Influence Of Spherical Arbor On Thermal Radiation Disturbance Of Wall In Summer

At present,there are many researches on the influence of tree shading on the thermal environment and energy consumption of buildings,but there is still a lack of research on the influence of tree on the thermal radiation of adjacent buildings without shading.The research on the influence of trees on thermal radiation on adjacent walls is helpful to the scientific selection and spatial allocation of trees,so that the ecological benefits of tree cooling and energy saving can be fully exerted in summer.In view of this,the effects of tree（osmanthus）spherical crown on the long wave and short wave thermal radiation disturbance of adjacent walls are discussed by the method of ENVI-met simulation and measurement.The main conclusions are as follows:（1）The method of using ENVI-met simulation to get the disturbance intensity of tree to the long and short wave thermal radiation of adjacent wall is proposed.The results of the experiment and simulation show that the canopy of trees will have thermal radiation disturbance to the adjacent wall in summer.The results of the comparison and simulation show that the envi met simulation method proposed in this paper has a good accuracy,and can be used to simulate the thermal radiation disturbance intensity of trees to the wall.The results show that the canopy has two functions under the condition of no shade.Firstly,the net heat absorption of adjacent walls is reduced by shortwave scattering radiation in the sky.On the other hand,the long wave radiation heat transfer between the wall and the arbor crown replaces the long wave radiation heat transfer between the wall and the surface of the adjacent ground.（2）The peak value of net thermal radiation disturbance intensity of trees to adjacent walls under 27 scenarios obtained by ENVI-met software is obtained.The fitting surface diagram between the peak disturbance intensity and D_C and D_W-T under different LAD conditions is obtained by fitting analysis,and the functional relationship between the peak disturbance intensity and D_C and D_W-T is obtained.The results show that the disturbance intensity of the wall near the tree is characterized by composite function attenuation,and the attenuation process includes three stages,namely,fast attenuation area（less than 5m）,attenuation area（5m-10m）and slow zone（more than 10 m）.The vertical disturbance intensity of adjacent wall is linear function with vertical center distance,and it is negative correlation.（3）The results of thermal radiation disturbance of trees in different planting directions are simulated and analyzed by ENVI-met software.It is found that the vegetation on the wall has better disturbance effect.The closer the center of the building,the larger the disturbance range,the better the cooling effect is between the East and the West.Except for the west side,the closer the distance between the other side walls,the larger the disturbance peak and the larger the scope.The farther the distance between the wall crown and the higher the disturbance peak value,the lower the disturbance range due to the influence of long wave thermal radiation.The above research methods and results are helpful to the selection of tree species,the design of green space and the evaluation of the impact of trees on the energy consumption of indoor refrigeration.