Numerical simulation simultaneous use of longitudinal ventilation and smoke extraction from the ceiling in fires inside tunnels

Document Type : Research Article

Authors

1 Department of Mechanical Engineering, khayyam university, mashhad, Iran

2 Mechanical engineering, Khayyam university

Abstract

Ventilation is essential to provide a smoke-free path for safe passenger evacuation and effective rescue services in case of a tunnel fire, because the closure tunnels increase consequences of accidents significantly. In the present study, the simultaneous use of longitudinal ventilation and smoke extraction from the ceiling in fires inside tunnels and physical phenomena has been investigated. Fire dynamics simulator will be used as a CFD tool. This simulation was performed to investigate the effect of the longitudinal distance of the smoke extraction system from the fire source on the smoke back-layering length and the maximum temperature in the two operating conditions used by this system downstream and upstream the fire source. In the present work, the smoke extraction system is located on the ceiling of the tunnel. The results show that using a smoke extraction system upstream of the fire source will increase the maximum temperature, but using the same system downstream will reduce the temperature throughout the tunnel and prevent smoke back-layering. However, attention to the smoke extraction velocity prevents the plug-holding phenomenon. The results also show that the simultaneous use of two smoke extraction systems at the upstream or downstream of the fire source will have a better result and The maximum temperature is reduced by 10%.

Keywords

Main Subjects

References

[1] P.H. Thomas, The movement of smoke in horizontal passages against an air flow, Fire Safety Science, 723 (1968) -1--1.
 [2] B. Niknam, H. madani, H. Salarirad, Determining Critical Wind Velocity During Fire Accident in Alborz Tunnel, Amirkabir Journal of Mechanical Engineering, 44(1) (2012) 47-55(In Persian).
[3] Y.J. Ko, G.V. Hadjisophocleous, Study of smoke backlayering during suppression in tunnels, Fire safety journal, 58 (2013) 240-247.
[4] M. Mounesan, M.R. Talaee, H. molatefi, Investigation of effective parameters on critical ventilation velocity in underground tunnels, Amirkabir Journal of Mechanical Engineering, 48(1) (2016) 41-54 (In Persian).
[5] Z. Tang, Y. Liu, J. Yuan, Z. Fang, Study of the critical velocity in tunnels with longitudinal ventilation and spray systems, Fire Safety Journal, 90 (2017) 139-147.
[6] G. Heidarinejad, R. Vasheghani Farahani, Numerical Simulation of Fire in Tunnel with Ventilation and Suppression Systems, Modares Mechanical Engineering, 18(8) (2018) 209-220(In Persian).
[7] S.O. Haghani, E. Barati, Numerical study on the effect of blower location on the maximum temperature and spread of smoke in case of fire inside tunnels, Amirkabir Journal of Mechanical Engineering, 52(11) (2019) 171-180 (In Persian).
[8] Y. Zhang, S. Xing, R. Chen, L. Chen, T. Li, P. Mao, Experimental study on maximum temperature beneath tunnel ceiling under the condition of double fire sources, Tunnelling and Underground Space Technology, 106 (2020) 103624.
[9] J. Kong, Z. Xu, W. You, B. Wang, Y. Liang, T. Chen, Study of smoke back-layering length with different longitudinal fire locations in inclined tunnels under natural ventilation, Tunnelling and Underground Space Technology, 107 (2021) 103663.
[10] N. Meng, X. Hu, M. Tian, Effect of blockage on critical ventilation velocity in longitudinally ventilated tunnel fires, Tunnelling and Underground Space Technology, 106 (2020) 103580.
[11] N. Chalasani, M. Greiner, A. Suo-Anttila, Benchmarking of Container Analysis Fire Environment simulation using the memorial tunnel fire ventilation tests, Journal of Fire Protection Engineering, 22(1) (2012) 45-70.
[12] F.W. Mowrer, P.A. Friday, Comparison of FDS Model Predictions With FM/SNL Fire Test Data, (2001).
[13] J. Floyd, G. Forney, S. Hostikka, T. Korhonen, R. McDermott, and K. B. McGrattan, Fire Dynamics Simulator Technical Reference Guide vol. Volume 1: Mathematical Model, NIST special publication, 1018, (2012).
[14] Y.Z. Li, B. Lei, H. Ingason, Study of critical velocity and backlayering length in longitudinally ventilated tunnel fires, Fire safety journal, 45(6-8) (2010) 361-370.
[15] K.B. McGrattan, H.R. Baum, R.G. Rehm, Large eddy simulations of smoke movement, Fire Safety Journal, 30(2) (1998) 161-178.
[16] Y. Wu, M.A. Bakar, Control of smoke flow in tunnel fires using longitudinal ventilation systems–a study of the critical velocity, Fire Safety Journal, 35(4) (2000) 363-390.
Amirkabir Journal of Mechanical Engineering
Volume 53, Issue 7
October 2021
Pages 4411-4428

Files

Share

How to cite

Statistics