Application Of Tunnel Ventilation System In Metro Station

Subway station is an underground building which have the characteristics of large space、 complex equipment and large personnel flow density. At the same time, the basic set of ventilation and air conditioning systems, which directly lead to the station ventilation and air conditioning system equipment load become huge, its energy consumption accounts for the total energy consumption of the entire subway operation 30%～40%. In view of the above problems, this paper takes a subway station in Chongqing as the research object, using local conditions to study the applicability of the wind system in the subway station.First of all, the paper take the station summer fresh air cooling as the research background, combined with the subway burial characteristics, analysis the Chongqing soil temperature distribution characteristics and the initial soil temperature calculation method, gives the station tunnel soil physical parameters selection basis. On the basis of the analysis, the heat transfer characteristics of the station tunnel are analyzed, and the calculation model of heat transfer in subway station is established and simplified.Then, the FLUENT software is used to simulate the effect of different tunnel length, air supply speed, temperature and section area. Analysis the change rule of the length, wind speed, area and send wind temperature on the subway station tunnel outlet temperature and cooling efficiency, which provides reference for the actual engineering design.Finally, according to the actual engineering situation, the influence of different layout forms on the tunnel heat transfer is simulated. Based on the tunnel heat transfer model with different cross sectional area, the paper propose the optimal placement scheme, giving the optimal arrangement mode and the recommended value of the cross section area. The paper compare of the two tunnel layout under the optimized arrangement, the conclusion is drawn that the max range of the optimized tunnel cooling efficiency is 9%, which provides reference for the engineering optimization and the energy saving of the station.