Human Heat Exchange Mechanism And Experimental Study In High Temperature And High Humidity Environment Of Mine

For operators engaged in high-intensity physical labor in the high temperature and high humidity mine environment,the excess heat generated in the body needs to be released into the environment in time.Because the ambient temperature of the mine is close to that of the human body,the contribution of sensible heat dissipation from radiation and convection becomes very small,and the latent heat dissipation of sweat evaporation becomes the main way of human heat dissipation.However,the high humidity environment in the mine increases the difficulty of sweat evaporation,especially when the temperature of the human body is lower than the ambient temperature,the heat in the environment is transferred to the human body in the way of convection and radiation,which intensifies the accumulation of heat in the body,and the excess heat in the body is more difficult to emit,affecting the health of practitioners in mines.In order to solve the problem of heat accumulation in the thermal environment of high temperature and high humidity mine,it is necessary to carry out new research on the theory and method of heat exchange between human body and environment according to the underground environmental conditions of mine and the particularity of miners engaged in heavy manual labor.This paper adopts literature research,theoretical analysis and experimental research,this paper analyzes the heat transfer path and mode of the human body engaged in heavy physical labor in the underground environment of high temperature and high humidity mine from the body to the body surface,and then from the body surface to the external environment through the working clothing,and analyzes the influence of environmental factors and working clothing factors on the heat dissipation mode and heat dissipation intensity of the miners.The existing thermal comfort equation suitable for building environment and the evaluation model for predicting human thermal comfort are studied and expanded.The main research achievements are as follows:(1)Based on the physiological structure of human body and the latest imaging results of human body structure,it is found that in addition to the blood circulation heat transfer system,there is also circulation heat transfer system of water liquid and water vapor in the body,and heat transfer system of water liquid and water vapor circulation is the main way of total heat transfer.For miners who are engaged in heavy physical labor and sweat a lot in the underground environment of high temperature and humidity mines,the heat transferred by the water liquid and water vapor circulation system is more dominant.(2)Based on the vibration characteristics of human respiration movement and limb movement,a vibration-driven heat convection model of heat transfer in vivo was established,which broke through the limitations of the original "human heat exchange based on blood circulation heat transfer".(3)Through the measurement and analysis of human physiological parameters,it is verified that the human heat transfer system of water liquid and water vapor circulation is the main way of heat dissipation for human body engaged in heavy physical labor in high temperature and high humidity environment,and the heat dissipation contribution of blood circulation system is very small.(4)Based on the characteristics of miners’ work clothes,the thermal characteristic parameters such as the thermal resistance of mine work clothes were studied.The relationship between relative humidity and the total thermal resistance of mine work clothes,and the relationship between wind speed and the total thermal resistance of mine work clothes were obtained through the experimental data.The relationship between surface thermal resistance and wind speed was obtained by combining the literature data.A heat and humidity transfer mechanism of two dimension is proposed which can enhance the heat dissipation intensity from the surface to the environment.(5)In view of the fact that the evaporative heat dissipation of human body,which is engaged in heavy physical labor and sweat a lot,plays a dominant role in the heat dissipation of human body in the underground mine under high temperature and humidity environment,the existing thermal comfort equation of human body and the evaluation model of predicted thermal comfort of human body were analyzed and improved,and a new model suitable for the evaluation of human thermal comfort in the underground mine environment was established.The human body heat exchange mechanism in the mine high temperature and high humidity environment obtained in the paper and the research results obtained in the experiment,enrich and improve the heat exchange theory of "human body-clothing-environment",reduce the risk of heat injury and wet injury of underground workers,and provide a reference for scientific guidance of mining enterprises to improve the operating environment and improve the heat exchange performance of working clothing,which has important scientific value and practical significance.