Research For Airflow Feature And Noise Of Under-Seat Air Supplies Of Theatre Air Conditioning System

In recent years, the displacement ventilation is applied in the places like auditorium region of theater, conference hall and gymnasium, where the seats are fixed and elevation between ground and roof is high. In order to provide effective air conditioning effect and reasonable air distribution to the air conditioning object (audience), one kind of special displacement ventilation—under-seat air supplies of air conditioning system appears. Its outlet is combined with seat and under seat. It delivers the processed air to the region where audience sits. In order to simplify blast pipe and distribute the air equably, the static pressure trunk is mounted under ground to supply air. This kind of special air conditioning system is of good indoor thermal delamination characteristic, energy saving and improvement of air quality.The under-seat air supplies of air conditioning system delivers processed air to activity area directly, absorbs the heat come out from human bodies. In theater where personnel density is big, auditorium has the shape of ladder, the air-conditioning faces the problems that how to design the parameter of air-supplying within reason, how to guarantee thermal comfort, whether the noise meet to standard. Domestic research of this system is at the start stage. This paper designed and built the experimental model and used the method of Computed Fluid Dynamics, did some test research and applied analysis to this system.Because the under-seat air supplies of air conditioning system applies the principle of displacement ventilation, this paper introduces some basic concept and principle, heat transfer theory, flow field characteristic, thermal comfort of displacement ventilation. The experimental model is established. The temperature field, the velocity field, the noise field of the system are tested and analyzed. The same model is simulated with CFD. Its results are contrasted with the experimental results. Because the CFD model is accurate, it is used to simulate the under-seat air supplies of theater air conditioning system. The reflection of flow field characteristic is more detailed and direct-viewing. Some factors which have influence to the system are analyzed.The experimental and CFD simulated results indicate, in a room with an under-seat air supplies of air conditioning system , when the load is not too big and the parameter of air-supplying is reasonable, its vertical gradient of temperature and air velocity can well fulfill the human body′s comfortable request to temperature and air velocity. The noise which this system produces conforms to indoor allowable noise standard. Under suitable simplification and boundary condition, RNG k-εmodel may be used to forecast air distribution of ventilation system. The results provide gist to design, appraisal and optimization of this system through experimenting on and simulating the air-conditioned environment and the sound environment. It is helpful to research and popularize this system.