Flow Characteristics And Control Method Of Fire Smoke In Rescue Station Of Extra-Long Railway Tunnel

When the extra-long railway tunnel length more than20km, for fire rescue, usually need to set up the rescue station.Rescue station provides safe passage for evacuation, therefore, reasonable design of ventilation system of the flue gas has been effectively controlled, to ensure that the fire safety environment is the key to rescue station rescue station construction. In order to make the rescue station to be able to play on its extra-long railway tunnel fire safety role, it is necessary to study deeply gas flow characteristics and control method of the fire rescue station, and according to the fire safety control standard, rescue station, reasonably determine the mode of ventilation and ventilation system parameters, both to save construction cost and operation cost, to improve the rescue has important station fire safety.This paper combined with the structure similar facilities and rescue station evacuation model and rescue station features that can ensure that the personnel in the passageway entrance not cross channel blocking the relationship between quantity and size of type. With reference to the relevant specification rescue station research model and fire model. Then the application of FDS fire simulation analysis of longitudinal ventilation under different wind speed rescue station on properties of smoke flow and temperature distribution in software, the flue gas distribution and variation in different conditions under longitudinal ventilation tunnel. The results show that:when the longitudinal wind speed reached the critical wind velocity of conventional tunnel fire3m/s, downstream environment is no more bad ventilation, smoke control and does not meet the standard rescue station, and when the longitudinal velocity reaches4m/s, above the fire source gas layer is damaged, the fire environment on both sides to achieve the control standard. But because the smoke layer is damaged, this passage has gas invasion, ventilation speed can be set to1m/s in the cross channel to inhibit gas invasion of cross passage. Further calculation through the flue gas of different heat release rate under fire rescue station when the flow, the longitudinal ventilation velocity rescue station and suitable than conventional tunnel critical wind speed increases by about27%. Finally, according to the pattern and fire control parameters of evacuation and rescue station flue gas flow characteristics, personnel, the characteristics of lateral ventilation exhaust ventilation should be the nearest fire is more suitable for the rescue station, combined with the rescue station fire control index and conventional tunnel semi-transverse ventilation design gives a kind of design method of fire rescue station cross ventilation, gives the corresponding parameters suggestions. The calculation results show that, using transverse ventilation to control standards at the same time, the flue gas is controlled upper space station the length of1/4region in the rescue, was lower than the longitudinal ventilation advantages.Through this study, can not only improve our extra-long railway tunnel ventilation and fire research theory, but also provides theoretical basis and technical references for the rescue station fire ventilation design.