ÖLÇEKLENDİRİLMİŞ BİR METRO İSTASYONUNDA KÜÇÜK ÖLÇEKLİ SIVI HAVUZ YANGINLARININ YANGIN TASARIM EĞRİSİ SEÇİMİ

Öz

n-heptan havuz yangını 1:100 ölçekli bir metro istasyonunda sayısal ve deneysel olarak incelenmiştir. Fire Dynamics Simulator (FDS v6.7.5) yazılımı ile istasyonda farklı tasarım eğrileri uygulanarak duman ve sıcaklık dağılımı araştırılmıştır. Sıfır piston etkisi altında 10 ml n-heptan yakıt için deneysel ve sayısal çalışmalar yapılmıştır. Performansa dayalı tasarımı geliştirmek ve yapılar için güvenilir yangın simülasyon sonuçları elde etmek için sayısal çalışmalarda güvenilir girdiler tanımlamak gerekmektedir. Çalışmanın amacı, küçük ölçekli hidrokarbon havuz yangınları için en uygun yangın tasarım eğrisini seçmek ve sayısal çalışmayı deneysel sonuçlardan bağımsız hale getirmektir. Bu çalışmada, t2, tanh, Eurocode 1 (BS EN 1991-1-2), eksponansiyel ve ikinci dereceden yangın eğrileri incelenmiş ve deneysel sonuçlarla doğrulanmıştır. FDS kullanılarak elde edilen sayısal sonuçlar deneysel verilerle doğrulanmış ve ikinci dereceden hariç tüm yangın tasarım eğrileri ile uyumlu olduğu gözlenmiştir. Yangın süresi boyunca büyüme, tam gelişme ve bozunma aşamalarını içeren eksponansiyel yangın tasarımı eğrisinin deneysel verilere daha yakın sonuçlar verdiği gözlemlenmiştir. Deneysel sonuçlardan bağımsız olarak, eksponansiyel yangın tasarım eğrisi kullanılarak yapılan sayısal çalışmadan elde edilen sıcaklık dağılım sonuçları ile literatürden elde edilen radyasyon/türbülans parametrelerinin deneysel sonuçlarla ortalama %5 farklılık gösterdiği görülmüştür. Ayrıca t2 ve tanh yangın tasarım eğrilerinin de deneysel sonuçlarla %6.92 ve %9.02 gibi kabul edilebilir farklılıklar gösterdiği, Eurocode HC’nin ise %12.17’lik fark ile daha uzak olduğu gözlenmiştir. Bu nedenle küçük ölçekli hidrokarbon havuz yangınlarında eksponansiyel tasarım eğrisi kullanılarak yangın tasarımının yapılabileceği söylenebilir.

Anahtar Kelimeler

• Yangın gelişimi
• Yangın tasarım eğrisi
• Havuz yangını
• N-heptan
• Fire dynamics simulator (FDS)

DESIGN FIRE CURVE SELECTION OF SMALL SCALE POOL FIRES IN A SCALED METRO STATION

Öz

n-heptane pool fire was numerically and experimentally investigated in a 1:100 scaled metro station. Fire Dynamics Simulator (FDS v6.7.5) has been applied to investigate smoke and temperature distribution by implementing different design curves in the station. Experimental and numerical studies were performed for 10 ml n-heptane fuel under zero piston effect. To develop performance-based design and to obtain reliable fire simulation results for structures, reasonable input conditions are essential for numerical studies. The aim of the study is to select most suitable fire design curve and make the numerical study independent of the experimental results for small scale hydrocarbon pool fires. In this study, t2, tanh, Eurocode 1 (BS EN 1991-1-2), exponential, and quadratic fire curves were investigated and validated with experimental results. The numerical results obtained using FDS were validated with experimental data and good agreement was observed for all design fire curves except quadratic one. It was observed that the exponential design fire curve predicted more similarly to the experimental data over the fire duration including growth, fully developed and decay phases. Regardless of the experimental results, it was seen that the temperature distribution results obtained from the numerical study using exponential fire design curve and the radiation / turbulence parameters obtained from the literature were found to have an average of 5% difference with the experimental results. It was also seen that the t2 and tanh curves have acceptable differences of 6.92% and 9.02%, respectively, and the Eurocode HC is less suitable than the other curves with a difference of 12.17%. Therefore, it can be said that in small scale hydrocarbon pool fires, fire design can be done using exponential design curve.

Anahtar Kelimeler

• Fire development
• Design fire curve
• Pool fire
• N-heptane
• Fire dynamics simulator (FDS)

Kaynakça

1. Australian Government, State and Territories of Australia, International Fire Engineering Guidelines, 2005.
2. Aybay, O., 2010, Time-Conservative Finite-Volume Method with Large-Eddy Simulation for Computational Aeroacoustics, Ph.D. Thesis, Durham University, Durham, UK.
3. Baek, B., Oh, C. B., Lee, E. J., 2017, Nam, D. G., Application Study of Design Fire Curves for Liquid Pool Fires in a Compartment, Fire Sci. Eng., 31, 4, 43-51.
4. Baek, B., Oh, C. B., Lee, C. Y., 2018, Evaluation of Modified Design Fire Curves for Liquid Pool Fires Using the FDS and CFAST, Fire Sci. Eng., 32, 2, 7-16.
5. Berberoğlu, M. İ., 2008, Fire Modelling and Simulation for Subway Stations, M.Sc. Thesis, Gazi University Institute of Science and Technology, Ankara, Turkey.
6. Blinov, V. I. and Khudiakov, G.N., 1957, The Burning of Liquid Pools, Doklady Akademi Nauk SSSR, 113, 1094.
7. Bordbar, H., Hostikka, S., 2019, Numerical Solution of LBL Spectral Radiation of a N-Heptane Pool Fire, Proceedings of the 9th International Symposium on Radiative Transfer, RAD-19.
8. BS EN 1991-1-2 Eurocode 1: Actions on Structures - Part 1-2: General Actions - Actions on Structures Exposed To Fire, 2002.

9. BS ISO-TR 13387-2 Fire Safety Engineering - Part 2: Design Fire Scenarios and Design Fires, 1999.
10. Ciani, F., Capobellin, M., 2018, Fire Growth Rate Strategies in FDS, 3rd European Symposium on Fire Safety Science.
11. Dobashi, R., Okura, T., Nagaoka, R., Hayashi, Y., Mog, T, 2016, Experimental Study on Flame Height and Radiant Heat of Fire Whirls, Fire Technol. 52, 1069–1080.
12. Drysdale, D., 2011, An Introduction to Fire Dynamics, A John Wiley & Sons, University of Edinburgh, Scotland, UK.
13. Hall, A. R., 1973, Pool Burning: A Review, In Oxidation and Combustion Reviews, Volume 6 (ed. C.F.H. Tipper), 169–225, Elsevier, Amsterdam.
14. Hietaniemi, J., Hostikka S., and Vaari J., 2004, FDS Simulation of Fire Spread – Comparison of Model Results with Experimental Data, VTT Working Papers 4, VTT Building and Transport, Espoo, Finland.
15. Hottel, H. C., 1959, Review: Certain Laws Governing The Diffusive Burning Of Liquids by Blinov and Khudiakov (1957) (Dokl. Akad. Nauk SSSR, 113, 1096). Fire Research Abstracts and Reviews, 1, 41–43.
16. Ingason, H., Li, Y. Z., Lönnermark, A., 2015, Tunnel Fire Dynamics, Springer, New York.
17. Ingason, H., 2009, Design Fire Curves for Tunnels, Fire Safety Journal, 44, 259–265.
18. Kang, Q., Lu S., Chen, B., 2010, Experimental Study on Burning Rate of Small Scale Heptane Pool Fires, Chinese Science Bulletin, 55, 10, 973–979.
19. Khan, M., Tewarson, A., and Chaos, M., 2015, Combustion Characteristics of Materials and Generation of Fire Products, SFPE Handbook of Fire Protection Engineering, 5th ed. Springer, New York.
20. McDermott, R., McGrattan K., and Floyd, J., 2011, A Simple Reaction Time Scale for Under-Resolved Fire Dynamics. In Fire Safety Science – Proceedings of the 10th International Symposium, 809– 820, University of Maryland, College Park, Maryland, USA.
21. McGrattan, K., Hostikka, S., McDermott, R., Floyd, J., and Vanella M., 2021a, NIST Special Publication 1018-1 Sixth Edition Fire Dynamics Simulator Technical Reference Guide Volume 1: Mathematical Model.
22. McGrattan, K., Hostikka, S., McDermott, R., Floyd, J., and Vanella M., 2021b, NIST Special Publication 1018-3 Sixth Edition, Fire Dynamics Simulator, Technical Reference Guide VTT Technical Research Centre of Finland, Volume 3: Validation.
23. McGrattan, K., Hostikka, S., McDermott, R., Floyd, J., and Vanella M., 2021c, NIST Special Publication 1019 Sixth Edition, Fire Dynamics Simulator User's Guide.
24. NFPA (National Fire Protection Association) 204 - Standard for Smoke and Heat Venting, 2015.
25. NFPA (National Fire Protection Association) 130 - Standard for Fixed Guideway Transit and Passenger Rail Systems, 2020.
26. Numajiri, F., Furukawa, K., 1998, Short Communication: Mathematical Expression Of Heat Release Rate Curve and Proposal of ‘Burning Index’, Fire Mater, 22, 39–42.
27. NUREG -1824, Verification and Validation of Selected Fire Models for Nuclear Power Plant Applications, U.S. Nuclear Regulatory Commission, 2007.
28. Quintiere, J. G., 1997, Fire Growth: An Overview, Fire Technology First Quarter, Department of Fire Protection Engineering, University of Maryland, College Park, USA.
29. Staffansson, L., 2010, Selecting Design Fires. Department of Fire Safety Engineering and Systems Safety, Lund University, Sweden.
30. Sudheer, S., 2013, Characterization of Open Pool Fires and Study of Heat Transfer in Bodies Engulfed in Pool Fires, Ph.D. Thesis, Indian Institute of Technology, Bombay, India.
31. Tewarson, A., 1986, Prediction of Fire Properties of Materials Part 1: Aliphatic and Aromatic Hydrocarbons and Related Polymers, Technical Report NBS-GCR-86-521, National Institute of Standards and Technology, Gaithersburg, MD, USA.
32. TS 825 Thermal insulation requirements for buildings, TSE Turkish Standard, 2013.
33. Xin, Y., Gore J. P., McGrattan K.B., Rehm R.G., and Baum H.R., 2002, Large Eddy Simulation of Buoyant Turbulent Pool Fires, In Twenty-Ninth Symposium (International) on Combustion, 259–266. Combustion Institute, Pittsburgh, Pennsylvania.
34. Xin, Y, 2005a, Baroclinic Effects on Fire Flow Field, In Proceedings of the Fourth Joint Meeting of the U.S. Sections of the Combustion Institute, Combustion Institute, Pittsburgh, Pennsylvania, USA.
35. Xin, Y., Gore J. P., McGrattan K. B., Rehm R. G., and Baum H. R., 2005b, Fire Dynamics Simulation of A Turbulent Buoyant flame Using A Mixture-Fraction-Based Combustion Model, Combustion and Flame, 141, 329–335.
36. Xin, Y., and Gore, J. P., 2005c, Two-Dimensional Soot Distributions in Buoyant Turbulent Fires, In Thirtieth Symposium (International) on Combustion, Combustion Institute, Pittsburgh, Pennsylvania, USA.
37. Yao, W., Yin, J., Hu X., Wang, J., Zhang, H., 2013, Numerical Modeling of Liquid -Heptane Pool Fires Based On Heat Feedback Equilibrium, Procedia Engineering, 62, 377-388.
38. Yin, J., Yao, W., Liua, Q., Wua N., Zhoub Z., Wuc Y., Zhang H., 2013, Experimental Study of N-Heptane Pool Fire Behaviors under Dynamic Pressures in an Altitude Chamber, Procedia Engineering, 52, 548-556.