Experimental validation of tunnel ventilation system under emergency operation.

To validate the emergency operation modes of a 7 km long underground railway tunnel ventilation system, a full-scale experimental investigation has been performed. The results of the test showed that the tunnel ventilation system can successfully provide the critical air velocity necessary for a fire sized 13.6 MW. Alternatively, the large reservoir for smoke under the tunnel ceiling may give more time for escape and ought to be considered when planning for the emergency procedure. The system is now operating commercially. The paper discusses the analytical and experimental results in detail.