Comparison of Smoke Extraction Modes in Underground Channel Fires

The performance of five different smoke extraction modes for an underground channel fire was numerically investigated originally in this paper. Results have shown that mechanical air supplying from adjacent smoke bays will intensify the air entrainment and increase the smoke production, which lead to a reduction of smoke temperature and buoyancy so that it's easier for smoke to descend to the lower level of the building space. The smoke exhausting process is not effective while using the smoke vents remote to the fire region as the fresh air is strongly sucked into the vents instead of smoke. Compared with the commonly used smoke extraction mode with all the smoke bays together, exhausting the fire-induced smoke with relatively high velocity by using the vents inside of or close to the fire is able to achieve a more effective smoke exhausting process. The most effective smoke extraction mode has also been validated by simulating a platform fire scenario in a full-scale subway station.