The Influence Of Supplying Air Parameters For Air Flow Structure Under The Top Air Supply System

Nowadays,people spend more and more time in the office,the requirement of indoor environment is become higher and higher,so the application of air conditioning system is become more and more extensive.How to improve the indoor air quality and conserving energy and the personal how to control of the thermal environment of large room has become an important direction of the development of the current office building air conditioning.One way to solve this problem is to use the top air supply system.Therefore,this paper will use numerical simulation method to study and analyze the air quality in the top air supply room.This paper simulate single office with top air supply system,just change supply air speed 、 height、Angle,so comparison and analysis of these factors for the effects of room’s temperature and CO₂ concentration.The temperature simulation results show that the increase of wind speed can reduce the room temperature and temperature stratification（The temperature gradually increased along the height of the room）of the upper part of the room at any height and Angle.In addition,for the same height and wind speed,the influence of different angles on the room temperature was compared,can find the best air supply angle was 90°,followed by 45°,and then 135°.At last,giving to the same wind speed and send wind angle,comparison the influence of different height on the room temperature and room temperature stratification.It was found,when send wind angle is45°,rely on the air supply effect from well to bad,the height is 1.9m,1.4m,2.6m and 1.2m respectively.Found that for 90°supplying air,when wind speed is 1 m/s and 1.5 m/s,supply air effect from good to bad,in turn,is the height of 1.4 m,1.9 m,1.2 m,2.6 m,when the wind speed of 2 m/s,supply air effect from good to bad,in turn,is the height of1.9 m,1.4 m,1.2 m,2.6 m.For 135°supplying air,when wind speed of 2 m/s,the effect of supplying air from good to bad,in turn,is the height of 1.2 m,1.4 m,1.9 m,2.6 m,when the wind speed is 1 m/s and 1.5 m/s,the effect of supplying air from good to bad,in turn,is the height of 1.9 m,1.4 m,1.2 m,2.6 m.The results of CO₂ concentration simulation show that the increase of wind speed can reduce the CO₂ concentration near the human body and the stratification of CO₂ in the lower height of the room,regardless of any supplying air height and Angle.In addition,for the same height and wind speed,the influence of different angles on the room temperaturewas compared and found that the best supplying air angle was 90°,followed by 135°,and then 45°.At last,the influence of different height on the CO₂ concentration and room CO₂ concentration stratification when giving to the same wind speed and Angle.It was found that the supplying air effect from good to poor was 2.6m,1.9m,1.4m and 1.2m,respectively,.For 90°and 135°supplying air,increase the height,can be found CO₂ concentration down more and more low,even reaching nearly to 0 in the upper part of room,but CO₂ concentration around the body and at the bottom of room nearly no change.Conclusion: after a series of comparisons,the increase of wind speed is conducive to deduce the indoor temperature and temperature stratification phenomenon,and improving the efficiency of the discharge of CO₂.At any height,wind speed,the 90° supplying air ’effect of to reduce the indoor temperature and eliminate indoor CO₂ concentration is better than 45°and 135° supplying air.All in all,The inlet height of 1.9m can better deduce the temperature of the room with different Angle and wind speed.In the case of45°supplying air,with the increase of height,the efficiency of eliminate CO₂ concentration is increase.For 90° and 135° air supply,increase the height of inlet,can reducing the upper room CO₂ concentration,but can’t reduce CO₂ concentration in the upper room.