Effects Of Supply Air Parameters On Airflow Patterns Of Impinging Jet Ventilation Systems

With the continuous improvement of living standards of the city, most of citizen’s daily time is still spent indoors. Therefore, with the requirement of air quality from citizen growing, we need to research the air distribution form in air-conditioned room when we choose air conditioning ventilation mode, so that it can make the demand of thermal comfort from interior staff.Based on the previous research, in the present study the commercial FLUENT software was used to simulate the distribution of flow field and temperature field by numerical simulation, when impinging jet ventilation system is applied to heat or cooling in large space in different air supply conditions; in addition, we aimed at the impinging ventilation system of heating room with changes in the different outlet sizes, location of air supply outlet, performing in numerical simulations. The influence of these factors on the indoor air diffusion, temperature field and thermal comfort were studied. It was analyzed and compared that temperature and wind speed in the plane of people’s ankle and typical plane, and temperature and wind speed through the height and depth of the room.The results show that, in the heating room by impinging jet ventilation system, the bigger the air velocity is, the longer the diffusion distance is, the more well-mixed the air flow is inside room of hot air. In the same air supply parameters, when impinging jet ventilation system is applied to cooling, the diffusion distance is longer than it used to heat. In the same air velocity, with the increase of air temperature, the more obvious the thermal buoyancy is, the shorter the diffusion distance is; when using a different outlet size,the larger the size outlet, the higher the temperature and the air velocity of the center of room flat position(where the air supply pipe cross section), the longer the diffusion distance, when the location of air supply outlet is in the middle of the room, the diffusion distance and the average temperature were smallest, when air supply outlet is in the middle of the wall, the average temperature of typical plane have gradually increased, when air supply outlet is in the corner, the diffusion distance of the airflow is the longest and the average temperature is the highest,but the influence of location of air supply outlet can be ignored for the active area(below two meters area), with the different air supply outlet, there were small differences in the temperature distribution and vertical stratification of typical plane.