Study On Local Thermal Comfort Of Human Body In Non-uniform Thermal Radiation Environment

The traditional air condition system uses the indoor temperature and humidity under the thermal comfort conditions of the human body in a uniform thermal environment as a design index,and usually uses the convective heat transfer of the air to achieve the purpose of adjusting the indoor warm environment.Due to the difference in temperature of the inner surface of the indoor enclosure structure,the human body is in a non-uniform heat radiation environment for a long time even in an environment where the air temperature is uniform.In the indoor non-uniform thermal environment,the overall thermal comfort of the human body is not only affected by the overall warm environment,but also by the local thermal comfort.In order to study the effect of the local thermal sensation of the human body on the overall thermal comfort in a non-uniform thermal radiation environment,the human body thermal regulation model of the Chinese adult male(18-25 years old)was constructed,and the shape and size of the human body and the human thermal property parameters were constructed.The validity of the model parameters is verified by experiments and literature.The results showed that the difference between the model and the skin temperature of the subjects in the experiment was 0.5?,and the maximum error of the thermal sensation calculation predicted by the whole body and various parts of the body and the experimental thermal sensation vote was less than 0.1;the difference between the skin temperature of the model and the literature The value is within 1.0?,and the whole body heat sensation is within 0.2.The human thermal regulation model can reproduce the skin temperature and skin load of the human body in a non-uniform warm environment.Secondly,the relationship between indoor thermal environment factors and skin temperature was studied using the human thermal regulation model.The results show that the effects of radiant temperature and air temperature are the highest,followed by wind speed and minimum relative humidity.The relationship between relative humidity,radiant temperature and various local skin temperatures of the human body,as well as the range of skin temperature of each part under thermal comfort conditions,is obtained.Then through design calculation,the influence of local thermal sensation on human thermal comfort in non-uniform thermal environment is studied.The way to improve the thermal comfort of human body is as follows:radiant heating of human foot and calf in winter working condition;summer working condition The human head,hands and small arms are radiantly cooled.An isothermal comfort line in a non-uniform thermal environment is obtained.When the indoor design temperature in winter is 16.0?,local heating of the feet and calves is performed and the radiation temperature is 22.0,28.2,34.0?,the overall thermal feeling of the human body can reach-1.0,-0.5,0.In summer,the indoor design temperature is 28.0?.When the head and hands are radiantly cooled and the radiant temperature is 24.5 and 23.0?,the overall thermal sensation of the human body can be increased from+1.0 to+0.5 and 0 respectively.