The Characteristics And Prediction Model Of Buoyancy-driven Ventilation In High-rise Residential Building With Atrium

High-rise residential building with atrium is a special type of modern residential buildings.On the one hand,it enhances the effect of natural ventilation by taken full advantage of stack effect, which causes better thermal comfort and less cooling energy consumption. On the other hand, flow field and temperature field are hard to be predicted accurately because the thermal environment in this building is affect by outdoor or indoor factors.At first, the development, application and research status of high-rise residential building with atrium are summerized.A "general prototype" which can represent this kind of building is conducted. Model experiment and CFD methods are used to investigate the common regularity in atrium and inhabitant's rooms.The reduce-scale model of 1/25 is established by the similarity criterion mainly with Archimedes number and the Reynolds Stress Model (RSM) is used to enhance the precision in CFD.Also the prediction model is established in this paper, which validated by the above two methods.It can calculate the thermal environment caused by various conditions and analyses the major factors.The results are as follows:(1)Results among prediction model,experiment and CFD agree with each other well,which shows the prediction model based on multizone and zonal methods is considered appropriate to calculate the fields of temperature and airflow in high-rise residential building with atrium accurately and rapidly, especially the field distribution in atrium.(2)Appearance of indoor thermal natural ventilation phenomena is affected by indoor heat intensity of all the upper apartments and itself, which is contrary to the one in atrium, the latter is affected by indoor heat intensity and ventilation rate of all the lower apartments.(3)The buoyancy-driven flow always crosses apartments from outdoor environment and mix with the air warmed by heat source,then flows into atrium with disturbance.Vertical ventilation rate,heat and temperature appear obvious accumulation in atrium,so that they are positive correlation with the height.Moreover, ventilation rate differences between apartments in upstairs and downstairs are negative correlation with the heat summation of all the upper apartments and itself. (4)Indoor heat intensity and cross section area of atrium are the most important factors to influence characters of thermal natural ventilation and thermal environment in high-rise residential building with atrium.Moreover, areas of windows in apartment only have an obvious act on the lower district of atrium, bottom and top apartments.