The CFD Simulation And Analysis Of Air Ditribution In Commercial Atrium

Modern buildings,the shopping mall is the most familiar place in the local people's life.With the improvement of living standards,the requirements on the mall environment & facilities are getting higher and higher.Atrium,as the most common type of architecture form in shopping mall,not only to satisfy people convenient shopping,having a rest,but also need to satisfy the requirement of people for indoor thermal comfort.The bottom of the atrium is the major area of activity and working,also is the key area for HVAC.The development of air conditioning technology,more and more tall buildings using the Non-full-room air conditioning form,such as stratified air conditioning,underfloor air etc.,are to meet the people's comfort requirements,and also expect to save energy by using reasonable airflow organization.Computational Fluid Dynamics(CFD)becomes effective and economical research method because of its unique advantage on airflow organization of air conditioning system.It apply numerical simulation in the air conditioning room to predict thermal comfort,as to provide technical support to optimize the design of air distribution.This thesis focuses on thermal environment characteristics of the atrium,combined with a commercial atrium in Zhengzhou City,air conditioning load in the atrium is calculated and then calculat the airflow,setting the atrium stratified air conditioning and displacement ventilation air conditioning in summer and winter of two kinds of forms,according to different conditions:air volume,air velocity and temperature,the outlet size,air outlet position and heights,the establishment of different physical model,using CFD simulation,and analysis and comparison of air distribution in summer and winter to determine the most suitable common airflow form in atrium of air conditioning systems.The conclusions of this thesis show that:(1)In summer condition,whether it is stratified air conditioning or displacement ventilation air conditioning,the air conditioning system in the atrium can meet the design requirements.For stratified airconditioning,the stratification height is 4m,and the temperature field obtained by the personnel activity area is also low,and adjusting the upward 10 ° air supply can alleviate the problem that the larger wind speed of the personnel activity area caused by the high wind speed 8m/s.The height of the layer is 8.5m,and the temperature of the personnel activity area is also increased,but the velocity field is attenuated by a long distance and time,and there is no sense of blowing.At this point,10°upward air supply,PMV value of personnel activities will be increased,so horizontal air supply is appropriate.(2)The analysis of winter conditions shows that the main source of indoor cooling capacity is the heat transfer in the glass curtain wall of the roof,and the temperature difference of 8~9 ? between the ground makes the natural convection caused by the chimney effect obvious.The air conditioning form of the upper air supply,which is heated near the roof,can effectively block the exchange of hot and cold air,but the system cannot be shared with the summer.Comparative analysis of4 m and 8.5m layered hot air,the two seasons of winter and summer use a set of air conditioning system,while in summer,the comfortability in personnel activity area by8.5m is not high than 4m,but also in the acceptable range,while the winter condition,from the view of 1.8m high plane temperature field,velocity field and uniformity of thermal comfort,the performance of 8.5m is much better than the 4m,so establish the stratification height 8.5m.(3)In summer,displacement ventilation form can get lower temperature field and velocity field than stratified air conditioning,so the energy saving potential is larger than the stratified air conditioning,but not for winter heating,and the air distribution sometimes can not match with the actual commercial atrium form,so the stratified air conditioning is used in commercial atrium.