| With the advancement of building technology,modernist buildings are increasingly adopting exterior facade decoration structures such as glass curtain walls and transparent roofs.Although they have the advantages of beautiful appearance and enhanced natural lighting,they will cause more solar radiation to enter the interior.The impact of solar radiation on the human thermal comfort significantly.Reasonable use of solar radiation can reduce building energy consumption.In ASHRAE Standard-55-2017,the calculation method of indoor solar radiation related variables is given,but there are still many problems that need to be explored in depth,such as applicability of solar radiation at different mean radiation temperature calculation method,the variation of the human thermal sensation at different radiation intensity,variation of the temperature of human skin,the body part and the overall heat exchange characteristics,variation common thermal environment evaluation,and the changing law of comfort zone.Therefore,this article conducts research on the above content:First,in an artificial climate room with precise control of temperature and humidity,a full-spectrum solar radiation simulation device with adjustable intensity is used to conduct thermal comfort experimental research when the sun is directly on the human body.6 experimental conditions are designed,respectively 18℃-0 W/m2(Ambient air temperature-radiation intensity),18℃-200 W/m2,22℃-0 W/m2,22℃-200 W/m2,22℃-300 W/m2,22℃-400 W/m2,total Get 150 valid questionnaires.The results show that when there is solar radiation,different calculation methods of average radiation temperature are different.The black bulb temperature measurement method is 2～3℃higher than the average radiation temperature calculated by other methods.The experimental results show that when direct sunlight hits the human body,solar radiation can significantly affect the skin temperature and its distribution of the human body.The skin temperature of the exposed part is significantly higher than that of the not irradiated symmetrical part;the overall and local thermal sensation of the human body increases with the radiation intensity.When the radiation intensity changes by 200 W/m~2,the overall thermal sensation changes by about 1 division.As the radiation intensity increases,the convection heat exchange,evaporation heat exchange,and total heat exchange increase,and the radiation heat exchange decreases.When the radiation intensity is 400 W/m2,the radiation heat exchange of the part directly exposed to the sun is all negative.In order to gain heat by radiation,with the increase of radiation intensity,the ratio of convection,radiation,and evaporation heat transfer to the total heat transfer changes from 32%,42%,and 17%to 34%,0%,and 60%,respectively.At the same time,this article analyzes the reasons for the difference between the predicted voting value PMV and the actual thermal sensation in the solar radiation environment from the perspective of the skin temperature.Under the experimental conditions,the skin temperature caused by the radiation rises by an average of 0.39℃,which can lead to the overall thermal sensation.An average increase of 0.64.The thermally neutral operating temperature in the presence of solar radiation is 1.86°C lower than the thermally neutral operating temperature in the absence of solar radiation.This article also analyzes the changes in the human body comfort zone under solar radiation,and it can be seen that solar radiation can significantly improve the human body’s thermal sensation.In summary,the thermal impact of solar radiation on the human body cannot be ignored,and solar radiation should be used rationally,which can not only improve the thermal comfort of the human body,but also save building energy consumption. |
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