Experimental investigation of the impact of water mist on high-speed non-premixed horizontal methane jet fires. (June 2020)

• Record Type: Journal Article
• Authors: Palis, Stephan; Sträubig, Felix; Voigt, Sascha; Knaust, Christian
• Is Part Of: Fire safety journal. Volume 114(2020)
• Publication Date: 2020-06
• Subjects: Jet fire -- Water mist -- Fire test -- Methane -- Supersonic flow -- Fixed firefighting system; Fire prevention -- Periodicals; Incendies -- Prévention -- Recherche -- Périodiques; Fire prevention -- Research; Periodicals; 628.92205
• DOI: 10.1016/j.firesaf.2020.103005
• Languages: English
• ISSNs: 0379-7112

Abstract

Abstract: In this paper, the influence of a fixed water mist firefighting system on a high-speed non-premixed horizontal methane jet fire is investigated with focus on its effect on temperatures and heat load of the jet fire and on its surroundings. Six tests are performed in which gas is released out of an orifice with a diameter of 1 mm and a release pressure of up to 186 bar. In addition to temperature and radiation measurements, the release pressure, gas mass flow rate and exhaust gas concentrations are detected to determine the heat release. Video and IR-analysis are used to evaluate the interactions between jet fire and water mist. The experiments show, that water mist reduces the temperatures inside the jet fire flow field and its radiative heat flux. It can lower the risk of ignition of adjacent surfaces and materials, as temperatures fall below autoignition temperatures of common materials like plastics. Although water mist does not extinguish the fire, it has an impact on the energy release by reducing combustion efficiency due to heat exchange with the water mist and oxygen displacement. Highlights: Interactions between a horizontal supersonic methane jet fire and water mist. Fire tests including temperature, heat flux, mass flow & heat release measurements. Water mist fails to extinguish the jet fire. Decrease of temperatures and radiation intensity reduces risk of fire spread. Combustion process affected by heat exchange with water mist & oxygen displacement.