THERMAL SCIENCE

International Scientific Journal

Thermal Science - Online First

Authors of this Paper

External Links

online first only

Study on the effect of width and slope of large cross-section tunnel on critical velocity of fire

ABSTRACT
when a tunnel fire occurs, due to the difference of tunnel width and slope, both smoke countercurrent length distribution law and critical velocity will become different, and these two are very important parameters in tunnel longitudinal ventilation design. Therefore, for the design of smoke control and longitudinal ventilation of the tunnel, based on actual highway tunnel size, this paper established and ran a series of numerical simulations through FDS simulation software to study tunnel width and slope's effect on smoke countercurrent length and critical velocity. The results of this paper show that smoke countercurrent length decreases with tunnel slope's increase and increases with tunnel width's increase. Through dimensionless analysis, the prediction formulas of smoke countercurrent length and critical wind speed of large cross-section tunnel about tunnel width, slope and height are modified and established. The research conclusions can provide a theoretical basis for the longitudinal ventilation design, smoke prevention and exhaust measures and personnel evacuation in large cross-section tunnel fires.
KEYWORDS
PAPER SUBMITTED: 2023-03-28
PAPER REVISED: 2023-07-10
PAPER ACCEPTED: 2023-08-17
PUBLISHED ONLINE: 2023-10-08
DOI REFERENCE: https://doi.org/10.2298/TSCI230328195S
REFERENCES
  1. Yao, Y.Z., et al., Experimental study on the effects of initial sealing time on fire behaviors in channel fires. International Journal of Thermal Science, 125 (2018) 273 282.
  2. Guo, Y.H., et al., Effect of Tunnel Cross Section on Smoke Stratification under Longitudinal Velocities. Refrigeration & Air Conditioning, 33 (06) (2019) 597 604.
  3. CTIF., World fire statistics. International association of fire and rescue service, (2018).
  4. Huang, Y.B., et al., Experimental investigation on maximum gas temperature beneath the ceiling in a branched tunnel fire. International Journal of Thermal Science, 145 (2019) 105997.
  5. Zhao, W.D., et al., Influences of inclined tunnel ceiling on plug holing phenomenon and mechanical smoke exhaust efficiency in tunnel fires
  6. Chen, C.K., et al., Experimental investigation on the influence of ramp slope on fire behaviors in a bifurcated tunnel. Tunnelling and Underground Space Technology, 104 (2020) 103522.
  7. Fan, C.G., et al., Experimental study of air entrainment mode with natural ventilation using shafts in road tunnel fire. International Journal of Heat and Mass Transfer, 56 (2013) 750 757.
  8. Fei, T., et al., A study on the maximum temperature of ceiling jet induced by rectangular source fires in a tunnel using ceiling smoke extraction. International Journal of Thermal Science, 127 (2018) 329 334.
  9. Ingason, H., et al., Model scale tunnel fire tests with longitudinal ventilation. Fire Safety Journal, 45 (6) (2010) 371 384.
  10. Weng, M.C., et al., Study on the critical velocity in a sloping tunnel fire under longitudinal ventilation. Applied Thermal Engineering, 94 (2016) 422 434.
  11. Weng, M.C., et al., Prediction of backlayering length and critical velocity in metro tunnel fires. Tunnelling and Underground Space Technology, 47 (2015) 64 72.
  12. Zhao, S.Z., et al., A numerical study on smoke movement in a metro tunnel with a non axisymmetric cross section. Tunnelling and Underground Space Technology, 73(Mar.) (2018) 187 202.
  13. Ingason, H., et al., Model scale tunnel fire tests with point extraction ventilation. Journal of Fire Protection Engineering, 21(1) (2011).
  14. Wu, Y., et al., 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.
  15. Chow, W.K., et al., Chow. C.L, Miao. L, Smoke movement in tilted tunnel fires with longitudinal ventilation. Fire Safety Journal, 75 (2015) 14 22.
  16. Ji, J., et al., Influence of cross sectional area and aspect ratio of shaft on natural ventilation in urban road tunnel. International Journal of Heat and Mass Transfer, 67 (2013) 420 431.
  17. Ji, J., et al., Effects of vertical shaft geometry on natural ventilation in urban road tunnel fires. Journal of Civil Engineering and Management, 20(4) (2014) 466 476.
  18. Fan, C.G., et al., Smoke movement characteristics under stack effect in a mine laneway fire. Applied Thermal Engineering, 110 (2017) 70 79.
  19. Shafee, S., Yozgatligil. A, An analysis of tunnel fire characteristics under the effects of vehicular blockage and tunnel inclination. Tunnelling and Underground Space Technology, 79(SEP.) (2018) 274 285.
  20. Zhang, X.L., et al., Numerical simulation on the maximum temperature and smoke back-layering length in a tilted tunnel under natural ventilation. Tunnelling and Underground Space Technology, 107 (2021) 103661.
  21. Thomas, P.H., The Movement of Smoke in Horizontal Passages against Air Flow. Fire Research Technical Paper, 7 (1) (1968) 1-8.
  22. Oka, Y., et al., Control of smoke flow in tunnel fires. Fire Safety Journal, 25 (4) (1995) 305-322.
  23. Li, Y.Z., et al., Study of critical velocity and backlayering length in longitudinally ventilated tunnel fires. Fire Safety Journal, 45(6-8) (2010) 361-370.
  24. Hyun Ko, Q., et al.,An Experimental Study of the Effect of the Slope on the Critical Velocity in Longitudinal Tunnel Fires. (2005).
  25. Weng, M.C., et al., Prediction of backlayering length and critical velocity in metro tunnel fires. Tunnelling and Underground Space Technology, 47 (2015) 64-72.
  26. Yi, L., et al., experimental study on critical velocity in sloping tunnel with longitudinal ventilation under fire. Tunnelling and Underground Space Technology, 43 (1) (2014) 198-203.
  27. Li, Y.Z., et al., Effect of cross section on critical velocity in longitudinally ventilated tunnel fires. Fire Safety Journal, 91 (jul.) (2017) 303-311.
  28. Li, Y.Z., et al., Discussions on critical velocity and critical Froude number for smoke control in tunnels with longitudinal ventilation. Fire Safety Journal, 99 (2018) 22-26.
  29. Li, J., et al., A study on the effects of the slope on the critical velocity for longitudinal ventilation in tilted tunnels. Tunnelling and Underground Space Technology, 89 (JUL.) (2019) 262-267.
  30. Jiang, L., et al., Control of light gas releases in ventilated tunnels. Journal of Fluid Mechanics, 872 (2019) 515-531.
  31. Chow, W.K., et al., Chow. Nadia C.L, A study on tilted tunnel fire under natural ventilation. Fire Safety Journal, 81 (2016) 44-57.
  32. Wan, H.X., et al., A numerical study on smoke back-layering length and inlet air velocity of fires in an inclined tunnel under natural ventilation with a vertical shaft. International Journal of Thermal Science, 138 (2019) 293-303.
  33. Yang, X.L., et al., Experimental investigation on the smoke back-layering length in a branched tunnel fire considering different longitudinal ventilations and fire locations. Case Studies in Thermal Engineering, 28 (2021) 101497.
  34. Jiang, L., et al., Effect of tunnel slope on the critical velocity of densimetric plumes and fire plumes in ventilated tunnels. Tunnelling and Underground Space Technology, 123 (2022) 104394-.
  35. Ji, J., et al., Experimental investigation on influence of different transverse fire locations on maximum smoke temperature under the tunnel ceiling, International Journal of Heat and Mass Transfer, 55 (17-18) (2012) 4817--4826.
  36. Mcgrattan, K., et al., Fire Dynamics Simulator User's Guide. National Institute of Standards and Technology, Gaithersburg. Maryland. (2018).
  37. Long, X.F,, et al., Numerical simulation of smoke pervasion in tunnel fire affected by ceiling flue, Journal of University of Science and Technology of China, 37 (4) (2009) 100-105.
  38. Ji, J., et al., Large eddy simulation of stack effect on natural smoke exhausting effect in urban road tunnel fires, International Journal of Heat and Mass Transfer, 66 (2013) 531-542.
  39. Thomas, P.H., The movement of buoyant fluid against a stream and the venting of underground fires. Fire Safety Science, 351 (1958) -1-1.
  40. Jean-Vantelon., et al., Investigation Of Fire-Induced Smoke Movement In Tunnels And Stations: An Application To The Paris Metro. Fire Safety Science, 3 (1991) 907-918.
  41. Liu, C., Study of ventilation control for fire-induced smoke in metro tunnel conjunction area. Northeastern University, (2019).
  42. Atkinson, G., et al., Smoke control in sloping tunnels. Fire Safety Journal, 27 (1996) 335-341.