An experimental study on the pool fire burning characteristics of n-heptane and ethanol in the tunnels

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2015

Öğrenci: TEVFİK ULUÇ YAMALI

Danışman: AHMET YOZGATLIGİL

Özet:

The road and railway tunnel disasters in recent decades drew the attention of fire safety engineers. The effects of mechanical ventilation, tunnel geometry, physical and chemical properties of fuel on fire characteristics such as heat release rate, smoke temperature distributions along the tunnel and burning rate are experimentally examined on full scaled, large scaled and reduced scaled tunnel models. Although there are many studies on the effects of conventional fuels like gasoline and diesel, the blended fuels and radiative effects of fire are barely addressed in tunnel fire scenarios. In this study, heptane pool fires and 10 %, 20 % and 30 % volumetric fractions of ethanol blended heptane pool fires are studied with square and rectangular pan geometries under 0.5 m/s to 2.5 m/s ventilation conditions with 0.5 m/s incremental intervals in a reduced scale tunnel model based on the Froude number scaling. Two separate experimental matrices are prepared with one variable at a time approach. The fuel mass, temperature distribution, O2, CO2 and CO gas concentration are measured and are compared to observe the effect of changing parameters. The interior wall surfaces of tunnel are covered with high reflecting material for particular ethanol pool fires. The radiative heat flux of fire, the back radiation of walls and combustion gases are respectively measured through a series of experiments.