Investigation of The Effects of Jet Fan Sequence to Smoke and Heat Control for Tunnel Fires

Abstract

In this study, fire models for two different locations from the tunnel entrance are created. To discharge the smoke due to the fire outside the tunnel, three axial jet fans are considered to be positioned at different points along the tunnel. For the created fire models, different fire scenarios for open and closed positions of these jet fans inside the tunnel are created. Thus, the effects of the fire location and fan sequence on temperature, smoke, CO and O2 values are investigated. It is observed that the open or closed status of the fans had a significant effect on temperature and smoke distribution inside the tunnel. When none of the fans was open, it is found that the temperature and smoke levels inside the tunnel increased at a high level. It is observed that when only the 3rd fan was open, the improve-ment effect on fire-induced smoke, temperature, CO and O2 values were at a very low level. However, when only the 1st fan or only the 2nd fan was open, it is found that smoke and temperature control inside the tunnel was more effective. When all the fans were open, it is observed that smoke, temperature and CO value were at the minimum level and the O2 value was at the maximum level compared to all other states. Therefore, it is determined that the optimum smoke and heat control was achieved in all fans are open status for the investigated parameter range.