细水雾灭火系统扑救铁路隧道救援站内客车火灾的全尺寸试验研究

研究了细水雾灭火系统对铁路隧道救援站火灾的扑救性能。试验在铁路隧道救援站全尺寸模拟隧道平台上开展,研究了隧道内不同纵向通风条件下,细水雾灭火系统作用前后隧道内的温度场、燃烧成分、火源热辐射参量的分布及变化。结果表明,细水雾灭火系统可有效抑制模拟隧道内火灾,验证了细水雾灭火系统在铁路隧道救援站内的可行性和有效性。

Full-scale experimental rescue study on the water-mist railway tunnel-fire fighting system

The present experimental study serial is intended to offer a kind of authentic water-mist railway tunnel fire-extinguishing system and the fire-suppressing experience so as to gain the on-spot railway tunnel protection effects.The entire experimental process has been realized by way of integrating into one organic link the save performance of the water mist system,the tunnel fire-fighting actions while the train stopping at the rescue station and all the other saving deeds carried out in the tunnel.Thus,it can be said that such a large full-scale experimental rescue study is unprecedented at home,which was conducted at first in a laboratory-scale experimental condition with different longitudinal ventilation installations.For the limited purpose,we have made all the necessary preparations and laid out the changing situations with the fire features,such as temperatures,combustion products and thermal radiation fluxes in the tunnel,and carefully made water mist system with all the measures needed.The results of the serial experiments show that the water mist system is in a full position to put out the top train fire effectively.The smoke temperature distribution and the concentration of the combustion products in case of a tunnel fire are likely to be strongly influenced by the longitudinal airflow.In addition,the distance from the fire source of the maximum smoke temperature beneath the ceiling tends to increase with the great longitudinal ventilation velocity,whereas the maximum smoke temperature under the ceiling of the tunnel would decrease with the increase of distance from the fire source.Since the dilution of CO concentration in the smoke layer along the tunnel is dominated by the fresh air mass entrainment into the smoke flow,the ventilation velocity can also be accelerated with the smoke spread to the downstream from the fire source,and,in turn,and,therefore,is likely to promote the combustion.Besides,the CO concentration is increased under the lower ventilation velocity in the smoke layer,though it would be decreased when the ventilation velocity is high enough.Furthermore,once the water mist system is turned on,it would help to bring down the temperature in the tunnel.After that,CO concentration could be changed due to the work of the water mist system,and the change of fuel type and longitudinal airflow,the thermal radiation fluxes would continually fall to the zero.And,thus,the experimental data of ours can provide the effective measures so that the water mist system can suppress and save the simulation tunnel fire,help rescue the personnel to evacuate,and protect tunnel structure from being damaged.The results of our experiments also verify the feasibility and efficiency of the water mist system for the railway tunnel rescue uses.