Theoretical Analysis And Experimental Study Of Human Sleep Thermal Comfort

With the development of our country's economy and the continuous improvement of people's living standards,people's requirements for the air quality and thermal comfort of the sleeping environment are also increasing,and more attention is paid to environmental and non-environmental indicators that affect human thermal sensation and thermal comfort.Based on the theory of comfortableness under the awake state,this dissertation studies the thermal comfort of human body in sleep state and proposes a device that can meet the thermal comfort of human body in sleep state.Through the experimental study of the device,it is attempted to obtain the relevant parameter range satisfying the human sleep comfort under various working conditions.The human sleep comfort is different from the comfortable condition in the awake state.This difference is manifested in physiological,psychological and various physical conditions.When the human body is in thermal neutrality,the sleeping environment temperature,humidity,wind speed,etc.can only be changed within a small range..The research focuses on the heat transfer and mass transfer angles of human body.Based on the heat balance equation,the paper derives the heat balance equation and PMV equation for sleep state.Based on the two equations,the passive sleep thermal comfort technology is analyzed.The results show that passive sleep thermal comfort technology can certainly guarantee sleep comfort to a certain extent,but it is easily affected by the external environment,can not guarantee the indoor environment temperature is higher or lower,and is supplemented by active sleep thermal comfort.By supplementing the method of active sleep thermal comfort technology,that is,the proper use of thermal conduction and heat dissipation,the comfort of sleep can be guaranteed.The results of the study showed that:(1)Using the modified human sleep PMV equation,it was calculated that the neutral temperature of the human body satisfying the thermal comfort when sleeping in the shorts was 28.2°C.(2)The use of 0.2,0.4,0.75 m~2·K/W three types of bedding,can guarantee 7764h sleep comfort throughout the year,the guaranteed rate of 87.3%,in addition,different bedding coverage order will also have an impact on its total thermal resistance.When the thickness of the inner layer quilt is less than the thickness of the outer layer of the quilt,it is more conducive to heat preservation when the cover with a small thermal conductivity is covered in the inner layer.(3)Using a subjective questionnaire to survey and measure the surface temperature of the human body's skin,we can ensure that the body's sleep quality can be guaranteed when the heat conduction sleep bed is introduced into the water at 27°C to 30°C.At this point the human body surface temperature should be in the range of 34.7°C~35°C,the back temperature should be in the range of 34.2°C~34.4°C,the side temperature should be in the range of 34.1°C~34.3°C,to meet the skin temperature requirements of the human body under sleep conditions.