Hypobaric Environment

With the development of the economy and society, more and more people payattention to the comfort of the indoor environment, and the thermal environment is themain factor influencing people comfort level, thus the study of human thermalcomfort has been developed rapidly in recent years. People’s indoor activity level ofwork and life is no longer only the mild activities but gradually becomes diversified,and the metabolic rate has increased significantly, the activity levels have increasedfrom the mild to the moderate and the severe. The land area of1000meters above sealevel in China accounts for about60%of the national land area, and China is acountry with the largest plateau population in the world, and the aviation sector alsorelates to low pressure environment, which make the human thermal comfort in thehypobaric pressure field become a hot study topic. So this article based on the abovepresent situation carries out studys of the human thermal sensation in the mild,moderate, and severe levels of activity under hypobaric environment.The human thermal sensation, thermal comfort, heat capacity and physiologicalparameters under hypobaric environment will change when compared with normalatmospheric pressure, which can affect the body’s evaluation of the thermalenvironment, and the thermal comfort evaluation model will also change. This articlebased on the analysis of the above variables builds the thermal sensation predictionmodel, which applys to the different atmospheric pressure and different levels ofactivity within0.8atm. with the change of pressureWhen doing experiments, we firstly study the change rules of human thermalsensation, thermal comfort, skin temperature and metabolic rate with pressure changeby detailing range of atmosphere pressure; Secondly, we study the change rules ofhuman thermal sensation in different levels of activity under hypobaric environmentat different environment temperature by increasing the range of ambient temperatureand setting different activity intensities.We analyze the measured values of thermal sensation，compare TSV with thepredictive values of PMV model, and analyse the change rate of the TSV and PMV with the reduce of pressure;we put forward the concept of comprehensive index of theskin from the angle of the skin temperature and skin moist degree, and study thehuman body thermal acceptable range; we obtain the neutral mean skin temperatureunder different atmosphere pressure at different activity levels by analyzing therelationship among skin temperature, sweating, human thermal sensation, andcompared with the results of the skin temperature index; we analyze the variationrules of each heat dissipation，the proportion of each heat to total heat release and therelative ratio of sensible heat heat and latent heat dissipation with the change ofenvironment pressure, temperature and activity levels, and use (1-Q/M) as controlvariable study the relationship between TSV and (1-Q/M).