| In line with the development of the concept of modern structure design, newly-built structures of large space, unique in style, large in dimention, have become more and more diverse in dealing with air distribution. Against this backdrop, traditional experience on which many design institutes have relied when designing such structures as gymnasiums, fail to meet various requirements.To counter this problem, this thesis will take Wuxi Gymnasium as its research subject, CFD simulation software as a tool, and conduct a simulation study on different forms of air distribution for the air conditioning system applicable to the gymnasium in question. Then a comparative study on the research results will be advanced with a bid to providing some guidance for the practical design of gymnasium-related projects.A qualitative analysis on some common air distribution forms was made and the accuracy of the CFD model designed based on Wuxi Gymnasium was proved through the on-spot test conducted before in this thesis. Then from the perspective of practical application, a simulation study will be innitiated on the temperature field and velocity field of three other air distribution designs and the existing design applicable to this gymnasium. These three designs are: 1. lateral supply lower return (one single nozzle); 2.lateral supply lower return (double jet nozzle); 3.upper supply and lateral supply lower return (two combined). Their features, comfort and energy consumption will be analyzed respectively.The research result has indicated that,1. The existing air distribution design and other three designs all can basically satisfy the design requirements of the air conditioning system of the gymnasium in question.2. Design 1 doesn't divide the audience area from the mark area, rather it adopts lateral supply lower return (one single nozzle), so it's not ideal in temperature control of the mark area with a average temperature of about 27℃. On the other hand, this design is proved effective in air flow control of the mark area, having satisfied the standard <0.2m/s, an average air flow of 0.35m/s in the audience area and average temperature of 26.6℃.3. Design 2 adopts lateral supply lower return, which can reduce the long-distance air supply, thus transfering the design focus to the audience area , which has best suited the characteristic of high density of the audience area. In this design, the air flow in the audience area will increase to 0.4m/s, yet highly effective in temperature control, maintaining it around 26.4℃. And the average wind velocity in the mark area is 0.2m/s, temperature 26.6℃, both meeting the design requirements.4. In Design3 making use of upper jet nozzle, air is directly supplied to the mark area in a vertical way , which is effective in reducing temperature, adjusting the temperature in the central mark area to 26.4℃while not so good in air flow control with a velocity as fast as 0.25m/s.When supplying air to the audience area by lateral supply, the average air flow in the audience area is 0.25m/s, with an average temperature of 27℃.5.The original design of Wuxi gymnasium, by adopting upper jet nozzle supply to supply air directly to the mark area vertically ,the air flow is about 0.2m/s and the temperature is well controlled at 24.5℃,by suppling air to the audience area from under the stadium bleachers, has well controlled the air flow, reaching 0.1m/s, and 24.6℃in temperature.6.An comparative analysis on energy consumption among the above four designs has shown that the original design is most effective in conserving energy with the total consumption of 193.5kw, lower than the other three by 110.4kw,83.5 kw,51.5 kw.
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