Study On The Influence Of Outdoor Radiation Characteristics On Human Thermal Comfort In Cold Regions

As the urban population increases,it is particularly important to create healthy and comfortable outdoor open spaces for urban residents.Due to the population explosion phenomenon and the current global climate deterioration,outdoor thermal comfort has caused widespread concern worldwide.Researchers at home and abroad have found that outdoor air temperature,solar radiation,wind speed,humidity and other microclimate parameters are the key factors that affect outdoor thermal comfort.The spatial radiation heterogeneity of solar radiation and wind speed,the dynamic effect of solar radiation on thermal comfort throughout the year,and the coupling law with other environmental parameters on thermal comfort are still unclear.In addition,the importance of solar radiation in the thermal comfort evaluation index and the uncertainty of the thermal comfort index results caused by the uncertainty of solar radiation have not been fully demonstrated.Therefore,in view of the above problems combined with China’s climate characteristics,a systematic study on how solar radiation affects outdoor thermal comfort and evaluation indicators in cold regions.This article first conducts a one-and-a-half-year field survey and questionnaire survey on the public space on the Tianjin campus.Obtain microclimate parameters: air temperature,relative humidity,wind speed,black ball temperature,and long and short wave radiation fluxes in six directions of east,west,north,south,up and down,and obtain the subject’s subjective thermal response to the thermal environment: thermal sensory voting Data information such as thermal comfort voting,microclimate parameter preference voting and thermal acceptability voting.A total of 52 experiments were carried out in Tianjin,collecting 3536 valid questionnaires and 206 environmental conditions.The frequency of occurrence of various environmental parameters covers more than 80% of the frequency of environmental parameters in Tianjin,providing systematic and comprehensive data support for subsequent research.Then the solar radiation and subjective thermal sensation were analyzed in detail.Considering the coupling relationship between environmental parameters,using the guiding ideology of control variables,the air temperature with strong interaction of solar radiation is divided into a temperature interval with a gradient of every 5 ℃,and the wind speed is divided into no wind,medium wind speed and high wind speed Three levels.Determine the performance of solar radiation at different temperatures in the absence of wind,and establish a quantitative relationship between solar radiation and thermal sensory voting.Then,the influence factors of wind speed are added to determine the effect of solar radiation in different temperature ranges and different wind speed sections,and compare the reduction effect of wind speed on solar radiation.Finally,calculate the physiological equivalent temperature PET,analyze the weight of the effect of solar radiation on PET results,analyze the uncertainty of PET caused by the uncertainty of solar radiation,and combine the thermal sensation voting results of thermal comfort experiments to establish solar radiation Quantitative relationship between the three of PET.