Factors Of Air Distribution Around Building Atrium Of The Air-conditioner In Winter

In recent years, the construction industry is developing rapidly in China with kinds of buildings appear. However, the thing accompanied with the fast construction development was the large amount of energy consumption. It was reported that the building energy consumption accounted for about 27.6% of the total social energy consumption in China, in which the energy consumption by air conditioning heating was 60%. The air distribution and thermal comfort in huge building atrium are hot research topics in the field of Heating, Ventilation and Air-conditioning(HVAC) all the time. As the global energy crisis, creating an acceptable indoor thermal environment as well as restricting the energy consumption are drawing researchers’attention.The paper studied the atrium distribution with air conditioning opened in winter by computational fluid dynamics(CFD). Software GAMBIT was used to build geometric model and mesh, and software FLUENT was used to compute. The k-ε equation with standard SIMPLE algorithm was used to simulate the turbulence flow in the atrium. The boundary conditions was set as the second class of wall boundary condition. The temperature and velocity field in atrium with different supply air flow direction, supply air temperature temperature difference and vent height were simulated. The rating system of atrium air distribution was modified.The simulation results showed that:the atrium was with a good indoor thermal environment in winter when the supply air direction was 20 °-30 °. Within the range, increasing the angle,can improve the space diffusion effectiveness factor. Air velocity should be controlled between 3.5m/s-5.5m/s, the thermal comfort was good in working area, and the space diffusion effectiveness factor was greater. When supply air temperature difference increased from 4 ℃ and 8℃, the thermal comfort would change a little, but space diffusion effectiveness factor would decrease. When the supply air temperature difference increased to 10 ℃, the thermal comfort was poor, and the space diffusion effectiveness factor would decrease. When the vent height was 4m, thermal comfort was good in working area, but when the vent height increased to 6m and 8m, the thermal comfort would become poor, and the space diffusion effectiveness factor would decrease.Based on the weighting coefficient, air distribution under different conditions were assessed comprehensively. Considering the thermal comfort and energy savings, the optimal parameter values of supply air (air direction 30℃,air velocity 5.5m/s, air temperature 8℃, and vent height 4m) were determined for the building atrium.